Comment by somat

2BSD is still hanging on getting updates and forked projects to this day. My understanding is that it's longevity in the face of the existence of 4bsd is because it is 16-bit clean, These days it is mainly for people who want a unix for their microcontroller.

Here is one, https://github.com/RetroBSD/retrobsd. This is for the pic32, so I may be wrong about the 16-bit thing.

I don't know if anyone has done it but it looks like it could fit, perhaps not on a original 8086 PC, but perhaps a 286 with 640K.