Implement save states in a more universal fashion

[NeoTechni]

Devs seem to have trouble implementing save states, requiring either significant FPGA elements or planning.
Why was it not done in a more universal fashion, offloading the majority of the work to the OS itself?
I'd suggest doing it in a manner closer to how emulators work where they just dump the contents of RAM to a file
This could be implemented via the core having a settings file (Analogue Pocket uses JSON for example) that defines the areas of RAM needing dumping

[sorgelig]

You probably have no idea how save states are working or mess it with normal saves. MiSTer already implements save states more or less universally from OS side, but 99.999% of save state implementation is in FPGA and it cannot be universal for all cores. Implementing save states is like half-way of rewriting the core.

[birdybro]

@NeoTechni It's open source. Feel free to contribute with a pull request if you come up with a better way to do it.

However, there is some naivete in your comment. Just picking the sections of memory to save is not the hardest part. The hard part is laboriously adding pauses throughout the core where necessary and meticulously adding proper savestate bus handling throughout in a way that is custom to each core.

Example:

MiSTer-devel/Gameboy_MiSTer@ca8b55d