Clean up Runtime for Doxygen comments requirement.

[mirror_edk2.git] / MdeModulePkg / Core / RuntimeDxe / Crc32.c

/** @file\r
  CalculateCrc32 Boot Services as defined in DXE CIS.\r
\r
Copyright (c) 2006, Intel Corporation. <BR>\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
  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
**/\r
\r
\r
#include <PiDxe.h>\r
\r
UINT32  mCrcTable[256];\r
\r
/**\r
  Calculate CRC32 for target data.\r
\r
  @param  Data                  The target data.\r
  @param  DataSize              The target data size.\r
  @param  CrcOut                The CRC32 for target data.\r
\r
  @retval EFI_SUCCESS           The CRC32 for target data is calculated successfully.\r
  @retval EFI_INVALID_PARAMETER Some parameter is not valid, so the CRC32 is not\r
                                calculated.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
RuntimeDriverCalculateCrc32 (\r
  IN  VOID    *Data,\r
  IN  UINTN   DataSize,\r
  OUT UINT32  *CrcOut\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
\r
/**\r
  Reverse bits for 32bit data.\r
  This is a internal function.\r
\r
  @param  Value                 The data to be reversed.\r
\r
  @return                       Data reversed.\r
\r
**/\r
UINT32\r
ReverseBits (\r
  UINT32  Value\r
  )\r
{\r
  UINTN   Index;\r
  UINT32  NewValue;\r
\r
  NewValue = 0;\r
  for (Index = 0; Index < 32; Index++) {\r
    if ((Value & (1 << Index)) != 0) {\r
      NewValue = NewValue | (1 << (31 - Index));\r
    }\r
  }\r
\r
  return NewValue;\r
}\r
\r
/**\r
  Initialize CRC32 table.\r
**/\r
VOID\r
RuntimeDriverInitializeCrc32Table (\r
  VOID\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) != 0) {\r
        Value = (Value << 1) ^ 0x04c11db7;\r
      } else {\r
        Value = Value << 1;\r
      }\r
    }\r
\r
    mCrcTable[TableEntry] = ReverseBits (Value);\r
  }\r
}\r