Assembly LanguageI Arithmetic Operations 4 Create your own a

Assembly Language–I (Arithmetic Operations)

4. Create your own arithmetic example and code it in Assembly language.

In all the above problems:

1. Present, in the write-up, the problem and the Assembly--Code

2. Give, in the write-up, the result (printScreen)

3. Discuss the results

Solution

The following example 3 and 4 digits, store the digits in the EAX and EBX

register, respectively, add the values, store the result in a memory location

\'sum\' and finally display the result.

a. Program in Assembly Language:

section   .text
   global _start    ;must be declared for using gcc
  
_start:             ;tell linker entry point
   mov   eax,\'3\'
   sub     eax, \'0\'
  
   mov    ebx, \'4\'
   sub     ebx, \'0\'
   add    eax, ebx
   add   eax, \'0\'
  
   mov    [sum], eax
   mov   ecx,msg  
   mov   edx, len
   mov   ebx,1   ;file descriptor (stdout)
   mov   eax,4   ;system call number (sys_write)
   int   0x80   ;call kernel
  
   mov   ecx,sum
   mov   edx, 1
   mov   ebx,1   ;file descriptor (stdout)
   mov   eax,4   ;system call number (sys_write)
   int   0x80   ;call kernel
  
   mov   eax,1   ;system call number (sys_exit)
   int   0x80   ;call kernel
  
section .data
   msg db \"The sum is:\", 0xA,0xD
   len equ $ - msg
   segment .bss
   sum resb 1

b. Output on the screen

   The sum is:
   7

c. Performed sum operation of 3 and 4 and got the 7 as result.