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authorHimanshu Sahdev aka CunningLearner <sahdev.himan@gmail.com>2019-09-08 12:29:27 +0530
committerPatrick Georgi <pgeorgi@google.com>2019-09-13 09:59:17 +0000
commit2b84008ed9a5d14b519834d6d85c4955fa326684 (patch)
tree07876b00b84a80db6911a127a710838a2eba49a2
parent7f50afb0c79fc041a8533586172cae53284d3c9b (diff)
downloadcoreboot-2b84008ed9a5d14b519834d6d85c4955fa326684.tar.xz
arch/x86/bootblock_crt0.S: Leverage eax in protected mode entry
Leverage already used eax register in bootblock_protected_mode_entry. Avoid another register ebx just for preserving eax value as it is not needed and is not used at all after moving the value into mm0. Allow EBX to be preserved for other usage. Change-Id: Ia668b78f2f97cf026692f1fe63ff8a382a162474 Signed-off-by: Himanshu Sahdev <himanshusah@hcl.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/35292 Reviewed-by: Arthur Heymans <arthur@aheymans.xyz> Reviewed-by: Aaron Durbin <adurbin@chromium.org> Reviewed-by: Furquan Shaikh <furquan@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
-rw-r--r--src/arch/x86/bootblock_crt0.S3
1 files changed, 1 insertions, 2 deletions
diff --git a/src/arch/x86/bootblock_crt0.S b/src/arch/x86/bootblock_crt0.S
index c07363d856..3cb57e058c 100644
--- a/src/arch/x86/bootblock_crt0.S
+++ b/src/arch/x86/bootblock_crt0.S
@@ -47,11 +47,10 @@ bootblock_protected_mode_entry:
/* MMX registers required here */
/* BIST result in eax */
- movl %eax, %ebx
+ movd %eax, %mm0
/* Get an early timestamp */
rdtsc
- movd %ebx, %mm0
movd %eax, %mm1
movd %edx, %mm2
#endif