Quality RTOS & Embedded Software

FreeRTOS Extended Maintenance Program (EMP) registration now open.
FreeRTOS-Plus-TCP v3.0.0 released:
Featured FreeRTOS IoT Integrations:
Delta Over-the-Air Updates:
December 2021 Releases:
NOTE: FreeRTOS Long Term Support (LTS) libraries are now available in the FreeRTOS-LTS repository on Github. Read the What’s New post

FreeRTOS LTS Libraries


FreeRTOS long term support (LTS) releases receive security and critical bug fixes (should any be necessary) for at least two years following their release. That ongoing maintenance enables you to incorporate bug fixes throughout a development and deployment cycle without the costly disruption of updating to a new major version of FreeRTOS libraries. Long term support is provided courtesy of AWS for the benefit of the entire FreeRTOS community.

AWS also offers the FreeRTOS Extended Maintenance Plan (EMP) that provides you with security patches and critical bug fixes on your chosen FreeRTOS LTS version for up to an additional 10 years. Visit the EMP page on the AWS site for details.

The 202012.01 FreeRTOS LTS release covers the following libraries: FreeRTOS kernel, FreeRTOS-Plus-TCP, coreMQTT, coreHTTP, corePKCS11, coreJSON, AWS IoT Device Shadow, AWS IoT OTA, AWS IoT Jobs, AWS IoT Device Defender, and AWS IoT Fleet Provisioning. Subsequent releases starting from 202012.02 version provides LTS patches for security and critical bug fixes.

Note:This download contains source code for just the latest FreeRTOS 202012 Long Term Support (LTS) libraries, with no build projects of examples. The primary FreeRTOS download contains example projects. Refer to the FAQ for details.

FreeRTOS LTS libraries are also available from partner toolchains. See the blog post.

LTS Status

The following table lists the libraries that are part of the FreeRTOS 202012 LTS release. All meet the LTS modularity and Code Quality Checklist requirements other than the kernel and TCP stack, both of which still comply with their original quality requirements.

Last Updated: 09/21/2022

Library Version Maintained at least until
FreeRTOS Kernel 10.4.3-LTS-Patch-3 March 31, 2023
FreeRTOS-Plus-TCP 2.3.2-LTS-Patch-2 March 31, 2023
coreMQTT 1.1.0 March 31, 2023
coreHTTP 2.0.0 March 31, 2023
corePKCS11 3.0.0 March 31, 2023
coreJSON 3.0.0 March 31, 2023
backoffAlgorithm 1.0.0 March 31, 2023
AWS IoT Device Shadow 1.0.2 March 31, 2023
AWS IoT OTA 3.0.0 March 31, 2023
AWS IoT Jobs 1.1.0 March 31, 2023
AWS IoT Device Defender 1.1.0 March 31, 2023

FreeRTOS LTS Patches

For the latest information, subscribe to Github Notifications by watching the FreeRTOS LTS repository. For the complete list of updates for each patch, view the Changelog.

Patch Version Updates Post
202012.05 LTS Includes security patches for the FreeRTOS kernel (10.4.3-LTS-Patch-3). Security Updates
202012.04 LTS Includes critical bug fixes for the FreeRTOS-Plus-TCP library (2.3.2-LTS-Patch-2). Release notes
202012.03 LTS Includes security patches for the FreeRTOS kernel (10.4.3-LTS-Patch-2). Security Updates
202012.02 LTS Includes security patches for the FreeRTOS kernel (10.4.3-LTS-Patch-1) and TCP libraries (V2.3.2-LTS-Patch-1). Security Updates
202012.01 LTS Added AWS IoT OTA, AWS Device Defender, and AWS IoT Jobs library to 202012.00 LTS Blog Post

LTS Code Quality Checklist

The table below documents the LTS release code quality requirements.

# Category Checks
1 Complexity Score Functions shall have a GNU Complexity score less than 8.
2 Coding Standard Functions shall comply with the MISRA 2012 coding standard.
3 Static Checking Functions shall pass Coverity static checking.
4 APSEC review and pentest Libraries must pass AWS security review.
5 Code Testing, including memory safety proofs All code shall have extensive unit and function tests, with Gcov reports detailing test coverage, as well as CBMC memory safety proofs.
6 Requirements Documentation All libraries shall have documented requirements, which may include resource, dependency, and porting requirements (as applicable).
7 Design Documentation All libraries shall have design documentation, including application and cloud interface, state machines, and synchronization (as applicable).
8 Compiler Warning The code shall compile with GCC using the -Wall and -Wextra command line options without generating compiler warnings.
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