nRF5340 Adding a custom HCI_RPMsg child image to an application

[Austin Hellenbrand]

Hello, 

I have two projects, one for the application core (modified BLE Peripheral sample) and the second is for the network core (modified HCI_RPMsg sample). I am currently using nRF Connect SDK v1.9.0 with VS Code and I have a nRF5340DK. 

Following this post (NRF5340 Multi-Image example configuration help), I was able to build my application core image with my customized HCI_RPMsg project as a child image. However, this required adding/modifying files within the SDK install, which isn't an ideal solution.

I have also tried following the defining and enabling a child-image guide, but the pm_config.h files were not being generated for the HCI_RPMsg image. 

Is there a way I can do this without having to modify the SDK? If not, is this something that could be added to the SDK in the future? 

Regards, 

Austin

[Amanda Hsieh]

Hi, 

The NCS_SAMPLE_EMPTY_APP_CORE_CHILD_IMAGE is used while running with empty_app_core, so I think you could try to add CONFIG_PARTITION_MANAGER_ENABLED into the app proj.conf. To enable config for HCI_RPMsg, you could create hci_rpmsg.conf under child_image folder. 

-Amanda. 

[Austin Hellenbrand]

Hello,

Sorry, I'm not sure if you fully understood my question, let me try and rephrase it.

The application core is running an image that was started from the BLE peripheral sample and I have since added my own code. 

The network core is running an image that was started from the HCI_RPMsg sample. I have added a time sync mechanism based off of this post (Wireless timer synchronization among nRF5 devices) to the project. 

Both projects are located in my workspace folder outside of the SDK install. So is there a way to build my application image with my network core project as a child image that doesn't require modifying the SDK? 

Regards, 

Austin

[Amanda Hsieh]

Hi Austin, 

Austin Hellenbrand said:

So is there a way to build my application image with my network core project as a child image that doesn't require modifying the SDK? 

There is no config to run the custom network core project as a child. 

-Amanda

[Austin Hellenbrand]

Hello,

So the only way to achieve what I'm trying to do is to modify the build scripts in the SDK? Is there a plan to add this feature to the SDK in the future? If not, I think it should be considered. 

Regards,

Austin

[Amanda Hsieh]

Hi,

Austin Hellenbrand said:

So the only way to achieve what I'm trying to do is to modify the build scripts in the SDK?

Without modifying other NCS codes, that is the only way. In the NCS, there is the CONFIG_BT_RPMSG for building Bluetooth: HCI RPMsg as the child image (See Default build configuration). Maybe you could update Bluetooth: HCI RPMsg to your own network core project.

-Amanda 

[Austin Hellenbrand]

Hi, 

I am trying to avoid having a modified SDK. That way my projects aren't dependent on a specific SDK installation and I can easily update the SDK without having to redo my modifications. 

- Austin

[Pyry]

Hi,

I had a similar problem and ended up creating a symbolic link to the custom image project folder.

I simply renamed the hci_rpmsg folder in zephyr/samples/bluetooth to sdk_hci_rpmsg folder and then used ln -s /absolute/path/to/custom/image/folder hci_rpmsg to trick the build system to use the custom project instead.

Ultimately it would be nice to have an option to use a custom hci_rpmsg project but at least the sym link works and allows to have all the project files together and outside of the SDK tree.

I guess you could even automate the management of the symlink by creating a custom build command in visual studio code so that when you build your custom project it sets the symlink to your custom child image and when the build is done it sets the symlink to point to sdk_hci_rpmsg, which is the original one