XHCI: set dcbaap

This will be needed for USB (XHCI controller driver).

.gitignore

@@ -0,0 +1,4 @@
+.rscons*
+/x86_64-elf-gcc/
+/build/
+/qemu/

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "uefi-d"]
+	path = uefi-d
+	url = git://github.com/kubasz/uefi-d

Functions.c

@@ -1,94 +0,0 @@
-//Functions.c
-//05/07/03 Josh Holtrop
-//for HOS
-
-
-inline void outportb(unsigned int port, unsigned char value)		// Output a byte to a port
-{
-    asm volatile ("outb %%al,%%dx"::"d" (port), "a" (value));
-};
-
-inline void outportw(unsigned int port, unsigned int value)		// Output a word to a port
-{
-    asm volatile ("outw %%ax,%%dx"::"d" (port), "a" (value));
-};
-
-inline byte inportb(unsigned short port)
-{
-	unsigned char ret_val;
-
-	asm volatile("inb %w1,%b0"
-		: "=a"(ret_val)
-		: "d"(port));
-	return ret_val;
-};
-
-void enable_ints()
-{
-	asm("sti");
-};
-
-void disable_ints()
-{
-	asm("cli");
-};
-
-void remap_pics(int pic1, int pic2)
-{
-	byte	a1, a2;
-
-	a1 = inportb(PIC1_DATA);      //0x21
-	a2 = inportb(PIC2_DATA);      //0xA1
-
-	outportb(PIC1_COMMAND, ICW1_INIT+ICW1_ICW4);	//0x20, 0x10+0x01 00010001b
-	outportb(PIC2_COMMAND, ICW1_INIT+ICW1_ICW4);	//0xA0, 0x10+0x01 00010001b
-	outportb(PIC1_DATA, pic1);			//0x21, pic1
-	outportb(PIC2_DATA, pic2);			//0xA1, pic2
-	outportb(PIC1_DATA, 4);				//0x21, 0x04      00000100b
-	outportb(PIC2_DATA, 2);				//0xA1, 0x02      00000010b
-	outportb(PIC1_DATA, ICW4_8086);			//0x21, 0x01      00000001b
-	outportb(PIC2_DATA, ICW4_8086);			//0xA1, 0x01      00000001b
-
-	outportb(PIC1_DATA, a1);			//0x21
-	outportb(PIC2_DATA, a2);			//0xA1
-}
-
-inline void pic1_mask(byte mask)
-{
-	outportb(PIC1_DATA, mask);			//0x21, maskfield *OCW1*
-}
-
-inline void pic2_mask(byte mask)
-{
- 	outportb(PIC2_DATA, mask);			//0xA1, maskfield *OCW1*
-}
-
-inline void restart()
-{
-	outportb (0x64, 0xfe);
-	for (;;)
-	{
-	}
-}
-
-inline void eoi()
-{
-	outportb(0x20, 0x20);							//EOI
-}
-
-inline void eoi2()
-{
- 	outportb(0xA0, 0x20);
- 	outportb(0x20, 0x20);
-}
-
-
-
-
-
-
-
-
-
-
-

README.md

@@ -0,0 +1,81 @@
+# HOS System Requirements
+
+HOS requires:
+
+* A 64-bit CPU.
+* A UEFI system.
+* 128MB of RAM.
+
+# Building HOS
+
+From the top level of the repository, run:
+
+    ./rscons
+
+If you get errors about missing packages, install the packages and then re-run
+the build command.
+
+# Running HOS
+
+HOS can run on a physical machine, in VirtualBox, or in QEMU.
+
+## Physical Machine
+
+To install HOS to an EFI partition, follow these steps:
+
+1. Copy build/hello/HOS.EFI to EFI partition EFI/HOS.EFI. For example, from Linux:
+
+    sudo cp build/hello/HOS.EFI /boot/efi/EFI/HOS.EFI
+
+2. Register EFI loader for HOS (one time only) with command:
+
+    efibootmgr -c -d /dev/nvme1n1 -p 2 -l '\EFI\HOS.EFI' -L HOS
+
+(Update the -d device parameter and -p partition parameter as appropriate)
+
+3. Set boot order to desired boot order. Exact order will be system dependent. Example:
+
+    efibootmgr -o 2,0,6,5
+
+At this point you should be able to boot HOS from your EFI boot selection menu.
+If you use GRUB, you can optionally create a GRUB boot entry to load HOS.EFI
+with an entry like this:
+
+    menuentry 'HOS' {
+      insmod part_gpt
+      insmod chain
+      set root='(hd0,gpt1)'
+      chainloader /EFI/HOS.EFI
+    }
+
+Just update the root setting for the correction location to your system's EFI
+partition.
+
+## VirtualBox
+
+To create a VM in VirtualBox:
+
+1. Build HOS ("./rscons").
+2. In VirtualBox, select Machine -> New.
+3. Set name to HOS.
+4. Set Type to Other.
+5. Set Version to Other/Unknown (64-bit).
+6. Click Next.
+7. Set memory size to 512 MB.
+8. Click Next.
+9. Select Do not add a virtual hard disk.
+10. Click Create.
+11. From the HOS repository, create a VirtualBox VMDK image with "./rscons mk-vmdk".
+12. Move the HOS.vmdk file generated to the HOS VirtualBox folder.
+13. In VirtualBox Manager, open HOS VM settings.
+14. Under System, check the Enable EFI checkbox.
+15. Under System, change the Chipset to ICH9.
+16. Under Storage, add a hard disk and browse to select the HOS.vmdk file.
+17. To run HOS, either start the VM through VirtualBox or with "./rscons run-vb".
+
+## QEMU
+
+Make sure QEMU is installed (possibly the `qemu-desktop` package). Then:
+
+1. Build HOS ("./rscons").
+2. Run `./rscons run` to run HOS in QEMU.

Rsconscript

@@ -0,0 +1,248 @@
+require "tmpdir"
+
+project_name "HOS"
+path_prepend "x86_64-elf-gcc/bin"
+
+configure do
+  rscons "x86_64-elf-gcc.rb", "-b", "#{build_dir}/x86_64-elf-gcc"
+  check_d_compiler "ldc2", use: "ldc2"
+  check_c_compiler "x86_64-w64-mingw32-gcc", use: "x86_64-w64-mingw32-gcc"
+  check_c_compiler "x86_64-elf-gcc", use: "x86_64-elf-gcc"
+  check_c_compiler
+  check_program "mformat", on_fail: "Install the mtools package"
+  check_program "parted"
+  check_program "pkg-config"
+  check_cfg package: "freetype2", on_fail: "Install libfreetype-dev", use: "freetype"
+  sh %w[git submodule update --init]
+end
+
+# Kernel default font size.
+KFONT_SIZE = 16
+
+# One kilobyte.
+KB = 1024
+
+# One megabyte.
+MB = 1024 * 1024
+
+class HulkBinObj < Builder
+  def run(options)
+    @cache.mkdir_p(File.dirname(@target))
+    File.write(@target, <<EOF)
+.section ".rodata"
+.balign 4096
+.global _hulk_bin_start
+_hulk_bin_start:
+.incbin "#{@sources.first}"
+.balign 4096
+.global _hulk_bin_end
+_hulk_bin_end:
+EOF
+    unless @cache.up_to_date?(@target, nil, @sources, @env)
+      print_run_message("Creating HULK binary object <target>#{@target}<reset>", nil)
+      @cache.register_build(@target, nil, @sources, @env)
+    end
+    true
+  end
+end
+
+# Create a GPT disk image with an EFI partition containing the EFI image.
+class Image < Builder
+  def run(options)
+    unless @cache.up_to_date?(@target, nil, @sources, @env)
+      print_run_message("Creating disk image <target>#{@target}<reset>", nil)
+      efi_image_size = File.stat(@sources.first).size
+      efi_image_size_mb = (efi_image_size + MB - 1) / MB
+      partition_size_mb = efi_image_size_mb + 1
+      empty_mb = "\0".b * MB
+      File.binwrite(@target, empty_mb * partition_size_mb)
+      system(*%W[mformat -i #{@target} ::])
+      system(*%W[mmd -i #{@target} ::/EFI])
+      system(*%W[mmd -i #{@target} ::/EFI/BOOT])
+      system(*%W[mcopy -i #{@target} #{@sources.first} ::/EFI/BOOT/BOOTX64.EFI])
+      partition_contents = File.binread(@target)
+      disk_image = empty_mb + partition_contents + empty_mb
+      File.binwrite(@target, disk_image)
+      system(*%W[parted --script #{@target} mklabel gpt mkpart HOS fat32 1MiB #{partition_size_mb + 1}MiB])
+      @cache.register_build(@target, nil, @sources, @env)
+    end
+    true
+  end
+end
+
+class CheckThreadLocal < Builder
+  def run(options)
+    map_file = File.binread(@sources.first)
+    if map_file =~ /\.(tdata|tbss)\b/
+      $stderr.puts "Error: found thread-local data in #{@sources.first}"
+      false
+    else
+      true
+    end
+  end
+end
+
+class FontGen < Builder
+  def run(options)
+    if @command
+      finalize_command
+    else
+      fontgen = @vars["fontgen"]
+      @sources += [fontgen]
+      command = %W[#{fontgen} #{@sources.first} #{KFONT_SIZE} #{@target}]
+      standard_command("FontGen <target>#{@target}<reset>", command, {})
+    end
+  end
+end
+
+fontgen_env = env "fontgen", use: "freetype" do |env|
+  env.Program("^/fontgen", glob("src/fontgen/**/*.c"))
+end
+
+hulk_env = env "hulk", use: %w[ldc2 x86_64-elf-gcc] do |env|
+  env.add_builder(FontGen)
+  env.add_builder(CheckThreadLocal)
+  env.FontGen("^/src/hulk/kfont.d", "font/Hack-Regular.ttf",
+              "fontgen" => fontgen_env.expand("^/fontgen"))
+  env["sources"] = glob("src/hulk/**/*.d")
+  env["sources"] << "^/src/hulk/kfont.d"
+  cpu_attrs = %w[
+    -avx
+    -avx2
+    -avx512bf16
+    -avx512bitalg
+    -avx512bw
+    -avx512cd
+    -avx512dq
+    -avx512f
+    -avx512ifma
+    -avx512vbmi
+    -avx512vbmi2
+    -avx512vl
+    -avx512vnni
+    -avx512vp2intersect
+    -avx512vpopcntdq
+    -sse
+    -sse-unaligned-mem
+    -sse2
+    -sse3
+    -sse4.1
+    -sse4.2
+    -sse4a
+    -ssse3
+  ]
+  env["DFLAGS"] += %W[-g -mtriple=x86_64-unknown-elf -mattr=#{cpu_attrs.join(",")} --betterC -release -O3 --wi --enable-cross-module-inlining -code-model=kernel --disable-red-zone]
+  env["D_IMPORT_PATH"] += %w[src]
+  env["D_IMPORT_PATH"] << env.expand("^/src")
+  env["LD"] = "x86_64-elf-gcc"
+  env["LDFLAGS"] += %w[-g -nostdlib -Tsrc/hulk/hulk.ld -Wl,--gc-sections -Wl,-Map,${_TARGET}.map -Wl,--no-warn-rwx-segments]
+  env["LDCMD"] = %w[${LD} -o ${_TARGET} ${LDFLAGS} ${_SOURCES} ${LIBDIRPREFIX}${LIBPATH} ${LIBLINKPREFIX}${LIBS}]
+  env["OBJDUMP"] = "x86_64-elf-objdump"
+  env["OBJCOPY"] = "x86_64-elf-objcopy"
+  env.Program("^/hulk.elf", "${sources}")
+  env.produces("^/hulk.elf", "^/hulk.elf.map")
+  env.CheckThreadLocal(:hulk_map_check, "^/hulk.elf.map")
+  env.depends("^/hulk.elf", "src/hulk/hulk.ld")
+  env["SIZE"] = "x86_64-elf-size"
+  env.Size("^/hulk.elf.size", "^/hulk.elf")
+  env.Disassemble("^/hulk.elf.txt", "^/hulk.elf")
+  env.Command("^/hulk.bin", "^/hulk.elf",
+              "CMD" => %W[${OBJCOPY} -O binary ${_SOURCES} ${_TARGET}],
+              "CMD_DESC" => "Convert ELF to binary:")
+  env.add_build_hook do |builder|
+    if builder.target.end_with?(".o")
+      env.Disassemble("#{builder.target}.txt", builder.target)
+    end
+  end
+end
+
+hello_env = env "hello", use: %w[ldc2 x86_64-w64-mingw32-gcc] do |env|
+  env.add_builder(Image)
+  env.add_builder(CheckThreadLocal)
+  env.add_builder(HulkBinObj)
+  env["sources"] = glob("src/hello/**/*.d")
+  env["sources"] += %w[
+    src/hulk/serial.d
+    src/hulk/writef.d
+  ]
+  env["sources"] += glob("uefi-d/source/**/*.d")
+  env.HulkBinObj("^/hulk_bin.S", hulk_env.expand("^/hulk.bin"))
+  env.Object("^/hulk_bin.o", "^/hulk_bin.S")
+  env.depends("^/hulk_bin.o", hulk_env.expand("^/hulk.bin"))
+  env["sources"] << "^/hulk_bin.o"
+  env["DFLAGS"] += %w[-g -mtriple=x86_64-unknown-windows-coff --betterC -release -O3 --wi --enable-cross-module-inlining --disable-red-zone]
+  env["D_IMPORT_PATH"] += %w[src uefi-d/source]
+  env["LD"] = "x86_64-w64-mingw32-gcc"
+  env["LDFLAGS"] += %w[-g -nostdlib -Wl,-dll -shared -Wl,--subsystem,10 -e efi_main -Wl,-Map,${_TARGET}.map]
+  env["LDCMD"] = %w[${LD} -o ${_TARGET} ${LDFLAGS} ${_SOURCES} ${LIBDIRPREFIX}${LIBPATH} ${LIBLINKPREFIX}${LIBS}]
+  env["OBJDUMP"] = "x86_64-w64-mingw32-objdump"
+  env.Program("^/HOS.EFI", "${sources}")
+  env.produces("^/HOS.EFI", "^/HOS.EFI.map")
+  env.CheckThreadLocal(:hos_map_check, "^/HOS.EFI.map")
+  env["SIZE"] = "x86_64-w64-mingw32-size"
+  env.Size("^/HOS.size", "^/HOS.EFI")
+  env.Disassemble("^/HOS.txt", "^/HOS.EFI")
+  env.Image("^/HOS.img", "^/HOS.EFI")
+end
+
+task "run", desc: "Run HOS in QEMU" do
+  FileUtils.rm_rf("qemu")
+  FileUtils.mkdir_p("qemu")
+  img = hello_env.expand("^/HOS.img")
+  FileUtils.cp(img, "qemu")
+  ovmf = "OVMF.fd"
+  if File.exist?("/usr/share/edk2/x64/OVMF.fd")
+    ovmf = "/usr/share/edk2/x64/OVMF.fd"
+  elsif File.exist?("/usr/share/edk2/x64/OVMF.4m.fd")
+    ovmf = "/usr/share/edk2/x64/OVMF.4m.fd"
+  end
+  sh %W[
+    qemu-system-x86_64
+    -machine q35
+    -m 128M
+    -cpu max
+    -smp cpus=4
+    -serial file:qemu/serial.out
+    -bios #{ovmf}
+    -drive file=qemu/HOS.img,format=raw
+    -device qemu-xhci
+    -device usb-tablet]
+end
+
+# See README.md for how to set up VirtualBox for HOS.
+task "mk-vmdk", desc: "Create VirtualBox VMDK virtual drive for HOS" do
+  path = File.expand_path(hello_env.expand("^/HOS.img"))
+  sectors = File.stat(path).size / 512
+  File.binwrite("HOS.vmdk", <<EOF)
+# Disk DescriptorFile
+version=1
+CID=1d1c3615
+parentCID=ffffffff
+createType="fullDevice"
+
+# Extent description
+RW #{sectors} FLAT "#{path}" 0
+
+# The disk Data Base 
+#DDB
+
+ddb.virtualHWVersion = "4"
+ddb.adapterType="ide"
+ddb.geometry.cylinders="8"
+ddb.geometry.heads="16"
+ddb.geometry.sectors="63"
+ddb.uuid.image="03783b5a-7587-4d8b-ad04-9d70f70a94c2"
+ddb.uuid.parent="00000000-0000-0000-0000-000000000000"
+ddb.uuid.modification="00000000-0000-0000-0000-000000000000"
+ddb.uuid.parentmodification="00000000-0000-0000-0000-000000000000"
+ddb.geometry.biosCylinders="8"
+ddb.geometry.biosHeads="16"
+ddb.geometry.biosSectors="63"
+EOF
+  #sh %W[VBoxManage createmedium disk --filename=HOS.vmdk --variant=RawDisk --format=VMDK --property RawDrive=#{File.expand_path(hello_env.expand("^/HOS.img"))}]
+end
+
+# See README.md for how to set up VirtualBox for HOS.
+task "run-vb", desc: "Run HOS in VirtualBox" do
+  sh %W[VBoxManage startvm HOS]
+end

bootdef.inc

@@ -1,26 +0,0 @@
-
-%define VERSION		"0.1.2"			;HOS version
-
-%define BOOT_FAT_SEG	0x07E0			;right after boot sector
-%define BOOT_ROOT_SEG	0x0900			;right after FAT
-%define BOOT_KERNEL_SEG	0x0AC0			;right after ROOT_DIR
-%define BOOT_STAGE2_SEG	0x0B00			;right after KERNEL_SEG
-%define BOOT_STAGE2_ADD	0xB000			;address of stage2 to jump to, org at
-%define BOOT_KERNEL_ADD	0x100000		;final pmode kernel destination - physical
-%define BOOT_RD_ADD	0x200000		;2mb for ram disk
-
-%define BOOT_DATA_SEG	0x9000			;data gathered by stage2 loader goes here
-
-%define BOOT_HASRD	0x0000		;1
-%define BOOT_VESA	0x0002		;2 - 0 for console, otherwise VESA mode
-%define BOOT_VESA_OEM	0x0004		;258 - null-terminated OEM identification string
-%define BOOT_VESA_VBE	0x0106		;512 - copy of VESA VBEInfoBlock
-%define	BOOT_VESA_INFO	0x0306		;256 - copy of VESA ModeInfoBlock for selected mode
-%define BOOT_MEMENTRIES	0x040A		;4 - dword = number of memmap entries
-%define BOOT_MEMMAP	0x2000		;? -  memory map information
-
-
-
-%define BOOT_DRIVE	0x7C24		;1 - boot drive
-
-

functions.h

@@ -1,24 +0,0 @@
-//functions.h
-//05/07/03 Josh Holtrop
-//for HOS
-
-
-
-inline void outportb(unsigned int port, unsigned char value);
-inline void outportw(unsigned int port, unsigned int value);
-inline byte inportb(unsigned short port);
-void enable_ints();
-void disable_ints();
-inline void restart();
-void remap_pics(int pic1, int pic2);
-inline void pic1_mask(byte mask);
-inline void pic2_mask(byte mask);
-inline void eoi();
-inline void eoi2();
-
-
-
-
-
-
-

gdt.inc

@@ -1,68 +0,0 @@
-
-
-gdtr:
-	dw	gdt_end-gdt-1
-	dd	GDT
-gdt:
-	dd	0
-	dd	0
-KERNEL_CODE equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0x9A	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0xCF	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-KERNEL_DATA equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0xCF	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-VESA_CODE equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0x9A	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-VESA_DATA equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-VIDEO_TEXT equ $-gdt
-	dw	0x7FFF	;limit 15:0
-	dw	0x8000	;base  15:0
-	db	0x0B	;base  23:16
-	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-VIDEO_GRAPHICS equ $-gdt
-	dw	0xFFFF	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x0A	;base  23:16
-	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-USER_CODE equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0xFA	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0xCF	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-USER_DATA equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0xF2	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0xCF	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-gdt_end:
-
-
-

idt.inc

@@ -1,86 +0,0 @@
-
-idtr:
-	dw	50*8-1		;size of idt
-	dd	IDT		;address of idt
-
-
-%macro isr_label 1
-isr_%1:
-	mov	eax, %1
-	jmp	isr_main
-%endmacro
-
-isr_label	0
-isr_label	1
-isr_label	2
-isr_label	3
-isr_label	4
-isr_label	5
-isr_label	6
-isr_label	7
-isr_label	8
-isr_label	9
-isr_label	10
-isr_label	11
-isr_label	12
-isr_label	13
-isr_label	14
-isr_label	15
-isr_label	16
-isr_label	17
-isr_label	18
-isr_label	19
-isr_label	20
-isr_label	21
-isr_label	22
-isr_label	23
-isr_label	24
-isr_label	25
-isr_label	26
-isr_label	27
-isr_label	28
-isr_label	29
-isr_label	30
-isr_label	31
-isr_label	32
-isr_label	33
-isr_label	34
-isr_label	35
-isr_label	36
-isr_label	37
-isr_label	38
-isr_label	39
-isr_label	40
-isr_label	41
-isr_label	42
-isr_label	43
-isr_label	44
-isr_label	45
-isr_label	46
-isr_label	47
-isr_label	48
-isr_label	49
-
-isr_main:
-	pusha
-	push	ds
-	push	es
-
-	push	eax
-
-	call	_isr
-
-	pop	eax
-
-	pop	es
-	pop	ds
-	popa
-
-	iret
-
-	
-
-
-
-
-

k_defines.h

@@ -1,47 +0,0 @@
-//k_defines.h
-//03/17/03 Josh Holtrop
-
-#define	PIC1		0x20
-#define	PIC2		0xA0
-#define	PIC1_COMMAND	PIC1
-#define	PIC1_DATA	(PIC1+1)
-#define	PIC2_COMMAND	PIC2
-#define	PIC2_DATA	(PIC2+1)
-#define	PIC_EOI		0x20
-
-#define	ICW1_ICW4	0x01		/* ICW4 (not) needed */
-#define	ICW1_SINGLE	0x02		/* Single (cascade) mode */
-#define	ICW1_INTERVAL4	0x04		/* Call address interval 4 (8) */
-#define	ICW1_LEVEL	0x08		/* Level triggered (edge) mode */
-#define	ICW1_INIT	0x10		/* Initialization - required! */
-
-#define	ICW4_8086	0x01		/* 8086/88 (MCS-80/85) mode */
-#define	ICW4_AUTO	0x02		/* Auto (normal) EOI */
-#define	ICW4_BUF_SLAVE	0x08		/* Buffered mode/slave */
-#define	ICW4_BUF_MASTER	0x0C		/* Buffered mode/master */
-#define	ICW4_SFNM	0x10		/* Special fully nested (not) */
-
-#define BLUE_TXT	0x01
-#define RED_TXT		0x04
-#define WHITE_TXT	0x07
-#define CYAN_TXT	0x0B
-#define YELLOW_TXT	0x0E
-#define BRWHITE_TXT	0x0F
-
-#define FREERAM_START	0x268000
-
-#define KERNEL_PID	0x02
-
-typedef	unsigned char	byte;
-typedef	unsigned short	word;
-typedef	unsigned int	dword;
-
-typedef struct {
-	dword	lowdword;
-	dword	highdword;
-} __attribute__((packed)) qword;
-
-
-
-
-

kernel.asm

@@ -1,62 +0,0 @@
-
-%include "bootdef.inc"
-
-%define GDT	0x140000
-%define IDT	0x150000
-
-[global start]
-[extern _isr]
-[extern _k_init]
-
-bits 32
-
-start:
-	cli				;if they weren't already off
-	mov	edi, GDT
-	mov	esi, gdt
-	mov	ecx, gdt_end-gdt
-copy_gdt:
-	lodsb
-	stosb
-	loop	copy_gdt
-
-	mov	edi, IDT		;destination
-	mov	esi, isr_0		;address of isr0
-	mov	edx, isr_1-isr_0	;distance between isr labels
-	mov	ecx, 50			;number of isrlabels
-fill_idt:
-	mov	ebx, esi
-	mov	ax, si
-	stosw				;0 offset 15:0
-	mov	ax, KERNEL_CODE
-	stosw				;2 selector 15:0
-	mov	ax, 0x8E00
-	stosw				;4 [P][DPL][0][TYPE][0][0][0][0][0][0][0][0]
-	shr	esi, 16
-	mov	ax, si
-	stosw				;6 offset 31:16
-	mov	esi, ebx
-	add	esi, edx
-	loop	fill_idt
-
-	lgdt	[gdtr]			;load gdt
-	jmp	KERNEL_CODE:newgdtcontinue
-newgdtcontinue:
-	mov	ax, KERNEL_DATA
-	mov	es, ax
-	mov	ds, ax
-	mov	gs, ax
-	mov	fs, ax
-	mov	ss, ax
-	mov	esp, 0x1ffffc		;stack just under 2mb, moves downward
-	lidt	[idtr]			;load idt
-
-	call	_k_init
-	hlt				;halt processor when k_init is done
-	jmp	$			;shouldn't get here...	
-
-%include "gdt.inc"
-%include "idt.inc"
-
-
-

kernel.c

@@ -1,109 +0,0 @@
-//kernel.c
-//08/13/03 Josh Holtrop
-//Holtrop's Operating System
-
-#define VXR video_mode.XResolution
-#define VYR video_mode.YResolution
-
-#include "k_defines.h"
-
-#include "lib/string.h"
-#include "lib/io.h"
-
-#include "functions.h"
-#include "video.h"
-#include "mm.h"
-#include "keyboard.h"
-#include "mouse.h"
-
-void isr(dword num);
-void k_init();
-
-#include "mouse.c"
-#include "keyboard.c"
-#include "mm.c"
-#include "functions.c"
-#include "video.c"
-
-dword	timer = 0;
-
-void k_init()
-{
-	console_cls();
-	remap_pics(0x20, 0x28);
-	//set timer : 2e9c = 100hz
-	outportb(0x43, 0x34);
-	outportb(0x40, 0x9c); //lsb
-	outportb(0x40, 0x2e); //msb
-	video_init((ModeInfoBlock *) 0x90306);
-	video_rectf(VXR*3/11, 0, VXR*4/11, VYR-1, 0x00000088);      		//test rectangles, draws "HOS"
-	video_rectf(VXR*7/11, 0, VXR*8/11, VYR-1, 0x00000088);
-	video_rectf(VXR/11, 0, VXR*2/11, VYR*2/5, 0x00000088);
-	video_rectf(VXR/11, VYR*3/5, VXR*2/11, VYR-1, 0x00000088);
-	video_rectf(VXR*5/11, VYR/5, VXR*6/11, VYR*4/5, 0x00000088);
-	video_rectf(VXR*9/11, VYR/5, VXR-1, VYR*2/5, 0x00000088);
-	video_rectf(VXR*8/11, VYR*3/5, VXR*10/11, VYR*4/5, 0x00000088);
-
-	video_vert(10, 10, 16, 0x00ffff00);		//should be yellow 'H'
-	video_horiz(13, 10, 14, 0x00ffff00);
-	video_vert(14, 10, 16, 0x00ffff00);
-	
-	video_horiz(10, 17, 21, 0x00ffff00);
-	video_vert(19, 10, 16, 0x00ffff00);
-	video_horiz(16, 17, 21, 0x00ffff00);
-	
-	int a, b;
-	for (a = 0; a < 256; a++)
-	{
-		for (b = 0; b < 256; b++)
-		{
-			video_pset(a+5, b+30, (a<<16)|(b<<8));
-			video_pset(a+270, b+30, (a<<8)|(b));
-			video_pset(a+535, b+30, (a<<16)|(b));
-
-			video_pset(a+5, b+290, (a<<16)|(b<<8)|0x000000ff);
-			video_pset(a+270, b+290, (a<<8)|(b)|0x00ff0000);
-			video_pset(a+535, b+290, (a<<16)|(b)|0x0000ff00);
-		}
-	}
-
-	mm_init();
-	mouse_init();
-	enable_ints();
-	printf("Memory available to OS: %d MB (Bytes: %d)\n", mm_totalmem/0x100000, mm_totalmem);
-	pic1_mask(0);			//unmask IRQ's 0-7
-	pic2_mask(0);			//unmask IRQ's 8-15
-	dword key = 0;
-	for (;;)
-	{
-		key = kbdWaitKey();
-		putc(key);
-	}
-}
-
-void isr(dword num)
-{
-	switch(num)
-	{
-	case 0x20:         		// IRQ0 - timer interrupt
-		timer++;
-		(*(byte *)0xb8000)++;
-		eoi();
-		break;
-	case 0x21:  			// IRQ1 - keyboard interrupt
-		isr_keyboard();    	//isr_keybard() takes care of calling eoi()
-		break;
-	case 0x2C:			// IRQ12 - PS/2 mouse
-		isr_mouse();
-		eoi2();
-		break;
-	default:
-		printf("Interrupt %d (0x%x) Unhandled!!\n", num, num);
-		break;
-	}
-}
-
-
-
-
-

keyboard.c

@@ -1,250 +0,0 @@
-//Keyboard.c
-// Created: 04/17/03 Josh Holtrop
-// Modified: 09/09/03
-//for HOS
-
-#define KBD_BUFFER_LENGTH 64
-
-byte kbdFlags = 0;
-byte kbdAscii = 0;
-byte kbdScan = 0;
-
-dword kbdBuffer[KBD_BUFFER_LENGTH];
-int kbdBufferStart = 0;
-int kbdBufferLen = 0;
-byte kbdExt = 0;
-byte kbdExt2 = 0;
-byte ackReason = 0;		//used to record the reason why we would get an acknowledge byte (0xFA)
-
-
-                                   //nul esc            bksp tab              lctl            lsft            rsft lalt caps F1  F2  F3  F4  F5  F6  F7  F8  F9  F10 numScrlNumPad-------                                  unknown---- F11 F12 unknown....
-const byte SCAN2ASCII[128]      = "\000\0331234567890-=\010\011qwertyuiop[]\n\001asdfghjkl;'`\001\\zxcvbnm,./\001*\001 \001\001\001\001\001\001\001\001\001\001\001\001\001\001\001\001-\001\001\001+\001\001\001\001\001\002\002\002\001\001\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002";
-const byte SCAN2ASCIISHIFT[128] = "\000\033!@#$%^&*()_+\010\011QWERTYUIOP{}\n\001ASDFGHJKL:\"~\001|ZXCVBNM<>?\001*\001 \001\001\001\001\001\001\001\001\001\001\001\001\001789-456+1230.\002\002\002\001\001\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002\002";
-
-//====FUNCTIONS:
-
-void isr_keyboard()
-{
-	kbdScan = inportb(0x60);
-	//printf("\nKEYBOARD INTERRUPT: 0x%x", kbdScan);
-	byte inState = inportb(0x61);
-	outportb(0x61, inState|0x80);
-	outportb(0x61, inState);
-	
-	//printf("IRQ 1: %x\n", kbdScan);
-
-	if (kbdScan == 0xFA)	//250					//ACKnowledge
-	{
-		if (ackReason == 0xED)					//reset LEDs
-		{
-			outportb(0x64, (kbdFlags & 0x07));
-			printf("KBD_ACK!");
-		}
-		ackReason = 0;
-	}
-	if (kbdScan == 224)							//extended key
-	{
-		kbdExt = 1;
-		eoi();
-		return;
-	}
-	if (kbdScan == 225)
-	{
-		kbdExt2 = 2;
-		eoi();
-		return;
-	}
-
-//====handle control keys::
-	kbdAscii = 2;
-	switch (kbdScan)							//control keys
-	{
-		case KBD_SCAN_LSHIFT:
-			kbdFlags |= KBD_SHIFT;
-			kbdAscii = 1;
-			break;
-		case KBD_SCAN_RSHIFT:
-			kbdFlags |= KBD_SHIFT;
-			kbdAscii = 1;
-			break;
-		case KBD_SCAN_LCTRL:
-			kbdFlags |= KBD_CTRL;
-			kbdAscii = 1;
-			break;
-		case KBD_SCAN_LALT:
-			kbdFlags |= KBD_ALT;			
-			kbdAscii = 1;
-			break;
-
-		case KBD_SCAN_LSHIFT + KBD_SCAN_RELEASED:
-			kbdFlags &= (KBD_SHIFT ^ 0xFF);
-			kbdAscii = 1;
-			break;
-		case KBD_SCAN_RSHIFT + KBD_SCAN_RELEASED:
-			kbdFlags &= (KBD_SHIFT ^ 0xFF);
-			kbdAscii = 1;
-			break;
-		case KBD_SCAN_LCTRL + KBD_SCAN_RELEASED:
-			kbdFlags &= (KBD_CTRL ^ 0xFF);
-			kbdAscii = 1;
-			break;
-		case KBD_SCAN_LALT + KBD_SCAN_RELEASED:
-			kbdFlags &= (KBD_ALT ^ 0xFF);
-			kbdAscii = 1;
-			break;
-
-		case KBD_SCAN_CAPS+KBD_SCAN_RELEASED:
-			kbdFlags ^= KBD_CAPS;
-			kbdAscii = 1;
-			kbd_resetLEDs();			//update LEDs
-			break;
-		case KBD_SCAN_SCROLL+KBD_SCAN_RELEASED:
-			kbdFlags ^= KBD_SCROLL;
-			kbdAscii = 1;
-			kbd_resetLEDs();			//update LEDs
-			break;
-		case KBD_SCAN_NUM+KBD_SCAN_RELEASED:
-			kbdFlags ^= KBD_NUM;
-			kbdAscii = 1;
-			kbd_resetLEDs();			//update LEDs
-			break;
-	}
-	if (kbdAscii == 1)
-	{
-		if (kbdExt > 0)
-			kbdExt--;
-		eoi();
-		return;
-	}
-//====determine ASCII value of key::
-	if (kbdExt > 0)						//extended key, kbdScan holds extended key
-	{
-		kbdExt--;
-		kbdAscii = 1;
-		switch (kbdScan)
-		{
-			case KBD_SCANE_ENTER:
-				kbdAscii = '\n';	break;
-			case 53:				// '/' character (divide on numpad)
-				kbdAscii = '/';		break;
-		}
-	}
-	else if (kbdExt2 > 0)					//extended key 2
-	{
-		kbdExt2--;
-//		if (kbdScan == 69)				// (pause|break)
-//			kbdAscii = 2;				//flag ascii value of 1 means control character (pausebreak)
-//		else
-			kbdAscii = 2;				//flag ascii value of 2 means ignore key (or unknown value)
-	}
-	else							//not an extended key
-	{
-			// if letter key
-		if (((kbdScan >= 16) && (kbdScan <= 25)) || ((kbdScan >= 30) && (kbdScan <= 38)) || ((kbdScan >= 44) && (kbdScan <= 50)))
-		{
-			// if caps and shift are different (either one pressed, not both)
-			if (((kbdFlags & KBD_SHIFT) != 0) & ((kbdFlags & KBD_CAPS) != 0))
-				kbdAscii = SCAN2ASCII[kbdScan & 0x7F];
-			else if (((kbdFlags & KBD_SHIFT) == 0) & ((kbdFlags & KBD_CAPS) == 0))
-				kbdAscii = SCAN2ASCII[kbdScan & 0x7F];
-			else
-				kbdAscii = SCAN2ASCIISHIFT[kbdScan & 0x7F];
-		}
-			// if numpad key
-		else if ((kbdScan >= 71) && (kbdScan <= 83))
-		{
-			// if numlock on
-			if (kbdFlags & KBD_NUM)
-				kbdAscii = SCAN2ASCIISHIFT[kbdScan & 0x7F];
-			else
-				kbdAscii = SCAN2ASCII[kbdScan & 0x7F];
-		}
-			// other key
-		else
-		{
-			if ((kbdFlags & KBD_SHIFT) != 0)
-				kbdAscii = SCAN2ASCIISHIFT[kbdScan & 0x7F];
-			else
-				kbdAscii = SCAN2ASCII[kbdScan & 0x7F];
-		}
-	}
-
-//====do something with key::
-	if ((kbdScan == 83) & ((kbdFlags & KBD_CTRL) != 0) & ((kbdFlags & KBD_ALT) != 0))
-	{
-		printf("Initiating reboot.");
-		restart();
-	}
-	if (kbdAscii == 2)							//unknown key / ignore key
-	{
-		eoi();
-		return;
-	}
-	if (kbdScan < KBD_SCAN_RELEASED)					//a key was pressed, save it
-	{
-		if (kbdBufferLen >= KBD_BUFFER_LENGTH)				//no key slots available
-		{
-			eoi();
-			return;
-		}
-		else
-		{
-			kbdBuffer[(kbdBufferStart+kbdBufferLen++)%KBD_BUFFER_LENGTH] = (dword) ((kbdFlags << 16) | (kbdScan << 8) | kbdAscii);
-//			printf("S:%d\tL:%d\tR:%x\n", kbdBufferStart, kbdBufferLen, kbdBuffer[kbdBufferStart]);
-		}
-	}
-
-	eoi();
-
-//	if (key == 0xFA)							//ACKnowledge
-//		outportb(0x60, 0x3);
-}
-
-inline byte switchCase(byte asciiCode)
-{
-	if ((asciiCode >= 'A') & (asciiCode <= 'Z'))
-		return (asciiCode + ('a' - 'A'));
-	if ((asciiCode >= 'a') & (asciiCode <= 'z'))
-		return (asciiCode - ('a' - 'A'));
-	return asciiCode;
-}
-
-dword kbdGetKey()
-{
-	if (kbdBufferLen == 0)					//buffer empty
-		return 0;
-	dword retVal = kbdBuffer[kbdBufferStart];
-	kbdBufferStart++;
-	kbdBufferLen--;
-	if (kbdBufferStart >= KBD_BUFFER_LENGTH)
-		kbdBufferStart = 0;
-	return retVal;
-}
-
-dword kbdWaitKey()
-{
-	for (;;)
-	{
-		if (kbdBufferLen != 0)					//buffer empty
-			break;
-	}		
-	dword retVal = kbdBuffer[kbdBufferStart];
-	kbdBufferStart++;
-	kbdBufferLen--;
-	if (kbdBufferStart >= KBD_BUFFER_LENGTH)
-		kbdBufferStart = 0;
-	return retVal;
-}
-
-inline void kbd_resetLEDs()
-{
-	outportb(0x64, 0xED);
-	//outportb(0x64, (kbdFlags & 0x07));
-	ackReason = 0xED;
-}
-
-
-
-
-
-

keyboard.h

@@ -1,47 +0,0 @@
-//Keyboard.h
-// Created: 04/17/03 Josh Holtrop
-// Modified: 05/07/03
-//for HOS
-
-#define KBD_SCROLL 0x01
-#define KBD_NUM 0x02
-#define KBD_CAPS 0x04
-#define KBD_SHIFT 0x10
-#define KBD_CTRL 0x20
-#define KBD_ALT 0x40
-
-#define KBD_SCAN_RELEASED 128
-
-#define KBD_SCAN_LCTRL 29
-#define KBD_SCAN_LSHIFT 42
-#define KBD_SCAN_RSHIFT 54
-#define KBD_SCAN_LALT 56
-#define KBD_SCAN_SCROLL 70
-#define KBD_SCAN_CAPS 58
-#define KBD_SCAN_NUM 69
-
-#define KBD_SCANE_PRINTSCREEN 55
-#define KBD_SCANE_INS 82
-#define KBD_SCANE_HOME 71
-#define KBD_SCANE_PGUP 73
-#define KBD_SCANE_DEL 83
-#define KBD_SCANE_END 79
-#define KBD_SCANE_PGDN 81
-#define KBD_SCANE_ENTER 28
-
-#define KBD_SCANE_NULL 42
-
-
-
-//====PROTOTYPES:
-
-void isr_keyboard();
-inline void kbd_resetLEDs();
-inline byte kbd_ascii(dword keycode);
-inline byte kbd_scancode(dword keycode);
-inline byte kbd_flags(dword keycode);
-inline byte switchCase(byte asciiCode);
-dword kbdGetKey();
-dword kbdWaitKey();
-
-

lib/defines.h

@@ -1,7 +0,0 @@
-
-typedef unsigned int dword;
-typedef unsigned short word;
-typedef unsigned char byte;
-
-
-

lib/io.asm

@@ -1,532 +0,0 @@
-
-%macro jzfar 1
-	jnz	%%skip
-	jmp	%1
-%%skip:
-
-%endmacro
-
-[global _writeCursorPosition]
-[global _getCursorPosition]
-[global _putc]
-[global _puts]
-[global _printf]
-[global _console_scroll]
-[global _console_cls]
-[global _putHex]
-[global _putDec]
-[global _putDecu]
-
-
-;
-;void writeCursorPosition(word pos)
-;
-_writeCursorPosition:
-	push	ebp
-	mov	ebp, esp
-
-	push	eax
-	push	ebx
-	push	edx
-
-	mov	eax, [ebp+8]	;cursor position in ax
-
-	mov	bl, al
-	mov	dx, 0x03D4
-	mov	al, 0x0E
-	out	dx, al
-
-	inc	dx
-	mov	al, ah
-	out	dx, al
-
-	dec	dx
-	mov	al, 0x0F
-	out	dx, al
-
-	inc	dx
-	mov	al, bl
-	out	dx, al
-
-	pop	edx
-	pop	ebx
-	pop	eax
-	pop	ebp
-
-	ret
-
-
-;
-;word getCursorPosition()
-;
-_getCursorPosition:
-	push	ebx
-	push	edx
-
-	xor	eax, eax
-	mov	dx, 0x03D4
-	mov	al, 0x0E
-	out	dx, al
-
-	inc	dx
-	in	al, dx
-	mov	bl, al
-
-	dec	dx
-	mov	al, 0x0F
-	out	dx, al
-
-	inc	dx
-	in	al, dx
-	mov	ah, bl
-
-	pop	edx
-	pop	ebx
-
-	ret
-
-
-;
-;int putc(int chr)
-;
-_putc:
-	push	ebp
-	mov	ebp, esp
-	push	ebx
-	push	ecx
-	push	edx
-
-	call	_getCursorPosition
-	mov	ebx, eax
-	mov	ecx, ebx
-
-	mov	eax, [ebp+8]			;al=character
-	cmp	al, 10				;newline
-	jz	putc_newline
-	cmp	al, 9				;tab
-	jz	putc_tab	
-
-	shl	ebx, 1
-	add	ebx, 0xb8000
-	mov	ah, 0x07
-	mov	[ebx], ax
-	mov	eax, ecx
-	inc	eax
-	cmp	eax, 2000
-	jnz	putc_writeit2
-	call	_console_scroll
-	mov	eax, 2000-80
-putc_writeit2:
-	push	eax
-	call	_writeCursorPosition
-	add	esp, 4
-	jmp	putc_done
-
-putc_newline:
-	mov	eax, ebx			;eax = cursor position
-	mov	ebx, 80
-	xor	edx, edx
-	div	bx				;ax=dx:ax/bx, dx=remainder
-	mov	bx, 80
-	sub	bx, dx
-	mov	eax, ecx
-	add	eax, ebx			;eax = new cursor position
-	cmp	eax, 2000
-	jnz	putc_newline_writeit2
-	call	_console_scroll
-	mov	eax, 2000-80			;beginning of last row
-putc_newline_writeit2:
-	push	eax
-	call	_writeCursorPosition
-	add	esp, 4
-	jmp	putc_done
-
-putc_tab:
-	mov	eax, ebx			;eax = cursor position
-	mov	ebx, 8
-	div	bl				;al=ax/bl, ah=remainder
-	xor	edx, edx
-	mov	dl, ah
-	mov	bx, 8
-	sub	bx, dx
-	mov	eax, ecx
-	add	eax, ebx			;eax = new cursor position
-	cmp	eax, 2000
-	jnz	putc_tab_writeit2
-	call	_console_scroll
-	mov	eax, 2000-80			;beginning of last row
-putc_tab_writeit2:
-	push	eax
-	call	_writeCursorPosition
-	add	esp, 4
-
-putc_done:
-	pop	edx
-	pop	ecx
-	pop	ebx
-	pop	ebp
-
-	ret
-
-
-
-;
-;void printf(char *fmt, ... )
-;
-_printf:
-	push	ebp
-	mov	ebp, esp
-	pusha
-	mov	ebx, [ebp+8]			;ebx = position in format string
-	mov	esi, ebp
-	add	esi, 12				;esi = to next variable arg
-	xor	ecx, ecx			;ecx used if we encounter a '%'
-printf_loop:
-	mov	al, [ebx]
-	inc	ebx
-	cmp	al, 0
-	jzfar	printf_done
-	cmp	ecx, 1
-	jz	printf_special
-	cmp	al, '%'
-	jzfar	printf_percent
-
-	push	eax
-	call	_putc
-	add	esp, 4
-	jmp	printf_loop
-
-printf_special:
-	xor	ecx, ecx
-	cmp	al, 'd'
-	jz	printf_decimal
-	cmp	al, 'u'
-	jz	printf_decimalu
-	cmp	al, 'x'
-	jz	printf_hex
-	cmp	al, '%'
-	jz	printf_ppercent
-	cmp	al, 's'
-	jz	printf_string
-	cmp	al, 'c'
-	jz	printf_char
-	jmp	printf_special_done
-
-printf_decimal:
-	mov	eax, [esi]
-	push	eax
-	call	_putDec
-	add	esp, 4
-	jmp	printf_special_done
-
-printf_decimalu:
-	mov	eax, [esi]
-	push	eax
-	call	_putDecu
-	add	esp, 4
-	jmp	printf_special_done
-
-printf_hex:
-	mov	eax, [esi]
-	push	eax
-	call	_putHex
-	add	esp, 4
-	jmp	printf_special_done
-
-printf_ppercent:
-	push	eax
-	call	_putc
-	add	esp, 4
-	jmp	printf_special_done
-
-printf_string:
-	mov	eax, [esi]
-	push	eax
-	call	_puts
-	add	esp, 4
-	jmp	printf_special_done
-
-printf_char:
-	mov	eax, [esi]
-	push	eax
-	call	_putc
-	add	esp, 4
-	jmp	printf_special_done
-
-printf_special_done
-	add	esi, 4				;point to next extra argument
-	jmp	printf_loop
-
-printf_percent:
-	mov	ecx, 1
-	jmp	printf_loop
-
-
-printf_done:
-	popa
-	pop	ebp
-	ret
-
-
-
-;
-;void console_scroll()
-;
-_console_scroll:
-	pusha
-	mov	esi, 0xb8000+160
-	mov	edi, 0xb8000
-	mov	ecx, 960			;(2000-80)/2
-console_scroll_loop:
-	lodsd
-	stosd
-	loop	console_scroll_loop
-	mov	ax, 0x0720
-	mov	ecx, 80
-console_scroll_loop2:
-	stosw
-	loop	console_scroll_loop2
-	popa
-	ret
-
-;
-;void console_cls()
-;
-_console_cls:
-	pusha
-	mov	edi, 0xb8000
-	mov	ax, 0x0720
-	mov	ecx, 2000
-console_cls_loop:
-	stosw
-	loop	console_cls_loop
-	push	dword 0
-	call	_writeCursorPosition
-	add	esp, 4
-	popa
-	ret
-
-;
-;int putHex(dword number)
-;
-_putHex:
-	push	ebp
-	mov	ebp, esp
-	pusha
-	mov	eax, [ebp+8]			;eax = number to print
-	xor	ebx, ebx			;we have not printed a character yet
-	mov	ecx, 8				;counter for number of characters
-
-putHex_loop:
-	push	eax
-	push	ecx
-
-	dec	ecx
-	shl	ecx, 2				;edx=counter*4 (amount to shift by)
-	shr	eax, cl
-	and	eax, 0x0F
-	cmp	cl, 0
-	jz	putHex_notzero			;if number is 0
-	cmp	al, 0
-	jnz	putHex_notzero
-	cmp	bl, 0
-	jz	putHex_loop_end
-putHex_notzero:
-	mov	bl, 1
-	add	eax, '0'
-	cmp	eax, '9'
-	jbe	putHex_dontadjust
-	add	eax, 'A'-'9'-1
-putHex_dontadjust:
-	push	eax
-	call	_putc
-	add	esp, 4
-
-putHex_loop_end:
-	pop	ecx
-	pop	eax
-	loop	putHex_loop
-
-	popa
-	pop	ebp
-	ret
-
-
-;
-;int puts(char *str)
-;
-_puts:
-	push	ebp
-	mov	ebp, esp
-	push	esi
-	push	eax
-	mov	esi, [ebp+8]			;esi = to string
-puts_loop:
-	lodsb
-	cmp	al, 0
-	jz	puts_done
-	push	eax
-	call	_putc
-	add	esp, 4
-	jmp	puts_loop
-
-puts_done:
-	pop	eax
-	pop	esi
-	pop	ebp
-	ret
-
-
-
-
-
-
-_putDecu:
-	push	ebp
-	mov	ebp, esp
-	sub	esp, 24
-	mov	DWORD [ebp-4], 1
-	mov	BYTE [ebp-5], 0
-L2:
-	mov	edx, DWORD [ebp+8]
-	mov	eax, -858993459
-	mul	edx
-	mov	eax, edx
-	shr	eax, 3
-	cmp	eax, DWORD [ebp-4]
-	jae	L4
-	jmp	L3
-L4:
-	mov	eax, DWORD [ebp-4]
-	mov	edx, eax
-	sal	edx, 2
-	add	edx, eax
-	lea	eax, [edx+edx]
-	mov	DWORD [ebp-4], eax
-	jmp	L2
-L3:
-	nop
-L5:
-	cmp	DWORD [ebp-4], 1
-	ja	L7
-	jmp	L6
-L7:
-	mov	edx, DWORD [ebp+8]
-	mov	eax, edx
-	mov	edx, 0
-	div	DWORD [ebp-4]
-	mov	DWORD [ebp-12], eax
-	mov	al, BYTE [ebp-12]
-	mov	BYTE [ebp-5], al
-	mov	eax, 0
-	mov	al, BYTE [ebp-5]
-	imul	eax, DWORD [ebp-4]
-	sub	DWORD [ebp+8], eax
-	mov	edx, DWORD [ebp-4]
-	mov	eax, -858993459
-	mul	edx
-	mov	eax, edx
-	shr	eax, 3
-	mov	DWORD [ebp-4], eax
-	lea	eax, [ebp-5]
-	add	BYTE [eax], 48
-	sub	esp, 12
-	mov	eax, 0
-	mov	al, BYTE [ebp-5]
-	push	eax
-	call	_putc
-	add	esp, 16
-	jmp	L5
-L6:
-	sub	esp, 12
-	mov	al, BYTE [ebp+8]
-	add	eax, 48
-	and	eax, 255
-	push	eax
-	call	_putc
-	add	esp, 16
-	leave
-	ret
-
-
-
-
-_putDec:
-	push	ebp
-	mov	ebp, esp
-	sub	esp, 24
-	cmp	DWORD [ebp+8], 0
-	jns	L9
-	sub	esp, 12
-	push	45
-	call	_putc
-	add	esp, 16
-	neg	DWORD [ebp+8]
-L9:
-	mov	DWORD [ebp-4], 1
-	mov	BYTE [ebp-5], 0
-L10:
-	mov	eax, DWORD [ebp+8]
-	cmp	eax, DWORD [ebp-4]
-	jae	L12
-	jmp	L11
-L12:
-	mov	eax, DWORD [ebp-4]
-	mov	edx, eax
-	sal	edx, 2
-	add	edx, eax
-	lea	eax, [edx+edx]
-	mov	DWORD [ebp-4], eax
-	jmp	L10
-L11:
-	mov	edx, DWORD [ebp-4]
-	mov	eax, -858993459
-	mul	edx
-	mov	eax, edx
-	shr	eax, 3
-	mov	DWORD [ebp-4], eax
-L13:
-	cmp	DWORD [ebp-4], 1
-	ja	L15
-	jmp	L14
-L15:
-	mov	edx, DWORD [ebp+8]
-	mov	eax, edx
-	mov	edx, 0
-	div	DWORD [ebp-4]
-	mov	DWORD [ebp-12], eax
-	mov	al, BYTE [ebp-12]
-	mov	BYTE [ebp-5], al
-	mov	eax, 0
-	mov	al, BYTE [ebp-5]
-	imul	eax, DWORD [ebp-4]
-	sub	DWORD [ebp+8], eax
-	mov	edx, DWORD [ebp-4]
-	mov	eax, -858993459
-	mul	edx
-	mov	eax, edx
-	shr	eax, 3
-	mov	DWORD [ebp-4], eax
-	lea	eax, [ebp-5]
-	add	BYTE [eax], 48
-	sub	esp, 12
-	mov	eax, 0
-	mov	al, BYTE [ebp-5]
-	push	eax
-	call	_putc
-	add	esp, 16
-	jmp	L13
-L14:
-	sub	esp, 12
-	mov	al, BYTE [ebp+8]
-	add	eax, 48
-	and	eax, 255
-	push	eax
-	call	_putc
-	add	esp, 16
-	leave
-	ret
-
-
-
-

lib/io.h

@@ -1,18 +0,0 @@
-
-
-#ifndef __HIO_H__
-#define __HIO_H__ __HIO_H__
-
-void writeCursorPosition(dword pos);
-dword getCursorPosition();
-int putc(dword chr);
-int printf(char *fmt, ...);
-int puts(char *str);
-int putDec(int number);
-int putDecu(dword number);
-int putHex(dword number);
-void console_cls();
-void console_scroll();
-
-#endif
-

lib/string.c

@@ -1,13 +0,0 @@
-
-#include "string.h"
-
-int strlen(char *str)
-{
-	int retn = 0;
-	while (*str++ != 0)
-		retn++;
-	return retn;
-}
-
-
-

lib/string.h

@@ -1,8 +0,0 @@
-
-#ifndef __HSTRING_H__
-#define __HSTRING_H__ __HSTRING_H__
-
-int	strlen(char *str);
-
-#endif
-

link.ld

@@ -1,22 +0,0 @@
-OUTPUT_FORMAT("binary")
-ENTRY(start)
-SECTIONS
-{
-  .text  0x100000 : {
-    code = .; _code = .; __code = .;
-    *(.text)
-    . = ALIGN(4096);
-  }
-  .data  : {
-    data = .; _data = .; __data = .;
-    *(.data)
-    . = ALIGN(4096);
-  }
-  .bss  :
-  {
-    bss = .; _bss = .; __bss = .;
-    *(.bss)
-    . = ALIGN(4096);
-  }
-  end = .; _end = .; __end = .;
-}

mm.c

@@ -1,254 +0,0 @@
-// mm.c
-// 09/01/03 Josh Holtrop
-
-// 0x368000 is first available byte (this is right after the kernel @ 1mb and the initrd @ 2mb, 1440kb.
-
-
-pageblock *first_pageblock = (pageblock *) 0;
-dword	mm_totalmem = 0x100000;				//start counting from 1mb
-
-void	mm_init()
-{
-	dword	*memmap_entries = (dword *) 0x9040A;
-	memmap_entry	*maps = (memmap_entry *) 0x92000;
-	dword a;
-	for (a=0;a<(*memmap_entries);a++)
-	{
-		if (maps[a].attributes == 1)		// (1) mem free to OS
-		{
-			mm_totalmem += maps[a].limit.lowdword;
-			if  ((maps[a].base.lowdword + maps[a].limit.lowdword) > (FREERAM_START+8192))	//goes past where we start freeram
-			{
-				if (maps[a].base.lowdword < FREERAM_START)
-				{
-					maps[a].limit.lowdword = maps[a].limit.lowdword - (FREERAM_START - maps[a].base.lowdword);
-					maps[a].base.lowdword = FREERAM_START;	//block at least 4kb, starts >= FREERAM_START
-				}
-				if (first_pageblock == 0)	//no pageblock page set up yet, so set it up here
-				{
-					first_pageblock = (pageblock *) maps[a].base.lowdword;
-					maps[a].base.lowdword += 4096;
-					maps[a].limit.lowdword -= 4096;
-					mm_init_pageblockpage(first_pageblock);
-					first_pageblock->base = maps[a].base.lowdword;
-					first_pageblock->length = maps[a].limit.lowdword / 4096;
-					first_pageblock->pid = MM_PB_AVAIL;
-				}
-				else				//first_pageblock already set up, add on segment
-				{
-					pageblock *pb = first_pageblock;
-					for (;;)
-					{
-						if (pb->pid == MM_PB_NP)
-							break;
-						else
-							pb++;
-					}
-					pb->base = maps[a].base.lowdword;
-					pb->length = maps[a].limit.lowdword / 4096;
-					pb->pid = MM_PB_AVAIL;
-				}
-			}
-		}
-	}
-	if (first_pageblock == 0)
-	{
-		printf("ERROR! NO INITIAL PAGE BLOCK CREATED.");
-		asm("cli");
-		asm("hlt");
-		for (;;)
-		;
-	}
-}
-
-
-
-
-void	mm_init_pageblockpage(pageblock *pbp)
-{
-	int a;
-	for (a=0; a<256; a++)       				// 256 pageblock entries * 16 bytes per page block entry = 4096 bytes (1 page of pageblock entries)
-	{
-		pbp[a].base = 0;
-		pbp[a].length = 0;
-		pbp[a].pid = MM_PB_NP;
-		if (a<255)
-			pbp[a].link = (dword)(&pbp[a+1]);
-		else
-			pbp[a].link = 0;
-	}
-}
-
-
-void   *mm_palloc(dword numpages, dword proc_pid)
-{
- 	if (proc_pid < KERNEL_PID)
- 		return 0;
-	pageblock *pb = first_pageblock;
-	if (mm_freeentries() < 2)
-	{
-		if(mm_new_pageblock_page() == 0)
-			return 0;
-	}
-	pageblock *newentry = mm_nextpageblockentry();
-	for (;;)
-	{
-		if ((pb->pid == MM_PB_AVAIL) && (pb->length >= numpages))
-			break;
-		if (pb->link == 0)
-			return 0;
-		pb = (pageblock *)pb->link;
-	}
-	if (pb->length == numpages)		//dont need a new entry, just mark this one as used :)
-	{
-		pb->pid = proc_pid;
-		return (void *)pb->base;
-	}
-	else					//subtract out allocated number of pages from length
-	{
-		newentry->base = pb->base;
-		newentry->length = numpages;
-		newentry->pid = proc_pid;
-		pb->base += (numpages * 4096);
-		pb->length -= numpages;
-		return (void *)newentry->base;
-	}
-}
-
-
-dword	mm_freeentries()
-{
-	pageblock *pb = first_pageblock;
-	dword counter = 0;
-	for (;;)
-	{
-		if (pb->pid == MM_PB_NP)
-			counter++;
-		if (pb->link == 0)
-			return counter;
-		pb = (pageblock *) pb->link;
-	}
-}
-
-
-pageblock *mm_new_pageblock_page()  	//as of 09/26/03 this method leaks 4kb main memory per call, unrecoverable
-{
-	pageblock *pb = first_pageblock;
-	for (;;)
-	{
-		if ((pb->pid == MM_PB_AVAIL) && (pb->length > 1))
-		{
-			pageblock *retval = (pageblock *)pb->base;
-			pb->base += 4096;
-			pb->length--;
-			mm_init_pageblockpage(retval);			//zeros out, links new pageblock page
-			mm_lastpageblockentry()->link = (dword)retval;	//set up link to new pageblock page
-			return retval;
-		}
-		pb = (pageblock *) pb->link;
-		if (pb == 0)
-			return 0;
-	}
-}
-
-
-int	mm_pfree(void *ptr)
-{
- 	if (ptr == 0)
- 		return 2;
-	pageblock *pb = first_pageblock;
-	dword tofree = (dword) ptr;
-	for (;;)
-	{
-		if (pb->base == tofree)		// && (pb->pid == MM_PB_USED))
-		{
-			pb->pid = MM_PB_AVAIL;		//found block, mark available / coalesce it
-			mm_coalesce(pb);
-			return 0;
-		}
-		if (pb->link == 0)
-			return 1;
-		pb = (pageblock *) pb->link;
-	}
-}
-
-
-pageblock *mm_lastpageblockentry()
-{
-	pageblock *pb = first_pageblock;
-	for (;;)
-	{
-		if (pb->link == 0)
-			return pb;
-		pb = (pageblock *)pb->link;
-	}
-}
-
-
-pageblock *mm_nextpageblockentry()
-{
-	pageblock *pb = first_pageblock;
-	for (;;)
-	{
-		if (pb->pid == MM_PB_NP)
-			return pb;
-		if (pb->link == 0)
-			return 0;
-		pb = (pageblock *)pb->link;
-	}
-}
-
-
-dword mm_freemem()
-{
-	dword amount = 0;
-	pageblock *pb = first_pageblock;
-	for (;;)
-	{
-		if (pb->pid == MM_PB_AVAIL)
-			amount += (pb->length)*4096;
-		if (pb->link == 0)
-			return amount;
-		pb = (pageblock *) pb->link;
-	}
-}
-
-
-void	mm_coalesce(pageblock *pb)
-{
-	pageblock *pbc = first_pageblock;
-	for (;;)
-	{
-		if (pbc->pid == pb->pid)	//pid fields must match, both same process, both avail, or both not present
-		{
-			if ((pbc->base + (pbc->length * 4096)) == pb->base)	//pbc ends where pb starts
-			{
-				pbc->length += pb->length;
-				pb->pid = MM_PB_NP;
-				mm_coalesce(pbc);			//recursion: checks for any more page blocks to coalesce if one found
-				return;					//exit this recursion...
-			}
-			if ((pb->base + (pb->length * 4096)) == pbc->base)	//pb ends where pbc starts
-			{
-				pb->length += pbc->length;
-				pbc->pid = MM_PB_NP;
-				mm_coalesce(pb);
-				return;
-			}
-		}
-		if (pbc->link == 0)
-			return;
-		pbc = (pageblock *)pbc->link;
-	}
-}
-
-
-
-
-
-
-
-
-
-
-

mm.h

@@ -1,35 +0,0 @@
-
-
-typedef struct {
-	qword	base;
-	qword	limit;
-	dword	attributes;
-} __attribute__((packed)) memmap_entry;
-
-
-typedef struct {
-	dword	base;
-	dword	length;				//in pages
-	dword	pid;                            //normally PID of process, use NP, AVAIL for special flags
-	dword	link;				//leave dword instead of pointer so i dont have to worry about pointer arithmetic
-} __attribute__ ((packed)) pageblock;		//16 byte pageblock entry - 256 entries = 1 page
-
-
-void	mm_init();
-void	mm_init_pageblockpage(pageblock *pbp);
-void   *mm_palloc(dword numpages, dword proc_pid);
-void	mm_coalesce(pageblock *pb);
-int	mm_pfree(void *ptr);
-dword	mm_freeentries();
-dword	mm_freemem();
-pageblock *mm_new_pageblock_page();
-pageblock *mm_lastpageblockentry();
-pageblock *mm_nextpageblockentry();
-
-
-#define MM_PB_NP 0x00		//00000000
-#define MM_PB_AVAIL 0x01	//00000001
-
-
-
-

mouse.c

@@ -1,56 +0,0 @@
-// mouse.c
-// 10/03/03
-// Author: Josh Holtrop
-
-
-void mouse_init()
-{
-	outportb(0x64, 0x20);		//tell keyboard controller we are going to read keyboard controller command byte
-	byte temp = inportb(0x60);	//read keyboard controller command byte
-	outportb(0x64, 0x60);		//tell keyboard controller we are going to write keyboard controller command byte
-	outportb(0x60, 0x03 | (temp&0x40));	//write keyboard controller command byte: enable mouse/keyboard ints, include original XLATE bit from temp (bit6)
-
- 	outportb(0x64, 0xA8);	//enable mouse port
-
-	outportb(0x64, 0xD4);	//send command to mouse, not kbd
-	outportb(0x60, 0xF4);	//enable data reporting
-
-	//outportb(0x64, 0xD4);
-	//outportb(0x60, 0xE7);	//scaling 2:1
-}
-
-
-
-void isr_mouse()
-{
-	byte inb = inportb(0x60);	//read mouse byte
-	//printf("InB: %x\n", inb);
-	//return;
-	if ((inb == 0xFA) && (mouse_bytesRead < 1))		//ACK
-		return;
-	mouse_inbuffer[mouse_bytesRead] = inb;
-	mouse_bytesRead++;
-	if (mouse_bytesRead == 3)	//complete packet received
-	{
-		mouse_bytesRead = 0;
-		int adjx = (char) mouse_inbuffer[1];
-		int adjy = (char) mouse_inbuffer[2];
-		mouse_x += adjx;
-		mouse_y -= adjy;						//-= because screen y coordinates are opposite mouse y coordinates
-		if (mouse_inbuffer[0] & 0x01)	//left button
-		{
-			video_pset(VXR/2+mouse_x, VYR/2+mouse_y, 0x00FFFFFF);
-			printf("X: %d, Y: %d\n", mouse_x, mouse_y);
-		}
-		else
-		{
-			video_pset(VXR/2+mouse_x, VYR/2+mouse_y, 0x00000000);
-			printf("X: %d, Y: %d\n", mouse_x, mouse_y);
-		}
-	}
-}
-
-
-
-
-

mouse.h

@@ -1,17 +0,0 @@
-// mouse.h
-// 10/03/03
-// Author: Josh Holtrop
-
-
-int mouse_x = 0;
-int mouse_y = 0;
-int mouse_bytesRead = 0;
-byte mouse_inbuffer[16];
-
-void mouse_init();
-void isr_mouse();
-
-
-
-
-

readme.txt

@@ -0,0 +1,89 @@
+HOS - Holtrop's Operating System
+--------------------------------
+
+HOS is (in the process of becoming) a 32-bit, protected mode, graphical, multitasking operating system.
+It was written by me, Josh Holtrop, with help from a few others along the way.
+
+
+Goals: (A = accomplished, P = in progress, T = todo)
+----------------------------------------------------
+(A) Custom bootloader to load kernel from FAT-formatted boot media, options for video mode/ram disk
+(A) Multiboot compliance - kernel can be loaded by GRUB
+(A) 32-bit protected mode environment
+(A) VESA Support for graphics modes
+(A) PS/2 keyboard & mouse drivers
+(A) Utilize x86's paging architecture for virtual memory management
+
+(P) Console Manager
+(P) VFS abstraction layer for a single file system
+(P) ram disk driver
+(P) devfs file system driver
+(P) ext2 file system support
+
+(T) vfat file system support
+(T) Multitasking support
+(T) HASH command shell
+(T) Window Manager
+(T) Various other utilities/applications
+(T) Hard Drive (ATA) driver
+(T) cdrom (ATAPI) driver
+
+
+Change Log
+----------
+0.16
+12/16/04 - initrd going to be loaded as a gzipped ext2 image (kernel module) - faster loading!
+
+0.15
+07/10/04 - Multiboot support added, loadable by GRUB
+
+0.14
+05/21/04 - C++ support in kernel, can use classes & templates
+04/04/04 - video_line function for diagonal lines
+03/16/04 - new VFS design with support for a loop device
+03/01/04 - Thanks to Ben Meyer for helping me get a Makefile working and building on linux to work!
+
+0.13
+01/26/04 - functions added to read/write CMOS clock date and time
+01/19/04 - fixed bug GDTR/IDTR pointing to physical rather than linear table base address
+01/07/04 - fixed bug not reading sectors correctly from floppy
+12/28/03 - fixed bug not storing eax on interrupt
+12/25/03 - fixed bug in mm_palloc()
+12/25/03 - incorporated output functions as regular functions rather than as part of a linked library
+12/23/03 - re-written physical memory manager using bitmap instead of stack
+12/22/03 - kernel relocated to 3gb linear / 1mb+24kb physical to allow for app. address space
+
+0.12
+12/21/03 - sample bmp loader tested, works (tests loading a kernel of size ~ 932kb)
+12/20/03 - GDT/IDT now located at 1mb physical, before kernel
+10/30/03 - turns floppy motor off
+10/30/03 - keyboard LEDs working
+10/29/03 - paging functions working
+10/15/03 - physical memory management page allocators working
+
+0.11
+10/09/03 - PS/2 mouse driver
+
+0.10
+09/11/03 - Rewritten C and assembly kernel with VESA GUI mode support, keyboard driver
+
+0.05
+05/14/03 - HGUI24/HGUI32 commands finished for testing GUI on both 24bpp and 32bpp graphics cards
+05/14/03 - first web release!
+
+0.04
+03/09/03 - added VM shortcut command
+03/09/03 - press up to fill retrieve last inputted command for Nate Scholten
+03/08/03 - press clear to clear console input
+03/07/03 - added "shortcut" commands PC, IC, ? for Nate Scholten
+03/06/03 - added PROMPTC, INPUTC commands
+
+0.03
+12/30/02 - Command Line Interface working, accepting basic commands
+
+0.02
+12/11/02 - Assembly bootsector can load stage2 ("console")
+
+0.01
+12/01/02 - Real mode assembly bootsector boots from floppy disk successfully
+

rscons

@@ -0,0 +1,46 @@
+#!/usr/bin/env ruby
+
+# Copyright (c) 2013-2022 Josh Holtrop
+#
+# MIT License
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be
+# included in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+
+script = File.join(File.dirname(__FILE__), ".rscons-3.1.0-4892f95d56c30bbe9aa0c9964062ec5b.rb")
+unless File.exist?(script)
+  if File.read(__FILE__, mode: "rb") =~ /^#==>(.*)/
+    require "zlib"
+    require "base64"
+    encoded_compressed = $1
+    unescaped_compressed = Base64.decode64(encoded_compressed)
+    inflated = Zlib::Inflate.inflate(unescaped_compressed)
+    File.open(script, "wb") do |fh|
+      fh.write(inflated)
+    end
+  else
+    raise "Could not decompress."
+  end
+end
+load script
+if __FILE__ == $0
+  Rscons::Cli.new.run(ARGV)
+end
+#==>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 truncated

src/fontgen/fontgen.c

@@ -0,0 +1,235 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <ft2build.h>
+#include <stdio.h>
+#include FT_FREETYPE_H
+#include <string.h>
+#include <strings.h>
+#include <ctype.h>
+
+#define N_CHARS 128
+
+#define round_up_26_6(val) (((val) + 63) >> 6u)
+
+int max_advance;
+int max_top = -9999;
+int min_bottom = 9999;
+int line_height;
+int baseline_offset;
+
+typedef struct {
+    int width;
+    int height;
+    int top;
+    int left;
+    uint8_t * bitmap;
+} char_info_t;
+
+static char_info_t char_infos[N_CHARS];
+
+static void load_char(FT_Face face, int char_code)
+{
+    if (FT_Load_Char(face, char_code, FT_LOAD_RENDER) != 0)
+    {
+        return;
+    }
+    int advance = round_up_26_6(face->glyph->advance.x);
+    if (advance > max_advance)
+    {
+        max_advance = advance;
+    }
+    if ((face->glyph->bitmap.width == 0) ||
+            (face->glyph->bitmap.rows == 0))
+    {
+        return;
+    }
+    char_infos[char_code].width = face->glyph->bitmap.width;
+    char_infos[char_code].height = face->glyph->bitmap.rows;
+    char_infos[char_code].top = face->glyph->bitmap_top;
+    if (char_infos[char_code].top > max_top)
+    {
+        max_top = char_infos[char_code].top;
+    }
+    int bottom = char_infos[char_code].top - char_infos[char_code].height;
+    if (bottom < min_bottom)
+    {
+        min_bottom = bottom;
+    }
+    char_infos[char_code].left = face->glyph->bitmap_left;
+    char_infos[char_code].bitmap = malloc(char_infos[char_code].width * char_infos[char_code].height);
+    memcpy(char_infos[char_code].bitmap,
+            face->glyph->bitmap.buffer,
+            char_infos[char_code].width * char_infos[char_code].height);
+}
+
+static void generate_bytes(FILE * file, const uint8_t * bytes, int count)
+{
+    for (int i = 0; i < count; i++)
+    {
+        if (i % 8 == 0)
+        {
+            fprintf(file, "                ");
+        }
+        fprintf(file, "0x%02xu,", bytes[i]);
+        if ((i + 1) % 8 == 0)
+        {
+            fprintf(file, "\n");
+        }
+        else if (i < (count - 1))
+        {
+            fprintf(file, " ");
+        }
+    }
+    if (count % 8 != 0)
+    {
+        fprintf(file, "\n");
+    }
+}
+
+static bool generate(const char * d_file_name)
+{
+    FILE * fh = fopen(d_file_name, "wb");
+    fprintf(fh, "module hulk.kfont;\n");
+    fprintf(fh, "struct CharInfo {\n");
+    fprintf(fh, "    /** Glyph bitmap width. */\n");
+    fprintf(fh, "    ubyte width;\n");
+    fprintf(fh, "    /** Glyph bitmap height. */\n");
+    fprintf(fh, "    ubyte height;\n");
+    fprintf(fh, "    /** Glyph bitmap top offset (descent from top of text row). */\n");
+    fprintf(fh, "    ubyte top;\n");
+    fprintf(fh, "    /** Glyph bitmap left offset. */\n");
+    fprintf(fh, "    ubyte left;\n");
+    fprintf(fh, "    /** Glyph bitmap. */\n");
+    fprintf(fh, "    const ubyte[] bitmap;\n");
+    fprintf(fh, "};\n");
+    fprintf(fh, "struct FontInfo {\n");
+    fprintf(fh, "    /** Font line height. */\n");
+    fprintf(fh, "    ubyte line_height;\n");
+    fprintf(fh, "    /** Font advance. */\n");
+    fprintf(fh, "    ubyte advance;\n");
+    fprintf(fh, "    /** Characters. */\n");
+    fprintf(fh, "    const CharInfo[] chars;\n");
+    fprintf(fh, "};\n");
+    fprintf(fh, "/** Kernel font data. */\n");
+    fprintf(fh, "__gshared const FontInfo Kfont = {\n");
+    fprintf(fh, "    %du,\n", line_height);
+    fprintf(fh, "    %du,\n", max_advance);
+    fprintf(fh, "    [\n");
+    for (int i = 0; i < N_CHARS; i++)
+    {
+        fprintf(fh, "        /* %d */", i);
+        fprintf(fh, "        CharInfo(\n");
+        fprintf(fh, "            %du /* width */,\n", char_infos[i].width);
+        fprintf(fh, "            %du /* height */,\n", char_infos[i].height);
+        fprintf(fh, "            %du /* top */,\n", char_infos[i].top);
+        fprintf(fh, "            %du /* left */,\n", char_infos[i].left);
+        if (char_infos[i].width > 0)
+        {
+            fprintf(fh, "            [\n");
+            generate_bytes(fh, char_infos[i].bitmap, char_infos[i].width * char_infos[i].height);
+            fprintf(fh, "            ]\n");
+        }
+        else
+        {
+            fprintf(fh, "            []\n");
+        }
+        fprintf(fh, "        ),\n");
+    }
+    fprintf(fh, "    ],\n");
+    fprintf(fh, "};\n");
+    fclose(fh);
+    return true;
+}
+
+int main(int argc, char * argv[])
+{
+    /* Expect: font file, size, out file */
+    if (argc != 4)
+    {
+        fprintf(stderr, "Incorrect arguments\n");
+        return 1;
+    }
+    const char * font_file = argv[1];
+    int size = atoi(argv[2]);
+    const char * out_file = argv[3];
+
+    FT_Library ft_library;
+    if (FT_Init_FreeType(&ft_library) != 0)
+    {
+        fprintf(stderr, "Could not initialize freetype\n");
+        return 2;
+    }
+
+    FT_Face face;
+    if (FT_New_Face(ft_library, font_file, 0, &face) != 0)
+    {
+        fprintf(stderr, "Could not open %s\n", font_file);
+        return 3;
+    }
+
+    FT_Set_Pixel_Sizes(face, 0, size);
+
+    for (int i = 0; i < N_CHARS; i++)
+    {
+        load_char(face, i);
+    }
+    line_height = round_up_26_6(face->size->metrics.height);
+    baseline_offset = (line_height - (max_top - min_bottom)) / 2 - min_bottom;
+
+    if ((line_height < 1) || (line_height > 0xFF))
+    {
+        fprintf(stderr, "Error: invalid line_height %d\n", line_height);
+        return false;
+    }
+    if ((max_advance < 1) || (max_advance > 0xFF))
+    {
+        fprintf(stderr, "Error: invalid max_advance %d\n", max_advance);
+        return false;
+    }
+
+    for (int i = 0; i < N_CHARS; i++)
+    {
+        if ((char_infos[i].width < 0) || (char_infos[i].width > max_advance))
+        {
+            fprintf(stderr, "Error: invalid character %d width: %d (max advance %d)\n", i, char_infos[i].width, max_advance);
+            return false;
+        }
+        if ((char_infos[i].height < 0) || (char_infos[i].height > line_height))
+        {
+            fprintf(stderr, "Error: invalid character %d height: %d (line height %d)\n", i, char_infos[i].height, line_height);
+            return false;
+        }
+        if ((char_infos[i].left < 0) || (char_infos[i].left >= max_advance))
+        {
+            fprintf(stderr, "Error: invalid character %d left: %d (max advance %d)\n", i, char_infos[i].left, max_advance);
+            return false;
+        }
+        /* Adjust character top to be index downward from top of font box. */
+        char_infos[i].top = line_height - baseline_offset - char_infos[i].top;
+        if ((char_infos[i].top < 0) || (char_infos[i].top >= line_height))
+        {
+            fprintf(stderr, "Error: invalid character %d top: %d (line height %d)\n", i, char_infos[i].top, line_height);
+            return false;
+        }
+        if ((char_infos[i].left + char_infos[i].width) > max_advance)
+        {
+            fprintf(stderr, "Error: character %d left (%d) + width (%d) > advance (%d)\n",
+                    i, char_infos[i].left, char_infos[i].width, max_advance);
+            return false;
+        }
+        if ((char_infos[i].top + char_infos[i].height) > line_height)
+        {
+            fprintf(stderr, "Error: character %d top (%d) + height (%d) > line height (%d)\n",
+                    i, char_infos[i].top, char_infos[i].height, line_height);
+            return false;
+        }
+    }
+
+    if (!generate(out_file))
+    {
+        return 1;
+    }
+
+    return 0;
+}

src/hello/console.d

@@ -0,0 +1,88 @@
+/**
+ * HELLO console support.
+ */
+module hello.console;
+
+import uefi;
+import hello.hello;
+import core.stdc.stdarg;
+import hulk.writef;
+
+struct Console
+{
+    /**
+     * Write a character to the console.
+     *
+     * @param ch Character to write.
+     */
+    public static void write(ubyte ch)
+    {
+        if (ch == '\n')
+        {
+            write('\r');
+        }
+        CHAR16[2] s16 = [ch, 0];
+        st.ConOut.OutputString(st.ConOut, &s16[0]);
+    }
+
+    /**
+     * Write a formatted string to the console.
+     *
+     * @param s Format string.
+     * @param args Variable arguments structure.
+     */
+    public static void writef(string s, va_list args)
+    {
+        hulk.writef.writefv(function void(ubyte ch) {
+                    Console.write(ch);
+                }, s, args);
+    }
+
+    /**
+     * Write a formatted string to the console.
+     *
+     * @param s Format string.
+     */
+    public static extern (C) void writef(string s, ...)
+    {
+        va_list args;
+        va_start(args, s);
+        writef(s, args);
+        va_end(args);
+    }
+
+    /**
+     * Write a formatted string and newline to the console.
+     *
+     * @param s Format string.
+     */
+    public static extern (C) void writefln(string s, ...)
+    {
+        va_list args;
+        va_start(args, s);
+        writef(s, args);
+        writef("\n", args);
+        va_end(args);
+    }
+
+    /**
+     * Write a message to press any key and wait for a key to be pressed.
+     */
+    public static void wait_key()
+    {
+        writefln("Press any key...");
+        st.ConIn.Reset(st.ConIn, FALSE);
+        EFI_INPUT_KEY key;
+        while (st.ConIn.ReadKeyStroke(st.ConIn, &key) == EFI_NOT_READY)
+        {
+        }
+    }
+
+    /**
+     * Clear the console.
+     */
+    public static void clear()
+    {
+        st.ConOut.ClearScreen(st.ConOut);
+    }
+}

src/hello/hello.d

@@ -0,0 +1,579 @@
+/**
+ * HELLO, the HOS EFI Lightweight LOader.
+ */
+module hello.hello;
+
+import uefi;
+import hello.console;
+import hulk.bootinfo;
+import hulk.header;
+import hulk.pagetable;
+import hulk.cpu;
+import hulk.memory;
+import ldc.llvmasm;
+import hulk.serial;
+
+__gshared EFI_SYSTEM_TABLE * st;
+/** HULK binary start address, 4KB-aligned. */
+extern extern(C) __gshared ubyte _hulk_bin_start;
+/** HULK binary end address, 4KB-aligned. */
+extern extern(C) __gshared ubyte _hulk_bin_end;
+private align(4096) __gshared ubyte[1024 * 1024] scratch_buffer;
+/** Index to the memory map region being used to allocate page tables. */
+private __gshared size_t memory_map_page_table_alloc_index;
+
+private HulkHeader * hulk_header()
+{
+    return cast(HulkHeader *)&_hulk_bin_start;
+}
+
+private BootInfo * bootinfo()
+{
+    return &hulk_header().bootinfo;
+}
+
+private ulong hulk_bin_phys()
+{
+    return cast(ulong)&_hulk_bin_start;
+}
+
+private ulong hulk_bin_size()
+{
+    return cast(ulong)&_hulk_bin_end - cast(ulong)&_hulk_bin_start;
+}
+
+private ulong hulk_bss_size()
+{
+    return cast(ulong)hulk_header().hulk_bss_size;
+}
+
+private ulong hulk_stack_size()
+{
+    return hulk_header().stack_size;
+}
+
+private ulong hulk_virt_base_address()
+{
+    return hulk_header().virt_base;
+}
+
+private ulong hulk_virt_stack_top()
+{
+    return hulk_header().virt_stack_top;
+}
+
+private ulong hulk_virt_framebuffer_address()
+{
+    return hulk_header().virt_fb_buffer;
+}
+
+/**
+ * Detect if we're running in QEMU.
+ */
+private bool in_qemu()
+{
+    ulong * firmware_vendor = cast(ulong *) st.FirmwareVendor;
+    ulong fv1 = firmware_vendor[0];
+    return fv1 ==
+        ((cast(ulong)'E') |
+         (cast(ulong)'D' << 16) |
+         (cast(ulong)'K' << 32) |
+         (cast(ulong)' ' << 48));
+}
+
+/**
+ * Set a graphics mode.
+ */
+private bool set_graphics_mode()
+{
+    uint max_horizontal_resolution = in_qemu() ? 1920u : 0xFFFFFFFFu;
+    UINTN buffer_size = scratch_buffer.sizeof;
+    EFI_GUID gop_guid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+    EFI_HANDLE * handles = cast(EFI_HANDLE *)&scratch_buffer[0];
+    EFI_STATUS status = st.BootServices.LocateHandle(ByProtocol,
+            &gop_guid, null, &buffer_size, handles);
+    if (status != EFI_SUCCESS)
+    {
+        Console.writefln("LocateHandle: error %x", status);
+        return false;
+    }
+    EFI_HANDLE gop_handle = handles[0];
+    EFI_HANDLE gop_interface;
+    status = st.BootServices.HandleProtocol(gop_handle,
+            &gop_guid, &gop_interface);
+    if (status != EFI_SUCCESS)
+    {
+        Console.writefln("HandleProtocol: error %x", status);
+        return false;
+    }
+    if (gop_interface == null)
+    {
+        Console.writefln("null interface from HandleProtocol");
+        return false;
+    }
+    EFI_GRAPHICS_OUTPUT_PROTOCOL * gop = cast(EFI_GRAPHICS_OUTPUT_PROTOCOL *)gop_interface;
+    UINTN info_size;
+    EFI_GRAPHICS_OUTPUT_MODE_INFORMATION * info;
+    uint best_width;
+    uint best_mode_number;
+    for (uint mode_number = 0u;
+         (status = gop.QueryMode(gop, mode_number, &info_size, &info)) == EFI_SUCCESS;
+         mode_number++)
+    {
+        if ((info.HorizontalResolution > best_width) &&
+            (info.HorizontalResolution <= max_horizontal_resolution))
+        {
+            best_width = info.HorizontalResolution;
+            best_mode_number = mode_number;
+        }
+        st.BootServices.FreePool(info);
+    }
+    if ((status = gop.SetMode(gop, best_mode_number)) != EFI_SUCCESS)
+    {
+        Console.writefln("SetMode: Error %x\n", status);
+        return false;
+    }
+    bootinfo().fb.buffer = cast(uint *)gop.Mode.FrameBufferBase;
+    bootinfo().fb.width = gop.Mode.Info.HorizontalResolution;
+    bootinfo().fb.height = gop.Mode.Info.VerticalResolution;
+    bootinfo().fb.stride = gop.Mode.Info.PixelsPerScanLine;
+    bootinfo().fb.format = gop.Mode.Info.PixelFormat;
+    return true;
+}
+
+/**
+ * Walk the EFI memory map and translate it to the HULK bootinfo format.
+ */
+private void get_memory_map(ulong * physical_address_limit, UINTN * memory_map_key)
+{
+    immutable static ubyte[] efi_to_hulk_memory_map_type = [
+        BootInfo.MemoryRegion.Type.Reserved, // EfiReservedMemoryType
+        BootInfo.MemoryRegion.Type.Bootloader, // EfiLoaderCode
+        BootInfo.MemoryRegion.Type.Bootloader, // EfiLoaderData
+        BootInfo.MemoryRegion.Type.Bootloader, // EfiBootServicesCode
+        BootInfo.MemoryRegion.Type.Bootloader, // EfiBootServicesData
+        BootInfo.MemoryRegion.Type.Reserved, // EfiRuntimeServicesCode
+        BootInfo.MemoryRegion.Type.Reserved, // EfiRuntimeServicesData
+        BootInfo.MemoryRegion.Type.Conventional, // EfiConventionalMemory
+        BootInfo.MemoryRegion.Type.Unusable, // EfiUnusableMemory
+        BootInfo.MemoryRegion.Type.ACPIReclaim, // EfiACPIReclaimMemory
+        BootInfo.MemoryRegion.Type.ACPINVS, // EfiACPIMemoryNVS
+        BootInfo.MemoryRegion.Type.MemoryMappedIO, // EfiMemoryMappedIO
+        BootInfo.MemoryRegion.Type.MemoryMappedIOPortSpace, // EfiMemoryMappedIOPortSpace
+        BootInfo.MemoryRegion.Type.PalCode, // EfiPalCode
+    ];
+    *physical_address_limit = 0u;
+    UINTN memory_map_size = scratch_buffer.sizeof;
+    UINTN descriptor_size;
+    UINT32 descriptor_version;
+    ubyte * scratch_base = cast(ubyte *)&scratch_buffer[0];
+    UINTN status = st.BootServices.GetMemoryMap(
+            &memory_map_size,
+            cast(EFI_MEMORY_DESCRIPTOR *)scratch_base,
+            memory_map_key,
+            &descriptor_size,
+            &descriptor_version);
+    if (status != EFI_SUCCESS)
+    {
+        Console.writefln("GetMemoryMap: Error %x", status);
+        for (;;) {}
+    }
+    size_t n_entries = memory_map_size / descriptor_size;
+    size_t count;
+    bool found_bss;
+    bool found_stack;
+    bool found_fb_buffer1;
+    const(size_t) fb_size = (bootinfo().fb.stride * bootinfo().fb.height * 4u + PAGE_SIZE - 1u) & ~(PAGE_SIZE - 1u);
+    for (count = 0u; count < n_entries; count++)
+    {
+        if (count > bootinfo().memory_map.length)
+        {
+            Console.writefln("Memory map too large");
+            for (;;) {}
+        }
+        EFI_MEMORY_DESCRIPTOR * descriptor = cast(EFI_MEMORY_DESCRIPTOR *)&scratch_base[count * descriptor_size];
+        ulong end_address = descriptor.PhysicalStart + descriptor.NumberOfPages * 4096u;
+        if ((end_address > *physical_address_limit) &&
+            ((descriptor.Type == EfiLoaderCode) ||
+             (descriptor.Type == EfiLoaderData) ||
+             (descriptor.Type == EfiBootServicesCode) ||
+             (descriptor.Type == EfiBootServicesData) ||
+             (descriptor.Type == EfiRuntimeServicesCode) ||
+             (descriptor.Type == EfiRuntimeServicesData) ||
+             (descriptor.Type == EfiConventionalMemory)))
+        {
+            *physical_address_limit = end_address;
+        }
+        if (descriptor.Type >= efi_to_hulk_memory_map_type.length)
+        {
+            Serial.writefln("Unexpected descriptor type %u", descriptor.Type);
+            continue;
+        }
+        bootinfo().memory_map[count].base = descriptor.PhysicalStart;
+        bootinfo().memory_map[count].size = descriptor.NumberOfPages * 4096u;
+        bootinfo().memory_map[count].type = efi_to_hulk_memory_map_type[descriptor.Type];
+        if ((!found_bss) &&
+            (descriptor.Type == EfiConventionalMemory) &&
+            (bootinfo().memory_map[count].size >= hulk_bss_size()))
+        {
+            bootinfo().bss_phys = bootinfo().memory_map[count].base;
+            bootinfo().memory_map[count].base += hulk_bss_size();
+            bootinfo().memory_map[count].size -= hulk_bss_size();
+            Serial.writefln("Locating HULK BSS at %x:%x",
+                    bootinfo().bss_phys,
+                    bootinfo().bss_phys + hulk_bss_size() - 1u);
+            found_bss = true;
+        }
+        if ((!found_stack) &&
+            (descriptor.Type == EfiConventionalMemory) &&
+            (bootinfo().memory_map[count].size >= hulk_stack_size()))
+        {
+            bootinfo().stack_phys = bootinfo().memory_map[count].base;
+            bootinfo().memory_map[count].base += hulk_stack_size();
+            bootinfo().memory_map[count].size -= hulk_stack_size();
+            Serial.writefln("Locating HULK stack at %x:%x",
+                    bootinfo().stack_phys,
+                    bootinfo().stack_phys + hulk_stack_size() - 1u);
+            found_stack = true;
+        }
+        if ((!found_fb_buffer1) &&
+            (descriptor.Type == EfiConventionalMemory) &&
+            (bootinfo().memory_map[count].size >= fb_size))
+        {
+            bootinfo().fb_buffer1_phys = bootinfo().memory_map[count].base;
+            bootinfo().memory_map[count].base += fb_size;
+            bootinfo().memory_map[count].size -= fb_size;
+            Serial.writefln("Locating HULK FB1 at %x:%x",
+                    bootinfo().fb_buffer1_phys,
+                    bootinfo().fb_buffer1_phys + fb_size - 1u);
+            found_fb_buffer1 = true;
+        }
+        Serial.writefln("Memory range %x:%x (%u)",
+                bootinfo().memory_map[count].base,
+                bootinfo().memory_map[count].base + bootinfo().memory_map[count].size - 1u,
+                bootinfo().memory_map[count].type);
+    }
+    bootinfo().memory_map_count = count;
+    if ((!found_bss) || (!found_stack) || (!found_fb_buffer1))
+    {
+        for (;;) {}
+    }
+}
+
+private void * alloc_pt_page()
+{
+    BootInfo.MemoryRegion * regions = &bootinfo().memory_map[0];
+    for (;;)
+    {
+        BootInfo.MemoryRegion * region = &bootinfo().memory_map[memory_map_page_table_alloc_index];
+        if ((region.type == BootInfo.MemoryRegion.Type.Conventional) && (region.size >= PAGE_SIZE))
+        {
+            void * addr = cast(void *)region.base;
+            region.base += PAGE_SIZE;
+            region.size -= PAGE_SIZE;
+            return addr;
+        }
+        memory_map_page_table_alloc_index++;
+        if (memory_map_page_table_alloc_index >= bootinfo().memory_map_count)
+        {
+            return null;
+        }
+    }
+}
+
+/**
+ * Allocate a new page table.
+ */
+private PageTable * new_page_table()
+{
+    PageTable * pt = cast(PageTable *)alloc_pt_page();
+    if (pt == null)
+    {
+        return null;
+    }
+    memset64(pt, 0u, 512);
+    return pt;
+}
+
+/**
+ * Map a virtual address to a physical address using 4KB pages.
+ *
+ * @param source_page Source page address.
+ * @param dest_page Destination page address.
+ * @param pt_base Page table base address.
+ */
+private bool map4k(ulong source_page, ulong dest_page, PageTable * pt_base)
+{
+    PageTable * pt = pt_base;
+    for (size_t level = 0; level < 4u; level++)
+    {
+        PageTableEntry * ppte = pt.entry(source_page, level);
+        PageTableEntry pte = *ppte;
+        if (pte.present)
+        {
+            pt = pte.follow();
+        }
+        else
+        {
+            PageTable * next_pt;
+            ulong addr;
+            if (level < 3u)
+            {
+                next_pt = new_page_table();
+                if (next_pt == null)
+                {
+                    return false;
+                }
+                addr = cast(ulong)next_pt;
+            }
+            else
+            {
+                addr = dest_page;
+            }
+            *ppte = PageTableEntry(addr, PT_WRITABLE | PT_PRESENT);
+            pt = next_pt;
+        }
+    }
+    return true;
+}
+
+/**
+ * Map a virtual region to a physical region using 4KB pages.
+ *
+ * @param source Source address.
+ * @param dest Destination address.
+ * @param size Region size.
+ * @param pt_base Page table base address.
+ */
+private bool map4kregion(ulong source, ulong dest, size_t size, PageTable * pt_base)
+{
+    ulong end = source + size;
+    while (source < end)
+    {
+        if (!map4k(source, dest, pt_base))
+        {
+            return false;
+        }
+        source += 4096u;
+        dest += 4096u;
+    }
+    return true;
+}
+
+/**
+ * Map a virtual address to a physical address using 2MB pages.
+ *
+ * @param source_page Source page address.
+ * @param dest_page Destination page address.
+ * @param pt_base Page table base address.
+ */
+private bool map2m(ulong source_page, ulong dest_page, PageTable * pt_base)
+{
+    PageTable * pt = pt_base;
+    for (size_t level = 0; level < 3u; level++)
+    {
+        PageTableEntry * ppte = pt.entry(source_page, level);
+        PageTableEntry pte = *ppte;
+        if (pte.present)
+        {
+            pt = pte.follow();
+        }
+        else
+        {
+            PageTable * next_pt;
+            if (level < 2u)
+            {
+                next_pt = new_page_table();
+                if (next_pt == null)
+                {
+                    return false;
+                }
+                *ppte = PageTableEntry(next_pt, PT_WRITABLE | PT_PRESENT);
+            }
+            else
+            {
+                *ppte = PageTableEntry(dest_page, PT_HUGE_PAGE | PT_WRITABLE | PT_PRESENT);
+            }
+            pt = next_pt;
+        }
+    }
+    return true;
+}
+
+/**
+ * Map HULK virtual addresses to physical kernel location.
+ *
+ * @param pt_base Page table base address.
+ */
+private bool map_hulk(PageTable * pt_base)
+{
+    /* Map HULK bin region. */
+    ulong virt = hulk_virt_base_address();
+    if (!map4kregion(virt, hulk_bin_phys(), hulk_bin_size(), pt_base))
+    {
+        return false;
+    }
+    /* Map HULK bss region. */
+    virt += hulk_bin_size();
+    if (!map4kregion(virt, bootinfo().bss_phys, hulk_bss_size(), pt_base))
+    {
+        return false;
+    }
+    /* Zero BSS region. */
+    memset64(cast(void *)bootinfo().bss_phys, 0u, hulk_bss_size() / 8);
+    /* Map HULK stack. */
+    virt = hulk_virt_stack_top() - hulk_stack_size();
+    if (!map4kregion(virt, bootinfo().stack_phys, hulk_stack_size(), pt_base))
+    {
+        return false;
+    }
+    return true;
+}
+
+/**
+ * Build page tables in preparation to jump to HULK.
+ *
+ * @param physical_address_limit Maximum physical address to identity map.
+ */
+private bool build_page_tables(ulong physical_address_limit)
+{
+    PageTable * pt_base = new_page_table();
+    if (pt_base == null)
+    {
+        return false;
+    }
+    /* Map physical RAM. */
+    for (size_t addr = 0u; addr < physical_address_limit; addr += (2u * 1024u * 1024u))
+    {
+        if (!map2m(addr, addr, pt_base))
+        {
+            return false;
+        }
+    }
+    /* Map any memory regions that are outside physical RAM. */
+    for (size_t i = 0u; i < bootinfo().memory_map_count; i++)
+    {
+        ulong addr = bootinfo().memory_map[i].base;
+        if (addr >= physical_address_limit)
+        {
+            if (!map4kregion(addr, addr, bootinfo().memory_map[i].size, pt_base))
+            {
+                return false;
+            }
+        }
+    }
+    /* Map graphics framebuffer. */
+    ulong framebuffer_size = bootinfo().fb.height * bootinfo().fb.stride * 4u;
+    ulong fb_phys = cast(ulong)bootinfo().fb.buffer;
+    ulong fb_virt = hulk_virt_framebuffer_address();
+    if (!map4kregion(fb_virt, fb_phys, framebuffer_size, pt_base))
+    {
+        return false;
+    }
+    /* Map HULK regions. */
+    if (!map_hulk(pt_base))
+    {
+        return false;
+    }
+    /* Switch to the new page table. */
+    write_cr3(cast(ulong)pt_base);
+    return true;
+}
+
+/**
+ * Jump to HULK entry point.
+ */
+private void jump_to_hulk()
+{
+    __asm(
+            "jmpq *$0",
+            "r,{rsp}",
+            hulk_header().entry, hulk_virt_stack_top());
+}
+
+/**
+ * Find the ACPI XSDT.
+ *
+ * @return Whether it was found.
+ */
+private bool find_acpi_xsdt()
+{
+    for (size_t i = 0u; i < st.NumberOfTableEntries; i++)
+    {
+        if ((st.ConfigurationTable[i].VendorGuid == EFI_ACPI_TABLE_GUID) ||
+            (st.ConfigurationTable[i].VendorGuid == ACPI_TABLE_GUID))
+        {
+            enum ulong rsdp_magic = 0x20525450_20445352u;
+            const(EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER) * rdsp = cast(const(EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER) *)st.ConfigurationTable[i].VendorTable;
+            if (rdsp.Signature == rsdp_magic)
+            {
+                if (rdsp.Revision >= EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_REVISION)
+                {
+                    bootinfo().acpi_xsdt_phys = rdsp.XsdtAddress;
+                    return true;
+                }
+            }
+        }
+    }
+    return false;
+}
+
+/**
+ * EFI application entry point.
+ *
+ * @param image_handle EFI application handle.
+ * @param st Pointer to EFI system table.
+ */
+extern (C) EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE * st)
+{
+    .st = st;
+
+    Console.clear();
+
+    Console.writefln("Welcome to HELLO, HOS EFI Lightweight LOader, v0.1.0");
+    Console.writefln("Firmware vendor: '%S', version: 0x%x", st.FirmwareVendor, st.FirmwareVendor);
+
+    if (!find_acpi_xsdt())
+    {
+        Console.writefln("Error: Could not locate ACPI XSDT");
+        Console.wait_key();
+        return EFI_SUCCESS;
+    }
+
+    if (!set_graphics_mode())
+    {
+        Console.wait_key();
+        return EFI_SUCCESS;
+    }
+
+    ulong physical_address_limit;
+    UINTN memory_map_key;
+    for (;;)
+    {
+        get_memory_map(&physical_address_limit, &memory_map_key);
+
+        EFI_STATUS status = st.BootServices.ExitBootServices(image_handle, memory_map_key);
+        if (status == EFI_INVALID_PARAMETER)
+        {
+            continue;
+        }
+        if (status == EFI_SUCCESS)
+        {
+            break;
+        }
+        Console.writefln("ExitBootServices: Error %x", status);
+        Console.wait_key();
+        return EFI_SUCCESS;
+    }
+
+    if (!build_page_tables(physical_address_limit))
+    {
+        return EFI_SUCCESS;
+    }
+
+    bootinfo().hulk_phys = hulk_bin_phys();
+
+    jump_to_hulk();
+
+    return EFI_SUCCESS;
+}

src/hulk/acpi.d

@@ -0,0 +1,126 @@
+/**
+ * ACPI (Advanced Configuration and Power Interface) functionality.
+ */
+module hulk.acpi;
+
+import hulk.hurl;
+import hulk.klog;
+import hulk.memory;
+import hulk.hurl.a1;
+
+struct Acpi
+{
+    /**
+     * List of ACPI tables.
+     */
+    private static __gshared Header *[] tables;
+
+    enum uint XSDT_SIGNATURE = signature("XSDT");
+
+    /**
+     * ACPI table header structure.
+     */
+    public static struct Header
+    {
+        uint signature;
+        uint length;
+        ubyte revision;
+        ubyte checksum;
+        char[6] oemid;
+        char[8] oemtableid;
+        uint oem_revision;
+        uint creator_id;
+        uint creator_revision;
+    }
+
+    /**
+     * XSDT table.
+     */
+    static struct XSDT
+    {
+        Header header;
+        /* Table pointers are not ulong-aligned! They begin at offset 36. */
+        align(4) ulong[1] tables;
+    }
+    static assert(XSDT.tables.offsetof == 36);
+
+    /**
+     * Initialize ACPI.
+     */
+    public static void initialize(ulong acpi_xsdt_phys)
+    {
+        Klog.writefln("\a3Initializing ACPI");
+
+        /* Map the XSDT header. */
+        map_table(acpi_xsdt_phys, PAGE_SIZE);
+        const(XSDT) * xsdt = cast(const(XSDT) *)acpi_xsdt_phys;
+        if (xsdt.header.signature != XSDT_SIGNATURE)
+        {
+            Klog.fatal_error("XSDT signature invalid");
+            return;
+        }
+        /* Map the entire XSDT. */
+        if (xsdt.header.length > PAGE_SIZE)
+        {
+            map_table(acpi_xsdt_phys, xsdt.header.length);
+        }
+        size_t n_entries = (xsdt.header.length - xsdt.header.sizeof) / xsdt.tables[0].sizeof;
+        Header ** table_pointers = cast(Header **)A1.allocate(n_entries * (Header *).sizeof);
+        tables = table_pointers[0..n_entries];
+        for (size_t i = 0u; i < n_entries; i++)
+        {
+            ulong address = xsdt.tables[i];
+            map_table(address, PAGE_SIZE);
+            Header * header = cast(Header *)address;
+            uint length = header.length;
+            if (length > PAGE_SIZE)
+            {
+                map_table(address, length);
+            }
+            tables[i] = header;
+            uint signature = header.signature;
+            Klog.writefln("Found ACPI table '%c%c%c%c' at %p",
+                    signature & 0xFFu,
+                    (signature >> 8u) & 0xFFu,
+                    (signature >> 16u) & 0xFFu,
+                    (signature >> 24u) & 0xFFu,
+                    address);
+        }
+    }
+
+    /**
+     * Get pointer to ACPI table by name.
+     *
+     * @param name
+     *   Table name.
+     */
+    public static Header * get_table(string name)
+    {
+        uint signature = signature(name);
+        foreach (table; tables)
+        {
+            if (table.signature == signature)
+            {
+                return table;
+            }
+        }
+        Klog.fatal_error("Could not find requested ACPI table");
+        return null;
+    }
+
+    /**
+     * Map an ACPI table.
+     */
+    private static void map_table(ulong address, ulong length)
+    {
+        Hurl.identity_map_range(address, length, PT_WRITABLE | PT_DISABLE_CACHE | PT_NO_EXECUTE);
+    }
+
+    /**
+     * Convert table signature from string to 32-bit unsigned integer.
+     */
+    private static uint signature(string s)
+    {
+        return s[0] | (s[1] << 8) | (s[2] << 16) | (s[3] << 24);
+    }
+}

src/hulk/apic.d

@@ -0,0 +1,382 @@
+/**
+ * APIC (Advanced Programmable Interrupt Controller) functionality.
+ */
+module hulk.apic;
+
+import hulk.hurl;
+import hulk.acpi;
+import hulk.him;
+import hulk.rtc;
+import hulk.pit;
+import hulk.klog;
+import hulk.memory;
+
+struct Apic
+{
+    private enum DEBUG = false;
+    private enum DEFAULT_IO_APIC_ADDRESS = 0xFEC0_0000u;
+    private enum uint PERIODIC_MODE = 0x2_0000u;
+
+    private enum ulong IRQ_PIT = 0u;
+    private enum ulong IRQ_RTC = 8u;
+
+    /**
+     * MADT ACPI table structure.
+     */
+    static struct MADT
+    {
+        /**
+         * MADT table entry header.
+         */
+        static struct Entry
+        {
+            enum PROCESSOR_LOCAL_APIC = 0;
+            enum IO_APIC = 1;
+            enum IO_APIC_INTERRUPT_SOURCE_OVERRIDE = 2;
+            enum IO_APIC_NMI_SOURCE = 3;
+            enum LOCAL_APIC_NMI = 4;
+            enum LOCAL_APIC_ADDRESS_OVERRIDE = 5;
+            enum PROCESSOR_LOCAL_X2APIC = 9;
+
+            ubyte type;
+            ubyte length;
+        }
+
+        /**
+         * Processor Local APIC.
+         */
+        static struct Entry0
+        {
+            Entry header;
+            ubyte acpi_processor_id;
+            ubyte apic_id;
+            uint flags;
+        }
+        static assert(Entry0.sizeof == 8);
+
+        /**
+         * I/O APIC.
+         */
+        static struct Entry1
+        {
+            Entry header;
+            ubyte io_apic_id;
+            ubyte _reserved;
+            uint io_apic_address;
+            uint global_system_interrupt_base;
+        }
+        static assert(Entry1.sizeof == 12);
+
+        /**
+         * IO/APIC Interrupt Source Override.
+         */
+        static struct Entry2
+        {
+            Entry header;
+            ubyte bus_source;
+            ubyte irq_source;
+            uint global_system_interrupt;
+            ushort flags;
+            ushort _reserved;
+        }
+        static assert(Entry2.sizeof == 12);
+
+        /**
+         * IO/APIC Non-maskable interrupt source.
+         */
+        static struct Entry3
+        {
+            Entry header;
+            ubyte nmi_source;
+            ubyte _reserved;
+            ushort flags;
+            ubyte[4] global_system_interrupt;
+        }
+        static assert(Entry3.sizeof == 10);
+
+        /**
+         * Local APIC Non-maskable interrupts.
+         */
+        static struct Entry4
+        {
+            Entry header;
+            ubyte acpi_processor_id;
+            ubyte[2] flags;
+            ubyte lint_nr;
+        }
+        static assert(Entry4.sizeof == 6);
+
+        /**
+         * Local APIC Address Override.
+         */
+        static struct Entry5
+        {
+            Entry header;
+            ushort _reserved;
+            ubyte[8] local_apic_address;
+        }
+        static assert(Entry5.sizeof == 12);
+
+        /**
+         * Processor Local x2APIC.
+         */
+        static struct Entry9
+        {
+            Entry header;
+            ushort _reserved;
+            uint local_x2apic_id;
+            uint flags;
+            uint acpi_id;
+        }
+        static assert(Entry9.sizeof == 16);
+
+        Acpi.Header header;
+        uint local_apic_address;
+        uint flags;
+
+        static assert(MADT.sizeof == 0x2C);
+
+        /**
+         * Scan the MADT table.
+         */
+        public void scan()
+        {
+            apic_registers = cast(ApicRegisters *)local_apic_address;
+            const(void) * end = cast(const(void) *)(&this) + header.length;
+            const(Entry) * entry = cast(const(Entry) *)(cast(ulong)&this + MADT.sizeof);
+            bool first_io_apic = true;
+            size_t n_cpus = 0u;
+            while (entry < end)
+            {
+                if (DEBUG)
+                {
+                    Klog.writefln("MADT entry type %u, length %u", entry.type, entry.length);
+                }
+                switch (entry.type)
+                {
+                case Entry.PROCESSOR_LOCAL_APIC:
+                    Entry0 * e = cast(Entry0 *)entry;
+                    n_cpus++;
+                    if (DEBUG)
+                    {
+                        Klog.writefln("  ACPI processor ID: %u, APIC ID: %u, Flags: 0x%x",
+                                e.acpi_processor_id, e.apic_id, e.flags);
+                    }
+                    break;
+
+                case Entry.IO_APIC:
+                    Entry1 * e = cast(Entry1 *)entry;
+                    if (first_io_apic)
+                    {
+                        io_apic_registers = cast(IoApicRegisters *)e.io_apic_address;
+                        first_io_apic = false;
+                    }
+                    if (DEBUG)
+                    {
+                        Klog.writefln("  I/O APIC ID: %u, I/O APIC Address: 0x%x, GSIB: %u",
+                                e.io_apic_id, e.io_apic_address, e.global_system_interrupt_base);
+                    }
+                    break;
+
+                case Entry.IO_APIC_INTERRUPT_SOURCE_OVERRIDE:
+                    Entry2 * e = cast(Entry2 *)entry;
+                    if (e.global_system_interrupt < INT_APIC_COUNT)
+                    {
+                        irq_redirects[e.irq_source] = cast(ubyte)e.global_system_interrupt;
+                    }
+                    else
+                    {
+                        Klog.writefln("Warning: unexpected interrupt source override global system interrupt value: %u", e.global_system_interrupt);
+                    }
+                    if (DEBUG)
+                    {
+                        Klog.writefln("  Bus %u IRQ %u GSI %u Flags: 0x%x",
+                                e.bus_source, e.irq_source, e.global_system_interrupt, e.flags);
+                    }
+                    break;
+
+                case Entry.IO_APIC_NMI_SOURCE:
+                    Entry3 * e = cast(Entry3 *)entry;
+                    if (DEBUG)
+                    {
+                        uint global_system_interrupt;
+                        memcpy(&global_system_interrupt, &e.global_system_interrupt, 4u);
+                        Klog.writefln("  NMI Source: %u, Flags: 0x%x, GSI: %u",
+                                e.nmi_source, e.flags, global_system_interrupt);
+                    }
+                    break;
+
+                case Entry.LOCAL_APIC_NMI:
+                    Entry4 * e = cast(Entry4 *)entry;
+                    if (DEBUG)
+                    {
+                        ushort flags;
+                        memcpy(&flags, &e.flags, 2u);
+                        Klog.writefln("  ACPI Processor ID: %u, Flags: 0x%x, LINT#: %u",
+                                e.acpi_processor_id, flags, e.lint_nr);
+                    }
+                    break;
+
+                case Entry.LOCAL_APIC_ADDRESS_OVERRIDE:
+                    Entry5 * e = cast(Entry5 *)entry;
+                    if (DEBUG)
+                    {
+                        memcpy(&apic_registers, &e.local_apic_address, 8u);
+                        Klog.writefln("  Local APIC Address: 0x%x", apic_registers);
+                    }
+                    break;
+
+                case Entry.PROCESSOR_LOCAL_X2APIC:
+                    Entry9 * e = cast(Entry9 *)entry;
+                    if (DEBUG)
+                    {
+                        Klog.writefln("  x2APIC ID: %u, Flags: 0x%x, ACPI ID: %u",
+                                e.local_x2apic_id, e.flags, e.acpi_id);
+                    }
+                    break;
+
+                default:
+                    break;
+                }
+
+                /* Move to next entry. */
+                entry = cast(const(Entry) *)(cast(size_t)entry + entry.length);
+            }
+            if (n_cpus > 0u)
+            {
+                Klog.writefln("%u CPU(s) found", n_cpus);
+            }
+        }
+    }
+
+    /**
+     * APIC register structure.
+     */
+    static struct ApicRegister
+    {
+        public uint value;
+        alias value this;
+
+        private ubyte[12] _padding;
+    }
+
+    /**
+     * APIC registers.
+     */
+    static struct ApicRegisters
+    {
+        ApicRegister[2] _reserved0;
+        ApicRegister lapic_id;
+        ApicRegister lapic_version;
+        ApicRegister[4] _reserved1;
+        ApicRegister task_priority;
+        ApicRegister arbitration_priority;
+        ApicRegister processor_priority;
+        ApicRegister eoi;
+        ApicRegister remote_read;
+        ApicRegister logical_destination;
+        ApicRegister destination_format;
+        ApicRegister spurious_interrupt_vector;
+        ApicRegister[8] in_service;
+        ApicRegister[8] trigger_mode;
+        ApicRegister[8] interrupt_request;
+        ApicRegister error_status;
+        ApicRegister[6] _reserved2;
+        ApicRegister lvt_cmci;
+        ApicRegister[2] interrupt_command;
+        ApicRegister lvt_timer;
+        ApicRegister lvt_thermal_sensor;
+        ApicRegister lvt_performance_monitoring_counters;
+        ApicRegister[2] lvt_lint;
+        ApicRegister lvt_error;
+        ApicRegister initial_count;
+        ApicRegister current_count;
+        ApicRegister[4] _reserved3;
+        ApicRegister divide_configuration;
+    }
+
+    /**
+     * I/O APIC registers.
+     */
+    static struct IoApicRegisters
+    {
+        ApicRegister address;
+        ApicRegister data;
+    }
+
+    alias ISRHandler = void function();
+    private static __gshared ApicRegisters * apic_registers;
+    private static __gshared IoApicRegisters * io_apic_registers;
+    private static __gshared ISRHandler[INT_APIC_COUNT] irq_handlers;
+    private static __gshared ubyte[INT_APIC_COUNT] irq_redirects;
+
+    /**
+     * Initialize APIC.
+     */
+    public static void initialize()
+    {
+        Klog.writefln("\a3Initializing APIC");
+        io_apic_registers = cast(IoApicRegisters *)DEFAULT_IO_APIC_ADDRESS;
+        for (ubyte i = 0u; i < INT_APIC_COUNT; i++)
+        {
+            irq_redirects[i] = i;
+        }
+        MADT * madt = cast(MADT *)Acpi.get_table("APIC");
+        madt.scan();
+        Klog.writefln("APIC found at %p", apic_registers);
+        Klog.writefln("I/O APIC found at %p", io_apic_registers);
+        Hurl.map(cast(ulong)apic_registers, cast(ulong)apic_registers,
+                PT_WRITABLE | PT_WRITE_THROUGH | PT_DISABLE_CACHE | PT_NO_EXECUTE);
+        Hurl.map(cast(ulong)io_apic_registers, cast(ulong)io_apic_registers,
+                PT_WRITABLE | PT_WRITE_THROUGH | PT_DISABLE_CACHE | PT_NO_EXECUTE);
+        /* Enable local APIC to receive interrupts and set spurious interrupt
+         * vector to 0xFF. */
+        apic_registers.spurious_interrupt_vector.value = 0x100u | INT_APIC_SPURIOUS;
+        apic_registers.lvt_timer.value = INT_APIC_TIMER;
+        apic_registers.lvt_lint[0].value = INT_APIC_LINT0;
+        apic_registers.lvt_lint[1].value = INT_APIC_LINT1;
+        /* Enable PIT interrupt. */
+        configure_io_apic_irq(IRQ_PIT, &Pit.isr);
+        /* Enable RTC interrupt. */
+        configure_io_apic_irq(IRQ_RTC, &Rtc.isr);
+    }
+
+    /**
+     * Configure routing for an I/O APIC IRQ.
+     */
+    private static void configure_io_apic_irq(size_t orig_irq, ISRHandler isr_handler)
+    {
+        size_t io_apic_irq = irq_redirects[orig_irq];
+        ulong entry = INT_APIC_BASE + io_apic_irq;
+        io_apic_registers.address.value = cast(uint)(0x10u + io_apic_irq * 2u);
+        io_apic_registers.data.value = entry & 0xFFFF_FFFFu;
+        io_apic_registers.address.value = cast(uint)(0x10u + io_apic_irq * 2u + 1u);
+        io_apic_registers.data.value = entry >> 32u;
+        irq_handlers[io_apic_irq] = isr_handler;
+    }
+
+    /**
+     * Signal APIC end of interrupt.
+     */
+    public static void eoi()
+    {
+        apic_registers.eoi.value = 0u;
+    }
+
+    /**
+     * APIC interrupt handler.
+     */
+    public static void isr(ulong vector)
+    {
+        ulong io_apic_irq = vector - INT_APIC_BASE;
+        if ((io_apic_irq < INT_APIC_COUNT) && (irq_handlers[io_apic_irq] != null))
+        {
+            irq_handlers[io_apic_irq]();
+        }
+        else
+        {
+            Klog.writefln("Unhandled APIC ISR %u", vector);
+        }
+        eoi();
+    }
+}

src/hulk/bootinfo.d

@@ -0,0 +1,77 @@
+/**
+ * HULK boot information.
+ */
+module hulk.bootinfo;
+
+/**
+ * HULK boot information structure.
+ */
+struct BootInfo
+{
+    /**
+     * Framebuffer description structure.
+     */
+    struct Framebuffer
+    {
+        /** Framebuffer physical base address. */
+        uint * buffer;
+        /** Horizontal resolution. */
+        uint width;
+        /** Vertical resolution. */
+        uint height;
+        /** Number of pixels per scan line. */
+        uint stride;
+        /** Pixel format. */
+        uint format;
+    }
+
+    /**
+     * Memory map entry description structure.
+     */
+    struct MemoryRegion
+    {
+        enum Type
+        {
+            Reserved,
+            Bootloader,
+            Conventional,
+            Unusable,
+            ACPIReclaim,
+            ACPINVS,
+            MemoryMappedIO,
+            MemoryMappedIOPortSpace,
+            PalCode,
+        }
+
+        /** Base address of the memory region. */
+        ulong base;
+        /** Size in bytes of the memory region. */
+        size_t size;
+        /** Type of the memory region. */
+        ubyte type;
+    }
+
+    /* Framebuffer parameters. */
+    Framebuffer fb;
+
+    /* Memory map. */
+    MemoryRegion[1000] memory_map;
+
+    /* Number of memory map entries. */
+    size_t memory_map_count;
+
+    /* Physical address of HULK. */
+    ulong hulk_phys;
+
+    /* Physical address used for HULK bss section. */
+    ulong bss_phys;
+
+    /* Physical address of stack while jumping to HULK. */
+    ulong stack_phys;
+
+    /* Physical address of framebuffer buffer1. */
+    ulong fb_buffer1_phys;
+
+    /* Physical address of ACPI XSDT table. */
+    ulong acpi_xsdt_phys;
+}

src/hulk/console.d

@@ -0,0 +1,276 @@
+/**
+ * HULK Console functionality.
+ */
+module hulk.console;
+
+import hulk.fb;
+import hulk.kfont;
+import hulk.ver;
+import hulk.rtc;
+import hulk.writef;
+
+/**
+ * Represent the HULK console.
+ *
+ * Coordinate (0,0) is the top-left console position.
+ */
+struct Console
+{
+    /** Border color. */
+    private enum BORDER_COLOR = 0xFF8000u;
+
+    /** Heading color. */
+    private enum HEADING_COLOR = 0x0066FFu;
+
+    /** Console page width in text columns. */
+    private static __gshared size_t m_width;
+
+    /** Console page height in text rows. */
+    private static __gshared size_t m_height;
+
+    /** Current console page. */
+    private static __gshared size_t m_page;
+
+    /** Current page cursor X position. */
+    private static __gshared size_t m_x;
+
+    /** Current page cursor Y position. */
+    private static __gshared size_t m_y;
+
+    /** Number of delayed newline characters. */
+    private static __gshared size_t m_newlines;
+
+    /** Active console escape code. */
+    private static __gshared char m_escape_code;
+
+    /** Flag to indicate the previous character was an escape character. */
+    private static __gshared bool m_escape;
+
+    /**
+     * Initialize the console.
+     */
+    public static void initialize()
+    {
+        size_t fb_console_height = Fb.height - Kfont.line_height - 1;
+        m_width = (Fb.width - 1) / 2 / Kfont.advance;
+        m_height = fb_console_height / Kfont.line_height;
+    }
+
+    /**
+     * Clear the console.
+     */
+    public static void clear()
+    {
+        Fb.clear();
+        m_page = 0u;
+        m_x = 0u;
+        m_y = 0u;
+        draw();
+    }
+
+    /**
+     * Write a character to the console (buffer newlines).
+     *
+     * @param ch Character to write.
+     */
+    public static void write(char ch)
+    {
+        if (ch == '\n')
+        {
+            render_heading_end();
+            m_escape_code = 0u;
+            m_newlines++;
+        }
+        else
+        {
+            dowrite(ch);
+        }
+    }
+
+    private static void render_heading_start()
+    {
+        if ('0' <= m_escape_code && m_escape_code <= '9' && m_x < (m_width - 1))
+        {
+            size_t heading_level = m_escape_code - ('0' - 1);
+            size_t nx = m_x + heading_level;
+            if (nx >= m_width)
+            {
+                nx = m_width - 1;
+            }
+            size_t hx = fb_x(m_page, m_x);
+            size_t hy = fb_y(m_y) + Kfont.line_height / 2 - 1;
+            size_t hwidth = (nx - m_x - 1) * Kfont.advance + Kfont.advance / 2 - 1;
+            Fb.rect(hx, hy, hwidth, 2, HEADING_COLOR);
+            Fb.rect(hx + hwidth, fb_y(m_y) + Kfont.line_height / 8,
+                    2, Kfont.line_height * 3 / 4, HEADING_COLOR);
+            m_x = nx;
+        }
+    }
+
+    private static void render_heading_end()
+    {
+        if ('0' <= m_escape_code && m_escape_code <= '9' && m_x < (m_width - 1))
+        {
+            size_t heading_level = m_escape_code - ('0' - 1);
+            size_t nx = m_x + heading_level;
+            if (nx >= m_width)
+            {
+                nx = m_width - 1;
+            }
+            size_t hwidth = (nx - m_x - 1) * Kfont.advance + Kfont.advance / 2 - 1;
+            size_t hx = fb_x(m_page, nx) - hwidth;
+            size_t hy = fb_y(m_y) + Kfont.line_height / 2 - 1;
+            Fb.rect(hx, hy, hwidth, 2, HEADING_COLOR);
+            Fb.rect(hx - 2, fb_y(m_y) + Kfont.line_height / 8,
+                    2, Kfont.line_height * 3 / 4, HEADING_COLOR);
+            m_x = nx;
+        }
+    }
+
+    /**
+     * Write a character to the console (no newline buffering).
+     *
+     * @param ch Character to write.
+     */
+    private static void dowrite(char ch)
+    {
+        if (m_newlines != 0u)
+        {
+            size_t newlines = m_newlines;
+            m_newlines = 0u;
+            for (size_t i = 0u; i < newlines; i++)
+            {
+                dowrite('\n');
+            }
+        }
+        if (m_escape)
+        {
+            m_escape_code = ch;
+            render_heading_start();
+            m_escape = false;
+            return;
+        }
+        if (ch == '\a')
+        {
+            m_escape = true;
+            return;
+        }
+        if (ch == '\n')
+        {
+            m_x = 0u;
+            m_y++;
+        }
+        else
+        {
+            render_char(fb_x(m_page, m_x), fb_y(m_y), ch);
+            m_x++;
+            if (m_x == m_width)
+            {
+                m_x = 0u;
+                m_y++;
+            }
+        }
+        if (m_y == m_height)
+        {
+            if (m_page == 0u)
+            {
+                m_page = 1u;
+                m_x = 0u;
+                m_y = 0u;
+            }
+            else
+            {
+                m_y--;
+                shift_rows();
+            }
+        }
+    }
+
+    /**
+     * Shift console rows.
+     */
+    private static void shift_rows()
+    {
+        /* Shift up page 0 */
+        Fb.copy_rect(fb_x(0u, 0u), fb_y(1u),
+                m_width * Kfont.advance, (m_height - 1u) * Kfont.line_height,
+                fb_x(0u, 0u), fb_y(0u));
+        /* Copy page 1 first row to page 0 last row. */
+        Fb.copy_rect(fb_x(1u, 0u), fb_y(0u),
+                m_width * Kfont.advance, Kfont.line_height,
+                fb_x(0u, 0u), fb_y(m_height - 1u));
+        /* Shift up page 1 */
+        Fb.copy_rect(fb_x(1u, 0u), fb_y(1u),
+                m_width * Kfont.advance, (m_height - 1u) * Kfont.line_height,
+                fb_x(1u, 0u), fb_y(0u));
+        /* Erase page 1 last row. */
+        Fb.rect(fb_x(1u, 0u), fb_y(m_height - 1u),
+                m_width * Kfont.advance, Kfont.line_height, 0u);
+    }
+
+    /**
+     * Render a character.
+     *
+     * @param x X position.
+     * @param y Y position.
+     * @param ch Character to render.
+     */
+    private static void render_char(size_t x, size_t y, char ch)
+    {
+        if (ch > 127)
+        {
+            ch = 0u;
+        }
+        const(CharInfo) * ci = &Kfont.chars[ch];
+        Fb.blit_alpha_bitmap(x + ci.left, y + ci.top, ci.bitmap, ci.width, ci.height);
+    }
+
+    /**
+     * Get the framebuffer X coordinate corresponding to the console page X position.
+     */
+    private static size_t fb_x(size_t page, size_t x)
+    {
+        return x * Kfont.advance + page * (m_width * Kfont.advance + 1);
+    }
+
+    /**
+     * Get the framebuffer Y coordinate corresponding to the console page Y position.
+     */
+    private static size_t fb_y(size_t y)
+    {
+        return (y + 1) * Kfont.line_height + 1;
+    }
+
+    /**
+     * Draw console.
+     */
+    private static draw()
+    {
+        static __gshared string header_text = "Welcome to HOS v" ~ VERSION ~ "!";
+        Fb.rect(0u, Kfont.line_height, Fb.width, 1, BORDER_COLOR);
+        Fb.rect(m_width * Kfont.advance, Kfont.line_height, 1, Fb.height - Kfont.line_height, BORDER_COLOR);
+        size_t x = 0;
+        foreach (c; header_text)
+        {
+            render_char(x, 0, c);
+            x += Kfont.advance;
+        }
+        update_header();
+    }
+
+    /**
+     * Update console header.
+     */
+    public static update_header()
+    {
+        __gshared uint x;
+        x = Fb.width - 8 * Kfont.advance;
+        Fb.rect(x - 1, 0, 1, Kfont.line_height, BORDER_COLOR);
+        Fb.rect(x, 0, Fb.width - x, Kfont.line_height, 0);
+        Rtc.time rtc_time = Rtc.read_rtc_time();
+        writef(function(ubyte ch) {
+                render_char(x, 0, ch);
+                x += Kfont.advance;
+                }, "%02u:%02u:%02u", rtc_time.hour, rtc_time.minute, rtc_time.second);
+    }
+}

src/hulk/cpu.d

@@ -0,0 +1,261 @@
+/**
+ * CPU functionality.
+ */
+module hulk.cpu;
+
+import ldc.llvmasm;
+
+/** CR0 bits. @{ */
+enum ulong CR0_PE = 0x1u;
+enum ulong CR0_MP = 0x2u;
+enum ulong CR0_EM = 0x4u;
+enum ulong CR0_TS = 0x8u;
+enum ulong CR0_ET = 0x10u;
+enum ulong CR0_NE = 0x20u;
+enum ulong CR0_WP = 0x1_0000u;
+enum ulong CR0_AM = 0x4_0000u;
+enum ulong CR0_NW = 0x2000_0000u;
+enum ulong CR0_CD = 0x4000_0000u;
+enum ulong CR0_PG = 0x8000_0000u;
+/** @} */
+
+/** CR4 bits. @{ */
+enum ulong CR4_VME = 0x1u;
+enum ulong CR4_PVI = 0x2u;
+enum ulong CR4_TSD = 0x4u;
+enum ulong CR4_DE = 0x8u;
+enum ulong CR4_PSE = 0x10u;
+enum ulong CR4_PAE = 0x20u;
+enum ulong CR4_MCE = 0x40u;
+enum ulong CR4_PGE = 0x80u;
+enum ulong CR4_PCE = 0x100u;
+enum ulong CR4_OSFXSR = 0x200u;
+enum ulong CR4_OSXMMEXCPT = 0x400u;
+enum ulong CR4_UMIP = 0x800u;
+enum ulong CR4_VMXE = 0x2000u;
+enum ulong CR4_SMXE = 0x4000u;
+enum ulong CR4_FSGSBASE = 0x1_0000u;
+enum ulong CR4_PCIDE = 0x2_0000u;
+enum ulong CR4_OSXSAVE = 0x4_0000u;
+enum ulong CR4_SMEP = 0x10_0000u;
+enum ulong CR4_SMAP = 0x20_0000u;
+enum ulong CR4_PKE = 0x40_0000u;
+enum ulong CR4_CET = 0x80_0000u;
+enum ulong CR4_PKS = 0x100_0000u;
+/** @} */
+
+/** XCR0 bits. @{ */
+enum ulong XCR0_X87 = 0x1u;
+enum ulong XCR0_SSE = 0x2u;
+enum ulong XCR0_AVX = 0x4u;
+enum ulong XCR0_BNDREG = 0x8u;
+enum ulong XCR0_BNDSCR = 0x10u;
+enum ulong XCR0_OPMASK = 0x20u;
+enum ulong XCR0_ZMM_HI256 = 0x40u;
+enum ulong XCR0_HI16_ZMM = 0x80u;
+enum ulong XCR0_PKRU = 0x100u;
+/** @} */
+
+/** MSR register numbers. @{ */
+enum uint MSR_PAT = 0x277u;
+enum uint MSR_EFER = 0xC000_0080u;
+/** @} */
+
+/** EFER flags. @{ */
+enum uint EFER_SCE = 0x1u;
+enum uint EFER_LME = 0x100u;
+enum uint EFER_LMA = 0x400u;
+enum uint EFER_NXE = 0x800u;
+enum uint EFER_SVME = 0x1000u;
+enum uint EFER_LMSLE = 0x2000u;
+enum uint EFER_FFXSR = 0x4000u;
+enum uint EFER_TCE = 0x8000u;
+/** @} */
+
+/** CPUID 1 bits. @{ */
+enum uint CPUID_1_EDX_FPU = 0x1u;
+enum uint CPUID_1_EDX_VME = 0x2u;
+enum uint CPUID_1_EDX_DE = 0x4u;
+enum uint CPUID_1_EDX_PSE = 0x8u;
+enum uint CPUID_1_EDX_TSC = 0x10u;
+enum uint CPUID_1_EDX_MSR = 0x20u;
+enum uint CPUID_1_EDX_PAE = 0x40u;
+enum uint CPUID_1_EDX_MCE = 0x80u;
+enum uint CPUID_1_EDX_CX8 = 0x100u;
+enum uint CPUID_1_EDX_APIC = 0x200u;
+enum uint CPUID_1_EDX_SEP = 0x800u;
+enum uint CPUID_1_EDX_MTRR = 0x1000u;
+enum uint CPUID_1_EDX_PGE = 0x2000u;
+enum uint CPUID_1_EDX_MCA = 0x4000u;
+enum uint CPUID_1_EDX_CMOV = 0x8000u;
+enum uint CPUID_1_EDX_PAT = 0x1_0000u;
+enum uint CPUID_1_EDX_PSE36 = 0x2_0000u;
+enum uint CPUID_1_EDX_PSN = 0x4_0000u;
+enum uint CPUID_1_EDX_CLFSH = 0x8_0000u;
+enum uint CPUID_1_EDX_DS = 0x20_0000u;
+enum uint CPUID_1_EDX_ACPI = 0x40_0000u;
+enum uint CPUID_1_EDX_MMX = 0x80_0000u;
+enum uint CPUID_1_EDX_FXSR = 0x100_0000u;
+enum uint CPUID_1_EDX_SSE = 0x200_0000u;
+enum uint CPUID_1_EDX_SSE2 = 0x400_0000u;
+enum uint CPUID_1_EDX_SS = 0x800_0000u;
+enum uint CPUID_1_EDX_HTT = 0x1000_0000u;
+enum uint CPUID_1_EDX_TM = 0x2000_0000u;
+enum uint CPUID_1_EDX_IA64 = 0x4000_0000u;
+enum uint CPUID_1_EDX_PBE = 0x8000_0000u;
+enum uint CPUID_1_ECX_SSE3 = 0x1u;
+enum uint CPUID_1_ECX_PCLMULQDQ = 0x2u;
+enum uint CPUID_1_ECX_DTES64 = 0x4u;
+enum uint CPUID_1_ECX_MONITOR = 0x8u;
+enum uint CPUID_1_ECX_DSCPL = 0x10u;
+enum uint CPUID_1_ECX_VMX = 0x20u;
+enum uint CPUID_1_ECX_SMX = 0x40u;
+enum uint CPUID_1_ECX_EST = 0x80u;
+enum uint CPUID_1_ECX_TM2 = 0x100u;
+enum uint CPUID_1_ECX_SSSE3 = 0x200u;
+enum uint CPUID_1_ECX_CNXTID = 0x400u;
+enum uint CPUID_1_ECX_SDBG = 0x800u;
+enum uint CPUID_1_ECX_FMA = 0x1000u;
+enum uint CPUID_1_ECX_CX16 = 0x2000u;
+enum uint CPUID_1_ECX_XTPR = 0x4000u;
+enum uint CPUID_1_ECX_PDCM = 0x8000u;
+enum uint CPUID_1_ECX_PCID = 0x2_0000u;
+enum uint CPUID_1_ECX_DCA = 0x4_0000u;
+enum uint CPUID_1_ECX_SSE41 = 0x8_0000u;
+enum uint CPUID_1_ECX_SSE42 = 0x10_0000u;
+enum uint CPUID_1_ECX_X2APIC = 0x20_0000u;
+enum uint CPUID_1_ECX_MOVBE = 0x40_0000u;
+enum uint CPUID_1_ECX_POPCNT = 0x80_0000u;
+enum uint CPUID_1_ECX_TSCDEADLINE = 0x100_0000u;
+enum uint CPUID_1_ECX_AES = 0x200_0000u;
+enum uint CPUID_1_ECX_XSAVE = 0x400_0000u;
+enum uint CPUID_1_ECX_OSXSAVE = 0x800_0000u;
+enum uint CPUID_1_ECX_AVX = 0x1000_0000u;
+enum uint CPUID_1_ECX_F16C = 0x2000_0000u;
+enum uint CPUID_1_ECX_RDRND = 0x4000_0000u;
+enum uint CPUID_1_ECX_HYPERVISOR = 0x8000_0000u;
+/** @} */
+
+void cli()
+{
+    __asm("cli", "");
+}
+
+void sti()
+{
+    __asm("sti", "");
+}
+
+void hlt()
+{
+    __asm("hlt", "");
+}
+
+ulong read_cr0()
+{
+    return __asm!ulong("mov %cr0, %rax", "={rax}");
+}
+
+void write_cr0(ulong v)
+{
+    __asm("mov $0, %cr0", "r", v);
+}
+
+ulong read_cr2()
+{
+    return __asm!ulong("mov %cr2, %rax", "={rax}");
+}
+
+ulong read_cr3()
+{
+    return __asm!ulong("mov %cr3, %rax", "={rax}");
+}
+
+void write_cr3(ulong v)
+{
+    __asm("mov $0, %cr3", "r", v);
+}
+
+ulong read_cr4()
+{
+    return __asm!ulong("mov %cr4, %rax", "={rax}");
+}
+
+void write_cr4(ulong v)
+{
+    __asm("mov $0, %cr4", "r", v);
+}
+
+ulong read_rflags()
+{
+    return __asm!ulong(`
+            pushf
+            mov (%rsp), %rax
+            add $$8, %rsp`, "={rax}");
+}
+
+ulong rdmsr(uint msr)
+{
+    return __asm!ulong(`
+            rdmsr
+            shl $$32, %rdx
+            or %rdx, %rax`, "={rax},{ecx},~{rdx}", msr);
+}
+
+void wrmsr(uint msr, ulong value)
+{
+    __asm(`wrmsr`, "{ecx},{edx},{eax}", msr, value >> 32u, value);
+}
+
+ulong xgetbv(uint xcr)
+{
+    return __asm!ulong(`
+            xgetbv
+            shl $$32, %rdx
+            or %rdx, %rax`, "={rax},{ecx},~{rdx}", xcr);
+}
+
+void xsetbv(uint xcr, ulong value)
+{
+    __asm(`xsetbv`, "{ecx},{edx},{eax}", xcr, value >> 32u, value);
+}
+
+ubyte in8(ushort ioaddr)
+{
+    return __asm!ubyte("inb %dx, %al", "={al},{dx}", ioaddr);
+}
+
+ushort in16(ushort ioaddr)
+{
+    return __asm!ushort("inw %dx, %ax", "={ax},{dx}", ioaddr);
+}
+
+uint in32(ushort ioaddr)
+{
+    return __asm!uint("inl %dx, %eax", "={eax},{dx}", ioaddr);
+}
+
+void out8(ushort ioaddr, ubyte v)
+{
+    __asm("outb %al, %dx", "{dx},{al}", ioaddr, v);
+}
+
+void out16(ushort ioaddr, ushort v)
+{
+    __asm("outw %ax, %dx", "{dx},{ax}", ioaddr, v);
+}
+
+void out32(ushort ioaddr, uint v)
+{
+    __asm("outl %eax, %dx", "{dx},{eax}", ioaddr, v);
+}
+
+void cpuid1(uint * ebx, uint * ecx, uint * edx)
+{
+    __asm("cpuid", "=*{ebx},=*{ecx},=*{edx},{eax}", ebx, ecx, edx, 1u);
+}
+
+void swint(ubyte swint_id)()
+{
+    mixin(`__asm("int $$`, cast(int)cast(uint)swint_id, `", "");`);
+}

src/hulk/fb.d

@@ -0,0 +1,242 @@
+/**
+ * HULK Framebuffer support.
+ */
+module hulk.fb;
+
+import hulk.memory;
+import hulk.kfont;
+
+/**
+ * Represent a graphical frame buffer.
+ *
+ * Coordinate (0,0) is the top-left corner of the framebuffer.
+ *
+ * TODO: Handle other pixel formats. Currently only BGRx is supported.
+ */
+struct Fb
+{
+    /** Device frame buffer base address. */
+    private __gshared static uint * m_device_buffer;
+
+    /** Frame buffer 1 base address. */
+    private __gshared static uint * m_buffer1;
+
+    /** Frame buffer width. */
+    private __gshared static uint m_width;
+
+    /** Frame buffer height. */
+    private __gshared static uint m_height;
+
+    /** Frame buffer stride. */
+    private __gshared static uint m_stride;
+
+    /** Number of pixels in the frame buffer (whether visible or not). */
+    private __gshared static uint m_buffer_size;
+
+    /**
+     * Get the framebuffer width.
+     */
+    public static @property uint width()
+    {
+        return m_width;
+    }
+
+    /**
+     * Get the framebuffer height.
+     */
+    public static @property uint height()
+    {
+        return m_height;
+    }
+
+    /**
+     * Initialize a frame buffer.
+     *
+     * @param device_buffer Device frame buffer base address.
+     * @param buffer1 Frame buffer 1 base address.
+     * @param width Frame buffer width.
+     * @param height Frame buffer height.
+     * @param stride Frame buffer stride.
+     */
+    static void initialize(uint * device_buffer, uint * buffer1, uint width, uint height, uint stride)
+    {
+        m_device_buffer = device_buffer;
+        m_buffer1 = buffer1;
+        m_width = width;
+        m_height = height;
+        m_stride = stride;
+        m_buffer_size = stride * height;
+    }
+
+    /**
+     * Clear the frame buffer to the given color.
+     *
+     * @param color Color to clear to.
+     */
+    static void clear(uint color = 0u)
+    {
+        memset32(m_buffer1, color, m_buffer_size);
+        memset32(m_device_buffer, color, m_buffer_size);
+    }
+
+    /**
+     * Draw a solid rectangle on the framebuffer.
+     *
+     * @param x X coordinate of left of rectangle.
+     * @param y Y coordinate of top of rectangle.
+     * @param width Width of rectangle.
+     * @param height Height of rectangle.
+     * @param color Color of rectangle.
+     */
+    static void rect(size_t x, size_t y, size_t width, size_t height, uint color)
+    {
+        for (size_t iy = 0u; iy < height; iy++)
+        {
+            size_t buffer_index = buffer_index(x, y);
+            memset32(&m_buffer1[buffer_index], color, width);
+            memset32(&m_device_buffer[buffer_index], color, width);
+            y++;
+        }
+    }
+
+    /**
+     * Draw a horizontal line.
+     *
+     * @param x X coordinate of left of line.
+     * @param y Y coordinate of line.
+     * @param width Width of line.
+     * @param color Color of line.
+     */
+    static void hline(size_t x, size_t y, size_t width, uint color)
+    {
+        size_t buffer_index = buffer_index(x, y);
+        memset32(&m_buffer1[buffer_index], color, width);
+        memset32(&m_device_buffer[buffer_index], color, width);
+    }
+
+    /**
+     * Draw a vertical line.
+     *
+     * @param x X coordinate of line.
+     * @param y Y coordinate of top of line.
+     * @param height Height of line.
+     * @param color Color of line.
+     */
+    static void vline(size_t x, size_t y, size_t height, uint color)
+    {
+        size_t buffer_index = buffer_index(x, y);
+        for (size_t iy = 0u; iy < height; iy++)
+        {
+            m_buffer1[buffer_index] = color;
+            m_device_buffer[buffer_index] = color;
+            buffer_index += m_stride;
+        }
+    }
+
+    /**
+     * Blit an 8-bit alpha bitmap to the framebuffer.
+     * The foreground will be white (based on the alpha value), and the
+     * background black.
+     *
+     * @param x X coordinate of left of target location.
+     * @param y Y coordinate of top of target location.
+     * @param alpha_bitmap 8-bit alpha-channel bitmap.
+     * @param width Bitmap width.
+     * @param height Bitmap height.
+     */
+    static void blit_alpha_bitmap(size_t x, size_t y, const(ubyte) * alpha_bitmap,
+            size_t width, size_t height)
+    {
+        size_t bitmap_index;
+        for (size_t iy = 0u; iy < height; iy++)
+        {
+            size_t row_buffer_index = buffer_index(x, y);
+            for (size_t ix = 0u; ix < width; ix++)
+            {
+                size_t buffer_index = row_buffer_index + ix;
+                ubyte alpha = alpha_bitmap[bitmap_index];
+                m_buffer1[buffer_index] = (alpha << 16u) | (alpha << 8u) | alpha;
+                bitmap_index++;
+            }
+            memcpy32(&m_device_buffer[row_buffer_index], &m_buffer1[row_buffer_index], width);
+            y++;
+        }
+    }
+
+    /**
+     * Blit an 8-bit alpha bitmap to the framebuffer.
+     * The foreground will be white (based on the alpha value), and the
+     * background black.
+     *
+     * @param x X coordinate of left of target location.
+     * @param y Y coordinate of top of target location.
+     * @param alpha_bitmap 8-bit alpha-channel bitmap.
+     * @param width Bitmap width.
+     * @param height Bitmap height.
+     */
+    static void blit_alpha_bitmap(size_t x, size_t y, const(ubyte)[] alpha_bitmap,
+            size_t width, size_t height)
+    {
+        blit_alpha_bitmap(x, y, alpha_bitmap.ptr, width, height);
+    }
+
+    /**
+     * Copy framebuffer rows up in the framebuffer.
+     *
+     * @param y Y coordinate of top of region to copy up.
+     * @param height Height of region to copy up.
+     * @param offset Number of rows to copy region up by.
+     */
+    static void copy_rows_up(size_t y, size_t height, size_t offset)
+    {
+        size_t dest_buffer_index = buffer_index(0u, y - offset);
+        size_t src_buffer_index = buffer_index(0u, y);
+        memcpy32(&m_buffer1[dest_buffer_index],
+                 &m_buffer1[src_buffer_index],
+                 (m_stride * height));
+        memcpy32(&m_device_buffer[dest_buffer_index],
+                &m_buffer1[dest_buffer_index],
+                (m_stride * height));
+    }
+
+    /**
+     * Copy a rectangle in the framebuffer.
+     *
+     * @param sx X coordinate of left of source rectangle.
+     * @param sy Y coordinate of top of source rectangle.
+     * @param width Width of rectangle to copy.
+     * @param height Height of rectangle to copy.
+     * @param dx X coordinate of left of destination rectangle.
+     * @param dy Y coordinate of top of destination rectangle.
+     */
+    static void copy_rect(size_t sx, size_t sy, size_t width, size_t height,
+            size_t dx, size_t dy)
+    {
+        size_t dest_buffer_index = buffer_index(dx, dy);
+        size_t src_buffer_index = buffer_index(sx, sy);
+        for (size_t y = 0u; y < height; y++)
+        {
+            memcpy32(&m_buffer1[dest_buffer_index],
+                     &m_buffer1[src_buffer_index],
+                     width);
+            memcpy32(&m_device_buffer[dest_buffer_index],
+                     &m_buffer1[dest_buffer_index],
+                     width);
+            dest_buffer_index += m_stride;
+            src_buffer_index += m_stride;
+        }
+    }
+
+    /**
+     * Return the buffer index for the given X and Y coordinates.
+     *
+     * @param x X coordinate from left side of framebuffer.
+     * @param y Y coordinate from bottom side of framebuffer.
+     *
+     * @return Buffer index for the given X and Y coordinates.
+     */
+    private static size_t buffer_index(size_t x, size_t y)
+    {
+        return y * m_stride + x;
+    }
+}

src/hulk/gdt.d

@@ -0,0 +1,58 @@
+/**
+ * GDT (Global Descriptor Table) functionality.
+ */
+module hulk.gdt;
+
+import ldc.llvmasm;
+
+struct Gdt
+{
+    struct gdtr_t
+    {
+        ushort limit;
+        align(2) ulong offset;
+    }
+    static assert(gdtr_t.sizeof == 10u);
+
+    public enum size_t SELECTOR_NULL = 0x00u;
+    public enum size_t SELECTOR_KERNEL_CODE = 0x08u;
+    public enum size_t SELECTOR_KERNEL_DATA = 0x10u;
+    public enum size_t SELECTOR_COUNT = 3u;
+
+    static __gshared ulong[SELECTOR_COUNT] gdt;
+    static __gshared gdtr_t gdtr;
+
+    public static void initialize()
+    {
+        gdt[SELECTOR_KERNEL_CODE / ulong.sizeof] = 0x00_A_F_9A_000000_0000u;
+        gdt[SELECTOR_KERNEL_DATA / ulong.sizeof] = 0x00_C_F_92_000000_0000u;
+        gdtr.limit = gdt.sizeof - 1u;
+        gdtr.offset = cast(ulong)&gdt;
+        lgdt(&gdtr);
+        load_data_selectors(SELECTOR_KERNEL_DATA);
+        load_code_selector(SELECTOR_KERNEL_CODE);
+    }
+
+    private static void lgdt(gdtr_t * gdtr)
+    {
+        __asm("lgdt $0", "*m", gdtr);
+    }
+
+    private static void load_data_selectors(ulong selector)
+    {
+        __asm(`mov %ax, %ds
+               mov %ax, %es
+               mov %ax, %fs
+               mov %ax, %gs
+               mov %ax, %ss`, "{rax}", selector);
+    }
+
+    private static void load_code_selector(ulong selector)
+    {
+        __asm(`push %rax
+               movabs $$1f, %rax
+               push %rax
+               lretq
+               1:`, "{rax}", selector);
+    }
+}

src/hulk/header.d

@@ -0,0 +1,40 @@
+/**
+ * HULK image header.
+ */
+module hulk.header;
+
+import hulk.bootinfo;
+
+/**
+ * Header describing the HULK image.
+ */
+struct HulkHeader
+{
+    /**
+     * HULK BSS size.
+     *
+     * The OS loader must map memory to a zeroed range of this size.
+     *
+     * This value is really an integer, but is stored as a pointer because it
+     * is provided by the linker and LDC does not like us to cast it.
+     */
+    void * hulk_bss_size;
+
+    /** Entry point. */
+    void * entry;
+
+    /** Stack size. */
+    ulong stack_size;
+
+    /** Virtual base address. */
+    ulong virt_base;
+
+    /** Stack top virtual address. */
+    ulong virt_stack_top;
+
+    /** Framebuffer virtual address. */
+    ulong virt_fb_buffer;
+
+    /** HULK boot information. */
+    BootInfo bootinfo;
+}

src/hulk/him.d

@@ -0,0 +1,329 @@
+/**
+ * HULK Interrupt Manager.
+ */
+module hulk.him;
+
+import hulk.gdt;
+import ldc.llvmasm;
+import hulk.fb;
+import hulk.console;
+import hulk.klog;
+import hulk.apic;
+import hulk.cpu;
+import hulk.kfont;
+import hulk.thread;
+
+/** Number if Interrupt Service Routines. */
+private enum N_ISRS = 256;
+
+/** Interrupt stack frame indices. */
+public static enum
+{
+    ISF_RBP,
+    ISF_R15,
+    ISF_R14,
+    ISF_R13,
+    ISF_R12,
+    ISF_R11,
+    ISF_R10,
+    ISF_R9,
+    ISF_R8,
+    ISF_RDI,
+    ISF_RSI,
+    ISF_RDX,
+    ISF_RCX,
+    ISF_RBX,
+    ISF_RAX,
+    ISF_ERROR_CODE,
+    ISF_RIP,
+    ISF_CS,
+    ISF_RFLAGS,
+    ISF_RSP,
+    ISF_SS,
+    ISF_COUNT,
+}
+
+private static __gshared string[ISF_COUNT] ISF_NAMES = [
+    "RBP",
+    "R15",
+    "R14",
+    "R13",
+    "R12",
+    "R11",
+    "R10",
+    "R9",
+    "R8",
+    "RDI",
+    "RSI",
+    "RDX",
+    "RCX",
+    "RBX",
+    "RAX",
+    "Error Code",
+    "RIP",
+    "CS",
+    "RFLAGS",
+    "RSP",
+    "SS",
+];
+
+/** Interrupt IDs. @{ */
+public enum ulong INT_PAGE_FAULT = 0x0Eu;
+
+/* The I/O APIC is configured to map IRQ 0 to interrupt 64 (0x40). */
+public enum ulong INT_APIC_BASE = 0x40u; /* IRQ 0 */
+public enum ulong INT_APIC_COUNT = 24u;
+
+public enum ulong INT_APIC_TIMER = 0x70u;
+public enum ulong INT_APIC_LINT0 = 0x71u;
+public enum ulong INT_APIC_LINT1 = 0x72u;
+public enum ulong INT_KERNEL_SWINT = 0x80u;
+public enum ulong INT_APIC_SPURIOUS = 0xFFu;
+/** @} */
+
+static foreach(isr; 0 .. N_ISRS)
+{
+    mixin(`private extern(C) void isr_`, isr, `();`);
+}
+
+private string isrs_list(int index = 0)()
+{
+    static if (index < 256)
+    {
+        return "&isr_" ~ index.stringof ~ ",\n" ~ isrs_list!(index + 1)();
+    }
+    else
+    {
+        return "";
+    }
+}
+
+mixin(`private static __gshared extern(C) void function()[N_ISRS] isrs = [`,
+        isrs_list(),
+        `];`);
+
+/** Interrupt suspend level (0 when interrupts are enabled). */
+private __gshared size_t interrupt_suspend_level;
+
+/** Interrupt nest level (0 when not in an interrupt handler). */
+private __gshared size_t interrupt_level;
+
+/**
+ * Suspend interrupts.
+ *
+ * This function disables interrupts. Calls can be nested and interrupts will
+ * be enabled only when the outermost pair of
+ * suspend_interrupts()/resume_interrupts() is complete.
+ */
+void suspend_interrupts()
+{
+    if (interrupt_level == 0)
+    {
+        cli();
+        interrupt_suspend_level++;
+    }
+}
+
+/**
+ * Resume interrupts.
+ *
+ * Calls can be nested and interrupts will be enabled only when the outermost
+ * pair of suspend_interrupts()/resume_interrupts() is complete.
+ */
+void resume_interrupts()
+{
+    if (interrupt_level == 0)
+    {
+        interrupt_suspend_level--;
+        if (interrupt_suspend_level == 0)
+        {
+            sti();
+        }
+    }
+}
+
+struct Him
+{
+    /**
+     * IDT descriptor entry type.
+     */
+    struct descriptor_t
+    {
+        ulong[2] descriptor;
+
+        this(T)(size_t index, ulong dpl, bool trap, T offset)
+        {
+            descriptor[0] =
+                0x0000_8E_00_0000_0000u |
+                ((cast(ulong)offset & 0xFFFF_0000u) << 32u) |
+                (dpl << 45u) |
+                ((trap ? 1uL : 0uL) << 40u) |
+                (Gdt.SELECTOR_KERNEL_CODE << 16u) |
+                (cast(ulong)offset & 0xFFFFu);
+            descriptor[1] = cast(ulong)offset >> 32u;
+        }
+    }
+
+    /**
+     * IDTR register format.
+     */
+    struct idtr_t
+    {
+        ushort limit;
+        align(2) ulong offset;
+    }
+    static assert(idtr_t.sizeof == 10u);
+
+    private static __gshared idtr_t idtr;
+    private static __gshared align(0x10) descriptor_t[N_ISRS] idt;
+    static assert(idt.sizeof == (N_ISRS * 16u));
+
+    public static void initialize()
+    {
+        set_isrs();
+        idtr.limit = idt.sizeof - 1u;
+        idtr.offset = cast(ulong)&idt;
+        lidt(&idtr);
+    }
+
+    private static void lidt(idtr_t * idtr)
+    {
+        __asm("lidt $0", "*m", idtr);
+    }
+
+    private static void set_isrs()
+    {
+        static bool isr_has_error_code(size_t isr)
+        {
+            return (isr == 8) ||
+                ((10 <= isr) && (isr <= 14)) ||
+                (isr == 17) ||
+                (isr == 21) ||
+                (isr == 29) ||
+                (isr == 30);
+        }
+
+        static bool isr_is_trap(size_t isr)
+        {
+            return (isr < 32u) && (isr != 2u);
+        }
+
+        __asm("jmp 1f", "");
+        static foreach(isr; 0 .. N_ISRS)
+        {
+            mixin("__asm(`isr_", isr, ":
+                " ~ (isr_has_error_code(isr) ? "" : "pushq $$0") ~ "
+                pushq %rax
+                mov $$", isr, ", %rax
+                jmp isr_common`, ``);");
+        }
+
+        __asm(`isr_common:
+            pushq %rbx
+            pushq %rcx
+            pushq %rdx
+            pushq %rsi
+            pushq %rdi
+            pushq %r8
+            pushq %r9
+            pushq %r10
+            pushq %r11
+            pushq %r12
+            pushq %r13
+            pushq %r14
+            pushq %r15
+            pushq %rbp
+            mov %rsp, %rbp
+            mov %rsp, %rsi
+            and $$0xFFFFFFFFFFFFFFF0, %rsp
+            mov %rsp, %rdx
+            mov %rax, %rdi
+            movabs $$isr, %rax
+            callq *%rax
+            mov %rax, %rsp
+            popq %rbp
+            popq %r15
+            popq %r14
+            popq %r13
+            popq %r12
+            popq %r11
+            popq %r10
+            popq %r9
+            popq %r8
+            popq %rdi
+            popq %rsi
+            popq %rdx
+            popq %rcx
+            popq %rbx
+            popq %rax
+            add $$8, %rsp
+            iretq
+            1:`, ``);
+
+        for (size_t isr = 0; isr < N_ISRS; isr++)
+        {
+            idt[isr] = descriptor_t(isr, 0u, isr_is_trap(isr), isrs[isr]);
+        }
+    }
+
+}
+
+/**
+ * Interrupt service routine.
+ *
+ * This function returns the stack pointer of the thread to execute when
+ * returning from this function.
+ */
+public extern(C) ulong * isr(ulong vector, ulong * stack_frame, ulong * rsp)
+{
+    interrupt_level++;
+    if (interrupt_level == 1)
+    {
+        Thread.current_thread.stack_pointer = stack_frame;
+    }
+    if ((vector >= INT_APIC_BASE) && (vector < (INT_APIC_BASE + INT_APIC_COUNT)))
+    {
+        Apic.isr(vector);
+    }
+    else
+    {
+        switch (vector)
+        {
+        case INT_APIC_TIMER:
+        case INT_APIC_LINT0:
+        case INT_APIC_LINT1:
+        case INT_APIC_SPURIOUS:
+            Apic.isr(vector);
+            break;
+
+        case INT_KERNEL_SWINT:
+            Thread.handle_swint(stack_frame);
+            break;
+
+        default:
+            Fb.rect(0, 0, Fb.width, Kfont.line_height, 0xCC0000u);
+            Klog.writefln("\n **** Unhandled ISR %u ****", vector);
+            for (size_t i = 0u; i < ISF_COUNT; i++)
+            {
+                Klog.writef(ISF_NAMES[i]);
+                Klog.writefln(" = 0x%x", stack_frame[i]);
+            }
+            Klog.writefln("CR2 = 0x%p", read_cr2());
+            __asm("cli", "");
+            for (;;)
+            {
+                __asm("hlt", "");
+            }
+        }
+    }
+    Thread.current_thread = Thread.current_thread.list_next;
+    interrupt_level--;
+    if (interrupt_level == 0)
+    {
+        return Thread.current_thread.stack_pointer;
+    }
+    else
+    {
+        return rsp;
+    }
+}

src/hulk/hippo.d

@@ -0,0 +1,218 @@
+/**
+ * HIPPO, the HOS In-place Physical Page Organizer.
+ *
+ * HIPPO maintains a list of free physical pages "in place", meaning that the
+ * available page itself is used as the linked list entry so separate memory
+ * is not needed to keep track of the available pages.
+ */
+module hulk.hippo;
+
+import hulk.hurl;
+import hulk.klog;
+
+struct Hippo
+{
+    /**
+     * Linked list node entry for a single page.
+     */
+    private static struct PhysicalPage
+    {
+        PhysicalPage * next;
+    }
+
+    /**
+     * Linked list node entry for a region.
+     */
+    private static struct Region
+    {
+        ulong size;
+        Region * next;
+    }
+
+    /**
+     * Linked list of free physical pages.
+     */
+    private static __gshared PhysicalPage * free_pages;
+
+    /**
+     * Linked list of free regions.
+     */
+    private static __gshared Region * regions;
+
+    /**
+     * Number of free physical pages.
+     */
+    private static __gshared size_t m_n_free_pages;
+
+    /**
+     * Free a physical page.
+     *
+     * @param phys Physical page address.
+     */
+    public static void free_page(T)(T phys)
+    {
+        PhysicalPage * pp = cast(PhysicalPage *)phys;
+        pp.next = free_pages;
+        free_pages = pp;
+        m_n_free_pages++;
+    }
+
+    /**
+     * Allocate a physical page.
+     *
+     * @return Page address, or null if no pages are available.
+     */
+    public static void * allocate_page()
+    {
+        PhysicalPage * pp;
+        if (free_pages !is null)
+        {
+            pp = free_pages;
+            free_pages = free_pages.next;
+            m_n_free_pages--;
+        }
+        else if (regions !is null)
+        {
+            pp = cast(PhysicalPage *)(cast(ulong)regions + regions.size - PAGE_SIZE);
+            regions.size -= PAGE_SIZE;
+            if (regions.size == 0)
+            {
+                regions = regions.next;
+            }
+            m_n_free_pages--;
+        }
+        return cast(void *)pp;
+    }
+
+    /**
+     * Free a physical memory region.
+     */
+    public static void free_region(T)(T start, ulong size)
+    {
+        if (size == PAGE_SIZE)
+        {
+            free_page(start);
+            return;
+        }
+
+        if (regions is null)
+        {
+            /* The free regions list is empty. Append this new region. */
+            regions = cast(Region *)start;
+            regions.size = size;
+            regions.next = null;
+        }
+        else if (size < regions.size)
+        {
+            /* The new region is smaller than the first one in the list.
+             * Add the new region to the beginning of the list. */
+            Region * new_region = cast(Region *)start;
+            new_region.size = size;
+            new_region.next = regions;
+            regions = new_region;
+        }
+        else
+        {
+            /* Find the last free region that is smaller than this one. */
+            Region * region = regions;
+            while (region.next !is null && region.next.size < size)
+            {
+                region = region.next;
+            }
+
+            /* Add the new region after this entry. */
+            Region * new_region = cast(Region *)start;
+            new_region.size = size;
+            new_region.next = region.next;
+            region.next = new_region;
+        }
+
+        m_n_free_pages += size >> 12;
+    }
+
+    /**
+     * Allocate a region with the given size and alignment.
+     *
+     * @param size Region size.
+     * @param alignment Region alignment.
+     */
+    public static void * allocate_aligned_region(ulong size, ulong alignment)
+    {
+        Region ** regionp = &regions;
+        for (;;)
+        {
+            Region * region = *regionp;
+            if (region is null)
+            {
+                break;
+            }
+
+            /* The size of the region must be large enough */
+            if (region.size >= size)
+            {
+                /* The alignment contstraint must be satisfied. */
+                if ((cast(ulong)region & (alignment - 1)) == 0)
+                {
+                    /* The region start address happens to already be aligned. */
+                    if (region.size > size)
+                    {
+                        /* Region found is larger that needed. */
+                        Region * new_region = cast(Region *)(cast(ulong)region + size);
+                        new_region.size = region.size - size;
+                        new_region.next = region.next;
+                        *regionp = new_region;
+                        return region;
+                    }
+                    else
+                    {
+                        /* Region happens to be the size requested. */
+                        *regionp = region.next;
+                        return region;
+                    }
+                }
+                else
+                {
+                    /* This region is large enough but not aligned. See if an
+                     * aligned subregion can be found at the end. */
+                    ulong start = (cast(ulong)region + region.size - size) & ~(alignment - 1);
+                    if (start > cast(ulong)region)
+                    {
+                        /* The aligned subregion does fit in this region. */
+                        region.size = (start - cast(ulong)region);
+                        ulong region_end = cast(ulong)region + region.size;
+                        if (region_end > (start + size))
+                        {
+                            /* There is another region following the aligned
+                             * subregion that we must reclaim. */
+                            free_region(start + size, region_end - (start + size));
+                        }
+                        return cast(void *)start;
+                    }
+                }
+            }
+
+            regionp = &region.next;
+        }
+        return null;
+    }
+
+    /**
+     * Get the number of free pages.
+     *
+     * @return The number of free pages.
+     */
+    public static @property size_t n_free_pages()
+    {
+        return m_n_free_pages;
+    }
+
+    public static void dump_regions()
+    {
+        Region * region = regions;
+        while (region !is null)
+        {
+            Klog.writefln("HIPPO free region: %p %uKB", region, region.size >> 10);
+            region = region.next;
+        }
+    }
+}

src/hulk/hulk.d

@@ -0,0 +1,114 @@
+/**
+ * HULK, the HOS Ultra Light Kernel.
+ */
+module hulk.hulk;
+
+import hulk.header;
+import hulk.fb;
+import hulk.console;
+import hulk.memory;
+import ldc.attributes;
+import hulk.kfont;
+import hulk.klog;
+import hulk.hurl;
+import hulk.hippo;
+import hulk.pci;
+import hulk.gdt;
+import hulk.him;
+import hulk.cpu;
+import ldc.llvmasm;
+import hulk.pic;
+import hulk.acpi;
+import hulk.apic;
+import hulk.rtc;
+import hulk.serial;
+import hulk.usb;
+import hulk.pit;
+import hulk.time;
+import hulk.test;
+import hulk.thread;
+
+extern extern(C) __gshared ubyte _hulk_bss_size;
+
+@(ldc.attributes.section(".hulk_header"))
+private __gshared HulkHeader hulk_header = {
+    &_hulk_bss_size, /* hulk_bss_size */
+    &hulk_start, /* entry */
+    Thread.STACK_SIZE, /* stack_size */
+    Hurl.HULK_BASE, /* virt_base */
+    Hurl.HULK_STACK_TOP, /* virt_stack_top */
+    Hurl.HULK_FRAMEBUFFER, /* virt_fb_buffer */
+};
+
+private void initialize_cpu()
+{
+    /* Enable SSE. */
+    /* Turn off CR0.EM and turn on CR0.MP. */
+    write_cr0((read_cr0() & ~CR0_EM) | CR0_MP);
+    /* Set CR4.OSFXSR and CR4.OSXMMEXCPT. */
+    write_cr4(read_cr4() | CR4_OSFXSR | CR4_OSXMMEXCPT);
+
+    /* Enable OSXSAVE. */
+    write_cr4(read_cr4() | CR4_OSXSAVE);
+
+    /* Turn on NXE (no execute enable) flag in the EFER MSR. */
+    wrmsr(MSR_EFER, rdmsr(MSR_EFER) | EFER_NXE);
+}
+
+/**
+ * HULK entry point.
+ */
+void hulk_start()
+{
+    suspend_interrupts();
+
+    initialize_cpu();
+    Serial.initialize();
+    Gdt.initialize();
+    Him.initialize();
+    Fb.initialize(cast(uint *)Hurl.HULK_FRAMEBUFFER,
+            cast(uint *)hulk_header.bootinfo.fb_buffer1_phys,
+            hulk_header.bootinfo.fb.width,
+            hulk_header.bootinfo.fb.height,
+            hulk_header.bootinfo.fb.stride);
+    Console.initialize();
+    Console.clear();
+    Klog.initialize();
+
+    Klog.writefln("\a5Welcome to HULK, the HOS UltraLight Kernel!");
+
+    Hurl.initialize(&hulk_header);
+    Pic.initialize();
+    Acpi.initialize(hulk_header.bootinfo.acpi_xsdt_phys);
+    Apic.initialize();
+    Rtc.initialize();
+    Pit.initialize();
+    Pci.initialize();
+    Thread.initialize();
+
+    resume_interrupts();
+
+    Usb.initialize();
+
+    /* Run kernel tests. */
+    Test.run();
+    Klog.writefln("\a5HULK Initialization Complete!");
+//    Thread.start(&th);
+//    Time.msleep(1);
+//    Time.msleep(500);
+//    Klog.writefln("Main thread!");
+    /* Idle loop. */
+    for (;;)
+    {
+        hlt();
+    }
+}
+
+void th()
+{
+    for (;;)
+    {
+        Klog.writefln("Hello from thread.");
+        Time.msleep(1000);
+    }
+}

src/hulk/hulk.ld

@@ -0,0 +1,65 @@
+SECTIONS
+{
+    . = 0xFFFFFFFF80000000;
+    _hulk_mem_start = .;
+    _hulk_header_start = .;
+
+    .hulk_header :
+    {
+        KEEP(*(.hulk_header))
+    }
+
+    . = ALIGN(4K);
+    _hulk_header_end = .;
+    _hulk_text_start = .;
+
+    .text :
+    {
+        *(.text)
+        *(.text.*)
+    }
+
+    . = ALIGN(4K);
+    _hulk_text_end = .;
+    _hulk_rodata_start = .;
+
+    .rodata :
+    {
+        *(.rodata)
+        *(.rodata.*)
+    }
+
+    . = ALIGN(4K);
+
+    _hulk_rodata_end = .;
+    _hulk_data_start = .;
+
+    .data :
+    {
+        *(.data)
+        *(.data.*)
+    }
+
+    . = ALIGN(4K);
+    _hulk_data_end = .;
+    _hulk_binary_size = . - _hulk_mem_start;
+    _hulk_bss_start = .;
+
+    .bss :
+    {
+        *(COMMON)
+        *(.bss)
+        *(.bss.*)
+    }
+
+    . = ALIGN(4K);
+    _hulk_bss_end = .;
+    _hulk_mem_end = .;
+
+    _hulk_header_size = _hulk_header_end - _hulk_header_start;
+    _hulk_text_size = _hulk_text_end - _hulk_text_start;
+    _hulk_rodata_size = _hulk_rodata_end - _hulk_rodata_start;
+    _hulk_data_size = _hulk_data_end - _hulk_data_start;
+    _hulk_bss_size = _hulk_bss_end - _hulk_bss_start;
+    _hulk_mem_size = _hulk_mem_end - _hulk_mem_start;
+}

src/hulk/hurl/a1.d

@@ -0,0 +1,67 @@
+/**
+ * A1 memory allocator.
+ */
+module hulk.hurl.a1;
+
+import hulk.hurl;
+import hulk.hippo;
+import hulk.util;
+import hulk.pagetable;
+import hulk.memory;
+
+/**
+ * The A1 memory allocator is a one-shot memory allocator for kernel memory
+ * that is allocated but never freed.
+ */
+struct A1
+{
+    /**
+     * Number of bytes allocated in the A1 region so far.
+     */
+    private static __gshared size_t allocated;
+
+    /**
+     * Allocate memory.
+     *
+     * @param size
+     *   Size of memory to allocate.
+     *
+     * @return Address of allocated memory. This address will always be aligned
+     *   to a multiple of 16 bytes.
+     */
+    public static void * allocate(size_t size)
+    {
+        /* Round size up to a multiple of 16. */
+        size = round_up_power_2(size, 16u);
+
+        ulong address = Hurl.A1_BASE + allocated;
+
+        ulong current_limit = round_up_power_2(address, PAGE_SIZE);
+
+        allocated += size;
+
+        ulong desired_limit = round_up_power_2(Hurl.A1_BASE + allocated, PAGE_SIZE);
+
+        while (desired_limit > current_limit)
+        {
+            void * page = Hippo.allocate_page();
+            Hurl.map(current_limit, page, PT_WRITABLE);
+            current_limit += PAGE_SIZE;
+        }
+
+        memset64(cast(void *)address, 0, size / 8);
+
+        return cast(void *)address;
+    }
+
+    /**
+     * Allocate memory to store an instance of a given type.
+     *
+     * @return Address of allocated memory. This address will always be aligned
+     *   to a multiple of 16 bytes.
+     */
+    public static T * allocate(T)()
+    {
+        return cast(T *)allocate(T.sizeof);
+    }
+}

src/hulk/hurl/hurl.d

@@ -0,0 +1,359 @@
+/**
+ * HURL, the HOS Unreal Region Locator.
+ *
+ * HURL provides virtual memory management for HULK.
+ */
+module hulk.hurl.hurl;
+
+public import hulk.pagetable;
+import hulk.cpu;
+import hulk.hippo;
+import hulk.memory;
+import hulk.klog;
+import hulk.bootinfo;
+import hulk.header;
+import hulk.linker_addresses;
+import hulk.util;
+
+struct Hurl
+{
+    /** HULK base address. */
+    enum ulong HULK_BASE = 0xFFFF_FFFF_8000_0000u;
+
+    /** HULK stack top address. */
+    enum ulong HULK_STACK_TOP = 0xFFFF_FFFF_9000_0000u;
+
+    /** HULK framebuffer address. */
+    enum ulong HULK_FRAMEBUFFER = 0xFFFF_FFFF_9000_0000u;
+
+    /** A1 allocator range base address. */
+    enum ulong A1_BASE = 0xFFFF_FFFF_A000_0000u;
+
+    /**
+     * Pointer to the base page table.
+     */
+    private static __gshared PageTable * m_pt_base;
+
+    /**
+     * Build HULK page tables.
+     *
+     * @param physical_address_limit
+     *   Limit of physical memory.
+     */
+    private static void build_page_tables(HulkHeader * header, size_t physical_address_limit)
+    {
+        m_pt_base = allocate_pt();
+        /* Identity map all physical RAM. */
+        map_range(0u,
+                0u,
+                physical_address_limit,
+                PT_WRITABLE | PT_NO_EXECUTE);
+        ulong phys_address = header.bootinfo.hulk_phys;
+        ulong virt_address = HULK_BASE;
+        /* Map HULK header region. */
+        map_range(virt_address,
+                phys_address,
+                LinkerAddresses.hulk_header_size,
+                PT_NO_EXECUTE);
+        phys_address += LinkerAddresses.hulk_header_size;
+        virt_address += LinkerAddresses.hulk_header_size;
+        /* Map HULK text region. */
+        map_range(virt_address,
+                phys_address,
+                LinkerAddresses.hulk_text_size,
+                0u);
+        phys_address += LinkerAddresses.hulk_text_size;
+        virt_address += LinkerAddresses.hulk_text_size;
+        /* Map HULK rodata region. */
+        map_range(virt_address,
+                phys_address,
+                LinkerAddresses.hulk_rodata_size,
+                PT_NO_EXECUTE);
+        phys_address += LinkerAddresses.hulk_rodata_size;
+        virt_address += LinkerAddresses.hulk_rodata_size;
+        /* Map HULK data region. */
+        map_range(virt_address,
+                phys_address,
+                LinkerAddresses.hulk_data_size,
+                PT_WRITABLE | PT_NO_EXECUTE);
+        virt_address += LinkerAddresses.hulk_data_size;
+        /* Map HULK BSS region. */
+        map_range(virt_address,
+                header.bootinfo.bss_phys,
+                LinkerAddresses.hulk_bss_size,
+                PT_WRITABLE | PT_NO_EXECUTE);
+        /* Map HULK stack. */
+        map_range(HULK_STACK_TOP - header.stack_size,
+                header.bootinfo.stack_phys,
+                header.stack_size,
+                PT_WRITABLE | PT_NO_EXECUTE);
+        /* Map device framebuffer. */
+        map_range(HULK_FRAMEBUFFER,
+                cast(ulong)header.bootinfo.fb.buffer,
+                header.bootinfo.fb.height * header.bootinfo.fb.stride * 4u,
+                PT_PAT | PT_WRITABLE | PT_NO_EXECUTE);
+        /* Map framebuffer buffer1. */
+        map_range(cast(ulong)header.bootinfo.fb_buffer1_phys,
+                cast(ulong)header.bootinfo.fb_buffer1_phys,
+                header.bootinfo.fb.height * header.bootinfo.fb.stride * 4u,
+                PT_WRITABLE | PT_NO_EXECUTE);
+        write_cr3(cast(ulong)m_pt_base);
+    }
+
+    /**
+     * Reclaim the pages that were used for the bootloader page tables.
+     *
+     * @param pt
+     *   The page table to reclaim pages from.
+     * @param level
+     *   Page table level (internally used while recursing the page tables).
+     *
+     * @return Number of pages reclaimed.
+     */
+    private static size_t reclaim_bootloader_page_table_pages(PageTable * pt, size_t level = 0u)
+    {
+        map(pt, pt, PT_WRITABLE | PT_NO_EXECUTE);
+        size_t reclaimed_pages;
+        for (size_t i = 0u; i < PageTable.N_ENTRIES; i++)
+        {
+            PageTableEntry pte = (*pt)[i];
+            if (pte.present && (level < 2u) && !pte.huge)
+            {
+                /* For the first two levels of page tables, first
+                 * recurse and free pages from the lower level page
+                 * tables before reclaiming this entry. */
+                reclaimed_pages += reclaim_bootloader_page_table_pages(pte.follow(), level + 1u);
+            }
+        }
+        Hippo.free_page(pt);
+        reclaimed_pages++;
+        return reclaimed_pages;
+    }
+
+    /**
+     * Initialize HURL.
+     *
+     * @param bootinfo HULK boot information structure.
+     */
+    public static void initialize(HulkHeader * header)
+    {
+        PageTable * bootloader_pt_base = cast(PageTable *)read_cr3();
+
+        /*
+         * Ok, what we do here is iterate through all of the memory map regions
+         * in the bootinfo memory_map array and mark each page that is not in
+         * use in a reserved range as available. Within the available memory
+         * regions, we have to watch out for the following items:
+         *   1) HULK binary (header + text + rodata + data)
+         *   2) Framebuffer
+         * In addition to these ranges, there are also pages for the following
+         * purposes that are not represented in the memory map from the
+         * bootloader:
+         *   3) HULK BSS
+         *   4) HULK stack
+         *   5) bootloader page table pages
+         *   6) framebuffer buffer1
+         */
+        size_t usable_memory;
+        size_t physical_address_limit;
+        const(size_t) fb_size = round_up_power_2(header.bootinfo.fb.height * header.bootinfo.fb.stride * 4u, PAGE_SIZE);
+        ulong[2][2] reserved_regions = [
+            [header.bootinfo.hulk_phys, LinkerAddresses.hulk_binary_size],
+            [cast(ulong)header.bootinfo.fb.buffer, fb_size],
+        ];
+        for (size_t ri = 0u; ri < reserved_regions.length; ri++)
+        {
+            Klog.writefln("Reserved region %p %uKB", reserved_regions[ri][0], reserved_regions[ri][1] >> 10);
+            reserved_regions[ri][1] += reserved_regions[ri][0];
+        }
+        for (size_t bii = 0u; bii < header.bootinfo.memory_map_count; bii++)
+        {
+            if ((header.bootinfo.memory_map[bii].type == BootInfo.MemoryRegion.Type.Bootloader) ||
+                (header.bootinfo.memory_map[bii].type == BootInfo.MemoryRegion.Type.Conventional))
+            {
+                ulong phys = header.bootinfo.memory_map[bii].base;
+                ulong size = header.bootinfo.memory_map[bii].size;
+                ulong phys_end = phys + size;
+                if (phys_end > physical_address_limit)
+                {
+                    physical_address_limit = phys_end;
+                }
+                usable_memory += header.bootinfo.memory_map[bii].size;
+                add_region(phys, size, reserved_regions);
+            }
+        }
+
+        /* Set PAT4 to indicate Write Combining so we can set the PAT bit in a
+         * page table entry to use Write Combining for that page. */
+        wrmsr(MSR_PAT, (rdmsr(MSR_PAT) & 0xFFFF_FF00_FFFF_FFFFu) | 0x0000_0001_0000_0000u);
+
+        /*
+         * Now that we have available physical pages to allocate from, we can
+         * build new page tables to replace the bootloader page tables.
+         */
+        build_page_tables(header, physical_address_limit);
+
+        /*
+         * After we have switched to the newly constructed page tables, we can
+         * iterate through and free the bootloader page tables. They are most
+         * likely already mapped because we just identity mapped every page up
+         * to the physical_address_limit determined above. But just in case the
+         * bootloader used the last pages of RAM for the page table pages, we
+         * will make sure to map them as we traverse them.
+         */
+        size_t reclaimed_bootloader_page_table_memory = reclaim_bootloader_page_table_pages(bootloader_pt_base) << 10u;
+        usable_memory += reclaimed_bootloader_page_table_memory;
+
+        usable_memory += LinkerAddresses.hulk_bss_size;
+        usable_memory += header.stack_size;
+        usable_memory += fb_size;
+        Klog.writefln("Usable memory: %uKB", usable_memory >> 10u);
+        Klog.writefln("Kernel size: %uKB", (LinkerAddresses.hulk_binary_size + LinkerAddresses.hulk_bss_size + header.stack_size) >> 10u);
+        Klog.writefln("Free pages: %u", Hippo.n_free_pages);
+//        Hippo.dump_regions();
+    }
+
+    /**
+     * Add a region of available physical memory.
+     *
+     * @param start Start address of region.
+     * @param size Size of region.
+     * @param reserved_regions List of reserved regions to exclude.
+     */
+    private static void add_region(ulong start, ulong size, ulong[2][] reserved_regions)
+    {
+        ulong end = start + size;
+        bool split;
+
+        /* Skip empty regions. */
+        if (size == 0)
+        {
+            return;
+        }
+
+        for (size_t rri = 0; rri < reserved_regions.length; rri++)
+        {
+            /* Skip this region if it is entirely within a reserved region. */
+            if (reserved_regions[rri][0] <= start && reserved_regions[rri][1] >= end)
+            {
+                return;
+            }
+
+            /* Check if the region is partly reserved but the beginning is free. */
+            if (reserved_regions[rri][0] > start && reserved_regions[rri][0] < end)
+            {
+                split = true;
+                add_region(start, reserved_regions[rri][0] - start, reserved_regions);
+            }
+
+            /* Check if the region is partly reserved but the end is free. */
+            if (reserved_regions[rri][1] > start && reserved_regions[rri][1] < end)
+            {
+                split = true;
+                add_region(reserved_regions[rri][1], end - reserved_regions[rri][1], reserved_regions);
+            }
+
+            if (split)
+            {
+                return;
+            }
+        }
+
+        /* If a region makes it here, it did not overlap with any reserved
+         * region, so the entire region can be used. */
+//        Klog.writefln("HURL: freeing region %p %uKB", start, size >> 10);
+        Hippo.free_region(start, size);
+    }
+
+    public static void map(ulong virtual, ulong physical, ulong flags)
+    {
+        PageTable * pt = m_pt_base;
+        for (size_t level = 0; level < 4u; level++)
+        {
+            PageTableEntry * ppte = pt.entry(virtual, level);
+            if (level < 3u)
+            {
+                PageTableEntry pte = *ppte;
+                if (pte.present)
+                {
+                    pt = pte.follow();
+                }
+                else
+                {
+                    PageTable * next_pt = allocate_pt();
+                    *ppte = PageTableEntry(next_pt, PT_WRITABLE | PT_PRESENT);
+                    pt = next_pt;
+                }
+            }
+            else
+            {
+                *ppte = PageTableEntry(cast(ulong)physical, flags | PT_PRESENT);
+            }
+        }
+    }
+
+    public static void map(T, U)(T virtual, U physical, ulong flags)
+    {
+        map(cast(ulong)virtual, cast(ulong)physical, flags);
+    }
+
+    public static void map_range(ulong virtual, ulong physical, size_t length, ulong flags)
+    {
+        size_t end = virtual + length;
+        while (virtual < end)
+        {
+            map(virtual, physical, flags);
+            virtual += PAGE_SIZE;
+            physical += PAGE_SIZE;
+        }
+    }
+
+    public static void map_range(T, U)(T virtual, U physical, size_t length, ulong flags)
+    {
+        map_range(cast(ulong)virtual, cast(ulong)physical, length, flags);
+    }
+
+    public static void identity_map_range(ulong address, size_t length, ulong flags)
+    {
+        size_t end = address + length;
+        for (size_t page = address & 0xFFFF_FFFF_FFFF_F000u; page < end; page += PAGE_SIZE)
+        {
+            map(page, page, flags);
+        }
+    }
+
+    public static void identity_map_range(T)(T address, size_t length, ulong flags)
+    {
+        identity_map_range(cast(ulong)address, length, flags);
+    }
+
+    public static void debug_lookup(void * address)
+    {
+        Klog.writefln("Debugging page table lookup of 0x%x", address);
+        PageTable * pt = m_pt_base;
+        for (size_t level = 0; level < 4u; level++)
+        {
+            PageTableEntry pte = *pt.entry(address, level);
+            Klog.writefln("Level %u, index %u, entry = 0x%x", level, pt.index(address, level), pte);
+            if (pte.present)
+            {
+                pt = pte.follow();
+            }
+            else
+            {
+                break;
+            }
+            if (pte.huge)
+            {
+                break;
+            }
+        }
+    }
+
+    private static PageTable * allocate_pt()
+    {
+        PageTable * pt = cast(PageTable *)Hippo.allocate_page();
+        memset64(pt, 0u, PAGE_SIZE / 8u);
+        return pt;
+    }
+}

src/hulk/hurl/package.d

@@ -0,0 +1,3 @@
+module hulk.hurl;
+
+public import hulk.hurl.hurl;

src/hulk/klog.d

@@ -0,0 +1,87 @@
+/**
+ * HULK Kernel Log buffer.
+ */
+module hulk.klog;
+
+import core.stdc.stdarg;
+import hulk.console;
+static import hulk.writef;
+import hulk.cpu;
+
+struct Klog
+{
+    /**
+     * Kernel buffer size log.
+     * 16 gives a kernel buffer size of 64KB.
+     */
+    private enum size_t KLOG_SIZE_LOG = 16u;
+
+    /** Kernel buffer size.  */
+    private enum size_t KLOG_SIZE = 1u << KLOG_SIZE_LOG;
+
+    /** Kernel log buffer. */
+    private static __gshared align(4096) ubyte[KLOG_SIZE] klog_buffer;
+
+    /** Write index in the kernel log buffer. */
+    private static __gshared size_t klog_index;
+
+    /**
+     * Initialize the klog module.
+     */
+    public static void initialize()
+    {
+    }
+
+    /**
+     * Write a formatted string to the kernel log.
+     *
+     * @param s Format string.
+     * @param args Variable arguments structure.
+     */
+    public static void writef(string s, va_list args)
+    {
+        hulk.writef.writefv(function void(ubyte ch) {
+                    Console.write(ch);
+                }, s, args);
+    }
+
+    /**
+     * Write a formatted string to the kernel log.
+     *
+     * @param s Format string.
+     */
+    public static extern (C) void writef(string s, ...)
+    {
+        va_list args;
+        va_start(args, s);
+        writef(s, args);
+        va_end(args);
+    }
+
+    /**
+     * Write a formatted string and newline to the kernel log.
+     *
+     * @param s Format string.
+     */
+    public static extern (C) void writefln(string s, ...)
+    {
+        va_list args;
+        va_start(args, s);
+        writef(s, args);
+        writef("\n", args);
+        va_end(args);
+    }
+
+    /**
+     * Print a fatal kernel error and loop forever.
+     */
+    public static void fatal_error(T...)(T args)
+    {
+        writef("FATAL ERROR: ");
+        writefln(args);
+        cli();
+        for (;;)
+        {
+        }
+    }
+}

src/hulk/linker_addresses.d

@@ -0,0 +1,139 @@
+/**
+ * This module provides access to linker-defined symbols.
+ */
+module hulk.linker_addresses;
+
+private extern extern(C) __gshared ubyte _hulk_header_start;
+private extern extern(C) __gshared ubyte _hulk_header_end;
+private extern extern(C) __gshared ubyte _hulk_header_size;
+
+private extern extern(C) __gshared ubyte _hulk_text_start;
+private extern extern(C) __gshared ubyte _hulk_text_end;
+private extern extern(C) __gshared ubyte _hulk_text_size;
+
+private extern extern(C) __gshared ubyte _hulk_rodata_start;
+private extern extern(C) __gshared ubyte _hulk_rodata_end;
+private extern extern(C) __gshared ubyte _hulk_rodata_size;
+
+private extern extern(C) __gshared ubyte _hulk_data_start;
+private extern extern(C) __gshared ubyte _hulk_data_end;
+private extern extern(C) __gshared ubyte _hulk_data_size;
+
+private extern extern(C) __gshared ubyte _hulk_bss_start;
+private extern extern(C) __gshared ubyte _hulk_bss_end;
+private extern extern(C) __gshared ubyte _hulk_bss_size;
+
+/* hulk_binary includes header, text, rodata, and data */
+private extern extern(C) __gshared ubyte _hulk_binary_size;
+
+/* hulk_mem includes header, text, rodata, data, and bss */
+private extern extern(C) __gshared ubyte _hulk_mem_start;
+private extern extern(C) __gshared ubyte _hulk_mem_end;
+private extern extern(C) __gshared ubyte _hulk_mem_size;
+
+/**
+ * This struct provides access to linker-defined symbols.
+ */
+public struct LinkerAddresses
+{
+    public static @property ulong hulk_header_start()
+    {
+        return cast(ulong)&_hulk_header_start;
+    }
+
+    public static @property ulong hulk_header_end()
+    {
+        return cast(ulong)&_hulk_header_end;
+    }
+
+    public static @property ulong hulk_header_size()
+    {
+        return cast(ulong)&_hulk_header_size;
+    }
+
+
+    public static @property ulong hulk_text_start()
+    {
+        return cast(ulong)&_hulk_text_start;
+    }
+
+    public static @property ulong hulk_text_end()
+    {
+        return cast(ulong)&_hulk_text_end;
+    }
+
+    public static @property ulong hulk_text_size()
+    {
+        return cast(ulong)&_hulk_text_size;
+    }
+
+
+    public static @property ulong hulk_rodata_start()
+    {
+        return cast(ulong)&_hulk_rodata_start;
+    }
+
+    public static @property ulong hulk_rodata_end()
+    {
+        return cast(ulong)&_hulk_rodata_end;
+    }
+
+    public static @property ulong hulk_rodata_size()
+    {
+        return cast(ulong)&_hulk_rodata_size;
+    }
+
+
+    public static @property ulong hulk_data_start()
+    {
+        return cast(ulong)&_hulk_data_start;
+    }
+
+    public static @property ulong hulk_data_end()
+    {
+        return cast(ulong)&_hulk_data_end;
+    }
+
+    public static @property ulong hulk_data_size()
+    {
+        return cast(ulong)&_hulk_data_size;
+    }
+
+
+    public static @property ulong hulk_bss_start()
+    {
+        return cast(ulong)&_hulk_bss_start;
+    }
+
+    public static @property ulong hulk_bss_end()
+    {
+        return cast(ulong)&_hulk_bss_end;
+    }
+
+    public static @property ulong hulk_bss_size()
+    {
+        return cast(ulong)&_hulk_bss_size;
+    }
+
+
+    public static @property ulong hulk_binary_size()
+    {
+        return cast(ulong)&_hulk_binary_size;
+    }
+
+
+    public static @property ulong hulk_mem_start()
+    {
+        return cast(ulong)&_hulk_mem_start;
+    }
+
+    public static @property ulong hulk_mem_end()
+    {
+        return cast(ulong)&_hulk_mem_end;
+    }
+
+    public static @property ulong hulk_mem_size()
+    {
+        return cast(ulong)&_hulk_mem_size;
+    }
+}

src/hulk/list.d

@@ -0,0 +1,100 @@
+/**
+ * Linked list functionality.
+ */
+module hulk.list;
+
+/**
+ * Linked list mixin.
+ */
+mixin template List(T)
+{
+    /**
+     * Next item in linked list.
+     */
+    T * list_next;
+
+    /**
+     * Previous item in linked list.
+     */
+    T * list_prev;
+
+    /**
+     * Initialize linked list fields.
+     */
+    public void list_init()
+    {
+        list_next = &this;
+        list_prev = &this;
+    }
+
+    /**
+     * Add this item after another in a list.
+     */
+    public void list_insert_after(T * item)
+    {
+        list_next = item.list_next;
+        list_prev = item;
+        item.list_next = &this;
+        list_next.list_prev = &this;
+    }
+
+    /**
+     * Add this item before another in a list.
+     */
+    public void list_insert_before(T * item)
+    {
+        list_next = item;
+        list_prev = item.list_prev;
+        item.list_prev = &this;
+        list_prev.list_next = &this;
+    }
+
+    /**
+     * Remove this item from the list.
+     */
+    public void list_remove()
+    {
+        list_next.list_prev = list_prev;
+        list_prev.list_next = list_next;
+        list_init();
+    }
+
+    /**
+     * Get the number of items in this list.
+     */
+    public @property size_t list_count() const
+    {
+        size_t count = 1;
+        const(T) * item = &this;
+        while (item.list_next != &this)
+        {
+            count++;
+            item = item.list_next;
+        }
+        return count;
+    }
+
+    /**
+     * Allow foreach iteration through this linked list.
+     */
+    public int opApply(scope int delegate(T *) dg)
+    {
+        T * item = &this;
+        T * last = item.list_prev;
+        for (;;)
+        {
+            T * next = item.list_next;
+            int result = dg(item);
+            if (result != 0)
+            {
+                return result;
+            }
+            if (item == last)
+            {
+                break;
+            }
+            item = next;
+        }
+        return 0;
+    }
+}

src/hulk/memory.d

@@ -0,0 +1,62 @@
+/**
+ * Memory-related functions.
+ */
+module hulk.memory;
+
+import ldc.llvmasm;
+
+void memset(void * dest, ubyte v, size_t n)
+{
+    __asm("rep stosb",
+          "{al},{rcx},{rdi},~{rcx},~{rdi},~{memory}",
+          v, n, dest);
+}
+
+void memset16(void * dest, ushort v, size_t n)
+{
+    __asm("rep stosw",
+          "{ax},{rcx},{rdi},~{rcx},~{rdi},~{memory}",
+          v, n, dest);
+}
+
+void memset32(void * dest, uint v, size_t n)
+{
+    __asm("rep stosl",
+          "{eax},{rcx},{rdi},~{rcx},~{rdi},~{memory}",
+          v, n, dest);
+}
+
+void memset64(void * dest, ulong v, size_t n)
+{
+    __asm("rep stosq",
+          "{rax},{rcx},{rdi},~{rcx},~{rdi},~{memory}",
+          v, n, dest);
+}
+
+void memcpy(void * dest, const(void) * src, size_t n)
+{
+    __asm("rep movsb",
+          "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
+          n, src, dest);
+}
+
+void memcpy16(void * dest, const(void) * src, size_t n)
+{
+    __asm("rep movsw",
+          "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
+          n, src, dest);
+}
+
+void memcpy32(void * dest, const(void) * src, size_t n)
+{
+    __asm("rep movsl",
+          "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
+          n, src, dest);
+}
+
+void memcpy64(void * dest, const(void) * src, size_t n)
+{
+    __asm("rep movsq",
+          "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
+          n, src, dest);
+}

src/hulk/mtrr.d

@@ -0,0 +1,70 @@
+/**
+ * MTRR (Memory Type Range Register) support for HULK.
+ */
+module hulk.mtrr;
+
+import hulk.cpu;
+import hulk.klog;
+
+enum ulong MTRR_TYPE_UC = 0u; /* Uncacheable */
+enum ulong MTRR_TYPE_WC = 1u; /* Write-Combining */
+enum ulong MTRR_TYPE_WT = 4u; /* Writethrough */
+enum ulong MTRR_TYPE_WP = 5u; /* Write-Protect */
+enum ulong MTRR_TYPE_WB = 6u; /* Writeback */
+
+enum uint MSR_MTRRCAP = 0xFEu;
+enum uint MSR_MTRRDEFTYPE = 0x2FFu;
+enum uint MSR_MTRRPHYSBASE0 = 0x200u;
+enum uint MSR_MTRRPHYSMASK0 = 0x201u;
+
+enum ulong MTRRCAP_WC = 0x400u;
+enum ulong MTRRCAP_FIX = 0x100u;
+enum ulong MTRRCAP_VCNT_MASK = 0xFFu;
+
+enum ulong MTRRDEFTYPE_E = 0x800u;
+enum ulong MTRRDEFTYPE_FE = 0x400u;
+enum ulong MTRRDEFTYPE_TYPE_MASK = 0xFFu;
+
+enum ulong MTRRPHYSBASE_PHYSBASE_MASK = 0x000F_FFFF_FFFF_F000u;
+enum ulong MTRRPHYSBASE_TYPE_MASK = 0xFFu;
+
+enum ulong MTRRPHYSMASK_PHYSMASK_MASK = 0x000F_FFFF_FFFF_F000u;
+enum ulong MTRRPHYSMASK_VALID = 0x800u;
+
+struct Mtrr
+{
+    public static void initialize()
+    {
+        uint ebx;
+        uint ecx;
+        uint edx;
+        cpuid1(&ebx, &ecx, &edx);
+        if ((edx & CPUID_1_EDX_MTRR) == 0u)
+        {
+            Klog.writefln("CPU does not support MTRR");
+            return;
+        }
+        const(ulong) mtrrcap = rdmsr(MSR_MTRRCAP);
+        const(ulong) mtrrdeftype = rdmsr(MSR_MTRRDEFTYPE);
+    }
+
+    private static ulong get_phys_base(uint n)
+    {
+        return rdmsr(MSR_MTRRPHYSBASE0 + 2u * n);
+    }
+
+    private static void set_phys_base(uint n, ulong physbase)
+    {
+        wrmsr(MSR_MTRRPHYSBASE0 + 2u * n, physbase);
+    }
+
+    private static ulong get_phys_mask(uint n)
+    {
+        return rdmsr(MSR_MTRRPHYSMASK0 + 2u * n);
+    }
+
+    private static void set_phys_mask(uint n, ulong physmask)
+    {
+        wrmsr(MSR_MTRRPHYSMASK0 + 2u * n, physmask);
+    }
+}

src/hulk/pagetable.d

@@ -0,0 +1,194 @@
+/**
+ * Page table structures.
+ */
+module hulk.pagetable;
+
+/** Page table entry attributes. @{ */
+enum ulong PT_PRESENT = 0x1u;
+enum ulong PT_WRITABLE = 0x2u;
+enum ulong PT_USER = 0x4u;
+enum ulong PT_WRITE_THROUGH = 0x8u;
+enum ulong PT_DISABLE_CACHE = 0x10u;
+enum ulong PT_ACCESSED = 0x20u;
+enum ulong PT_DIRTY = 0x40u;
+enum ulong PT_PAT = 0x80u; /* Page table entry bit. */
+enum ulong PT_HUGE_PAGE = 0x80u; /* Page directory entry bit. */
+enum ulong PT_GLOBAL = 0x100u;
+enum ulong PT_NO_EXECUTE = 0x8000_0000_0000_0000u;
+/** @} */
+
+/** Page size in bytes. */
+enum ulong PAGE_SIZE = 4096u;
+
+/**
+ * Structure that represents a page table entry.
+ */
+struct PageTableEntry
+{
+    /** The raw page table entry is a 64-bit ulong. */
+    public ulong entry;
+    alias entry this;
+
+    /**
+     * Construct a page table entry.
+     *
+     * @param address
+     *   Address pointed to by the page table entry (ulong or pointer).
+     * @param flags
+     *   Page table flags (ORed set of PT_*).
+     */
+    this(T)(T address, ulong flags = 0u)
+    {
+        entry = cast(ulong)address | flags;
+    }
+
+    /**
+     * Return whether the page is present.
+     */
+    public @property bool present() const
+    {
+        return (entry & PT_PRESENT) != 0u;
+    }
+
+    /**
+     * Return whether the page is writable.
+     */
+    public @property bool writable() const
+    {
+        return (entry & PT_WRITABLE) != 0u;
+    }
+
+    /**
+     * Return whether the page is a user page.
+     */
+    public @property bool user() const
+    {
+        return (entry & PT_USER) != 0u;
+    }
+
+    /**
+     * Return whether the page is write-through.
+     */
+    public @property bool write_through() const
+    {
+        return (entry & PT_WRITE_THROUGH) != 0u;
+    }
+
+    /**
+     * Return whether the page has disable cache set.
+     */
+    public @property bool disable_cache() const
+    {
+        return (entry & PT_DISABLE_CACHE) != 0u;
+    }
+
+    /**
+     * Return whether the page is huge.
+     */
+    public @property bool huge() const
+    {
+        return (entry & PT_HUGE_PAGE) != 0u;
+    }
+
+    /**
+     * Return whether the page is global.
+     */
+    public @property bool global() const
+    {
+        return (entry & PT_GLOBAL) != 0u;
+    }
+
+    /**
+     * Return whether the page is no-execute.
+     */
+    public @property bool no_execute() const
+    {
+        return (entry & PT_NO_EXECUTE) != 0u;
+    }
+
+    /**
+     * Return whether the page is dirty.
+     */
+    public @property bool dirty() const
+    {
+        return (entry & PT_DIRTY) != 0u;
+    }
+
+    /**
+     * Return whether the page is accessed.
+     */
+    public @property bool accessed() const
+    {
+        return (entry & PT_ACCESSED) != 0u;
+    }
+
+    /**
+     * Follow the page table entry to the next page table it points to.
+     */
+    public PageTable * follow() const
+    {
+        return cast(PageTable *)(entry & 0x7FFF_FFFF_FFFF_F000u);
+    }
+}
+static assert(PageTableEntry.sizeof == 8u);
+
+/**
+ * Structure that represents a page table.
+ */
+struct PageTable
+{
+    /** Number of page table entries in a page table. */
+    enum size_t N_ENTRIES = 512u;
+
+    /** Page table entries. */
+    private PageTableEntry[N_ENTRIES] entries;
+
+    /**
+     * Access the PageTableEntry for the given address and page table level.
+     *
+     * @param address
+     *   Address to look up the page table entry (ulong or pointer).
+     * @param level
+     *   Page table level (0-4).
+     */
+    public PageTableEntry * entry(T)(T address, ulong level)
+    {
+        return &entries[index(cast(ulong)address, level)];
+    }
+
+    /**
+     * Determine the index into the page table for the given address and page
+     * table level.
+     *
+     * @param address
+     *   Address to look up the page table entry (ulong or pointer).
+     * @param level
+     *   Page table level (0-4).
+     */
+    public ulong index(T)(T address, ulong level)
+    {
+        return (cast(ulong)address >> (39u - (9u * level))) & 0x1FFu;
+    }
+
+    /**
+     * Access a page table entry by linear index.
+     *
+     * @param index
+     *   Page table index (0-511).
+     *
+     * @return PageTableEntry at the given index.
+     */
+    public PageTableEntry opIndex(size_t index)
+    {
+        return entries[index];
+    }
+}
+static assert(PageTable.sizeof == 4096u);
+
+/**
+ * Get the base address of the page containing the given address.
+ */
+T page_address(T)(T address)
+{
+    return cast(T)(cast(ulong)address & ~(PAGE_SIZE - 1u));
+}

src/hulk/pci.d

@@ -0,0 +1,452 @@
+/**
+ * PCI (Peripheral Component Interconnect) functionality.
+ */
+module hulk.pci;
+
+import hulk.cpu;
+import hulk.klog;
+import hulk.hurl;
+import hulk.hurl.a1;
+import hulk.range;
+import hulk.usb.xhci;
+import hulk.acpi;
+import hulk.list;
+
+struct Pci
+{
+    /** IO address for PCI configuration address. */
+    enum IO_ADDR_CONFIG_ADDRESS = 0xCF8u;
+
+    /** IO address for PCI configuration data. */
+    enum IO_ADDR_CONFIG_DATA = 0xCFCu;
+
+    /** Maximum number of devices on a bus. */
+    enum MAX_DEVICES_PER_BUS = 32;
+
+    /** Maximum number of functions on a devices. */
+    enum MAX_FUNCTIONS_PER_DEVICE = 8;
+
+    /** XHCI controller device type. */
+    enum XHCI_CONTROLLER = Type(0x0Cu, 0x03u, 0x30u);
+
+    /**
+     * MCFG ACPI table structure.
+     */
+    static struct MCFG
+    {
+        /* PCI Segment Group Memory Area Descriptor. */
+        static struct SGMADesc
+        {
+            uint[2] base_address_a;
+            ushort pci_segment_group_number;
+            ubyte start_pci_bus_number;
+            ubyte end_pci_bus_number;
+            uint _reserved;
+
+            public @property ulong base_address() const
+            {
+                return base_address_a[0] | (cast(ulong)base_address_a[1] << 32);
+            }
+        }
+        static assert(SGMADesc.sizeof == 16);
+        static assert(SGMADesc.alignof == 4);
+
+        Acpi.Header header;
+        uint[2] _reserved;
+        SGMADesc[0] sgma_descs;
+
+        size_t n_sgma_descs()
+        {
+            return (header.length - MCFG.sgma_descs.offsetof) / MCFG.SGMADesc.sizeof;
+        }
+    }
+
+    /**
+     * PCI device address (bus number, device number, function number).
+     */
+    struct Address
+    {
+        uint address;
+        alias address this;
+
+        this(ubyte bus_nr, ubyte device_nr, ubyte function_nr)
+        {
+            this.address = (bus_nr << 16u) | (device_nr << 8u) | function_nr;
+        }
+
+        /**
+         * Bus number (0-255).
+         */
+        public @property ubyte bus_nr() const
+        {
+            return cast(ubyte)(address >> 16u);
+        }
+
+        /**
+         * Device number (0-31).
+         */
+        public @property ubyte device_nr() const
+        {
+            return cast(ubyte)(address >> 8u);
+        }
+
+        /**
+         * Function number (0-7).
+         */
+        public @property ubyte function_nr() const
+        {
+            return cast(ubyte)address;
+        }
+    }
+
+    /**
+     * PCI device type (class ID, subclass ID, interface ID).
+     */
+    struct Type
+    {
+        uint type;
+        alias type this;
+
+        this(ubyte class_id, ubyte subclass_id, ubyte interface_id)
+        {
+            this.type = (class_id << 16u) | (subclass_id << 8u) | interface_id;
+        }
+
+        /**
+         * Class ID.
+         */
+        public @property ubyte class_id() const
+        {
+            return cast(ubyte)(type >> 16u);
+        }
+
+        /**
+         * Subclass ID.
+         */
+        public @property ubyte subclass_id() const
+        {
+            return cast(ubyte)(type >> 8u);
+        }
+
+        /**
+         * Interface ID.
+         */
+        public @property ubyte interface_id() const
+        {
+            return cast(ubyte)type;
+        }
+    }
+
+    /**
+     * PCI device object.
+     */
+    static struct Device
+    {
+        Configuration * config;
+        Address address;
+        Type type;
+        bool multifunction;
+        Range[6] memory_ranges;
+
+        mixin List!Device;
+
+        void initialize(Address address, Configuration * config)
+        {
+            list_init();
+            this.config = config;
+            this.address = address;
+            type = Type(config.class_id, config.subclass_id, config.interface_id);
+            Klog.writefln("Found PCI device %04x:%04x (%02x:%02x:%02x) at %02u:%02u.%u",
+                    config.vendor_id, config.device_id,
+                    type.class_id, type.subclass_id, type.interface_id,
+                    address.bus_nr, address.device_nr, address.function_nr);
+            multifunction = (address.function_nr == 0u) && ((config.header_type & 0x80u) != 0u);
+            ubyte header_type = config.header_type & 0x7Fu;
+
+            if (header_type == 0u)
+            {
+                map_memory_regions();
+            }
+        }
+
+        private void map_memory_regions()
+        {
+            size_t range_index;
+            uint[2] r;
+            uint[2] s;
+            for (uint bar_idx = 0u; bar_idx < config.header0.base_addresses.length; bar_idx++)
+            {
+                /* Read the BAR. */
+                r[0] = config.header0.base_addresses[bar_idx];
+                /* Skip zeroed BARs. */
+                if (r[0] == 0u)
+                {
+                    continue;
+                }
+                /* Skip I/O BARs. */
+                if ((r[0] & 1u) != 0u)
+                {
+                    continue;
+                }
+                bool is_64bit;
+                uint bar_type = (r[0] >> 1u) & 0x3u;
+                if (bar_type == 0u)
+                {
+                    /* 32-bit region. */
+                    r[1] = 0u;
+                }
+                else if ((bar_type == 2u) && (bar_idx < 5u))
+                {
+                    /* 64-bit region. */
+                    is_64bit = true;
+                    r[1] = config.header0.base_addresses[bar_idx + 1];
+                }
+                else
+                {
+                    continue;
+                }
+
+                /* Determine the region length. */
+                config.header0.base_addresses[bar_idx] = 0xFFFF_FFFFu;
+                s[0] = config.header0.base_addresses[bar_idx];
+                config.header0.base_addresses[bar_idx] = r[0];
+                if (is_64bit)
+                {
+                    config.header0.base_addresses[bar_idx + 1] = 0xFFFF_FFFFu;
+                    s[1] = config.header0.base_addresses[bar_idx + 1];
+                    config.header0.base_addresses[bar_idx + 1] = r[1];
+                }
+                else
+                {
+                    s[1] = 0xFFFF_FFFFu;
+                }
+                ulong mm_region_address = (cast(ulong)r[0] & 0xFFFF_FFF0u) | (cast(ulong)r[1] << 32u);
+                ulong length = ~((cast(ulong)s[0] & 0xFFFF_FFF0u) | (cast(ulong)s[1] << 32u)) + 1u;
+                ulong flags = (r[0] & 0x8) != 0u ? PT_WRITE_THROUGH : 0u;
+                Hurl.identity_map_range(mm_region_address, length, PT_WRITABLE | flags);
+                memory_ranges[range_index].address = mm_region_address;
+                memory_ranges[range_index].length = length;
+                range_index++;
+                if (is_64bit)
+                {
+                    bar_idx++;
+                }
+            }
+        }
+    }
+
+    /**
+     * Device list.
+     */
+    public static __gshared Device * devices;
+
+    private static uint read_config_register(Address address, uint register_id)
+    {
+        uint cfg_addr = 0x8000_0000u |
+            (address.bus_nr << 16u) |
+            (address.device_nr << 11u) |
+            (address.function_nr << 8u) |
+            (register_id << 2u);
+        out32(IO_ADDR_CONFIG_ADDRESS, cfg_addr);
+        return in32(IO_ADDR_CONFIG_DATA);
+    }
+
+    private static void write_config_register(Address address, uint register_id, uint value)
+    {
+        uint cfg_addr = 0x8000_0000u |
+            (address.bus_nr << 16u) |
+            (address.device_nr << 11u) |
+            (address.function_nr << 8u) |
+            (register_id << 2u);
+        out32(IO_ADDR_CONFIG_ADDRESS, cfg_addr);
+        out32(IO_ADDR_CONFIG_DATA, value);
+    }
+
+    static struct Configuration
+    {
+        static struct HeaderType0
+        {
+            ushort vendor_id;
+            ushort device_id;
+            ushort command;
+            ushort status;
+            ubyte revision_id;
+            ubyte interface_id;
+            ubyte subclass_id;
+            ubyte class_id;
+            ubyte cache_line_size;
+            ubyte latency_timer;
+            ubyte header_type;
+            ubyte bist;
+
+            uint[6] base_addresses;
+            uint cardbus_cis_pointer;
+            ushort subsystem_vendor_id;
+            ushort subsystem_id;
+            uint expansion_rom_base_address;
+            ubyte capabilities_pointer;
+            ubyte[7] _reserved;
+            ubyte interrupt_line;
+            ubyte interrupt_pin;
+            ubyte min_grant;
+            ubyte max_latency;
+        }
+
+        /**
+         * PCI configuration format for header type 1 (PCI-to-PCI bridge).
+         */
+        static struct HeaderType1
+        {
+            ushort vendor_id;
+            ushort device_id;
+            ushort command;
+            ushort status;
+            ubyte revision_id;
+            ubyte interface_id;
+            ubyte subclass_id;
+            ubyte class_id;
+            ubyte cache_line_size;
+            ubyte latency_timer;
+            ubyte header_type;
+            ubyte bist;
+
+            uint[2] base_addresses;
+            ubyte primary_bus_nr;
+            ubyte secondary_bus_nr;
+            ubyte subordinate_bus_nr;
+            ubyte secondary_latency_timer;
+            ubyte io_base;
+            ubyte io_limit;
+            ushort secondary_status;
+            ushort memory_base;
+            ushort memory_limit;
+            ushort prefetchable_memory_base;
+            ushort prefetchable_memory_limit;
+            uint prefetchable_base_high;
+            uint prefetchable_limit_high;
+            ushort io_base_high;
+            ushort io_limit_high;
+            ubyte capability_pointer;
+            ubyte[3] _reserved;
+            uint expansion_rom_base_address;
+            ubyte interrupt_line;
+            ubyte interrupt_pin;
+            ushort bridge_control;
+        }
+
+        /**
+         * PCI configuration format for header type 2 (PCI-to-CardBus bridge).
+         */
+        static struct HeaderType2
+        {
+            ushort vendor_id;
+            ushort device_id;
+            ushort command;
+            ushort status;
+            ubyte revision_id;
+            ubyte interface_id;
+            ubyte subclass_id;
+            ubyte class_id;
+            ubyte cache_line_size;
+            ubyte latency_timer;
+            ubyte header_type;
+            ubyte bist;
+
+            uint cardbus_base_address;
+            ubyte capability_list_offset;
+            ubyte _reserved;
+            ushort secondary_status;
+            ubyte pci_bus_nr;
+            ubyte cardbus_bus_nr;
+            ubyte subordinate_bus_nr;
+            ubyte cardbus_latency_timer;
+            uint base_address_0;
+            uint memory_limit_0;
+            uint base_address_1;
+            uint memory_limit_1;
+            uint io_base_address_0;
+            uint io_limit_0;
+            uint io_base_address_1;
+            uint io_limit_1;
+            ubyte interrupt_line;
+            ubyte interrupt_pin;
+            ushort bridge_control;
+            ushort subsystem_device_id;
+            ushort subsystem_vendor_id;
+            uint legacy_base_address;
+        }
+
+        union
+        {
+            struct
+            {
+                ushort vendor_id;
+                ushort device_id;
+                ushort command;
+                ushort status;
+                ubyte revision_id;
+                ubyte interface_id;
+                ubyte subclass_id;
+                ubyte class_id;
+                ubyte cache_line_size;
+                ubyte latency_timer;
+                ubyte header_type;
+                ubyte bist;
+            }
+            HeaderType0 header0;
+            HeaderType1 header1;
+            HeaderType2 header2;
+        }
+    }
+
+    private static void scan(ubyte bus_nr, ubyte device_nr, ubyte function_nr, ulong config_address)
+    {
+        Configuration * config = cast(Configuration *)config_address;
+        if (config.vendor_id != 0xFFFFu)
+        {
+            Device * device = A1.allocate!Device();
+            if (devices == null)
+            {
+                devices = device;
+            }
+            else
+            {
+                device.list_insert_before(devices);
+            }
+            device.initialize(Address(bus_nr, device_nr, function_nr), config);
+            if (device.multifunction)
+            {
+                for (function_nr = 1u; function_nr < MAX_FUNCTIONS_PER_DEVICE; function_nr++)
+                {
+                    config_address += PAGE_SIZE;
+                    scan(bus_nr, device_nr, function_nr, config_address);
+                }
+            }
+        }
+    }
+
+    public static void initialize()
+    {
+        Klog.writefln("\a3Initializing PCI");
+        MCFG * mcfg = cast(MCFG *)Acpi.get_table("MCFG");
+        size_t n_sgma_descs = mcfg.n_sgma_descs;
+        for (size_t i = 0u; i < n_sgma_descs; i++)
+        {
+            MCFG.SGMADesc * sgma_desc = &mcfg.sgma_descs[i];
+            ulong base_address = sgma_desc.base_address;
+            uint start_pci_bus = sgma_desc.start_pci_bus_number;
+            uint end_pci_bus = sgma_desc.end_pci_bus_number;
+            ulong n_buses = (end_pci_bus - start_pci_bus) + 1u;
+            ulong map_length = PAGE_SIZE * MAX_FUNCTIONS_PER_DEVICE * MAX_DEVICES_PER_BUS * n_buses;
+            Hurl.identity_map_range(base_address, map_length, PT_WRITABLE | PT_DISABLE_CACHE | PT_NO_EXECUTE);
+            for (uint bus_nr = start_pci_bus; bus_nr <= end_pci_bus; bus_nr++)
+            {
+                for (ubyte device_nr = 0u; device_nr < MAX_DEVICES_PER_BUS; device_nr++)
+                {
+                    ulong device_address = base_address + ((bus_nr - start_pci_bus) * (MAX_DEVICES_PER_BUS * MAX_FUNCTIONS_PER_DEVICE) + device_nr * MAX_FUNCTIONS_PER_DEVICE) * PAGE_SIZE;
+                    scan(cast(ubyte)bus_nr, device_nr, 0u, device_address);
+                }
+            }
+        }
+    }
+}

src/hulk/pic.d

@@ -0,0 +1,16 @@
+/**
+ * PIC (Programmable Interrupt Controller) functionality.
+ */
+module hulk.pic;
+
+import hulk.cpu;
+
+struct Pic
+{
+    public static void initialize()
+    {
+        /* Disable the PIC. */
+        out8(0xA1u, 0xFFu);
+        out8(0x21u, 0xFFu);
+    }
+}

src/hulk/pit.d

@@ -0,0 +1,45 @@
+/**
+ * PIT (Programmable Interval Timer) functionality.
+ */
+module hulk.pit;
+
+import hulk.cpu;
+import hulk.klog;
+import hulk.console;
+import hulk.time;
+
+struct Pit
+{
+    /** PIT input frequency in 1/1000 Hz. */
+    private enum ulong PIT_FREQUENCY_1000HZ = 1_193_181_667u;
+    private enum ulong TARGET_INTERRUPT_HZ = 1000u;
+    private enum ulong TARGET_INTERRUPT_1000HZ = TARGET_INTERRUPT_HZ * 1000u;
+    private enum ulong PIT_DIVIDER = (PIT_FREQUENCY_1000HZ + TARGET_INTERRUPT_1000HZ / 2u) / TARGET_INTERRUPT_1000HZ;
+
+    /** PIT channel 0 I/O port. */
+    private enum ubyte PORT_CH_0 = 0x40u;
+    /** PIT channel 1 I/O port. */
+    private enum ubyte PORT_CH_1 = 0x41u;
+    /** PIT channel 2 I/O port. */
+    private enum ubyte PORT_CH_2 = 0x42u;
+    /** PIT mode/command register I/O port. */
+    private enum ubyte PORT_MC = 0x43u;
+
+    private enum ubyte MC_CH_0 = 0x00u;
+    private enum ubyte MC_LO_HI = 0x30u;
+    private enum ubyte MC_RATE_GENERATOR = 0x04u;
+    private enum ubyte MC_BINARY = 0x00u;
+
+    public static void initialize()
+    {
+        Klog.writefln("\a3Initializing PIT");
+        out8(PORT_MC, MC_CH_0 | MC_LO_HI | MC_RATE_GENERATOR | MC_BINARY);
+        out8(PORT_CH_0, PIT_DIVIDER & 0xFFu);
+        out8(PORT_CH_0, PIT_DIVIDER >> 8u);
+    }
+
+    public static void isr()
+    {
+        Time.ms_isr();
+    }
+}

src/hulk/range.d

@@ -0,0 +1,27 @@
+module hulk.range;
+
+/**
+ * Representation of a memory range.
+ */
+struct Range
+{
+    /** Range base address. */
+    void * _address;
+
+    /** Range length. */
+    size_t length;
+
+    /** Set the range address. */
+    @property void * address(T)(T a)
+    {
+        static assert(T.sizeof == size_t.sizeof);
+        _address = cast(void *)a;
+        return _address;
+    }
+
+    /** Get the range address. */
+    @property void * address()
+    {
+        return _address;
+    }
+}

src/hulk/rtc.d

@@ -0,0 +1,150 @@
+/**
+ * RTC (Real-Time Clock) functionality.
+ */
+module hulk.rtc;
+
+import hulk.cpu;
+import hulk.klog;
+import hulk.console;
+
+struct Rtc
+{
+    private enum ubyte PORT_SELECT = 0x70u;
+    private enum ubyte PORT_DATA = 0x71u;
+
+    private enum ubyte DISABLE_NMI = 0x80u;
+
+    private enum ubyte REG_RTC_SECONDS = 0x0u;
+    private enum ubyte REG_RTC_MINUTES = 0x2u;
+    private enum ubyte REG_RTC_HOURS = 0x4u;
+    private enum ubyte REG_RTC_DAY = 0x7u;
+    private enum ubyte REG_RTC_MONTH = 0x8u;
+    private enum ubyte REG_RTC_YEAR = 0x9u;
+    private enum ubyte REG_SR_A = 0xAu;
+    private enum ubyte REG_SR_B = 0xBu;
+    private enum ubyte REG_SR_C = 0xCu;
+
+    private enum ubyte SR_A_RTC_UPDATE_IN_PROGRESS = 0x80u;
+    private enum ubyte SR_B_24HOUR = 0x02u;
+    private enum ubyte SR_B_BINARY = 0x04u;
+    private enum ubyte SR_B_ENABLE_IRQ = 0x40u;
+
+    private static __gshared bool rtc_24hour_mode;
+    private static __gshared bool rtc_binary_mode;
+
+    static struct time
+    {
+        public ubyte year;
+        public ubyte month;
+        public ubyte day;
+        public ubyte hour;
+        public ubyte minute;
+        public ubyte second;
+    }
+
+    public static void initialize()
+    {
+        Klog.writefln("\a3Initializing RTC");
+
+        /* Enable IRQ 8 to receive RTC interrupts. */
+        ubyte sr_b = read_register(REG_SR_B, true);
+        write_register(REG_SR_B, sr_b | SR_B_ENABLE_IRQ, true);
+
+        /* Record RTC mode flags from status register B. */
+        rtc_24hour_mode = (sr_b & SR_B_24HOUR) != 0u;
+        rtc_binary_mode = (sr_b & SR_B_BINARY) != 0u;
+
+        /* Send EOI to enable more RTC interrupts and re-enable NMIs. */
+        eoi();
+
+        time t = Rtc.read_rtc_time();
+        Klog.writefln("System time is 20%02u-%02u-%02u %02u:%02u:%02u",
+                t.year, t.month, t.day, t.hour, t.minute, t.second);
+    }
+
+    private static ubyte read_register(ubyte register, bool disable_nmi = false)
+    {
+        out8(PORT_SELECT, register | (disable_nmi ? DISABLE_NMI : 0u));
+        return in8(PORT_DATA);
+    }
+
+    private static void write_register(ubyte register, ubyte value, bool disable_nmi = false)
+    {
+        out8(PORT_SELECT, register | (disable_nmi ? DISABLE_NMI : 0u));
+        out8(PORT_DATA, value);
+    }
+
+    private static void eoi()
+    {
+        /* Read from status register C to clear the interrupt. */
+        read_register(REG_SR_C);
+    }
+
+    public static void isr()
+    {
+        static __gshared ulong count;
+        count++;
+        if ((count % 1024) == 0u)
+        {
+            Console.update_header();
+        }
+        eoi();
+    }
+
+    public static time read_rtc_time()
+    {
+        time[2] times;
+        size_t reads;
+        do
+        {
+            times[reads & 1] = read_rtc_time_unsafe();
+            reads++;
+        } while ((reads < 2u) || (times[0] != times[1]));
+        return times[0];
+    }
+
+    private static time read_rtc_time_unsafe()
+    {
+        time t;
+        while ((read_register(REG_SR_A) & SR_A_RTC_UPDATE_IN_PROGRESS) != 0u)
+        {
+        }
+        t.year = read_rtc_time_register(REG_RTC_YEAR);
+        t.month = read_rtc_time_register(REG_RTC_MONTH);
+        t.day = read_rtc_time_register(REG_RTC_DAY);
+        t.minute = read_rtc_time_register(REG_RTC_MINUTES);
+        t.second = read_rtc_time_register(REG_RTC_SECONDS);
+        /* Hour field is treated differently because it might have 'PM' flag
+         * in highest bit if we're in 24-hour mode. */
+        ubyte hour = read_register(REG_RTC_HOURS);
+        ubyte pm = hour >> 7u;
+        hour &= 0x7Fu;
+        if (!rtc_binary_mode)
+        {
+            /* Hour is in BCD format; convert to binary. */
+            hour = bcd_to_binary(hour);
+        }
+        if (!rtc_24hour_mode)
+        {
+            /* Hour is in 12-hour format; convert to 24-hour format. */
+            hour = cast(ubyte)((hour % 12u) + pm * 12u);
+        }
+        t.hour = hour;
+        return t;
+    }
+
+    private static ubyte read_rtc_time_register(ubyte register)
+    {
+        ubyte value = read_register(register);
+        if (!rtc_binary_mode)
+        {
+            value = bcd_to_binary(value);
+        }
+        return value;
+    }
+
+    private static ubyte bcd_to_binary(ubyte bcd)
+    {
+        return (bcd & 0xFu) + ((bcd & 0xF0u) >> 4u) * 10u;
+    }
+}

src/hulk/serial.d

@@ -0,0 +1,74 @@
+/**
+ * Serial port access.
+ */
+module hulk.serial;
+
+import hulk.cpu;
+import core.stdc.stdarg;
+static import hulk.writef;
+
+struct Serial
+{
+    enum BASE_PORT = 0x3F8;
+
+    /**
+     * Initialize the serial module.
+     */
+    static void initialize()
+    {
+    }
+
+    /**
+     * Write a character to the serial port.
+     *
+     * @param ch Character to write.
+     */
+    static void write(ubyte ch)
+    {
+        if (ch == '\n')
+        {
+            out8(BASE_PORT, '\r');
+        }
+        out8(BASE_PORT, ch);
+    }
+
+    /**
+     * Write a formatted string to the serial port.
+     *
+     * @param s Format string.
+     * @param args Variable arguments structure.
+     */
+    public static void writef(string s, va_list args)
+    {
+        hulk.writef.writefv(function void(ubyte ch) {
+                    Serial.write(ch);
+                }, s, args);
+    }
+
+    /**
+     * Write a formatted string to the serial port.
+     *
+     * @param s Format string.
+     */
+    public static extern (C) void writef(string s, ...)
+    {
+        va_list args;
+        va_start(args, s);
+        writef(s, args);
+        va_end(args);
+    }
+
+    /**
+     * Write a formatted string and newline to the serial port.
+     *
+     * @param s Format string.
+     */
+    public static extern (C) void writefln(string s, ...)
+    {
+        va_list args;
+        va_start(args, s);
+        writef(s, args);
+        writef("\n", args);
+        va_end(args);
+    }
+}

src/hulk/test.d

@@ -0,0 +1,139 @@
+/**
+ * Kernel tests.
+ */
+module hulk.test;
+
+import hulk.klog;
+import hulk.list;
+import hulk.time;
+import hulk.hurl.a1;
+import core.volatile;
+
+struct Test
+{
+    /**
+     * Run tests.
+     */
+    public static void run()
+    {
+        Klog.writefln("\a3Running kernel tests");
+        test_pit();
+        test_list();
+        Klog.writefln("\a3Kernel tests complete");
+    }
+
+    private static void test_pit()
+    {
+        Klog.writefln("Testing PIT...");
+        /* Check that PIT millisecond interrupt is firing. */
+        size_t uptime = Time.uptime();
+        while (Time.uptime() <= uptime)
+        {
+        }
+    }
+
+    private static void test_list()
+    {
+        Klog.writefln("Testing list...");
+
+        struct S
+        {
+            size_t v;
+            mixin List!S;
+            void initialize()
+            {
+                list_init();
+            }
+        }
+
+        S * s1 = A1.allocate!S();
+        s1.initialize();
+        s1.v = 33;
+        assert_eq(1, s1.list_count);
+        S * s2 = A1.allocate!S();
+        s2.initialize();
+        s2.v = 42;
+        s2.list_insert_after(s1);
+        S * s3 = A1.allocate!S();
+        s3.initialize();
+        s3.v = 55;
+        s3.list_insert_before(s1);
+        size_t count;
+        assert_eq(3, s1.list_count);
+        assert_eq(3, s2.list_count);
+        assert_eq(3, s3.list_count);
+        foreach (entry; *s1)
+        {
+            switch (count)
+            {
+            case 0:
+                assert_eq(33, entry.v);
+                break;
+            case 1:
+                assert_eq(42, entry.v);
+                break;
+            case 2:
+                assert_eq(55, entry.v);
+                break;
+            case 3:
+                assert_eq(0, 1);
+                break;
+            default:
+                break;
+            }
+            count++;
+        }
+        foreach (entry; *s3)
+        {
+            if (entry.v == 33)
+            {
+                entry.list_remove();
+            }
+        }
+        assert_eq(2, s3.list_count);
+        count = 0;
+        foreach (entry; *s3)
+        {
+            switch (count)
+            {
+            case 0:
+                assert_eq(55, entry.v);
+                break;
+            case 1:
+                assert_eq(42, entry.v);
+                break;
+            case 2:
+                assert_eq(0, 1);
+                break;
+            default:
+                break;
+            }
+            count++;
+        }
+        foreach (entry; *s2)
+        {
+            if (entry.v == 42)
+            {
+                entry.list_remove();
+            }
+        }
+        assert_eq(1, s2.list_count);
+        assert_eq(1, s3.list_count);
+    }
+
+    private static void assert_eq(T)(T first, T second, size_t line_number = __LINE__)
+    {
+        if (first != second)
+        {
+            Klog.fatal_error("Assertion failed! %x != %x (line %u)", first, second, line_number);
+        }
+    }
+
+    private static void assert_neq(T)(T first, T second, size_t line_number = __LINE__)
+    {
+        if (first == second)
+        {
+            Klog.fatal_error("Assertion failed! %x == %x (line %u)", first, second, line_number);
+        }
+    }
+}

src/hulk/thread.d

@@ -0,0 +1,143 @@
+/**
+ * Kernel thread functionality.
+ */
+module hulk.thread;
+
+import hulk.hurl.a1;
+import hulk.him;
+import hulk.gdt;
+import hulk.memory;
+import hulk.list;
+import hulk.cpu;
+import hulk.hurl;
+import ldc.llvmasm;
+
+struct Thread
+{
+    /* TODO: currently kernel thread stack size is fixed. */
+    enum STACK_SIZE = 16 * 1024;
+
+    enum ulong INT_TCTRL_YIELD = 0;
+
+    /** Interrupt stack template. */
+    static immutable __gshared ulong[ISF_COUNT] interrupt_stack_template = [
+        0x16161616_16161616u, /* RBP */
+        0x15151515_15151515u, /* R15 */
+        0x14141414_14141414u, /* R14 */
+        0x13131313_13131313u, /* R13 */
+        0x12121212_12121212u, /* R12 */
+        0x11111111_11111111u, /* R11 */
+        0x10101010_10101010u, /* R10 */
+        0x09090909_09090909u, /* R9 */
+        0x08080808_08080808u, /* R8 */
+        0x06060606_06060606u, /* RDI */
+        0x05050505_05050505u, /* RSI */
+        0x04040404_04040404u, /* RDX */
+        0x03030303_03030303u, /* RCX */
+        0x02020202_02020202u, /* RBX */
+        0x01010101_01010101u, /* RAX */
+        0u, /* Error Code */
+        0u, /* RIP */
+        Gdt.SELECTOR_KERNEL_CODE, /* CS */
+        0u, /* RFLAGS */
+        0u, /* RSP */
+        Gdt.SELECTOR_KERNEL_DATA, /* SS */
+    ];
+
+    /** List of all runnable kernel threads. */
+    private static __gshared Thread * runnable_threads;
+
+    /** Currently executing kernel thread. */
+    static __gshared Thread * current_thread;
+
+    /** Current kernel thread stack pointer. */
+    ulong * stack_pointer;
+    static assert(stack_pointer.offsetof == 0);
+
+    /** Base address of kernel thread stack. */
+    void * stack_addr;
+
+    mixin List!Thread;
+
+    /**
+     * Initialize a kernel thread.
+     */
+    public void initialize(void function() fn)
+    {
+        list_init();
+        suspend_interrupts();
+        list_insert_after(current_thread);
+        resume_interrupts();
+        stack_addr = A1.allocate(STACK_SIZE);
+        ulong * stack_top = cast(ulong *)(stack_addr + STACK_SIZE);
+        stack_pointer = stack_top - ISF_COUNT;
+        memcpy64(stack_pointer, &interrupt_stack_template[0], ISF_COUNT);
+        stack_pointer[ISF_RIP] = cast(ulong)fn;
+        stack_pointer[ISF_RFLAGS] = read_rflags();
+        stack_pointer[ISF_RSP] = cast(ulong)stack_top;
+    }
+
+    /**
+     * Initialize first kernel thread.
+     */
+    public void initialize_first_thread()
+    {
+        list_init();
+        runnable_threads = &this;
+        stack_addr = cast(void *)(Hurl.HULK_STACK_TOP - STACK_SIZE);
+    }
+
+    /**
+     * Initialize kernel threading.
+     */
+    public static void initialize()
+    {
+        Thread * thread = A1.allocate!Thread();
+        thread.initialize_first_thread();
+        current_thread = thread;
+    }
+
+    /**
+     * Create and start a kernel thread.
+     *
+     * TODO: fn must not return.
+     * TODO: threads are always runnable.
+     * TODO: threads cannot be destroyed.
+     */
+    public static Thread * start(void function() fn)
+    {
+        Thread * thread = A1.allocate!Thread();
+        thread.initialize(fn);
+        swint(INT_TCTRL_YIELD);
+        return thread;
+    }
+
+    /**
+     * Trigger a thread management software interrupt.
+     */
+    public static void swint(T1)(T1 v1)
+    {
+        mixin(`__asm("int $$`, cast(int)INT_KERNEL_SWINT, `", "{rax}", v1);`);
+    }
+
+    /**
+     * Handle a thread management software interrupt.
+     *
+     * This function is called in interrupt context.
+     *
+     * @param stack_frame
+     *   Pointer to the stack frame.
+     */
+    public static void handle_swint(ulong * stack_frame)
+    {
+        switch (stack_frame[ISF_RAX])
+        {
+        case INT_TCTRL_YIELD:
+            Thread.current_thread = Thread.current_thread.list_next;
+            break;
+
+        default:
+            break;
+        }
+    }
+}

src/hulk/time.d

@@ -0,0 +1,42 @@
+/**
+ * Time functionality.
+ */
+module hulk.time;
+
+import hulk.volatile;
+
+struct Time
+{
+    /** System uptime (ms). */
+    private static __gshared Volatile!ulong s_uptime;
+
+    /**
+     * Millisecond ISR.
+     */
+    public static void ms_isr()
+    {
+        s_uptime++;
+    }
+
+    /**
+     * Get system uptime (ms).
+     */
+    public static @property ulong uptime()
+    {
+        return s_uptime;
+    }
+
+    /**
+     * Sleep for the given amount of time (ms).
+     *
+     * @param count
+     *   Number of milliseconds to sleep for.
+     */
+    public static void msleep(ulong count)
+    {
+        ulong wait_for = uptime() + count + 1;
+        while (uptime() < wait_for)
+        {
+        }
+    }
+}

src/hulk/usb/package.d

@@ -0,0 +1,3 @@
+module hulk.usb;
+
+public import hulk.usb.usb;

src/hulk/usb/usb.d

@@ -0,0 +1,24 @@
+/**
+ * USB (Universal Serial Bus) functionality.
+ */
+module hulk.usb.usb;
+
+import hulk.klog;
+import hulk.usb.xhci;
+import hulk.pci;
+
+struct Usb
+{
+    public static void initialize()
+    {
+        Klog.writefln("\a3Initializing USB");
+
+        foreach (pci_device; *Pci.devices)
+        {
+            if (pci_device.type == Pci.XHCI_CONTROLLER)
+            {
+                XHCI.build(pci_device);
+            }
+        }
+    }
+}

src/hulk/usb/xhci.d

@@ -0,0 +1,535 @@
+/**
+ * eXtensible Host Controller Interface for Universal Serial Bus
+ *
+ * Documentation:
+ * - https://wiki.osdev.org/EXtensible_Host_Controller_Interface
+ * - https://www.intel.com/content/dam/www/public/us/en/documents/technical-specifications/extensible-host-controler-interface-usb-xhci.pdf
+ */
+
+module hulk.usb.xhci;
+
+import hulk.pci;
+import hulk.hurl;
+import hulk.hurl.a1;
+import hulk.hippo;
+import hulk.klog;
+import hulk.time;
+import hulk.volatile;
+
+struct XHCI
+{
+    /**
+     * Located at PCI base address.
+     *
+     * All are read-only.
+     */
+    struct CapabilityRegisters
+    {
+        /**
+         * Offset from beginning of capability registers to beginning of
+         * operational registers.
+         */
+        Volatile!ubyte capability_length;
+
+        ubyte _reserved01;
+
+        /**
+         * Interface version number supported (psuedo-BSD).
+         */
+        Volatile!ushort hci_version;
+
+        /**
+         * HCSPARAMS1.
+         * 7:0 number of device slots (MaxSlots)
+         * 18:8 number of interrupters (MaxIntrs)
+         * 23:19 reserved
+         * 31:24 number of ports (MaxPorts)
+         */
+        Volatile!uint hcs_params1;
+
+        @property ubyte max_slots()
+        {
+            return this.hcs_params1 & 0xFFu;
+        }
+
+        /**
+         * 3:0 isochronous scheduling threshold (IST)
+         * 7:4 event ring segment table max (ERST Max)
+         * 20:8 reserved
+         * 25:21 max scratchpad buffers (high 5 bits; xHCI v1.1+)
+         * 26 scratchpad restore (SPR)
+         * 31:27 max scratchpad buffers (low 5 bits)
+         */
+        Volatile!uint hcs_params2;
+
+        @property size_t max_scratchpad_buffers()
+        {
+            uint v = this.hcs_params2;
+            return (v >> 27u) | ((v >> (21 - 5)) & 0x3E0u);
+        }
+
+        /**
+         * 7:0 U1 device exit latency
+         * 15:8 reserved
+         * 31:16 U2 device exit latency
+         */
+        Volatile!uint hcs_params3;
+
+        /**
+         * 0 64-bit addressing capability (AC64)
+         * 1 BW negotiation capability (BNC)
+         * 2 context size (CSZ)
+         * 3 port power control (PPC)
+         * 4 port indicators (PIND)
+         * 5 light HC reset capability (LHRC)
+         * 6 latency tolerance messaging capability (LTC)
+         * 7 no secondary SID support (NSS)
+         * 8 parse all event data (PAE; xHCI v1.1+)
+         * 9 stopped - short packet capability (SPC; xHCI v1.1+)
+         * 10 stopped EDTLA capability (SEC; xHCI v1.1+)
+         * 11 continuous frame ID capability (CFC; xHCI v1.1+)
+         * 15:12 maximum primary stream array size (MaxPSASize)
+         * 31:16 xHCI extended capabilities pointer (xECP)
+         *   offset in 32-bit words from base of capability registers to base
+         *   of capabilities list
+         */
+        Volatile!uint hcc_params1;
+
+        /**
+         * 1:0 reserved
+         * 31:2 doorbell array offset in 32-bit words
+         *   offset in 32-bit words from base of capability registers to the
+         *   doorbell array
+         */
+        Volatile!uint doorbell_offset;
+
+        /**
+         * 4:0 reserved
+         * 31:5 runtime register space offset
+         */
+        Volatile!uint rts_offset;
+
+        /**
+         * 0 U3 entry capability (U3C)
+         * 1 ConfigEP command max exit latency too large (CMC)
+         * 2 force save context capability (FSC)
+         * 3 compliance transition capability (CTC)
+         * 4 large ESIT payload capability (LEC)
+         * 5 configuration information capability (CIC)
+         * 6 extended TBC capability (ETC)
+         * 7 extended TBC TRB status capability (ETC_TSC)
+         * 8 get/set extended property capability (GSC; xHCI v1.1+)
+         * 9 virtualization based trusted I/O capability (VTC; xHCI v1.2+)
+         * 31:10 reserved
+         */
+        Volatile!uint hcc_params2;
+
+        /**
+         * 11:0 reserved
+         * 31:12 VTIO register space offset (xHCI v1.2+)
+         */
+        Volatile!uint vtios_offset;
+    }
+    static assert(CapabilityRegisters.sizeof == 0x24u);
+
+    /**
+     * Located at offset capability_length from PCI base address.
+     */
+    struct OperationalRegisters
+    {
+        /**
+         * 0 run/stop (RS)
+         * 1 host controller reset (HCRST)
+         * 2 interrupter enable (INTE)
+         * 3 host system error enable (HSEE)
+         * 6:4 reserved
+         * 7 light host controller reset (LHCRST)
+         * 8 controller save state (CSS)
+         * 9 controller restore state (CRS)
+         * 10 enable wrap event (EWE)
+         * 11 enable U3 MFINDEX stop (UE3S)
+         * 12 stopped short packet enable (SPE; xHCI v1.1+)
+         * 13 CEM enable (CME; xHCI v1.1+)
+         * 14 extended TBC enable (ETE; xHCI v1.2+)
+         * 15 extended TBC TRB status enable (TSC_EN; xHCI v1.2+)
+         * 16 VTIO enable (VTIOE; xHCI v1.2+)
+         * 31:17 reserved
+         */
+        Volatile!uint usb_command;
+
+        /**
+         * 0 HCHalted
+         * 1 reserved
+         * 2 Host System Error (HSE)
+         * 3 Event Interrupt (EINT)
+         * 4 Port Change Detected (PCD)
+         * 7:5 reserved
+         * 8 Save State Status (SSS)
+         * 9 Restore State Status (RSS)
+         * 10 Save/Restore Error (SRE)
+         * 11 Controller Not Ready (CNR)
+         * 12 Host Controller Error (HCE)
+         * 31:13 reserved
+         */
+        Volatile!uint usb_status;
+
+        /**
+         * 15:0 Page Size (actual page size is 2^(x+12))
+         * 31:16 reserved
+         */
+        Volatile!uint page_size;
+
+        uint[2] _reserved01;
+
+        /**
+         * 15:0 Notification Enable
+         * 31:16 reserved
+         */
+        Volatile!uint dn_ctrl;
+
+        /**
+         * 0 Ring Cycle State (RCS)
+         * 1 Command Stop (CS)
+         * 2 Command Abort (CA)
+         * 3 Command Ring Running (CRR)
+         * 5:4 reserved
+         * 63:6 Command Ring Pointer
+         */
+        Volatile!ulong cr_ctrl;
+
+        uint[4] _reserved02;
+
+        /**
+         * 5:0 reserved
+         * 63:6 Device Context Base Address Array Pointer
+         */
+        Volatile!ulong dcbaap;
+
+        /**
+         * 7:0 Max Device Slots Enabled (MaxSlotsEn)
+         * 8 U3 Entry Enable (U3E; xHCI v1.1+)
+         * 9 Configuration Information Enable (CIE; xHCI v1.1+)
+         * 31:10 reserved
+         */
+        Volatile!uint config;
+
+        uint _reserved03;
+    }
+    static assert(OperationalRegisters.sizeof == 0x40u);
+
+    /**
+     * Located at offset 0x400 from start of Operational Registers.
+     *
+     * There is one set of these registers for each port of the root hub.
+     */
+    struct PortRegisters
+    {
+        /**
+         * Port Status and Control
+         *
+         * 0 Current Connect Status
+         * 1 Port Enabled/Disabled
+         * 2 reserved
+         * 3 Over-current active
+         * 4 Port Reset
+         * 8:5 Port Link State
+         * 9 Port Power
+         * 13:10 Port Speed
+         * 15:14 Port Indicator Control
+         * 16 Port Link State Write Strobe
+         * 17 Connect Status Change
+         * 18 Port Enable/Disable Change
+         * 19 Warm Port Reset Change
+         * 20 Over-current Change
+         * 21 Port Reset Change
+         * 22 Port Link State Change
+         * 23 Port Config Error Change
+         * 24 Cold Attach Status
+         * 25 Wake on Connect Enable
+         * 26 Wake on Disconnect Enable
+         * 27 Wake on Over-current Enable
+         * 29:28 reserved
+         * 30 Device Removable
+         * 31 Warm Port Reset
+         */
+        Volatile!uint portsc;
+
+        /**
+         * Port Power Management Status and Control
+         */
+        Volatile!uint portpmsc;
+
+        /**
+         * Port Link Info
+         */
+        Volatile!uint portli;
+
+        /**
+         * Port Hardware LPM Control (xHCI v1.1+)
+         */
+        Volatile!uint porthlpmc;
+    }
+    static assert(PortRegisters.sizeof == 0x10u);
+
+    /**
+     * Located at offset rts_offset from PCI base address.
+     */
+    struct RuntimeRegisters
+    {
+        /**
+         * Microframe index. Incremented by controller each microframe.
+         */
+        Volatile!uint mfindex;
+
+        uint[7] _reserved01;
+
+        /**
+         * Interrupter register sets.
+         */
+        InterrupterRegister[0] ir;
+    }
+
+    /**
+     * Interrupter register set.
+     *
+     * A copy of this register set is present for each interrupter.
+     */
+    struct InterrupterRegister
+    {
+        /**
+         * Interrupter Management Register.
+         * 0 Interrupt Pending (IP)
+         * 1 Interrupt Enable
+         * 31:2 reserved
+         */
+        Volatile!uint imr;
+
+        /**
+         * Interrupter Moderation.
+         * 15:0 Interrupt Moderation Interval
+         * 31:16 Interrupt Moderation Counter
+         */
+        Volatile!uint im;
+
+        /**
+         * Event Ring Segment Table Size.
+         * 15:0 Event Ring Segment Table Size
+         * 31:16 reserved
+         */
+        Volatile!uint ersts;
+
+        uint reserved;
+
+        /**
+         * Event Ring Segment Table Base Address.
+         * 5:0 reserved
+         * 63:6 Event Ring Segment Table Base Address
+         */
+        Volatile!ulong erstba;
+
+        /**
+         * Event Ring Dequeue Pointer.
+         * 2:0 Dequeue ERST Segment Index
+         * 3 Event Handler Busy
+         * 63:4 Event Ring Dequeue Pointer
+         */
+        Volatile!ulong erdp;
+    }
+
+    /**
+     * Located at offset doorbell_offset from PCI base address.
+     *
+     * The number of these is given by HCSPARAMS1.MaxSlots + 1 (for the command
+     * ring).
+     */
+    struct DoorbellRegister
+    {
+        Volatile!ubyte target;
+        ubyte _reserved01;
+        Volatile!ushort task_id;
+    }
+    static assert(DoorbellRegister.sizeof == 4u);
+
+    private CapabilityRegisters * m_capability_registers;
+    private OperationalRegisters * m_operational_registers;
+    private PortRegisters * m_port_registers;
+    private RuntimeRegisters * m_runtime_registers;
+    private DoorbellRegister * m_doorbell_registers;
+
+    void initialize(Pci.Device * pci_device)
+    {
+        void * base_address = pci_device.memory_ranges[0].address;
+        Klog.writefln("Found XHCI controller at address %p", base_address);
+        m_capability_registers = cast(CapabilityRegisters *)base_address;
+        m_operational_registers = cast(OperationalRegisters *)(base_address + m_capability_registers.capability_length);
+        m_port_registers = cast(PortRegisters *)(cast(void *)m_operational_registers + 0x400);
+        m_runtime_registers = cast(RuntimeRegisters *)(base_address + m_capability_registers.rts_offset);
+        m_doorbell_registers = cast(DoorbellRegister *)(base_address + m_capability_registers.doorbell_offset);
+        dump_extended_capabilities();
+        if (!reset())
+        {
+            Klog.writefln("XHCI controller failed to initialize");
+            return;
+        }
+
+        /* Allocate memory for various controller data structures. */
+        ubyte * page = cast(ubyte *)Hippo.allocate_page();
+        /* Device Context Index: 2K */
+        void ** device_context_index = cast(void **)page;
+        /* Input Control Context: 64 bytes */
+        void * input_control_context = &page[2048];
+        /* Slot Context: 64 bytes */
+        void * slot_context = &page[2048 + 64];
+        /* Endpoint Context: 64 bytes */
+        void * endpoint_context = &page[2048 + 64 + 64];
+        /* Stream Context: 16 bytes */
+        void * stream_context = &page[2048 + 64 + 64 + 64];
+        /* Stream Array (Linear): 1M */
+        void * stream_array_linear = Hippo.allocate_aligned_region(1024 * 1024, PAGE_SIZE);
+        /* Stream Array (Pri/Sec): 4K */
+        void * stream_array_pri_sec = Hippo.allocate_page();
+        /* Transfer Ring Segments: 64K */
+        void * transfer_ring_segments = Hippo.allocate_aligned_region(64 * 1024, 64 * 1024);
+        /* Command Ring Segments: 64K */
+        void * command_ring_segments = Hippo.allocate_aligned_region(64 * 1024, 64 * 1024);
+        /* Event Ring Segments: 64K */
+        void * event_ring_segments = Hippo.allocate_aligned_region(64 * 1024, 64 * 1024);
+        /* Event Ring Segment Table: 512K */
+        void * event_ring_segment_table = Hippo.allocate_aligned_region(512 * 1024, PAGE_SIZE);
+        /* Scratchpad Buffer Array: 248 bytes */
+        void ** scratchpad_buffer_array = cast(void **)Hippo.allocate_aligned_region(2 * PAGE_SIZE, PAGE_SIZE);
+
+        size_t n_scratchpad_buffers = m_capability_registers.max_scratchpad_buffers;
+        for (size_t i = 0u; i < n_scratchpad_buffers; i++)
+        {
+            void * scratchpad_buffer = Hippo.allocate_page();
+            scratchpad_buffer_array[i] = scratchpad_buffer;
+        }
+
+        device_context_index[0] = scratchpad_buffer_array;
+
+        size_t max_slots = m_capability_registers.max_slots;
+        for (size_t i = 0u; i < max_slots; i++)
+        {
+            void * addr;
+            if ((i & 1) == 0)
+            {
+                page = cast(ubyte *)Hippo.allocate_page();
+                addr = page;
+            }
+            else
+            {
+                addr = &page[2048];
+            }
+            device_context_index[1 + i] = addr;
+        }
+
+        m_operational_registers.dcbaap = cast(ulong)device_context_index;
+        /* TODO: write cr_ctrl. */
+        /+ TODO:
+        m_operational_registers.config = m_capability_registers.hcs_params1 & 0xFu;
+        m_operational_registers.dn_ctrl = 1u << 1u;
+        +/
+        /* TODO: set up interrupt register set. */
+        Klog.writefln("XHCI controller initialization successful");
+    }
+
+    private void dump_extended_capabilities()
+    {
+        size_t ext_cap_off = (m_capability_registers.hcc_params1 >> 16u);
+        if (ext_cap_off != 0u)
+        {
+            Klog.writefln("Extended capabilities:");
+            uint * extended_capabilities = cast(uint *)m_capability_registers + ext_cap_off;
+            for (;;)
+            {
+                uint ec0 = extended_capabilities[0];
+                size_t next_offset = (ec0 >> 8u) & 0xFFu;
+                size_t len = next_offset;
+                if (len < 1u)
+                {
+                    len = 1u;
+                }
+                ubyte type = ec0 & 0xFFu;
+                if (type == 2u)
+                {
+                    len = 4u;
+                }
+                for (size_t i = 0u; i < len; i++)
+                {
+                    uint ecv = extended_capabilities[i];
+                    Klog.writef(" %02X %02X %02X %02X",
+                            ecv & 0xFFu,
+                            (ecv >> 8u) & 0xFFu,
+                            (ecv >> 16u) & 0xFFu,
+                            (ecv >> 24u) & 0xFFu);
+                }
+                Klog.writef("\n");
+                if (next_offset == 0u)
+                {
+                    break;
+                }
+                extended_capabilities += next_offset;
+            }
+        }
+    }
+
+    private bool reset()
+    {
+        /* Clear run/stop bit. */
+        m_operational_registers.usb_command &= ~0x1u;
+
+        /* Wait for HCHalted bit to be set. */
+        enum halt_timeout = 40u;
+        for (size_t halt_timeout_counter = 0u;;)
+        {
+            Time.msleep(1u);
+
+            if ((m_operational_registers.usb_status & 1u) != 0u)
+            {
+                break;
+            }
+
+            halt_timeout_counter++;
+            if (halt_timeout_counter >= halt_timeout)
+            {
+                Klog.writefln("XHCI controller failed to halt");
+                return false;
+            }
+        }
+
+        /* Set HC reset bit. */
+        m_operational_registers.usb_command |= (1u << 1u);
+
+        /* Wait for controller to be ready. */
+        enum reset_timeout = 100u;
+        for (size_t reset_timeout_counter = 0u;;)
+        {
+            Time.msleep(1u);
+
+            if (((m_operational_registers.usb_command & (1u << 1u)) == 0u) &&
+                ((m_operational_registers.usb_status & (1u << 11u)) == 0u))
+            {
+                break;
+            }
+
+            reset_timeout_counter++;
+            if (reset_timeout_counter >= reset_timeout)
+            {
+                Klog.writefln("XHCI controller failed to reset");
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    static void build(Pci.Device * pci_device)
+    {
+        if (pci_device.memory_ranges[0].address != null)
+        {
+            XHCI * xhci = A1.allocate!XHCI();
+            xhci.initialize(pci_device);
+        }
+    }
+}

src/hulk/util.d

@@ -0,0 +1,17 @@
+/**
+ * HULK utility functions.
+ */
+module hulk.util;
+
+/**
+ * Round a value up to the next power of 2.
+ *
+ * @param v Value to round up.
+ * @param p Power of 2 to round up to.
+ *
+ * @return Rounded up value.
+ */
+ulong round_up_power_2(ulong v, ulong p)
+{
+    return (v + p - 1u) & ~(p - 1u);
+}

src/hulk/ver.d

@@ -0,0 +1,3 @@
+module hulk.ver;
+
+enum VERSION = "0.18.0";

src/hulk/volatile.d

@@ -0,0 +1,35 @@
+module hulk.volatile;
+
+import core.volatile;
+
+struct Volatile(T)
+{
+    private T value;
+
+    public @property T read()
+    {
+        return volatileLoad(&value);
+    }
+    alias read this;
+
+    public void opAssign(T value)
+    {
+        volatileStore(&this.value, value);
+    }
+
+    public T opUnary(string s)()
+    {
+        T v = read();
+        mixin(s ~ "v;");
+        volatileStore(&this.value, v);
+        return v;
+    }
+
+    public T opOpAssign(string s)(T rhs)
+    {
+        T v = read();
+        mixin("v " ~ s ~ "= rhs;");
+        volatileStore(&this.value, v);
+        return v;
+    }
+}

src/hulk/writef.d

@@ -0,0 +1,191 @@
+/**
+ * HULK Formatted stream writing support.
+ */
+module hulk.writef;
+
+import core.stdc.stdarg;
+
+alias ch_out_fn = void function(ubyte);
+
+/**
+ * Format a string and write characters to the given output function.
+ *
+ * @param ch_out Character output function.
+ * @param s Format string.
+ * @param args Variable arguments structure.
+ *
+ * @return Number of characters written.
+ */
+size_t writefv(ch_out_fn ch_out, string s, va_list args)
+{
+    size_t length_written;
+    bool escape = false;
+    char pad = ' ';
+    size_t width;
+    foreach (char c; s)
+    {
+        if (escape)
+        {
+            if (c == 'c')
+            {
+                ulong ch;
+                va_arg(args, ch);
+                ch_out(cast(ubyte)ch);
+                length_written++;
+                escape = false;
+            }
+            else if (c == 'p')
+            {
+                ulong v;
+                va_arg(args, v);
+                length_written += write_hex(v, true, true, pad, width, ch_out);
+                escape = false;
+            }
+            else if (c == 'x')
+            {
+                ulong v;
+                va_arg(args, v);
+                length_written += write_hex(v, false, false, pad, width, ch_out);
+                escape = false;
+            }
+            else if (c == 'X')
+            {
+                ulong v;
+                va_arg(args, v);
+                length_written += write_hex(v, true, false, pad, width, ch_out);
+                escape = false;
+            }
+            else if (c == 'u')
+            {
+                ulong v;
+                va_arg(args, v);
+                length_written += write_udec(v, pad, width, ch_out);
+                escape = false;
+            }
+            else if ((c == '0') && (width == 0u))
+            {
+                pad = '0';
+            }
+            else if (('0' <= c) && (c <= '9'))
+            {
+                width = (width * 10u) + (c - '0');
+            }
+            else
+            {
+                ch_out(c);
+                escape = false;
+            }
+        }
+        else if (c == '%')
+        {
+            escape = true;
+            pad = ' ';
+            width = 0u;
+        }
+        else
+        {
+            ch_out(c);
+        }
+    }
+    return length_written;
+}
+
+/**
+ * Format a string and write characters to the given output function.
+ *
+ * @param ch_out Character output function.
+ * @param s Format string.
+ *
+ * @return Number of characters written.
+ */
+extern(C) size_t writef(ch_out_fn ch_out, string s, ...)
+{
+    va_list args;
+    va_start(args, s);
+    size_t rv = writefv(ch_out, s, args);
+    va_end(args);
+    return rv;
+}
+
+/**
+ * Format a value in hexadecimal to the given output function.
+ *
+ * @param v Value to format.
+ * @param upper Whether to use uppercase letters.
+ * @param pointer Whether to format as a pointer.
+ * @param pad Pad character to use.
+ * @param width Field width.
+ * @param ch_out Character output function.
+ *
+ * @return Number of characters written.
+ */
+private size_t write_hex(ulong v, bool upper, bool pointer, char pad, size_t width, ch_out_fn ch_out)
+{
+    static __gshared const(char)[16] hex_chars_lower = "0123456789abcdef";
+    static __gshared const(char)[16] hex_chars_upper = "0123456789ABCDEF";
+    char[19] buf;
+    size_t digit;
+    size_t buf_idx;
+    do
+    {
+        ulong n = v & 0xFu;
+        buf[buf_idx] = upper ? hex_chars_upper[n] : hex_chars_lower[n];
+        v >>= 4u;
+        buf_idx++;
+        digit++;
+        if (pointer && ((digit % 4) == 0) && (v != 0u))
+        {
+            buf[buf_idx] = '_';
+            buf_idx++;
+        }
+    } while (v != 0u);
+    size_t length_written = buf_idx;
+    while (width > buf_idx)
+    {
+        ch_out(pad);
+        width--;
+        length_written++;
+    }
+    do
+    {
+        buf_idx--;
+        ch_out(buf[buf_idx]);
+    } while (buf_idx != 0u);
+    return length_written;
+}
+
+/**
+ * Format a value in decimal to the given output function.
+ *
+ * @param v Value to format.
+ * @param pad Pad character to use.
+ * @param width Field width.
+ * @param ch_out Character output function.
+ *
+ * @return Number of characters written.
+ */
+private size_t write_udec(ulong v, char pad, size_t width, ch_out_fn ch_out)
+{
+    char[20] buf;
+    size_t i;
+    do
+    {
+        ulong d = v % 10u;
+        buf[i] = cast(char)(d + '0');
+        v /= 10u;
+        i++;
+    } while (v != 0u);
+    size_t length_written = i;
+    while (width > i)
+    {
+        ch_out(pad);
+        width--;
+        length_written++;
+    }
+    do
+    {
+        i--;
+        ch_out(buf[i]);
+    } while (i != 0u);
+    return length_written;
+}

stage1.asm

@@ -1,228 +0,0 @@
-
-%include "bootdef.inc"
-
-[bits 16]
-
-org 0x7c00
-
-	jmp short start
-
-; --------------------------------------------------
-; data portion of the "DOS BOOT RECORD"
-; ----------------------------------------------------------------------
-brINT13Flag     DB      90H             ; 0002h - 0EH for INT13 AH=42 READ
-brOEM           DB      'MSDOS5.0'      ; 0003h - OEM ID - Windows 95B
-brBPS           DW      512             ; 000Bh - Bytes per sector
-brSPC           DB      1               ; 000Dh - Sector per cluster
-brSc_b4_fat	DW      1               ; 000Eh - Reserved sectors
-brFATs          DB      2               ; 0010h - FAT copies
-brRootEntries   DW      0E0H		; 0011h - Root directory entries
-brSectorCount   DW      2880		; 0013h - Sectors in volume, < 32MB
-brMedia         DB      240		; 0015h - Media descriptor
-brSPF           DW      9               ; 0016h - Sectors per FAT
-brSc_p_trk	DW      18              ; 0018h - Sectors per head/track
-brHPC           DW      2		; 001Ah - Heads per cylinder
-brSc_b4_prt	DD      0               ; 001Ch - Hidden sectors
-brSectors       DD      0	        ; 0020h - Total number of sectors
-brDrive		DB      0               ; 0024h - Physical drive no.
-		DB      0               ; 0025h - Reserved (FAT32)
-		DB      29H             ; 0026h - Extended boot record sig (FAT32)
-brSerialNum     DD      404418EAH       ; 0027h - Volume serial number
-brLabel         DB      'HOS 0.1.1  '   ; 002Bh - Volume label
-brFSID          DB      'FAT12   '      ; 0036h - File System ID
-;------------------------------------------------------------------------
-
-start:
-	jmp	0:jmphere		;ensure that cs=0 and ip=0x7c...
-jmphere:
-	;dl=drive number, save it!
-	xor	ax, ax
-	mov	ds, ax
-	mov	[brDrive], dl
-	cli
-	mov	ss, ax
-	mov	sp, 0x7Bfe		;right under boot sector
-	sti
-
-	mov	ax, 0xb800
-	mov	ds, ax
-	mov	es, ax
-
-	xor	di, di
-	mov	ax, 0x0700
-	mov	cx, 2000
-cls:
-	stosw
-	loop	cls
-
-enable_a20:
-	in	al, 0x64
-	test	al, 2
-	jnz	enable_a20
-	mov	al, 0xD1
-	out	0x64, al
-ea20_2:	in	al, 0x64
-	and	ax, byte 2
-	jnz	ea20_2
-	mov	al, 0xDF
-	out	0x60, al
-
-unreal:
-	xor	ax, ax
-	mov	es, ax
-	mov	ds, ax
-
-	lgdt	[gdtr]		;load gdt
-	cli
-	push	es
-	push	ds		;save segment values
-	mov	ebx, cr0
-	inc	bl
-	mov	cr0, ebx	;pmode!
-	mov	ax, KERNEL_DATA
-	mov	es, ax
-	mov	ds, ax		;load segment limits
-	dec	bl
-	mov	cr0, ebx	;back to real mode!
-	pop	ds
-	pop	es		;segments back, with 4gb limits!
-	sti
-
-;now lets read in the FAT and root directory so we can search for the kernel file...
-	mov	ax, 0x0209		;FAT1
-	mov	cx, 0x0002
-	xor	dh, dh
-	mov	dl, [brDrive]
-	mov	bx, BOOT_FAT_SEG
-	mov	es, bx
-	xor	bx, bx
-	int	0x13
-
-	mov	ax, 0x020E		;root directory
-	mov	cx, 0x0002		;cyl/sect
-	mov	dh, 0x01		;head
-	mov	dl, [brDrive]		;drive
-	mov	bx, BOOT_ROOT_SEG
-	mov	es, bx
-	xor	bx, bx
-	int	0x13
-
-;k now read root directory
-	mov	bx, BOOT_ROOT_SEG
-	mov	ds, bx
-	xor	si, si			;k now ds:si points to beginning of root directory
-	mov	es, si
-	mov	cx, 224			;max root entries
-loop_compare:
-	mov	di, stage2
-	push	cx
-	push	si			;save pointer to root dir entry
-	mov	cx, 11
-loop_name:
-	cmpsb
-	loopz	loop_name
-	jnz	goon			;cx didn't get to zero, bad file
-	pop	si
-	pop	cx
-	jmp	found_file		;good file, ds:si points to start of root directory entry
-goon:
-	pop	si
-	pop	cx
-	add	si, 32
-	loop	loop_compare
-
-error:
-	jmp	$			;halt! no kernel file found!
-
-found_file:				;ds:si points to root dir entry
-	xor	ax, ax
-	mov	gs, ax
-	mov	ax, BOOT_STAGE2_SEG
-	mov	es, ax
-
-	mov	ax, [ds:si+26]
-	mov	bx, BOOT_FAT_SEG
-	mov	ds, bx			;ds points to beginning of FAT
-	xor	di, di
-
-readstage2_loop:
-	cmp	ax, 0xff7
-	jg	readstage2_done
-	inc	di
-	push	ax
-	call	getCHSfromCluster
-	mov	ax, 0x0201
-	mov	dl, [gs:BOOT_DRIVE]
-	xor	bx, bx
-	int	0x13
-	mov	bx, es
-	add	bx, 0x0020
-	mov	es, bx
-	pop	ax			;current logical cluster #
-
-	mov	cx, ax			;cx=logical cluster
-	mov	dx, 3
-	mul	dx
-	shr	ax, 1			;ax=logical cluster * 3 / 2
-	mov	si, ax
-	test	cl, 1			;is bit0 set?
-	jnz	odd_cluster
-even_cluster:
-	lodsw
-	and	ax, 0x0fff
-	jmp	got_cluster
-odd_cluster:
-	lodsw
-	shr	ax, 4
-got_cluster:
-	jmp	readstage2_loop
-
-readstage2_done:
-
-	jmp	0:BOOT_STAGE2_ADD
-
-;------------------------------------------------------
-getCHSfromCluster:
-	;input: ax=lba of sector on floppy (0-2879)
-	add	ax, 31			;convert logical cluster# to lba#
-	xor	dx, dx			;lba->chs
-	mov	bx, 18
-	div	bx
-	inc	dx
-	mov	cl, dl			;sector# (1-18)
-	xor	dx, dx
-	mov	bx, 2
-	div	bx
-	mov	ch, al			;cylinder# (0-79)
-	mov	dh, dl			;head# (0-1)
-	ret
-
-
-;-------------------------------------------------------
-gdtr:
-	dw	gdt_end-gdt-1
-	dd	gdt
-gdt:
-	dd	0
-	dd	0
-
-KERNEL_DATA equ $-gdt
-	db	0xff		;segment 16 = 4gb data
-	db	0xff
-	db	0x00
-	db	0x00
-	db	0x00
-	db	0x92
-	db	0xcf		;cf
-	db	0x00
-
-gdt_end:
-
-
-
-stage2:	db	"STAGE2  BIN"
-
-times 510-($-$$)	db 0
-
-db	0x55, 0xaa
-

stage2.asm

@@ -1,920 +0,0 @@
-
-%include "bootdef.inc"
-
-%define VESA_MODEINFO_SEG 0x0120
-%define VESA_MODELIST_SEG 0x0140
-%define GOOD_MODELIST_SEG 0x0160
-
-[bits 16]
-
-org BOOT_STAGE2_ADD
-
-
-;k now read root directory
-	mov	bx, BOOT_ROOT_SEG
-	mov	ds, bx
-	xor	si, si			;k now ds:si points to beginning of root directory
-	mov	es, si
-	mov	cx, 224			;max root entries
-loop_compare:
-	mov	di, kernel
-	push	cx
-	push	si			;save pointer to root dir entry
-	mov	cx, 11
-loop_name:
-	cmpsb
-	loopz	loop_name
-	jnz	goon			;cx didn't get to zero, bad file
-	pop	si
-	pop	cx
-	jmp	found_file		;good file, ds:si points to start of root directory entry
-goon:
-	pop	si
-	pop	cx
-	loop	loop_compare
-
-error:
-	jmp	$			;halt! no kernel file found!
-
-found_file:				;ds:si points to root dir entry of kernel file
-	xor	ax, ax
-	mov	gs, ax
-	mov	ax, [ds:si+26]
-	mov	bx, BOOT_FAT_SEG
-	mov	ds, bx			;ds points to beginning of FAT
-	mov	edi, BOOT_KERNEL_ADD
-
-readkernel_loop:
-	cmp	ax, 0xff7
-	jg	readkernel_done
-	push	ax
-	call	getCHSfromCluster
-	mov	ax, 0x0201
-	mov	dl, [gs:BOOT_DRIVE]
-	mov	bx, BOOT_KERNEL_SEG
-	mov	es, bx
-	xor	bx, bx
-	int	0x13
-	mov	cx, 256
-	xor	ax, ax
-	mov	es, ax
-	mov	esi, BOOT_KERNEL_SEG*16
-copykernel_loop:
-	mov	ax, [es:esi]
-	mov	[es:edi], ax
-	inc	esi
-	inc	esi
-	inc	edi
-	inc	edi
-	loop	copykernel_loop
-
-	pop	ax			;current logical cluster #
-
-	mov	cx, ax			;cx=logical cluster
-	mov	dx, 3
-	mul	dx
-	shr	ax, 1			;ax=logical cluster * 3 / 2
-	mov	si, ax
-	test	cl, 1			;is bit0 set?
-	jnz	odd_cluster
-even_cluster:
-	lodsw
-	and	ax, 0x0fff
-	jmp	got_cluster
-odd_cluster:
-	lodsw
-	shr	ax, 4
-got_cluster:
-	jmp	readkernel_loop
-
-;------------------------------------------------------
-readkernel_done:			;-------------put more real mode init stuff here!
-					;----ask to load RD from floppy
-	mov	ax, 0xb800
-	mov	es, ax
-	xor	ax, ax
-	mov	ds, ax
-	xor	di, di
-	mov	cx, 2000
-	mov	ax, 0x0700
-cls_loop:
-	stosw
-	loop	cls_loop
-
-	mov	dx, 0x3d4		;move cursor off screen...
-	mov	al, 0x0e
-	out	dx, al
-	inc	dx
-	mov	al, 0xff
-	out	dx, al
-	dec	dx
-	mov	al, 0x0f
-	out	dx, al
-	inc	dx
-	out	dx, al
-
-	xor	di, di
-	mov	si, txt_welcome
-	mov	ah, 0x1f
-	call	puts
-
-	mov	di, 160
-	mov	si, txt_rd1
-	mov	ah, 7
-	call	puts
-
-	mov	si, txt_rd2
-	mov	di, 160*2
-	call	puts
-
-	mov	di, 160*3
-	mov	si, txt_input
-	call	puts
-
-get_rd:
-	xor	ax, ax
-	int	0x16
-	cmp	al, '1'
-	jz	got_rd
-	cmp	al, '2'
-	jnz	get_rd
-got_rd:	
-	stosb
-	sub	al, '1'
-	push	ds
-	mov	bx, BOOT_DATA_SEG		;segment for data to send kernel
-	mov	ds, bx
-	mov	[ds:BOOT_HASRD], al
-	pop	ds				;ds=0
-	cmp	al, 0				;dont load rd
-	jz	no_rd
-
-	mov	cx, 80
-	mov	edi, 0xb8000+160*4
-filler_loop:
-	mov	word [ds:edi], 0x0400+177
-	inc	edi
-	inc	edi
-	loop	filler_loop
-	mov	cx, 80				;80 cylinders to read
-	xor	si, si
-	mov	edi, BOOT_RD_ADD		;ram disk address
-read_cylinder:
-	push	cx
-	mov	bx, 0x0100
-	mov	es, bx
-	xor	bx, bx
-	mov	ax, 0x0224
-	mov	cx, si
-	mov	ch, cl
-	mov	cl, 1
-	xor	dx, dx
-	mov	dl, [gs:BOOT_DRIVE]
-	int	0x13
-
-	mov	ebx, 0xb8000
-	add	bx, si
-	shl	bl, 1
-	mov	word [ds:ebx+160*4], 0x0200+219
-
-	push	si
-	mov	esi, 0x1000
-	mov	cx, 0x2400
-copydisk_loop:
-	mov	ax, [ds:esi]
-	inc	esi
-	inc	esi
-	mov	[ds:edi], ax
-	inc	edi
-	inc	edi
-	loop	copydisk_loop
-
-	pop	si				;what cylinder# we are on...
-	inc	si
-	pop	cx
-	loop	read_cylinder
-
-;------------------------------------------------------
-no_rd:
-	mov	ax, BOOT_DATA_SEG
-	mov	es, ax
-	mov	di, BOOT_MEMMAP			;store memmap info in es:di for kernel
-	xor	edx, edx
-	mov	ax, 0x0100
-	mov	ds, ax
-	xor	ebx, ebx
-getmemmap_loop:
-	push	es
-	push	di
-	push	edx
-	mov	ax, 0x0100			;get memory map
-	mov	es, ax
-	xor	di, di
-	mov	eax, 0x0000E820
-	mov	ecx, 0x00000014
-	;mov	ebx, 0x00000000
-	mov	edx, 0x534D4150			;'SMAP'
-	int	0x15
-	jc	getmemmap_carry
-	cmp	eax, 0x534D4150			;eax should be 'SMAP' on return...
-	jnz	getmemmap_error
-	cmp	ebx, 0
-	jz	getmemmap_done
-
-	pop	edx				;now, copy memmap entry to es:di on the stack
-	pop	di
-	pop	es
-	xor	si, si
-	mov	cx, 20
-getmemmap_copymem_loop:
-	lodsb
-	stosb
-	loop	getmemmap_copymem_loop
-	inc	edx
-	jmp	getmemmap_loop
-
-getmemmap_error:
-	mov	ax, 0xb800
-	mov	es, ax
-	mov	di, 160*24
-	xor	ax, ax
-	mov	ds, ax
-	mov	si, txt_memerror
-	mov	ah, 0x04
-	call	puts
-	hlt
-	jmp	$
-
-getmemmap_carry:
-	dec	edx
-getmemmap_done:
-	pop	edx
-	pop	di
-	pop	es
-
-	xor	si, si
-	mov	cx, 20
-getmemmap_done_copymem_loop:
-	lodsb
-	stosb
-	loop	getmemmap_done_copymem_loop
-	inc	edx
-
-	mov	di, BOOT_MEMENTRIES
-	mov	[es:di], edx			;save # of memmap entries for kernel
-
-						;on to vesa info...
-	xor	ax, ax
-	mov	gs, ax
-	mov	ds, ax
-	mov	ax, 0xb800
-	mov	es, ax
-	mov	di, 160
-	mov	cx, 2000-80
-	mov	ax, 0x0700
-cls_vesa_loop:
-	stosw
-	loop	cls_vesa_loop
-	mov	si, txt_vesa
-	mov	di, 160*1
-	mov	ah, 7
-	call	puts
-
-	push	di
-	mov	ax, 0x0100
-	mov	es, ax
-	xor	di, di
-	mov	dword [es:di], "2EBV"
-	mov	ax, 0x4F00
-
-	int	0x10
-	pop	di
-	cmp	ax, 0x004F
-	jz	vesa_good
-	mov	si, txt_novesa
-	mov	ax, 0xb800
-	mov	es, ax
-	mov	ah, 7
-	call	puts
-	mov	ax, BOOT_DATA_SEG
-	mov	ds, ax
-	mov	word [ds:BOOT_VESA], 0
-	jmp	vesa_done
-vesa_good:
-	mov	ax, 0xb800
-	mov	es, ax
-	mov	ax, 0x0100
-	mov	ds, ax
-	xor	si, si
-	mov	bx, [4]
-	mov	al, bh
-	call	puthex
-	mov	al, '.'
-	stosb
-	mov	al, 7
-	stosb
-	mov	al, bl
-	call	puthex
-	add	di, 4
-	cmp	bh, 2
-	jge	vesa_good2
-	xor	ax, ax
-	mov	ds, ax
-	mov	si, txt_vesaold
-	mov	ah, 7
-	call	puts
-	mov	ax, BOOT_DATA_SEG
-	mov	ds, ax
-	mov	word [ds:BOOT_VESA], 0
-	jmp	vesa_done
-vesa_good2:
-	mov	ebx, [6]			;something like 0x00000E60
-	mov	edx, [14]
-	mov	si, bx
-	shr	ebx, 16
-	mov	ds, bx				;ds:si points to null-terminated OEM identification string
-	mov	ah, 2
-	push	si
-	call	puts
-	pop	si
-	mov	ax, BOOT_DATA_SEG
-	mov	es, ax
-	mov	di, BOOT_VESA_OEM
-vesa_copyoem:
-	lodsb
-	stosb
-	or	al, al
-	jnz	vesa_copyoem
-	mov	ax, 0x0100
-	mov	ds, ax
-	xor	si, si
-	mov	di, BOOT_VESA_VBE
-	mov	cx, 512
-vesa_copyvbe:
-	lodsb
-	stosb
-	loop	vesa_copyvbe
-
-	mov	si, dx
-	shr	edx, 16
-	mov	ds, dx				;ds:si points to video mode list
-	mov	ax, VESA_MODELIST_SEG
-	mov	es, ax
-	xor	di, di
-vesa_copymodes:
-	lodsw
-	stosw
-	cmp	ax, 0xffff
-	jnz	vesa_copymodes
-
-	mov	ax, GOOD_MODELIST_SEG
-	mov	es, ax
-	xor	di, di
-	mov	cx, 256
-	mov	ax, 0xffff
-clear_good_mode_list_loop:
-	stosw
-	loop	clear_good_mode_list_loop
-
-	mov	ax, VESA_MODELIST_SEG
-	mov	ds, ax
-	xor	si, si				;ds:si points to video mode list where we can edit it :)
-	mov	ax, GOOD_MODELIST_SEG
-	mov	es, ax
-	xor	di, di
-	xor	dx, dx				;dx=what good mode # we are on
-vesa_readmodeinfo_loop:
-	lodsw
-	cmp	ax, 0xffff
-	jz	vesa_endofmodes
-	push	ax				;save mode#
-	call	checkmode
-	cmp	ax, 0
-	jz	vesa_readmodeinfo_good
-	pop	ax
-	jmp	vesa_readmodeinfo_loop
-vesa_readmodeinfo_good:
-	pop	ax				;restore mode#
-	stosw
-	call	vesa_showmodeinfo
-	inc	dx
-	jmp	vesa_readmodeinfo_loop
-
-vesa_endofmodes:				;here we have a list of good modes at GOOD_MODELIST_SEG:0
-	xor	ax, ax
-	mov	ds, ax
-	mov	si, txt_consolemode
-	mov	ax, 0xb800
-	mov	es, ax
-	mov	di, 160*2
-	mov	ah, 7
-	call	puts
-	mov	di, 160*3
-	mov	cx, dx
-	mov	al, 'b'
-vesa_displaylabels:
-	stosb
-	push	ax
-	mov	al, 7
-	stosb
-	mov	al, '.'
-	stosb
-	mov	al, 7
-	stosb
-	pop	ax
-	inc	al
-	add	di, 160-4
-	loop	vesa_displaylabels		;done drawing screen of VESA choices, now ask for one
-						;valid options are 'a' through (al-1)
-	mov	bl, al
-	xor	ax, ax
-	mov	ds, ax
-	mov	di, 160*24
-	mov	si, txt_input
-	mov	ah, 14
-	call	puts
-vesa_getchoice:
-	xor	ax, ax
-	int	0x16
-	cmp	al, 'a'
-	jl	vesa_getchoice
-	cmp	al, bl
-	jge	vesa_getchoice
-	stosb
-	push	ax
-	mov	al, 14
-	stosb
-	pop	ax
-	xor	ah, ah
-	sub	ax, 'a'
-	cmp	ax, 0
-	jz	vesa_consolemode_only
-	mov	cx, ax				;cx holds good mode# (1=first good vesa mode)
-	dec	cx
-	mov	ax, GOOD_MODELIST_SEG
-	mov	ds, ax
-	shl	cx, 1
-	mov	si, cx				;ds:si points to word containing selected mode#
-	lodsw
-	mov	cx, ax
-	mov	dx, ax				;cx and dx hold mode#
-
-	mov	ax, VESA_MODEINFO_SEG
-	mov	es, ax
-	xor	di, di
-	mov	ax, 0x4F01
-	int	0x10
-	call	checkvesa
-
-	mov	ax, VESA_MODEINFO_SEG
-	mov	ds, ax
-	xor	si, si
-	mov	ax, BOOT_DATA_SEG
-	mov	es, ax
-	mov	di, BOOT_VESA_INFO
-	mov	cx, 256
-vesa_copymodeinfo_loop:
-	lodsb
-	stosb
-	loop	vesa_copymodeinfo_loop		;store ModeInfoBlock for current
-
-	mov	[es:BOOT_VESA], dx		;store mode# for kernel
-
-;	mov	ax, 0xb800
-;	mov	es, ax
-;	xor	di, di
-;	mov	al, dh
-;	call	puthex2
-;	mov	al, dl
-;	call	puthex2
-
-	mov	bx, dx
-	or	bx, 0x4000			;set "use LFB" bit of mode#
-	mov	ax, 0x4F02
-	int	0x10				;switch to graphics mode!!!
-	call	checkvesa
-
-	jmp	vesa_done
-
-vesa_consolemode_only:
-	mov	ax, BOOT_DATA_SEG
-	mov	es, ax
-	mov	word [es:BOOT_VESA], 0
-
-	jmp	vesa_done
-
-;------------------------------------------------------
-vesa_showmodeinfo:
-	pusha
-	push	es
-	push	ds
-	mov	ax, VESA_MODEINFO_SEG
-	mov	ds, ax
-	xor	si, si
-	mov	ax, 0xb800
-	mov	es, ax
-
-	mov	cx, dx
-
-	mov	ax, 160
-	mul	dx				;ax=160*mod#
-	add	ax, 160*3+6			;offset first line of modes and room on left for label
-	mov	di, ax
-
-	mov	ax, [ds:18]
-	call	console_putDec
-	add	di, 10
-	mov	al, 'x'
-	call	console_putChar
-	inc	di
-	inc	di
-	mov	ax, [ds:20]
-	call	console_putDec
-	add	di, 10
-	mov	al, 'x'
-	call	console_putChar
-	inc	di
-	inc	di
-	xor	ah, ah
-	mov	al, [ds:25]
-	call	console_putDec
-	add	di, 8
-	mov	al, [ds:0]
-	test	al, 0x80
-	jz	vesa_showmodeinfo_done
-	mov	al, 'L'
-	call	console_putChar
-	mov	al, 'F'
-	call	console_putChar
-	mov	al, 'B'
-	call	console_putChar
-	inc	di
-	inc	di
-	mov	ebx, [ds:40]
-	mov	eax, ebx
-	shr	eax, 24
-	call	puthex2
-	mov	eax, ebx
-	shr	eax, 16
-	call	puthex2
-	mov	al, bh
-	call	puthex2
-	mov	al, bl
-	call	puthex2
-vesa_showmodeinfo_done:
-	pop	ds
-	pop	es
-	popa
-	ret
-
-;------------------------------------------------------
-checkmode:
-	push	bx
-	push	cx
-	push	dx
-	push	es
-	push	ds
-	push	di
-	push	si
-	mov	cx, ax				;cx=modenumber
-	mov	ax, VESA_MODEINFO_SEG
-	mov	es, ax
-	xor	di, di
-	mov	ax, 0x4F01
-	int	0x10
-	call	checkvesa
-	xor	di, di				;es:di -> ModeInfoBlock struc
-	mov	ax, [es:di]			;ModeAttributes
-	test	al, 1				;mode supported
-	jz	vesa_modenogood
-	test	al, 8				;color mode
-	jz	vesa_modenogood
-	test	al, 0x10			;graphics mode
-	jz	vesa_modenogood
-	test	al, 0x80			;Linear Frame Buffer supported
-	jz	vesa_modenogood
-	mov	al, [es:di+25]			;BitsPerPixel
-	cmp	al, 16
-	jz	vesa_bppok
-	cmp	al, 24
-	jz	vesa_bppok
-	cmp	al, 32
-	jnz	vesa_modenogood
-vesa_bppok:
-	mov	ax, [es:di+18]			;XResolution
-	mov	bx, [es:di+20]			;YResolution
-	cmp	ax, 640				;640x480
-	jnz	res_goon1
-	cmp	bx, 480
-	jnz	vesa_modenogood
-	jmp	vesa_modegood
-res_goon1:
-	cmp	ax, 800
-	jnz	res_goon2
-	cmp	bx, 600
-	jnz	vesa_modenogood
-	jmp	vesa_modegood
-res_goon2:
-	cmp	ax, 1024
-	jnz	res_goon3
-	cmp	bx, 768
-	jnz	vesa_modenogood
-	jmp	vesa_modegood
-res_goon3:
-	cmp	ax, 1280
-	jnz	res_goon4
-	cmp	bx, 1024
-	jz	vesa_modegood
-	cmp	bx, 960
-	jz	vesa_modegood
-	jmp	vesa_modenogood
-res_goon4:
-	cmp	ax, 1600
-	jnz	vesa_modenogood
-	cmp	bx, 1200
-	jnz	vesa_modenogood
-vesa_modegood:
-	pop	si
-	pop	di
-	pop	ds
-	pop	es
-	pop	dx
-	pop	cx
-	pop	bx
-	xor	ax, ax
-	ret
-vesa_modenogood:
-	pop	si
-	pop	di
-	pop	ds
-	pop	es
-	pop	dx
-	pop	cx
-	pop	bx
-	mov	ax, 0xffff
-	ret
-
-;------------------------------------------------------
-vesa_done:
-
-;	xor	ax, ax				;wait for keypress...
-;	int	0x16
-
-	jmp	go_pm
-
-;------------------------------------------------------
-puts:
-	lodsb
-	or	al, al
-	jz	puts_done
-	stosb
-	mov	al, ah
-	stosb
-	jmp	puts
-puts_done:
-	ret
-
-;------------------------------------------------------
-checkvesa:
-	cmp	ax, 0x004F
-	jnz	vesaerror
-	ret
-vesaerror:
-	mov	ax, 0xb800
-	mov	es, ax
-	xor	ax, ax
-	mov	ds, ax
-	mov	si, txt_vesaerror
-	mov	di, 160*24
-	mov	ah, 4
-	call	puts
-	cli
-	hlt
-
-;-------Function console_putDec
-;input:
-; AX = number to display
-;output:
-; number written in decimal to es:di
-console_putDec:
-	pusha
-	xor	dx, dx
-	xor	bh, bh			;no characters written yet
-	mov	cx, 10000
-	div	cx			;ax=quotiont, dx=remainder
-	add	ax, '0'
-	cmp	ax, '0'
-	je	.goon1
-	call	console_putChar
-	mov	bh, 1
-
-.goon1:
-	mov	ax, dx			;load remainder to ax
-	xor	dx, dx
-	mov	cx, 1000
-	div	cx			;ax=quotiont, dx=remainder
-	add	ax, '0'
-	cmp	ax, '0'
-	je	.goon11
-	call	console_putChar
-	mov	bh, 1
-	jmp	.goon2
-.goon11:
-	cmp	bh, 0
-	je	.goon2
-	call	console_putChar
-
-.goon2:
-	mov	ax, dx			;load remainder to ax
-	xor	dx, dx
-	mov	cx, 100
-	div	cx			;ax=quotiont, dx=remainder
-	add	ax, '0'
-	cmp	ax, '0'
-	je	.goon21
-	call	console_putChar
-	mov	bh, 1
-	jmp	.goon3
-.goon21:
-	cmp	bh, 0
-	je	.goon3
-	call	console_putChar
-
-.goon3:
-	mov	ax, dx			;load remainder to ax
-	xor	dx, dx
-	mov	cx, 10
-	div	cx			;ax=quotiont, dx=remainder
-	add	ax, '0'
-	cmp	ax, '0'
-	je	.goon31
-	call	console_putChar
-	mov	bh, 1
-	jmp	.goon4
-.goon31:
-	cmp	bh, 0
-	je	.goon4
-	call	console_putChar
-.goon4:					;here dx contains last remainder
-	mov	ax, dx
-	add	ax, '0'
-	call	console_putChar
-
-	popa
-	ret
-
-;------------------------------------------------------
-console_putChar:
-	stosb
-	mov	al, 7
-	stosb
-	ret
-
-;------------------------------------------------------
-puthex:
-	;es:di points to video memory
-	;al holds hex value
-
-	push	ax
-	mov	ah, al
-	shr	ax, 4
-	and	al, 0x0F
-	add	al, '0'
-	cmp	al, '9'
-	jle	puthex_goon1
-	add	al, 'A'-'9'-1
-puthex_goon1:
-	cmp	al, '0'
-	jz	puthex_skipzero
-	stosb
-	mov	al, 7
-	stosb
-puthex_skipzero:
-	pop	ax
-	push	ax
-	and	al, 0x0F
-	add	al, '0'
-	cmp	al, '9'
-	jle	puthex_goon2
-	add	al, 'A'-'9'-1
-puthex_goon2:
-	stosb
-	mov	al, 7
-	stosb
-	pop	ax
-	ret
-
-;------------------------------------------------------
-puthex2:
-	;es:di points to video memory, always displays 2 characters!
-	;al holds hex value
-
-	push	ax
-	mov	ah, al
-	shr	ax, 4
-	and	al, 0x0F
-	add	al, '0'
-	cmp	al, '9'
-	jle	puthex2_goon1
-	add	al, 'A'-'9'-1
-puthex2_goon1:
-	stosb
-	mov	al, 7
-	stosb
-	pop	ax
-	push	ax
-	and	al, 0x0F
-	add	al, '0'
-	cmp	al, '9'
-	jle	puthex2_goon2
-	add	al, 'A'-'9'-1
-puthex2_goon2:
-	stosb
-	mov	al, 7
-	stosb
-	pop	ax
-	ret
-
-;------------------------------------------------------
-txt_welcome: db	"                             Welcome to HOS v", VERSION, "!                             ", 0
-txt_rd1: db	"1. Do not load an initial ram disk", 0
-txt_rd2: db	"2. Load initial ram disk from floppy", 0
-txt_input: db	"Enter your selection: ", 0
-txt_vesa: db	"VESA version: ", 0
-txt_vesaerror: db "VESA function call error! Halting system!", 0
-txt_novesa: db	"VESA not found. Starting in console mode...", 0
-txt_vesaold: db	"VESA version 2.0 required. Starting in console mode...", 0
-txt_consolemode: db "a. Console mode only.", 0
-txt_memerror: db "Extended Memory Map information unavailable! Halting system...", 0
-
-;------------------------------------------------------
-getCHSfromCluster:
-	;input: ax=lba of sector on floppy (0-2879)
-	add	ax, 31			;convert logical cluster# to lba#
-	xor	dx, dx			;lba->chs
-	mov	bx, 18
-	div	bx
-	inc	dx
-	mov	cl, dl			;sector# (1-18)
-	xor	dx, dx
-	mov	bx, 2
-	div	bx
-	mov	ch, al			;cylinder# (0-79)
-	mov	dh, dl			;head# (0-1)
-	ret
-
-
-;-------------------------------------------------------
-gdtr:
-	dw	gdt_end-gdt-1
-	dd	gdt
-gdt:
-	dd	0
-	dd	0
-
-KERNEL_CODE equ $-gdt
-	db	0xff		;limit	7:0
-	db	0xff		;limit	15:8
-	db	0x00		;base	7:0
-	db	0x00		;base	15:8
-	db	0x00		;base	23:16
-	db	0x9a		;access
-	db	0xcf		;flags / limit 19:16
-	db	0x00		;base	31:24
-
-KERNEL_DATA equ $-gdt
-	db	0xff		;segment 16 = 4gb data
-	db	0xff
-	db	0x00
-	db	0x00
-	db	0x00
-	db	0x92
-	db	0xcf		;cf
-	db	0x00
-
-gdt_end:
-
-;------------------------------------------------------
-go_pm:
-	xor	ax, ax
-	mov	ds, ax
-	lgdt	[gdtr]
-	cli
-	mov	eax, cr0
-	inc	eax
-	mov	cr0, eax
-
-	jmp	KERNEL_CODE:pmode
-
-bits 32
-pmode:
-	mov	ax, KERNEL_DATA
-	mov	es, ax
-	mov	ds, ax
-	mov	fs, ax
-	mov	gs, ax
-	jmp	KERNEL_CODE:BOOT_KERNEL_ADD
-
-kernel:	db	"KERNEL  BIN", 0
-
-

tetris.c

@@ -1,7 +0,0 @@
-
-// tetris.x
-// Author: Josh Holtrop
-// Date: 09/30/03
-
-
-

video.c

@@ -1,147 +0,0 @@
-//video.c
-// 08/13/03 Josh Holtrop
-
-
-void video_init(ModeInfoBlock *mib)
-{
-	video_mode = *mib;
-
-	switch(video_mode.BitsPerPixel)
-	{
-	case 16:
-		vid_ptr16 = (word *) video_mode.PhysBasePtr;
-		break;
-	case 24:
-		vid_ptr24 = (byte *) video_mode.PhysBasePtr;
-		break;
-	case 32:
-		vid_ptr32 = (dword *) video_mode.PhysBasePtr;
-	}
-
-	dword tot = ((video_mode.XResolution) * (video_mode.YResolution));
-	int a;
-	for (a = 0; a < tot; a++)
-	{
-		if (a < (tot / 4))
-			video_psetp(a, 0x00FF0000);
-				else if (a < (tot / 2))
-			video_psetp(a, 0x0000FF00);
-		else if (a < ((tot * 3) / 4))
-			video_psetp(a, 0x000000FF);
-		else
-			video_psetp(a, 0x00FFFFFF);		
-	}
-}
-
-void video_horiz(int y, int x1, int x2, dword color)
-{
-	checkBoundsy(y);
-	checkBoundsx(x1);
-	checkBoundsx(x2);
-	if (x1 > x2)
-	{
-		int tmp = x2;
-		x2 = x1;
-		x1 = tmp;
-	}
-	int pixel = y*video_mode.XResolution+x1;
-	int a;
-	for (a = 0; a <= (x2-x1); a++)
-	{
-		video_psetp(pixel, color);
-		pixel++;
-	}
-}
-
-void video_vert(int x, int y1, int y2, dword color)
-{
-	checkBoundsx(x);
-	checkBoundsy(y1);
-	checkBoundsy(y2);
-	if (y1 > y2)
-	{
-		int tmp = y2;
-		y2 = y1;
-		y1 = tmp;
-	}
-	int pixel = y1*video_mode.XResolution+x;
-	int a;
-	for (a = 0; a <= (y2-y1); a++)
-	{
-		video_psetp(pixel, color);
-		pixel+=video_mode.XResolution;
-	}
-}
-
-void video_rect(int x1, int y1, int x2, int y2, dword color)
-{
-	checkBoundsx(x1);
-	checkBoundsx(x2);
-	checkBoundsy(y1);
-	checkBoundsy(y2);
-	if (x2 < x1)
-	{
-		int tmp = x2;
-		x2 = x1;
-		x1 = tmp;
-	}
-	if (y2 < y1)
-	{
-		int tmp = y2;
-		y2 = y1;
-		y1 = tmp;
-	}
-	video_horiz(y1, x1, x2, color);
-	video_horiz(y2, x1, x2, color);
-	video_vert(x1, y1, y2, color);
-	video_vert(x2, y1, y2, color);
-}
-
-void video_rectf(int x1, int y1, int x2, int y2, dword color)
-{
-	checkBoundsx(x1);
-	checkBoundsx(x2);
-	checkBoundsy(y1);
-	checkBoundsy(y2);
-	if (x2 < x1)
-	{
-		int tmp = x2;
-		x2 = x1;
-		x1 = tmp;
-	}
-	if (y2 < y1)
-	{
-		int tmp = y2;
-		y2 = y1;
-		y1 = tmp;
-	}
-	int a;
-	for (a = 0; a <= (y2-y1); a++)
-		video_horiz(y1+a, x1, x2, color);
-}
-
-inline void video_pset(int x, int y, dword color)
-{
-	video_psetp(y*video_mode.XResolution+x, color);
-}
-
-void video_psetp(int pixel, dword color)
-{
-	switch(video_mode.BitsPerPixel)
-	{
-	case 16:
-		vid_ptr16[pixel] = ((color&0xFF)>>3) | ((((color>>8)&0xFF)>>2)<<5) | ((((color>>16)&0xFF)>>3)<<11);
-		//vid_ptr16[pixel] = ((color&0xFF)>>3) | ((((color>>8)&0xFF)>>3)<<5) | ((((color>>16)&0xFF)>>3)<<10);
-		break;
-	case 24:
-		vid_ptr24[pixel*3] = color & 0xFF;
-		vid_ptr24[pixel*3+1] = (color>>8) & 0xFF;
-		vid_ptr24[pixel*3+2] = (color>>16) & 0xFF;
-		break;
-	case 32:
-		vid_ptr32[pixel] = color;
-	}
-}
-
-
-

video.h

@@ -1,66 +0,0 @@
-//video.h
-// 08/18/03 Josh Holtrop
-
-
-void video_init();
-void video_horiz(int y, int x1, int x2, dword color);
-void video_vert(int x, int y1, int y2, dword color);
-void video_rect(int x1, int y1, int x2, int y2, dword color);
-void video_rectf(int x1, int y1, int x2, int y2, dword color);
-inline void video_pset(int x, int y, dword color);
-void video_psetp(int pixel, dword color);
-
-
-#define checkBoundsx(x) (x<0 ? x=0 : (x>=video_mode.XResolution ? x=video_mode.XResolution-1 : 0))
-#define checkBoundsy(x) (x<0 ? x=0 : (x>=video_mode.YResolution ? x=video_mode.YResolution-1 : 0))
-
-typedef struct{
-	word	ModeAttributes;
-	byte	WinAAttributes;
-	byte	WinBAttributes;
-	word	WinGranularity;
-	word	WinSize;
-	word	WinASegment;
-	word	WinBSegment;
-	dword	WinFuncPtr;
-	word	BytesPerScanLine;
-
-	word	XResolution;
-	word	YResolution;
-	byte	XCharSize;
-	byte	YCharSize;
-	byte	NumberOfPlanes;
-	byte	BitsPerPixel;
-	byte	NumberOfBanks;
-	byte	MemoryModel;
-	byte	BankSize;
-	byte	NumberOfImagePages;
-	byte	Reserved1;
-
-	byte	RedMaskSize;
-	byte	RedFieldPosition;
-	byte	GreenMaskSize;
-	byte	GreenFieldPosition;
-	byte	BlueMaskSize;
-	byte	BlueFieldPosition;
-	byte	RsvdMaskSize;
-	byte	RsvdFieldPosition;
-	byte	DirectColorModeInfo;
-
-	dword	PhysBasePtr;
-	dword	OffScreenMemOffset;
-	word	OffScreenMemSize;
-	byte	Reserved[206];
-} ModeInfoBlock;
-
-ModeInfoBlock	video_mode;
-byte	*vid_ptr24;
-word	*vid_ptr16;
-dword	*vid_ptr32;
-
-
-
-
-
-
-

vmm.c

@@ -1,27 +0,0 @@
-
-// vmm.c
-// Author: Josh Holtrop
-// Date: 09/30/03
-
-
-void	*malloc(dword bytes)
-{
-
-
-}
-
-
-
-int	free(void *ptr);
-{
-
-
-
-
-}
-
-
-
-
-
-

vmm.h

@@ -1,13 +0,0 @@
-
-// vmm.h
-// Author: Josh Holtrop
-// Date: 09/30/03
-
-
-void   *malloc(dword bytes);
-int	free(void *ptr);
-
-
-
-
-

x86_64-elf-gcc.rb

@@ -0,0 +1,85 @@
+project_name "x86_64-elf-gcc"
+binutils_version = "2.41"
+binutils_checksum = "ae9a5789e23459e59606e6714723f2d3ffc31c03174191ef0d015bdf06007450"
+gcc_version = "13.2.0"
+gcc_checksum = "e275e76442a6067341a27f04c5c6b83d8613144004c0413528863dc6b5c743da"
+install_path = File.expand_path("x86_64-elf-gcc")
+target = "x86_64-elf"
+path_prepend "#{install_path}/bin"
+
+configure do
+  check_c_compiler "gcc"
+  check_program "make"
+  check_program "bison"
+  check_program "flex"
+  check_program "texi2any", on_fail: "Install the texinfo package"
+  check_program "wget"
+  check_lib "gmp", on_fail: "Install the libgmp-dev package"
+  check_lib "mpc", on_fail: "Install the libmpc-dev package"
+  check_lib "mpfr", on_fail: "Install the libmpfr-dev package"
+end
+
+default do
+  unless Dir.exist?(install_path)
+    puts "Building cross compiler toolchain..."
+
+    # Download archives.
+    puts "Downloading binutils..."
+    download "https://ftp.gnu.org/gnu/binutils/binutils-#{binutils_version}.tar.xz",
+      "#{build_dir}/binutils-#{binutils_version}.tar.xz",
+      sha256sum: binutils_checksum
+
+    puts "Downloading gcc..."
+    download "https://ftp.gnu.org/gnu/gcc/gcc-#{gcc_version}/gcc-#{gcc_version}.tar.xz",
+      "#{build_dir}/gcc-#{gcc_version}.tar.xz",
+      sha256sum: gcc_checksum
+
+    # Extract archives.
+    puts "Extracting binutils..."
+    sh "tar", "xJf", "binutils-#{binutils_version}.tar.xz",
+      chdir: build_dir
+
+    puts "Extracting gcc..."
+    sh "tar", "xJf", "gcc-#{gcc_version}.tar.xz",
+      chdir: build_dir
+
+    # Build binutils.
+    puts "Building binutils..."
+    rm_rf "#{build_dir}/build-binutils"
+    mkdir_p "#{build_dir}/build-binutils"
+    cd "#{build_dir}/build-binutils" do
+      sh %W[../binutils-#{binutils_version}/configure
+        --target=#{target} --prefix=#{install_path} --with-sysroot --disable-nls
+        --disable-werror]
+      sh "make"
+      sh "make install"
+    end
+
+    # Build gcc.
+    puts "Building gcc..."
+    rm_rf "#{build_dir}/build-gcc"
+    mkdir_p "#{build_dir}/build-gcc"
+    cd "#{build_dir}/build-gcc" do
+      sh %W[../gcc-#{gcc_version}/configure
+        --target=#{target} --prefix=#{install_path} --disable-nls
+        --enable-languages=c --without-headers]
+      sh "make all-gcc"
+      sh "make all-target-libgcc"
+      sh "make install-gcc"
+      sh "make install-target-libgcc"
+    end
+
+    # Remove archives and build directories if everything succeeded.
+    puts "Cleaning up..."
+    rm_f "#{build_dir}/binutils-#{binutils_version}.tar.xz"
+    rm_rf "#{build_dir}/binutils-#{binutils_version}"
+    rm_rf "#{build_dir}/build-binutils"
+    rm_f "#{build_dir}/gcc-#{gcc_version}.tar.xz"
+    rm_rf "#{build_dir}/gcc-#{gcc_version}"
+    rm_rf "#{build_dir}/build-gcc"
+  end
+end
+
+distclean do
+  rm_rf install_path
+end