Re: [edk2-devel] [Patch] AdvancedFeaturePkg/Cmos: Add Cmos related libraries.

["Liming Gao" <liming.gao@intel.com>]

Eric:
 The title should include edk2-platform/ devel-MinPlatform so that people know this patch for edk2-platform devel-MinPlatform branch.

>-----Original Message-----
>From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
>Dong, Eric
>Sent: Tuesday, May 07, 2019 3:28 PM
>To: devel@edk2.groups.io
>Cc: Ni, Ray <ray.ni@intel.com>; Kubacki, Michael A
><michael.a.kubacki@intel.com>; Desimone, Nathaniel L
><nathaniel.l.desimone@intel.com>
>Subject: [edk2-devel] [Patch] AdvancedFeaturePkg/Cmos: Add Cmos related
>libraries.
>
>https://bugzilla.tianocore.org/show_bug.cgi?id=1552
>
>Add two libraries used to provide CMOS related operation.
>
>CmosAccessLib exports below APIs:
>  CmosWrite32
>  CmosWrite16
>  CmosWrite8
>  CmosRead32
>  CmosRead16
>  CmosRead8
>  CmosInit
>
>PlatformCmosAccessLib export below APIs:
>  PlatformCmosGetEntry
>  PlatformCmosGetNmiState
>
>PlatformCmosAccessLib will be consumed by CmosAccessLib.
>
>Cc: Ray Ni <ray.ni@intel.com>
>Cc: Michael Kubacki <michael.a.kubacki@intel.com>
>Cc: Nate Desimone <nathaniel.l.desimone@intel.com>
>Signed-off-by: Eric Dong <eric.dong@intel.com>
>---
> .../Cmos/Include/Library/CmosAccessLib.h      | 112 ++++
> .../Include/Library/PlatformCmosAccessLib.h   |  74 +++
> .../Library/CmosAccessLib/CmosAccessLib.c     | 492 ++++++++++++++++++
> .../Library/CmosAccessLib/CmosAccessLib.inf   |  34 ++
> .../CmosAccessLib/CmosAccessLibInternal.h     |  41 ++
> .../PlatformCmosAccessLibNull.c               |  45 ++
> .../PlatformCmosAccessLibNull.inf             |  30 ++
> 7 files changed, 828 insertions(+)
> create mode 100644
>Platform/Intel/AdvancedFeaturePkg/Cmos/Include/Library/CmosAccessLib.h
> create mode 100644
>Platform/Intel/AdvancedFeaturePkg/Cmos/Include/Library/PlatformCmosAcc
>essLib.h
> create mode 100644
>Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosAcc
>essLib.c
> create mode 100644
>Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosAcc
>essLib.inf
> create mode 100644
>Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosAcc
>essLibInternal.h
> create mode 100644
>Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLibN
>ull/PlatformCmosAccessLibNull.c
> create mode 100644
>Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLibN
>ull/PlatformCmosAccessLibNull.inf
>
>diff --git
>a/Platform/Intel/AdvancedFeaturePkg/Cmos/Include/Library/CmosAccessLib
>.h
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Include/Library/CmosAccessLib
>.h
>new file mode 100644
>index 0000000..5f5029c
>--- /dev/null
>+++
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Include/Library/CmosAccessLib
>.h
>@@ -0,0 +1,112 @@
>+/** @file
>+  CmosAccessLib header file.
>+
>+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>+This program and the accompanying materials are licensed and made
>available under
>+the terms and conditions of the BSD License that accompanies this
>distribution.
>+The full text of the license may be found at
>+http://opensource.org/licenses/bsd-license.php.
>+
>+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
>BASIS,
>+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
>EXPRESS OR IMPLIED.
>+
>+**/
>+
>+#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/AdvancedFeaturePkg/Cmos/Include/Library/PlatformCmos
>AccessLib.h
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Include/Library/PlatformCmos
>AccessLib.h
>new file mode 100644
>index 0000000..8c44ae2
>--- /dev/null
>+++
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Include/Library/PlatformCmos
>AccessLib.h
>@@ -0,0 +1,74 @@
>+/** @file
>+  Platform CMOS Access Library Header File.
>+
>+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>+This program and the accompanying materials are licensed and made
>available under
>+the terms and conditions of the BSD License that accompanies this
>distribution.
>+The full text of the license may be found at
>+http://opensource.org/licenses/bsd-license.php.
>+
>+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
>BASIS,
>+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
>EXPRESS OR IMPLIED.
>+
>+**/
>+
>+#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/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
>ccessLib.c
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
>ccessLib.c
>new file mode 100644
>index 0000000..403d8ff
>--- /dev/null
>+++
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
>ccessLib.c
>@@ -0,0 +1,492 @@
>+/** @file
>+  CmosAccessLib implementation.
>+
>+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>+This program and the accompanying materials are licensed and made
>available under
>+the terms and conditions of the BSD License that accompanies this
>distribution.
>+The full text of the license may be found at
>+http://opensource.org/licenses/bsd-license.php.
>+
>+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
>BASIS,
>+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
>EXPRESS OR IMPLIED.
>+
>+**/
>+
>+#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/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
>ccessLib.inf
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
>ccessLib.inf
>new file mode 100644
>index 0000000..9decaf4
>--- /dev/null
>+++
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
>ccessLib.inf
>@@ -0,0 +1,34 @@
>+### @file
>+# Library producing CMOS access functionality.
>+#
>+# Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>+#
>+# 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
>+# http://opensource.org/licenses/bsd-license.php
>+#
>+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
>BASIS,
>+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
>EXPRESS OR IMPLIED.
>+#
>+###
>+[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
>+  AdvancedFeaturePkg/AdvancedFeaturePkg.dec
>\ No newline at end of file
>diff --git
>a/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
>ccessLibInternal.h
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
>ccessLibInternal.h
>new file mode 100644
>index 0000000..9b6d086
>--- /dev/null
>+++
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
>ccessLibInternal.h
>@@ -0,0 +1,41 @@
>+/** @file
>+  CmosAccessLib internal header file.
>+
>+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>+This program and the accompanying materials are licensed and made
>available under
>+the terms and conditions of the BSD License that accompanies this
>distribution.
>+The full text of the license may be found at
>+http://opensource.org/licenses/bsd-license.php.
>+
>+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
>BASIS,
>+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
>EXPRESS OR IMPLIED.
>+
>+**/
>+
>+#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/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLib
>Null/PlatformCmosAccessLibNull.c
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLib
>Null/PlatformCmosAccessLibNull.c
>new file mode 100644
>index 0000000..b24a3f5
>--- /dev/null
>+++
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLib
>Null/PlatformCmosAccessLibNull.c
>@@ -0,0 +1,45 @@
>+/** @file
>+  Platform CMOS Access Library.
>+
>+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>+This program and the accompanying materials are licensed and made
>available under
>+the terms and conditions of the BSD License that accompanies this
>distribution.
>+The full text of the license may be found at
>+http://opensource.org/licenses/bsd-license.php.
>+
>+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
>BASIS,
>+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
>EXPRESS OR IMPLIED.
>+
>+**/
>+
>+#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/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLib
>Null/PlatformCmosAccessLibNull.inf
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLib
>Null/PlatformCmosAccessLibNull.inf
>new file mode 100644
>index 0000000..4816464
>--- /dev/null
>+++
>b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLib
>Null/PlatformCmosAccessLibNull.inf
>@@ -0,0 +1,30 @@
>+### @file
>+# Library producing CMOS access functionalities are relevant to platform.
>+#
>+# Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>
>+#
>+# 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
>+# http://opensource.org/licenses/bsd-license.php
>+#
>+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS"
>BASIS,
>+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER
>EXPRESS OR IMPLIED.
>+#
>+###
>+
>+[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
>+  AdvancedFeaturePkg/AdvancedFeaturePkg.dec
>\ No newline at end of file
>--
>2.21.0.windows.1
>
>
>