汇编MOVS指令

<pre><code class=”lang-bash”>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
</code></pre>