- Start
- Setup XCS and RPi
- Setup RPi Network and SSH
- Setup RPi Peripherals
- Setup Cross-compile environment
- Cross-compile and Install Userland
- > Cross-compile and Install OpenCV
- Cross-compile and Install ROS
- Compile and Install OpenCV
- Compile and Install ROS
- Remote ROS (RPi node and XCS master)
- ROS package development (RPi/XCS)
- Compile and Install WiringPi
This section will cross-compile and install OpenCV, its additional modules, gtk support and python bindings.
- Setup of XCS and RPi
- Setup of RPi Network and SSH
- Setup of the Cross-compile environment
- Compilation and Installation of the Userland libaries.
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To run OpenCV, additional packages on the RPi are required.
XCS~$ ssh rpizero-local RPI~$ sudo apt-get install python2.7 python-dev python-numpy python3 python3-dev python3-numpy libgtk2.0-dev libavcodec-dev libavformat-dev libswscale-dev libjpeg-dev libpng-dev libtiff-dev libjasper-dev libdc1394-22-devPython and numpy need to be installed so
OpenCVcan create the Python-bindings.Other libraries are used to process images, generate GUI's (via X-server) and other imaging processes.
Note that this download might take a while as a lot of packages need to be downloaded and installed.
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Sync RPi with the XCS. This ensures all symbolic links will be corrected.
XCS~$ $XC_RPI_BASE/rpicross_notes/scripts/sync-rpi-xcs.sh rpizero-local-root
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Download and unzip the
OpenCVsources.XCS~$ cd $XC_RPI_SRC XCS~$ wget https://github.com/opencv/opencv/archive/4.3.0.zip XCS~$ unzip 4.3.0.zip XCS~$ rm 4.3.0.zip XCS~$ wget https://github.com/opencv/opencv_contrib/archive/4.3.0.zip XCS~$ unzip 4.3.0.zip XCS~$ rm 4.3.0.zip -
After downloading, we need to edit the
OpenCV-arm toolchain as it does not support the Raspberry Pi Zeroarmv6 hfcore properly.XCS~$ nano $XC_RPI_SRC/opencv-4.3.0/platforms/linux/arm.toolchain.cmakeChange the '-mthumb' flags to '-marm'. The resulting file should look similarly to:
... if(CMAKE_SYSTEM_PROCESSOR STREQUAL arm) set(CMAKE_CXX_FLAGS "-marm ${CMAKE_CXX_FLAGS}") set(CMAKE_C_FLAGS "-marm ${CMAKE_C_FLAGS}") set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -Wl,-z,nocopyreloc") endif() ...The OpenCV toolchain presumes that a
thumbinstruction-set is available which consists of 32 and 16 bits instructions. As athumbinstruction-set uses multiple widths of instructions, this architecture is able to combine instructions and hence speed up processing time. Onlyarmv7or higher has this ability, hence it does not apply to the BCM2835 of the RPi. -
OpenCV comes with it's own toolchain for cross-compilation, but we also need to use our own toolchain as it contains several settings regarding "rootfs". Luckily CMake makes it possible to merge these files. To compile OpenCV a special toolchain (rpi-generic-toolchain-opencv-4.3.0.cmake) is created and placed in this repo. Its contents are:
include( $ENV{XC_RPI_BASE}/rpicross_notes/rpi-generic-toolchain.cmake ) include( $ENV{XC_RPI_SRC}/opencv-4.3.0/cmake/OpenCVMinDepVersions.cmake )If you use a different OpenCV version or directory structure, please make sure you edit this file accordingly.
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The commands for building
OpenCVthen becomes:XCS~$ mkdir -p $XC_RPI_BUILD/opencv XCS~$ cd $XC_RPI_BUILD/opencv XCS~$ cmake \ -D BUILD_TESTS=NO \ -D BUILD_PERF_TESTS=NO \ -D BUILD_PYTHON_SUPPORT=ON \ -D BUILD_NEW_PYTHON_SUPPORT=ON \ -D CMAKE_INSTALL_PREFIX=$XC_RPI_ROOTFS/usr \ -D OPENCV_EXTRA_MODULES_PATH=$XC_RPI_SRC/opencv_contrib-4.3.0/modules \ -D CMAKE_TOOLCHAIN_FILE=$XC_RPI_BASE/rpicross_notes/rpi-generic-toolchain-opencv-4.3.0.cmake \ $XC_RPI_SRC/opencv-4.3.0Which produces a summary looking like:
-- General configuration for OpenCV 4.3.0 ===================================== -- Version control: unknown -- -- Extra modules: -- Location (extra): /home/pi/rpi/src/opencv_contrib-4.3.0/modules -- Version control (extra): unknown -- -- Platform: -- Timestamp: 2020-04-28T10:52:55Z -- Host: Linux 4.15.0-96-generic x86_64 -- Target: Linux 1 arm -- CMake: 3.10.2 -- CMake generator: Unix Makefiles -- CMake build tool: /usr/bin/make -- Configuration: Release -- -- CPU/HW features: -- Baseline: -- requested: DETECT -- disabled: VFPV3 NEON -- -- C/C++: -- Built as dynamic libs?: YES -- C++ standard: 11 -- C++ Compiler: /usr/bin/arm-linux-gnueabihf-g++ (ver 4.9.3) -- C++ flags (Release): -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wsign-promo -Wuninitialized -Winit-self -Wno-delete-non-virtual-dtor -Wno-comment -Wno-missing-field-initializers -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG -DNDEBUG -- C++ flags (Debug): -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wsign-promo -Wuninitialized -Winit-self -Wno-delete-non-virtual-dtor -Wno-comment -Wno-missing-field-initializers -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -fvisibility=hidden -fvisibility-inlines-hidden -g -O0 -DDEBUG -D_DEBUG -- C Compiler: /usr/bin/arm-linux-gnueabihf-gcc -- C flags (Release): -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wuninitialized -Winit-self -Wno-comment -Wno-missing-field-initializers -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -fvisibility=hidden -O3 -DNDEBUG -DNDEBUG -- C flags (Debug): -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs -B/home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf -B/home/pi/rpi/rootfs/lib/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -isystem /home/pi/rpi/rootfs/usr/include/arm-linux-gnueabihf -isystem /home/pi/rpi/rootfs/usr/include -isystem /home/pi/rpi/rootfs/usr/local/include -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wuninitialized -Winit-self -Wno-comment -Wno-missing-field-initializers -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections -fvisibility=hidden -g -O0 -DDEBUG -D_DEBUG -- Linker flags (Release): -Wl,--gc-sections -Wl,--as-needed -- Linker flags (Debug): -Wl,--gc-sections -Wl,--as-needed -- ccache: NO -- Precompiled headers: NO -- Extra dependencies: dl m pthread rt -- 3rdparty dependencies: -- -- OpenCV modules: -- To be built: aruco bgsegm bioinspired calib3d ccalib core datasets dnn dnn_objdetect dnn_superres dpm face features2d flann freetype fuzzy gapi hfs highgui img_hash imgcodecs imgproc intensity_transform line_descriptor ml objdetect optflow phase_unwrapping photo plot python2 python3 quality rapid reg rgbd saliency shape stereo stitching structured_light superres surface_matching text tracking video videoio videostab xfeatures2d ximgproc xobjdetect xphoto -- Disabled: world -- Disabled by dependency: - -- Unavailable: alphamat cnn_3dobj cudaarithm cudabgsegm cudacodec cudafeatures2d cudafilters cudaimgproc cudalegacy cudaobjdetect cudaoptflow cudastereo cudawarping cudev cvv hdf java js matlab ovis sfm ts viz -- Applications: apps -- Documentation: NO -- Non-free algorithms: NO -- -- GUI: -- GTK+: YES (ver 2.24.32) -- GThread : YES (ver 2.58.3) -- GtkGlExt: NO -- -- Media I/O: -- ZLib: /home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf/libz.so (ver 1.2.11) -- JPEG: /home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf/libjpeg.so (ver 62) -- WEBP: build (ver encoder: 0x020f) -- PNG: /home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf/libpng.so (ver 1.6.36) -- TIFF: /home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf/libtiff.so (ver 42 / 4.1.0) -- JPEG 2000: /home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf/libjasper.so (ver 1.900.1) -- HDR: YES -- SUNRASTER: YES -- PXM: YES -- PFM: YES -- -- Video I/O: -- DC1394: YES (2.2.5) -- FFMPEG: NO -- avcodec: YES (58.35.100) -- avformat: YES (58.20.100) -- avutil: YES (56.22.100) -- swscale: YES (5.3.100) -- avresample: NO -- GStreamer: NO -- v4l/v4l2: YES (linux/videodev2.h) -- -- Parallel framework: pthreads -- -- Trace: YES (with Intel ITT) -- -- Other third-party libraries: -- Lapack: NO -- Custom HAL: NO -- Protobuf: build (3.5.1) -- -- OpenCL: YES (no extra features) -- Include path: /home/pi/rpi/src/opencv-4.3.0/3rdparty/include/opencl/1.2 -- Link libraries: Dynamic load -- -- Python 2: -- Interpreter: /usr/bin/python2.7 (ver 2.7.17) -- Libraries: /home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf/libpython2.7.so (ver 2.7.16) -- numpy: /home/pi/rpi/rootfs/usr/lib/python2.7/dist-packages/numpy/core/include (ver undefined - cannot be probed because of the cross-compilation) -- install path: /home/pi/rpi/rootfs/usr/local/lib/python2.7/site-packages/cv2/python-2.7 -- -- Python 3: -- Interpreter: /usr/bin/python3 (ver 3.6.9) -- Libraries: /home/pi/rpi/rootfs/usr/lib/arm-linux-gnueabihf/libpython3.7m.so (ver 3.7.3) -- numpy: /home/pi/rpi/rootfs/usr/lib/python3/dist-packages/numpy/core/include (ver undefined - cannot be probed because of the cross-compilation) -- install path: /home/pi/rpi/rootfs/usr/local/lib/python3.7/site-packages/cv2/python-3.6 -- -- Python (for build): /usr/bin/python2.7 -- -- Install to: /home/pi/rpi/rootfs/usr -- ----------------------------------------------------------------- -- -- Configuring done -- Generating done -- Build files have been written to: /home/pi/rpi/build/opencvNote the detection of libraries such as
gtk, additional modules such asfreetypeand the proper settings forPython. -
When all is fine,
OpenCVcan be build and installed (which might take a while).XCS~$ make -j 4 XCS~$ make installNote that the installation directory is not specified with the installation-call
make installas the installation directory is already defined during the CMake process: the last line of the CMake overview should state:Install to: /home/pi/rpi/rootfs/usr
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Sync the updated "rootfs" with the RPi:
XCS~$ $XC_RPI_BASE/rpicross_notes/scripts/sync-xcs-rpi.sh rpizero-local-root -
During the building process "rootfs" has been linked in the python-config files of OpenCV for the RPi. We need to fix this on the RPi:
XCS~$ ssh rpizero-local RPI~$ sudo nano /usr/local/lib/python2.7/site-packages/cv2/config-2.7.py RPI~$ sudo nano /usr/local/lib/python2.7/site-packages/cv2/config.py RPI~$ sudo nano /usr/local/lib/python3.7/site-packages/cv2/config-3.6.py RPI~$ sudo nano /usr/local/lib/python3.7/site-packages/cv2/config.pyDepending on the python versions on the RPi and on the XCS, multiple configs might require adjustments. Also note that the config-names depend on the python versions and hence might differ from the above overview.
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For each config, remove the "rootfs" reference from the path. The result should look like:
- config-X.py:
PYTHON_EXTENSIONS_PATHS = [ os.path.join('/usr/local/lib/python3.7/site-packages/cv2', 'python-3.6') ] + PYTHON_EXTENSIONS_PATHS- config.py:
BINARIES_PATHS = [ os.path.join('/usr', 'lib') ] + BINARIES_PATHS -
You can now test your python-bindings:
- python2:
RPI~$ PYTHONPATH=/usr/local/lib/python2.7/site-packages python -c 'import cv2; print(cv2.__version__)'- python3:
RPI~$ PYTHONPATH=/usr/local/lib/python3.7/site-packages python3 -c 'import cv2; print(cv2.__version__)'Both should print out
4.3.0. If you encounter any issues, see Troubleshooting. -
A more permanent way to set
PYTHONPATHis to use.bashrcRPI~$ nano ~/.bashrcAdd to following lines:
#Ensure Python is able to find packages export PYTHONPATH=/usr/local/lib/python2.7/site-packages:$PYTHONPATHNote that you both python3 and python2 use the same
PYTHONPATH, hence care should be taken when setting this in.bashrc: the different versions are not interchangeable! -
Reload Bash after you set
PYTHONPATHRPI~$ source ~/.bashrc -
Testing the bindings can now be done with:
- python2:
RPI~$ python -c 'import cv2; print(cv2.__version__)'- python3:
RPI~$ python3 -c 'import cv2; print(cv2.__version__)'
To test if OpenCV is compiled and installed properly we're going to display an image on the RPi. For this we need an image on the RPi. If you have installed the Pi Camera, you can use a previously taken test-image.
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Create the build-dir and build the application
XCS~$ mkdir -p $XC_RPI_BUILD/hello/ocv XCS~$ cd $XC_RPI_BUILD/hello/ocv XCS~$ cmake \ -D CMAKE_TOOLCHAIN_FILE=$XC_RPI_BASE/rpicross_notes/rpi-generic-toolchain.cmake \ $XC_RPI_BASE/rpicross_notes/hello/ocv XCS~$ make -
Sync and run.
XCS~$ scp hellocv rpizero-local:~/ XCS~$ ssh -X rpizero-local RPI~$ ./hellocv testcam.jpgAs a result, a window should be open displaying the image.
Depending on the size of the image, this may take a while.
raise ImportError('ERROR: recursion is detected during loading of "cv2" binary extensions. Check OpenCV installation.')
ImportError: ERROR: recursion is detected during loading of "cv2" binary extensions. Check OpenCV installation.
Check the config (config-XX.py) files on the RPi in:
/usr/local/lib/python2.7/site-packages/cv2/or/usr/local/lib/python3.7/site-packages/cv2/
Make sure that references to rootfs are cleared, as specified above.
raise ImportError('OpenCV loader: missing configuration file: {}. Check OpenCV installation.'.format(fnames))
ImportError: OpenCV loader: missing configuration file: ['config-3.7.py', 'config-3.py']. Check OpenCV installation.
Check if you have set the proper PYTHONPATH for the proper python-version:
- python2:
PYTHONPATH=/usr/local/lib/python2.7/site-packages:$PYTHONPATH - python3:
PYTHONPATH=/usr/local/lib/python3.7/site-packages:$PYTHONPATH
If your HOST had a different python version (e.g. python3.6) then the RPi (e.g. python3.7) you might need to fix the config setting:
RPI~$ sudo cp /usr/local/lib/python3.7/site-packages/cv2/config-3.6.py /usr/local/lib/python3.7/site-packages/cv2/config-3.7.py
(process:7909): Gtk-WARNING **: 12:30:05.379: Locale not supported by C library.
Using the fallback 'C' locale.
(Display window:7909): Gtk-WARNING **: 12:30:05.407: cannot open display:
Ensure you are your connected to the RPi with a shell supporting the "-X server". If you do, check if there is a warning upon login on the RPi. If you see "Warning: untrusted X11 forwarding setup failed: xauth key data not generated" you might need to use the "-Y" instead of "-X" option when connecting via SSH.