Xilinx Ethernet MAC - working with DMA (EDK)

Hi all,
I am having some difficulties working with the DMA of the ethernet
mac.
I've downloaded a ref. design of web-server over the virtex-2P (with
ppc 405) - it works well. However I would like to add a DMA -> which
means that every packet that is recieved will be directly written to
the DIMM that is on board (xupv2p E.B.). I tried to read the docs
explaining the proceadure, BUT GOT LOST.

help someone??

thanks,

Guy