[Solved] Cannot find libs for cross-compiling (BBB) while Host PC works fine

[Bartholomew]

Hi all,

this example with projectfile does nothing and works fine on my Host PC (Linux Host 3.13.0-37-generic x86_64 GNU/Linux):

@#-------------------------------------------------

Project created by QtCreator 2014-10-13T18:43:25

#-------------------------------------------------

QT += core
QT -= gui

TARGET = Marker-Test
target.files = Marker-Test
target.path = /home/ubuntu/workspace/temp
INSTALLS += target

TARGET = Marker-Test
CONFIG += console
CONFIG -= app_bundle

TEMPLATE = app

SOURCES += main.cpp \

INCLUDEPATH += /usr/local/opencv-2.4.9/include
/usr/include/c++/4.8/

#just an example lib!
LIBS += -L/usr/lib -lgs@

This example works finde on my Host. If i compile and run it on my Host PC for my BeagleboneBlack, sometimes there is an error but not allways:

1. error: cannot find -lgs (depends on the libs)
2. error: collect2: error: ld returned 1 exit status

How can i solve this problem? If i do not include any lib it works fine on my BBB.

Thanks
Bart

[SGaist]

Hi,

Do you have all of these libraries available on the BBB sysroot your are using to build your applications ?

[Bartholomew]

Hi,

on my Host PC:

1. I installed Qt with the Online Installer
2. I downloaded qt-everywhere-opensource-src-5.2.1
   2.1 @./configure -v -opensource -confirm-license -prefix /opt/Qt/5.2.1-BBB -xplatform linux-arm-gnueabihf-g++ -device linux-beagleboneblack-g++ -device-option CROSS_COMPILE=/usr/local/linaro/bin/arm-linux-gnueabihf-@
   2.2 make
   2.3 make install
   2.4 I copied the folder to my BBB => /usr/5.2.1-BBB
   2.5 added the PATH in /etc/environment
3. added on my Host in Qt the "Kits" and "Devices"

everything works fine and I can develop little progs (read values from IC2 and so on)

Now I compiled openCV on my Host for the Host and everything works very well (detect something...)

On my BBB:

1. I downloaded openCV according to this manual: "http://docs.opencv.org/trunk/doc/tutorials/introduction/linux_install/linux_install.html":http://docs.opencv.org/trunk/doc/tutorials/introduction/linux_install/linux_install.html
2. I got these error(s) from first post
3. I tried to include any lib that exists on my BBB to, like: -L/usr/lib -lgs

The problem I think is not openCV. The problems are in general.

[Bartholomew]

I got the correct linking for INCLUDEPATH and LIBS

but the error is still there:
/usr/local/opencv-2.4.9/lib/libopencv_calib3d.so:-1: error: file not recognized: File format not recognized
error: collect2: error: ld returned 1 exit status

[SGaist]

You are giving the wrong paths to the libraries. You can't use your host libraries to link to your cross-compiled software.

Where are the arm version located ?

[Bartholomew]

Yes thanks now I know that this was my problem.
I cross-compiled openCV with the arm-gnueabi.toolchain.cmake from ~/opencv-2.4.9/platforms/linux and it worked very well.

Now I did the same with ArUco (this was my original problem) with:

@cmake -DCMAKE_TOOLCHAIN_FILE=/home/basti/Downloads/aruco-1.2.5/linux/arm-gnueabi.toolchain.cmake -DCMAKE_PREFIX_PATH=/usr/local/opencv-2.4.9-hardfp /home/basti/Downloads/aruco-1.2.5@
@sudo make -j4@

and I get this error:
@make[2]: *** No rule to make target /home/basti/Downloads/opencv-2.4.9/platforms/linux/build_hardfp/lib/libopencv_videostab.so.2.4.9', needed bysrc/libaruco.so.1.2.5'. Stop.
make[2]: *** Waiting for unfinished jobs....
[ 45%] Building CXX object src/CMakeFiles/aruco.dir/cameraparameters.cpp.o
make[1]: *** [src/CMakeFiles/aruco.dir/all] Error 2
make: *** [all] Error 2@

Do you know what I am doing wrong?

[SGaist]

Are you sure the prefix path is correct ?

[Bartholomew]

The prefix path from aruco was correct. The install prefix from opencv was wrong.