One bootloader to rule them all

RE: One bootloader to rule them all

Sigurd Hellesvik — Fri, 27 Jan 2023 12:05:31 GMT

Headsup: If you mark a case with "Verified Answer", it no longer is in my queue.
I sometimes check my "closed" cases, which is how I caught this one.
So if you want to make sure that I still see your new questions after that, make sure to tag me in the comments as such Sigurd Hellesvik

[quote user="PB"]Also on top of this, is there any implementation of nRF5 SDK DFU protocol in C or other language than Python available? T[/quote]

nrf52832 serial dfu mode implementation procedure in nrfutil application

It is 4 years old, but it is still true today.
It is regarding the nRF5 SDK after all.

Regards,
Sigurd Hellesvik

RE: One bootloader to rule them all

PB — Tue, 24 Jan 2023 19:21:36 GMT

Thank you very much for all the invaluable information! I will be processing this slowly and let you know when I come up with anything. Indeed it seems that CONFIG_FLASH_LOAD_OFFSET is the way to go.

Also on top of this, is there any implementation of nRF5 SDK DFU protocol in C or other language than Python available? There is quite a few cases to cover in nRF5 SDK DFU so thought that maybe you might be aware of existing implementations.

RE: One bootloader to rule them all

Sigurd Hellesvik — Tue, 24 Jan 2023 08:55:39 GMT

nRF5 Bootloader with nRF Connect SDK application

Yes, you can do this.
The application does not care which bootloader runs it.

For BLE, the nRF5 bootloader used the Softdevice.
So if you want DFU over BLE, you need to include an extra Softdevice into your device.
This extra softdevice will require less flash space than the application, so it may solve your flash-space issues.

To make sure that you have unused flash-space for the nRF5 bootloader+softdevice before the application, you can use "CONFIG_FLASH_LOAD_OFFSET".

Any nRF5 communication between the application and Softdevice might become problematic. Such as buttonless DFU.
I have not tested this though.
It will likely be easier to use some other mechanism to trigger DFU, such as pulling a pin.

Update the nRF5 Bootloader to MCUboot

If you decide that you want to update to MCUboot, see Hang with nRF5 SDK 17.1.0 Bootloader and nRF Connect SDK 2.1.0 application

Does this answer your questions?

Regards,
Sigurd Hellesvik

RE: One bootloader to rule them all

Sigurd Hellesvik — Mon, 23 Jan 2023 16:19:54 GMT

Hi,

It seems like it takes some more time than planned to find good answers for your questions.

I hope to answer in 1 or 2 days.

Here is what I have so far:

[quote user=""]1. Is there a single bootloader which would support USB/UART and BLE DFU? Looking for 1 application slot, no external flash available.[/quote]

As far as I know, there is no such solution for MCUboot.
MCUboot does not have any support for BLE DFU.
MCUboot also have a requirement of same-size slots.

It seems that you need to make quite large changes to MCUboot if you want to change either of these two things.

I discussed something similar with another customer in BLE Recovery Image

Keep in mind that this was more regarding stability than space.

[quote user=""]2. Is there any way to have nRF5 SDK based bootloader to be able to flash Zephyr based builds? We have so much done with nRF5 SDK that migrating to new SDK defeats the purpose[/quote]

I am mostly experienced with the NRF Connect SDK. And my colleague who is most likely to know this have been out of office last week.
I will discuss this with him tomorrow, to figure out if it is possible or not.

If it works, I am inclined to think that the old bootloader would be the best solution for you.

[quote user=""]3. How could we swap between Zephyr/nRF-Connect-SDK and nRF5 SDK AP+SD builds?[/quote]

We have a script for converting devices from the nRF5 Bootloader to MCUboot.
I will find this tomorrow.

Regards,
Sigurd Hellesvik

RE: One bootloader to rule them all

Sigurd Hellesvik — Thu, 19 Jan 2023 11:53:14 GMT

Hi,

I will look into your questions and return with more information on Monday.

Regards,
Sigurd Hellesvik