reliance-edge VS DAPLink

+1 littlefs, we have used it in production, and it ran pretty well. One more option is reliance edge, it has nice GUI configuration tool, but it distributed over GPLv2

If you just want to transfer data without necessarily using a filesystem on your storage device, check out daplink. It implements a virtual FAT filesystem over USB so you can copy over firmware updates easily.

From what I've found that DAP-Link is actually an ARM Mbed open source project to basically be similar to STM32 ST-Link: https://github.com/ARMmbed/DAPLink

It's used for flashing the BBC micro:bit in both Microsoft MakeCode (makecode.microbit.org) and the micro:bit Python Editor (python.microbit.org). MakeCode uses it for lots of other devices like MakeCode Arcade too https://arcade.makecode.com )

It's amazing for students to be able to quickly get a program they've written in their browser onto a device in their hands that can respond to and interact with the real world.

Also great because with MicroPython and the Python Editor you get a standalone Python environment including REPL that's completely isolated from the PC - schools love it because no matter what the students do they're not going to break the host PCs.

(The firmware that implements web USB on the micro:bit's USB interface chip is open source, DAPLink https://github.com/ARMmbed/DAPLink - poke

https://github.com/ARMmbed/DAPLink/blob/main/source/daplink/...

Note the nested do { do { } while (); if (err) break;} while(); if (err) break;

Should that code be rewritten? Most certainly it should, and it should be given a proper Error type. However, when you are first porting it, you need to match semantics or you get a bunch of off-by-one, missed error, or missed end of stream bugs. And, as you point out, the Rust loop{} equivalents suck.

We've all written suboptimal code, and we all live in a suboptimal world. :)

I checked for DAPLink, but this seems to require keil, based on what I read in the readme.