[PATCH v2 6/9] ARM: Thumb-2: Fix CONFIG_THUMB2_KERNEL breakage in compressed/head.S

Dave Martin dave.martin at linaro.org
Mon Nov 22 13:04:22 EST 2010


Some instruction operand combinations are used here
which are nor permitted in Thumb-2.

In particular, most uses of pc as an operand are
disallowed in Thumb-2, and deprecated in ARM from
ARMv7 onwards.

The modified code introduced by this patch should be
compatible with all architecture versions >= v3, with
or without CONFIG_THUMB2_KERNEL.

Applies cleanly on v2.6.37-rc1.

Signed-off-by: Dave Martin <dave.martin at linaro.org>
Acked-by: Catalin Marinas <catalin.marinas at arm.com>
Reviewed-by: Will Deacon <will.deacon at arm.com>
---
 arch/arm/boot/compressed/head.S |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S
index 6825c34..1f65080 100644
--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -174,7 +174,8 @@ not_angel:
 		ldr	sp, [r0, #28]
 #ifdef CONFIG_AUTO_ZRELADDR
 		@ determine final kernel image address
-		and	r4, pc, #0xf8000000
+		mov	r4, pc
+		and	r4, r4, #0xf8000000
 		add	r4, r4, #TEXT_OFFSET
 #else
 		ldr	r4, =zreladdr
@@ -445,7 +446,8 @@ __setup_mmu:	sub	r3, r4, #16384		@ Page directory size
  */
 		mov	r1, #0x1e
 		orr	r1, r1, #3 << 10
-		mov	r2, pc, lsr #20
+		mov	r2, pc
+		mov	r2, r2, lsr #20
 		orr	r1, r1, r2, lsl #20
 		add	r0, r3, r2, lsl #2
 		str	r1, [r0], #4
-- 
1.7.1




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