#kernel build system and can use its lanauge
ifneq($(KERNELRELEASE),)
 obj-m:=helloworld.o
else
 KDIR:= /lib/modules/2.6.33.3-85.fc13.i686/build
all:
 make -C $(KDIR) M=$(PWD) modules
clean:
 rm -f *.ko *.o *.mod.o *.mod.c *.symvers
endif

错误是：

makefile:2:*** missing separator . stop

但对于ifneq($(KERNELRELEASE),),如果我之前添加了一个标签,我会收到另一个错误：

makefile:2: ***commands commence before first target. stop