child image file structure and DFU upload includes child image.

[szhaulai]

Hello support team,

I have question on how should i setup child image. In my project i need to use hci_rpmsg sample as child image for the bluetooth. However, the current consumption is high, so i have to add 

CONFIG_LOG=n
CONFIG_SERIAL=n

into prj.conf into the hci_rpmsg sample in ncs folder. I read this document, it says it is possible to add the custom config for childimage to the project folder instead of changing the ncs folder. 

I use ncs 2.5 now and I really have difficulty to understand the document for ncs2.5. I wish you have example that show me how to include hci_rpmsg sample as a child build and that can use my custom prj.conf. I add file child_image/hci_rpmsg.prj to my project folder, it doesn't show any sign that the child image is rebuilt.  
It would be great if you can show me an example how to setup the CMakeList.txt and how to arrange the .conf file for both project and child image.  

Second question, I have DFU setup in my project, when I flash the firmware to the board through usb cable. The child image is updated. However, when uploading firmware through nrf connected device manager DFU update, the child image is not renewed. What could be the reason? 

Please let me know if you need more information. 

Thanks for help

[Sigurd Hellesvik]

Hi,

See https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-8-bootloaders-and-dfu-fota/topic/multi-image-builds-and-the-partition-manager/ for some extra info on this.

However, the current consumption is high, so i have to add 

Agreed.

I wish you have example that show me how to include hci_rpmsg sample as a child build and that can use my custom prj.conf.

https://github.com/nrfconnect/sdk-nrf/tree/v2.5.3/samples/bluetooth/peripheral_status

I add file child_image/hci_rpmsg.prj to my project folder, it doesn't show any sign that the child image is rebuilt.

Delete the build folder and rebuild.
I recommend that you put something wrong into the config file, to get a build error. That way you know that it tries to build this file.
Then when you build correctly you can check build/hci_rpmsg/zephyr/.config to see that your changes is included.

It would be great if you can show me an example how to setup the CMakeList.txt and how to arrange the .conf file for both project and child image.  

No need to use CMakeLists.txt. If you use the path project/child_image/hci_rpmsg.conf the file will be included automatically.

Second question, I have DFU setup in my project, when I flash the firmware to the board through usb cable. The child image is updated. However, when uploading firmware through nrf connected device manager DFU update, the child image is not renewed. What could be the reason? 

Updating the network core is more complex.
See https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-8-bootloaders-and-dfu-fota/

Regards,
Sigurd Hellesvik