Re: [edk2] [PATCH v2] IntelFsp2Pkg: FSP should not override IDT

2018-10-25 Thread Yao, Jiewen 
Reviewed-by: jiewen@intel.com

> -Original Message-
> From: Chiu, Chasel
> Sent: Tuesday, October 23, 2018 5:34 PM
> To: edk2-devel@lists.01.org
> Cc: Yao, Jiewen ; Desimone, Nathaniel L
> ; Chiu, Chasel 
> Subject: [PATCH v2] IntelFsp2Pkg: FSP should not override IDT
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1265
> 
> FSP should not override IDT table when it is initialized
> by boot loader. IDT should be re-initialized in FSP only
> when it is invalid.
> To mitigate temporary memory usage a PCD
> PcdFspMaxInterruptSupported created for platform to decide
> how many interrupts the FSP IDT table can support.
> 
> Test: Verified on internal platform and boots successfully.
> 
> Cc: Jiewen Yao 
> Cc: Desimone Nathaniel L 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Chasel Chiu 
> ---
>  IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf |  1 +
>  IntelFsp2Pkg/FspSecCore/SecMain.c   | 24
> +++-
>  IntelFsp2Pkg/FspSecCore/SecMain.h   |  6 ++
>  IntelFsp2Pkg/IntelFsp2Pkg.dec   |  4 
>  4 files changed, 26 insertions(+), 9 deletions(-)
> 
> diff --git a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> index c61af10b8a..dafe6f5993 100644
> --- a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> +++ b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> @@ -62,6 +62,7 @@
>gIntelFsp2PkgTokenSpaceGuid.PcdTemporaryRamSize  ##
> CONSUMES
>gIntelFsp2PkgTokenSpaceGuid.PcdFspTemporaryRamSize   ##
> CONSUMES
>gIntelFsp2PkgTokenSpaceGuid.PcdFspHeapSizePercentage ##
> CONSUMES
> +  gIntelFsp2PkgTokenSpaceGuid.PcdFspMaxInterruptSupported  ##
> CONSUMES
> 
>  [Ppis]
>gEfiTemporaryRamSupportPpiGuid
> ## PRODUCES
> diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.c
> b/IntelFsp2Pkg/FspSecCore/SecMain.c
> index 37fd4dfdeb..ddbfc4fcdf 100644
> --- a/IntelFsp2Pkg/FspSecCore/SecMain.c
> +++ b/IntelFsp2Pkg/FspSecCore/SecMain.c
> @@ -70,6 +70,7 @@ SecStartup (
>UINT32  Index;
>FSP_GLOBAL_DATA PeiFspData;
>UINT64  ExceptionHandler;
> +  UINTN   IdtSize;
> 
>//
>// Process all libraries constructor function linked to SecCore.
> @@ -98,13 +99,26 @@ SecStartup (
>// |   |
>// |---|>  TempRamBase
>IdtTableInStack.PeiService  = NULL;
> -  ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
> -  for (Index = 0; Index < SEC_IDT_ENTRY_COUNT; Index ++) {
> -CopyMem ((VOID*)[Index],
> (VOID*), sizeof (UINT64));
> +  AsmReadIdtr ();
> +  if ((IdtDescriptor.Base == 0) && (IdtDescriptor.Limit == 0x)) {
> +ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
> +for (Index = 0; Index < FixedPcdGet8(PcdFspMaxInterruptSupported);
> Index ++) {
> +  CopyMem ((VOID*)[Index],
> (VOID*), sizeof (UINT64));
> +}
> +IdtSize = sizeof (IdtTableInStack.IdtTable);
> +  } else {
> +if (IdtDescriptor.Limit + 1 > sizeof (IdtTableInStack.IdtTable)) {
> +  //
> +  // ERROR: IDT table size from boot loader is larger than FSP can
> support, DeadLoop here!
> +  //
> +  CpuDeadLoop();
> +} else {
> +  IdtSize = IdtDescriptor.Limit + 1;
> +}
> +CopyMem ((VOID *) (UINTN) , (VOID *)
> IdtDescriptor.Base, IdtSize);
>}
> -
>IdtDescriptor.Base  = (UINTN) 
> -  IdtDescriptor.Limit = (UINT16)(sizeof (IdtTableInStack.IdtTable) - 1);
> +  IdtDescriptor.Limit = (UINT16)(IdtSize - 1);
> 
>AsmWriteIdtr ();
> 
> diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.h
> b/IntelFsp2Pkg/FspSecCore/SecMain.h
> index 291bc5ca5c..19ac2fbfc1 100644
> --- a/IntelFsp2Pkg/FspSecCore/SecMain.h
> +++ b/IntelFsp2Pkg/FspSecCore/SecMain.h
> @@ -1,6 +1,6 @@
>  /** @file
> 
> -  Copyright (c) 2014 - 2016, Intel Corporation. All rights reserved.
> +  Copyright (c) 2014 - 2018, Intel Corporation. All rights reserved.
>This program and the accompanying materials
>are licensed and made available under the terms and conditions of the
> BSD License
>which accompanies this distribution.  The full text of the license may be
> found at
> @@ -29,8 +29,6 @@
>  #include 
>  #include 
> 
> -#define SEC_IDT_ENTRY_COUNT34
> -
>  typedef VOID (*PEI_CORE_ENTRY) ( \
>IN CONST  EFI_SEC_PEI_HAND_OFF*SecCoreData, \
>IN CONST  EFI_PEI_PPI_DESCRIPTOR  *PpiList \
> @@ -38,7 +36,7 @@ typedef VOID (*PEI_CORE_ENTRY) ( \
> 
>  typedef struct _SEC_IDT_TABLE {
>EFI_PEI_SERVICES  *PeiService;
> -  UINT64IdtTable[SEC_IDT_ENTRY_COUNT];
> +  UINT64IdtTable[FixedPcdGet8
> (PcdFspMaxInterruptSupported)];
>  } SEC_IDT_TABLE;
> 
>  /**
> diff --git a/IntelFsp2Pkg/IntelFsp2Pkg.dec b/IntelFsp2Pkg/IntelFsp2Pkg.dec
> index 5b037d65e2..50496241da 100644
> --- a/IntelFsp2Pkg/IntelFsp2Pkg.dec
> +++ b/IntelFsp2Pkg/IntelFsp2Pkg.dec
> @@ -86,6 +86,10 @@
># x % of FSP temporary memory will be used for heap
># (100

Re: [edk2] [PATCH v2] IntelFsp2Pkg: FSP should not override IDT

2018-10-23 Thread Chiu, Chasel 
Hello,

Please see my reply below inline.

Thanks!
Chasel


-Original Message-
From: af...@apple.com [mailto:af...@apple.com] 
Sent: Tuesday, October 23, 2018 6:29 PM
To: Chiu, Chasel 
Cc: edk2-devel@lists.01.org; Yao, Jiewen 
Subject: Re: [edk2] [PATCH v2] IntelFsp2Pkg: FSP should not override IDT



> On Oct 23, 2018, at 2:33 AM, Chasel, Chiu  wrote:
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1265
> 
> FSP should not override IDT table when it is initialized by boot 
> loader. IDT should be re-initialized in FSP only when it is invalid.
> To mitigate temporary memory usage a PCD PcdFspMaxInterruptSupported 
> created for platform to decide how many interrupts the FSP IDT table 
> can support.
> 
> Test: Verified on internal platform and boots successfully.
> 
> Cc: Jiewen Yao 
> Cc: Desimone Nathaniel L 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Chasel Chiu 
> ---
> IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf |  1 +
> IntelFsp2Pkg/FspSecCore/SecMain.c   | 24 +++-
> IntelFsp2Pkg/FspSecCore/SecMain.h   |  6 ++
> IntelFsp2Pkg/IntelFsp2Pkg.dec   |  4 
> 4 files changed, 26 insertions(+), 9 deletions(-)
> 
> diff --git a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf 
> b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> index c61af10b8a..dafe6f5993 100644
> --- a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> +++ b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> @@ -62,6 +62,7 @@
>   gIntelFsp2PkgTokenSpaceGuid.PcdTemporaryRamSize  ## CONSUMES
>   gIntelFsp2PkgTokenSpaceGuid.PcdFspTemporaryRamSize   ## CONSUMES
>   gIntelFsp2PkgTokenSpaceGuid.PcdFspHeapSizePercentage ## CONSUMES
> +  gIntelFsp2PkgTokenSpaceGuid.PcdFspMaxInterruptSupported  ## CONSUMES
> 
> [Ppis]
>   gEfiTemporaryRamSupportPpiGuid  ## PRODUCES
> diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.c 
> b/IntelFsp2Pkg/FspSecCore/SecMain.c
> index 37fd4dfdeb..ddbfc4fcdf 100644
> --- a/IntelFsp2Pkg/FspSecCore/SecMain.c
> +++ b/IntelFsp2Pkg/FspSecCore/SecMain.c
> @@ -70,6 +70,7 @@ SecStartup (
>   UINT32  Index;
>   FSP_GLOBAL_DATA PeiFspData;
>   UINT64  ExceptionHandler;
> +  UINTN   IdtSize;
> 
>   //
>   // Process all libraries constructor function linked to SecCore.
> @@ -98,13 +99,26 @@ SecStartup (
>   // |   |
>   // |---|>  TempRamBase
>   IdtTableInStack.PeiService  = NULL;
> -  ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
> -  for (Index = 0; Index < SEC_IDT_ENTRY_COUNT; Index ++) {
> -CopyMem ((VOID*)[Index], 
> (VOID*), sizeof (UINT64));
> +  AsmReadIdtr ();
> +  if ((IdtDescriptor.Base == 0) && (IdtDescriptor.Limit == 0x)) {

Are these architectural value at reset?

Thanks,

Andrew Fish

Chasel: Yes, these are default values from reset.

> +ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
> +for (Index = 0; Index < FixedPcdGet8(PcdFspMaxInterruptSupported); Index 
> ++) {
> +  CopyMem ((VOID*)[Index], 
> (VOID*), sizeof (UINT64));
> +}
> +IdtSize = sizeof (IdtTableInStack.IdtTable);  } else {
> +if (IdtDescriptor.Limit + 1 > sizeof (IdtTableInStack.IdtTable)) {
> +  //
> +  // ERROR: IDT table size from boot loader is larger than FSP can 
> support, DeadLoop here!
> +  //
> +  CpuDeadLoop();
> +} else {
> +  IdtSize = IdtDescriptor.Limit + 1;
> +}
> +CopyMem ((VOID *) (UINTN) , (VOID *) 
> + IdtDescriptor.Base, IdtSize);
>   }
> -
>   IdtDescriptor.Base  = (UINTN) 
> -  IdtDescriptor.Limit = (UINT16)(sizeof (IdtTableInStack.IdtTable) - 
> 1);
> +  IdtDescriptor.Limit = (UINT16)(IdtSize - 1);
> 
>   AsmWriteIdtr ();
> 
> diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.h 
> b/IntelFsp2Pkg/FspSecCore/SecMain.h
> index 291bc5ca5c..19ac2fbfc1 100644
> --- a/IntelFsp2Pkg/FspSecCore/SecMain.h
> +++ b/IntelFsp2Pkg/FspSecCore/SecMain.h
> @@ -1,6 +1,6 @@
> /** @file
> 
> -  Copyright (c) 2014 - 2016, Intel Corporation. All rights 
> reserved.
> +  Copyright (c) 2014 - 2018, Intel Corporation. All rights 
> + reserved.
>   This program and the accompanying materials
>   are licensed and made available under the terms and conditions of the BSD 
> License
>   which accompanies this distribution.  The full text of the license 
> may be found at @@ -29,8 +29,6 @@ #include  
> #include 
> 
> -#define SEC_IDT_ENTRY_COUNT34
> -
> typedef VOID (*PEI_CORE_ENTRY) ( \
>   IN CONST  EFI_SEC_PEI_HAND_OFF*SecCoreData, \
>   IN CONST  EFI_PEI_PPI_DESCRIPTOR  *PpiList \ @@ -38,7 +36,7 @

Re: [edk2] [PATCH v2] IntelFsp2Pkg: FSP should not override IDT

2018-10-23 Thread Andrew Fish 



> On Oct 23, 2018, at 2:33 AM, Chasel, Chiu  wrote:
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1265
> 
> FSP should not override IDT table when it is initialized
> by boot loader. IDT should be re-initialized in FSP only
> when it is invalid.
> To mitigate temporary memory usage a PCD
> PcdFspMaxInterruptSupported created for platform to decide
> how many interrupts the FSP IDT table can support.
> 
> Test: Verified on internal platform and boots successfully.
> 
> Cc: Jiewen Yao 
> Cc: Desimone Nathaniel L 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Chasel Chiu 
> ---
> IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf |  1 +
> IntelFsp2Pkg/FspSecCore/SecMain.c   | 24 +++-
> IntelFsp2Pkg/FspSecCore/SecMain.h   |  6 ++
> IntelFsp2Pkg/IntelFsp2Pkg.dec   |  4 
> 4 files changed, 26 insertions(+), 9 deletions(-)
> 
> diff --git a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf 
> b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> index c61af10b8a..dafe6f5993 100644
> --- a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> +++ b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
> @@ -62,6 +62,7 @@
>   gIntelFsp2PkgTokenSpaceGuid.PcdTemporaryRamSize  ## CONSUMES
>   gIntelFsp2PkgTokenSpaceGuid.PcdFspTemporaryRamSize   ## CONSUMES
>   gIntelFsp2PkgTokenSpaceGuid.PcdFspHeapSizePercentage ## CONSUMES
> +  gIntelFsp2PkgTokenSpaceGuid.PcdFspMaxInterruptSupported  ## CONSUMES
> 
> [Ppis]
>   gEfiTemporaryRamSupportPpiGuid  ## PRODUCES
> diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.c 
> b/IntelFsp2Pkg/FspSecCore/SecMain.c
> index 37fd4dfdeb..ddbfc4fcdf 100644
> --- a/IntelFsp2Pkg/FspSecCore/SecMain.c
> +++ b/IntelFsp2Pkg/FspSecCore/SecMain.c
> @@ -70,6 +70,7 @@ SecStartup (
>   UINT32  Index;
>   FSP_GLOBAL_DATA PeiFspData;
>   UINT64  ExceptionHandler;
> +  UINTN   IdtSize;
> 
>   //
>   // Process all libraries constructor function linked to SecCore.
> @@ -98,13 +99,26 @@ SecStartup (
>   // |   |
>   // |---|>  TempRamBase
>   IdtTableInStack.PeiService  = NULL;
> -  ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
> -  for (Index = 0; Index < SEC_IDT_ENTRY_COUNT; Index ++) {
> -CopyMem ((VOID*)[Index], 
> (VOID*), sizeof (UINT64));
> +  AsmReadIdtr ();
> +  if ((IdtDescriptor.Base == 0) && (IdtDescriptor.Limit == 0x)) {

Are these architectural value at reset?

Thanks,

Andrew Fish

> +ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
> +for (Index = 0; Index < FixedPcdGet8(PcdFspMaxInterruptSupported); Index 
> ++) {
> +  CopyMem ((VOID*)[Index], 
> (VOID*), sizeof (UINT64));
> +}
> +IdtSize = sizeof (IdtTableInStack.IdtTable);
> +  } else {
> +if (IdtDescriptor.Limit + 1 > sizeof (IdtTableInStack.IdtTable)) {
> +  //
> +  // ERROR: IDT table size from boot loader is larger than FSP can 
> support, DeadLoop here!
> +  //
> +  CpuDeadLoop();
> +} else {
> +  IdtSize = IdtDescriptor.Limit + 1;
> +}
> +CopyMem ((VOID *) (UINTN) , (VOID *) 
> IdtDescriptor.Base, IdtSize);
>   }
> -
>   IdtDescriptor.Base  = (UINTN) 
> -  IdtDescriptor.Limit = (UINT16)(sizeof (IdtTableInStack.IdtTable) - 1);
> +  IdtDescriptor.Limit = (UINT16)(IdtSize - 1);
> 
>   AsmWriteIdtr ();
> 
> diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.h 
> b/IntelFsp2Pkg/FspSecCore/SecMain.h
> index 291bc5ca5c..19ac2fbfc1 100644
> --- a/IntelFsp2Pkg/FspSecCore/SecMain.h
> +++ b/IntelFsp2Pkg/FspSecCore/SecMain.h
> @@ -1,6 +1,6 @@
> /** @file
> 
> -  Copyright (c) 2014 - 2016, Intel Corporation. All rights reserved.
> +  Copyright (c) 2014 - 2018, Intel Corporation. All rights reserved.
>   This program and the accompanying materials
>   are licensed and made available under the terms and conditions of the BSD 
> License
>   which accompanies this distribution.  The full text of the license may be 
> found at
> @@ -29,8 +29,6 @@
> #include 
> #include 
> 
> -#define SEC_IDT_ENTRY_COUNT34
> -
> typedef VOID (*PEI_CORE_ENTRY) ( \
>   IN CONST  EFI_SEC_PEI_HAND_OFF*SecCoreData, \
>   IN CONST  EFI_PEI_PPI_DESCRIPTOR  *PpiList \
> @@ -38,7 +36,7 @@ typedef VOID (*PEI_CORE_ENTRY) ( \
> 
> typedef struct _SEC_IDT_TABLE {
>   EFI_PEI_SERVICES  *PeiService;
> -  UINT64IdtTable[SEC_IDT_ENTRY_COUNT];
> +  UINT64IdtTable[FixedPcdGet8 (PcdFspMaxInterruptSupported)];
> } SEC_IDT_TABLE;
> 
> /**
> diff --git a/IntelFsp2Pkg/IntelFsp2Pkg.dec b/IntelFsp2Pkg/IntelFsp2Pkg.dec
> index 5b037d65e2..50496241da 100644
> --- a/IntelFsp2Pkg/IntelFsp2Pkg.dec
> +++ b/IntelFsp2Pkg/IntelFsp2Pkg.dec
> @@ -86,6 +86,10 @@
>   # x % of FSP temporary memory will be used for heap
>   # (100 - x) % of FSP temporary memory will be used for stack
>   gIntelFsp2PkgTokenSpaceGuid.PcdFspHeapSizePercentage|50| 
> UINT8|0x1004
> +  #
> +  # Maximal

[edk2] [PATCH v2] IntelFsp2Pkg: FSP should not override IDT

2018-10-23 Thread Chasel, Chiu 
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1265

FSP should not override IDT table when it is initialized
by boot loader. IDT should be re-initialized in FSP only
when it is invalid.
To mitigate temporary memory usage a PCD
PcdFspMaxInterruptSupported created for platform to decide
how many interrupts the FSP IDT table can support.

Test: Verified on internal platform and boots successfully.

Cc: Jiewen Yao 
Cc: Desimone Nathaniel L 
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Chasel Chiu 
---
 IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf |  1 +
 IntelFsp2Pkg/FspSecCore/SecMain.c   | 24 +++-
 IntelFsp2Pkg/FspSecCore/SecMain.h   |  6 ++
 IntelFsp2Pkg/IntelFsp2Pkg.dec   |  4 
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf 
b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
index c61af10b8a..dafe6f5993 100644
--- a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
+++ b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
@@ -62,6 +62,7 @@
   gIntelFsp2PkgTokenSpaceGuid.PcdTemporaryRamSize  ## CONSUMES
   gIntelFsp2PkgTokenSpaceGuid.PcdFspTemporaryRamSize   ## CONSUMES
   gIntelFsp2PkgTokenSpaceGuid.PcdFspHeapSizePercentage ## CONSUMES
+  gIntelFsp2PkgTokenSpaceGuid.PcdFspMaxInterruptSupported  ## CONSUMES
 
 [Ppis]
   gEfiTemporaryRamSupportPpiGuid  ## PRODUCES
diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.c 
b/IntelFsp2Pkg/FspSecCore/SecMain.c
index 37fd4dfdeb..ddbfc4fcdf 100644
--- a/IntelFsp2Pkg/FspSecCore/SecMain.c
+++ b/IntelFsp2Pkg/FspSecCore/SecMain.c
@@ -70,6 +70,7 @@ SecStartup (
   UINT32  Index;
   FSP_GLOBAL_DATA PeiFspData;
   UINT64  ExceptionHandler;
+  UINTN   IdtSize;
 
   //
   // Process all libraries constructor function linked to SecCore.
@@ -98,13 +99,26 @@ SecStartup (
   // |   |
   // |---|>  TempRamBase
   IdtTableInStack.PeiService  = NULL;
-  ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
-  for (Index = 0; Index < SEC_IDT_ENTRY_COUNT; Index ++) {
-CopyMem ((VOID*)[Index], 
(VOID*), sizeof (UINT64));
+  AsmReadIdtr ();
+  if ((IdtDescriptor.Base == 0) && (IdtDescriptor.Limit == 0x)) {
+ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
+for (Index = 0; Index < FixedPcdGet8(PcdFspMaxInterruptSupported); Index 
++) {
+  CopyMem ((VOID*)[Index], 
(VOID*), sizeof (UINT64));
+}
+IdtSize = sizeof (IdtTableInStack.IdtTable);
+  } else {
+if (IdtDescriptor.Limit + 1 > sizeof (IdtTableInStack.IdtTable)) {
+  //
+  // ERROR: IDT table size from boot loader is larger than FSP can 
support, DeadLoop here!
+  //
+  CpuDeadLoop();
+} else {
+  IdtSize = IdtDescriptor.Limit + 1;
+}
+CopyMem ((VOID *) (UINTN) , (VOID *) 
IdtDescriptor.Base, IdtSize);
   }
-
   IdtDescriptor.Base  = (UINTN) 
-  IdtDescriptor.Limit = (UINT16)(sizeof (IdtTableInStack.IdtTable) - 1);
+  IdtDescriptor.Limit = (UINT16)(IdtSize - 1);
 
   AsmWriteIdtr ();
 
diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.h 
b/IntelFsp2Pkg/FspSecCore/SecMain.h
index 291bc5ca5c..19ac2fbfc1 100644
--- a/IntelFsp2Pkg/FspSecCore/SecMain.h
+++ b/IntelFsp2Pkg/FspSecCore/SecMain.h
@@ -1,6 +1,6 @@
 /** @file
 
-  Copyright (c) 2014 - 2016, Intel Corporation. All rights reserved.
+  Copyright (c) 2014 - 2018, Intel Corporation. All rights reserved.
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD 
License
   which accompanies this distribution.  The full text of the license may be 
found at
@@ -29,8 +29,6 @@
 #include 
 #include 
 
-#define SEC_IDT_ENTRY_COUNT34
-
 typedef VOID (*PEI_CORE_ENTRY) ( \
   IN CONST  EFI_SEC_PEI_HAND_OFF*SecCoreData, \
   IN CONST  EFI_PEI_PPI_DESCRIPTOR  *PpiList \
@@ -38,7 +36,7 @@ typedef VOID (*PEI_CORE_ENTRY) ( \
 
 typedef struct _SEC_IDT_TABLE {
   EFI_PEI_SERVICES  *PeiService;
-  UINT64IdtTable[SEC_IDT_ENTRY_COUNT];
+  UINT64IdtTable[FixedPcdGet8 (PcdFspMaxInterruptSupported)];
 } SEC_IDT_TABLE;
 
 /**
diff --git a/IntelFsp2Pkg/IntelFsp2Pkg.dec b/IntelFsp2Pkg/IntelFsp2Pkg.dec
index 5b037d65e2..50496241da 100644
--- a/IntelFsp2Pkg/IntelFsp2Pkg.dec
+++ b/IntelFsp2Pkg/IntelFsp2Pkg.dec
@@ -86,6 +86,10 @@
   # x % of FSP temporary memory will be used for heap
   # (100 - x) % of FSP temporary memory will be used for stack
   gIntelFsp2PkgTokenSpaceGuid.PcdFspHeapSizePercentage|50| 
UINT8|0x1004
+  #
+  # Maximal Interrupt supported in IDT table.
+  #
+  gIntelFsp2PkgTokenSpaceGuid.PcdFspMaxInterruptSupported |34| 
UINT8|0x1005
 
 [PcdsFixedAtBuild,PcdsDynamic,PcdsDynamicEx]
   gIntelFsp2PkgTokenSpaceGuid.PcdFspReservedMemoryLength 
|0x0010|UINT32|0x4653
-- 
2.13.3.windows.1

___