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 UINT32
  78 ReverseBits (
  79   UINT32  Value
  80   )
  81 /*++
  82
  83 Routine Description:
  84
  85   Reverse bits for 32bit data.
  86
  87 Arguments:
  88
  89   Value - the data to be reversed.
  90
  91 Returns:
  92
  93   UINT32 data reversed.
  94
  95 --*/
  96 {
  97   UINTN   Index;
  98   UINT32  NewValue;
  99
 100   NewValue = 0;
 101   for (Index = 0; Index < 32; Index++) {
 102     if (Value & (1 << Index)) {
 103       NewValue = NewValue | (1 << (31 - Index));
 104     }
 105   }
 106
 107   return NewValue;
 108 }
 109
 110 VOID
 111 RuntimeDriverInitializeCrc32Table (
 112   VOID
 113   )
 114 /*++
 115
 116 Routine Description:
 117
 118   Initialize CRC32 table.
 119
 120 Arguments:
 121
 122   None.
 123
 124 Returns:
 125
 126   None.
 127
 128 --*/
 129 {
 130   UINTN   TableEntry;
 131   UINTN   Index;
 132   UINT32  Value;
 133
 134   for (TableEntry = 0; TableEntry < 256; TableEntry++) {
 135     Value = ReverseBits ((UINT32) TableEntry);
 136     for (Index = 0; Index < 8; Index++) {
 137       if (Value & 0x80000000) {
 138         Value = (Value << 1) ^ 0x04c11db7;
 139       } else {
 140         Value = Value << 1;
 141       }
 142     }
 143
 144     mCrcTable[TableEntry] = ReverseBits (Value);
 145   }
 146 }