<code asm>
#PURPOSE: Simple program that exits and returns a
#         status code back to the Linux kernel
#
#INPUT:   none
#
#OUTPUT:  returns a status code. This can be viewed
#         by typing
#
#         echo $?
#
#         after running the program
#
#VARIABLES:
#         %eax holds the system call number
#         %ebx holds the return status
#
 .section .data

 .section .text
 .globl _start
_start:
 movl $1, %eax  # this is the linux kernel command
                # number (system call) for exiting
                # a program

 movl $4, %ebx  # this is the status number we will
                # return to the operating system.
                # Change this around and it will
                # return different things to
                # echo $?

 int $0x80      # this wakes up the kernel to run
                # the exit command
</code>
<code bash>
$ as test.s -o test.o
$ ld test.o -o test
$ ./test
$ echo $?
</code>
====== GCC Inline Assembly ======
<code asm>
asm (""
     : 輸出暫存器  // "=r"
     : 輸入暫存器  // "r"
     : 會被修改到的暫存器 (clobber));
</code>
<code  asm>
asm ("nop");

__asm__("movl $1, %eax\n\t"
	 "movl $4, %ebx\n\t"
	 "int $0x80");
</code>
  * [[http://learn.akae.cn/media/ch19s05.html|5. C内联汇编]]
  * [[http://sourceware.org/binutils/docs-2.22/as/index.html|Using as]]
  * [[http://ibiblio.org/gferg/ldp/GCC-Inline-Assembly-HOWTO.html|GCC-Inline-Assembly-HOWTO]]
  * [[http://www.ethernut.de/en/documents/arm-inline-asm.html|ARM GCC Inline Assembler Cookbook]]
====== x86 ======
  * [[http://learn.akae.cn/media/ch18.html|第 18 章 x86汇编程序基础]]
  * [[wp>x86 assembly language]]
  * [[wb>x86 Assembly]]
  * [[http://www.acm.uiuc.edu/sigwin/old/workshops/winasmtut.pdf|Windows Assembly Programming Tutorial]]

Intel (NASM):<code asm>
  mov eax, 4 ; mov 目標 源
</code>

AT&T (GAS):<code asm>
  mov $4, %eax; mov 源 目標
</code>
====== 6502 ======

====== 外部連結 ======
  * [[http://learn.akae.cn/media/ch18.html|第 18 章 x86汇编程序基础]]
  * [[http://tldp.org/HOWTO/Assembly-HOWTO/|Linux Assembly HOWTO]]
  * [[wp>Assembly language]]
  * [[wp>Netwide Assembler]]
    * [[http://www.nasm.us/|The Netwide Assembler]] 
  * [[http://www.ibm.com/developerworks/cn/linux/l-gas-nasm.html|Linux 汇编器：对比 GAS 和 NASM]]
  * [[http://www.ibiblio.org/gferg/ldp/GCC-Inline-Assembly-HOWTO.html|GCC-Inline-Assembly-HOWTO]]
  * [[http://asm.sourceforge.net/articles/linasm.html|Using Assembly Language in Linux]]
  * [[http://www.reversing.be/article.php?story=20051203194931893|Inline Assembly On GCC using Intel Syntax]]