Unsure if this is working, not sure if I have the tools to even know if
it does.
I could spend the time to actually write the packet by hand, or I could
probably spend ~2x the time and get smoltcp up.
Either way, the HW is validated, I am bringing up a link, I can talk to
LiteEth, so past here is driver stuff
Had some issues due to lack of startup code (stack pointer was unset,
leading to underflow in address space), so decided to just get the rust
FW started instead of finding some startup code to use.