OK, so I have no idea what exactly evtest or any of the stuff like this is (I am fairly familiar with Linux, just not the core elements like how it handles input) but I found what I needed to do from here, and this is what I came up with:
Lakka:~ # cat /proc/bus/input/devices
(I’ve cut out an entry for my USB mouse and strangely two entries for one USB Compaq keyboard)
I: Bus=0005 Vendor=1949 Product=0402 Version=011b N: Name="Gamepad" P: Phys=b8:27:eb:9c:7f:9d S: Sysfs=/devices/platform/soc/3f201000.serial/tty/ttyAMA0/hci0/hci0:11/0005:1949:0402.0007/input/input6 U: Uniq=00:ff:01:00:24:e2 H: Handlers=sysrq kbd leds mouse1 js0 event3 B: PROP=0 B: EV=12001f B: KEY=20 0 0 0 0 0 0 0 0 ffff0000 70000 10000 2008007 ff9f387a c9415fff febeffdf ffefffff ffffffff fffffffe B: REL=103 B: ABS=30027 B: MSC=10 B: LED=1f
Lakka:~ # udevadm info --name=input/event3 P: /devices/platform/soc/3f201000.serial/tty/ttyAMA0/hci0/hci0:11/0005:1949:0402.0007/input/input6/event3 N: input/event3 E: DEVNAME=/dev/input/event3 E: DEVPATH=/devices/platform/soc/3f201000.serial/tty/ttyAMA0/hci0/hci0:11/0005:1949:0402.0007/input/input6/event3 E: ID_BUS=bluetooth E: ID_INPUT=1 E: ID_INPUT_KEY=1 E: ID_INPUT_KEYBOARD=1 E: ID_INPUT_MOUSE=1 E: MAJOR=13 E: MINOR=67 E: SUBSYSTEM=input E: USEC_INITIALIZED=10275994456
So, I did “get an event”. I should also say that when I try to bind the controller in RetroArch, on the part in which it asks you to press a button on the controller, when I press a button on the controller, nothing happens, it justs acts as if I never pressed anything and times out and moves on to the next key to bind.