Cross Compiling

LibOSDP can be compiled with your cross compiler by passing a toolchain file to cmake. This can be done by invoking cmake with the command line argument -DCMAKE_TOOLCHAIN_FILE=/path/to/toolchain-file.cmake.

If your toolchain is installed in /opt/toolchain/armv8l-linux-gnueabihf/ and the sysroot is present in /opt/toolchain/armv8l-linux-gnueabihf/sysroot, the toolchain-file.cmake file should look like this:

set(CMAKE_SYSTEM_NAME Linux)
set(CMAKE_SYSTEM_PROCESSOR arm)

# specify the cross compiler and sysroot
set(TOOLCHAIN_INST_PATH /opt/toolchain/armv8l-linux-gnueabihf)
set(CMAKE_C_COMPILER    ${TOOLCHAIN_INST_PATH}/bin/armv8l-linux-gnueabihf-gcc)
set(CMAKE_CXX_COMPILER  ${TOOLCHAIN_INST_PATH}/bin/armv8l-linux-gnueabihf-g++)
set(CMAKE_SYSROOT       ${TOOLCHAIN_INST_PATH}/sysroot)

# don't search for programs in the build host directories
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_FIND_ROOT_PATH_MODE_PACKAGE ONLY)

For convenience, the toolchain-file.cmake file can be placed in a common path (probably where the toolchain is installed) and referenced from our build directory.

mkdir build && cd build
cmake -DCMAKE_TOOLCHAIN_FILE=/opt/toolchain/armv8l-linux-gnueabihf/toolchain-file.cmake ..
make