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QT5.2.x crosscompile general advice

  • Hi everyone,

    i'm trying to cross-compile QT5.2 for my raspberry, like most of you do ;-)
    I need some general advice.

    What I've done:

    What do i have to do differently so that i can:

    • crosscompile and install QT on my host linux, e.g. to one folder. The beginners guide somehow merges the compiled QT file into a wheezy image. But i want to keep my existing raspbian system
    • copy that folder to my raspberry and run a qt-programm

    My System:

    • raspberry: NOOBS - raspbian image
    • Host: Linux Debian (downloaded the newest version via net-installer; i don't know which version exactly)

    Thanks a lot for your help,

  • Hi Mindstomer,

    actually i don't mind any more to use a fresh raspbian installation. If it keeps me from more headache, then that's the way to go.

    bq. I followed it as well and I got it working after pulling a few hairs.

    Ok, that's the interesting part now.

    • Which parts did you follow exactly and which did you have to change? Even if the changes were small.
    • Any other steps you needed to do, which is not explained in the guide?
    • Did you follow the guide itself or did you use the script "bakeqtpi.bash"?

    bq. Not all modules in the guide will work

    • Can you tell me which ones won't work?
    • What about QtQuick or qmlviewer/qmlscene?

    Thanks a lot for your help. Would be great if i could finally built it.

  • Hi Mindstormer,

    thanks so much. That were exactly the hints i needed.

    • I used the latest rasbpian image
    • I didn't use the bakeqt.bash script
    • I didn't use the patch

    Now, i could successfully run the QTquick example, which i cross-compiled on my host-pc with qtcreator.

    There are still a few things i'm stuck with, so you might be able to help with those as well:

    • qmlviewer/qmlscene don't come with the normal download of the qt5 binaries, right? Where do i get them?
    • Some qt5 module folders were empty, that was the same for you, right? But, the folder qtjsbackend doesn't exist at all. Same for you?
    • Weird: i can compile and run a qtquick hello world programm on my raspberry, but cannot compile it for my debian host desktop:
      /mnt/rasp-pi-rootfs/usr/local/qt5pi/include/QtGui/qopengl.h:82: Fehler: GLES2/gl2.h: No such file or directory
    • How can i automatically mount the RPI image at the start of my debian host?
      What's the entry in /etc/fstab for the following mount command:
      sudo mount -o loop,offset=62914560 2014-01-07-wheezy-raspbian.img /mnt/rasp-pi-rootfs
    • Where do i have to enter the following command from the beginners tutorial. I cannot find the edit field in QTcreator

    Then go to the “Rasperry Pi” kit tab->System Environment and add LD_LIBRARY_PATH which is set to /usr/local/qt5pi/lib

    Thanks so much again for your help,

  • Hi Mindstormer,

    it now works for me well enough, to keep it that way. ;-)
    I still cannot run an application on the desktop AND on the raspberry pi. I have to build two different apps for it.
    I thought that's one of the big advantages of QT that i can create a qml app and run it on the desktop. When it's finished i would deploy it to my raspberry, simple by changing the kit?!

    Thanks anyway, Ben

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