Linux 内核模块hello world

hello.c:

#include <linux/module.h>
#include <linux/init.h> 
#include <linux/moduleparam.h>


#define DRIVER_AUTHOR "LeslieChu"
#define DRIVER_DESC "test hello module"
#define VERSION "1.0.0"
#define ALIAS  "HeiMod"
#define LICENSE "GPL"

/*导出模块变量*/
int abc = 3;
int i = 0;
module_param(abc,int,S_IRUGO);

/*定义模块信息，通过modinfo查看*/
MODULE_LICENSE(LICENSE);
MODULE_AUTHOR(DRIVER_AUTHOR );        
MODULE_DESCRIPTION(DRIVER_DESC );    
MODULE_VERSION(VERSION);
MODULE_ALIAS(ALIAS);

/*加载模块*/
static int __init first_init (void)
{
    printk("the first mode insmod\n");
    for(i=0;i<abc;i++)
        printk("the i is : %d\n",i);
    return 0;
}

/*导出模块函数符号*/
static void haha(void)
{
    for(i=0;i<abc;i++)
    printk("+++++i=%d\n",i);
    }

/*卸载模块*/
static void __exit first_exit (void)
{
    printk("the first mode rmmod\n");
}

/*注册模块*/
module_init(first_init);
module_exit(first_exit);
EXPORT_SYMBOL(haha);  

Makefile:

KERNELDIR=/usr/src/linux-headers-3.2.0-30-generic
#/usr/src/linux-headers-$(uname -r)
PWD:=$(shell pwd)
obj-m:=hello.o
default:
	make -C $(KERNELDIR) M=$(PWD) modules
clean:
	rm -rf *.o  .cmd *.ko *.mod.c .tmp_versions *.order  *.sym*

安装 模块：insmod hello.ko
卸载模块: rmmod hello
查看模块安装卸载的log：tail /var/log/kernel.log -n 10