Commit fd80f6b

cmd_/home/dennis/book_sourcecode/chap01/demodev.ko := ld -r -m elf_x86_64 -T /home/dennis/Linux/linux-3.1.6/scripts/module-common.lds --build-id -o /home/dennis/book_sourcecode/chap01/demodev.ko /home/dennis/book_sourcecode/chap01/demodev.o /home/dennis/book_sourcecode/chap01/demodev.mod.o

/home/dennis/book_sourcecode/chap01/demodev.ko

/home/dennis/book_sourcecode/chap01/demodev.o

obj-m := demodev.o

KERNELDIR := /lib/modules/$(shell uname -r)/build

PWD := $(shell pwd)

default:

$(MAKE) -C $(KERNELDIR) M=$(PWD) modules

clean:

rm -f *.o *.ko *.mod.* *.order *.symvers

set module parameters with below command:

#insmod demodev.ko dolphin=5 demodev_str="hello,world"

#include <linux/module.h>

#include <linux/kernel.h>

static void my_exp_function(void)

{

printk(KERN_INFO "A function exported to the external world...\n");

}

EXPORT_SYMBOL(my_exp_function);

int dolphin;

module_param(dolphin, int, 0);

static char demodev_str[64] = "kernel module:demodev";

module_param_string(demodev_str, demodev_str, sizeof(demodev_str), 0);//(name, string, length, perm)

static int demodev_init(void)

{

printk(KERN_INFO "demodev_init(): dolphin=%d, demodev_str=%s\n", dolphin, demodev_str);

return 0;

}

static void demodev_exit(void)

{

printk(KERN_INFO "demodev_exit()\n");

}

module_init(demodev_init);

module_exit(demodev_exit);

MODULE_LICENSE("GPL");

MODULE_AUTHOR("dennis chen @ AMDLinuxFGL");

MODULE_DESCRIPTION("A simple kernel module as an illustration");