[Feature] Cross-compilation support

[totchi-lagawi]

Hi!

So far, there is no way to cross-compile the project except manually reviewing the build scripts and building manually. It could be nice to detect the arch of the current system and, if it does not match the target arch, automatically add the required cross-compile flag to CMake calls (which means adding toolchain files) and to ./configure for libserialport.

[jsm174]

Hello!

I worked on most of the cmake/platform/CI processes and to be honest, cross compiling is not my strong suite. (I'm sure there are much better and correct ways to do all this.)

Although libzedmd can be used completely standalone, it is a large part of the Visual Pinball (standalone) ecosystem:

libdmdutil
libzedmd
libserum/libserum-concentrate
libdof
libpupdmd
libaltsound
libpinmame

All these projects use a similar cmake/platform/CI.

If you'd like to volunteer to add support, that would be great! If it works out, it could be implement on all these other projects.

[totchi-lagawi]

Actually, I had to compile libzedmd to obtain the zedmd-client-portable binary, which isn't distributed with Batocera 41... I managed to build it for aarch64 by tweaking a little bit the flags passed to CMake/./configure. I'll try to modify the scripts to automatically cross-compile.

[totchi-lagawi]

Alllright, turns out I forgot about this... Sorry...

May I ask you why you used scripts to download and compile the required libraries instead of doing it with CMake?
I think it would be way easier to provide support for cross-compilation this way.

[mkalkbrenner]

Alllright, turns out I forgot about this... Sorry...

May I ask you why you used scripts to download and compile the required libraries instead of doing it with CMake? I think it would be way easier to provide support for cross-compilation this way.

That's a question for @jsm174
with libzedmd we simply follow the patterns used by the VPX eco-system