LightMemoryTest.c

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#include "LightMemoryTest.h"
 
//
// Global:
// Since this driver will only ever produce one instance of the memory test
// protocol, so we do not need to dynamically allocate the PrivateData.
//
EFI_PHYSICAL_ADDRESS    mCurrentAddress;
LIST_ENTRY              *mCurrentLink;
NONTESTED_MEMORY_RANGE  *mCurrentRange;
UINT64                  mTestedSystemMemory;
UINT64                  mNonTestedSystemMemory;
 
UINT32  GenericMemoryTestMonoPattern[GENERIC_CACHELINE_SIZE / 4] = {
  0x5a5a5a5a,
  0xa5a5a5a5,
  0x5a5a5a5a,
  0xa5a5a5a5,
  0x5a5a5a5a,
  0xa5a5a5a5,
  0x5a5a5a5a,
  0xa5a5a5a5,
  0x5a5a5a5a,
  0xa5a5a5a5,
  0x5a5a5a5a,
  0xa5a5a5a5,
  0x5a5a5a5a,
  0xa5a5a5a5,
  0x5a5a5a5a,
  0xa5a5a5a5
};
 
INTN
EFIAPI
CompareMemWithoutCheckArgument (
  IN      CONST VOID  *DestinationBuffer,
  IN      CONST VOID  *SourceBuffer,
  IN      UINTN       Length
  )
{
  ASSERT (Length > 0);
  while ((--Length != 0) &&
         (*(INT8 *)DestinationBuffer == *(INT8 *)SourceBuffer))
  {
    DestinationBuffer = (INT8 *)DestinationBuffer + 1;
    SourceBuffer      = (INT8 *)SourceBuffer + 1;
  }
 
  return (INTN)*(UINT8 *)DestinationBuffer - (INTN)*(UINT8 *)SourceBuffer;
}
 
EFI_STATUS
ConstructBaseMemoryRange (
  IN  GENERIC_MEMORY_TEST_PRIVATE  *Private
  )
{
  UINTN                            NumberOfDescriptors;
  EFI_GCD_MEMORY_SPACE_DESCRIPTOR  *MemorySpaceMap;
  UINTN                            Index;
 
  //
  // Base memory will always below 4G
  //
  gDS->GetMemorySpaceMap (&NumberOfDescriptors, &MemorySpaceMap);
 
  for (Index = 0; Index < NumberOfDescriptors; Index++) {
    if ((MemorySpaceMap[Index].GcdMemoryType == EfiGcdMemoryTypeSystemMemory) ||
        (MemorySpaceMap[Index].GcdMemoryType == EfiGcdMemoryTypeMoreReliable))
    {
      Private->BaseMemorySize += MemorySpaceMap[Index].Length;
    }
  }
 
  return EFI_SUCCESS;
}
 
VOID
DestroyLinkList (
  IN  GENERIC_MEMORY_TEST_PRIVATE  *Private
  )
{
  LIST_ENTRY              *Link;
  NONTESTED_MEMORY_RANGE  *NontestedRange;
 
  Link = Private->NonTestedMemRanList.BackLink;
 
  while (Link != &Private->NonTestedMemRanList) {
    RemoveEntryList (Link);
    NontestedRange = NONTESTED_MEMORY_RANGE_FROM_LINK (Link);
    gBS->FreePool (NontestedRange);
    Link = Private->NonTestedMemRanList.BackLink;
  }
}
 
EFI_STATUS
ConvertToTestedMemory (
  IN UINT64  BaseAddress,
  IN UINT64  Length,
  IN UINT64  Capabilities
  )
{
  EFI_STATUS  Status;
 
  Status = gDS->RemoveMemorySpace (
                  BaseAddress,
                  Length
                  );
  if (!EFI_ERROR (Status)) {
    Status = gDS->AddMemorySpace (
                    ((Capabilities & EFI_MEMORY_MORE_RELIABLE) == EFI_MEMORY_MORE_RELIABLE) ?
                    EfiGcdMemoryTypeMoreReliable : EfiGcdMemoryTypeSystemMemory,
                    BaseAddress,
                    Length,
                    Capabilities &~
                    (EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED | EFI_MEMORY_TESTED | EFI_MEMORY_RUNTIME)
                    );
  }
 
  return Status;
}
 
EFI_STATUS
UpdateMemoryMap (
  IN  GENERIC_MEMORY_TEST_PRIVATE  *Private
  )
{
  LIST_ENTRY              *Link;
  NONTESTED_MEMORY_RANGE  *Range;
 
  Link = Private->NonTestedMemRanList.ForwardLink;
 
  while (Link != &Private->NonTestedMemRanList) {
    Range = NONTESTED_MEMORY_RANGE_FROM_LINK (Link);
 
    ConvertToTestedMemory (
      Range->StartAddress,
      Range->Length,
      Range->Capabilities &~
      (EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED | EFI_MEMORY_TESTED | EFI_MEMORY_RUNTIME)
      );
    Link = Link->ForwardLink;
  }
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
DirectRangeTest (
  IN  GENERIC_MEMORY_TEST_PRIVATE  *Private,
  IN  EFI_PHYSICAL_ADDRESS         StartAddress,
  IN  UINT64                       Length,
  IN  UINT64                       Capabilities
  )
{
  EFI_STATUS  Status;
 
  //
  // Perform a dummy memory test, so directly write the pattern to all range
  //
  WriteMemory (Private, StartAddress, Length);
 
  //
  // Verify the memory range
  //
  Status = VerifyMemory (Private, StartAddress, Length);
  if (EFI_ERROR (Status)) {
    return Status;
  }
 
  //
  // Add the tested compatible memory to system memory using GCD service
  //
  ConvertToTestedMemory (
    StartAddress,
    Length,
    Capabilities &~
    (EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED | EFI_MEMORY_TESTED | EFI_MEMORY_RUNTIME)
    );
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
ConstructNonTestedMemoryRange (
  IN  GENERIC_MEMORY_TEST_PRIVATE  *Private
  )
{
  NONTESTED_MEMORY_RANGE           *Range;
  BOOLEAN                          NoFound;
  UINTN                            NumberOfDescriptors;
  EFI_GCD_MEMORY_SPACE_DESCRIPTOR  *MemorySpaceMap;
  UINTN                            Index;
 
  //
  // Non tested memory range may be span 4G here
  //
  NoFound = TRUE;
 
  gDS->GetMemorySpaceMap (&NumberOfDescriptors, &MemorySpaceMap);
 
  for (Index = 0; Index < NumberOfDescriptors; Index++) {
    if ((MemorySpaceMap[Index].GcdMemoryType == EfiGcdMemoryTypeReserved) &&
        ((MemorySpaceMap[Index].Capabilities & (EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED | EFI_MEMORY_TESTED)) ==
         (EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED))
        )
    {
      NoFound = FALSE;
      //
      // Light version do not need to process >4G memory range
      //
      gBS->AllocatePool (
             EfiBootServicesData,
             sizeof (NONTESTED_MEMORY_RANGE),
             (VOID **)&Range
             );
 
      Range->Signature    = EFI_NONTESTED_MEMORY_RANGE_SIGNATURE;
      Range->StartAddress = MemorySpaceMap[Index].BaseAddress;
      Range->Length       = MemorySpaceMap[Index].Length;
      Range->Capabilities = MemorySpaceMap[Index].Capabilities;
 
      mNonTestedSystemMemory += MemorySpaceMap[Index].Length;
      InsertTailList (&Private->NonTestedMemRanList, &Range->Link);
    }
  }
 
  if (NoFound) {
    return EFI_NOT_FOUND;
  }
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
WriteMemory (
  IN  GENERIC_MEMORY_TEST_PRIVATE  *Private,
  IN  EFI_PHYSICAL_ADDRESS         Start,
  IN  UINT64                       Size
  )
{
  EFI_PHYSICAL_ADDRESS  Address;
 
  Address = Start;
 
  //
  // Add 4G memory address check for IA32 platform
  // NOTE: Without page table, there is no way to use memory above 4G.
  //
  if (Start + Size > MAX_ADDRESS) {
    return EFI_SUCCESS;
  }
 
  while (Address < (Start + Size)) {
    CopyMem ((VOID *)(UINTN)Address, Private->MonoPattern, Private->MonoTestSize);
    Address += Private->CoverageSpan;
  }
 
  //
  // bug bug: we may need GCD service to make the code cache and data uncache,
  // if GCD do not support it or return fail, then just flush the whole cache.
  //
  if (Private->Cpu != NULL) {
    Private->Cpu->FlushDataCache (Private->Cpu, Start, Size, EfiCpuFlushTypeWriteBackInvalidate);
  }
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
VerifyMemory (
  IN  GENERIC_MEMORY_TEST_PRIVATE  *Private,
  IN  EFI_PHYSICAL_ADDRESS         Start,
  IN  UINT64                       Size
  )
{
  EFI_PHYSICAL_ADDRESS            Address;
  INTN                            ErrorFound;
  EFI_MEMORY_EXTENDED_ERROR_DATA  *ExtendedErrorData;
 
  Address           = Start;
  ExtendedErrorData = NULL;
 
  //
  // Add 4G memory address check for IA32 platform
  // NOTE: Without page table, there is no way to use memory above 4G.
  //
  if (Start + Size > MAX_ADDRESS) {
    return EFI_SUCCESS;
  }
 
  //
  // Use the software memory test to check whether have detected miscompare
  // error here. If there is miscompare error here then check if generic
  // memory test driver can disable the bad DIMM.
  //
  while (Address < (Start + Size)) {
    ErrorFound = CompareMemWithoutCheckArgument (
                   (VOID *)(UINTN)(Address),
                   Private->MonoPattern,
                   Private->MonoTestSize
                   );
    if (ErrorFound != 0) {
      //
      // Report uncorrectable errors
      //
      ExtendedErrorData = AllocateZeroPool (sizeof (EFI_MEMORY_EXTENDED_ERROR_DATA));
      if (ExtendedErrorData == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }
 
      ExtendedErrorData->DataHeader.HeaderSize = (UINT16)sizeof (EFI_STATUS_CODE_DATA);
      ExtendedErrorData->DataHeader.Size       = (UINT16)(sizeof (EFI_MEMORY_EXTENDED_ERROR_DATA) - sizeof (EFI_STATUS_CODE_DATA));
      ExtendedErrorData->Granularity           = EFI_MEMORY_ERROR_DEVICE;
      ExtendedErrorData->Operation             = EFI_MEMORY_OPERATION_READ;
      ExtendedErrorData->Syndrome              = 0x0;
      ExtendedErrorData->Address               = Address;
      ExtendedErrorData->Resolution            = 0x40;
 
      REPORT_STATUS_CODE_EX (
        EFI_ERROR_CODE,
        EFI_COMPUTING_UNIT_MEMORY | EFI_CU_MEMORY_EC_UNCORRECTABLE,
        0,
        &gEfiGenericMemTestProtocolGuid,
        NULL,
        (UINT8 *)ExtendedErrorData + sizeof (EFI_STATUS_CODE_DATA),
        ExtendedErrorData->DataHeader.Size
        );
 
      return EFI_DEVICE_ERROR;
    }
 
    Address += Private->CoverageSpan;
  }
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
InitializeMemoryTest (
  IN EFI_GENERIC_MEMORY_TEST_PROTOCOL  *This,
  IN  EXTENDMEM_COVERAGE_LEVEL         Level,
  OUT BOOLEAN                          *RequireSoftECCInit
  )
{
  EFI_STATUS                   Status;
  GENERIC_MEMORY_TEST_PRIVATE  *Private;
  EFI_CPU_ARCH_PROTOCOL        *Cpu;
 
  Private             = GENERIC_MEMORY_TEST_PRIVATE_FROM_THIS (This);
  *RequireSoftECCInit = FALSE;
 
  //
  // This is initialize for default value, but some value may be reset base on
  // platform memory test driver.
  //
  Private->CoverLevel   = Level;
  Private->BdsBlockSize = TEST_BLOCK_SIZE;
  Private->MonoPattern  = GenericMemoryTestMonoPattern;
  Private->MonoTestSize = GENERIC_CACHELINE_SIZE;
 
  //
  // Initialize several internal link list
  //
  InitializeListHead (&Private->NonTestedMemRanList);
 
  //
  // Construct base memory range
  //
  ConstructBaseMemoryRange (Private);
 
  //
  // get the cpu arch protocol to support flash cache
  //
  Status = gBS->LocateProtocol (
                  &gEfiCpuArchProtocolGuid,
                  NULL,
                  (VOID **)&Cpu
                  );
  if (!EFI_ERROR (Status)) {
    Private->Cpu = Cpu;
  }
 
  //
  // Create the CoverageSpan of the memory test base on the coverage level
  //
  switch (Private->CoverLevel) {
    case EXTENSIVE:
      Private->CoverageSpan = GENERIC_CACHELINE_SIZE;
      break;
 
    case SPARSE:
      Private->CoverageSpan = SPARSE_SPAN_SIZE;
      break;
 
    //
    // Even the BDS do not need to test any memory, but in some case it
    // still need to init ECC memory.
    //
    default:
      Private->CoverageSpan = QUICK_SPAN_SIZE;
      break;
  }
 
  //
  // This is the first time we construct the non-tested memory range, if no
  // extended memory found, we know the system have not any extended memory
  // need to be test
  //
  Status = ConstructNonTestedMemoryRange (Private);
  if (Status == EFI_NOT_FOUND) {
    return EFI_NO_MEDIA;
  }
 
  //
  // ready to perform the R/W/V memory test
  //
  mTestedSystemMemory = Private->BaseMemorySize;
  mCurrentLink        = Private->NonTestedMemRanList.ForwardLink;
  mCurrentRange       = NONTESTED_MEMORY_RANGE_FROM_LINK (mCurrentLink);
  mCurrentAddress     = mCurrentRange->StartAddress;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
GenPerformMemoryTest (
  IN EFI_GENERIC_MEMORY_TEST_PROTOCOL  *This,
  OUT UINT64                           *TestedMemorySize,
  OUT UINT64                           *TotalMemorySize,
  OUT BOOLEAN                          *ErrorOut,
  IN BOOLEAN                           TestAbort
  )
{
  EFI_STATUS                      Status;
  GENERIC_MEMORY_TEST_PRIVATE     *Private;
  EFI_MEMORY_RANGE_EXTENDED_DATA  *RangeData;
  UINT64                          BlockBoundary;
 
  Private       = GENERIC_MEMORY_TEST_PRIVATE_FROM_THIS (This);
  *ErrorOut     = FALSE;
  RangeData     = NULL;
  BlockBoundary = 0;
 
  //
  // In extensive mode the boundary of "mCurrentRange->Length" may will lost
  // some range that is not Private->BdsBlockSize size boundary, so need
  // the software mechanism to confirm all memory location be covered.
  //
  if (mCurrentAddress < (mCurrentRange->StartAddress + mCurrentRange->Length)) {
    if ((mCurrentAddress + Private->BdsBlockSize) <= (mCurrentRange->StartAddress + mCurrentRange->Length)) {
      BlockBoundary = Private->BdsBlockSize;
    } else {
      BlockBoundary = mCurrentRange->StartAddress + mCurrentRange->Length - mCurrentAddress;
    }
 
    //
    // If TestAbort is true, means user cancel the memory test
    //
    if (!TestAbort && (Private->CoverLevel != IGNORE)) {
      //
      // Report status code of every memory range
      //
      RangeData = AllocateZeroPool (sizeof (EFI_MEMORY_RANGE_EXTENDED_DATA));
      if (RangeData == NULL) {
        return EFI_OUT_OF_RESOURCES;
      }
 
      RangeData->DataHeader.HeaderSize = (UINT16)sizeof (EFI_STATUS_CODE_DATA);
      RangeData->DataHeader.Size       = (UINT16)(sizeof (EFI_MEMORY_RANGE_EXTENDED_DATA) - sizeof (EFI_STATUS_CODE_DATA));
      RangeData->Start                 = mCurrentAddress;
      RangeData->Length                = BlockBoundary;
 
      REPORT_STATUS_CODE_EX (
        EFI_PROGRESS_CODE,
        EFI_COMPUTING_UNIT_MEMORY | EFI_CU_MEMORY_PC_TEST,
        0,
        &gEfiGenericMemTestProtocolGuid,
        NULL,
        (UINT8 *)RangeData + sizeof (EFI_STATUS_CODE_DATA),
        RangeData->DataHeader.Size
        );
 
      //
      // The software memory test (R/W/V) perform here. It will detect the
      // memory mis-compare error.
      //
      WriteMemory (Private, mCurrentAddress, BlockBoundary);
 
      Status = VerifyMemory (Private, mCurrentAddress, BlockBoundary);
      if (EFI_ERROR (Status)) {
        //
        // If perform here, means there is mis-compare error, and no agent can
        // handle it, so we return to BDS EFI_DEVICE_ERROR.
        //
        *ErrorOut = TRUE;
        return EFI_DEVICE_ERROR;
      }
    }
 
    mTestedSystemMemory += BlockBoundary;
    *TestedMemorySize    = mTestedSystemMemory;
 
    //
    // If the memory test restart after the platform driver disable dimms,
    // the NonTestSystemMemory may be changed, but the base memory size will
    // not changed, so we can get the current total memory size.
    //
    *TotalMemorySize = Private->BaseMemorySize + mNonTestedSystemMemory;
 
    //
    // Update the current test address pointing to next BDS BLOCK
    //
    mCurrentAddress += Private->BdsBlockSize;
 
    return EFI_SUCCESS;
  }
 
  //
  // Change to next non tested memory range
  //
  mCurrentLink = mCurrentLink->ForwardLink;
  if (mCurrentLink != &Private->NonTestedMemRanList) {
    mCurrentRange   = NONTESTED_MEMORY_RANGE_FROM_LINK (mCurrentLink);
    mCurrentAddress = mCurrentRange->StartAddress;
    return EFI_SUCCESS;
  } else {
    //
    // Here means all the memory test have finished
    //
    *TestedMemorySize = mTestedSystemMemory;
    *TotalMemorySize  = Private->BaseMemorySize + mNonTestedSystemMemory;
    return EFI_NOT_FOUND;
  }
}
 
EFI_STATUS
EFIAPI
GenMemoryTestFinished (
  IN EFI_GENERIC_MEMORY_TEST_PROTOCOL  *This
  )
{
  EFI_STATUS                   Status;
  GENERIC_MEMORY_TEST_PRIVATE  *Private;
 
  Private = GENERIC_MEMORY_TEST_PRIVATE_FROM_THIS (This);
 
  //
  // Perform Data and Address line test only if not ignore memory test
  //
  if (Private->CoverLevel != IGNORE) {
    Status = PerformAddressDataLineTest (Private);
    ASSERT_EFI_ERROR (Status);
  }
 
  //
  // Add the non tested memory range to system memory map through GCD service
  //
  UpdateMemoryMap (Private);
 
  //
  // we need to free all the memory allocate
  //
  DestroyLinkList (Private);
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
EFIAPI
GenCompatibleRangeTest (
  IN EFI_GENERIC_MEMORY_TEST_PROTOCOL  *This,
  IN EFI_PHYSICAL_ADDRESS              StartAddress,
  IN UINT64                            Length
  )
{
  EFI_STATUS                       Status;
  GENERIC_MEMORY_TEST_PRIVATE      *Private;
  EFI_GCD_MEMORY_SPACE_DESCRIPTOR  Descriptor;
  EFI_PHYSICAL_ADDRESS             CurrentBase;
  UINT64                           CurrentLength;
 
  Private = GENERIC_MEMORY_TEST_PRIVATE_FROM_THIS (This);
 
  //
  // Check if the parameter is below 16MB
  //
  if (StartAddress + Length > 0x1000000) {
    return EFI_INVALID_PARAMETER;
  }
 
  CurrentBase = StartAddress;
  do {
    //
    // Check the required memory range status; if the required memory range span
    // the different GCD memory descriptor, it may be cause different action.
    //
    Status = gDS->GetMemorySpaceDescriptor (
                    CurrentBase,
                    &Descriptor
                    );
    if (EFI_ERROR (Status)) {
      return Status;
    }
 
    if ((Descriptor.GcdMemoryType == EfiGcdMemoryTypeReserved) &&
        ((Descriptor.Capabilities & (EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED | EFI_MEMORY_TESTED)) ==
         (EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED))
        )
    {
      CurrentLength = Descriptor.BaseAddress + Descriptor.Length - CurrentBase;
      if (CurrentBase + CurrentLength > StartAddress + Length) {
        CurrentLength = StartAddress + Length - CurrentBase;
      }
 
      Status = DirectRangeTest (
                 Private,
                 CurrentBase,
                 CurrentLength,
                 Descriptor.Capabilities
                 );
      if (EFI_ERROR (Status)) {
        return Status;
      }
    }
 
    CurrentBase = Descriptor.BaseAddress + Descriptor.Length;
  } while (CurrentBase < StartAddress + Length);
 
  //
  // Here means the required range already be tested, so just return success.
  //
  return EFI_SUCCESS;
}
 
EFI_STATUS
PerformAddressDataLineTest (
  IN  GENERIC_MEMORY_TEST_PRIVATE  *Private
  )
{
  LIST_ENTRY              *ExtendedLink;
  NONTESTED_MEMORY_RANGE  *ExtendedRange;
  BOOLEAN                 InExtendedRange;
  EFI_PHYSICAL_ADDRESS    TestAddress;
 
  //
  // Light version no data line test, only perform the address line test
  //
  TestAddress = (EFI_PHYSICAL_ADDRESS)0x1;
  while (TestAddress < MAX_ADDRESS && TestAddress > 0) {
    //
    // only test if the address falls in the enabled range
    //
    InExtendedRange = FALSE;
    ExtendedLink    = Private->NonTestedMemRanList.BackLink;
    while (ExtendedLink != &Private->NonTestedMemRanList) {
      ExtendedRange = NONTESTED_MEMORY_RANGE_FROM_LINK (ExtendedLink);
      if ((TestAddress >= ExtendedRange->StartAddress) &&
          (TestAddress < (ExtendedRange->StartAddress + ExtendedRange->Length))
          )
      {
        InExtendedRange = TRUE;
      }
 
      ExtendedLink = ExtendedLink->BackLink;
    }
 
    if (InExtendedRange) {
      *(EFI_PHYSICAL_ADDRESS *)(UINTN)TestAddress = TestAddress;
      Private->Cpu->FlushDataCache (Private->Cpu, TestAddress, 1, EfiCpuFlushTypeWriteBackInvalidate);
      if (*(EFI_PHYSICAL_ADDRESS *)(UINTN)TestAddress != TestAddress) {
        return EFI_ACCESS_DENIED;
      }
    }
 
    TestAddress = LShiftU64 (TestAddress, 1);
  }
 
  return EFI_SUCCESS;
}
 
//
// Driver entry here
//
GENERIC_MEMORY_TEST_PRIVATE  mGenericMemoryTestPrivate = {
  EFI_GENERIC_MEMORY_TEST_PRIVATE_SIGNATURE,
  NULL,
  NULL,
  {
    InitializeMemoryTest,
    GenPerformMemoryTest,
    GenMemoryTestFinished,
    GenCompatibleRangeTest
  },
  (EXTENDMEM_COVERAGE_LEVEL)0,
  0,
  0,
  NULL,
  0,
  0,
  {
    NULL,
    NULL
  }
};
 
EFI_STATUS
EFIAPI
GenericMemoryTestEntryPoint (
  IN  EFI_HANDLE        ImageHandle,
  IN  EFI_SYSTEM_TABLE  *SystemTable
  )
{
  EFI_STATUS            Status;
  VOID                  *HobList;
  EFI_BOOT_MODE         BootMode;
  EFI_PEI_HOB_POINTERS  Hob;
 
  //
  // Use the generic pattern to test compatible memory range
  //
  mGenericMemoryTestPrivate.MonoPattern  = GenericMemoryTestMonoPattern;
  mGenericMemoryTestPrivate.MonoTestSize = GENERIC_CACHELINE_SIZE;
 
  //
  // Get the platform boot mode
  //
  HobList = GetHobList ();
 
  Hob.Raw = HobList;
  if (Hob.Header->HobType != EFI_HOB_TYPE_HANDOFF) {
    return EFI_NOT_FOUND;
  }
 
  BootMode = Hob.HandoffInformationTable->BootMode;
 
  //
  // Get the platform boot mode and create the default memory test coverage
  // level and span size for compatible memory test using
  //
  switch (BootMode) {
    case BOOT_WITH_FULL_CONFIGURATION:
    case BOOT_WITH_DEFAULT_SETTINGS:
      mGenericMemoryTestPrivate.CoverageSpan = SPARSE_SPAN_SIZE;
      break;
 
    case BOOT_WITH_FULL_CONFIGURATION_PLUS_DIAGNOSTICS:
      mGenericMemoryTestPrivate.CoverageSpan = GENERIC_CACHELINE_SIZE;
      break;
 
    default:
      mGenericMemoryTestPrivate.CoverageSpan = QUICK_SPAN_SIZE;
      break;
  }
 
  //
  // Install the protocol
  //
  Status = gBS->InstallProtocolInterface (
                  &mGenericMemoryTestPrivate.Handle,
                  &gEfiGenericMemTestProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  &mGenericMemoryTestPrivate.GenericMemoryTest
                  );
 
  return Status;
}