MCUboot override: Unknown CMake command "add_child_image"

[maximevince]

[EDITED after more investigation]

I am using workflow 4, where I have my own application's manifest "west.yml" (See https://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.5.0/nrf/dm_adding_code.html#workflow-4-application-as-the-manifest-repository)

The file structure is like this:

application
├── bootloader
│   └── mcuboot
├── manifest 
│   └── west.yaml -> my own west.yml, which imports nrf-sdk and where 'mcuboot' is defined as a project, too
├── nrf
│   └── west.yaml -> ncs's west.yml, which is being "imported" (which also contains the 'mcuboot' project)

When overriding the "mcuboot" project inside my own west.yaml, I cannot seem to properly build a multi-image hex including MCUboot anymore.

Simple test project, on ncs v1.5.0:

west build -b nrf52840dk_nrf52840 zephyr/samples/hello_world -- -DCONFIG_BOOTLOADER_MCUBOOT=y

This results in:

CMake Error at /home/vinz/Work/git/snt_zephyr/nrf/modules/mcuboot/CMakeLists.txt:112 (add_child_image):
Unknown CMake command "add_child_image".

Full terminal output:

-- west build: generating a build system
Including boilerplate (Zephyr base): /home/vinz/Work/git/snt_zephyr/zephyr/cmake/app/boilerplate.cmake
-- Application: /home/vinz/Work/git/snt_zephyr/zephyr/samples/hello_world
-- Zephyr version: 2.4.99 (/home/vinz/Work/git/snt_zephyr/zephyr)
-- Found Python3: /usr/bin/python3.9 (found suitable exact version "3.9.2") found components: Interpreter 
-- Found west (found suitable version "0.10.1", minimum required is "0.7.1")
-- Board: nrf52840dk_nrf52840
-- Cache files will be written to: /home/vinz/.cache/zephyr
-- Found dtc: /usr/bin/dtc (found suitable version "1.6.0", minimum required is "1.4.6")
-- Found toolchain: gnuarmemb (/home/vinz/gnuarmemb/gcc-arm-none-eabi-10-2020-q4-major)
-- Found BOARD.dts: /home/vinz/Work/git/snt_zephyr/zephyr/boards/arm/nrf52840dk_nrf52840/nrf52840dk_nrf52840.dts
-- Generated zephyr.dts: /home/vinz/Work/git/snt_zephyr/build/zephyr/zephyr.dts
-- Generated devicetree_unfixed.h: /home/vinz/Work/git/snt_zephyr/build/zephyr/include/generated/devicetree_unfixed.h
-- Generated device_extern.h: /home/vinz/Work/git/snt_zephyr/build/zephyr/include/generated/device_extern.h
Parsing /home/vinz/Work/git/snt_zephyr/zephyr/Kconfig
Loaded configuration '/home/vinz/Work/git/snt_zephyr/zephyr/boards/arm/nrf52840dk_nrf52840/nrf52840dk_nrf52840_defconfig'
Merged configuration '/home/vinz/Work/git/snt_zephyr/zephyr/samples/hello_world/prj.conf'
Merged configuration '/home/vinz/Work/git/snt_zephyr/build/zephyr/misc/generated/extra_kconfig_options.conf'
Configuration saved to '/home/vinz/Work/git/snt_zephyr/build/zephyr/.config'
Kconfig header saved to '/home/vinz/Work/git/snt_zephyr/build/zephyr/include/generated/autoconf.h'
-- The C compiler identification is GNU 10.2.1
-- The CXX compiler identification is GNU 10.2.1
-- The ASM compiler identification is GNU
-- Found assembler: /home/vinz/gnuarmemb/gcc-arm-none-eabi-10-2020-q4-major/bin/arm-none-eabi-gcc
CMake Error at /home/vinz/Work/git/snt_zephyr/nrf/modules/mcuboot/CMakeLists.txt:112 (add_child_image):
  Unknown CMake command "add_child_image".


-- Configuring incomplete, errors occurred!
See also "/home/vinz/Work/git/snt_zephyr/build/CMakeFiles/CMakeOutput.log".
See also "/home/vinz/Work/git/snt_zephyr/build/CMakeFiles/CMakeError.log".

I am on Arch Linux, with CMake 3.19.7.
I tried using ARM GCC Embedded, Zephyr SDK 0.11.3, 0.12.3, but to no avail.
Also tried to remove zephyr cache (rf -rf ~/cache/zephyr), but the result is the same.

When I remove my own "mcuboot" project from my west.yml, and therefor the one imported from nrf/west.yml is used instead, everything works as expected.
Except of course, then I cannot use my custom "mcuboot" softfork.

Is this a known issue? How can I use my own "mcuboot" softfork, without having to fork the "nrf-sdk" repo as well?

[maximevince]

Apparently, it's caused by the fact that I have overriden the "mcuboot" project in my own west.yml manifest.

Although it's pointing to the exact same revision:

manifest:
  remotes:
    - name: ncs
      url-base: https://github.com/nrfconnect
    <...>
  projects:
    <...>
    - name: mcuboot
      repo-path: sdk-mcuboot
      revision: v1.7.99-ncs1
      remote: ncs
      path: bootloader/mcuboot

I am not entirely sure what is causing this issue, since effectively checked out git revisions are the same.

Since I want to make some changes to the default MCUboot configuration (especially pm.yml), I will need to refer to my own fork.

Any suggestions on how to proceed?

[Sigurd]

Hi,

The function add_child_image is defined here, https://github.com/nrfconnect/sdk-nrf/blob/v1.5.0/cmake/multi_image.cmake#L42 , so need to have that.

When I remove my own "mcuboot" project from my west.yml

 Is your own custom mcuboot project repo based on nordic sdk-mcuboot , or the upstream mcuboot ?

[maximevince]

Thanks Sigurd. I understand where to find the "add_child_image", but the CMake build system still can't find it.

All I did was override the "mcuboot" project with a softfork (without any changes!) of the  nordic sdk-mcuboot (the one the original west.yml pointed at).

Did you try to create a custom west.yml, where you import the NCS manifest, but also override the mcuboot project? I image you will find similar results.

[k.szpila]

Hi, I stumbled upon the same problem. For some reason
this happens when `sdk-nrf` project is not first repo in a `project:` node.

This results in an error `Unknown CMake command "add_child_image".`

manifest:

defaults:

remote: upstream

remotes:

- name: upstream

url-base: https://github.com/nrfconnect

projects:

- name: cmock

path: test/cmock

revision: c243b9a7a7b3c471023193992b46cf1bd1910450

remote: throwtheswitch

- name: sdk-nrf

remote: upstream

path: nrf

revision: v1.3.0

This works:

manifest:

defaults:

remote: upstream

remotes:

- name: upstream

url-base: https://github.com/nrfconnect

projects:

- name: sdk-nrf

remote: upstream

path: nrf

revision: v1.3.0

- name: cmock

path: test/cmock

revision: c243b9a7a7b3c471023193992b46cf1bd1910450

remote: throwtheswitch

[maximevince]

Awesome, thanks!
It's a pity Nordic does not seem to be aware of the problem nor the solution.