EdkModulePkg/Universal/Runtime/RuntimeDxe/Crc32.c

   1 /*++
   2
   3 Copyright (c) 2006, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   Crc32.c
  15
  16 Abstract:
  17
  18   CalculateCrc32 Boot Services as defined in DXE CIS.
  19
  20   This Boot Services is in the Runtime Driver because this service is
  21   also required by SetVirtualAddressMap() when the EFI System Table and
  22   EFI Runtime Services Table are converted from physical address to
  23   virtual addresses.  This requires that the 32-bit CRC be recomputed.
  24
  25 Revision History:
  26
  27 --*/
  28
  29 #include "Runtime.h"
  30
  31 UINT32  mCrcTable[256];
  32
  33 EFI_STATUS
  34 EFIAPI
  35 RuntimeDriverCalculateCrc32 (
  36   IN  VOID    *Data,
  37   IN  UINTN   DataSize,
  38   OUT UINT32  *CrcOut
  39   )
  40 /*++
  41
  42 Routine Description:
  43
  44   Calculate CRC32 for target data
  45
  46 Arguments:
  47
  48   Data     - The target data.
  49   DataSize - The target data size.
  50   CrcOut   - The CRC32 for target data.
  51
  52 Returns:
  53
  54   EFI_SUCCESS           - The CRC32 for target data is calculated successfully.
  55   EFI_INVALID_PARAMETER - Some parameter is not valid, so the CRC32 is not
  56                           calculated.
  57
  58 --*/
  59 {
  60   UINT32  Crc;
  61   UINTN   Index;
  62   UINT8   *Ptr;
  63
  64   if (Data == NULL || DataSize == 0 || CrcOut == NULL) {
  65     return EFI_INVALID_PARAMETER;
  66   }
  67
  68   Crc = 0xffffffff;
  69   for (Index = 0, Ptr = Data; Index < DataSize; Index++, Ptr++) {
  70     Crc = (Crc >> 8) ^ mCrcTable[(UINT8) Crc ^ *Ptr];
  71   }
  72
  73   *CrcOut = Crc ^ 0xffffffff;
  74   return EFI_SUCCESS;
  75 }
  76
  77 STATIC
  78 UINT32
  79 ReverseBits (
  80   UINT32  Value
  81   )
  82 /*++
  83
  84 Routine Description:
  85
  86   Reverse bits for 32bit data.
  87
  88 Arguments:
  89
  90   Value - the data to be reversed.
  91
  92 Returns:
  93
  94   UINT32 data reversed.
  95
  96 --*/
  97 {
  98   UINTN   Index;
  99   UINT32  NewValue;
 100
 101   NewValue = 0;
 102   for (Index = 0; Index < 32; Index++) {
 103     if (Value & (1 << Index)) {
 104       NewValue = NewValue | (1 << (31 - Index));
 105     }
 106   }
 107
 108   return NewValue;
 109 }
 110
 111 VOID
 112 RuntimeDriverInitializeCrc32Table (
 113   VOID
 114   )
 115 /*++
 116
 117 Routine Description:
 118
 119   Initialize CRC32 table.
 120
 121 Arguments:
 122
 123   None.
 124
 125 Returns:
 126
 127   None.
 128
 129 --*/
 130 {
 131   UINTN   TableEntry;
 132   UINTN   Index;
 133   UINT32  Value;
 134
 135   for (TableEntry = 0; TableEntry < 256; TableEntry++) {
 136     Value = ReverseBits ((UINT32) TableEntry);
 137     for (Index = 0; Index < 8; Index++) {
 138       if (Value & 0x80000000) {
 139         Value = (Value << 1) ^ 0x04c11db7;
 140       } else {
 141         Value = Value << 1;
 142       }
 143     }
 144
 145     mCrcTable[TableEntry] = ReverseBits (Value);
 146   }
 147 }