How to run QT application on X-window of the embedded platform

uniquez

Hi, I have an urgent problem with QT run the embedded platform：
I have an embedded EVM-Board, which runs Ubuntu with X-window desktop. The system runs like a PC linking monitor, keyboard and mouse.

Now I want to run a QT application on X-window of the embedded system. After I downloaded QT-lib and QT-application to the file-system and run the QT-application on the terminal, the application could run and the printf-info had no problem. However, there was no QT-window to display on the monitor.

I guess there is someting wrong with my compliled QT-lib or lack of some QT-tools。

Please tell me where is my problem, and whether X-window system needs QVFB to run QT application (no matter on X86 or embedded platform)？

My enviorment:
hardware platform: TI DM8148(ARM+DSP)
complile system: Ubuntu 11.04
complie tool：linux-arm-gnueabi-g++
embedded system : Ubuntu 11.04
QT opensource：qt-everywhere-opensource-src-4.8.1.tar.gz

my install QT-lib configure:
./configure -prefix /usr/local/Trolltech/Qt-4.8.1 -arm -xplatform qws/linux-arm-gnueabi-g++ -embedded arm -little-endian -release -opensource -fast -no-accessibility -scripttools -svg -webkit -shared -javascript-jit -qt-sql-sqlite -no-qt3support -no-mmx -no-3dnow -no-sse -no-sse2 -silent -qt-libpng -qt-libjpeg -qt-libtiff -make libs -nomake examples -nomake docs -nomake demo -no-nis -no-cups -no-iconv -no-dbus -qt-freetype -armfpa -qt-gfx-linuxfb -qt-gfx-transformed -qt-gfx-multiscreen -no-gfx-vnc -no-gfx-qvfb -qt-kbd-linuxinput -qt-mouse-linuxinput -no-glib

board export:
export QTDIR=/home/qt
export LD_LIBRARY_PATH=/lib/qt-lib
export QT_QWS_FONTDIR=/lib/qt-lib/fonts
export QWS_DISPLAY=“LinuxFb:/dev/fb0”

Serg

Hello.
Your Qt-lib is compiled for embedded Linux (it writes directly to Linux framebuffer, eliminating the need for the X Window System). Don't use "-embedded" option. You should build Qt for X11 to run Qt GUI applications over X-window system. Check installation guide: http://qt-project.org/doc/qt-4.8/install-x11.html . In this sense your system is not embedded.
QVFB can be used for development and debugging purposes when you writing applications that works without X11: http://doc.qt.nokia.com/4.7-snapshot/qvfb.html .

uniquez

Thank for you help very much.

From what you said, is my Ubuntu system not embedded, even if the system is based on ARM-platform? If it is true, how to configure these parameters : -arm -xplatform qws/linux-arm-gnueabi-g++ -qt-gfx-linuxfb -qt-gfx-transformed -qt-gfx-multiscreen -no-gfx-vnc -no-gfx-qvfb -qt-kbd-linuxinput -qt-mouse-linuxinput ? Because my QT-application will run the ARM-platform, I think these parameters are needed, at least，QT-lib will be compiled using qws/linux-arm-gnueabi-g++.

By the way, I have a little confuse with the question: in this sense, whether I need compile QVFB to run QT application on my system(ARM+Ubuntu+X-window)?

Sorry for my bad English. If you understand what I said, please give me some help again.

Serg

bq. By the way, I have a little confuse with the question: in this sense, whether I need compile QVFB to run QT application on my system(ARM+Ubuntu+X-window)?

No, you don't need it.

bq. From what you said, is my Ubuntu system not embedded, even if the system is based on ARM-platform? If it is true, how to configure these parameters : -arm -xplatform qws/linux-arm-gnueabi-g++ -qt-gfx-linuxfb -qt-gfx-transformed -qt-gfx-multiscreen -no-gfx-vnc -no-gfx-qvfb -qt-kbd-linuxinput -qt-mouse-linuxinput ?

"-no-gfx-vnc", "-no-gfx-qvfb" - it's default options, just miss it.

"-qt-gfx-linuxfb", "-qt-gfx-transformed", "-qt-gfx-multiscreen", "-qt-kbd-linuxinput", "-qt-mouse-linuxinput" - it's screen, keyboard and mouse handling options. Miss it and use default values because X11 system manages this things.

If you compiling Qt on you Ubuntu(arm), try to use default "./configure" options. It will automatically detect your processor type. If you use cross-compilation then you should specify target platform as "linux-arm-gnueabi-g++" (not qws), check "./configure --help".

uniquez

Thanks for you help me again.

Now I am more clearer to my question. I will cross-compile QT-lib and QT-application on my X86-computer, and I will download the compiled QT-lib and QT-application on my EVM-board((ARM+Ubuntu+X-window)) to run. So I need using my cross-compilation(linux-arm-gnueabi-g++) to cross-compile.

one question i want to make sure:
[quote author="Serg" date="1337013285"]bq. you should specify target platform as “linux-arm-gnueabi-g++” (not qws),[/quote]
what does this sentence mean? do you mean configure like this：＂./configure -xplatform qws/linux-arm-gnueabi-g++＂. Especially, what does *''(not qws)" *mean?

Or you can tell me more details to "./configure", yeah i have check “./configure —help”.
Thank you so much for your warm-heart!!!

Serg

-xplatform used with -embedded only, you should use -platform.

I'm not sure, but I think it will be correct: "./confugure -platform arm-none-linux-gnueabi-g++". Also you should correctly configure environment variables (e.g. CC, LD, etc.) on your host system for cross-compilation (check cross-compiler documentation).

uniquez

Yesterday I tried to compile QT-LIB following what you said. However, when I compiling the qt-everywhere-opensource-src-4.8.1, there is a error :

/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")

My configure is "./confugure -platform arm-none-linux-gnueabi-g++" as you told me , and I think I configure environment variables correctly.
Can you tell me where someting wrong is? Thank you very much.

Serg

You should use qmake for target platform (that runs on x86, but produces output for arm), not native qmake.

uniquez

Sorry to reply later beacause I was busy for other things these days.

[quote author="Serg" date="1337231425"]You should use qmake for target platform (that runs on x86, but produces output for arm), not native qmake.[/quote]

I think "qmake" is a tool used for generating Makefile, so it runs on x86, and produces output(Makefile) for X86 not for arm. Is that true?

By the way, I find an other way to get qt-lib for X11 based arm. I link the system with internet, and use “apt-get instal libqt4-dev”, then the ubuntu can download qt-lib for arm. However, when I run a QT test-program(compiled linking downloaded QT-lib) on my system, the program can output a window, but have an error:"undefined symbol: _ZN7QWidget8qwsEventEP8QWSEvent". Can you tell me what wrong about this way to get QT-lib and run QT-program.

Thanks for your warm-heart again!!!

Serg

bq. I think “qmake” is a tool used for generating Makefile, so it runs on x86, and produces output(Makefile) for X86 not for arm. Is that true?

The qmake tool requires a platform and compiler specific qmake.conf file describing the various default values, to generate the appropriate Makefiles. You should use correct qmake.conf file.

bq. However, when I run a QT test-program(compiled linking downloaded QT-lib) on my system, the program can output a window, but have an error:“undefined symbol: _ZN7QWidget8qwsEventEP8QWSEvent”. Can you tell me what wrong about this way to get QT-lib and run QT-program.

Looks like your program uses QWidget::qwsEvent(), that is not available in non-embedded linux environments. "Check this thread":http://qt-project.org/forums/viewthread/3043 .

uniquez

The second question.
My test program can run on Ubuntu on my PC, which is non-embendded linux environment too. And I am sure my test program (just a MainWindow) not using QWidget::qwsEvent()。

uniquez

The first question.
When I use "./configure -xplatform linux-arm-gnueabi-g++ "to configure, there is no error about "/home/xushaofan/qt_4.8.1_pkg/qt-x11-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting “)”)", but it generate an error:

"Basic XLib functionality test failed!
You might need to modify the include and library search paths by editing
QMAKE_INCDIR_X11 and QMAKE_LIBDIR_X11 in /home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/mkspecs/linux-arm-gnueabi-g++."

I find the variables of QMAKE_INCDIR_X11 and QMAKE_LIBDIR_X11 is in the /mkspecs/common/linux.conf, and I change the variables to XLib's path， but this error remain.

How to solve this problem?

Serg

qt-everywhere-opensource-src-x.y.z/mkspecs directory used for (cross) compiling Qt for various targets.
qt-everywhere-opensource-src-x.y.z/mkspecs/qws directory used for (cross) compiling Qt embedded for various targets.

So, I checked "mkspecs directory":http://qt.gitorious.org/qt/qt/trees/4.8/mkspecs and found a mistake.

bq. I’m not sure, but I think it will be correct: “./configure -platform arm-none-linux-gnueabi-g++”.

Correct is: "./configure -platform linux-arm-gnueabi-g++".

uniquez

Correct is: “./configure -platform linux-arm-gnueabi-g++”.

But in /mkspecs directory, there is no folder of "linux-arm-gnueabi-g++",and my qt opensource's version is 4.8.1. So I just copied /mkspecs/qws/linux-arm-gnueabi-g++ to /mkspecs. I think what I did is not true, but I dont know how to get linux-arm-gnueabi-g++ in /mkspecs.

Serg

About second question.
Your qt test program was built on arm system as a native program? Can you show ldd output?

bq. But in /mkspecs directory, there is no folder of “linux-arm-gnueabi-g++”,and my qt opensource’s version is 4.8.1. So I just copied /mkspecs/qws/linux-arm-gnueabi-g++ to /mkspecs. I think what I did is not true, but I dont know how to get linux-arm-gnueabi-g++ in /mkspecs.

Copy it from qt.gitorious, Are you checked the link "mkspecs directory":http://qt.gitorious.org/qt/qt/trees/4.8/mkspecs ?

uniquez

My cross compiler is arm-none-linux-gnueabi-g++ not linux-arm-gnueabi-g++.

I copy the folder of linux-arm-gnueabi-g++ from qt.gitorious to /mkspecs, and I replace "linux-arm-gnueabi-g++" for "arm-none-linux-gnueabi-g++ ". Then I configure "./configure -platform linux-arm-gnueabi-g++",there is two errors:

/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
/home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/bin/qmake: 1: Syntax error: word unexpected (expecting ")")
Basic XLib functionality test failed!
You might need to modify the include and library search paths by editing
QMAKE_INCDIR_X11 and QMAKE_LIBDIR_X11 in /home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/mkspecs/linux-arm-gnueabi-g++.

But if I configure "./configure -xplatform linux-arm-gnueabi-g++" after clean configure, there just an error:

Basic XLib functionality test failed!
You might need to modify the include and library search paths by editing
QMAKE_INCDIR_X11 and QMAKE_LIBDIR_X11 in /home/xushaofan/qt_4.8.1_pkg/qt-everywhere-opensource-src-4.8.1/mkspecs/linux-arm-gnueabi-g++.

Serg

So, there are two ways:

Write your own mkspec for arm-none-linux-gnueabi-g++ compiler (or find in google). Then ./configure -arch arm -xplatform arm-none-linux-gnueabi-g++;
"sudo apt-get install g++-arm-linux-gnueabi" and try to use mkspec from qt.gitorius. Then ./configure -arch arm -xplatform linux-arm-gnueabi-g++.

bq. Basic XLib functionality test failed! You might need to modify the include and library search paths by editing QMAKE_INCDIR_X11 and QMAKE_LIBDIR_X11

You need to specify X11 include files and libraries, arm libs!

uniquez

You need to specify X11 include files and libraries, arm libs!

================================

I have specified X11 include files and libraries(for arm)' path by modifing linux.conf in /mkspecs/common, but the error remain. Is it right?

It is too later tonight, I will compile QT-lib following what you said tomorrow.
Anyway, thank you help me again and again.

uniquez

By the way, the X11 include files and libraries are provided in filesytems by TI ezsdk.

Serg

bq. I have specified X11 include files and libraries(for arm)’ path by modifing linux.conf in /mkspecs/common, but the error remain. Is it right?

I'm think it's right.

This error can be when libXext is missed.
Here is "Qt for X11 requirements":http://qt-project.org/doc/qt-4.8/requirements-x11.html. Ensure that you have all required libs.