6 Replies Latest reply on Apr 18, 2014 11:10 AM by Tokoro

    galileo desktop with vnc howto

    tinkerer8473

      Here is a graphical display from the Galileo board shown on my laptop using vnc.

       

      I used ssh from my laptop to the Galileo and then chroot to debian and started the vnc4server.

      From my laptop I ran xcalc on the Galileo. I just got this running and haven't done anything else yet.

       

      clanton-window.png

      Here are the steps I used:

      1. Partition sdcard for galileo 0.7.5-2 in the first partition and debian squeeze in the second partition.

      2. Setup debian and then chroot to mmcblk0p2 and run vnc4server -geometry 1280x800 -depth 16

      3. From laptop run xvncviewer. In the window run xcalc, geany or anything...

        • 1. Re: galileo desktop with vnc howto
          MarcIII

          If you ssh from a Linux/Unix/cygwin system with the ssh -X option (or define a remote DISPLAY variable) then you don't even need to start the VNC server. Saves memory on Galileo and avoids the painful "desktop on desktop" interface.

          • 2. Re: galileo desktop with vnc howto
            tinkerer8473

            Thanks for the tip about X forwarding with ssh. Saving memory and bandwidth would be good. This is new to me and looks very promising.

             

            I just have a few more howtos to read. Also, working without a chroot would be a lot easier so I might switch. I don't really need the encryption or compression offered by ssh and vpn while just on my lan except I can see how that is important when a Galileo is controlling the floodgates over the internet. Good thing this is only a learning exercise.

            • 3. Re: galileo desktop with vnc howto
              MarcIII

              If encryption is a performance problem then there are other X11 alternatives - still not using the awkward "desktop on desktop" VNC approach. Here is one good article, there are plenty others on the internet:

               

              http://www.biac.duke.edu/library/documentation/xwin32/security.html

              • 4. Re: galileo desktop with vnc howto
                tinkerer8473

                OK. I finally got X forwarding to work. That is better for many purposes.

                 

                I had been getting the error: No protocol specified. ...cannot open display...

                To fix this I created a login on the galileo with the same username and password and then ran xhost +galileo on my notebook and then xterm from the galileo would pop up on my notebook without the entire desktop. That is very nice.

                 

                I didn't know the X forwarding would work without an Xserver. Still stress testing libpthread ... so far so good.

                 

                Thanks for the help.

                • 5. Re: galileo desktop with vnc howto
                  MarcIII

                  You actually need and have an Xserver: it's running on your desktop.

                   

                  Compared to the VNC or Windows Remote Desktop the "server" terminology is reversed. That's because Xserver is not an application server, it is a DISPLAY server = the exact opposite. So the Xserver is always running where the physical screen is.

                   

                  If you are using "xhost +" then you are not using X "forwarding" but just plain (and insecure) X11 connections instead. X11 is actually a network protocol by design. Using xauth is a bit more secure than xhost, see link above. None of them encrypts traffic, you have to "forward" using ssh for that.

                   

                  To make things much more confusing, VNC on Linux is actually making remotely accessible an... Xserver. It does this by implementing a virtual DISPLAY, see here http://www.hep.phy.cam.ac.uk/vnc_docs/xvnc.html

                   

                  While the "destop-on-desktop" interface is bordering on unusable, keep in mind that there is one thing VNC gives you over plain X connections: detached mode. I tend to use GNU screen instead for detached mode.

                  • 6. Re: galileo desktop with vnc howto
                    Tokoro

                    Hi, everyone,

                     

                    Here's an another way to get VNC work with Galileo.

                    http://wiki.tokor.org/index.php?Intel%A4%CEGalileo%A4%CBVNC%C0%DC%C2%B3%A4%B9%A4%EB%A1%A1-%A1%A1Galileo

                    (Written in Japanese, so Google Translation might help you)

                     

                    This solution uses Xvfb(X virtual frame buffer) installed on Yocto Linux (eglibc).

                    Much simpler for many users

                     

                    Hope this helps.