Compile QT 5.8 to cross-compile Beaglebone

jsulm

@Andrey-Shmelew said in Compile QT 5.8 to cross-compile Beaglebone:

How can I be sure that the application will work identiaclly on Windows Host machine and on Linux BeagleBone Board?

Do you want to use your app on Windows and BBB?
To be sure it behaves the same you need to test on both.
To develop on Windows for BBB you need the Qt libs built for BBB on your Windows machine as well + cross compiler + sysroot.

Andrey Shmelew

@jsulm said in Compile QT 5.8 to cross-compile Beaglebone:

Do you want to use your app on Windows and BBB?

I want to use my application on BBB, but i want it develop and debug on Windows first.
I plan to develop multithread stable secutiy system based on BBB/Qt/QML. I already have the Qt libs built for BBB on your Windows machine as well + cross compiler + sysroot. But Qt libs was prebuilt. Now i can develop app on Windows and deploy it on BBB, but i am not sure it is the best way.

jsulm

@Andrey-Shmelew said in Compile QT 5.8 to cross-compile Beaglebone:

but i am not sure it is the best way

Why not? It is the usual way to develop for other devices. Personally I would prefer Linux as development machine, but it is doable on Windows as well.

Andrey Shmelew

@jsulm

You think i should ignore mismatches of libraries versions (*.so.5.3.2 against Qt creator 5.8.0) and keep going?

jsulm

@Andrey-Shmelew There is no QtCreator 5.8 - current version is 4.2.2.
QtCreator is not the same as Qt. QtCreator is an IDE, Qt is a C++ framework. You can use any Qt version with QtCreator. QtCreator version doesn't matter at all.
Or do you mean you have Qt 5.8 built for BBB on your Windows machine?

Andrey Shmelew

@jsulm
i have
on Host Windows 10:
Qt Creator 4.1.0
Based on Qt 5.7.0 (MSVC 2013, 32 bit)
Qt Creator has a Kit for BBB

on Host Windows 10:
GNU toolchaon for BeagleBone, GCC version 4.9.2 (libs, compiler, gdb debugger, sysroot)

Andrey Shmelew

@Andrey-Shmelew

trying to compile Qt 5.8 for BBB.
Configure script:

../qt-everywhere-opensource-src-5.8.0/configure -platform win32-g++ -xplatform linux-arm-gnueabi-g++ -release -device linux-beagleboard-g++ -sysroot C:/SysGCC/Beaglebone/arm-linux-gnueabihf/sysroot -prefix /usr/local/qt5 -device-option CROSS_COMPILE=C:/SysGCC/Beaglebone/bin/arm-linux-gnueabihf- -opensource -confirm-license -v

the output

Configure summary:

Building on:  arm
Building for: arm
Configuration: cross_compile compile_examples enable_new_dtags largefile neon precompile_header shared rpath accessibility release c++11 concurrent dbus no-pkg-config mremap reduce_exports stl
Build options:
  Mode ................................... release
  Building shared libraries .............. yes
  Using C++ standard ..................... C++11
  Using gold linker ...................... no
  Using new DTAGS ........................ yes
  Using precompiled headers .............. yes
  Using LTCG ............................. no
  Target compiler supports:
    NEON ................................. yes
  Build parts ............................ libs examples
Qt modules and options:
  Qt Concurrent .......................... yes
  Qt D-Bus ............................... yes
  Qt D-Bus directly linked to libdbus .... no
  Qt Gui ................................. yes
  Qt Widgets ............................. yes
Support enabled for:
  Accessibility .......................... yes
  Using pkg-config ....................... no
  QML debugging .......................... yes
  udev ................................... no
  Using system zlib ...................... yes
Qt Core:
  DoubleConversion ....................... yes
    Using system DoubleConversion ........ no
  GLib ................................... no
  iconv .................................. no
  ICU .................................... no
  Logging backends:
    journald ............................. no
    syslog ............................... no
  Using system PCRE ...................... no
Qt Network:
  getaddrinfo() .......................... no
  getifaddrs() ........................... no
  IPv6 ifname ............................ no
  libproxy ............................... no
  OpenSSL ................................ no
    Qt directly linked to OpenSSL ........ no
  SCTP ................................... no
  Use system proxies ..................... yes
Qt Sql:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. no
  OCI (Oracle) ........................... no
  ODBC ................................... no
  PostgreSQL ............................. no
  SQLite2 ................................ no
  SQLite ................................. yes
    Using system provided SQLite ......... no
  TDS (Sybase) ........................... no
Qt Gui:
  FreeType ............................... yes
    Using system FreeType ................ no
  HarfBuzz ............................... yes
    Using system HarfBuzz ................ no
  Fontconfig ............................. no
  Image formats:
    GIF .................................. yes
    ICO .................................. yes
    JPEG ................................. yes
      Using system libjpeg ............... no
    PNG .................................. yes
      Using system libpng ................ no
  OpenGL:
    EGL .................................. no
    Desktop OpenGL ....................... no
    OpenGL ES 2.0 ........................ no
    OpenGL ES 3.0 ........................ no
    OpenGL ES 3.1 ........................ no
  Session Management ..................... yes
Features used by QPA backends:
  evdev .................................. no
  libinput ............................... no
  mtdev .................................. no
  tslib .................................. no
  xkbcommon-evdev ........................ no
QPA backends:
  DirectFB ............................... no
  EGLFS .................................. no
  LinuxFB ................................ no
  Mir client ............................. no
Qt Widgets:
  GTK+ ................................... no
  Styles ................................. Fusion Windows
Qt PrintSupport:
  CUPS ................................... no
Qt SerialBus:
  Socket CAN ............................. no
  Socket CAN FD .......................... no
QtXmlPatterns:
  XML schema support ..................... yes
Qt QML:
  QML interpreter ........................ yes
  QML network support .................... yes
Qt Quick:
  Direct3D 12 ............................ no
  AnimatedImage item ..................... yes
  Canvas item ............................ yes
  Support for Quick Designer ............. yes
  Flipable item .......................... yes
  GridView item .......................... yes
  ListView item .......................... yes
  Path support ........................... yes
  PathView item .......................... yes
  Positioner items ....................... yes
  ShaderEffect item ...................... yes
  Sprite item ............................ yes
Qt Gamepad:
  SDL2 ................................... no
Qt 3D:
  System Assimp .......................... no
Qt Wayland Client ........................ no
Qt Wayland Compositor .................... no
Qt Bluetooth:
  BlueZ .................................. no
  BlueZ Low Energy ....................... no
  Linux Crypto API ....................... no
Qt Multimedia:
  ALSA ................................... no
  GStreamer 1.0 .......................... no
  GStreamer 0.10 ......................... no
  Video for Linux ........................ no
  OpenAL ................................. no
  PulseAudio ............................. no
  Resource Policy (libresourceqt5) ....... no
  DirectShow ............................. no
  Windows Media Foundation ............... no
Qt Location:
  Gypsy GPS Daemon ....................... no
  WinRT Geolocation API .................. no
Qt Sensors:
  sensorfw ............................... no
Qt WebEngine:
  Proprietary Codecs ..................... no
  Spellchecker ........................... yes
  ALSA ................................... no
  PulseAudio ............................. no

Note: QtSerialBus: Cannot find linux/can.h and linux/can/raw.h Linux headers for socketCAN support.

Note: No wayland-egl support detected. Cross-toolkit compatibility disabled.

WARNING: No QPA platform plugin enabled! This will
produce a Qt that cannot run GUI applications.
The dependencies needed for xcb to build are listed in
src/plugins/platforms/xcb/README

ERROR: detected a std::atomic implementation that fails for function pointers.
Please apply the patch corresponding to your Standard Library vendor, found in
  qtbase/config.tests/common/atomicfptr

ERROR: The OpenGL functionality tests failed!
You might need to modify the include and library search paths by editing QMAKE_INCDIR_OPENGL[_ES2],
QMAKE_LIBDIR_OPENGL[_ES2] and QMAKE_LIBS_OPENGL[_ES2] in the mkspec for your platform.

Have 1 Warning and 2 Errors :( :( :( :( :(
What do i do wrong? Help!
(qt 5.5.0 compiled succesfully earlier)

mzimmers

This is the command that I used to configure Qt for BBB. Obviously, you'll need to change some pathnames, but it might work better than what you're doing now.

opt/Qt/5.8/Src/qtbase/configure -platform linux-g++ -xplatform linux-arm-gnueabi-g++ -release -device linux-beagleboard-g++ \
 -sysroot /opt/arm-toolchain/sysroot-glibc-linaro-2.23-2017.02-arm-linux-gnueabihf/ \
 -prefix /opt/QtForBBB/ \
 -device-option CROSS_COMPILE=/opt/arm-toolchain/gcc-linaro-6.3.1-2017.02-x86_64_arm-linux-gnueabihf/bin/arm-linux-gnueabihf- \
 -qt-xcb \
 -nomake tests -nomake examples -no-opengl

Andrey Shmelew

@mzimmers

ok, i see you are using Linux host machine.
Where to download linaro toolchain?

jsulm

@Andrey-Shmelew

https://www.linaro.org/downloads/

Andrey Shmelew

@mzimmers
i Cross Compiled Qt 5.8, so now when i try do deploy, and i've got an errors:

/usr/test/untitled2: /usr/lib/arm-linux-gnueabihf/libQt5PrintSupport.so.5: no version information available (required by /usr/test/untitled2)
/usr/test/untitled2: /usr/lib/arm-linux-gnueabihf/libQt5Script.so.5: no version information available (required by /usr/test/untitled2)
/usr/test/untitled2: /usr/lib/arm-linux-gnueabihf/libQt5Gui.so.5: no version information available (required by /usr/test/untitled2)
/usr/test/untitled2: /usr/lib/arm-linux-gnueabihf/libQt5Widgets.so.5: no version information available (required by /usr/test/untitled2)
/usr/test/untitled2: /usr/lib/arm-linux-gnueabihf/libQt5SerialPort.so.5: no version information available (required by /usr/test/untitled2)
/usr/test/untitled2: /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5: no version information available (required by /usr/test/untitled2)
libEGL warning: DRI3: Screen seems not DRI3 capable
libEGL warning: DRI2: failed to authenticate
/usr/test/untitled2: relocation error: /usr/test/untitled2: symbol _ZN9QDateTimeC1EOS_, version Qt_5 not defined in file libQt5Core.so.5 with link time reference
Application finished with exit code 127.

Help...?

jsulm

@Andrey-Shmelew How do you deploy?
And I guess you get this errors when you try to start your app on the target device, right?
Do the Qt libraries /usr/lib/arm-linux-gnueabihf/libQt5* have the same version number as the cross compiled Qt (5.8)?
To me it looks like you're using a different Qt version on the target device.
See http://doc.qt.io/qt-5/linux-deployment.html for deployment to a Linux system.

Andrey Shmelew

@jsulm said in Compile QT 5.8 to cross-compile Beaglebone:

And I guess you get this errors when you try to start your app on the target device, right?

absolutely!

Do the Qt libraries /usr/lib/arm-linux-gnueabihf/libQt5* have the same version number as the cross compiled Qt (5.8)?

No, they have 5.3.2 version number.

if i replace libQt5SerialPort.so.5 (version 5.3.2) by libQt5SerialPort.so.5 (version 5.8.0); i've got errors:

/usr/test/untitled2: /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5: no version information available (required by /usr/lib/arm-linux-gnueabihf/libQt5SerialPort.so.5)
/usr/test/untitled2: /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5: no version information available (required by /usr/lib/arm-linux-gnueabihf/libQt5SerialPort.so.5)
/usr/test/untitled2: /usr/lib/arm-linux-gnueabihf/libstdc++.so.6: version `CXXABI_1.3.9' not found (required by /usr/lib/arm-linux-gnueabihf/libQt5SerialPort.so.5)

jsulm

@Andrey-Shmelew If you replace then replace all used libraries not just one of them!
And actually you should NOT replace system libraries as other applications could depend on them!
Instead deploy your app together with needed libraries as described in the link I posted before.

Andrey Shmelew

@jsulm

thanks for the link.

probably i should paste all of needed libraries to separate folder (for example "/usr/lib/my5-8libs")

and then somehow to link my application to these libraries?

jsulm

@Andrey-Shmelew You can put the libs into a separate folder, but you should use /usr/local/lib/... not /usr/lib
But then you either need to tell the system where to find them using LD_LIBRARY_PATH (described in the link I posted), or use RPATH to set the path to the libs in your executable, see https://en.wikipedia.org/wiki/Rpath
Using /usr/local/lib probably does not require LD_LIBRARY_PATH nor RPATH, but any other locations not searched by the OS by default do.

Andrey Shmelew

what 's the problem might be here when i start an application:

This application failed to start because it could not find or load the Qt platform plugin "xcb"
in "".

Reinstalling the application may fix this problem.
Aborted

it came when i uploaded new libraries 5.8.0 to /usr/lib/new5dot8libs/
and entered commands:

LD_LIBRARY_PATH=/usr/lib/new5dot8libs
export LD_LIBRARY_PATH

mzimmers

@Andrey-Shmelew something is not right with your path variable. I notice that your command is overwriting (rather than adding to) any existing LD_LIBRARY_PATH variable; is this intentional? One of these methods is more conventional:

PATH=$PATH:/new/path
PATH=/new/path:$PATH

Also, did you put this command in a startup script? I'm not sure the export will survive a system restart.

Andrey Shmelew

hi! i have absolutely the same trouble:
i reproduse it with absolutely minimal qml example
When i deploy qt 5.5 application on beaglebone device (arm linux gnueabihf) - then works perfectly
When i deploy qt 5.8 - the error appears:

QQmlApplicationEngine failed to load component
qrc:/main.qml:-1 File not found

// this somehow works but the window is blank
main.cpp:

#include <QGuiApplication>
#include <QQuickView>

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);

    QQuickView view;
    view.setSource(QUrl::fromLocalFile("main.qml"));
    view.show();

    return app.exec();
}

jsulm

@Andrey-Shmelew You're using a relative path:

view.setSource(QUrl::fromLocalFile("main.qml"));

Depending from where you start your app the file will not be found.
You should construct an absolute path at runtime using http://doc.qt.io/qt-5/qcoreapplication.html#applicationDirPath