How to cross compile on macOS for a different macOS architecture about chezscheme

[mflatt]

You're right that BUILDING needs more instructions, at a minimum, and probably there should be more direct support in the configure and make files.

Here's a recipe that should work:

• Build for your current architecture with ./configure and make (but no need to install).
• Build tarm64osx boot files with make tarm64osx.boot.
• Re-configure with ./configure -m=tarm64osx CFLAGS="-arch arm64" --prefix=/tmp/out, replacing /tmp/out with a place where you'd like the result to end up.
• Build with make kernel, which builds just the C-implemented kernel for Arm64 without trying to run it. (This will also take advantage of the fact that the earlier make created bin/zuo, and that one will be used.)
• Use make install to gather everything into (your replacement for) /tmp/out.

This recipe should work in general, except that more work may be needed to select the right C compiler in the middle step, depending on how the target platform relates to the current one.

[ryandesign]

Thanks, I'm trying that out.

We are also currently using the configure args --threads --libkernel LZ4=-llz4 ZLIB=-lz. Should I now be specifying those in the first configure invocation, the second one, or both?

[mflatt]

The second configure is the relevant one for those flags, since I think those are meant to configure the result. They would be fine to use for the first ./configure to build for the current machine, since you have those libraries installed universal.