Your question raises suspicions that you may not fully understand what a "ROM" is - let me explain.
ROM means -R-ead -O-nly -M--emory, which is generally a type of solid state memory chip where the program and data for a game cart (or arcade game PCB) are stored. The contents of these chips are only read, not modified, by the system that runs them. ROMs are found in all your game carts, SNES, Genesis, Gameboy etc. So the term ROM is much older than emulation.
A ROM file on your computer is a copy or "dump" of the program and data contained on the original game cart, PCB etc. It's is NOT something created by emu programmers - that's a common misconception with some newbies.
So, using the above as a guide, generally speaking ROM files used for PC emus are exactly what you'd use on GP32 emus.