From e7670f6c1e52ae6d2a43ff75a8bcfa7a5c86e47b Mon Sep 17 00:00:00 2001 From: Wolfgang Denk Date: Thu, 14 Feb 2008 22:43:22 +0100 Subject: PPC: Use r2 instead of r29 as global data pointer R29 was an unlucky choice as with recent toolchains (gcc-4.2.x) gcc will refuse to use load/store multiple insns; instead, it issues a list of simple load/store instructions upon function entry and exit, resulting in bigger code size, which in turn makes the build for a few boards fail. Use r2 instead. Signed-off-by: Wolfgang Denk --- README | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'README') diff --git a/README b/README index a5ffbb5ad15..b4966a0df66 100644 --- a/README +++ b/README @@ -3499,7 +3499,7 @@ GCC's implementation. For PowerPC, the following registers have specific use: R1: stack pointer - R2: TOC pointer + R2: reserved for system use R3-R4: parameter passing and return values R5-R10: parameter passing R13: small data area pointer @@ -3508,7 +3508,7 @@ For PowerPC, the following registers have specific use: (U-Boot also uses R14 as internal GOT pointer.) - ==> U-Boot will use R29 to hold a pointer to the global data + ==> U-Boot will use R2 to hold a pointer to the global data Note: on PPC, we could use a static initializer (since the address of the global data structure is known at compile time), -- cgit v1.2.3