It works, it was a bad GCC CPU configuration.
For people that build directly on the final target, use this CPU.mk
#
# This file is subject to the terms of the GFX License. If a copy of
# the license was not distributed with this file, you can obtain one at:
#
# http://ugfx.org/license.html
#
#
# See readme.txt for the make API
#
# Requirements:
#
# NONE
#
# no more flags, let GCC set the right values