An introduction to Arm Mbed OS 6

Mbed OS is an open-source operating system for Internet of Things (IoT) Cortex-M boards: low-powered, constrained and connected. Mbed OS provides an abstraction layer for the microcontrollers it runs on, so that developers can write C/C++ applications that run on any Mbed-enabled board.

The Mbed OS source code is available on GitHub and on our release page.

Profiles and RTOS

The full profile of Mbed OS is an RTOS (it includes Keil RTX and all RTOS APIs), so it supports deterministic, multithreaded, real-time software execution. The RTOS primitives are always available, allowing drivers and applications to rely on threads, semaphores, mutexes and other RTOS features. It also includes all APIs by default, although you can remove unused ones at build time.

The bare metal profile doesn't include Keil RTX and is therefore not an RTOS - it is designed for applications that do not require complex thread management. It is also designed for constrained devices, and therefore focuses on minimizing the size of the final application: by default, it includes only the smallest possible set of APIs, to which you can manually add APIs that your application requires. The bare metal profile can use the small C libraries (which are not thread safe) to further minimize the size of the application. Mbed 2 users who want to move to Mbed OS 6 should use the bare metal profile.

Licensing

We release Mbed OS under an Apache 2.0 license, so you can confidently use it in commercial and personal projects. For more information about licensing, please see our licensing documentation.

Getting started

Our quick start guides show how to build an example application for both the full profile and bare metal profile, on Mbed CLI, Mbed Studio and the Mbed Online Compiler.

Recently updated documentation

• We're moving to GitHub Actions instead of Travis CI. We've updated the contribution guidelines on Continuous integration testing accordingly.
• A new section on Docker use in Mbed OS describes how you can set up a build environment for Mbed OS projects using Docker. This is the easiest and quickest way to get a build environment set up.
• We've added a section describing driver interfaces and polymorphism. Polymorphic driver interfaces in MbedOS are still experimental, and not enabled by default. You can start writing code that takes advantage of driver polymorphism now, but be sure to read the notes on backwards compatibility and caveats.
• A new section about optimizing for throughput and power consumption with Bluetooth Low Energy (BLE). We've also removed old material relating to services which are no longer supported and instead provided links to the Experimental services for Mbed OS BLE repository.
• We've updated the unit testing information to reflect changes to the version of CMake used. You will need to update to CMake version 3.19 or above and alter your test code structure.
• A new Mbed CLI1 to CLI2 migration guide.
• A new tutorial about link time optimization.
• A new PSA porting guide.
• New information about API life cycle and how to contribute experimental APIs and use them in an application.
• Tickless mode porting updates.
• A new section for the bare metal profile, including moving Mbed 2 applications to bare metal and porting targets from Mbed 2.
• We've grouped our API references with the relevant tutorials and configuration information so you can work on a feature from start to finish in a single area of the docs.
• Updated information about serial communication with your development board and using printf() to debug.
• A list of deprecated APIs and their replacements.