diff options
Diffstat (limited to 'src/bootloader/hdd2.asm')
| -rw-r--r-- | src/bootloader/hdd2.asm | 388 |
1 files changed, 0 insertions, 388 deletions
diff --git a/src/bootloader/hdd2.asm b/src/bootloader/hdd2.asm deleted file mode 100644 index db5aa38..0000000 --- a/src/bootloader/hdd2.asm +++ /dev/null @@ -1,388 +0,0 @@ -BITS 16 -ORG 0x8000 - -%define SECTOR_BUFFER 0x9000 -%define INODE_NBLOCKS 20 -%define INODE_DBP0 24 -%define INODE_SIBP 64 -%define INODE_DIBP 68 -%define INODE_TIBP 72 -%define INODE_QIBP 76 - -mov esp, 0xFFFF -jmp start - -checkA20: - ; Stolen from https://wiki.osdev.org/A20_Line - pushf - push ds - push es - push di - push si - cli - xor ax, ax - mov es, ax - not ax - mov ds, ax - mov di, 0x0500 - mov si, 0x0510 - mov al, byte [es:di] - push ax - mov al, byte [ds:si] - push ax - mov byte [es:di], 0x00 - mov byte [ds:si], 0xFF - cmp byte [es:di], 0xFF - pop ax - mov byte [ds:si], al - pop ax - mov byte [es:di], al - mov ax, 0 - jz checkA20_exit - mov ax, 1 - checkA20_exit: - pop si - pop di - pop es - pop ds - popf - ret - -last_max_level db 0 -getrecursive: - push edi - push esi - push ecx - - mov eax, edi - cmp al, byte [last_max_level] - jna .last_max_level_updated - mov byte [last_max_level], al - .last_max_level_updated: - - mov eax, esi - call 0x7c26 - - mov eax, dword [esp] - sub eax, 10 - - cmp byte [last_max_level], 1 - jna .check1 - mov ebx, 1 - shl ebx, 7 - sub eax, ebx - .check1: - cmp byte [last_max_level], 2 - jna .check2 - mov ebx, 1 - shl ebx, 14 - sub eax, ebx - .check2: - cmp byte [last_max_level], 3 - jna .check3 - mov ebx, 1 - shl ebx, 21 - sub eax, ebx - .check3: - mov ecx, dword [esp+8] - dec ecx - push ecx - shl ecx, 3 - sub ecx, dword [esp] - add esp, 4 - shr eax, cl - - mov eax, dword [SECTOR_BUFFER+(4*eax)] - - cmp dword [esp+8], 1 - jna .finish_recursion - mov edi, [esp+8] - dec edi - mov esi, eax - mov ecx, [esp] - call getrecursive - .finish_recursion: - mov byte [last_max_level], 0 - - pop ecx - pop esi - pop edi - ret - -get_block: - push ecx - push ebx - - xor ebx, ebx - inc ebx - shl ebx, 21 - add ebx, 9 - cmp ecx, ebx - jna .gtb1 - - mov edi, 4 - mov esi, dword [SECTOR_BUFFER+INODE_QIBP] - call getrecursive - jmp .get_block_end - - .gtb1: - xor ebx, ebx - inc ebx - shl ebx, 14 - add ebx, 9 - cmp ecx, ebx - jna .gtb2 - - mov edi, 3 - mov esi, dword [SECTOR_BUFFER+INODE_TIBP] - call getrecursive - jmp .get_block_end - - .gtb2: - xor ebx, ebx - inc ebx - shl ebx, 7 - add ebx, 9 - cmp ecx, ebx - jna .gtb3 - - mov edi, 2 - mov esi, dword [SECTOR_BUFFER+INODE_DIBP] - call getrecursive - jmp .get_block_end - - .gtb3: - cmp ecx, 9 - jna .gtb4 - - mov edi, 1 - mov esi, dword [SECTOR_BUFFER+INODE_SIBP] - call getrecursive - jmp .get_block_end - - .gtb4: - mov eax, SECTOR_BUFFER+INODE_DBP0 - mov eax, dword [eax+(4*ecx)] - - .get_block_end: - pop ebx - pop ecx - ret - -noa20 db "A20 could not be enabled.", 0 -loading db "Loading kernel...", 0x0A, 0x0D, 0x00 -booting db "Booting...", 0x0A, 0x0D, 0x00 -nomem db "BIOS does not support memory detection!", 0 -memno20 db "BIOS returns memory detection with 24 bytes. This has never been seen!", 0 - -start: - call checkA20 - test ax, ax - jnz A20_ENABLED - - in al, 0x92 - or al, 2 - out 0x92, al - - call checkA20 - test ax, ax - jnz A20_ENABLED - - mov si, noa20 - call 0x7c07 - jmp $ - -A20_ENABLED: - ; Inspired by https://wiki.osdev.org/Unreal_Mode - cli - push ds - lgdt [gdtinfo] - - mov eax, cr0 - or al, 1 - mov cr0, eax - - jmp $+2 - - mov bx, 0x08 - mov ds, bx - - and al, 0xFE - mov cr0, eax - pop ds - - mov si, loading - call 0x7c07 - - mov word [0x7c1a], SECTOR_BUFFER - - mov eax, 3 - call 0x7c26 - mov edx, dword [SECTOR_BUFFER + INODE_NBLOCKS] - - xor ecx, ecx -LOAD_KERNEL: - push edx - - mov eax, 3 - call 0x7c26 - call get_block - call 0x7c26 - - mov eax, ecx - shl eax, 9 - add eax, 0x200000 - - push ecx - xor ecx, ecx - .LOAD_KERNEL_L: - mov ebx, ecx - add ebx, SECTOR_BUFFER - mov ebx, dword [ebx] - - mov edx, ebx - mov ebx, eax - add ebx, ecx - mov dword [ebx], edx - - add ecx, 4 - cmp ecx, 2048 - jl .LOAD_KERNEL_L - pop ecx - - inc ecx - pop edx - cmp ecx, edx - jl LOAD_KERNEL - -mov si, booting -call 0x7c07 - -mov dl, [0x7c15] -mov byte [0x9000], dl - -mov di, 0xA000 -mov eax, 0xE820 -xor ebx, ebx -mov ecx, 24 -mov edx, 0x534D4150 -int 0x15 - -jc BIOS_NO_MEM -cmp eax, 0x534D4150 -jnz BIOS_NO_MEM -cmp cl, 20 -jnz BIOS_MEM_NO20 - -MEM_L: - test ebx, ebx - jz MEM_FINISHED - - mov ax, di - xor ch, ch - add ax, cx - mov di, ax - - mov eax, 0xE820 - mov ecx, 24 - int 0x15 - jmp MEM_L - -MEM_FINISHED: - mov eax, cr0 - or al, 1 - mov cr0, eax - - mov ax, 0x08 - mov ds, ax - mov es, ax - mov fs, ax - mov gs, ax - mov ss, ax - -; Infomation: https://wiki.osdev.org/ELF -mov ebx, 0x20002C -mov dl, byte [ebx] -push dx - -mov ebx, 0x20001C -mov ebx, dword [ebx] -push ebx - -xor dh, dh -PHT: - xor eax, eax - mov al, dh - shl eax, 5 - add eax, dword [esp] - add eax, 0x200000 - mov ebx, eax - - mov eax, dword [ebx] - cmp eax, 1 - jnz .PHT_ignore - - add ebx, 4 - mov eax, dword [ebx] - add eax, 0x200000 - push eax - - add ebx, 4 - mov eax, dword [ebx] - push eax - - add ebx, 8 - mov eax, dword [ebx] - push eax - - push dx - xor ecx, ecx - .MOVE_KERNEL_L: - mov ebx, [esp+10] - add ebx, ecx - mov ebx, dword [ebx] - - mov eax, ebx - mov ebx, dword [esp+6] - add ebx, ecx - mov dword [ebx], eax - - add ecx, 4 - cmp ecx, dword [esp+2] - jl .MOVE_KERNEL_L - pop dx - add esp, 12 - - .PHT_ignore: - inc dh - cmp dh, dl - jl PHT - -jmp (codedesc - gdt):protectedMode - -protectedMode: - BITS 32 - mov ebx, 0x100000 - mov eax, dword [ebx] - jmp eax - -BITS 16 -BIOS_NO_MEM: - mov si, nomem - call 0x7c07 - jmp $ -BIOS_MEM_NO20: - mov si, memno20 - call 0x7c07 - jmp $ - -gdtinfo: - dw gdt_end - gdt - 1 - dd gdt - gdt dd 0, 0 - flatdesc db 0xff, 0xff, 0, 0, 0, 10010010b, 11001111b, 0 - codedesc db 0xff, 0xff, 0, 0, 0, 10011010b, 11001111b, 0 - gdt_end: - -kernelbin db "KERNEL.BIN", 0x3B, "1" -kernelbin_len equ ($ - kernelbin)
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