Sysbuild and mcuboot without partition manager

[AndrewSafehear]

Hello,

I would like to use sysbuild and mcuboot without the partition manager but the sdk does not let me disable it.

I'm trying to disable the partition manager with the sysbuild/with-mcuboot sample for the nrf52840dk_nrf52840 board.

# Sysbuild configuration file.

# Enable MCUboot per default for this sample.
SB_CONFIG_BOOTLOADER_MCUBOOT=y
SB_CONFIG_PARTITION_MANAGER=n

Is there a way to disable it ?

[Amanda Hsieh]

Hi, 

The Partition Manager is activated for all multi-image builds, regardless of which build strategy is used for the child image. 

CONFIG_PARTITION_MANAGER_ENABLED is a read-only option, and it's not possible to disable that way or manually disable those other options. See https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/kconfig/index.html and the description of https://github.com/nrfconnect/sdk-nrf/blob/main/subsys/partition_manager/Kconfig#L9

Regards,
Amanda H. 

[AndrewSafehear]

Hello,

Then why is the option SB_CONFIG_PARTITION_MANAGER not read only ? sdk-nrf/sysbuild/Kconfig.sysbuild at main · nrfconnect/sdk-nrf (github.com) and sdk-nrf/sysbuild/CMakeLists.txt at main · nrfconnect/sdk-nrf (github.com).

I've found that the Kconfig that is forcing the partition manager is the Kconfig.template.build_strategy file where PARTITION_MANAGER_ENABLED is selected. Like you said regardless of which build strategy is used, it is activated.

While tinkering with this, I've found that the Kconfig imply keyword is better than select. When you search for the imply keyword in the documentation, you can find that there is a pitfall while using the select keyword.

But as the build strategy force the partition manager, this commit become kind of useless kconfig: control PARTITION_MANAGER_ENABLED through sysbuild · nrfconnect/sdk-nrf@250bbe3 (github.com).
After changing those select PARTITION_MANAGER_ENABLED into imply PARTITION_MANAGER_ENABLED, the project build correctly.

The problem is that now, mcuboot is not finding the primary slot, because of the partition not being at the right place in the flash.

When I put those lines inside the Kconfig.defconfig of the nrf52840dk_nrf52840 it's working as intended.

config FLASH_BASE_ADDRESS
      default 0x200 if BOOTLOADER_MCUBOOT  && !PARTITION_MANAGER_ENABLED
config ROM_START_OFFSET
      default 0x0

The problem is that I need to tinker the nrf-sdk to make it work...

Is it possible to at least switch to the imply keyword ? We use a custom nRF52840 board and I can change my own Kconfig.defconfig file.

Regards,

Andrew

[Amanda Hsieh]

Hi, 

The thing is, if you disable PM, then none of the NCS stuff will work, you might be able to use mcuboot and their app, but there would be no b0 support, not sure if Bluetooth would work, signing might fail, etc.

-Amanda H.

[AndrewSafehear]

Hi,

So there is no way of only switching from the keyword select to the keyword imply inside the Kconfig.template.build_strategy file ?

It's not breaking anything, only letting the user the choice of disabling the partition manager at his own risk.

Andrew

[Amanda Hsieh]

Hi, 

We don't suggest and support to do that way. 

-Amanda H.

[HamzaDot]

Hi, 

What was the idea behind introducing partition manager instead of using devicetree on zephyr for B0 bootloader and MCUBoot? 

Furthermore, is it possible to generate B0 bootloader and MCUBoot without partition manager and NCS?