I'm in extremely early stages of writing up some documentation for how to build a Linux distro for a Raspberry Pi 3, gauging interest and figuring out pain points. Shoot me an email [my username]@gmail if you've got ideas or requests!
That sounds interesting. I think your guide would be extra helpful if it focused on building a distro that has as much of the system loaded into memory as possible to minimize amount of reads from the SD card, and which is configured with a read-only file system and never even tries to write to the SD card. That would be very useful. SD card corruption is a pain!
Maybe we can somehow refer to each other? I wrote a guide for a custom board I made running Linux, but it's very low level up to tge stage of getting the kernel running with a minimal user land.
I would be happy to refer to you at the end of mine: brainyv2.hak8or.com