Posted On: Mar 2, 2021

FreeRTOS Long Term Support (LTS) release 202012.01 now includes the over-the-air update (OTA), AWS IoT Device Defender, and AWS IoT Jobs libraries in the first LTS release (FreeRTOS 202012.00 LTS). With this release, developers can use the FreeRTOS LTS libraries to update firmware, manage device fleets, and monitor fleet metrics for their microcontroller-based IoT devices. In addition, developers can rely on a FreeRTOS version that provides feature stability, and security patches and critical bug fixes for two years.

The OTA library makes it easier to download and perform cryptographic verification of firmware updates. You can use the OTA library with your preferred MQTT library, HTTP library, and underlying operating system (e.g. FreeRTOS, Linux). The Device Defender library enables customers to send device metrics to the AWS IoT Device Defender service. This library also supports custom metrics, a feature that helps you monitor operational health metrics that are unique to your fleet or use case. For example, you can define a new metric to monitor the memory usage or CPU usage on your devices. The Jobs library helps you notify connected IoT devices of a pending Job. Jobs can be used to manage fleets of devices, update firmware and security certificates, or perform administrative tasks such as restarting devices and performing diagnostics.

Updating firmware remotely over-the-air and monitoring device metrics are critical to improving and maintaining security of IoT devices over their lifecycle. Given the importance of these functionalities for customers building IoT devices using FreeRTOS LTS libraries, we have included the OTA, Device Defender and Jobs libraries in the LTS release – FreeRTOS 202012.01 LTS. These libraries are additive – there are no changes, fixes, or features added to pre-existing FreeRTOS LTS libraries. In addition, to give developers at least two years of maintenance on all LTS libraries, we have extended support for FreeRTOS 202012.01 LTS to March 31, 2023.

Like the rest of the FreeRTOS LTS libraries, the OTA, Device Defender and Jobs libraries have been refactored to improve design flexibility, security, and code quality. First, each LTS library comes in its own GitHub repository, which makes it easier for developers to integrate and update libraries in their FreeRTOS projects. Second, the Device Defender and Jobs libraries have been validated for memory safety with the C Bounded Model Checker (CBMC) automated reasoning tool to mitigate code security issues such as buffer overflow. Lastly, all LTS libraries have undergone code quality checks including MISRA-C compliance and Coverity static analysis to enhance code safety, portability, and reliability in embedded systems (see LTS Code Quality Checklist).  

You can find more information on the FreeRTOS LTS libraries on and get started by downloading source code from or GitHub.