lab2asm

SYSEXIT = 1
SYSREAD = 3
SYSWRITE = 4

STDIN = 0
STDOUT = 1

SYSCALL = 0x80
EXIT_SUCCESS = 0

MAX_INPUT_SIZE = 0xFF
LENGTH_SIZE = 0x01

.align 32

.data
    dataSize: .byte 0x00
    readingCounter: .byte 0x00
    readingAflag: .byte 0x01
    outputBuffer: .byte 0x00

.bss
    .lcomm numberA, MAX_INPUT_SIZE
    .lcomm numberB, MAX_INPUT_SIZE

.text

.global _start

_start:
    # dbg
    mov $0, %rax
    mov $dataSize, %eax

    # wczytanie dlugosci danych
    mov $SYSREAD, %eax
    mov $STDIN, %ebx
    mov $dataSize, %ecx
    mov $LENGTH_SIZE, %edx

    int $SYSCALL

    # wczytanie liczby A
    mov (dataSize), %al
    mov %al, (readingCounter)

    mov $numberA, %ecx
    # mov $1, %r14 # counter to read numberA then numberB and jump further
loadingLoop:
    cmpb $0, (readingCounter)
    je afterLoadingLoop

    mov $SYSREAD, %eax
    mov $STDIN, %ebx
    mov $1, %edx

    int $SYSCALL

    decb (readingCounter)
    add $1, %ecx
    jmp loadingLoop

afterLoadingLoop:
    cmpb $0, (readingAflag) # meaning data is loaded
    je dataProcessing
    decb (readingAflag)

    mov (dataSize), %al
    mov %al, (readingCounter)
    mov $numberB, %ecx
    jmp loadingLoop

dataProcessing:
    #add
    clc
    lahf
    mov $0, %ecx
addingLoop:
    cmp (dataSize), %ecx
    je end

    movb numberA(,%ecx,1), %al
    sahf
    adcb numberB(,%ecx,1), %al
    lahf
    movb %al, (outputBuffer)

    mov $SYSWRITE, %eax
    mov $STDOUT, %ebx
    mov $outputBuffer, %ecx
    mov $1, %edx

    int $SYSCALL

    inc %ecx

    jmp addingLoop


end:
    mov $SYSEXIT, %eax
    mov $EXIT_SUCCESS, %ebx

    int $SYSCALL