Add support for EverDrive-64

[Polprzewodnikowy]

Direct reads from SD card to SDRAM is still unimplemented for everdrives in libdragon: DragonMinded/libdragon#345.

[riggles1]

As far as the old chinese clones go, is there a possibility of those getting supported? They're floating around everywhere at this point as people get them, then stop using them as they upgrade to something better.

With open source flashcarts being a thing it would be nice if new software for already existing clones can give them some better use.

Been recently returning to my old clone that was laying around after learning about alternative menues, to document the issues that affect altra64
https://github.com/ariahiro64/altra64/issues

As far as capabilities go, you have perfect compatibility with functional saving if you use two firmware SD cards, as the original clone firmware handles flashram saving but not alt/altra64. (except for Animal Crossing and Stadium 2 which are lost causes on older flashcarts anyway).

So the potential is there.

[Polprzewodnikowy]

Yes, i think it is possible to support ED64 clones as libdragon already incorporates libcart which claims to support these carts. SD card access shouldn't be a problem but one big issue before adding support for anything other than SC64 is figuring out how other flashcarts actually load data. Sadly there's little to none documentation of many registers used by ED64. There's altra64 code but as you already mentioned it has issues with some of the ROMs.

To summarize, ED64 support depends only on figuring out how to load data into the flashcart and correctly set specific registers. Anything other than that is generic to all flashcarts and should be already supported.

[riggles1]

Ah that makes sense, I'd suspect the big hurdle with that then would be flashram games as only ED64 clone firmware knows how to grab that save type. As far as loading the games everything console compatible loads and plays with altra64, given that the file+path character length isn't too long.

Would be neat to see some support at least I suspect a lot of these are basically dead weighs in people's collections. Appreciate the reply! Will be testing.

[networkfusion]

I have done some work towards this here: https://github.com/networkfusion/N64FlashcartMenu/tree/ed64-vseries . I am unsure of others progress in the area, but IMHO it should enable a Proof of concept.

And... definitely needs a more experienced C developer to improve the implementation!

[networkfusion]

I have now added a draft PR. If further help is needed with the implementation, please let me know.

[SlaughterRidge]

I can confirm that PR44 does at the very least run roms on the EverDrive 2.0. I tested roms that require the expansion pack and ones that do not require it.

EDIT: to add to this, saving does not appear to work, at least for the games I tested. The EverDrive 2.0/2.5 requires using the reset button to write save files to the SD.

[networkfusion]

EDIT: to add to this, saving does not appear to work, at least for the games I tested. The EverDrive 2.0/2.5 requires using the reset button to write save files to the SD.

Are you suggesting that the last played game is saving, but only when you have pressed reset? or it is still not working regardless of when you press reset?