MdeModulePkg/Universal/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 // The package level header files this module uses
  31 //
  32 #include <PiDxe.h>
  33
  34 UINT32  mCrcTable[256];
  35
  36 EFI_STATUS
  37 EFIAPI
  38 RuntimeDriverCalculateCrc32 (
  39   IN  VOID    *Data,
  40   IN  UINTN   DataSize,
  41   OUT UINT32  *CrcOut
  42   )
  43 /*++
  44
  45 Routine Description:
  46
  47   Calculate CRC32 for target data
  48
  49 Arguments:
  50
  51   Data     - The target data.
  52   DataSize - The target data size.
  53   CrcOut   - The CRC32 for target data.
  54
  55 Returns:
  56
  57   EFI_SUCCESS           - The CRC32 for target data is calculated successfully.
  58   EFI_INVALID_PARAMETER - Some parameter is not valid, so the CRC32 is not
  59                           calculated.
  60
  61 --*/
  62 {
  63   UINT32  Crc;
  64   UINTN   Index;
  65   UINT8   *Ptr;
  66
  67   if (Data == NULL || DataSize == 0 || CrcOut == NULL) {
  68     return EFI_INVALID_PARAMETER;
  69   }
  70
  71   Crc = 0xffffffff;
  72   for (Index = 0, Ptr = Data; Index < DataSize; Index++, Ptr++) {
  73     Crc = (Crc >> 8) ^ mCrcTable[(UINT8) Crc ^ *Ptr];
  74   }
  75
  76   *CrcOut = Crc ^ 0xffffffff;
  77   return EFI_SUCCESS;
  78 }
  79
  80 STATIC
  81 UINT32
  82 ReverseBits (
  83   UINT32  Value
  84   )
  85 /*++
  86
  87 Routine Description:
  88
  89   Reverse bits for 32bit data.
  90
  91 Arguments:
  92
  93   Value - the data to be reversed.
  94
  95 Returns:
  96
  97   UINT32 data reversed.
  98
  99 --*/
 100 {
 101   UINTN   Index;
 102   UINT32  NewValue;
 103
 104   NewValue = 0;
 105   for (Index = 0; Index < 32; Index++) {
 106     if (Value & (1 << Index)) {
 107       NewValue = NewValue | (1 << (31 - Index));
 108     }
 109   }
 110
 111   return NewValue;
 112 }
 113
 114 VOID
 115 RuntimeDriverInitializeCrc32Table (
 116   VOID
 117   )
 118 /*++
 119
 120 Routine Description:
 121
 122   Initialize CRC32 table.
 123
 124 Arguments:
 125
 126   None.
 127
 128 Returns:
 129
 130   None.
 131
 132 --*/
 133 {
 134   UINTN   TableEntry;
 135   UINTN   Index;
 136   UINT32  Value;
 137
 138   for (TableEntry = 0; TableEntry < 256; TableEntry++) {
 139     Value = ReverseBits ((UINT32) TableEntry);
 140     for (Index = 0; Index < 8; Index++) {
 141       if (Value & 0x80000000) {
 142         Value = (Value << 1) ^ 0x04c11db7;
 143       } else {
 144         Value = Value << 1;
 145       }
 146     }
 147
 148     mCrcTable[TableEntry] = ReverseBits (Value);
 149   }
 150 }