Probably not too hard. There's a port of NitrOS-9 to this crazy thing, for example: https://www.frontiernet.net/~mmarlette/Cloud-9/Hardware/Libe...

I haven't tried his CUBIX on his emulator yet, but there's a certain richness to systems that start with a full fledged debugger on the bare metal. And he's got his own assembler, Forth, BASIC, APL, C compiler...