Should you backup NVRAM before firmware update? about zigpy-znp

[puddly]

Running cc2538-bsl.py with -evw will indeed erase everything, including the NVRAM. Running it without -e doesn't seem to work and leaves my device unbootable until reflashed with the mass erase option.

When restoring NVRAM your network will have a bunch of routing errors for a bit because zigpy-znp at the moment doesn't proactively send route discovery messages like zigbee2mqtt does. It'll take a few minutes for everything to sync back up.

[MarhyCZ]

Ok, understood, and the NVRAM backup/restore is mandatory, so without it, it would not work without recreating network? (the zha/zigpy does not cache the settings that are needed like pan_id etc.?). Sorry for asking and not finding it by myself.

I also see that your library has a flash.write tool. So can I just use that and feed it the .hex firmware file from Koenkk? If that handles the upgrade more gracefully, maybe I can put a commit to a README.md with info about fw upgrade through your library? (Because I am not sure if the users actually know about this, or if its intentional that way.)

However thanks for a really fast reply!

[puddly]

Not a problem, I'll update the documentation to make this stuff more clear.

1. That's correct. Upgrading the firmware wipes all of your settings and because zigpy/ZHA assumes your device persists all of your settings, your network will be completely gone if you don't back it up before upgrading.
2. flash_read/write only works with the CC2531's bootloader, unfortunately. I should probably rename it. You'll have to use cc2538-bsl.py for sticks using the CC2652R/RB.

[MarhyCZ]

Now its totally clear!
I almost didn't realize this and pushed the enter for the fw upgrade without even backing it up..

So big thanks for all the info! Hope you are staying safe.