# This is a standard makefile for building a kernel module.
# It looks a bit backwards compared to a normal makefile, but that's because
# the kernel supplies its own sub-makefile that we use to build the module.
# 
# The M= option tells the kernel's makefile where to find the module's source
# files, and the -C option sets the context directory for make.
#
# The obj-m variable tells the kernel's makefile what the module's object file
# should be called. In this case, it's demo_module.o. This is how the sub-makefile
# infers the name of the module's source file.
# 
# This build is highly sensitive to compiler version, and requires the system gcc
# to be the same version as the gcc that built the current kernel.

obj-m = demo_module.o

all:
	make -C /lib/modules/$(shell uname -r)/build/ M=$(PWD) modules

clean:
	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean