Any issues modifying EEPROM past 4k for Pi Pico?

[OpenZSD]

Since the Pi Pico EEPROM isn't a true EEPROM but a section of flash. Assuming the program isn't too large, if I modify EEPROM.cpp to use 8k or 16k, is there any concern? I know each commit() will wear out that chunk equally as it writes to the entire EEPROM section.

[earlephilhower]

You need to update the linker info as well to make that work. It's passed in thru boards.txt. OTW it just won't work and you'll try and write past end of flash.

But there's not a good reason to use EEPROM at all. It's there for legacy compatibilty (like pgm_read_byte). Why not LittleFS with a small filesystem partition? Something like

LittleFS.begin();
File f = LittleFS.open("state.bin", "w");
f.write(&state, sizeof(state));
f.close();

and on app start

LittleFS.begin();
File f = LittleFS.open(state.bin", "r");
f.read(&state, sizeof(state));
f.close();

Error checking would be good too, but skipped here for brevity. You could also cycle through A/B versions of the file to help survive power cuts during update.

[earlephilhower]

As an added benefit, LittleFS also will wear-level across the space you give it. So if you give it 512K of space it'll record ~60 copies (some overhead for FS layout) of the data before actually rewriting an existing block.