MCUboot’s serial recovery of the networking core image

In addition to the recovery of the application core image, also the networking core image can be recovered. When you build MCUboot for the nRF5340 DK or the Thingy:53, you can use this feature with one of the following options:

  • CONFIG_NRF53_MULTI_IMAGE_UPDATE - Simultaneous multi-image DFU.

  • CONFIG_NRF53_RECOVERY_NETWORK_CORE - Serial recovery for the network core in the one image pair mode, where CONFIG_UPDATEABLE_IMAGE_NUMBER is set to == 1.

To upload the networking image, use the following command:

./mcumgr image upload <build_dir_path>/zephyr/net_core_app_update.bin -e -n 3 -c serial_conn

serial_conn is the serial connection configuration. For more information on MCUmgr image management, see Image Management.

To enable the serial recovery of the network core while the multi-image update is not enabled in the MCUboot, set the following options:

Additionally, define and include the following memory partitions:

  • mcuboot_primary and mcuboot_secondary - Partitions for the application core image slots.

  • mcuboot_primary_1 - Partition for the network core image slot.

  • pcd_sram - Partition used for command exchange between the application core and the network core (see CONFIG_PCD_APP).

Note

When using MCUboot with the CONFIG_NRF53_RECOVERY_NETWORK_CORE option enabled, the application core does not have direct access to the network core flash memory. Due to this, mcuboot_primary_1 must be used as the RAM partition mediator.

Container for firmware update binaries

The build system will automatically place both the application core and the network core update binaries (app_update.bin and net_core_app_update.bin) into a container package named dfu_application.zip. This container package can be used by update tools to pass both images during the simultaneous update of multiple images.