riscv-openocd/contrib/itmdump.c

442 lines
8.9 KiB
C

/*
* Copyright (C) 2010 by David Brownell
*
* This program 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 3 of the License, or (at
* your option) any later version.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
/*
* Simple utility to parse and dump ARM Cortex-M3 SWO trace output. Once the
* mechanisms work right, this information can be used for various purposes
* including profiling (particularly easy for flat PC-sample profiles) and
* for debugging.
*
* SWO is the Single Wire Output found on some ARM cores, most notably on the
* Cortex-M3. It combines data from several sources:
*
* - Software trace (ITM): so-called "printf-style" application messaging
* using "ITM stimulus ports"; and differential timestamps.
* - Hardware trace (DWT): for profiling counters and comparator matches.
* - TPIU may issue sync packets.
*
* The trace data format is defined in Appendix E, "Debug ITM and DWT packet
* protocol", of the ARMv7-M Architecture Reference Manual (DDI 0403C). It
* is a superset of the ITM data format from the Coresight TRM.
*
* The trace data has two encodings. The working assumption is that data
* gets into this program using the UART encoding.
*/
#include <errno.h>
#include <libgen.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
/* Example ITM trace word (0xWWXXYYZZ) parsing for task events, sent
* on port 31 (Reserved for "the" RTOS in CMSIS v1.30)
* WWXX: event code (0..3 pre-assigned, 4..15 reserved)
* YY: task priority
* ZZ: task number
*
* NOTE that this specific encoding could be space-optimized; and that
* trace data streams could also be history-sensitive.
*/
static void show_task(int port, unsigned data)
{
unsigned code = data >> 16;
char buf[16];
switch (code) {
case 0:
strcpy(buf, "run");
break;
case 1:
strcpy(buf, "block");
break;
case 2:
strcpy(buf, "create");
break;
case 3:
strcpy(buf, "destroy");
break;
/* 4..15 reserved for other infrastructure ops */
default:
sprintf(buf, "code %d", code);
break;
}
printf("TASK %d, pri %d: %s",
(data >> 0) & 0xff,
(data >> 8) & 0xff,
buf);
}
static void show_reserved(FILE *f, char *label, int c)
{
unsigned i;
printf("%s - %#02x", label, c);
for (i = 0; (c & 0x80) && i < 4; i++) {
c = fgetc(f);
if (c == EOF) {
printf("(ERROR %d - %s) ", errno, strerror(errno));
break;
}
printf(" %#02x", c);
}
printf("\n");
}
static bool read_varlen(FILE *f, int c, unsigned *value)
{
unsigned size;
unsigned char buf[4];
unsigned i;
*value = 0;
switch (c & 3) {
case 3:
size = 4;
break;
case 2:
size = 2;
break;
case 1:
size = 1;
break;
default:
printf("INVALID SIZE\n");
return false;
}
memset(buf, 0, sizeof buf);
if (fread(buf, 1, size, f) != size)
goto err;
*value = (buf[3] << 24)
+ (buf[2] << 16)
+ (buf[1] << 8)
+ (buf[0] << 0);
return true;
err:
printf("(ERROR %d - %s)\n", errno, strerror(errno));
return;
}
static void show_hard(FILE *f, int c)
{
unsigned type = c >> 3;
unsigned value;
unsigned size;
char *label;
printf("DWT - ", type);
if (!read_varlen(f, c, &value))
return;
printf("%#x", value);
switch (type) {
case 0: /* event counter wrapping */
printf("overflow %s%s%s%s%s%s",
(value & (1 << 5)) ? "cyc " : "",
(value & (1 << 4)) ? "fold " : "",
(value & (1 << 3)) ? "lsu " : "",
(value & (1 << 2)) ? "slp " : "",
(value & (1 << 1)) ? "exc " : "",
(value & (1 << 0)) ? "cpi " : "");
break;
case 1: /* exception tracing */
switch (value >> 12) {
case 1:
label = "entry to";
break;
case 2:
label = "exit from";
break;
case 3:
label = "return to";
break;
default:
label = "?";
break;
}
printf("%s exception %d", label, value & 0x1ff);
break;
case 2: /* PC sampling */
if (c == 0x15)
printf("PC - sleep");
else
printf("PC - %#08x", value);
break;
case 8: /* data tracing, pc value */
case 10:
case 12:
case 14:
printf("Data trace %d, PC %#08x", (c >> 4) & 3, value);
/* optionally followed by data value */
break;
case 9: /* data tracing, address offset */
case 11:
case 13:
case 15:
printf("Data trace %d, address offset %#04x",
(c >> 4) & 3, value);
/* always followed by data value */
break;
case 16 ... 23: /* data tracing, data value */
printf("Data trace %d, ", (c >> 4) & 3);
label = (c & 0x8) ? "write" : "read";
switch (c & 3) {
case 3:
printf("word %s, value %#08x", label, value);
break;
case 2:
printf("halfword %s, value %#04x", label, value);
break;
case 1:
printf("byte %s, value %#02x", label, value);
break;
}
break;
default:
printf("UNDEFINED");
break;
}
printf("\n");
return;
}
/*
* Table of SWIT (SoftWare InstrumentTation) message dump formats, for
* ITM port 0..31 application data.
*
* Eventually this should be customizable; all usage is application defined.
*
* REVISIT there can be up to 256 trace ports, via "ITM Extension" packets
*/
struct {
int port;
void (*show)(int port, unsigned data);
} format[] = {
{ .port = 31, .show = show_task, },
};
static void show_swit(FILE *f, int c)
{
unsigned size;
unsigned port = c >> 3;
unsigned char buf[4];
unsigned value = 0;
unsigned i;
printf("SWIT %u - ", port);
if (!read_varlen(f, c, &value))
return;
printf("%#08x", value);
for (i = 0; i <= sizeof(format) / sizeof(format[0]); i++) {
if (format[i].port == port) {
printf(", ");
format[i].show(port, value);
break;
}
}
printf("\n");
return;
err:
printf("(ERROR %d - %s)\n", errno, strerror(errno));
return;
}
static void show_timestamp(FILE *f, int c)
{
unsigned counter = 0;
char *label = "";
bool delayed = false;
printf("TIMESTAMP - ");
/* Format 2: header only */
if (!(c & 0x80)) {
switch (c) {
case 0: /* sync packet -- coding error! */
case 0x70: /* overflow -- ditto! */
printf("ERROR - %#02x\n", c);
break;
default:
/* synchronous to ITM */
counter = c >> 4;
goto done;
}
return;
}
/* Format 1: one to four bytes of data too */
switch (c) {
default:
label = ", reserved control\n";
break;
case 0xc:
/* synchronous to ITM */
break;
case 0xd:
label = ", timestamp delayed";
delayed = true;
break;
case 0xe:
label = ", packet delayed";
delayed = true;
break;
case 0xf:
label = ", packet and timetamp delayed";
delayed = true;
break;
}
c = fgetc(f);
if (c == EOF)
goto err;
counter = c & 0x7f;
if (!(c & 0x80))
goto done;
c = fgetc(f);
if (c == EOF)
goto err;
counter |= (c & 0x7f) << 7;
if (!(c & 0x80))
goto done;
c = fgetc(f);
if (c == EOF)
goto err;
counter |= (c & 0x7f) << 14;
if (!(c & 0x80))
goto done;
c = fgetc(f);
if (c == EOF)
goto err;
counter |= (c & 0x7f) << 21;
done:
/* REVISIT should we try to convert from delta values? */
printf("+%u%s\n", counter, label);
return;
err:
printf("(ERROR %d - %s) ", errno, strerror(errno));
goto done;
}
int main(int argc, char **argv)
{
FILE *f = stdin;
int c;
/* parse arguments */
while ((c = getopt(argc, argv, "f:")) != EOF) {
switch (c) {
case 'f':
/* e.g. from UART connected to /dev/ttyUSB0 */
f = fopen(optarg, "r");
if (!f) {
perror(optarg);
return 1;
}
break;
default:
usage:
fprintf(stderr, "usage: %s [-f input]",
basename(argv[0]));
return 1;
}
}
/* Parse data ... records have a header then data bytes.
* NOTE: we assume getc() deals in 8-bit bytes.
*/
bool overflow = false;
while ((c = getc(f)) != EOF) {
/* Sync packet ... 7 zeroes, 0x80 */
if (c == 0) {
int i;
for (i = 0; i < 6; i++) {
c = fgetc(f);
if (c == EOF)
break;
if (c != 0)
goto bad_sync;
}
c = fgetc(f);
if (c == 0x80) {
printf("SYNC\n");
continue;
}
bad_sync:
printf("BAD SYNC\n");
continue;
}
/* Overflow packet */
if (c == 0x70) {
/* REVISIT later, report just what overflowed!
* Timestamp and SWIT can happen. Non-ITM too?
*/
overflow = true;
printf("OVERFLOW ...\n");
continue;
}
overflow = false;
switch (c & 0x0f) {
case 0x00: /* Timestamp */
show_timestamp(f, c);
break;
case 0x04: /* "Reserved" */
show_reserved(f, "RESERVED", c);
break;
case 0x08: /* ITM Extension */
/* FIXME someday, handle these ... */
show_reserved(f, "ITM EXT", c);
break;
case 0x0c: /* DWT Extension */
show_reserved(f, "DWT EXT", c);
break;
default:
if (c & 4)
show_hard(f, c);
else
show_swit(f, c);
break;
}
}
return 0;
}