xref: /openbmc/u-boot/lib/crc32.c (revision f51cdaf1)
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
12 #include <common.h>
13 #endif
14 #include <compiler.h>
15 #include <u-boot/crc.h>
16 
17 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
18 #include <watchdog.h>
19 #endif
20 #include "u-boot/zlib.h"
21 
22 #define local static
23 #define ZEXPORT	/* empty */
24 
25 #define tole(x) cpu_to_le32(x)
26 
27 #ifdef DYNAMIC_CRC_TABLE
28 
29 local int crc_table_empty = 1;
30 local uint32_t crc_table[256];
31 local void make_crc_table OF((void));
32 
33 /*
34   Generate a table for a byte-wise 32-bit CRC calculation on the polynomial:
35   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.
36 
37   Polynomials over GF(2) are represented in binary, one bit per coefficient,
38   with the lowest powers in the most significant bit.  Then adding polynomials
39   is just exclusive-or, and multiplying a polynomial by x is a right shift by
40   one.  If we call the above polynomial p, and represent a byte as the
41   polynomial q, also with the lowest power in the most significant bit (so the
42   byte 0xb1 is the polynomial x^7+x^3+x+1), then the CRC is (q*x^32) mod p,
43   where a mod b means the remainder after dividing a by b.
44 
45   This calculation is done using the shift-register method of multiplying and
46   taking the remainder.  The register is initialized to zero, and for each
47   incoming bit, x^32 is added mod p to the register if the bit is a one (where
48   x^32 mod p is p+x^32 = x^26+...+1), and the register is multiplied mod p by
49   x (which is shifting right by one and adding x^32 mod p if the bit shifted
50   out is a one).  We start with the highest power (least significant bit) of
51   q and repeat for all eight bits of q.
52 
53   The table is simply the CRC of all possible eight bit values.  This is all
54   the information needed to generate CRC's on data a byte at a time for all
55   combinations of CRC register values and incoming bytes.
56 */
57 local void make_crc_table()
58 {
59   uint32_t c;
60   int n, k;
61   uLong poly;		/* polynomial exclusive-or pattern */
62   /* terms of polynomial defining this crc (except x^32): */
63   static const Byte p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
64 
65   /* make exclusive-or pattern from polynomial (0xedb88320L) */
66   poly = 0L;
67   for (n = 0; n < sizeof(p)/sizeof(Byte); n++)
68     poly |= 1L << (31 - p[n]);
69 
70   for (n = 0; n < 256; n++)
71   {
72     c = (uLong)n;
73     for (k = 0; k < 8; k++)
74       c = c & 1 ? poly ^ (c >> 1) : c >> 1;
75     crc_table[n] = tole(c);
76   }
77   crc_table_empty = 0;
78 }
79 #else
80 /* ========================================================================
81  * Table of CRC-32's of all single-byte values (made by make_crc_table)
82  */
83 
84 local const uint32_t crc_table[256] = {
85 tole(0x00000000L), tole(0x77073096L), tole(0xee0e612cL), tole(0x990951baL),
86 tole(0x076dc419L), tole(0x706af48fL), tole(0xe963a535L), tole(0x9e6495a3L),
87 tole(0x0edb8832L), tole(0x79dcb8a4L), tole(0xe0d5e91eL), tole(0x97d2d988L),
88 tole(0x09b64c2bL), tole(0x7eb17cbdL), tole(0xe7b82d07L), tole(0x90bf1d91L),
89 tole(0x1db71064L), tole(0x6ab020f2L), tole(0xf3b97148L), tole(0x84be41deL),
90 tole(0x1adad47dL), tole(0x6ddde4ebL), tole(0xf4d4b551L), tole(0x83d385c7L),
91 tole(0x136c9856L), tole(0x646ba8c0L), tole(0xfd62f97aL), tole(0x8a65c9ecL),
92 tole(0x14015c4fL), tole(0x63066cd9L), tole(0xfa0f3d63L), tole(0x8d080df5L),
93 tole(0x3b6e20c8L), tole(0x4c69105eL), tole(0xd56041e4L), tole(0xa2677172L),
94 tole(0x3c03e4d1L), tole(0x4b04d447L), tole(0xd20d85fdL), tole(0xa50ab56bL),
95 tole(0x35b5a8faL), tole(0x42b2986cL), tole(0xdbbbc9d6L), tole(0xacbcf940L),
96 tole(0x32d86ce3L), tole(0x45df5c75L), tole(0xdcd60dcfL), tole(0xabd13d59L),
97 tole(0x26d930acL), tole(0x51de003aL), tole(0xc8d75180L), tole(0xbfd06116L),
98 tole(0x21b4f4b5L), tole(0x56b3c423L), tole(0xcfba9599L), tole(0xb8bda50fL),
99 tole(0x2802b89eL), tole(0x5f058808L), tole(0xc60cd9b2L), tole(0xb10be924L),
100 tole(0x2f6f7c87L), tole(0x58684c11L), tole(0xc1611dabL), tole(0xb6662d3dL),
101 tole(0x76dc4190L), tole(0x01db7106L), tole(0x98d220bcL), tole(0xefd5102aL),
102 tole(0x71b18589L), tole(0x06b6b51fL), tole(0x9fbfe4a5L), tole(0xe8b8d433L),
103 tole(0x7807c9a2L), tole(0x0f00f934L), tole(0x9609a88eL), tole(0xe10e9818L),
104 tole(0x7f6a0dbbL), tole(0x086d3d2dL), tole(0x91646c97L), tole(0xe6635c01L),
105 tole(0x6b6b51f4L), tole(0x1c6c6162L), tole(0x856530d8L), tole(0xf262004eL),
106 tole(0x6c0695edL), tole(0x1b01a57bL), tole(0x8208f4c1L), tole(0xf50fc457L),
107 tole(0x65b0d9c6L), tole(0x12b7e950L), tole(0x8bbeb8eaL), tole(0xfcb9887cL),
108 tole(0x62dd1ddfL), tole(0x15da2d49L), tole(0x8cd37cf3L), tole(0xfbd44c65L),
109 tole(0x4db26158L), tole(0x3ab551ceL), tole(0xa3bc0074L), tole(0xd4bb30e2L),
110 tole(0x4adfa541L), tole(0x3dd895d7L), tole(0xa4d1c46dL), tole(0xd3d6f4fbL),
111 tole(0x4369e96aL), tole(0x346ed9fcL), tole(0xad678846L), tole(0xda60b8d0L),
112 tole(0x44042d73L), tole(0x33031de5L), tole(0xaa0a4c5fL), tole(0xdd0d7cc9L),
113 tole(0x5005713cL), tole(0x270241aaL), tole(0xbe0b1010L), tole(0xc90c2086L),
114 tole(0x5768b525L), tole(0x206f85b3L), tole(0xb966d409L), tole(0xce61e49fL),
115 tole(0x5edef90eL), tole(0x29d9c998L), tole(0xb0d09822L), tole(0xc7d7a8b4L),
116 tole(0x59b33d17L), tole(0x2eb40d81L), tole(0xb7bd5c3bL), tole(0xc0ba6cadL),
117 tole(0xedb88320L), tole(0x9abfb3b6L), tole(0x03b6e20cL), tole(0x74b1d29aL),
118 tole(0xead54739L), tole(0x9dd277afL), tole(0x04db2615L), tole(0x73dc1683L),
119 tole(0xe3630b12L), tole(0x94643b84L), tole(0x0d6d6a3eL), tole(0x7a6a5aa8L),
120 tole(0xe40ecf0bL), tole(0x9309ff9dL), tole(0x0a00ae27L), tole(0x7d079eb1L),
121 tole(0xf00f9344L), tole(0x8708a3d2L), tole(0x1e01f268L), tole(0x6906c2feL),
122 tole(0xf762575dL), tole(0x806567cbL), tole(0x196c3671L), tole(0x6e6b06e7L),
123 tole(0xfed41b76L), tole(0x89d32be0L), tole(0x10da7a5aL), tole(0x67dd4accL),
124 tole(0xf9b9df6fL), tole(0x8ebeeff9L), tole(0x17b7be43L), tole(0x60b08ed5L),
125 tole(0xd6d6a3e8L), tole(0xa1d1937eL), tole(0x38d8c2c4L), tole(0x4fdff252L),
126 tole(0xd1bb67f1L), tole(0xa6bc5767L), tole(0x3fb506ddL), tole(0x48b2364bL),
127 tole(0xd80d2bdaL), tole(0xaf0a1b4cL), tole(0x36034af6L), tole(0x41047a60L),
128 tole(0xdf60efc3L), tole(0xa867df55L), tole(0x316e8eefL), tole(0x4669be79L),
129 tole(0xcb61b38cL), tole(0xbc66831aL), tole(0x256fd2a0L), tole(0x5268e236L),
130 tole(0xcc0c7795L), tole(0xbb0b4703L), tole(0x220216b9L), tole(0x5505262fL),
131 tole(0xc5ba3bbeL), tole(0xb2bd0b28L), tole(0x2bb45a92L), tole(0x5cb36a04L),
132 tole(0xc2d7ffa7L), tole(0xb5d0cf31L), tole(0x2cd99e8bL), tole(0x5bdeae1dL),
133 tole(0x9b64c2b0L), tole(0xec63f226L), tole(0x756aa39cL), tole(0x026d930aL),
134 tole(0x9c0906a9L), tole(0xeb0e363fL), tole(0x72076785L), tole(0x05005713L),
135 tole(0x95bf4a82L), tole(0xe2b87a14L), tole(0x7bb12baeL), tole(0x0cb61b38L),
136 tole(0x92d28e9bL), tole(0xe5d5be0dL), tole(0x7cdcefb7L), tole(0x0bdbdf21L),
137 tole(0x86d3d2d4L), tole(0xf1d4e242L), tole(0x68ddb3f8L), tole(0x1fda836eL),
138 tole(0x81be16cdL), tole(0xf6b9265bL), tole(0x6fb077e1L), tole(0x18b74777L),
139 tole(0x88085ae6L), tole(0xff0f6a70L), tole(0x66063bcaL), tole(0x11010b5cL),
140 tole(0x8f659effL), tole(0xf862ae69L), tole(0x616bffd3L), tole(0x166ccf45L),
141 tole(0xa00ae278L), tole(0xd70dd2eeL), tole(0x4e048354L), tole(0x3903b3c2L),
142 tole(0xa7672661L), tole(0xd06016f7L), tole(0x4969474dL), tole(0x3e6e77dbL),
143 tole(0xaed16a4aL), tole(0xd9d65adcL), tole(0x40df0b66L), tole(0x37d83bf0L),
144 tole(0xa9bcae53L), tole(0xdebb9ec5L), tole(0x47b2cf7fL), tole(0x30b5ffe9L),
145 tole(0xbdbdf21cL), tole(0xcabac28aL), tole(0x53b39330L), tole(0x24b4a3a6L),
146 tole(0xbad03605L), tole(0xcdd70693L), tole(0x54de5729L), tole(0x23d967bfL),
147 tole(0xb3667a2eL), tole(0xc4614ab8L), tole(0x5d681b02L), tole(0x2a6f2b94L),
148 tole(0xb40bbe37L), tole(0xc30c8ea1L), tole(0x5a05df1bL), tole(0x2d02ef8dL)
149 };
150 #endif
151 
152 #if 0
153 /* =========================================================================
154  * This function can be used by asm versions of crc32()
155  */
156 const uint32_t * ZEXPORT get_crc_table()
157 {
158 #ifdef DYNAMIC_CRC_TABLE
159   if (crc_table_empty) make_crc_table();
160 #endif
161   return (const uint32_t *)crc_table;
162 }
163 #endif
164 
165 /* ========================================================================= */
166 # if __BYTE_ORDER == __LITTLE_ENDIAN
167 #  define DO_CRC(x) crc = tab[(crc ^ (x)) & 255] ^ (crc >> 8)
168 # else
169 #  define DO_CRC(x) crc = tab[((crc >> 24) ^ (x)) & 255] ^ (crc << 8)
170 # endif
171 
172 /* ========================================================================= */
173 
174 /* No ones complement version. JFFS2 (and other things ?)
175  * don't use ones compliment in their CRC calculations.
176  */
177 uint32_t ZEXPORT crc32_no_comp(uint32_t crc, const Bytef *buf, uInt len)
178 {
179     const uint32_t *tab = crc_table;
180     const uint32_t *b =(const uint32_t *)buf;
181     size_t rem_len;
182 #ifdef DYNAMIC_CRC_TABLE
183     if (crc_table_empty)
184       make_crc_table();
185 #endif
186     crc = cpu_to_le32(crc);
187     /* Align it */
188     if (((long)b) & 3 && len) {
189 	 uint8_t *p = (uint8_t *)b;
190 	 do {
191 	      DO_CRC(*p++);
192 	 } while ((--len) && ((long)p)&3);
193 	 b = (uint32_t *)p;
194     }
195 
196     rem_len = len & 3;
197     len = len >> 2;
198     for (--b; len; --len) {
199 	 /* load data 32 bits wide, xor data 32 bits wide. */
200 	 crc ^= *++b; /* use pre increment for speed */
201 	 DO_CRC(0);
202 	 DO_CRC(0);
203 	 DO_CRC(0);
204 	 DO_CRC(0);
205     }
206     len = rem_len;
207     /* And the last few bytes */
208     if (len) {
209 	 uint8_t *p = (uint8_t *)(b + 1) - 1;
210 	 do {
211 	      DO_CRC(*++p); /* use pre increment for speed */
212 	 } while (--len);
213     }
214 
215     return le32_to_cpu(crc);
216 }
217 #undef DO_CRC
218 
219 uint32_t ZEXPORT crc32 (uint32_t crc, const Bytef *p, uInt len)
220 {
221      return crc32_no_comp(crc ^ 0xffffffffL, p, len) ^ 0xffffffffL;
222 }
223 
224 /*
225  * Calculate the crc32 checksum triggering the watchdog every 'chunk_sz' bytes
226  * of input.
227  */
228 uint32_t ZEXPORT crc32_wd (uint32_t crc,
229 			   const unsigned char *buf,
230 			   uInt len, uInt chunk_sz)
231 {
232 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
233 	const unsigned char *end, *curr;
234 	int chunk;
235 
236 	curr = buf;
237 	end = buf + len;
238 	while (curr < end) {
239 		chunk = end - curr;
240 		if (chunk > chunk_sz)
241 			chunk = chunk_sz;
242 		crc = crc32 (crc, curr, chunk);
243 		curr += chunk;
244 		WATCHDOG_RESET ();
245 	}
246 #else
247 	crc = crc32 (crc, buf, len);
248 #endif
249 
250 	return crc;
251 }
252