Inquiry regarding NCSDK-38697: Unexpected DFU behavior when migrating from Partition Manager to Devicetree (NCS v3.2.4 to v3.3.1)

[a.da]

Hello.

We are developing a project based on the nRF54L15 SoC, utilizing MCUboot, image compression, and TF-M (Trusted Firmware-M).
As part of our upgrade from NCS v3.2.4 to v3.3.1, we are currently working on migrating our flash partitioning approach from Partition Manager to Devicetree.

We are aware of the known issue NCSDK-38697, which is highly critical for us. However, there seems to be a discrepancy between the description of NCSDK-38697 and our actual test results.
NCSDK-38697: Updating compressed DFU for an old project does not work with the new partitioning approach with DTS
nrfconnectdocs.nordicsemi.com/.../known_issues.html

Here is what we observed during our DFU testing:

• PM to DTS: When we applied a Devicetree-configured firmware update to a device currently running Partition Manager-configured firmware, the DFU update succeeded.
• DTS to DTS: Conversely, when we applied a Devicetree-configured firmware update to a device already running Devicetree-configured firmware, the DFU update failed.

Is this behavior expected or somehow related to the phenomenon described in NCSDK-38697?

Additionally, could you please provide a rough timeline on when NCSDK-38697 is expected to be fixed?
Since the migration guide mentions that the Partition Manager will be deprecated and removed in the future, we would like to complete our transition to Devicetree as early as possible.

Best regards,

a.da

[Amanda Hsieh]

Hi, 

Here is what we observed during our DFU testing:

• PM to DTS: When we applied a Devicetree-configured firmware update to a device currently running Partition Manager-configured firmware, the DFU update succeeded.
• DTS to DTS: Conversely, when we applied a Devicetree-configured firmware update to a device already running Devicetree-configured firmware, the DFU update failed.

Is this behavior expected or somehow related to the phenomenon described in NCSDK-38697?

No, you are not affected by NCSDK-38697 since you can successfully update the DTS partition project to the project using the PM partition initially.  

Is the issue about updating using the MCUboot instance built with DTS partitioning of 3.2.4?

Do you modify the Devicetree partition to update? It should use the same DTS partitioning to update. 

Regards,
Amanda H.

[a.da]

Hi Amanda, thanks for your reply.

Amanda Hsieh said:

Is the issue about updating using the MCUboot instance built with DTS partitioning of 3.2.4?

No.
This is a DFU from an NCS v3.3.1 DTS configuration to another NCS v3.3.1 DTS configuration.
To be clear, the device was completely erased and flashed before we conducted these tests.

Amanda Hsieh said:

Do you modify the Devicetree partition to update? It should use the same DTS partitioning to update. 

For the DTS-to-DTS DFU, the only thing we modified was the VERSION file.

Why are you asking such an elementary question?
We are well aware that the flash partition layout must remain strictly identical for a compressed DFU to work.

We look forward to your update.

Best regards,

a.da

[Amanda Hsieh]

Could you provide a simple project to help reproduce the issue on nRF54L15DK?