Partition Manager and device tree partitions

[sachrmed]

I needed to add my own partition to the primary flash, and was able to do so successfully by adding a section to the device tree partitions.

However, when adding MCUBoot, the build would fail. I found that this was due to the build invoking a multi-image build and thus using Partition Manager.

I'd like this partition to remain at a static address, so I was able to get things going by creating a pm_static.yml in my project with the appropriate address and size.

I'm now cleaning things up, and if I remove the partitions and "zephyr,code-partition = &slot0_partition;" from the dts, the build fails since it cannot find a boot partition.

I see this in the build log:

devicetree error: /chosen: undefined node label 'boot_partition'

Do I have to define both partitions in the dts as well as in partition manager?

Thanks!

[Marte Myrvold]

Hi,

When you build a multi-image application, the partitions in devicetree should be ignored.
However, in the case of MCUboot, the MCUboot child image is built before Partition Manager runs, and MCUboot is using boot_partition in the file bootloader/mcuboot/boot/zephyr/dts.overlay.

If interested, you can add printing to the Partition Manager script, nrf/scripts/partition_manager.py, to see when it runs during the build process (for testing/debugging purposes). As an example, I added the following right before PartitionError:

print("------------------")
print("Partition Manager")
print("------------------")

After adding this and building, I can see that the Partition Manager script only runs after the MCUboot child image is done building (which you can see from === child image mcuboot - end ===).

Best regards,
Marte

[sachrmed]

Thank you for the reply Marte!

I suppose all I need in the dts is a simple config like so, and leave the rest to Partition Manager?

&flash0 {

    partitions {
        compatible = "fixed-partitions";

        boot_partition: partition@0 {
            label = "mcuboot";
            reg = <0x000000000 0x0000C000>;
        };
    };
};

[Marte Myrvold]

Hi,

Yes, that is correct.
I have been out of the office, so I apologize for the delay. Have you been able to test this while I was away?

Best regards,
Marte

[sachrmed]

Thanks for the reply Marte, and no problem with the delay

Indeed I have tested it and it seems to be working.

[Marte Myrvold]

That is great to hear

[puz_md]

Hi Marte,

if MCUboot is compiled before the partition manager runs, then how does it know the locations of the application partitions / slots? Do I have to match the devicetree partition definitions with pm_static.yml?

Best regards,
Michael