After building my Pi2 (for the living room), I decided that I’d use my old Pi1 for the bedroom. Just another image install and a new SD card and I’d be set.

Or so I thought. Last night I batch loaded a bunch of ROMs and find that RetroPie is either showing a black screen, a scrambled screen, or just the “CHOOSE” option. You can F4 to exit and restart, but same problem.

After deleting ROMs, paring down ROMs, etc I finally uncovered the issue.

At first it seemed that the quantity of ROMs was the problem (it is running on an older Raspberry Pi, after all). Was it the Master System? SNES? It was weird.

So I slowly re-loaded my ROMs. And the second I added ANY GBA ROMs it started acting up. Here’s why:

I was stupid. I forgot to double-check the install instructions for GBA games. You need to have a BIOS file for that emulator. I had done this on my Pi2, but forgot to do it on my Pi1.

What’s happening is this: Emulation Station attempts to generate screen backgrounds for each of the emulators. To do this, it needs to run the emulator (I’m guessing). It hit the GBA, didn’t find the BIOS, and failed in an unfriendly way.

Putting the GBA BIOS in the proper directory, like I should have done, has fixed the problem. Horray!