Remove HOS v0.16 sources

Move cross compiler to i686-elf-gcc directory.
Automatically build cross compiler using rscons subsidiary script.

.gitignore

@@ -0,0 +1,3 @@
+.rscons*
+/i686-elf-gcc/
+/build/

Makefile

@@ -1,37 +0,0 @@
-
-KERNEL_FILE := hos.gz
-MKISOFS     := genisoimage
-ISO         := hos.iso
-QEMU        := qemu-system-x86_64
-BOCHS       := bochs
-
-# default target: build the kernel and ISO image
-all: kernel iso
-
-# build the kernel
-.PHONY: kernel
-kernel:
-	$(MAKE) -C $@
-
-# build the ISO image
-.PHONY: iso
-iso: $(ISO) kernel
-
-$(ISO): kernel
-	cp kernel/$(KERNEL_FILE) iso/boot
-	-rm -f $(ISO)
-	$(MKISOFS) -R -b boot/grub/stage2_eltorito -no-emul-boot \
-		-boot-load-size 4 -boot-info-table -o $(ISO) iso
-
-.PHONY: qemu
-qemu: iso
-	$(QEMU) -cdrom $(ISO) -boot d -m 384 -localtime
-
-.PHONY: bochs
-bochs: iso
-	-$(BOCHS)
-
-.PHONY: clean
-clean:
-	$(MAKE) -C kernel clean
-	-rm -f $(ISO) iso/boot/$(KERNEL_FILE)

Rsconscript

@@ -0,0 +1,166 @@
+path_prepend "i686-elf-gcc/bin"
+
+configure do
+  rscons "i686-elf-gcc.rb", "-b", "#{build_dir}/i686-elf-gcc"
+  check_c_compiler "i686-elf-gcc"
+  check_program "genext2fs"
+  check_program "grub-mkstandalone"
+  check_program "mformat", on_fail: "Install the mtools package"
+  check_program "xorriso"
+  check_cfg package: "freetype2", on_fail: "Install libfreetype-dev", use: "freetype"
+end
+
+require "tmpdir"
+
+# EFI (w/ GRUB) partition size (MiB)
+EFI_PART_SIZE = 8
+# HOS partition size (MiB)
+HOS_PART_SIZE = 4
+# Kernel default font size
+KFONT_SIZE = 15
+
+class BiosImage < Builder
+  def run(options)
+    unless @cache.up_to_date?(@target, nil, @sources, @env)
+      print_run_message("Generating BIOS boot image #{@target}", nil)
+      Dir.mktmpdir do |tmpdir|
+        # Create iso directory.
+        FileUtils.mkdir_p("#{tmpdir}/iso/boot/grub")
+        File.open("#{tmpdir}/iso/boot/grub/grub.cfg", "wb") do |fh|
+          fh.write(<<EOF)
+set default="0"
+set timeout=1
+menuentry "HOS" {
+insmod multiboot2
+multiboot2 /hos.elf
+}
+EOF
+        end
+        @sources.each do |source|
+          FileUtils.cp(source, "#{tmpdir}/iso")
+        end
+        # Build bootable GRUB image.
+        system(*%W[grub-mkrescue -o #{@target} #{tmpdir}/iso], err: "#{@env.build_root}/grub-mkrescue.log")
+      end
+      @cache.register_build(@target, nil, @sources, @env)
+    end
+    true
+  end
+end
+
+class EfiImage < Builder
+  def run(options)
+    unless @cache.up_to_date?(@target, nil, @sources, @env)
+      print_run_message("Generating EFI boot image #{@target}", nil)
+      Dir.mktmpdir do |tmpdir|
+        # Build a standalone GRUB.
+        File.open("#{tmpdir}/grub.cfg", "wb") do |fh|
+          fh.write(<<EOF)
+insmod part_gpt
+configfile (hd0,gpt2)/grub.cfg
+EOF
+        end
+        system(*%W[grub-mkstandalone -O x86_64-efi -o #{tmpdir}/BOOTX64.EFI boot/grub/grub.cfg=#{tmpdir}/grub.cfg])
+        # Create EFI partition.
+        system(*%W[dd if=/dev/zero of=#{tmpdir}/efi.part bs=1M count=#{EFI_PART_SIZE}], err: "/dev/null")
+        system(*%W[mformat -i #{tmpdir}/efi.part ::])
+        system(*%W[mmd -i #{tmpdir}/efi.part ::/EFI])
+        system(*%W[mmd -i #{tmpdir}/efi.part ::/EFI/BOOT])
+        system(*%W[mcopy -i #{tmpdir}/efi.part #{tmpdir}/BOOTX64.EFI ::/EFI/BOOT])
+        # Create ext2 HOS partition.
+        FileUtils.mkdir_p("#{tmpdir}/ext2")
+        @sources.each do |source|
+          FileUtils.cp(source, "#{tmpdir}/ext2")
+        end
+        File.open("#{tmpdir}/ext2/grub.cfg", "wb") do |fh|
+          fh.write(<<EOF)
+set default="0"
+set timeout=1
+menuentry "HOS" {
+insmod part_gpt
+insmod multiboot2
+set root=(hd0,gpt2)
+multiboot2 /hos.elf
+}
+EOF
+        end
+        system(*%W[genext2fs -b #{HOS_PART_SIZE * 1024} -d #{tmpdir}/ext2 #{tmpdir}/ext2.part])
+        # Create full disk image.
+        system(*%W[dd if=/dev/zero of=#{@target} bs=1M count=#{EFI_PART_SIZE + HOS_PART_SIZE + 2}], err: "/dev/null")
+        system(*%W[parted -s #{@target} mklabel gpt])
+        system(*%W[parted -s #{@target} mkpart efi 1MiB #{EFI_PART_SIZE + 1}MiB])
+        system(*%W[parted -s #{@target} mkpart hos #{EFI_PART_SIZE + 1}MiB #{EFI_PART_SIZE + HOS_PART_SIZE + 1}MiB])
+        system(*%W[dd if=#{tmpdir}/efi.part of=#{@target} bs=1M seek=1 conv=notrunc], err: "/dev/null")
+        system(*%W[dd if=#{tmpdir}/ext2.part of=#{@target} bs=1M seek=#{1 + EFI_PART_SIZE} conv=notrunc], err: "/dev/null")
+      end
+      @cache.register_build(@target, nil, @sources, @env)
+    end
+    true
+  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
+
+class Size < Builder
+  def run(options)
+    if @command
+      finalize_command
+    else
+      @vars["_SOURCES"] = @sources
+      @vars["_TARGET"] = @target
+      command = @env.build_command(%w[${SIZE} ${_SOURCES}], @vars)
+      standard_command("Size <target>#{@target}<reset>", command, stdout: @target)
+    end
+  end
+end
+
+# FontGen Environment
+fontgen_env = env "fontgen", use: "freetype" do |env|
+  env["CC"] = "gcc"
+  env.Program("^/fontgen.bin", glob("fontgen/**/*.c"))
+end
+
+# Kernel Environment
+kernel_env = env "kernel" do |env|
+  env.add_builder(EfiImage)
+  env.add_builder(BiosImage)
+  env.add_builder(FontGen)
+  env.add_builder(Size)
+  env["OBJDUMP"] = "i686-elf-objdump"
+  env["SIZE"] = "i686-elf-size"
+  env["CCFLAGS"] += %w[-ffreestanding -Wall -O2]
+  env["LDFLAGS"] += %w[-ffreestanding -nostdlib -T src/link.ld]
+  env["LDFLAGS"] += %W[-Wl,-Map,${_TARGET}.map]
+  env["LIBS"] += %w[gcc]
+  env.FontGen("^/kfont/kfont.c", "font/Hack-Regular.ttf",
+             "fontgen" => fontgen_env.expand("^/fontgen.bin"))
+  env.barrier
+  env["CPPPATH"] += ["#{env.build_root}/kfont"]
+  env.Program("^/hos.elf", glob("src/**/*.{S,c}") + ["^/kfont/kfont.c"])
+  env.depends("#{env.build_root}/hos.elf", "src/link.ld")
+  env.Disassemble("^/hos.elf.txt", "^/hos.elf")
+  env.Size("^/hos.elf.size", "^/hos.elf")
+  env.EfiImage("^/hos-efi.img", %w[^/hos.elf])
+  env.BiosImage("^/hos.img", %w[^/hos.elf])
+end
+
+task "run", desc: "Run HOS in QEMU" do
+  img = kernel_env.expand("^/hos.img")
+  sh %W[qemu-system-x86_64 -hda #{img}]
+end
+
+task "run-efi", desc: "Run HOS EFI in QEMU" do
+  img = kernel_env.expand("^/hos-efi.img")
+  sh %W[qemu-system-x86_64 -bios OVMF.fd -hda #{img}]
+end

bochsrc

@@ -1,52 +0,0 @@
-# configuration file generated by Bochs
-plugin_ctrl: unmapped=1, biosdev=1, speaker=1, extfpuirq=1, gameport=1, pci_ide=1, acpi=1, ioapic=1
-config_interface: textconfig
-display_library: sdl
-megs: 32
-romimage: file="/usr/share/bochs/BIOS-bochs-latest"
-vgaromimage: file="/usr/share/bochs/VGABIOS-lgpl-latest"
-boot: cdrom
-floppy_bootsig_check: disabled=0
-# no floppya
-# no floppyb
-ata0: enabled=1, ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14
-ata0-master: type=cdrom, path="hos.iso", status=inserted, biosdetect=auto, model="Generic 1234"
-ata1: enabled=1, ioaddr1=0x170, ioaddr2=0x370, irq=15
-ata2: enabled=0
-ata3: enabled=0
-parport1: enabled=1, file=""
-parport2: enabled=0
-com1: enabled=1, mode=null, dev=""
-com2: enabled=0
-com3: enabled=0
-com4: enabled=0
-usb_uhci: enabled=0
-usb_ohci: enabled=0
-i440fxsupport: enabled=1
-vga_update_interval: 50000
-vga: extension=vbe
-cpu: count=1, ips=4000000, reset_on_triple_fault=1, cpuid_limit_winnt=0
-print_timestamps: enabled=0
-# no gdb stub
-port_e9_hack: enabled=0
-text_snapshot_check: enabled=0
-private_colormap: enabled=0
-clock: sync=none, time0=local
-# no cmosimage
-ne2k: enabled=0
-pnic: enabled=0
-sb16: enabled=0
-# no loader
-log: -
-logprefix: %t%e%d
-panic: action=ask
-error: action=report
-info: action=report
-debug: action=ignore
-pass: action=fatal
-keyboard_type: mf
-keyboard_serial_delay: 250
-keyboard_paste_delay: 100000
-keyboard_mapping: enabled=0, map=
-user_shortcut: keys=none
-mouse: enabled=0, type=ps2

fontgen/fontgen.c

@@ -0,0 +1,224 @@
+#include <stdlib.h>
+#include <stdint.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 const char * bare_header_name(const char * h_file_name)
+{
+    const char * p = rindex(h_file_name, '/');
+    if (p == NULL)
+    {
+        p = h_file_name;
+    }
+    else
+    {
+        p++;
+    }
+    return p;
+}
+
+static char * include_guard_name(const char * h_file_name)
+{
+    const char * p = bare_header_name(h_file_name);
+    char * guard_name = malloc(strlen(p) + 1);
+    strcpy(guard_name, p);
+    char * m = guard_name;
+    while (*m != '\0')
+    {
+        if ('a' <= *m && *m <= 'z')
+        {
+            *m = toupper(*m);
+        }
+        else if (('0' <= *m && *m <= '9') || ('A' <= *m && *m <= 'Z'))
+        {
+            /* no change */
+        }
+        else
+        {
+            *m = '_';
+        }
+        m++;
+    }
+    return guard_name;
+}
+
+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 void generate(const char * c_file_name)
+{
+    char * h_file_name = malloc(strlen(c_file_name) + 1);
+    strcpy(h_file_name, c_file_name);
+    h_file_name[strlen(h_file_name) - 1] = 'h';
+    char * guard = include_guard_name(h_file_name);
+
+    FILE * h_file = fopen(h_file_name, "wb");
+    fprintf(h_file, "#ifndef %s\n", guard);
+    fprintf(h_file, "#define %s\n\n", guard);
+    fprintf(h_file, "#include <stdint.h>\n");
+    fprintf(h_file, "typedef struct {\n    int width;\n    int height;\n    int top;\n    int left;\n    const uint8_t * bitmap;\n} fontgen_char_info_t;\n");
+    fprintf(h_file, "typedef struct {\n    int line_height;\n    int advance;\n    int baseline_offset;\n    const fontgen_char_info_t ** char_infos;\n} fontgen_font_t;\n");
+    fprintf(h_file, "extern const fontgen_font_t kfont;\n");
+    fprintf(h_file, "#endif\n");
+    fclose(h_file);
+
+    FILE * c_file = fopen(c_file_name, "wb");
+    fprintf(c_file, "#include \"%s\"\n", bare_header_name(h_file_name));
+    fprintf(c_file, "#include <stddef.h>\n");
+    for (int i = 0; i < N_CHARS; i++)
+    {
+        if (char_infos[i].width > 0)
+        {
+            fprintf(c_file, "static const uint8_t char_bitmap_%d[] = {\n", i);
+            generate_bytes(c_file, char_infos[i].bitmap, char_infos[i].width * char_infos[i].height);
+            fprintf(c_file, "};\n");
+        }
+        fprintf(c_file, "static const fontgen_char_info_t char_%d = {\n", i);
+        fprintf(c_file, "    %d,\n", char_infos[i].width);
+        fprintf(c_file, "    %d,\n", char_infos[i].height);
+        fprintf(c_file, "    %d,\n", char_infos[i].top);
+        fprintf(c_file, "    %d,\n", char_infos[i].left);
+        if (char_infos[i].width > 0)
+        {
+            fprintf(c_file, "    char_bitmap_%d,\n", i);
+        }
+        else
+        {
+            fprintf(c_file, "    NULL,\n");
+        }
+        fprintf(c_file, "};\n\n");
+    }
+    fprintf(c_file, "const fontgen_char_info_t * char_infos[] = {\n");
+    for (int i = 0; i < N_CHARS; i++)
+    {
+        fprintf(c_file, "    &char_%d,\n", i);
+    }
+    fprintf(c_file, "};\n");
+    fprintf(c_file, "const fontgen_font_t kfont = {\n");
+    fprintf(c_file, "    %d,\n", line_height);
+    fprintf(c_file, "    %d,\n", max_advance);
+    fprintf(c_file, "    %d,\n", baseline_offset);
+    fprintf(c_file, "    char_infos,\n");
+    fprintf(c_file, "};\n");
+    fclose(c_file);
+}
+
+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;
+
+    generate(out_file);
+
+    return 0;
+}

i686-elf-gcc.rb

@@ -0,0 +1,75 @@
+binutils_version = "2.35"
+binutils_checksum = "1b11659fb49e20e18db460d44485f09442c8c56d5df165de9461eb09c8302f85"
+gcc_version = "10.2.0"
+gcc_checksum = "b8dd4368bb9c7f0b98188317ee0254dd8cc99d1e3a18d0ff146c855fe16c1d8c"
+install_path = File.expand_path("i686-elf-gcc")
+target = "i686-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)
+    # Download archives.
+    download "https://ftp.gnu.org/gnu/binutils/binutils-#{binutils_version}.tar.xz",
+      "#{build_dir}/binutils-#{binutils_version}.tar.xz",
+      sha256sum: binutils_checksum
+
+    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.
+    sh "tar", "xJf", "binutils-#{binutils_version}.tar.xz",
+      chdir: build_dir
+
+    sh "tar", "xJf", "gcc-#{gcc_version}.tar.xz",
+      chdir: build_dir
+
+    # Build 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.
+    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,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.
+    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

iso/boot/grub/menu.lst

@@ -1,6 +0,0 @@
-
-timeout 2
-default 0
-
-title HOS
-kernel /boot/hos.gz

kernel/Makefile

@@ -1,45 +0,0 @@
-
-CROSS_COMPILE   := i586-elf-
-
-export LD       := $(CROSS_COMPILE)ld
-export CC       := $(CROSS_COMPILE)gcc
-export CXX      := $(CROSS_COMPILE)g++
-export OBJDUMP  := $(CROSS_COMPILE)objdump
-export NASM     := nasm
-
-export HOS_TOPLEVEL := $(shell pwd)
-LDSCRIPT        := link.ld
-KERNEL          := hos
-export CPPFLAGS := -I$(HOS_TOPLEVEL) -I$(HOS_TOPLEVEL)/include
-export CFLAGS   := -Wall -O2 -g
-export CXXFLAGS := -Wall -O2 -fno-rtti -fno-exceptions -g
-export LDFLAGS  := -T $(LDSCRIPT) -Map $(KERNEL).map
-export LDLIBS   := `$(CC) -print-libgcc-file-name`
-
-SUBDIRS         := boot mm lang isr sys
-SUBDIRS_clean   := $(SUBDIRS:%=%.clean)
-
-.PHONY: all
-all: $(KERNEL).gz
-
-$(KERNEL).gz: $(KERNEL)
-	gzip -c $< > $@
-
-$(KERNEL): $(KERNEL).o
-	$(LD) $(LDFLAGS) -o $@ $<
-	$(OBJDUMP) --disassemble --source $@ > $@.dump
-#	strip $@
-	
-$(KERNEL).o: $(SUBDIRS)
-	$(LD) -r -o $@ $(foreach subdir,$(SUBDIRS),$(subdir)/$(subdir)_all.o) $(LDLIBS)
-
-.PHONY: $(SUBDIRS)
-$(SUBDIRS):
-	$(MAKE) -C $@ SUBDIR=$@
-
-.PHONY: clean
-clean: $(SUBDIRS_clean)
-	-rm -f *~ $(KERNEL) $(KERNEL).{gz,o,elf,dump,map}
-
-%.clean:
-	$(MAKE) -C $* clean clean=1

kernel/boot/Makefile

@@ -1,2 +0,0 @@
-
-include $(HOS_TOPLEVEL)/subdir.mak

kernel/boot/boot.asm

@@ -1,23 +0,0 @@
-; boot.asm
-; Author: Josh Holtrop
-; Date: 2009-06-25
-; Adapted from HOS 0.16 source
-
-%define CONSOLE_MEMORY              0xB8000
-
-; Symbols from C
-extern k_bootstrap, bootstrap_stack
-
-;**************************************************************************
-;* This is the entry point for the kernel.                                *
-;**************************************************************************
-[global start]
-start:
-    mov     cx, 0x0700 + 'a'
-    mov     [CONSOLE_MEMORY+160*8+0*2], cx
-
-    mov     esp, bootstrap_stack+4096       ; set up temporary stack space
-
-    push    eax                             ; multiboot bootloader magic value
-    push    ebx                             ; pointer to multiboot info struct
-    call    k_bootstrap

kernel/boot/k_bootstrap.cc

@@ -1,85 +0,0 @@
-
-#include "k_bootstrap.h"
-#include "k_main.h"
-#include "hos_types.h"
-#include "hos_defines.h"
-#include "multiboot.h"
-#include "sys/cpu.h"
-#include "k_early_panic.h"
-#include "mm/mm.h"
-#include "mm/stack.h"
-#include "lang/kio.h"
-#include "isr/interrupts.h"
-
-#define DEBUG_LETTER(col,chr) *(u16_t *)(KERNEL_OFFSET + CONSOLE_MEMORY \
-                                  + 160 * 8 + (col) * 2) \
-                                  = 0x0700 | (chr)
-extern "C" {
-
-u8_t bootstrap_stack[4096];
-
-/**************************************************************************
- * Multiboot header data block                                            *
- *************************************************************************/
-u32_t mb_header[] __attribute__ ((section (".multiboot_header") )) = {
-    MB_HEADER_MAGIC,                            /* magic */
-    MB_HEADER_FLAGS,                            /* flags */
-    -(MB_HEADER_MAGIC + MB_HEADER_FLAGS)        /* checksum */
-};
-
-/**************************************************************************
- * This function is invoked to bootstrap the kernel.                      *
- *************************************************************************/
-void k_bootstrap(mb_info_t * mb_info, u32_t mb_magic)
-{
-    DEBUG_LETTER(1, 'b');
-
-    if (mb_magic != MB_BOOTLOADER_MAGIC)
-    {
-        k_early_panic("Bad multiboot magic identifier!");
-    }
-
-    if ( ! (mb_info->flags & MB_BOOTLOADER_MMAP) )
-    {
-        k_early_panic("No memory map provided by bootloader!");
-    }
-
-    for (mb_mmap_t * mmap = (mb_mmap_t *) (mb_info->mmap_addr + KERNEL_OFFSET),
-                   * end = (mb_mmap_t *) ((u32_t)mmap + mb_info->mmap_length);
-         mmap < end;
-         mmap = (mb_mmap_t *) (((u32_t)mmap) + mmap->size + 4))
-    {
-//        kprintf(" ** size: %d, type: %d ", mmap->size, mmap->type);
-        mm_record_mmap_entry(mmap);
-    }
-
-    DEBUG_LETTER(2, 'c');
-
-    /*
-     * These functions could destroy the multiboot information block and
-     * associated structures, so we must be finished reading those structures
-     * before calling them.
-     */
-    mm_bootstrap();
-    DEBUG_LETTER(3, 'd');
-    interrupts_bootstrap();
-    DEBUG_LETTER(4, 'e');
-    kio_bootstrap();
-    DEBUG_LETTER(5, 'f');
-
-    /* begin using the permanent stack */
-    write_esp(KERNEL_STACK_TOP);
-    k_main();
-
-    idle_loop();
-}
-
-void idle_loop()
-{
-    for (;;)
-    {
-        __asm__ __volatile__ ("hlt");
-    }
-}
-
-} /* extern "C" */

kernel/boot/k_bootstrap.h

@@ -1,17 +0,0 @@
-
-#ifndef K_BOOTSTRAP_H
-#define K_BOOTSTRAP_H
-
-#include "hos_types.h"
-#include "multiboot.h"
-
-extern "C" {
-
-void k_bootstrap(mb_info_t * mb_info, u32_t mb_magic)
-    __attribute__ ((noreturn));
-void idle_loop()
-    __attribute__ ((noreturn));
-
-}
-
-#endif

kernel/boot/k_early_panic.c

@@ -1,18 +0,0 @@
-
-#include "hos_types.h"
-#include "hos_defines.h"
-#include "k_early_panic.h"
-
-void k_early_panic(const char * msg)
-{
-    char * dest = (char *) (CONSOLE_MEMORY + KERNEL_OFFSET);
-    while (*msg)
-    {
-        *dest++ = *msg++;
-        *dest++ = 0x04;         /* red error message */
-    }
-
-    /* infinite loop */
-    for (;;)
-        ;
-}

kernel/boot/k_early_panic.h

@@ -1,15 +0,0 @@
-
-#ifndef K_EARLY_PANIC_H
-#define K_EARLY_PANIC_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-void k_early_panic(const char * msg);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif

kernel/boot/k_main.cc

@@ -1,28 +0,0 @@
-
-#include "k_main.h"
-#include "lang/kio.h"
-#include "mm/mm.h"
-#include "sys/timer.h"
-#include "sys/pic.h"
-#include "isr/interrupts.h"
-
-extern "C" {
-
-void k_main()
-{
-    kprintf("Kernel load address: 0x%08x\n", KERNEL_CODE);
-    kprintf("Kernel code size: %d KB (%d bytes)\n",
-            (KERNEL_DATA - KERNEL_CODE) >> 10, KERNEL_DATA - KERNEL_CODE);
-    kprintf("Kernel data size: %d KB (%d bytes)\n",
-            (KERNEL_BSS - KERNEL_DATA) >> 10, KERNEL_BSS - KERNEL_DATA);
-    kprintf("Kernel bss size:  %d KB (%d bytes)\n",
-            (KERNEL_END - KERNEL_BSS) >> 10, KERNEL_END - KERNEL_BSS);
-    mm_print_memory_map();
-    timer_init(KERNEL_TIMER_FREQ);
-    pic_remap(0x20, 0x28);
-    pic_mask1(0x0);
-    pic_mask2(0x0);
-    interrupts_enable();
-}
-
-} /* extern "C" */

kernel/boot/k_main.h

@@ -1,11 +0,0 @@
-
-#ifndef K_MAIN_H
-#define K_MAIN_H
-
-extern "C" {
-
-void k_main();
-
-}
-
-#endif

kernel/include/hos_defines.h

@@ -1,47 +0,0 @@
-
-#ifndef HOS_DEFINES_H
-#define HOS_DEFINES_H
-
-#include "hos_types.h"
-
-#define KERNEL_OFFSET           0x00000000
-
-#define PAGE_LOG_SIZE           12u
-#define PAGE_SIZE               (1 << PAGE_LOG_SIZE)
-#define PAGE_HIGH_MASK          (0xFFFFFFFFu << PAGE_LOG_SIZE)
-#define PAGE_LOW_MASK           (0xFFFFFFFFu >> (32 - PAGE_LOG_SIZE))
-
-#define CONSOLE_MEMORY          0xB8000
-
-#define KERNEL_CODE             (&_code)
-#define KERNEL_DATA             (&_data)
-#define KERNEL_BSS              (&_bss)
-#define KERNEL_END              (&_end)
-
-#define KERNEL_PHYSICAL_ADDRESS ((u32_t)(KERNEL_CODE - KERNEL_OFFSET))
-#define KERNEL_VIRTUAL_ADDRESS  ((u32_t)KERNEL_CODE)
-#define KERNEL_SIZE             ((u32_t)(KERNEL_END - KERNEL_CODE))
-
-#define KERNEL_TIMER_FREQ       1000
-
-#define BUILD_BUG_ON(condition) \
-    do { \
-        typedef struct { int negative_width_test : ((condition)?-1:1); } \
-            BUILD_BUG_ON_DUMMY_STRUCT; \
-    } \
-    while(0)
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-extern  u8_t    _code;
-extern  u8_t    _data;
-extern  u8_t    _bss;
-extern  u8_t    _end;
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif

kernel/include/hos_types.h

@@ -1,55 +0,0 @@
-
-#ifndef HOS_TYPES_H
-#define HOS_TYPES_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-typedef unsigned char       u8_t;
-typedef signed char         s8_t;
-typedef unsigned short      u16_t;
-typedef signed short        s16_t;
-typedef unsigned int        u32_t;
-typedef signed int          s32_t;
-typedef unsigned long long  u64_t;
-typedef signed long long    s64_t;
-
-typedef struct
-{
-    u32_t   gs;
-    u32_t   fs;
-    u32_t   es;
-    u32_t   ds;
-
-    u32_t   edi;
-    u32_t   esi;
-    u32_t   ebp;
-    u32_t   esp_junk;               /* the esp value saved by 'pusha' */
-    u32_t   ebx;
-    u32_t   edx;
-    u32_t   ecx;
-    u32_t   eax;
-
-    u32_t   error;                  /* valid on exceptions 8, 10-14 */
-
-    u32_t   eip;
-    u32_t   cs;
-    u32_t   eflags;
-    u32_t   esp;                    /* present if privilege transition */
-    u32_t   ss;
-} int_stack_t;
-
-typedef struct
-{
-    u16_t   limit;
-    u32_t   base;
-} __attribute__ ((packed)) gdtr_t;
-
-typedef gdtr_t idtr_t;
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif

kernel/include/multiboot.h

@@ -1,154 +0,0 @@
-
-#ifndef MULTIBOOT_H
-#define MULTIBOOT_H
-
-#include "hos_types.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* The magic number for the Multiboot header. */
-#define MB_HEADER_MAGIC             0x1BADB002
-#define MB_HEADER_FLAGS             0x00000003
-
-#define MB_HEADER_ALIGN_MODULES     (1 << 0)
-#define MB_HEADER_MEM_INFO          (1 << 1)
-#define MB_HEADER_VIDEO_INFO        (1 << 2)
-#define MB_HEADER_KLUDGE_OFFSETS    (1 << 16)
-
-/* The magic number passed by a Multiboot-compliant boot loader. */
-#define MB_BOOTLOADER_MAGIC         0x2BADB002
-
-#define MB_BOOTLOADER_MEM_INFO      (1 << 0)
-#define MB_BOOTLOADER_BOOT_DEVICE   (1 << 1)
-#define MB_BOOTLOADER_COMMAND_LINE  (1 << 2)
-#define MB_BOOTLOADER_MODS          (1 << 3)
-#define MB_BOOTLOADER_AOUT          (1 << 4)
-#define MB_BOOTLOADER_ELF           (1 << 5)
-#define MB_BOOTLOADER_MMAP          (1 << 6)
-#define MB_BOOTLOADER_DRIVES        (1 << 7)
-#define MB_BOOTLOADER_CONFIG        (1 << 8)
-#define MB_BOOTLOADER_APM           (1 << 9)
-#define MB_BOOTLOADER_GRAPHICS      (1 << 10)
-
-#define MB_DRIVE_MODE_CHS           0
-#define MB_DRIVE_MODE_LBA           1
-
-#define MB_MMAP_TYPE_RAM            1
-
-/* The Multiboot header. */
-typedef struct
-{
-    u32_t   magic;
-    u32_t   flags;
-    u32_t   checksum;
-    u32_t   header_addr;        // if flags[16]
-    u32_t   load_addr;          // if flags[16]
-    u32_t   load_end_addr;      // if flags[16]
-    u32_t   bss_end_addr;       // if flags[16]
-    u32_t   entry_addr;         // if flags[16]
-    u32_t   mode_type;          // if flags[2]
-    u32_t   width;              // if flags[2]
-    u32_t   height;             // if flags[2]
-    u32_t   depth;              // if flags[2]
-} mb_header_t;
-
-/* The symbol table for a.out. */
-typedef struct
-{
-    u32_t   tabsize;
-    u32_t   strsize;
-    u32_t   addr;
-    u32_t   reserved;
-} mb_aout_symbol_table_t;
-
-/* The section header table for ELF. */
-typedef struct
-{
-    u32_t   num;
-    u32_t   size;
-    u32_t   addr;
-    u32_t   shndx;
-} mb_elf_section_header_table_t;
-
-/* The Multiboot information. */
-typedef struct
-{
-    u32_t   flags;
-    u32_t   mem_lower;          // present if flags[0] is set
-    u32_t   mem_upper;
-    u32_t   boot_device;        // 1
-    u32_t   cmdline;            // 2
-    u32_t   mods_count;         // 3
-    u32_t   mods_addr;          // 3
-    union
-    {
-        mb_aout_symbol_table_t          aout_sym;   // 4
-        mb_elf_section_header_table_t   elf_sec;    // 5
-    };
-    u32_t   mmap_length;        // 6
-    u32_t   mmap_addr;          // 6
-    u32_t   drives_length;      // 7
-    u32_t   drives_addr;        // 7
-    u32_t   config_table;       // 8
-    u32_t   bootloader_name;    // 9
-    u32_t   apm_table;          // 10
-
-    u32_t   vbe_control_info;   // 11
-    u32_t   vbe_mode_info;      // 11
-    u16_t   vbe_mode;           // 11
-    u16_t   vbe_interface_seg;  // 11
-    u16_t   vbe_interface_off;  // 11
-    u16_t   vbe_interface_len;  // 11
-} mb_info_t;
-
-/* The module structure. */
-typedef struct
-{
-    u32_t   mod_start;
-    u32_t   mod_end;
-    u32_t   string;
-    u32_t   reserved;
-} mb_module_t;
-
-/* The memory map. Be careful that the offset 0 is base_addr_low, not size. */
-typedef struct
-{
-    u32_t   size;                 // offset -4
-    u64_t   base;                 // offset 0
-    u64_t   length;
-    u32_t   type;
-} mb_mmap_t;
-
-/* The drive structure */
-typedef struct
-{
-    u32_t   size;
-    u8_t    drive_number;
-    u8_t    drive_mode;
-    u8_t    drive_cylinders;
-    u8_t    drive_heads;
-    u8_t    drive_sectors;
-    u16_t   drive_ports[1];
-} mb_drive_t;
-
-/* APM table structure */
-typedef struct
-{
-    u16_t   version;
-    u16_t   cseg;
-    u32_t   offset;
-    u16_t   cseg_16;
-    u16_t   dseg;
-    u16_t   flags;
-    u16_t   cseg_len;
-    u16_t   cseg_16_len;
-    u16_t   dseg_len;
-} mb_apm_t;
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif

kernel/include/portio.h

@@ -1,37 +0,0 @@
-
-#ifndef PORTIO_H
-#define PORTIO_H
-
-#include "hos_types.h"
-
-#define outportb(port, val) \
-    __asm__ __volatile__ ("outb %%al, %%dx" : : "a" (val), "d" (port));
-
-#define outportw(port, val) \
-    __asm__ __volatile__ ("outw %%ax, %%dx" : : "a" (val), "d" (port));
-
-#define outportd(port, val) \
-    __asm__ __volatile__ ("outl %%eax, %%dx" : : "a" (val), "d" (port));
-
-static inline u8_t inportb(u16_t port)
-{
-    u8_t val;
-    __asm__ __volatile__ ("inb %%dx, %%al" : "=a" (val) : "d" (port));
-    return val;
-}
-
-static inline u16_t inportw(u16_t port)
-{
-    u16_t val;
-    __asm__ __volatile__ ("inw %%dx, %%al" : "=a" (val) : "d" (port));
-    return val;
-}
-
-static inline u32_t inportd(u16_t port)
-{
-    u32_t val;
-    __asm__ __volatile__ ("inl %%dx, %%al" : "=a" (val) : "d" (port));
-    return val;
-}
-
-#endif

kernel/isr/Makefile

@@ -1,2 +0,0 @@
-
-include $(HOS_TOPLEVEL)/subdir.mak

kernel/isr/interrupts.cc

@@ -1,110 +0,0 @@
-
-#include "hos_types.h"
-#include "interrupts.h"
-#include "mm/mm.h"
-#include "lang/kio.h"
-#include "sys/pic.h"
-#include "sys/cpu.h"
-
-extern "C" {
-
-idtr_t idtr;
-
-void isr(u8_t int_num, int_stack_t * istack)
-{
-    switch (int_num)
-    {
-    case 0x20:                  /* timer interrupt */
-        (*(u16_t *)CONSOLE_MEMORY)++;
-        pic_eoi();
-        break;
-    case 0x21:
-        /* TODO: keyboard hook */
-        pic_eoi();
-        break;
-    default:
-        kputs("--------------------------------------------------------------------------------");
-        kprintf("Unhandled Interrupt #%d\n", int_num);
-        kprintf("    ds: 0x%08x     es: 0x%08x     fs: 0x%08x     gs: 0x%08x\n",
-                istack->ds, istack->es, istack->fs, istack->gs);
-        kprintf("   eax: 0x%08x    ebx: 0x%08x    ecx: 0x%08x    edx: 0x%08x\n",
-                istack->eax, istack->ebx, istack->ecx, istack->edx);
-        kprintf("   ebp: 0x%08x    esi: 0x%08x    edi: 0x%08x eflags: 0x%08x\n",
-                istack->ebp, istack->esi, istack->edi, istack->eflags);
-        kprintf("    cs: 0x%08x    eip: 0x%08x     ss: 0x%08x    esp: 0x%08x\n",
-                istack->cs, istack->eip, istack->ss, istack->esp);
-        kprintf("   cr0: 0x%08x    cr2: 0x%08x    cr3: 0x%08x\n",
-                read_cr0(), read_cr2(), read_cr3());
-        kprintf(" Error: 0x%08x (%d)\n", istack->error, istack->error);
-        kputs("--------------------------------------------------------------------------------");
-
-        kprintf("Halting!\n");
-        for (;;)
-            ;
-        break;
-    }
-}
-
-} /* extern "C" */
-
-void interrupts_bootstrap()
-{
-    u32_t idt_phys = mm_page_alloc();
-    u32_t idt_virt = mm_early_vpage_alloc();
-    mm_map(idt_virt, idt_phys, 0, 1);
-
-    u64_t * idt = (u64_t *) idt_virt;
-    idt[0]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_0,  0);
-    idt[1]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_1,  0);
-    idt[2]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_2,  0);
-    idt[3]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_3,  0);
-    idt[4]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_4,  0);
-    idt[5]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_5,  0);
-    idt[6]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_6,  0);
-    idt[7]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_7,  0);
-    idt[8]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_8,  0);
-    idt[9]  = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_9,  0);
-    idt[10] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_10, 0);
-    idt[11] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_11, 0);
-    idt[12] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_12, 0);
-    idt[13] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_13, 0);
-    idt[14] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_14, 0);
-    idt[15] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_15, 0);
-    idt[16] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_16, 0);
-    idt[17] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_17, 0);
-    idt[18] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_18, 0);
-    idt[19] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_19, 0);
-    idt[20] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_20, 0);
-    idt[21] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_21, 0);
-    idt[22] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_22, 0);
-    idt[23] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_23, 0);
-    idt[24] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_24, 0);
-    idt[25] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_25, 0);
-    idt[26] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_26, 0);
-    idt[27] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_27, 0);
-    idt[28] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_28, 0);
-    idt[29] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_29, 0);
-    idt[30] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_30, 0);
-    idt[31] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_31, 0);
-    idt[32] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_32, 0);
-    idt[33] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_33, 0);
-    idt[34] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_34, 0);
-    idt[35] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_35, 0);
-    idt[36] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_36, 0);
-    idt[37] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_37, 0);
-    idt[38] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_38, 0);
-    idt[39] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_39, 0);
-    idt[40] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_40, 0);
-    idt[41] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_41, 0);
-    idt[42] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_42, 0);
-    idt[43] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_43, 0);
-    idt[44] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_44, 0);
-    idt[45] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_45, 0);
-    idt[46] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_46, 0);
-    idt[47] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_47, 0);
-    idt[48] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_48, 0);
-    idt[49] = MAKE_IDT_DESCRIPTOR(KERNEL_CODE_SEGMENT, isr_49, 0);
-    idtr.base = idt_phys;
-    idtr.limit = 49 * sizeof(idt[0]) - 1;
-    __asm__ __volatile__ ("lidt (idtr)" : : : "memory");
-}

kernel/isr/interrupts.h

@@ -1,79 +0,0 @@
-
-#ifndef INTERRUPTS_H
-#define INTERRUPTS_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-void isr(u8_t int_num, int_stack_t * int_stack);
-
-extern void isr_0();
-extern void isr_1();
-extern void isr_2();
-extern void isr_3();
-extern void isr_4();
-extern void isr_5();
-extern void isr_6();
-extern void isr_7();
-extern void isr_8();
-extern void isr_9();
-extern void isr_10();
-extern void isr_11();
-extern void isr_12();
-extern void isr_13();
-extern void isr_14();
-extern void isr_15();
-extern void isr_16();
-extern void isr_17();
-extern void isr_18();
-extern void isr_19();
-extern void isr_20();
-extern void isr_21();
-extern void isr_22();
-extern void isr_23();
-extern void isr_24();
-extern void isr_25();
-extern void isr_26();
-extern void isr_27();
-extern void isr_28();
-extern void isr_29();
-extern void isr_30();
-extern void isr_31();
-extern void isr_32();
-extern void isr_33();
-extern void isr_34();
-extern void isr_35();
-extern void isr_36();
-extern void isr_37();
-extern void isr_38();
-extern void isr_39();
-extern void isr_40();
-extern void isr_41();
-extern void isr_42();
-extern void isr_43();
-extern void isr_44();
-extern void isr_45();
-extern void isr_46();
-extern void isr_47();
-extern void isr_48();
-extern void isr_49();
-
-#ifdef __cplusplus
-}
-#endif
-
-#define MAKE_IDT_DESCRIPTOR(selector, offset, dpl) \
-    (u64_t) ( ( (((u64_t) offset) & 0xFFFF0000ull) << 32 )  /* offset 31:16 */ \
-            | ( ( (u64_t) 0x1ull) << 47 )                   /* present */      \
-            | ( (((u64_t) dpl) & 0x3) << 45 )               /* DPL */          \
-            | ( ( (u64_t) 0xEull) << 40 )                   /* TODO: gate? */  \
-            | ( (((u64_t) selector) & 0xFFFFull) << 16 )    /* selector */     \
-            | ( (((u64_t) offset) & 0x0000FFFFull) ) )      /* offset 15:0 */
-
-void interrupts_bootstrap();
-
-#define interrupts_enable() __asm__ __volatile__ ("sti");
-#define interrupts_disable() __asm__ __volatile__ ("cli");
-
-#endif

kernel/isr/isr.asm

@@ -1,56 +0,0 @@
-
-; C ISR routine
-[extern isr]
-
-
-; Macro for creating a single ISR label
-; We need to push a junk value on the stack first
-; if the interrupt number is not 8 or 10-14.
-; This is to properly align the stack for both exceptions
-; having and not having error codes.
-%macro isr_label 1
-[global isr_%1]
-isr_%1:
-    %if ( (%1 != 8) && (%1 < 10 || %1 > 14) )
-        push    eax                 ; junk value to take error code stack space
-    %endif
-    pusha                           ; eax, ecx, edx, ebx, esp, ebp, esi, edi
-    mov     al, %1                  ; save interrupt number in al
-    %if ($ - isr_common) < 127      ; do a short jump and save 3 bytes if we can
-        jmp short isr_common
-    %else
-        jmp     isr_common
-    %endif
-%endmacro
-
-
-; The common ISR routine
-isr_common:
-    push    ds
-    push    es
-    push    fs
-    push    gs
-
-    push    esp                     ; pointer to interrupt stack
-    push    eax                     ; interrupt number
-    call    isr
-    pop     eax                     ; restore stack pointer (this is shorter
-    pop     eax                     ; than "add esp, 8" and "lea esp, [esp+8]")
-
-    pop     gs
-    pop     fs
-    pop     es
-    pop     ds
-    popa                            ; edi, esi, ebp, <null>, ebx, edx, ecx, eax
-    lea     esp, [esp+4]            ; bypass error code
-
-    iret
-
-
-; Loop to create all of our ISR entry points
-%assign i 0
-%rep 50
-    isr_label i
-    %assign i i+1
-%endrep
-

kernel/lang/Makefile

@@ -1,2 +0,0 @@
-
-include $(HOS_TOPLEVEL)/subdir.mak

kernel/lang/kio.cc

@@ -1,317 +0,0 @@
-
-#include "hos_types.h"
-#include "hos_defines.h"
-#include "kio.h"
-#include "string.h"
-#include "portio.h"
-
-#include <limits.h>
-#include <stdarg.h>                 /* va_*() */
-
-static void fmt_d2a(char * buf, int val);
-static void fmt_u2a(char * buf, unsigned int val);
-static void fmt_ll2a(char * buf, long long val);
-static void fmt_ull2a(char * buf, unsigned long long val);
-static void fmt_x2a(char * buf, unsigned int val);
-static void fmt_xl2a(char * buf, unsigned long long val);
-static void fmt_o2a(char * buf, unsigned int val);
-
-static int cursor_x, cursor_y;
-
-static void writeCursorPosition(int x, int y)
-{
-    u16_t pos = 80 * y + x;
-    outportb(0x3D4, 0x0E);
-    outportb(0x3D5, pos >> 8);
-    outportb(0x3D4, 0x0F);
-    outportb(0x3D5, pos);
-}
-
-extern "C" {
-
-void kio_bootstrap()
-{
-    cursor_x = 0;
-    cursor_y = 9;
-    writeCursorPosition(cursor_x, cursor_y);
-}
-
-void kprintf(const char * fmt, ...)
-{
-    va_list args;
-    va_start(args, fmt);
-
-    kvprintf(fmt, args);
-
-    va_end(args);
-}
-
-void kvprintf(const char * fmt, va_list args)
-{
-    char tmpbuf[25];
-    for ( ; *fmt; fmt++)
-    {
-        if (*fmt == '%')
-        {
-            fmt++;
-            if (*fmt)
-            {
-                int width = 0;
-                char pad_char = ' ';
-                bool pad_right = false;
-                if (*fmt == '0')
-                {
-                    pad_char = '0';
-                    fmt++;
-                }
-                else if (*fmt == '-')
-                {
-                    pad_right = true;
-                    fmt++;
-                }
-                for ( ; '0' <= *fmt && *fmt <= '9'; fmt++)
-                {
-                    if (width == 0)
-                    {
-                        width = *fmt - '0';
-                    }
-                    else
-                    {
-                        width *= 10;
-                        width += *fmt - '0';
-                    }
-                }
-                switch (*fmt)
-                {
-                    case 'c':
-                        kputc(va_arg(args, int));
-                        break;
-                    case 'd':
-                        fmt_d2a(tmpbuf, va_arg(args, int));
-                        kputs_pad(tmpbuf, width, pad_char, pad_right);
-                        break;
-                    case 'l':
-                        fmt_ll2a(tmpbuf, va_arg(args, long long));
-                        kputs_pad(tmpbuf, width, pad_char, pad_right);
-                        break;
-                    case 'L':
-                        fmt_ull2a(tmpbuf, va_arg(args, unsigned long long));
-                        kputs_pad(tmpbuf, width, pad_char, pad_right);
-                        break;
-                    case 'o':
-                        fmt_o2a(tmpbuf, va_arg(args, unsigned int));
-                        kputs_pad(tmpbuf, width, pad_char, pad_right);
-                        break;
-                    case 's':
-                        kputs_pad(va_arg(args, char *),
-                                  width, pad_char, pad_right);
-                        break;
-                    case 'u':
-                        fmt_u2a(tmpbuf, va_arg(args, unsigned int));
-                        kputs_pad(tmpbuf, width, pad_char, pad_right);
-                        break;
-                    case 'x':
-                        fmt_x2a(tmpbuf, va_arg(args, unsigned int));
-                        kputs_pad(tmpbuf, width, pad_char, pad_right);
-                        break;
-                    case 'X':
-                        fmt_xl2a(tmpbuf, va_arg(args, unsigned long long));
-                        kputs_pad(tmpbuf, width, pad_char, pad_right);
-                        break;
-                    case '%':
-                        kputc('%');
-                        break;
-                }
-            }
-        }
-        else
-        {
-            kputc(*fmt);
-        }
-        if (!*fmt)
-        {
-            break;
-        }
-    }
-}
-
-void kputc(char c)
-{
-    u16_t * console_memory = (u16_t *) CONSOLE_MEMORY;
-    console_memory += 80 * cursor_y + cursor_x;
-    switch (c)
-    {
-        case '\t':
-            {
-                int to_advance = 8 - (cursor_x & 0x3);
-                while (to_advance--)
-                {
-                    *console_memory++ = 0x0720;
-                }
-            }
-            break;
-        case '\n':
-            cursor_x = 0;
-            cursor_y++;
-            break;
-        default:
-            *console_memory = 0x0700 | (c & 0xFF);
-            cursor_x++;
-            break;
-    }
-    if (cursor_x >= 80)
-    {
-        cursor_x = 0;
-        cursor_y++;
-    }
-    if (cursor_y >= 25)
-    {
-        memcpy((u8_t *) CONSOLE_MEMORY,
-               (u8_t *) (CONSOLE_MEMORY + 80 * 2),
-               2 * 80 * 24);
-        memsetw((u16_t *) (CONSOLE_MEMORY + 2 * 80 * 24), 0x0720, 80);
-        cursor_y = 24;
-    }
-    writeCursorPosition(cursor_x, cursor_y);
-}
-
-void kputs(const char * s)
-{
-    while (*s)
-    {
-        kputc(*s);
-        s++;
-    }
-}
-
-void kputs_pad(const char * s, int width, char pad_char, bool pad_right)
-{
-    int len = strlen(s);
-    if (pad_right)
-    {
-        kputs(s);
-    }
-    int num_pad_chars = width - len;
-    for (int i = 0; i < num_pad_chars; i++)
-    {
-        kputc(pad_char);
-    }
-    if (!pad_right)
-    {
-        kputs(s);
-    }
-}
-
-} /* extern "C" */
-
-static void fmt_d2a(char * buf, int val)
-{
-    if (val < 0)
-    {
-        *buf++ = '-';
-        val = -val;
-    }
-    fmt_u2a(buf, (unsigned int) val);
-}
-
-static void fmt_u2a(char * buf, unsigned int val)
-{
-    bool printing = false;
-    for (unsigned int div = 1000000000; div >= 1; div /= 10)
-    {
-        unsigned int n = val / div;
-        if (n || div == 1)
-        {
-            printing = true;
-        }
-        if (printing)
-        {
-            *buf++ = '0' + n;
-        }
-        val -= n * div;
-    }
-    *buf = '\0';
-}
-
-static void fmt_ll2a(char * buf, long long val)
-{
-    if (val < 0)
-    {
-        *buf++ = '-';
-        val = -val;
-    }
-    fmt_ull2a(buf, (unsigned long long) val);
-}
-
-static void fmt_ull2a(char * buf, unsigned long long val)
-{
-    bool printing = false;
-    for (unsigned long long div = 10000000000000000000ull; div >= 1; div /= 10)
-    {
-        unsigned long long n = val / div;
-        if (n || div == 1)
-        {
-            printing = true;
-        }
-        if (printing)
-        {
-            *buf++ = '0' + n;
-        }
-        val -= n * div;
-    }
-    *buf = '\0';
-}
-
-static void fmt_x2a(char * buf, unsigned int val)
-{
-    bool printing = false;
-    for (int s = 28; s >= 0; s -= 4)
-    {
-        unsigned int n = (val >> s) & 0xF;
-        if (n || s == 0)
-        {
-            printing = true;
-        }
-        if (printing)
-        {
-            *buf++ = "0123456789abcdef"[n];
-        }
-    }
-    *buf = '\0';
-}
-
-static void fmt_xl2a(char * buf, unsigned long long val)
-{
-    bool printing = false;
-    for (int s = 60; s >= 0; s -= 4)
-    {
-        unsigned int n = (val >> s) & 0xF;
-        if (n || s == 0)
-        {
-            printing = true;
-        }
-        if (printing)
-        {
-            *buf++ = "0123456789abcdef"[n];
-        }
-    }
-    *buf = '\0';
-}
-
-static void fmt_o2a(char * buf, unsigned int val)
-{
-    bool printing = false;
-    for (int s = 30; s >= 0; s -= 3)
-    {
-        unsigned int n = (val >> s) & 0x7;
-        if (n || s == 0)
-        {
-            printing = true;
-        }
-        if (printing)
-        {
-            *buf++ = "01234567"[n];
-        }
-    }
-    *buf = '\0';
-}

kernel/lang/kio.h

@@ -1,27 +0,0 @@
-
-#ifndef KIO_H
-#define KIO_H
-
-#include <stdarg.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-void kio_bootstrap();
-
-void kprintf(const char * fmt, ...);
-
-void kvprintf(const char * fmt, va_list args);
-
-void kputc(char c);
-
-void kputs(const char * s);
-
-void kputs_pad(const char * s, int width, char pad_char, bool pad_right);
-
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-
-#endif

kernel/lang/string.cc

@@ -1,73 +0,0 @@
-
-#include "string.h"
-
-extern "C" {
-
-void strcpy(char * dst, const char * src)
-{
-    while (*src)
-    {
-        *dst++ = *src++;
-    }
-    *dst = '\0';
-}
-
-u32_t strlen(const char * s)
-{
-    u32_t len = 0;
-    while (*s++)
-    {
-        len++;
-    }
-    return len;
-}
-
-void memcpy(u8_t * dst, u8_t * src, u32_t size)
-{
-    for (u32_t n = 0; n < size; n++)
-    {
-        *dst++ = *src++;
-    }
-}
-
-void memcpyw(u16_t * dst, u16_t * src, u32_t size)
-{
-    for (u32_t n = 0; n < size; n++)
-    {
-        *dst++ = *src++;
-    }
-}
-
-void memcpyd(u32_t * dst, u32_t * src, u32_t size)
-{
-    for (u32_t n = 0; n < size; n++)
-    {
-        *dst++ = *src++;
-    }
-}
-
-void memset(u8_t * dst, u8_t val, u32_t size)
-{
-    for (u32_t n = 0; n < size; n++)
-    {
-        *dst++ = val;
-    }
-}
-
-void memsetw(u16_t * dst, u16_t val, u32_t size)
-{
-    for (u32_t n = 0; n < size; n++)
-    {
-        *dst++ = val;
-    }
-}
-
-void memsetd(u32_t * dst, u32_t val, u32_t size)
-{
-    for (u32_t n = 0; n < size; n++)
-    {
-        *dst++ = val;
-    }
-}
-
-} /* extern "C" */

kernel/lang/string.h

@@ -1,27 +0,0 @@
-
-#ifndef STRING_H
-#define STRING_H
-
-#include "hos_defines.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-void strcpy(char * dst, const char * src);
-
-u32_t strlen(const char * s);
-
-void memcpy(u8_t * dst, u8_t * src, u32_t size);
-void memcpyw(u16_t * dst, u16_t * src, u32_t size);
-void memcpyd(u32_t * dst, u32_t * src, u32_t size);
-
-void memset(u8_t * dst, u8_t val, u32_t size);
-void memsetw(u16_t * dst, u16_t val, u32_t size);
-void memsetd(u32_t * dst, u32_t val, u32_t size);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif

kernel/link.ld

@@ -1,34 +0,0 @@
-OUTPUT_FORMAT(elf32-i386)
-ENTRY(start)
-virt = 0x00100000;
-phys = 0x00100000;
-SECTIONS
-{
-    .text virt : AT(phys) {
-        code = .; _code = .; __code = .;
-        *(.multiboot_header*)
-        *(.text*)
-        *(.gnu.linkonce*)
-        . = ALIGN(4096);
-    }
-    .rodata : {
-        *(.rodata*)
-        . = ALIGN(4096);
-    }
-    .other : {
-        *(.eh_*)
-        *(.rel*)
-        . = ALIGN(4096);
-    }
-    .data : {
-        data = .; _data = .; __data = .;
-        *(.data*)
-        . = ALIGN(4096);
-    }
-    .bss : {
-        bss = .; _bss = .; __bss = .;
-        *(.bss*)
-        . = ALIGN(4096);
-    }
-    end = .; _end = .; __end = .;
-}

kernel/mm/Makefile

@@ -1,2 +0,0 @@
-
-include $(HOS_TOPLEVEL)/subdir.mak

kernel/mm/mm.cc

@@ -1,405 +0,0 @@
-
-#include <stddef.h>
-
-#include "mm.h"
-#include "stack.h"
-#include "boot/k_early_panic.h"
-#include "lang/string.h"
-#include "lang/kio.h"
-#include "sys/cpu.h"
-
-#define MM_MAX_MMAP_ENTRIES 64
-
-/* mmap management */
-static mm_mem_range_t mm_mmap_entries[MM_MAX_MMAP_ENTRIES];
-static int mm_mmap_num_entries = 0;
-
-/* free/total page statistics */
-static int mm_num_free_pages = 0;
-static int mm_num_total_pages = 0;
-
-gdtr_t mm_gdtr;
-static u64_t * mm_gdt;              /* NOT mapped into virtual address space */
-static u32_t mm_heap_base;          /* virtual address of start of heap */
-static pagedirectory_t * early_page_directory_ptr;
-
-/* physical addresses of page allocation pages to map in before the heap */
-static u32_t page_alloc_page_numbers[1025]; /* supports 4GB physical memory */
-static int last_page_alloc_page = -1; /* index of last valid page alloc page */
-static int page_alloc_page_index = -1;
-static mm_page_alloc_page_t * page_alloc_pages;
-static int page_alloc_pages_index = -1;
-
-/**************************************************************************
- * Internal Functions                                                     *
- *************************************************************************/
-static void record_phys_page(u32_t base_address);
-
-/**************************************************************************
- * Compile-time tests                                                     *
- *************************************************************************/
-static void build_tests()
-{
-    /* check that a mm_page_alloc_page_t fits exactly in a page */
-    BUILD_BUG_ON(sizeof(mm_page_alloc_page_t) != PAGE_SIZE);
-}
-
-/**************************************************************************
- * This function is run in segmented memory before paging is in effect.   *
- * Record an mmap entry from the bootloader into our kernel space.        *
- *************************************************************************/
-void mm_record_mmap_entry(mb_mmap_t * mmap)
-{
-    if (mm_mmap_num_entries < MM_MAX_MMAP_ENTRIES)
-    {
-        if (mmap->type == MB_MMAP_TYPE_RAM)
-        {
-            mm_mmap_entries[mm_mmap_num_entries].base   = mmap->base;
-            mm_mmap_entries[mm_mmap_num_entries].length = mmap->length;
-            mm_mmap_num_entries++;
-        }
-    }
-    else
-    {
-        k_early_panic("Too many mmap_entries!");
-    }
-}
-
-/**************************************************************************
- * This function is run in segmented memory before paging is in effect.   *
- * It is run after the bootloader information has been read, so we can    *
- * overwrite that memory now.                                             *
- *************************************************************************/
-void mm_bootstrap()
-{
-    u32_t max_ram_address = KERNEL_PHYSICAL_ADDRESS + KERNEL_SIZE - 1;
-
-    if (mm_mmap_num_entries < 1)
-    {
-        k_early_panic("No mmap entries read from bootloader!");
-    }
-
-    mm_heap_base = (u32_t) KERNEL_END;
-    page_alloc_pages = (mm_page_alloc_page_t *) mm_heap_base;
-
-    for (int mmap_idx = 0; mmap_idx < mm_mmap_num_entries; mmap_idx++)
-    {
-        u32_t base_address = mm_mmap_entries[mmap_idx].base;
-        u32_t address_limit = base_address + mm_mmap_entries[mmap_idx].length;
-
-        if (base_address & PAGE_LOW_MASK)
-        {
-            /* start of this mmap range is not page-aligned */
-            base_address = (base_address & PAGE_HIGH_MASK) + PAGE_SIZE;
-        }
-        if (address_limit & PAGE_LOW_MASK)
-        {
-            /* end of this mmap range is not page-aligned */
-            address_limit &= PAGE_HIGH_MASK;
-        }
-
-        /* record the highest RAM address found */
-        if ((address_limit - 1) > max_ram_address)
-        {
-            max_ram_address = (address_limit - 1);
-        }
-
-        /*
-         * loop through every page in the mmap range and add
-         * pages into the free page linked list
-         */
-        for (; base_address < address_limit; base_address += PAGE_SIZE)
-        {
-            /* check to make sure the page doesn't overlap the kernel */
-            if ( base_address + PAGE_SIZE <= KERNEL_PHYSICAL_ADDRESS
-              || base_address >= KERNEL_PHYSICAL_ADDRESS + KERNEL_SIZE )
-            {
-                record_phys_page(base_address);
-                mm_num_free_pages++;
-            }
-            mm_num_total_pages++;
-        }
-    }
-
-    if (mm_num_free_pages < 10)
-    {
-        k_early_panic("Not enough free pages of RAM!");
-    }
-
-    /* ok, now mm_early_page_alloc() should be functional */
-
-    /* move the heap back to after the page allocation pages */
-    mm_heap_base = (u32_t) &page_alloc_pages[last_page_alloc_page + 1];
-
-    /* ok, now mm_early_vpage_alloc() should be functional */
-
-    /* allocate the page directory */
-    u32_t page_directory_phys = mm_early_page_alloc();
-    early_page_directory_ptr = (pagedirectory_t *)
-        (page_directory_phys + KERNEL_OFFSET);
-
-    /* Clear the page directory */
-    for (unsigned int i = 0; i < NUM_PAGETABLE_ENTRIES; i++)
-    {
-        (*early_page_directory_ptr)[i] = 0;
-    }
-
-    /* ok, now mm_early_map() should be functional */
-
-    /* map in the page directory itself so we can modify it once paging is on */
-    (*early_page_directory_ptr)[PAGE_DIR_SELF_REF_INDEX] =
-        (page_directory_phys) | (0x1 << 1) | (0x1);
-
-    /* map in the physical page allocator pages */
-    for (int i = 0; i <= last_page_alloc_page; i++)
-    {
-        mm_early_map((u32_t) &page_alloc_pages[i],
-                page_alloc_page_numbers[i], 0, 1);
-    }
-
-    /* map the kernel's virtual address space into RAM */
-    for (u32_t page_base = KERNEL_VIRTUAL_ADDRESS;
-         page_base < KERNEL_VIRTUAL_ADDRESS + KERNEL_SIZE;
-         page_base += PAGE_SIZE)
-    {
-        /* map page_base to page_base - KERNEL_OFFSET */
-        mm_early_map(page_base, page_base - KERNEL_OFFSET, 0, 1);
-    }
-
-    /* map console memory */
-    mm_early_map(CONSOLE_MEMORY, CONSOLE_MEMORY, 0, 1);
-
-    /* set up the global descriptor table */
-    u32_t gdt_base = mm_early_page_alloc();
-    mm_gdt = (u64_t *) ((u32_t) gdt_base + (u32_t) KERNEL_OFFSET);
-    mm_gdt[0] = 0x0ull;
-    mm_gdt[1] = MAKE_DESCRIPTOR(0, 0xFFFFF, 1, 0, 1, 1);    /* kernel code */
-    mm_gdt[2] = MAKE_DESCRIPTOR(0, 0xFFFFF, 1, 0, 1, 0);    /* kernel data */
-    mm_gdtr.limit = 3 * sizeof(mm_gdt[0]) - 1;
-    mm_gdtr.base = gdt_base;
-
-    __asm__ __volatile__ (
-            "lgdt (mm_gdtr);\n"
-            "jmp $0x08, $42f;\n"
-            "42:\n"
-            "mov $0x10, %%cx\n"
-            "mov %%cx, %%ss\n"
-            "mov %%cx, %%ds\n"
-            "mov %%cx, %%es\n"
-            "mov %%cx, %%fs\n"
-            "mov %%cx, %%gs\n"
-            : /* no outputs */
-            : /* no inputs */
-            : "ecx");
-
-    /* set the page directory base register */
-    write_cr3(page_directory_phys);
-
-    /* set up permanent stack before enabling paging */
-    stack_bootstrap();
-
-    /* turn on paging */
-    write_cr0(read_cr0() | (1 << 31));
-}
-
-/**************************************************************************
- * This function is run in segmented memory before paging is in effect.   *
- * Record a physical page in the page allocation pages.                   *
- *************************************************************************/
-static void record_phys_page(u32_t base_address)
-{
-    if (page_alloc_page_index < 0)
-    {
-        /* allocate a new page alloc page */
-        last_page_alloc_page++;
-        page_alloc_pages_index++;
-        page_alloc_page_numbers[last_page_alloc_page] = base_address;
-        page_alloc_page_index = 0;
-    }
-    else
-    {
-        mm_page_alloc_page_t * current_page_alloc_page =
-            (mm_page_alloc_page_t *)
-            (page_alloc_page_numbers[page_alloc_pages_index] + KERNEL_OFFSET);
-        page_alloc_page_index++;
-        (*current_page_alloc_page)[page_alloc_page_index] = base_address;
-        if (page_alloc_page_index == NUM_PAGETABLE_ENTRIES - 1)
-        {
-            page_alloc_page_index = -1;
-        }
-    }
-}
-
-/**************************************************************************
- * Map virtual_address to physical_address.                               *
- * Both addresses should be page-aligned.                                 *
- * This 'early' version can be used during segmented bootstrapping        *
- *************************************************************************/
-int mm_early_map(u32_t virtual_address, u32_t physical_address,
-                 u32_t user_mode, u32_t writable)
-{
-    u32_t directory_index = (virtual_address >> 22) & 0x3FF;
-    u32_t table_index = (virtual_address >> 12) & 0x3FF;
-
-    if ((*early_page_directory_ptr)[directory_index] == 0)
-    {
-        /* allocate a new page table */
-        u32_t page_table_phys = mm_early_page_alloc();
-        if (page_table_phys == 0)
-        {
-            return 0;
-        }
-        pagedirectory_entry_t * page_table_virt = (pagedirectory_entry_t *)
-            (page_table_phys + KERNEL_OFFSET);
-        for (unsigned int i = 0; i < NUM_PAGETABLE_ENTRIES; i++)
-        {
-            page_table_virt[i] = 0;
-        }
-        (*early_page_directory_ptr)[directory_index] = page_table_phys
-                                  | (0x1 << 2)  /* PTs can be user mode */
-                                  | (0x1 << 1)  /* writable */
-                                  | (0x1);      /* present */
-    }
-    u32_t page_table_phys =
-        (*early_page_directory_ptr)[directory_index] & PAGE_HIGH_MASK;
-
-    pagedirectory_entry_t * page_table =
-        (pagedirectory_entry_t *) (page_table_phys + KERNEL_OFFSET);
-
-    page_table[table_index] = (physical_address & PAGE_HIGH_MASK)
-                            | ((user_mode & 0x1) << 2)
-                            | ((writable & 0x1) << 1)
-                            | 0x1;      /* present */
-
-    return 1;
-}
-
-/**************************************************************************
- * Map virtual_address to physical_address.                               *
- * Both addresses should be page-aligned.                                 *
- *************************************************************************/
-int mm_map(u32_t virtual_address, u32_t physical_address,
-           u32_t user_mode, u32_t writable)
-{
-    u32_t directory_index = (virtual_address >> 22) & 0x3FF;
-    u32_t table_index = (virtual_address >> 12) & 0x3FF;
-    pagedirectory_entry_t * page_dir_entry = (pagedirectory_entry_t *)
-        (PAGE_DIR_SELF_REF2 | (directory_index << 2));
-
-    if (*page_dir_entry == 0)
-    {
-        /* allocate a new page table */
-        u32_t page_table_phys = mm_page_alloc();
-        if (page_table_phys == 0)
-        {
-            return 0;
-        }
-        *page_dir_entry = page_table_phys
-                        | (0x1 << 2)    /* PTs can be user mode */
-                        | (0x1 << 1)    /* writable */
-                        | (0x1);        /* present */
-        pagedirectory_entry_t * page_table = (pagedirectory_entry_t *)
-            (PAGE_DIR_SELF_REF | (directory_index << 12));
-        for (unsigned int i = 0; i < NUM_PAGETABLE_ENTRIES; i++)
-        {
-            page_table[i] = 0;
-        }
-    }
-
-    pagedirectory_entry_t * page_table_entry = (pagedirectory_entry_t *)
-        (PAGE_DIR_SELF_REF | (directory_index << 12) | (table_index << 2));
-
-    *page_table_entry = (physical_address & PAGE_HIGH_MASK)
-                      | ((user_mode & 0x1) << 2)
-                      | ((writable & 0x1) << 1)
-                      | 0x1;      /* present */
-
-    return 1;
-}
-
-/**************************************************************************
- * Returns the physical base address of a page in RAM                     *
- * or 0 if no pages were available                                        *
- * This 'early' version can be used during segmented bootstrapping        *
- *************************************************************************/
-u32_t mm_early_page_alloc()
-{
-    u32_t page_address = 0;
-    if (page_alloc_pages_index >= 0)
-    {
-        if (page_alloc_page_index >= 0)
-        {
-            mm_page_alloc_page_t * current_pap = (mm_page_alloc_page_t *)
-                (page_alloc_page_numbers[page_alloc_pages_index]
-                    + KERNEL_OFFSET);
-            page_address = (*current_pap)[page_alloc_page_index];
-            page_alloc_page_index--;
-        }
-        else
-        {
-            /* return the page allocation page itself */
-            page_address = page_alloc_page_numbers[page_alloc_pages_index];
-            page_alloc_pages_index--;
-            page_alloc_page_index = NUM_PAGETABLE_ENTRIES - 1;
-        }
-        mm_num_free_pages--;
-    }
-    return page_address;
-}
-
-/**************************************************************************
- * Returns the physical base address of a page in RAM                     *
- * or 0 if no pages were available                                        *
- *************************************************************************/
-u32_t mm_page_alloc()
-{
-    u32_t page_address = 0;
-    if (page_alloc_pages_index >= 0)
-    {
-        if (page_alloc_page_index >= 0)
-        {
-            page_address =
-                page_alloc_pages[page_alloc_pages_index][page_alloc_page_index];
-            page_alloc_page_index--;
-        }
-        else
-        {
-            /* return the page allocation page itself */
-            page_address = page_alloc_page_numbers[page_alloc_pages_index];
-            page_alloc_pages_index--;
-            page_alloc_page_index = NUM_PAGETABLE_ENTRIES - 1;
-        }
-        mm_num_free_pages--;
-    }
-    return page_address;
-}
-
-/**************************************************************************
- * This function allocates a virtual page. It should only be called       *
- * during the bootstrap process, before the kernel begins its normal      *
- * operation. It adjusts the heap pointer to push it back beyond any      *
- * bootstrap pages allocated.                                             *
- *************************************************************************/
-u32_t mm_early_vpage_alloc()
-{
-    u32_t vaddress = mm_heap_base;
-    mm_heap_base += PAGE_SIZE;
-    return vaddress;
-}
-
-void mm_print_memory_map()
-{
-    kprintf("Bootloader provided memory map:\n");
-    kprintf("  Base Address       Length\n");
-    for (int i = 0; i < mm_mmap_num_entries; i++)
-    {
-        kprintf("  0x%016X 0x%016X (%l bytes / %l KB / %l MB)\n",
-                mm_mmap_entries[i].base,
-                mm_mmap_entries[i].length,
-                mm_mmap_entries[i].length,
-                mm_mmap_entries[i].length >> 10,
-                mm_mmap_entries[i].length >> 20);
-    }
-    kprintf("Used pages: %d\n", mm_num_total_pages - mm_num_free_pages);
-    kprintf("Free pages: %d\n", mm_num_free_pages);
-}

kernel/mm/mm.h

@@ -1,65 +0,0 @@
-
-#ifndef MM_H
-#define MM_H MM_H
-
-#include "hos_types.h"
-#include "hos_defines.h"
-#include "multiboot.h"
-
-#define KERNEL_CODE_SEGMENT 0x08
-#define KERNEL_DATA_SEGMENT 0x10
-
-typedef u32_t pagedirectory_entry_t;
-
-#define NUM_PAGETABLE_ENTRIES   (PAGE_SIZE / sizeof(pagedirectory_entry_t))
-
-#define PAGE_DIR_SELF_REF   (0x20000000u - (PAGE_SIZE * NUM_PAGETABLE_ENTRIES))
-#define PAGE_DIR_SELF_REF_INDEX ((PAGE_DIR_SELF_REF >> 22) & 0x3FF)
-#define PAGE_DIR_SELF_REF2  (PAGE_DIR_SELF_REF | (PAGE_DIR_SELF_REF_INDEX << 12))
-
-typedef pagedirectory_entry_t pagedirectory_t[NUM_PAGETABLE_ENTRIES];
-
-typedef struct
-{
-    u64_t   base;
-    u64_t   length;
-} mm_mem_range_t;
-
-typedef u32_t mm_page_alloc_page_t[NUM_PAGETABLE_ENTRIES];
-
-/* http://courses.ece.illinois.edu/ece391/references/descriptors.pdf */
-/* granularity: 0: limit in bytes; 1: limit in pages */
-/* dpl: 0: system mode; 3: user mode */
-/* normal: 0: TSS/LDT/call gate; 1: code/data segment */
-/* code_seg: 0: data segment; 1: code segment */
-#define MAKE_DESCRIPTOR(base, limit, granularity, dpl, normal, code_seg)       \
-        (u64_t) ( ( (((u64_t) base) & 0xFF000000ull) << 32 ) /* base 31:24 */  \
-                | ( (((u64_t) granularity) & 0x1ull) << 55 ) /* granularity */ \
-                | ( ( (u64_t) 0x1ull) << 54 )                /* 32-bit */      \
-                | ( (((u64_t) limit) & 0xF0000ull) << 32 )   /* limit 19:16 */ \
-                | ( ( (u64_t) 0x1ull) << 47 )                /* present */     \
-                | ( (((u64_t) dpl) & 0x3ull) << 45 )         /* dpl */         \
-                | ( (((u64_t) normal) & 0x1ull) << 44 )      /* normal */      \
-                | ( (((u64_t) code_seg) & 0x1ull) << 43 )    /* code seg */    \
-                | ( ( (u64_t) 0x2ull) << 40 )                /* ? */           \
-                | ( (((u64_t) base) & 0x00FFFFFFull) << 16)  /* base 23:00 */  \
-                | ( (((u64_t) limit) & 0x0000FFFFull) ) )    /* limit 15:00 */
-
-typedef u64_t descriptor_t;
-
-void mm_record_mmap_entry(mb_mmap_t * mmap);
-void mm_bootstrap();
-
-int mm_early_map(u32_t virtual_address, u32_t physical_address,
-                 u32_t user_mode, u32_t writable);
-int mm_map(u32_t virtual_address, u32_t physical_address,
-           u32_t user_mode, u32_t writable);
-
-u32_t mm_early_page_alloc();
-u32_t mm_page_alloc();
-u32_t mm_early_vpage_alloc();
-
-void mm_print_memory_map();
-
-#endif
-

kernel/mm/stack.cc

@@ -1,19 +0,0 @@
-
-#include "stack.h"
-#include "mm.h"
-#include "hos_defines.h"
-
-void stack_bootstrap()
-{
-    /*
-     * running from our temporary stack while segmentation is enabled,
-     * set up the "permanent" stack for use while paging
-     */
-    u32_t stack_page_virt = KERNEL_STACK_TOP - PAGE_SIZE;
-    for (int i = 0; i < STACK_INITIAL_SIZE; i++)
-    {
-        u32_t stack_page_phys = mm_early_page_alloc();
-        mm_early_map(stack_page_virt, stack_page_phys, 0, 1);
-        stack_page_virt -= PAGE_SIZE;
-    }
-}

kernel/mm/stack.h

@@ -1,13 +0,0 @@
-
-#ifndef STACK_H
-#define STACK_H
-
-#include "mm/mm.h"
-
-#define KERNEL_STACK_TOP    PAGE_DIR_SELF_REF
-
-#define STACK_INITIAL_SIZE 2        /* number of initial stack pages */
-
-void stack_bootstrap();
-
-#endif

kernel/subdir.mak

@@ -1,54 +0,0 @@
-
-ASMOBJS         := $(patsubst %.asm,%.o,$(wildcard *.asm))
-COBJS           := $(patsubst %.c,%.o,$(wildcard *.c))
-CXXOBJS         := $(patsubst %.cc,%.o,$(wildcard *.cc))
-CDEPS           := $(COBJS:.o=.dep)
-CXXDEPS         := $(CXXOBJS:.o=.dep)
-DEPS			:= $(CDEPS) $(CXXDEPS)
-OUTPUT_FILE     := $(SUBDIR)_all.o
-
-ifdef SUBDIRS
-SUBDIRS_clean   := $(SUBDIRS:%=%.clean)
-endif
-
-all: $(OUTPUT_FILE)
-
-$(OUTPUT_FILE): $(ASMOBJS) $(COBJS) $(CXXOBJS) $(SUBDIRS)
-	$(LD) -r -o $@ $(ASMOBJS) $(COBJS) $(CXXOBJS) $(foreach subdir,$(SUBDIRS),$(subdir)/$(subdir)_all.o)
-
-%.o: %.asm
-	$(NASM) -f elf -o $@ -l $<.lst $<
-
-%.o: %.c
-	$(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $<
-
-%.o: %.cc
-	$(CXX) -c -o $@ $(CPPFLAGS) $(CXXFLAGS) $<
-
-ifdef SUBDIRS
-.PHONY: $(SUBDIRS)
-$(SUBDIRS):
-	$(MAKE) -C $@ SUBDIR=$@
-endif
-
-# Make dependency files
-%.dep: %.c
-	@set -e; rm -f $@; \
-	  $(CC) -MM $(CPPFLAGS) $< | sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' > $@
-
-%.dep: %.cc
-	@set -e; rm -f $@; \
-	  $(CXX) -MM $(CPPFLAGS) $< | sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' > $@
-
-clean: $(SUBDIRS_clean)
-	-rm -f *.o *.dep *.lst *~
-
-ifdef SUBDIRS
-%.clean:
-	$(MAKE) -C $* clean clean=1
-endif
-
-# Include dependency files
-ifndef clean
--include $(DEPS)
-endif

kernel/sys/Makefile

@@ -1,2 +0,0 @@
-
-include $(HOS_TOPLEVEL)/subdir.mak

kernel/sys/cpu.h

@@ -1,40 +0,0 @@
-
-#ifndef CPU_H
-#define CPU_H
-
-#include "hos_types.h"
-
-static u32_t read_cr0() __attribute__ ((unused));
-static u32_t read_cr0()
-{
-    u32_t val;
-    __asm__ __volatile__ ("movl %%cr0, %0" : "=r" (val));
-    return val;
-}
-
-static u32_t read_cr2() __attribute__ ((unused));
-static u32_t read_cr2()
-{
-    u32_t val;
-    __asm__ __volatile__ ("movl %%cr2, %0" : "=r" (val));
-    return val;
-}
-
-static u32_t read_cr3() __attribute__ ((unused));
-static u32_t read_cr3()
-{
-    u32_t val;
-    __asm__ __volatile__ ("movl %%cr3, %0" : "=r" (val));
-    return val;
-}
-
-#define write_cr0(val) \
-    __asm__ __volatile__ ("movl %0, %%cr0" : : "r" (val));
-
-#define write_cr3(val) \
-    __asm__ __volatile__ ("movl %0, %%cr3" : : "r" (val));
-
-#define write_esp(val) \
-    __asm__ __volatile__ ("movl %0, %%esp" : : "r" (val));
-
-#endif

kernel/sys/pic.cc

@@ -1,29 +0,0 @@
-
-#include "pic.h"
-#include "portio.h"
-
-/*
- * Re-maps the Programmable Interrupr Controllers
- * so IRQ0->pic1 base address, IRG8->pic2 base address
- */
-void pic_remap(u8_t base1, u8_t base2)
-{
-    u8_t    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, base1);     /* 0x21, pic1 */
-    outportb(PIC2_DATA, base2);     /* 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 */
-}
-
-

kernel/sys/pic.h

@@ -1,46 +0,0 @@
-
-#ifndef PIC_H
-#define PIC_H
-
-#include "hos_types.h"
-#include "portio.h"
-
-#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) */
-
-void pic_remap(u8_t base1, u8_t base2);
-
-/* Masks interrupts on first Programmable Interrupt Controller */
-#define pic_mask1(mask) outportb(PIC1_DATA, mask) /* 0x21, maskfield *OCW1* */
-
-/* Masks interrupts on second Programmable Interrupt Controller */
-#define pic_mask2(mask) outportb(PIC2_DATA, mask) /* 0xA1, maskfield *OCW1* */
-
-/* Signals an End Of Interrupt signal to the first PIC */
-#define pic_eoi() outportb(0x20, 0x20)
-
-/* Signals an End Of Interrupt signal to both the second and first PIC unit */
-static inline void pic_eoi2()
-{
-        outportb(0xA0, 0x20);
-        outportb(0x20, 0x20);
-}
-
-#endif

kernel/sys/timer.cc

@@ -1,12 +0,0 @@
-
-#include "timer.h"
-#include "portio.h"
-
-void timer_init(u32_t freq)
-{
-    /* how many ticks the PIT must wait before issuing an interrupt */
-    u32_t wait = 1193180 / freq;
-    outportb(0x43, 0x34);
-    outportb(0x40, wait);       /* LSB */
-    outportb(0x40, wait >> 8);  /* MSB */
-}

kernel/sys/timer.h

@@ -1,9 +0,0 @@
-
-#ifndef TIMER_H
-#define TIMER_H
-
-#include "hos_types.h"
-
-void timer_init(u32_t freq);
-
-#endif

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
+

src/boot.S

@@ -0,0 +1,18 @@
+.global hos_start
+.type hos_start, @function
+hos_start:
+    /* Set stack pointer. */
+    mov $_stack_end, %esp
+ 
+    /* Jump to C. */
+    push $0
+    push $0
+    push $0
+    push %ebx
+    call hos_main
+ 
+    cli
+1:  hlt
+    jmp 1b
+ 
+.size hos_start, . - hos_start

src/fb.c

@@ -0,0 +1,116 @@
+#include "fb.h"
+#include <stddef.h>
+#include "mem.h"
+
+static struct {
+    uint32_t * addr;
+    uint32_t width;
+    uint32_t height;
+    uint32_t pitch;
+} fb;
+
+static inline uint32_t build_pixel(uint8_t r, uint8_t g, uint8_t b)
+{
+    return (r << 16u) | (g << 8u) | b;
+}
+
+static inline void fb_set_pixel(int x, int y, uint8_t r, uint8_t g, uint8_t b)
+{
+    fb.addr[fb.pitch * y + x] = build_pixel(r, g, b);
+}
+
+void fb_clear(void)
+{
+    memset32(fb.addr, 0u, fb.pitch * fb.height);
+}
+
+void fb_init(uint32_t * addr, uint32_t width, uint32_t height, uint32_t pitch)
+{
+    fb.addr = addr;
+    fb.width = width;
+    fb.height = height;
+    fb.pitch = pitch / 4u;
+    fb_clear();
+}
+
+uint32_t * fb_addr(void)
+{
+    return fb.addr;
+}
+
+bool fb_ready(void)
+{
+    return fb.addr != NULL;
+}
+
+uint32_t fb_width(void)
+{
+    return fb.width;
+}
+
+uint32_t fb_height(void)
+{
+    return fb.height;
+}
+
+void fb_blend_alpha8(const uint8_t * bitmap, int width, int height, int pitch, int x, int y, uint8_t r, uint8_t g, uint8_t b)
+{
+    if (((x + width) <= 0) || (x >= (int)fb.width) || ((y + height) <= 0) || (y >= (int)fb.height))
+    {
+        return;
+    }
+    if (x < 0)
+    {
+        width += x;
+        bitmap += (-x);
+        x = 0;
+    }
+    if (y < 0)
+    {
+        height += y;
+        bitmap += ((-y) * pitch);
+        y = 0;
+    }
+    if ((x + width) > (int)fb.width)
+    {
+        width = (int)fb.width - x;
+    }
+    if ((y + height) > (int)fb.height)
+    {
+        height = (int)fb.height - y;
+    }
+    uint32_t * target = &fb.addr[fb.pitch * y + x];
+    for (int row = 0; row < height; row++)
+    {
+        for (int col = 0; col < width; col++)
+        {
+            uint32_t alpha = bitmap[col];
+            uint32_t current_pixel = target[col];
+            uint8_t cr = (current_pixel >> 16u) & 0xFFu;
+            uint8_t cg = (current_pixel >> 8u) & 0xFFu;
+            uint8_t cb = current_pixel & 0xFFu;
+            uint8_t pr = alpha * r / 255u;
+            uint8_t pg = alpha * g / 255u;
+            uint8_t pb = alpha * b / 255u;
+            uint32_t current_alpha = 255u - alpha;
+            uint32_t pixel = build_pixel(
+                    pr + current_alpha * cr / 255u,
+                    pg + current_alpha * cg / 255u,
+                    pb + current_alpha * cb / 255u);
+            target[col] = pixel;
+        }
+        bitmap += pitch;
+        target += fb.pitch;
+    }
+}
+
+void fb_fill(int x, int y, int width, int height, uint8_t r, uint8_t g, uint8_t b)
+{
+    uint32_t * target = &fb.addr[fb.pitch * y + x];
+    uint32_t pixel = build_pixel(r, g, b);
+    for (int row = 0; row < height; row++)
+    {
+        memset32(target, pixel, width);
+        target += fb.pitch;
+    }
+}

src/fb.h

@@ -0,0 +1,16 @@
+#ifndef FB_H
+#define FB_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+void fb_init(uint32_t * addr, uint32_t width, uint32_t height, uint32_t pitch);
+bool fb_ready(void);
+uint32_t * fb_addr(void);
+uint32_t fb_width(void);
+uint32_t fb_height(void);
+void fb_blend_alpha8(const uint8_t * bitmap, int width, int height, int pitch, int x, int y, uint8_t r, uint8_t g, uint8_t b);
+void fb_fill(int x, int y, int width, int height, uint8_t r, uint8_t g, uint8_t b);
+void fb_clear(void);
+
+#endif

src/fb_text.c

@@ -0,0 +1,11 @@
+#include "fb_text.h"
+#include "kfont.h"
+#include "fb.h"
+
+void fb_text_render_char(int c, int x, int y, uint8_t r, uint8_t g, uint8_t b)
+{
+    const fontgen_char_info_t * char_info = kfont.char_infos[c];
+    y += kfont.line_height - kfont.baseline_offset - char_info->top;
+    x += char_info->left;
+    fb_blend_alpha8(char_info->bitmap, char_info->width, char_info->height, char_info->width, x, y, r, g, b);
+}

src/fb_text.h

@@ -0,0 +1,8 @@
+#ifndef FB_TEXT_H
+#define FB_TEXT_H
+
+#include <stdint.h>
+
+void fb_text_render_char(int c, int x, int y, uint8_t r, uint8_t g, uint8_t b);
+
+#endif

src/gdt.S

@@ -0,0 +1,16 @@
+.global gdt_set
+.extern gdtr
+.type gdt_set, @function
+gdt_set:
+    lgdt gdtr
+    jmp $0x8, $gdt_set_reload
+gdt_set_reload:
+    mov $0x10, %ax
+    mov %ax, %ds
+    mov %ax, %es
+    mov %ax, %fs
+    mov %ax, %gs
+    mov %ax, %ss
+    ret
+
+.size gdt_set, . - gdt_set

src/gdt.c

@@ -0,0 +1,20 @@
+#include "gdt.h"
+
+static const gdt_entry_t gdt_entries[] = {
+    /* Null descriptor */
+    0u,
+    /* Code segment for kernel */
+    gdt_build_entry(0u, 0xFFFFFu, 1u, 0u, 1u, 1u, 0u, 1u, 0u, 1u, 1u, 0u),
+    /* Data segment for kernel */
+    gdt_build_entry(0u, 0xFFFFFu, 1u, 0u, 1u, 0u, 0u, 1u, 0u, 1u, 1u, 0u),
+};
+
+gdtr_t gdtr;
+
+void gdt_init(void)
+{
+    gdtr.size = sizeof(gdt_entries);
+    gdtr.offset_lower = (uintptr_t)gdt_entries & 0xFFFFu;
+    gdtr.offset_upper = (uintptr_t)gdt_entries >> 16u;
+    gdt_set();
+}

src/gdt.h

@@ -0,0 +1,34 @@
+#ifndef GDT_H
+#define GDT_H
+
+#include <stdint.h>
+
+typedef struct {
+    uint16_t size;
+    uint16_t offset_lower;
+    uint16_t offset_upper;
+    uint16_t _reserved;
+} gdtr_t;
+
+typedef uint64_t gdt_entry_t;
+#define gdt_build_entry(base, limit, pr, privl, s, ex, dc, rw, ac, gr, sz, l) \
+    (gdt_entry_t)( \
+            (((gdt_entry_t)base << 32) & 0xFF00000000000000ull) | /* Base 0:15 */ \
+            (((gdt_entry_t)gr & 0x1u) << 55) | /* Granularity (0 = bytes, 1 = blocks) */ \
+            (((gdt_entry_t)sz & 0x1u) << 54) | /* Size (0 = 16-bit, 1 = 32-bit) */ \
+            (((gdt_entry_t)l & 0x1u) << 53) | /* L flag (x86_64 code) */ \
+            (((gdt_entry_t)limit << 32) & 0x000F000000000000ull) | /* Limit 16:19 */ \
+            (((gdt_entry_t)pr & 0x1u) << 47) | /* Present flag */ \
+            (((gdt_entry_t)privl & 0x3u) << 45) | /* Privilege (ring level) */ \
+            (((gdt_entry_t)s & 0x1u) << 44) | /* Type (0 = system, 1 = code/data) */ \
+            (((gdt_entry_t)ex & 0x1u) << 43) | /* Executable flag */ \
+            (((gdt_entry_t)dc & 0x1u) << 42) | /* Direction/Conforming */ \
+            (((gdt_entry_t)rw & 0x1u) << 41) | /* Readable/Writable */ \
+            (((gdt_entry_t)ac & 0x1u) << 40) | /* Accessed flag */ \
+            (((gdt_entry_t)base << 16) & 0x000000FFFFFF0000ull) | /* Base 0:23 */ \
+             ((gdt_entry_t)limit & 0x000000000000FFFFull)) /* Limit 0:15 */
+
+void gdt_init(void);
+void gdt_set(void);
+
+#endif

src/hos_main.c

@@ -0,0 +1,25 @@
+#include <stdint.h>
+#include "fb.h"
+#include "mbinfo.h"
+#include "klog.h"
+#include "gdt.h"
+#include "mm.h"
+
+void hos_main(uint32_t mbinfo_addr)
+{
+    gdt_init();
+    if (!mbinfo_init(mbinfo_addr))
+    {
+        return;
+    }
+    if (!fb_ready())
+    {
+        return;
+    }
+    klog_init();
+    klog_printf("Welcome to HOS!\n");
+    mm_init();
+    mbinfo_load();
+    klog_printf("Found %dKB of usable RAM\n", mm_get_total_ram() / 1024u);
+    klog_printf("Kernel is %dKB at 0x%x\n", mm_get_kernel_size() / 1024u, mm_get_kernel_address());
+}

src/hos_printf.c

@@ -0,0 +1,281 @@
+#include "hos_printf.h"
+#include <stdint.h>
+#include <stdbool.h>
+#include "string.h"
+
+static size_t format_dec(char * buffer, int32_t v)
+{
+    size_t sz = 0u;
+    bool printing = false;
+    if (v < 0)
+    {
+        buffer[sz++] = '-';
+        v = -v;
+    }
+    for (int32_t div = 1000000000; div >= 1; div /= 10)
+    {
+        int32_t digit = v / div;
+        v %= div;
+        if ((digit != 0) || (div == 1))
+        {
+            printing = true;
+        }
+        if (printing)
+        {
+            buffer[sz++] = digit + '0';
+        }
+    }
+    return sz;
+}
+
+static size_t format_dec64(char * buffer, int64_t v)
+{
+    size_t sz = 0u;
+    bool printing = false;
+    if (v < 0)
+    {
+        buffer[sz++] = '-';
+        v = -v;
+    }
+    for (int64_t div = 1000000000000000000; div >= 1; div /= 10)
+    {
+        int64_t digit = v / div;
+        v %= div;
+        if ((digit != 0) || (div == 1))
+        {
+            printing = true;
+        }
+        if (printing)
+        {
+            buffer[sz++] = digit + '0';
+        }
+    }
+    return sz;
+}
+
+static size_t format_udec(char * buffer, int32_t v)
+{
+    size_t sz = 0u;
+    for (int32_t div = 1000000000u; div >= 1u; div /= 10u)
+    {
+        int32_t digit = v / div;
+        v %= div;
+        if ((digit != 0) || (sz > 0u) || (div == 1))
+        {
+            buffer[sz++] = digit + '0';
+        }
+    }
+    return sz;
+}
+
+static size_t format_udec64(char * buffer, uint64_t v)
+{
+    size_t sz = 0u;
+    for (uint64_t div = 10000000000000000000u; div >= 1u; div /= 10u)
+    {
+        uint64_t digit = v / div;
+        v %= div;
+        if ((digit != 0) || (sz > 0u) || (div == 1))
+        {
+            buffer[sz++] = digit + '0';
+        }
+    }
+    return sz;
+}
+
+static size_t format_hex(char * buffer, uint32_t v, bool upper)
+{
+    const char upper_hex[] = "0123456789ABCDEF";
+    const char lower_hex[] = "0123456789abcdef";
+    size_t sz = 0u;
+    for (int i = 28; i >= 0; i -= 4)
+    {
+        uint8_t n = (v >> i) & 0xFu;
+        if ((sz > 0u) || (n != 0u) || (i == 0))
+        {
+            buffer[sz] = upper ? upper_hex[n] : lower_hex[n];
+            sz++;
+        }
+    }
+    return sz;
+}
+
+static size_t format_hex64(char * buffer, uint64_t v, bool upper)
+{
+    const char upper_hex[] = "0123456789ABCDEF";
+    const char lower_hex[] = "0123456789abcdef";
+    size_t sz = 0u;
+    for (int i = 60; i >= 0; i -= 4)
+    {
+        uint8_t n = (v >> i) & 0xFu;
+        if ((sz > 0u) || (n != 0u) || (i == 0))
+        {
+            buffer[sz] = upper ? upper_hex[n] : lower_hex[n];
+            sz++;
+        }
+    }
+    return sz;
+}
+
+static void pad_write(const stream_t * stream, const char * data, size_t length, bool leading_zero, bool left_just, size_t width)
+{
+    if (left_just)
+    {
+        stream->write(data, length);
+        while (length < width)
+        {
+            stream->write1(' ');
+            length++;
+        }
+    }
+    else
+    {
+        char fill = leading_zero ? '0' : ' ';
+        size_t l = length;
+        while (l < width)
+        {
+            stream->write1(fill);
+            l++;
+        }
+        stream->write(data, length);
+    }
+}
+
+void hos_vprintf(const stream_t * stream, const char * fmt, va_list va)
+{
+    bool in_conv = false;
+    char c;
+    char buffer[22];
+    size_t width;
+    bool leading_zero;
+    bool left_just;
+    bool long_flag;
+    size_t length;
+    while ((c = *fmt))
+    {
+        if (in_conv)
+        {
+            switch (c)
+            {
+            case '%':
+                stream->write1('%');
+                break;
+            case 'X':
+                {
+                    if (long_flag)
+                    {
+                        uint64_t v = va_arg(va, uint64_t);
+                        length = format_hex(buffer, v, true);
+                    }
+                    else
+                    {
+                        uint32_t v = va_arg(va, uint32_t);
+                        length = format_hex(buffer, v, true);
+                    }
+                    pad_write(stream, buffer, length, leading_zero, left_just, width);
+                }
+                break;
+            case 'c':
+                {
+                    char ch = va_arg(va, int);
+                    pad_write(stream, &ch, 1u, leading_zero, left_just, width);
+                }
+                break;
+            case 'd':
+                {
+                    if (long_flag)
+                    {
+                        int64_t v = va_arg(va, int64_t);
+                        length = format_dec64(buffer, v);
+                    }
+                    else
+                    {
+                        int32_t v = va_arg(va, int32_t);
+                        length = format_dec(buffer, v);
+                    }
+                    pad_write(stream, buffer, length, leading_zero, left_just, width);
+                }
+                break;
+            case 's':
+                {
+                    const char * s = va_arg(va, const char *);
+                    pad_write(stream, s, strlen(s), leading_zero, left_just, width);
+                }
+                break;
+            case 'u':
+                {
+                    if (long_flag)
+                    {
+                        uint64_t v = va_arg(va, uint64_t);
+                        length = format_udec64(buffer, v);
+                    }
+                    else
+                    {
+                        uint32_t v = va_arg(va, uint32_t);
+                        length = format_udec(buffer, v);
+                    }
+                    pad_write(stream, buffer, length, leading_zero, left_just, width);
+                }
+                break;
+            case 'x':
+                {
+                    if (long_flag)
+                    {
+                        uint64_t v = va_arg(va, uint64_t);
+                        length = format_hex64(buffer, v, false);
+                    }
+                    else
+                    {
+                        uint32_t v = va_arg(va, uint32_t);
+                        length = format_hex(buffer, v, false);
+                    }
+                    pad_write(stream, buffer, length, leading_zero, left_just, width);
+                }
+                break;
+            }
+            in_conv = false;
+        }
+        else if (c == '%')
+        {
+            in_conv = true;
+            width = 0u;
+            leading_zero = false;
+            left_just = false;
+            long_flag = false;
+            if (fmt[1] == '-')
+            {
+                left_just = true;
+                fmt++;
+            }
+            if (fmt[1] == '0')
+            {
+                leading_zero = true;
+                fmt++;
+            }
+            while (('0' <= fmt[1]) && (fmt[1] <= '9'))
+            {
+                width *= 10u;
+                width += (fmt[1] - '0');
+                fmt++;
+            }
+            if (fmt[1] == 'l')
+            {
+                long_flag = true;
+                fmt++;
+            }
+        }
+        else
+        {
+            stream->write1(c);
+        }
+        fmt++;
+    }
+}
+
+void hos_printf(const stream_t * stream, const char * fmt, ...)
+{
+    va_list va;
+    va_start(va, fmt);
+    hos_vprintf(stream, fmt, va);
+    va_end(va);
+}

src/hos_printf.h

@@ -0,0 +1,10 @@
+#ifndef HOS_PRINTF_H
+#define HOS_PRINTF_H
+
+#include "stream.h"
+#include <stdarg.h>
+
+void hos_vprintf(const stream_t * stream, const char * fmt, va_list va);
+void hos_printf(const stream_t * stream, const char * fmt, ...);
+
+#endif

src/klog.c

@@ -0,0 +1,103 @@
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdarg.h>
+#include "klog.h"
+#include "kfont.h"
+#include "fb.h"
+#include "fb_text.h"
+#include "stream.h"
+#include "hos_printf.h"
+#include "mem.h"
+
+static struct {
+    size_t console_width;
+    size_t console_height;
+    size_t x;
+    size_t y;
+    bool need_shift;
+} klog;
+
+static void shift_line(void)
+{
+    uint32_t * fb = fb_addr();
+    uint32_t w = fb_width();
+    size_t console_fb_line_words = w * kfont.line_height;
+    for (size_t row = 0u; row < klog.console_height; row++)
+    {
+        memcpy32(fb, fb + console_fb_line_words, console_fb_line_words);
+        fb += console_fb_line_words;
+    }
+    fb_fill(0, kfont.line_height * (klog.console_height - 1u), w, kfont.line_height, 0u, 0x2Cu, 0x55u);
+}
+
+static void klog_fb_write1(char c)
+{
+    if (klog.need_shift)
+    {
+        shift_line();
+        klog.need_shift = false;
+    }
+    if (c == '\n')
+    {
+        if (klog.y == (klog.console_height - 1u))
+        {
+            klog.need_shift = true;
+        }
+        else
+        {
+            klog.y++;
+        }
+        klog.x = 0u;
+    }
+    else
+    {
+        int px = klog.x * kfont.advance;
+        int py = klog.y * kfont.line_height;
+        fb_text_render_char(c, px, py, 0xFFu, 0x80u, 0u);
+        klog.x++;
+        if (klog.x == klog.console_width)
+        {
+            if (klog.y == (klog.console_height - 1u))
+            {
+                klog.need_shift = true;
+            }
+            else
+            {
+                klog.y++;
+            }
+            klog.x = 0u;
+        }
+    }
+}
+
+static void klog_fb_write(const char * src, size_t length)
+{
+    for (size_t i = 0u; i < length; i++)
+    {
+        klog_fb_write1(src[i]);
+    }
+}
+
+static const stream_t klog_fb_stream = {
+    klog_fb_write,
+    klog_fb_write1,
+};
+
+void klog_init(void)
+{
+    klog.console_width = fb_width() / kfont.advance;
+    klog.console_height = fb_height() / kfont.line_height;
+    klog.x = 0u;
+    klog.y = 0u;
+    klog.need_shift = false;
+    fb_fill(0, 0, fb_width(), fb_height(), 0u, 0x2Cu, 0x55u);
+}
+
+void klog_printf(const char * fmt, ...)
+{
+    va_list va;
+    va_start(va, fmt);
+    hos_vprintf(&klog_fb_stream, fmt, va);
+    va_end(va);
+}

src/klog.h

@@ -0,0 +1,7 @@
+#ifndef KLOG_H
+#define KLOG_H
+
+void klog_init(void);
+void klog_printf(const char * fmt, ...);
+
+#endif

src/link.ld

@@ -0,0 +1,41 @@
+ENTRY(hos_start)
+
+SECTIONS
+{
+    . = 1M;
+    _hos_mem_start = .;
+
+    .text BLOCK(4K) : ALIGN(4K)
+    {
+        *(.multiboot)
+        *(.text)
+    }
+
+    .rodata BLOCK(4K) : ALIGN(4K)
+    {
+        *(.rodata)
+    }
+
+    .data BLOCK(4K) : ALIGN(4K)
+    {
+        *(.data)
+    }
+
+    _stack_size = 16K;
+    .stack (NOLOAD) : ALIGN(4K)
+    {
+        _stack_start = .;
+        . = . + _stack_size;
+        _stack_end = .;
+    }
+
+    .bss BLOCK(4K) : ALIGN(4K)
+    {
+        *(COMMON)
+        *(.bss)
+    }
+
+    . = ALIGN(4K);
+
+    _hos_mem_end = .;
+}

src/mbinfo.c

@@ -0,0 +1,100 @@
+#include "multiboot2.h"
+#include "fb.h"
+#include "mem.h"
+#include <stdint.h>
+#include "klog.h"
+#include "mm.h"
+
+static uint32_t mbinfo[2048];
+
+static void mbinfo_process_tag(const multiboot2_info_tag_t * tag)
+{
+    switch (tag->type)
+    {
+    case MULTIBOOT2_INFO_BOOT_COMMAND_LINE:
+        {
+            multiboot2_info_boot_command_line_t * cl =
+                (multiboot2_info_boot_command_line_t *)tag;
+            klog_printf("Kernel boot command line: '%s'\n", cl->string);
+        }
+        break;
+
+    case MULTIBOOT2_INFO_BOOT_LOADER_NAME:
+        {
+            multiboot2_info_boot_loader_name_t * bln =
+                (multiboot2_info_boot_loader_name_t *)tag;
+            klog_printf("Boot loader: '%s'\n", bln->string);
+        }
+        break;
+
+    case MULTIBOOT2_INFO_MEMORY_MAP:
+        {
+            multiboot2_info_memory_map_t * mmap_info =
+                (multiboot2_info_memory_map_t *)tag;
+            size_t sz = sizeof(mmap_info->header) +
+                sizeof(mmap_info->entry_size) +
+                sizeof(mmap_info->entry_version);
+            multiboot2_info_memory_map_entry_t * entry = &mmap_info->entries[0];
+            for (;;)
+            {
+                sz += mmap_info->entry_size;
+                if (sz > mmap_info->header.size)
+                {
+                    break;
+                }
+                if (entry->type == MULTIBOOT2_MEMORY_MAP_TYPE_RAM)
+                {
+                    klog_printf("Memory region %16lx : %16lx\n",
+                            entry->base_addr,
+                            entry->length);
+                    mm_register_ram_region(entry->base_addr, entry->length);
+                }
+                entry = (multiboot2_info_memory_map_entry_t *)((uintptr_t)entry + mmap_info->entry_size);
+            }
+        }
+        break;
+
+    case MULTIBOOT2_INFO_FRAMEBUFFER_INFO:
+        {
+            multiboot2_info_framebuffer_info_t * fbinfo =
+                (multiboot2_info_framebuffer_info_t *)tag;
+            fb_init((uint32_t *)(uintptr_t)fbinfo->framebuffer_addr,
+                    fbinfo->framebuffer_width,
+                    fbinfo->framebuffer_height,
+                    fbinfo->framebuffer_pitch);
+        }
+        break;
+    }
+}
+
+static void process_tags(const multiboot2_info_tag_t * tag, bool init)
+{
+    while (tag->type != 0u)
+    {
+        if ((init && (tag->type == MULTIBOOT2_INFO_FRAMEBUFFER_INFO)) ||
+                (!init && (tag->type != MULTIBOOT2_INFO_FRAMEBUFFER_INFO)))
+        {
+            mbinfo_process_tag(tag);
+        }
+        tag = multiboot2_info_next_tag(tag);
+    }
+}
+
+bool mbinfo_init(uint32_t mbinfo_addr)
+{
+    multiboot2_info_header_t * mbinfo_header = (multiboot2_info_header_t *)mbinfo_addr;
+    if (mbinfo_header->total_size <= sizeof(mbinfo))
+    {
+        memcpy32(mbinfo, mbinfo_header, mbinfo_header->total_size / 4u);
+        multiboot2_info_tag_t * tag = (multiboot2_info_tag_t *)(mbinfo + sizeof(multiboot2_info_header_t) / 4u);
+        process_tags(tag, true);
+        return true;
+    }
+    return false;
+}
+
+void mbinfo_load(void)
+{
+    multiboot2_info_tag_t * tag = (multiboot2_info_tag_t *)(mbinfo + sizeof(multiboot2_info_header_t) / 4u);
+    process_tags(tag, false);
+}

src/mbinfo.h

@@ -0,0 +1,10 @@
+#ifndef MBINFO_H
+#define MBINFO_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+bool mbinfo_init(uint32_t mbinfo_addr);
+void mbinfo_load(void);
+
+#endif

src/mem.h

@@ -0,0 +1,49 @@
+#ifndef MEM_H
+#define MEM_H
+
+#include <stddef.h>
+
+static inline void memcpy(void * dest, const void * src, size_t n)
+{
+    uint32_t r0, r1, r2;
+    __asm__ __volatile__ (
+            "cld\n\t"
+            "rep movsb"
+            : "=&c" (r0), "=&S" (r1), "=&D" (r2)
+            : "2" (dest), "1" (src), "0" (n)
+            : "memory");
+}
+
+static inline void memcpy32(void * dest, const void * src, size_t count)
+{
+    uint32_t r0, r1, r2;
+    __asm__ __volatile__ (
+            "cld\n\t"
+            "rep movsd"
+            : "=&c" (r0), "=&S" (r1), "=&D" (r2)
+            : "2" (dest), "1" (src), "0" (count)
+            : "memory");
+}
+
+static inline void * memmove(void * dest, const void * src, size_t count)
+{
+    return __builtin_memmove(dest, src, count);
+}
+
+static inline void * memset(void * dest, int val, size_t count)
+{
+    return __builtin_memset(dest, val, count);
+}
+
+static inline void memset32(void * dest, uint32_t val, size_t count)
+{
+    uint32_t r0, r1;
+    __asm__ __volatile__ (
+            "cld\n\t"
+            "rep stosl"
+            : "=&c" (r0), "=&D" (r1)
+            : "a" (val), "1" (dest), "0" (count)
+            : "memory");
+}
+
+#endif

src/mm.c

@@ -0,0 +1,91 @@
+#include "mm.h"
+
+typedef struct mm_page_entry_s {
+    size_t count;
+    struct mm_page_entry_s * next;
+} mm_region_entry_t;
+
+static mm_region_entry_t * mm_next_free_region;
+static size_t mm_free_pages;
+static size_t mm_total_ram;
+static size_t kernel_start_address;
+static size_t kernel_size;
+
+extern uint8_t _hos_mem_start;
+extern uint8_t _hos_mem_end;
+
+static void mm_add_ram_region(size_t base, size_t size)
+{
+    mm_region_entry_t * region = (mm_region_entry_t *)base;
+    size_t pages = size / PAGE_SIZE;
+    region->count = pages;
+    region->next = mm_next_free_region;
+    mm_next_free_region = region;
+    mm_total_ram += size;
+    mm_free_pages = pages;
+}
+
+void mm_register_ram_region(uint64_t base, size_t size)
+{
+    /* Ignore any RAM region above 4GB. */
+    if (base >= 0x100000000ull)
+    {
+        return;
+    }
+    if ((base + size) > 0x100000000ull)
+    {
+        size = (size_t)(0x100000000ull - base);
+    }
+    size_t end_address = mm_page_floor((size_t)base + size);
+    size_t start_address = mm_page_ceil(base);
+    size = end_address - start_address;
+    if (size < PAGE_SIZE)
+    {
+        return;
+    }
+    size_t kernel_end_address = kernel_start_address + kernel_size;
+    /* Add regions before and after kernel RAM. */
+    if (start_address < kernel_start_address)
+    {
+        /* RAM region begins before kernel RAM. */
+        size_t this_sz = size;
+        if ((start_address + this_sz) > kernel_start_address)
+        {
+            this_sz = kernel_start_address - start_address;
+        }
+        mm_add_ram_region(start_address, this_sz);
+    }
+    if ((start_address + size) > kernel_end_address)
+    {
+        /* RAM region ends after kernel RAM. */
+        size_t this_sz = size;
+        if (start_address < kernel_end_address)
+        {
+            this_sz = (start_address + size) - kernel_end_address;
+            start_address = kernel_end_address;
+        }
+        mm_add_ram_region(start_address, this_sz);
+    }
+}
+
+void mm_init(void)
+{
+    kernel_start_address = mm_page_floor((size_t)&_hos_mem_start);
+    kernel_size = mm_page_ceil((size_t)&_hos_mem_end - kernel_start_address);
+    mm_total_ram = kernel_size;
+}
+
+size_t mm_get_total_ram(void)
+{
+    return mm_total_ram;
+}
+
+size_t mm_get_kernel_address(void)
+{
+    return kernel_start_address;
+}
+
+size_t mm_get_kernel_size(void)
+{
+    return kernel_size;
+}

src/mm.h

@@ -0,0 +1,25 @@
+#ifndef MM_H
+#define MM_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+#define PAGE_SIZE 4096u
+
+static inline size_t mm_page_floor(size_t bytes)
+{
+    return bytes & ~(PAGE_SIZE - 1u);
+}
+
+static inline size_t mm_page_ceil(size_t bytes)
+{
+    return (bytes + PAGE_SIZE - 1u) & ~(PAGE_SIZE - 1u);
+}
+
+void mm_init(void);
+void mm_register_ram_region(uint64_t base, size_t size);
+size_t mm_get_total_ram(void);
+size_t mm_get_kernel_address(void);
+size_t mm_get_kernel_size(void);
+
+#endif

src/multiboot2.h

@@ -0,0 +1,127 @@
+#ifndef MULTIBOOT2_H
+#define MULTIBOOT2_H
+
+#include <stdint.h>
+
+#define MULTIBOOT2_MAGIC 0xE85250D6u
+#define MULTIBOOT2_ARCHITECTURE_I386 0u
+
+typedef struct {
+    uint32_t magic;
+    uint32_t architecture;
+    uint32_t header_length;
+    uint32_t checksum;
+} multiboot2_header_t;
+#define multiboot2_header(magic, architecture, header_length) \
+    {(magic), (architecture), (header_length), (uint32_t)(0x100000000u - (magic) - (architecture) - (header_length))}
+#define multiboot2_header_default() \
+    multiboot2_header(MULTIBOOT2_MAGIC, MULTIBOOT2_ARCHITECTURE_I386, sizeof(multiboot2_header_t))
+
+typedef struct {
+    uint16_t type;
+    uint16_t flags;
+    uint32_t size;
+} multiboot2_tag_t;
+#define multiboot2_end_tag() {0u, 0u, 8u}
+
+typedef struct {
+    multiboot2_tag_t header;
+    uint32_t width;
+    uint32_t height;
+    uint32_t depth;
+    uint32_t _padding;
+} multiboot2_framebuffer_tag_t;
+#define multiboot2_framebuffer_tag(width, height, depth) \
+    {{5u, 0u, 20u}, width, height, depth}
+
+#define MULTIBOOT2_INFO_TAG_ALIGNMENT 8u
+#define MULTIBOOT2_INFO_BOOT_COMMAND_LINE 1u
+#define MULTIBOOT2_INFO_BOOT_LOADER_NAME 2u
+#define MULTIBOOT2_INFO_MODULES 3u
+#define MULTIBOOT2_INFO_BASIC_MEMORY_INFO 4u
+#define MULTIBOOT2_INFO_BIOS_BOOT_DEVICE 5u
+#define MULTIBOOT2_INFO_MEMORY_MAP 6u
+#define MULTIBOOT2_INFO_VBE_INFO 7u
+#define MULTIBOOT2_INFO_FRAMEBUFFER_INFO 8u
+#define MULTIBOOT2_INFO_ELF_SYMBOLS 9u
+#define MULTIBOOT2_INFO_APM_TABLE 10u
+#define MULTIBOOT2_INFO_EFI_32BIT_SYSTEM_TABLE_POINTER 11u
+#define MULTIBOOT2_INFO_EFI_64BIT_SYSTEM_TABLE_POINTER 12u
+#define MULTIBOOT2_INFO_SMBIOS_TABLES 13u
+#define MULTIBOOT2_INFO_ACPI_OLD_RSDP 14u
+#define MULTIBOOT2_INFO_NETWORKING_INFO 16u
+#define MULTIBOOT2_INFO_EFI_MEMORY_MAP 17u
+#define MULTIBOOT2_INFO_EFI_BOOT_SERVICES_NOT_TERMINATED 18u
+#define MULTIBOOT2_INFO_EFI_32BIT_IMAGE_HANDLE_POINTER 19u
+#define MULTIBOOT2_INFO_EFI_64BIT_IMAGE_HANDLE_POINTER 20u
+#define MULTIBOOT2_INFO_IMAGE_LOAD_BASE_PHYSICAL_ADDRESS 21u
+
+typedef struct {
+    uint32_t total_size;
+    uint32_t _reserved;
+} multiboot2_info_header_t;
+
+typedef struct {
+    uint32_t type;
+    uint32_t size;
+} multiboot2_info_tag_t;
+#define multiboot2_info_next_tag(current_tag) \
+    (multiboot2_info_tag_t *)(((uintptr_t)current_tag + current_tag->size + MULTIBOOT2_INFO_TAG_ALIGNMENT - 1u) & ~(MULTIBOOT2_INFO_TAG_ALIGNMENT - 1u))
+
+typedef struct {
+    multiboot2_info_tag_t header;
+    char string[];
+} multiboot2_info_boot_command_line_t;
+
+typedef struct {
+    multiboot2_info_tag_t header;
+    char string[];
+} multiboot2_info_boot_loader_name_t;
+
+typedef struct {
+    multiboot2_info_tag_t header;
+    uint32_t mem_lower;
+    uint32_t mem_upper;
+} multiboot2_info_basic_memory_info_t;
+
+#define MULTIBOOT2_MEMORY_MAP_TYPE_RAM 1u
+#define MULTIBOOT2_MEMORY_MAP_TYPE_ACPI 3u
+#define MULTIBOOT2_MEMORY_MAP_TYPE_PRESERVE 4u
+#define MULTIBOOT2_MEMORY_MAP_TYPE_DEFECTIVE 5u
+
+typedef struct {
+    uint64_t base_addr;
+    uint64_t length;
+    uint32_t type;
+    uint32_t _reserved;
+} multiboot2_info_memory_map_entry_t;
+
+typedef struct {
+    multiboot2_info_tag_t header;
+    uint32_t entry_size;
+    uint32_t entry_version;
+    multiboot2_info_memory_map_entry_t entries[];
+} multiboot2_info_memory_map_t;
+
+typedef struct {
+    multiboot2_info_tag_t header;
+    uint16_t vbe_mode;
+    uint16_t vbe_interface_set;
+    uint16_t vbe_interface_off;
+    uint16_t vbe_interface_len;
+    uint8_t vbe_control_info[512];
+    uint8_t vbe_mode_info[256];
+} multiboot2_info_vbe_info_t;
+
+typedef struct {
+    multiboot2_info_tag_t header;
+    uint64_t framebuffer_addr;
+    uint32_t framebuffer_pitch;
+    uint32_t framebuffer_width;
+    uint32_t framebuffer_height;
+    uint8_t framebuffer_bpp;
+    uint8_t framebuffer_type;
+    uint8_t _reserved;
+} multiboot2_info_framebuffer_info_t;
+
+#endif

src/multiboot_header.c

@@ -0,0 +1,12 @@
+#include "multiboot2.h"
+
+/* Multiboot2 Header. */
+struct {
+    multiboot2_header_t header;
+    multiboot2_framebuffer_tag_t framebuffer_tag;
+    multiboot2_tag_t end_tag;
+} multiboot_header __attribute__((section(".multiboot"))) = {
+    multiboot2_header_default(),
+    multiboot2_framebuffer_tag(1600u, 900u, 32u),
+    multiboot2_end_tag(),
+};

src/stream.h

@@ -0,0 +1,12 @@
+#ifndef STREAM_H
+#define STREAM_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct {
+    void (*write)(const char * src, size_t length);
+    void (*write1)(char c);
+} stream_t;
+
+#endif

src/string.h

@@ -0,0 +1,26 @@
+#ifndef STRING_H
+#define STRING_H
+
+#include <stddef.h>
+
+static inline size_t strlen(const char * s)
+{
+    size_t r = 0u;
+    while (*s++ != (char)0)
+    {
+        r++;
+    }
+    return r;
+}
+
+static inline char * strcpy(char * dest, const char * src)
+{
+    return __builtin_strcpy(dest, src);
+}
+
+static inline char * strncpy(char * dest, const char * src, size_t n)
+{
+    return __builtin_strncpy(dest, src, n);
+}
+
+#endif

util/build-i586-elf-gcc.sh

@@ -1,100 +0,0 @@
-#!/bin/bash -x
-
-BINUTILS_VERSION=${BINUTILS_VERSION:-"2.20"}
-GCC_VERSION=${GCC_VERSION:-"4.4.2"}
-TARGET=${TARGET:-"i586-elf"}
-PREFIX=${PREFIX:-"$HOME/local/$TARGET"}
-GNUFTP=ftp://ftp.gnu.org/gnu
-export PATH=$PREFIX/bin:$PATH
-
-mkdir -p build-binutils build-gcc
-
-if [ ! -f "binutils-$BINUTILS_VERSION.tar.bz2" ]; then
-    wget "$GNUFTP/binutils/binutils-$BINUTILS_VERSION.tar.bz2"
-    if [ $? != 0 ]; then
-        echo "Error downloading binutils"
-        exit 1
-    fi
-fi
-
-if [ ! -f "gcc-$GCC_VERSION.tar.bz2" ]; then
-    wget "$GNUFTP/gcc/gcc-$GCC_VERSION/gcc-$GCC_VERSION.tar.bz2"
-    if [ $? != 0 ]; then
-        echo "Error downloading gcc"
-        exit 1
-    fi
-fi
-
-if [ ! -d "binutils-$BINUTILS_VERSION" ]; then
-    tar xvjf "binutils-$BINUTILS_VERSION.tar.bz2"
-    if [ $? != 0 ]; then
-        echo "Error extracting binutils"
-        exit 1
-    fi
-fi
-
-if [ ! -d "gcc-$GCC_VERSION" ]; then
-    tar xvjf "gcc-$GCC_VERSION.tar.bz2"
-    if [ $? != 0 ]; then
-        echo "Error extracting gcc"
-        exit 1
-    fi
-fi
-
-
-# build binutils
-dum=`which $TARGET-ar`
-if [ $? != 0 ]; then
-    pushd build-binutils
-    ../binutils-$BINUTILS_VERSION/configure --target=$TARGET --prefix=$PREFIX --disable-nls
-    if [ $? != 0 ]; then
-        echo "Error configuring binutils"
-        exit 1
-    fi
-    make all
-    if [ $? != 0 ]; then
-        echo "Error building binutils"
-        exit 1
-    fi
-    make install
-    if [ $? != 0 ]; then
-        echo "Error installing binutils"
-        exit 1
-    fi
-    popd
-fi
-
-
-# build gcc
-dum=`which $TARGET-gcc`
-if [ $? != 0 ]; then
-    pushd build-gcc
-    ../gcc-$GCC_VERSION/configure --target=$TARGET --prefix=$PREFIX --disable-nls --enable-languages=c,c++ --without-headers
-    if [ $? != 0 ]; then
-        echo "Error configuring gcc"
-        exit 1
-    fi
-    make all-gcc
-    if [ $? != 0 ]; then
-        echo "Error building gcc"
-        exit 1
-    fi
-    make install-gcc
-    if [ $? != 0 ]; then
-        echo "Error installing gcc"
-        exit 1
-    fi
-    make all-target-libgcc
-    if [ $? != 0 ]; then
-        echo "Error building libgcc"
-        exit 1
-    fi
-    make install-target-libgcc
-    if [ $? != 0 ]; then
-        echo "Error installing libgcc"
-        exit 1
-    fi
-    popd
-fi
-
-exit 0