[voidUpdate]

I feel like this would definitely be possible. I was reminded of https://mitxela.com/projects/kiloboot, which uses an ENC28J60 for the ethernet stuff. I feel like you could probably quite easily bitbang SPI, given it's quite a forgiving protocol, just dedicate a couple of addresses in the memory space to interact directly with the bus (maybe with a separate shift register chip if you want to make things a bit easier). If you give up writing anything to the screen, I'd imagine you could just spin until something happened on the ethernet side, then read the requested path, pull some data off the ROM that corresponds to that path and send it back again