REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4395
FSP specification defines the TempRamInit API preserved register list
which including EBX/RBX, however current implementation unexpectedly
overriding EBX/RBX register that should be fixed.
Cc: Nate DeSimone <nathaniel.l.desim...@intel.com>
Cc: Star Zeng <star.z...@intel.com>
Signed-off-by: Chasel Chiu <chasel.c...@intel.com>
---
IntelFsp2Pkg/FspSecCore/Ia32/SaveRestoreSseNasm.inc | 7 +++++++
IntelFsp2Pkg/Include/SaveRestoreSseAvxNasm.inc | 21 ++++++++++++++++++++-
2 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/IntelFsp2Pkg/FspSecCore/Ia32/SaveRestoreSseNasm.inc
b/IntelFsp2Pkg/FspSecCore/Ia32/SaveRestoreSseNasm.inc
index a222f2e376..016f943b43 100644
--- a/IntelFsp2Pkg/FspSecCore/Ia32/SaveRestoreSseNasm.inc
+++ b/IntelFsp2Pkg/FspSecCore/Ia32/SaveRestoreSseNasm.inc
@@ -157,6 +157,9 @@ NextAddress:
; Use CpuId instruction (CPUID.01H:EDX.SSE[bit 25] = 1) to test
; whether the processor supports SSE instruction.
;
+ ; Save EBX to MM2
+ ;
+ movd mm2, ebx
mov eax, 1
cpuid
bt edx, 25
@@ -169,6 +172,10 @@ NextAddress:
bt ecx, 19
jnc SseError
%endif
+ ;
+ ; Restore EBX from MM2
+ ;
+ movd ebx, mm2
;
; Set OSFXSR bit (bit #9) & OSXMMEXCPT bit (bit #10)
diff --git a/IntelFsp2Pkg/Include/SaveRestoreSseAvxNasm.inc
b/IntelFsp2Pkg/Include/SaveRestoreSseAvxNasm.inc
index 38c807a311..002a5a1412 100644
--- a/IntelFsp2Pkg/Include/SaveRestoreSseAvxNasm.inc
+++ b/IntelFsp2Pkg/Include/SaveRestoreSseAvxNasm.inc
@@ -255,6 +255,10 @@ NextAddress:
; Use CpuId instruction (CPUID.01H:EDX.SSE[bit 25] = 1) to test
; whether the processor supports SSE instruction.
;
+ ; Save RBX to R11
+ ; Save RCX to R10
+ ;
+ mov r11, rbx
mov r10, rcx
mov rax, 1
cpuid
@@ -266,7 +270,12 @@ NextAddress:
;
bt ecx, 19
jnc SseError
- mov rcx, r10
+ ;
+ ; Restore RBX from R11
+ ; Restore RCX from R10
+ ;
+ mov rbx, r11
+ mov rcx, r10
;
; Set OSFXSR bit (bit #9) & OSXMMEXCPT bit (bit #10)
@@ -284,6 +293,11 @@ NextAddress:
%endmacro
%macro ENABLE_AVX 0
+ ;
+ ; Save RBX to R11
+ ; Save RCX to R10
+ ;
+ mov r11, rbx
mov r10, rcx
mov eax, 1
cpuid
@@ -307,6 +321,11 @@ EnableAvx:
xgetbv ; result in edx:eax
or eax, 00000006h ; Set XCR0 bit #1 and bit #2 to enable SSE
state and AVX state
xsetbv
+ ;
+ ; Restore RBX from R11
+ ; Restore RCX from R10
+ ;
+ mov rbx, r11
mov rcx, r10
%endmacro
--
2.35.0.windows.1
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