Saving and Restoring the Operational EUI64#

NCPs in the field may have their EUI64 already programmed in the factory. These cannot be reprogrammed by the standard token restoration mechanism, but rather require special handling.

An additional stack token is created with an NVM3 key name NVM3KEY_STACK_RESTORED_EUI64. It is part of the znet token group. This is initialized to blank (0xFFFFFFFFFFFFFFFF) and used to store the EUI of the operational node that is being backed up to the host in the function sl_zigbee_af_trust_center_backup_save_tokens_to_file.

When restoring, the host writes this token on the NCP. The NCP has a strong implementation of zigbee_get_restored_eui64 as part of the Token Interface component. It supplies any restored EUI64 during NCP boot up. The new NCP firmware then starts to use the restored EUI64 instead of its own factory-programmed one.