Hacking Does anyone know how to patch a rom so that the sav saves directly to the rom?

[DOU456]

I recently used ds's Burn2Slot homebrew to switch from rom to another in a repro, when using it, it does not recognize it

I investigated and it is probably because the Chinese use a rom patching system so that it saves itself and for that reason my Pokémon repros weigh 32mb (?

 

[FAST6191]

For most purposes it is not a thing on the GBA. The only things that do it officially are usually going to be floppy disc based systems like the Amiga and notably the famicom disk system/fds (a Japan only addon for the NES that has some notable games/versions thereof).

However some repros out there rather than handling saves like a flash cart or original cart instead choose to edit the save handling extensively to instead write to the ROM chip they use. The term that appears to have gained favour is batteryless for which https://gbatemp.net/threads/gba-automatic-batteryless-patcher.629015/ might be what you are looking for.