| /* crc32.c |
| Copyright (C) 2009-2017 Free Software Foundation, Inc. |
| |
| This file is part of the libiberty library. |
| |
| This file is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| In addition to the permissions in the GNU General Public License, the |
| Free Software Foundation gives you unlimited permission to link the |
| compiled version of this file into combinations with other programs, |
| and to distribute those combinations without any restriction coming |
| from the use of this file. (The General Public License restrictions |
| do apply in other respects; for example, they cover modification of |
| the file, and distribution when not linked into a combined |
| executable.) |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| #include "libiberty.h" |
| |
| /* This table was generated by the following program. |
| |
| #include <stdio.h> |
| |
| int |
| main () |
| { |
| unsigned int i, j; |
| unsigned int c; |
| int table[256]; |
| |
| for (i = 0; i < 256; i++) |
| { |
| for (c = i << 24, j = 8; j > 0; --j) |
| c = c & 0x80000000 ? (c << 1) ^ 0x04c11db7 : (c << 1); |
| table[i] = c; |
| } |
| |
| printf ("static const unsigned int crc32_table[] =\n{\n"); |
| for (i = 0; i < 256; i += 4) |
| { |
| printf (" 0x%08x, 0x%08x, 0x%08x, 0x%08x", |
| table[i + 0], table[i + 1], table[i + 2], table[i + 3]); |
| if (i + 4 < 256) |
| putchar (','); |
| putchar ('\n'); |
| } |
| printf ("};\n"); |
| return 0; |
| } |
| |
| For more information on CRC, see, e.g., |
| http://www.ross.net/crc/download/crc_v3.txt. */ |
| |
| static const unsigned int crc32_table[] = |
| { |
| 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, |
| 0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005, |
| 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61, |
| 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, |
| 0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, |
| 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75, |
| 0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, |
| 0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd, |
| 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039, |
| 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, |
| 0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81, |
| 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d, |
| 0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, |
| 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95, |
| 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, |
| 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, |
| 0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae, |
| 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072, |
| 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, |
| 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, |
| 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde, |
| 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, |
| 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066, |
| 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba, |
| 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, |
| 0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692, |
| 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6, |
| 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, |
| 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, |
| 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, |
| 0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, |
| 0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a, |
| 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637, |
| 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, |
| 0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, |
| 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53, |
| 0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, |
| 0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b, |
| 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff, |
| 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, |
| 0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, |
| 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b, |
| 0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, |
| 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3, |
| 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, |
| 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, |
| 0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f, |
| 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3, |
| 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, |
| 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, |
| 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8, |
| 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, |
| 0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30, |
| 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec, |
| 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, |
| 0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654, |
| 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0, |
| 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, |
| 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18, |
| 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, |
| 0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, |
| 0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c, |
| 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668, |
| 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4 |
| }; |
| |
| /* |
| |
| @deftypefn Extension {unsigned int} crc32 (const unsigned char *@var{buf}, @ |
| int @var{len}, unsigned int @var{init}) |
| |
| Compute the 32-bit CRC of @var{buf} which has length @var{len}. The |
| starting value is @var{init}; this may be used to compute the CRC of |
| data split across multiple buffers by passing the return value of each |
| call as the @var{init} parameter of the next. |
| |
| This is used by the @command{gdb} remote protocol for the @samp{qCRC} |
| command. In order to get the same results as gdb for a block of data, |
| you must pass the first CRC parameter as @code{0xffffffff}. |
| |
| This CRC can be specified as: |
| |
| Width : 32 |
| Poly : 0x04c11db7 |
| Init : parameter, typically 0xffffffff |
| RefIn : false |
| RefOut : false |
| XorOut : 0 |
| |
| This differs from the "standard" CRC-32 algorithm in that the values |
| are not reflected, and there is no final XOR value. These differences |
| make it easy to compose the values of multiple blocks. |
| |
| @end deftypefn |
| |
| */ |
| |
| unsigned int |
| xcrc32 (const unsigned char *buf, int len, unsigned int init) |
| { |
| unsigned int crc = init; |
| while (len--) |
| { |
| crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *buf) & 255]; |
| buf++; |
| } |
| return crc; |
| } |