Hi i every one i am new to linux kernel programming .I am participating in Eudyptula Challenge .Recently i submitted my solutions to Task 01 but i gives me reply like the below "Please read the requirements for the Makefile and allow the module to be built against any kernel source tree on the filesystem, not just those kernels that happened to be installed in /lib/ at some point in time." And my make file is like this ifneq ($(KERNELRELEASE),) obj-m += helloworld.o else default: make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules clean: make -C /lib/modules/$(shell uname -r)/bulid M=$(PWD) clean end So can any please tell me how to allow the module to be built against any kernel source tree on the filesystem? or can any one pleae tell me what does it mean? Thank you