Linux内核编程入门的第一个程序

书本再好也难免出错，调试通才是硬道理，运行通才是真正的硬道理。

 

hellomod.c

 

#include <linux/netdevice.h>

#include <linux/kernel.h>

#include <linux/init.h>

 

static int __init lkp_init(void)

{

     printk("<1>Hello,World! from the kernel space...\n");

     return 0;

}

 

static void __exit lkp_cleanup(void)

{

     printk("<1>Goodbye,World! leaving kernel space...\n");

}

module_init(lkp_init);

module_exit(lkp_cleanup);

MODULE_LICENSE("GPL");

Makefile

obj-m += hellomod.o

 

doit

make -C /usr/src/kernels/2.6.18-274.7.1.el5-i686 SUBDIRS=$PWD modules

 

[root@localhost testNic]# ./doit

make: Entering directory `/usr/src/kernels/2.6.18-274.7.1.el5-i686'

  CC [M]  /home/testNic/hellomod.o

  Building modules, stage 2.

  MODPOST

  CC      /home/testNic/hellomod.mod.o

  LD [M]  /home/testNic/hellomod.ko

make: Leaving directory `/usr/src/kernels/2.6.18-274.7.1.el5-i686'

[root@localhost testNic]# insmod hellomod.ko

[root@localhost testNic]# lsmod

Module                  Size  Used by

hellomod                5632  0

[root@localhost testNic]# tail /var/log/messages

Nov  1 01:53:12 localhost kernel: Hello,World! from the kernel space...

[root@localhost testNic]# rmmod hellomod

[root@localhost testNic]# tail /var/log/messages

Nov  1 01:53:12 localhost kernel: Hello,World! from the kernel space...

Nov  1 01:57:14 localhost kernel: Goodbye,World! leaving kernel space...

 

太美妙了！