【Linux设备驱动程序（第三版）】----模块参数

 【Linux设备驱动程序（第三版）】----模块参数

HelloWorldParam.c

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

MODULE_LICENSE("Dual BSD/GPL");

static char *whom = "world";
static int howmany = 1;

module_param(whom, charp, S_IRUGO);
module_param(howmany, int, S_IRUGO);

static int __init hello_init(void)
{
	printk(KERN_ALERT "Hello, World!\n");
	int i;
	for( i = 0; i < howmany; i++)
		printk(KERN_ALERT "(%d) Hello, %s\n", i, whom);
	return 0;
}

static void __exit hello_exit(void)
{
	printk(KERN_ALERT "Goodbye,world!\n");
}

module_init(hello_init);
module_exit(hello_exit);

Makefile

obj-m:= HelloWorldParam.o
modules-objs:= HelloWorldParam.o

KDIR:= /usr/src/linux-headers-2.6.31-14-generic/
PWD:= $(shell pwd)

default:
	make -C $(KDIR) M=$(PWD) modules
clean:
	rm -rf *.ko *.mod.c *.mod.o *.o *.markers *.symvers *.order

装载

insmod HelloWordParam howmany=10 whom="Tom"

查看Log(dmesg)

[89611.281829] Hello, World!
[89611.281833] (0) Hello, Tom
[89611.281834] (1) Hello, Tom
[89611.281835] (2) Hello, Tom
[89611.281836] (3) Hello, Tom
[89611.281837] (4) Hello, Tom
[89611.281838] (5) Hello, Tom
[89611.281840] (6) Hello, Tom
[89611.281841] (7) Hello, Tom
[89611.281842] (8) Hello, Tom
[89611.281843] (9) Hello, Tom