[POWERPC] Cleanup zImage handling of kernel entry with flat device tree

This makes 2 changes to clean up the flat device tree handling
logic in the zImage wrapper.

First, there were two callbacks from the dt_ops structure used for
producing a final flat tree to pass to the kerne: dt_ops.ft_pack()
which packed the flat tree (possibly a no-op) and dt_ops.ft_addr()
which retreived the address of the final blob.  Since they were only
ever called together, this patch combines the two into a single new
callback, dt_ops.finalize().  This new callback does whatever
platform-dependent things are necessary to produce a final flat device
tree blob, and returns the blob's addres.

Second, the current logic calls the kernel with a flat device tree if
one is build into the zImage wrapper, otherwise it boots the kernel
with a PROM pointer, expecting the kernel to copy the OF device tree
itself.  This approach precludes the possibility of the platform
wrapper code building a flat device tree from whatever
platform-specific information firmware provides.  Thus, this patch
takes the more sensible approach of invoking the kernel with a flat
tree if the dt_ops.finalize callback provides one (by whatever means).

So, the dt_ops.finalize callback can be NULL, or can be a function
which returns NULL.  In either case, the zImage wrapper logic assumes
that this is a platform with OF and invokes the kernel accordingly.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/arch/powerpc/boot/ops.h b/arch/powerpc/boot/ops.h
index 59832fb..8abb651 100644
--- a/arch/powerpc/boot/ops.h
+++ b/arch/powerpc/boot/ops.h
@@ -35,8 +35,7 @@ struct dt_ops {
 			const int buflen);
 	int	(*setprop)(const void *phandle, const char *name,
 			const void *buf, const int buflen);
-	void	(*ft_pack)(void);
-	unsigned long (*ft_addr)(void);
+	unsigned long (*finalize)(void);
 };
 extern struct dt_ops dt_ops;