In the device tree for Ebony, the 'ranges' property in the node for
the EBC bridge shows the mappings from the chip select / address lines
actually used for the EBC peripherals into the address space of the
OPB.  At present, these mappings are hardcoded in ebony.dts for the
mappings set up by the OpenBIOS firmware when it configures the EBC
bridge.

This replaces the hardcoded mappings with code in the zImage to
read the EBC configuration registers and create an appropriate ranges
property based on them.  This should make the zImage and kernel more
robust to changes in firmware configuration.  In particular, some of
the Ebony's DIP switches can change the effective address of the Flash
and other peripherals in OPB space.  With this patch, the kernel will
be able to cope with at least some of the possible variations.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The ebony_exit() function which resets the Ebony board should in fact
be common to most if not all 44x boards.  This moves the function out
into 44x.c, renaming it, so it can be used by other 44x platforms.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This adds platform support code for the Ebony (440GP) evaluation
board.  This includes both code in arch/powerpc/platforms/44x for
board initialization, and zImage wrapper code to correctly tweak the
flattened device tree based on information from the firmware.  The
zImage supports both IBM OpenBIOS (aka "treeboot") and old versions of
uboot which don't support a flattened device tree.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>