Bad Linux ARM zImage magic on BBblack

I am try to build a xenomai kernel following this url

RCN Kernels with Xenomai patches added.

I get the zImage and dtb modules file, and I copy it to a SD card with ubuntu 12.04 rootfs.
and boot form the sdcard. I got this error:

It's probally looking under the /boot/ directory on the "fat" partition..