From e6bee80814c3a0d7eab89d28142fe68c4a670f31 Mon Sep 17 00:00:00 2001
From: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
Date: Tue, 19 Jan 2010 14:41:58 +0100
Subject: [PATCH] ppc: Update README about the new GOT ptr.
r14 is no longer used as non volatile GOT ptr. Instead
the volatile r12 is used so be sure to do GET_GOT in
asm code when you need to access global data.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
---
README | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/README b/README
index 7affe10fb2..263bb05076 100644
--- a/README
+++ b/README
@@ -3922,7 +3922,9 @@ For PowerPC, the following registers have specific use:
R30: GOT pointer
R31: frame pointer
- (U-Boot also uses R14 as internal GOT pointer.)
+ (U-Boot also uses R12 as internal GOT pointer. r12
+ is a volatile register so r12 needs to be reset when
+ going back and forth between asm and C)
==> U-Boot will use R2 to hold a pointer to the global data
--
2.39.5