Fvb.c

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#include "PiDxe.h"
#include <Guid/EventGroup.h>
#include <Guid/SystemNvDataGuid.h>
#include <Guid/VariableFormat.h>
 
#include <Protocol/FirmwareVolumeBlock.h>
#include <Protocol/DevicePath.h>
 
#include <Library/UefiLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/BaseLib.h>
#include <Library/UefiRuntimeLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/DevicePathLib.h>
#include <Library/PcdLib.h>
#include <Library/PlatformFvbLib.h>
#include "Fvb.h"
 
#define EFI_AUTHENTICATED_VARIABLE_GUID \
{ 0xaaf32c78, 0x947b, 0x439a, { 0xa1, 0x80, 0x2e, 0x14, 0x4e, 0xc3, 0x77, 0x92 } }
 
//
// Virtual Address Change Event
//
// This is needed for runtime variable access.
//
EFI_EVENT  mEmuVarsFvbAddrChangeEvent = NULL;
 
//
// This is the single instance supported by this driver.  It
// supports the FVB and Device Path protocols.
//
EFI_FW_VOL_BLOCK_DEVICE  mEmuVarsFvb = {
  FVB_DEVICE_SIGNATURE,
  {     // DevicePath
    {
      {
        HARDWARE_DEVICE_PATH,
        HW_MEMMAP_DP,
        {
          sizeof (MEMMAP_DEVICE_PATH),
          0
        }
      },
      EfiMemoryMappedIO,
      0,
      0,
    },
    {
      END_DEVICE_PATH_TYPE,
      END_ENTIRE_DEVICE_PATH_SUBTYPE,
      {
        sizeof (EFI_DEVICE_PATH_PROTOCOL),
        0
      }
    }
  },
  NULL,               // BufferPtr
  EMU_FVB_BLOCK_SIZE, // BlockSize
  EMU_FVB_SIZE,       // Size
  {     // FwVolBlockInstance
    FvbProtocolGetAttributes,
    FvbProtocolSetAttributes,
    FvbProtocolGetPhysicalAddress,
    FvbProtocolGetBlockSize,
    FvbProtocolRead,
    FvbProtocolWrite,
    FvbProtocolEraseBlocks,
    NULL
  },
};
 
VOID
EFIAPI
FvbVirtualAddressChangeEvent (
  IN EFI_EVENT  Event,
  IN VOID       *Context
  )
{
  EfiConvertPointer (0x0, &mEmuVarsFvb.BufferPtr);
}
 
//
// FVB protocol APIs
//
 
EFI_STATUS
EFIAPI
FvbProtocolGetPhysicalAddress (
  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
  OUT       EFI_PHYSICAL_ADDRESS                 *Address
  )
{
  EFI_FW_VOL_BLOCK_DEVICE  *FvbDevice;
 
  FvbDevice = FVB_DEVICE_FROM_THIS (This);
 
  *Address = (EFI_PHYSICAL_ADDRESS)(UINTN)FvbDevice->BufferPtr;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
FvbProtocolGetBlockSize (
  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
  IN        EFI_LBA                              Lba,
  OUT       UINTN                                *BlockSize,
  OUT       UINTN                                *NumberOfBlocks
  )
{
  EFI_FW_VOL_BLOCK_DEVICE  *FvbDevice;
 
  if (Lba >= EMU_FVB_NUM_TOTAL_BLOCKS) {
    return EFI_INVALID_PARAMETER;
  }
 
  FvbDevice = FVB_DEVICE_FROM_THIS (This);
 
  *BlockSize      = FvbDevice->BlockSize;
  *NumberOfBlocks = (UINTN)(EMU_FVB_NUM_TOTAL_BLOCKS - Lba);
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
FvbProtocolGetAttributes (
  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
  OUT       EFI_FVB_ATTRIBUTES_2                 *Attributes
  )
{
  *Attributes =
    (EFI_FVB_ATTRIBUTES_2)(
                           EFI_FVB2_READ_ENABLED_CAP |
                           EFI_FVB2_READ_STATUS |
                           EFI_FVB2_WRITE_ENABLED_CAP |
                           EFI_FVB2_WRITE_STATUS |
                           EFI_FVB2_ERASE_POLARITY
                           );
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
FvbProtocolSetAttributes (
  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
  IN OUT    EFI_FVB_ATTRIBUTES_2                 *Attributes
  )
{
  return EFI_ACCESS_DENIED;
}
 
EFI_STATUS
EFIAPI
FvbProtocolEraseBlocks (
  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
  ...
  )
{
  EFI_FW_VOL_BLOCK_DEVICE  *FvbDevice;
  VA_LIST                  Args;
  EFI_LBA                  StartingLba;
  UINTN                    NumOfLba;
  UINT8                    *ErasePtr;
  UINTN                    EraseSize;
 
  FvbDevice = FVB_DEVICE_FROM_THIS (This);
 
  //
  // Check input parameters
  //
  VA_START (Args, This);
  do {
    StartingLba = VA_ARG (Args, EFI_LBA);
    if (StartingLba == EFI_LBA_LIST_TERMINATOR) {
      break;
    }
 
    NumOfLba = VA_ARG (Args, UINTN);
 
    if ((StartingLba > EMU_FVB_NUM_TOTAL_BLOCKS) ||
        (NumOfLba > EMU_FVB_NUM_TOTAL_BLOCKS - StartingLba))
    {
      VA_END (Args);
      return EFI_INVALID_PARAMETER;
    }
  } while (1);
 
  VA_END (Args);
 
  //
  // Erase blocks
  //
  VA_START (Args, This);
  do {
    StartingLba = VA_ARG (Args, EFI_LBA);
    if (StartingLba == EFI_LBA_LIST_TERMINATOR) {
      break;
    }
 
    NumOfLba = VA_ARG (Args, UINTN);
 
    ErasePtr  = FvbDevice->BufferPtr;
    ErasePtr += (UINTN)StartingLba * FvbDevice->BlockSize;
    EraseSize = NumOfLba * FvbDevice->BlockSize;
 
    SetMem (ErasePtr, EraseSize, ERASED_UINT8);
  } while (1);
 
  VA_END (Args);
 
  //
  // Call platform hook
  //
  VA_START (Args, This);
  PlatformFvbBlocksErased (This, Args);
  VA_END (Args);
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
FvbProtocolWrite (
  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
  IN        EFI_LBA                              Lba,
  IN        UINTN                                Offset,
  IN OUT    UINTN                                *NumBytes,
  IN        UINT8                                *Buffer
  )
{
  EFI_FW_VOL_BLOCK_DEVICE  *FvbDevice;
  UINT8                    *FvbDataPtr;
  EFI_STATUS               Status;
 
  FvbDevice = FVB_DEVICE_FROM_THIS (This);
 
  if ((Lba >= EMU_FVB_NUM_TOTAL_BLOCKS) ||
      (Offset > FvbDevice->BlockSize))
  {
    return EFI_INVALID_PARAMETER;
  }
 
  Status = EFI_SUCCESS;
  if (*NumBytes > FvbDevice->BlockSize - Offset) {
    *NumBytes = FvbDevice->BlockSize - Offset;
    Status    = EFI_BAD_BUFFER_SIZE;
  }
 
  FvbDataPtr  = FvbDevice->BufferPtr;
  FvbDataPtr += (UINTN)Lba * FvbDevice->BlockSize;
  FvbDataPtr += Offset;
 
  CopyMem (FvbDataPtr, Buffer, *NumBytes);
  PlatformFvbDataWritten (This, Lba, Offset, *NumBytes, Buffer);
  return Status;
}
 
EFI_STATUS
EFIAPI
FvbProtocolRead (
  IN CONST  EFI_FIRMWARE_VOLUME_BLOCK2_PROTOCOL  *This,
  IN        EFI_LBA                              Lba,
  IN        UINTN                                Offset,
  IN OUT    UINTN                                *NumBytes,
  IN OUT    UINT8                                *Buffer
  )
{
  EFI_FW_VOL_BLOCK_DEVICE  *FvbDevice;
  UINT8                    *FvbDataPtr;
  EFI_STATUS               Status;
 
  FvbDevice = FVB_DEVICE_FROM_THIS (This);
 
  if ((Lba >= EMU_FVB_NUM_TOTAL_BLOCKS) ||
      (Offset > FvbDevice->BlockSize))
  {
    return EFI_INVALID_PARAMETER;
  }
 
  Status = EFI_SUCCESS;
  if (*NumBytes > FvbDevice->BlockSize - Offset) {
    *NumBytes = FvbDevice->BlockSize - Offset;
    Status    = EFI_BAD_BUFFER_SIZE;
  }
 
  FvbDataPtr  = FvbDevice->BufferPtr;
  FvbDataPtr += (UINTN)Lba * FvbDevice->BlockSize;
  FvbDataPtr += Offset;
 
  CopyMem (Buffer, FvbDataPtr, *NumBytes);
  PlatformFvbDataRead (This, Lba, Offset, *NumBytes, Buffer);
  return Status;
}
 
EFI_STATUS
ValidateFvHeader (
  IN EFI_FIRMWARE_VOLUME_HEADER  *FwVolHeader
  )
{
  UINT16  Checksum;
 
  //
  // 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 != EMU_FVB_SIZE) ||
      (FwVolHeader->HeaderLength != EMU_FV_HEADER_LENGTH)
      )
  {
    DEBUG ((DEBUG_INFO, "EMU Variable FVB: Basic FV headers were invalid\n"));
    return EFI_NOT_FOUND;
  }
 
  //
  // Verify the header checksum
  //
  Checksum = CalculateSum16 ((VOID *)FwVolHeader, FwVolHeader->HeaderLength);
 
  if (Checksum != 0) {
    DEBUG ((DEBUG_INFO, "EMU Variable FVB: FV checksum was invalid\n"));
    return EFI_NOT_FOUND;
  }
 
  return EFI_SUCCESS;
}
 
VOID
InitializeFvAndVariableStoreHeaders (
  IN  VOID  *Ptr
  )
{
  //
  // Templates for authenticated variable FV header
  //
  STATIC FVB_FV_HDR_AND_VARS_TEMPLATE  FvAndAuthenticatedVarTemplate = {
    { // EFI_FIRMWARE_VOLUME_HEADER FvHdr;
      // UINT8                     ZeroVector[16];
      { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
 
      // EFI_GUID                  FileSystemGuid;
      EFI_SYSTEM_NV_DATA_FV_GUID,
 
      // UINT64                    FvLength;
      EMU_FVB_SIZE,
 
      // UINT32                    Signature;
      EFI_FVH_SIGNATURE,
 
      // EFI_FVB_ATTRIBUTES_2      Attributes;
      0x4feff,
 
      // UINT16                    HeaderLength;
      EMU_FV_HEADER_LENGTH,
 
      // UINT16                    Checksum;
      0,
 
      // UINT16                    ExtHeaderOffset;
      0,
 
      // UINT8                     Reserved[1];
      { 0 },
 
      // UINT8                     Revision;
      EFI_FVH_REVISION,
 
      // EFI_FV_BLOCK_MAP_ENTRY    BlockMap[1];
      {
        {
          EMU_FVB_NUM_TOTAL_BLOCKS, // UINT32 NumBlocks;
          EMU_FVB_BLOCK_SIZE        // UINT32 Length;
        }
      }
    },
    // EFI_FV_BLOCK_MAP_ENTRY     EndBlockMap;
    { 0, 0 }, // End of block map
    { // VARIABLE_STORE_HEADER      VarHdr;
      // EFI_GUID  Signature;     // need authenticated variables for secure boot
      EFI_AUTHENTICATED_VARIABLE_GUID,
 
      // UINT32  Size;
      (
        FixedPcdGet32 (PcdFlashNvStorageVariableSize) -
        OFFSET_OF (FVB_FV_HDR_AND_VARS_TEMPLATE, VarHdr)
      ),
 
      // UINT8   Format;
      VARIABLE_STORE_FORMATTED,
 
      // UINT8   State;
      VARIABLE_STORE_HEALTHY,
 
      // UINT16  Reserved;
      0,
 
      // UINT32  Reserved1;
      0
    }
  };
 
  EFI_FIRMWARE_VOLUME_HEADER  *Fv;
 
  //
  // Copy the template structure into the location
  //
  CopyMem (
    Ptr,
    &FvAndAuthenticatedVarTemplate,
    sizeof FvAndAuthenticatedVarTemplate
    );
 
  //
  // Update the checksum for the FV header
  //
  Fv           = (EFI_FIRMWARE_VOLUME_HEADER *)Ptr;
  Fv->Checksum = CalculateCheckSum16 (Ptr, Fv->HeaderLength);
}
 
EFI_STATUS
EFIAPI
FvbInitialize (
  IN EFI_HANDLE        ImageHandle,
  IN EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS            Status;
  VOID                  *Ptr;
  VOID                  *SubPtr;
  BOOLEAN               Initialize;
  EFI_HANDLE            Handle;
  EFI_PHYSICAL_ADDRESS  Address;
  RETURN_STATUS         PcdStatus;
 
  DEBUG ((DEBUG_INFO, "EMU Variable FVB Started\n"));
 
  //
  // Verify that the PCD's are set correctly.
  //
  ASSERT (
    FixedPcdGet32 (PcdFlashNvStorageFtwSpareSize) %
    EMU_FVB_BLOCK_SIZE == 0
    );
  if (
      (PcdGet32 (PcdFlashNvStorageVariableSize) +
       PcdGet32 (PcdFlashNvStorageFtwWorkingSize)
      ) >
      EMU_FVB_NUM_SPARE_BLOCKS * EMU_FVB_BLOCK_SIZE
      )
  {
    DEBUG ((DEBUG_ERROR, "EMU Variable invalid PCD sizes\n"));
    return EFI_INVALID_PARAMETER;
  }
 
  if (PcdGet64 (PcdFlashNvStorageVariableBase64) != 0) {
    DEBUG ((
      DEBUG_INFO,
      "Disabling EMU Variable FVB since "
      "flash variables appear to be supported.\n"
      ));
    return EFI_ABORTED;
  }
 
  //
  // By default we will initialize the FV contents.  But, if
  // PcdEmuVariableNvStoreReserved is non-zero, then we will
  // use this location for our buffer.
  //
  // If this location does not have a proper FV header, then
  // we will initialize it.
  //
  Initialize = TRUE;
  if (PcdGet64 (PcdEmuVariableNvStoreReserved) != 0) {
    Ptr = (VOID *)(UINTN)PcdGet64 (PcdEmuVariableNvStoreReserved);
    DEBUG ((
      DEBUG_INFO,
      "EMU Variable FVB: Using pre-reserved block at %p\n",
      Ptr
      ));
    Status = ValidateFvHeader (Ptr);
    if (!EFI_ERROR (Status)) {
      DEBUG ((DEBUG_INFO, "EMU Variable FVB: Found valid pre-existing FV\n"));
      Initialize = FALSE;
    }
  } else {
    Ptr = AllocateRuntimePages (EFI_SIZE_TO_PAGES (EMU_FVB_SIZE));
  }
 
  mEmuVarsFvb.BufferPtr = Ptr;
 
  //
  // Initialize the main FV header and variable store header
  //
  if (Initialize) {
    SetMem (Ptr, EMU_FVB_SIZE, ERASED_UINT8);
    InitializeFvAndVariableStoreHeaders (Ptr);
  }
 
  PcdStatus = PcdSet64S (PcdFlashNvStorageVariableBase64, (UINTN)Ptr);
  ASSERT_RETURN_ERROR (PcdStatus);
 
  //
  // Initialize the Fault Tolerant Write data area
  //
  SubPtr    = (VOID *)((UINT8 *)Ptr + PcdGet32 (PcdFlashNvStorageVariableSize));
  PcdStatus = PcdSet64S (
                PcdFlashNvStorageFtwWorkingBase64,
                (UINTN)SubPtr
                );
  ASSERT_RETURN_ERROR (PcdStatus);
 
  //
  // Initialize the Fault Tolerant Write spare block
  //
  SubPtr = (VOID *)((UINT8 *)Ptr +
                    EMU_FVB_NUM_SPARE_BLOCKS * EMU_FVB_BLOCK_SIZE);
  PcdStatus = PcdSet64S (
                PcdFlashNvStorageFtwSpareBase64,
                (UINTN)SubPtr
                );
  ASSERT_RETURN_ERROR (PcdStatus);
 
  //
  // Setup FVB device path
  //
  Address                                              = (EFI_PHYSICAL_ADDRESS)(UINTN)Ptr;
  mEmuVarsFvb.DevicePath.MemMapDevPath.StartingAddress = Address;
  mEmuVarsFvb.DevicePath.MemMapDevPath.EndingAddress   = Address + EMU_FVB_SIZE - 1;
 
  //
  // Install the protocols
  //
  DEBUG ((DEBUG_INFO, "Installing FVB for EMU Variable support\n"));
  Handle = 0;
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &Handle,
                  &gEfiFirmwareVolumeBlock2ProtocolGuid,
                  &mEmuVarsFvb.FwVolBlockInstance,
                  &gEfiDevicePathProtocolGuid,
                  &mEmuVarsFvb.DevicePath,
                  NULL
                  );
  ASSERT_EFI_ERROR (Status);
 
  //
  // Register for the virtual address change event
  //
  Status = gBS->CreateEventEx (
                  EVT_NOTIFY_SIGNAL,
                  TPL_NOTIFY,
                  FvbVirtualAddressChangeEvent,
                  NULL,
                  &gEfiEventVirtualAddressChangeGuid,
                  &mEmuVarsFvbAddrChangeEvent
                  );
  ASSERT_EFI_ERROR (Status);
 
  return EFI_SUCCESS;
}