SafeRTOS

Free

Certified version of FreeRTOS by TUEV SUED against IEC 61508 (basic functional safety standard) up to SIL3 (the highest safety integrity level for a single software component), ISO 26262 ASIL D (automotive standard) and EN62304 (medical device standard).

FreeFree tier

Type

Open Source

Company

WITTENSTEIN high integrity systems (WHIS)

Visit Website GitHub (38 stars)

About SafeRTOS

SAFERTOS is a pre-certified safety-critical real-time operating system (RTOS) for embedded processors, developed and owned by WITTENSTEIN high integrity systems (WHIS). It is based on the FreeRTOS functional model but has undergone a full HAZOP analysis and a rigorous IEC 61508 SIL 3 development lifecycle, achieving pre-certification by TÜV SÜD for IEC 61508 SIL 3 and ISO 26262 ASIL D. SAFERTOS delivers superior performance and dependability while consuming minimal resources. It includes features such as task isolation, ultra-low power mode, OSEK API wrapper, and safety plugins. Customers can prototype with FreeRTOS and upgrade to SAFERTOS at the start of formal development. Each license includes a Design Assurance Package (DAP) that provides full lifecycle documentation to simplify certification of the end application. SAFERTOS is royalty-free and offers perpetual licensing.

Key Features

Pre-certified by TÜV SÜD to IEC 61508 SIL 3 and ISO 26262 ASIL D

Based on FreeRTOS functional model for easy migration

Task isolation and separation for safety-critical integrity

Ultra-low power mode for energy-sensitive applications

OSEK API wrapper for automotive compatibility

Safety plugins extend functionality

Design Assurance Package (DAP) includes full design lifecycle documentation

Delivered with full source code

Royalty-free, perpetual licensing

Supports a wide range of processors and compiler combinations

Pros & Cons

Pros

Pre-certified by TÜV SÜD to highest safety integrity levels, reducing certification effort for end products
Based on widely-used FreeRTOS API, simplifying migration for developers
Design Assurance Package provides full transparency and traceability for safety audits
Low resource consumption despite advanced safety features
Royalty-free licensing model reduces per-unit costs

Cons

Commercial product with upfront license cost (not free open source)
Limited to supported processor/compiler combinations (contact vendor for custom platforms)
Less community support compared to FreeRTOS; relies on vendor support

Best For

Safety-critical embedded systems in automotive (ISO 26262 ASIL D)Industrial control systems requiring IEC 61508 SIL 3 certificationMedical device software (potential EN 62304 compliance via certification evidence)Aerospace and defense applications needing pre-certified RTOSMigration from FreeRTOS to a certified RTOS for production systems

FAQ

What is SAFERTOS?

SAFERTOS is a pre-certified safety-critical real-time operating system (RTOS) developed by WITTENSTEIN high integrity systems. It is based on the FreeRTOS functional model but hardened and certified by TÜV SÜD for IEC 61508 SIL 3 and ISO 26262 ASIL D.

How does SAFERTOS differ from FreeRTOS?

SAFERTOS shares the same functional model and API as FreeRTOS, making migration simple. However, SAFERTOS has undergone a full hazard analysis (HAZOP) and is developed under a safety-certified lifecycle, with pre-certification by TÜV SÜD. FreeRTOS itself is not safety-certified.

What is included with a SAFERTOS license?

Each license includes full source code, the Design Assurance Package (DAP) containing all design lifecycle documentation, and support for a specific processor/compiler combination. Licensing is royalty-free and perpetual.

Can I prototype with FreeRTOS and then switch to SAFERTOS?

Yes. WHIS recommends prototyping with FreeRTOS and then converting to SAFERTOS at the start of formal development, as both share the same functional model.

Which safety standards does SAFERTOS support?

SAFERTOS is pre-certified by TÜV SÜD for IEC 61508 SIL 3 and ISO 26262 ASIL D. It also supports a wide range of international development standards.