[dpdk-dev] ARM Clang cross-compilation

["Juraj Linkeš" <juraj.linkes@pantheon.tech>]

Hi dpdk devs,

Has anyone tried to do an x86 -> aarch64 cross compilation using clang (I'm using an 4.15.0-91-generic Ubuntu 18.04 VM as the build machine)? I've tried a meson build with this cross file:
[binaries]
c = 'clang-9'
cpp = 'clang++-9'
ar = 'llvm-ar-9'
strip = 'llvm-strip-9'
llvm-config = 'llvm-config-9'
pcap-config = ''

[host_machine]
system = 'linux'
cpu_family = 'aarch64'
cpu = 'armv8-a'
endian = 'little'

[properties]
implementor_id = 'generic'
implementor_pn = 'default'

But I'm hitting these errors:
../lib/librte_eal/common/include/arch/arm/rte_pause_64.h:23:15: error: invalid instruction mnemonic 'yield'
        asm volatile("yield" ::: "memory");
                     ^
<inline asm>:1:2: note: instantiated into assembly here
        yield
        ^~~~~

Full log here https://pastebin.com/raw/r04MVYti.

Looking at meson docs, I was under the impression that I only needed the right config in the cross-file, but I don't know whether there's a problem with my cross file or there's a problem with the build.

Any help would be appreciated.
Thanks,
Juraj