１.笔者刚学linux驱动开发，看到网上很多说要现建立内核树。在笔者到官网下载源码时，源码下面有如下说明： If you are simply trying to build third-party modules for your kernel, you do not want this package. Install the appropriate linux-headers package instead. 意思是，如果你只是想为内核编译第三方的模块，那么，你不需下载此源码包。安装内核头文件包或许会更适合你。
２.如果你的ubuntu是保持更新的，你的系统是安装有内核头文件包的，不信你到/usr/src目录下查看，是不是有linux-headers-2.6.xx-xx-generic的文件夹呢，呵呵。我现在可以说，你可以在此开发你的驱动程序了。
３.笔者也是初学，有见笑的，大家多指正，emial： tonychen123@qq.com； 转载注明出处：http://sites.google.com/site/tonychen123site，作者：tony
４.环境本来就有了看来，所以我的文章，本来应该叫驱动开发最简单例子才合适……另，我要示例的是最简单，也是个最没用的驱动演示，名字叫tst，包含源码tst.c及makefile文件，编译出来的模块名叫tst.ko
Ｃontent：
１）建立你的实验目录并创建tst.c源文件：
代码： 全选
tony@ubuntu:~/mini2440$ mkdir mtst; cd mtst
tony@ubuntu:~/mini2440/mtst$ vim tst.c
＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
/*
* File: tst.c
*
* A very simple kernel module demo
*
* Copyright 2009, Tony, <tonychen123@qq.com>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation;
*
*/
#include <linux/module.h> /* Needed by all modules */
#include <linux/kernel.h> /* Needed for KERN_INFO */
#include <linux/init.h> /*Needed for the macros */
static int __init tst_start(viod)
{
printk(KERN_INFO "Loading my so simple module...\n");
printk(KERN_INFO "I love Ubuntu\n");
return 0;
}
static void __exit tst_end(void)
{
printk(KERN_INFO "From tst module: Goodbye, Tony.\n");
}
module_init(tst_start);
module_exit(tst_end);
/* end */２）创建Ｍakefile文件：
代码： 全选
tony@ubuntu:~/mini2440/mtst$ vim Makefile
=================================================================
obj-m = tst.o
K_DIR = $(shell uname -r)
PWD = $(shell pwd)
all:
make -C /lib/modules/$(K_DIR)/build M=$(PWD) modules
clean:
make -C /lib/modules/$(K_DIR)/build M=$(PWD) clean
# end #代码： 全选
tony@ubuntu:~/mini2440/mtst$ sudo make Ｎote：好像要用sudo才行！
make -C /lib/modules/2.6.28-12-generic/build M=/home/tony/mini2440/mtst modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.28-12-generic'
CC [M] /home/tony/mini2440/mtst/tst.o
/home/tony/mini2440/mtst/tst.c:19: warning: function declaration isn’t a prototype
Building modules, stage 2.
MODPOST 1 modules Ｎote：生成一个module！
CC /home/tony/mini2440/mtst/tst.mod.o
LD [M] /home/tony/mini2440/mtst/tst.ko
make[1]: Leaving directory `/usr/src/linux-headers-2.6.28-12-generic'
tony@ubuntu:~/mini2440/mtst$
代码： 全选
tony@ubuntu:~/mini2440/mtst$ su Ｎote：加载模块要有root特权
Password:
root@ubuntu:/home/tony/mini2440/mtst# insmod tst.ko Ｎote：加载模块要有root特权
root@ubuntu:/home/tony/mini2440/mtst# dmesg | tail
[ 25.464531] r8169: eth0: link up
[ 25.464534] r8169: eth0: link up
[ 54.931357] UDF-fs: No VRS found
[ 54.981587] ISO 9660 Extensions: Microsoft Joliet Level 3
[ 55.013712] ISOFS: changing to secondary root
[ 2932.746291] module init
[ 3138.097884] Cleanup module
[ 7444.574136] tst: module license 'unspecified' taints kernel.
[ 7444.575117] Loading my so simple module... Ｎote：注意这两行，就是我们的模块加载信息
[ 7444.575121] I love Ubuntu
root@ubuntu:/home/tony/mini2440/mtst# lsmod | grep tst
tst 9344 0
root@ubuntu:/home/tony/mini2440/mtst# rmmod tst.ko
root@ubuntu:/home/tony/mini2440/mtst# lsmod | grep tst
root@ubuntu:/home/tony/mini2440/mtst# dmesg | tail
[ 25.464534] r8169: eth0: link up
[ 54.931357] UDF-fs: No VRS found
[ 54.981587] ISO 9660 Extensions: Microsoft Joliet Level 3
[ 55.013712] ISOFS: changing to secondary root
[ 2932.746291] module init
[ 3138.097884] Cleanup module
[ 7444.574136] tst: module license 'unspecified' taints kernel.
[ 7444.575117] Loading my so simple module...
[ 7444.575121] I love Ubuntu
[ 7559.570808] From tst module: Goodbye, Tony. Ｎote：呵呵，模块正常卸载
root@ubuntu:/home/tony/mini2440/mtst# /* end Ｂye ~ */
