[PATCH 5/5] UefiPayloadPkg: Add support for Firmware Volume Block Protocol

["Sean Rhodes" <sean@starlabs.systems>]

This adds support for FVB in order to support a platform independent
and non-volatile variable store on UefiPayloadPkg. The variable store
makes use the SmmStoreLib to provide an unauthenticed variable store.

Since commit bc744f5893fc4d53275ed26dd8d968011c6a09c1 coreboot supports
the SMMSTORE v2 feature. It implements a SMI handler that is able to
write, read and erase pages in the boot media (SPI flash).
The communication is done using a fixed communication buffer that is
allocated in CBMEM. The existence of this optional feature is advertised
by a coreboot table.
When the SMMSTORE feature is not available the variable emulation is used
by setting PcdEmuVariableNvModeEnable to TRUE.

The DXE component provides runtime services and takes care of virtual to
physical mapping the communication buffers between SMM and OS.

The contents of the variable store can be accessed and modified by any
priviledged application. As authentication is done by runtime services
only the store shouldn't be used to store authenticated variables.

Tested on Linux and Windows 10 on real hardware.
Currently this cannot be tested on coreboot and qemu as it doesn't support
the SMMSTORE on qemu.

Cc: Guo Dong <guo.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Maurice Ma <maurice.ma@intel.com>
Cc: Benjamin You <benjamin.you@intel.com>
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Sean Rhodes <sean@starlabs.systems>
---
 .../SmmStoreFvb/SmmStoreFvbRuntime.c          | 282 ++++++
 .../SmmStoreFvb/SmmStoreFvbRuntime.h          | 111 +++
 .../SmmStoreFvb/SmmStoreFvbRuntimeDxe.c       | 849 ++++++++++++++++++
 .../SmmStoreFvb/SmmStoreFvbRuntimeDxe.inf     |  66 ++
 UefiPayloadPkg/UefiPayloadPkg.dsc             |  24 +-
 UefiPayloadPkg/UefiPayloadPkg.fdf             |   4 +
 6 files changed, 1330 insertions(+), 6 deletions(-)
 create mode 100644 UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntime.c
 create mode 100644 UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntime.h
 create mode 100644 UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.c
 create mode 100644 UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.inf

diff --git a/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntime.c b/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntime.c
new file mode 100644
index 0000000000..08d5c408fb
--- /dev/null
+++ b/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntime.c
@@ -0,0 +1,282 @@
+/** @file  SmmStoreFvbRuntime.c
+
+  Copyright (c) 2022, 9elements GmbH<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/UefiLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/DxeServicesTableLib.h>
+#include <Library/DevicePathLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/PcdLib.h>
+#include <Library/SmmStoreLib.h>
+
+#include "SmmStoreFvbRuntime.h"
+
+STATIC EFI_EVENT  mSmmStoreVirtualAddrChangeEvent;
+
+//
+// Global variable declarations
+//
+SMMSTORE_INSTANCE  *mSmmStoreInstance;
+
+SMMSTORE_INSTANCE  mSmmStoreInstanceTemplate = {
+  SMMSTORE_SIGNATURE, // Signature
+  NULL,               // Handle ... NEED TO BE FILLED
+  {
+    FvbGetAttributes,      // GetAttributes
+    FvbSetAttributes,      // SetAttributes
+    FvbGetPhysicalAddress, // GetPhysicalAddress
+    FvbGetBlockSize,       // GetBlockSize
+    FvbRead,               // Read
+    FvbWrite,              // Write
+    FvbEraseBlocks,        // EraseBlocks
+    NULL,                  // ParentHandle
+  }, //  FvbProtoccol
+  0, // BlockSize ... NEED TO BE FILLED
+  0, // LastBlock ... NEED TO BE FILLED
+  0, // MmioAddress ... NEED TO BE FILLED
+  {
+    {
+      {
+        HARDWARE_DEVICE_PATH,
+        HW_MEMMAP_DP,
+        {
+          (UINT8)(sizeof (MEMMAP_DEVICE_PATH)),
+          (UINT8)(sizeof (MEMMAP_DEVICE_PATH) >> 8)
+        }
+      },
+      EfiMemoryMappedIO,
+      (EFI_PHYSICAL_ADDRESS)0, // NEED TO BE FILLED
+      (EFI_PHYSICAL_ADDRESS)0, // NEED TO BE FILLED
+    },
+    {
+      END_DEVICE_PATH_TYPE,
+      END_ENTIRE_DEVICE_PATH_SUBTYPE,
+      {
+        END_DEVICE_PATH_LENGTH,
+        0
+      }
+    }
+  } // DevicePath
+};
+
+/**
+  Initialize the SmmStore instance.
+
+
+  @param[in]      FvBase         The physical MMIO base address of the FV containing
+                                 the variable store.
+
+  @param[in]      NumberofBlocks Number of blocks within the FV.
+  @param[in]      BlockSize      The size in bytes of one block within the FV.
+  @param[in, out] Instance       The SmmStore instace to initialize
+
+**/
+STATIC
+EFI_STATUS
+SmmStoreInitInstance (
+  IN EFI_PHYSICAL_ADDRESS   FvBase,
+  IN UINTN                  NumberofBlocks,
+  IN UINTN                  BlockSize,
+  IN OUT SMMSTORE_INSTANCE  *Instance
+  )
+{
+  EFI_STATUS             Status;
+  FV_MEMMAP_DEVICE_PATH  *FvDevicePath;
+
+  ASSERT (Instance != NULL);
+
+  Instance->BlockSize   = BlockSize;
+  Instance->LastBlock   = NumberofBlocks - 1;
+  Instance->MmioAddress = FvBase;
+
+  FvDevicePath                                = &Instance->DevicePath;
+  FvDevicePath->MemMapDevPath.StartingAddress = FvBase;
+  FvDevicePath->MemMapDevPath.EndingAddress   = FvBase + BlockSize * NumberofBlocks - 1;
+
+  Status = FvbInitialize (Instance);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  Status = gBS->InstallMultipleProtocolInterfaces (
+                  &Instance->Handle,
+                  &gEfiDevicePathProtocolGuid,
+                  &Instance->DevicePath,
+                  &gEfiFirmwareVolumeBlockProtocolGuid,
+                  &Instance->FvbProtocol,
+                  NULL
+                  );
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  DEBUG ((DEBUG_INFO, "%a: Created a new instance\n", __FUNCTION__));
+
+  return Status;
+}
+
+/**
+  Fixup internal data so that EFI can be call 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
+**/
+STATIC
+VOID
+EFIAPI
+SmmStoreVirtualNotifyEvent (
+  IN EFI_EVENT  Event,
+  IN VOID       *Context
+  )
+{
+  // Convert Fvb
+  EfiConvertPointer (0x0, (VOID **)&mSmmStoreInstance->FvbProtocol.EraseBlocks);
+  EfiConvertPointer (0x0, (VOID **)&mSmmStoreInstance->FvbProtocol.GetAttributes);
+  EfiConvertPointer (0x0, (VOID **)&mSmmStoreInstance->FvbProtocol.GetBlockSize);
+  EfiConvertPointer (0x0, (VOID **)&mSmmStoreInstance->FvbProtocol.GetPhysicalAddress);
+  EfiConvertPointer (0x0, (VOID **)&mSmmStoreInstance->FvbProtocol.Read);
+  EfiConvertPointer (0x0, (VOID **)&mSmmStoreInstance->FvbProtocol.SetAttributes);
+  EfiConvertPointer (0x0, (VOID **)&mSmmStoreInstance->FvbProtocol.Write);
+  EfiConvertPointer (0x0, (VOID **)&mSmmStoreInstance->MmioAddress);
+  EfiConvertPointer (0x0, (VOID **)&mSmmStoreInstance);
+
+  return;
+}
+
+/**
+  The user Entry Point for module SmmStoreFvbRuntimeDxe. The user code starts with this function.
+
+  @param[in] ImageHandle    The firmware allocated handle for the EFI image.
+  @param[in] SystemTable    A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS       The entry point is executed successfully.
+  @retval other             Some error occurs when executing this entry point.
+
+**/
+EFI_STATUS
+EFIAPI
+SmmStoreInitialize (
+  IN EFI_HANDLE        ImageHandle,
+  IN EFI_SYSTEM_TABLE  *SystemTable
+  )
+{
+  EFI_STATUS            Status;
+  EFI_PHYSICAL_ADDRESS  MmioAddress;
+  UINTN                 BlockSize;
+  UINTN                 BlockCount;
+  UINT32                NvStorageBase;
+  UINT32                NvStorageSize;
+  UINT32                NvVariableSize;
+  UINT32                FtwWorkingSize;
+  UINT32                FtwSpareSize;
+
+  Status = SmmStoreLibInitialize ();
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: Failed to initialize SmmStoreLib\n", __FUNCTION__));
+    return Status;
+  }
+
+  Status = SmmStoreLibGetMmioAddress (&MmioAddress);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: Failed to get SmmStore MMIO address\n", __FUNCTION__));
+    SmmStoreLibDeinitialize ();
+    return Status;
+  }
+
+  Status = SmmStoreLibGetNumBlocks (&BlockCount);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: Failed to get SmmStore No. blocks\n", __FUNCTION__));
+    SmmStoreLibDeinitialize ();
+    return Status;
+  }
+
+  Status = SmmStoreLibGetBlockSize (&BlockSize);
+  if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_ERROR, "%a: Failed to get SmmStore block size\n", __FUNCTION__));
+    SmmStoreLibDeinitialize ();
+    return Status;
+  }
+
+  NvStorageSize = BlockCount * BlockSize;
+  NvStorageBase = MmioAddress;
+
+  FtwSpareSize   = (BlockCount / 2) * BlockSize;
+  FtwWorkingSize = BlockSize;
+  NvVariableSize = NvStorageSize - FtwSpareSize - FtwWorkingSize;
+  DEBUG ((DEBUG_INFO, "NvStorageBase:0x%x, NvStorageSize:0x%x\n", NvStorageBase, NvStorageSize));
+
+  if (NvVariableSize >= 0x80000000) {
+    SmmStoreLibDeinitialize ();
+    return EFI_INVALID_PARAMETER;
+  }
+
+  Status = PcdSet32S (PcdFlashNvStorageVariableSize, NvVariableSize);
+  ASSERT_EFI_ERROR (Status);
+  Status = PcdSet32S (PcdFlashNvStorageVariableBase, NvStorageBase);
+  ASSERT_EFI_ERROR (Status);
+  Status = PcdSet64S (PcdFlashNvStorageVariableBase64, NvStorageBase);
+  ASSERT_EFI_ERROR (Status);
+
+  Status = PcdSet32S (PcdFlashNvStorageFtwWorkingSize, FtwWorkingSize);
+  ASSERT_EFI_ERROR (Status);
+  Status = PcdSet32S (PcdFlashNvStorageFtwWorkingBase, NvStorageBase + NvVariableSize);
+  ASSERT_EFI_ERROR (Status);
+  Status = PcdSet64S (PcdFlashNvStorageFtwWorkingBase64, NvStorageBase + NvVariableSize);
+  ASSERT_EFI_ERROR (Status);
+
+  Status = PcdSet32S (PcdFlashNvStorageFtwSpareSize, FtwSpareSize);
+  ASSERT_EFI_ERROR (Status);
+  Status = PcdSet32S (PcdFlashNvStorageFtwSpareBase, NvStorageBase + NvVariableSize + FtwWorkingSize);
+  ASSERT_EFI_ERROR (Status);
+  Status = PcdSet64S (PcdFlashNvStorageFtwSpareBase64, NvStorageBase + NvVariableSize + FtwWorkingSize);
+  ASSERT_EFI_ERROR (Status);
+
+  mSmmStoreInstance = AllocateRuntimeCopyPool (sizeof (SMMSTORE_INSTANCE), &mSmmStoreInstanceTemplate);
+  if (mSmmStoreInstance == NULL) {
+    SmmStoreLibDeinitialize ();
+    DEBUG ((DEBUG_ERROR, "%a: Out of resources\n", __FUNCTION__));
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  Status = SmmStoreInitInstance (
+             MmioAddress,
+             BlockCount,
+             BlockSize,
+             mSmmStoreInstance
+             );
+  if (EFI_ERROR (Status)) {
+    DEBUG (
+      (
+       DEBUG_ERROR,
+       "%a: Fail to create instance for SmmStore\n",
+       __FUNCTION__
+      )
+      );
+    FreePool (mSmmStoreInstance);
+    SmmStoreLibDeinitialize ();
+    return Status;
+  }
+
+  //
+  // Register for the virtual address change event
+  //
+  Status = gBS->CreateEventEx (
+                  EVT_NOTIFY_SIGNAL,
+                  TPL_NOTIFY,
+                  SmmStoreVirtualNotifyEvent,
+                  NULL,
+                  &gEfiEventVirtualAddressChangeGuid,
+                  &mSmmStoreVirtualAddrChangeEvent
+                  );
+  ASSERT_EFI_ERROR (Status);
+
+  return Status;
+}
diff --git a/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntime.h b/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntime.h
new file mode 100644
index 0000000000..8015d12d13
--- /dev/null
+++ b/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntime.h
@@ -0,0 +1,111 @@
+/** @file  SmmStoreFvbRuntime.h
+
+  Copyright (c) 2022, 9elements GmbH<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef SMM_STORE_DXE_H_
+#define SMM_STORE_DXE_H_
+
+#include <Base.h>
+#include <PiDxe.h>
+
+#include <Guid/EventGroup.h>
+
+#include <Protocol/FirmwareVolumeBlock.h>
+
+#include <Library/DebugLib.h>
+#include <Library/IoLib.h>
+#include <Library/UefiLib.h>
+#include <Library/UefiRuntimeLib.h>
+
+#define SMMSTORE_SIGNATURE  SIGNATURE_32('S', 'M', 'M', 'S')
+#define INSTANCE_FROM_FVB_THIS(a)  CR(a, SMMSTORE_INSTANCE, FvbProtocol, SMMSTORE_SIGNATURE)
+
+typedef struct _SMMSTORE_INSTANCE SMMSTORE_INSTANCE;
+
+typedef struct {
+  MEMMAP_DEVICE_PATH          MemMapDevPath;
+  EFI_DEVICE_PATH_PROTOCOL    EndDevPath;
+} FV_MEMMAP_DEVICE_PATH;
+
+struct _SMMSTORE_INSTANCE {
+  UINT32                                 Signature;
+  EFI_HANDLE                             Handle;
+  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL    FvbProtocol;
+  UINTN                                  BlockSize;
+  UINTN                                  LastBlock;
+  EFI_PHYSICAL_ADDRESS                   MmioAddress;
+  FV_MEMMAP_DEVICE_PATH                  DevicePath;
+};
+
+//
+// SmmStoreFvbRuntimeDxe.c
+//
+
+EFI_STATUS
+EFIAPI
+FvbInitialize (
+  IN SMMSTORE_INSTANCE  *Instance
+  );
+
+EFI_STATUS
+EFIAPI
+FvbGetAttributes (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  OUT       EFI_FVB_ATTRIBUTES_2                 *Attributes
+  );
+
+EFI_STATUS
+EFIAPI
+FvbSetAttributes (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  IN OUT    EFI_FVB_ATTRIBUTES_2                 *Attributes
+  );
+
+EFI_STATUS
+EFIAPI
+FvbGetPhysicalAddress (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  OUT       EFI_PHYSICAL_ADDRESS                 *Address
+  );
+
+EFI_STATUS
+EFIAPI
+FvbGetBlockSize (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  IN        EFI_LBA                              Lba,
+  OUT       UINTN                                *BlockSize,
+  OUT       UINTN                                *NumberOfBlocks
+  );
+
+EFI_STATUS
+EFIAPI
+FvbRead (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  IN        EFI_LBA                              Lba,
+  IN        UINTN                                Offset,
+  IN OUT    UINTN                                *NumBytes,
+  IN OUT    UINT8                                *Buffer
+  );
+
+EFI_STATUS
+EFIAPI
+FvbWrite (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  IN        EFI_LBA                              Lba,
+  IN        UINTN                                Offset,
+  IN OUT    UINTN                                *NumBytes,
+  IN        UINT8                                *Buffer
+  );
+
+EFI_STATUS
+EFIAPI
+FvbEraseBlocks (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  ...
+  );
+
+#endif // SMM_STORE_DXE_H_
diff --git a/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.c b/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.c
new file mode 100644
index 0000000000..14d4ec324d
--- /dev/null
+++ b/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.c
@@ -0,0 +1,849 @@
+/** @file  SmmStoreFvbRuntimeDxe.c
+
+  Copyright (c) 2022, 9elements GmbH<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiDxe.h>
+
+#include <Library/PcdLib.h>
+#include <Library/BaseLib.h>
+#include <Library/HobLib.h>
+#include <Library/UefiLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/DxeServicesTableLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/SmmStoreLib.h>
+
+#include <Guid/VariableFormat.h>
+#include <Guid/SystemNvDataGuid.h>
+#include <Guid/NvVarStoreFormatted.h>
+
+#include "SmmStoreFvbRuntime.h"
+
+///
+/// The Firmware Volume Block Protocol is the low-level interface
+/// to a firmware volume. File-level access to a firmware volume
+/// should not be done using the Firmware Volume Block Protocol.
+/// Normal access to a firmware volume must use the Firmware
+/// Volume Protocol. Typically, only the file system driver that
+/// produces the Firmware Volume Protocol will bind to the
+/// Firmware Volume Block Protocol.
+///
+
+/**
+  Initialises the FV Header and Variable Store Header
+  to support variable operations.
+
+  @param[in]  Instance - Pointer to SmmStore instance
+
+**/
+EFI_STATUS
+InitializeFvAndVariableStoreHeaders (
+  IN SMMSTORE_INSTANCE  *Instance
+  )
+{
+  EFI_STATUS                  Status;
+  VOID                        *Headers;
+  UINTN                       HeadersLength;
+  EFI_FIRMWARE_VOLUME_HEADER  *FirmwareVolumeHeader;
+  VARIABLE_STORE_HEADER       *VariableStoreHeader;
+  UINT32                      NvStorageFtwSpareSize;
+  UINT32                      NvStorageFtwWorkingSize;
+  UINT32                      NvStorageVariableSize;
+  UINT64                      NvStorageFtwSpareBase;
+  UINT64                      NvStorageFtwWorkingBase;
+  UINT64                      NvStorageVariableBase;
+
+  HeadersLength = sizeof (EFI_FIRMWARE_VOLUME_HEADER) + sizeof (EFI_FV_BLOCK_MAP_ENTRY) + sizeof (VARIABLE_STORE_HEADER);
+  Headers       = AllocateZeroPool (HeadersLength);
+
+  NvStorageFtwWorkingSize = PcdGet32 (PcdFlashNvStorageFtwWorkingSize);
+  NvStorageFtwSpareSize   = PcdGet32 (PcdFlashNvStorageFtwSpareSize);
+  NvStorageVariableSize   = PcdGet32 (PcdFlashNvStorageVariableSize);
+
+  NvStorageFtwSpareBase = (PcdGet64 (PcdFlashNvStorageFtwSpareBase64) != 0) ?
+                          PcdGet64 (PcdFlashNvStorageFtwSpareBase64) : PcdGet32 (PcdFlashNvStorageFtwSpareBase);
+  NvStorageFtwWorkingBase = (PcdGet64 (PcdFlashNvStorageFtwWorkingBase64) != 0) ?
+                            PcdGet64 (PcdFlashNvStorageFtwWorkingBase64) : PcdGet32 (PcdFlashNvStorageFtwWorkingBase);
+  NvStorageVariableBase = (PcdGet64 (PcdFlashNvStorageVariableBase64) != 0) ?
+                          PcdGet64 (PcdFlashNvStorageVariableBase64) : PcdGet32 (PcdFlashNvStorageVariableBase);
+
+  // FirmwareVolumeHeader->FvLength is declared to have the Variable area AND the FTW working area AND the FTW Spare contiguous.
+  if ((NvStorageVariableBase + NvStorageVariableSize) != NvStorageFtwWorkingBase) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: NvStorageFtwWorkingBase is not contiguous with NvStorageVariableBase region\n",
+      __FUNCTION__
+      ));
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if ((NvStorageFtwWorkingBase + NvStorageFtwWorkingSize) != NvStorageFtwSpareBase) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: NvStorageFtwSpareBase is not contiguous with NvStorageFtwWorkingBase region\n",
+      __FUNCTION__
+      ));
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Check if the size of the area is at least one block size
+  if ((NvStorageVariableSize <= 0) || (NvStorageVariableSize / Instance->BlockSize <= 0)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: NvStorageVariableSize is 0x%x, should be atleast one block size\n",
+      __FUNCTION__,
+      NvStorageVariableSize
+      ));
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if ((NvStorageFtwWorkingSize <= 0) || (NvStorageFtwWorkingSize / Instance->BlockSize <= 0)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: NvStorageFtwWorkingSize is 0x%x, should be atleast one block size\n",
+      __FUNCTION__,
+      NvStorageFtwWorkingSize
+      ));
+    return EFI_INVALID_PARAMETER;
+  }
+
+  if ((NvStorageFtwSpareSize <= 0) || (NvStorageFtwSpareSize / Instance->BlockSize <= 0)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "%a: NvStorageFtwSpareSize is 0x%x, should be atleast one block size\n",
+      __FUNCTION__,
+      NvStorageFtwSpareSize
+      ));
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // Ensure the Variable area Base Addresses are aligned on a block size boundaries
+  if ((NvStorageVariableBase % Instance->BlockSize != 0) ||
+      (NvStorageFtwWorkingBase % Instance->BlockSize != 0) ||
+      (NvStorageFtwSpareBase % Instance->BlockSize != 0))
+  {
+    DEBUG ((DEBUG_ERROR, "%a: NvStorage Base addresses must be aligned to block size boundaries", __FUNCTION__));
+    return EFI_INVALID_PARAMETER;
+  }
+
+  //
+  // EFI_FIRMWARE_VOLUME_HEADER
+  //
+  FirmwareVolumeHeader = (EFI_FIRMWARE_VOLUME_HEADER *)Headers;
+  CopyGuid (&FirmwareVolumeHeader->FileSystemGuid, &gEfiSystemNvDataFvGuid);
+  FirmwareVolumeHeader->FvLength =
+    PcdGet32 (PcdFlashNvStorageVariableSize) +
+    PcdGet32 (PcdFlashNvStorageFtwWorkingSize) +
+    PcdGet32 (PcdFlashNvStorageFtwSpareSize);
+  FirmwareVolumeHeader->Signature  = EFI_FVH_SIGNATURE;
+  FirmwareVolumeHeader->Attributes = (EFI_FVB_ATTRIBUTES_2)(
+                                                            EFI_FVB2_READ_ENABLED_CAP   | // Reads may be enabled
+                                                            EFI_FVB2_READ_STATUS        | // Reads are currently enabled
+                                                            EFI_FVB2_STICKY_WRITE       | // A block erase is required to flip bits into EFI_FVB2_ERASE_POLARITY
+                                                            EFI_FVB2_MEMORY_MAPPED      | // It is memory mapped
+                                                            EFI_FVB2_ERASE_POLARITY     | // After erasure all bits take this value (i.e. '1')
+                                                            EFI_FVB2_WRITE_STATUS       | // Writes are currently enabled
+                                                            EFI_FVB2_WRITE_ENABLED_CAP    // Writes may be enabled
+                                                            );
+  FirmwareVolumeHeader->HeaderLength          = sizeof (EFI_FIRMWARE_VOLUME_HEADER) + sizeof (EFI_FV_BLOCK_MAP_ENTRY);
+  FirmwareVolumeHeader->Revision              = EFI_FVH_REVISION;
+  FirmwareVolumeHeader->BlockMap[0].NumBlocks = Instance->LastBlock + 1;
+  FirmwareVolumeHeader->BlockMap[0].Length    = Instance->BlockSize;
+  FirmwareVolumeHeader->BlockMap[1].NumBlocks = 0;
+  FirmwareVolumeHeader->BlockMap[1].Length    = 0;
+  FirmwareVolumeHeader->Checksum              = CalculateCheckSum16 ((UINT16 *)FirmwareVolumeHeader, FirmwareVolumeHeader->HeaderLength);
+
+  //
+  // VARIABLE_STORE_HEADER
+  //
+  VariableStoreHeader = (VARIABLE_STORE_HEADER *)((UINTN)Headers + FirmwareVolumeHeader->HeaderLength);
+  CopyGuid (&VariableStoreHeader->Signature, &gEfiVariableGuid);
+  VariableStoreHeader->Size   = PcdGet32 (PcdFlashNvStorageVariableSize) - FirmwareVolumeHeader->HeaderLength;
+  VariableStoreHeader->Format = VARIABLE_STORE_FORMATTED;
+  VariableStoreHeader->State  = VARIABLE_STORE_HEALTHY;
+
+  // Install the combined super-header in the NorFlash
+  Status = FvbWrite (&Instance->FvbProtocol, 0, 0, &HeadersLength, Headers);
+
+  FreePool (Headers);
+  return Status;
+}
+
+/**
+  Check the integrity of firmware volume header.
+
+  @retval  EFI_SUCCESS   - The firmware volume is consistent
+  @retval  EFI_NOT_FOUND - The firmware volume has been corrupted.
+
+**/
+EFI_STATUS
+ValidateFvHeader (
+  VOID
+  )
+{
+  UINT16                      Checksum;
+  EFI_FIRMWARE_VOLUME_HEADER  *FwVolHeader;
+  VARIABLE_STORE_HEADER       *VariableStoreHeader;
+  UINTN                       VariableStoreLength;
+  UINTN                       FvLength;
+  EFI_STATUS                  TempStatus;
+  UINTN                       BufferSize;
+  UINTN                       BufferSizeReqested;
+
+  BufferSizeReqested = sizeof (EFI_FIRMWARE_VOLUME_HEADER);
+  FwVolHeader        = (EFI_FIRMWARE_VOLUME_HEADER *)AllocatePool (BufferSizeReqested);
+  if (!FwVolHeader) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  BufferSize = BufferSizeReqested;
+  TempStatus = SmmStoreLibRead (0, 0, &BufferSize, (UINT8 *)FwVolHeader);
+  if (EFI_ERROR (TempStatus) || (BufferSizeReqested != BufferSize)) {
+    FreePool (FwVolHeader);
+    return EFI_DEVICE_ERROR;
+  }
+
+  FvLength = PcdGet32 (PcdFlashNvStorageVariableSize) + PcdGet32 (PcdFlashNvStorageFtwWorkingSize) +
+             PcdGet32 (PcdFlashNvStorageFtwSpareSize);
+
+  //
+  // Verify the header revision, header signature, length
+  // Length of FvBlock cannot be 2**64-1
+  // HeaderLength cannot be an odd number
+  //
+  if (  (FwVolHeader->Revision  != EFI_FVH_REVISION)
+     || (FwVolHeader->Signature != EFI_FVH_SIGNATURE)
+     || (FwVolHeader->FvLength  != FvLength)
+        )
+  {
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: No Firmware Volume header present\n",
+      __FUNCTION__
+      ));
+    FreePool (FwVolHeader);
+    return EFI_NOT_FOUND;
+  }
+
+  // Check the Firmware Volume Guid
+  if ( CompareGuid (&FwVolHeader->FileSystemGuid, &gEfiSystemNvDataFvGuid) == FALSE ) {
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: Firmware Volume Guid non-compatible\n",
+      __FUNCTION__
+      ));
+    FreePool (FwVolHeader);
+    return EFI_NOT_FOUND;
+  }
+
+  BufferSizeReqested = FwVolHeader->HeaderLength;
+  FreePool (FwVolHeader);
+  FwVolHeader = (EFI_FIRMWARE_VOLUME_HEADER *)AllocatePool (BufferSizeReqested);
+  if (!FwVolHeader) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  BufferSize = BufferSizeReqested;
+  TempStatus = SmmStoreLibRead (0, 0, &BufferSize, (UINT8 *)FwVolHeader);
+  if (EFI_ERROR (TempStatus) || (BufferSizeReqested != BufferSize)) {
+    FreePool (FwVolHeader);
+    return EFI_DEVICE_ERROR;
+  }
+
+  // Verify the header checksum
+  Checksum = CalculateSum16 ((UINT16 *)FwVolHeader, FwVolHeader->HeaderLength);
+  if (Checksum != 0) {
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: FV checksum is invalid (Checksum:0x%X)\n",
+      __FUNCTION__,
+      Checksum
+      ));
+    FreePool (FwVolHeader);
+    return EFI_NOT_FOUND;
+  }
+
+  BufferSizeReqested  = sizeof (VARIABLE_STORE_HEADER);
+  VariableStoreHeader = (VARIABLE_STORE_HEADER *)AllocatePool (BufferSizeReqested);
+  if (!VariableStoreHeader) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  BufferSize = BufferSizeReqested;
+  TempStatus = SmmStoreLibRead (0, FwVolHeader->HeaderLength, &BufferSize, (UINT8 *)VariableStoreHeader);
+  if (EFI_ERROR (TempStatus) || (BufferSizeReqested != BufferSize)) {
+    FreePool (VariableStoreHeader);
+    FreePool (FwVolHeader);
+    return EFI_DEVICE_ERROR;
+  }
+
+  // Check the Variable Store Guid
+  if (!CompareGuid (&VariableStoreHeader->Signature, &gEfiVariableGuid) &&
+      !CompareGuid (&VariableStoreHeader->Signature, &gEfiAuthenticatedVariableGuid))
+  {
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: Variable Store Guid non-compatible\n",
+      __FUNCTION__
+      ));
+    FreePool (FwVolHeader);
+    FreePool (VariableStoreHeader);
+    return EFI_NOT_FOUND;
+  }
+
+  VariableStoreLength = PcdGet32 (PcdFlashNvStorageVariableSize) - FwVolHeader->HeaderLength;
+  if (VariableStoreHeader->Size != VariableStoreLength) {
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: Variable Store Length does not match\n",
+      __FUNCTION__
+      ));
+    FreePool (FwVolHeader);
+    FreePool (VariableStoreHeader);
+    return EFI_NOT_FOUND;
+  }
+
+  FreePool (FwVolHeader);
+  FreePool (VariableStoreHeader);
+
+  return EFI_SUCCESS;
+}
+
+/**
+ The GetAttributes() function retrieves the attributes and
+ current settings of the block.
+
+ @param This         Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
+
+ @param Attributes   Pointer to EFI_FVB_ATTRIBUTES_2 in which the attributes and
+                     current settings are returned.
+                     Type EFI_FVB_ATTRIBUTES_2 is defined in EFI_FIRMWARE_VOLUME_HEADER.
+
+ @retval EFI_SUCCESS The firmware volume attributes were returned.
+
+ **/
+EFI_STATUS
+EFIAPI
+FvbGetAttributes (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  OUT       EFI_FVB_ATTRIBUTES_2                 *Attributes
+  )
+{
+  EFI_FVB_ATTRIBUTES_2  FlashFvbAttributes;
+
+  FlashFvbAttributes = (EFI_FVB_ATTRIBUTES_2)(
+                                              EFI_FVB2_READ_STATUS      | // Reads are currently enabled
+                                              EFI_FVB2_WRITE_STATUS     | // Writes are enabled
+                                              EFI_FVB2_STICKY_WRITE     | // A block erase is required to flip bits into EFI_FVB2_ERASE_POLARITY
+                                              EFI_FVB2_MEMORY_MAPPED    | // It is memory mapped
+                                              EFI_FVB2_ERASE_POLARITY     // After erasure all bits take this value (i.e. '1')
+                                              );
+
+  *Attributes = FlashFvbAttributes;
+
+  DEBUG ((DEBUG_BLKIO, "FvbGetAttributes(0x%X)\n", *Attributes));
+
+  return EFI_SUCCESS;
+}
+
+/**
+ The SetAttributes() function sets configurable firmware volume attributes
+ and returns the new settings of the firmware volume.
+
+
+ @param This                     Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
+
+ @param Attributes               On input, Attributes is a pointer to EFI_FVB_ATTRIBUTES_2
+                                 that contains the desired firmware volume settings.
+                                 On successful return, it contains the new settings of
+                                 the firmware volume.
+                                 Type EFI_FVB_ATTRIBUTES_2 is defined in EFI_FIRMWARE_VOLUME_HEADER.
+
+ @retval EFI_SUCCESS             The firmware volume attributes were returned.
+
+ @retval EFI_INVALID_PARAMETER   The attributes requested are in conflict with the capabilities
+                                 as declared in the firmware volume header.
+
+ **/
+EFI_STATUS
+EFIAPI
+FvbSetAttributes (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  IN OUT    EFI_FVB_ATTRIBUTES_2                 *Attributes
+  )
+{
+  DEBUG ((DEBUG_ERROR, "FvbSetAttributes(0x%X) is not supported\n", *Attributes));
+  return EFI_UNSUPPORTED;
+}
+
+/**
+ The GetPhysicalAddress() function retrieves the base address of
+ a memory-mapped firmware volume. This function should be called
+ only for memory-mapped firmware volumes.
+
+ @param This               Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
+
+ @param Address            Pointer to a caller-allocated
+                           EFI_PHYSICAL_ADDRESS that, on successful
+                           return from GetPhysicalAddress(), contains the
+                           base address of the firmware volume.
+
+ @retval EFI_SUCCESS       The firmware volume base address was returned.
+
+ @retval EFI_NOT_SUPPORTED The firmware volume is not memory mapped.
+
+ **/
+EFI_STATUS
+EFIAPI
+FvbGetPhysicalAddress (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  OUT       EFI_PHYSICAL_ADDRESS                 *Address
+  )
+{
+  SMMSTORE_INSTANCE  *Instance;
+
+  Instance = INSTANCE_FROM_FVB_THIS (This);
+
+  ASSERT (Address != NULL);
+  *Address = Instance->MmioAddress;
+
+  return EFI_SUCCESS;
+}
+
+/**
+ The GetBlockSize() function retrieves the size of the requested
+ block. It also returns the number of additional blocks with
+ the identical size. The GetBlockSize() function is used to
+ retrieve the block map (see EFI_FIRMWARE_VOLUME_HEADER).
+
+
+ @param This                     Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
+
+ @param Lba                      Indicates the block for which to return the size.
+
+ @param BlockSize                Pointer to a caller-allocated UINTN in which
+                                 the size of the block is returned.
+
+ @param NumberOfBlocks           Pointer to a caller-allocated UINTN in
+                                 which the number of consecutive blocks,
+                                 starting with Lba, is returned. All
+                                 blocks in this range have a size of
+                                 BlockSize.
+
+
+ @retval EFI_SUCCESS             The firmware volume base address was returned.
+
+ @retval EFI_INVALID_PARAMETER   The requested LBA is out of range.
+
+ **/
+EFI_STATUS
+EFIAPI
+FvbGetBlockSize (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  IN        EFI_LBA                              Lba,
+  OUT       UINTN                                *BlockSize,
+  OUT       UINTN                                *NumberOfBlocks
+  )
+{
+  EFI_STATUS         Status;
+  SMMSTORE_INSTANCE  *Instance;
+
+  Instance = INSTANCE_FROM_FVB_THIS (This);
+
+  DEBUG ((DEBUG_BLKIO, "FvbGetBlockSize(Lba=%ld, BlockSize=0x%x, LastBlock=%ld)\n", Lba, Instance->BlockSize, Instance->LastBlock));
+
+  if (Lba > Instance->LastBlock) {
+    DEBUG ((DEBUG_ERROR, "FvbGetBlockSize: ERROR - Parameter LBA %ld is beyond the last Lba (%ld).\n", Lba, Instance->LastBlock));
+    Status = EFI_INVALID_PARAMETER;
+  } else {
+    *BlockSize      = (UINTN)Instance->BlockSize;
+    *NumberOfBlocks = (UINTN)(Instance->LastBlock - Lba + 1);
+
+    DEBUG ((DEBUG_BLKIO, "FvbGetBlockSize: *BlockSize=0x%x, *NumberOfBlocks=0x%x.\n", *BlockSize, *NumberOfBlocks));
+
+    Status = EFI_SUCCESS;
+  }
+
+  return Status;
+}
+
+/**
+ Reads the specified number of bytes into a buffer from the specified block.
+
+ The Read() function reads the requested number of bytes from the
+ requested block and stores them in the provided buffer.
+ Implementations should be mindful that the firmware volume
+ might be in the ReadDisabled state. If it is in this state,
+ the Read() function must return the status code
+ EFI_ACCESS_DENIED without modifying the contents of the
+ buffer. The Read() function must also prevent spanning block
+ boundaries. If a read is requested that would span a block
+ boundary, the read must read up to the boundary but not
+ beyond. The output parameter NumBytes must be set to correctly
+ indicate the number of bytes actually read. The caller must be
+ aware that a read may be partially completed.
+
+ @param This                 Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
+
+ @param Lba                  The starting logical block index from which to read.
+
+ @param Offset               Offset into the block at which to begin reading.
+
+ @param NumBytes             Pointer to a UINTN.
+                             At entry, *NumBytes contains the total size of the buffer.
+                             At exit, *NumBytes contains the total number of bytes read.
+
+ @param Buffer               Pointer to a caller-allocated buffer that will be used
+                             to hold the data that is read.
+
+ @retval EFI_SUCCESS         The firmware volume was read successfully,  and contents are
+                             in Buffer.
+
+ @retval EFI_BAD_BUFFER_SIZE Read attempted across an LBA boundary.
+                             On output, NumBytes contains the total number of bytes
+                             returned in Buffer.
+
+ @retval EFI_ACCESS_DENIED   The firmware volume is in the ReadDisabled state.
+
+ @retval EFI_DEVICE_ERROR    The block device is not functioning correctly and could not be read.
+
+ **/
+EFI_STATUS
+EFIAPI
+FvbRead (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  IN        EFI_LBA                              Lba,
+  IN        UINTN                                Offset,
+  IN OUT    UINTN                                *NumBytes,
+  IN OUT    UINT8                                *Buffer
+  )
+{
+  UINTN              BlockSize;
+  SMMSTORE_INSTANCE  *Instance;
+
+  Instance = INSTANCE_FROM_FVB_THIS (This);
+
+  DEBUG ((DEBUG_BLKIO, "FvbRead(Parameters: Lba=%ld, Offset=0x%x, *NumBytes=0x%x, Buffer @ 0x%08x)\n", Lba, Offset, *NumBytes, Buffer));
+
+  // Cache the block size to avoid de-referencing pointers all the time
+  BlockSize = Instance->BlockSize;
+
+  // The read must not span block boundaries.
+  // We need to check each variable individually because adding two large values together overflows.
+  if ((Offset               >= BlockSize) ||
+      (*NumBytes            >  BlockSize) ||
+      ((Offset + *NumBytes) >  BlockSize))
+  {
+    DEBUG ((DEBUG_ERROR, "FvbRead: ERROR - EFI_BAD_BUFFER_SIZE: (Offset=0x%x + NumBytes=0x%x) > BlockSize=0x%x\n", Offset, *NumBytes, BlockSize));
+    return EFI_BAD_BUFFER_SIZE;
+  }
+
+  // We must have some bytes to read
+  if (*NumBytes == 0) {
+    return EFI_BAD_BUFFER_SIZE;
+  }
+
+  return SmmStoreLibRead (Lba, Offset, NumBytes, Buffer);
+}
+
+/**
+ Writes the specified number of bytes from the input buffer to the block.
+
+ The Write() function writes the specified number of bytes from
+ the provided buffer to the specified block and offset. If the
+ firmware volume is sticky write, the caller must ensure that
+ all the bits of the specified range to write are in the
+ EFI_FVB_ERASE_POLARITY state before calling the Write()
+ function, or else the result will be unpredictable. This
+ unpredictability arises because, for a sticky-write firmware
+ volume, a write may negate a bit in the EFI_FVB_ERASE_POLARITY
+ state but cannot flip it back again.  Before calling the
+ Write() function,  it is recommended for the caller to first call
+ the EraseBlocks() function to erase the specified block to
+ write. A block erase cycle will transition bits from the
+ (NOT)EFI_FVB_ERASE_POLARITY state back to the
+ EFI_FVB_ERASE_POLARITY state. Implementations should be
+ mindful that the firmware volume might be in the WriteDisabled
+ state. If it is in this state, the Write() function must
+ return the status code EFI_ACCESS_DENIED without modifying the
+ contents of the firmware volume. The Write() function must
+ also prevent spanning block boundaries. If a write is
+ requested that spans a block boundary, the write must store up
+ to the boundary but not beyond. The output parameter NumBytes
+ must be set to correctly indicate the number of bytes actually
+ written. The caller must be aware that a write may be
+ partially completed. All writes, partial or otherwise, must be
+ fully flushed to the hardware before the Write() service
+ returns.
+
+ @param This                 Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL instance.
+
+ @param Lba                  The starting logical block index to write to.
+
+ @param Offset               Offset into the block at which to begin writing.
+
+ @param NumBytes             The pointer to a UINTN.
+                             At entry, *NumBytes contains the total size of the buffer.
+                             At exit, *NumBytes contains the total number of bytes actually written.
+
+ @param Buffer               The pointer to a caller-allocated buffer that contains the source for the write.
+
+ @retval EFI_SUCCESS         The firmware volume was written successfully.
+
+ @retval EFI_BAD_BUFFER_SIZE The write was attempted across an LBA boundary.
+                             On output, NumBytes contains the total number of bytes
+                             actually written.
+
+ @retval EFI_ACCESS_DENIED   The firmware volume is in the WriteDisabled state.
+
+ @retval EFI_DEVICE_ERROR    The block device is malfunctioning and could not be written.
+
+
+ **/
+EFI_STATUS
+EFIAPI
+FvbWrite (
+  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  IN        EFI_LBA                              Lba,
+  IN        UINTN                                Offset,
+  IN OUT    UINTN                                *NumBytes,
+  IN        UINT8                                *Buffer
+  )
+{
+  UINTN              BlockSize;
+  SMMSTORE_INSTANCE  *Instance;
+
+  Instance = INSTANCE_FROM_FVB_THIS (This);
+
+  DEBUG ((DEBUG_BLKIO, "FvbWrite(Parameters: Lba=%ld, Offset=0x%x, *NumBytes=0x%x, Buffer @ 0x%08x)\n", Lba, Offset, *NumBytes, Buffer));
+
+  // Cache the block size to avoid de-referencing pointers all the time
+  BlockSize = Instance->BlockSize;
+
+  // The read must not span block boundaries.
+  // We need to check each variable individually because adding two large values together overflows.
+  if ((Offset               >= BlockSize) ||
+      (*NumBytes            >  BlockSize) ||
+      ((Offset + *NumBytes) >  BlockSize))
+  {
+    DEBUG ((DEBUG_ERROR, "FvbRead: ERROR - EFI_BAD_BUFFER_SIZE: (Offset=0x%x + NumBytes=0x%x) > BlockSize=0x%x\n", Offset, *NumBytes, BlockSize));
+    return EFI_BAD_BUFFER_SIZE;
+  }
+
+  // We must have some bytes to read
+  if (*NumBytes == 0) {
+    return EFI_BAD_BUFFER_SIZE;
+  }
+
+  return SmmStoreLibWrite (Lba, Offset, NumBytes, Buffer);
+}
+
+/**
+ Erases and initialises a firmware volume block.
+
+ The EraseBlocks() function erases one or more blocks as denoted
+ by the variable argument list. The entire parameter list of
+ blocks must be verified before erasing any blocks. If a block is
+ requested that does not exist within the associated firmware
+ volume (it has a larger index than the last block of the
+ firmware volume), the EraseBlocks() function must return the
+ status code EFI_INVALID_PARAMETER without modifying the contents
+ of the firmware volume. Implementations should be mindful that
+ the firmware volume might be in the WriteDisabled state. If it
+ is in this state, the EraseBlocks() function must return the
+ status code EFI_ACCESS_DENIED without modifying the contents of
+ the firmware volume. All calls to EraseBlocks() must be fully
+ flushed to the hardware before the EraseBlocks() service
+ returns.
+
+ @param This                     Indicates the EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL
+ instance.
+
+ @param ...                      The variable argument list is a list of tuples.
+                                 Each tuple describes a range of LBAs to erase
+                                 and consists of the following:
+                                 - An EFI_LBA that indicates the starting LBA
+                                 - A UINTN that indicates the number of blocks to erase.
+
+                                 The list is terminated with an EFI_LBA_LIST_TERMINATOR.
+                                 For example, the following indicates that two ranges of blocks
+                                 (5-7 and 10-11) are to be erased:
+                                 EraseBlocks (This, 5, 3, 10, 2, EFI_LBA_LIST_TERMINATOR);
+
+ @retval EFI_SUCCESS             The erase request successfully completed.
+
+ @retval EFI_ACCESS_DENIED       The firmware volume is in the WriteDisabled state.
+
+ @retval EFI_DEVICE_ERROR        The block device is not functioning correctly and could not be written.
+                                 The firmware device may have been partially erased.
+
+ @retval EFI_INVALID_PARAMETER   One or more of the LBAs listed in the variable argument list do
+                                 not exist in the firmware volume.
+
+ **/
+EFI_STATUS
+EFIAPI
+FvbEraseBlocks (
+  IN CONST EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
+  ...
+  )
+{
+  EFI_STATUS         Status;
+  VA_LIST            Args;
+  EFI_LBA            StartingLba; // Lba from which we start erasing
+  UINTN              NumOfLba;    // Number of Lba blocks to erase
+  SMMSTORE_INSTANCE  *Instance;
+
+  Instance = INSTANCE_FROM_FVB_THIS (This);
+
+  Status = EFI_SUCCESS;
+
+  // Before erasing, check the entire list of parameters to ensure all specified blocks are valid
+
+  VA_START (Args, This);
+  do {
+    // Get the Lba from which we start erasing
+    StartingLba = VA_ARG (Args, EFI_LBA);
+
+    // Have we reached the end of the list?
+    if (StartingLba == EFI_LBA_LIST_TERMINATOR) {
+      // Exit the while loop
+      break;
+    }
+
+    // How many Lba blocks are we requested to erase?
+    NumOfLba = VA_ARG (Args, UINTN);
+
+    // All blocks must be within range
+    DEBUG ((
+      DEBUG_BLKIO,
+      "FvbEraseBlocks: Check if: ( StartingLba=%ld + NumOfLba=%Lu - 1 ) > LastBlock=%ld.\n",
+      StartingLba,
+      (UINT64)NumOfLba,
+      Instance->LastBlock
+      ));
+    if ((NumOfLba == 0) || ((StartingLba + NumOfLba - 1) > Instance->LastBlock)) {
+      VA_END (Args);
+      DEBUG ((DEBUG_ERROR, "FvbEraseBlocks: ERROR - Lba range goes past the last Lba.\n"));
+      Status = EFI_INVALID_PARAMETER;
+      goto EXIT;
+    }
+  } while (TRUE);
+
+  VA_END (Args);
+
+  //
+  // To get here, all must be ok, so start erasing
+  //
+  VA_START (Args, This);
+  do {
+    // Get the Lba from which we start erasing
+    StartingLba = VA_ARG (Args, EFI_LBA);
+
+    // Have we reached the end of the list?
+    if (StartingLba == EFI_LBA_LIST_TERMINATOR) {
+      // Exit the while loop
+      break;
+    }
+
+    // How many Lba blocks are we requested to erase?
+    NumOfLba = VA_ARG (Args, UINTN);
+
+    // Go through each one and erase it
+    while (NumOfLba > 0) {
+      // Erase it
+      DEBUG ((DEBUG_BLKIO, "FvbEraseBlocks: Erasing Lba=%ld\n", StartingLba));
+      Status = SmmStoreLibEraseBlock (StartingLba);
+      if (EFI_ERROR (Status)) {
+        VA_END (Args);
+        Status = EFI_DEVICE_ERROR;
+        goto EXIT;
+      }
+
+      // Move to the next Lba
+      StartingLba++;
+      NumOfLba--;
+    }
+  } while (TRUE);
+
+  VA_END (Args);
+
+EXIT:
+  return Status;
+}
+
+/**
+  Initialized the Firmware Volume if necessary and installs the
+  gEdkiiNvVarStoreFormattedGuid protocol.
+
+  @param Instance                    Pointer to SmmStore instance
+
+ **/
+EFI_STATUS
+EFIAPI
+FvbInitialize (
+  IN SMMSTORE_INSTANCE  *Instance
+  )
+{
+  EFI_STATUS     Status;
+  UINT32         FvbNumLba;
+  EFI_BOOT_MODE  BootMode;
+
+  ASSERT ((Instance != NULL));
+
+  BootMode = GetBootModeHob ();
+  if (BootMode == BOOT_WITH_DEFAULT_SETTINGS) {
+    Status = EFI_INVALID_PARAMETER;
+  } else {
+    // Determine if there is a valid header at the beginning of the NorFlash
+    Status = ValidateFvHeader ();
+  }
+
+  // Install the Default FVB header if required
+  if (EFI_ERROR (Status)) {
+    // There is no valid header, so time to install one.
+    DEBUG ((DEBUG_INFO, "%a: The FVB Header is not valid.\n", __FUNCTION__));
+    DEBUG ((
+      DEBUG_INFO,
+      "%a: Installing a correct one for this volume.\n",
+      __FUNCTION__
+      ));
+
+    // Erase all the NorFlash that is reserved for variable storage
+    FvbNumLba = (PcdGet32 (PcdFlashNvStorageVariableSize) +
+                 PcdGet32 (PcdFlashNvStorageFtwWorkingSize) +
+                 PcdGet32 (PcdFlashNvStorageFtwSpareSize)) / Instance->BlockSize;
+
+    Status = FvbEraseBlocks (&Instance->FvbProtocol, (EFI_LBA)0, FvbNumLba, EFI_LBA_LIST_TERMINATOR);
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+
+    // Install all appropriate headers
+    Status = InitializeFvAndVariableStoreHeaders (Instance);
+    if (EFI_ERROR (Status)) {
+      return Status;
+    }
+  } else {
+    DEBUG ((DEBUG_INFO, "%a: FVB header is valid\n", __FUNCTION__));
+  }
+
+  //
+  // The driver implementing the variable read service can now be dispatched;
+  // the varstore headers are in place.
+  //
+  Status = gBS->InstallProtocolInterface (
+                  &gImageHandle,
+                  &gEdkiiNvVarStoreFormattedGuid,
+                  EFI_NATIVE_INTERFACE,
+                  NULL
+                  );
+  ASSERT_EFI_ERROR (Status);
+
+  return Status;
+}
diff --git a/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.inf b/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.inf
new file mode 100644
index 0000000000..2bd8886bcc
--- /dev/null
+++ b/UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.inf
@@ -0,0 +1,66 @@
+## @file
+#  Component description file for SmmStore module
+#
+#  This module produces the FirmwareVolumeBlock protocol on top of the
+#  SmmStore provided by bootloader and installs the NvVarStoreFormatted protocol.
+#
+#  Copyright (c) 2022, 9elements GmbH<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = SmmStoreFvbRuntimeDxe
+  FILE_GUID                      = A0402FCA-6B25-4CEA-B7DD-C08F99714B29
+  MODULE_TYPE                    = DXE_RUNTIME_DRIVER
+  VERSION_STRING                 = 1.0
+  ENTRY_POINT                    = SmmStoreInitialize
+
+[Sources.common]
+  SmmStoreFvbRuntimeDxe.c
+  SmmStoreFvbRuntime.h
+  SmmStoreFvbRuntime.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
+  UefiPayloadPkg/UefiPayloadPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  DebugLib
+  HobLib
+  SmmStoreLib
+  UefiLib
+  UefiDriverEntryPoint
+  UefiBootServicesTableLib
+  UefiRuntimeLib
+  DxeServicesTableLib
+
+[Guids]
+  gEfiSystemNvDataFvGuid
+  gEfiVariableGuid                  ## PRODUCES ## PROTOCOL
+  gEfiAuthenticatedVariableGuid
+  gEfiEventVirtualAddressChangeGuid
+  gEdkiiNvVarStoreFormattedGuid     ## PRODUCES ## PROTOCOL
+
+[Protocols]
+  gEfiDevicePathProtocolGuid          ## BY_START
+  gEfiFirmwareVolumeBlockProtocolGuid ## BY_START
+
+[Pcd]
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingSize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase64
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase64
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64
+
+[Depex]
+  TRUE
diff --git a/UefiPayloadPkg/UefiPayloadPkg.dsc b/UefiPayloadPkg/UefiPayloadPkg.dsc
index cf440fee58..0f6421612c 100644
--- a/UefiPayloadPkg/UefiPayloadPkg.dsc
+++ b/UefiPayloadPkg/UefiPayloadPkg.dsc
@@ -97,6 +97,7 @@
   #
   # EMU:      UEFI payload with EMU variable
   # SPI:      UEFI payload with SPI NV variable support
+  # SMMSTORE: UEFI payload with coreboot SMM NV variable support
   # NONE:     UEFI payload with no variable modules
   #
   DEFINE VARIABLE_SUPPORT      = EMU
@@ -261,9 +262,11 @@
   LockBoxLib|MdeModulePkg/Library/LockBoxNullLib/LockBoxNullLib.inf
   FileExplorerLib|MdeModulePkg/Library/FileExplorerLib/FileExplorerLib.inf
   AuthVariableLib|MdeModulePkg/Library/AuthVariableLibNull/AuthVariableLibNull.inf
-  SmmStoreLib|UefiPayloadPkg/Library/SmmStoreLib/SmmStoreLib.inf
 !if $(VARIABLE_SUPPORT) == "EMU"
   TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
+!elseif $(VARIABLE_SUPPORT) == "SMMSTORE"
+  SmmStoreLib|UefiPayloadPkg/Library/SmmStoreLib/SmmStoreLib.inf
+  TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
 !elseif $(VARIABLE_SUPPORT) == "SPI"
   PlatformSecureLib|SecurityPkg/Library/PlatformSecureLibNull/PlatformSecureLibNull.inf
   TpmMeasurementLib|SecurityPkg/Library/DxeTpmMeasurementLib/DxeTpmMeasurementLib.inf
@@ -379,15 +382,13 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE
 
 [PcdsFixedAtBuild]
-  gEfiMdeModulePkgTokenSpaceGuid.PcdMaxVariableSize|0x10000
   gEfiMdeModulePkgTokenSpaceGuid.PcdMaxHardwareErrorVariableSize|0x8000
   gEfiMdeModulePkgTokenSpaceGuid.PcdVariableStoreSize|0x10000
 !if $(VARIABLE_SUPPORT) == "EMU"
   gEfiMdeModulePkgTokenSpaceGuid.PcdEmuVariableNvModeEnable        |TRUE
-!else
+!elseif $(VARIABLE_SUPPORT) == "SPI" || $(VARIABLE_SUPPORT) == "SMMSTORE"
   gEfiMdeModulePkgTokenSpaceGuid.PcdEmuVariableNvModeEnable        |FALSE
 !endif
-
   gEfiMdeModulePkgTokenSpaceGuid.PcdVpdBaseAddress|0x0
   gEfiMdeModulePkgTokenSpaceGuid.PcdStatusCodeUseMemory|FALSE
   gEfiMdeModulePkgTokenSpaceGuid.PcdUse1GPageTable|TRUE
@@ -445,7 +446,6 @@
   gUefiCpuPkgTokenSpaceGuid.PcdCpuMaxLogicalProcessorNumber|$(MAX_LOGICAL_PROCESSORS)
   gUefiCpuPkgTokenSpaceGuid.PcdCpuNumberOfReservedVariableMtrrs|0
   gUefiPayloadPkgTokenSpaceGuid.PcdBootloaderParameter|0
-
 ################################################################################
 #
 # Pcd DynamicEx Section - list of all EDK II PCD Entries defined by this Platform
@@ -473,15 +473,19 @@
 !endif
   gEfiMdeModulePkgTokenSpaceGuid.PcdResetOnMemoryTypeInformationChange|FALSE
   gEfiMdeModulePkgTokenSpaceGuid.PcdEmuVariableNvStoreReserved|0
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase|0
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64|0
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase|0
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase|0
   gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut|3
-!if $(VARIABLE_SUPPORT) == "SPI"
+!if $(VARIABLE_SUPPORT) == "SPI" || $(VARIABLE_SUPPORT) == "SMMSTORE"
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize  |0
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingSize|0
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize  |0
   gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase  |0
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64|0
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase64|0
+  gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase64|0
 !endif
   # Disable SMM S3 script
   gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiS3Enable|FALSE
@@ -697,6 +701,14 @@
 
 !if $(VARIABLE_SUPPORT) == "EMU"
   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
+!elseif $(VARIABLE_SUPPORT) == "SMMSTORE"
+  UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.inf
+  MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.inf
+  MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf {
+    <LibraryClasses>
+      NULL|MdeModulePkg/Library/VarCheckUefiLib/VarCheckUefiLib.inf
+      NULL|EmbeddedPkg/Library/NvVarStoreFormattedLib/NvVarStoreFormattedLib.inf
+  }
 !elseif $(VARIABLE_SUPPORT) == "SPI"
   MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmm.inf {
     <LibraryClasses>
diff --git a/UefiPayloadPkg/UefiPayloadPkg.fdf b/UefiPayloadPkg/UefiPayloadPkg.fdf
index c7b04978ad..ca44f48f6d 100644
--- a/UefiPayloadPkg/UefiPayloadPkg.fdf
+++ b/UefiPayloadPkg/UefiPayloadPkg.fdf
@@ -140,6 +140,10 @@ INF PcAtChipsetPkg/PcatRealTimeClockRuntimeDxe/PcatRealTimeClockRuntimeDxe.inf
 
 !if $(VARIABLE_SUPPORT) == "EMU"
   INF MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
+!elseif $(VARIABLE_SUPPORT) == "SMMSTORE"
+  INF UefiPayloadPkg/SmmStoreFvb/SmmStoreFvbRuntimeDxe.inf
+  INF MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.inf
+  INF MdeModulePkg/Universal/Variable/RuntimeDxe/VariableRuntimeDxe.inf
 !elseif $(VARIABLE_SUPPORT) == "SPI"
   INF UefiPayloadPkg/FvbRuntimeDxe/FvbSmm.inf
   INF MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.inf
-- 
2.32.0