Ability to log firmware version and decode this message without having the elf at hand

[t-moe]

Sometimes I want to read the logs from a device where I dont know the exact firmware it is running.

Sure I can print the firmware version to the serial port on bootup without using defmt and then use defmt-rzcobs to properly frame the encoded messages.

But it would be nice, if I could also emit the firmware version using defmt.

Could we maybe create a macro that is invoked like defmt::version("0.1.2-g127abc") which always uses id 0 and the format string "{}" ?
This could then be decoded without having the actual elf at hand.

( How do you guys solve the problem, of knowing which version a target runs? )

[jonathanpallant]

It's a great question. I'd love to know a bit more about your specific scenario!

For me personally, it's never come up because either a) I just flashed the board, or b) I used an OTA update system like Pelion so I know what version was deployed using that system.

If you only have a finite set of possible firmware versions, you could just try them all and see which one works?