[TUHS] Revisiting 6th Edition: rxv64

[Dan Cross]

I've mentioned tangentially this a few times, but over the weekend I
finally got around to dusting off the code and getting it running:
https://github.com/dancrossnyc/rxv64.git

rxv64 is a rewrite of MIT's xv6, which in turn, reimagines 6th Edition
as a purely pedagogical system, implemented in ISO C for 32-bit SMP
x86 machines.

Building on xv6, rxv64 is implemented in Rust and targets 64-bit
x86_64. It works well enough to boot up, run a shell, and run
commands, but it doesn't really have much of a userland at present.

I started this as a pedagogical tool, being something that one could
point working engineers at as an example of a "real" operating system
implemented on real hardware in Rust. The code could surely be made
safer and more comprehensible, but cycles are short at present, and
it's better to just get it out there.

Have fun.

        - Dan C.