diff --git a/stage1/hdd/bootsect.asm b/stage1/hdd/bootsect.asm index 8332b180..3f56af84 100644 --- a/stage1/hdd/bootsect.asm +++ b/stage1/hdd/bootsect.asm @@ -16,29 +16,24 @@ start: cld jmp 0x0000:.initialise_cs .initialise_cs: - xor ax, ax - mov ds, ax - mov es, ax - mov ss, ax + xor bx, bx + mov ds, bx + mov es, bx + mov ss, bx mov sp, 0x7c00 sti - ; Some BIOSes don't pass the correct boot drive number, - ; so we need to do the job - .check_drive: ; Limine isn't made for floppy disks, these are dead anyways. ; So if the value the BIOS passed is <0x80, just assume it has passed - ; an incorrect value - test dl, 0x80 - jz .fix_drive + ; an incorrect value. + cmp dl, 0x80 + jae .continue - ; Drive numbers from 0x80..0x8f should be valid - test dl, 0x70 - jz .continue - - .fix_drive: - ; Try to fix up the mess the BIOS have done - mov dl, 0x80 + ; Error out (BX zeroed out above) + push 0xb800 + pop es + mov dword [es:bx], 'F ! ' + jmp err .continue: ; Make sure int 13h extensions are supported