I have configured the gamepad using these lines:
cd /opt/retropie/emulators/RetroArch/installdir/bin
Then I used the ./retroarch-joyconfig
and mapped the controller.
After that I am stuck, I can find the .cfg but I do not know what to do.
I tried skipping the step and tried to play a game, but it still does not work – The gamepad works fine in EmulationStation btw.