The core input remapping option doesn’t work for me either, so its likely an upstream issue that will need to be addressed. Taalas and I have been trying to sort out the whole configs things as well- you can see our progress here: https://github.com/taalas/RetroPie-Artwork/issues/2 it has diagrams that show the default retropad configurations (they are also on all of the retropie wiki pages)
As far as I understand it without the ability to modify the core inputs you have potentially two options that I can think of (both of which aren’t super effective)
– Autoconfigs: you can set up your autoconfigs for each controller to be mapped as you like for the genesis and then either swap out the files (which will be in /opt/retropie/configs/all/retroarch-joypads) or reconfigure them each time you switch emulators (which is also an inconvenience)
– Retroarch.cfg you can modify this file to be hardcoded specific to when you open the megadrive emulator /opt/retropie/configs/megadrive/retroarch.cfgand I’ve found out something in regards to player order (at least with autoconfigs, it may also apply to retroarch.cfg)- its based off of where you plug in your usb:
But there may also be a more effective way than what I can think of, if you’ve got any better ideas I’d be happy to hear them as I’m interested in finding a solution myself :)