Linux Kernel custom module build skips module

Question

I'm trying to cross-compile (arm64) a custom module on my linux box. So what I did so far is:

• install the target Kernel sources
• install the cross-compiler
• enable module and build the Kernels with the cross-compiler. So far, so good, at the end I have an "Image" file correctly built

Now, I'm trying to build my module. I move in the folder where I have the sources. This is the Makefile:

bj-m := my_module.o
PWD := $(shell pwd)
DEBUG := 1
my_module-objs += my_module_core.o my_module_utils.o
ccflags-y += -O2 -Wall -DDEBUG

all:
        make ARCH=arm64 CROSS_COMPILE=$(CROSS) -C $(KERNEL) M=$(PWD) modules

Then I try to run the build with

make KERNEL=/tmp/linux-kernel-src/ CROSS=aarch64-linux-gnu-

and I get this result:

make[1]: Entering directory '/tmp/linux-kernel-src'
  Building modules, stage 2.
  MODPOST 0 modules
make[1]: Leaving directory '/tmp/linux-kernel-src'

So it looks like I have no errors, but the build process is just skipping all the files contained in my current folder which should be compiled and nothing happens.

I think I'm missing something obvious...but I'm not catching what...do you have any idea?

I saw another post with a very similar issue (Building kernel module), but this had a square bracket in the path and this is not my case.

Thanks a lot!

Answer 1

OK, I'm officially stupid! I found it out, it was just missing "o" at the beginning of the Makefile

:-(

obj-m := my_module.o

Sorry for this!