[U-Boot] [PATCH RFC 1/3] arm920t: do not set register useless

[Andreas Bießmann]

in case we are still at relocation target address before relocation we
do not need to load the registers needed for relocation. We should
instead skip the whole relocation part and jump over to clear_bss.

Also prepare to not use target address twice. When we use a scratch
register here r6 is unchanged and can be used later on.

Signed-off-by: Andreas Bießmann <andreas.devel at googlemail.com>
---
 arch/arm/cpu/arm920t/start.S |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arm/cpu/arm920t/start.S b/arch/arm/cpu/arm920t/start.S
index 01edb9b..71de373 100644
--- a/arch/arm/cpu/arm920t/start.S
+++ b/arch/arm/cpu/arm920t/start.S
@@ -208,15 +208,16 @@ stack_setup:
 	mov	sp, r4
 
 	adr	r0, _start
+	cmp	r0, r6
+	beq	clear_bss		/* skip relocation */
+	mov	r1, r6
 	ldr	r2, _TEXT_BASE
 	ldr	r3, _bss_start_ofs
 	add	r2, r0, r3		/* r2 <- source end address	    */
-	cmp	r0, r6
-	beq	clear_bss
 
 copy_loop:
 	ldmia	r0!, {r9-r10}		/* copy from source address [r0]    */
-	stmia	r6!, {r9-r10}		/* copy to   target address [r1]    */
+	stmia	r1!, {r9-r10}		/* copy to   target address [r1]    */
 	cmp	r0, r2			/* until source end address [r2]    */
 	blo	copy_loop
 
-- 
1.7.3.2