Issue
138 January 2002
EXPLORING QNX
NEUTRINO
by
Duane Mattern
Yes,
QNX has been around for a while. But, that doesn’t mean
it’s outdated nor that it isn’t a helpful solution to
some of today’s real-time problems. Duane takes us step
by step through everything from downloading the eval copy
to displaying bootable images in real time.
Start
• Installation
• Tools • Hardware
• Examples •
What's Missing?•
What You Get
•
Sources & PDF
The
QNX real-time operating system (RTOS) isn’t new. It’s
been around since the early 1980s. When I first encountered
QNX in ’87 I thought, "this is a lot better than
Windows." Today, it’s still better than Windows for
real-time applications. In addition, QNX has added a lot
of GUI applications, making it competitive on the desktop.
Since
September 2000, we’ve been able to download QNX real-time
platform (RTP) for evaluation, prototyping, personal use,
or other noncommercial purposes at no charge. And, since
July 2001, RTP has included the x86 version of QNX Neutrino
6.1. Through-out the article, I will refer to these as
QNX unless a distinction needs to be made.
What
is QNX? QNX is a RTOS with a microkernel architecture.
It supports MIPS, PowerPC, SH4, StrongArm, and x86 hardware.
It is scalable from constrained embedded to multiprocessor
platforms. The architecture provides multitasking, priority-driven
preemptive scheduling, synchronization, and TCP/IP protocol.
Utilities including PPP, DHCP, NFS, RPC, and SNMP are
provided as well.
QNX
has native message-based networking called Qnet. The Photon
microGUI windowing system is a GUI with a small memory
footprint. For GUI applications, there is also an integrated
development environment called Photon Application Builder
(PhAB), which reminds me of Visual Basic with drag-and-drop
controls. And, don’t forget about the self-hosting capabilities
that simplify development. QNX is not Unix but they have
a lot in common. QNX even uses a version of the GNU GCC
compiler.
For
anyone who wants to do hard real-time work, QNX is a good
place to start. If you’ve ever attempted to do real-time
work under Windows, you know how difficult it can be to
get deterministic timing. Windows CE is a possibility
if you want to drop $2500 (US $) in a hurry for Platform
Builder. For simple jobs, you can jump backward to MS-DOS,
but then you start to have problems with software and
hardware support.
Linux
is a possibility for real-time applications, but you have
to make a tough choice. Which real-time implementation
of Linux do you want? There are many choices to evaluate.
The list includes RTLinux from FSMLabs, Embedix from Lineo,
Hard Hat from MontaVista, TimeSys, and others. [1] The
different approaches to scheduling and the supported hardware
complicate the choice. If you want to start quickly and
for free with a proven RTOS, then QNX is a good candidate
to explore.
