Blurr filter asm

section .text
    global _start

_start:

    call openFileIn         ;open the org image
    call readFromFileIn     ;read the data
    call closeFileIn        ;close file

    call openFileOut        ;open output file
    call writeToFile        ;write the data in data
    call closeFileOut       ;close file

    call exitProg           ;exit process

openFileIn:
    ;opening the file roller1.raw
    mov eax, 5
    mov ebx, fileName
    mov edx, 0777
    int 0x80

    mov [fd_in], eax    ;get pointer to indexbuffer
    ret

openFileOut:
    ;opening the file roller1.raw
    mov eax, 5
    mov ebx, outName
    ;mov ecx, 1
    mov edx, 0777
    int 0x80

    mov [fd_out], eax   ;get pointer to indexbuffer
    ret

writeToFile:
    ;1. Put sys_write(), 4, in EAX
    ;2. Put fileDesc in EBX
    ;3. Put the pointer to data in ECX
    ;4. Put buffer size of data in EDX
    ;5. call kernel

    ;returns the actual nr of bytes written in EAX

    ;mov ecx, [info + 2]
    ;mov [blurr], ecx

    ;mov ax, [info + 2]
    ;movzx eax, ax
    ;mov bx, [info + 3]
    ;movzx ebx, bx

    ;d6 + d5 = 1AB
    ;add eax, ebx
    ;mov [blurr], eax

    call blurrTopRow


    ;mov eax, 4
    ;mov ebx, [fd_out]
    ;mov ecx, info
    ;mov edx, IMAGE_SIZE
    ;int 0x80



    mov eax, 4
    mov ebx, [fd_out]
    mov ecx, blurr
    mov edx, 1
    int 0x80

    ret

blurrTopRow:
    ;from 0 - 251 there will be no pixels above the active pixel

    ;first pixel
    ;set sum to 0
    ;mov [sum], byte 0

    ;set ah to 0 to be sure that no other values changes the byte
    ;save byte in al, ax should be [0000](ah) value(al)
    mov ah, byte 0
    mov al, byte [info + 0]

    ;store sum all pixels in sum, divition will be done here
    add [sum], ax

    ;add pixel beside it (1)
    ;mov ah, byte 0
    mov al, byte [info + 1]

    ;add the value to sum
    ;add [sum], ax    If i add this value, the program stops working


    ;divsion here, edx has to be 0

    ;add the pixels below the first pixel
    ;move data to the first 8-bits
    mov ah, 0
    mov al, byte [info + 251]
    add [sum], ax

    ;set the last 8-bits in the 16-bit register (ax) to 0
    ;to avoid messing up the value
    mov ah, 0
    mov al, byte [info + 252]
    add [sum], ax

    mov eax, 0
    mov ax, [sum]

    mov ebp, 4
    mov edx, 0
    idiv ebp

    mov [blurr], al

    ret

readFromFileIn:
    ;Process: Read from file
    ;1. put the system call sys_read() number 3 in EAX
    ;2. Put the file descriptor in the EBX register
    ;3. Put the pointer to the input buffer in the ECX register
    ;4. Put the buffer size, in EDX
    ;5. call kernel


    ;the system call returns the number of bytes rad in the EAX
    ;register, in case of error code is in the EAX register

    ;read the file
    mov eax, 3
    mov ebx, [fd_in]    ;pointer to inputBuffer
    mov ecx, info       ;buffer size
    mov edx, IMAGE_SIZE
    int 0x80

    ret

readFromFileOut:
    ;Process: Read from file
    ;1. put the system call sys_read() number 3 in EAX
    ;2. Put the file descriptor in the EBX register
    ;3. Put the pointer to the input buffer in the ECX register
    ;4. Put the buffer size, in EDX
    ;5. call kernel


    ;the system call returns the number of bytes rad in the EAX
    ;register, in case of error code is in the EAX register

    ;read the file
    mov eax, 3
    mov ebx, [fd_in]    ;pointer to inputBuffer
    mov ecx, info       ;buffer size
    mov edx, IMAGE_SIZE
    int 0x80

    ret

printBuffer:
    ;1. put syscall sys_write to EAX
    ;2. put an argument in EBX
    ;3. put the data into ECX
    ;4. put the size of the segment in EDX
    ;5. call kernel
    mov eax, 4
    mov ebx, 1
    mov ecx, info
    mov edx, IMAGE_SIZE

    int 0x80
    ret

closeFileIn:
    ;Closing a file
    ;1.Put the system call sys_close(), 6, in the EAX register
    ;2.Put the file descriptor in the EBX register
    mov EAX, 6
    mov EBX, [fd_in]
    int 80h

    ;the system call returns error code in eax
    ret

closeFileOut:
    ;Closing a file
    ;1.Put the system call sys_close(), 6, in the EAX register
    ;2.Put the file descriptor in the EBX register
    mov EAX, 6
    mov EBX, [fd_out]
    int 80h

    ret

exitProg:
    ;call system exit
    mov eax, 1
    int 0x80

section .data
fileName db 'roller1.raw', 0 ;glöm förfan inte nollan
;lenfFileName equ $-fileName ; adress
outName db 'roller2.raw', 0
;lenOutName equ $-fileName
IMAGE_SIZE equ 64256

section .bss
fd_out resb 1
fd_in resb 1
info resb 64256
blurr resb 64256
sum resw 1