Bootloader for nrf Connect SDK

[Akhil Francis]

Hello, I'd like to use the nRF Connect SDK to add DFU functionality to the nrf52810. Is there any sample code for that? I intend to use the B0 bootloader (the NRF immutable bootloader) as my bootloader. Bootloader, will it support BLE connectivity for application upgrades? Can I use the nRF connect app's DFU feature for the app upgrade by creating a zip file of the application as previously?

[Einar Thorsrud]

Hi,

I'd like to use the nRF Connect SDK to add DFU functionality to the nrf52810

You normally use MCUBoot as the main bootloader, and optionally the nRF Immutable Bootloader to achieve secure boot and an upgradable bootloader. See FOTA over Bluetooth Low Energy in the getting started section. This also describe the SMP server sample in Zephyr, that demonstrates DFU over different transports, including BLE.

Can I use the nRF connect app's DFU feature for the app upgrade by creating a zip file of the application as previously?

Yes, it supports DFU over SMP so you need an SMP sever in your application (refer to the mentioned SMP server sample).

Note that DFU in the nRF Connect SDK is always dual bank, so as the nRF52810 has a quite small flash you may need to use external flash for the secondary slot (or alternatively consider moving to a device with larger internal flash).

[Akhil Francis]

Okay, if I am using only the nRF immutable bootloader, it won't support application upgrade over BLE?

[Einar Thorsrud]

It is possible to support DFU over BLE with nRF immutable bootloader as well. That will be more proprietary though (using the Configuration channel and Device Firmware Upgrade module like the nRF Dekstop reference application), or something you device on your own. With MCUBoot and SMP server you get a standardized solution with a number of supporting tools etc out of the box.

If you have a preference to use the nRF immutable bootloader as the only bootloader, see how that is done in nRF Desktop.