Virtual Console Controller Input

I apologize if this is the wrong place to ask this:


On real Wii hardware, you can use a GameCube controller to play Virtual Console titles. (if your Wii has GameCube ports)

When doing this, are GameCube Controller inputs mapped directly to Virtual Console buttons?
Or, are GameCube Controller inputs mapped to Classic Controller inputs which are then mapped to Virtual Console buttons?


If GameCube Controller inputs are first being mapped to Classic Controller inputs, is the mapping performed by the OS or the VC?


The reason I want to know this is because I want to modify the default VC GameCube button mappings in software at the lowest stage possible.
If GameCube inputs are being converted to Classic Controller inputs before reaching the VC, then the only GameCube inputs able to reach the VC are ones that have been mapped to Classic Controller functions.


To my knowledge, the GameCube's analog triggers are not mapped to the Classic Controller.
So, if the VC sees the GameCube controller as a Classic Controller, I can't map the analog triggers to anything.