MIDI
[mw/milkymist.git] / tools / crc32.c
1 /*
2  * CRC32 computation tool
3  * 2009, Sebastien Bourdeauducq - http://lekernel.net
4  * This file is part of Milkymist.
5  */
6
7 /* crc32.c -- compute the CRC-32 of a data stream
8  * Copyright (C) 1995-1998 Mark Adler
9  * For conditions of distribution and use, see copyright notice in zlib.h
10  */
11
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <sys/types.h>
15 #include <sys/stat.h>
16 #include <sys/mman.h>
17 #include <string.h>
18 #include <fcntl.h>
19 #include <unistd.h>
20
21 const unsigned int crc_table[256] = {
22         0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
23         0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
24         0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
25         0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
26         0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
27         0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
28         0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
29         0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
30         0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
31         0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
32         0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
33         0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
34         0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
35         0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
36         0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
37         0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
38         0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
39         0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
40         0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
41         0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
42         0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
43         0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
44         0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
45         0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
46         0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
47         0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
48         0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
49         0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
50         0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
51         0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
52         0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
53         0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
54         0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
55         0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
56         0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
57         0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
58         0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
59         0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
60         0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
61         0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
62         0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
63         0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
64         0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
65         0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
66         0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
67         0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
68         0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
69         0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
70         0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
71         0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
72         0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
73         0x2d02ef8dL
74 };
75
76 #define DO1(buf) crc = crc_table[((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8);
77 #define DO2(buf)  DO1(buf); DO1(buf);
78 #define DO4(buf)  DO2(buf); DO2(buf);
79 #define DO8(buf)  DO4(buf); DO4(buf);
80
81 static unsigned int crc32(const unsigned char *buffer, unsigned int len)
82 {
83         unsigned int crc;
84         crc = 0;
85         crc = crc ^ 0xffffffffL;
86         while(len >= 8) {
87                 DO8(buffer);
88                 len -= 8;
89         }
90         if(len) do {
91                 DO1(buffer);
92         } while(--len);
93         return crc ^ 0xffffffffL;
94 }
95
96 int main(int argc, char *argv[])
97 {
98         int fd;
99         unsigned char *buffer;
100         unsigned int length;
101         unsigned int crc;
102         
103         if(
104              (argc != 2)
105          && ((argc != 3) && !strcmp(argv[2], "write"))
106         ) {
107                 fprintf(stderr, "Usage: crc32 <filename> [write]\n");
108                 return 1;
109         }
110         
111         fd = open(argv[1], O_RDONLY);
112         if(fd == -1) {
113                 perror("open");
114                 return 1;
115         }
116         
117         length = lseek(fd, 0, SEEK_END);
118         lseek(fd, 0, SEEK_SET);
119         
120         buffer = mmap(NULL, length, PROT_READ, MAP_SHARED, fd, 0);
121         if(!buffer) {
122                 perror("mmap");
123                 close(fd);
124                 return 1;
125         }
126         crc = crc32(buffer, length);
127         printf("CRC32 (%s): %08x\n", argv[1], crc);
128         munmap(buffer, length);
129         close(fd);
130         
131         if(argc == 3) {
132                 /* Write the CRC32 in big endian at the end of the file */
133                 char b[4];
134                 
135                 fd = open(argv[1], O_WRONLY|O_APPEND);
136                 if(fd == -1) {
137                         perror("open");
138                         return 1;
139                 }
140                 b[0] = (crc & 0xff000000) >> 24;
141                 b[1] = (crc & 0x00ff0000) >> 16;
142                 b[2] = (crc & 0x0000ff00) >> 8;
143                 b[3] = (crc & 0x000000ff) >> 0;
144                 write(fd, &b[0], 4);
145                 close(fd);
146         }
147         
148         return 0;
149 }