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 Arguments:
  45
  46 Returns:
  47
  48 --*/
  49 {
  50   UINT32  Crc;
  51   UINTN   Index;
  52   UINT8   *Ptr;
  53
  54   if (Data == NULL || DataSize == 0 || CrcOut == NULL) {
  55     return EFI_INVALID_PARAMETER;
  56   }
  57
  58   Crc = 0xffffffff;
  59   for (Index = 0, Ptr = Data; Index < DataSize; Index++, Ptr++) {
  60     Crc = (Crc >> 8) ^ mCrcTable[(UINT8) Crc ^ *Ptr];
  61   }
  62
  63   *CrcOut = Crc ^ 0xffffffff;
  64   return EFI_SUCCESS;
  65 }
  66
  67 UINT32
  68 ReverseBits (
  69   UINT32  Value
  70   )
  71 /*++
  72
  73 Routine Description:
  74
  75 Arguments:
  76
  77 Returns:
  78
  79 --*/
  80 {
  81   UINTN   Index;
  82   UINT32  NewValue;
  83
  84   NewValue = 0;
  85   for (Index = 0; Index < 32; Index++) {
  86     if (Value & (1 << Index)) {
  87       NewValue = NewValue | (1 << (31 - Index));
  88     }
  89   }
  90
  91   return NewValue;
  92 }
  93
  94 VOID
  95 RuntimeDriverInitializeCrc32Table (
  96   VOID
  97   )
  98 /*++
  99
 100 Routine Description:
 101
 102 Arguments:
 103
 104 Returns:
 105
 106 --*/
 107 {
 108   UINTN   TableEntry;
 109   UINTN   Index;
 110   UINT32  Value;
 111
 112   for (TableEntry = 0; TableEntry < 256; TableEntry++) {
 113     Value = ReverseBits ((UINT32) TableEntry);
 114     for (Index = 0; Index < 8; Index++) {
 115       if (Value & 0x80000000) {
 116         Value = (Value << 1) ^ 0x04c11db7;
 117       } else {
 118         Value = Value << 1;
 119       }
 120     }
 121
 122     mCrcTable[TableEntry] = ReverseBits (Value);
 123   }
 124 }