Partition Manager and device tree partitions

RE: Partition Manager and device tree partitions

Udi Vahaba — Mon, 23 Sep 2024 08:59:11 GMT

Hello, i'm facing the same issue.
when using the CONFIG_PARTITION_MANAGER_ENABLED=y i can see that the partitions are generated dynamically.
so i tried to remove from my dts the fixed partitions:

&flash0 {

	partitions {
		compatible = "fixed-partitions";
		#address-cells = < 0x1 >;
		#size-cells = < 0x1 >;
		boot_partition: partition@0 {
			label = "mcuboot";
			reg = < 0x0 0xc000 >;
		};
		slot0_partition: partition@c000 {
			label = "image-0";
			reg = < 0xc000 0x76000 >;
		};
		slot1_partition: partition@82000 {
			label = "image-1";
			reg = < 0x82000 0x76000 >;
		};
		storage_partition: partition@f8000 {
			label = "storage";
			reg = < 0xf8000 0x8000 >;
		};
	};
};

I tried to delete the whole node, and also the partitions sub-node. both ways make the build to fail.

It is not making sense to keep them in the DTS if they are generated with the partition manager..
so is there a way to remove them from the dts?

RE: Partition Manager and device tree partitions

liteyear — Sat, 15 Jun 2024 01:42:58 GMT

Okay thanks. I still get occasional build errors complaining about missing partitions like "slot0_partition", now that I've stripped out fixed-partitions, but they always turn out to be a KConfig issue, not DT. So I suppose it makes sense the references will remain, even in the scenarios where the DT definitions aren't required.

RE: Partition Manager and device tree partitions

Vidar Berg — Fri, 14 Jun 2024 13:13:06 GMT

Hello,

I understand the confusion. I hope this is something we will be able to address in the not too distant future by aligning on a common solution for upstream Zephyr and our nRF Connect SDK.

In the nRF Connect SDK, the multi-image build feature requires the use of the partition manager, but the multi-image support with parent/child images is currently being replaced by the Sysbuild feature from upstream. The partition manager allows the memory layout to be controlled dynamically based on what is enabled by the parent image (bootloader, settings storage, etc.). Before Sysbuild (a multi-image build equivalent) was introduced in Zephyr upstream, you would have to build firmware images such as MCUBoot separately.

[quote user=""]As far as I can tell now (at least since ncs v2.5.2), if MCUBoot is enabled with CONFIG_BOOTLOADER_MCUBOOT, the build becomes a "Multi-image build". That enables Partition Manager, which makes fixed-partitions in the DTS irrelevant.[/quote]

This is correct. The project will become a multi-image project when enabling child images. For instance, when you enable MCUBoot, or Bluetooth. With Bluetooth enabled, the Bluetooth controller FW for the network core will also be automatically included as a child-image.

[quote user=""]incorrect. So which is it? Does MCUBoot make fixed-partitions necessary, or unnecessary?[/quote]

The DT would still be relevant if you built the MCUBoot project separetly instead of building it as a child-image to your parent applicaiton.

Best regards,

Vidar