powerPC 860 Port to asm/powerpc, early_dev_init problem

[Gray, Steve - UK]

Hi List
I have a PPC860 on our own embedded platform.
I using a denx kernel snapshot from the git repository date 4 Feb 2008
I am using U-boot 1.3.1 with CONFIG_OF_LIBFDT enable, and have ported
into the kernel tree, the necessary makefiles and Kconfig changes, to
give me a kernel that now compiles,

I am able to get this to work as required with asm/ppc, and drop to a
Busybox prompt and mount rootFS over NFS
Oon reading the list this will be dropped this summer, so I have
undertaken the role to port this into the asm/powerpc branch.
I have a problem that I am not able to understand and am looking to the
list for some help.

Using a BDI-3000 I can step through the kernel startup code and
encounter a problem as described below

early_init_devtree prom.c @ line 1042, params = 0x7ffec0
Call of_scan_flat_dt prom.c @ line 1058 now my debugger is showing the
passed value as 0xc07ffec0
This now results in a bus error when accessing *p at line 104 of prom.c

This Flat device tree is new to me, and to many others I guess. 
Im pretty sure that I may of simply overlooked something with this new
flat device tree but am not sure what. 
I also don't understand why the parameter has changed?
Can any body point me back into the right direction?
Thanks in advance
Steve