-- 其實是因為大多使用 CMake 的 project 都是 host - target 同一系統，所以 detect, config 都是自動。但是現在要 build for target，就要讓 CMake 可以做 cross build.
看起來，是要用 -DCMAKE_TOOLCHAIN_FILE=maytoolchain.cmake
然後寫 mytoolchain.cmake
裡面指定toolchain path, name 和一堆 flag, library 等...
然後goole CMAKE_TOOLCHAIN_FILE 可以找一堆 sample,,
cross build served..
準備好 toolchain.cmake
set(CMAKE_SYSTEM_NAME Linux)
set(TOOLCHAIN_PATH /usr/local/linaro-aarch64-2018.08-gcc8.2)
set(CMAKE_C_COMPILER ${TOOLCHAIN_PATH}/bin/aarch64-linux-gnu-gcc)
set(CMAKE_CXX_COMPILER ${TOOLCHAIN_PATH}/bin/aarch64-linux-gnu-g++)
run cmake....
served.build$ cmake -DCMAKE_TOOLCHAIN_FILE=~/toolchain.cmake ../servedError:
CMake Error at /usr/share/cmake-3.10/Modules/FindBoost.cmake:1947 (message):
Unable to find the requested Boost libraries.
Boost version: 1.65.1
Boost include path: /usr/include
Could not find the following Boost libraries:
boost_system
No Boost libraries were found. You may need to set BOOST_LIBRARYDIR to the
directory containing Boost libraries or BOOST_ROOT to the location of
Boost.
in case cross-build boost: .. 結果沒用到，target system 的 boost 1.66.0 也可以用。所以不用 port boost
依照Error message，把 target system 的 boost package folder copy 到/tmp
要安排一下，把lib 和 header(include) 依照下面方式放好..
/tmp/boost/include/boost /tmp/boost/lib並且把 修改 toolchain.cmake，加入
set(BOOST_ROOT /tmp/boost)一樣..
served.build$ cmake -DCMAKE_TOOLCHAIN_FILE=~/toolchain.cmake ../served -- The C compiler identification is GNU 8.2.1 -- The CXX compiler identification is GNU 8.2.1 -- Check for working C compiler: /usr/local/linaro-aarch64-2018.08-gcc8.2/bin/aarch64-linux-gnu-gcc -- Check for working C compiler: /usr/local/linaro-aarch64-2018.08-gcc8.2/bin/aarch64-linux-gnu-gcc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Detecting C compile features -- Detecting C compile features - done -- Check for working CXX compiler: /usr/local/linaro-aarch64-2018.08-gcc8.2/bin/aarch64-linux-gnu-g++ -- Check for working CXX compiler: /usr/local/linaro-aarch64-2018.08-gcc8.2/bin/aarch64-linux-gnu-g++ -- works -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Detecting CXX compile features -- Detecting CXX compile features - done CMake Warning at /usr/share/cmake-3.10/Modules/FindBoost.cmake:801 (message): New Boost version may have incorrect or missing dependencies and imported targets Call Stack (most recent call first): /usr/share/cmake-3.10/Modules/FindBoost.cmake:907 (_Boost_COMPONENT_DEPENDENCIES) /usr/share/cmake-3.10/Modules/FindBoost.cmake:1558 (_Boost_MISSING_DEPENDENCIES) CMakeLists.txt:71 (FIND_PACKAGE) -- Boost version: 1.66.0 -- Found the following Boost libraries: -- system -- Could NOT find RAGEL (missing: RAGEL_EXECUTABLE) -- Could NOT find RAGEL (missing: RAGEL_EXECUTABLE) -- Looking for pthread.h -- Looking for pthread.h - found -- Looking for pthread_create -- Looking for pthread_create - not found -- Looking for pthread_create in pthreads -- Looking for pthread_create in pthreads - not found -- Looking for pthread_create in pthread -- Looking for pthread_create in pthread - found -- Found Threads: TRUE -- Performing Test COMPILER_SUPPORTS_CXX11 -- Performing Test COMPILER_SUPPORTS_CXX11 - Success -- Performing Test COMPILER_SUPPORTS_CXX0X -- Performing Test COMPILER_SUPPORTS_CXX0X - Success -- Configuring done -- Generating done -- Build files have been written to: /home/charles-chang/githubgitlab/served.build成功了...
到 served/bin/ 下 check file ，都是 ARM aarch64 ELF 沒錯。
放到 target board 上 run ..
- 把 served/lib/ 下的so copy 到 /lib/ 下
- 有用到 boost_system.so，所以要記得把 target build system 的 so 也 copy 到 /lib/ 下
