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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 Analysis Toolkit (SAT) User's Guide
Events and the Kernel
Classes and events

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
    - Introduction
    - Events and the Kernel
      - Generating events: a typical scenario
      - Simple and combine events
      - Fast and wide modes
      - Classes and events
        Communication class: _NTO_TRACE_COMM
        The _NTO_TRACE_COMM class includes events related to communication.
        Control class: _NTO_TRACE_CONTROL
        The _NTO_TRACE_CONTROL class includes events related to the control of tracing itself.
        Interrupt classes: _NTO_TRACE_INTENTER, _NTO_TRACE_INTEXIT, _NTO_TRACE_INT_HANDLER_ENTER, and _NTO_TRACE_INT_HANDLER_EXIT
        These classes track interrupts.
        Kernel-call classes: _NTO_TRACE_KERCALLENTER, _NTO_TRACE_KERCALLEXIT, and _NTO_TRACE_KERCALLINT
        These classes track kernel calls.
        Process class: _NTO_TRACE_PROCESS
        The _NTO_TRACE_PROCESS class includes events related to the creation and destruction of processes.
        Security class: _NTO_TRACE_SEC
        (QNX Neutrino 7.0 or later) The _NTO_TRACE_SEC class includes events related to security.
        System class: _NTO_TRACE_SYSTEM
        The _NTO_TRACE_SYSTEM class includes events related to the system as a whole.
        Thread class: _NTO_TRACE_THREAD
        The _NTO_TRACE_THREAD class includes events related to state changes for threads.
        User class: _NTO_TRACE_USER
        The _NTO_TRACE_USER class includes custom events that your program creates.
        Virtual thread class: _NTO_TRACE_VTHREAD
        The _NTO_TRACE_VTHREAD class includes events related to state changes for virtual threads, special objects related to Transparent Distributed Processing (TDP) over Qnet.
    - Kernel Buffer Management
      As the instrumented kernel intercepts events, it stores them in a ring of buffers.
    - Capturing Trace Data
    - Filtering
    - Interpreting Trace Data
      Once the data has been captured, you may process it, either in real time or offline.
    - Tutorials: Controlling event tracing
    - Sample Programs
    - Current Trace Events and Data
  - System Architecture
    The System Architecture guide accompanies the QNX Neutrino RTOS and is intended for both application developers and end-users.
  - 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.

Classes and events

There can be a lot of events in even a small trace, so they're organized into classes to make them easier for you to manage:

(The <sys/trace.h> header file also defines an _NTO_TRACE_EMPTY class, but it's a placeholder and isn't currently used.)

The sections that follow list the events for each class, along with a description of when the events are emitted, as well as the labels that traceprinter and the IDE use to identify the events.

For information about the data for each event, see the Current Trace Events and Data appendix.

Page updated: March 12, 2026