initial commit
This commit is contained in:
6
.gitignore
vendored
Normal file
6
.gitignore
vendored
Normal file
@@ -0,0 +1,6 @@
|
||||
*.iso
|
||||
isodir
|
||||
sysroot
|
||||
|
||||
.idea
|
||||
.vscode
|
||||
14
boot.ld
Normal file
14
boot.ld
Normal file
@@ -0,0 +1,14 @@
|
||||
ENTRY(_start)
|
||||
|
||||
SECTIONS
|
||||
{
|
||||
. = 0x7C00;
|
||||
|
||||
.text : {
|
||||
*(.text)
|
||||
}
|
||||
|
||||
.data : {
|
||||
*(.data)
|
||||
}
|
||||
}
|
||||
129
boot.s
Normal file
129
boot.s
Normal file
@@ -0,0 +1,129 @@
|
||||
.code16
|
||||
.text
|
||||
.global _start
|
||||
_start:
|
||||
ljmp $0x07C0, $something
|
||||
|
||||
something:
|
||||
cli
|
||||
cld
|
||||
|
||||
mov %cs, %ax
|
||||
mov %ax, %ds
|
||||
mov %ax, %es
|
||||
|
||||
# stack stuff
|
||||
mov $0x0000, %ax
|
||||
mov %ax, %ss
|
||||
mov $0xFFF0, %sp
|
||||
|
||||
# copy the first 12 bytes of our MBR table entry
|
||||
mov %dl, (disk_number)
|
||||
mov $mbr_entry, %di
|
||||
mov $12, %cx
|
||||
rep movsb
|
||||
|
||||
mov $0, %ah
|
||||
int $0x13
|
||||
|
||||
mov $0x08, %ah
|
||||
int $0x13
|
||||
and 0b00111111, %cl
|
||||
mov %cl, (total_sectors)
|
||||
mov %ch, (total_cylinders)
|
||||
mov %dh, (total_heads)
|
||||
|
||||
mov $0x1000, %ax
|
||||
mov %ax, %es
|
||||
mov $0x0000, %bx
|
||||
|
||||
mov (disk_number), %dl
|
||||
mov $0, %ch #cylinder
|
||||
mov $0, %dh #head
|
||||
mov $2, %cl #sector
|
||||
|
||||
load_sector:
|
||||
mov $1, %al
|
||||
mov $0x02, %ah
|
||||
int $0x13
|
||||
|
||||
mov (kernel_sectors), %ax
|
||||
cmp $0xffff, %ax
|
||||
jne check_last_sector
|
||||
mov %es:20, %eax
|
||||
shr $9, %eax
|
||||
inc %eax
|
||||
|
||||
check_last_sector:
|
||||
dec %ax
|
||||
mov %ax, kernel_sectors
|
||||
cmp $0, %ax
|
||||
je done
|
||||
|
||||
move: # inc our offset. If it hits 0, we've moved a segment, inc that too.
|
||||
add $512, %bx
|
||||
cmp $0, %bx
|
||||
jnz read_next_sector
|
||||
mov %es, %ax
|
||||
add $1000, %ax
|
||||
mov %ax, %es
|
||||
|
||||
read_next_sector: # find the next valid sector, head, cylinder combo on the disk
|
||||
inc %cl
|
||||
mov (total_sectors), %al
|
||||
cmp %al, %cl
|
||||
jle load_sector
|
||||
mov $1, %cl #go back to sector 1.. of the next head
|
||||
|
||||
inc %dh #next head
|
||||
mov (total_heads), %al
|
||||
cmp %al, %dh
|
||||
jle load_sector
|
||||
mov $0, %dh # go back to head 0.. of the next cylinder
|
||||
|
||||
inc %ch # next cylinder
|
||||
mov (total_cylinders), %al
|
||||
cmp %al, %ch
|
||||
jle load_sector
|
||||
# no more disk... fall through
|
||||
done:
|
||||
mov $0, %ah
|
||||
int $0x13
|
||||
|
||||
mov $0x1000, %ax
|
||||
mov %ax, %ds
|
||||
ljmp $0x1000, $0x0000
|
||||
|
||||
disk_number:
|
||||
.byte 0
|
||||
total_cylinders:
|
||||
.byte 0
|
||||
total_heads:
|
||||
.byte 0
|
||||
total_sectors:
|
||||
.byte 0
|
||||
|
||||
kernel_sectors:
|
||||
.word 0xFFFF
|
||||
|
||||
mbr_entry:
|
||||
partition_status:
|
||||
.byte 0
|
||||
partition_start_chs:
|
||||
.byte 0
|
||||
.byte 0
|
||||
.byte 0
|
||||
partition_type:
|
||||
.byte 0
|
||||
partition_stop_chs:
|
||||
.byte 0
|
||||
.byte 0
|
||||
.byte 0
|
||||
partition_start_lba:
|
||||
.long 0
|
||||
partition_start_length:
|
||||
.long 0
|
||||
|
||||
.org 510
|
||||
magic:
|
||||
.word 0xAA55
|
||||
45
compile_commands.json
Normal file
45
compile_commands.json
Normal file
@@ -0,0 +1,45 @@
|
||||
[
|
||||
{
|
||||
"file": "boot.s",
|
||||
"arguments": [
|
||||
"/home/slinky/opt/cross/bin/i686-elf-gcc",
|
||||
"-m32",
|
||||
"-c",
|
||||
"boot.s",
|
||||
"-o",
|
||||
"boot.o"
|
||||
],
|
||||
"directory": "/home/slinky/source/RockOS",
|
||||
"output": "boot.o"
|
||||
},
|
||||
{
|
||||
"file": "prekernel.s",
|
||||
"arguments": [
|
||||
"/home/slinky/opt/cross/bin/i686-elf-gcc",
|
||||
"-m32",
|
||||
"-c",
|
||||
"prekernel.s",
|
||||
"-o",
|
||||
"prekernel.o"
|
||||
],
|
||||
"directory": "/home/slinky/source/RockOS",
|
||||
"output": "prekernel.o"
|
||||
},
|
||||
{
|
||||
"file": "kmain.c",
|
||||
"arguments": [
|
||||
"/home/slinky/opt/cross/bin/i686-elf-gcc",
|
||||
"-m32",
|
||||
"-ffreestanding",
|
||||
"-O2",
|
||||
"-Wall",
|
||||
"-Wextra",
|
||||
"-c",
|
||||
"kmain.c",
|
||||
"-o",
|
||||
"kmain.o"
|
||||
],
|
||||
"directory": "/home/slinky/source/RockOS",
|
||||
"output": "kmain.o"
|
||||
}
|
||||
]
|
||||
24
kernel.ld
Normal file
24
kernel.ld
Normal file
@@ -0,0 +1,24 @@
|
||||
ENTRY(_start)
|
||||
|
||||
SECTIONS
|
||||
{
|
||||
. = 0x10000;
|
||||
|
||||
.text : {
|
||||
*(.text)
|
||||
}
|
||||
|
||||
.rodata : {
|
||||
*(.rodata)
|
||||
}
|
||||
|
||||
.data : {
|
||||
*(.data)
|
||||
}
|
||||
|
||||
.bss : {
|
||||
*(.bss)
|
||||
}
|
||||
|
||||
_end = .;
|
||||
}
|
||||
26
kmain.c
Normal file
26
kmain.c
Normal file
@@ -0,0 +1,26 @@
|
||||
#include <stdint.h>
|
||||
|
||||
extern void halt();
|
||||
|
||||
typedef struct {
|
||||
uint16_t offset_low;
|
||||
uint16_t selector;
|
||||
uint8_t zero;
|
||||
uint8_t flags;
|
||||
uint16_t offset_high;
|
||||
} idt_entry_t __attribute__((packed));
|
||||
|
||||
typedef struct {
|
||||
uint16_t limit;
|
||||
uint32_t base;
|
||||
} idt_ptr_t;
|
||||
|
||||
idt_entry_t idt[256];
|
||||
idt_ptr_t idtr;
|
||||
|
||||
void load_idt() {}
|
||||
|
||||
void kmain() {
|
||||
load_idt();
|
||||
halt();
|
||||
}
|
||||
42
makefile
Normal file
42
makefile
Normal file
@@ -0,0 +1,42 @@
|
||||
CC = i686-elf-gcc
|
||||
LD = i686-elf-ld
|
||||
OBJCOPY = i686-elf-objcopy
|
||||
|
||||
CFLAGS = -m32 -ffreestanding -O2 -Wall -Wextra -nostdlib
|
||||
ASFLAGS = -m32
|
||||
|
||||
.PHONY: all clean run
|
||||
|
||||
all: os.img
|
||||
|
||||
boot.o: boot.s
|
||||
$(CC) $(ASFLAGS) -c boot.s -o boot.o
|
||||
|
||||
boot.elf: boot.o boot.ld
|
||||
$(LD) -T boot.ld -o boot.elf boot.o
|
||||
|
||||
boot.bin: boot.elf
|
||||
$(OBJCOPY) -O binary boot.elf boot.bin
|
||||
|
||||
prekernel.o: prekernel.s
|
||||
$(CC) $(ASFLAGS) -c prekernel.s -o prekernel.o
|
||||
|
||||
kmain.o: kmain.c
|
||||
$(CC) $(CFLAGS) -c kmain.c -o kmain.o
|
||||
|
||||
kernel.elf: prekernel.o kmain.o kernel.ld
|
||||
$(LD) -T kernel.ld -o kernel.elf prekernel.o kmain.o
|
||||
|
||||
kernel.bin: kernel.elf
|
||||
$(OBJCOPY) -O binary kernel.elf kernel.bin
|
||||
|
||||
os.img: boot.bin kernel.bin
|
||||
dd if=boot.bin of=os.img bs=512 count=1
|
||||
dd if=kernel.bin of=os.img bs=512 seek=1
|
||||
truncate -s 1440k os.img
|
||||
|
||||
run: os.img
|
||||
qemu-system-i386 -drive format=raw,file=os.img
|
||||
|
||||
clean:
|
||||
rm -f *.o *.elf *.bin os.img
|
||||
153
prekernel.s
Normal file
153
prekernel.s
Normal file
@@ -0,0 +1,153 @@
|
||||
.code16
|
||||
.text
|
||||
.global _start
|
||||
_start:
|
||||
jmp everything
|
||||
|
||||
.org 20
|
||||
.global kernel_size
|
||||
kernel_size:
|
||||
.long _end - _start
|
||||
|
||||
everything:
|
||||
mov $0x1000, %ax
|
||||
mov %ax, %es
|
||||
mov %ax, %ds
|
||||
|
||||
# reset disk
|
||||
mov $0, %ah
|
||||
int $0x13
|
||||
|
||||
# stop the cursor
|
||||
mov $1, %ah
|
||||
mov $0,%cl
|
||||
mov $0x20,%ch
|
||||
int $0x11
|
||||
|
||||
# get the system memory, if this call fails then halt
|
||||
clc
|
||||
mov $0, %bx
|
||||
mov $0xe801, %ax
|
||||
int $0x15
|
||||
jc halt
|
||||
shr $10, %ax
|
||||
shr $4, %bx
|
||||
add %ax, %bx
|
||||
mov %bx, total_mem_mb-_start
|
||||
|
||||
# vga text mode
|
||||
mov $0x0003, %ax
|
||||
int $0x10
|
||||
|
||||
enable_a20:
|
||||
#enable the a20 gate
|
||||
inb $0x92, %al
|
||||
orb $2, %al
|
||||
outb %al, $0x92
|
||||
prep_protected:
|
||||
cli
|
||||
lgdt (gdt_init-_start)
|
||||
mov %cr0, %eax
|
||||
or $0x01, %eax
|
||||
mov %eax, %cr0 # protected bit set
|
||||
ljmpl $8, $protected
|
||||
|
||||
halt16:
|
||||
jmp halt16
|
||||
|
||||
.code32
|
||||
protected:
|
||||
mov $2*8, %ax
|
||||
mov %ax, %es
|
||||
mov %ax, %ds
|
||||
mov %ax, %ss
|
||||
mov $5*8, %ax
|
||||
ltr %ax
|
||||
mov $0, %ax
|
||||
mov %ax, %fs
|
||||
mov %ax, %gs
|
||||
mov $0xFFF0, %sp
|
||||
mov $0xFFF0, %bp
|
||||
ljmpl $8, $kmain
|
||||
|
||||
.align 4
|
||||
.global video_info_struct
|
||||
video_info_struct:
|
||||
.word 0
|
||||
.byte 0,0
|
||||
.word 0,0,0,0
|
||||
.long 0
|
||||
.global video_xbytes
|
||||
video_xbytes:
|
||||
.word 0
|
||||
.global video_xres
|
||||
video_xres:
|
||||
.word 0
|
||||
.global video_yres
|
||||
video_yres:
|
||||
.word 0
|
||||
.byte 0,0,0,0,0,0,0,0,0
|
||||
.byte 0,0,0,0,0,0,0,0,0
|
||||
.global video_buffer
|
||||
video_buffer:
|
||||
.long 0
|
||||
.long 0
|
||||
.word 0
|
||||
.word 0
|
||||
.byte 0,0,0,0,0,0,0,0,0,0
|
||||
.long 0
|
||||
.rept 190
|
||||
.byte 0
|
||||
.endr
|
||||
|
||||
# some assembly stubs we can call from the kernel
|
||||
|
||||
.global idt_load
|
||||
.extern idtr
|
||||
idt_load:
|
||||
lidt (idtr)
|
||||
ret
|
||||
|
||||
.global gdt_load
|
||||
gdt_load:
|
||||
lgdt (gdt_init)
|
||||
ret
|
||||
|
||||
.global reboot
|
||||
reboot:
|
||||
cli
|
||||
lidt reboot_struct
|
||||
int $1
|
||||
reboot_struct:
|
||||
.word 0
|
||||
.long 0
|
||||
|
||||
.global halt
|
||||
halt:
|
||||
cli
|
||||
hlt
|
||||
jmp halt
|
||||
|
||||
# kernel data structures
|
||||
|
||||
.align 16
|
||||
.global gdt
|
||||
gdt:
|
||||
.word 0,0,0,0
|
||||
.word 0xffff, 0x0000, 0x9a00, 0x00cf
|
||||
.word 0xffff, 0x0000, 0x9200, 0x00cf
|
||||
.word 0xffff, 0x0000, 0xfa00, 0x00cf
|
||||
.word 0xffff, 0x0000, 0xf200, 0x00cf
|
||||
.word 0x0068, (tss-_start), 0x8901, 0x00cf
|
||||
gdt_init:
|
||||
.word gdt_init-gdt
|
||||
.long gdt
|
||||
|
||||
.align 16
|
||||
.global tss
|
||||
tss:
|
||||
.long 0
|
||||
|
||||
.global total_mem_mb
|
||||
total_mem_mb:
|
||||
.word 0
|
||||
Reference in New Issue
Block a user