Re: [edk2-devel] [PATCH v3 01/15] PcAtChipsetPkg: Add MMIO Support to RTC driver

["Guomin Jiang" <guomin.jiang@intel.com>]

Hi Ard,

When build MinPlatform, it will show Edk2Platforms/Platform/Intel/MinPlatformPkg/Pci/Library/PciSegmentInfoLibSimple/PciSegmentInfoLibSimple.c:34:1: error: conflicting types for ‘GetPciSegmentInfo’

Could you confirm it?

Thanks
Guomin
> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ard
> Biesheuvel
> Sent: Thursday, June 25, 2020 7:25 PM
> To: Sami Mujawar <sami.mujawar@arm.com>; devel@edk2.groups.io
> Cc: leif@nuviainc.com; Ni, Ray <ray.ni@intel.com>;
> Alexandru.Elisei@arm.com; Andre.Przywara@arm.com;
> Matteo.Carlini@arm.com; Laura.Moretta@arm.com; nd@arm.com
> Subject: Re: [edk2-devel] [PATCH v3 01/15] PcAtChipsetPkg: Add MMIO
> Support to RTC driver
> 
> On 6/24/20 3:34 PM, Sami Mujawar wrote:
> > Some virtual machine managers like Kvmtool emulate the MC146818 RTC
> > controller in the MMIO space so that architectures that do not support
> > I/O Mapped I/O can use the RTC. This patch adds MMIO support to the
> > RTC controller driver.
> >
> > The PCD PcdRtcUseMmio has been added to select I/O or MMIO support.
> >    If PcdRtcUseMmio is:
> >      TRUE  - Indicates the RTC port registers are in MMIO space.
> >      FALSE - Indicates the RTC port registers are in I/O space.
> >              Default is I/O space.
> >
> > Additionally two new PCDs PcdRtcIndexRegister64 and
> > PcdRtcTargetRegister64 have been introduced to provide the base
> > address for the RTC registers in the MMIO space.
> >
> > When MMIO support is selected (PcdRtcUseMmio == TRUE) the driver
> > converts the pointers to the RTC MMIO registers so that the RTC
> > registers are accessible post ExitBootServices.
> >
> > Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
> 
> Can't we implement this without function pointers? What Leif suggested was
> using STATIC helper functions for read and write, where each one has a test
> for the feature PCD to decide whether to use the IO or the MMIO version.
> 
> Using function pointers is unneeded complexity, especially given the fact
> that we need to fix up their values when the address space is virtually
> remapped by the OS.
> 
> > ---
> >
> > Notes:
> >      v3:
> >      - Make PcdRtcUseMmio a feature PCD.                               [Sami]
> >      - Read the RTC MMIO base address from the DT.                     [Andre]
> >      - Introduce PCDs for RTC Index and Target register base           [Sami]
> >        address in the MMIO space.
> >      - Move RTC MMIO region mapping code to a separate platform
> [Sami]
> >        specific library. This library also reads the base addresses
> >        for the RTC from DT and configures the RTC Index and Target
> >        register PCDs.
> >        Ref: https://edk2.groups.io/g/devel/topic/74200905#60307
> >
> >      v2:
> >      - Code review comments incorporated.                              [Sami]
> >
> >      v1:
> >      - Add support to read/write from RTC registers using MMIO access
> [Sami]
> >      - Use wrapper functions for RtcRead/Write accessors               [Leif]
> >        Ref: https://edk2.groups.io/g/devel/topic/30915281#30695
> >
> >   PcAtChipsetPkg/PcAtChipsetPkg.dec                                          |  16 +++
> >   PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c                         | 119
> +++++++++++++++++---
> >   PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.h                         |  31
> +++++
> >   PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtcEntry.c                    |
> 72 +++++++++++-
> >
> PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRuntime
> Dxe.inf |   8 ++
> >   5 files changed, 230 insertions(+), 16 deletions(-)
> >
> > diff --git a/PcAtChipsetPkg/PcAtChipsetPkg.dec
> > b/PcAtChipsetPkg/PcAtChipsetPkg.dec
> > index
> >
> 88de5cceea593176c3a2425a5963b66b789f2b9e..ed2d95550b8d153995b30cdc
> 290c
> > f3bb905e211b 100644
> > --- a/PcAtChipsetPkg/PcAtChipsetPkg.dec
> > +++ b/PcAtChipsetPkg/PcAtChipsetPkg.dec
> > @@ -6,6 +6,7 @@
> >   #
> >   # Copyright (c) 2009 - 2019, Intel Corporation. All rights reserved.<BR>
> >   # Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
> > +# Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.<BR>
> >   #
> >   # SPDX-License-Identifier: BSD-2-Clause-Patent
> >   #
> > @@ -41,6 +42,13 @@ [PcdsFeatureFlag]
> >     # @Prompt Configure HPET to use MSI.
> >
> >
> gPcAtChipsetPkgTokenSpaceGuid.PcdHpetMsiEnable|TRUE|BOOLEAN|0x00
> 001000
> >
> > +  ## Indicates the RTC port registers are in MMIO space, or in I/O space.
> > +  #  Default is I/O space.<BR><BR>
> > +  #   TRUE  - RTC port registers are in MMIO space.<BR>
> > +  #   FALSE - RTC port registers are in I/O space.<BR>
> > +  # @Prompt RTC port registers use MMIO.
> > +
> > +
> gPcAtChipsetPkgTokenSpaceGuid.PcdRtcUseMmio|FALSE|BOOLEAN|0x0000
> 0021
> > +
> >   [PcdsFixedAtBuild, PcdsDynamic, PcdsDynamicEx,
> PcdsPatchableInModule]
> >     ## This PCD specifies the base address of the HPET timer.
> >     # @Prompt HPET base address.
> > @@ -68,6 +76,14 @@ [PcdsFixedAtBuild, PcdsDynamic, PcdsDynamicEx,
> PcdsPatchableInModule]
> >     # @Expression 0x80000001 |
> gPcAtChipsetPkgTokenSpaceGuid.PcdMaximalValidYear <
> gPcAtChipsetPkgTokenSpaceGuid.PcdMinimalValidYear + 100
> >
> >
> gPcAtChipsetPkgTokenSpaceGuid.PcdMaximalValidYear|2097|UINT16|0x000
> 000
> > 0E
> >
> > +  ## Specifies RTC Index Register address in MMIO space.
> > +  # @Prompt RTC Index Register address
> > +
> > +
> gPcAtChipsetPkgTokenSpaceGuid.PcdRtcIndexRegister64|0x0|UINT64|0x00
> 0
> > + 00022
> > +
> > +  ## Specifies RTC Target Register address in MMIO space.
> > +  # @Prompt RTC Target Register address
> > +
> > +
> gPcAtChipsetPkgTokenSpaceGuid.PcdRtcTargetRegister64|0x0|UINT64|0x00
> > + 000023
> > +
> >   [PcdsFixedAtBuild, PcdsPatchableInModule]
> >     ## Defines the ACPI register set base address.
> >     #  The invalid 0xFFFF is as its default value. It must be configured to the
> real value.
> > diff --git a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
> > b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
> > index
> >
> 52af17941786ef81c3911512ee64551724e67209..5ddc06549103ce9944054d3a0
> 5b7
> > 3803f7037ec2 100644
> > --- a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
> > +++ b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.c
> > @@ -3,6 +3,7 @@
> >
> >   Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
> >   Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
> > +Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.<BR>
> >
> >   SPDX-License-Identifier: BSD-2-Clause-Patent
> >
> > @@ -10,6 +11,9 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
> >
> >   #include "PcRtc.h"
> >
> > +extern UINTN  mRtcIndexRegister;
> > +extern UINTN  mRtcTargetRegister;
> > +
> >   //
> >   // Days of month.
> >   //
> > @@ -21,6 +25,28 @@ UINTN mDayOfMonth[] = { 31, 29, 31, 30, 31, 30, 31,
> 31, 30, 31, 30, 31 };
> >   CHAR16 mTimeZoneVariableName[] = L"RTC";
> >
> >   /**
> > +  A function pointer that evaluates to a function that reads the RTC
> > + content  through its registers either using IO or MMIO access.
> > +
> > +  @param  Address   Address offset of RTC. It is recommended to use
> > +                    macros such as RTC_ADDRESS_SECONDS.
> > +
> > +  @return The data of UINT8 type read from RTC.
> > +**/
> > +RTC_READ  RtcRead;
> > +
> > +/**
> > +  A function pointer that evaluates to a function that reads the RTC
> > +content
> > +  through its registers either using IO or MMIO access.
> > +
> > +  @param  Address   Address offset of RTC. It is recommended to use
> > +                    macros such as RTC_ADDRESS_SECONDS.
> > +
> > +  @return The data of UINT8 type read from RTC.
> > +**/
> > +RTC_WRITE RtcWrite;
> > +
> > +/**
> >     Compare the Hour, Minute and Second of the From time and the To
> time.
> >
> >     Only compare H/M/S in EFI_TIME and ignore other fields here.
> > @@ -54,41 +80,96 @@ IsWithinOneDay (
> >     );
> >
> >   /**
> > -  Read RTC content through its registers.
> > +  Read RTC content through its registers using IO access.
> >
> > -  @param  Address  Address offset of RTC. It is recommended to use
> macros such as
> > -                   RTC_ADDRESS_SECONDS.
> > +  @param  Address   Address offset of RTC. It is recommended to use
> > +                    macros such as RTC_ADDRESS_SECONDS.
> >
> >     @return The data of UINT8 type read from RTC.
> >   **/
> > +STATIC
> >   UINT8
> > -RtcRead (
> > -  IN  UINT8 Address
> > +EFIAPI
> > +IoRtcRead (
> > +  IN  UINTN Address
> >     )
> >   {
> > -  IoWrite8 (PcdGet8 (PcdRtcIndexRegister), (UINT8) (Address | (UINT8)
> > (IoRead8 (PcdGet8 (PcdRtcIndexRegister)) & 0x80)));
> > +  IoWrite8 (
> > +    PcdGet8 (PcdRtcIndexRegister),
> > +    (UINT8)(Address | (UINT8)(IoRead8 (PcdGet8 (PcdRtcIndexRegister)) &
> 0x80))
> > +    );
> >     return IoRead8 (PcdGet8 (PcdRtcTargetRegister));
> >   }
> >
> >   /**
> > -  Write RTC through its registers.
> > +  Write RTC through its registers  using IO access.
> >
> > -  @param  Address  Address offset of RTC. It is recommended to use
> macros such as
> > -                   RTC_ADDRESS_SECONDS.
> > -  @param  Data     The content you want to write into RTC.
> > +  @param  Address   Address offset of RTC. It is recommended to use
> > +                    macros such as RTC_ADDRESS_SECONDS.
> > +  @param  Data      The content you want to write into RTC.
> >
> >   **/
> > +STATIC
> >   VOID
> > -RtcWrite (
> > -  IN  UINT8   Address,
> > +EFIAPI
> > +IoRtcWrite (
> > +  IN  UINTN   Address,
> >     IN  UINT8   Data
> >     )
> >   {
> > -  IoWrite8 (PcdGet8 (PcdRtcIndexRegister), (UINT8) (Address | (UINT8)
> > (IoRead8 (PcdGet8 (PcdRtcIndexRegister)) & 0x80)));
> > +  IoWrite8 (
> > +    PcdGet8 (PcdRtcIndexRegister),
> > +    (UINT8)(Address | (UINT8)(IoRead8 (PcdGet8 (PcdRtcIndexRegister)) &
> 0x80))
> > +    );
> >     IoWrite8 (PcdGet8 (PcdRtcTargetRegister), Data);
> >   }
> >
> >   /**
> > +  Read RTC content through its registers using MMIO access.
> > +
> > +  @param  Address   Address offset of RTC. It is recommended to use
> > +                    macros such as RTC_ADDRESS_SECONDS.
> > +
> > +  @return The data of UINT8 type read from RTC.
> > +**/
> > +STATIC
> > +UINT8
> > +EFIAPI
> > +MmioRtcRead (
> > +  IN  UINTN Address
> > +  )
> > +{
> > +  MmioWrite8 (
> > +    mRtcIndexRegister,
> > +    (UINT8)(Address | (UINT8)(MmioRead8 (mRtcIndexRegister) & 0x80))
> > +    );
> > +  return MmioRead8 (mRtcTargetRegister); }
> > +
> > +/**
> > +  Write RTC through its registers using MMIO access.
> > +
> > +  @param  Address   Address offset of RTC. It is recommended to use
> > +                    macros such as RTC_ADDRESS_SECONDS.
> > +  @param  Data      The content you want to write into RTC.
> > +
> > +**/
> > +STATIC
> > +VOID
> > +EFIAPI
> > +MmioRtcWrite (
> > +  IN  UINTN   Address,
> > +  IN  UINT8   Data
> > +  )
> > +{
> > +  MmioWrite8 (
> > +    mRtcIndexRegister,
> > +    (UINT8)(Address | (UINT8)(MmioRead8 (mRtcIndexRegister) & 0x80))
> > +    );
> > +  MmioWrite8 (mRtcTargetRegister, Data); }
> > +
> > +/**
> >     Initialize RTC.
> >
> >     @param  Global            For global use inside this module.
> > @@ -113,6 +194,18 @@ PcRtcInit (
> >     BOOLEAN         Pending;
> >
> >     //
> > +  // Initialize the RtcRead and RtcWrite functions  // based on the
> > + chosen IO/MMIO access.
> > +  //
> > +  if (FeaturePcdGet (PcdRtcUseMmio)) {
> > +    RtcRead = MmioRtcRead;
> > +    RtcWrite = MmioRtcWrite;
> > +  } else {
> > +    RtcRead = IoRtcRead;
> > +    RtcWrite = IoRtcWrite;
> > +  }
> > +
> > +  //
> >     // Acquire RTC Lock to make access to RTC atomic
> >     //
> >     if (!EfiAtRuntime ()) {
> > diff --git a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.h
> > b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.h
> > index
> >
> 47293ce44c5a1f4792892892f7da40d7f0a5a001..4074261c2ca5dbc7b0727ea796
> 11
> > 54eaf41c0e38 100644
> > --- a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.h
> > +++ b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtc.h
> > @@ -3,6 +3,7 @@
> >
> >   Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
> >   Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
> > +Copyright (c) 2019 - 2020, ARM Limited. All rights reserved.<BR>
> >
> >   SPDX-License-Identifier: BSD-2-Clause-Patent
> >
> > @@ -371,4 +372,34 @@ PcRtcAcpiTableChangeCallback (
> >     IN EFI_EVENT        Event,
> >     IN VOID             *Context
> >     );
> > +
> > +/**
> > +  Function pointer to Read RTC content through its registers.
> > +
> > +  @param  Address   Address offset of RTC. It is recommended to use
> > +                    macros such as RTC_ADDRESS_SECONDS.
> > +
> > +  @return The data of UINT8 type read from RTC.
> > +**/
> > +typedef
> > +UINT8
> > +(EFIAPI *RTC_READ) (
> > +  IN  UINTN Address
> > +  );
> > +
> > +/**
> > +  Function pointer to Write RTC through its registers.
> > +
> > +  @param  Address   Address offset of RTC. It is recommended to use
> > +                    macros such as RTC_ADDRESS_SECONDS.
> > +  @param  Data      The content you want to write into RTC.
> > +
> > +**/
> > +typedef
> > +VOID
> > +(EFIAPI *RTC_WRITE) (
> > +  IN  UINTN   Address,
> > +  IN  UINT8   Data
> > +  );
> > +
> >   #endif
> > diff --git a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtcEntry.c
> > b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtcEntry.c
> > index
> >
> ccda6331373bfe4069b0a59495b5e5cc731c8fc8..e30883e53333aae655bbf891f8
> 6d
> > 1a6ed739715f 100644
> > --- a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtcEntry.c
> > +++ b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcRtcEntry.c
> > @@ -2,16 +2,33 @@
> >     Provides Set/Get time operations.
> >
> >   Copyright (c) 2006 - 2018, Intel Corporation. All rights
> > reserved.<BR>
> > +Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.<BR>
> >   SPDX-License-Identifier: BSD-2-Clause-Patent
> >
> >   **/
> >
> > +#include <Library/DxeServicesTableLib.h>
> >   #include "PcRtc.h"
> >
> >   PC_RTC_MODULE_GLOBALS  mModuleGlobal;
> >
> >   EFI_HANDLE             mHandle = NULL;
> >
> > +STATIC EFI_EVENT       mVirtualAddrChangeEvent;
> > +
> > +UINTN                  mRtcIndexRegister;
> > +UINTN                  mRtcTargetRegister;
> > +
> > +//
> > +// Function pointer for the Rtc Read interface function //
> > +extern RTC_READ   RtcRead;
> > +
> > +//
> > +// Function pointer for the Rtc Write interface function // extern
> > +RTC_WRITE  RtcWrite;
> > +
> >   /**
> >     Returns the current time and date information, and the time-keeping
> capabilities
> >     of the hardware platform.
> > @@ -106,6 +123,34 @@ PcRtcEfiSetWakeupTime (
> >   }
> >
> >   /**
> > +  Fixup internal data so that EFI can be called in virtual mode.
> > +  Call the passed in Child Notify event and convert any pointers in
> > + lib to virtual mode.
> > +
> > +  @param[in]    Event   The Event that is being processed
> > +  @param[in]    Context Event Context
> > +**/
> > +VOID
> > +EFIAPI
> > +LibRtcVirtualNotifyEvent (
> > +  IN EFI_EVENT        Event,
> > +  IN VOID             *Context
> > +  )
> > +{
> > +  // Only needed if you are going to support the OS calling RTC
> > +functions in
> > +  // virtual mode. You will need to call EfiConvertPointer (). To
> > +convert any
> > +  // stored physical addresses to virtual address. After the OS
> > +transitions to
> > +  // calling in virtual mode, all future runtime calls will be made
> > +in virtual
> > +  // mode.
> > +  EfiConvertPointer (0x0, (VOID**)&mRtcIndexRegister);
> > +  EfiConvertPointer (0x0, (VOID**)&mRtcTargetRegister);
> > +
> > +  // Convert the RtcRead and RtcWrite pointers for runtime use.
> > +  EfiConvertPointer (0x0, (VOID**)&RtcRead);
> > +  EfiConvertPointer (0x0, (VOID**)&RtcWrite); }
> > +
> > +/**
> >     The user Entry Point for PcRTC module.
> >
> >     This is the entry point for PcRTC module. It installs the UEFI
> > runtime service @@ -125,12 +170,17 @@ InitializePcRtc (
> >     IN EFI_SYSTEM_TABLE                      *SystemTable
> >     )
> >   {
> > -  EFI_STATUS  Status;
> > -  EFI_EVENT   Event;
> > +  EFI_STATUS             Status;
> > +  EFI_EVENT              Event;
> >
> >     EfiInitializeLock (&mModuleGlobal.RtcLock, TPL_CALLBACK);
> >     mModuleGlobal.CenturyRtcAddress = GetCenturyRtcAddress ();
> >
> > +  if (FeaturePcdGet (PcdRtcUseMmio)) {
> > +    mRtcIndexRegister = (UINTN)PcdGet64 (PcdRtcIndexRegister64);
> > +    mRtcTargetRegister = (UINTN)PcdGet64 (PcdRtcTargetRegister64);  }
> > +
> >     Status = PcRtcInit (&mModuleGlobal);
> >     ASSERT_EFI_ERROR (Status);
> >
> > @@ -165,7 +215,23 @@ InitializePcRtc (
> >                     NULL,
> >                     NULL
> >                     );
> > -  ASSERT_EFI_ERROR (Status);
> > +  if (EFI_ERROR (Status)) {
> > +    ASSERT_EFI_ERROR (Status);
> > +    return Status;
> > +  }
> > +
> > +  if (FeaturePcdGet (PcdRtcUseMmio)) {
> > +    // Register for the virtual address change event
> > +    Status = gBS->CreateEventEx (
> > +                    EVT_NOTIFY_SIGNAL,
> > +                    TPL_NOTIFY,
> > +                    LibRtcVirtualNotifyEvent,
> > +                    NULL,
> > +                    &gEfiEventVirtualAddressChangeGuid,
> > +                    &mVirtualAddrChangeEvent
> > +                    );
> > +    ASSERT_EFI_ERROR (Status);
> > +  }
> >
> >     return Status;
> >   }
> > diff --git
> >
> a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRuntim
> eD
> > xe.inf
> >
> b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRuntim
> eD
> > xe.inf index
> >
> c73ee98105e510f9e4e23c1a6c1e5c505325d2c9..0d8eca28b65954b073a72fc4fe
> 5a
> > d6247320e79d 100644
> > ---
> >
> a/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRuntim
> eD
> > xe.inf
> > +++
> b/PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRunt
> > +++ imeDxe.inf
> > @@ -6,6 +6,7 @@
> >   #
> >   # Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
> >   # Copyright (c) 2017, AMD Inc. All rights reserved.<BR>
> > +# Copyright (c) 2018 - 2020, ARM Limited. All rights reserved.<BR>
> >   #
> >   # SPDX-License-Identifier: BSD-2-Clause-Patent
> >   #
> > @@ -61,6 +62,11 @@ [Guids]
> >     ## SOMETIMES_CONSUMES ## SystemTable
> >     gEfiAcpiTableGuid
> >
> > +  gEfiEventVirtualAddressChangeGuid
> > +
> > +[FeaturePcd]
> > +  gPcAtChipsetPkgTokenSpaceGuid.PcdRtcUseMmio                   ##
> CONSUMES
> > +
> >   [FixedPcd]
> >     gPcAtChipsetPkgTokenSpaceGuid.PcdInitialValueRtcRegisterA     ##
> CONSUMES
> >     gPcAtChipsetPkgTokenSpaceGuid.PcdInitialValueRtcRegisterB     ##
> CONSUMES
> > @@ -72,6 +78,8 @@ [Pcd]
> >     gPcAtChipsetPkgTokenSpaceGuid.PcdMaximalValidYear             ##
> CONSUMES
> >     gPcAtChipsetPkgTokenSpaceGuid.PcdRtcIndexRegister             ##
> CONSUMES
> >     gPcAtChipsetPkgTokenSpaceGuid.PcdRtcTargetRegister            ##
> CONSUMES
> > +  gPcAtChipsetPkgTokenSpaceGuid.PcdRtcIndexRegister64           ##
> CONSUMES
> > +  gPcAtChipsetPkgTokenSpaceGuid.PcdRtcTargetRegister64          ##
> CONSUMES
> >
> >   [Depex]
> >     gEfiVariableArchProtocolGuid AND gEfiVariableWriteArchProtocolGuid
> >
> 
> 
>