git.rot13.org Git - simavr/blob - simavr/sim/sim_gdb.c

   1 /*
   2         sim_gdb.c
   3
   4         Copyright 2008, 2009 Michel Pollet <buserror@gmail.com>
   5
   6         This file is part of simavr.
   7
   8         simavr is free software: you can redistribute it and/or modify
   9         it under the terms of the GNU General Public License as published by
  10         the Free Software Foundation, either version 3 of the License, or
  11         (at your option) any later version.
  12
  13         simavr is distributed in the hope that it will be useful,
  14         but WITHOUT ANY WARRANTY; without even the implied warranty of
  15         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16         GNU General Public License for more details.
  17
  18         You should have received a copy of the GNU General Public License
  19         along with simavr.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <netinet/in.h>
  23 #include <netinet/tcp.h>
  24 #include <arpa/inet.h>
  25 #include <sys/socket.h>
  26 #include <sys/time.h>
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29 #include <unistd.h>
  30 #include <string.h>
  31 #include <errno.h>
  32 #include <poll.h>
  33 #include <pthread.h>
  34 #include "sim_avr.h"
  35 #include "sim_hex.h"
  36 #include "avr_eeprom.h"
  37 #include "sim_gdb.h"
  38
  39 #define DBG(w)
  40
  41 #define WATCH_LIMIT (32)
  42
  43 typedef struct {
  44         uint32_t len; /**< How many points are taken (points[0] .. points[len - 1]). */
  45         struct {
  46                 uint32_t addr; /**< Which address is watched. */
  47                 uint32_t size; /**< How large is the watched segment. */
  48                 uint32_t kind; /**< Bitmask of enum avr_gdb_watch_type values. */
  49         } points[WATCH_LIMIT];
  50 } avr_gdb_watchpoints_t;
  51
  52 typedef struct avr_gdb_t {
  53         avr_t * avr;
  54         int             listen; // listen socket
  55         int             s;              // current gdb connection
  56
  57         avr_gdb_watchpoints_t breakpoints;
  58         avr_gdb_watchpoints_t watchpoints;
  59 } avr_gdb_t;
  60
  61
  62 /**
  63  * Returns the index of the watchpoint if found, -1 otherwise.
  64  */
  65 static int gdb_watch_find(const avr_gdb_watchpoints_t * w, uint32_t addr)
  66 {
  67         for (int i = 0; i < w->len; i++) {
  68                 if (w->points[i].addr == addr) {
  69                         return i;
  70                 }
  71         }
  72
  73         return -1;
  74 }
  75
  76 /**
  77  * Returns -1 on error, 0 otherwise.
  78  */
  79 static int gdb_watch_add_or_update(avr_gdb_watchpoints_t * w, enum avr_gdb_watch_type kind, uint32_t addr,
  80                 uint32_t size)
  81 {
  82         /* If the watchpoint exists, update it. */
  83         int i = gdb_watch_find(w, addr);
  84         if (i != -1) {
  85                 w->points[i].size = size;
  86                 w->points[i].kind |= kind;
  87                 return 0;
  88         }
  89
  90         /* Otherwise add it. */
  91         if (w->len == WATCH_LIMIT) {
  92                 return -1;
  93         }
  94
  95         w->points[w->len].kind = kind;
  96         w->points[w->len].addr = addr;
  97         w->points[w->len].size = size;
  98
  99         w->len++;
 100
 101         return 0;
 102 }
 103
 104 /**
 105  * Returns -1 on error or if the specified point does not exist, 0 otherwise.
 106  */
 107 static int gdb_watch_rm(avr_gdb_watchpoints_t * w, enum avr_gdb_watch_type kind, uint32_t addr)
 108 {
 109         int i = gdb_watch_find(w, addr);
 110         if (i == -1) {
 111                 return -1;
 112         }
 113
 114         w->points[i].kind &= ~kind;
 115         if (w->points[i].kind) {
 116                 return 0;
 117         }
 118
 119         for (i = i + 1; i < w->len; i++) {
 120                 w->points[i - 1] = w->points[i];
 121         }
 122
 123         w->len--;
 124
 125         return 0;
 126 }
 127
 128 static void gdb_watch_clear(avr_gdb_watchpoints_t * w)
 129 {
 130         w->len = 0;
 131 }
 132
 133 static void gdb_send_reply(avr_gdb_t * g, char * cmd)
 134 {
 135         uint8_t reply[1024];
 136         uint8_t * dst = reply;
 137         uint8_t check = 0;
 138         *dst++ = '$';
 139         while (*cmd) {
 140                 check += *cmd;
 141                 *dst++ = *cmd++;
 142         }
 143         sprintf((char*)dst, "#%02x", check);
 144         DBG(printf("%s '%s'\n", __FUNCTION__, reply);)
 145         send(g->s, reply, dst - reply + 3, 0);
 146 }
 147
 148 static void gdb_send_quick_status(avr_gdb_t * g, uint8_t signal)
 149 {
 150         char cmd[64];
 151
 152         sprintf(cmd, "T%02x20:%02x;21:%02x%02x;22:%02x%02x%02x00;",
 153                 signal ? signal : 5, g->avr->data[R_SREG],
 154                 g->avr->data[R_SPL], g->avr->data[R_SPH],
 155                 g->avr->pc & 0xff, (g->avr->pc>>8)&0xff, (g->avr->pc>>16)&0xff);
 156         gdb_send_reply(g, cmd);
 157 }
 158
 159 static int gdb_change_breakpoint(avr_gdb_watchpoints_t * w, int set, enum avr_gdb_watch_type kind,
 160                 uint32_t addr, uint32_t size)
 161 {
 162         DBG(printf("set %d kind %d addr %08x len %d\n", set, kind, addr, len);)
 163
 164         if (set) {
 165                 return gdb_watch_add_or_update(w, kind, addr, size);
 166         } else {
 167                 return gdb_watch_rm(w, kind, addr);
 168         }
 169
 170         return -1;
 171 }
 172
 173 static int gdb_write_register(avr_gdb_t * g, int regi, uint8_t * src)
 174 {
 175         switch (regi) {
 176                 case 0 ... 31:
 177                         g->avr->data[regi] = *src;
 178                         return 1;
 179                 case 32:
 180                         g->avr->data[R_SREG] = *src;
 181                         return 1;
 182                 case 33:
 183                         g->avr->data[R_SPL] = src[0];
 184                         g->avr->data[R_SPH] = src[1];
 185                         return 2;
 186                 case 34:
 187                         g->avr->pc = src[0] | (src[1] << 8) | (src[2] << 16) | (src[3] << 24);
 188                         return 4;
 189         }
 190         return 1;
 191 }
 192
 193 static int gdb_read_register(avr_gdb_t * g, int regi, char * rep)
 194 {
 195         switch (regi) {
 196                 case 0 ... 31:
 197                         sprintf(rep, "%02x", g->avr->data[regi]);
 198                         break;
 199                 case 32:
 200                         sprintf(rep, "%02x", g->avr->data[R_SREG]);
 201                         break;
 202                 case 33:
 203                         sprintf(rep, "%02x%02x", g->avr->data[R_SPL], g->avr->data[R_SPH]);
 204                         break;
 205                 case 34:
 206                         sprintf(rep, "%02x%02x%02x00",
 207                                 g->avr->pc & 0xff, (g->avr->pc>>8)&0xff, (g->avr->pc>>16)&0xff);
 208                         break;
 209         }
 210         return strlen(rep);
 211 }
 212
 213 static void gdb_handle_command(avr_gdb_t * g, char * cmd)
 214 {
 215         avr_t * avr = g->avr;
 216         char rep[1024];
 217         uint8_t command = *cmd++;
 218         switch (command) {
 219                 case '?':
 220                         gdb_send_quick_status(g, 0);
 221                         break;
 222                 case 'G': {     // set all general purpose registers
 223                         // get their binary form
 224                         read_hex_string(cmd, (uint8_t*)rep, strlen(cmd));
 225                         uint8_t *src = (uint8_t*)rep;
 226                         for (int i = 0; i < 35; i++)
 227                                 src += gdb_write_register(g, i, src);
 228                         gdb_send_reply(g, "OK");
 229                 }       break;
 230                 case 'g': {     // read all general purpose registers
 231                         char * dst = rep;
 232                         for (int i = 0; i < 35; i++)
 233                                 dst += gdb_read_register(g, i, dst);
 234                         gdb_send_reply(g, rep);
 235                 }       break;
 236                 case 'p': {     // read register
 237                         unsigned int regi = 0;
 238                         sscanf(cmd, "%x", &regi);
 239                         gdb_read_register(g, regi, rep);
 240                         gdb_send_reply(g, rep);
 241                 }       break;
 242                 case 'P': {     // write register
 243                         unsigned int regi = 0;
 244                         char * val = strchr(cmd, '=');
 245                         if (!val)
 246                                 break;
 247                         *val++ = 0;
 248                         sscanf(cmd, "%x", &regi);
 249                         read_hex_string(val, (uint8_t*)rep, strlen(val));
 250                         gdb_write_register(g, regi, (uint8_t*)rep);
 251                         gdb_send_reply(g, "OK");
 252                 }       break;
 253                 case 'm': {     // read memory
 254                         avr_flashaddr_t addr;
 255                         uint32_t len;
 256                         sscanf(cmd, "%x,%x", &addr, &len);
 257                         uint8_t * src = NULL;
 258                         if (addr < avr->flashend) {
 259                                 src = avr->flash + addr;
 260                         } else if (addr >= 0x800000 && (addr - 0x800000) <= avr->ramend) {
 261                                 src = avr->data + addr - 0x800000;
 262                         } else if (addr >= 0x810000 && (addr - 0x810000) <= avr->e2end) {
 263                                 avr_eeprom_desc_t ee = {.offset = (addr - 0x810000)};
 264                                 avr_ioctl(avr, AVR_IOCTL_EEPROM_GET, &ee);
 265                                 if (ee.ee)
 266                                         src = ee.ee;
 267                                 else {
 268                                         gdb_send_reply(g, "E01");
 269                                         break;
 270                                 }
 271                         } else if (addr >= 0x800000 && (addr - 0x800000) == avr->ramend+1 && len == 2) {
 272                                 // Allow GDB to read a value just after end of stack.
 273                                 // This is necessary to make instruction stepping work when stack is empty
 274                                 printf("GDB read just past end of stack %08x, %08x; returning zero\n", addr, len);
 275                                 gdb_send_reply(g, "0000");
 276                                 break;
 277                         } else {
 278                                 printf("read memory error %08x, %08x (ramend %04x)\n", addr, len, avr->ramend+1);
 279                                 gdb_send_reply(g, "E01");
 280                                 break;
 281                         }
 282                         char * dst = rep;
 283                         while (len--) {
 284                                 sprintf(dst, "%02x", *src++);
 285                                 dst += 2;
 286                         }
 287                         *dst = 0;
 288                         gdb_send_reply(g, rep);
 289                 }       break;
 290                 case 'M': {     // write memory
 291                         uint32_t addr, len;
 292                         sscanf(cmd, "%x,%x", &addr, &len);
 293                         char * start = strchr(cmd, ':');
 294                         if (!start) {
 295                                 gdb_send_reply(g, "E01");
 296                                 break;
 297                         }
 298                         if (addr < 0xffff) {
 299                                 read_hex_string(start + 1, avr->flash + addr, strlen(start+1));
 300                                 gdb_send_reply(g, "OK");
 301                         } else if (addr >= 0x800000 && (addr - 0x800000) <= avr->ramend) {
 302                                 read_hex_string(start + 1, avr->data + addr - 0x800000, strlen(start+1));
 303                                 gdb_send_reply(g, "OK");
 304                         } else if (addr >= 0x810000 && (addr - 0x810000) <= avr->e2end) {
 305                                 read_hex_string(start + 1, (uint8_t*)rep, strlen(start+1));
 306                                 avr_eeprom_desc_t ee = {.offset = (addr - 0x810000), .size = len, .ee = (uint8_t*)rep };
 307                                 avr_ioctl(avr, AVR_IOCTL_EEPROM_SET, &ee);
 308                                 gdb_send_reply(g, "OK");
 309                         } else {
 310                                 printf("write memory error %08x, %08x\n", addr, len);
 311                                 gdb_send_reply(g, "E01");
 312                         }
 313                 }       break;
 314                 case 'c': {     // continue
 315                         avr->state = cpu_Running;
 316                 }       break;
 317                 case 's': {     // step
 318                         avr->state = cpu_Step;
 319                 }       break;
 320                 case 'r': {     // deprecated, suggested for AVRStudio compatibility
 321                         avr->state = cpu_StepDone;
 322                         avr_reset(avr);
 323                 }       break;
 324                 case 'Z':       // set clear break/watchpoint
 325                 case 'z': {
 326                         uint32_t kind, addr, len;
 327                         int set = (command == 'Z');
 328                         sscanf(cmd, "%d,%x,%x", &kind, &addr, &len);
 329 //                      printf("breakpoint %d, %08x, %08x\n", kind, addr, len);
 330                         switch (kind) {
 331                                 case 0: // software breakpoint
 332                                 case 1: // hardware breakpoint
 333                                         if (addr > avr->flashend ||
 334                                                         gdb_change_breakpoint(&g->breakpoints, set, 1 << kind, addr, len) == -1) {
 335                                                 gdb_send_reply(g, "E01");
 336                                                 break;
 337                                         }
 338
 339                                         gdb_send_reply(g, "OK");
 340                                         break;
 341                                 case 2: // write watchpoint
 342                                 case 3: // read watchpoint
 343                                 case 4: // access watchpoint
 344                                         /* Mask out the offset applied to SRAM addresses. */
 345                                         addr &= ~0x800000;
 346                                         if (addr > avr->ramend ||
 347                                                         gdb_change_breakpoint(&g->watchpoints, set, 1 << kind, addr, len) == -1) {
 348                                                 gdb_send_reply(g, "E01");
 349                                                 break;
 350                                         }
 351
 352                                         gdb_send_reply(g, "OK");
 353                                         break;
 354                                 default:
 355                                         gdb_send_reply(g, "");
 356                                         break;
 357                         }
 358                 }       break;
 359                 default:
 360                         gdb_send_reply(g, "");
 361                         break;
 362         }
 363 }
 364
 365 static int gdb_network_handler(avr_gdb_t * g, uint32_t dosleep)
 366 {
 367         fd_set read_set;
 368         int max;
 369         FD_ZERO(&read_set);
 370
 371         if (g->s != -1) {
 372                 FD_SET(g->s, &read_set);
 373                 max = g->s + 1;
 374         } else {
 375                 FD_SET(g->listen, &read_set);
 376                 max = g->listen + 1;
 377         }
 378         struct timeval timo = { 0, dosleep };   // short, but not too short interval
 379         int ret = select(max, &read_set, NULL, NULL, &timo);
 380
 381         if (ret == 0)
 382                 return 0;
 383
 384         if (FD_ISSET(g->listen, &read_set)) {
 385                 g->s = accept(g->listen, NULL, NULL);
 386
 387                 if (g->s == -1) {
 388                         perror("gdb_network_handler accept");
 389                         sleep(5);
 390                         return 1;
 391                 }
 392         int i = 1;
 393         setsockopt (g->s, IPPROTO_TCP, TCP_NODELAY, &i, sizeof (i));
 394                 g->avr->state = cpu_Stopped;
 395                 printf("%s connection opened\n", __FUNCTION__);
 396         }
 397
 398         if (g->s != -1 && FD_ISSET(g->s, &read_set)) {
 399                 uint8_t buffer[1024];
 400
 401                 ssize_t r = recv(g->s, buffer, sizeof(buffer)-1, 0);
 402
 403                 if (r == 0) {
 404                         printf("%s connection closed\n", __FUNCTION__);
 405                         close(g->s);
 406                         gdb_watch_clear(&g->breakpoints);
 407                         gdb_watch_clear(&g->watchpoints);
 408                         g->avr->state = cpu_Running;    // resume
 409                         g->s = -1;
 410                         return 1;
 411                 }
 412                 if (r == -1) {
 413                         perror("gdb_network_handler recv");
 414                         sleep(1);
 415                         return 1;
 416                 }
 417                 buffer[r] = 0;
 418         //      printf("%s: received %d bytes\n'%s'\n", __FUNCTION__, r, buffer);
 419         //      hdump("gdb", buffer, r);
 420
 421                 uint8_t * src = buffer;
 422                 while (*src == '+' || *src == '-')
 423                         src++;
 424                 // control C -- lets send the guy a nice status packet
 425                 if (*src == 3) {
 426                         src++;
 427                         g->avr->state = cpu_StepDone;
 428                         printf("GDB hit control-c\n");
 429                 }
 430                 if (*src  == '$') {
 431                         // strip checksum
 432                         uint8_t * end = buffer + r - 1;
 433                         while (end > src && *end != '#')
 434                                 *end-- = 0;
 435                         *end = 0;
 436                         src++;
 437                         DBG(printf("GDB command = '%s'\n", src);)
 438
 439                         send(g->s, "+", 1, 0);
 440
 441                         gdb_handle_command(g, (char*)src);
 442                 }
 443         }
 444         return 1;
 445 }
 446
 447 int avr_gdb_processor(avr_t * avr, int sleep)
 448 {
 449         if (!avr || !avr->gdb)
 450                 return 0;
 451         avr_gdb_t * g = avr->gdb;
 452
 453         if (avr->state == cpu_Running && gdb_watch_find(&g->breakpoints, avr->pc) != -1) {
 454                 DBG(printf("avr_gdb_processor hit breakpoint at %08x\n", avr->pc);)
 455                 gdb_send_quick_status(g, 0);
 456                 avr->state = cpu_Stopped;
 457         } else if (avr->state == cpu_StepDone) {
 458                 gdb_send_quick_status(g, 0);
 459                 avr->state = cpu_Stopped;
 460         }
 461         // this also sleeps for a bit
 462         return gdb_network_handler(g, sleep);
 463 }
 464
 465
 466 int avr_gdb_init(avr_t * avr)
 467 {
 468         avr_gdb_t * g = malloc(sizeof(avr_gdb_t));
 469         memset(g, 0, sizeof(avr_gdb_t));
 470
 471         avr->gdb = NULL;
 472
 473         if ((g->listen = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
 474                 fprintf(stderr, "Can't create socket: %s", strerror(errno));
 475                 return -1;
 476         }
 477
 478         int i = 1;
 479         setsockopt(g->listen, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 480
 481         struct sockaddr_in address = { 0 };
 482         address.sin_family = AF_INET;
 483         address.sin_port = htons (avr->gdb_port);
 484
 485         if (bind(g->listen, (struct sockaddr *) &address, sizeof(address))) {
 486                 fprintf(stderr, "Can not bind socket: %s", strerror(errno));
 487                 return -1;
 488         }
 489         if (listen(g->listen, 1)) {
 490                 perror("listen");
 491                 return -1;
 492         }
 493         printf("avr_gdb_init listening on port %d\n", avr->gdb_port);
 494         g->avr = avr;
 495         g->s = -1;
 496         avr->gdb = g;
 497         // change default run behaviour to use the slightly slower versions
 498         avr->run = avr_callback_run_gdb;
 499         avr->sleep = avr_callback_sleep_gdb;
 500
 501         return 0;
 502 }