Hi tkaiser, I've been reading you for a while. You are technically good and I agree with most of what you said, although often your tone is questionable
Regarding the kernel. I do not believe in anyone - not just Sinovoip - but really, no one. Seriously now. I am a former Red Hat employee and I do know few things about backporting patches.
The kernel released by Sinovoip is not a vanilla 3.4.x Linux kernel. It's just the original Allwinner Android kernel. Despite that, I managed to backport all the A83t drivers to vanilla 3.4.112 - that wasn't a problem. The problem is that Android changes some of the core kernel interfaces, specifically, I am stuck with the interface provided by the following files:
And I also have minor issues in the following files:
Doing a reverse-backport Android->Vanilla 3.4.39->Vanilla 3.4.112 - does not work on these sources. I think it's doable anyway. But using only my free time it will take a while before I will achieve anything.
I will write more in the second part of my Banana PI M3 post. You can message me privately if you want more information.