用于arm linux的QT构建应用程序

Question

I got a little confused when it comes to QT and cross compiling appliations for my arm-linux:

So far I have a linux running on my AT91SAM9263-EK and an appropriate filessystem including QT libs build via buildroot.

Also I have build QT-4.8 on my ubuntu.

Now I want to build an example application:

1. I created a makefile in an examples folder in QT on my ubuntu using qmake; I used the given qmake.conf in mkspecs/qws/linux-arm-g++.

2. when executing make I get an error because it includes qatomic_i386.h and the message "error: impossible constraint in 'asm'". this header file does obviously not match to my arm toolchain.

my question: how to configure Qt on my ubuntu to build Qt binaries for my embedded linux on arm? Do I need to include any libs build by the arm toolchain?

any help is appreciated!

regards

EDIT: I use the -spec flag and pass the path to "mkspecs/qws/arm-linux-g++" where a "qmake.conf" is located. I did not change anything in here because I dont know wich qmake variable are relevant to link to my arm related libs. So the right compiler is used, which I could verify when the make process starts. But I observed that in a config file called qconfig.h there is an ARCH flag which is set to i386 but I didnt figure out how one can configure this. I dont think I should manually edit this file.

EDIT2: someone knows whats behind the file qconfig.h?? should I adjust it manually?

Answer 1

I will solve it by myself :)

After struggling a while and scanning the web I got a little deeper involved how everything works together. I did not understand how to generate an executable for my ARM target device. I figured out two things:

1. do not add your QT path for X11 at the beginning in your PATH variable. this might mess up your cross compilation.

2. edit the qmake.conf correspondingly. add your libs build for the target device which in my case are located within buildroot. Add theses lines to your qmake.conf file:
   QMAKE_CFLAGS += -O3 -march=armv5te
   QMAKE_CXXFLAGS += -O3 -march=armv5te
   QMAKE_INCDIR_QT = /home/user/arm/toolchain/buildroot-2010.11/output/staging/usr/include
   QMAKE_LIBDIR_QT = /home/user/arm/toolchain/buildroot-2010.11/output/staging/usr/lib

I got it running now. thanks to everyone!

Answer 2

Yes, either you provide the Qt libraries in your toolchain or you tell qmake where to find them. Also, I suspect you're calling qmake without the -spec parameters. If you are using the qmake you find in your distribution, it will use the default spec, which is not arm I guess. Add the -spec parameter and point it to the arm mkspec. Also, make sure the generated g++ commands link to the correct Qt libs compiled for arm.

Answer 3

You shall install QtSDK for embedded linux befor you use it to build your application. I'm afraid you just have QtSDK for x86 right now. After QtSDK for embedded linux installed, it has qws/linux-arm-g++ as the default mkspace typically. If you don't have QtSDK for embedded linux, you can build it from source. Then run qmake to create Makefile for you application.

$QTDIR_FOR_ARM/qmake

Reference: Installing Qt for Embedded Linux and Cross-Compiling Qt for Embedded Linux Applications