NRF54L15 FOTA 2.8.0 SDK Clarification

[dmacpro91]

I'm trying to get FOTA updates working on the NRF54L15 DK. I noticed there isn't a dedicated guide available for these yet so have been using this page: https://docs.nordicsemi.com/bundle/ncs-2.8.0/page/nrf/app_dev/device_guides/nrf54l/fota_update.html

I've enabled the recommended config options, but I'm not getting a *.zip archive after building. Is there a more comprehensive guide on how to setup FOTA using the NRF54L15?

[AHaug]

Hi,

The way you've set it up is almost correct for the "non-sysbuild" way to do this i.e the old way to do this. To set it up using sysbuild you have to enable the bootloader through sysbuild.conf using the sysbuild config for the MCUboot companion component (SB_CONFIG_BOOTLOADER_MCUBOOT) that replaces the old Kconfig for the MCUboot child_image (CONFIG_BOOTLOADER_MCUBOOT). In short, the guide itself is as comprehensive as one needs given that you already know how sysbuild and companion components works vs how the deprecated child images work (same thing, new name and structure), but it omits explaining the following:

As described in the steps you linked:

• Enable the SB_CONFIG_BOOTLOADER_MCUBOOT option to use MCUboot as a bootloader. You can do this by, for example, setting the option in the sysbuild.conf file. For more information, go to the Adding MCUboot as an immutable bootloader page.

sysbuild.conf overwrites prj.conf for those Kconfigurations that sysbuild has a replacement from, meaning that since you don't state anything about MCUboot within sysbuild.conf, then sysbuild does not include anything about MCUboot and overwrites the mention of MCUboot in prj.conf with nothing.

Here's some other useful links that you can keep close until the devacademy gets updated (est. February) to explain more about sysbuild and DFU using sysbuild: 

1. The guide you used links to https://docs.nordicsemi.com/bundle/ncs-2.8.0/page/nrf/app_dev/bootloaders_dfu/mcuboot_nsib/bootloader_mcuboot_nsib.html at the top, but you should pay extra attention to 
   1. https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/app_dev/bootloaders_dfu/mcuboot_nsib/bootloader_adding_sysbuild.html and 
   2. https://docs.nordicsemi.com/bundle/ncs-2.8.0/page/nrf/app_dev/companion_components.html 
2. https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/app_dev/bootloaders_dfu/sysbuild_image_ids.html 
3. https://docs.nordicsemi.com/bundle/ncs-2.9.0/page/nrf/app_dev/config_and_build/sysbuild/sysbuild_forced_options.html 

To fix your issue assuming that you also have CONFIG_BT_PERIPHERAL in your prj.conf:

1. Create a sysbuild.conf within your project (same level as prj.conf)
2. add SB_CONFIG_BOOTLOADER_MCUBOOT=y to sysbuild.conf
3. Remove CONFIG_BOOTLOADER_MCUBOOT=y from prj.conf 
4. Add CONFIG_NCS_SAMPLE_MCUMGR_BT_OTA_DFU=y to your prj.conf
5. Build and now you should observe 

This will be equivalent as building with the fragments:  "west build -b board_target -- -DSB_CONFIG_BOOTLOADER_MCUBOOT=y -DCONFIG_NCS_SAMPLE_MCUMGR_BT_OTA_DFU=y"

Let me know if this allows you to generate the update zip that you need

Kind regards,
Andreas

[dmacpro91]

Ah I thought proj.conf was roughly equivalent to/overrode sysbuild.conf. I've been trying to learn this new system as fast as possible so may have overlooked that detail. After doing what you recommended I was able to successfully build and get a dfu_application!

[AHaug]

Yeah, I can see the confusion there. It's "the same but different", but it should allow for a much better multi-image build system.

Nonetheless, glad to hear you were successful! 

Also FYI, the sysbuild course on our academy pages that I referred to got published yesterday: https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-8-sysbuild/topic/sysbuild-explained/ 

The first exercise in the bootloader course was also updated to sysbuild now (with more to come this week)

Kind regards,
Andreas