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nyan: Use asm volatile instead of plain asm so it doesn't get optimized out.

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If an asm blob isn't marked as volatile, gcc is free to throw it out if it
doesn't think it produces any values that are actually used. To prevent that
from happening, add volatile to some asm blobs in the nyan romstage code.

BUG=None
TEST=Booted on nyan rev1.
BRANCH=None

Change-Id: I819e068e738e94ea749fcb72bba2eee080e1dfb1
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/185610
Reviewed-by: Julius Werner <jwerner@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
This commit is contained in:
Gabe Black 2014-02-08 05:01:06 -08:00 • committed by chrome-internal-fetch
commit 76c09581d6
2 changed files with 4 additions and 2 deletions
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3
src/mainboard/google/nyan/romstage.c
View file

@ -136,6 +136,7 @@ static void __attribute__((noinline)) romstage(void)
/* Stub to force arm_init_caches to the top, before any stack/memory accesses */
void main(void)
{
asm ("bl arm_init_caches" ::: "r0","r1","r2","r3","r4","r5","ip");
asm volatile ("bl arm_init_caches"
::: "r0","r1","r2","r3","r4","r5","ip");
romstage();
}

3
src/mainboard/google/nyan_big/romstage.c
View file

@ -136,6 +136,7 @@ static void __attribute__((noinline)) romstage(void)
/* Stub to force arm_init_caches to the top, before any stack/memory accesses */
void main(void)
{
asm ("bl arm_init_caches" ::: "r0","r1","r2","r3","r4","r5","ip");
asm volatile ("bl arm_init_caches"
::: "r0","r1","r2","r3","r4","r5","ip");
romstage();
}