Test harness

[IsaacWoods]

As the kernel gets larger and more complex, it would be great if we could perform some unit and regression testing to make sure we don't break stuff. The end goal is to have a test harness using some virtualisation framework to run the kernel on some emulator, and then be able to extract diagnostics from said emulator to record for any failed tests. It would also be nice if the actual syntax of the tests was nice and didn't interfere with kernel code too much, so maybe this should wait until external test harnesses are a thing?

Some interesting resources that other people in the Rust kernel space have come across are:

• Discussion about testing over at rust-x86
• Similar sort of thing for the rxinu kernel
• The utest framework