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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 QNX Neutrino 7.1.
OS Components & Operations
System Architecture
The System Architecture guide accompanies the QNX Neutrino RTOS and is intended for both application developers and end-users.
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.
High Availability Manager
The High Availability Manager (HAM) provides a mechanism for monitoring processes and services on your system.
HAM hierarchy
The High Availability Manager consists of three main components.

QNX Momentics IDE User's Guide
This User's Guide describes version 7.1 of the Integrated Development Environment (IDE) that's part of the QNX Momentics 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 QNX Neutrino 7.1.
- Quickstart Guide
- OS Components & Operations
  - Adaptive Partitioning User's Guide
  - Boot Optimization Guide
    The Boot Optimization Guide describes techniques you can use to reduce the time from your board's initial power on until you have a fully functional QNX system running on the board.
  - Building Embedded Systems
    The Building Embedded Systems guide is intended for developers who are developing or building BSPs for QNX Neutrino RTOS embedded systems.
  - Core Networking Stack User's Guide
    This guide introduces you to the QNX Neutrino Core Networking stack and its manager, io-pkt.
  - Customizing a BSP
    While QNX provides Board Support Packages (BSPs) for many common platforms and their individual variants, in some cases, you need a BSP for a board that QNX does not provide. If this is the case, you can modify a QNX BSP or develop your own.
  - Device Publishers Developer's Guide
  - High Availability Framework Developer's Guide
  - High-Performance Networking Stack (io-sock) User's Guide
    This guide contains instructions for implementing and using the QNX Neutrino High-Performance Networking Stack and its manager, io-sock.
  - Instant Device Activation
  - Migrating to QNX SDP 7.1
  - PCI Server User's Guide
  - Persistent Publish/Subscribe Developer's Guide
  - Platform-independent Publish/Subscribe Developer's Guide
    This guide is intended for application developers who want to use the Platform-independent Publish Subscribe (PiPS) framework to exchange information with other applications. First, the overall PiPS design and data-exchange model are explained. Then, tutorials on using PiPS are given. These tutorials cover key tasks such as selecting a publish-subscribe provider to use and writing plugins that read and write custom data types.
  - QDB Developer's Guide
  - QNX Helpers Developer's Guide
    These libraries provide QNX helpers, including helpers that assist with logging, string conversion, and number and type sizes.
  - SMMUMAN User's Guide
  - System Analysis Toolkit (SAT) User's Guide
  - System Architecture
    The System Architecture guide accompanies the QNX Neutrino RTOS and is intended for both application developers and end-users.
    - The Philosophy of the QNX Neutrino RTOS
      The primary goal of the QNX Neutrino RTOS 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 Neutrino Microkernel
      The microkernel implements the core POSIX features used in embedded realtime systems, along with the fundamental QNX Neutrino message-passing services.
    - Interprocess Communication (IPC)
      Interprocess Communication 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 Instrumented Microkernel
      An instrumented version of the microkernel (procnto-instr) is equipped with a sophisticated tracing and profiling mechanism that lets you monitor your system's execution in real time. The procnto-instr module works on both single-CPU and SMP systems.
    - Multicore Processing
    - Process Manager
      The process manager is capable of creating 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 Neutrino RTOS 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.
    - Filesystems
      The QNX Neutrino RTOS 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.
    - PPS
      The QNX Neutrino Persistent Publish/Subscribe (PPS) service is a small, extensible publish/subscribe service that offers persistence across reboots. It's designed to provide a simple and easy-to-use solution for both publish/subscribe and persistence in embedded systems, answering a need for building loosely connected systems using asynchronous publications and notifications.
    - 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 Neutrino RTOS, the networking services execute outside the kernel. Developers are presented with a single unified interface, regardless of the configuration and number of networks involved.
    - Native Networking (Qnet)
      In the Interprocess Communication (IPC) chapter earlier in this manual, we described message passing in the context of a single node. But the true power of the QNX Neutrino RTOS lies in its ability to take the message-passing paradigm and extend it transparently over a network of microkernels. This chapter describes QNX Neutrino native networking (via the Qnet protocol).
    - TCP/IP Networking
      As the Internet has grown to become more and more visible in our daily lives, the protocol it's based on—IP (Internet Protocol)—has become increasingly important. The IP protocol and tools that go with it are ubiquitous, making IP the de facto choice for many private networks.
    - 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.
      - An OS for HA
        If you had to design an HA-capable OS from the ground up, would you start with a single executable environment? In this simple, high-performance design, all OS components, device drivers, applications, the works, would all run without memory protection in kernel mode.
      - Custom hardware support
        While many operating systems provide HA support in a hardware-specific way (e.g., via PCI Hot Plug), QNX Neutrino isn't tied to PCI. Your particular HA system may be built on a custom chassis, in which case an OS that offers a PCI-based HA solution may not address your needs at all.
      - Client library
        The High Availability client-side library provides a drop-in enhancement solution for many standard C Library I/O operations.
      - High Availability Manager
        The High Availability Manager (HAM) provides a mechanism for monitoring processes and services on your system.
        The HAM and the Guardian
        As a self-monitoring manager, the HAM is resilient to internal failures. If, for whatever reason, the HAM itself is stopped abnormally, it can immediately and completely reconstruct its own state. A mirror process called the Guardian perpetually stands ready and waiting to take over the HAM's role. Since all state information is maintained in shared memory, the Guardian can assume the exact same state that the original HAM was in before the failure.
        HAM hierarchy
        The High Availability Manager consists of three main components.
        Entities
        Entities are the fundamental units of observation/monitoring in the system.
        Conditions
        Conditions are associated with entities; a condition represents the entity's state.
        Actions
        Actions are associated with conditions. Actions are executed when the appropriate conditions are true with respect to a specific entity.
        Publishing autonomously detected conditions
        Entities or other components in the system can inform the HAM about conditions (events) that they deem interesting, and the HAM in turn can deliver these conditions (events) to other components in the system that have expressed interest in (subscribed to) them.
        Subscribing to autonomously published conditions
        To express their interest in events published by other components, subscribers can use the ham_condition_state() and ham_condition_raise() API calls.
        The HAM as a filesystem
        Effectively, the HAM's internal state is like a hierarchical filesystem, where entities are like directories, conditions associated with those entities are like subdirectories, and actions inside those conditions are like leaf nodes of this tree structure.
        Multistage recovery
        The HAM can perform a multistage recovery, executing several actions in a certain order. This technique is useful whenever strict dependencies exist between various actions in a sequence. In most cases, recovery requires more than a single restart mechanism in order to properly restore the system's state to what it was before a failure.
        HAM API
        The basic mechanism to talk to the HAM is to use its API. This API is implemented as a library that you can link against. The library is thread-safe and cancellation-safe.
    - Adaptive Partitioning
    - What is Real Time and Why Do I Need It?
    - Glossary
  - Technotes
  - User's Guide
    The QNX Neutrino User's Guide is intended for all users of a QNX Neutrino RTOS system, from system administrators to end users.
- Audio & Graphics API
- Multimedia
- Networking Middleware
- Programming
- Sensor Framework
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX Neutrino RTOS system and developers who want to create a QNX Neutrino resource manager free from vulnerabilities.
- Utilities & Libraries
QNX Hypervisor
The QNX Hypervisor allows you to run multiple OSs on a target system so you can separate critical and non-critical functions, support a wide variety of applications, and reduce hardware costs.
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX software in Amazon Web Services (AWS) and Microsoft Azure (Azure).
QNX Advanced Virtualization Frameworks User's Guide
This User's Guide is aimed at all systems integrators and developers who want to design and build embedded systems using the QNX Advanced Virtualization Frameworks.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

HAM hierarchy

The High Availability Manager consists of three main components.

Page updated: March 12, 2026