Enabling Qt on VxWorks

Qt, a versatile cross-platform framework, is widely recognized for its ability to create rich graphical user interfaces (GUIs) and robust applications across various operating systems. When paired with VxWorks, a real-time operating system (RTOS) developed by Wind River, Qt becomes a powerful tool for embedded systems development, particularly in industries like aerospace, defense, medical, and industrial automation. This article explores the process of enabling Qt on VxWorks, its benefits, and key considerations for developers.

Why Qt on VxWorks?

#

VxWorks is renowned for its deterministic performance and reliability, making it a staple in mission-critical applications. However, its native tools for GUI development are limited. Qt fills this gap by providing a modern, feature-rich framework that supports everything from basic widgets to advanced OpenGL-accelerated visualizations like Qt Quick. By enabling Qt on VxWorks, developers can create visually appealing, user-friendly interfaces without sacrificing the real-time capabilities of the RTOS.

Qt’s support for VxWorks has evolved significantly over the years. While earlier versions like Qt 4.8 were supported on VxWorks 6.9, recent releases such as Qt 5.15 LTS and Qt 6.8 have been optimized for VxWorks 7 and beyond, leveraging newer hardware capabilities and offering improved performance.

Prerequisites for Enabling Qt on VxWorks

#

Before diving into the setup process, ensure you have the following:

• Commercial Qt License: Qt for VxWorks is available only under a commercial license from The Qt Company. Contact their sales team for access to the source packages.
• VxWorks Development Environment: Install Wind River’s VxWorks SDK, including the VxWorks Development Shell and a compatible toolchain (e.g., for ARM or x86_64 architectures).
• Supported Hardware: Qt has been verified on platforms like the Freescale i.MX6 (ARM-v7) and Intel NUC (x86_64). Ensure your target hardware aligns with these specifications or is compatible with VxWorks BSPs (Board Support Packages).
• Host System: A Linux (e.g., Ubuntu) or Windows host is required for building Qt, though Linux is recommended for the latest versions.

Steps to Enable Qt on VxWorks

#

Here’s a high-level guide to setting up Qt on VxWorks, based on typical workflows outlined in Qt’s official documentation:

1. Obtain Qt Source Code:

• Log into your Qt Account and download the appropriate VxWorks source package (e.g., Qt 5.15.16 or Qt 6.8.1).
• Alternatively, request access through Qt Professional Services for the latest supported releases.

2. Set Up the VxWorks Development Shell:

• On your host machine, navigate to the VxWorks installation directory and launch the development shell:

cd <VxWorks_installation_directory>
./wrenv.sh -p vxworks
export WIND_CC_SYSROOT=<path_to_VxWorks_VSB_directory>

• This configures the environment with the necessary compiler and linker tools.

3. Configure Qt for VxWorks:

• Extract the Qt source package and navigate to its root directory.
• Run the configure script with options tailored to your device. For example, for an i.MX6 target:

./configure -commercial -confirm-license -device vxworks-imx6 \
  -device-option CROSS_COMPILE=arm -prefix /sd1:1/qt5rtp \
  -sysroot <path_to_vxworks_vsb_dir>/fsl_imx6_1_1_11_0_VSB \
  -no-gcc-sysroot -extprefix <path_to_host_dir>/qt5rtp \
  -hostprefix <path_to_host_dir>/qt5rtp -no-openssl \
  -nomake tools -nomake examples

• Use -static if you prefer a statically linked build to reduce dependencies.

4. Build and Install Qt:

• Compile the source using a build tool like ninja or make:

ninja
ninja install

• This installs Qt to the specified prefix, ready for deployment to the target.

5. Deploy to the VxWorks Target:

• Transfer the compiled Qt libraries and your application to the VxWorks filesystem (e.g., via FTP or SD card).
• Launch the application using the VxWorks shell, ensuring the correct environment variables are set if using shared libraries:

putenv "LD_LIBRARY_PATH=/sd0:1/lib"
cd "/sd0:1"
rtpSp("<your_qt_app>", 200, 0x100000, 0, 0x01000000)

6. Test and Debug:

• Use Qt Creator’s VxWorks plugin (available with newer releases) for seamless deployment and debugging. Configure the target’s IP address in Qt Creator to upload and run the application directly.

Key Features and Considerations

#

• Platform Plugins: Qt on VxWorks supports plugins like EGLFS (for GPU-accelerated devices) and VxWorksFB (for non-accelerated setups). EGLFS is recommended for modern devices with OpenGL ES 2.0 support, enabling Qt Quick 2 functionality.
• Graphics Memory: For high-resolution displays, ensure at least 128 MB of GPU memory is available to avoid performance issues.
• Module Selection: Exclude unnecessary modules (e.g., -skip ) during configuration to optimize the binary size for embedded constraints.
• Input Handling: Configure environment variables like QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS for touchscreens or disable built-in input handlers if needed.

Benefits of Qt on VxWorks

#

• Rich GUIs: Leverage Qt Quick for dynamic, hardware-accelerated interfaces.
• Cross-Platform Compatibility: Reuse code across VxWorks and other platforms supported by Qt.
• Real-Time Performance: Combine VxWorks’ determinism with Qt’s efficient rendering.
• Ecosystem Support: Access Qt Creator and a vast library of modules for rapid development.

Challenges and Solutions

#

• Hardware Variability: Not all VxWorks BSPs include graphics libraries by default. You may need to create a custom CMake toolchain file to integrate them.
• License Costs: The commercial license requirement may be a barrier for small projects. Evaluate your needs against Qt’s pricing model.
• Learning Curve: Developers new to VxWorks or Qt may need time to master the configuration process. Refer to Qt’s VxWorks documentation for detailed guidance.

Conclusion

#

Enabling Qt on VxWorks opens the door to sophisticated embedded applications with modern interfaces, all while retaining the RTOS’s real-time strengths. As of March 1, 2025, Qt 6.8.1 is fully supported on VxWorks 24.03, with ongoing enhancements like the Qt Creator plugin improving the development experience. Whether you’re building a medical device or an aerospace control system, this combination offers a compelling solution for today’s embedded challenges. Start by securing your Qt license and experimenting with a supported reference board—your next innovative project awaits!