Ok it is done my first kernel is compiled.
So in the root of the build is also a system.map.

I enabled in my config (from kernel plus) some netfilter related things which where also activated in the N900 kernel-power to get the same functionality like logging.

CONFIG_IP_NF_TARGET_REJECT=m
CONFIG_IP_NF_TARGET_LOG=m
CONFIG_IP_NF_TARGET_NETMAP=m

Now I will test it thumbs up that it is working.