This example was developed to address the gap in the existing samples that didn't provide clear boilerplate code for making custom application and netcore images while supporting BT LE in nRF5340.
With this example, the developer should be able to set a working structure to get the development going. There are multiple ways to accomplish the same task so the reader should not think this as the only way to accomplish the task. Having said that the example is aiming to adopt the latest best practices but as the best practices are a moving target, anybody with more up to date approach to enhance the codebase should not be shy to suggest pull requests to improve the sample.
This sample supports multi-image builds as well as flashing both cores 'as-is' from VS. The sample has been tested with nRF Connect SDK 2.5.0.
Multi-image requires using sysbuild so when configuring the project. File sysbuild.conf is used for pushing configuration parameters from the top image to the netcore. Most cases one should be able to perform core specific configurations through prj.conf but eg. forcing the build system to include MCUBoot in netcore requires the parent image configuration through the file.
The project is using MCUBoot on both images. Both application and netcore assets have child_image folder for configuring mcuboot. This example has nothing special around MCUBoot for being multicore. Both MCUBoots share the keyfile priv.pem in the root.
The example have minimal BT configuration to enable connecting and also included Device Information Service (DIS) as basic service to test.
Some BT settings must be shared between the netcore- and multicore-images to ensure seamless co-operation between the images. This is more related to the lower-layer parameters. It is not clear what are all the parameters that should be shared and thus the current implementation only includes an educated guess.