Update to rscons 2.3.0

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

.gitignore

@@ -0,0 +1,13 @@
+/hos.flp
+/hos_initrd
+/hos_initrd.gz
+*.lst
+*.map
+*.bin
+.rscons*
+/i686-elf-gcc/build*/
+/i686-elf-gcc/*.xz
+/i686-elf-gcc/binutils-*/
+/i686-elf-gcc/gcc-*/
+/i686-elf-gcc/i686-elf-gcc/
+/build/

Makefile

@@ -1,88 +1,15 @@
-# Makefile for HOS
-# Josh Holtrop
-# Created: 07/09/04
-
-FLOPPY=/dev/fd0
-FLOPPY_IMAGE=hos.flp
-FLOPPY_MOUNT=./mnt_flp
-GRUB_IMAGE=grub.flp
-INITRD=hos_initrd
-INITRD_DIR=initrd
-INITRD_MOUNT=./mnt_initrd
-INITRD_SIZE=100			#initrd size in kb
-MOUNT=sudo mount
-UMOUNT=sudo umount
-
-# Do not print "Entering directory ..."
-MAKEFLAGS += --no-print-directory
-
-.PHONY:	all clean initrd apps grub_image install install_img depend copy_image bochs bochsq
-
+.PHONY: all
 all:
-	make -C kernel
-	make -C rmmod
+	./rscons build
 
+.PHONY: run-efi
+run-efi: all
+	qemu-system-x86_64 -bios OVMF.fd -hda build/hos-efi.img
+
+.PHONY: run
+run: all
+	qemu-system-x86_64 -hda build/hos.img
+
+.PHONY: clean
 clean:
-	-make -C kernel clean
-	-make -C rmmod clean
-	-rm -f *~ *.out hos.flp \#* hos_initrd hos_initrd.gz
-
-apps:
-	make -C apps
-
-grub_image:
-	dd if=/dev/zero of=$(GRUB_IMAGE) bs=1024 seek=1440 count=0
-	-mkdir $(FLOPPY_MOUNT)
-	mke2fs -F $(GRUB_IMAGE)
-	$(MOUNT) -t ext2 -o loop $(GRUB_IMAGE) $(FLOPPY_MOUNT)
-	-mkdir -p $(FLOPPY_MOUNT)/boot/grub
-	-cp /boot/grub/stage1 /boot/grub/stage2 /boot/grub/e2fs_stage1_5 $(FLOPPY_MOUNT)/boot/grub
-	$(UMOUNT) $(FLOPPY_MOUNT)
-	-rmdir $(FLOPPY_MOUNT)
-	echo "(fd0) $(GRUB_IMAGE)" > grub_image_device.map.tmp
-	echo "root (fd0)" > grub_commands.tmp
-	echo "setup (fd0)" >> grub_commands.tmp
-	echo "quit" >> grub_commands.tmp
-	grub --device-map grub_image_device.map.tmp < grub_commands.tmp
-	rm grub_commands.tmp
-	rm grub_image_device.map.tmp
-
-copy_image:
-	cp $(GRUB_IMAGE) $(FLOPPY_IMAGE)
-
-install:	FDEV=$(FLOPPY)
-install_img:	FDEV=$(FLOPPY_IMAGE)
-install_img:	MOUNT_FLAGS=-o loop
-install_img: copy_image
-install install_img:
-	-mkdir $(FLOPPY_MOUNT)
-	$(MOUNT) -t ext2 $(MOUNT_FLAGS) $(FDEV) $(FLOPPY_MOUNT)
-	-cp kernel/kernel.bin $(FLOPPY_MOUNT)
-	-cp rmmod/rmmod.bin $(FLOPPY_MOUNT)
-	-cp menu.lst $(FLOPPY_MOUNT)/boot/grub
-	-cp $(INITRD).gz $(FLOPPY_MOUNT)/$(INITRD).gz
-	$(UMOUNT) $(FLOPPY_MOUNT)
-	-rmdir $(FLOPPY_MOUNT)
-
-initrd:
-	dd if=/dev/zero of=$(INITRD) bs=1024 count=$(INITRD_SIZE)
-	mke2fs -Fv -m0 -r0 -i1024 $(INITRD)
-	-mkdir $(INITRD_MOUNT)
-	$(MOUNT) -t ext2 -o loop $(INITRD) $(INITRD_MOUNT)
-	cp -Pr $(INITRD_DIR)/* $(INITRD_MOUNT)
-	$(UMOUNT) $(INITRD_MOUNT)
-	rm -rf $(INITRD_MOUNT)
-	gzip -c $(INITRD) > $(INITRD).gz
-
-depend:
-	make -C kernel depend
-
-bochs:
-	bochs
-
-bochsq:
-	echo 'c' | bochs -q
-
-wordcount:
-	find . -regex '\(.*\.[ch]\)\|\(.*\.asm\)\|\(.*\.inc\)\|\(.*\.cpp\)' | xargs cat | wc
-
+	./rscons clean

Rsconscript

@@ -0,0 +1,155 @@
+path_prepend "i686-elf-gcc/i686-elf-gcc/bin"
+
+configure do
+  rscons "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
+
+build do
+  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
+        @sources += ["build/fontgen"]
+        command = %W[build/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} ${_SOURCES}], @vars)
+        standard_command("Size <target>#{@target}<reset>", command, stdout: @target)
+      end
+    end
+  end
+
+  # FontGen Environment
+  Environment.new(use: "freetype") do |env|
+    env["CC"] = "gcc"
+    env.Program("build/fontgen", glob("fontgen/**/*.c"))
+  end
+
+  # Kernel Environment
+  Environment.new do |env|
+    env.add_builder(EfiImage)
+    env.add_builder(BiosImage)
+    env.add_builder(FontGen)
+    env.add_builder(Size)
+    env["OBJDUMP"] = "i686-elf-objdump"
+    env["SIZE"] = "i686-elf-size"
+    env["CCFLAGS"] += %w[-ffreestanding -Wall -O2]
+    env["LDFLAGS"] += %w[-ffreestanding -nostdlib -T src/link.ld]
+    env["LDFLAGS"] += %W[-Wl,-Map,${_TARGET}.map]
+    env["LIBS"] += %w[gcc]
+    env.FontGen("^/kfont/kfont.c", "font/Hack-Regular.ttf")
+    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("build/hos-efi.img", %w[^/hos.elf])
+    env.BiosImage("build/hos.img", %w[^/hos.elf])
+  end
+end

configure

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec ./rscons configure "$@"

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/Rsconscript

@@ -0,0 +1,17 @@
+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
+
+build do
+  unless File.exist?("i686-elf-gcc")
+    system("./build.sh")
+  end
+end

i686-elf-gcc/build.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+
+BINUTILS_VERSION="2.35"
+BINUTILS_CHECKSUM="1b11659fb49e20e18db460d44485f09442c8c56d5df165de9461eb09c8302f85"
+GCC_VERSION="10.2.0"
+GCC_CHECKSUM="b8dd4368bb9c7f0b98188317ee0254dd8cc99d1e3a18d0ff146c855fe16c1d8c"
+
+if [ ! -e binutils-${BINUTILS_VERSION}.tar.xz ]; then
+  wget -O binutils-${BINUTILS_VERSION}.tar.xz https://ftp.gnu.org/gnu/binutils/binutils-${BINUTILS_VERSION}.tar.xz
+fi
+
+if [[ ! `sha256sum binutils-${BINUTILS_VERSION}.tar.xz` =~ $BINUTILS_CHECKSUM ]]; then
+  echo "Invalid binutils-${BINUTILS_VERSION}.tar.xz checksum"
+  exit
+fi
+
+if [ ! -d binutils-${BINUTILS_VERSION} ]; then
+  tar xJf binutils-${BINUTILS_VERSION}.tar.xz
+fi
+
+if [ ! -e gcc-${GCC_VERSION}.tar.xz ]; then
+  wget -O gcc-${GCC_VERSION}.tar.xz https://ftp.gnu.org/gnu/gcc/gcc-${GCC_VERSION}/gcc-${GCC_VERSION}.tar.xz
+fi
+
+if [[ ! `sha256sum gcc-${GCC_VERSION}.tar.xz` =~ $GCC_CHECKSUM ]]; then
+  echo "Invalid gcc-${GCC_VERSION}.tar.xz checksum"
+  exit
+fi
+
+if [ ! -d gcc-${GCC_VERSION} ]; then
+  tar xJf gcc-${GCC_VERSION}.tar.xz
+fi
+
+export PREFIX="$PWD/i686-elf-gcc"
+export TARGET="i686-elf"
+export PATH="$PREFIX/bin:$PATH"
+
+function build_binutils()
+{
+  rm -rf build-binutils
+  mkdir -p build-binutils
+  (
+    cd build-binutils
+    ../binutils-${BINUTILS_VERSION}/configure --target="$TARGET" --prefix="$PREFIX" --with-sysroot --disable-nls --disable-werror && \
+    make && \
+    make install
+  )
+}
+
+function build_gcc()
+{
+  rm -rf build-gcc
+  mkdir -p build-gcc
+  (
+    cd build-gcc
+    ../gcc-${GCC_VERSION}/configure --target="$TARGET" --prefix="$PREFIX" --disable-nls --enable-languages=c,c++ --without-headers && \
+    make all-gcc && \
+    make all-target-libgcc && \
+    make install-gcc && \
+    make install-target-libgcc
+  )
+}
+
+build_binutils && build_gcc

i686-elf-gcc/clean.sh

@@ -0,0 +1,2 @@
+#!/bin/sh
+rm -rf build build-* binutils* gcc-*

i686-elf-gcc/configure

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec ../rscons configure

kernel/Makefile

@@ -5,18 +5,19 @@
 
 # Assembler Information:
 NASM=nasm
-NASM_FLAGS=-f aout
+NASM_FLAGS=-f elf32
 
 # C/C++ Information:
-CPPFLAGS=-fleading-underscore -fno-builtin -nostdlib -nostartfiles -nodefaultlibs -I. -Wall
+CPPFLAGS=-ffreestanding -fno-builtin -nostdlib -nostartfiles -nodefaultlibs -I. -Wall -m32 -fno-pic
 # -S -masm=intel
 CC=gcc
 CXX=g++
-CXXFLAGS=-fno-rtti -fno-exceptions -D_HOS_CPP_
+CXXFLAGS=-fno-rtti -fno-exceptions -D_HOS_CPP_ -std=gnu++98
 
 # Linker Information:
-LD=ld
-LDFLAGS=-nodefaultlibs -nostdlib --no-demangle -T link.ld
+LD=gcc
+LDFLAGS=-ffreestanding -fno-builtin -nostartfiles -nodefaultlibs -nostdlib -Wl,--no-demangle -T link.ld -m32
+LIBS=-static-libgcc
 
 # Files
 OBJS=boot.o lang/lang_a.o \
@@ -43,7 +44,7 @@ CXXSRC=lang/string.cpp lang/new.cpp char/misc_char.cpp char/vconsole.cpp \
 .PHONY:	all depend clean html
 
 all: $(OBJS)
-	$(LD) $(LDFLAGS) -Map kernel.map $(OBJS) -o kernel.bin
+	$(LD) $(LDFLAGS) -Wl,-Map -Wl,kernel.map $(OBJS) -o kernel.bin $(LIBS)
 	@echo '		Kernel built: ' `ls -sk kernel.bin | cut -d' ' -f1`kb
 
 depend:

kernel/boot.asm

@@ -25,23 +25,23 @@
 %define KERNEL_P PHYS_START+0x8000	;1mb+32kb - the kernel's physical address
 %define KERNEL_V KERNEL_P+VIRT_OFFSET	;3gb+1mb+32kb, the virtual address of the kernel
 
-extern _k_init, _isr, _k_mbsave, _end, _rm_params, _initrd, _tss0
+extern k_init, isr, k_mbsave, end, rm_params, initrd, tss0
 	
 [bits 32]
 
-[global _start]
-_start:
+[global start]
+start:
 
 multiboot_header:
 	dd	MULTIBOOT_MAGIC					;magic
 	dd	MULTIBOOT_FLAGS					;flags
 	dd	-(MULTIBOOT_MAGIC + MULTIBOOT_FLAGS)		;checksum
 
-	dd	multiboot_header-VIRT_OFFSET			;header_addr
-	dd	_start-VIRT_OFFSET				;load_addr
+	dd	0x100000000+multiboot_header-VIRT_OFFSET			;header_addr
+	dd	0x100000000+start-VIRT_OFFSET				;load_addr
 	dd	0						;load_end_addr
-	dd	_end-VIRT_OFFSET				;bss_end_addr
-	dd	multiboot_entry-VIRT_OFFSET			;entry_addr
+	dd	0x100000000+end-VIRT_OFFSET				;bss_end_addr
+	dd	0x100000000+multiboot_entry-VIRT_OFFSET			;entry_addr
 
 ;	dd	1						;mode_type
 ;	dd	80						;width
@@ -53,7 +53,7 @@ multiboot_entry:
 ;This is where the kernel begins execution from the bootloader.
 ;At this point, a temporary gdt is set up to "map" 0xC000_0000 to 0x0.
 	cli					;should already be off...
-	lgdt	[gdtrbs32-VIRT_OFFSET]
+	lgdt	[0x100000000+gdtrbs32-VIRT_OFFSET]
 	jmp	KERNEL_CODE_BS32:segmented_start
 segmented_start:
 	mov	cx, KERNEL_DATA_BS32
@@ -68,7 +68,7 @@ segmented_start:
 	add	ebx, VIRT_OFFSET
 	push	eax
 	push	ebx				;pointer to multiboot info structure
-	call	_k_mbsave			;save multiboot info structures
+	call	k_mbsave			;save multiboot info structures
 	add	esp, 8
 
 	cmp	eax, 0				; eax = pointer to mb_module_t struct for rmmod
@@ -86,7 +86,7 @@ segmented_start:
 	rep	movsd				; copy rmmod to first 1mb
 	
 	mov	ebx, pm_return			; return address
-	mov	ecx, _rm_params			; put real mode params here (video mode etc...)
+	mov	ecx, rm_params			; put real mode params here (video mode etc...)
 	sub	ecx, VIRT_OFFSET
 	
 	jmp	0xC0005010			; jump to rmmod
@@ -161,8 +161,8 @@ newgdtcontinue:
 	lidt	[idtr]				;load idt
 	mov	[PDBR_V], dword 0		;unmap 0x0, we are running completely paged at 0xC000_0000
 
-	mov	edi, GDT_V + TSS0_SEG + 2	; copy _tss0 base address
-	mov	eax, _tss0			;  into the GDT descrtiptor
+	mov	edi, GDT_V + TSS0_SEG + 2	; copy tss0 base address
+	mov	eax, tss0			;  into the GDT descrtiptor
 	stosw					;  for TSS0
 	shr	eax, 16
 	stosb
@@ -170,7 +170,7 @@ newgdtcontinue:
 	shr	eax, 8
 	stosb
 
-	call	_k_init				;C kernel initialization
+	call	k_init				;C kernel initialization
 
 	mov	ax, TSS0_SEG
 	ltr	ax
@@ -187,7 +187,7 @@ idle_loop:					; system idle loop
 ;-------------------------------------------------------
 gdtrbs32:
 	dw	gdt_endbs32-gdtbs32-1
-	dd	gdtbs32-VIRT_OFFSET
+	dd	0x100000000+gdtbs32-VIRT_OFFSET
 gdtbs32:			; 0 = null descriptor
 	dd	0
 	dd	0

kernel/fs/ext2/Ext2OpenFile.cpp

@@ -29,7 +29,7 @@ Ext2OpenFile::Ext2OpenFile(Ext2fs *fs, u32_t inum, int mode)
 	myBlockCacheStatus = 0;		/* 0: invalid; 1: valid; 2: dirty */
 	fs->readInode(inum, &myInode);
 	myCache = new Ext2BlockCache(fs, inum, &myInode);
-	lock(&Ext2OpenFileListLock);
+	lockit(&Ext2OpenFileListLock);
 	if ((mode & VFS_MODE_RW_MASK) == VFS_MODE_WRITE)
 	{
 		if ((mode & VFS_MODE_WRITE_MASK) == VFS_MODE_TRUNCATE)
@@ -62,7 +62,7 @@ Ext2OpenFile::Ext2OpenFile(Ext2fs *fs, u32_t inum, int mode)
 Ext2OpenFile::~Ext2OpenFile()
 {
 	/* remove ourselves from the open file list */
-	lock(&Ext2OpenFileListLock);
+	lockit(&Ext2OpenFileListLock);
 	u32_t size = Ext2OpenFileList->size();
 	for (u32_t i = 0; i < size; i++)
 	{

kernel/functions.h

@@ -9,9 +9,15 @@
 #include "hos_defines.h"
 #include "sys/io.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 extern u32_t _code;
 extern u32_t _bss;
 extern u32_t _end;
+#ifdef __cplusplus
+}
+#endif
 
 //Enables (SeTs) Interrupt Flag on the processor
 static inline void enable_ints()

kernel/hos_defines.h

@@ -44,9 +44,15 @@ typedef unsigned char		u8_t;
 typedef unsigned char		byte;
 typedef	int			lock_t;
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 extern u32_t _end;
 extern u32_t _bss;
 extern u32_t start;
+#ifdef __cplusplus
+}
+#endif
 
 #endif
 

kernel/idt.inc

@@ -97,7 +97,7 @@ isr_main_nodup:
 
 	push	esp
 	push	eax		;interrupt number
-	call	_isr
+	call	isr
 	add	esp, 8
 
 	pop	gs

kernel/lang/lang.asm

@@ -13,8 +13,8 @@
 %endmacro
 
 ;implements a lock
-[global _lock]
-_lock:
+[global lockit]
+lockit:
 	push	ebp
 	mov	ebp, esp
 	push	eax
@@ -35,8 +35,8 @@ _lock_loop0:
 	ret
 
 ;releases a lock
-[global _unlock]
-_unlock:
+[global unlock]
+unlock:
 	push	ebp
 	mov	ebp, esp
 	push	esi
@@ -50,15 +50,15 @@ _unlock:
 
 ;returns the value in the CR0 register
 ;extern dword read_cr0();
-[global _read_cr0]
-_read_cr0:
+[global read_cr0]
+read_cr0:
 	mov	eax, cr0;
 	ret
 
 ;stores the parameter to the CR0 register
 ;extern dword write_cr0(dword cr0);
-[global _write_cr0]
-_write_cr0:
+[global write_cr0]
+write_cr0:
 	push	ebp
 	mov	ebp, esp
 	mov	eax, [ebp+8]
@@ -68,8 +68,8 @@ _write_cr0:
 
 ;returns the value in the CR2 register
 ;extern dword read_cr2();
-[global _read_cr2]
-_read_cr2:
+[global read_cr2]
+read_cr2:
 	mov	eax, cr2;
 	ret
 
@@ -77,16 +77,16 @@ _read_cr2:
 
 ;returns the value in the CR3 register
 ;extern dword read_cr3();
-[global _read_cr3]
-_read_cr3:
+[global read_cr3]
+read_cr3:
 	mov	eax, cr3;
 	ret
 
 
 ;stores the parameter to the CR3 register
 ;extern dword write_cr3(dword cr3);
-[global _write_cr3]
-_write_cr3:
+[global write_cr3]
+write_cr3:
 	push	ebp
 	mov	ebp, esp
 	mov	eax, [ebp+8]
@@ -96,16 +96,16 @@ _write_cr3:
 
 
 ; read ss register
-[global _read_ss]
-_read_ss:
+[global read_ss]
+read_ss:
 	mov	ax, ss
 	ret
 
 
 ;copies a string from the source to the destination parameter
 ;extern void strcpy(char *dest, char *src);
-[global _strcpy]
-_strcpy:
+[global strcpy]
+strcpy:
 	push	ebp
 	mov	ebp, esp
 	push	esi
@@ -124,8 +124,8 @@ strcpyloop:
 
 ;copies memory of n bytes from src to destination
 ;void memcpy(void *dest, void *src, dword n);
-[global _memcpy]
-_memcpy:
+[global memcpy]
+memcpy:
 	push	ebp
 	mov	ebp, esp
 	push	esi
@@ -147,8 +147,8 @@ _memcpy:
 
 ;copies memory of n words (n*2 bytes) from src to destination
 ;void memcpyw(void *dest, void *src, dword n);
-[global _memcpyw]
-_memcpyw:
+[global memcpyw]
+memcpyw:
 	push	ebp
 	mov	ebp, esp
 	push	esi
@@ -170,8 +170,8 @@ _memcpyw:
 
 ;copies memory of n dwords (n*4 bytes) from src to destination
 ;void memcpyd(void *dest, void *src, dword n);
-[global _memcpyd]
-_memcpyd:
+[global memcpyd]
+memcpyd:
 	push	ebp
 	mov	ebp, esp
 	push	esi
@@ -193,8 +193,8 @@ _memcpyd:
 
 ;sets num bytes at buffer to the value of c
 ;void *memset(void *buffer, int c, int num);
-[global _memset]
-_memset:
+[global memset]
+memset:
 	push	ebp
 	mov	ebp, esp
 	push	edi
@@ -215,8 +215,8 @@ _memset:
 
 ;sets num words at buffer to the value of c
 ;void *memsetw(void *buffer, int c, int num);
-[global _memsetw]
-_memsetw:
+[global memsetw]
+memsetw:
 	push	ebp
 	mov	ebp, esp
 	push	edi
@@ -237,8 +237,8 @@ _memsetw:
         
 ;sets num dwords at buffer to the value of c
 ;void *memsetd(void *buffer, int c, int num);
-[global _memsetd]
-_memsetd:
+[global memsetd]
+memsetd:
 	push	ebp
 	mov	ebp, esp
 	push	edi
@@ -259,8 +259,8 @@ _memsetd:
 
 ;returns the number of characters in a string
 ;extern dword strlen(char *str);
-[global _strlen]
-_strlen:
+[global strlen]
+strlen:
 	push	ebp
 	mov	ebp, esp
 	push	esi
@@ -284,8 +284,8 @@ strlendone:
 ;this function invalidates the page directory/table entry that
 ; would be used to access the memory address given in the parameter
 ;extern void invlpg_(dword addr);
-[global _invlpg_]
-_invlpg_:
+[global invlpg_]
+invlpg_:
 	mov	eax, [esp+4]
 	invlpg	[eax]
 	ret
@@ -294,8 +294,8 @@ _invlpg_:
 ;
 ;void writeCursorPosition(word pos)
 ;
-[global _writeCursorPosition]
-_writeCursorPosition:
+[global writeCursorPosition]
+writeCursorPosition:
 	push	ebp
 	mov	ebp, esp
 
@@ -333,8 +333,8 @@ _writeCursorPosition:
 ;
 ;word getCursorPosition()
 ;
-[global _getCursorPosition]
-_getCursorPosition:
+[global getCursorPosition]
+getCursorPosition:
 	push	ebx
 	push	edx
 

kernel/lang/lang.h

@@ -9,7 +9,7 @@
 #include "hos_defines.h"
 
 /* lang.asm */
-void	lock(lock_t *addr);
+void	lockit(lock_t *addr);
 void	unlock(lock_t *addr);
 u32_t read_cr0();
 u32_t write_cr0(u32_t cr0);

kernel/lang/vector.h

@@ -15,6 +15,8 @@ template<typename type>
 class vector
 {
 protected:
+    typedef type * type_ptr_t;
+
 	/* Pointers to vector elements */
 	type	**myData;
 
@@ -25,127 +27,80 @@ protected:
 	unsigned int	myAllocated;
 
 	/* Causes the vector to double in its allocated size */
-	void	grow();
-
-public:
-	/* Constructors/Destructor */
-	vector<type>();
-	vector<type>(unsigned int size);
-	vector<type>(const vector<type> & v1);
-	~vector<type>();
-
-	/* Assignment operator */
-	vector<type> & operator=(const vector<type> & v1);
-
-	/* Returns the size of the vector */
-	unsigned int	size() const;
-
-	/* Add an element to the end of the vector */
-	vector<type> & add(type elem);
-
-	/* Remove an element from the vector */
-	vector<type> & remove(unsigned int index);
-
-	/* Insert an element into a position in the vector */
-	vector<type> & insert(type elem, unsigned int position);
-
-	/* Direct access operators */
-	const type & operator[](unsigned int index) const;
-	type & operator[](unsigned int index);
-
-	/* Returns pointer to data */
-	type **data();
-};
-
-template<typename type>
-vector<type>::vector<type>()
-{
-	myData = NULL;
-	mySize = 0;
-	myAllocated = 0;
-}
-
-template<typename type>
-vector<type>::vector<type>(unsigned int size)
-{
-	myData = new (type *)[size];
-	mySize = 0;
-	myAllocated = size;
-}
-
-template<typename type>
-vector<type>::vector<type>(const vector<type> & v1)
-{
-	mySize = v1.mySize;
-	myAllocated = v1.myAllocated;
-	myData = new (type *)[myAllocated];
-	for (u32_t i = 0; i < mySize; i++)
-		myData[i] = new type(*v1.myData[i]);
-}
-
-template<typename type>
-vector<type>::~vector<type>()
-{
-	for (unsigned int i = 0; i < mySize; i++)
-		delete myData[i];
-	delete[] myData;
-}
-
-template<typename type>
-vector<type> & vector<type>::operator=(const vector<type> & v1)
-{
-	mySize = v1.mySize;
-	myAllocated = v1.myAllocated;
-	myData = new (type *)[myAllocated];
-	for (u32_t i = 0; i < mySize; i++)
-		myData[i] = new type(*v1.myData[i]);
-	return *this;
-}
-
-template<typename type>
-u32_t	vector<type>::size() const
-{
-	return mySize;
-}
-
-template<typename type>
-const type & vector<type>::operator[](unsigned int index) const
-{
-	return *myData[index];
-}
-
-template<typename type>
-type & vector<type>::operator[](unsigned int index)
-{
-	return *myData[index];
-}
-
-template<typename type>
-vector<type> & vector<type>::add(type elem)
-{
-	while (mySize >= myAllocated)
-		grow();
-	myData[mySize++] = new type(elem);
-	return *this;
-}
-
-template<typename type>
-void vector<type>::grow()
-{
+	void	grow()
+    {
         myAllocated <<= 1;
         if (myAllocated == 0)
             myAllocated = 1;
-	type **data_new = new (type *)[myAllocated];
+        type **data_new = new type_ptr_t[myAllocated];
         for (unsigned int i = 0; i < mySize; i++)
             data_new[i] = myData[i];
         if (myData)
             delete[] myData;
         myData = data_new;
-}
+    }
 
-template<typename type>
-vector<type> & vector<type>::remove(unsigned int index)
-{
+public:
+	/* Constructors/Destructor */
+	vector<type>()
+    {
+        myData = NULL;
+        mySize = 0;
+        myAllocated = 0;
+    }
+
+	vector<type>(unsigned int size)
+    {
+        myData = new type_ptr_t[size];
+        mySize = 0;
+        myAllocated = size;
+    }
+
+	vector<type>(const vector<type> & v1)
+    {
+        mySize = v1.mySize;
+        myAllocated = v1.myAllocated;
+        myData = new type_ptr_t[myAllocated];
+        for (u32_t i = 0; i < mySize; i++)
+            myData[i] = new type(*v1.myData[i]);
+    }
+
+	~vector<type>()
+    {
+        for (unsigned int i = 0; i < mySize; i++)
+            delete myData[i];
+        delete[] myData;
+    }
+
+	/* Assignment operator */
+	vector<type> & operator=(const vector<type> & v1)
+    {
+        mySize = v1.mySize;
+        myAllocated = v1.myAllocated;
+        myData = new type_ptr_t[myAllocated];
+        for (u32_t i = 0; i < mySize; i++)
+            myData[i] = new type(*v1.myData[i]);
+        return *this;
+    }
+
+	/* Returns the size of the vector */
+	unsigned int	size() const
+    {
+        return mySize;
+    }
+
+	/* Add an element to the end of the vector */
+	vector<type> & add(type elem)
+    {
+        while (mySize >= myAllocated)
+            grow();
+        myData[mySize++] = new type(elem);
+        return *this;
+    }
+
+	/* Remove an element from the vector */
+	vector<type> & remove(unsigned int index)
+    {
         if (index < mySize)
         {
             delete myData[index];
@@ -154,11 +109,11 @@ vector<type> & vector<type>::remove(unsigned int index)
             mySize--;
         }
         return *this;
-}
+    }
 
-template<typename type>
-vector<type> & vector<type>::insert(type elem, unsigned int position)
-{
+	/* Insert an element into a position in the vector */
+	vector<type> & insert(type elem, unsigned int position)
+    {
         if (position <= mySize)
         {
             if (mySize >= myAllocated)
@@ -169,13 +124,24 @@ vector<type> & vector<type>::insert(type elem, unsigned int position)
             mySize++;
         }
         return *this;
-}
+    }
 
+	/* Direct access operators */
+	const type & operator[](unsigned int index) const
+    {
+        return *myData[index];
+    }
 
-template<typename type>
-type **vector<type>::data()
-{
+	type & operator[](unsigned int index)
+    {
+        return *myData[index];
+    }
+
+	/* Returns pointer to data */
+	type **data()
+    {
         return myData;
-}
+    }
+};
 
 #endif

kernel/link.ld

@@ -1,10 +1,11 @@
 OUTPUT_FORMAT("binary")
-ENTRY(_start)
+ENTRY(start)
 SECTIONS
 {
   .text  0xC0108000 : {
     code = .; _code = .; __code = .;
     *(.text)
+    *(.eh_frame*)
   }
   .gnulinkonce : {
     *(.gnu.linkonce*)
@@ -12,8 +13,8 @@ SECTIONS
   }
   .data  : {
     data = .; _data = .; __data = .;
-    *(.data)
-    *(.rodata)
+    *(.data*)
+    *(.rodata*)
     . = ALIGN(4096);
   }
   .bss  : {

readme.txt

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

rscons

@@ -0,0 +1,21 @@
+#!/usr/bin/env ruby
+script = File.join(File.dirname(__FILE__), ".rscons-2.3.0-272f26340e9affa341050e282d22641f.rb")
+unless File.exists?(script)
+  if File.read(__FILE__, mode: "rb") =~ /^#==>(.*)/
+    require "zlib"
+    require "base64"
+    encoded_compressed = $1
+    unescaped_compressed = Base64.decode64(encoded_compressed)
+    inflated = Zlib::Inflate.inflate(unescaped_compressed)
+    File.open(script, "wb") do |fh|
+      fh.write(inflated)
+    end
+  else
+    raise "Could not decompress."
+  end
+end
+load script
+if __FILE__ == $0
+  Rscons::Cli.run(ARGV)
+end
+#==>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 truncated

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