By default JELOS 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.
By default JELOS will expand the configuration file according to the first controller mednafen finds. This only happens when the config file doesn't exist (meaning the first time or if you manually delete it). After the initial expansion you are free to customize the controls.
To add/change mapping you can edit /storage/.config/game/configs/hypseus/hypinput.ini under [KEYBOARD] section by changing third number for a function from 0 (disabled) to a corresponding joystick value. You can identify joystick values by running jstest /dev/input/js0 over ssh.
For example the following would assign quit to L1 and pause to R1
These instruction only work for aarm64 devices. This is not implemented for x86_64 devices.
Press L1 + START + SELECT while in EmulationStation to swtich between Screen and HDMI output.
While this should work; it doesn't always result in the correct resolution. The best way to get consistent results is to turn off the device, plug in an HDMI cable and reboot.
"Why doesn't hot-plugging just work?"... Hot-plug HDMI switching is a fairly complex action to accomplish and not something we have implemented on any device. If you are a developer and interested in helping to build this functionality please start here: Contribute