Certified C libraries for ISO26262 software

C libraries from Tasking have been certified by TÜV NORD for compliance with ISO 26262 functional safety requirements for automotive software.

This means Tasking can now supply certified versions of the C library with 600 functions which can be licensed separately in addition to the compiler toolset. Using certified software components significantly reduces the costs, the time and effort required for final certification of safety-related systems.

Using a certified C Library is crucial and required by functional safety standards because the library code is incorporated into the application and installed on the target device. A faulty library can jeopardize the functional safety of the application. Therefore, both a qualified compiler and a qualified C library must be used for the development of software that must meet functional safety requirements according to standards such as ISO 26262 or IEC 61508.

The Certified C Libraries are specifically designed for use in embedded systems and are highly optimized for code size, execution speed, and the accuracy of mathematical functions. This expands on the TriCore qualified C libraries developed for the Infineon Aurix microcontroller.

The libraries are ISO C compliant and provide approximately 600 functions. Of these, about 200 functions are suitable for use in ASIL-D software, while the remaining functions are qualified for use in lower-level ASIL or QM software. This allows for easy integration of the library into existing projects, interfacing with third-party operating systems, and enables the use of printf-style debugging and logging.

The libraries come with a safety manual in both human readable (pdf) and machine readable (ReqIF) format. The ReqIF format enhances the automated import of guidelines from the safety manual into the user’s requirements management system. Formal evidence for correct integration of the library is created via a coverage analysis of the guidance in the safety manual, eliminating the need for additional verification of library functions on the user’s part.

The structure of the ReqIF file is such that all safety requirements are uniquely identifiable and allows reuse and sharing of safety analyses performed by different development teams, as well as (partial) reuse of safety analyses performed on different versions of the QClib product.

Using a Certified C Library reduces the cost and lead time of safety related software and reduces product liability risks.