-----Original Message-----
From: David Brown [mailto:david.brown@linaro.org]
Sent: 29 August 2017 15:57
To: Cufi, Carles <Carles.Cufi@nordicsemi.no>
Cc: zephyr-devel@lists.zephyrproject.org
Subject: Re: [Zephyr-devel] Zephyr DFU protocol

On Tue, Aug 29, 2017 at 09:14:31AM +0000, Cufi, Carles wrote:

While having one single protocol would definitely be a boon, I am not
sure LWM2M will fit the bill in terms of RAM and ROM requirements, and
we still need something for the UART recovery mode in the bootloader,
which will probably end up being the Newt Manager Protocol since I
don't think we can fit LWM2M into a bootloader.

Given that there are other parties that have an interest in lwm2m, I
think we should put our focus into supporting newtmgr for upgrades.
The other protocols (lwm2m, and USB DFU) will probably be implemented as
there is need for them.

I completely agree with you. I would like to focus our (Nordic's) efforts into the simple protocol first, that works over UART and BLE, while the work towards LWM2M and other advanced protocols proceeds in parallel. The image management code will of course be protocol-independent, so once those PRs that Andrzej has sent are merged all other teams will be able to benefit from them.

What would be nice would be to take the target-side newtmgr code, and
make it into its own project. We would need to refactor and abstract
the operating system interfaces so that we can use the same codebase for
multiple platforms. This would be similar to how mcuboot is now its own
project that works on Zephyr and Mynewt (and soon RIOT).

That would be my preference as well, but it might not be as trivial as it sounds. I need to discuss this further with the Mynewt developers, because some of the abstractions (namely mbuf) might not be easy to port. Once we choose a protocol, and if this ends up being NMP, I would like to start those discussions ASAP with the contributions of the Mynewt community.

Regards,

Carles