From e6bee80814c3a0d7eab89d28142fe68c4a670f31 Mon Sep 17 00:00:00 2001 From: Joakim Tjernlund 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 --- README | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/README b/README index 7affe10fb..263bb0507 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