Use of EXTRA_ZEPHYR_MODULES and custom board within a project with several freestanding apps

RE: Use of EXTRA_ZEPHYR_MODULES and custom board within a project with several freestanding apps

Vidar Berg — Fri, 16 Aug 2024 12:58:34 GMT

Hi,

I tried testing this on my end but did not encounter any build errors. I've attached the test sample I created. Could you please review it to see what we are doing differently?

devzone.nordicsemi.com/.../external_5F00_module_5F00_test.zip

Folder structure:

external_module_test/
├── hello_world
│   ├── build
│   ├── CMakeLists.txt
│   ├── prj.conf
│   ├── README.rst
│   ├── sample.yaml
│   └── src
├── hello_world_1
│   ├── build
│   ├── CMakeLists.txt
│   ├── prj.conf
│   ├── README.rst
│   ├── sample.yaml
│   └── src
└── my_module
├── boards
└── zephyr

RE: Use of EXTRA_ZEPHYR_MODULES and custom board within a project with several freestanding apps

Ignacio — Fri, 16 Aug 2024 12:21:03 GMT

Thanks for the prompt reply Vidar. If I try to set the module directly on the proect folder, I get the below error. Is there a way to overcome this? Is it a requirement to place the modules files on a separate directory?

CMake Error at /opt/ncs/v2.6.0/zephyr/CMakeLists.txt:591 (add_subdirectory):
The binary directory

/home/x/git/zephyr_project_sample/source/build

is already used to build a source directory. It cannot be used to build
source directory

/home/x/git/zephyr_project_sample

Specify a unique binary directory name.

RE: Use of EXTRA_ZEPHYR_MODULES and custom board within a project with several freestanding apps

Vidar Berg — Fri, 16 Aug 2024 09:55:51 GMT

Hello,

I beleive you need to specify the absolute path to your zephyr module when setting it from your CMakelists.txt file before find_package().

e.g.,

cmake_minimum_required(VERSION ...
set(EXTRA_ZEPHYR_MODULES "${CMAKE_CURRENT_SOURCE_DIR}/../")

find_package(..

Also, 'boards' should be a subdirectory of your module directory.

e.g.,

my_module/
├── boards
│ └── arm
└── zephyr
└── module.yml

module.yml

build:
  settings:
    board_root: .

Another way to use an out-of-tree board without creating a new Zephyr module is to append the path to your board root to the BOARD_ROOT variable by adding the following line to your CMakeLists.txt file:

list(APPEND BOARD_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/../)

Regardless of the approach you use, you may need to specify the board root path in the VS code extension for it to detect your custom board:

https://docs.nordicsemi.com/bundle/nrf-connect-vscode/page/guides/bd_boards_devices.html#finding-new-boards

Best regards,

Vidar