(Sorry for my bad english^^)
On SNES (RetroPie 3.0 Beta 2), I got it to work!
First, I switched to “lr-snes9x-next” (/home/pi/RetroPie-Setup/retropie_setup.sh, “Install individual emulators…”, “lr-snes9x-next”).
Then, I opened /opt/retropie/configs/snes/retroarch.cfg and added the following line:
input_libretro_device_p2 = “257”
If you have configured your controllers in “/opt/retropie/emulators/retroarch/configs”, then you need nothing more to do – just connect your gamepad and run your Game. Successfully tested with Bomberman…