section .text

   global _start        ;must be declared for using gcc

​

_start:                 ;tell linker entry point

   mov  ecx, len

   mov  esi, s1

   mov  edi, s2

   cld

   rep  movsb

​

   mov  edx,20          ;message length

   mov  ecx,s2          ;message to write

   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

s1 db 'Hello, world!',0 ;string 1

len equ $-s1

​

section  .bss

s2 resb 20              ;destination

​