kernel cross-compiled with clang for ARM architecture

[Damjan Marion]

Hi,

I managed to cross-compile latest -CURRENT + Ben's patches with clang and compiled kernel boots on pandaboard.
Pandaboard support is still work in progress, but clang compiled kernel boots up to the same point like gcc version.

I  used latest clang/llvm from svn with following:

CC="/opt/llvm/bin/clang -mcpu=cortex-a9 -ccc-host-triple arm-unknown-freebsd -mfloat-abi=soft"
WERROR=""

This works both on FreeBSD and Mac OS X host.

Issues:
 - integrated assembler for ARM doesn't work properly ( I filled bugs [1] and [2])
 - gnu as works ok but newer version of binutils is needed which supports ARMv7 instructions
 - i had to patch [3] clang to invoke cross linker properly (thanks to guys form #freebsd-clang )


Regards,

Damjan

[1] http://llvm.org/bugs/show_bug.cgi?id=9760
[2] http://llvm.org/bugs/show_bug.cgi?id=9762
[3] http://llvm.org/bugs/show_bug.cgi?id=9777