diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/entry.asm | 112 | ||||
| -rw-r--r-- | src/main.c | 32 |
2 files changed, 143 insertions, 1 deletions
diff --git a/src/entry.asm b/src/entry.asm index 0567f61..65ce0fc 100644 --- a/src/entry.asm +++ b/src/entry.asm @@ -98,8 +98,118 @@ stage_two: mov si, disk_success_msg call print - jmp $ + mov ax, [superblock + 1024 + 8] ; Inode table + mov cx, 2 + mul cx ; ax = cx * ax + + mov [lba], ax ; Sector + + mov ax, 2 + mov [count], ax ; Read 1024 bytes + + mov bx, 0x1000 ; Copy data to 0x1000 + mov [dest], bx + + call disk_read + + ; TODO: File crawling instead of fixed inode + xor bx, bx + mov bx, 0x1200 ; First block (4 * 128) + mov cx, [bx + 28] ; Number of sectors for inode + lea di, [bx + 40] ; Address of first block pointer + + mov bx, 0x5000 + mov [dest + 2], bx + mov bx, 0 ; Inode location = 0xF0000 + mov [dest], bx + call stage_three_load + jmp protected_mode_enter + +stage_three_load: + xor ax, ax ; Clear ax + mov dx, ax ; Clear dx + mov ax, [di] ; Set ax = block pointer + mov dx, 2 ; Mul 2 for sectors + mul dx ; ax = dx * ax + + mov [lba], ax + mov [dest], bx + + call disk_read + + add bx, 0x400 ; 1kb increase + add di, 0x4 ; Move to next block pointer + sub cx, 0x2 ; Read 2 blocks + jnz stage_three_load + ret + + nop + hlt + +protected_mode_enter: + cli ; Turn off interrupts + + in al, 0x92 ; Enable A20 + or al, 2 + out 0x92, al + + ; Clear registers + xor ax, ax + mov ds, ax + mov es, ax + mov fs, ax + mov gs, ax + + lgdt [gdt_desc] ; Load GDT + + mov eax, cr0 + or eax, 1 ; Set bit 0 + mov cr0, eax + + jmp 08h:protected_mode ; JUMP! + +bits 32 ; Woah! +protected_mode: + xor eax, eax + + mov ax, 10h ; Set data segement indentifier + mov ds, ax + mov es, ax + mov fs, ax + mov gs, ax + mov ss, ax ; Stack segment + mov esp, 0x00900000 ; Move stack pointer + + mov edx, 0x00050000 + lea eax, [edx] + call eax + +; GDT +align 32 +gdt: +gdt_null: + dd 0 + dd 0 +gdt_code: + dw 0xFFFF + dw 0 + db 0 + db 0x9A + db 0xCF + db 0 +gdt_data: + dw 0xFFFF + dw 0 + db 0 + db 0x92 + db 0xcF + db 0 +gdt_end: +gdt_desc: + dw gdt_end - gdt - 1 + dd gdt times 1024 - ($ - $$) db 0 + superblock: @@ -1,5 +1,37 @@ +unsigned char inb(unsigned short port) +{ + unsigned char value; + __asm__ volatile("inb %1, %0" : "=a"(value) : "Nd"(port)); + return value; +} + +void outb(unsigned short port, unsigned char data) +{ + __asm__ volatile("outb %0, %1" ::"a"(data), "Nd"(port)); +} + +int is_transmit_empty() +{ + return inb(0x3f8 + 5) & 0x20; +} + +void serial_put(char ch) +{ + while (is_transmit_empty() == 0) + ; + outb(0x3f8, (unsigned char)ch); +} + int main(int argc, char *argv[]) { + outb(0x3f8 + 1, 0x00); + outb(0x3f8 + 3, 0x80); + outb(0x3f8 + 0, 0x03); + outb(0x3f8 + 1, 0x00); + outb(0x3f8 + 3, 0x03); + outb(0x3f8 + 2, 0xC7); + outb(0x3f8 + 4, 0x0B); + serial_put('a'); while (1) { }; return 0; |