Ohh, I see the pattern I do not like either :D (it is not specific to here but in general).

It is using the common but again not entirely again. And in practice I like having the USEMODULE += boards_common... in the common one too as it somehow defines that the board extends the common one. So let's not rush and see for the root cause first.

I think that somehow none of the common should define board_init but here only board_common_kw41z_init and be called from the main board_init. Here we still have code duplication as both define the led_init code.
Having these generic names somehow goes against the function namespacing rule too.
Do you think it makes sense ?

Would changing to a boards_common_kw41z_init be a valid change here for you ?
Starting a change like this may require a tracking issue to do it everywhere too.

And going like this, even maybe boards should define board_board_name_init. This would be required to allow reusing a board and extend it. (also needs to not define 'board' but 'board_board_name' module and all).

And in practice I like having the USEMODULE += boards_common... in the common one too as it somehow defines that the board extends the common one

The use of USEMODULE += boards_common_... is here to tell the build system that this board also uses the common board_init function. It's like having the common board_init in a shared module that is pulled in when a specific board can use it because it doesn't have specific initializations. So for me it makes more sense as it is now.

Do you think it makes sense ?

I see your point but I'm not sure this should be discussed here.

Would changing to a boards_common_kw41z_init be a valid change here for you ?

I'm not sure what would be the impact in term of code size, while I see the benefits in terms of flexibility. The problem is also that several boards are using the board_init function already, so it will end up in code duplication (several time the same main board_init function instead of only one implemented in one place).

The use of USEMODULE += boards_common_... is here to tell the build system that this board also uses the common board_init function. It's like having the common board_init in a shared module that is pulled in when a specific board can use it because it doesn't have specific initializations. So for me it makes more sense as it is now.

Currently it also says "use led_init" which is in common, and the content on board_init is duplicated.

But it is a different question/topic that touches the way to define boards and common boards in the C part.

Do you think it makes sense ?

I see your point but I'm not sure this should be discussed here.

Indeed it is not the place to discuss it, it was to ask some more background and see long term alternatives.

Would changing to a boards_common_kw41z_init be a valid change here for you ?

I'm not sure what would be the impact in term of code size, while I see the benefits in terms of flexibility. The problem is also that several boards are using the board_init function already, so it will end up in code duplication (several time the same main board_init function instead of only one implemented in one place).

It would still be implemented in one place but would be one more function call

board_init()
{
    board_common_auie_init();
    /* Allows having here my_board_specific_init(); */
} 

Right now, all the kw41z boards using common/kw41z/Makefile.features also use the common Makefile.dep and Makefile.include which is what I needed.

As phynode-kw41z does not use the common/kw41z module, it does not adds the directory in DIRS in its Makefile.

So it makes sense.

I will do a comparison of the reset/flash/debug output.

I get the same output for the variables with master and this PR

DEBUG_ADAPTER_ID=toto BOARD=phynode-kw41z make --no-print-directory -C examples/hello-world/ \
    info-debug-variable-FLASHER \
    info-debug-variable-FFLAGS \
    info-debug-variable-OPENOCD_ADAPTER_INIT \
    info-debug-variable-OPENOCD_PRE_FLASH_CMDS \
    info-debug-variable-INCLUDES \
    info-debug-variable-CPU \
    info-debug-variable-CPU_MODEL
/home/harter/work/git/RIOT/dist/tools/openocd/openocd.sh
flash /home/harter/work/git/RIOT/examples/hello-world/bin/phynode-kw41z/hello-world.elf
-c source [find interface/cmsis-dap.cfg] -c cmsis_dap_serial toto
-c kinetis fcf_source write
-isystem /opt/gcc-arm-none-eabi-7-2018-q2-update/arm-none-eabi/include/newlib-nano -I/home/harter/work/git/RIOT/core/include -I/home/harter/work/git/RIOT/drivers/include -I/home/harter/work/git/RIOT/sys/include -I/home/harter/work/git/RIOT/boards/phynode-kw41z/include -I/home/harter/work/git/RIOT/boards/common/kw41z/include -I/home/harter/work/git/RIOT/cpu/kinetis/include -I/home/harter/work/git/RIOT/cpu/cortexm_common/include -I/home/harter/work/git/RIOT/cpu/cortexm_common/include/vendor -I/home/harter/work/git/RIOT/sys/libc/include
kinetis
mkw41z512vht4

Thanks :)