Best Real-Time Operating Systems (RTOS) for Linux

Developed in partnership with the world’s leading chip companies over a 15-year period, and now downloaded every 170 seconds, FreeRTOS is a market-leading real-time operating system (RTOS) for microcontrollers and small microprocessors. Distributed freely under the MIT open source license, FreeRTOS includes a kernel and a growing set of IoT libraries suitable for use across all industry sectors. FreeRTOS is built with an emphasis on reliability and ease of use. With proven robustness, tiny footprint, and wide device support, the FreeRTOS kernel is trusted by world-leading companies as the de facto standard for microcontrollers and small microprocessors. With detailed pre-configured demos and Internet of Things (IoT) reference integrations, there is no need to determine how to setup a project. Quickly download, compile, and get to market faster. Our partner ecosystem provides a breadth of options including community contributions and professional support.

Arm Mbed OS is a free, open-source IoT operating system that includes all the necessary features to develop IoT products. The OS includes everything you need to develop smart, connected products on Arm Cortex-M based hardware, including machine learning capabilities, security, connectivity stacks, an RTOS kernel and drivers for sensors and I/O devices. Arm Mbed OS is designed for the Internet of Things. It is integrated with connectivity, machine learning, networking, and security stacks and is supported with software libraries, development hardware, tutorials and examples. From hardware to the cloud, Mbed OS supports more than 70 silicon, module, cloud, and OEM partners, optimizing your developer choice. By using the Mbed OS API, your application code can remain clean, portable, and simple, while taking advantage of security, communications and machine learning. The integrated solution reduces development cost, time, and risk.

The SCIOPTA architecture is specifically designed to provide excellent real-time performance and small size. Internal data structures, memory management, interprocess communication and time management are highly optimized. SCIOPTA is a pre-emptive real-time kernel. Interrupts can be serviced at any time, even inside the kernel. SCIOPTA is a message based real-time operating system. A powerful set of system calls is available to control the resources. Standardized processes and interprocess communication result in clear system designs and are easy to write, to read and to maintain. As processes are communicating with well defined messages and processes can be grouped into modules, SCIOPTA systems are very well suited for team work in big projects. The time-to-market will be reduced dramatically. SCIOPTA is designed on a message based architecture allowing direct message passing between processes. Messages are mainly used for interprocess communication and synchronization.

Since 1980, thousands of companies have deployed QNX’s real-time operating systems to ensure the ideal combination of performance, security and reliability in mission-critical systems. At the core of QNX technology is the QNX Neutrino® Real-time Operating System (RTOS), a full-featured RTOS enabling next-generation products in every industry where reliability matters, including automotive, medical devices, robotics, transportation, and industrial embedded systems. With the QNX microkernel architecture, a component failure doesn’t bring down other components or the kernel. The failed component is simply shut down and restarted without adversely affecting the rest of the system. The QNX Neutrino RTOS offers the determinism only a real-time OS can provide. Techniques such as adaptive partitioning guarantee critical processes get the cycles they need to complete their tasks on time, while maintaining the performance your complex embedded systems require.

Deos™, DDC-I’s safety-critical time and space partitioned real-time operating system (RTOS) that has been verified to the guidance of DO-178C/ED-12C Design Assurance Level A (DAL A) for Avionics Applications, supports ARINC 653 APEX, rate monotonic scheduling (RMS), and is targeted at the FACE Safety Base Profile. It has been field proven as a safety-critical RTOS since its first verification and audit to DAL A by Transport Canada in 1998, and it has been certified and is flying in 10’s of thousands of aircraft. Since the initial verification, it has continually evolved throughout the last two decades with new processors and features in subsequent baselines, and it has been successfully audited by the world’s various governmental certification authorities (FAA, ENAC, JAA, EASA, CAAC, and others) and airframe and Avionics Supplier Designated Engineering Representatives (DERs).

INTEGRITY uses hardware memory protection to isolate and protect embedded applications. Secure partitions guarantee each task the resources it needs to run correctly and fully protect the operating system and user tasks from errant and malicious code, including denial-of-service attacks, worms, and Trojan horses. To help developers jumpstart product development, Green Hills Software offers an extensive array of middleware integrated and validated for INTEGRITY, including FFS, FAT, NFS, and journaling file systems, IPv4/IPv6 host and routing networking stacks, FIPS 140-2 certified Suite B enabled embedded encryption library, and more. Each of these middleware packages has been pre- integrated and tested to run seamlessly with and take full advantage of INTEGRITY’s advanced RTOS capabilities. For selected industries, Green Hills Software offers platforms that provide a completely integrated ecosystem. Each platform includes the INTEGRITY RTOS as well as development tools.

The MQX real-time operating system (RTOS) provides real-time performance within a small, configurable footprint. The RTOS is tightly integrated with 32-bit MCUs and MPUs from NXP and is provided with commonly used device drivers. The MQX RTOS is designed to have a modern, component-based microkernel architecture allowing for customization by feature, size, and speed by selecting the components engineers wish to include while meeting the tight memory constraints of embedded systems. The MQX RTOS can be configured to take as little as 8 KB of ROM and 2.5K RAM on Arm Cortex M4, including kernel, 2 task applications,1 LW Semaphore, interrupt stack, queues, and memory manager. Provides a fully-functional RTOS core with additional, optional services. Components are linked in only if needed, preventing unused functions from bloating the memory footprint. Key components are included in both full and lightweight versions for further control of size, RAM/ROM utilization and performance options.

OpenWrt is a highly extensible GNU/Linux distribution for embedded devices (typically wireless routers). Unlike many other distributions for routers, OpenWrt is built from the ground up to be a full-featured, easily modifiable operating system for embedded devices. In practice, this means that you can have all the features you need with none of the bloat, powered by a modern Linux kernel. Instead of trying to create a single, static firmware, OpenWrt provides a fully writable filesystem with optional package management. This frees you from the restrictions of the application selection and configuration provided by the vendor and allows you to use packages to customize an embedded device to suit any application. For developers, OpenWrt provides a framework to build an application without having to create a complete firmware image and distribution around it.

Enea OSE is a robust, high-performance, a real-time operating system optimized for multi-processor systems requiring true deterministic real-time behavior and high availability. It shortens development time, enhances reliability and reduces lifetime maintenance costs for a wide range of systems, from wireless devices and automobiles to medical instruments and telecom infrastructure. Enea OSE is optimized for communication and control systems requiring high performance and hard real-time characteristics. It is deployed extensively in the areas of telecom networking systems, wireless devices, industrial automation, medical equipment, automotive and transportation equipment, as well as other embedded systems. The twice award-winning design of the Enea OSE multicore kernel provides the ease-of-use of Symmetric Multi-Processing (SMP) together with the scalability and determinism of Asymmetric Multi-Processing (AMP) and the performance of bare metal.

PikeOS offers a separation kernel-based hypervisor with multiple partitions for many other operating systems and applications. It enables you to build smart devices for the Internet-of-Things (IoT) according to the quality, Safety and Security standards of your industry. Due to its separation kernel approach, PikeOS is the first choice for systems which demand protection against Cyber-Security attacks. In addition to the broad usage within millions of IoT and edge systems, it has also been deployed within various high critical communication infrastructures. PikeOS brings together virtualization and real-time by means of unique and never seen before technologies. It allows you to migrate numerous complex embedded circuit boards in to a single hardware. It does not stop when it comes to new hardware concepts such as Big-SoCs with multiple heterogeneous processor cores. PikeOS runs on several architectures, supporting processors that come with a memory management unit (MMU).

From simple embedded environmental sensors and LED wearables to sophisticated embedded controllers, smart watches, and IoT wireless applications. Implements configurable architecture-specific stack-overflow protection, kernel object and device driver permission tracking, and thread isolation with thread-level memory protection on x86, ARC, and ARM architectures, userspace, and memory domains. For platforms without MMU/MPU and memory constrained devices, supports combining application-specific code with a custom kernel to create a monolithic image that gets loaded and executed on a system’s hardware. Both the application code and kernel code execute in a single shared address space.

eLxr Pro from Wind River is a commercial enterprise-grade Linux solution designed for cloud-to-edge deployments, supporting mission-critical workloads like AI, machine learning, and computer vision. Built on the open-source eLxr distribution, eLxr Pro offers flexible, long-term support, security monitoring, and ongoing updates. It ensures compatibility with hardware accelerators and compliance with industry standards. By providing expert consultative services and performance optimizations, eLxr Pro helps businesses scale their edge computing solutions while managing costs, security, and resources effectively.