Cross-Compile RPi3 with Qt5.7

iiiwww

the problem is same as others on RPi3 for a simple window with no word, no fonts needed:

Unable to query physical screen size, defaulting to 100 dpi.
To override, set QT_QPA_EGLFS_PHYSICAL_WIDTH and QT_QPA_EGLFS_PHYSICAL_HEIGHT (in millimeters).

tool chain gcc-linaro-arm-linux-gnueabihf-raspbian-x64
plattform: ubuntu 16.10 x64
rpi3: raspbian jess, PIXEL - (2017-01-11 ), and many others

Really do not know why everyone has the same problem even they followed the instructions

Anyone who could sovlve it , please help. thanks

iiiwww

even I followed this instruction
https://forum.qt.io/topic/75228/crosscompile-qt5-7-additional-dependencies

on RPi3 it replied
This application failed to start because it could not find or load the Qt platform plugin "eglfs"
in "".
Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, xcb.
Reinstalling the application may fix this problem.
Aborted

plattform: ubuntu 16.10 x64
rpi3: raspbian jess, PIXEL - (2017-01-11 )

SGaist

Hi,

You should run your application with the QT_DEBUG_PLUGINS environment variable set to 1 to see what is happening with the loading of the platform plugin.

iiiwww

Hi @SGaist thx for your suggestion

on the RPi3
1 export QT_DEBUG_PLUGINS=1
2 ./qopenglwidget

it replied the following, but how to deal with it?

================================================
./qopenglwidget: /usr/lib/arm-linux-gnueabihf/libQt5Widgets.so.5: no version information available (required by ./qopenglwidget)
./qopenglwidget: /usr/lib/arm-linux-gnueabihf/libQt5Gui.so.5: no version information available (required by ./qopenglwidget)
./qopenglwidget: /usr/lib/arm-linux-gnueabihf/libQt5Core.so.5: no version information available (required by ./qopenglwidget)
QFactoryLoader::QFactoryLoader() checking directory path "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms" ...
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqeglfs.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqeglfs.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.2",
"MetaData": {
"Keys": [
"eglfs"
]
},
"className": "QEglFSIntegrationPlugin",
"debug": false,
"version": 328450
}

Got keys from plugin meta data ("eglfs")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqkms.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqkms.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.2",
"MetaData": {
"Keys": [
"kms"
]
},
"className": "QKmsIntegrationPlugin",
"debug": false,
"version": 328450
}

Got keys from plugin meta data ("kms")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqlinuxfb.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqlinuxfb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.2",
"MetaData": {
"Keys": [
"linuxfb"
]
},
"className": "QLinuxFbIntegrationPlugin",
"debug": false,
"version": 328450
}

Got keys from plugin meta data ("linuxfb")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqminimal.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqminimal.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.2",
"MetaData": {
"Keys": [
"minimal"
]
},
"className": "QMinimalIntegrationPlugin",
"debug": false,
"version": 328450
}

Got keys from plugin meta data ("minimal")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqminimalegl.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqminimalegl.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.2",
"MetaData": {
"Keys": [
"minimalegl"
]
},
"className": "QMinimalEglIntegrationPlugin",
"debug": false,
"version": 328450
}

Got keys from plugin meta data ("minimalegl")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqoffscreen.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqoffscreen.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.2",
"MetaData": {
"Keys": [
"offscreen"
]
},
"className": "QOffscreenIntegrationPlugin",
"debug": false,
"version": 328450
}

Got keys from plugin meta data ("offscreen")
QFactoryLoader::QFactoryLoader() looking at "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.so"
Found metadata in lib /usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.so, metadata=
{
"IID": "org.qt-project.Qt.QPA.QPlatformIntegrationFactoryInterface.5.2",
"MetaData": {
"Keys": [
"xcb"
]
},
"className": "QXcbIntegrationPlugin",
"debug": false,
"version": 328450
}

Got keys from plugin meta data ("xcb")
QFactoryLoader::QFactoryLoader() checking directory path "/home/pi/platforms" ...
loaded library "/usr/lib/arm-linux-gnueabihf/qt5/plugins/platforms/libqxcb.so"
QXcbConnection: Could not connect to display
Aborted

iiiwww

tried ubuntu 16.04 x64
same instructions with -qt-xcb
still not work any way

Hi @SGaist, I wonder it might be the problem with RPi3. Because most instructions are based on RPi2.
thx

SGaist

Without any other indication the xcb plugin is loaded however it seems you don't have any X server running or do you ?

iiiwww

Hi @SGaist, thx
Would you please give any instruction about the X server setting or something that could make the app run on the RPi3?
Just follow the instruction from Qt, but it has no effect.

thx

SGaist

Do you want to have your application running alone on your Pi or have it run in a desktop environment like on your desktop computer ?

iiiwww

Hi @SGaist, thx
I wish the app could be cross-compiled on the x86 or x64 Desktop PC, and then it could run on the RPi3, full window or only window are both acceptable.
1 running alone on RPi
2 have it run in a desktop environment like on desktop computer
So how should I do for these two kinds? I would like to try for this two different situations.
Would you please give me some suggestion in detail? I am new to RPi cross-compile.
thx

jsulm

@iiiwww Regarding2: do you have a desktop environment on your RPi? If not install one (for example Pixel or LXDE or whatever you like) and then try to run your app.
See here https://www.raspberrypi.org/forums/viewtopic.php?f=66&t=133691
For LXDE:

sudo apt-get install lxde-core lxappearance

SGaist

And for one you need to use one of the other backend, eglfs for example.

iiiwww

thx @jsulm I use raspbian with PIXEL

@SGaist I have tried every way , but it seemed not work on my RPi 3, the error above were what I met even with raspbian PIXEL, really have no idea how to deal with them.
so I wonder if you could give me some suggestion with detaileds.

thx