Custom PPSSPP shaders

[WonkoTheSane]

This might be a silly question...

But if i am able to generate or even handpaint Normal Maps for a specific texture (dumped using the texture export function), is there a way to get those to work as expected using a shader?
Would a shader even be able to read texture info the way ppspp could and use that?
If at all possible, this could mean drastically improved appearance of models.

e.g:
Dump texture using "save new texture" feature in psp.
Use that texture to generate or guesstimate bump map info.
Save that image with same name as texture, maybe add suffix "_normal"
Have shader read that info and generate the illusion of geometry/lighting effects?