cross compile WiringPi

Dear 丶 2023-10-05 16:53 6阅读 0赞

刚入手了树莓派4代8G，与我之前的树莓派2代有很大进步，包括板载的wifi5，供电为typec，双hdmi，直接插入microsd，还有一个装配精度上乘的塑料壳。

下面开始讲如何交叉编译动态库，使用的工具有centos7虚拟机、raspberrypi-tool、wiringPi源码、cmake。

版本情况：

centos7.4 1708

raspberrypi-tool 下载地址[https://github.com/raspberrypi/tools][https_github.com_raspberrypi_tools]

wiringPi 下载地址[https://github.com/mm1994uestc/WiringPi][https_github.com_mm1994uestc_WiringPi]

cmake 3.19.2 下载地址[https://github.com/Kitware/CMake/releases/download/v3.19.2/cmake-3.19.2.tar.gz][https_github.com_Kitware_CMake_releases_download_v3.19.2_cmake-3.19.2.tar.gz]

操作步骤：

1.安装cmake

将下载的压缩包解压到用户目录，执行./configure，然后make，make install即可

2.安装raspberrypi-tool

将压缩包解压到用户目录即可，如/home/user/

3.编译wiringPi

将压缩包解压到用户目录，进入WiringPi-master，创建一个wiringPi\_build目录

创建一个交叉编译配置文件如下

文件名为：Toolchain-rpi.cmake

# Define our host system
    SET(CMAKE_SYSTEM_NAME Linux)
    SET(CMAKE_SYSTEM_VERSION 1)
    # Define the cross compiler locations
    SET(CMAKE_C_COMPILER   /home/user/tools-master/arm-bcm2708/arm-rpi-4.9.3-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc)
    SET(CMAKE_CXX_COMPILER /home/user/tools-master/arm-bcm2708/arm-rpi-4.9.3-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc)
    # Define the sysroot path for the RaspberryPi distribution in our tools folder 
    SET(CMAKE_FIND_ROOT_PATH /home/user/tools-master/arm-bcm2708/arm-rpi-4.9.3-linux-gnueabihf/arm-linux-gnueabihf/sysroot/)
    # Use our definitions for compiler tools
    SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
    # Search for libraries and headers in the target directories only
    SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
    SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
    set(CMAKE_CXX_STANDARD 11)
    set(CMAKE_CXX_STANDARD_REQUIRED True)

再到wiringPi目录下创建一个CMakeLists.txt，内容如下

cmake_minimum_required(VERSION 3.0)
    # Have CMake find our pthreads library within our toolchain (required for this library)
    set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
    find_package(Threads REQUIRED)
    # add all the *.c files as sources
    FILE(GLOB SRC_FILES *.c)
    # make this output a shared library (with .so output)
    add_library (wiringPi SHARED ${SRC_FILES})
    # be sure to include the current source directory for header files
    target_include_directories (wiringPi PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
    # add the following required libraries:
    # Threads, Math, Crypt, and RealTime
    target_link_libraries(wiringPi ${CMAKE_THREAD_LIBS_INIT} crypt m rt)

然后在wiringPi\_build目录下执行 cmake ../wiringPi -DCMAKE\_TOOLCHAIN\_FILE=Toolchain-rpi.cmake

会在build目录下创建一个Makefile

然后执行make就会在build目录下产生一个libwiringPi.so库文件

[https_github.com_raspberrypi_tools]: https://github.com/raspberrypi/tools
[https_github.com_mm1994uestc_WiringPi]: https://github.com/mm1994uestc/WiringPi
[https_github.com_Kitware_CMake_releases_download_v3.19.2_cmake-3.19.2.tar.gz]: https://github.com/Kitware/CMake/releases/download/v3.19.2/cmake-3.19.2.tar.gz