Over-the-Air (OTA) Upgrade Overview
The Golioth Zephyr SDK is deprecated. Please use the Golioth Firmware SDK. (Migration Guide)
This section will guide you through Over-The-Air (OTA) firmware updates for embedded devices using the Golioth Device Firmware Update (DFU) service. The Golioth Zephyr SDK includes DFU sample code which runs on all Continuously Verified Boards. A walkthrough is included here to help you become familiar with the process. You'll also find an in-depth code review that discusses how the DFU sample works.
OTA Overview
OTA Service Architecture
The following diagram illustrates the architecture of the sample within the Device SDK architecture. The DFU sample can be found in the Golioth zephyr-sdk repository.
Device Side
The firmware update process is based around the open source MCUboot project. MCUboot uses multiple flash memory slots so a newly-downloaded firmware can exist alongside the currently running firmware. After download the device reboots. The signature of the firmware binary is verified and the device ensures the new firmware is running properly (if not it will revert to the known-working copy in the other slot). The update process completes when the device updates the Golioth servers with the version number of the newly updated firmware.
Cloud Side
The Golioth Cloud stores firmware as "artifacts" that can optionally include tags and blueprints to filter which devices are targeted. For example, you might tag a few devices as "dev" to test firmware rollouts, or categorize a hardware blueprint for all of the "nRF9160_asset_tracker" devices in your IoT fleet. A release is created using the artifact. Devices will automatically see the new version and begin the update process. Golioth includes a one-click rollback feature if you ever need to revert a rollout.