Pinebook Pro not booting

[Jeremiah Cornelius]

Thank you for your answer. I only created that GPT layout temporarily, because I needed some disk space I could work on. I did not intend to use it as my boot drive and was expecting to be able to boot from a microSD card.
My situation now is:

* The only OS that boots from a microSD card is android
* It doesn't matter whether eMMC is plugged in or enabled
* Linux does not boot

So essentially, I have a bricked device. Everyone has told me that this shouldn't be possible. I know that. But somehow, it's still bricked. I have verified my Linux SD-cards, they are correctly flashed.
I do not have a UART adapter at hands, that works reliably at these speeds.

I find it just extraordinarily strange that just Android boots. At least that means that my SoC is somewhat ok

Don't despair. "Bricking" is a term for an unrecoverable item, without functioning firmware, at low enough a level, that repair must be done with physical replacement of components. It's unhelpful to your progress, adopting a "bricked" mindset!
I have done a lot of work with uBoot on other small devices, like routers and ShivaPlug. I understand the frustration. 

You successfully verify the hardware by booting a functional Android! So SoC is more than "somewhat ok", it's fully functional!

I would ignore being distracted by SD card images at this point. You need first to return to "factory state" as your baseline.
https://forum.pine64.org/newreply.php?ti...lyto=55736

Then, if this is successful, begin experimenting with SD images. If you need "extra space", don't wipe the eMMC. This is your "safety net". A USB thumbdrive is probably the best for holding a blob of disk image, if you are short on SD space.

I hope this to be helpful and reassuring.