/*++

Copyright (c) 2005, Intel Corporation                                                         
All rights reserved. This program and the accompanying materials                          
are licensed and made available under the terms and conditions of the BSD License         
which accompanies this distribution. The full text of the license may be found at         
http://opensource.org/licenses/bsd-license.php                                            
                                                                                          
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

Module Name:

  CRC.c

Abstract:

  CRC32 functions

Revision History

--*/

#include "EfiShellLib.h"

UINT32  CRCTable[256] = {
  0x00000000,
  0x77073096,
  0xEE0E612C,
  0x990951BA,
  0x076DC419,
  0x706AF48F,
  0xE963A535,
  0x9E6495A3,
  0x0EDB8832,
  0x79DCB8A4,
  0xE0D5E91E,
  0x97D2D988,
  0x09B64C2B,
  0x7EB17CBD,
  0xE7B82D07,
  0x90BF1D91,
  0x1DB71064,
  0x6AB020F2,
  0xF3B97148,
  0x84BE41DE,
  0x1ADAD47D,
  0x6DDDE4EB,
  0xF4D4B551,
  0x83D385C7,
  0x136C9856,
  0x646BA8C0,
  0xFD62F97A,
  0x8A65C9EC,
  0x14015C4F,
  0x63066CD9,
  0xFA0F3D63,
  0x8D080DF5,
  0x3B6E20C8,
  0x4C69105E,
  0xD56041E4,
  0xA2677172,
  0x3C03E4D1,
  0x4B04D447,
  0xD20D85FD,
  0xA50AB56B,
  0x35B5A8FA,
  0x42B2986C,
  0xDBBBC9D6,
  0xACBCF940,
  0x32D86CE3,
  0x45DF5C75,
  0xDCD60DCF,
  0xABD13D59,
  0x26D930AC,
  0x51DE003A,
  0xC8D75180,
  0xBFD06116,
  0x21B4F4B5,
  0x56B3C423,
  0xCFBA9599,
  0xB8BDA50F,
  0x2802B89E,
  0x5F058808,
  0xC60CD9B2,
  0xB10BE924,
  0x2F6F7C87,
  0x58684C11,
  0xC1611DAB,
  0xB6662D3D,
  0x76DC4190,
  0x01DB7106,
  0x98D220BC,
  0xEFD5102A,
  0x71B18589,
  0x06B6B51F,
  0x9FBFE4A5,
  0xE8B8D433,
  0x7807C9A2,
  0x0F00F934,
  0x9609A88E,
  0xE10E9818,
  0x7F6A0DBB,
  0x086D3D2D,
  0x91646C97,
  0xE6635C01,
  0x6B6B51F4,
  0x1C6C6162,
  0x856530D8,
  0xF262004E,
  0x6C0695ED,
  0x1B01A57B,
  0x8208F4C1,
  0xF50FC457,
  0x65B0D9C6,
  0x12B7E950,
  0x8BBEB8EA,
  0xFCB9887C,
  0x62DD1DDF,
  0x15DA2D49,
  0x8CD37CF3,
  0xFBD44C65,
  0x4DB26158,
  0x3AB551CE,
  0xA3BC0074,
  0xD4BB30E2,
  0x4ADFA541,
  0x3DD895D7,
  0xA4D1C46D,
  0xD3D6F4FB,
  0x4369E96A,
  0x346ED9FC,
  0xAD678846,
  0xDA60B8D0,
  0x44042D73,
  0x33031DE5,
  0xAA0A4C5F,
  0xDD0D7CC9,
  0x5005713C,
  0x270241AA,
  0xBE0B1010,
  0xC90C2086,
  0x5768B525,
  0x206F85B3,
  0xB966D409,
  0xCE61E49F,
  0x5EDEF90E,
  0x29D9C998,
  0xB0D09822,
  0xC7D7A8B4,
  0x59B33D17,
  0x2EB40D81,
  0xB7BD5C3B,
  0xC0BA6CAD,
  0xEDB88320,
  0x9ABFB3B6,
  0x03B6E20C,
  0x74B1D29A,
  0xEAD54739,
  0x9DD277AF,
  0x04DB2615,
  0x73DC1683,
  0xE3630B12,
  0x94643B84,
  0x0D6D6A3E,
  0x7A6A5AA8,
  0xE40ECF0B,
  0x9309FF9D,
  0x0A00AE27,
  0x7D079EB1,
  0xF00F9344,
  0x8708A3D2,
  0x1E01F268,
  0x6906C2FE,
  0xF762575D,
  0x806567CB,
  0x196C3671,
  0x6E6B06E7,
  0xFED41B76,
  0x89D32BE0,
  0x10DA7A5A,
  0x67DD4ACC,
  0xF9B9DF6F,
  0x8EBEEFF9,
  0x17B7BE43,
  0x60B08ED5,
  0xD6D6A3E8,
  0xA1D1937E,
  0x38D8C2C4,
  0x4FDFF252,
  0xD1BB67F1,
  0xA6BC5767,
  0x3FB506DD,
  0x48B2364B,
  0xD80D2BDA,
  0xAF0A1B4C,
  0x36034AF6,
  0x41047A60,
  0xDF60EFC3,
  0xA867DF55,
  0x316E8EEF,
  0x4669BE79,
  0xCB61B38C,
  0xBC66831A,
  0x256FD2A0,
  0x5268E236,
  0xCC0C7795,
  0xBB0B4703,
  0x220216B9,
  0x5505262F,
  0xC5BA3BBE,
  0xB2BD0B28,
  0x2BB45A92,
  0x5CB36A04,
  0xC2D7FFA7,
  0xB5D0CF31,
  0x2CD99E8B,
  0x5BDEAE1D,
  0x9B64C2B0,
  0xEC63F226,
  0x756AA39C,
  0x026D930A,
  0x9C0906A9,
  0xEB0E363F,
  0x72076785,
  0x05005713,
  0x95BF4A82,
  0xE2B87A14,
  0x7BB12BAE,
  0x0CB61B38,
  0x92D28E9B,
  0xE5D5BE0D,
  0x7CDCEFB7,
  0x0BDBDF21,
  0x86D3D2D4,
  0xF1D4E242,
  0x68DDB3F8,
  0x1FDA836E,
  0x81BE16CD,
  0xF6B9265B,
  0x6FB077E1,
  0x18B74777,
  0x88085AE6,
  0xFF0F6A70,
  0x66063BCA,
  0x11010B5C,
  0x8F659EFF,
  0xF862AE69,
  0x616BFFD3,
  0x166CCF45,
  0xA00AE278,
  0xD70DD2EE,
  0x4E048354,
  0x3903B3C2,
  0xA7672661,
  0xD06016F7,
  0x4969474D,
  0x3E6E77DB,
  0xAED16A4A,
  0xD9D65ADC,
  0x40DF0B66,
  0x37D83BF0,
  0xA9BCAE53,
  0xDEBB9EC5,
  0x47B2CF7F,
  0x30B5FFE9,
  0xBDBDF21C,
  0xCABAC28A,
  0x53B39330,
  0x24B4A3A6,
  0xBAD03605,
  0xCDD70693,
  0x54DE5729,
  0x23D967BF,
  0xB3667A2E,
  0xC4614AB8,
  0x5D681B02,
  0x2A6F2B94,
  0xB40BBE37,
  0xC30C8EA1,
  0x5A05DF1B,
  0x2D02EF8D
};

VOID
SetCrc (
  IN OUT EFI_TABLE_HEADER *Hdr
  )
/*++

Routine Description:

    Updates the CRC32 value in the table header

Arguments:

    Hdr     - The table to update

Returns:

    None

--*/
{
  ASSERT (Hdr != NULL);
  SetCrcAltSize (Hdr->HeaderSize, Hdr);
}

VOID
SetCrcAltSize (
  IN UINTN                  Size,
  IN OUT EFI_TABLE_HEADER   *Hdr
  )
/*++

Routine Description:

    Updates the CRC32 value in the table header

Arguments:

    Size    - Size
    Hdr     - The table to update

Returns:

    None

--*/
{
  ASSERT (Hdr != NULL);
  Hdr->CRC32  = 0;
  Hdr->CRC32  = CalculateCrc ((UINT8 *) Hdr, Size);
}

BOOLEAN
CheckCrc (
  IN UINTN                  MaxSize,
  IN OUT EFI_TABLE_HEADER   *Hdr
  )
/*++

Routine Description:

    Checks the CRC32 value in the table header

Arguments:

   MaxSize - The max size
   Hdr     - The table to check

Returns:

    TRUE if the CRC is OK in the table

--*/
{
  ASSERT (Hdr != NULL);
  return CheckCrcAltSize (MaxSize, Hdr->HeaderSize, Hdr);
}

BOOLEAN
CheckCrcAltSize (
  IN UINTN                  MaxSize,
  IN UINTN                  Size,
  IN OUT EFI_TABLE_HEADER   *Hdr
  )
/*++

Routine Description:

    Checks the CRC32 value in the table header

Arguments:

    MaxSize - The max size
    Size    - The size
    Hdr     - The table to check

Returns:

    TRUE if the CRC is OK in the table

--*/
{
  UINT32  Crc;
  UINT32  OrgCrc;
  BOOLEAN f;
  
  ASSERT (Hdr != NULL);

  if (Size == 0) {
    //
    // If header size is 0 CRC will pass so return FALSE here
    //
    return FALSE;
  }

  if (MaxSize && Size > MaxSize) {
    DEBUG ((EFI_D_ERROR, "CheckCrc32: Size > MaxSize\n"));
    return FALSE;
  }
  //
  // clear old crc from header
  //
  OrgCrc      = Hdr->CRC32;
  Hdr->CRC32  = 0;
  Crc         = CalculateCrc ((UINT8 *) Hdr, Size);

  //
  // set restults
  //
  Hdr->CRC32 = OrgCrc;

  //
  // return status
  //
  f = (BOOLEAN) (OrgCrc == (UINT32) Crc);
  if (!f) {
    DEBUG ((EFI_D_ERROR, "CheckCrc32: Crc check failed\n"));
  }

  return f;
}

UINT32
CalculateCrc (
  UINT8 *pt,
  UINTN Size
  )
/*++

Routine Description:

    Calculate the CRC32 value

Arguments:

   pt      - The pointer to the data
   Size    - The data size

Returns:

    The CRC value of the data

--*/
{
  UINTN Crc;

  ASSERT (pt != NULL);

  //
  // compute crc
  //
  Crc = 0xffffffff;
  while (Size) {
    Crc = (Crc >> 8) ^ CRCTable[(UINT8) Crc ^ *pt];
    pt += 1;
    Size -= 1;
  }

  Crc = Crc ^ 0xffffffff;
  return (UINT32) Crc;
}
