If the OTA firmware image is faulty, will the device be bricked?

If CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE is not enabled and the OTA firmware is faulty, the device will fail to connect to the cloud after reboot and lose its ability to receive future OTA updates — effectively bricking it if there is no other way to reflash.

warning

Enable CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE in the first firmware version shipped to devices. This option is implemented in the bootloader and cannot be enabled via OTA after the fact.