I posted to the Raspberry Pi forum about this the link is below. I am using a fresh build of Yocto Langdale 4.1.3 with the core-image-x11 image.
Raspberry Pi forum DSI display issue with Yocto
Basically the problem is that I have a 7" DSI display that is supposed to work without any special drivers with just the overlays.
My DSI display shows the text at bootup and the raspberry pi logo/loading screen but thats it.
If I connect an HDMI display everything works fine.
If I run "xrandr -q" it shows that the DSI display is connected and I can use the touchscreen of the DSI display to move the cursor on the hdmi screen.
How do I configure xinit/xrandr/matchbox-window-manager so that the terminal/x11 UI appears on the DSI display.
I am not sure what I need to do to make the display work.
What I want is for the X11 image to start up and display on the DSI display. I do not need HDMI to also work though if I could duplicate the output of the display over HDMI that would be awesome.