Boot loader appears to work somewhat, kernel is questionable
This commit is contained in:
70
asm/bootloader.S
Normal file
70
asm/bootloader.S
Normal file
@@ -0,0 +1,70 @@
|
||||
[bits 16] ; 16 bit real mode code
|
||||
[org 0x7C00] ; Origin at 0x7C00 (upper end of memory)
|
||||
|
||||
start:
|
||||
call blankScreen
|
||||
|
||||
mov dx, 0x0
|
||||
call setCursorPosition
|
||||
|
||||
mov si, _str_hello ; si = source index
|
||||
call printString
|
||||
mov dh, 0x1
|
||||
mov dl, 0x0
|
||||
call setCursorPosition
|
||||
|
||||
mov al, 0x17 ; read the remaining 16 tracks
|
||||
mov ch, 0x1 ; .... on track 1 ....
|
||||
mov cl, 0x1 ; .... starting at sector 1
|
||||
mov bx, 0x1000 ; 0x1000 is a standard kernel start location
|
||||
mov es, bx
|
||||
xor bx, bx ; bx = 0, es:bs = 0x1000:0
|
||||
call loadFloppyDiskSectors
|
||||
push ax
|
||||
mov ax, bx
|
||||
add ax, 0x2200 ; we just read 0x2200 bytes, move pointer in memory
|
||||
mov bx, ax
|
||||
pop ax
|
||||
mov al, 0x17 ; read 18 sectors per track for all future tracks
|
||||
mov cl, 0x1 ; start at sector 1 for all future tracks
|
||||
|
||||
mov di, 0x2FF ; abuse di as a counter, while (di < 80)
|
||||
; di is technically a destination index for stream
|
||||
; ops, but nothing is using it ATM, so gimme.
|
||||
_next_floppy_track:
|
||||
push ax
|
||||
mov ax, 0x2e
|
||||
call printCharacter
|
||||
mov ax, cx
|
||||
mov cx, di
|
||||
mov cl, al
|
||||
pop ax
|
||||
call loadFloppyDiskSectors
|
||||
push ax
|
||||
mov ax, bx
|
||||
add ax, 0x2400 ; each floppy track is (512b*18s)=0x2400 bytes long
|
||||
mov bx, ax
|
||||
pop ax
|
||||
inc di
|
||||
push cx
|
||||
mov cx, 0x50
|
||||
cmp di, cx ; di < 80 ?
|
||||
jg _end_floppy_read
|
||||
pop cx
|
||||
|
||||
_end_floppy_read:
|
||||
mov dh, 0x1
|
||||
mov dl, 0x0
|
||||
call setCursorPosition
|
||||
mov si, _str_floppydone
|
||||
call printString
|
||||
jmp 0x1000
|
||||
|
||||
%include "libinterrupt.S"
|
||||
|
||||
_str_hello db 'Piquant v0.1 Bootloader', 0xA, 0
|
||||
_str_loading db 'Loading', 0
|
||||
_str_floppydone db 'Kernel loaded', 0xA, 0
|
||||
|
||||
times 510 - ($ - $$) db 0 ; fill up to 510 bytes with 0
|
||||
dw 0xAA55 ; magic bootloader signature
|
||||
Reference in New Issue
Block a user