交叉编译Makefile

ifneq  ($(KERNELRELEASE),)
obj-m:=test_mod.o
else
KDIR := /home/hdy/Downloads/linux-4.19.77
PWD:=$(shell pwd)
all:                                                                            
    make -C $(KDIR) M=$(PWD) modules
clean:
    rm -f *.ko *.o *.symvers *.o.cmd *.cmd.o .test*
endif

注意KDIR一定要写经过make config之后的内核源码的路径