Home
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running the QNX OS 8.0.
System Architecture
The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
Resource Managers
To give the QNX OS a great degree of flexibility, to minimize the runtime memory requirements of the final system, and to cope with the wide variety of devices that may be found in a custom embedded system, the OS allows user-written processes to act as resource managers that can be started and stopped dynamically.
Resource manager architecture
The resource manager shared library
In a custom embedded system, part of the design effort may be spent writing a resource manager, because there may not be an off-the-shelf driver available for the custom hardware component in the system.

QNX Momentics IDE User's Guide
This User's Guide describes version 8.0 of the Integrated Development Environment (IDE) that's part of the QNX Tool Suite.
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running the QNX OS 8.0.
- Quickstart Guide
- System Architecture
  The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
  - The Philosophy of the QNX OS
    The primary goal of the QNX OS is to deliver the open systems POSIX API in a robust, scalable form suitable for a wide range of systems—from tiny, resource-constrained embedded systems to high-end distributed computing environments. The OS supports several processor families, including x86 and ARM.
  - The QNX OS Microkernel
    The microkernel implements the core POSIX features used in embedded realtime systems, along with the fundamental QNX OS message-passing services.
  - Interprocess Communication (IPC)
    Interprocess Communication (IPC) plays a fundamental role in the transformation of the microkernel from an embedded realtime kernel into a full-scale POSIX operating system. As various service-providing processes are added to the microkernel, IPC is the glue that connects those components into a cohesive whole.
  - The Microkernel Instrumentation
    The microkernel (procnto-smp-instr) is equipped with a sophisticated tracing and profiling mechanism that lets you monitor your system's execution in real time. This instrumentation works on both single-CPU and SMP systems.
  - Process Manager
    The Process Manager can create and manage multiple POSIX processes, each of which may contain multiple POSIX threads.
  - Dynamic Linking
    In a typical system, a number of programs will be running. Each program relies on a number of functions, some of which will be standard C library functions, like printf(), malloc(), write(), etc.
  - Resource Managers
    To give the QNX OS a great degree of flexibility, to minimize the runtime memory requirements of the final system, and to cope with the wide variety of devices that may be found in a custom embedded system, the OS allows user-written processes to act as resource managers that can be started and stopped dynamically.
    - How do client programs talk to resource managers?
      Since the QNX OS is a distributed, microkernel OS with virtually all nonkernel functionality provided by user-installable programs, a clean and well-defined interface is required between client programs and resource managers.
    - Resource manager architecture
      - Message types
      - The resource manager shared library
        In a custom embedded system, part of the design effort may be spent writing a resource manager, because there may not be an off-the-shelf driver available for the custom hardware component in the system.
        Automatic default message handling
        If there are functions that the resource manager doesn't want to handle for some reason (e.g., a digital-to-analog converter doesn't support a function such as lseek(), or the software doesn't require it), the shared library will conveniently supply default actions.
        open(), dup(), and close()
        Another convenient service that the resource manager shared library provides is the automatic handling of dup() messages.
        Multiple thread handling
        One of the salient features of the QNX OS is the ability to use threads. By using multiple threads, a resource manager can be structured so that several threads are waiting for messages and then simultaneously handling them.
        Dispatch functions
        Combine messages
        In order to provide support for atomic operations, the OS supports combine messages. A combine message is constructed by the client's C library and consists of a number of I/O and/or connect messages packaged together into one.
        Second-level default message handling
        Since a large number of the messages received by a resource manager deal with a common set of attributes, the OS provides another level of default handling.
    - Summary
      By supporting pathname space mapping, by having a well-defined interface to resource managers, and by providing a set of libraries for common resource manager functions, the QNX OS offers the developer unprecedented flexibility and simplicity in developing drivers for new hardware—a critical feature for many embedded systems.
  - Filesystems
    The QNX OS provides a rich variety of filesystems. Like most service-providing processes in the OS, these filesystems execute outside the kernel; applications use them by communicating via messages generated by the shared-library implementation of the POSIX API.
  - Character I/O
    A key requirement of any realtime operating system is high-performance character I/O.
  - Networking Architecture
    As with other service-providing processes in the QNX OS, the networking services execute outside the kernel. Developers are presented with a single unified interface, regardless of the configuration and number of networks involved.
  - TCP/IP Networking
    Our TCP/IP stack is included in the io-sock networking stack and uses the common FreeBSD API.
  - High Availability
    The term High Availability (HA) is commonly used in telecommunications and other industries to describe a system's ability to remain up and running without interruption for extended periods of time.
  - What is Real Time and Why Do I Need It?
    Real time is an often misunderstood—and misapplied—property of operating systems. This appendix provides a summary of some of the critical elements of realtime computing and discusses a few design considerations and benefits.
  - Glossary
- OS Components & Operations
- Graphics
- Programming
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX OS system and developers who want to create a QNX OS resource manager free from vulnerabilities.
- Utilities & Libraries
- Migrating to QNX OS 8.0
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX OS in the Amazon cloud environment.
QNX Toolkit for Visual Studio Code
This User's Guide describes the QNX^® Toolkit for Visual Studio Code. The guide introduces you to the QNX Toolkit by explaining the QNX development environment and how to build, run, and debug your QNX^® Operating System (OS) applications and systems.
QNX Hypervisor User's Guide
This User's Guide explains the QNX hypervisor architecture and provides instructions for installing and running a QNX Hypervisor system, changing system components and configuration, and using hypervisor features such as virtual devices (vdevs).
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation, explains how to obtain technical support, and provides some information about licensing.

The resource manager shared library

QNX SDP8.0System ArchitectureDeveloperUser

In a custom embedded system, part of the design effort may be spent writing a resource manager, because there may not be an off-the-shelf driver available for the custom hardware component in the system.

Our resource manager shared library makes this task relatively simple.

Page updated: March 05, 2025