I'm thinking about writing a tiny pure-guest UNIX-like OS in Rust, mostly for learning purposes. I don't mean something like virtualization and hypervisor, but a set of programs or single executable emulates a UNIX-like environment the same as Cygwin and MinGW runtimes do. Maybe also include some Plan9-like clustering but definitely not in the first releases.
The idea is about showing the Rust usage for OS programming but without no_std and bare metal complexities -- just by using code portions that behave like an OS but run as a generic program for mainstream OSes like Linux & Windows. Maybe some sort of emulation will be required for example file system calls, and network stack wrapping, but in a very thin layer.
What code can I use as references to dive into this topic?
ps: WASM kernel runs in a browser... mmm... just a variant.