Skip to content


Switch branches/tags

cortex_m0 cortex_m3 cortex_m4 cortex_m7

Azure RTOS ThreadX

This advanced real-time operating system (RTOS) is designed specifically for deeply embedded applications. Among the multiple benefits it provides are advanced scheduling facilities, message passing, interrupt management, and messaging services. Azure RTOS ThreadX has many advanced features, including picokernel architecture, preemption threshold, event chaining, and a rich set of system services.


Documentation for this library can be found here:

Understanding inter-component dependencies

The main components of Azure RTOS are each provided in their own repository, but there are dependencies between them--shown in the following graph--that are important to understand when setting up your builds.

dependency graph

Building and using the library


Install the following tools:

Cloning the repo

$ git clone

Building as a static library

Each component of Azure RTOS comes with a composable CMake-based build system that supports many different MCUs and host systems. Integrating any of these components into your device app code is as simple as adding a git submodule and then including it in your build using the CMake command add_subdirectory().

While the typical usage pattern is to include threadx into your device code source tree to be built & linked with your code, you can compile this project as a standalone static library to confirm your build is set up correctly.

$ cmake -Bbuild -DCMAKE_TOOLCHAIN_FILE=cmake/cortex_m4.cmake -GNinja .

$ cmake --build ./build

NOTE: You will have to take the dependency graph above into account when building anything other than threadx itself.

Repository Structure and Usage

Branches & Releases

The master branch has the most recent code with all new features and bug fixes. It does not represent the latest General Availability (GA) release of the library.


Each official release (preview or GA) will be tagged to mark the commit and push it into the Github releases tab, e.g. v6.0-rel.

Directory layout

- cmake
- common
  - inc
  - src
- ports
  - cortex_m0/gnu
    - inc
    - src
  - cortex_m3/gnu
    - inc
    - src
  - cortex_m4/gnu
    - inc
    - src
  - cortex_m7/gnu
    - inc
    - src
- samples


Azure RTOS provides OEMs with components to secure communication and to create code and data isolation using underlying MCU/MPU hardware protection mechanisms. It is ultimately the responsibility of the device builder to ensure the device fully meets the evolving security requirements associated with its specific use case.

Adaptation layer for ThreadX

Azure RTOS ThreadX is an advanced real-time operating system (RTOS) designed specifically for deeply embedded applications. To help ease application migration to Auzre RTOS, ThreadX provides adaption layers for various legacy RTOS APIs (FreeRTOS, POSIX, OSEK, etc.).


License terms for using Azure RTOS are defined in the LICENSE.txt file of this repo. Please refer to this file for all definitive licensing information. No additional license fees are required for deploying Azure RTOS on hardware defined in the LICENSED-HARDWARE.txt file. If you are using hardware not defined in the LICENSED-HARDWARE.txt file or have licensing questions in general, please contact Microsoft directly at

Contribution, feedback, issues, and professional support

If you encounter any bugs, have suggestions for new features, or if you would like to become an active contributor to this project, please follow the instructions provided in the contribution guideline for the corresponding repo.

For basic support, click Issues in the command bar or post a question to Stack Overflow using the threadx and azure-rtos tags.

Professional support plans ( are available from Microsoft.

Additional Resources

The following are references to additional Azure RTOS and Azure IoT in general:

Content Link
TraceX Installer
Azure RTOS Documentation and Guides:
Azure RTOS Website:
Azure RTOS Sales Questions:
Azure RTOS Product Support Policy
Azure RTOS Functional Safety Artifacts
For technical questions check out Microsoft Q/A for Azure IoT
Internet of Things Show for latest announcements and online training
IoT Tech Community


Azure RTOS ThreadX is an advanced real-time operating system (RTOS) designed specifically for deeply embedded applications.







No packages published