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me239



Joined: 06 Jan 2011
Posts: 200
me239
Hello everybody! I just got done writing some more code to execute another program under my OS, but I keep running into the same problem. The code is identical to my bootloader. What's wrong with it?
Code:
progornot:
    mov ax, 0003
    int 10h
    mov         si, buff
    mov         di, filen
    call        parsefat
    xor     cx, cx
        xor     dx, dx
        mov     ax, 20h
        mul     word[RootEntries]
        div     word[BytesPerSector]
        xchg    cx, ax
        mov     al, byte[NumberofFATs]
        mul     word[SectorsPerFAT]
        add     ax, word[ReservedSectors]
        mov     word[datasector], ax
        add     word[datasector], cx
        mov     bx, 0x0200
        push    0
        pop     es
        call    ReadSectors
        mov     ax, 0e32h
        int     10h
        mov     cx, word[RootEntries]
        mov     di, 200h
loop1:
        push    cx
        mov     cx, 11
        mov     si, filen
        push    di
        rep     cmpsb
        pop     di
        jz      LoadFat
        add     di, 32d
        loop    loop1
        jmp     fail
LoadFat:
        mov     ax, 0e32h
        int     10h
        mov     dx, word[di+1ah]
        mov     word[cluster], dx
        xor     ax, ax
        mov     al, [NumberofFATs]
        mul     word[SectorsPerFAT]
        mov     cx, ax
        mov     ax, word[ReservedSectors]
        mov     bx, 200h
        call    ReadSectors
        mov     ax, 0e33h
        int     10h
        mov     ax, 500h
        mov     es, ax
        xor     bx, bx
        push    bx
LoadImage:
        mov     ax, word[cluster]
        pop     bx
        call    ClusterLBA
        xor     cx, cx
        mov     cl, byte[SectorsPerCluster]
        call    ReadSectors
        push    bx
        mov     ax, word[cluster]
        mov     cx, ax
        mov     dx, ax
        shr     dx, 1
        add     cx, dx
        mov     bx, 200h
        add     bx, cx
        mov     dx, word[bx]
        test    ax, 1
        jnz     odd_cluster
even_cluster:
        and     dx, 0000111111111111b
        jmp     done2
odd_cluster:
        shr     dx, 4
done2:
        mov     word[cluster], dx
        cmp     dx, 0ff0h
        jb      LoadImage
exectute:
        push    500h
        push    0
        retf
fail:
        ;clc
        ret
        ;mov     ax, 0e46h
        ;int     10h
        ;xor     ax, ax
        ;int     16h
        ;hlt
        ;jmp     $
ReadSectors:
        mov     di, 5
sectloop:
        push    ax
        push    bx
        push    cx
        call    LBACHS
        mov     ah, 02
        mov     al, 1
        mov     ch, byte[absolutetrack]
        mov     cl, byte[absolutesector]
        mov     dh, byte[absolutehead]
        mov     dl, byte[DriveNumber]
        int     13h
        jnc     success
        xor     ax, ax
        int     13h
        dec     di
        pop     cx
        pop     bx
        pop     ax
        jnz     sectloop
        int     18h
success:
        mov     al, 'S'
        mov     ah, 0eh
        int     10h
        pop     cx bx ax
        add     bx, word[BytesPerSector]
        inc     ax
        loop    ReadSectors
        ret
ClusterLBA:
        sub     ax, 2
        xor     cx, cx
        mov     cl, byte[SectorsPerCluster]
        mul     cx
        add     ax, word[datasector]
        ret
LBACHS:
        xor     dx, dx
        div     word[SectorsPerTrack]
        inc     dl
        mov     byte[absolutesector], dl
        xor     dx, dx
        div     word[HeadsPerCylinder]
        mov     byte[absolutehead], dl
        mov     byte[absolutetrack], al
        ret    
Post 06 Jun 2011, 06:41
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