flasher works again :D
   Debugging it was greatly helped by having labeled my pin wires.
   I was looking into the firmware and discovered it had a debugging mode
   that opened an interactive terminal.
   I added a command to the terminal source to send test values on the
   various pins, outputting text describing where each logic level should
   end up.
   I found one of my wires was miswired and mislabeled in a hard-to-notice
   way. Maybe I rewired it wrongly after it fell out or something. I
   tested and verified each voltage level, ignoring logic flow.
   Annnd now it works!
   Now to clean things up and use it again.
   Topic _seems_ resolved. Ideally I contribute code successfully to
   coreboot, a larger goal.
   In the meantime, I found a local makerspace and started a radio tool.