MBR 어셈블리어와 간단한 해석 03

LBA를 활용하기 위한 int 13 명령어 확인

0000:06E6 mov dl, [bp+00]

0000:06E9 pusha

0000:06EA mov bx, 55AA

0000:06ED mov ah, 41

0000:06EF int 13 ;INT 13

0000:06F1 jb 0729

0000:06F3 cmp bx, AA55

0000:06F7 jne 0729

0000:06F9 test cl, 01

0000:06FC je 0729

0000:06FE popa

해석 : Verify that the int 13 command to leverage the LBA address value works effectively.

 

확장한 int13 명령어를 읽을 수 있으면 LBA 주소값을 불러옵니다

0000:06FF pusha

0000:0700 push 0000

0000:0702 push 0000

0000:0704 push word ptr [bp+0A]

0000:0707 push word ptr [bp+08]

0000:070A push 0000

0000:070C push 7C00

0000:070F push 0001

0000:0711 push 0010

0000:0713 mov ah, 42 ;INT 13

0000:0715 mov si, sp

0000:0717 int 13

0000:0719 popa

0000:071A popa

0000:071B jnb 072B

0000:071D dec di

0000:071E je 072B

0000:0720 xor ah, ah

0000:0722 mov dl, [bp+00]

0000:0725 int 13

0000:0727 jmp 06FF

해석 : Read the bootable 512 bytes and overwrite them at 0:7C00.

In sum, you find a bootable entry in the partition entry table, and then find out if there is anything else that is viable. If there is only one bootable entry, load the boot sector into memory 0:7C00 by referring to the LBA address value.

출처 : Me