asm sum

section .data
    prompt1 db 'Enter first number: ', 0
    prompt1_len equ $ - prompt1
    prompt2 db 'Enter second number: ', 0
    prompt2_len equ $ - prompt2
    result_msg db 'The sum is: ', 0
    result_msg_len equ $ - result_msg
    newline db 0xa

section .bss
    num1 resb 6        ; Reserve 6 bytes for first number string
    num2 resb 6        ; Reserve 6 bytes for second number string
    sum resb 6         ; Reserve 6 bytes for sum string

section .text
    global _start

_start:
    ; Print first prompt
    mov eax, 4
    mov ebx, 1
    mov ecx, prompt1
    mov edx, prompt1_len
    int 0x80

    ; Read first number
    mov eax, 3
    mov ebx, 0
    mov ecx, num1
    mov edx, 6
    int 0x80

    ; Print second prompt
    mov eax, 4
    mov ebx, 1
    mov ecx, prompt2
    mov edx, prompt2_len
    int 0x80

    ; Read second number
    mov eax, 3
    mov ebx, 0
    mov ecx, num2
    mov edx, 6
    int 0x80

    ; Convert string to integer and add
    mov esi, num1
    call atoi          ; Convert first number to integer (result in eax)
    mov ebx, eax       ; Save first number in ebx
    mov esi, num2
    call atoi          ; Convert second number to integer (result in eax)
    add eax, ebx       ; Add the numbers

    ; Convert result back to string
    mov esi, sum
    call itoa

    ; Print result message
    mov eax, 4
    mov ebx, 1
    mov ecx, result_msg
    mov edx, result_msg_len
    int 0x80

    ; Print sum
    mov eax, 4
    mov ebx, 1
    mov ecx, sum
    mov edx, 6
    int 0x80

    ; Print newline
    mov eax, 4
    mov ebx, 1
    mov ecx, newline
    mov edx, 1
    int 0x80

    ; Exit program
    mov eax, 1
    mov ebx, 0
    int 0x80

; Function to convert ASCII string to integer
atoi:
    xor eax, eax    ; Zero out eax
    xor ebx, ebx    ; Zero out ebx
.next_digit:
    mov bl, [esi]   ; Get next character
    cmp bl, 0xa     ; Check for newline
    je .done
    cmp bl, 0x20    ; Check for space
    je .done
    sub bl, '0'     ; Convert ASCII to number
    imul eax, 10    ; Multiply current number by 10
    add eax, ebx    ; Add new digit
    inc esi         ; Move to next character
    jmp .next_digit
.done:
    ret

; Function to convert integer to ASCII string
itoa:
    push esi        ; Save esi
    add esi, 5      ; Point to end of buffer
    mov byte [esi], 0xa ; Add newline at end
    mov ebx, 10     ; Divisor
.next_digit:
    dec esi         ; Move back one position
    xor edx, edx    ; Clear edx for division
    div ebx         ; Divide eax by 10
    add dl, '0'     ; Convert remainder to ASCII
    mov [esi], dl   ; Store ASCII digit
    test eax, eax   ; Check if quotient is zero
    jnz .next_digit ; If not zero, continue
    pop esi         ; Restore esi
    ret