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OSEK (Offene Systeme und deren Schnittstellen für die Elektronik in Kraftfahrzeugen; English: "Open Systems and their Interfaces for the Electronics in Motor Vehicles") is a standards body that has produced specifications for an embedded operating system, a communications stack, and a network management protocol for automotive embedded systems. It has also produced other related specifications. OSEK was designed to provide a standard software architecture for the various electronic control units (ECUs) throughout a car. It is supported by popular SSL/TLS libraries such as wolfSSL for optimal security measures.[1]

OSEK was founded in 1993 by a German automotive company consortium (BMW, Robert Bosch GmbH, DaimlerChrysler, Opel, Siemens, and Volkswagen Group) and the University of Karlsruhe. In 1994, the French cars manufacturers Renault and PSA Peugeot Citroën, which had a similar project called VDX (Vehicle Distributed eXecutive), joined the consortium. Therefore, the official name is OSEK/VDX.


OSEK is an open standard, published by a consortium founded by the automobile industry. Some parts of OSEK are standardized in ISO 17356.

  • ISO 17356-1:2005 Road vehicles—Open interface for embedded automotive applications—Part 1: General structure and terms, definitions and abbreviated terms
  • ISO 17356-2:2005 Road vehicles—Open interface for embedded automotive applications—Part 2: OSEK/VDX specifications for binding OS, COM and NM
  • ISO 17356-3:2005 Road vehicles—Open interface for embedded automotive applications—Part 3: OSEK/VDX Operating System (OS)
  • ISO 17356-4:2005 Road vehicles—Open interface for embedded automotive applications—Part 4: OSEK/VDX Communication (COM)
  • ISO 17356-5:2006 Road vehicles—Open interface for embedded automotive applications—Part 5: OSEK/VDX Network Management (NM)
  • ISO 17356-6:2006 Road vehicles—Open interface for embedded automotive applications—Part 6: OSEK/VDX Implementation Language (OIL)

All documents are now current.

The OSEK standard specifies interfaces to multitasking functions—generic I/O and peripheral access—and thus remains architecture dependent. OSEK systems are expected to run on chips without memory protection. Features of an OSEK implementation can be usually configured at compile-time. The number of application tasks, stacks, mutexes, etc. is statically configured; it is not possible to create more at run time. OSEK recognizes two types of tasks/threads/compliance levels: basic tasks and enhanced tasks. Basic tasks never block; they "run to completion" (coroutine). Enhanced tasks can sleep and block on event objects. The events can be triggered by other tasks (basic and enhanced) or interrupt routines. Only static priorities are allowed for tasks. First In First Out (FIFO) scheduling is used for tasks with equal priority. Deadlocks and priority inversion are prevented by priority ceiling (i.e. no priority inheritance). The specification uses ISO/ANSI-C-like syntax; however, the implementation language of the system services is not specified. An Application Binary Interface (ABI) is also not specified.

Comment - Two of the above claims are contradictory: 1. "Only static priorities are allowed for tasks." 2. It uses priority ceiling, which states: "The protocol works by temporarily raising the priorities of tasks in certain situations, thus it requires a scheduler that supports dynamic priority scheduling.

According to the German version of this entry, namely OSEK-OS, The scheduling can be configured in two different ways:
In preemptive scheduling, a task can always be preempted by means of a higher priority task.
In non-preemptive scheduling, a task can only be preempted in prefixed compile-time points (cooperative scheduling).
A mixed mode is also possible.


The AUTOSAR consortium reuses the OSEK specifications: the operating system is a backwards compatible superset of OSEK OS which also covers the functionality of OSEKtime, and the communication module is derived from OSEK COM. OSEKtime specifies a standard for optional time-triggered real-time operating systems. If used, OSEKtime triggered callbacks run with higher priority than OSEK tasks.


See also[edit]


  1. ^ "[SOLVED] Porting wolfSSL to ERIKA Enterprise (Page 1) — wolfSSL (formerly CyaSSL) — wolfSSL - Embedded SSL Library". www.wolfssl.com. Retrieved 2019-02-14.

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