MdeModulePkg/Variable: Add a file for NV variable functions

This change adds a dedicated file for variable operations specific
to non-volatile variables. This decreases the overall length of the
relatively large Variable.c file.

Cc: Dandan Bi <dandan.bi@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Michael Kubacki <michael.a.kubacki@intel.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>

6 files changed, 408 insertions, 316 deletions

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
index 2e32905..0bd2f22 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
@@ -23,6 +23,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 **/

 

 #include "Variable.h"

+#include "VariableNonVolatile.h"

 #include "VariableParsing.h"

 

 VARIABLE_MODULE_GLOBAL  *mVariableModuleGlobal;

@@ -3080,25 +3081,6 @@ ReclaimForOS(
 }

 

 /**

-  Get non-volatile maximum variable size.

-

-  @return Non-volatile maximum variable size.

-

-**/

-UINTN

-GetNonVolatileMaxVariableSize (

-  VOID

-  )

-{

-  if (PcdGet32 (PcdHwErrStorageSize) != 0) {

-    return MAX (MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxAuthVariableSize)),

-                PcdGet32 (PcdMaxHardwareErrorVariableSize));

-  } else {

-    return MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxAuthVariableSize));

-  }

-}

-

-/**

   Get maximum variable size, covering both non-volatile and volatile variables.

 

   @return Maximum variable size.

@@ -3123,303 +3105,6 @@ GetMaxVariableSize (
 }

 

 /**

-  Init real non-volatile variable store.

-

-  @param[out] VariableStoreBase Output pointer to real non-volatile variable store base.

-

-  @retval EFI_SUCCESS           Function successfully executed.

-  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

-  @retval EFI_VOLUME_CORRUPTED  Variable Store or Firmware Volume for Variable Store is corrupted.

-

-**/

-EFI_STATUS

-InitRealNonVolatileVariableStore (

-  OUT EFI_PHYSICAL_ADDRESS              *VariableStoreBase

-  )

-{

-  EFI_FIRMWARE_VOLUME_HEADER            *FvHeader;

-  VARIABLE_STORE_HEADER                 *VariableStore;

-  UINT32                                VariableStoreLength;

-  EFI_HOB_GUID_TYPE                     *GuidHob;

-  EFI_PHYSICAL_ADDRESS                  NvStorageBase;

-  UINT8                                 *NvStorageData;

-  UINT32                                NvStorageSize;

-  FAULT_TOLERANT_WRITE_LAST_WRITE_DATA  *FtwLastWriteData;

-  UINT32                                BackUpOffset;

-  UINT32                                BackUpSize;

-  UINT32                                HwErrStorageSize;

-  UINT32                                MaxUserNvVariableSpaceSize;

-  UINT32                                BoottimeReservedNvVariableSpaceSize;

-  EFI_STATUS                            Status;

-  VOID                                  *FtwProtocol;

-

-  mVariableModuleGlobal->FvbInstance = NULL;

-

-  //

-  // Allocate runtime memory used for a memory copy of the FLASH region.

-  // Keep the memory and the FLASH in sync as updates occur.

-  //

-  NvStorageSize = PcdGet32 (PcdFlashNvStorageVariableSize);

-  NvStorageData = AllocateRuntimeZeroPool (NvStorageSize);

-  if (NvStorageData == NULL) {

-    return EFI_OUT_OF_RESOURCES;

-  }

-

-  NvStorageBase = NV_STORAGE_VARIABLE_BASE;

-  ASSERT (NvStorageBase != 0);

-

-  //

-  // Copy NV storage data to the memory buffer.

-  //

-  CopyMem (NvStorageData, (UINT8 *) (UINTN) NvStorageBase, NvStorageSize);

-

-  Status = GetFtwProtocol ((VOID **)&FtwProtocol);

-  //

-  // If FTW protocol has been installed, no need to check FTW last write data hob.

-  //

-  if (EFI_ERROR (Status)) {

-    //

-    // Check the FTW last write data hob.

-    //

-    GuidHob = GetFirstGuidHob (&gEdkiiFaultTolerantWriteGuid);

-    if (GuidHob != NULL) {

-      FtwLastWriteData = (FAULT_TOLERANT_WRITE_LAST_WRITE_DATA *) GET_GUID_HOB_DATA (GuidHob);

-      if (FtwLastWriteData->TargetAddress == NvStorageBase) {

-        DEBUG ((EFI_D_INFO, "Variable: NV storage is backed up in spare block: 0x%x\n", (UINTN) FtwLastWriteData->SpareAddress));

-        //

-        // Copy the backed up NV storage data to the memory buffer from spare block.

-        //

-        CopyMem (NvStorageData, (UINT8 *) (UINTN) (FtwLastWriteData->SpareAddress), NvStorageSize);

-      } else if ((FtwLastWriteData->TargetAddress > NvStorageBase) &&

-                 (FtwLastWriteData->TargetAddress < (NvStorageBase + NvStorageSize))) {

-        //

-        // Flash NV storage from the Offset is backed up in spare block.

-        //

-        BackUpOffset = (UINT32) (FtwLastWriteData->TargetAddress - NvStorageBase);

-        BackUpSize = NvStorageSize - BackUpOffset;

-        DEBUG ((EFI_D_INFO, "Variable: High partial NV storage from offset: %x is backed up in spare block: 0x%x\n", BackUpOffset, (UINTN) FtwLastWriteData->SpareAddress));

-        //

-        // Copy the partial backed up NV storage data to the memory buffer from spare block.

-        //

-        CopyMem (NvStorageData + BackUpOffset, (UINT8 *) (UINTN) FtwLastWriteData->SpareAddress, BackUpSize);

-      }

-    }

-  }

-

-  FvHeader = (EFI_FIRMWARE_VOLUME_HEADER *) NvStorageData;

-

-  //

-  // Check if the Firmware Volume is not corrupted

-  //

-  if ((FvHeader->Signature != EFI_FVH_SIGNATURE) || (!CompareGuid (&gEfiSystemNvDataFvGuid, &FvHeader->FileSystemGuid))) {

-    FreePool (NvStorageData);

-    DEBUG ((EFI_D_ERROR, "Firmware Volume for Variable Store is corrupted\n"));

-    return EFI_VOLUME_CORRUPTED;

-  }

-

-  VariableStore = (VARIABLE_STORE_HEADER *) ((UINTN) FvHeader + FvHeader->HeaderLength);

-  VariableStoreLength = NvStorageSize - FvHeader->HeaderLength;

-  ASSERT (sizeof (VARIABLE_STORE_HEADER) <= VariableStoreLength);

-  ASSERT (VariableStore->Size == VariableStoreLength);

-

-  //

-  // Check if the Variable Store header is not corrupted

-  //

-  if (GetVariableStoreStatus (VariableStore) != EfiValid) {

-    FreePool (NvStorageData);

-    DEBUG((EFI_D_ERROR, "Variable Store header is corrupted\n"));

-    return EFI_VOLUME_CORRUPTED;

-  }

-

-  mNvFvHeaderCache = FvHeader;

-

-  *VariableStoreBase = (EFI_PHYSICAL_ADDRESS) (UINTN) VariableStore;

-

-  HwErrStorageSize = PcdGet32 (PcdHwErrStorageSize);

-  MaxUserNvVariableSpaceSize = PcdGet32 (PcdMaxUserNvVariableSpaceSize);

-  BoottimeReservedNvVariableSpaceSize = PcdGet32 (PcdBoottimeReservedNvVariableSpaceSize);

-

-  //

-  // Note that in EdkII variable driver implementation, Hardware Error Record type variable

-  // is stored with common variable in the same NV region. So the platform integrator should

-  // ensure that the value of PcdHwErrStorageSize is less than the value of

-  // (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)).

-  //

-  ASSERT (HwErrStorageSize < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)));

-  //

-  // Ensure that the value of PcdMaxUserNvVariableSpaceSize is less than the value of

-  // (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)) - PcdGet32 (PcdHwErrStorageSize).

-  //

-  ASSERT (MaxUserNvVariableSpaceSize < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER) - HwErrStorageSize));

-  //

-  // Ensure that the value of PcdBoottimeReservedNvVariableSpaceSize is less than the value of

-  // (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)) - PcdGet32 (PcdHwErrStorageSize).

-  //

-  ASSERT (BoottimeReservedNvVariableSpaceSize < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER) - HwErrStorageSize));

-

-  mVariableModuleGlobal->CommonVariableSpace = ((UINTN) VariableStoreLength - sizeof (VARIABLE_STORE_HEADER) - HwErrStorageSize);

-  mVariableModuleGlobal->CommonMaxUserVariableSpace = ((MaxUserNvVariableSpaceSize != 0) ? MaxUserNvVariableSpaceSize : mVariableModuleGlobal->CommonVariableSpace);

-  mVariableModuleGlobal->CommonRuntimeVariableSpace = mVariableModuleGlobal->CommonVariableSpace - BoottimeReservedNvVariableSpaceSize;

-

-  DEBUG ((EFI_D_INFO, "Variable driver common space: 0x%x 0x%x 0x%x\n", mVariableModuleGlobal->CommonVariableSpace, mVariableModuleGlobal->CommonMaxUserVariableSpace, mVariableModuleGlobal->CommonRuntimeVariableSpace));

-

-  //

-  // The max NV variable size should be < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)).

-  //

-  ASSERT (GetNonVolatileMaxVariableSize () < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)));

-

-  return EFI_SUCCESS;

-}

-

-/**

-  Init emulated non-volatile variable store.

-

-  @param[out] VariableStoreBase Output pointer to emulated non-volatile variable store base.

-

-  @retval EFI_SUCCESS           Function successfully executed.

-  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

-

-**/

-EFI_STATUS

-InitEmuNonVolatileVariableStore (

-  EFI_PHYSICAL_ADDRESS  *VariableStoreBase

-  )

-{

-  VARIABLE_STORE_HEADER *VariableStore;

-  UINT32                VariableStoreLength;

-  BOOLEAN               FullyInitializeStore;

-  UINT32                HwErrStorageSize;

-

-  FullyInitializeStore = TRUE;

-

-  VariableStoreLength = PcdGet32 (PcdVariableStoreSize);

-  ASSERT (sizeof (VARIABLE_STORE_HEADER) <= VariableStoreLength);

-

-  //

-  // Allocate memory for variable store.

-  //

-  if (PcdGet64 (PcdEmuVariableNvStoreReserved) == 0) {

-    VariableStore = (VARIABLE_STORE_HEADER *) AllocateRuntimePool (VariableStoreLength);

-    if (VariableStore == NULL) {

-      return EFI_OUT_OF_RESOURCES;

-    }

-  } else {

-    //

-    // A memory location has been reserved for the NV variable store.  Certain

-    // platforms may be able to preserve a memory range across system resets,

-    // thereby providing better NV variable emulation.

-    //

-    VariableStore =

-      (VARIABLE_STORE_HEADER *)(VOID*)(UINTN)

-        PcdGet64 (PcdEmuVariableNvStoreReserved);

-    if ((VariableStore->Size == VariableStoreLength) &&

-        (CompareGuid (&VariableStore->Signature, &gEfiAuthenticatedVariableGuid) ||

-         CompareGuid (&VariableStore->Signature, &gEfiVariableGuid)) &&

-        (VariableStore->Format == VARIABLE_STORE_FORMATTED) &&

-        (VariableStore->State == VARIABLE_STORE_HEALTHY)) {

-      DEBUG((

-        DEBUG_INFO,

-        "Variable Store reserved at %p appears to be valid\n",

-        VariableStore

-        ));

-      FullyInitializeStore = FALSE;

-    }

-  }

-

-  if (FullyInitializeStore) {

-    SetMem (VariableStore, VariableStoreLength, 0xff);

-    //

-    // Use gEfiAuthenticatedVariableGuid for potential auth variable support.

-    //

-    CopyGuid (&VariableStore->Signature, &gEfiAuthenticatedVariableGuid);

-    VariableStore->Size       = VariableStoreLength;

-    VariableStore->Format     = VARIABLE_STORE_FORMATTED;

-    VariableStore->State      = VARIABLE_STORE_HEALTHY;

-    VariableStore->Reserved   = 0;

-    VariableStore->Reserved1  = 0;

-  }

-

-  *VariableStoreBase = (EFI_PHYSICAL_ADDRESS) (UINTN) VariableStore;

-

-  HwErrStorageSize = PcdGet32 (PcdHwErrStorageSize);

-

-  //

-  // Note that in EdkII variable driver implementation, Hardware Error Record type variable

-  // is stored with common variable in the same NV region. So the platform integrator should

-  // ensure that the value of PcdHwErrStorageSize is less than the value of

-  // (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)).

-  //

-  ASSERT (HwErrStorageSize < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)));

-

-  mVariableModuleGlobal->CommonVariableSpace = ((UINTN) VariableStoreLength - sizeof (VARIABLE_STORE_HEADER) - HwErrStorageSize);

-  mVariableModuleGlobal->CommonMaxUserVariableSpace = mVariableModuleGlobal->CommonVariableSpace;

-  mVariableModuleGlobal->CommonRuntimeVariableSpace = mVariableModuleGlobal->CommonVariableSpace;

-

-  return EFI_SUCCESS;

-}

-

-/**

-  Init non-volatile variable store.

-

-  @retval EFI_SUCCESS           Function successfully executed.

-  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

-  @retval EFI_VOLUME_CORRUPTED  Variable Store or Firmware Volume for Variable Store is corrupted.

-

-**/

-EFI_STATUS

-InitNonVolatileVariableStore (

-  VOID

-  )

-{

-  VARIABLE_HEADER                       *Variable;

-  VARIABLE_HEADER                       *NextVariable;

-  EFI_PHYSICAL_ADDRESS                  VariableStoreBase;

-  UINTN                                 VariableSize;

-  EFI_STATUS                            Status;

-

-  if (PcdGetBool (PcdEmuVariableNvModeEnable)) {

-    Status = InitEmuNonVolatileVariableStore (&VariableStoreBase);

-    if (EFI_ERROR (Status)) {

-      return Status;

-    }

-    mVariableModuleGlobal->VariableGlobal.EmuNvMode = TRUE;

-    DEBUG ((DEBUG_INFO, "Variable driver will work at emulated non-volatile variable mode!\n"));

-  } else {

-    Status = InitRealNonVolatileVariableStore (&VariableStoreBase);

-    if (EFI_ERROR (Status)) {

-      return Status;

-    }

-    mVariableModuleGlobal->VariableGlobal.EmuNvMode = FALSE;

-  }

-

-  mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase = VariableStoreBase;

-  mNvVariableCache = (VARIABLE_STORE_HEADER *) (UINTN) VariableStoreBase;

-  mVariableModuleGlobal->VariableGlobal.AuthFormat = (BOOLEAN)(CompareGuid (&mNvVariableCache->Signature, &gEfiAuthenticatedVariableGuid));

-

-  mVariableModuleGlobal->MaxVariableSize = PcdGet32 (PcdMaxVariableSize);

-  mVariableModuleGlobal->MaxAuthVariableSize = ((PcdGet32 (PcdMaxAuthVariableSize) != 0) ? PcdGet32 (PcdMaxAuthVariableSize) : mVariableModuleGlobal->MaxVariableSize);

-

-  //

-  // Parse non-volatile variable data and get last variable offset.

-  //

-  Variable  = GetStartPointer (mNvVariableCache);

-  while (IsValidVariableHeader (Variable, GetEndPointer (mNvVariableCache))) {

-    NextVariable = GetNextVariablePtr (Variable, mVariableModuleGlobal->VariableGlobal.AuthFormat);

-    VariableSize = (UINTN) NextVariable - (UINTN) Variable;

-    if ((Variable->Attributes & (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_HARDWARE_ERROR_RECORD)) == (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_HARDWARE_ERROR_RECORD)) {

-      mVariableModuleGlobal->HwErrVariableTotalSize += VariableSize;

-    } else {

-      mVariableModuleGlobal->CommonVariableTotalSize += VariableSize;

-    }

-

-    Variable = NextVariable;

-  }

-  mVariableModuleGlobal->NonVolatileLastVariableOffset = (UINTN) Variable - (UINTN) mNvVariableCache;

-

-  return EFI_SUCCESS;

-}

-

-/**

   Flush the HOB variable to flash.

 

   @param[in] VariableName       Name of variable has been updated or deleted.

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableNonVolatile.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableNonVolatile.c
new file mode 100644
index 0000000..0637a82
--- /dev/null
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableNonVolatile.c
@@ -0,0 +1,334 @@
+/** @file

+  Common variable non-volatile store routines.

+

+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>

+SPDX-License-Identifier: BSD-2-Clause-Patent

+

+**/

+

+#include "VariableNonVolatile.h"

+#include "VariableParsing.h"

+

+extern VARIABLE_MODULE_GLOBAL  *mVariableModuleGlobal;

+

+/**

+  Get non-volatile maximum variable size.

+

+  @return Non-volatile maximum variable size.

+

+**/

+UINTN

+GetNonVolatileMaxVariableSize (

+  VOID

+  )

+{

+  if (PcdGet32 (PcdHwErrStorageSize) != 0) {

+    return MAX (MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxAuthVariableSize)),

+                PcdGet32 (PcdMaxHardwareErrorVariableSize));

+  } else {

+    return MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxAuthVariableSize));

+  }

+}

+

+/**

+  Init emulated non-volatile variable store.

+

+  @param[out] VariableStoreBase Output pointer to emulated non-volatile variable store base.

+

+  @retval EFI_SUCCESS           Function successfully executed.

+  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

+

+**/

+EFI_STATUS

+InitEmuNonVolatileVariableStore (

+  OUT EFI_PHYSICAL_ADDRESS  *VariableStoreBase

+  )

+{

+  VARIABLE_STORE_HEADER *VariableStore;

+  UINT32                VariableStoreLength;

+  BOOLEAN               FullyInitializeStore;

+  UINT32                HwErrStorageSize;

+

+  FullyInitializeStore = TRUE;

+

+  VariableStoreLength = PcdGet32 (PcdVariableStoreSize);

+  ASSERT (sizeof (VARIABLE_STORE_HEADER) <= VariableStoreLength);

+

+  //

+  // Allocate memory for variable store.

+  //

+  if (PcdGet64 (PcdEmuVariableNvStoreReserved) == 0) {

+    VariableStore = (VARIABLE_STORE_HEADER *) AllocateRuntimePool (VariableStoreLength);

+    if (VariableStore == NULL) {

+      return EFI_OUT_OF_RESOURCES;

+    }

+  } else {

+    //

+    // A memory location has been reserved for the NV variable store.  Certain

+    // platforms may be able to preserve a memory range across system resets,

+    // thereby providing better NV variable emulation.

+    //

+    VariableStore =

+      (VARIABLE_STORE_HEADER *)(VOID*)(UINTN)

+        PcdGet64 (PcdEmuVariableNvStoreReserved);

+    if ((VariableStore->Size == VariableStoreLength) &&

+        (CompareGuid (&VariableStore->Signature, &gEfiAuthenticatedVariableGuid) ||

+         CompareGuid (&VariableStore->Signature, &gEfiVariableGuid)) &&

+        (VariableStore->Format == VARIABLE_STORE_FORMATTED) &&

+        (VariableStore->State == VARIABLE_STORE_HEALTHY)) {

+      DEBUG((

+        DEBUG_INFO,

+        "Variable Store reserved at %p appears to be valid\n",

+        VariableStore

+        ));

+      FullyInitializeStore = FALSE;

+    }

+  }

+

+  if (FullyInitializeStore) {

+    SetMem (VariableStore, VariableStoreLength, 0xff);

+    //

+    // Use gEfiAuthenticatedVariableGuid for potential auth variable support.

+    //

+    CopyGuid (&VariableStore->Signature, &gEfiAuthenticatedVariableGuid);

+    VariableStore->Size       = VariableStoreLength;

+    VariableStore->Format     = VARIABLE_STORE_FORMATTED;

+    VariableStore->State      = VARIABLE_STORE_HEALTHY;

+    VariableStore->Reserved   = 0;

+    VariableStore->Reserved1  = 0;

+  }

+

+  *VariableStoreBase = (EFI_PHYSICAL_ADDRESS) (UINTN) VariableStore;

+

+  HwErrStorageSize = PcdGet32 (PcdHwErrStorageSize);

+

+  //

+  // Note that in EdkII variable driver implementation, Hardware Error Record type variable

+  // is stored with common variable in the same NV region. So the platform integrator should

+  // ensure that the value of PcdHwErrStorageSize is less than the value of

+  // (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)).

+  //

+  ASSERT (HwErrStorageSize < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)));

+

+  mVariableModuleGlobal->CommonVariableSpace = ((UINTN) VariableStoreLength - sizeof (VARIABLE_STORE_HEADER) - HwErrStorageSize);

+  mVariableModuleGlobal->CommonMaxUserVariableSpace = mVariableModuleGlobal->CommonVariableSpace;

+  mVariableModuleGlobal->CommonRuntimeVariableSpace = mVariableModuleGlobal->CommonVariableSpace;

+

+  return EFI_SUCCESS;

+}

+

+/**

+  Init real non-volatile variable store.

+

+  @param[out] VariableStoreBase Output pointer to real non-volatile variable store base.

+

+  @retval EFI_SUCCESS           Function successfully executed.

+  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

+  @retval EFI_VOLUME_CORRUPTED  Variable Store or Firmware Volume for Variable Store is corrupted.

+

+**/

+EFI_STATUS

+InitRealNonVolatileVariableStore (

+  OUT EFI_PHYSICAL_ADDRESS              *VariableStoreBase

+  )

+{

+  EFI_FIRMWARE_VOLUME_HEADER            *FvHeader;

+  VARIABLE_STORE_HEADER                 *VariableStore;

+  UINT32                                VariableStoreLength;

+  EFI_HOB_GUID_TYPE                     *GuidHob;

+  EFI_PHYSICAL_ADDRESS                  NvStorageBase;

+  UINT8                                 *NvStorageData;

+  UINT32                                NvStorageSize;

+  FAULT_TOLERANT_WRITE_LAST_WRITE_DATA  *FtwLastWriteData;

+  UINT32                                BackUpOffset;

+  UINT32                                BackUpSize;

+  UINT32                                HwErrStorageSize;

+  UINT32                                MaxUserNvVariableSpaceSize;

+  UINT32                                BoottimeReservedNvVariableSpaceSize;

+  EFI_STATUS                            Status;

+  VOID                                  *FtwProtocol;

+

+  mVariableModuleGlobal->FvbInstance = NULL;

+

+  //

+  // Allocate runtime memory used for a memory copy of the FLASH region.

+  // Keep the memory and the FLASH in sync as updates occur.

+  //

+  NvStorageSize = PcdGet32 (PcdFlashNvStorageVariableSize);

+  NvStorageData = AllocateRuntimeZeroPool (NvStorageSize);

+  if (NvStorageData == NULL) {

+    return EFI_OUT_OF_RESOURCES;

+  }

+

+  NvStorageBase = NV_STORAGE_VARIABLE_BASE;

+  ASSERT (NvStorageBase != 0);

+

+  //

+  // Copy NV storage data to the memory buffer.

+  //

+  CopyMem (NvStorageData, (UINT8 *) (UINTN) NvStorageBase, NvStorageSize);

+

+  Status = GetFtwProtocol ((VOID **)&FtwProtocol);

+  //

+  // If FTW protocol has been installed, no need to check FTW last write data hob.

+  //

+  if (EFI_ERROR (Status)) {

+    //

+    // Check the FTW last write data hob.

+    //

+    GuidHob = GetFirstGuidHob (&gEdkiiFaultTolerantWriteGuid);

+    if (GuidHob != NULL) {

+      FtwLastWriteData = (FAULT_TOLERANT_WRITE_LAST_WRITE_DATA *) GET_GUID_HOB_DATA (GuidHob);

+      if (FtwLastWriteData->TargetAddress == NvStorageBase) {

+        DEBUG ((DEBUG_INFO, "Variable: NV storage is backed up in spare block: 0x%x\n", (UINTN) FtwLastWriteData->SpareAddress));

+        //

+        // Copy the backed up NV storage data to the memory buffer from spare block.

+        //

+        CopyMem (NvStorageData, (UINT8 *) (UINTN) (FtwLastWriteData->SpareAddress), NvStorageSize);

+      } else if ((FtwLastWriteData->TargetAddress > NvStorageBase) &&

+                 (FtwLastWriteData->TargetAddress < (NvStorageBase + NvStorageSize))) {

+        //

+        // Flash NV storage from the Offset is backed up in spare block.

+        //

+        BackUpOffset = (UINT32) (FtwLastWriteData->TargetAddress - NvStorageBase);

+        BackUpSize = NvStorageSize - BackUpOffset;

+        DEBUG ((DEBUG_INFO, "Variable: High partial NV storage from offset: %x is backed up in spare block: 0x%x\n", BackUpOffset, (UINTN) FtwLastWriteData->SpareAddress));

+        //

+        // Copy the partial backed up NV storage data to the memory buffer from spare block.

+        //

+        CopyMem (NvStorageData + BackUpOffset, (UINT8 *) (UINTN) FtwLastWriteData->SpareAddress, BackUpSize);

+      }

+    }

+  }

+

+  FvHeader = (EFI_FIRMWARE_VOLUME_HEADER *) NvStorageData;

+

+  //

+  // Check if the Firmware Volume is not corrupted

+  //

+  if ((FvHeader->Signature != EFI_FVH_SIGNATURE) || (!CompareGuid (&gEfiSystemNvDataFvGuid, &FvHeader->FileSystemGuid))) {

+    FreePool (NvStorageData);

+    DEBUG ((DEBUG_ERROR, "Firmware Volume for Variable Store is corrupted\n"));

+    return EFI_VOLUME_CORRUPTED;

+  }

+

+  VariableStore = (VARIABLE_STORE_HEADER *) ((UINTN) FvHeader + FvHeader->HeaderLength);

+  VariableStoreLength = NvStorageSize - FvHeader->HeaderLength;

+  ASSERT (sizeof (VARIABLE_STORE_HEADER) <= VariableStoreLength);

+  ASSERT (VariableStore->Size == VariableStoreLength);

+

+  //

+  // Check if the Variable Store header is not corrupted

+  //

+  if (GetVariableStoreStatus (VariableStore) != EfiValid) {

+    FreePool (NvStorageData);

+    DEBUG((DEBUG_ERROR, "Variable Store header is corrupted\n"));

+    return EFI_VOLUME_CORRUPTED;

+  }

+

+  mNvFvHeaderCache = FvHeader;

+

+  *VariableStoreBase = (EFI_PHYSICAL_ADDRESS) (UINTN) VariableStore;

+

+  HwErrStorageSize = PcdGet32 (PcdHwErrStorageSize);

+  MaxUserNvVariableSpaceSize = PcdGet32 (PcdMaxUserNvVariableSpaceSize);

+  BoottimeReservedNvVariableSpaceSize = PcdGet32 (PcdBoottimeReservedNvVariableSpaceSize);

+

+  //

+  // Note that in EdkII variable driver implementation, Hardware Error Record type variable

+  // is stored with common variable in the same NV region. So the platform integrator should

+  // ensure that the value of PcdHwErrStorageSize is less than the value of

+  // (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)).

+  //

+  ASSERT (HwErrStorageSize < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)));

+  //

+  // Ensure that the value of PcdMaxUserNvVariableSpaceSize is less than the value of

+  // (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)) - PcdGet32 (PcdHwErrStorageSize).

+  //

+  ASSERT (MaxUserNvVariableSpaceSize < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER) - HwErrStorageSize));

+  //

+  // Ensure that the value of PcdBoottimeReservedNvVariableSpaceSize is less than the value of

+  // (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)) - PcdGet32 (PcdHwErrStorageSize).

+  //

+  ASSERT (BoottimeReservedNvVariableSpaceSize < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER) - HwErrStorageSize));

+

+  mVariableModuleGlobal->CommonVariableSpace = ((UINTN) VariableStoreLength - sizeof (VARIABLE_STORE_HEADER) - HwErrStorageSize);

+  mVariableModuleGlobal->CommonMaxUserVariableSpace = ((MaxUserNvVariableSpaceSize != 0) ? MaxUserNvVariableSpaceSize : mVariableModuleGlobal->CommonVariableSpace);

+  mVariableModuleGlobal->CommonRuntimeVariableSpace = mVariableModuleGlobal->CommonVariableSpace - BoottimeReservedNvVariableSpaceSize;

+

+  DEBUG ((

+    DEBUG_INFO,

+    "Variable driver common space: 0x%x 0x%x 0x%x\n",

+    mVariableModuleGlobal->CommonVariableSpace,

+    mVariableModuleGlobal->CommonMaxUserVariableSpace,

+    mVariableModuleGlobal->CommonRuntimeVariableSpace

+    ));

+

+  //

+  // The max NV variable size should be < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)).

+  //

+  ASSERT (GetNonVolatileMaxVariableSize () < (VariableStoreLength - sizeof (VARIABLE_STORE_HEADER)));

+

+  return EFI_SUCCESS;

+}

+

+/**

+  Init non-volatile variable store.

+

+  @retval EFI_SUCCESS           Function successfully executed.

+  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

+  @retval EFI_VOLUME_CORRUPTED  Variable Store or Firmware Volume for Variable Store is corrupted.

+

+**/

+EFI_STATUS

+InitNonVolatileVariableStore (

+  VOID

+  )

+{

+  VARIABLE_HEADER                       *Variable;

+  VARIABLE_HEADER                       *NextVariable;

+  EFI_PHYSICAL_ADDRESS                  VariableStoreBase;

+  UINTN                                 VariableSize;

+  EFI_STATUS                            Status;

+

+  if (PcdGetBool (PcdEmuVariableNvModeEnable)) {

+    Status = InitEmuNonVolatileVariableStore (&VariableStoreBase);

+    if (EFI_ERROR (Status)) {

+      return Status;

+    }

+    mVariableModuleGlobal->VariableGlobal.EmuNvMode = TRUE;

+    DEBUG ((DEBUG_INFO, "Variable driver will work at emulated non-volatile variable mode!\n"));

+  } else {

+    Status = InitRealNonVolatileVariableStore (&VariableStoreBase);

+    if (EFI_ERROR (Status)) {

+      return Status;

+    }

+    mVariableModuleGlobal->VariableGlobal.EmuNvMode = FALSE;

+  }

+

+  mVariableModuleGlobal->VariableGlobal.NonVolatileVariableBase = VariableStoreBase;

+  mNvVariableCache = (VARIABLE_STORE_HEADER *) (UINTN) VariableStoreBase;

+  mVariableModuleGlobal->VariableGlobal.AuthFormat = (BOOLEAN)(CompareGuid (&mNvVariableCache->Signature, &gEfiAuthenticatedVariableGuid));

+

+  mVariableModuleGlobal->MaxVariableSize = PcdGet32 (PcdMaxVariableSize);

+  mVariableModuleGlobal->MaxAuthVariableSize = ((PcdGet32 (PcdMaxAuthVariableSize) != 0) ? PcdGet32 (PcdMaxAuthVariableSize) : mVariableModuleGlobal->MaxVariableSize);

+

+  //

+  // Parse non-volatile variable data and get last variable offset.

+  //

+  Variable  = GetStartPointer (mNvVariableCache);

+  while (IsValidVariableHeader (Variable, GetEndPointer (mNvVariableCache))) {

+    NextVariable = GetNextVariablePtr (Variable, mVariableModuleGlobal->VariableGlobal.AuthFormat);

+    VariableSize = (UINTN) NextVariable - (UINTN) Variable;

+    if ((Variable->Attributes & (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_HARDWARE_ERROR_RECORD)) == (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_HARDWARE_ERROR_RECORD)) {

+      mVariableModuleGlobal->HwErrVariableTotalSize += VariableSize;

+    } else {

+      mVariableModuleGlobal->CommonVariableTotalSize += VariableSize;

+    }

+

+    Variable = NextVariable;

+  }

+  mVariableModuleGlobal->NonVolatileLastVariableOffset = (UINTN) Variable - (UINTN) mNvVariableCache;

+

+  return EFI_SUCCESS;

+}

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableNonVolatile.h b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableNonVolatile.h
new file mode 100644
index 0000000..43653f2
--- /dev/null
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableNonVolatile.h
@@ -0,0 +1,67 @@
+/** @file

+  Common variable non-volatile store routines.

+

+Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>

+SPDX-License-Identifier: BSD-2-Clause-Patent

+

+**/

+

+#ifndef _VARIABLE_NON_VOLATILE_H_

+#define _VARIABLE_NON_VOLATILE_H_

+

+#include "Variable.h"

+

+/**

+  Get non-volatile maximum variable size.

+

+  @return Non-volatile maximum variable size.

+

+**/

+UINTN

+GetNonVolatileMaxVariableSize (

+  VOID

+  );

+

+/**

+  Init emulated non-volatile variable store.

+

+  @param[out] VariableStoreBase Output pointer to emulated non-volatile variable store base.

+

+  @retval EFI_SUCCESS           Function successfully executed.

+  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

+

+**/

+EFI_STATUS

+InitEmuNonVolatileVariableStore (

+  EFI_PHYSICAL_ADDRESS  *VariableStoreBase

+  );

+

+/**

+  Init real non-volatile variable store.

+

+  @param[out] VariableStoreBase Output pointer to real non-volatile variable store base.

+

+  @retval EFI_SUCCESS           Function successfully executed.

+  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

+  @retval EFI_VOLUME_CORRUPTED  Variable Store or Firmware Volume for Variable Store is corrupted.

+

+**/

+EFI_STATUS

+InitRealNonVolatileVariableStore (

+  OUT EFI_PHYSICAL_ADDRESS              *VariableStoreBase

+  );

+

+/**

+  Init non-volatile variable store.

+

+  @retval EFI_SUCCESS           Function successfully executed.

+  @retval EFI_OUT_OF_RESOURCES  Fail to allocate enough memory resource.

+  @retval EFI_VOLUME_CORRUPTED  Variable Store or Firmware Volume for Variable Store is corrupted.

+

+**/

+EFI_STATUS

+InitNonVolatileVariableStore (

+  VOID

+  );

+

+#endif

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
index c35e5fe..08a5490 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
@@ -36,6 +36,8 @@
   Variable.c

   VariableDxe.c

   Variable.h

+  VariableNonVolatile.c

+  VariableNonVolatile.h

   VariableParsing.c

   VariableParsing.h

   PrivilegePolymorphic.h

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf
index 626738b..6dc2721 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf
@@ -45,6 +45,8 @@
   Variable.c

   VariableTraditionalMm.c

   VariableSmm.c

+  VariableNonVolatile.c

+  VariableNonVolatile.h

   VariableParsing.c

   VariableParsing.h

   VarCheck.c

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf
index ff714b1..f8a3742 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf
@@ -45,6 +45,8 @@
   Variable.c

   VariableSmm.c

   VariableStandaloneMm.c

+  VariableNonVolatile.c

+  VariableNonVolatile.h

   VariableParsing.c

   VariableParsing.h

   VarCheck.c