GUI Application with iot image

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1

Hi all,

I am trying to develop a qt gui application with iot image(Because I want eMMC boot, since SD card may be displaced in a rough shaking environment).
For this purpose, I got the latest iot image and followed the procedure given below.

root@beaglebone:~# sudo apt-get update

root@beaglebone:~# sudo apt-get upgrade

root@beaglebone:~# sudo apt-get install build-essential

root@beaglebone:~# sudo apt-get install ``qt``4``-``dev-tools

root@beaglebone:~# sudo apt-get install ``openbox

root@beaglebone:~# sudo apt-get install ``xinit

root@beaglebone:~# sudo apt-get install ``x11-apps

root@beaglebone:~# export DISPLAY=:0.0
``root@beaglebone:~# `export XAUTHORITY=/root/.Xauthority```

``

And .xinitrc is as follows

oclock -geometry +1450+920 -bg ivory -fg blue &
./My_App -style plastique &
xrandr
xrandr --output HDMI-0 --mode 1024x768 --rate 60
xset s off # don’t activate screensaver
xset -dpms # disable DPMS (Energy Star) features.
xset s noblank # don’t blank the video device
exec /etc/alternatives/x-window-manager

But it is showing the following error message, when I give startx command

root@beaglebone:~# startx

X.Org X Server 1.19.2
Release Date: 2017-03-02
X Protocol Version 11, Revision 0
Build Operating System: Linux 4.9.0-8-armmp-lpae armv7l Debian
Current Operating System: Linux beaglebone 4.14.71-ti-r80 #1 SMP PREEMPT Fri Oct 5 23:50:11 UTC 2018 armv7l
Kernel command line: console=ttyO0,115200n8 bone_capemgr.uboot_capemgr_enabled=1 root=/dev/mmcblk0p1 ro rootfstype=ext4 rootwait coherent_pool=1M net.ifnames=0 quiet
Build Date: 03 November 2018 05:53:43AM
xorg-server 2:1.19.2-1+deb9u5 (https://www.debian.org/support)
Current version of pixman: 0.34.0
Before reporting problems, check http://wiki.x.org
to make sure that you have the latest version.
Markers: (–) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: “/var/log/Xorg.0.log”, Time: Thu Dec 13 13:20:11 2018
(==) Using config file: “/etc/X11/xorg.conf”
(==) Using system config directory “/usr/share/X11/xorg.conf.d”
(EE)
Fatal server error:
(EE) no screens found(EE)
(EE)
Please consult the The X.Org Foundation support
at http://wiki.x.org
for help.
(EE) Please also check the log file at “/var/log/Xorg.0.log” for additional information.
(EE)
(EE) Server terminated with error (1). Closing log file.
^Cxinit: giving up
xinit: unable to connect to X server: Connection refused

/var/log/Xorg.0.log shows :

compiled for 1.19.2, module version = 0.0.2
[ 1467.811] ABI class: X.Org Video Driver, version 23.0
[ 1467.811] (EE) open /dev/fb0: No such file or directory
[ 1467.812] (EE) No devices detected.
[ 1467.813] (EE)
Fatal server error:
[ 1467.815] (EE) no screens found(EE)

But the same application with the same contents of .xinitrc working fine with the latest lxqt images.

I think I may be missing installation of some packages.

Is it possible to develop a gui application with iot image, without installing any desktop?
Please suggest some workaround to come out of this issue.

Thanks & Regards,
Sajeevan.K

2

On Thu, 13 Dec 2018 05:39:22 -0800 (PST), sajeevan k
<sajeevank@laxven.com> declaimed the
following:

I think I may be missing installation of some packages.
Is it possible to develop a gui application with iot image, without
installing any desktop?
Please suggest some workaround to come out of this issue.

  "Develop" -- technically, yes...

  "Execute" -- only by having a working X-server (your application is an
X-client). You specified the display to be local, so the server needs to be
local. With an X-server running on another computer (with its display) you
could have the Beagle DISPLAY set to that other computer and the clients
would send rendering commands over the network.

  Using a local server without a window manager/desktop is something I'm
afraid I can't help with... At the least, you probably need a window
manager -- which would be OpenBox, but additional configuration may be
needed to make it usable.

http://openbox.org/wiki/Help:Getting_started#Starting_Openbox_without_the_graphical_log_in
"""
In that case you need to run Openbox from your ~/.xinitrc file
"""

3

Hi Dennis Lee,

Thank You for Your quick reply.
When I further analyze this problem, with another card, it is found that this problem is not there in that
card. So I doubt, there is some hardware problem with the first card.

But in the second card, I am facing another issue, related to uboot overlays. I would raise another post, if required , regarding this issue.

Thank You very much for Your support.

Thanks and Regards,
Sajeevan.K