Minimalistic kernel module

mykmod: Makefile

obj-m += mykmod.o

all:
	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

clean:
	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

mykmod: mykmod.c

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

static int __init mykmod_init(void)
{
	printk(KERN_INFO "Hello World\n");
	return 0;
}

static void __exit mykmod_exit(void)
{
	printk(KERN_INFO "Good bye World\n");
}

module_init(mykmod_init);
module_exit(mykmod_exit);