/** @file
  Helper functions for calculating CRC32 checksum

;******************************************************************************
;* Copyright (c) 2012, Insyde Software Corp. All Rights Reserved.
;*
;* You may not reproduce, distribute, publish, display, perform, modify, adapt,
;* transmit, broadcast, present, recite, release, license or otherwise exploit
;* any part of this publication in any form, by any means, without the prior
;* written permission of Insyde Software Corporation.
;*
;******************************************************************************
*/

UINT32  mCrcTable[256];


/**
  This internal function reverses bits for 32bit data.

  @param  Value                 The data to be reversed.

  @return                       Data reversed.

**/
UINT32
ReverseBits (
  UINT32  Value
  )
{
  UINTN   Index;
  UINT32  NewValue;

  NewValue = 0;
  for (Index = 0; Index < 32; Index++) {
    if ((Value & (1 << Index)) != 0) {
      NewValue = NewValue | (1 << (31 - Index));
    }
  }

  return NewValue;
}

/**
  Initialize CRC32 table.

  @param  none

  @retval none
**/
VOID
InitializeCrc32Table (
  VOID
  )
{
  UINTN   TableEntry;
  UINTN   Index;
  UINT32  Value;

  for (TableEntry = 0; TableEntry < 256; TableEntry++) {
    Value = ReverseBits ((UINT32) TableEntry);
    for (Index = 0; Index < 8; Index++) {
      if ((Value & 0x80000000) != 0) {
        Value = (Value << 1) ^ 0x04c11db7;
      } else {
        Value = Value << 1;
      }
    }

    mCrcTable[TableEntry] = ReverseBits (Value);
  }
}