; -- Assembly Calculator ---------------------------------------
;								
; This project is a practice for my low-level programming study	
; --------------------------------------------------------------

; x86_64 linux syscalls table
;
; 0: read	(needs fd, where to save and length)
; 1: write 	(needs fd, string and string length)
; 60: exit	(needs status code)

global _start

section .bss
    fnum resb 128
    snum resb 128

; "variables" read-only
section .rodata
    title db "Assembly Calculator v1.0 by /synt-xerror", 0xA
    titlel equ $ - title
    
    fir db 0xA, "Enter the first number: "
    firl equ $ - fir
    
    sec db "Enter the second number: "
    secl equ $ - sec

section .text

_start:
    ; print title
    mov rax, 1
    mov rdi, 1
    mov rsi, title
    mov rdx, titlel
    syscall

    ; ask to enter first number
    mov rax, 1
    mov rdi, 1
    mov rsi, fir
    mov rdx, firl
    syscall
    
    ; input to enter the first number
    mov rax, 0
    mov rdi, 0
    mov rsi, fnum
    mov rdx, 128
    syscall

    ; ask to enter second number
    mov rax, 1
    mov rdi, 1
    mov rsi, sec
    mov rdx, secl
    syscall

    ; input to enter the second number
    mov rax, 0
    mov rdi, 0
    mov rsi, snum
    mov rdx, 128
    syscall

    ; exit
    mov rax, 60
    mov rdi, 0
    syscall