So... I have had a couple of STM32F103C8T6 "bluepill" boards laying around for a few years and decided to do something with them.
After some uninteresting attempts with Arduino, I found Mecrisp-Stellaris Forth (http://mecrisp.sourceforge.net/) which works great. This lead me to wonder if there are any 9P implementations in Forth (surely not?) Yes! there is one by iru (https://github.com/iru-/9p4). Then I thought about the impossible: a 9p file server in mecrisp forth. I discovered someone had already done exactly that: https://hub.darcs.net/pointfree/ForthFS -Skip