Qt offers all the necessary tools to design, develop, build, and deploy your application onto the target.

This guide describes how to use the GUIs of Qt tools to develop Linux applications on a Qualcomm device. It describes the overall process and provides step-by-step instructions for the following tasks:

• Designing a simple UI using Qt Design Studio.
• Creating a project in Qt Creator and utilizing the ready-made Qt Onboard image for the Qualcomm device.
• Building and debugging the project on the target device.

Overview

The following figure illustrates the basic concept of the software development process when you're using Qt tools and Qt Onboard.

• Development Host is your development computer running Qt tools on Windows, Linux, or macOS.
• Qt tools includes development tools such as Qt Creator and Qt Design Studio, and quality assurance (QA) tools such as Squish.
• QBSP SDK contains a cross-compilation toolchain that is integrated into Qt Creator, and a device image that you can use to boot your device using Qt Onboard.
• Target Device is your development target that runs your embedded Linux application.
• Upload and debug an application (via Ethernet, Wi-Fi, or USB). Use Qt Creator to upload and debug your application on the target device.
• Flash a QBSP image represents ways (such as SD card) to install Linux on the target device.

Applicable Qualcomm target devices

The instructions in this guide apply to the following Qualcomm target devices:

• Qualcomm DragonWing IQ-9075

The Qt versions you can see in the images and examples of this guide are indicative and might not represent the latest available version.

Installing Qt Onboard

Before you start installation, check Requirements related to development host to make sure your host has all the necessary dependencies installed.

To install Qt Onboard, open the instructions that match your current situation.

Installing Qt Onboard on the target device

Before you can test your Qt applications on the target device, you must flash the target device with an image containing Qt Onboard.

Flashing Qt Onboard Image on the target device

Flash the Qt Onboard image to your device as follows:

1. Add or update udev rules as instructed in Update udev rules on your host.
2. Connect the target device to your host with a suitable USB-C cable.
3. Put the target device into Emergency Download (EDL) mode. For more information on how to do this, see Move to EDL mode.
4. Download and install a Qualcomm Download (QDL) tool from Qualcomm Software Center.
5. Run the following scripts to flash the image to your device:

   cd <INSTALL_DIR>/6.11.0/qualcomm/qcs9075-iq-9075-evk/images/qcom-qt-image-qcs9075-iq-9075-evk.rootfs/
   <path-to-qdl>/qdl prog_firehose_ddr.elf rawprogram*.xml patch*.xml

For more information on flashing Qualcomm devices, see Github: qualcomm-linux/meta-qcom.

Configure the target device

Deploying examples and applications from Qt Creator typically installs files under the /usr directory. On Qualcomm Linux, this directory is mounted as read‑only by default.

You need to remount the file system with read-write access to enable deployment to proceed successfully. Enable read–write access by running the following command on the device:

mount -o remount,rw /usr

Connecting the target device

Create a connection between the target device and Qt Creator to run, debug, and analyze applications on it. The following section describes how to set up a device using Ethernet or Wi-Fi connectivity.

Connecting the target device via Ethernet or Wi-Fi

Connect your target device to network either via Ethernet or Wi-Fi connectivity.

To connect via Wi-Fi, use nmcli on the device, for example:

nmcli dev wifi connect "<SSID>" password "<password>"

After your target device is connected and has an IP address, set it up to be used in Qt Creator with the following steps:

1. Open Qt Creator.
2. Select Edit > Preferences.
3. In the Preferences window:
   1. Select Devices.
   2. Select Add > Remote Linux Device > Start Wizard.
4. In the New Remote Linux Device Configuration Setup window:
   1. Enter the name to identify this configuration.
   2. Enter the device's host name or IP address.
   3. Enter root as user name.
   4. Select Next.

   

5. To enable deployment without a password prompt, deploy an SSH key to the device. The default password for Qualcomm Linux devices is oelinux123.

   

6. On the Devices tab, select OK.

Creating an application UI in Qt Design Studio

Create a cross-platform UI with Qt Design Studio, also for embedded Linux applications, with the following steps:

1. Open Qt Design Studio.
2. Select Create Project.
3. In Presets, select General.
   • Name your project. Pay attention to the project path—later on, you open your project from this location with Qt Creator.
   • Adjust display resolution and orientation to suit your display.
4. Select Enable CMake Generator. With the resulting CMakeLists.txt file, you can open your project in Qt Creator.
5. Make sure your Target Qt Version matches the version of Qt installed on your machine.
6. Select Create.

Now you can modify your UI as you wish. Once it's ready, select Save All to make sure that you can open your UI project in Qt Creator.

Configuring and building an application in Qt Creator

To configure and build an application in Qt Creator, follow these steps:

1. Open Qt Creator.
2. Navigate to the project you created with Qt Design Studio.
3. Select CMakeLists.txt to open the project.
4. In the Configure Project window:
   • Select your Qualcomm kit.
   • Select Configure Project.

Finally, select Build > Build Project to build the project you configured.

Running an application on the target device

After setting up your device, you can upload and start your application on the Qualcomm device as follows:

1. Open Qt Creator.
2. Select File > Open File or Project.
3. Navigate to the project you configured earlier and select Open.
4. In the Projects window, select Run (1).

For more information on how to deploy Qt projects to the device, see Tutorial: Deploying your first project.

For more information on how to build applications on Docker devices, see Build on Docker devices.

Debugging an application

For more information on using Qt Creator to debug an application, see Debugging.

Customizing Qt Onboard for a Qualcomm device

Qt Onboard for embedded Linux is built using the tools and resources from the Yocto Project. For more information on how to set up a building environment for building Qt Onboard, see Setting up environment for building Qt Onboard.

The following table lists the MACHINE values of the currently available Qualcomm devices:

The following steps provide an example on how to build Qt Onboard for a Qualcomm device:

1. Initialize the build environment from the manifest repository:

   cd <BuildDir>
   repo init -u https://code.qt.io/yocto/meta-qbsp-qcom
   repo sync

2. Configure the build environment for Linux:

   EXTRALAYERS="meta-qcom-qim-product-sdk meta-boot2qt/meta-boot2qt meta-qbsp-qcom meta-qt6" MACHINE=qcs9075-iq-9075-evk DISTRO=qcom-wayland source setup-environment

3. Enable Qt commercial modules by adding the following to conf/local.conf:

   echo 'QT_EDITION = "commercial"' >> conf/local.conf
   echo 'QT_COMMERCIAL_MODULES = "1"' >> conf/local.conf

4. Start building a QBSP for Qt Onboard:

   bitbake meta-qbsp-qcom

   After the build has been completed, you can find the QBSP file at build-qcs9075-iq-9075-evk/tmp-glibc/deploy/qbsp/meta-qbsp-qcom-x86_64-qcs9075-iq-9075-evk-6.11.0.qbsp

Troubleshooting

If you have any issues with your Qualcomm device, turn to Qualcomm Support Forums for more information.

For more information on troubleshooting Qt Onboard, see Troubleshooting.