Convert the following C program to assembly. Test code checks it. 1 uint16_t u16

Question

Convert the following C program to assembly. Test code checks it. 1 uint16_t u16_a; 2 uint16_t u16_b; 3 uint16_t u16_c; 4 5 void translation_approach_ex_1(void) 6 u16 c = u16 a + u16 b; 7 // End Data .bss First define a variable named_u16_a , then define _u16_b , then define_u16_c, all of which occupy two bytes of memorv. Make all variables visible to C The variable below is used by the test code; you may ignore it u8_test: .space 1 .global _u8_test Code .text Write assembly which implements the C given above Save and run

Explanation / Answer

Assembly code:

segment .bss

u_16_a resb 2
u_16_b resb 2
u_16_c resb 1

section   .text
global _start ;must be declared for using gcc
_start:   ;tell linker entry point
mov   ecx,u_16_a
sub ecx, '0'   
mov    edx, u_16_b
sub edx, '0'   
call sum ;call sum procedure

mov    [u_16_c], eax
mov   ecx, msg  
mov   edx, len
mov   ebx,1   ;file descriptor (stdout)
mov   eax,u_16_a   ;system call number (sys_write)
int   0x80   ;call kernel
   mov   ecx, u_16_c
mov   edx, u_16_b
mov   ebx, 1   ;file descriptor (stdout)
mov   eax, u_16_a ;system call number (sys_write)
int   0x80   ;call kernel
   mov   eax, u_16_b   ;system call number (sys_exit)
int   0x80   ;call kernel
sum:
mov eax, ecx
add eax, edx
add eax, '0'
ret
  
section .data
msg db "The sum is:", 0xA,0xD
len equ $- msg   

segment .bss
u_16_c resb 1

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