@mitu , thanks for your reply.

I have not used Pastebin before, so I hope I am doing this right.

I have one controller plugged in; the GameCube controller through the Mayflash adaptor. I have remapped the controller to use the xboxdrv using these instructions and I only configured the xboxdrv controller through the EmulationStation Configure Input tool, which explains why the runcommand.log says the controller on Pad #0 does not have a profile but the xboxdrv controller on Pad #1 does have a profile.

[INFO] [udev]: Plugged pad: Wii U GameCube Adapter Port 1 (0:0) on port #0. [INFO] [udev]: Pad #0 (/dev/input/event0) supports force feedback. [INFO] [udev]: Pad #0 (/dev/input/event0) supports 4 force feedback effects. [INFO] [Autoconf]: 4 profiles found. [INFO] [Autoconf]: no profiles found for Wii U GameCube Adapter Port 1 (0/0). [INFO] [udev]: Plugged pad: Wii_GameCube_Port_1_(xboxdrv) (0:0) on port #1. [INFO] [udev]: Pad #1 (/dev/input/event1) supports force feedback. [INFO] [udev]: Pad #1 (/dev/input/event1) supports 16 force feedback effects. [INFO] [Autoconf]: 4 profiles found. [INFO] [Autoconf]: selected configuration: /home/pi/.config/retroarch/autoconfig/Wii_GameCube_Port_1_(xboxdrv).cfg [INFO] [Joypad]: Found joypad driver: "udev".

In the RetroPad section (see the full runcommand.log in the pastebin link below) it looks like the Start Button is mapped correctly. If the Start Button worked for me, I can see how to edit the config file to fix the button mapping.

For what it is worth, I first configured the Gamecube Controller without the xboxdrv and I had the same results; the Start, DPAD, A and B buttons worked fine in EmulationStation and seemed dead in the RetroArch emulator. Here is the complete runcommand.log

http://paste.ubuntu.com/26183051/

Thanks for your time.