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

["Kubacki, Michael A" <michael.a.kubacki@intel.com>]

Agree, this is not a feature but code that may be reused to support multiple features.

We do need a new location to hold such reusable code. Liming, would you like to 
send the RFC to request this new package?

Thanks,
Michael

> -----Original Message-----
> From: Gao, Liming
> Sent: Monday, May 13, 2019 5:37 AM
> To: devel@edk2.groups.io; Dong, Eric <eric.dong@intel.com>
> Cc: Ni, Ray <ray.ni@intel.com>; Kubacki, Michael A
> <michael.a.kubacki@intel.com>; Desimone, Nathaniel L
> <nathaniel.l.desimone@intel.com>
> Subject: RE: [edk2-devel] [Patch] [edk2-platforms]
> AdvancedFeaturePkg/Cmos: Add Cmos related libraries.
> 
> Eric:
>   Now, edk2-platform devel-MinPlatform branch has merged into edk2-
> platform master branch.
> 
>   For this change, I propose to add new GenericBoardPkg in Platform\Intel
> directory for the common board features.
> 
> Thanks
> Liming
> > -----Original Message-----
> > From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
> > Dong, Eric
> > Sent: Tuesday, May 7, 2019 3:31 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] [edk2-platforms] 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/PlatformCmosAc
> c
> > essLib.h  create mode 100644
> >
> Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosAcc
> es
> > sLib.c  create mode 100644
> >
> Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosAcc
> es
> > sLib.inf  create mode 100644
> >
> Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosAcc
> es
> > sLibInternal.h  create mode 100644
> >
> Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLibN
> u
> > ll/PlatformCmosAccessLibNull.c  create mode 100644
> >
> Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLibN
> u
> > ll/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/CmosAcces
> > +++ sLib.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
> A
> > ccessLib.h
> >
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Include/Library/PlatformCmos
> A
> > ccessLib.h
> > new file mode 100644
> > index 0000000..8c44ae2
> > --- /dev/null
> > +++
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Include/Library/PlatformC
> > +++ mosAccessLib.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
> cc
> > essLib.c
> >
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
> cc
> > essLib.c
> > new file mode 100644
> > index 0000000..403d8ff
> > --- /dev/null
> > +++
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/Cmo
> > +++ sAccessLib.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
> cc
> > essLib.inf
> >
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
> cc
> > essLib.inf
> > new file mode 100644
> > index 0000000..9decaf4
> > --- /dev/null
> > +++
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/Cmo
> > +++ sAccessLib.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
> cc
> > essLibInternal.h
> >
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/CmosA
> cc
> > essLibInternal.h
> > new file mode 100644
> > index 0000000..9b6d086
> > --- /dev/null
> > +++
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/CmosAccessLib/Cmo
> > +++ sAccessLibInternal.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/PlatformCmosAccessLi
> b
> > Null/PlatformCmosAccessLibNull.c
> >
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLi
> b
> > Null/PlatformCmosAccessLibNull.c
> > new file mode 100644
> > index 0000000..b24a3f5
> > --- /dev/null
> > +++
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAcces
> > +++ sLibNull/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/PlatformCmosAccessLi
> b
> > Null/PlatformCmosAccessLibNull.inf
> >
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAccessLi
> b
> > Null/PlatformCmosAccessLibNull.inf
> > new file mode 100644
> > index 0000000..4816464
> > --- /dev/null
> > +++
> b/Platform/Intel/AdvancedFeaturePkg/Cmos/Library/PlatformCmosAcces
> > +++ sLibNull/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
> >
> >
> >