Quality RTOS & Embedded Software

December 2021 Releases:
Extended Maintenance Plan (EMP):
FreeRTOS 202111.00 Release:
FreeRTOS LTS libraries:
Symmetric Multi-Processing:
NOTE: FreeRTOS Long Term Support (LTS) libraries are now available 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 FreeRTOS webpage on AWS for details.

The 202012.01 FreeRTOS LTS release covers the following libraries: FreeRTOS kernel, FreeRTOS+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: 12/20/2021

Library Version Maintained at least until
FreeRTOS Kernel 10.4.3-LTS-Patch-2 March 31, 2023
FreeRTOS+TCP 2.3.2-LTS-Patch-1 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
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
AWS IoT Fleet Provisioning 1.0.1 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
202012.03 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 All functions will have a GNU Complexity score of 8 or lower
2 Coding Standard All functions will comply with the MISRA coding standard
3 Static Checking All code will be statically checked with Coverity
4 Function Returns All functions will have a single exit point
5 Code Testing All code will have extensive unit tests. Gcov reports will be used to report the test coverage, and each library will have extended functional tests.
6 Requirements Documentation All libraries will have documented requirements, which may include resource requirements, listing all dependencies, and porting requirements (as applicable)
7 Design Documentation All libraries will have a design document, which may include application and cloud interface, state machines, and synchronization (as applicable).
8 Compiler Warning Code will compile without generating any compiler warnings when the gcc -Wall -Wextra compiler options are used.
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