uf2

In case you haven't seen the UF2 file format, it's specifically designed to be robust w.r.t ensuring that the content makes it to the target intact despite common OS quirks. https://github.com/microsoft/uf2 - Data is divided into 512 byte blocks, which lines up with the mass storage transfer size. - Each block has an identifying magic sequence, a payload address, and size, which can be used to identify the destination. - This allows the emulated storage to ignore metadata blocks and to handle out-of-order and repeated blocks.

There aren't but someday I plan to write one. QMK does already save some things into "EEPROM" (more realistically, flash on the MCU), like whether you've enabled NKRO, which LED pattern is selected, etc. Because it's opaque, it ends up just being another trap for the inexperienced. "I pressed a key and now my keyboard doesn't work." Yup, that can happen thanks to the magic of persistent storage.) I think the reason QMK doesn't use flash for keymaps is because it was simply designed before that was within the capabilities of the hardware it ran on. My Ergodox firmware just barely fits in the 32k of available flash on the 32u4, for example. But a STM32F103 has twice or 4x that much flash, so there is much more room to breathe and add creature comforts. (You can also use USB mass storage to flash devices, see UF2: https://github.com/mic