Patrick Georgi has submitted this change. ( https://review.coreboot.org/c/coreboot/+/35292 )
Change subject: arch/x86/bootblock_crt0.S: Leverage eax in protected mode entry ......................................................................
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 --- M src/arch/x86/bootblock_crt0.S 1 file changed, 1 insertion(+), 2 deletions(-)
Approvals: build bot (Jenkins): Verified Aaron Durbin: Looks good to me, approved Furquan Shaikh: Looks good to me, approved Arthur Heymans: Looks good to me, but someone else must approve
diff --git a/src/arch/x86/bootblock_crt0.S b/src/arch/x86/bootblock_crt0.S index c07363d..3cb57e0 100644 --- a/src/arch/x86/bootblock_crt0.S +++ b/src/arch/x86/bootblock_crt0.S @@ -47,11 +47,10 @@ /* 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