3 files changed, 15 insertions, 6 deletions
diff --git a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
index 61b7ddca4c..7b05cae641 100644
--- a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
+++ b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
@@ -1,7 +1,7 @@
 ## @file
 #  Sec Core for FSP
 #
-#  Copyright (c) 2016 - 2019, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2016 - 2021, Intel Corporation. All rights reserved.<BR>
 #
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
@@ -59,6 +59,7 @@
   gIntelFsp2PkgTokenSpaceGuid.PcdFspTemporaryRamSize           ## CONSUMES
   gIntelFsp2PkgTokenSpaceGuid.PcdFspHeapSizePercentage         ## CONSUMES
   gIntelFsp2PkgTokenSpaceGuid.PcdFspMaxInterruptSupported      ## CONSUMES
+  gIntelFsp2PkgTokenSpaceGuid.PcdFspPrivateTemporaryRamSize    ## CONSUMES
 
 [Ppis]
   gEfiTemporaryRamSupportPpiGuid                              ## PRODUCES
diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.c b/IntelFsp2Pkg/FspSecCore/SecMain.c
index c8de52e1d5..540571187a 100644
--- a/IntelFsp2Pkg/FspSecCore/SecMain.c
+++ b/IntelFsp2Pkg/FspSecCore/SecMain.c
@@ -1,6 +1,6 @@
 /** @file
 
-  Copyright (c) 2014 - 2020, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2014 - 2021, Intel Corporation. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -150,15 +150,18 @@ SecStartup (
   SecCoreData.BootFirmwareVolumeBase = BootFirmwareVolume;
   SecCoreData.BootFirmwareVolumeSize = (UINT32)((EFI_FIRMWARE_VOLUME_HEADER *)BootFirmwareVolume)->FvLength;
 
-  SecCoreData.TemporaryRamBase       = (VOID*)(UINTN) TempRamBase;
+  //
+  // Support FSP reserved temporary memory from the whole temporary memory provided by bootloader.
+  // FSP reserved temporary memory will not be given to PeiCore.
+  //
+  SecCoreData.TemporaryRamBase       = (UINT8 *)(UINTN) TempRamBase  + PcdGet32 (PcdFspPrivateTemporaryRamSize);
+  SecCoreData.TemporaryRamSize       = SizeOfRam - PcdGet32 (PcdFspPrivateTemporaryRamSize);
   if (PcdGet8 (PcdFspHeapSizePercentage) == 0) {
-    SecCoreData.TemporaryRamSize       = SizeOfRam; // stack size that is going to be copied to the permanent memory
     SecCoreData.PeiTemporaryRamBase    = SecCoreData.TemporaryRamBase;
     SecCoreData.PeiTemporaryRamSize    = SecCoreData.TemporaryRamSize;
     SecCoreData.StackBase              = (VOID *)GetFspEntryStack(); // Share the same boot loader stack
     SecCoreData.StackSize              = 0;
   } else {
-    SecCoreData.TemporaryRamSize       = SizeOfRam;
     SecCoreData.PeiTemporaryRamBase    = SecCoreData.TemporaryRamBase;
     SecCoreData.PeiTemporaryRamSize    = SecCoreData.TemporaryRamSize * PcdGet8 (PcdFspHeapSizePercentage) / 100;
     SecCoreData.StackBase              = (VOID*)(UINTN)((UINTN)SecCoreData.TemporaryRamBase + SecCoreData.PeiTemporaryRamSize);
diff --git a/IntelFsp2Pkg/IntelFsp2Pkg.dec b/IntelFsp2Pkg/IntelFsp2Pkg.dec
index 60d40ab6b9..ec7b9a7702 100644
--- a/IntelFsp2Pkg/IntelFsp2Pkg.dec
+++ b/IntelFsp2Pkg/IntelFsp2Pkg.dec
@@ -1,7 +1,7 @@
 ## @file
 # Provides driver and definitions to build fsp in EDKII bios.
 #
-# Copyright (c) 2014 - 2019, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2014 - 2021, Intel Corporation. All rights reserved.<BR>
 # SPDX-License-Identifier: BSD-2-Clause-Patent
 #
 ##
@@ -98,6 +98,11 @@
   # Maximal Interrupt supported in IDT table.
   #
   gIntelFsp2PkgTokenSpaceGuid.PcdFspMaxInterruptSupported |        34| UINT8|0x10000005
+  #
+  # Allows FSP-M to reserve a section of Temporary RAM for implementation specific use.
+  # Reduces the amount of memory available for the PeiCore heap.
+  #
+  gIntelFsp2PkgTokenSpaceGuid.PcdFspPrivateTemporaryRamSize |0x00000000|UINT32|0x10000006
 
 [PcdsFixedAtBuild,PcdsDynamic,PcdsDynamicEx]
   gIntelFsp2PkgTokenSpaceGuid.PcdFspReservedMemoryLength |0x00100000|UINT32|0x46530000