Dennis Núñez

PhD (c) in AI and Neuroimaging. CEA / Inria / Université Paris-Saclay

Add graphical environment with Xephyr Disp. Server to Parallella Board

Requirements: Ubuntu PC and Parallella Board.

First you should to set all configurations of the previous post Add Graphical Environment (

Install Xephyr in your Ubuntu PC:

$ sudo apt-get install xserver-xephyr

Able or Disable PCManFM Desktop mode:

I recommend to disable 'PCManFM Desktop mode' for faster displaying. Edit the next files (On Parallella Board):

$ sudo nano /etc/xdg/lxsession/LXDE/autostart

$ sudo nano ~/.config/lxsession/LXDE/autostart

, to able or disable 'PCManFM Desktop mode', in both files add or delete respectively the next line, and save:

@pcmanfm --desktop --profile LXDE

Set a background image:

Put a background image file in your home directory ( e.g. /home/technical/lxde_wallpaper.png ). Then edit the next files (On Parallella Board):

$ sudo nano /etc/xdg/lxsession/LXDE/autostart

$ sudo nano ~/.config/lxsession/LXDE/autostart

, add this line to the bottom of the both files:

@feh --bg-fill /home/technical/lxde_wallpaper.png

After set PCManFM Desktop mode and background image:

On Parallella Board:

$ sync $ sudo reboot


Notice that my PC IP is, and Parallella uses Obviously you have to adjust those to your values.

Check your IP here if you are using Ubuntu:

1.Open Xephyr

Launch Xephyr Server in your Ubuntu PC. Open a terminal and type:

$ Xephyr -ac -br -keybd ephyr,,,xkbmodel=pc105,xkblayout=es -noreset -screen 1280x720 :1

You can change the value 1280x720 to: 640x489, 1280x720, 1366x768, ...

2.Connect to Parallella

Open a terminal in Ubuntu PC and type:

$ ssh -X parallella@

3.Export Parallella Display

In the terminal that you are connected to Parallella, type:

$ export DISPLAY=

You just tell that DISPLAY should be run to the remote machine with the IP (my PC IP is and DISPLAY :1 which is the Xephyr Session. GNOME’s display should be :0, and is used.

4.Run XServer

In ssh terminal, that you are connected to Parallella, try to run your graphical environment. I have a default LXDE.

$ startlxde

Another option for steps 2, 3 and 4

Instead of the points 2 and 3, in Ubuntu PC:

$ DISPLAY=:1 ssh -Y parallella@

Then continue with step 4, in ssh terminal connected to Parallella:

$ startlxde


Start with Xephyr Display Server and disable 'PCManFM Desktop mode' and set a background image: