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

 obj-m += hello.o
 obj-m += chrdev1.o
 obj-m += chrdev2.o
 obj-m += chrdev3.o
 obj-m += chrdev4.o

 modules:
	 $(MAKE) -C $(KERNAL_DIR) M=$(PWD) modules
	 @make clear

 clear:
	 @rm -f *.o *.cmd *.mod *.mod.c 
	 @rm -rf *~ core .depend .tmp_versions Module.symvers modules.order -f
	 @rm -f .*.cmd .*.o.d

 clean:
	 @rm -f *.ko