如何在x86_64上交叉编译Raspberry Pi项目？(因路径无效而丢失*.so)

Question

我正在x86_64/Ubuntu 13.04上交叉编译Raspberry Pi项目.调用cmake后:

cmake -DCMAKE_TOOLCHAIN_FILE=./Toolchain-raspberry.pi .

然后make,链接失败:

/opt/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/../lib/gcc/arm-linux-gnueabihf/4.7.2/../../../../arm-linux-gnueabihf/bin/ld: cannot find -lopencv_gpu
...

问题是cmake生成的Makefile以下列方式调用链接器:

/opt/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-g++       CMakeFiles/Watson.dir/main.cpp.o  -o Watson -rdynamic -lopencv_gpu -lopencv_contrib -lopencv_legacy -lopencv_objdetect -lopencv_calib3d -lopencv_features2d -lopencv_video -lopencv_highgui -lopencv_ml -lopencv_imgproc -lopencv_flann -lopencv_core 

它没有指定这些共享库的路径.但是,如果我手动将--sysroot/opt/rpi-rootfs / flag添加到上面的命令,则链接会成功.

在交叉编译时,建议让cmake指定共享库的正确路径的方法是什么？

这是我的Toolchain-raspberry.pi文件:

SET(CMAKE_SYSTEM_NAME Linux)
SET(CMAKE_SYSTEM_VERSION 1)

SET(CMAKE_C_COMPILER /opt/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-gcc)
SET(CMAKE_CXX_COMPILER /opt/tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-g++)

SET(CMAKE_FIND_ROOT_PATH "/opt/rpi-rootfs/")
SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

这是我的CMakeList.txt文件:

cmake_minimum_required(VERSION 2.8)

project(watson)
add_executable(Watson main.cpp)

find_package(OpenCV REQUIRED)
target_link_libraries(Watson ${OpenCV_LIBS})

目标中的/ usr和/ lib目录是rsync到/ opt/rpi-rootfs /并且所有必需的*.so文件都在那里.阅读完cmake文档后,我原本期望设置CMAKE_FIND_ROOT_PATH可以解决这个问题,但显然没有.我使用的是cmake版本2.8.10.1.

Answer 1

通过我的实践，

INCLUDE_DIRECTORIES(/opt/rpi-rootfs/usr/include)
LINK_DIRECTORIES(
    /opt/rpi-rootfs/usr/lib
    /opt/rpi-rootfs/lib
)

将工作