Bootloader DFU update invalidates App

[Locky]

I am testing with SDK6.1 S110 7.1. I've noticed that when I try and update the Bootloader image using the Android MCP app, everything updates fine. I have logic in place that has the Bootloader image start the App. HOWEVER if after updating the Bootloader and then running in the App the Power is removed. Upon restoring power rather than the Application starting (it should still be valid) the device starts in Bootloader mode. This is only possible if the App image was somehow invalidated.

I've repeated this test several times to be certain that its a Bootloader issue. If I DFU update the App, everything works fine, even after power cycles. So its definitely something in the dfu code which is invalidating the Application. Is this expected behavior?

Thanks,

KL

[Hung Bui]

@Locky: What you experience is similar to this: devzone.nordicsemi.com/.../

It's a bug on our DFU in SDK v6.1 and v7.0. The fix has been implemented in SDK v7.1 In the case above, you can find the explanation of the bug by Adrian at the bottom.

If you want to implement the fix please follow what we did in bootloader_dfu_update_process in update_status.status_code == DFU_UPDATE_SD_SWAPPED case.

I would suggest you to use the lastest SDK which is v9.0. The chip you going to use in production will be rev 3 chip.

[Locky]

Thank you Hung. We are looking to migrate to the latest SDK next month.