MdeModulePkg/Core/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
  30 #include <PiDxe.h>
  31
  32 UINT32  mCrcTable[256];
  33
  34 EFI_STATUS
  35 EFIAPI
  36 RuntimeDriverCalculateCrc32 (
  37   IN  VOID    *Data,
  38   IN  UINTN   DataSize,
  39   OUT UINT32  *CrcOut
  40   )
  41 /*++
  42
  43 Routine Description:
  44
  45   Calculate CRC32 for target data
  46
  47 Arguments:
  48
  49   Data     - The target data.
  50   DataSize - The target data size.
  51   CrcOut   - The CRC32 for target data.
  52
  53 Returns:
  54
  55   EFI_SUCCESS           - The CRC32 for target data is calculated successfully.
  56   EFI_INVALID_PARAMETER - Some parameter is not valid, so the CRC32 is not
  57                           calculated.
  58
  59 --*/
  60 {
  61   UINT32  Crc;
  62   UINTN   Index;
  63   UINT8   *Ptr;
  64
  65   if (Data == NULL || DataSize == 0 || CrcOut == NULL) {
  66     return EFI_INVALID_PARAMETER;
  67   }
  68
  69   Crc = 0xffffffff;
  70   for (Index = 0, Ptr = Data; Index < DataSize; Index++, Ptr++) {
  71     Crc = (Crc >> 8) ^ mCrcTable[(UINT8) Crc ^ *Ptr];
  72   }
  73
  74   *CrcOut = Crc ^ 0xffffffff;
  75   return EFI_SUCCESS;
  76 }
  77
  78 STATIC
  79 UINT32
  80 ReverseBits (
  81   UINT32  Value
  82   )
  83 /*++
  84
  85 Routine Description:
  86
  87   Reverse bits for 32bit data.
  88
  89 Arguments:
  90
  91   Value - the data to be reversed.
  92
  93 Returns:
  94
  95   UINT32 data reversed.
  96
  97 --*/
  98 {
  99   UINTN   Index;
 100   UINT32  NewValue;
 101
 102   NewValue = 0;
 103   for (Index = 0; Index < 32; Index++) {
 104     if (Value & (1 << Index)) {
 105       NewValue = NewValue | (1 << (31 - Index));
 106     }
 107   }
 108
 109   return NewValue;
 110 }
 111
 112 VOID
 113 RuntimeDriverInitializeCrc32Table (
 114   VOID
 115   )
 116 /*++
 117
 118 Routine Description:
 119
 120   Initialize CRC32 table.
 121
 122 Arguments:
 123
 124   None.
 125
 126 Returns:
 127
 128   None.
 129
 130 --*/
 131 {
 132   UINTN   TableEntry;
 133   UINTN   Index;
 134   UINT32  Value;
 135
 136   for (TableEntry = 0; TableEntry < 256; TableEntry++) {
 137     Value = ReverseBits ((UINT32) TableEntry);
 138     for (Index = 0; Index < 8; Index++) {
 139       if (Value & 0x80000000) {
 140         Value = (Value << 1) ^ 0x04c11db7;
 141       } else {
 142         Value = Value << 1;
 143       }
 144     }
 145
 146     mCrcTable[TableEntry] = ReverseBits (Value);
 147   }
 148 }