I was under the impression that Theo had put a hard "fuck no" on ever porting OpenBSD to the Pi until Broadcom fully opens up the hardware (full documentation and blob-free booting). While Broadcom has been releasing documentation, there are no official plans that I'm aware of for ever booting the Pi without the firmware blob.

Don't get me wrong, I will gladly welcome OpenBSD on the Pi if it ever happens; one of my favorite OSes on one of my favorite platforms. But I'm not holding my breath.

As for other SoCs/boards; there simply is no other board with the combination of support, community, power, cost efficiency, and versatility that the Pi enjoys. Pretty much any other SBC is lacking in one or more areas critical to making such an endeavor worthwhile. The only thing that comes close is the Nvidia Jetson TX2, and it's cost prohibitive for this kind of project when you can get a mainstream AMD64 ultrabook for half the price of that board alone.

Broadcom released documentation and driver source code for VideoCore in 2014 so it should be easier to port things to the RPi now: https://en.wikipedia.org/wiki/Free_and_open-source_graphics_...

AFAIK Linux distribution for the RPi still use the closed-source bootloader, which is some commercial RTOS that needs to sit on a FAT partition and runs on the VideoCore chip (!). There is work on a Free Software bootloader: https://github.com/christinaa/rpi-open-firmware