Does anyone know where the authors sourced the RDU2? Google brings up a bunch of git commits and the website of the company that makes them (ZII), but the website doesn't seem to list the part number and nowhere obvious seems to sell them. Sarkari Result Pnr Status Showbox

Which makes some amount of sense, since it's evidently used for in-flight-entertainment systems? But then that's a very specific porting job for hardware that most other people won't even be able to find, let alone flash.