There is a difference between X11, and what we call 'framebuffer', or fbdev_window.If you have setup the device to use the X windowing system, then instead of setting up EGL to pass in a window that is of type fbdev_window, but you would want to create an X11 window and pass that into EGL instead. (Note it will allow you to use fbdev with an X11 environment, but there is no guarantee what the output may do)Similarly, the reverse is true if you are running in fbdev mode, without X support. You will need to setup EGL to take in an fbdev_window instead of an X11 window.I hope that clarifies a few things, please feel free to contact us further if you need further assistance.