linux内核编程helloworld（中级）

传入参数

[root@bogon modules]# cat first.c

#include<linux/kernel.h>

#include<linux/stat.h>

#include<linux/moduleparam.h>

#include<linux/init.h>

#include<linux/module.h>

static short int a=1;

static int b=2;

static long int c=3;

static char *d="bp";

static int myintArray[2]={-1,-1};

static int arr_argc=0;

module_param(a,short,S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP);

MODULE_PARM_DESC(a,"a short integer");

module_param(b,int ,S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);

MODULE_PARM_DESC(b,"an integer");

module_param(c,long,S_IRUSR);

MODULE_PARM_DESC(c,"a long integer");

module_param(d,charp,0000);

MODULE_PARM_DESC(d,"a char string");

module_param_array(myintArray,int,&arr_argc,0000);

MODULE_PARM_DESC(myintArray,"an array of integers");

static int __initdata hellodata=3;

static int __init bp_init(void){

    int i;

    printk(KERN_ALERT "hello world\n");

    printk(KERN_ALERT "a is a short integer:%d\n",a);

    printk(KERN_ALERT "b is a integer:%d\n",b);

    printk(KERN_ALERT "c is a long integer:%d\n",c);

    printk(KERN_ALERT "d is a string:%s\n",d);

    for(i=0;i<(sizeof(myintArray)/sizeof(int));i++)

        printk(KERN_ALERT "myintArray[%d] is %d\n",i,myintArray[i]);

    printk(KERN_ALERT   "\nhi,this is bp %d \n",hellodata);

    return 0;

}

static void __exit bp_exit(void){

    printk(KERN_ALERT   "\ngoobye bp\n");

}

module_init(bp_init);

module_exit(bp_exit);

MODULE_LICENSE("GPL");

MODULE_AUTHOR("by bp");

MODULE_DESCRIPTION("this is test of bp");

MODULE_SUPPORTED_DEVICE("testdevice");

[root@bogon modules]# cat Makefile

obj-m=first.o

default:

    make -C /usr/src/kernels/`uname -r` M=$(PWD) modules

clean:

    make -C /usr/src/kernels/`uname -r` M=$(PWD) clean

[root@bogon modules]# make

make -C /usr/src/kernels/`uname -r` M=/root/modules modules

make[1]: Entering directory `/usr/src/kernels/3.10.0-514.el7.x86_64'

  Building modules, stage 2.

  MODPOST 1 modules

make[1]: Leaving directory `/usr/src/kernels/3.10.0-514.el7.x86_64'

[root@bogon modules]# insmod first.ko a=100

[root@bogon modules]# rmmod first

[root@bogon modules]#

运行效果