52840 DFU mcuboot

[Clever Huang]

hi，all

Chip: nrf52840

SDK: NCS 2.9.0

We are currently developing an integrated factory testing function using mcuBoot's DFU. We want to make slot 0 the default for factory testing-related applications and slot 1 for manually signed final applications. (imgtool.py sign).

After factory testing is complete, we want to switch to the slot 1 application via a command.

We have completed most of the work and can switch and boot normally,

but after sending the command（boot_request_upgrade()）, we need to wait approximately 40 seconds (is this due to the firmware swap process?).

Is there a way to speed up this process? Otherwise, it will affect production efficiency.

Or is it possible to simply boot directly to slot 1 without performing the swap operation?

Best Regards!

[Einar Thorsrud]

Hi,

The time it takes to swap the images depend on the size of the images, but for large images it is possible to see 40 seconds as you do. I do not have a good way around this. However, I wonder if you can tackle it at a system level? Can you do the testing while SWD is still connected, and then program the application firmware via SWD after testing but before disconnecting the programmer?

[Clever Huang]

hi，Einar

thanks for your reply.

Since the installation structure cannot be programmed using swd, we conducted wireless testing before proceeding to formal application.
I would like to confirm whether the dfu based on mcuBoot requires an swap operation.

In other words, can the application only start execution from slot 0, and cannot be specified to run directly from slot 1?

Best Regards!

[Einar Thorsrud]

Hi,

MCUBoot itself supports DirectXIP mode, where an application can run from any of the slots. This requiers the application to be built for that slot though, or position independent applications. It is not supported in the nRF Connect SDK, but if it is needed, you should be able to get it to work with some adjustments. See this thread.