can not build world or kernel: /usr/src/sys/boot/i386/cdboot/cdboot.S:597:10: error: .code16 not supported yet

I can not build FreeBSD 10.0-CURRENT/amd64, the build terminates with
the following error when building with CLANG either worl or kernel.

Is there something I missed? How to solve?

regards,
Oliver




clang -O2 -fno-strict-aliasing -pipe -pipe -O3 -fno-strict-aliasing
-march=native -I/usr/src/sys/boot/i386/cdboot/../common -ffreestanding
-mpreferred-stack-boundary=2  -mno-mmx -mno-3dnow -mno-sse -mno-sse2
-mno-sse3 -msoft-float -m32 -march=i386 -std=gnu99 -Qunused-arguments
 -m32 -c /usr/src/sys/boot/i386/cdboot/cdboot.S
/usr/src/sys/boot/i386/cdboot/cdboot.S:112:10: error: .code16 not
supported yet
  .code16
         ^
/usr/src/sys/boot/i386/cdboot/cdboot.S:144:3: error: ambiguous
instructions require an explicit suffix (could be 'orb', 'orw', 'orl',
or 'orq')
  or $0x1,0x8(%bx) # kargs->bootflags |=
  ^
/usr/src/sys/boot/i386/cdboot/cdboot.S:272:10: error: .code16 not
supported yet
  .code16
         ^
/usr/src/sys/boot/i386/cdboot/cdboot.S:597:10: error: .code16 not
supported yet
  .code16
         ^
*** [cdboot.o] Error code 1

Stop in /usr/src/sys/boot/i386/cdboot.
*** [all] Error code 1

Stop in /usr/src/sys/boot/i386.
*** [all] Error code 1

Stop in /usr/src/sys/boot.
*** [all] Error code 1

Stop in /usr/src/sys.
*** [all] Error code 1

Stop in /usr/src.
*** [all] Error code 1