How to delete the default child_image or configure it to my own cpunet project

[kpi_xie]

mcu: nrf5340

board: nrf5340dk_nrf5340_cpuapp

sdk: v2.6.1

When I configure CONFIG_BOARD_ENABLE_CPUNET to enable cpunet, there isn't an issue. However, when I configure CONFIG_BOOTLOADER_MCUBOOT to enable mcuboot in my cpuapp project, a cpunet child_image appears in the build configuration. It seems the script automatically generates the BOARD_NRF5340DK_NRF5340_CPUAPP configuration, which then adds empty_net_core as a child_image to my project. I do not need these additions. I attempted to find how it was added but found no related child_image configuration in my project. So, how can I remove this child_image or configure it to use my own project?

[Charlie]

HI,

Thanks for checking with us. The prupose to add nRF5340: Empty firmware for network core is explained in its document:

When building an MCUboot child image with the nRF5340 Simultaneous multi-image DFU feature, the empty network core sample is built together with the application to prevent build failures related to missing Partition Manager definitions in the Multi-image builds.

If you genuinely don't need any network core image and want to remove it entirely, you might need to modify the build configuration. However, this is not recommended as it may lead to build failures or incorrect partitioning. The automatic addition of the network core image is controlled by the CONFIG_NCS_SAMPLE_EMPTY_NET_CORE_CHILD_IMAGE option, which depends on CONFIG_SOC_NRF53_CPUNET_ENABLE. You might be able to disable this by setting CONFIG_SOC_NRF53_CPUNET_ENABLE=n in your project configuration, but this could have unintended consequences.

If you want to use your own network core project instead of the empty_net_core, you can configure it as a child image. This can be done by adding a child_image directory in your project with the appropriate configuration files. For example, you could add a file named child_image/hci_rpmsg.conf or child_image/hci_rpmsg/prj.conf to configure a custom network core image Multi-image builds and the Partition Manager.

Best regards,

Charlie