RE: nrf5340 DFU using serially connected WIFI module

AHaug — Wed, 09 Aug 2023 08:03:47 GMT

Hi,

[quote user=""] I can get the encrypted binary data into the nrf5340 via the serial wifi module but how can I flash it to the appropriate half in the memory the same way the BLE DFU does ?[/quote]

Can you explain some more about how you transfer the encrypted binary data to the nrf5340? Where do you put the new image? Is it in the secondary mcuboot slot? Is it located on an arbitrary location on the external flash not allocated to MCUBOOT/DFU/The application?

You should be able to use the SMP Protocol with any communication protocol as it is protocol agnostic, but we don't have any samples or guides for how to combine SMP with wifi. (Some unofficial samples written by a colleague can be seen here: https://github.com/hellesvik-nordic/samples_for_nrf_connect_sdk/tree/main/bootloader_samples/smp)
Do note that although MCUBoot supports encrypted DFU, we don't have any samples or guides on how to do this, but it is possible to do with the components in the SDK. Do also note that this is not something we test either. However if you've already implemented your own solution for this, you may disregard this item

You should be able to run, sign and encrypt the update image using the imgtool: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.1.0/mcuboot/imgtool.html#signing-images. So using the imgtool with -E key_to_encrypt should technically encrypt the image.
I recommend you to have a look at these public Devzone tickets with related information for how to do encrypted DFU:
nRF52840 + NCS + MCUBoot, CC310-enabled image encryption?
MCUBoot with serial UART and image encryption

Some of these tickets may be using older NCS releases so some differences may occur w.r.t. project configurations.

Kind regards,
Andreas