[messe]

More of a suggestion for a future design, but how about using DOOM's software rendering over X forwarding (potentially over SSH)? You'd need to have the card present itself as a network interface, which would add to the complexity and cost however.

What's the highest baud rate the serial interface supports? You could theoretically get PPP over serial working, but I suspect at best you could only manage a few frames per second. 320x200x4bpp at 1fps requires a 256k baud rate minimum, and that's just streaming the video, without any overhead—I suppose you could apply compression: ssh -C with the "none" cipher; or just compress each frame as a PNG, but I'm thinking outloud—this would probably involve writing your own renderer.

[antoinealb]

With the USB gadget Driver in Linux you can have the existing USB Hardware enumerate as a USB Ethernet adapter without too much config work so that would not add much to the BoM :)