Hello, world：linux 内核模块版

//hello.c


#include <linux/init.h>
#include <linux/module.h>
MODULE_LICENSE("Dual BSD/GPL");

static int hello_init(void)
{
    printk(KERN_ALERT "Hello world, zieckey!\n");
    return 0;
}

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

module_init(hello_init);
module_exit(hello_exit);

# Makefile
ifneq ($(KERNELRELEASE),)
  obj-m := -DEXPORT_SYMTAB
  obj-m := hello.o
else


# your kernel dir


KERNELDIR ?= /usr/src/kernels/2.6.21-1.3194.fc7-i686
PWD := $(shell pwd)
default:
    $(MAKE) -C $(KERNELDIR) M=$(PWD) modules
clean:
    rm *.o *.mod.c *.symvers *.ko
endif