NRf9151 - external flash with MCUboot

RE: NRf9151 - external flash with MCUboot

Syed Maysum Abbas Zaidi — Thu, 16 Jul 2026 14:11:34 GMT

Hi,

Great to hear that. Yes you can check it properly and feel free to get back to us if anything comes up. Thanks.

Best Regards,
Syed Maysum

RE: NRf9151 - external flash with MCUboot

mmohorcic — Thu, 16 Jul 2026 13:08:20 GMT

Hello,

Thank you for your help.

Together with the updates in the repo, going very slowly and checking everything it seems like i have a working version.
https://github.com/NordicDeveloperAcademy/ncs-inter/tree/preview

Setting the partitions like so, fixing the mcuboot and configuration files... :

It seems that it works.

I'll do some more extensive testing before i confirm a working solution, but so far it seems OK.

Thank you for your help!

RE: NRf9151 - external flash with MCUboot

Syed Maysum Abbas Zaidi — Fri, 10 Jul 2026 15:22:49 GMT

Hi,

Thanks a lot for providing the project files. I can see that your MCUboot overlay doesn’t set zephyr,code-partition = &boot_partition. MCUboot may inherit &slot0_partition (0x10000) from the board DTS, while MCUboot is flashed at boot_partition (0x0). That mismatch can cause an immediate fault. Can you try adding this to your MCUboot overlay:

/ {
    chosen {
        zephyr,code-partition = &boot_partition;
    };
};

This tells MCUboot it runs from the correct address (0x0). Try and let us know if it fixes the issue.

Best Regards,
Syed Maysum

RE: NRf9151 - external flash with MCUboot

mmohorcic — Thu, 09 Jul 2026 12:52:43 GMT

Hi,

Thanks for you response.

Yes, the board is fully tested without the mcuboot (including flash access, power consumption)

Sorry for late response, It took me quite some time to remove everything else and to produce minimal definition that should in my mind work. Looking at differences it is quite close to a DK with removed unused periphery.

Board named mcuboot_minimal

- i created a new custom board using the nrf connect tool with 9151 SOC (3.4 NRF release)
- partitioning remove slot1
- add ext_flash and add slot1
- in ____common.dtsi define flash and uart interface
- in same file define console and uart to avoid any weird behaviour

Attached in zip file.

I'll try to further minimize and optimize the build.

Best,
Miha M

devzone.nordicsemi.com/.../clnMcu.zip

RE: NRf9151 - external flash with MCUboot

Syed Maysum Abbas Zaidi — Wed, 08 Jul 2026 10:49:27 GMT

Hi,

Thanks for the detailed description. To help pinpoint the issue, could you share

- Your custom board DTS file
- Your sysbuild.conf and MCUboot files (sysbuild/mcuboot.conf and overlay)

And does the board boot without MCUboot (plain hello_world)?

Best Regards,
Syed Maysum