OSEK

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.

• Arctic Core is a dual license (GPL/proprietary) AUTOSAR implementation with OSEK implementation.
• Chalandi Amine OSEK 2.2.3, implementation for ARM Cortex M3.
• Elektrobit tresos is a commercial implementation of an OSEK RTOS
• ERIKA Enterprise (ERIKA Enterprise, external link) is an implementation of the OSEK OS (BCC1, BCC2, ECC1, ECC2), OIL, ORTI specifications, provided with an Eclipse plugin and support for Microchip dsPIC, PIC32, AVR, Nios II, ARM7, S12XS, Tricore1, Mico32, PPC z7, esi-RISC, MSP430, Cortex Mx. (License: GPL and GPL linking exception). ERIKA Enterprise has been officially certified OSEK-VDX on ARM Cortex-M4 and for Infineon tricore AURIX.
• ev3OSEK is a Free / Open Source implementation for the Mindstorms EV3 robots
• FreeOSEK is a Free / Open Source OSEK-VDX Implementation (BSD license)
• mKernel is another Free / Open Source implementation (GPL license) with Partially OSEK/VDX compliant oil generator supporting only the Microchip PIC18F4550.
• nxtOSEK (nxOSEK/JSP, external link) is a Free / Open Source implementation for the Mindstorms NXT robots
• openOSEK is a Free / Open Source implementation (LGPL license) (last update in 2011).
• PICOS18 at the Wayback Machine (archived 2012-07-07) is another Free / Open Source implementation (GPL license) with support for Microchip PIC18.
• RTA-OS and RTA-OSEK are commercial implementations by ETAS of an OSEK RTOS with support for a broad range of micro-controllers, including Linux and Windows PC (Unknown license).
• TOPPERS-OSEK GPL license, runs on m68k, sh1, sh2, sh3, h8, arm 4, m32r, MicroBlaze, tms320c54x, xstormy16, mips3, Nios II
• Trampoline LGPL license, runs on Infineon C166, PowerPC
• Trioz OSEK RTOS is a commercial implementation of an OSEK RTOS (Unknown license)
• Vector’s osCAN is a commercial implementation of an OSEK RTOS (Unknown license)

• Controller Area Network (CAN)
• IEC 61508 is a standard for programmable electronic safety-related systems.
• ISO 26262 Road vehicle safety norm
• Safety standards

• OSEK VDX Portal at the Wayback Machine (archived 2016-03-07)
• Autosar