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Compiling Qt fro Raspberry pi 2



  • Hello,

    Is there any special requirements to compile QT5 for rpi2? I mean some tuning parameters for cpu? I made linux-rasp-pi2-g++ and added the fallowing parameters in qmake.conf:
    -marm
    -mfpu=neon-vfpv4
    -mtune=cortex-a7
    -mabi=aapcs-linux
    -mcpu=cortex-a7
    -mfloat-abi=hard.

    Is it correct? or I wasted time for it?


  • Moderators

    Looks fine. Does it compile?



  • @sierdzio

    Yes it compiled and works fine, but if there is some more tuning parameters available for rpi2 please let me know.



  • A device mkspec was added for Raspberry Pi 2 in 5.5 branch:
    http://code.qt.io/cgit/qt/qtbase.git/tree/mkspecs/devices/linux-rasp-pi2-g++/qmake.conf



  • Thank you



  • @_nezticle
    Can you explain me what this means and what this has as extra opposed to not having this?


  • Lifetime Qt Champion

    @jorricks the device mkspec provides Qt's build system with default/optimized parameters suited to build Qt specifically for that device



  • @SGaist
    Thank you for your reply!
    Sorry for asking the following question here but I figured you'd probably know it

    paulo@westeros:~/opt/qt5/qtimageformats$ /usr/local/qt5pi/bin/qmake .
    It says my qmake can not be found.. Do you have any clue what this step actually should be then?
    (following http://qt-project.org/wiki/RaspberryPi_Beginners_guide)

    Kind regards,


  • Lifetime Qt Champion

    Did you first install the Qt version your just built ?



  • @SGaist Ah.. The instruction should have been /mnt/rasp-pi-rootfs/usr/local/qt5pi/bin/qmake .
    sorry for bothering you!



  • @jorricks Indeed... I noticed this too last night, when I was working through the tutorial. I got Qt5 to build, but there were a number of library path problems--so I ended up just scrapping the entire build, and installing Qt4 from the repositories.

    It doesn't yet appear that the RPi2 Model B is quite ready for prime-time, at least where Qt5 is concerned. I am sure that people are getting it to work--but it isn't exactly straightforward at this time, and there do seem to be problems left to solve once the build completes.

    TB



  • @tcbetka said:

    It doesn't yet appear that the RPi2 Model B is quite ready for prime-time, at least where Qt5 is concerned. I am sure that people are getting it to work--but it isn't exactly straightforward at this time, and there do seem to be problems left to solve once the build completes.

    Eay TCBetka,
    There is a tutorial now that let's you build it nativly on the raspberry pi 2. Works like a charm!
    Caution though, you will not be able to cross-compile I believe.
    Kind regards,



  • @_nezticle Stupid noob question.... (So sorry.. I'm learning!)

    I have a Raspberry Pi2, I would like to get 5.5.0-beta working on it. (or any other slightly earlier version for that matter)
    You mentioned they have "a device mkspec was added for Raspberry Pi 2 in 5.5 branch:"

    So I downloaded the qt-everywhere-opensource-src-5.5.0-beta and I would like to get it installed on my Pi 2.
    What command do I use to get it to successfully install on my Raspberry Pi 2?

    Do I use ./configure -prefix $PWD/qtbase -opensource -nomake tests like the README says or do I add something else to get it to install for just the Pi 2?

    Ultimately I'd like to install Qt Creator 3.4.0 (or maybe an earlier version?) so I can run .pro files that cryptocurreny wallets have available. [eg. https://github.com/sherlockcoin/navajocoin (the NavajoCoin-qt.pro file)]

    Here's what I see:
    Build instructions

    Debian

    First, make sure that the required packages for Qt5 development of your distribution are installed, for Debian and Ubuntu these are:

    apt-get install qt5-default qt5-qmake qtbase5-dev-tools qttools5-dev-tools
    build-essential libboost-dev libboost-system-dev
    libboost-filesystem-dev libboost-program-options-dev libboost-thread-dev
    libssl-dev libdb++-dev
    then execute the following:

    qmake
    make
    Alternatively, install Qt Creator and open the navajocoin-qt.pro file.

    An executable named navajocoin-qt will be built.

    I've tried the 1st part, and it won't work (probably because this is a Pi 2 I'm assuming)
    So, I need help with the 2nd part.

    Many Many Thanks to anybody that can help me!


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