Hi folks,

It's probably worth sharing something I found yesterday, running Debian Wheezy binaries on a couple of different ARMv8 machines...

libgc embeds a copy of libatomic-ops, and until very recently, libatomic-ops has been continuing to use (deprecated) CP15 barriers [1] when building for ARMv7 instead of the recommended DMB instruction. On v7 machines that's been working fine, but v8 does not support these old-style barriers at all. I found this trying to run w3m, and it failed immediately with "Illegal instruction". There's ongoing discussion about a kernel patch for arm64 to catch this exception (and others) [2], but it's not gone upstream yet. Other packages that I can see using ligbc on Debian are:

asymptote chase debfoster ecl fauhdlc gcc-3.3 goo guile-2.0 inkscape kaya neko parser stalin synopsis w3m

There may be quite a few more using older versions of libatomic-ops too - be warned. :-(

[1] e.g. mcr 15, 0, r3, cr7, cr10, {5} [2] http://comments.gmane.org/gmane.linux.ports.arm.kernel/361430

Cheers,