REAL-TIME OPERATING SYSTEMS AND STANDARDS - Hard Real-Time Computing Systems: Predictable Scheduling Algorithms and Applications - page 419

12

REAL-TIME OPERATING
SYSTEMS AND STANDARDS

This chapter presents a brief overview of the state of art of real-time systems and stan-
dards. It first discusses the most common operating systems standard interfaces that
play a major role for developing portable real-time applications. Then, it gives a brief
description of the most used commercial and open source real-time kernels available
today, including some research kernels developed within academia to make experi-
ments with some novel features and lead future development. Finally, it presents a set
of development tools that can be used to speed up system analysis and implementation.

12.1 STANDARDS FOR REAL-TIME OPERATING

SYSTEMS

The role of standards in operating systems is very important as it provides portability
of applications from one platform to another. In addition, standards allow the possibil-
ity of having several kernel providers for a single application, so promoting competi-
tion among vendors and increasing quality. Current operating system standards mostly
specify portability at the source code level, requiring the application developer to re-
compile the application for every different platform. There are four main operating
system standards available today:

POSIX, the main general-purpose operating system standard, with real-time ex-
tensions (RT-POSIX);

OSEK, for the automotive industry;

APEX, for avionics systems;

μ ITRON, for small embedded systems.