[Patch 2/3] [edk2-platform] Platform/Intel: Add Cmos related modules to BoardModulePkg

["Dong, Eric" <eric.dong@intel.com>]

Add Cmos related libraries to BoardModulePkg. Totally two
library have been added, one is CmosAccessLib and the other
is PlatformCmosAccessLib. PlatformCmosAccessLib will be used
by CmosAccessLib.

These two libraries provide the generic operations for CMOS
access.

APIs exports by PlatformCmosAccessLib include:
  PlatformCmosGetEntry
  PlatformCmosGetNmiState

APIs exports by CmosAccessLib include:
  CmosRead8
  CmosWrite8
  CmosRead16
  CmosWrite16
  CmosRead32
  CmosWrite32
  CmosInit

Sign-off-by: Eric Dong <eric.dong@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael Kubacki <michael.a.kubacki@intel.com>
Cc: Sai Chaganty <rangasai.v.chaganty@intel.com>
Cc: Oram, Isaac W <isaac.w.oram@intel.com>
Signed-off-by: Eric Dong <eric.dong@intel.com>
---
 .../Intel/BoardModulePkg/BoardModulePkg.dec   |   8 +-
 .../Include/Library/CmosAccessLib.h           | 106 ++++
 .../Include/Library/PlatformCmosAccessLib.h   |  68 +++
 .../Library/CmosAccessLib/CmosAccessLib.c     | 486 ++++++++++++++++++
 .../Library/CmosAccessLib/CmosAccessLib.inf   |  28 +
 .../CmosAccessLib/CmosAccessLibInternal.h     |  35 ++
 .../PlatformCmosAccessLibNull.c               |  39 ++
 .../PlatformCmosAccessLibNull.inf             |  23 +
 8 files changed, 792 insertions(+), 1 deletion(-)
 create mode 100644 Platform/Intel/BoardModulePkg/Include/Library/CmosAccessLib.h
 create mode 100644 Platform/Intel/BoardModulePkg/Include/Library/PlatformCmosAccessLib.h
 create mode 100644 Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLib.c
 create mode 100644 Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLib.inf
 create mode 100644 Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLibInternal.h
 create mode 100644 Platform/Intel/BoardModulePkg/Library/PlatformCmosAccessLibNull/PlatformCmosAccessLibNull.c
 create mode 100644 Platform/Intel/BoardModulePkg/Library/PlatformCmosAccessLibNull/PlatformCmosAccessLibNull.inf

diff --git a/Platform/Intel/BoardModulePkg/BoardModulePkg.dec b/Platform/Intel/BoardModulePkg/BoardModulePkg.dec
index 94de8989c4..6b41d65aee 100644
--- a/Platform/Intel/BoardModulePkg/BoardModulePkg.dec
+++ b/Platform/Intel/BoardModulePkg/BoardModulePkg.dec
@@ -21,6 +21,12 @@
 
 
 [Includes]
-
+  Include
 
 [LibraryClasses]
+  ##  @libraryclass    Provide services to access CMOS area.
+  CmosAccessLib|Include/Library/CmosAccessLib.h
+
+  ##  @libraryclass    Provide platform relevant services to access CMOS area.
+  PlatformCmosAccessLib|Include/Library/PlatformCmosAccessLib.h
+
diff --git a/Platform/Intel/BoardModulePkg/Include/Library/CmosAccessLib.h b/Platform/Intel/BoardModulePkg/Include/Library/CmosAccessLib.h
new file mode 100644
index 0000000000..0bc08670ab
--- /dev/null
+++ b/Platform/Intel/BoardModulePkg/Include/Library/CmosAccessLib.h
@@ -0,0 +1,106 @@
+/** @file
+  CmosAccessLib header file.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _CMOS_ACCESS_LIB_H_
+#define _CMOS_ACCESS_LIB_H_
+
+/**
+  Read a byte value from a CMOS address.
+
+  @param [in] Address   Location to read from CMOS
+
+  @return The byte value read from the CMOS address.
+**/
+UINT8
+EFIAPI
+CmosRead8 (
+  IN  UINT8 Address
+  );
+
+/**
+  Write a byte value to a CMOS address.
+
+  @param [in] Address Location to write to CMOS.
+  @param [in] Data    The byte value write to the CMOS address.
+**/
+VOID
+EFIAPI
+CmosWrite8 (
+  IN UINT8 Address,
+  IN UINT8 Data
+  );
+
+/**
+  Read a word value from a CMOS address.
+
+  @param [in] Address   Location to read from CMOS
+
+  @return The word value read from the CMOS address.
+**/
+UINT16
+EFIAPI
+CmosRead16 (
+  IN  UINT8  Address
+  );
+
+/**
+  Write a word value to a CMOS address.
+
+  @param [in] Address Location to write to CMOS.
+  @param [in] Data    The word value write to the CMOS address.
+**/
+VOID
+EFIAPI
+CmosWrite16 (
+  IN UINT8  Address,
+  IN UINT16 Data
+  );
+
+/**
+  Read a dword value from a CMOS address.
+
+  @param [in] Address   Location to read from CMOS
+
+  @return The dword value read from the CMOS address.
+**/
+UINT32
+EFIAPI
+CmosRead32 (
+  IN  UINT8  Address
+  );
+
+/**
+  Write a dword value to a CMOS address.
+
+  @param [in] Address Location to write to CMOS.
+  @param [in] Data    The dword value write to the CMOS address.
+**/
+VOID
+EFIAPI
+CmosWrite32 (
+  IN UINT8  Address,
+  IN UINT32 Data
+  );
+
+/**
+  Initialize the CMOS.
+
+  It initialize the CMOS area when Force is TRUE or the checksum is incorrect.
+
+  @param[in]  Force  TRUE indicating initializing the CMOS area without checking the checksum.
+
+  @retval TRUE  The CMOS is initialized to default value.
+  @retval FALSE The CMOS isn't initialized to default value.
+**/
+BOOLEAN
+EFIAPI
+CmosInit (
+  IN  BOOLEAN     Force
+  );
+
+#endif // _CMOS_ACCESS_LIB_H_
diff --git a/Platform/Intel/BoardModulePkg/Include/Library/PlatformCmosAccessLib.h b/Platform/Intel/BoardModulePkg/Include/Library/PlatformCmosAccessLib.h
new file mode 100644
index 0000000000..337ff41847
--- /dev/null
+++ b/Platform/Intel/BoardModulePkg/Include/Library/PlatformCmosAccessLib.h
@@ -0,0 +1,68 @@
+/** @file
+  Platform CMOS Access Library Header File.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _PLATFORM_CMOS_ACCESS_LIB_H_
+#define _PLATFORM_CMOS_ACCESS_LIB_H_
+
+///
+/// Flag indicating checksum calculation doesn't include this location.
+/// NOTE: If a location isn't shown in platform CMOS entry table,
+///       it means checksum calculation doesn't include the location.
+///
+#define CMOS_EXCLUDE_FROM_CHECKSUM    BIT0
+
+///
+/// Flag indicating initialization doesn't cover this location.
+/// NOTE: If a location isn't shown in platform CMOS entry table,
+///       it means the location is initialized with CMOS_DEFAULT_VALUE (0).
+///
+#define CMOS_EXCLUDE_FROM_INIT_DATA   BIT1
+
+///
+/// Flag indicating the location cannot be accessed.
+/// NOTE: 0x0 ~ 0xD is implictly inaccessible.
+///
+#define CMOS_EXCLUDE_FROM_ACCESS      (BIT3 | CMOS_EXCLUDE_FROM_CHECKSUM | CMOS_EXCLUDE_FROM_INIT_DATA)
+
+///
+/// Flag indicating the checksum location
+/// NOTE: At most two entries can have this flag set.
+///
+#define CMOS_CHECKSUM_LOCATION        (BIT2 | CMOS_EXCLUDE_FROM_CHECKSUM | CMOS_EXCLUDE_FROM_INIT_DATA)
+
+#define CMOS_DEFAULT_VALUE            0x00
+
+typedef struct {
+  UINT8 Address;
+  UINT8 DefaultValue;
+  UINT8 Attributes;
+} CMOS_ENTRY;
+
+/**
+  Return the platform CMOS entries.
+
+  @param [out] EntryCount Return the count of platform CMOS entries.
+
+  @return Platform CMOS entries.
+**/
+CMOS_ENTRY *
+EFIAPI
+PlatformCmosGetEntry (
+  OUT UINTN       *EntryCount
+  );
+
+/**
+  Return the NMI enable status.
+**/
+BOOLEAN
+EFIAPI
+PlatformCmosGetNmiState (
+  VOID
+  );
+
+#endif // _PLATFORM_CMOS_ACCESS_LIB_H_
diff --git a/Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLib.c b/Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLib.c
new file mode 100644
index 0000000000..82d512cb9f
--- /dev/null
+++ b/Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLib.c
@@ -0,0 +1,486 @@
+/** @file
+  CmosAccessLib implementation.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "CmosAccessLibInternal.h"
+
+/**
+  Return the entry for the specified address in entries returned
+  from platform.
+
+  @param [in] Address  The CMOS address to find.
+
+  @return A pointer to CMOS_ENTRY for the specified address,
+          or NULL if not found.
+**/
+CMOS_ENTRY *
+CmosAccessLibLocateEntry (
+  IN UINT8      Address
+  )
+{
+  UINTN              Index;
+  UINTN              Count;
+  CMOS_ENTRY         *Entries;
+
+  Entries = PlatformCmosGetEntry (&Count);
+  for (Index = 0; Index < Count; Index++) {
+    if (Entries[Index].Address == Address) {
+      return &Entries[Index];
+    }
+  }
+
+  return NULL;
+}
+
+/**
+  Test the attributes of the Entry and return ValueIfSet if test passes
+  or !ValueIfSet if test fails. It returns DefaultValue if the Entry is
+  NULL.
+
+  @param [in] Address      The CMOS address.
+  @param [in] Attributes   The attributes to test.
+  @param [in] ValueIfSet   The value to return if test passes.
+  @param [in] DefaultValue The value to return if Entry is NULL.
+  @param [in] Entry        Pointer to entry.
+
+  @retval ValueIfSet   If test passes.
+  @retval !ValueIfSet  If test fails.
+  @retval DefaultValue If the Entry is NULL.
+**/
+BOOLEAN
+CmosAccessLibCheckAttribute (
+  IN UINT8      Address,
+  IN UINT8      Attributes,
+  IN BOOLEAN    ValueIfSet,
+  IN BOOLEAN    DefaultValue,
+  IN CMOS_ENTRY *Entry        OPTIONAL
+  )
+{
+  if (Entry != NULL) {
+    ASSERT (Entry->Address == Address);
+    if ((Entry->Attributes & Attributes) == Attributes) {
+      return ValueIfSet;
+    } else {
+      return !ValueIfSet;
+    }
+  }
+
+  return DefaultValue;
+}
+
+/**
+  Check if the CMOS address needs Checksum calculation.
+
+  @param [in] Address CMOS address to be checked
+  @param [in] Entry   Pointer to entry.
+
+  @retval TRUE       CMOS address needs Checksum calculation.
+  @retval FALSE      CMOS address doesn't need Checksum calculation.
+**/
+BOOLEAN
+CmosAccessLibNeedChecksum (
+  IN UINT8       Address,
+  IN CMOS_ENTRY  *Entry OPTIONAL
+  )
+{
+  return CmosAccessLibCheckAttribute (Address, CMOS_EXCLUDE_FROM_CHECKSUM, FALSE, FALSE, Entry);
+}
+
+
+/**
+  Check if the CMOS address needs to fill default data.
+
+  @param [in] Address CMOS address to be checked
+  @param [in] Entry   Pointer to entry.
+
+  @retval TRUE       CMOS address need to fill default data.
+  @retval FALSE      CMOS address doesn't need to fill default data.
+**/
+BOOLEAN
+CmosAccessLibNeedFillDefault (
+  IN UINT8       Address,
+  IN CMOS_ENTRY  *Entry OPTIONAL
+  )
+{
+  return CmosAccessLibCheckAttribute (Address, CMOS_EXCLUDE_FROM_INIT_DATA, FALSE, TRUE, Entry);
+}
+
+/**
+  Check if the CMOS address is accessible.
+
+  @param [in] Address CMOS address to be checked.
+  @param [in] Entry   Pointer to entry.
+
+  @retval TRUE       CMOS address is accessible.
+  @retval FALSE      CMOS address isn't accessible.
+**/
+BOOLEAN
+CmosAccessLibIsAccessible (
+  IN UINT8       Address,
+  IN CMOS_ENTRY  *Entry OPTIONAL
+  )
+{
+  //
+  // CMOS 0-9, A, B, C, D are for RTC.
+  //
+  if (Address <= 0xD) {
+    return FALSE;
+  }
+  return CmosAccessLibCheckAttribute (Address, CMOS_EXCLUDE_FROM_ACCESS, FALSE, TRUE, Entry);
+}
+
+/**
+  Return the CMOS location to store checksum.
+
+  @param [out] Location Return the CMOS location to store the checksum.
+**/
+VOID
+CmosAccessLibGetChecksumLocation (
+  OUT CMOS_CHECKSUM_LOCATION_INFO *Location
+  )
+{
+  UINTN                       Index;
+  UINTN                       Count;
+  CMOS_ENTRY                  *Entries;
+
+  Location->Length = 0;
+
+  Entries = PlatformCmosGetEntry (&Count);
+  for (Index = 0; Index < Count; Index++) {
+    if ((Entries[Index].Attributes & CMOS_CHECKSUM_LOCATION) == CMOS_CHECKSUM_LOCATION) {
+      Location->Length++;
+      if (Location->Length == 1) {
+        Location->LowByteAddress = Entries[Index].Address;
+      } else if (Location->Length == 2) {
+        Location->HighByteAddress = Entries[Index].Address;
+        break;
+      }
+    }
+  }
+
+  ASSERT (Location->Length <= 2);
+}
+
+/**
+  Calculate the sum of CMOS values who need checksum calculation.
+
+  @param [in] Location The CMOS location to store the checksum.
+
+  @return The sum.
+**/
+UINT16
+CmosAccessLibCalculateSum (
+  IN CMOS_CHECKSUM_LOCATION_INFO *Location
+  )
+{
+  UINT16                      Sum;
+  UINTN                       Index;
+  UINTN                       Count;
+  CMOS_ENTRY                  *Entries;
+
+  if (Location->Length == 0) {
+    return 0;
+  }
+
+  Sum = 0;
+  Entries = PlatformCmosGetEntry (&Count);
+  for (Index = 0; Index < Count; Index++) {
+    if (CmosAccessLibNeedChecksum (Entries[Index].Address, &Entries[Index])) {
+      Sum += CmosRead8 (Entries[Index].Address);
+    }
+  }
+
+  if (Location->Length == 1) {
+    return (UINT8) Sum;
+  } else {
+    return Sum;
+  }
+}
+
+/**
+  Return the checksum value stored in CMOS.
+
+  @param [in] Location The CMOS location to store the checksum.
+
+  @return The checksum value.
+**/
+UINT16
+CmosAccessLibReadChecksum (
+  IN CMOS_CHECKSUM_LOCATION_INFO *Location
+  )
+{
+  UINT16                      Checksum;
+
+  Checksum = 0;
+
+  switch (Location->Length) {
+  case 2:
+    Checksum = (CmosRead8 (Location->HighByteAddress) << 8);
+    //
+    // Fall to case 1 to get the low byte value
+    //
+  case 1:
+    Checksum += CmosRead8 (Location->LowByteAddress);
+    break;
+
+  default:
+    break;
+  }
+  return Checksum;
+}
+
+
+/**
+  Write the Checksum to appropriate address.
+
+  @param [in] Location The CMOS location to store the checksum.
+  @param [in] Checksum The checksum value.
+**/
+VOID
+CmosAccessLibWriteChecksum (
+  CMOS_CHECKSUM_LOCATION_INFO *Location,
+  IN UINT16                   Checksum
+  )
+{
+
+  switch (Location->Length) {
+  case 0:
+    break;
+  case 2:
+    CmosWrite8 (Location->HighByteAddress, Checksum >> 8);
+    //
+    // Fall to case 1 to update low byte value
+    //
+  case 1:
+    CmosWrite8 (Location->LowByteAddress, (UINT8) Checksum);
+    break;
+  }
+}
+
+/**
+  Read a byte value from a CMOS address.
+
+  @param [in] Address   Location to read from CMOS
+
+  @return The byte value read from the CMOS address.
+**/
+UINT8
+EFIAPI
+CmosRead8 (
+  IN  UINT8 Address
+  )
+{
+  if (!CmosAccessLibIsAccessible (Address, CmosAccessLibLocateEntry (Address))) {
+    return 0xFF;
+  }
+
+  if (Address <= CMOS_BANK0_LIMIT) {
+    if (PlatformCmosGetNmiState ()) {
+      Address |= BIT7;
+    }
+    IoWrite8 (PORT_70, Address);
+    return IoRead8 (PORT_71);
+  } else {
+    IoWrite8 (PORT_72, Address);
+    return IoRead8 (PORT_73);
+  }
+}
+
+/**
+  Write a byte value to a CMOS address.
+
+  It's an internal function that doesn't update the checksum.
+
+  @param [in] Address Location to write to CMOS.
+  @param [in] Data    The byte value write to the CMOS address.
+**/
+VOID
+CmosAccessLibICmosWrite8 (
+  IN UINT8 Address,
+  IN UINT8 Data
+  )
+{
+  if (Address <= CMOS_BANK0_LIMIT) {
+    if (PlatformCmosGetNmiState ()) {
+      Address |= BIT7;
+    }
+    IoWrite8 (PORT_70, Address);
+    IoWrite8 (PORT_71, Data);
+  } else {
+    IoWrite8 (PORT_72, Address);
+    IoWrite8 (PORT_73, Data);
+  }
+}
+
+/**
+  Write a byte value to a CMOS address.
+
+  @param [in] Address Location to write to CMOS.
+  @param [in] Data    The byte value write to the CMOS address.
+**/
+VOID
+EFIAPI
+CmosWrite8 (
+  IN UINT8 Address,
+  IN UINT8 Data
+  )
+{
+  UINT8                       OriginalData;
+  CMOS_ENTRY                  *Entry;
+  CMOS_CHECKSUM_LOCATION_INFO ChecksumLocation;
+
+  Entry = CmosAccessLibLocateEntry (Address);
+
+  if (!CmosAccessLibIsAccessible (Address, Entry)) {
+    return;
+  }
+
+  OriginalData = CmosRead8 (Address);
+
+  CmosAccessLibICmosWrite8 (Address, Data);
+
+  if (CmosAccessLibNeedChecksum (Address, Entry)) {
+    //
+    // Sum of Data + Checksum = New Sum of Data + New Checksum = 0
+    // New Sum of Data - Sum of Data = Checksum - New Checksum
+    // New Checksum = Checksum - (New Sum of Data - Sum of Data)
+    //
+    CmosAccessLibGetChecksumLocation (&ChecksumLocation);
+    CmosAccessLibWriteChecksum (
+      &ChecksumLocation,
+      CmosAccessLibReadChecksum (&ChecksumLocation) - (Data - OriginalData)
+      );
+  }
+}
+
+/**
+  Read a word value from a CMOS address.
+
+  @param [in] Address   Location to read from CMOS
+
+  @return The word value read from the CMOS address.
+**/
+UINT16
+EFIAPI
+CmosRead16 (
+  IN  UINT8  Address
+  )
+{
+  return CmosRead8 (Address) + (CmosRead8 (Address + 1) << 8);
+}
+
+/**
+  Write a word value to a CMOS address.
+
+  @param [in] Address Location to write to CMOS.
+  @param [in] Data    The word value write to the CMOS address.
+**/
+VOID
+EFIAPI
+CmosWrite16 (
+  IN UINT8  Address,
+  IN UINT16 Data
+  )
+{
+  CmosWrite8 (Address, (UINT8) Data);
+  CmosWrite8 (Address + 1, (UINT8) (Data >> 8));
+}
+
+/**
+  Read a dword value from a CMOS address.
+
+  @param [in] Address   Location to read from CMOS
+
+  @return The dword value read from the CMOS address.
+**/
+UINT32
+EFIAPI
+CmosRead32 (
+  IN  UINT8  Address
+  )
+{
+  return CmosRead16 (Address) + (CmosRead16 (Address + 2) << 16);
+}
+
+/**
+  Write a dword value to a CMOS address.
+
+  @param [in] Address Location to write to CMOS.
+  @param [in] Data    The dword value write to the CMOS address.
+**/
+VOID
+EFIAPI
+CmosWrite32 (
+  IN UINT8  Address,
+  IN UINT32 Data
+  )
+{
+  CmosWrite16 (Address, (UINT16) Data);
+  CmosWrite16 (Address + 2, (UINT16) (Data >> 16));
+}
+
+
+/**
+  Initialize the CMOS.
+
+  It initialize the CMOS area when Force is TRUE or the checksum is incorrect.
+
+  @param[in]  Force  TRUE indicating initializing the CMOS area without checking the checksum.
+
+  @retval TRUE  The CMOS is initialized to default value.
+  @retval FALSE The CMOS isn't initialized to default value.
+**/
+BOOLEAN
+EFIAPI
+CmosInit (
+  IN  BOOLEAN     Force
+  )
+{
+  UINTN                       Address;
+  CMOS_ENTRY                  *Entry;
+  CMOS_CHECKSUM_LOCATION_INFO ChecksumLocation;
+  UINT16                      Checksum;
+
+  CmosAccessLibGetChecksumLocation (&ChecksumLocation);
+
+  if (!Force) {
+    //
+    // Initialize the CMOS area when checksum is incorrect.
+    //
+    Checksum = CmosAccessLibCalculateSum (&ChecksumLocation) + CmosAccessLibReadChecksum (&ChecksumLocation);
+    if (ChecksumLocation.Length == 1) {
+      Checksum = (UINT8) Checksum;
+    }
+
+    if (Checksum != 0) {
+      Force = TRUE;
+    }
+  }
+
+  if (Force) {
+    //
+    // Traverse through entire CMOS location and fill it with zero
+    //
+    for (Address = 0; Address <= CMOS_BANK1_LIMIT; Address++) {
+      Entry = CmosAccessLibLocateEntry ((UINT8) Address);
+      if (CmosAccessLibNeedFillDefault ((UINT8) Address, Entry)) {
+        CmosAccessLibICmosWrite8 ((UINT8) Address, (Entry == NULL) ? CMOS_DEFAULT_VALUE : Entry->DefaultValue);
+      }
+    }
+
+    //
+    // Write the New checksum to the Checksum field
+    //
+    CmosAccessLibWriteChecksum (
+      &ChecksumLocation,
+      (UINT16) (0x10000 - CmosAccessLibCalculateSum (&ChecksumLocation))
+      );
+    return TRUE;
+  }
+
+  return FALSE;
+}
diff --git a/Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLib.inf b/Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLib.inf
new file mode 100644
index 0000000000..77ea219f2c
--- /dev/null
+++ b/Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLib.inf
@@ -0,0 +1,28 @@
+### @file
+# Library producing CMOS access functionality.
+#
+# Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+###
+[Defines]
+  INF_VERSION    = 0x00010005
+  BASE_NAME      = CmosAccessLib
+  FILE_GUID      = FF6B645D-C001-4ACE-9CA1-199F97C2D601
+  VERSION_STRING = 1.0
+  MODULE_TYPE    = BASE
+  LIBRARY_CLASS  = CmosAccessLib
+
+[Sources]
+  CmosAccessLib.c
+  CmosAccessLibInternal.h
+
+[LibraryClasses]
+  IoLib
+  DebugLib
+  PlatformCmosAccessLib
+
+[Packages]
+  MdePkg/MdePkg.dec
+  BoardModulePkg/BoardModulePkg.dec
\ No newline at end of file
diff --git a/Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLibInternal.h b/Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLibInternal.h
new file mode 100644
index 0000000000..61baec3f92
--- /dev/null
+++ b/Platform/Intel/BoardModulePkg/Library/CmosAccessLib/CmosAccessLibInternal.h
@@ -0,0 +1,35 @@
+/** @file
+  CmosAccessLib internal header file.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _CMOS_ACCESS_LIB_INTERNALS_
+#define _CMOS_ACCESS_LIB_INTERNALS_
+
+#include <Base.h>
+#include <Uefi.h>
+#include <Library/IoLib.h>
+#include <Library/DebugLib.h>
+#include <Library/CmosAccessLib.h>
+#include <Library/PlatformCmosAccessLib.h>
+
+// CMOS access Port address
+
+#define PORT_70            0x70
+#define PORT_71            0x71
+#define PORT_72            0x72
+#define PORT_73            0x73
+
+#define CMOS_BANK0_LIMIT   0x7F
+#define CMOS_BANK1_LIMIT   0xFF
+
+typedef struct {
+   UINT8  Length;
+   UINT8  LowByteAddress;
+   UINT8  HighByteAddress;
+} CMOS_CHECKSUM_LOCATION_INFO;
+
+#endif // _CMOS_ACCESS_LIB_INTERNALS_
diff --git a/Platform/Intel/BoardModulePkg/Library/PlatformCmosAccessLibNull/PlatformCmosAccessLibNull.c b/Platform/Intel/BoardModulePkg/Library/PlatformCmosAccessLibNull/PlatformCmosAccessLibNull.c
new file mode 100644
index 0000000000..dbd7ad5cf4
--- /dev/null
+++ b/Platform/Intel/BoardModulePkg/Library/PlatformCmosAccessLibNull/PlatformCmosAccessLibNull.c
@@ -0,0 +1,39 @@
+/** @file
+  Platform CMOS Access Library.
+
+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Library/PlatformCmosAccessLib.h>
+
+/**
+  Return the platform CMOS entries.
+
+  @param [out] EntryCount Return the count of platform CMOS entries.
+
+  @return Platform CMOS entries.
+**/
+CMOS_ENTRY *
+EFIAPI
+PlatformCmosGetEntry (
+  OUT UINTN       *EntryCount
+  )
+{
+  *EntryCount = 0;
+  return NULL;
+}
+
+/**
+  Return the NMI enable status.
+**/
+BOOLEAN
+EFIAPI
+PlatformCmosGetNmiState (
+  VOID
+  )
+{
+  return FALSE;
+}
diff --git a/Platform/Intel/BoardModulePkg/Library/PlatformCmosAccessLibNull/PlatformCmosAccessLibNull.inf b/Platform/Intel/BoardModulePkg/Library/PlatformCmosAccessLibNull/PlatformCmosAccessLibNull.inf
new file mode 100644
index 0000000000..4fb158ae48
--- /dev/null
+++ b/Platform/Intel/BoardModulePkg/Library/PlatformCmosAccessLibNull/PlatformCmosAccessLibNull.inf
@@ -0,0 +1,23 @@
+### @file
+# Library producing CMOS access functionalities are relevant to platform.
+#
+# Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+###
+[Defines]
+  INF_VERSION    = 0x00010005
+  BASE_NAME      = PlatformCmosAccessLib
+  FILE_GUID      = C315A8B6-FF6C-41D1-A934-7330501F308C
+  VERSION_STRING = 1.0
+  MODULE_TYPE    = BASE
+  LIBRARY_CLASS  = PlatformCmosAccessLib
+
+
+[Sources]
+  PlatformCmosAccessLibNull.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  BoardModulePkg/BoardModulePkg.dec

-- 
2.21.0.windows.1