mcumgr - device bricked when firmware in Slot 1 got somehow Permanent flag

RE: mcumgr - device bricked when firmware in Slot 1 got somehow Permanent flag

Carl Richard — Wed, 09 Sep 2020 08:53:34 GMT

Great that you manage to reproduce the issue, Lukáš! I'll await the logs and will do some more testing here aswell.

Just a note: you are working in the NCS environment, correct? In that case, correctly signed .bin files are available in the build folder of your project. They are located at <project_root>/build/zephyr/app_update.bin. I recommend using this file for DFU.

Best regards,
Carl Richard

RE: mcumgr - device bricked when firmware in Slot 1 got somehow Permanent flag

Lukáš — Tue, 08 Sep 2020 13:50:39 GMT

Hi Carl,

I think we have figured out the issue as it can now be reproduced. The issue is that since we do a lot of development and testing, sometimes we managed not to sign the firmware with the correct mcuboot certificate. And for some reason, the mcuboot is not invalidating the image in the second slot when it has an incorrect certificate. We don't have enabled logs for mcuboot, so we cannot really tell what is wrong. But we will try to debug it further and when we have logs, we will post it here.

RE: mcumgr - device bricked when firmware in Slot 1 got somehow Permanent flag

Carl Richard — Tue, 08 Sep 2020 13:18:21 GMT

Hi, Lukáš!

Apologies for the late answer. I'm working on the issue now and have created a similar test setup to yours.

The issue is probably related to the remote reset functionality describes in the SMP server sample. Do you have SMP/BLE functionality in the firmware you are flashing over DFU? Note aswell that the slots can be set as "permanent" using the "confirm" operation.

Best regards,
Carl Richard