Controller core-specific configurations

Description

RetroArch maps a connected controller to an internal controller (I think it's called retropad), and then maps the retropad to the "real controller".

This works pretty well, but there are some dge cases.

For example, the GameBoy Advance has following input buttons:

• A
• B
• L
• R
• Start
• Select
• D-PAD

The wiimote has

• A
• B
• 1
• 2
• +
• -
• D-PAD

and HOME

The retropad has a superset; at least

• A
• B
• X
• Y
• L
• R
• Start
• Select
• D-PAD

All button of the wiimote are mapped to the retropad, the A.B,1,2 buttons of the wiimote are mapped to A,B,X,Y

Which means, that when playing GBA with a wiimote, L,R cannot be used, and the buttons mapped to X,Y are "lost"/effectively unused.

I'm not suggesting that the default mappings of the wiimote (or other remotes) should be changed, they might make sense for other platforms, but do not make sense for the GBA.

The same issue might apply with other combinations of controllers and cores, it is not necessarily wiimote/GBA specific.

Expected behavior

Being able to configure retroarch in such a way that when using any wiimote with a GBA core, to map some buttons to L,R instead of X,Y.

Actual behavior

Either the buttons are remapped globally (for all cores), or L,R cannot be used with a wiimote.

Steps to reproduce the bug

1. Use a wiimote
2. Do not change the global mapping
3. Try to use L,R with a GBA core

Bisect Results

AFAIK the behavior is unchanged.

Version/Commit

You can find this information under Information/System Information

RetroArch - Frontend for libretro
Version: 1.16.0 (Git 14cb373) Oct 2 2023
Compiler: GCC (9.4.0) 64-bit

Environment information

• OS: Debian

No source file, test, or entry point is named. Start by locating RetroArch's controller-mapping configuration and how it identifies cores; done means a wiimote can map its buttons to GBA L/R on a per-core basis without changing mappings for other cores.