git.gag.com Git - fw/stlink/blob - src/gdb-server.c

   1 /* -*- tab-width:8 -*- */
   2
   3 /*
   4  Copyright (C)  2011 Peter Zotov <whitequark@whitequark.org>
   5  Use of this source code is governed by a BSD-style
   6  license that can be found in the LICENSE file.
   7 */
   8
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <stdlib.h>
  12 #include <unistd.h>
  13 #include <sys/types.h>
  14 #include <sys/socket.h>
  15 #include <netinet/in.h>
  16 #include <arpa/inet.h>
  17 #include "gdb-remote.h"
  18 #include "stlink-hw.h"
  19
  20 static const char hex[] = "0123456789abcdef";
  21
  22 static const char* current_memory_map = NULL;
  23
  24 struct chip_params {
  25         uint32_t chip_id;
  26         char* description;
  27         uint32_t max_flash_size, flash_pagesize;
  28         uint32_t sram_size;
  29         uint32_t bootrom_base, bootrom_size;
  30 } const devices[] = {
  31         { 0x412, "Low-density device",
  32           0x8000,   0x400, 0x2800,  0x1ffff000, 0x800  },
  33         { 0x410, "Medium-density device",
  34           0x20000,  0x400, 0x5000,  0x1ffff000, 0x800  },
  35         { 0x414, "High-density device",
  36           0x80000,  0x800, 0x10000, 0x1ffff000, 0x800  },
  37         { 0x418, "Connectivity line device",
  38           0x40000,  0x800, 0x10000, 0x1fffb000, 0x4800 },
  39         { 0x420, "Medium-density value line device",
  40           0x20000,  0x400, 0x2000,  0x1ffff000, 0x800  },
  41         { 0x428, "High-density value line device",
  42           0x80000,  0x800, 0x8000,  0x1ffff000, 0x800  },
  43         { 0x430, "XL-density device",
  44           0x100000, 0x800, 0x18000, 0x1fffe000, 0x1800 },
  45         { 0 }
  46 };
  47
  48 int serve(struct stlink* sl, int port);
  49 char* make_memory_map(const struct chip_params *params, uint32_t flash_size);
  50
  51 int main(int argc, char** argv) {
  52         if(argc != 3) {
  53                 fprintf(stderr, "Usage: %s <port> /dev/sgX\n", argv[0]);
  54                 return 1;
  55         }
  56
  57         struct stlink *sl = stlink_quirk_open(argv[2], 0);
  58         if (sl == NULL)
  59                 return 1;
  60
  61         if(stlink_current_mode(sl) != STLINK_DEV_DEBUG_MODE)
  62                 stlink_enter_swd_mode(sl);
  63
  64         uint32_t chip_id;
  65
  66         stlink_read_mem32(sl, 0xE0042000, 4);
  67         chip_id = sl->q_buf[0] | (sl->q_buf[1] << 8) | (sl->q_buf[2] << 16) |
  68                 (sl->q_buf[3] << 24);
  69
  70         printf("Chip ID is %08x.\n", chip_id);
  71
  72         const struct chip_params* params = NULL;
  73
  74         for(int i = 0; i < sizeof(devices) / sizeof(devices[0]); i++) {
  75                 if(devices[i].chip_id == (chip_id & 0xFFF)) {
  76                         params = &devices[i];
  77                         break;
  78                 }
  79         }
  80
  81         if(params == NULL) {
  82                 fprintf(stderr, "Cannot recognize the connected device!\n");
  83                 return 0;
  84         }
  85
  86         printf("Device connected: %s\n", params->description);
  87         printf("Device parameters: SRAM: 0x%x bytes, Flash: up to 0x%x bytes in pages of 0x%x bytes\n",
  88                 params->sram_size, params->max_flash_size, params->flash_pagesize);
  89
  90         uint32_t flash_size;
  91
  92         stlink_read_mem32(sl, 0x1FFFF7E0, 4);
  93         flash_size = sl->q_buf[0] | (sl->q_buf[1] << 8);
  94
  95         printf("Flash size is %d KiB.\n", flash_size);
  96
  97         current_memory_map = make_memory_map(params, flash_size * 0x400);
  98
  99         int port = atoi(argv[1]);
 100
 101         while(serve(sl, port) == 0);
 102
 103         stlink_close(sl);
 104
 105         return 0;
 106 }
 107
 108 static const char* const memory_map_template =
 109   "<?xml version=\"1.0\"?>"
 110   "<!DOCTYPE memory-map PUBLIC \"+//IDN gnu.org//DTD GDB Memory Map V1.0//EN\""
 111   "     \"http://sourceware.org/gdb/gdb-memory-map.dtd\">"
 112   "<memory-map>"
 113   "  <memory type=\"rom\" start=\"0x00000000\" length=\"0x%x\"/>"       // code = sram, bootrom or flash; flash is bigger
 114   "  <memory type=\"ram\" start=\"0x20000000\" length=\"0x%x\"/>"       // sram 8k
 115   "  <memory type=\"flash\" start=\"0x08000000\" length=\"0x%x\">"
 116   "    <property name=\"blocksize\">0x%x</property>"
 117   "  </memory>"
 118   "  <memory type=\"ram\" start=\"0x40000000\" length=\"0x1fffffff\"/>" // peripheral regs
 119   "  <memory type=\"ram\" start=\"0xe0000000\" length=\"0x1fffffff\"/>" // cortex regs
 120   "  <memory type=\"rom\" start=\"0x%08x\" length=\"0x%x\"/>"           // bootrom
 121   "  <memory type=\"rom\" start=\"0x1ffff800\" length=\"0x8\"/>"        // option byte area
 122   "</memory-map>";
 123
 124 char* make_memory_map(const struct chip_params *params, uint32_t flash_size) {
 125         /* This will be freed in serve() */
 126         char* map = malloc(4096);
 127         map[0] = '\0';
 128
 129         snprintf(map, 4096, memory_map_template,
 130                         flash_size,
 131                         params->sram_size,
 132                         flash_size, params->flash_pagesize,
 133                         params->bootrom_base, params->bootrom_size);
 134
 135         return map;
 136 }
 137
 138 #define CODE_BREAK_NUM  6
 139
 140 #define CODE_BREAK_LOW  0x01
 141 #define CODE_BREAK_HIGH 0x02
 142
 143 struct code_hw_breakpoint {
 144         stm32_addr_t addr;
 145         int          type;
 146 };
 147
 148 struct code_hw_breakpoint code_breaks[CODE_BREAK_NUM];
 149
 150 static void init_code_breakpoints(struct stlink* sl) {
 151         memset(sl->q_buf, 0, 4);
 152         sl->q_buf[0] = 0x03; // KEY | ENABLE
 153         stlink_write_mem32(sl, 0xe0002000, 4);
 154
 155         memset(sl->q_buf, 0, 4);
 156         for(int i = 0; i < CODE_BREAK_NUM; i++) {
 157                 code_breaks[i].type = 0;
 158                 stlink_write_mem32(sl, 0xe0002008 + i * 4, 4);
 159         }
 160 }
 161
 162 static int update_code_breakpoint(struct stlink* sl, stm32_addr_t addr, int set) {
 163         stm32_addr_t fpb_addr = addr & ~0x3;
 164         int type = addr & 0x2 ? CODE_BREAK_HIGH : CODE_BREAK_LOW;
 165
 166         if(addr & 1) {
 167                 fprintf(stderr, "update_code_breakpoint: unaligned address %08x\n", addr);
 168                 return -1;
 169         }
 170
 171         int id = -1;
 172         for(int i = 0; i < CODE_BREAK_NUM; i++) {
 173                 if(fpb_addr == code_breaks[i].addr ||
 174                         (set && code_breaks[i].type == 0)) {
 175                         id = i;
 176                         break;
 177                 }
 178         }
 179
 180         if(id == -1) {
 181                 if(set) return -1; // Free slot not found
 182                 else    return 0;  // Breakpoint is already removed
 183         }
 184
 185         struct code_hw_breakpoint* brk = &code_breaks[id];
 186
 187         brk->addr = fpb_addr;
 188
 189         if(set) brk->type |= type;
 190         else    brk->type &= ~type;
 191
 192         memset(sl->q_buf, 0, 4);
 193
 194         if(brk->type == 0) {
 195                 #ifdef DEBUG
 196                 printf("clearing hw break %d\n", id);
 197                 #endif
 198
 199                 stlink_write_mem32(sl, 0xe0002008 + id * 4, 4);
 200         } else {
 201                 sl->q_buf[0] = ( brk->addr        & 0xff) | 1;
 202                 sl->q_buf[1] = ((brk->addr >> 8)  & 0xff);
 203                 sl->q_buf[2] = ((brk->addr >> 16) & 0xff);
 204                 sl->q_buf[3] = ((brk->addr >> 24) & 0xff) | (brk->type << 6);
 205
 206                 #ifdef DEBUG
 207                 printf("setting hw break %d at %08x (%d)\n",
 208                         id, brk->addr, brk->type);
 209                 printf("reg %02x %02x %02x %02x\n",
 210                         sl->q_buf[3], sl->q_buf[2], sl->q_buf[1], sl->q_buf[0]);
 211                 #endif
 212
 213                 stlink_write_mem32(sl, 0xe0002008 + id * 4, 4);
 214         }
 215
 216         return 0;
 217 }
 218
 219 #define FLASH_BASE 0x08000000
 220 #define FLASH_PAGE 0x400
 221 #define FLASH_PAGE_MASK (~((1 << 10) - 1))
 222 #define FLASH_SIZE (FLASH_PAGE * 128)
 223
 224 struct flash_block {
 225         stm32_addr_t addr;
 226         unsigned     length;
 227         uint8_t*     data;
 228
 229         struct flash_block* next;
 230 };
 231
 232 static struct flash_block* flash_root;
 233
 234 static int flash_add_block(stm32_addr_t addr, unsigned length) {
 235         if(addr < FLASH_BASE || addr + length > FLASH_BASE + FLASH_SIZE) {
 236                 fprintf(stderr, "flash_add_block: incorrect bounds\n");
 237                 return -1;
 238         }
 239
 240         if(addr % FLASH_PAGE != 0 || length % FLASH_PAGE != 0) {
 241                 fprintf(stderr, "flash_add_block: unaligned block\n");
 242                 return -1;
 243         }
 244
 245         struct flash_block* new = malloc(sizeof(struct flash_block));
 246         new->next = flash_root;
 247
 248         new->addr   = addr;
 249         new->length = length;
 250         new->data   = calloc(length, 1);
 251
 252         flash_root = new;
 253
 254         return 0;
 255 }
 256
 257 static int flash_populate(stm32_addr_t addr, uint8_t* data, unsigned length) {
 258         int fit_blocks = 0, fit_length = 0;
 259
 260         for(struct flash_block* fb = flash_root; fb; fb = fb->next) {
 261                 /* Block: ------X------Y--------
 262                  * Data:            a-----b
 263                  *                a--b
 264                  *            a-----------b
 265                  * Block intersects with data, if:
 266                  *  a < Y && b > x
 267                  */
 268
 269                 unsigned X = fb->addr, Y = fb->addr + fb->length;
 270                 unsigned a = addr, b = addr + length;
 271                 if(a < Y && b > X) {
 272                         // from start of the block
 273                         unsigned start = (a > X ? a : X) - X;
 274                         unsigned end   = (b > Y ? Y : b) - X;
 275
 276                         memcpy(fb->data + start, data, end - start);
 277
 278                         fit_blocks++;
 279                         fit_length += end - start;
 280                 }
 281         }
 282
 283         if(fit_blocks == 0) {
 284                 fprintf(stderr, "Unfit data block %08x -> %04x\n", addr, length);
 285                 return -1;
 286         }
 287
 288         if(fit_length != length) {
 289                 fprintf(stderr, "warning: data block %08x -> %04x truncated to %04x\n",
 290                         addr, length, fit_length);
 291                 fprintf(stderr, "(this is not an error, just a GDB glitch)\n");
 292         }
 293
 294         return 0;
 295 }
 296
 297 static int flash_go(struct stlink* sl) {
 298         int error = -1;
 299
 300         // Some kinds of clock settings do not allow writing to flash.
 301         stlink_reset(sl);
 302
 303         for(struct flash_block* fb = flash_root; fb; fb = fb->next) {
 304                 #ifdef DEBUG
 305                 printf("flash_do: block %08x -> %04x\n", fb->addr, fb->length);
 306                 #endif
 307
 308                 unsigned length = fb->length;
 309                 for(stm32_addr_t page = fb->addr; page < fb->addr + fb->length; page += 0x400) {
 310                         #ifdef DEBUG
 311                         printf("flash_do: page %08x\n", page);
 312                         #endif
 313
 314                         stlink_erase_flash_page(sl, page);
 315
 316                         if(stlink_write_flash(sl, page, fb->data + (page - fb->addr),
 317                                         length > 0x400 ? 0x400 : length) < 0)
 318                                 goto error;
 319                 }
 320
 321         }
 322
 323         stlink_reset(sl);
 324
 325         error = 0;
 326
 327 error:
 328         for(struct flash_block* fb = flash_root, *next; fb; fb = next) {
 329                 next = fb->next;
 330                 free(fb->data);
 331                 free(fb);
 332         }
 333
 334         flash_root = NULL;
 335
 336         return error;
 337 }
 338
 339 int serve(struct stlink* sl, int port) {
 340         int sock = socket(AF_INET, SOCK_STREAM, 0);
 341         if(sock < 0) {
 342                 perror("socket");
 343                 return 1;
 344         }
 345
 346         unsigned int val = 1;
 347         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 348
 349         struct sockaddr_in serv_addr = {0};
 350         serv_addr.sin_family = AF_INET;
 351         serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
 352         serv_addr.sin_port = htons(port);
 353
 354         if(bind(sock, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
 355                 perror("bind");
 356                 return 1;
 357         }
 358
 359         if(listen(sock, 5) < 0) {
 360                 perror("listen");
 361                 return 1;
 362         }
 363
 364         stlink_force_debug(sl);
 365         stlink_reset(sl);
 366         init_code_breakpoints(sl);
 367
 368         printf("Listening at *:%d...\n", port);
 369
 370         int client = accept(sock, NULL, NULL);
 371         if(client < 0) {
 372                 perror("accept");
 373                 return 1;
 374         }
 375
 376         close(sock);
 377
 378         printf("GDB connected.\n");
 379
 380         /*
 381          * To allow resetting the chip from GDB it is required to
 382          * emulate attaching and detaching to target.
 383          */
 384         unsigned int attached = 1;
 385
 386         while(1) {
 387                 char* packet;
 388
 389                 int status = gdb_recv_packet(client, &packet);
 390                 if(status < 0) {
 391                         fprintf(stderr, "cannot recv: %d\n", status);
 392                         return 1;
 393                 }
 394
 395                 #ifdef DEBUG
 396                 printf("recv: %s\n", packet);
 397                 #endif
 398
 399                 char* reply = NULL;
 400
 401                 switch(packet[0]) {
 402                 case 'q': {
 403                         if(packet[1] == 'P' || packet[1] == 'C' || packet[1] == 'L') {
 404                                 reply = strdup("");
 405                                 break;
 406                         }
 407
 408                         char *separator = strstr(packet, ":"), *params = "";
 409                         if(separator == NULL) {
 410                                 separator = packet + strlen(packet);
 411                         } else {
 412                                 params = separator + 1;
 413                         }
 414
 415                         unsigned queryNameLength = (separator - &packet[1]);
 416                         char* queryName = calloc(queryNameLength + 1, 1);
 417                         strncpy(queryName, &packet[1], queryNameLength);
 418
 419                         #ifdef DEBUG
 420                         printf("query: %s;%s\n", queryName, params);
 421                         #endif
 422
 423                         if(!strcmp(queryName, "Supported")) {
 424                                 reply = strdup("PacketSize=3fff;qXfer:memory-map:read+");
 425                         } else if(!strcmp(queryName, "Xfer")) {
 426                                 char *type, *op, *annex, *s_addr, *s_length;
 427                                 char *tok = params;
 428
 429                                 type     = strsep(&tok, ":");
 430                                 op       = strsep(&tok, ":");
 431                                 annex    = strsep(&tok, ":");
 432                                 s_addr   = strsep(&tok, ",");
 433                                 s_length = tok;
 434
 435                                 unsigned addr = strtoul(s_addr, NULL, 16),
 436                                        length = strtoul(s_length, NULL, 16);
 437
 438                                 #ifdef DEBUG
 439                                 printf("Xfer: type:%s;op:%s;annex:%s;addr:%d;length:%d\n",
 440                                         type, op, annex, addr, length);
 441                                 #endif
 442
 443                                 const char* data = NULL;
 444
 445                                 if(!strcmp(type, "memory-map") && !strcmp(op, "read"))
 446                                         data = current_memory_map;
 447
 448                                 if(data) {
 449                                         unsigned data_length = strlen(data);
 450                                         if(addr + length > data_length)
 451                                                 length = data_length - addr;
 452
 453                                         if(length == 0) {
 454                                                 reply = strdup("l");
 455                                         } else {
 456                                                 reply = calloc(length + 2, 1);
 457                                                 reply[0] = 'm';
 458                                                 strncpy(&reply[1], data, length);
 459                                         }
 460                                 }
 461                         }
 462
 463                         if(reply == NULL)
 464                                 reply = strdup("");
 465
 466                         free(queryName);
 467
 468                         break;
 469                 }
 470
 471                 case 'v': {
 472                         char *params = NULL;
 473                         char *cmdName = strtok_r(packet, ":;", &params);
 474
 475                         cmdName++; // vCommand -> Command
 476
 477                         if(!strcmp(cmdName, "FlashErase")) {
 478                                 char *s_addr, *s_length;
 479                                 char *tok = params;
 480
 481                                 s_addr   = strsep(&tok, ",");
 482                                 s_length = tok;
 483
 484                                 unsigned addr = strtoul(s_addr, NULL, 16),
 485                                        length = strtoul(s_length, NULL, 16);
 486
 487                                 #ifdef DEBUG
 488                                 printf("FlashErase: addr:%08x,len:%04x\n",
 489                                         addr, length);
 490                                 #endif
 491
 492                                 if(flash_add_block(addr, length) < 0) {
 493                                         reply = strdup("E00");
 494                                 } else {
 495                                         reply = strdup("OK");
 496                                 }
 497                         } else if(!strcmp(cmdName, "FlashWrite")) {
 498                                 char *s_addr, *data;
 499                                 char *tok = params;
 500
 501                                 s_addr = strsep(&tok, ":");
 502                                 data   = tok;
 503
 504                                 unsigned addr = strtoul(s_addr, NULL, 16);
 505                                 unsigned data_length = status - (data - packet);
 506
 507                                 // Length of decoded data cannot be more than
 508                                 // encoded, as escapes are removed.
 509                                 // Additional byte is reserved for alignment fix.
 510                                 uint8_t *decoded = calloc(data_length + 1, 1);
 511                                 unsigned dec_index = 0;
 512                                 for(int i = 0; i < data_length; i++) {
 513                                         if(data[i] == 0x7d) {
 514                                                 i++;
 515                                                 decoded[dec_index++] = data[i] ^ 0x20;
 516                                         } else {
 517                                                 decoded[dec_index++] = data[i];
 518                                         }
 519                                 }
 520
 521                                 // Fix alignment
 522                                 if(dec_index % 2 != 0)
 523                                         dec_index++;
 524
 525                                 #ifdef DEBUG
 526                                 printf("binary packet %d -> %d\n", data_length, dec_index);
 527                                 #endif
 528
 529                                 if(flash_populate(addr, decoded, dec_index) < 0) {
 530                                         reply = strdup("E00");
 531                                 } else {
 532                                         reply = strdup("OK");
 533                                 }
 534                         } else if(!strcmp(cmdName, "FlashDone")) {
 535                                 if(flash_go(sl) < 0) {
 536                                         reply = strdup("E00");
 537                                 } else {
 538                                         reply = strdup("OK");
 539                                 }
 540                         } else if(!strcmp(cmdName, "Kill")) {
 541                                 attached = 0;
 542
 543                                 reply = strdup("OK");
 544                         }
 545
 546                         if(reply == NULL)
 547                                 reply = strdup("");
 548
 549                         break;
 550                 }
 551
 552                 case 'c':
 553                         stlink_run(sl);
 554
 555                         while(1) {
 556                                 int status = gdb_check_for_interrupt(client);
 557                                 if(status < 0) {
 558                                         fprintf(stderr, "cannot check for int: %d\n", status);
 559                                         return 1;
 560                                 }
 561
 562                                 if(status == 1) {
 563                                         stlink_force_debug(sl);
 564                                         break;
 565                                 }
 566
 567                                 stlink_status(sl);
 568                                 if(sl->core_stat == STLINK_CORE_HALTED) {
 569                                         break;
 570                                 }
 571
 572                                 usleep(100000);
 573                         }
 574
 575                         reply = strdup("S05"); // TRAP
 576                         break;
 577
 578                 case 's':
 579                         stlink_step(sl);
 580
 581                         reply = strdup("S05"); // TRAP
 582                         break;
 583
 584                 case '?':
 585                         if(attached) {
 586                                 reply = strdup("S05"); // TRAP
 587                         } else {
 588                                 /* Stub shall reply OK if not attached. */
 589                                 reply = strdup("OK");
 590                         }
 591                         break;
 592
 593                 case 'g':
 594                         stlink_read_all_regs(sl);
 595
 596                         reply = calloc(8 * 16 + 1, 1);
 597                         for(int i = 0; i < 16; i++)
 598                                 sprintf(&reply[i * 8], "%08x", htonl(sl->reg.r[i]));
 599
 600                         break;
 601
 602                 case 'p': {
 603                         unsigned id = strtoul(&packet[1], NULL, 16), reg = 0xDEADDEAD;
 604
 605                         if(id < 16) {
 606                                 stlink_read_reg(sl, id);
 607                                 reg = htonl(sl->reg.r[id]);
 608                         } else if(id == 0x19) {
 609                                 stlink_read_reg(sl, 16);
 610                                 reg = htonl(sl->reg.xpsr);
 611                         } else {
 612                                 reply = strdup("E00");
 613                         }
 614
 615                         reply = calloc(8 + 1, 1);
 616                         sprintf(reply, "%08x", reg);
 617
 618                         break;
 619                 }
 620
 621                 case 'P': {
 622                         char* s_reg = &packet[1];
 623                         char* s_value = strstr(&packet[1], "=") + 1;
 624
 625                         unsigned reg   = strtoul(s_reg,   NULL, 16);
 626                         unsigned value = strtoul(s_value, NULL, 16);
 627
 628                         if(reg < 16) {
 629                                 stlink_write_reg(sl, ntohl(value), reg);
 630                         } else if(reg == 0x19) {
 631                                 stlink_write_reg(sl, ntohl(value), 16);
 632                         } else {
 633                                 reply = strdup("E00");
 634                         }
 635
 636                         if(!reply) {
 637                                 reply = strdup("OK");
 638                         }
 639
 640                         break;
 641                 }
 642
 643                 case 'G':
 644                         for(int i = 0; i < 16; i++) {
 645                                 char str[9] = {0};
 646                                 strncpy(str, &packet[1 + i * 8], 8);
 647                                 uint32_t reg = strtoul(str, NULL, 16);
 648                                 stlink_write_reg(sl, ntohl(reg), i);
 649                         }
 650
 651                         reply = strdup("OK");
 652                         break;
 653
 654                 case 'm': {
 655                         char* s_start = &packet[1];
 656                         char* s_count = strstr(&packet[1], ",") + 1;
 657
 658                         stm32_addr_t start = strtoul(s_start, NULL, 16);
 659                         unsigned     count = strtoul(s_count, NULL, 16);
 660
 661                         unsigned adj_start = start % 4;
 662
 663                         stlink_read_mem32(sl, start - adj_start, (count % 4 == 0) ?
 664                                                 count : count + 4 - (count % 4));
 665
 666                         reply = calloc(count * 2 + 1, 1);
 667                         for(int i = 0; i < count; i++) {
 668                                 reply[i * 2 + 0] = hex[sl->q_buf[i + adj_start] >> 4];
 669                                 reply[i * 2 + 1] = hex[sl->q_buf[i + adj_start] & 0xf];
 670                         }
 671
 672                         break;
 673                 }
 674
 675                 case 'M': {
 676                         char* s_start = &packet[1];
 677                         char* s_count = strstr(&packet[1], ",") + 1;
 678                         char* hexdata = strstr(packet, ":") + 1;
 679
 680                         stm32_addr_t start = strtoul(s_start, NULL, 16);
 681                         unsigned     count = strtoul(s_count, NULL, 16);
 682
 683                         for(int i = 0; i < count; i ++) {
 684                                 char hex[3] = { hexdata[i*2], hexdata[i*2+1], 0 };
 685                                 uint8_t byte = strtoul(hex, NULL, 16);
 686                                 sl->q_buf[i] = byte;
 687                         }
 688
 689                         if((count % 4) == 0 && (start % 4) == 0) {
 690                                 stlink_write_mem32(sl, start, count);
 691                         } else {
 692                                 stlink_write_mem8(sl, start, count);
 693                         }
 694
 695                         reply = strdup("OK");
 696
 697                         break;
 698                 }
 699
 700                 case 'Z': {
 701                         if(packet[1] == '1') {
 702                                 stm32_addr_t addr = strtoul(&packet[3], NULL, 16);
 703                                 if(update_code_breakpoint(sl, addr, 1) < 0) {
 704                                         reply = strdup("E00");
 705                                 } else {
 706                                         reply = strdup("OK");
 707                                 }
 708                         } else {
 709                                 reply = strdup("");
 710                         }
 711
 712                         break;
 713                 }
 714
 715                 case 'z': {
 716                         if(packet[1] == '1') {
 717                                 stm32_addr_t addr = strtoul(&packet[3], NULL, 16);
 718                                 update_code_breakpoint(sl, addr, 0);
 719
 720                                 reply = strdup("OK");
 721                         } else {
 722                                 reply = strdup("");
 723                         }
 724
 725                         break;
 726                 }
 727
 728                 case '!': {
 729                         /*
 730                          * Enter extended mode which allows restarting.
 731                          * We do support that always.
 732                          */
 733
 734                         reply = strdup("OK");
 735
 736                         break;
 737                 }
 738
 739                 case 'R': {
 740                         /* Reset the core. */
 741
 742                         stlink_reset(sl);
 743                         init_code_breakpoints(sl);
 744
 745                         attached = 1;
 746
 747                         reply = strdup("OK");
 748
 749                         break;
 750                 }
 751
 752                 default:
 753                         reply = strdup("");
 754                 }
 755
 756                 if(reply) {
 757                         #ifdef DEBUG
 758                         printf("send: %s\n", reply);
 759                         #endif
 760
 761                         int result = gdb_send_packet(client, reply);
 762                         if(result != 0) {
 763                                 fprintf(stderr, "cannot send: %d\n", result);
 764                                 return 1;
 765                         }
 766
 767                         free(reply);
 768                 }
 769
 770                 free(packet);
 771         }
 772
 773         return 0;
 774 }