1 /*
2 * Dec 5, 2000 Matt Domsch <Matt_Domsch@dell.com>
3 * - Copied crc32.c from the linux/drivers/net/cipe directory.
4 * - Now pass seed as an arg
5 * - changed unsigned long to uint32_t, added #include<stdint.h>
6 * - changed len to be an unsigned long
7 * - changed crc32val to be a register
8 * - License remains unchanged! It's still GPL-compatable!
9 */
10
11 /* ============================================================= */
12 /* COPYRIGHT (C) 1986 Gary S. Brown. You may use this program, or */
13 /* code or tables extracted from it, as desired without restriction. */
14 /* */
15 /* First, the polynomial itself and its table of feedback terms. The */
16 /* polynomial is */
17 /* 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+X^0 */
18 /* */
19 /* Note that we take it "backwards" and put the highest-order term in */
20 /* the lowest-order bit. The X^32 term is "implied"; the LSB is the */
21 /* X^31 term, etc. The X^0 term (usually shown as "+1") results in */
22 /* the MSB being 1. */
23 /* */
24 /* Note that the usual hardware shift register implementation, which */
25 /* is what we're using (we're merely optimizing it by doing eight-bit */
26 /* chunks at a time) shifts bits into the lowest-order term. In our */
27 /* implementation, that means shifting towards the right. Why do we */
28 /* do it this way? Because the calculated CRC must be transmitted in */
29 /* order from highest-order term to lowest-order term. UARTs transmit */
30 /* characters in order from LSB to MSB. By storing the CRC this way, */
31 /* we hand it to the UART in the order low-byte to high-byte; the UART */
32 /* sends each low-bit to hight-bit; and the result is transmission bit */
33 /* by bit from highest- to lowest-order term without requiring any bit */
34 /* shuffling on our part. Reception works similarly. */
35 /* */
36 /* The feedback terms table consists of 256, 32-bit entries. Notes: */
37 /* */
38 /* The table can be generated at runtime if desired; code to do so */
39 /* is shown later. It might not be obvious, but the feedback */
40 /* terms simply represent the results of eight shift/xor opera- */
41 /* tions for all combinations of data and CRC register values. */
42 /* */
43 /* The values must be right-shifted by eight bits by the "updcrc" */
44 /* logic; the shift must be unsigned (bring in zeroes). On some */
45 /* hardware you could probably optimize the shift in assembler by */
46 /* using byte-swap instructions. */
47 /* polynomial $edb88320 */
48 /* */
49 /* -------------------------------------------------------------------- */
50
51 #include <config.h>
52 #include <stdint.h>
53
54 static const uint32_t crc32_tab[] = {
55 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
56 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
57 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
58 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
59 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
60 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
61 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
62 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
63 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
64 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
65 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
66 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
67 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
68 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
69 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
70 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
71 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
72 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
73 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
74 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
75 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
76 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
77 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
78 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
79 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
80 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
81 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
82 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
83 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
84 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
85 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
86 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
87 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
88 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
89 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
90 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
91 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
92 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
93 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
94 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
95 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
96 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
97 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
98 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
99 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
100 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
101 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
102 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
103 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
104 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
105 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
106 0x2d02ef8dL
107 };
108
109 /* Return a 32-bit CRC of the contents of the buffer. */
110
111 uint32_t
112 __efi_crc32(const void *buf, unsigned long len, uint32_t seed)
113 {
114 unsigned long i;
115 register uint32_t crc32val;
116 const unsigned char *s = buf;
117
118 crc32val = seed;
119 for (i = 0; i < len; i ++)
120 {
121 crc32val =
122 crc32_tab[(crc32val ^ s[i]) & 0xff] ^
123 (crc32val >> 8);
124 }
125 return crc32val;
126 }