Building Qt 5.8 for Raspberry Pi on Debian Jessie

25/09/2017 - 17:41
Average: 4.5 (13 votes)

The previous version of Raspbian (aka Debian Jessie) comes with an old (5.3.2) version of Qt (Note: Even Stretch has an old version of Qt 5.7.1, see Raspbian Stretch specific tutorial) that is pretty much outdated and does not support the Raspberry Pi properly. Afaik there are no up-to-date backports so the only way to get the latest version of Qt (at time of writing, using LTS version 5.8.0) up and running on your Pi is to build it yourself.

These instructions will build version of Qt that uses the eglfs interface and therefore runs applications fullscreen, without X11 support. You can optionally add Wayland support by installing the required development packages.

Building Qt on the Raspberry Pi is quite straightforward and in short consist of the following steps:

  1. Downloading sources
  2. Preparing the sources
  3. Installing required dependencies
  4. Installing optional dependencies
  5. Configuring the build
  6. Compiling
  7. Installing the build

This tutorial is written for the full source of version 5.8.0 but any older or later version should work just as well if you have specific needs.

It is fully possible to build only parts using the submodule specific packages, but this tutorial will not go into that.

Changelog

  • 23.08.2017 - Mention Stretch old version
  • 12.03.2017 - New configuration method

Download the Qt 5.8.0 source archive

Download the single source tar file from Qt.io, version 5.8.0. The package is quite large, 354M, so depending on your bandwidth it might take some time to download.

wget http://download.qt.io/official_releases/qt/5.8/5.8.0/single/qt-everywhere-opensource-src-5.8.0.tar.xz

Un-tar the source archive

Un-tar the source acrhive in a suitable location, with enough space. This will take about 5 minutes on a Raspberry Pi 3 and even more on an older model, so go grab a coffe.

tar xf qt-everywhere-opensource-src-5.8.0.tar.xz

Create a shadow build directory outside of the source tree

mkdir build
cd build

Install build dependencies

You will need to install plenty of packages to be able to build Qt. Some packages are optional and depends on your particular needs.

Install required packages

apt-get install build-essential libfontconfig1-dev libdbus-1-dev libfreetype6-dev libicu-dev libsqlite3-dev libssl-dev libpng12-dev libjpeg9-dev libglib2.0-dev

Install optional packages

For bluetooth support:

apt-get install bluez libbluetooth-dev

For audio & gstreamer multimedia support

apt-get install libasound2-dev pulseaudio libpulse-dev libgstreamer0.10-dev libgstreamer-plugins-base1.0-dev

Support for various databases (PostgreSQL, MariaDB/MySQL)

apt-get install libpq-dev libmariadbclient-dev

Printing support using CUPS

apt-get install libcups2-dev

Wayland support

apt-get install libxkbcommon-dev libwayland-dev

Configure the build

For some odd reason Qt insists on being configured for cross-compiling, even when doing a native build. And some options won't work or will make other options fail. Fortunately we can work around it by running the configure script twice, first to get everything detected properly, then to fixup missing features. You can choose to build faster armv7 (For Pi 2 or later only) or slower armv6 (Work on all models), just change  linux-rasp-pi-g++ to linux-rasp-pi2-g++ the following configuration commandlines.

Note that we are disabling the qtwebengine as unfortunately compiling them requires more memory than a Pi can provide.

First, run configure with the following options:

../qt-everywhere-opensource-src-5.8.0/configure -v -opengl es2 -eglfs -no-gtk -device linux-rasp-pi-g++ \
-device-option CROSS_COMPILE=/usr/bin/ -opensource -confirm-license -reduce-exports \
-force-pkg-config -nomake examples -no-compile-examples -skip qtwayland -skip qtwebengine -release \
-qt-pcre -ssl -evdev -system-freetype -fontconfig -glib -prefix /opt/Qt5.8

Make sure that the configure script detects Raspberry Pi EGLFS, look for the following output:

QPA backends:
  DirectFB ............................... no
  EGLFS .................................. yes
  EGLFS details:
...
    EGLFS Rasberry Pi .................... yes

Now run configure again, this time with almost the same options, but with sysroot setting:

../qt-everywhere-opensource-src-5.8.0/configure -v -opengl es2 -eglfs -no-gtk -device linux-rasp-pi-g++ \
-device-option CROSS_COMPILE=/usr/bin/ -opensource -confirm-license -reduce-exports \
-force-pkg-config -nomake examples -no-compile-examples -skip qtwayland -skip qtwebengine -release \
-qt-pcre -ssl -evdev -system-freetype -fontconfig -glib -sysroot / -prefix /opt/Qt5.8 -recheck

Now Qt should be configured properly with all features enabled that we need.

Compile Qt

To compile run:

make

or if you are using any of the quad-core Pis, append the -j4 parameter to build in parallel.

The compilation takes just under 2 hours (108 minutes 15.718 seconds to be exact) on a Raspberry Pi 3 when built with parallel make (make -j4). On a Raspberry Pi 2 it will take a bit more, a build of 5.4.2 took about 3 hours to complete.

real    108m15.718s
user    389m28.410s
sys     18m38.870s

Install the build

The compilation should finnish without any errors, if it does not, double check that you have all the dependecies installed and run configure correctly.

If all is well, install Qt by running

make install

You now have Qt 5.8 installed in /opt/Qt5.8 ready to be used. To configure your Qt project(s) to build with this version run qmake from the installation directory:

/opt/Qt5.8/bin/qmake

Happy coding!

 

Keywords: 
qt
raspberry pi
debian
jessie
stretch