Add Framebuffer object

Unfortunately, crashes... :(

.gitignore

@@ -1,3 +1,3 @@
 .rscons*
-/i686-elf-gcc/
+/x86_64-elf-gcc/
 /build/

.gitmodules

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

Rsconscript

@@ -1,98 +1,52 @@
-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
+project_name "HOS"
+path_prepend "x86_64-elf-gcc/bin"
+
+configure do
+  rscons "x86_64-elf-gcc.rb", "-b", "#{build_dir}/x86_64-elf-gcc"
+  check_d_compiler "ldc2", use: "ldc2"
+  check_c_compiler "x86_64-w64-mingw32-gcc", use: "x86_64-w64-mingw32-gcc"
+  check_c_compiler "x86_64-elf-gcc", use: "x86_64-elf-gcc"
+  check_c_compiler
+  check_program "mformat", on_fail: "Install the mtools package"
+  check_cfg package: "freetype2", on_fail: "Install libfreetype-dev", use: "freetype"
+  sh %w[git submodule update --init]
+end
+
+# Kernel default font size.
 KFONT_SIZE = 15
 
-class BiosImage < Builder
+class HulkBinObj < 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
-}
+    FileUtils.mkdir_p(File.dirname(@target))
+    File.write(@target, <<EOF)
+.section ".rodata"
+.balign 4096
+.global hulk_bin_start
+hulk_bin_start:
+.incbin "#{@sources.first}"
+.balign 4096
+.global hulk_bin_end
+hulk_bin_end:
 EOF
-        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
+    unless @cache.up_to_date?(@target, nil, @sources, @env)
+      print_run_message("Creating HULK binary object <target>#{@target}<reset>", nil)
       @cache.register_build(@target, nil, @sources, @env)
     end
     true
   end
 end
 
-class EfiImage < Builder
+class Image < 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
+      print_run_message("Creating disk image <target>#{@target}<reset>", nil)
+      File.binwrite(@target, "\0" * (1440 * 1024))
+      system(*%W[mformat -i #{@target} -f 1440 ::])
+      system(*%W[mmd -i #{@target} ::/EFI])
+      system(*%W[mmd -i #{@target} ::/EFI/BOOT])
+      system(*%W[mcopy -i #{@target} #{@sources.first} ::/EFI/BOOT])
       @cache.register_build(@target, nil, @sources, @env)
     end
     true
@@ -112,55 +66,60 @@ class FontGen < Builder
   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} ${_SOURCES}], @vars)
-      standard_command("Size <target>#{@target}<reset>", command, stdout: @target)
+fontgen_env = env "fontgen", use: "freetype" do |env|
+  env.Program("^/fontgen", glob("src/fontgen/**/*.c"))
+end
+
+hulk_env = env "hulk", use: %w[ldc2 x86_64-elf-gcc] do |env|
+  env["sources"] = glob("src/hulk/**/*.d")
+  env["DFLAGS"] += %w[-mtriple=x86_64-unknown-elf --betterC -release -O3 --wi --enable-cross-module-inlining]
+  env["D_IMPORT_PATH"] += %w[src]
+  env["LD"] = "x86_64-elf-gcc"
+  env["LDFLAGS"] += %w[-nostdlib -Tsrc/hulk/hulk.ld -Wl,-Map,${_TARGET}.map]
+  env["LDCMD"] = %w[${LD} -o ${_TARGET} ${LDFLAGS} ${_SOURCES} ${LIBDIRPREFIX}${LIBPATH} ${LIBLINKPREFIX}${LIBS}]
+  env["OBJDUMP"] = "x86_64-elf-objdump"
+  env["OBJCOPY"] = "x86_64-elf-objcopy"
+  env.Program("^/hulk.elf", "${sources}")
+  env.depends("^/hulk.elf", "src/hulk/hulk.ld")
+  env["SIZE"] = "x86_64-elf-size"
+  env.Size("^/hulk.size", "^/hulk.elf")
+  env.Disassemble("^/hulk.txt", "^/hulk.elf")
+  env.Command("^/hulk.bin", "^/hulk.elf",
+              "CMD" => %W[${OBJCOPY} -O binary ${_SOURCES} ${_TARGET}],
+              "CMD_DESC" => "Convert ELF to binary:")
+  env.add_build_hook do |builder|
+    if builder.target.end_with?(".o")
+      env.Disassemble("#{builder.target}.txt", builder.target)
     end
   end
 end
 
-# 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,${_TARGET}.map]
-  env["LIBS"] += %w[gcc]
-  env.FontGen("^/kfont/kfont.c", "font/Hack-Regular.ttf",
-             "fontgen" => fontgen_env.expand("^/fontgen.bin"))
-  env.barrier
-  env["CPPPATH"] += ["#{env.build_root}/kfont"]
-  env.Program("^/hos.elf", glob("src/**/*.{S,c}") + ["^/kfont/kfont.c"])
-  env.depends("#{env.build_root}/hos.elf", "src/link.ld")
-  env.Disassemble("^/hos.elf.txt", "^/hos.elf")
-  env.Size("^/hos.elf.size", "^/hos.elf")
-  env.EfiImage("^/hos-efi.img", %w[^/hos.elf])
-  env.BiosImage("^/hos.img", %w[^/hos.elf])
+hello_env = env "hello", use: %w[ldc2 x86_64-w64-mingw32-gcc] do |env|
+  env.add_builder(Image)
+  env.add_builder(HulkBinObj)
+  env["sources"] = glob("src/hello/**/*.d")
+  env["sources"] += glob("uefi-d/source/**/*.d")
+  env.HulkBinObj("^/hulk_bin.S", hulk_env.expand("^/hulk.bin"))
+  env.Object("^/hulk_bin.o", "^/hulk_bin.S")
+  env.depends("^/hulk_bin.o", hulk_env.expand("^/hulk.bin"))
+  env["sources"] << "^/hulk_bin.o"
+  env["DFLAGS"] += %w[-mtriple=x86_64-unknown-windows-coff --betterC -release -O3 --wi --enable-cross-module-inlining]
+  env["D_IMPORT_PATH"] += %w[src uefi-d/source]
+  env["LD"] = "x86_64-w64-mingw32-gcc"
+  env["LDFLAGS"] += %w[-nostdlib -Wl,-dll -shared -Wl,--subsystem,10 -e efi_main -Wl,-Map,${_TARGET}.map]
+  env["LDCMD"] = %w[${LD} -o ${_TARGET} ${LDFLAGS} ${_SOURCES} ${LIBDIRPREFIX}${LIBPATH} ${LIBLINKPREFIX}${LIBS}]
+  env["OBJDUMP"] = "x86_64-w64-mingw32-objdump"
+  env.Program("^/BOOTX64.EFI", "${sources}")
+  env["SIZE"] = "x86_64-w64-mingw32-size"
+  env.Size("^/BOOTX64.size", "^/BOOTX64.EFI")
+  env.Disassemble("^/BOOTX64.txt", "^/BOOTX64.EFI")
+  env.Image("^/hos.img", "^/BOOTX64.EFI")
 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}]
+  Dir.mktmpdir do |tmpdir|
+    img = hello_env.expand("^/hos.img")
+    FileUtils.cp(img, tmpdir)
+    sh %W[qemu-system-x86_64 -bios OVMF.fd -drive file=#{tmpdir}/hos.img,format=raw]
+  end
 end

rscons

@@ -1,9 +1,9 @@
 #!/usr/bin/env ruby
 
 # Copyright (c) 2013-2022 Josh Holtrop
-# 
+#
 # MIT License
-# 
+#
 # Permission is hereby granted, free of charge, to any person obtaining
 # a copy of this software and associated documentation files (the
 # "Software"), to deal in the Software without restriction, including
@@ -11,10 +11,10 @@
 # distribute, sublicense, and/or sell copies of the Software, and to
 # permit persons to whom the Software is furnished to do so, subject to
 # the following conditions:
-# 
+#
 # The above copyright notice and this permission notice shall be
 # included in all copies or substantial portions of the Software.
-# 
+#
 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
@@ -24,7 +24,7 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 
-script = File.join(File.dirname(__FILE__), ".rscons-3.0.0-077c0388ca4d1d902141299abcc4b8f6.rb")
+script = File.join(File.dirname(__FILE__), ".rscons-3.0.2-c49c635f1e4166223367979510498b28.rb")
 unless File.exists?(script)
   if File.read(__FILE__, mode: "rb") =~ /^#==>(.*)/
     require "zlib"
@@ -43,4 +43,4 @@ load script
 if __FILE__ == $0
   Rscons::Cli.new.run(ARGV)
 end
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Line truncated
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Line truncated

src/hello/console.d

@@ -0,0 +1,178 @@
+/**
+ * HELLO console support.
+ */
+module hello.console;
+
+import uefi;
+import hello.hello;
+import core.stdc.stdarg;
+
+/**
+ * Format a hexadecimal value to a string.
+ *
+ * @param s String buffer.
+ * @param v Value to format.
+ * @param ptr If true, always output all 16 digits, and separate the upper and
+ *   lower halves with an underscore.
+ */
+private size_t format_hex(CHAR16 * s, ulong v, bool ptr)
+{
+    string hex_chars = "0123456789ABCDEF";
+    bool print = ptr;
+    size_t si = 0u;
+    for (size_t i = 0u; i < 16u; i++)
+    {
+        if (ptr && (i == 8u))
+        {
+            s[si++] = '_';
+        }
+        ulong n = (v >> (60u - 4u * i)) & 0xFu;
+        if (n != 0u)
+        {
+            print = true;
+        }
+        if (print || (i == 15u))
+        {
+            s[si++] = hex_chars[n];
+        }
+    }
+    return si;
+}
+
+/**
+ * Format a decimal value to a string.
+ *
+ * @param s String buffer.
+ * @param v Value to format.
+ */
+private size_t format_dec(CHAR16 * s, ulong v)
+{
+    string dec_chars = "0123456789";
+    bool print;
+    char[20] buf;
+    size_t buf_i;
+    while ((buf_i == 0u) || (v != 0u))
+    {
+        ulong n = v % 10u;
+        buf[buf_i++] = dec_chars[n];
+        v /= 10u;
+    }
+    for (size_t si = 0u; si < buf_i; si++)
+    {
+        s[si] = buf[buf_i - si - 1u];
+    }
+    return buf_i;
+}
+
+/**
+ * Write a string to the console.
+ *
+ * @param s Format string.
+ * @param args Variable arguments structure.
+ */
+void write(string s, va_list args)
+{
+    __gshared static CHAR16[256] s16;
+    size_t i = 0u;
+    bool escape = false;
+    foreach (char c; s)
+    {
+        if (escape)
+        {
+            if (c == '%')
+            {
+                s16[i++] = '%';
+            }
+            else if (c == 'x')
+            {
+                ulong v;
+                va_arg(args, v);
+                i += format_hex(&s16[i], v, false);
+            }
+            else if (c == 'p')
+            {
+                ulong v;
+                va_arg(args, v);
+                i += format_hex(&s16[i], v, true);
+            }
+            else if (c == 'S')
+            {
+                const(CHAR16) * s2;
+                va_arg(args, s2);
+                for (size_t s2_i = 0u; s2[s2_i] != 0; s2_i++)
+                {
+                    s16[i++] = s2[s2_i];
+                }
+            }
+            else if (c == 'u')
+            {
+                ulong v;
+                va_arg(args, v);
+                i += format_dec(&s16[i], v);
+            }
+            else
+            {
+                s16[i++] = c;
+            }
+            escape = false;
+        }
+        else if (c == '%')
+        {
+            escape = true;
+        }
+        else
+        {
+            s16[i++] = c;
+        }
+    }
+    s16[i++] = 0u;
+    st.ConOut.OutputString(st.ConOut, &s16[0]);
+}
+
+/**
+ * Write a string to the console.
+ *
+ * @param s Format string.
+ */
+extern (C) void write(string s, ...)
+{
+    va_list args;
+    va_start(args, s);
+    write(s, args);
+    va_end(args);
+}
+
+/**
+ * Write a string to the console.
+ *
+ * @param s Format string.
+ */
+extern (C) void writeln(string s, ...)
+{
+    va_list args;
+    va_start(args, s);
+    write(s, args);
+    write("\r\n", args);
+    va_end(args);
+}
+
+/**
+ * Write a message to press any key and wait for a key to be pressed.
+ */
+void wait_key()
+{
+    writeln("Press any key...");
+    st.ConIn.Reset(st.ConIn, FALSE);
+    EFI_INPUT_KEY key;
+    while (st.ConIn.ReadKeyStroke(st.ConIn, &key) == EFI_NOT_READY)
+    {
+    }
+}
+
+/**
+ * Clear the console.
+ */
+void clear()
+{
+    st.ConOut.ClearScreen(st.ConOut);
+}

src/hello/hello.d

@@ -0,0 +1,344 @@
+/**
+ * HELLO, the HOS EFI Lightweight LOader.
+ */
+module hello.hello;
+
+import uefi;
+import console = hello.console;
+import scratch = hello.scratch;
+import hulk.bootinfo;
+import hulk.header : HulkHeader = Header;
+import hos.page_table;
+import hos.cpu;
+import hos.memory;
+
+__gshared EFI_SYSTEM_TABLE * st;
+private __gshared BootInfo bootinfo;
+private __gshared UINTN memory_map_key;
+extern extern(C) __gshared ubyte hulk_bin_start;
+
+/**
+ * Detect if we're running in QEMU.
+ */
+private bool in_qemu()
+{
+    ulong * firmware_vendor = cast(ulong *) st.FirmwareVendor;
+    ulong fv1 = firmware_vendor[0];
+    return fv1 ==
+        ((cast(ulong)'E') |
+         (cast(ulong)'D' << 16) |
+         (cast(ulong)'K' << 32) |
+         (cast(ulong)' ' << 48));
+}
+
+/**
+ * Set a graphics mode.
+ */
+private bool set_graphics_mode()
+{
+    uint max_horizontal_resolution = in_qemu() ? 1920u : 0xFFFFFFFFu;
+    UINTN buffer_size = scratch.free();
+    EFI_GUID gop_guid = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+    EFI_HANDLE * handles = cast(EFI_HANDLE *)scratch.current();
+    EFI_STATUS status = st.BootServices.LocateHandle(ByProtocol,
+            &gop_guid, null, &buffer_size, handles);
+    if (status != EFI_SUCCESS)
+    {
+        console.writeln("LocateHandle: error %x", status);
+        return false;
+    }
+    EFI_HANDLE gop_handle = handles[0];
+    EFI_HANDLE gop_interface;
+    status = st.BootServices.HandleProtocol(gop_handle,
+            &gop_guid, &gop_interface);
+    if (status != EFI_SUCCESS)
+    {
+        console.writeln("HandleProtocol: error %x", status);
+        return false;
+    }
+    if (gop_interface == null)
+    {
+        console.writeln("null interface from HandleProtocol");
+        return false;
+    }
+    EFI_GRAPHICS_OUTPUT_PROTOCOL * gop = cast(EFI_GRAPHICS_OUTPUT_PROTOCOL *)gop_interface;
+    UINTN info_size;
+    EFI_GRAPHICS_OUTPUT_MODE_INFORMATION * info;
+    uint best_width;
+    uint best_mode_number;
+    for (uint mode_number = 0u;
+         (status = gop.QueryMode(gop, mode_number, &info_size, &info)) == EFI_SUCCESS;
+         mode_number++)
+    {
+        if ((info.HorizontalResolution > best_width) &&
+            (info.HorizontalResolution <= max_horizontal_resolution))
+        {
+            best_width = info.HorizontalResolution;
+            best_mode_number = mode_number;
+        }
+        st.BootServices.FreePool(info);
+    }
+    if ((status = gop.SetMode(gop, best_mode_number)) != EFI_SUCCESS)
+    {
+        console.writeln("SetMode: Error %x\n", status);
+        return false;
+    }
+    bootinfo.fb.buffer = cast(uint *)gop.Mode.FrameBufferBase;
+    bootinfo.fb.width = gop.Mode.Info.HorizontalResolution;
+    bootinfo.fb.height = gop.Mode.Info.VerticalResolution;
+    bootinfo.fb.stride = gop.Mode.Info.PixelsPerScanLine;
+    bootinfo.fb.format = gop.Mode.Info.PixelFormat;
+    return true;
+}
+
+/**
+ * Walk the EFI memory map and translate it to the HULK bootinfo format.
+ *
+ * @return Maximum physical address to identity map.
+ */
+private ulong get_memory_map()
+{
+    UINTN memory_map_size = scratch.free();
+    UINTN descriptor_size;
+    UINT32 descriptor_version;
+    ubyte * scratch_base = scratch.current();
+    UINTN status = st.BootServices.GetMemoryMap(
+            &memory_map_size,
+            cast(EFI_MEMORY_DESCRIPTOR *)scratch_base,
+            &memory_map_key,
+            &descriptor_size,
+            &descriptor_version);
+    if (status != EFI_SUCCESS)
+    {
+        console.writeln("GetMemoryMap: Error %x", status);
+        return 0u;
+    }
+    ulong max_physical_address;
+    size_t n_entries = memory_map_size / descriptor_size;
+    size_t count;
+    for (count = 0u; count < n_entries; count++)
+    {
+        if (count > bootinfo.memory_map.length)
+        {
+            console.writeln("Memory map too large");
+            for (;;)
+            {
+            }
+        }
+        EFI_MEMORY_DESCRIPTOR * descriptor = cast(EFI_MEMORY_DESCRIPTOR *)&scratch_base[count * descriptor_size];
+        ulong end_address = descriptor.PhysicalStart + descriptor.NumberOfPages * 4096u;
+        if ((end_address > max_physical_address) &&
+            ((descriptor.Type == EfiLoaderCode) ||
+             (descriptor.Type == EfiLoaderData) ||
+             (descriptor.Type == EfiBootServicesCode) ||
+             (descriptor.Type == EfiBootServicesData) ||
+             (descriptor.Type == EfiRuntimeServicesCode) ||
+             (descriptor.Type == EfiRuntimeServicesData) ||
+             (descriptor.Type == EfiConventionalMemory)))
+        {
+            max_physical_address = end_address;
+        }
+        bootinfo.memory_map[count].base = descriptor.PhysicalStart;
+        bootinfo.memory_map[count].size = descriptor.NumberOfPages * 4096u;
+        bootinfo.memory_map[count].type = cast(ubyte)descriptor.Type;
+    }
+    bootinfo.memory_map_count = count;
+    return max_physical_address;
+}
+
+/**
+ * Allocate a new page table.
+ */
+private PageTableEntry * new_page_table()
+{
+    PageTableEntry * pt = cast(PageTableEntry *)scratch.alloc(1u);
+    memset64(pt, 0u, 512);
+    return pt;
+}
+
+/**
+ * Map a virtual address to a physical address using 4KB pages.
+ *
+ * @param source_page Source page address.
+ * @param dest_page Destination page address.
+ * @param pt_base Page table base address.
+ */
+private void map4k(ulong source_page, ulong dest_page, PageTableEntry * pt_base)
+{
+    PageTableEntry * pt = pt_base;
+    PageTableEntry * next_pt;
+    for (size_t level = 0; level < 4u; level++)
+    {
+        size_t pt_index = PageTableEntry.page_table_index(source_page, level);
+        if (pt[pt_index].present())
+        {
+            pt = pt[pt_index].next();
+        }
+        else
+        {
+            ulong addr;
+            if (level < 3u)
+            {
+                next_pt = new_page_table();
+                addr = cast(ulong)next_pt;
+            }
+            else
+            {
+                addr = dest_page;
+            }
+            pt[pt_index] = PageTableEntry(addr,
+                    0u, 0u, 0u, 0u, 0u, 0u, 1u, 1u);
+            pt = next_pt;
+        }
+    }
+}
+
+/**
+ * Map a virtual address to a physical address using 2MB pages.
+ *
+ * @param source_page Source page address.
+ * @param dest_page Destination page address.
+ * @param pt_base Page table base address.
+ */
+private void map2m(ulong source_page, ulong dest_page, PageTableEntry * pt_base)
+{
+    PageTableEntry * pt = pt_base;
+    PageTableEntry * next_pt;
+    for (size_t level = 0; level < 3u; level++)
+    {
+        size_t pt_index = PageTableEntry.page_table_index(source_page, level);
+        if (pt[pt_index].present())
+        {
+            pt = pt[pt_index].next();
+        }
+        else
+        {
+            if (level < 2u)
+            {
+                next_pt = new_page_table();
+                pt[pt_index] = PageTableEntry(cast(ulong)next_pt,
+                        0u, 0u, 0u, 0u, 0u, 0u, 1u, 1u);
+            }
+            else
+            {
+                pt[pt_index] = PageTableEntry(dest_page,
+                        0u, 0u, 1u, 0u, 0u, 0u, 1u, 1u);
+            }
+            pt = next_pt;
+        }
+    }
+}
+
+/**
+ * Map HULK virtual addresses to physical kernel location.
+ *
+ * @param pt_base Page table base address.
+ */
+private void map_hulk(PageTableEntry * pt_base)
+{
+    ulong virt = HULK_VIRTUAL_START;
+    ulong phys = cast(ulong)&hulk_bin_start;
+    HulkHeader * hulk_header = cast(HulkHeader *)&hulk_bin_start;
+    size_t end_phys = phys + cast(size_t)hulk_header.total_size;
+    while (phys < end_phys)
+    {
+        map4k(virt, phys, pt_base);
+        virt += 4096u;
+        phys += 4096u;
+    }
+}
+
+/**
+ * Build page tables in preparation to jump to HULK.
+ *
+ * @param max_physical_address Maximum physical address to identity map.
+ */
+private void build_page_tables(ulong max_physical_address)
+{
+    PageTableEntry * pt_base = new_page_table();
+    /* Map physical RAM. */
+    for (size_t addr = 0u; addr < max_physical_address; addr += (2u * 1024u * 1024u))
+    {
+        map2m(addr, addr, pt_base);
+    }
+    /* Map any memory regions that are outside physical RAM. */
+    for (size_t i = 0u; i < bootinfo.memory_map_count; i++)
+    {
+        if (bootinfo.memory_map[i].base > max_physical_address)
+        {
+            for (size_t offset = 0u; offset < bootinfo.memory_map[i].size; offset += 4096u)
+            {
+                ulong addr = bootinfo.memory_map[i].base + offset;
+                map4k(addr, addr, pt_base);
+            }
+        }
+    }
+    /* Map graphics framebuffer. */
+    ulong framebuffer_size = bootinfo.fb.height * bootinfo.fb.stride * 4u;
+    for (size_t offset = 0u; offset < framebuffer_size; offset += 4096u)
+    {
+        ulong addr = cast(ulong)bootinfo.fb.buffer + offset;
+        map4k(addr, addr, pt_base);
+    }
+    /* Map HULK to its requested starting virtual address. */
+    map_hulk(pt_base);
+    /* Switch to the new page table. */
+    write_cr3(cast(ulong)pt_base);
+}
+
+/**
+ * Jump to HULK entry point.
+ */
+private void jump_to_hulk()
+{
+    HulkHeader * hulk_header = cast(HulkHeader *)&hulk_bin_start;
+    void function(BootInfo *) hulk_start = cast(void function(BootInfo *))hulk_header.entry;
+    hulk_start(&bootinfo);
+}
+
+/**
+ * EFI application entry point.
+ *
+ * @param image_handle EFI application handle.
+ * @param st Pointer to EFI system table.
+ */
+extern (C) EFI_STATUS efi_main(EFI_HANDLE image_handle, EFI_SYSTEM_TABLE * st)
+{
+    .st = st;
+
+    console.clear();
+
+    console.writeln("HELLO, HOS EFI Lightweight LOader, v0.1.0");
+    console.writeln("Firmware vendor: '%S', version: 0x%x", st.FirmwareVendor, st.FirmwareVendor);
+
+    if (!set_graphics_mode())
+    {
+        console.wait_key();
+        return EFI_SUCCESS;
+    }
+
+    ulong max_physical_address;
+    for (;;)
+    {
+        max_physical_address = get_memory_map();
+
+        EFI_STATUS status = st.BootServices.ExitBootServices(image_handle, memory_map_key);
+        if (status == EFI_INVALID_PARAMETER)
+        {
+            continue;
+        }
+        if (status == EFI_SUCCESS)
+        {
+            break;
+        }
+        console.writeln("ExitBootServices: Error %x", status);
+        console.wait_key();
+        return EFI_SUCCESS;
+    }
+
+    build_page_tables(max_physical_address);
+
+    jump_to_hulk();
+
+    return EFI_SUCCESS;
+}

src/hello/scratch.d

@@ -0,0 +1,36 @@
+/**
+ * HELLO scratch buffer.
+ */
+module hello.scratch;
+
+/* Scratch buffer. */
+private align(4096) __gshared ubyte[1024 * 1024] scratch;
+
+/* Number of scratch buffer bytes used. */
+private __gshared size_t scratch_used;
+
+/**
+ * Get the number of free bytes in the scratch buffer.
+ */
+size_t free()
+{
+    return scratch.sizeof - scratch_used;
+}
+
+/**
+ * Get the current free scratch buffer address.
+ */
+ubyte * current()
+{
+    return &scratch[scratch_used];
+}
+
+/**
+ * Allocate pages from the scratch buffer.
+ */
+ubyte * alloc(size_t n = 1)
+{
+    ubyte * address = &scratch[scratch_used];
+    scratch_used += 4096u * n;
+    return address;
+}

src/hos/cpu.d

@@ -0,0 +1,26 @@
+import ldc.llvmasm;
+
+ulong read_cr0()
+{
+    return __asm!ulong("mov %cr0, %rax", "={rax}");
+}
+
+ulong read_cr2()
+{
+    return __asm!ulong("mov %cr2, %rax", "={rax}");
+}
+
+ulong read_cr3()
+{
+    return __asm!ulong("mov %cr3, %rax", "={rax}");
+}
+
+void write_cr3(ulong v)
+{
+    __asm("mov $0, %cr3", "r", v);
+}
+
+ulong read_cr4()
+{
+    return __asm!ulong("mov %cr4, %rax", "={rax}");
+}

src/hos/memory.d

@@ -0,0 +1,57 @@
+import ldc.llvmasm;
+
+void memset(void * dest, ubyte v, size_t n)
+{
+    __asm("rep stosb",
+          "{al},{rcx},{rdi},~{rcx},~{rdi},~{memory}",
+          v, n, dest);
+}
+
+void memset16(void * dest, ushort v, size_t n)
+{
+    __asm("rep stosw",
+          "{ax},{rcx},{rdi},~{rcx},~{rdi},~{memory}",
+          v, n, dest);
+}
+
+void memset32(void * dest, uint v, size_t n)
+{
+    __asm("rep stosl",
+          "{eax},{rcx},{rdi},~{rcx},~{rdi},~{memory}",
+          v, n, dest);
+}
+
+void memset64(void * dest, ulong v, size_t n)
+{
+    __asm("rep stosq",
+          "{rax},{rcx},{rdi},~{rcx},~{rdi},~{memory}",
+          v, n, dest);
+}
+
+void memcpy(void * dest, void * src, size_t n)
+{
+    __asm("rep movsb",
+          "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
+          n, src, dest);
+}
+
+void memcpy16(void * dest, void * src, size_t n)
+{
+    __asm("rep movsw",
+          "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
+          n, src, dest);
+}
+
+void memcpy32(void * dest, void * src, size_t n)
+{
+    __asm("rep movsl",
+          "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
+          n, src, dest);
+}
+
+void memcpy64(void * dest, void * src, size_t n)
+{
+    __asm("rep movsq",
+          "{rcx},{rsi},{rdi},~{rcx},~{rsi},~{rdi},~{memory}",
+          n, src, dest);
+}

src/hos/page_table.d

@@ -0,0 +1,33 @@
+struct PageTableEntry
+{
+    ulong entry;
+
+    this(ulong address, ulong no_execute, ulong global,
+            ulong huge, ulong disable_cache, ulong write_through, ulong user,
+            ulong writable, ulong present)
+    {
+        entry = (present |
+                (writable << 1) |
+                (user << 2) |
+                (write_through << 3) |
+                (disable_cache << 4) |
+                (huge << 7) |
+                (global << 8) |
+                (no_execute << 63)) | address;
+    }
+
+    bool present()
+    {
+        return (entry & 0x1u) != 0u;
+    }
+
+    PageTableEntry * next()
+    {
+        return cast(PageTableEntry *)(entry & 0x7FFF_FFFF_FFFF_F000u);
+    }
+
+    static ulong page_table_index(ulong address, size_t level)
+    {
+        return ((address >> (39u - 9u * level)) & 0x1FFu);
+    }
+}

src/hulk/bootinfo.d

@@ -0,0 +1,52 @@
+/**
+ * HULK boot information.
+ */
+module hulk.bootinfo;
+
+/**
+ * HULK boot information structure.
+ */
+struct BootInfo
+{
+    /**
+     * Framebuffer description structure.
+     */
+    struct Framebuffer
+    {
+        /** Framebuffer base address. */
+        uint * buffer;
+        /** Horizontal resolution. */
+        uint width;
+        /** Vertical resolution. */
+        uint height;
+        /** Number of pixels per scan line. */
+        uint stride;
+        /** Pixel format. */
+        uint format;
+    }
+
+    /**
+     * Memory map entry description structure.
+     */
+    struct MemoryRegion
+    {
+        /** Base address of the memory region. */
+        ulong base;
+        /** Size in bytes of the memory region. */
+        size_t size;
+        /** Type of the memory region. */
+        ubyte type;
+    }
+
+    /* Framebuffer parameters. */
+    Framebuffer fb;
+
+    /* Memory map. */
+    MemoryRegion[800] memory_map;
+
+    /* Number of memory map entries. */
+    size_t memory_map_count;
+}
+
+/** HULK base virtual address. */
+enum ulong HULK_VIRTUAL_START = 0x0000_4000_0000_0000u;

src/hulk/framebuffer.d

@@ -0,0 +1,56 @@
+/**
+ * HULK Framebuffer support.
+ */
+module hulk.framebuffer;
+
+import hos.memory;
+
+/**
+ * Represent a graphical frame buffer.
+ *
+ * TODO: Handle other pixel formats. Currently only ARGB is supported.
+ */
+struct Framebuffer
+{
+    /** Frame buffer base address. */
+    private uint * m_buffer;
+
+    /** Frame buffer width. */
+    private uint m_width;
+
+    /** Frame buffer height. */
+    private uint m_height;
+
+    /** Frame buffer stride. */
+    private uint m_stride;
+
+    /** Number of pixels in the frame buffer (whether visible or not). */
+    private uint m_buffer_size;
+
+    /**
+     * Initialize a frame buffer.
+     *
+     * @param buffer Frame buffer base address.
+     * @param width Frame buffer width.
+     * @param height Frame buffer height.
+     * @param stride Frame buffer stride.
+     */
+    void initialize(uint * buffer, uint width, uint height, uint stride)
+    {
+        m_buffer = buffer;
+        m_width = width;
+        m_height = height;
+        m_stride = stride;
+        m_buffer_size = stride * height;
+    }
+
+    /**
+     * Clear the frame buffer to the given color.
+     *
+     * @param color Color to clear to.
+     */
+    void clear(uint color = 0u)
+    {
+        memset32(m_buffer, color, m_buffer_size);
+    }
+}

src/hulk/header.d

@@ -0,0 +1,23 @@
+/**
+ * HULK image header.
+ */
+module hulk.header;
+
+/**
+ * Header describing the HULK image.
+ */
+struct Header
+{
+    /**
+     * Total size of memory to be mapped.
+     *
+     * The OS loader must ensure that virtual memory is mapped for this entire
+     * size.
+     * This value is really an integer, but is stored as a pointer because it
+     * is provided by the linker and LDC does not like us to cast it.
+     */
+    void * total_size;
+
+    /** Entry point. */
+    void * entry;
+}

src/hulk/hulk.d

@@ -0,0 +1,40 @@
+/**
+ * HULK, the HOS Ultra Light Kernel.
+ */
+module hulk.hulk;
+
+import hulk.header;
+import hulk.bootinfo;
+import hulk.framebuffer;
+import hos.memory;
+import ldc.attributes;
+
+private __gshared Framebuffer fb;
+
+extern extern(C) __gshared ubyte _hulk_total_size;
+
+@(ldc.attributes.section(".hulk_header"))
+private __gshared Header hulk_header = {
+    &_hulk_total_size,
+    &hulk_start,
+};
+
+/**
+ * HULK entry point.
+ *
+ * @param bootinfo Pointer to HULK boot information structure.
+ */
+extern(C) void hulk_start(ulong rdi, ulong rsi, ulong rdx, BootInfo * bootinfo)
+{
+    fb.initialize(bootinfo.fb.buffer, bootinfo.fb.width, bootinfo.fb.height, bootinfo.fb.stride);
+    fb.clear(0xFF8800u);
+
+    for (size_t y = 100u; y < 120u; y++)
+    {
+        memset32(&bootinfo.fb.buffer[y * bootinfo.fb.stride + 20u], 0x001199u, 20u);
+    }
+
+    for (;;)
+    {
+    }
+}

src/hulk/hulk.ld

@@ -0,0 +1,32 @@
+SECTIONS
+{
+    . = 0x0000400000000000;
+    _hulk_mem_start = .;
+
+    .rodata BLOCK(4K) : ALIGN(4K)
+    {
+        *(.hulk_header)
+        *(.rodata)
+    }
+
+    .text BLOCK(4K) : ALIGN(4K)
+    {
+        *(.text)
+    }
+
+    .data BLOCK(4K) : ALIGN(4K)
+    {
+        *(.data)
+    }
+
+    .bss BLOCK(4K) : ALIGN(4K)
+    {
+        *(COMMON)
+        *(.bss)
+    }
+
+    . = ALIGN(4K);
+
+    _hulk_mem_end = .;
+    _hulk_total_size = _hulk_mem_end - _hulk_mem_start;
+}

x86_64-elf-gcc.rb

@@ -1,9 +1,10 @@
+project_name "x86_64-elf-gcc"
 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"
+install_path = File.expand_path("x86_64-elf-gcc")
+target = "x86_64-elf"
 path_prepend "#{install_path}/bin"
 
 configure do
@@ -53,7 +54,7 @@ default do
     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]
+        --enable-languages=c --without-headers]
       sh "make all-gcc"
       sh "make all-target-libgcc"
       sh "make install-gcc"