Basically I found what appears to be the only e-mail backup I made of my old GBA emulator FatMan, complete with source, binaries and a few demos. However it seems to be from several months before I was actually able to get any public domain ROMs running. My journal posts from that time show what needs to be fixed though, the LDR and STR instructions, which is weird since it's like me leaving myself instructions for the futue.
Anyway I'm going to see if I can convert it to C# and get a few demos running during the Christmas break.
This isn't actually the GBA version of Doom, so keep your pants on. It's just a screenshot of id.Net converted to GBA format and then loaded into video RAM using the GBA's DMA.