os-k/boot/loader/loader.asm

161 lines
6.2 KiB
NASM

;=----------------------------------------------------------------------------=;
; GNU GPL OS/K ;
; ;
; Desc: Kernel (second stage) Loader for OS/K ;
; (x86_64 architecture only) ;
; ;
; ;
; Copyright © 2018-2019 The OS/K Team ;
; ;
; This file is part of OS/K. ;
; ;
; OS/K is free software: you can redistribute it and/or modify ;
; it under the terms of the GNU General Public License as published by ;
; the Free Software Foundation, either version 3 of the License, or ;
; (at your option) any later version. ;
; ;
; OS/K is distributed in the hope that it will be useful, ;
; but WITHOUT ANY WARRANTY; without even the implied warranty of ;
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;
; GNU General Public License for more details. ;
; ;
; You should have received a copy of the GNU General Public License ;
; along with OS/K. If not, see <https://www.gnu.org/licenses/>. ;
;=----------------------------------------------------------------------------=;
%define DEBUG
[BITS 32]
[global _start]
[ORG 0x100000] ; Where GRUB loads us.
%include "boot/loader/multiboot/header.inc"
;; NORMAL ENTRY POINT, BUT A LITTLE BIT UNUSED SINCE WE NEVER USE IT BECAUSE...
_start:
mov ax, cs ; correcting cs after the horrible far jump
mov ds, ax ; hm... And ds too
mov es, ax ; And es because it is jealous
;mov [Bootdrv], dl
xor dl, dl
jmp 0x0000:_loader ; pas sûr
;; MAGNIFICENT MULTIBOOT HEADER FOR GRUB ------------------------------------ ;;
MB_header:
align 4
dd MB_HEADER_MAGIC
dd MB_HEADER_FLAGS
dd CHECKSUM
dd MB_header ; Header address
dd _start ; Address of code entry point
dd 00 ; (end of code) not necessary
dd 00 ; (bss) not necessary
dd MB_start ; entry address GRUB will start at
;; MULTIBOOT POINT ENTRY FOR GRUB ------------------------------------------- ;;
MB_start:
mov esp, KERNEL_STACK ; Setup the stack
push 0 ; Reset EFLAGS
popf
push eax ; 2nd argument is magic number
push ebx ; 1st argument multiboot info pointer
mov ecx, eax
call _loader
add esp, 8 ; Cleanup arguments "A la MIPS"
jmp Die ; Aufwiedersehen
;; THE HOLES ---------------------------------------------------------------- ;;
; ---------------------------------------------------------------------------- ;
; Prints 'ERR:XX' where 'XX' is the str in AX ;
; ---------------------------------------------------------------------------- ;
Error:
mov dword [0xb8000], 0x4f524f45
mov dword [0xb8004], 0x4f3a4f52
mov dword [0xb8008], 0x4f204f20
mov byte [0xb800a], al
mov byte [0xb800c], ah
mov byte [0xb800d], 0x4f
jmp Die
; ---------------------------------------------------------------------------- ;
; Kills the mind of your computer to get it prostrated ;
; ---------------------------------------------------------------------------- ;
Die:
cli
hlt ; die nooooow
;jmp 0xF000:0xFFF0
jmp $
;; THE CODE ----------------------------------------------------------------- ;;
; ---------------------------------------------------------------------------- ;
; _loader ;
; ;
; This is the function that initiates the launch of OS/K. It verifies that ;
; Grub has properly loaded this loader and makes the appropriate setup so ;
; that the kernel will work properly ;
; ;
; Why this original design ? Because it works well and prevent us to cause ;
; triple faults by aligment error or too long jumps (yup, it can be a problem);
; ;
; ---------------------------------------------------------------------------- ;
_loader:
jmp lbegin
%include "boot/loader/multiboot/check.inc"
%include "boot/loader/cpu/cpuid.inc"
%include "boot/loader/mem/structures.inc"
%include "boot/loader/mem/management.inc"
lbegin:
call MB_check
call Check_cpuid
call Is64Bits
call CheckA20
call Setup_paging
call Go64
lgdt [GDT64.pointer]
jmp GDT64.code:l64
[BITS 64]
%include "boot/loader/io/terminal.inc"
%include "boot/loader/io/ata.inc"
%include "boot/loader/cpu/cpu.inc"
Salut db 0x09, " Booting OS/K ", 0x09, 0x0A, 0x0D, 0x0
ReadAttempt db 0x09, " Attempt to read a sector with ATA commands...", 0
l64:
;; Some cleanup
mov ax, 0
mov ss, ax
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
;; Hello world
mov bl, 0x0A
mov esi, Salut
call write
;; Read ATA
mov bl, 0x0F
mov esi, ReadAttempt
call write
call temporize
;; Reading a sector of the disk
mov bl, 1
mov bh, 1
call ata_read
jmp Die