Linux kernel module example

library.c

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

MODULE_LICENSE("GPL");

static int hello_init(void) {
    printk(KERN_INFO "Goodbye, cruel world!\n");
    return 0;
}
 
static void hello_exit(void) {
    printk(KERN_INFO "Goodbye once more, cruel world!\n");
}
 
module_init(hello_init);
module_exit(hello_exit);

Makefile

obj-m := library.o
 
default:
	$(MAKE) -C /home/matwey/lab/linux/ M=$(PWD) modules
 
builtin:
	$(MAKE) -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
 
clean:
	$(MAKE) -C /home/matwey/lab/linux/ M=$(PWD) clean