Far as I can tell? The typical approach is installing mednafen via sudo apt-get install; then using it to run GB/GBC/GBA/NES ROMs. One of the posts there shows you how to write a .SH launcher for it, as well.
https://bbs.nextthing.co/t/mednafen-emulator-configuration-gbc-gba-snes-nes/5027
That said, some kind of RPie for it, even a mini-version, would be pretty fantastic. Maybe someone can splinter off RP and include only the emus/scripts that the hardware currently supports; but not have ES run on boot; but rather from within CHIP's internal OS instead? Bear in mind that the RAM on PocketCHIP is way more conservative than Pi Zero/2/3; so having frontends running in the background will mess with in-game performance; hence the suggestion to minimize it.
But what should we call it? "RetroCHIP?"
