Hi @Durrsly thanks for feedbacks, for prboom_libretro.so you need to place prboom.wad into your rom folder (available into Makefiles.zip). For gpsp you need a gba bios. Hope this could help you.
Ah, I see. I got PrBoom working. It seems perfectly playable.
I also found that Mednafen is picky about it's PS1 BIOS, so I placed the proper BIOS in there. I tried Vib-Ribbon, JoJo's Bizarre Adventure, and Ultimate Battle 22. Vib-Ribbon froze the whole program, Ultimate Battle 22 and JoJo still crashed to desktop.
I also tried Stella, which worked perfectly.
Heh, managed to crash the PCSX-R core "playing" JoJo. I was playing around in practice mode and attempted Dio's knife throw and it crashed.