[PATCH] ARM: Fix bad SP address after relocating kernel

[Tony Lindgren]

Otherwise cache_clean_flush can overwrite some of the relocated
area depending on where the kernel image gets loaded. This fixes
booting on n900 after commit 6d7d0ae51574943bf571d269da3243257a2d15db
(ARM: 6750/1: improvements to compressed/head.S).

Thanks to Aaro Koskinen <aaro.koskinen at nokia.com> for debugging
the address of the relocated area that gets corrupted, and to
Nicolas Pitre <nicolas.pitre at linaro.org> for the other uncompress
related fixes.

Signed-off-by: Tony Lindgren <tony at atomide.com>

---

I think this is the right fix.. And we don't want to mess with the
ZBOOT_ROM sp address, right?

--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -253,6 +253,15 @@ restart:	adr	r0, LC0
 		/* Preserve offset to relocated code. */
 		sub	r6, r9, r6
 
+#ifndef CONFIG_ZBOOT_ROM
+		/*
+		 * Fix sp to use the relocated address in case old sp is
+		 * within the relocated area. Otherwise cache_clean_flush
+		 * will trash some of the relocated area.
+		 */
+		add	sp, r6
+#endif
+
 		bl	cache_clean_flush
 
 		adr	r0, BSYM(restart)