Request: ability to disable appending RTC data to save file

[apbeckman]

This consistently causes problems with the portability of save files in Pokémon games, as well as compatibility with save editors such as pkmn-chest — which displays an error message saying the file is invalid once an in-game save has been performed using mGBA. This can be fixed by opening the file in a hex editor and deleting the last 16 bytes,though it'd be more convenient to just not write them to begin with

[profi200]

The data is needed to keep the RTC in sync and working the same way it would on a real gamecart. Open an issue on these tools that think a save with RTC footer is invalid.

[endrift]

Specifically, that data is the data that is stored on the RTC itself along with a bit of synchronization data so that it can be moved between systems without the clock becoming wrong. This includes to and from cartridges, where the clock would be flat wrong without it.

FlashGBX for example knows how to read/write this data for cartridges, and editors like PKHeX have already added support for this footer too.