lib_generic/crc32.c

   1 /*
   2  * This file is derived from crc32.c from the zlib-1.1.3 distribution
   3  * by Jean-loup Gailly and Mark Adler.
   4  */
   5
   6 /* crc32.c -- compute the CRC-32 of a data stream
   7  * Copyright (C) 1995-1998 Mark Adler
   8  * For conditions of distribution and use, see copyright notice in zlib.h
   9  */
  10
  11 #ifndef USE_HOSTCC      /* Shut down "ANSI does not permit..." warnings */
  12 #include <common.h>
  13 #else
  14 #include <stdint.h>
  15 #endif
  16
  17 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
  18 #include <watchdog.h>
  19 #endif
  20 #include "zlib.h"
  21
  22 #define local static
  23 #define ZEXPORT /* empty */
  24
  25 #ifdef DYNAMIC_CRC_TABLE
  26
  27 local int crc_table_empty = 1;
  28 local uint32_t crc_table[256];
  29 local void make_crc_table OF((void));
  30
  31 /*
  32   Generate a table for a byte-wise 32-bit CRC calculation on the polynomial:
  33   x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1.
  34
  35   Polynomials over GF(2) are represented in binary, one bit per coefficient,
  36   with the lowest powers in the most significant bit.  Then adding polynomials
  37   is just exclusive-or, and multiplying a polynomial by x is a right shift by
  38   one.  If we call the above polynomial p, and represent a byte as the
  39   polynomial q, also with the lowest power in the most significant bit (so the
  40   byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p,
  41   where a mod b means the remainder after dividing a by b.
  42
  43   This calculation is done using the shift-register method of multiplying and
  44   taking the remainder.  The register is initialized to zero, and for each
  45   incoming bit, x^32 is added mod p to the register if the bit is a one (where
  46   x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by
  47   x (which is shifting right by one and adding x^32 mod p if the bit shifted
  48   out is a one).  We start with the highest power (least significant bit) of
  49   q and repeat for all eight bits of q.
  50
  51   The table is simply the CRC of all possible eight bit values.  This is all
  52   the information needed to generate CRC's on data a byte at a time for all
  53   combinations of CRC register values and incoming bytes.
  54 */
  55 local void make_crc_table()
  56 {
  57   uint32_t c;
  58   int n, k;
  59   uLong poly;           /* polynomial exclusive-or pattern */
  60   /* terms of polynomial defining this crc (except x^32): */
  61   static const Byte p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
  62
  63   /* make exclusive-or pattern from polynomial (0xedb88320L) */
  64   poly = 0L;
  65   for (n = 0; n < sizeof(p)/sizeof(Byte); n++)
  66     poly |= 1L << (31 - p[n]);
  67
  68   for (n = 0; n < 256; n++)
  69   {
  70     c = (uLong)n;
  71     for (k = 0; k < 8; k++)
  72       c = c & 1 ? poly ^ (c >> 1) : c >> 1;
  73     crc_table[n] = c;
  74   }
  75   crc_table_empty = 0;
  76 }
  77 #else
  78 /* ========================================================================
  79  * Table of CRC-32's of all single-byte values (made by make_crc_table)
  80  */
  81 local const uint32_t crc_table[256] = {
  82   0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
  83   0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
  84   0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
  85   0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
  86   0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
  87   0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
  88   0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
  89   0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
  90   0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
  91   0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
  92   0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
  93   0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
  94   0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
  95   0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
  96   0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
  97   0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
  98   0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
  99   0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
 100   0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
 101   0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
 102   0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
 103   0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
 104   0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
 105   0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
 106   0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
 107   0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
 108   0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
 109   0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
 110   0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
 111   0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
 112   0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
 113   0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
 114   0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
 115   0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
 116   0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
 117   0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
 118   0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
 119   0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
 120   0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
 121   0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
 122   0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
 123   0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
 124   0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
 125   0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
 126   0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
 127   0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
 128   0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
 129   0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
 130   0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
 131   0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
 132   0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
 133   0x2d02ef8dL
 134 };
 135 #endif
 136
 137 #if 0
 138 /* =========================================================================
 139  * This function can be used by asm versions of crc32()
 140  */
 141 const uint32_t * ZEXPORT get_crc_table()
 142 {
 143 #ifdef DYNAMIC_CRC_TABLE
 144   if (crc_table_empty) make_crc_table();
 145 #endif
 146   return (const uint32_t *)crc_table;
 147 }
 148 #endif
 149
 150 /* ========================================================================= */
 151 #define DO1(buf) crc = crc_table[((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8);
 152 #define DO2(buf)  DO1(buf); DO1(buf);
 153 #define DO4(buf)  DO2(buf); DO2(buf);
 154 #define DO8(buf)  DO4(buf); DO4(buf);
 155
 156 /* ========================================================================= */
 157 uint32_t ZEXPORT crc32 (uint32_t crc, const Bytef *buf, uInt len)
 158 {
 159 #ifdef DYNAMIC_CRC_TABLE
 160     if (crc_table_empty)
 161       make_crc_table();
 162 #endif
 163     crc = crc ^ 0xffffffffL;
 164     while (len >= 8)
 165     {
 166       DO8(buf);
 167       len -= 8;
 168     }
 169     if (len) do {
 170       DO1(buf);
 171     } while (--len);
 172     return crc ^ 0xffffffffL;
 173 }
 174
 175 #if defined(CONFIG_CMD_JFFS2) || \
 176         (defined(CONFIG_CMD_NAND) \
 177         && !defined(CONFIG_NAND_LEGACY))
 178
 179 /* No ones complement version. JFFS2 (and other things ?)
 180  * don't use ones compliment in their CRC calculations.
 181  */
 182 uint32_t ZEXPORT crc32_no_comp(uint32_t crc, const Bytef *buf, uInt len)
 183 {
 184 #ifdef DYNAMIC_CRC_TABLE
 185     if (crc_table_empty)
 186       make_crc_table();
 187 #endif
 188     while (len >= 8)
 189     {
 190       DO8(buf);
 191       len -= 8;
 192     }
 193     if (len) do {
 194       DO1(buf);
 195     } while (--len);
 196
 197     return crc;
 198 }
 199
 200 #endif
 201
 202 /*
 203  * Calculate the crc32 checksum triggering the watchdog every 'chunk_sz' bytes
 204  * of input.
 205  */
 206 uint32_t ZEXPORT crc32_wd (uint32_t crc,
 207                            const unsigned char *buf,
 208                            uInt len, uInt chunk_sz)
 209 {
 210 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
 211         const unsigned char *end, *curr;
 212         int chunk;
 213
 214         curr = buf;
 215         end = buf + len;
 216         while (curr < end) {
 217                 chunk = end - curr;
 218                 if (chunk > chunk_sz)
 219                         chunk = chunk_sz;
 220                 crc = crc32 (crc, curr, chunk);
 221                 curr += chunk;
 222                 WATCHDOG_RESET ();
 223         }
 224 #else
 225         crc = crc32 (crc, buf, len);
 226 #endif
 227
 228         return crc;
 229 }