Simple Addition Assembly Language Program

Question

Hi Friends,

I am trying to compile the Assembly code it has an unknown error.
I just want it to ask the user to put an input for digits to add them n gives a correct output.

SYS_EXIT equ 1
SYS_READ equ 3
SYS_WRITE equ 4
STDIN equ 0
STDOUT equ 1

segment .data

msg1 db "Enter a digit ", 0xA,0xD
len1 equ $- msg1

msg2 db "Please enter a second digit", 0xA,0xD
len2 equ $- msg2

msg3 db "The sum is: "
len3 equ $- msg3

segment .bss

num1 resb 2
num2 resb 2
res resb 1

section .text
global _start ;must be declared for using gcc

_start: ;tell linker entry point
mov eax, SYS_WRITE
mov ebx, STDOUT
mov ecx, msg1
mov edx, len1
int 0x80

mov eax, SYS_READ
mov ebx, STDIN
mov ecx, num1
mov edx, 2
int 0x80

mov eax, SYS_WRITE
mov ebx, STDOUT
mov ecx, msg2
mov edx, len2
int 0x80

mov eax, SYS_READ
mov ebx, STDIN
mov ecx, num2
mov edx, 2
int 0x80

mov eax, SYS_WRITE
mov ebx, STDOUT
mov ecx, msg3
mov edx, len3
int 0x80

; moving the first number to eax register and second number to ebx
; and subtracting ascii '0' to convert it into a decimal number

mov eax, [num1]
sub eax, '0'

mov ebx, [num2]
sub ebx, '0'

; add eax and ebx
add eax, ebx
; add '0' to to convert the sum from decimal to ASCII
add eax, '0'

; storing the sum in memory location res
mov [res], eax

; print the sum
mov eax, SYS_WRITE
mov ebx, STDOUT
mov ecx, res
mov edx, 1
int 0x80

exit:

mov eax, SYS_EXIT
xor ebx, ebx
int 0x80

Answer 1

What error do you get?