Start the .elf with the homebrew launcher. The system menu will be loaded and you can use your device. You can attach and detach devices at any time, but maybe it will result in a random crash.
The official GC Adapter, PS3/PS4 Pad, Mouse, Keyboard and a few other devices are currenty supported, check out the controller_patcher repository for the full list(https://github.com/Maschell/controller_patcher), also 99% of the logic is this reposistory.
You can plug in the controller in any port, if mutiple pads are connected only one pad is used.<br/>
Mapping is the same as gc-to-vpad by FIX94. To quoute him:<br/>
"It just works like you would expect for the most part except for Z, holding down Z will switch L to gamepad L, R to gamepad R and start to gamepad minus. This is done for convenience purposes."<br/>
In order to build this application, you need the custom liboGC and portlibs modified/created by dimok. You can find them on the loadiine_gx2 repo (https://github.com/dimok789/loadiine_gx2/releases/tag/v0.2). Simply put the files in your devkit folder and run the Makefile of HID to VPAD.
A big thanks goes out to <b>dimok</b> for creating the HBL, the dynamic libs and every stuff he made. The "environment" of this app is copied from ddd, turned out to be a "hello world" with useful extra stuff.