Implement emulated EEPROM

[Drugantibus]

Made some changes to implement emulated EEPROM in NVM to persist settings on power loss as seen in qmk's #6068, using @daltona's mdloader fork and his qmk alt-eeprom branch. Thank you so much Alexandre!

Tested it for several weeks, seems to be stable and behave as expected. Still a couple of bugs to fix and features to add, but so far so good.

[daltona]

You're welcome Alessandro !

I also have a branch somewhere with VIA support should you be interested, I can create a pull request on your repo !

[Drugantibus]

Hey!

Oh awesome, that would be nice to try out :)
Let me push a new via branch, as it will probably break my existing raw HID implementation I assume?
Thanks again both for your work and for your kindness :)

[Drugantibus]

Hey @daltona, sorry for getting back to you after all this time, the EEPROM works perfectly and I forgot about your comment 😅
I was messing around with your VIA patch but I never got it anywhere close to working. Everytime I flash a VIA firmware I get really weird behaviour on my board, i.e. some keys don't work at all (usually in "zones", like bnm,./), some keys are mapped incorrectly, and the RGB is in a weird state. Since these errors are not consistent (dead keys are not always the same, RGB bootup state is different), I suspect it has to do with the content of my EEPROM. I guess I'd need to resize the NVM as tzarc mentions here? Is this possible to do using your mdloader or would I need a J-Link?

Thanks :)