It should be possible without even touching the kernel code. The player is run from init, so a modified init could be created that allowed the user to make a selection before launching the player or another app. This requires knowledge of how to recognize when the user has pressed a button. I am not sure if anyone has figured out/documented how to do this yet.

Hmmm, actually on second thought this would not allow you to load the compression kernel because the kernel is already loaded at this point. That code should really get added to the player rather than the kernel (didn't someone from empeg sort of commit to this in another thread?).

Choosing a kernel to load is actually much trickier. You are getting into bootloader teritory at that point. Rather nasty stuff as I understand it.

-Mike