Porting software from Wii to Wii U

[benwiley4000]

I have done some GBA dev but nothing for Wii. I want to try to port Fake-08, an open source multi platform PICO-8 emulator that I believe uses WUT for its Wii U build, to the Wii. Since Wii and Wii U are similar I feel this must be possible, but I don't know where to start with understanding the platform differences. Is anyone aware of a guide somewhere that could help me understand how to migrate in one direction or the other between Wii and Wii U?

[WinterMute]

The WiiU port uses SDL2 so there isn't really much need to worry about platform differences. You can just use the Wii SDL2 port & figuring out minor differences with buttons & paths.