Questions about adding single driver modules

Hi,

I am trying to get the official Hardkernel RTC board working. This board requires the driver module "rtc-pcf8563.ko" which is not included in the image by default.

So I went through the kernel compiling tutorial, to add this module to my "own" kernel, and copy it over to my main system.

First problem: the kernel version was different: main system is at version 4.18.8, while the module was compiled for 4.18.20. I could fix this by myself be defining the KERNELBRANCH='tag:v4.18.8'.

Second problem: the "linux family" has changed. My main system is at Armbian version 5.60 for family "odroidc2". The driver module was compiled for "meson64". Until now, I could not fix this.

So when I try to load this module, this fails with "Exec format error".

So basically three questions come to my mind:

1. What can I do to fix the problem with the different linux families by myself?
2. Is there another way to compile just a single driver module for a specific kernel version for a specific board/linux family? Or is this just the way to go to compile "everything at once"?
3. What about adding the driver module for the PCF8563 to the kernel by default?

Greetings,

Jojo