Been digging around the Arm makefiles. We already compile for Armv6 specifically, but not for the specific Arm device being used, and as far as I can see we don't set -mfloat-abi=softfp, although since the kernel is integer anyway I am not sure that would make any difference.
This is the c flags line for Arm, not sure whether -msoft-float is the best option, and it appears Thumb is enabled - not sure that is necessary. I think the following tuning is done
tune-$(CONFIG_CPU_V6) :=$(call cc-option,-mtune=arm1136j-s,-mtune=strongarm)
KBUILD_CFLAGS +=$(CFLAGS_ABI) $(CFLAGS_THUMB2) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
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