Chapter 4. Analyzed features

One of the first conclusions achieved in the first project meeting was then importance of the standards, and in particular the realtime extensions defined in the POSIX standard. POSIX is a mature, well developed, independent set of standards then are followed by most of the UNIX industry. Also the use of already existing standards in the open source community is a must.

OSEK is a RTOS specification designed to fulfil the requirement of the automotive industry. It was designed for systems with small hardware resources like 8 bit processes with no MMU. Although there are some ports of Linux to small processors like MC68000 family, Linux and RTLinux are specially designed for mid-range to high range processors. This is why we decided to select POSIX as the reference standard used in this analysis.

POSIX stands for stands for Portable Operating System Interface, and is an IEEE standard designed to facilitate application portability. It is the codification and standardisation of the common core of UNIX™ APIs, and realtime OS. A detailed list and status of all the sub-standards that are part of POSIX can be found in the PACS web page. The subset of POSIX standards that are related to real time or embedded systems are listed below:

Following is the list of features that has been studied in every analyzed RTOS: