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|
;
;disk_load_16
;
[bits 16]
STR_LBA:
db "LBA Support Detected",0
STR_CHS:
db "No CHS Support!)",0
STR_ERROR:
db "Disk Read Error",0
STR_DONE:
db "Stage 2 Loaded",0
disk_load_16:
pusha
; check if LBA is supported
mov ah,0x41
mov bx,0x55aa
int 0x13
jnc disk_load_lba
jmp disk_load_chs
disk_load_lba:
mov bx, STR_LBA
call print_string
call print_nextline
mov dl,[BOOT_DRIVE]
xor ah,ah
mov ah,0x42
mov bx,0
mov ds,bx
lea si,[lba_adr]
int 0x13
jnc disk_load_finish
jmp disk_load_error
disk_load_chs:
mov bx, STR_CHS
call print_string
call print_nextline
jmp $
mov bx,0 ;target es:bx
mov es,bx
mov bx,0x7e00
mov al,50 ;number of sectors to read
mov ah,0x02 ;BIOS read sector func
mov cl,2 ; sector
mov ch,0 ; cylinder
mov dl,[BOOT_DRIVE]
mov dh,0 ;head
int 0x13 ;bios interrupt
jnc disk_load_finish
disk_load_error:
call print_nextline
mov bx, STR_ERROR
call print_string
call print_nextline
jmp $
disk_load_finish:
call print_nextline
mov bx, STR_DONE
call print_string
call print_nextline
popa
ret
;; here we hold the lba addr
lba_adr:
dw 0x10 ; size of packet ( 16 byte)
dw 16 ; number of sectors to read
; target is 0x7e00
dw 0x7e00 ; target addr. offset
dw 0x0000 ; target addr. sector
dd 1 ; first sector to read
dd 0
|
