How to install on a Allwinner A20 (Banana Pi Router)

Hi everybody!

I've tried to install Alpine Linux on my Banana Pi Router, which is built around the Allwinner A20 CPU. What I did so far was:

- formatting an SD card with a FAT32 partition at first and an ext4 partition
- extracted the generic arm image to the FAT32 partition. I got a bunch of errors like ("Can't change file owner to uid 0, gid 0. Operation not permitted").
- copied the dualcore u-boot, as written in the README.txt file

However, I'm out of luck, nothing happened. Then, i took a closer look and found out that there is no generic dtb for the a20 (as well as for any candidate of the banana species). So I tried the DAU approach and just copied a BPI-R1 dtb from one of the Banana Pi router images. It didn't surprised me much that this didn't worked out. However, as I'm not that experienced with the arm architecture, I'm out of Ideas for now. Does anybody have some tips and advice for me how to get this done?

Greetings,
Markus