A few years ago [Serge Vakulenko] started the RetroBSD project–a 16-bit port of the old 2.11BSD operating system to the Microchip PIC32 microcontroller. This was impressive, but version 2 of BSD is, to most people, old news and somewhat difficult to use compared to modern BSD and Linux operating systems.
[Serge] has been at it again, however, and now has a port of 4.4BSD–LiteBSD–running on the PIC32MZ. According to [Alexandru Voica] there is about 200K of user space memory in the basic build, and by removing some OS features, you could double or triple that figure.
If you aren’t familiar with BSD, it is the Berkeley Unix derivative. Unlike Linux (which was a rewrite of Unix functionality), BSD forked the original Unix source and added features. Version 4 of BSD adds several key features including TCP/IP networking, and LiteBSD includes an IPV4 stack and an Ethernet driver (a WiFi driver is in the works). You can view a talk about the history of BSD from [Kirk McKusick] (one of the prime people behind BSD) below.
We’ve seen RetroBSD on micros before, but with the 2.11BSD heritage, RetroBSD doesn’t have the potential that LiteBSD does. It is interesting, though, that the driver structure is compatible so that both projects can easily share driver source code. Maybe [Jaromir] will upgrade his laptop.
Thanks [Alexandru Voica] for the tip. PIC32 diagram courtesy Microchip.