我的交叉编译器找不到共享库

Question

I am coding with Eclipse on a Debian VM, and cross-compile for a Raspberry Pi Zero. I would like to use the mraa library, but after hours of struggle I still cannot make it work. - On the target (Raspi zero) I can compile mraa locally using CMake, simply following the author's instructions. It works perfectly when I play with a c++ example locally. - On the host, I copied the *.so files from the target, but the cross-compiler is not liking it (undefined reference errors). In the Eclipse settings, I added the header directory to the include path, the shared lib directory to the library search path (-L) and I added the -lmraa flag.

What am I doing wrong? Am I supposed to compile MRAA on the host using CMake? If so, how do I define my cross-compiler with CMake?

Answer 1

Sorry for not editing my question earlier, but sometimes the question becomes clear only once you find the answer...

Essentially, I wanted to use a library (MRAA) for which I had the source code and a cmake file. I thought that I could simply run cmake on the target (my RasPi Zero), then transfer the .so (shared libraries) files to my host in order to cross-compile with Eclipse. But it didn't work.

So instead I compiled the library using cmake on the host. For it to work, you need to provide a link to a cross-compiler as well as a link to a root file system similar to the target because of all the dependencies. So I created a toolchain.cmake file to define everything and called this toolchain file as an option when I ran cmake.

Everything is explained here: http://www.vtk.org/Wiki/CMake_Cross_Compiling

The cross-compiler and the root file system are provided here: https://github.com/raspberrypi/tools/tree/master/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64

And this seems to be the proper way to use someone else's shared library when the compiled version does not exist for your target (in my case, a Raspberry Pi Zero).