use movsl for copying resume memory back

It's not significantly faster, but easier to read and smaller.

Change-Id: Ibab0b478873912d67bf1f07743f628586353368a
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/755
Reviewed-by: Mathias Krause <minipli@googlemail.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

diff --git a/src/arch/x86/boot/wakeup.S b/src/arch/x86/boot/wakeup.S
index a1df4d5597700ce8b0dd0d591f94a4ea42973232..8ae337ca5d068b9d5ed59958511875d1bc8c471a 100644 (file)
--- a/src/arch/x86/boot/wakeup.S
+++ b/src/arch/x86/boot/wakeup.S
@@ -38,23 +38,12 @@ __wakeup:
        movw    %ax, (__wakeup_segment)
 
        /* Then overwrite coreboot with our backed up memory */
-       movl 8(%esp), %esi
-       movl 12(%esp), %edi
-       movl 16(%esp), %ecx
-       shrl    $4, %ecx
-1:
-       movl    0(%esi),%eax
-       movl    4(%esi),%edx
-       movl    8(%esi),%ebx
-       movl    12(%esi),%ebp
-       addl    $16,%esi
-       subl    $1,%ecx
-       movl    %eax,0(%edi)
-       movl    %edx,4(%edi)
-       movl    %ebx,8(%edi)
-       movl    %ebp,12(%edi)
-       leal    16(%edi),%edi
-       jne     1b
+       cld
+       movl    8(%esp), %esi
+       movl    12(%esp), %edi
+       movl    16(%esp), %ecx
+       shrl    $2, %ecx
+       rep     movsl
 
        /* Activate the right segment descriptor real mode. */
        ljmp    $0x28, $RELOCATED(1f)