Access each byte in raw file

section .text
    global _start

_start:

    call openFileIn         ;open the org image
    call readFromFileIn     ;read the data

    ;call printBuffer

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

    MOV ecx, fd_in          ;store the pointer to the data
    INC ecx                 ;increase the counter, i++

    MOV ebx, [ecx]          ;store the value of that adress

    CMP [testWord], ebx     ;I expect ebx to hold 0x00 (one byte size)
    JE printYay             ;If they are equal, print yay to shell

    MOV ecx, ebx            ;store value in ebx in a desperate attempt for
                            ;getting some insight of the value i've got



    ;print out first element in info
    ;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, char
    MOV edx, 1
    int 0x80

    ;The value does not give me any character or symbol in bash when program
    ;is run

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

conditionalTest:
    INC edx
    CMP edx, 10         ;Compare dx with 0
    JLE conditionalTest

    call printYay

    ret

printYay:
    ;output the message
    MOV eax, 4
    MOV ebx, 1
    MOV ecx, yayString
    MOV edx, yayStringLen
    int 0x80

    call exitProg

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


section .bss
fd_out resb 1
fd_in resb 1
info resb 64256

char resb 1


section .data

fileName db 'roller2.raw', 0 ;glöm förfan inte nollan
outName db 'roller3.raw', 0
IMAGE_SIZE equ 64256

yayString db 'Yay', 0
yayStringLen equ $ - yayString

testWord DW 0x00