SDK 3.4.0 build/flash issue

RE: SDK 3.4.0 build/flash issue

Vidar Berg — Wed, 05 Aug 2026 17:24:18 GMT

Thank you for the kind feedback. The default memory layout is now defined by the Devicetree include file here: https://github.com/nrfconnect/sdk-zephyr/blob/ncs-v3.4.0/dts/vendor/nordic/nrf91xx_partition.dtsi. However, unlike on the nRF54L Series, this file also includes the boot partition for a bootloader, which I had not noticed until now. This means that you will get an empty partition at address 0 unless you also include MCUboot in your build (-DSB_CONFIG_BOOTLOADER_MCUBOOT=y) or create a Devicetree overlay that removes the boot_partition.

[quote user="embeddedCoder"]I've still not got my head round where to set it in an overlay for DTS for the TF-M. Perhaps it was using slot0_partition rather than boot_partition? I still can't see where it was picking it up from.[/quote]

Yes, this is exactly the problem. The slot is picked up from the DT include file linked above. This section of the SDK documentation explains how you can change the partitions https://nrfconnectdocs.nordicsemi.com/ncs/latest/nrf/app_dev/device_guides/nrf91/nrf91_dt_partitions.html#configuring-partitions-on-an-nrf91-series-device. For example, if you want to remove the boot_partition.

I do think it is a bit unfortunate that basic Zephyr samples, such as "Hello World" do not work out of the box when building for nRF91 series devices with TF-M. I will report this internally. Hopefully, we can come up with a better solution.

RE: SDK 3.4.0 build/flash issue

embeddedCoder — Tue, 04 Aug 2026 19:36:13 GMT

Yes, that was the problem, without the CMake flag TF-M origin was 0x00010000.

I've still not got my head round where to set it in an overlay for DTS for the TF-M. Perhaps it was using slot0_partition rather than boot_partition? I still can't see where it was picking it up from.

Thanks for your help, for being so responsive, and for such clear instructions/screen shots which were very easy to follow.

RE: SDK 3.4.0 build/flash issue

Vidar Berg — Tue, 04 Aug 2026 10:44:17 GMT

Hello,

It sounds like the issue is that the application is being placed elsewhere in flash, since the old application continues to run after flashing. This could be related to the transition from using Partition Manager to static Devicetree partitions for managing the memory layout (Migrating partition configuration from Partition Manager to devicetree (DTS)). As you may have seen, Partition Manager is no longer enabled by default in SDK v3.4.0, and I would say this is the biggest difference between the two releases.

Are you using the nrf9151dk as your build target, or have you defined your own board. Either way, as a test, please try building with the Partition manager enabled by passing the CMake argument below to your build command.

-DSB_CONFIG_PARTITION_MANAGER=y

You may also verify the start address of the TF-M and application image from the *.map output. TF-M should be starting at 0x0.

Best regards,

Vidar