2 files changed, 19 insertions, 2 deletions
diff --git a/IntelFsp2Pkg/FspSecCore/Ia32/FspApiEntryT.nasm b/IntelFsp2Pkg/FspSecCore/Ia32/FspApiEntryT.nasm
index 088bd7ee7f..90de12f9af 100644
--- a/IntelFsp2Pkg/FspSecCore/Ia32/FspApiEntryT.nasm
+++ b/IntelFsp2Pkg/FspSecCore/Ia32/FspApiEntryT.nasm
@@ -185,6 +185,16 @@ endstruc
 global ASM_PFX(LoadUpdPointerToECX)
 ASM_PFX(LoadUpdPointerToECX):
   ;
+  ; Inputs:
+  ;   esp -> stack with FsptUpdDataPtr parameter
+  ; Outputs:
+  ;   eax -> Address of FspInfoHeader
+  ;   ecx -> Address of FSP-T UPD structure
+  ; Register Usage:
+  ;   ebp is used for return address.
+  ;   All others reserved.
+  ;
+
   ; esp + 4 is input UPD parameter
   ; If esp + 4 is NULL the default UPD should be used
   ; ecx will be the UPD region that should be used
@@ -600,6 +610,7 @@ ASM_PFX(TempRamInitApi):
   SAVE_EDX
 
   CALL_EBP  ASM_PFX(LoadUpdPointerToECX) ; ECX for UPD param
+  mov       esi, eax                     ; eax contains FspInfoHeader address after previous call
   SAVE_ECX                               ; save UPD param to slot 3 in xmm6
 
   mov       edx, ASM_PFX(PcdGet32 (PcdTemporaryRamSize))
diff --git a/IntelFsp2Pkg/FspSecCore/X64/FspApiEntryT.nasm b/IntelFsp2Pkg/FspSecCore/X64/FspApiEntryT.nasm
index 3e7a6400a2..d50b3317c9 100644
--- a/IntelFsp2Pkg/FspSecCore/X64/FspApiEntryT.nasm
+++ b/IntelFsp2Pkg/FspSecCore/X64/FspApiEntryT.nasm
@@ -451,19 +451,25 @@ ASM_PFX(TempRamInitApi):
   ;
   ; Save Input Parameter in YMM10
   ;
+  SAVE_RCX
+  ;
+  ; Get FspInfoHeader address
+  ;
+  CALL_RDI  ASM_PFX(AsmGetFspInfoHeaderNoStack)
+  mov       rsi, rax
+  LOAD_RCX
   cmp       rcx, 0
   jnz       ParamValid
 
   ;
   ; Fall back to default UPD
   ;
-  CALL_RDI  ASM_PFX(AsmGetFspInfoHeaderNoStack)
   xor       rcx, rcx
   mov       ecx,  DWORD [rax + 01Ch]      ; Read FsptImageBaseAddress
   add       ecx,  DWORD [rax + 024h]      ; Get Cfg Region base address = FsptImageBaseAddress + CfgRegionOffset
-ParamValid:
   SAVE_RCX
 
+ParamValid:
   mov       rdx, ASM_PFX(PcdGet32 (PcdTemporaryRamSize))
   mov       edx, DWORD [rdx]
   ;