Initial import.

[mirror_edk2.git] / EdkModulePkg / Universal / Runtime / RuntimeDxe / Crc32.c

/*++\r
\r
Copyright (c) 2006, Intel Corporation                                                         \r
All rights reserved. This program and the accompanying materials                          \r
are licensed and made available under the terms and conditions of the BSD License         \r
which accompanies this distribution.  The full text of the license may be found at        \r
http://opensource.org/licenses/bsd-license.php                                            \r
                                                                                          \r
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     \r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             \r
\r
Module Name:\r
\r
  Crc32.c\r
\r
Abstract:\r
\r
  CalculateCrc32 Boot Services as defined in DXE CIS.\r
\r
  This Boot Services is in the Runtime Driver because this service is\r
  also required by SetVirtualAddressMap() when the EFI System Table and\r
  EFI Runtime Services Table are converted from physical address to \r
  virtual addresses.  This requires that the 32-bit CRC be recomputed.\r
\r
Revision History:\r
\r
--*/\r
\r
#include "Runtime.h"\r
\r
UINT32  mCrcTable[256];\r
\r
EFI_STATUS\r
EFIAPI\r
RuntimeDriverCalculateCrc32 (\r
  IN  VOID    *Data,\r
  IN  UINTN   DataSize,\r
  OUT UINT32  *CrcOut\r
  )\r
/*++\r
\r
Routine Description:\r
\r
Arguments:\r
\r
Returns:\r
\r
--*/\r
{\r
  UINT32  Crc;\r
  UINTN   Index;\r
  UINT8   *Ptr;\r
\r
  if (Data == NULL || DataSize == 0 || CrcOut == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  Crc = 0xffffffff;\r
  for (Index = 0, Ptr = Data; Index < DataSize; Index++, Ptr++) {\r
    Crc = (Crc >> 8) ^ mCrcTable[(UINT8) Crc ^ *Ptr];\r
  }\r
\r
  *CrcOut = Crc ^ 0xffffffff;\r
  return EFI_SUCCESS;\r
}\r
\r
UINT32\r
ReverseBits (\r
  UINT32  Value\r
  )\r
/*++\r
\r
Routine Description:\r
\r
Arguments:\r
\r
Returns:\r
\r
--*/\r
{\r
  UINTN   Index;\r
  UINT32  NewValue;\r
\r
  NewValue = 0;\r
  for (Index = 0; Index < 32; Index++) {\r
    if (Value & (1 << Index)) {\r
      NewValue = NewValue | (1 << (31 - Index));\r
    }\r
  }\r
\r
  return NewValue;\r
}\r
\r
VOID\r
RuntimeDriverInitializeCrc32Table (\r
  VOID\r
  )\r
/*++\r
\r
Routine Description:\r
\r
Arguments:\r
\r
Returns:\r
\r
--*/\r
{\r
  UINTN   TableEntry;\r
  UINTN   Index;\r
  UINT32  Value;\r
\r
  for (TableEntry = 0; TableEntry < 256; TableEntry++) {\r
    Value = ReverseBits ((UINT32) TableEntry);\r
    for (Index = 0; Index < 8; Index++) {\r
      if (Value & 0x80000000) {\r
        Value = (Value << 1) ^ 0x04c11db7;\r
      } else {\r
        Value = Value << 1;\r
      }\r
    }\r
\r
    mCrcTable[TableEntry] = ReverseBits (Value);\r
  }\r
}\r