[U-Boot] compiled failed when turned off gcc optimazition

Hi, experts: I tried to turn off gcc optimazition by changing config.mk file: OPTFLAGS= -O0 #-fomit-frame-pointer

But failed to compile u-boot, it tipped: ...... /home/lion/Origen0921/arm-2010.09/bin/arm-none-eabi-ld: arch/arm/cpu/armv7/libarmv7.o: relocation R_ARM_MOVW_ABS_NC against `a local symbol' can not be used when making a shared object; recompile with -fPIC arch/arm/cpu/armv7/libarmv7.o: could not read symbols: Bad value make[1]: *** [u-boot] Error 1 make[1]: Leaving directory `/home/lion/DebugLinux/uboot-0627/u-boot' make: *** [smdkc100] Error 2

Best wishes,