2 * This file is part of the sigrok project.
4 * Copyright (C) 2012 Petteri Aimonen <jpa@sr.mail.kapsi.fi>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 /* The VCD input module has the following options:
22 * numprobes: Maximum number of probes to use. The probes are
23 * detected in the same order as they are listed
24 * in the $var sections of the VCD file.
26 * skip: Allows skipping until given timestamp in the file.
27 * This can speed up analyzing of long captures.
29 * Value < 0: Skip until first timestamp listed in
32 * Value = 0: Do not skip, instead generate samples
33 * beginning from timestamp 0.
35 * Value > 0: Start at the given timestamp.
37 * downsample: Divide the samplerate by the given factor.
38 * This can speed up analyzing of long captures.
40 * compress: Compress idle periods longer than this value.
41 * This can speed up analyzing of long captures.
42 * Default 0 = don't compress.
44 * Based on Verilog standard IEEE Std 1364-2001 Version C
47 * - $var with 'wire' and 'reg' types of scalar variables
48 * - $timescale definition for samplerate
49 * - multiple character variable identifiers
51 * Most important unsupported features:
52 * - vector variables (bit vectors etc.)
53 * - analog, integer and real number variables
54 * - $dumpvars initial value declaration
64 #include "libsigrok.h"
65 #include "libsigrok-internal.h"
67 /* Message logging helpers with driver-specific prefix string. */
68 #define DRIVER_LOG_DOMAIN "input/vcd: "
69 #define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
70 #define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args)
71 #define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args)
72 #define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args)
73 #define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args)
74 #define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args)
76 #define DEFAULT_NUM_PROBES 8
78 /* Read until specific type of character occurs in file.
79 * Skip input if dest is NULL.
81 * 'W' read until whitespace
82 * 'N' read until non-whitespace, and ungetc() the character
85 static gboolean read_until(FILE *file, GString *dest, char mode)
88 long startpos = ftell(file);
96 sr_err("Unexpected EOF, read started at %ld.", startpos);
100 if (mode == 'W' && g_ascii_isspace(c))
103 if (mode == 'N' && !g_ascii_isspace(c))
111 prev[0] = prev[1]; prev[1] = prev[2]; prev[2] = prev[3]; prev[3] = c;
112 if (prev[0] == '$' && prev[1] == 'e' && prev[2] == 'n' && prev[3] == 'd')
115 g_string_truncate(dest, dest->len - 3);
122 g_string_append_c(dest, c);
126 /* Reads a single VCD section from input file and parses it to structure.
127 * e.g. $timescale 1ps $end => "timescale" "1ps"
129 static gboolean parse_section(FILE *file, gchar **name, gchar **contents)
132 GString *sname, *scontents;
134 /* Skip any initial white-space */
135 if (!read_until(file, NULL, 'N')) return FALSE;
137 /* Section tag should start with $. */
138 if (fgetc(file) != '$')
140 sr_err("Expected $ at beginning of section.");
144 /* Read the section tag */
145 sname = g_string_sized_new(32);
146 status = read_until(file, sname, 'W');
148 /* Skip whitespace before content */
149 status = status && read_until(file, NULL, 'N');
151 /* Read the content */
152 scontents = g_string_sized_new(128);
153 status = status && read_until(file, scontents, '$');
154 g_strchomp(scontents->str);
156 /* Release strings if status is FALSE, return them if status is TRUE */
157 *name = g_string_free(sname, !status);
158 *contents = g_string_free(scontents, !status);
176 struct probe probes[SR_MAX_NUM_PROBES];
179 static void release_context(struct context *ctx)
182 for (i = 0; i < ctx->probecount; i++)
184 g_free(ctx->probes[i].name); ctx->probes[i].name = NULL;
185 g_free(ctx->probes[i].identifier); ctx->probes[i].identifier = NULL;
191 /* Remove empty parts from an array returned by g_strsplit. */
192 static void remove_empty_parts(gchar **parts)
195 gchar **dest = parts;
209 /* Parse VCD header to get values for context structure.
210 * The context structure should be zeroed before calling this.
212 static gboolean parse_header(FILE *file, struct context *ctx)
214 gchar *name = NULL, *contents = NULL;
215 gboolean status = FALSE;
217 while (parse_section(file, &name, &contents))
219 sr_dbg("Section '%s', contents '%s'.", name, contents);
221 if (g_strcmp0(name, "enddefinitions") == 0)
226 else if (g_strcmp0(name, "timescale") == 0)
228 /* The standard allows for values 1, 10 or 100
229 * and units s, ms, us, ns, ps and fs. */
230 struct sr_rational period;
231 if (sr_parse_period(contents, &period) == SR_OK)
233 ctx->samplerate = period.q / period.p;
234 if (period.q % period.p != 0)
236 /* Does not happen unless time value is non-standard */
237 sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
238 period.q, period.p, ctx->samplerate);
241 sr_dbg("Samplerate: %" PRIu64, ctx->samplerate);
245 sr_err("Parsing timescale failed.");
248 else if (g_strcmp0(name, "var") == 0)
250 /* Format: $var type size identifier reference $end */
251 gchar **parts = g_strsplit_set(contents, " \r\n\t", 0);
252 remove_empty_parts(parts);
254 if (g_strv_length(parts) != 4)
256 sr_warn("$var section should have 4 items");
258 else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
260 sr_info("Unsupported signal type: '%s'", parts[0]);
262 else if (strtol(parts[1], NULL, 10) != 1)
264 sr_info("Unsupported signal size: '%s'", parts[1]);
266 else if (ctx->probecount >= ctx->maxprobes)
268 sr_warn("Skipping '%s' because only %d probes requested.", parts[3], ctx->maxprobes);
272 sr_info("Probe %d is '%s' identified by '%s'.", ctx->probecount, parts[3], parts[2]);
273 ctx->probes[ctx->probecount].identifier = g_strdup(parts[2]);
274 ctx->probes[ctx->probecount].name = g_strdup(parts[3]);
281 g_free(name); name = NULL;
282 g_free(contents); contents = NULL;
291 static int format_match(const char *filename)
294 gchar *name = NULL, *contents = NULL;
297 file = fopen(filename, "r");
301 /* If we can parse the first section correctly,
302 * then it is assumed to be a VCD file.
304 status = parse_section(file, &name, &contents);
305 status = status && (*name != '\0');
314 static int init(struct sr_input *in, const char *filename)
316 struct sr_probe *probe;
318 char name[SR_MAX_PROBENAME_LEN + 1];
324 if (!(ctx = g_try_malloc0(sizeof(*ctx)))) {
325 sr_err("Input format context malloc failed.");
326 return SR_ERR_MALLOC;
329 num_probes = DEFAULT_NUM_PROBES;
335 param = g_hash_table_lookup(in->param, "numprobes");
337 num_probes = strtoul(param, NULL, 10);
340 release_context(ctx);
345 param = g_hash_table_lookup(in->param, "downsample");
347 ctx->downsample = strtoul(param, NULL, 10);
348 if (ctx->downsample < 1)
354 param = g_hash_table_lookup(in->param, "compress");
356 ctx->compress = strtoul(param, NULL, 10);
359 param = g_hash_table_lookup(in->param, "skip");
361 ctx->skip = strtoul(param, NULL, 10) / ctx->downsample;
365 /* Maximum number of probes to parse from the VCD */
366 ctx->maxprobes = num_probes;
368 /* Create a virtual device. */
369 in->sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, NULL, NULL, NULL);
372 for (i = 0; i < num_probes; i++) {
373 snprintf(name, SR_MAX_PROBENAME_LEN, "%d", i);
375 if (!(probe = sr_probe_new(i, SR_PROBE_LOGIC, TRUE, name)))
377 release_context(ctx);
381 in->sdi->probes = g_slist_append(in->sdi->probes, probe);
387 #define CHUNKSIZE 1024
389 /* Send N samples of the given value. */
390 static void send_samples(const struct sr_dev_inst *sdi, uint64_t sample, uint64_t count)
392 struct sr_datafeed_packet packet;
393 struct sr_datafeed_logic logic;
394 uint64_t buffer[CHUNKSIZE];
396 unsigned chunksize = CHUNKSIZE;
398 if (count < chunksize)
401 for (i = 0; i < chunksize; i++)
406 packet.type = SR_DF_LOGIC;
407 packet.payload = &logic;
408 logic.unitsize = sizeof(uint64_t);
413 if (count < chunksize)
416 logic.length = sizeof(uint64_t) * chunksize;
418 sr_session_send(sdi, &packet);
423 /* Parse the data section of VCD */
424 static void parse_contents(FILE *file, const struct sr_dev_inst *sdi, struct context *ctx)
426 GString *token = g_string_sized_new(32);
428 uint64_t prev_timestamp = 0;
429 uint64_t prev_values = 0;
431 /* Read one space-delimited token at a time. */
432 while (read_until(file, NULL, 'N') && read_until(file, token, 'W'))
434 if (token->str[0] == '#' && g_ascii_isdigit(token->str[1]))
436 /* Numeric value beginning with # is a new timestamp value */
438 timestamp = strtoull(token->str + 1, NULL, 10);
440 if (ctx->downsample > 1)
441 timestamp /= ctx->downsample;
443 /* Skip < 0 => skip until first timestamp.
444 * Skip = 0 => don't skip
445 * Skip > 0 => skip until timestamp >= skip.
449 ctx->skip = timestamp;
450 prev_timestamp = timestamp;
452 else if (ctx->skip > 0 && timestamp < (uint64_t)ctx->skip)
454 prev_timestamp = ctx->skip;
456 else if (timestamp == prev_timestamp)
458 /* Ignore repeated timestamps (e.g. sigrok outputs these) */
462 if (ctx->compress != 0 && timestamp - prev_timestamp > ctx->compress)
464 /* Compress long idle periods */
465 prev_timestamp = timestamp - ctx->compress;
468 sr_dbg("New timestamp: %" PRIu64, timestamp);
470 /* Generate samples from prev_timestamp up to timestamp - 1. */
471 send_samples(sdi, prev_values, timestamp - prev_timestamp);
472 prev_timestamp = timestamp;
475 else if (token->str[0] == '$' && token->len > 1)
477 /* This is probably a $dumpvars, $comment or similar.
478 * $dump* contain useful data, but other tags will be skipped until $end. */
479 if (g_strcmp0(token->str, "$dumpvars") == 0 ||
480 g_strcmp0(token->str, "$dumpon") == 0 ||
481 g_strcmp0(token->str, "$dumpoff") == 0 ||
482 g_strcmp0(token->str, "$end") == 0)
484 /* Ignore, parse contents as normally. */
488 /* Skip until $end */
489 read_until(file, NULL, '$');
492 else if (strchr("bBrR", token->str[0]) != NULL)
494 /* A vector value. Skip it and also the following identifier. */
495 read_until(file, NULL, 'N');
496 read_until(file, NULL, 'W');
498 else if (strchr("01xXzZ", token->str[0]) != NULL)
500 /* A new 1-bit sample value */
502 bit = (token->str[0] == '1');
504 g_string_erase(token, 0, 1);
507 /* There was a space between value and identifier.
510 read_until(file, NULL, 'N');
511 read_until(file, token, 'W');
514 for (i = 0; i < ctx->probecount; i++)
516 if (g_strcmp0(token->str, ctx->probes[i].identifier) == 0)
518 sr_dbg("Probe %d new value %d.", i, bit);
520 /* Found our probe */
522 prev_values |= (1 << i);
524 prev_values &= ~(1 << i);
530 if (i == ctx->probecount)
532 sr_dbg("Did not find probe for identifier '%s'.", token->str);
537 sr_warn("Skipping unknown token '%s'.", token->str);
540 g_string_truncate(token, 0);
543 g_string_free(token, TRUE);
546 static int loadfile(struct sr_input *in, const char *filename)
548 struct sr_datafeed_packet packet;
549 struct sr_datafeed_meta meta;
550 struct sr_config *src;
557 if ((file = fopen(filename, "r")) == NULL)
560 if (!parse_header(file, ctx))
562 sr_err("VCD parsing failed");
567 /* Send header packet to the session bus. */
568 std_session_send_df_header(in->sdi, DRIVER_LOG_DOMAIN);
570 /* Send metadata about the SR_DF_LOGIC packets to come. */
571 packet.type = SR_DF_META;
572 packet.payload = &meta;
573 samplerate = ctx->samplerate / ctx->downsample;
574 src = sr_config_new(SR_CONF_SAMPLERATE, (const void *)&samplerate);
575 meta.config = g_slist_append(NULL, src);
576 sr_session_send(in->sdi, &packet);
578 /* Parse the contents of the VCD file */
579 parse_contents(file, in->sdi, ctx);
581 /* Send end packet to the session bus. */
582 packet.type = SR_DF_END;
583 sr_session_send(in->sdi, &packet);
586 release_context(ctx);
592 SR_PRIV struct sr_input_format input_vcd = {
594 .description = "Value Change Dump",
595 .format_match = format_match,
597 .loadfile = loadfile,