Quality RTOS & Embedded Software

New FreeRTOS Long Term Support version released

It has already been 18 months since we introduced FreeRTOS Long Term Support (LTS). With FreeRTOS LTS, developers can rely on a FreeRTOS version that provides feature stability, and security patches and critical bug fixes for two years from the release date. We released the first LTS version (FreeRTOS 202012 LTS) with all libraries needed for secure AWS IoT connectivity and over-the-air updates. In addition, each FreeRTOS library was designed to be modular, with its own repository and minimal dependence on other libraries from this first LTS version. This enabled our partners to integrate the FreeRTOS libraries into their toolchains, making it easier for customers to build, update, and validate FreeRTOS based projects.

Today, we are excited to announce the second release of FreeRTOS Long Term Support (LTS) - FreeRTOS 202210.00 LTS. This release includes new libraries such as AWS IoT Fleet Provisioning and a Cellular LTE-M Interface for easier device provisioning and cellular connectivity. It also includes coreMQTT and FreeRTOS-Plus-TCP libraries with improved modularity and connectivity robustness. All libraries included in this FreeRTOS LTS version, summarized in the table below, will receive security and critical bug fixes until October 2024. With an LTS release, you can continue to maintain your existing FreeRTOS code base and avoid any potential disruptions resulting from FreeRTOS version upgrades.

Library LTS 202012 LTS 202210 Changes compared to previous LTS version
FreeRTOS Kernel 10.4.3 10.5.0 No API changes.
FreeRTOS-Plus-TCP 2.3.2 3.1.0 No API changes. Existing project builds will be affected due to improvements to file and folder structure.
coreMQTT 1.1.0 2.1.0 API changes.
coreHTTP 2.0.0 3.0.0 No API changes. HTTP parser updates.
corePKCS11 3.0.0 3.5.0 No API changes.
coreJSON 3.0.0 3.2.0 No API changes.
backoffAlgorithm 1.0.0 1.3.0 No API changes.
AWS IoT Device Shadow 1.0.2 1.3.0 No API changes.
AWS IoT OTA 3.0.0 3.4.0 No API changes.
AWS IoT Jobs 1.1.0 1.3.0 No API changes.
AWS IoT Device Defender 1.1.0 1.3.0 No API changes.
coreSNTP   1.2.0 New addition.
AWS IoT SigV4   1.2.0 New addition.
Cellular LTE-M Interface   1.3.0 New addition.
AWS IoT Fleet Provisioning   1.1.0 New addition.

Similar to the previous FreeRTOS LTS release, FreeRTOS 202210.00 LTS includes libraries that have been validated for memory safety with the C Bounded Model Checker (CBMC) automated reasoning tool to help mitigate code security issues such as buffer overflow. In addition, all LTS libraries have undergone certain code quality checks including MISRA-C compliance and Coverity static analysis to help improve code safety, portability, and reliability in embedded systems (see LTS Code Quality Checklist).

The support period for the previous LTS release will end in March 2023, providing you a six-month overlap between the LTS releases for easy migration of your project. See the migration guide and corresponding validation tests to upgrade your project to FreeRTOS 202210.00 LTS. If you prefer not to upgrade and want to continue receiving critical fixes on the previous LTS version beyond its expiry, you can consider the FreeRTOS Extended Maintenance Plan.

To qualify your development board (or update a qualified board) using the latest LTS version and list (or update) it in the AWS Partner Device Catalog, you can use the AWS IoT Device Tester for FreeRTOS 202210.00 LTS.

To learn more and get started, refer to the FreeRTOS LTS page and FreeRTOS LTS GitHub repository.

About the author

Tanmoy Sen is a Senior Product Manager at Amazon Web Services where he focuses on helping customers and embedded developers connect microcontroller-based devices to the cloud.
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