ubuntu下编译内核模块

在ubuntu下编写内核模块，需要一个源文件和一个makefile文件。
模块源文件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\n");
    return 0;
}

static void hello_exit(void){
    printk(KERN_ALERT "GoodBye,colin!\n");
}

module_init(hello_init);
module_exit(hello_exit);

makefile文件:

# Comment/uncomment the following line to disable/enable debugging
#DEBUG = y


# Add your debugging flag (or not) to CFLAGS
ifeq ($(DEBUG),y)
  DEBFLAGS = -O -g -DSCULL_DEBUG # "-O" is needed to expand inlines
else
  DEBFLAGS = -O2
endif

LDDINC=$(PWD)/../include

EXTRA_CFLAGS += $(DEBFLAGS)
EXTRA_CFLAGS += -I$(LDDINC)

ifneq ($(KERNELRELEASE),)
# call from kernel build system

#scull-objs := main.o pipe.o access.o

obj-m	:= hello.o

else

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

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

endif



clean:
	rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions

depend .depend dep:
	$(CC) $(EXTRA_CFLAGS) -M *.c > .depend


ifeq (.depend,$(wildcard .depend))
include .depend
endif