Cross-compilation settings for arm-apple-darwin ("M1 Macs")

[reishoku]

This patch enables cross-compilation of vde_vmnet along with vde_switch for arm64-apple-darwin (so-called "M1 Macs") on x86_64-apple-darwin (so-called "Intel Macs").

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At least on my environment, working steps to cross-compile are as follows:

1. (optional? not clear) Install Xcode (not Xcode Command Line Tools)
2. git clone https://github.com/virtualsquare/vde-2.git
3. cd vde-2
4. export SDKROOT=$(xcrun --sdk macosx --show-sdk-path)
5. export CC=$(xcrun --sdk macosx --find clang)
6. export CXX=$(xcrun --sdk macosx --find clang++)
7. export CFLAGS="-arch arm64e -isysroot $SDKROOT -Wno-error=implicit-function-declaration"
8. export CXXFLAGS=$CFLAGS
9. ./configure --prefix=/opt/vde --host=arm-apple-darwin --target=arm-apple-darwin --build=x86_64-apple-darwin
10. make -j3 V=1
11. sudo make install PREFIX=/opt/vde
12. git clone https://github.com/lima-vm/vde_vmnet
13. cd vde_vmnet
14. make -j3 PREFIX=/opt/vde
15. sudo make PREFIX=/opt/vde install
16. Done.

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Logs:

reishoku@Jasmine ~/D/v/vde_vmnet (master)> uname -a
Darwin Jasmine.local 21.1.0 Darwin Kernel Version 21.1.0: Wed Oct 13 17:33:23 PDT 2021; root:xnu-8019.41.5~1/RELEASE_X86_64 x86_64

reishoku@Jasmine ~/D/v/vde_vmnet (master)> file /opt/vde/bin/*
/opt/vde/bin/dpipe:        Mach-O 64-bit executable arm64e
/opt/vde/bin/unixcmd:      Mach-O 64-bit executable arm64e
/opt/vde/bin/vde_autolink: Mach-O 64-bit executable arm64e
/opt/vde/bin/vde_over_ns:  Mach-O 64-bit executable arm64e
/opt/vde/bin/vde_pcapplug: Mach-O 64-bit executable arm64e
/opt/vde/bin/vde_plug:     Mach-O 64-bit executable arm64e
/opt/vde/bin/vde_plug2tap: Mach-O 64-bit executable arm64e
/opt/vde/bin/vde_router:   Mach-O 64-bit executable arm64e
/opt/vde/bin/vde_switch:   Mach-O 64-bit executable arm64e
/opt/vde/bin/vde_vmnet:    Mach-O 64-bit executable arm64e
/opt/vde/bin/vdecmd:       Mach-O 64-bit executable arm64e
/opt/vde/bin/vdeterm:      Mach-O 64-bit executable arm64e
/opt/vde/bin/wirefilter:   Mach-O 64-bit executable arm64e

[reishoku]

Maybe creating FAT binary with lipo is better? I will work on this (creating FAT binary), if needed.

[AkihiroSuda]

This doesn't seem to install arm64 binary.

Probably you should install the binaries in name: Make section

[reishoku]

Thanks for the comment.

This should fix the issue, I assume.

[AkihiroSuda]

Thanks