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An Overview of the Zephyr RTOS

Telink Staff

May 19, 2021


IoT network over city

The Zephyr Project’s RTOS kernel is gaining traction as a best-in-class RTOS for resource-constrained devices.

A real-time operating system (RTOS) is a computer operating system designed to process data as it comes in, typically without buffer delays. By providing real-time responses to external events, synchronized multi-tasking, and efficient memory usage, an RTOS satisfies many of the unique demands of IoT use cases.

In 2003, Richard Barry created a lightweight operating system called FreeRTOS that quickly became many IoT device developers’ preferred option for embedded systems. In 2017, Barry handed off software infrastructure management responsibilities to Amazon. The tech giant now issues FreeRTOS under the free MIT License for use in both commercial and personal projects and reports that the OS kernel is downloaded once every 175 seconds.

While FreeRTOS’ popularity is well-deserved, there are a number of other open source RTOS that merit discussion, Zephyr foremost among them. As a Linux Foundation-hosted collaborative effort, the Zephyr ProjectTM unites leaders from across the tech industry in pursuit of the improvement of IoT device performance and interoperability.

What Is the Zephyr Project?

The Zephyr Project was conceived as a way to create a community-based, open source RTOS that is optimized for resource-constrained devices. Uniting companies, developers, and end users around the world to ensure balanced representation of all interests, it relies on active collaboration and feedback to evolve and meet the needs of its community. This symbiotic relationship among stakeholders advances the Zephyr Project’s support of new hardware, developer tools, sensors, and drivers while maximizing the functionality of IoT devices that run applications developed using the Zephyr RTOS.

Explanation of the Zephyr OS

Applicable in a wide variety of use cases, the Zephyr RTOS gives IoT developers the power to greatly extend the functionality of their devices. Zephyr delivers a highly configurable, modular architecture that lets developers build low-energy applications for devices ranging from simple connected sensors and wearables to modems and small wireless gateways.

The Benefits of the Zephyr RTOS

As more and more vendors bring new IoT systems to market, consumers will start finding it difficult to connect (and use) all these different devices together. A scalable, open platform like Zephyr mitigates this problem by making it easier for developers to build interoperable IoT applications across a range of device types. This means that, for example, your thermostat will be able to communicate with your security camera, which will be able to communicate with your smart home hub, which will be able to communicate with your smartphone.

Additionally, the Zephyr Project prioritizes the security of the Zephyr RTOS through a dedicated management group that constantly vets and debugs the kernel’s code. It also recently integrated its kernel with Trusted Firmware M, an open source Trusted Execution Environment framework.

Not only is the Zephyr RTOS product-ready thanks to its long-term support of security updates and auditable certifications, but it provides advanced memory management in userspace support and multi-processor support. Developers will also find powerful configuration tools such as Kconfig and Device Tree built right into the Zephyr platform. Finally, as alluded to above, Zephyr boasts a modular architecture that allows it to run on systems with as little as 8 KB of memory. Users have the flexibility to use the RTOS as-is or to disable as many modules as needed using the aforementioned Kconfig tool.

Telink’s Support for the Zephyr RTOS

Since its inception, the Zephyr Project has gained traction as a fast-growing open source RTOS. Its strength lies in a design that embodies everything developers need to build robust applications for IoT use cases, including a file system, wireless stacks, drivers, key security features, and long-term support firmware. Zephyr’s highly configurable software stack and rich connectivity also reduces RAM footprint and power consumption while supporting all the layers of the Bluetooth® LE 5.0 standard from the radio hardware up through the standard Generic Access Profile (GAP) and Generic Attribute Profiles (GATT).

Because the Zephyr RTOS is designed for high-performing, low-energy IoT applications, it is a natural fit for Telink’s portfolio of products that are built for a smarter IoT. That is why our TLSR9 Series is integrated into the Zephyr build system. What is more, we will soon release an SDK on the Zephyr Project’s open source repo that supports the development of applications for Zephyr across multiple protocols, including Bluetooth LE 5.0, Bluetooth Mesh, and OpenThread. (Developers can already find a standalone FreeRTOS module within the Telink SDK that they can enable if needed.)

Please visit our wiki to learn more about all our development tools, or ask us a question through our Technical Forum or by contacting us directly today.