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ppc: Update README about the new GOT ptr.

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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>
This commit is contained in:
Joakim Tjernlund 2010-01-19 14:41:58 +01:00 committed by Wolfgang Denk
parent 0f8aa15917
commit e6bee80814
1 changed files with 3 additions and 1 deletions
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@ -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