i discovered (trying) that autoconfiguration doesn't work for single emulators, like psx. so i read some internet guides.
i configured it manually, editing the file /opt/retropie/configs/psx/retroarch.cfg
@deltax5 you can build RetroPie on top of Linux. Check out the official documents for more info on doing that. I've got a little laptop running Ubuntu and it's pretty good. If you put RetroPie on top of that I think you'll be onto a winner. Pi3 is still not great for N64 emulation.