I have the following makefile which is supposed to build procdriver.c and thus output a .ko file. The issue is that even when I delete procdriver.c my makefile seems to be able to build a procdriver.ko file. I would like to try to find out from where it gets the source file it is building every time.TARGET = procdriverobj-m := procdriver.o procdriver-objs+= gpioLib.oKDIR:= /home/pi/myRpi/linuxPWD := $(shell pwd)all: gpioLib.o procdriver.c    echo<<in all    $(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules     rm -r -f .tmp_versions *.mod.c .*.cmd *.o *.symvers gpioLib.o: gpioLib.c gpioLib.h     gcc -c gpioLib.c -o gpioLib.oclean:    make -C $(KDIR) SUBDIRS=$(PWD) cleanThis is the output from the Makefile: http://paste.ubuntu.com/23575533/
How to see which files a Makefile uses?
linux;kernel;make;c