The System Architecture guide accompanies the QNX Neutrino realtime OS and is intended for both application developers and end-users.

The guide describes the philosophy of QNX Neutrino and the architecture used to robustly implement the OS. It covers message-passing services, followed by the details of the microkernel, the process manager, resource managers, the Photon microGUI, and other aspects of QNX Neutrino.

Note that certain features of the OS as described in this guide may still be under development for a given release.

For the latest news and information on any QNX product, visit our website (www.qnx.com). You'll find links to many useful areas -- Foundry 27, software downloads, featured articles by developers, forums, technical support options, and more.

The following table may help you find information quickly:

To find out about:	Go to:
OS design goals; message-passing IPC	The Philosophy of QNX Neutrino
System services	The QNX Neutrino Microkernel
Sharing information between processes	Interprocess Communication (IPC)
System event monitoring	The Instrumented Microkernel
Working on a system with more than one processor	Multicore Processing
Memory management, pathname management, etc.	Process Manager
Shared objects	Dynamic Linking
Device drivers	Resource Managers
Image, RAM, QNX 4, DOS, CD-ROM, Flash, NFS, CIFS, Ext2 filesystems	Filesystems
Serial and parallel devices	Character I/O
Network subsystem	Networking Architecture
Native QNX Neutrino networking	Native Networking (Qnet)
TCP/IP implementation	TCP/IP Networking
Fault recovery	High Availability
Sharing resources among competing processes	Adaptive Partitioning
Graphical environment	The Photon microGUI
Multimedia Engine (MME)	Multimedia
Terms used in QNX documentation	Glossary

To find out about:

Go to:

OS design goals; message-passing IPC

The Philosophy of QNX Neutrino

System services

The QNX Neutrino Microkernel

Sharing information between processes

Interprocess Communication (IPC)

System event monitoring

The Instrumented Microkernel

Working on a system with more than one processor

Multicore Processing

Memory management, pathname management, etc.

Process Manager

Shared objects

Dynamic Linking

Device drivers

Resource Managers

Image, RAM, QNX 4, DOS, CD-ROM, Flash, NFS, CIFS, Ext2 filesystems

Filesystems

Serial and parallel devices

Character I/O

Network subsystem

Networking Architecture

Native QNX Neutrino networking

Native Networking (Qnet)

TCP/IP implementation

TCP/IP Networking

Fault recovery

High Availability

Sharing resources among competing processes

Adaptive Partitioning

Graphical environment

The Photon microGUI

Multimedia Engine (MME)

Multimedia

Terms used in QNX documentation

Glossary

Typographical conventions

Throughout this manual, we use certain typographical conventions to distinguish technical terms. In general, the conventions we use conform to those found in IEEE POSIX publications. The following table summarizes our conventions:

Reference	Example
Code examples	`if( stream == NULL )`
Command options	`-lR`
Commands	`make`
Environment variables	PATH
File and pathnames	`/dev/null`
Function names	exit()
Keyboard chords	Ctrl-Alt-Delete
Keyboard input	`something you type`
Keyboard keys	Enter
Program output	`login:`
Programming constants	NULL
Programming data types	`unsigned short`
Programming literals	`0xFF`, `"message string"`
Variable names	stdin
User-interface components	Cancel

Reference

Example

Code examples

if( stream == NULL )

Command options

-lR

Commands

make

Environment variables

PATH

File and pathnames

/dev/null

Function names

exit()

Keyboard chords

Ctrl-Alt-Delete

Keyboard input

something you type

Keyboard keys

Enter

Program output

login:

Programming constants

NULL

Programming data types

unsigned short

Programming literals

0xFF, "message string"

Variable names

stdin

User-interface components

Cancel

Notes point out something important or useful.

Cautions tell you about commands or procedures that may have unwanted or undesirable side effects.

Warnings tell you about commands or procedures that could be dangerous to your files, your hardware, or even yourself.

Note to Windows users

In our documentation, we use a forward slash (/) as a delimiter in all pathnames, including those pointing to Windows files.

At the top and bottom of our HTML docs, you'll see some or all of these buttons:

Use this button:	To move:
	To the previous part of the document.
	"Up" in the document: In a prose book, this typically takes you to About This Guide. In a reference book, it takes you to the listing of items that start with a given letter. For example, if you're looking at the docs for abs(), this button takes you to the listing of the functions that start with `A`.
	To the keyword index.
	To the next part of the document.

Use this button:

To move:

To the previous part of the document.

"Up" in the document:

In a prose book, this typically takes you to About This Guide.
In a reference book, it takes you to the listing of items that start with a given letter. For example, if you're looking at the docs for abs(), this button takes you to the listing of the functions that start with A.

To the keyword index.

To the next part of the document.

Technical support

To obtain technical support for any QNX product, visit the Support + Services area on our website (www.qnx.com). You'll find a wide range of support options, including community forums.

About This Guide

What you'll find in this guide

Typographical conventions

Note to Windows users

Navigation buttons

Technical support