[POWERPC] Consolidate cuboot initialization code

The various cuboot platforms (i.e. pre-device tree aware u-boot for
83xx, 85xx and Ebony) share a certain amount of code for parsing the
boot parameters.  To a certain extent that's inevitable, since they
platforms have different definitions of the bd_t structure.  However,
with some macro work and a helper function, this patch improves the
situation a bit.

In the process, this fixes a bug on Ebony, which was incorrectly
handling the parameters passed form u-boot for the command line (the
bug was copied from 83xx and 85xx which have subsequently been fixed).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/boot/cuboot.h b/arch/powerpc/boot/cuboot.h
new file mode 100644
index 0000000..cd2aa7f
--- /dev/null
+++ b/arch/powerpc/boot/cuboot.h
@@ -0,0 +1,14 @@
+#ifndef _PPC_BOOT_CUBOOT_H_
+#define _PPC_BOOT_CUBOOT_H_
+
+void cuboot_init(unsigned long r4, unsigned long r5,
+		 unsigned long r6, unsigned long r7,
+		 unsigned long end_of_ram);
+
+#define CUBOOT_INIT() \
+	do { \
+		memcpy(&bd, (bd_t *)r3, sizeof(bd)); \
+		cuboot_init(r4, r5, r6, r7, bd.bi_memstart + bd.bi_memsize); \
+	} while (0)
+
+#endif /* _PPC_BOOT_CUBOOT_H_ */