Qt commercial provides us with a handy tool to write a prebuilt embedded Linux image to a thumb drive or SD card. It is a program called Boot to Qt Flashing Wizard, or b2qt-flashing-wizard.exe, which is located at Qt/Tools/b2qt. When you run it, you will be asked to select the device you're running and the Qt version that supports it. The following screenshot shows this:
After that, you will be asked to select the storage device to write the Linux image:
After you have clicked on the Next button, the Linux image will be written to the storage device:
Once it's done, you can then plug your thumb drive or SD card into your embedded device and start booting up your Linux system! You should see the Qt demo being started by default on the Linux system.
The following photograph shows the embedded Qt demo running on my 6-year-old Intel NUC. The performance is really decent even though my machine is pretty old now:
If your device is not officially supported by The Qt Company, then you will need to build your own custom Linux image, which is not exactly an easy task. Qt uses recipes from the Yockto Project (https://www.yoctoproject.org) to configure their Linux images, so you should too if you're trying to build your own Linux image.
To learn how to build your own custom Linux image using the tools provided by the Yockto Project, take a look at the documentation at https://doc.qt.io/QtForDeviceCreation/qtee-custom-embedded-linux-image.html. Do note that you can only build a Linux image from the source on a Linux system, such as Ubuntu. You can't do it on a Windows or macOS system. Luckily, the Yockto Project also provides us with a build bot that allows us to build on the cloud instead of doing it on our own machine.
In this section, we have learned how to set up an embedded Linux image for device creation on Qt. Next, we will learn how to build a cross-compiled Qt project.