i've tried to enable it --with-cpu=armv7 but it fails on my machine (Freescale i.MX51, armv7-a CortexA8) because -march=armv7 breaks it.

distro: CRUX ARMHF
toolchain: gcc-4.7.1, binutils-2.22, glibc-2.16.0
machine: Genesi EfikaMX Smarttop (T03) based on Freescale i.MX51 SoC


[...]
gcc ../ports/sysdeps/unix/sysv/linux/arm/sysdep.S -c    -I../include -I/mnt/DEVE
L/HVA/NEW/00/glibc/work/src/build/csu -I/mnt/DEVEL/HVA/NEW/00/glibc/work/src/bui
ld -I../ports/sysdeps/unix/sysv/linux/arm/nptl -I../ports/sysdeps/unix/sysv/linu
x/arm -I../nptl/sysdeps/unix/sysv/linux -I../nptl/sysdeps/pthread -I../sysdeps/p
thread -I../ports/sysdeps/unix/sysv/linux -I../sysdeps/unix/sysv/linux -I../sysd
eps/gnu -I../sysdeps/unix/inet -I../nptl/sysdeps/unix/sysv -I../ports/sysdeps/un
ix/sysv -I../sysdeps/unix/sysv -I../ports/sysdeps/unix/arm -I../nptl/sysdeps/uni
x -I../ports/sysdeps/unix -I../sysdeps/unix -I../sysdeps/posix -I../ports/sysdep
s/arm/armv7 -I../ports/sysdeps/arm/armv6t2 -I../ports/sysdeps/arm/nptl -I../port
s/sysdeps/arm -I../sysdeps/wordsize-32 -I../sysdeps/ieee754/flt-32 -I../sysdeps/
ieee754/dbl-64 -I../sysdeps/ieee754 -I../sysdeps/generic -I../nptl -I../ports  -I.. -I../libio -I. -nostdinc -isystem /usr/lib/gcc/arm-unknown-linux-gnueabihf/4.7.1/include -isystem /mnt/DEVEL/HVA/NEW/00/glibc/work/pkg/usr/include -D_LIBC_REENTRANT -include ../include/libc-symbols.h       -DASSEMBLER  -I/mnt/DEVEL/HVA/NEW/00/glibc/work/src/build/csu/.  -Wa,--noexecstack -march=armv7  -o /mnt/DEVEL/HVA/NEW/00/glibc/work/src/build/csu/sysdep.o -MD -MP -MF /mnt/DEVEL/HVA/NEW/00/glibc/work/src/build/csu/sysdep.o.dt -MT /mnt/DEVEL/HVA/NEW/00/glibc/work/src/build/csu/sysdep.o
../ports/sysdeps/unix/arm/sysdep.S: Assembler messages:
../ports/sysdeps/unix/arm/sysdep.S:47: Error: lo register required -- `sub pc,r0,#31'
../ports/sysdeps/unix/arm/sysdep.S:50: Error: invalid base register for register offset -- `ldr r2,[pc,r2]'
../ports/sysdeps/unix/arm/sysdep.S:52: Error: unshifted register required -- `mvn r0,#0'
make[2]: *** [/mnt/DEVEL/HVA/NEW/00/glibc/work/src/build/csu/sysdep.o] Error 1
make[2]: Leaving directory `/mnt/DEVEL/HVA/NEW/00/glibc/work/src/glibc-2.16.0/csu'
make[1]: *** [csu/subdir_lib] Error 2
make[1]: Leaving directory `/mnt/DEVEL/HVA/NEW/00/glibc/work/src/glibc-2.16.0'
make: *** [all] Error 2



Instead with -march=armv7-a it builds fine.
Here attached the (failure) build log and a quick dirty patch to 
fix it enabling also --with-cpu=armv7-a .

regards,
Nico
-- 
Sent from Genesi EfikaMX Smartbook - Freescale i.MX51 based