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QNX Software Development Platform
OS Components
Building Embedded Systems
The Building Embedded Systems guide is intended for developers who are developing or building BSPs for QNX OS embedded systems.
Startup Programs
The first program to run in a bootable OS image is the startup program; it completes the system configuration, then launches the OS kernel.

QNX Momentics IDE User's Guide
QNX Software Development Platform
- Quickstart Guide
- System Architecture
  The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
- OS Components
  - 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 OS embedded systems.
    - Overview
      QNX systems are built from the QNX OS standard release components, the architecture- and board-specific files provided in QNX BSPs, and customer and third-party components.
    - Working with QNX BSPs
      Before you attempt to write a new BSP or modify an existing one, it is helpful to know how to use a BSP.
    - Initial Program Loaders (IPLs)
      IPLs first set up the minimum environment needed to execute their compiled C code, then find the OS image and load it into memory, and then jump to the QNX startup code.
    - Startup Programs
      The first program to run in a bootable OS image is the startup program; it completes the system configuration, then launches the OS kernel.
      - Startup tasks
        The startup code configures the hardware, detects system resources, and loads and starts the OS kernel.
      - Source code directories
        BSPs always include a viable startup program binary, and source code you can use to build your own image with a modified or new startup program.
      - Source code structure
        Most of the startup code is stored in the main() function, which follows the _start() and _main() functions in the startup code sequence.
      - Modifying the startup program
        You can modify a startup program or even create a new one.
    - Kernel Callouts
      Kernel callouts are standalone pieces of code (or code fragments) that the kernel uses to perform hardware-specific functions. These callouts don't need to be statically linked to the kernel.
    - System Page
      The system page contains essential information about the system, including the system page's size, information about the hardware platform (including IRQs and the CPU), the cache size, and the location of kernel callouts in memory.
    - OS Images
      OS images are files that contains the OS, your executables, and any data files that might be related to your programs.
    - OS Image Buildfiles
      You can edit OS image buildfiles to configure OS images.
    - IPL Library
      The IPL library contains a set of routines for building a custom IPL.
    - Startup Library
      The startup library contains a rich set of routines ranging from high-level functions called by main() to utility functions for performing specific startup tasks.
    - Debugging QNX Embedded Systems
      The microkernel architecture of QNX OS means that debugging QNX embedded systems can be different from debugging other embedded systems.
    - Sample Buildfiles
      This appendix contains sample buildfiles that you can modify to support your hardware platform and your implementation requirements.
    - Glossary
  - 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.
  - 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 OS High-Performance Networking Stack and its manager, io-sock.
  - PCI Server User'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
  - SPI Framework Technote
  - System Analysis Toolkit (SAT) User's Guide
  - Technotes
  - User's Guide
    The QNX OS User's Guide is intended for all users of a QNX OS system, from system administrators to end users.
- 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 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 OS applications and systems.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

Startup Programs

QNX SDP8.0Building Embedded SystemsConfigurationDeveloper

The first program to run in a bootable OS image is the startup program; it completes the system configuration, then launches the OS kernel.

Startup programs are hardware platform-specific. Every QNX OS release includes startup programs for popular supported platforms. Additional startup programs are released with new BSPs, when these are made available.

The BIOS or UEFI (x86) or the ROM monitor (ARM), along with the IPL, look after the minimum configuration needed so the startup code can run, then load the OS image. If the IPL detects resources, it uses the startup header (startup.h) to pass this information on to the startup code (see The startup header in the Initial Program Loaders (IPLs) chapter).

One of the startup program's main tasks is to set up the system page. To help keep the OS kernel as platform-independent as possible, the startup code supplies some callouts to the kernel. The table below lists places to find more information.


Topic	See:
Startup programs	startup-* options and other startup-* entries in the Utilities Reference
System page	The System Page chapter in this guide
Kernel callouts	The Kernel Callouts chapter in this guide

Page updated: May 17, 2024