Cannot start X server on rpb-desktop-image

Hi Everyone,

I’m trying this Yocto OE image.

However, when I try to start X server, nothing can be seen after I do
export DISPLAY=:0
openbox &

Is anything wrong in my steps?



The build you are using have never had a released version, only snapshot pre-releases. Also it looks like the OE snapshots for DB410c have been switched off since I know there have been lots of changes to the distro since since March.

Do you experience the same problem with the (released) reference platform build:

Actually… I just tested this myself and can confirm that X11 is working OK for me with this build (glxgears is 900fps :wink: ).

@danielt I also tried the 16.06 build, but I find the problem is not X11. I can run glxgears on both 16.06 rpb & jethro-36 snapshot images, but cannot start openbox correctly. The error messages are as below.

Obt-Message: failed to open an Input Method
Openbox-Message: X server does not support locale.
Openbox-Message: Cannot set locale modifiers forthe X server.

Aren’t those messages warnings rather than errors? Whilst we could look at improving the out-of-the-box locale setup to squash the warnings I can’t see anything wrong with openbox’s behaviour. It is drawing window decorations and both mouse and keyboard are functioning OK.

@danielt It’s strange that I cannot see windows drawing and mouse cursor is not shown as well. Could you provide your commands to start openbox for me? Thank you!

I ran the following lines (as root) via the serial port:

export DISPLAY=:0
openbox &
glxgears &
xterm &

After running this I can see both windows, they are correctly decorated (e.g. they have a title bar), I am able to use the mouse to select the xterm window and the keyboard to issue commands.

Actually I probably had a space between the X and the &…

@danielt Thanks! I can see the same behavior now!

Hello All,

I was just wondering. If I want to do the same than you did here but without the window manager xorg, like opening an app in fullscreen with accelerated graphics would that be possible (like the xinitrd of the archlinux)? with the rpb-console-image ?

If you have any idea, I would be very interested.



Yes, that should be possible.

It depends on your use case but you might find it better to run some kind of kiosk friendly window manager (such as matchbox) since it will handle things like dialog boxes much more gracefully. You may also be glad for matchbox on the day you want to open an xterm to debug something ;-).


Thanks for your feedback Daniel.

I want the lighter system as possible and I only need to start an application in fullscreen mode. I don’t need to manage multiple windows.
I want to start a QT application as soon as possible with eglfs backend.

From your point of view is this use case necessarily needs a window manager?


I’d suggest its try-it-and-see time.

The main issue running without a window manager is that it makes the application responsible for ensuring its window covers the whole screen (i.e. select an appropriate initial window geometry). Normally applications realize full screen mode by setting their _NET_WM_STATE to fullscreen and letting the window manager worry how to do it. This means that it may not be enough to ask QT to run in fullscreen mode and you might have to find an alternative way to do it.

I am able to resize the window through my application my main worry now is to being able to build qt with opengl without X11 and this is another story because apparently X11 was building (because of some nice dependencies I guess) all the necessary opengl libs (or opengl is X11 dependant?).

But this start to be a duplicate of my other post ^^ :
and out of scope of this thread.

Thanks for your advices.


Ok. We can leave if for the other thread. In any case it sounds like we’ve not been understanding each other anyway. I’ve been describing how to run X11 without a window manager rather than how to do accelerated graphics without an X server.

My bad, indeed, I haven’t been clear enough…
Let start again and if you have any idea about the other problem let me know ;).