Power off during DFU upgrade

[RahulR]

Please see Nordic nRF5x Bluetooth DFU upgrade firmware process.

If device is powered off at the step "Copy new firmware" and powered on again device goes into bricked state. It can no longer be accessed via BLE but only be accessed through J-Link SWI pins.

Is there any solution to handle this scenario?

[Vidar Berg]

Hi,

Please let me know which SDK version this is based on. The copy routine is supposed to withstand unexpected resets, but I remember we had some problems with the earlier implementations of it that could potentially leave the device bricked.

[RahulR]

SDK 11.0.0

[Vidar Berg]

I don't recall any known issues with the copy routine in SDK 11, only with the secure bootloader introduced in SDK 12. Are you updating SD+BL, APP, or both when this happens?

[RahulR]

I am upgrading only Application.

In this case, if application gets corrupted during copying new firmware, it should at-lease broadcast in boot-loader mode, right?

[Vidar Berg]

RahulR said:

In this case, if application gets corrupted during copying new firmware, it should at-lease broadcast in boot-loader mode, right?

 Yes, worst case should be that the device falls back to DFU mode. I think the fact that it becomes bricked indicates that the bootloader is activating an invalid or corrupted application image. To get a better picture of what the problem is I think it would help if you could read out flash after a failed and succesfull DFU then compare the differences.

Reading flash with nrfjprog

nrfjprog --memrd 0x0 --n <size of flash in bytes> > flash_content.txt