fixed memory barrier bug in IDT initialization -- kernel still crashing when interrupts enabled but i think the memory management initialization is correct

git-svn-id: svn://anubis/hos/trunk@102 5b3e749e-e535-0410-8002-a9bb6afbdfca

.bochsrc

@@ -1,43 +0,0 @@
-# configuration file generated by Bochs
-config_interface: textconfig
-display_library: x
-megs: 32
-romimage: file=/usr/share/bochs/BIOS-bochs-latest, address=0xf0000
-vgaromimage: /usr/share/bochs/VGABIOS-lgpl-latest
-boot: floppy
-floppya: 1_44="hos.flp", status=inserted
-# no floppyb
-ata0: enabled=1, ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14
-ata1: enabled=0
-ata2: enabled=0
-ata3: enabled=0
-parport1: enabled=1, file=""
-com1: enabled=1, dev=""
-usb1: enabled=1, ioaddr=0xff80, irq=10
-# no sb16
-floppy_bootsig_check: disabled=0
-vga_update_interval: 30000
-keyboard_serial_delay: 20000
-keyboard_paste_delay: 100000
-floppy_command_delay: 50000
-ips: 500000
-text_snapshot_check: 0
-mouse: enabled=0
-private_colormap: enabled=0
-i440fxsupport: enabled=0
-clock: sync=none, time0=local
-# no ne2k
-newharddrivesupport: enabled=1
-# no loader
-log: -
-logprefix: %t%e%d
-debugger_log: -
-panic: action=ask
-error: action=report
-info: action=report
-debug: action=ignore
-pass: action=fatal
-keyboard_mapping: enabled=0, map=
-keyboard_type: mf
-user_shortcut: keys=none
-# no cmosimage

Makefile

@@ -1,48 +1,37 @@
-# Makefile for HOS
-# Josh Holtrop
-# Created: 07/09/04
 
-FLOPPY=/dev/fd0
-FLOPPY_MOUNT=./mnt_flp
-FLOPPY_IMAGE=hos.flp
-GRUB_IMAGE=grub.flp
+KERNEL_FILE := hos.gz
+MKISOFS     := genisoimage
+ISO         := hos.iso
+QEMU        := qemu-system-x86_64
+BOCHS       := bochs
 
-all:
-	make -C kernel
-#	make -C rmmod
+# default target: build the kernel and ISO image
+all: kernel iso
 
+# build the kernel
+.PHONY: kernel
+kernel:
+	$(MAKE) -C $@
+
+# build the ISO image
+.PHONY: iso
+iso: $(ISO) kernel
+
+$(ISO): kernel
+	cp kernel/$(KERNEL_FILE) iso/boot
+	-rm -f $(ISO)
+	$(MKISOFS) -R -b boot/grub/stage2_eltorito -no-emul-boot \
+		-boot-load-size 4 -boot-info-table -o $(ISO) iso
+
+.PHONY: qemu
+qemu: iso
+	$(QEMU) -cdrom $(ISO) -boot d -m 384 -localtime
+
+.PHONY: bochs
+bochs: iso
+	-$(BOCHS)
+
+.PHONY: clean
 clean:
-	make -C kernel clean
-	make -C include clean
-#	make -C rmmod clean
-	- rm *~ hos.flp
-
-
-grub:
-	- mkdir $(FLOPPY_MOUNT)
-	mke2fs $(FLOPPY)
-	mount -t ext2 $(FLOPPY) $(FLOPPY_MOUNT)
-	grub-install --root-directory=$(FLOPPY_MOUNT) fd0
-	umount $(FLOPPY_MOUNT)
-	- rmdir $(FLOPPY_MOUNT)
-
-grub_image:
-	dd if=$(FLOPPY) of=$(GRUB_IMAGE)
-
-install:
-	- mkdir $(FLOPPY_MOUNT)
-	mount -t ext2 $(FLOPPY) $(FLOPPY_MOUNT)
-	cp kernel/kernel.bin  $(FLOPPY_MOUNT)
-	cp menu.lst $(FLOPPY_MOUNT)/boot/grub
-	umount $(FLOPPY_MOUNT)
-	- rmdir $(FLOPPY_MOUNT)
-
-install_img:
-	- mkdir $(FLOPPY_MOUNT)
-	cp grub.flp $(FLOPPY_IMAGE)
-	mount -t ext2 -o loop $(FLOPPY_IMAGE) $(FLOPPY_MOUNT)
-	cp kernel/kernel.bin $(FLOPPY_MOUNT)
-	cp menu.lst $(FLOPPY_MOUNT)/boot/grub
-	umount $(FLOPPY_MOUNT)
-	- rmdir $(FLOPPY_MOUNT)
-
+	$(MAKE) -C kernel clean
+	-rm -f $(ISO) iso/boot/$(KERNEL_FILE)

bochsrc

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

include/Makefile

@@ -1,2 +0,0 @@
-clean:
-	- rm *~

include/kernel.h

@@ -1,23 +0,0 @@
-
-#ifndef __HOS_KERNEL_H__
-#define __HOS_KERNEL_H__ __HOS_KERNEL_H__
-
-#include "multiboot.h"
-
-#define VIRT_OFFSET 0xC0000000
-#define MAX_MODULES 16
-#define MAX_MMAP 16
-
-typedef unsigned int u32_t;
-typedef unsigned short u16_t;
-typedef unsigned char u8_t;
-
-/* returns true to callee if we should jump to a real mode module */
-int k_mbsave(mb_info_t *mbinfo, unsigned int mb_magic);
-
-void k_init();
-
-void isr();
-
-#endif
-

include/module.h

@@ -1,16 +0,0 @@
-
-#ifndef __HOS_MODULE_H__
-#define __HOS_MODULE_H__ __HOS_MODULE_H__
-
-#define MOD_REAL_MODE 1
-#define MOD_KERNEL 2
-
-typedef struct {
-	unsigned int mod_magic;		// "HOSM" = 0x484F534D
-	unsigned int mod_type;		// module type
-	void (*init) ();		// address of void initialization function
-	unsigned int reserved;
-} hos_module_header_t;
-
-#endif
-

include/multiboot.h

@@ -1,144 +0,0 @@
-
-#ifndef __HOS_MULTIBOOT_H__
-#define __HOS_MULTIBOOT_H__ __HOS_MULTIBOOT_H__
-
-/* The magic number for the Multiboot header. */
-#define MULTIBOOT_HEADER_MAGIC          0x1BADB002
-
-#define MB_HEADER_ALIGN_MODULES 0x01
-#define MB_HEADER_MEM_INFO 0x02
-#define MB_HEADER_VIDEO_INFO 0x04
-#define MB_HEADER_KLUDGE_OFFSETS 0x10000
-
-
-/* The magic number passed by a Multiboot-compliant boot loader. */
-#define MULTIBOOT_BOOTLOADER_MAGIC      0x2BADB002
-
-#define MB_BOOTLOADER_MEM_INFO 0x01
-#define MB_BOOTLOADER_BOOT_DEVICE 0x02
-#define MB_BOOTLOADER_COMMAND_LINE 0x04
-#define MB_BOOTLOADER_MODS 0x08
-#define MB_BOOTLOADER_AOUT 0x10
-#define MB_BOOTLOADER_ELF 0x20
-#define MB_BOOTLOADER_MMAP 0x40
-#define MB_BOOTLOADER_DRIVES 0x80
-#define MB_BOOTLOADER_CONFIG 0x0100
-#define MB_BOOTLOADER_APM 0x0200
-#define MB_BOOTLOADER_GRAPHICS 0x0400
-
-
-#define MB_DRIVE_MODE_CHS 0
-#define MB_DRIVE_MODE_LBA 1
-
-
-/* The Multiboot header. */
-typedef struct
-{
-	unsigned int magic;
-	unsigned int flags;
-	unsigned int checksum;
-	unsigned int header_addr;
-	unsigned int load_addr;
-	unsigned int load_end_addr;
-	unsigned int bss_end_addr;
-	unsigned int entry_addr;
-} mb_header_t;
-
-/* The symbol table for a.out. */
-typedef struct
-{
-	unsigned int tabsize;
-	unsigned int strsize;
-	unsigned int addr;
-	unsigned int reserved;
-} mb_aout_symbol_table_t;
-
-/* The section header table for ELF. */
-typedef struct
-{
-	unsigned int num;
-	unsigned int size;
-	unsigned int addr;
-	unsigned int shndx;
-} mb_elf_section_header_table_t;
-
-/* The Multiboot information. */
-typedef struct
-{
-	unsigned int flags;
-	unsigned int mem_lower;		// present if flags[0] is set
-	unsigned int mem_upper;
-	unsigned int boot_device;	// 1
-	unsigned int cmdline;		// 2
-	unsigned int mods_count;	// 3
-	unsigned int mods_addr;
-	union
-	{
-		mb_aout_symbol_table_t aout_sym;	// 4
-		mb_elf_section_header_table_t elf_sec;	// 5
-	};
-	unsigned int mmap_length;	// 6
-	unsigned int mmap_addr;
-	unsigned int drives_length;	// 7
-	unsigned int drives_addr;
-	unsigned int config_table;	// 8
-	unsigned int bootloader_name;	// 9
-	unsigned int apm_table;		// 10
-
-	unsigned int vbe_control_info;	// 11
-	unsigned int vbe_mode_info;
-	unsigned short vbe_mode;
-	unsigned short vbe_interface_seg;
-	unsigned short vbe_interface_off;
-	unsigned short vbe_interface_len;
-} mb_info_t;
-
-/* The module structure. */
-typedef struct
-{
-	unsigned int mod_start;
-	unsigned int mod_end;
-	unsigned int string;
-	unsigned int reserved;
-} mb_module_t;
-
-/* The memory map. Be careful that the offset 0 is base_addr_low, not size. */
-typedef struct
-{
-	unsigned int size;		//offset -4
-	unsigned int base_addr_low;	//offset 0
-	unsigned int base_addr_high;
-	unsigned int length_low;
-	unsigned int length_high;
-	unsigned int type;
-} mb_mmap_t;
-
-/* The drive structure */
-typedef struct
-{
-	unsigned int size;
-	unsigned char drive_number;
-	unsigned char drive_mode;
-	unsigned char drive_cylinders;
-	unsigned char drive_heads;
-	unsigned char drive_sectors;
-	unsigned short drive_ports[1];
-} mb_drive_t;
-
-/* APM table structure */
-typedef struct
-{
-	unsigned short version;
-	unsigned short cseg;
-	unsigned int offset;
-	unsigned short cseg_16;
-	unsigned short dseg;
-	unsigned short flags;
-	unsigned short cseg_len;
-	unsigned short cseg_16_len;
-	unsigned short dseg_len;
-} mb_apm_t;
-
-
-#endif
-

iso/boot/grub/menu.lst

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

kernel/Makefile

@@ -1,33 +1,45 @@
-# Makefile for HOS
-# Josh Holtrop
-# Created: 07/08/04
-# Modified: 07/09/04
 
-# Assembler Information:
-NASM=nasm
-NASM_FLAGS=-f aout
+CROSS_COMPILE   := i586-elf-
 
-# C Information:
-CC=gcc
-CC_FLAGS=-fleading-underscore -fno-builtin -nostdlib -nostartfiles -nodefaultlibs -I. -I../include -Wall
+export LD       := $(CROSS_COMPILE)ld
+export CC       := $(CROSS_COMPILE)gcc
+export CXX      := $(CROSS_COMPILE)g++
+export OBJDUMP  := $(CROSS_COMPILE)objdump
+export NASM     := nasm
 
-# Linker Information:
-LD=ld
-LD_FLAGS=-nodefaultlibs -nostdlib --no-demangle -T link.ld
+export HOS_TOPLEVEL := $(shell pwd)
+LDSCRIPT        := link.ld
+KERNEL          := hos
+export CPPFLAGS := -I$(HOS_TOPLEVEL) -I$(HOS_TOPLEVEL)/include
+export CFLAGS   := -Wall -O2 -g
+export CXXFLAGS := -Wall -O2 -fno-rtti -fno-exceptions -g
+export LDFLAGS  := -T $(LDSCRIPT) -Map $(KERNEL).map
+export LDLIBS   := `$(CC) -print-libgcc-file-name`
 
-all: Asm_Kernel C_Kernel
-	$(LD) $(LD_FLAGS) -Map boot.map boot.o kernel.o -o kernel.bin
+SUBDIRS         := boot mm lang isr sys
+SUBDIRS_clean   := $(SUBDIRS:%=%.clean)
 
-Asm_Kernel:
-	$(NASM) $(NASM_FLAGS) -l boot.lst boot.asm -o boot.o
+.PHONY: all
+all: $(KERNEL).gz
 
-C_Kernel:
-	$(CC) $(CC_FLAGS) -c kernel.c -o kernel.o
+$(KERNEL).gz: $(KERNEL)
+	gzip -c $< > $@
 
-#################################################
-# Clean up the source directory of any binaries #
-#################################################
-clean:
-	- rm *.s *.S *.o *.bin *~ *.map *.lst
+$(KERNEL): $(KERNEL).o
+	$(LD) $(LDFLAGS) -o $@ $<
+	$(OBJDUMP) --disassemble --source $@ > $@.dump
+#	strip $@
+	
+$(KERNEL).o: $(SUBDIRS)
+	$(LD) -r -o $@ $(foreach subdir,$(SUBDIRS),$(subdir)/$(subdir)_all.o) $(LDLIBS)
 
+.PHONY: $(SUBDIRS)
+$(SUBDIRS):
+	$(MAKE) -C $@ SUBDIR=$@
 
+.PHONY: clean
+clean: $(SUBDIRS_clean)
+	-rm -f *~ $(KERNEL) $(KERNEL).{gz,o,elf,dump,map}
+
+%.clean:
+	$(MAKE) -C $* clean clean=1

kernel/boot.asm

@@ -1,196 +0,0 @@
-;boot.asm
-;Author: Josh Holtrop
-;Date: 07/08/04
-;Modified: 07/10/04
-
-
-%define	MULTIBOOT_MAGIC	0x1BADB002
-%define	MULTIBOOT_FLAGS	0x00010003
-
-%define VIRT_OFFSET	0xC0000000	;3gb virtual address
-%define PHYS_START	0x00100000	;1mb physical address
-%define VIRT_STACK_TOP	0xCFFFFFFC	;3gb+256mb virtual address
-%define GDT_P	PHYS_START		;1mb physical - Global Descriptor Table space
-%define GDT_V	GDT_P+VIRT_OFFSET
-%define IDT_P	PHYS_START+0x2000	;1mb+8kb - Interrupt Descriptor Table space
-%define IDT_V	IDT_P+VIRT_OFFSET
-%define PDBR_P	PHYS_START+0x4000	;1mb+16kb - Page Directory Base Register (first PD)
-%define PDBR_V	PDBR_P+VIRT_OFFSET
-%define LOPT_P	PHYS_START+0x5000	;1mb+20kb - LOw Page Table for mapping first 4mb
-%define LOPT_V	LOPT_P+VIRT_OFFSET
-%define PT_STACK_P PHYS_START+0x6000	;1mb+24kb - page table for initial kernel stack pages (under 0xD0000000)
-%define PT_STACK_V PT_STACK_P+VIRT_OFFSET
-%define STACK_P	PHYS_START+0x7000	;1mb+28kb - initial 4kb kernel stack page
-%define STACK_V	STACK_P+VIRT_OFFSET
-%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
-
-[bits 32]
-
-[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	0						;load_end_addr
-	dd	_end-VIRT_OFFSET				;bss_end_addr
-	dd	multiboot_entry-VIRT_OFFSET			;entry_addr
-
-;	dd	1						;mode_type
-;	dd	80						;width
-;	dd	25						;height
-;	dd	0						;depth
-
-[global multiboot_entry]
-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]
-	jmp	KERNEL_CODE_BS32:segmented_start
-segmented_start:
-	mov	ax, KERNEL_DATA_BS32
-	mov	ss, ax
-	mov	ds, ax
-	mov	es, ax
-	mov	gs, ax
-	mov	fs, ax
-	mov	esp, STACK_V+0x1000		;ok, now we can access our data
-
-;aloop:
-;	inc dword [0xC00B8000]
-;	jmp	aloop
-
-
-;Then the multiboot info structures are saved to local data variables.
-	add	ebx, VIRT_OFFSET
-	push	eax
-	push	ebx				;pointer to multiboot info structure
-	call	_k_mbsave			;save multiboot info structures
-	add	esp, 8
-
-	cmp	eax, 0
-	jz	pm_return
-
-;go back to real mode to initialize video mode
-	mov	ebx, pm_return
-
-
-
-;Next we enable paging with the first 4mb mapped 1:1 virtual:physical
-; and with the 4mb starting at 0xC000_0000 mapped to the first 4mb physical.
-pm_return:
-	xor	eax, eax
-	mov	edi, PDBR_V
-	mov	ecx, 1024			;clear the PDBR
-	rep stosd
-	mov	edi, PT_STACK_V
-	mov	ecx, 1024			;clear the PT_STACK
-	rep stosd
-	mov	[PDBR_V], dword LOPT_P|0x03		;store the physical address of the LOw Page Table | (read/write, present)
-	mov	[PDBR_V+0xC00], dword LOPT_P|0x03	;store the physical address of the LOw Page Table | (read/write, present)
-	mov	[PDBR_V+0xCFC], dword PT_STACK_P|0x03	;store the physical address of the initial stack page page table | (read/write, present)
-	mov	[PT_STACK_V+0xFFC], dword STACK_P|0x03	;store the physical address of the initial stack page | (read/write, present)
-
-	mov	edi, LOPT_V
-	mov	ecx, 1024
-	mov	eax, 0x03			;starting physical address = 0x0 | (read/write, present flags)
-fill_lopt_loop:					;fill the page table
-	stosd
-	add	eax, 4096			;increment next phsyical address by 4kb
-	loop	fill_lopt_loop
-
-	mov	eax, PDBR_P
-	mov	cr3, eax			;store the Page Directory Base Address
-	mov	eax, cr0
-	or	eax, 0x80000000			;set Page Enable bit
-	mov	cr0, eax			;now paging is active!
-
-
-	mov	edi, GDT_V
-	mov	esi, gdt
-	mov	ecx, gdt_end-gdt
-	rep movsb
-
-	mov	edi, IDT_V		;destination
-	mov	esi, isr_0		;address of isr0
-	mov	edx, isr_1-isr_0	;distance between isr labels
-	mov	ecx, 50			;number of isrlabels
-fill_idt:
-	mov	ebx, esi
-	mov	ax, si
-	stosw				;0 offset 15:0
-	mov	ax, KERNEL_CODE
-	stosw				;2 selector 15:0
-	mov	ax, 0x8E00
-	stosw				;4 [P][DPL][0][TYPE][0][0][0][0][0][0][0][0]
-	shr	esi, 16
-	mov	ax, si
-	stosw				;6 offset 31:16
-	mov	esi, ebx
-	add	esi, edx
-	loop	fill_idt
-	mov	word	[IDT_V+0x30*8+4], 0xEE00	;interrupt 0x30 has user priviledges
-
-;Then we can start using our "real" gdt, then unmap the lower 4mb.
-	lgdt	[gdtr]			;load gdt
-	jmp	KERNEL_CODE:newgdtcontinue
-newgdtcontinue:
-	mov	ax, KERNEL_DATA
-	mov	es, ax
-	mov	ds, ax
-	mov	gs, ax
-	mov	fs, ax
-	mov	ss, ax
-	mov	esp, VIRT_STACK_TOP		;stack just under 3gb+256mb, moves downward
-	lidt	[idtr]				;load idt
-	mov	[PDBR_V], dword 0		;unmap 0x0, we are running completely paged at 0xC000_0000
-
-	call	_k_init			;C kernel initialization
-
-idle_loop:
-;	sti
-	hlt
-	jmp	idle_loop
-
-;-------------------------------------------------------
-gdtrbs32:
-	dw	gdt_endbs32-gdtbs32-1
-	dd	gdtbs32-VIRT_OFFSET
-gdtbs32:				;null descriptor
-	dd	0
-	dd	0
-
-	;a base of 0x4000_0000, when added to 0xC000_0000 will produce 0x0000_0000 physical before paging in effect
-KERNEL_CODE_BS32 equ $-gdtbs32
-	db	0xff		;limit	7:0
-	db	0xff		;limit	15:8
-	db	0x00		;base	7:0
-	db	0x00		;base	15:8
-	db	0x00		;base	23:16
-	db	0x9a		;access
-	db	0xcf		;flags / limit 19:16
-	db	0x40		;base	31:24
-
-KERNEL_DATA_BS32 equ $-gdtbs32
-	db	0xff		;limit	7:0
-	db	0xff		;limit	15:8
-	db	0x00		;base	7:0
-	db	0x00		;base	15:8
-	db	0x00		;base	23:16
-	db	0x92		;access
-	db	0xcf		;flags / limit 19:16
-	db	0x40		;base	31:24
-
-gdt_endbs32:
-
-%include "gdt.inc"
-%include "idt.inc"
-

kernel/boot/Makefile

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

kernel/boot/boot.asm

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

kernel/boot/k_bootstrap.cc

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

kernel/boot/k_bootstrap.h

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

kernel/boot/k_early_panic.c

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

kernel/boot/k_early_panic.h

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

kernel/boot/k_main.cc

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

kernel/boot/k_main.h

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

kernel/gdt.inc

@@ -1,71 +0,0 @@
-;gdt.inc
-;Author: Josh Holtrop
-;Date: 10/30/03
-;Modified: 03/02/04
-
-gdtr:
-	dw	gdt_end-gdt-1
-	dd	GDT_V
-gdt:
-	dd	0
-	dd	0
-KERNEL_CODE equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0x9A	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0xCF	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-KERNEL_DATA equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0xCF	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-USER_CODE equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0xFA	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0xCF	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-USER_DATA equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0xF2	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0xCF	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-VESA_CODE equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0x9A	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-VESA_DATA equ $-gdt
-	dw	0xffff	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x00	;base  23:16
-	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-VIDEO_TEXT equ $-gdt
-	dw	0x7FFF	;limit 15:0
-	dw	0x8000	;base  15:0
-	db	0x0B	;base  23:16
-	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-VIDEO_GRAPHICS equ $-gdt
-	dw	0xFFFF	;limit 15:0
-	dw	0x0000	;base  15:0
-	db	0x0A	;base  23:16
-	db	0x92	;access ([P][DPL][1][Executable][Direction/Conforming][Writable/Readable][A])
-	db	0x40	;flags ([G][D/B][0][0]) / limit 19:16
-	db	0x00	;base  31:24
-gdt_end:
-
-
-

kernel/idt.inc

@@ -1,92 +0,0 @@
-;idt.inc
-;Author: Josh Holtrop
-;Date: 10/30/03
-;Modified: 07/06/04
-
-idtr:
-	dw	50*8-1		;size of idt
-	dd	IDT_V		;address of idt
-
-
-%macro isr_label 1
-isr_%1:
-	push	eax
-	mov	eax, %1
-	jmp	isr_main
-%endmacro
-
-isr_label	0
-isr_label	1
-isr_label	2
-isr_label	3
-isr_label	4
-isr_label	5
-isr_label	6
-isr_label	7
-isr_label	8
-isr_label	9
-isr_label	10
-isr_label	11
-isr_label	12
-isr_label	13
-isr_label	14
-isr_label	15
-isr_label	16
-isr_label	17
-isr_label	18
-isr_label	19
-isr_label	20
-isr_label	21
-isr_label	22
-isr_label	23
-isr_label	24
-isr_label	25
-isr_label	26
-isr_label	27
-isr_label	28
-isr_label	29
-isr_label	30
-isr_label	31
-isr_label	32
-isr_label	33
-isr_label	34
-isr_label	35
-isr_label	36
-isr_label	37
-isr_label	38
-isr_label	39
-isr_label	40
-isr_label	41
-isr_label	42
-isr_label	43
-isr_label	44
-isr_label	45
-isr_label	46
-isr_label	47
-isr_label	48
-isr_label	49
-
-isr_main:
-	pusha
-	push	ds
-	push	es
-
-	push	eax	;interrupt number
-	call	_isr
-	add	esp, 4
-
-	pop	es
-	pop	ds
-	popa
-	pop	eax		;original saved eax
-
-	iret
-
-
-
-
-
-
-
-
-

kernel/include/hos_defines.h

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

kernel/include/hos_types.h

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

kernel/include/multiboot.h

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

kernel/include/portio.h

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

kernel/isr/Makefile

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

kernel/isr/interrupts.cc

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

kernel/isr/interrupts.h

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

kernel/isr/isr.asm

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

kernel/kernel.c

@@ -1,76 +0,0 @@
-
-#include "kernel.h"
-#include "multiboot.h"
-#include "module.h"
-
-mb_info_t mb_info_block;
-mb_mmap_t mb_mmap[MAX_MMAP];
-mb_module_t mb_modules[MAX_MODULES];
-mb_apm_t mb_apm_table;
-char mb_cmdline[256];
-
-/* This function runs in segmented memory - 0xC000_0000 is mapped to 0x0 but 0x0
-   itself is an invalid linear address. Therefore, the multiboot information addresses
-   must be manually adjusted by VIRT_OFFSET to become valid linear addresses. */
-int k_mbsave(mb_info_t *mbinfo, unsigned int mb_magic)
-{
-	if (mb_magic != MULTIBOOT_BOOTLOADER_MAGIC)
-	{
-		char *msg = "Bad multiboot magic identifier!";
-		char *dest = (char *) 0xC00B8000;
-		while (*msg)
-		{
-			*dest++ = *msg++;
-			*dest++ = 0x04;		//red error message
-		}
-		for (;;) ;
-	}
-	mb_info_block = *mbinfo;
-	if (mb_info_block.flags & MB_BOOTLOADER_COMMAND_LINE)
-	{
-		mb_info_block.cmdline += VIRT_OFFSET;
-		memcpy(mb_cmdline, mb_info_block.cmdline, 256);
-		mb_cmdline[255] = 0;
-	}
-	if (mb_info_block.flags & MB_BOOTLOADER_MODS)
-	{
-		mb_info_block.mods_addr += VIRT_OFFSET;
-		int i;
-		for (i = 0; i < mb_info_block.mods_count && i < MAX_MODULES; i++)
-		{
-			mb_modules[i] = ((mb_module_t *)mb_info_block.mods_addr)[i];
-		}
-	}
-	if (mb_info_block.flags & MB_BOOTLOADER_MMAP)
-	{
-		mb_info_block.mmap_addr += VIRT_OFFSET - 4;	//-4 to get to size field, not base_addr_low field
-		mb_mmap_t *mmap = (mb_mmap_t *)mb_info_block.mmap_addr;
-		int i, sz = 0;
-		for (i = 0; sz < mb_info_block.mmap_length && i < MAX_MMAP; i++)
-		{
-			sz += mmap->size;
-			mb_mmap[i] = *mmap;
-			mmap = (mb_mmap_t *)(((u32_t) mmap) + mmap->size);
-		}
-	}
-	if (mb_info_block.flags & MB_BOOTLOADER_APM)
-	{
-		mb_info_block.apm_table += VIRT_OFFSET;
-		mb_apm_table = *(mb_apm_t *)mb_info_block.apm_table;
-	}
-	return 0;
-}
-
-void k_init()
-{
-	for (;;)
-	{
-		(*(char*)0xC00B8000)++;
-	}
-}
-
-void isr()
-{
-	for (;;) ;
-}
-

kernel/lang/Makefile

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

kernel/lang/kio.cc

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

kernel/lang/kio.h

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

kernel/lang/string.cc

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

kernel/lang/string.h

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

kernel/link.ld

@@ -1,26 +1,34 @@
-OUTPUT_FORMAT("binary")
-ENTRY(_start)
-SECTIONS
-{
-  .text  0xC0108000 : {
-    code = .; _code = .; __code = .;
-    *(.text)
-    . = ALIGN(4096);
-  }
-  .data  : {
-    data = .; _data = .; __data = .;
-    *(.data)
-/*    . = ALIGN(4096); */
-  }
-  .rodata  : {
-    rodata = .; _rodata = .; __rodata = .;
-    *(.rodata)
-    . = ALIGN(4096);
-  }
-  .bss  : {
-    bss = .; _bss = .; __bss = .;
-    *(.bss)
-    . = ALIGN(4096);
-  }
-  end = .; _end = .; __end = .;
-}
+OUTPUT_FORMAT(elf32-i386)
+ENTRY(start)
+virt = 0x00100000;
+phys = 0x00100000;
+SECTIONS
+{
+    .text virt : AT(phys) {
+        code = .; _code = .; __code = .;
+        *(.multiboot_header*)
+        *(.text*)
+        *(.gnu.linkonce*)
+        . = ALIGN(4096);
+    }
+    .rodata : {
+        *(.rodata*)
+        . = ALIGN(4096);
+    }
+    .other : {
+        *(.eh_*)
+        *(.rel*)
+        . = ALIGN(4096);
+    }
+    .data : {
+        data = .; _data = .; __data = .;
+        *(.data*)
+        . = ALIGN(4096);
+    }
+    .bss : {
+        bss = .; _bss = .; __bss = .;
+        *(.bss*)
+        . = ALIGN(4096);
+    }
+    end = .; _end = .; __end = .;
+}

kernel/mm/Makefile

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

kernel/mm/mm.cc

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

kernel/mm/mm.h

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

kernel/mm/stack.cc

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

kernel/mm/stack.h

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

kernel/subdir.mak

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

kernel/sys/Makefile

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

kernel/sys/cpu.h

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

kernel/sys/pic.cc

@@ -0,0 +1,29 @@
+
+#include "pic.h"
+#include "portio.h"
+
+/*
+ * Re-maps the Programmable Interrupr Controllers
+ * so IRQ0->pic1 base address, IRG8->pic2 base address
+ */
+void pic_remap(u8_t base1, u8_t base2)
+{
+    u8_t    a1, a2;
+
+    a1 = inportb(PIC1_DATA);        /* 0x21 */
+    a2 = inportb(PIC2_DATA);        /* 0xA1 */
+
+    outportb(PIC1_COMMAND, ICW1_INIT+ICW1_ICW4); /* 0x20, 0x10+0x01 00010001b */
+    outportb(PIC2_COMMAND, ICW1_INIT+ICW1_ICW4); /* 0xA0, 0x10+0x01 00010001b */
+    outportb(PIC1_DATA, base1);     /* 0x21, pic1 */
+    outportb(PIC2_DATA, base2);     /* 0xA1, pic2 */
+    outportb(PIC1_DATA, 4);         /* 0x21, 0x04 00000100b */
+    outportb(PIC2_DATA, 2);         /* 0xA1, 0x02 00000010b */
+    outportb(PIC1_DATA, ICW4_8086); /* 0x21, 0x01 00000001b */
+    outportb(PIC2_DATA, ICW4_8086); /* 0xA1, 0x01 00000001b */
+
+    outportb(PIC1_DATA, a1);        /* 0x21 */
+    outportb(PIC2_DATA, a2);        /* 0xA1 */
+}
+
+

kernel/sys/pic.h

@@ -0,0 +1,46 @@
+
+#ifndef PIC_H
+#define PIC_H
+
+#include "hos_types.h"
+#include "portio.h"
+
+#define PIC1            0x20
+#define PIC2            0xA0
+#define PIC1_COMMAND    PIC1
+#define PIC1_DATA       (PIC1+1)
+#define PIC2_COMMAND    PIC2
+#define PIC2_DATA       (PIC2+1)
+#define PIC_EOI         0x20
+
+#define ICW1_ICW4       0x01            /* ICW4 (not) needed */
+#define ICW1_SINGLE     0x02            /* Single (cascade) mode */
+#define ICW1_INTERVAL4  0x04            /* Call address interval 4 (8) */
+#define ICW1_LEVEL      0x08            /* Level triggered (edge) mode */
+#define ICW1_INIT       0x10            /* Initialization - required! */
+
+#define ICW4_8086       0x01            /* 8086/88 (MCS-80/85) mode */
+#define ICW4_AUTO       0x02            /* Auto (normal) EOI */
+#define ICW4_BUF_SLAVE  0x08            /* Buffered mode/slave */
+#define ICW4_BUF_MASTER 0x0C            /* Buffered mode/master */
+#define ICW4_SFNM       0x10            /* Special fully nested (not) */
+
+void pic_remap(u8_t base1, u8_t base2);
+
+/* Masks interrupts on first Programmable Interrupt Controller */
+#define pic_mask1(mask) outportb(PIC1_DATA, mask) /* 0x21, maskfield *OCW1* */
+
+/* Masks interrupts on second Programmable Interrupt Controller */
+#define pic_mask2(mask) outportb(PIC2_DATA, mask) /* 0xA1, maskfield *OCW1* */
+
+/* Signals an End Of Interrupt signal to the first PIC */
+#define pic_eoi() outportb(0x20, 0x20)
+
+/* Signals an End Of Interrupt signal to both the second and first PIC unit */
+static inline void pic_eoi2()
+{
+        outportb(0xA0, 0x20);
+        outportb(0x20, 0x20);
+}
+
+#endif

kernel/sys/timer.cc

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

kernel/sys/timer.h

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

menu.lst

@@ -1,9 +0,0 @@
-
-timeout 10
-default 0
-
-title HOS 0.15
-root (fd0)
-kernel /kernel.bin
-
-

util/build-i586-elf-gcc.sh

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