Building Qt for a given device requires a toolchain and a sysroot. Additionally, some devices require vendor-specific adaptation code for EGL and OpenGL ES 2.0 support. This is not relevant for non-accelerated platforms, for example the ones using the LinuxFB plugin, which is meant for software-based rendering only. This means Qt Quick 2 is not functional in such a setup as it depends on OpenGL for rendering.
The directory qtbase/mkspecs/devices contains configuration and graphics adaptation code for a number of devices. For example, the linux-rasp-pi2-g++ mkspec contains build settings such as the optimal compiler and linker flags for the Raspberry Pi 2 device. The mkspec also contains information about either an implementation of the eglfs hooks (vendor-specific adaptation code), or a reference to the suitable eglfs device integration plugin. The device is selected through the configure tool’s -device parameter. The name that follows after this argument must, at least partially, match one of the subdirectories under devices.
There are currently some limitations to note with Qt 5 on the Raspberry Pi 2. Both the xcb and eglfs back ends for Qt are available.
The xcb back end supports widget applications and supports the X11 window manager running on the desktop so Qt-based applications will run in a window, which can be moved or resized. However, the OpenGL implementation on the Raspberry Pi is not compatible with xcb or X11, so applications that use OpenGL will not work with the xcb back end.
The eglfs back end supports widget-based and QML applications, and uses OpenGL, but will run in full screen mode and not be aware of any window manager.
The linuxfb back end, which directly uses the Linux video frame buffer, should also be available and work, although you will probably need to set some environment variables in order for the keyboard and mouse devices to work correctly.
You can select which back end to use at run time using command line options, i.e. “-platform xcb” or “-platform eglfs”. Normally, the default is to use the eglfs back end.
source package list
o summarize, you need to open the /etc/apt/sources.list file with a text editor and then add arch= between deb and the URL for each line. This is the example provided on the page: