Did you know there are two full-fledged BSDs available for PIC32 microcontrollers? It's true! There's RetroBSD (
http://retrobsd.org/) and LiteBSD (
http://litebsd.org/).
I'm a committer for both. I'll also be presenting about them both at the next NYC*BUG meeting in about a week and a half's time (July 6--yes, it will be livestreamed).
If you're interested in learning about the smallest BSDs, NYC is the place to be!