An Architectural Overview of QNX

This paper presents an architectural overview of the QNX operating system. QNX is an OS that provides applications with a fully network- and multiprocessor-distributed, realtime environment that delivers nearly the full, device-level performance of the underlying hardware. The OS architecture used to deliver this operating environment is that of a realtime microkernel surrounded by a collection of optional processes that provide POSIX- and UNIX-compatible system services. By including or excluding various resource managers at run time, QNX can be scaled down for ROM-based embedded systems, or scaled up to encompass hundreds of processors-either tightly or loosely connected by various LAN technologies.