nrf5340 Audio App with MCUBoot app verification timing

RE: nrf5340 Audio App with MCUBoot app verification timing

Vidar Berg — Wed, 29 Oct 2025 17:36:18 GMT

Good to hear! Thank you for the update.

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 16:29:06 GMT

Ok I figured it out. My sysbuild folder was located within the zephyr workspace but the folder structure is a little different. Once I moved the sysbuild to the proper folder, the kconfig in mcuboot/prj.conf started taking effect. Thanks for your help! It led me to the solution.

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 15:18:37 GMT

When I change the default to 'n' in the boot/zephyr/kconfig, then it is no longer set. So it appears for some reason my prj file isn't being applied.

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 15:13:25 GMT

When I select that, it goes to the prj file within the bootloader folder which as I stated earlier, would be overwritten if I did a West Update. This appears to be the problem. This project is not using the prj.conf file inside the sysbuild/mcuboot folder.

RE: nrf5340 Audio App with MCUBoot app verification timing

Vidar Berg — Wed, 29 Oct 2025 15:05:45 GMT

Both methods are supported. The difference is that sysbuild->mcuboot->prj.conf replaces the default configuration here https://github.com/nrfconnect/sdk-mcuboot/blob/main/boot/zephyr/prj.conf while sysbuild->mcuboot.conf just becomes an overlay on top of the default configuration file.

The UI in the Vs code extension allows you to verify which Kconfig files and fragments are included for the mcuboot build

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 14:26:23 GMT

Should the folder structure for the West t2 topology look like this in the tutorial or should it be sysbuild->mcuboot->prj.conf like I have read in other locations?

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 14:12:56 GMT

Actually it just looks like none of my settings in sysbuild->mcuboot->prj.conf are taking effect.

RE: nrf5340 Audio App with MCUBoot app verification timing

Vidar Berg — Wed, 29 Oct 2025 14:09:26 GMT

Just as a way to troubleshoot this, maybe you can try to change the default to 'n' here https://github.com/nrfconnect/sdk-mcuboot/blob/a8161d7dcccd9503c48678219dd535ebd24b7c3c/boot/zephyr/Kconfig#L544 and see if you still get the same result. If you do, it must be something else selecting this symbol in your build.

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 13:58:39 GMT

I added that and no difference. I think the proper term for my project configuration is West t2 topology. I will continue to look for where this is getting overwritten.

RE: nrf5340 Audio App with MCUBoot app verification timing

Vidar Berg — Wed, 29 Oct 2025 13:44:00 GMT

Did you also try with SB_CONFIG_MCUBOOT_APP_SYNC_UPDATEABLE_IMAGES=n too. I don't see it listed from the screenshot you posted.

It should not make any difference whether this is a standalone project or a "west project".

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 13:38:20 GMT

I already have the single app enabled in sysbuild.conf

When I pull in your project and add the setting to sysbuild/mcuboot/prj.conf, the output .config changes as I would expect. But the difference is this is a standalone project. The project I am having issues with is a West project. Do you have any way to test this same SerialRecovery project in a West environment?

RE: nrf5340 Audio App with MCUBoot app verification timing

Vidar Berg — Wed, 29 Oct 2025 13:16:11 GMT

None of these seem directly related to the issue. But I think the warning regarding UPDATEABLE_IMAGE_NUMBER and MCUBOOT_UPDATE_FOOTER_SIZE should go away if you add the following two lines to your sysbuild.conf

SB_CONFIG_MCUBOOT_MODE_SINGLE_APP=y
SB_CONFIG_MCUBOOT_APP_SYNC_UPDATEABLE_IMAGES=n

CONFIG_PM is not supported on the nRF53 (has no use), so you can remove CONFIG_PM=y from your project configuration.

Here is the project I used for test:

devzone.nordicsemi.com/.../hello_5F00_world_5F00_serial_5F00_recovery_5F00_usb.zip

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 13:01:50 GMT

I do have a couple of warnings I'm looking into.

warning: UPDATEABLE_IMAGE_NUMBER (defined at C:/Projects/Reach/hp-fw/zfw-wksp/handpiece-
fw/reach_hp\dfu/conf/Kconfig.dfu:149, C:/Projects/Reach/hp-fw/zfw-
wksp/nrf\samples\common\mcumgr_bt_ota_dfu/Kconfig:89, subsys/dfu/Kconfig:95) was assigned the value
'1' but got the value ''. Check these unsatisfied dependencies: ((AUDIO_DFU = 2 && NRF5340_AUDIO) ||
((BOARD_THINGY53_NRF5340_CPUAPP || BOARD_THINGY53_NRF5340_CPUAPP_NS) && SOC_SERIES_NRF53X &&
NCS_SAMPLE_MCUMGR_BT_OTA_DFU) || (!MCUBOOT && IMG_MANAGER)) (=n). See
http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_UPDATEABLE_IMAGE_NUMBER and/or look up
UPDATEABLE_IMAGE_NUMBER in the menuconfig/guiconfig interface. The Application Development Primer,
Setting Configuration Values, and Kconfig - Tips and Best Practices sections of the manual might be
helpful too.


warning: PM (defined at C:/Projects/Reach/hp-fw/zfw-
wksp/zephyr/soc/silabs\silabs_s2\efr32bg22\Kconfig.defconfig:12, C:/Projects/Reach/hp-fw/zfw-
wksp/zephyr/soc/silabs\silabs_s2\efr32bg27\Kconfig.defconfig:12, C:/Projects/Reach/hp-fw/zfw-
wksp/zephyr/soc/silabs\silabs_s2\efr32mg24\Kconfig.defconfig:12, subsys/pm/Kconfig:13) was assigned
the value 'y' but got the value 'n'. Check these unsatisfied dependencies: ((SOC_SERIES_EFR32BG22 &&
SOC_VENDOR_SILABS) || (SOC_SERIES_EFR32BG27 && SOC_VENDOR_SILABS) || (SOC_SERIES_EFR32MG24 &&
SOC_VENDOR_SILABS) || (SYS_CLOCK_EXISTS && HAS_PM)) (=n). See
http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_PM and/or look up PM in the
menuconfig/guiconfig interface. The Application Development Primer, Setting Configuration Values,
and Kconfig - Tips and Best Practices sections of the manual might be helpful too.


warning: MCUBOOT_UPDATE_FOOTER_SIZE (defined at subsys/dfu/Kconfig:54) was assigned the value '0x0'
but got the value ''. Check these unsatisfied dependencies: MCUBOOT_IMG_MANAGER (=n), IMG_MANAGER
(=n). See http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_MCUBOOT_UPDATE_FOOTER_SIZE and/or
look up MCUBOOT_UPDATE_FOOTER_SIZE in the menuconfig/guiconfig interface. The Application
Development Primer, Setting Configuration Values, and Kconfig - Tips and Best Practices sections of
the manual might be helpful too.

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 12:56:03 GMT

I reverted the prj.conf within the bootloader back to its original state. Then I rebuilt with the desired settings in my sysbuild/mcuboot/prj.conf and I get the same results. You can see here on the right that the result is to validate the slot.

RE: nrf5340 Audio App with MCUBoot app verification timing

Vidar Berg — Wed, 29 Oct 2025 12:40:25 GMT

Hello,

I couldn’t reproduce the issue of being unable to unselect the CONFIG_BOOT_VALIDATE_SLOT0 symbol.

Did you check the build output to see if there were any Kconfig warnings that might explain why the symbol ended up being selected even though it was set to =n in your config? It’s generally easier to troubleshoot Kconfig issues when it’s the other way around where you’re trying to enable something.

EDIT: I would also recommend considering the BOOT_VALIDATE_SLOT0_ONCE config. It's a bit safer.

Best regards,

Vidar

RE: nrf5340 Audio App with MCUBoot app verification timing

adunk — Wed, 29 Oct 2025 12:19:51 GMT

Previously I was able to see that the these settings were not taking effect by looking at the .config file in the build/mcuboot/zephyr folder. It was also obvious that the validation was taking place due to the 2 second delay before entering the application. Regardless of what settings I changed in the sysbuild/mcuboot/prj.conf file, they weren't being applied to the project.

After continuing to read about mcuboot, nordic, and zephyr, I tried making the change by selecting mcuboot in the vs code/Applications window and then using the nRF kconfig GUI Action. I changed the MCUBoot settings to Single slot and deselected "Validate image in the primary slot on every boot" and then I noticed that setting finally went away in the kconfig and then I loaded the code and it worked. This is great but the problem is it looks like the setting is being applied to the bootloader\mcuboot\boot\zephyr\prj.conf file. I want this setting to be within the project workspace such as within the sysbuild/mcuboot folder.

If I change the sdk and do a west update, these files will revert back to their original state and those settings are lost.