Commit | Line | Data |
---|---|---|
b7580524 | 1 | /* -*-c-*- |
2 | * | |
8656dc50 | 3 | * $Id: crc-mktab.c,v 1.6 2004/04/08 01:36:11 mdw Exp $ |
b7580524 | 4 | * |
5 | * Build CRC tables | |
6 | * | |
7 | * (c) 2000 Straylight/Edgeware | |
8 | */ | |
9 | ||
d4efbcd9 | 10 | /*----- Licensing notice --------------------------------------------------* |
b7580524 | 11 | * |
12 | * This file is part of the mLib utilities library. | |
13 | * | |
14 | * mLib is free software; you can redistribute it and/or modify | |
15 | * it under the terms of the GNU Library General Public License as | |
16 | * published by the Free Software Foundation; either version 2 of the | |
17 | * License, or (at your option) any later version. | |
d4efbcd9 | 18 | * |
b7580524 | 19 | * mLib is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
22 | * GNU Library General Public License for more details. | |
d4efbcd9 | 23 | * |
b7580524 | 24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with mLib; if not, write to the Free | |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
27 | * MA 02111-1307, USA. | |
28 | */ | |
29 | ||
b7580524 | 30 | /*----- Header files ------------------------------------------------------*/ |
31 | ||
a0150d8d MW |
32 | #include "config.h" |
33 | ||
b7580524 | 34 | #include <ctype.h> |
35 | #include <errno.h> | |
36 | #include <limits.h> | |
37 | #include <stdarg.h> | |
38 | #include <stdio.h> | |
39 | #include <stdlib.h> | |
40 | #include <string.h> | |
41 | ||
42 | #include "mdwopt.h" | |
43 | #include "quis.h" | |
44 | #include "report.h" | |
45 | ||
46 | /*----- Static variables --------------------------------------------------*/ | |
47 | ||
48 | static unsigned long poly = 0; | |
49 | static const char *guard = 0; | |
50 | static unsigned bits = 0; | |
51 | static unsigned chunk = 8; | |
52 | static const char *file = 0; | |
53 | static unsigned flags = 0; | |
54 | static const char *sym = 0; | |
55 | static const char *type = 0; | |
56 | static const char *inc = 0; | |
57 | static FILE *fp; | |
58 | ||
393cf1d9 | 59 | #define f_bogus 1u |
60 | #define f_ctab 2u | |
61 | #define f_reverse 4u | |
b7580524 | 62 | |
63 | #define BSCOL 72 | |
64 | ||
65 | /*----- Main code ---------------------------------------------------------*/ | |
66 | ||
67 | static unsigned long getint(const char *p, unsigned long max, | |
68 | const char *what) | |
69 | { | |
70 | char *pp; | |
71 | unsigned long x = strtoul(p, &pp, 0); | |
72 | if (*pp || (max && x > max)) | |
73 | die(EXIT_FAILURE, "bad %s `%s'", what, p); | |
74 | return (x); | |
75 | } | |
76 | ||
77 | static void version(FILE *fp) | |
78 | { | |
79 | pquis(fp, "$, mLib version " VERSION "\n"); | |
80 | } | |
81 | ||
82 | static void usage(FILE *fp) | |
83 | { | |
6f444bda | 84 | pquis(fp, "Usage: $ [-cr] [-o FILE] [-g GUARD] [-s SYM] [-i HEADER]\n\ |
d4efbcd9 | 85 | [-t TYPE] [-b BITS] [-B BITS] [-p POLY]\n"); |
b7580524 | 86 | } |
87 | ||
88 | static void help(FILE *fp) | |
89 | { | |
90 | version(fp); | |
91 | putc('\n', stdout); | |
92 | usage(fp); | |
93 | fputs("\n\ | |
94 | Emits a table containing precomuted values for CRC algorithms. A number\n\ | |
95 | of options are provided:\n\ | |
96 | \n\ | |
97 | -h, --help Show this help text.\n\ | |
98 | -v, --version Show the program's version number.\n\ | |
99 | -u, --usage Show a terse usage message.\n\ | |
100 | \n\ | |
101 | -c, --c-source Emit a C source file rather than a header.\n\ | |
102 | -b, --bits=BITS Emit a table for a BITS bits-wide CRC.\n\ | |
103 | -B, --bit-chunk=BITS Emit a table to process BITS bits at a time.\n\ | |
104 | -p, --polynomial=POLY Use the POLY as the dividing polynomial.\n\ | |
105 | -r, --reverse Create a `reversed' CRC table.\n\ | |
106 | -g, --guard=GUARD Use GUARD as a multiple-inclusion guard constant.\n\ | |
6f444bda | 107 | -i, --include=HEADER Include HEADER at top of C source file.\n\ |
108 | -s, --symbol=SYM Name the generated table SYM.\n\ | |
b7580524 | 109 | -t, --type=TYPE Give the table entries type TYPE in C source.\n\ |
110 | -o, --output=FILE Write the output to FILE.\n\ | |
111 | ", stdout); | |
112 | } | |
113 | ||
114 | unsigned long reflect(unsigned long x, unsigned b) | |
115 | { | |
116 | unsigned long y = 0; | |
117 | unsigned long xm, ym; | |
118 | unsigned i; | |
119 | if (!(flags & f_reverse)) | |
120 | return (x); | |
121 | xm = 1; | |
122 | ym = 1 << (b - 1); | |
123 | for (i = 0; i < b; i++) { | |
124 | if (x & xm) | |
125 | y |= ym; | |
126 | xm <<= 1; | |
127 | ym >>= 1; | |
128 | } | |
129 | return (y); | |
130 | } | |
131 | ||
132 | int main(int argc, char *argv[]) | |
133 | { | |
134 | unsigned n, t, nw; | |
135 | unsigned max, i; | |
136 | unsigned long mask; | |
137 | ||
138 | ego(argv[0]); | |
139 | ||
140 | for (;;) { | |
141 | static struct option opts[] = { | |
142 | { "help", 0, 0, 'h' }, | |
143 | { "version", 0, 0, 'v' }, | |
144 | { "usage", 0, 0, 'u' }, | |
145 | ||
146 | { "output", OPTF_ARGREQ, 0, 'o' }, | |
147 | { "c-source", 0, 0, 'c' }, | |
148 | { "symbol", OPTF_ARGREQ, 0, 's' }, | |
149 | { "type", OPTF_ARGREQ, 0, 't' }, | |
150 | { "include", OPTF_ARGREQ, 0, 'i' }, | |
151 | { "guard", OPTF_ARGREQ, 0, 'g' }, | |
152 | ||
153 | { "bits", OPTF_ARGREQ, 0, 'b' }, | |
154 | { "bit-chunk", OPTF_ARGREQ, 0, 'B' }, | |
155 | { "polynomial", OPTF_ARGREQ, 0, 'p' }, | |
156 | { "reverse", 0, 0, 'r' }, | |
157 | ||
158 | { 0, 0, 0, 0 } | |
159 | }; | |
160 | int i = mdwopt(argc, argv, "hvu o:cs:t:i:g: b:B:p:r", opts, 0, 0, 0); | |
161 | ||
162 | if (i < 0) | |
163 | break; | |
164 | switch (i) { | |
165 | case 'h': | |
166 | help(stdout); | |
167 | exit(0); | |
168 | case 'v': | |
169 | version(stdout); | |
170 | exit(0); | |
171 | case 'u': | |
172 | usage(stdout); | |
173 | exit(0); | |
174 | ||
175 | case 'o': | |
176 | file = optarg; | |
177 | break; | |
178 | case 'c': | |
179 | flags |= f_ctab; | |
180 | break; | |
181 | case 's': | |
182 | sym = optarg; | |
183 | break; | |
184 | case 't': | |
185 | type = optarg; | |
186 | break; | |
187 | case 'i': | |
188 | inc = optarg; | |
189 | break; | |
190 | case 'g': | |
191 | guard = optarg; | |
192 | break; | |
193 | ||
194 | case 'b': | |
195 | bits = getint(optarg, 32, "CRC width"); | |
196 | break; | |
197 | case 'B': | |
198 | chunk = getint(optarg, 32, "chunk size"); | |
199 | break; | |
200 | case 'p': | |
201 | poly = getint(optarg, 0xffffffff, "CRC poly"); | |
202 | break; | |
203 | case 'r': | |
204 | flags |= f_reverse; | |
205 | break; | |
206 | ||
207 | default: | |
208 | flags |= f_bogus; | |
209 | break; | |
210 | } | |
211 | } | |
212 | if ((flags & f_bogus) || optind != argc) { | |
213 | usage(stderr); | |
214 | exit(EXIT_FAILURE); | |
215 | } | |
216 | ||
217 | /* --- Sort out the various parameters --- */ | |
218 | ||
219 | if (!poly) { | |
220 | switch (bits) { | |
221 | case 16: | |
222 | if (flags & f_reverse) | |
223 | poly = 0x8408; | |
224 | else | |
225 | poly = 0x1021; | |
226 | break; | |
227 | case 32: | |
b7580524 | 228 | poly = 0x04c11db7; |
229 | flags |= f_reverse; | |
230 | bits = 32; | |
231 | break; | |
000ba0de | 232 | case 0: |
233 | die(EXIT_FAILURE, "no polynomial or bit width set"); | |
234 | break; | |
b7580524 | 235 | default: |
236 | die(EXIT_FAILURE, "no standard polynomials for %u bits", bits); | |
237 | break; | |
238 | } | |
239 | } | |
240 | ||
241 | if (!bits) { | |
242 | unsigned long x = poly; | |
243 | while (x > 1) { | |
244 | x >>= 8; | |
245 | bits += 8; | |
246 | } | |
247 | } | |
0521f473 | 248 | nw = (bits + 3)/4; |
b7580524 | 249 | |
250 | if ((flags & f_ctab) && !type) | |
251 | type = bits > 16 ? "unsigned long" : "unsigned short"; | |
252 | ||
253 | /* --- Start output --- */ | |
254 | ||
255 | if (!file) | |
256 | fp = stdout; | |
257 | else { | |
258 | if (!(flags & f_ctab) && !guard) { | |
259 | char *p; | |
260 | const char *q; | |
261 | if ((p = malloc(strlen(file) + 1)) == 0) | |
262 | die(EXIT_FAILURE, "not enough memory"); | |
263 | guard = p; | |
264 | for (q = file; *q; p++, q++) { | |
265 | if (isalnum((unsigned char)*q)) | |
0521f473 | 266 | *p = toupper((unsigned char)*q); |
b7580524 | 267 | else |
268 | *p = '_'; | |
269 | } | |
270 | *p++ = 0; | |
271 | } | |
272 | if ((fp = fopen(file, "w")) == 0) | |
273 | die(EXIT_FAILURE, "couldn't write `%s': %s", file, strerror(errno)); | |
274 | } | |
275 | ||
276 | if (!sym) | |
277 | sym = (flags & f_ctab) ? "crctab" : "CRC_TAB"; | |
278 | ||
279 | /* --- Dump out the first chunk of the file --- */ | |
280 | ||
281 | fprintf(fp, "\ | |
282 | /* -*-c-*-\n\ | |
283 | *\n\ | |
284 | * CRC table (poly = %0*lx%s) [generated]\n\ | |
285 | */\n\ | |
286 | \n", | |
287 | nw, poly, flags & f_reverse ? "; reversed" : ""); | |
288 | ||
289 | if (flags & f_ctab) { | |
290 | if (inc) | |
291 | fprintf(fp, "#include \"%s\"\n\n", inc); | |
292 | fprintf(fp, "%s %s[] = {\n", type, sym); | |
293 | } else { | |
294 | int n; | |
295 | if (guard) | |
296 | fprintf(fp, "#ifndef %s\n#define %s\n\n", guard, guard); | |
297 | n = fprintf(fp, "#define %s {", sym); | |
298 | while (n < BSCOL) { | |
299 | fputc('\t', fp); | |
300 | n = (n + 8) & ~7; | |
301 | } | |
302 | fputc('\n', fp); | |
303 | } | |
304 | ||
305 | /* --- Sort out the line width --- */ | |
306 | ||
307 | n = 1; | |
308 | while (2 + n * (nw + 4) < BSCOL) | |
309 | n <<= 1; | |
310 | n >>= 1; | |
0521f473 | 311 | max = 1 << chunk; |
312 | if (n > max) | |
313 | n = max; | |
b7580524 | 314 | t = 0; |
315 | while (((1 + n * (nw + 4)) & ~7) + 8 * t < BSCOL) | |
316 | t++; | |
317 | ||
318 | /* --- Start grinding --- */ | |
319 | ||
b7580524 | 320 | mask = 0xffffffff >> (32 - bits); |
321 | fputc(' ', fp); | |
322 | for (i = 0; i < max; i++) { | |
0521f473 | 323 | unsigned long x, y, z; |
b7580524 | 324 | unsigned j; |
0521f473 | 325 | unsigned ni, nn; |
326 | ||
327 | x = reflect(i, chunk); | |
328 | y = 0; | |
329 | nn = chunk; | |
330 | while (nn) { | |
331 | ni = bits; | |
332 | if (ni > nn) | |
333 | ni = nn; | |
334 | z = (x >> (nn - ni)) & (0xffffffff >> (32 - ni)); | |
335 | y ^= z << (bits - ni); | |
336 | for (j = 0; j < ni; j++) | |
337 | y = ((y << 1) ^ (y & (1 << (bits - 1)) ? poly : 0)) & mask; | |
338 | nn -= ni; | |
339 | } | |
340 | x = reflect(y, bits); | |
b7580524 | 341 | |
342 | fprintf(fp, " 0x%0*lx", nw, x); | |
343 | if (i == max - 1) { | |
344 | if (!(flags & f_ctab) && ((2 + n * (nw + 4)) & ~7) + 8 * t < BSCOL) | |
345 | fputc('\t', fp); | |
346 | } else | |
347 | fputc(',', fp); | |
348 | if (i + 1 == max || (i + 1)%n == 0) { | |
349 | if (!(flags & f_ctab)) { | |
350 | for (j = 0; j < t; j++) | |
351 | fputc('\t', fp); | |
352 | fputc('\\', fp); | |
353 | } | |
354 | fputc('\n', fp); | |
355 | if (i + 1 != max) | |
356 | fputc(' ', fp); | |
357 | } | |
358 | } | |
359 | ||
360 | /* --- Done --- */ | |
361 | ||
362 | fputs(flags & f_ctab ? "};\n" : "}\n", fp); | |
363 | if (!(flags & f_ctab) && guard) | |
364 | fputs("\n#endif\n", fp); | |
365 | ||
366 | return (0); | |
367 | } | |
368 | ||
369 | /*----- That's all, folks -------------------------------------------------*/ |