By default ROCKNIX will detect your controller and configure RetroArch hotkeys automatically. This is controlled by the "AUTOCONFIGURE RETROARCH HOTKEYS" option in the Settings > Controller & Bluetooth menu. While the option is enabled, RetroArch hotkeys will be overwritten by the above defaults each time RetroArch is launched. If this behavior is not desired that option can be disabled and your user-defined RetroArch hotkeys will be used instead.
Z and L button assignment can be changed directly in EmulationStation
Highlight the game and press X(NORTH)
Select ADVANCED GAME OPTIONS
Set EMULATOR to MUPEN64PLUSSA
Then change INPUT ONFIGURATION
Default: L1 = L, L2 = Z
Z & L SWAP: L1 = Z, L2 = L
You can also create your own custom controller configuration and add it to /storage/.configs/game/configs/mupen64plussa. Then update INPUT CONFIGURATION to CUSTOM following the same steps as above.
These commands will configure the Dual Screen, you will need to login to your device using SSH to run them.
You will need to toggle the "Enable SSH" option by pressing START and going to Network Settings. Also make sure that "Enable Wifi" is also toggled and your device is connected to your network. The IP address of your device can be found at the top of the Network Settings menu
However, this configuration is only temporary, as the settings will revert if the device is shutdown or restarted.
Additonally, these commands can be placed into a script and ran from the file manager to bypass the need to ssh.