Playing with HEAD/sparc64 and clang

Hi!

With the help of Roman Divacky, I started to play with clang on sparc64.
The build of the kernel and world completes (though, I use a patch to
pcpu.h provided by Roman). However, the loader fail to load the kernel,
and I'm not sure the world binaries are correct.

== Compilation ==

First, I cross-build kernel and world on an amd64 computer. The source
tree is at r271475. Here are the variables I set in the environment:

    export MAKEOBJDIRPREFIX=$(pwd)
    export TARGET=sparc64
    export TARGET_ARCH=sparc64

    export WITH_CLANG_BOOTSTRAP=y
    export WITH_CLANG=y
    export WITH_CLANG_IS_CC=y
    export WITH_LIBCPLUSPLUS=y

Compared to mail sent by Dimitry Andric in last February [1], I added
WITH_CLANG_BOOTSTRAP. Otherwise, clang isn't build early enough and the
host compiler is used (producing amd64 binaries).

== Kernel ==

When I boot the kernel built with clang, I get:
    jumping to kernel entry at 0xc00a8000
    Data Access Exception

Then, I'm left at the OpenBoot prompt.

== World ==

I install world in an alternate directory.

When I run bin/sh from that directory, it works.

When I set LD_LIBRARY_PATH to point to $directory/lib and run bin/sh, it
works.

When I run "chroot $directory /bin/sh", I get:
    Illegal instruction

The computer is a Sun Ultra60 with dual UltraSPARC II 450 MHz. Its dmesg
is here:
https://people.freebsd.org/~dumbbell/sparc64/freebsd-ultra60-dmesg.txt

I'm ready to provide any information required and test patches :)

[1]
https://lists.freebsd.org/pipermail/freebsd-sparc64/2014-February/009233.html

-- 
Jean-Sébastien Pédron

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2

iQJ8BAEBCgBmBQJUFGqnXxSAAAAAAC4AKGlzc3Vlci1mcHJAbm90YXRpb25zLm9w
ZW5wZ3AuZmlmdGhob3JzZW1hbi5uZXQ2NzA4N0ZEMUFFQUUwRTEyREJDNkE2RjAz
OUU5OTc2MUE1RkQ5NENDAAoJEDnpl2Gl/ZTMnikQAMiPv83O2F/j4q3qTTMj6PD7
paXHaPYayYCaVJp/FqiDHLI5xszryv+MzTR0WkvE2dTEcmPjGd9lMYme/mbrPmgb
BnMh9EIqrZSgwhXNkc3sHFkYmzcErbOCxc9xeGZmmeyIchBD53WVD56ln8NKRH/F
udO9Vd1Z+lWg3lMw54jk+hJXOIH41RwLbBqO4m+hmVedCZFwDVuoTbUuSrbL0JKy
aYBdziQ9uxc/tMrxIdKt+XUoZSv07f4sOUW4m5ikcRxI15abF7rW/+6SHgTn1S9h
JJK+hR/oMmP03tVfyzbaTYNiErPoGBkuSVhmdzQxQxxoKvXVGV7u/3e0sO3duiLh
pMoWamoVjyk55fBxJJ70HQol6L88JiNXeckoKh4gU7XiHZAHGuabezq9+Pa8cxgr
RgsOYWWNSOuPVJKba2cn2bytEzil8mfnM+vvlC5RKlGam9T/4ctCWSmulBZ7zqLk
kxDUOY5wyBHgw1fgzLhTK/iCGpxEaciC8VcJQc0DPXgz71C1ggavY1cLqTvNBUSk
aXYlZ9VQWWmJ7ygVwFqGyqrl5dqAk63sWhr1HsXFsirE8UctzbK13kp5YuHWbkgH
El5U5fVbZfAKHhJEXP+r9gEoz3YoiEZFl19GeK6M8UJ19nOMQmto315WqZKbI7ST
ofhBppPDW+QzUUYLFgqS
=c7Jx
-----END PGP SIGNATURE-----