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
 139 /*
 140  * DWT_COMP0     0xE0001020
 141  * DWT_MASK0     0xE0001024
 142  * DWT_FUNCTION0 0xE0001028
 143  * DWT_COMP1     0xE0001030
 144  * DWT_MASK1     0xE0001034
 145  * DWT_FUNCTION1 0xE0001038
 146  * DWT_COMP2     0xE0001040
 147  * DWT_MASK2     0xE0001044
 148  * DWT_FUNCTION2 0xE0001048
 149  * DWT_COMP3     0xE0001050
 150  * DWT_MASK3     0xE0001054
 151  * DWT_FUNCTION3 0xE0001058
 152  */
 153
 154 #define DATA_WATCH_NUM 4
 155
 156 enum watchfun { WATCHDISABLED = 0, WATCHREAD = 5, WATCHWRITE = 6, WATCHACCESS = 7 };
 157
 158 struct code_hw_watchpoint {
 159         stm32_addr_t addr;
 160         uint8_t mask;
 161         enum watchfun fun;
 162 };
 163
 164 struct code_hw_watchpoint data_watches[DATA_WATCH_NUM];
 165
 166 static void init_data_watchpoints(struct stlink *sl) {
 167         int i;
 168
 169         #ifdef DEBUG
 170         printf("init watchpoints\n");
 171         #endif
 172
 173         // set trcena in debug command to turn on dwt unit
 174         stlink_read_mem32(sl, 0xE000EDFC, 4);
 175         sl->q_buf[3] |= 1;
 176         stlink_write_mem32(sl, 0xE000EDFC, 4);
 177
 178         // make sure all watchpoints are cleared
 179         memset(sl->q_buf, 0, 4);
 180         for(int i = 0; i < DATA_WATCH_NUM; i++) {
 181                 data_watches[i].fun = WATCHDISABLED;
 182                 stlink_write_mem32(sl, 0xe0001028 + i * 16, 4);
 183         }
 184 }
 185
 186 static int add_data_watchpoint(struct stlink* sl, enum watchfun wf, stm32_addr_t addr, unsigned int len)
 187 {
 188         int i = 0;
 189         uint32_t mask, temp;
 190
 191         // computer mask
 192         // find a free watchpoint
 193         // configure
 194
 195         mask = -1;
 196         i = len;
 197         while(i) {
 198                 i >>= 1;
 199                 mask++;
 200         }
 201
 202         if((mask != -1) && (mask < 16)) {
 203                 for(i = 0; i < DATA_WATCH_NUM; i++) {
 204                         // is this an empty slot ?
 205                         if(data_watches[i].fun == WATCHDISABLED) {
 206                                 #ifdef DEBUG
 207                                 printf("insert watchpoint %d addr %x wf %u mask %u len %d\n", i, addr, wf, mask, len);
 208                                 #endif
 209
 210                                 data_watches[i].fun = wf;
 211                                 data_watches[i].addr = addr;
 212                                 data_watches[i].mask = mask;
 213
 214                                 // insert comparator address
 215                                 sl->q_buf[0] = (addr & 0xff);
 216                                 sl->q_buf[1] = ((addr >> 8) & 0xff);
 217                                 sl->q_buf[2] = ((addr >> 16) & 0xff);
 218                                 sl->q_buf[3] = ((addr >> 24)  & 0xff);
 219
 220                                 stlink_write_mem32(sl, 0xE0001020 + i * 16, 4);
 221
 222                                 // insert mask
 223                                 memset(sl->q_buf, 0, 4);
 224                                 sl->q_buf[0] = mask;
 225                                 stlink_write_mem32(sl, 0xE0001024 + i * 16, 4);
 226
 227                                 // insert function
 228                                 memset(sl->q_buf, 0, 4);
 229                                 sl->q_buf[0] = wf;
 230                                 stlink_write_mem32(sl, 0xE0001028 + i * 16, 4);
 231
 232                                 // just to make sure the matched bit is clear !
 233                                 stlink_read_mem32(sl,  0xE0001028 + i * 16, 4);
 234                                 return 0;
 235                         }
 236                 }
 237         }
 238
 239         #ifdef DEBUG
 240         printf("failure: add watchpoints addr %x wf %u len %u\n", addr, wf, len);
 241         #endif
 242         return -1;
 243 }
 244
 245 static int delete_data_watchpoint(struct stlink* sl, stm32_addr_t addr)
 246 {
 247         int i;
 248
 249         for(i = 0 ; i < DATA_WATCH_NUM; i++) {
 250                 if((data_watches[i].addr == addr) && (data_watches[i].fun != WATCHDISABLED)) {
 251                         #ifdef DEBUG
 252                         printf("delete watchpoint %d addr %x\n", i, addr);
 253                         #endif
 254
 255                         memset(sl->q_buf, 0, 4);
 256                         data_watches[i].fun = WATCHDISABLED;
 257                         stlink_write_mem32(sl, 0xe0001028 + i * 16, 4);
 258
 259                         return 0;
 260                 }
 261         }
 262
 263         #ifdef DEBUG
 264         printf("failure: delete watchpoint addr %x\n", addr);
 265         #endif
 266
 267         return -1;
 268 }
 269
 270 #define CODE_BREAK_NUM  6
 271 #define CODE_BREAK_LOW  0x01
 272 #define CODE_BREAK_HIGH 0x02
 273
 274 struct code_hw_breakpoint {
 275         stm32_addr_t addr;
 276         int          type;
 277 };
 278
 279 struct code_hw_breakpoint code_breaks[CODE_BREAK_NUM];
 280
 281 static void init_code_breakpoints(struct stlink* sl) {
 282         memset(sl->q_buf, 0, 4);
 283         sl->q_buf[0] = 0x03; // KEY | ENABLE
 284         stlink_write_mem32(sl, 0xe0002000, 4);
 285
 286         memset(sl->q_buf, 0, 4);
 287         for(int i = 0; i < CODE_BREAK_NUM; i++) {
 288                 code_breaks[i].type = 0;
 289                 stlink_write_mem32(sl, 0xe0002008 + i * 4, 4);
 290         }
 291 }
 292
 293 static int update_code_breakpoint(struct stlink* sl, stm32_addr_t addr, int set) {
 294         stm32_addr_t fpb_addr = addr & ~0x3;
 295         int type = addr & 0x2 ? CODE_BREAK_HIGH : CODE_BREAK_LOW;
 296
 297         if(addr & 1) {
 298                 fprintf(stderr, "update_code_breakpoint: unaligned address %08x\n", addr);
 299                 return -1;
 300         }
 301
 302         int id = -1;
 303         for(int i = 0; i < CODE_BREAK_NUM; i++) {
 304                 if(fpb_addr == code_breaks[i].addr ||
 305                         (set && code_breaks[i].type == 0)) {
 306                         id = i;
 307                         break;
 308                 }
 309         }
 310
 311         if(id == -1) {
 312                 if(set) return -1; // Free slot not found
 313                 else    return 0;  // Breakpoint is already removed
 314         }
 315
 316         struct code_hw_breakpoint* brk = &code_breaks[id];
 317
 318         brk->addr = fpb_addr;
 319
 320         if(set) brk->type |= type;
 321         else    brk->type &= ~type;
 322
 323         memset(sl->q_buf, 0, 4);
 324
 325         if(brk->type == 0) {
 326                 #ifdef DEBUG
 327                 printf("clearing hw break %d\n", id);
 328                 #endif
 329
 330                 stlink_write_mem32(sl, 0xe0002008 + id * 4, 4);
 331         } else {
 332                 sl->q_buf[0] = ( brk->addr        & 0xff) | 1;
 333                 sl->q_buf[1] = ((brk->addr >> 8)  & 0xff);
 334                 sl->q_buf[2] = ((brk->addr >> 16) & 0xff);
 335                 sl->q_buf[3] = ((brk->addr >> 24) & 0xff) | (brk->type << 6);
 336
 337                 #ifdef DEBUG
 338                 printf("setting hw break %d at %08x (%d)\n",
 339                         id, brk->addr, brk->type);
 340                 printf("reg %02x %02x %02x %02x\n",
 341                         sl->q_buf[3], sl->q_buf[2], sl->q_buf[1], sl->q_buf[0]);
 342                 #endif
 343
 344                 stlink_write_mem32(sl, 0xe0002008 + id * 4, 4);
 345         }
 346
 347         return 0;
 348 }
 349
 350 #define FLASH_BASE 0x08000000
 351 #define FLASH_PAGE 0x400
 352 #define FLASH_PAGE_MASK (~((1 << 10) - 1))
 353 #define FLASH_SIZE (FLASH_PAGE * 128)
 354
 355 struct flash_block {
 356         stm32_addr_t addr;
 357         unsigned     length;
 358         uint8_t*     data;
 359
 360         struct flash_block* next;
 361 };
 362
 363 static struct flash_block* flash_root;
 364
 365 static int flash_add_block(stm32_addr_t addr, unsigned length) {
 366         if(addr < FLASH_BASE || addr + length > FLASH_BASE + FLASH_SIZE) {
 367                 fprintf(stderr, "flash_add_block: incorrect bounds\n");
 368                 return -1;
 369         }
 370
 371         if(addr % FLASH_PAGE != 0 || length % FLASH_PAGE != 0) {
 372                 fprintf(stderr, "flash_add_block: unaligned block\n");
 373                 return -1;
 374         }
 375
 376         struct flash_block* new = malloc(sizeof(struct flash_block));
 377         new->next = flash_root;
 378
 379         new->addr   = addr;
 380         new->length = length;
 381         new->data   = calloc(length, 1);
 382
 383         flash_root = new;
 384
 385         return 0;
 386 }
 387
 388 static int flash_populate(stm32_addr_t addr, uint8_t* data, unsigned length) {
 389         int fit_blocks = 0, fit_length = 0;
 390
 391         for(struct flash_block* fb = flash_root; fb; fb = fb->next) {
 392                 /* Block: ------X------Y--------
 393                  * Data:            a-----b
 394                  *                a--b
 395                  *            a-----------b
 396                  * Block intersects with data, if:
 397                  *  a < Y && b > x
 398                  */
 399
 400                 unsigned X = fb->addr, Y = fb->addr + fb->length;
 401                 unsigned a = addr, b = addr + length;
 402                 if(a < Y && b > X) {
 403                         // from start of the block
 404                         unsigned start = (a > X ? a : X) - X;
 405                         unsigned end   = (b > Y ? Y : b) - X;
 406
 407                         memcpy(fb->data + start, data, end - start);
 408
 409                         fit_blocks++;
 410                         fit_length += end - start;
 411                 }
 412         }
 413
 414         if(fit_blocks == 0) {
 415                 fprintf(stderr, "Unfit data block %08x -> %04x\n", addr, length);
 416                 return -1;
 417         }
 418
 419         if(fit_length != length) {
 420                 fprintf(stderr, "warning: data block %08x -> %04x truncated to %04x\n",
 421                         addr, length, fit_length);
 422                 fprintf(stderr, "(this is not an error, just a GDB glitch)\n");
 423         }
 424
 425         return 0;
 426 }
 427
 428 static int flash_go(struct stlink* sl) {
 429         int error = -1;
 430
 431         // Some kinds of clock settings do not allow writing to flash.
 432         stlink_reset(sl);
 433
 434         for(struct flash_block* fb = flash_root; fb; fb = fb->next) {
 435                 #ifdef DEBUG
 436                 printf("flash_do: block %08x -> %04x\n", fb->addr, fb->length);
 437                 #endif
 438
 439                 unsigned length = fb->length;
 440                 for(stm32_addr_t page = fb->addr; page < fb->addr + fb->length; page += 0x400) {
 441                         #ifdef DEBUG
 442                         printf("flash_do: page %08x\n", page);
 443                         #endif
 444
 445                         stlink_erase_flash_page(sl, page);
 446
 447                         if(stlink_write_flash(sl, page, fb->data + (page - fb->addr),
 448                                         length > 0x400 ? 0x400 : length) < 0)
 449                                 goto error;
 450                 }
 451
 452         }
 453
 454         stlink_reset(sl);
 455
 456         error = 0;
 457
 458 error:
 459         for(struct flash_block* fb = flash_root, *next; fb; fb = next) {
 460                 next = fb->next;
 461                 free(fb->data);
 462                 free(fb);
 463         }
 464
 465         flash_root = NULL;
 466
 467         return error;
 468 }
 469
 470 int serve(struct stlink* sl, int port) {
 471         int sock = socket(AF_INET, SOCK_STREAM, 0);
 472         if(sock < 0) {
 473                 perror("socket");
 474                 return 1;
 475         }
 476
 477         unsigned int val = 1;
 478         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 479
 480         struct sockaddr_in serv_addr = {0};
 481         serv_addr.sin_family = AF_INET;
 482         serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
 483         serv_addr.sin_port = htons(port);
 484
 485         if(bind(sock, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
 486                 perror("bind");
 487                 return 1;
 488         }
 489
 490         if(listen(sock, 5) < 0) {
 491                 perror("listen");
 492                 return 1;
 493         }
 494
 495         stlink_force_debug(sl);
 496         stlink_reset(sl);
 497         init_code_breakpoints(sl);
 498         init_data_watchpoints(sl);
 499
 500         printf("Listening at *:%d...\n", port);
 501
 502         int client = accept(sock, NULL, NULL);
 503         if(client < 0) {
 504                 perror("accept");
 505                 return 1;
 506         }
 507
 508         close(sock);
 509
 510         printf("GDB connected.\n");
 511
 512         /*
 513          * To allow resetting the chip from GDB it is required to
 514          * emulate attaching and detaching to target.
 515          */
 516         unsigned int attached = 1;
 517
 518         while(1) {
 519                 char* packet;
 520
 521                 int status = gdb_recv_packet(client, &packet);
 522                 if(status < 0) {
 523                         fprintf(stderr, "cannot recv: %d\n", status);
 524                         return 1;
 525                 }
 526
 527                 #ifdef DEBUG
 528                 printf("recv: %s\n", packet);
 529                 #endif
 530
 531                 char* reply = NULL;
 532
 533                 switch(packet[0]) {
 534                 case 'q': {
 535                         if(packet[1] == 'P' || packet[1] == 'C' || packet[1] == 'L') {
 536                                 reply = strdup("");
 537                                 break;
 538                         }
 539
 540                         char *separator = strstr(packet, ":"), *params = "";
 541                         if(separator == NULL) {
 542                                 separator = packet + strlen(packet);
 543                         } else {
 544                                 params = separator + 1;
 545                         }
 546
 547                         unsigned queryNameLength = (separator - &packet[1]);
 548                         char* queryName = calloc(queryNameLength + 1, 1);
 549                         strncpy(queryName, &packet[1], queryNameLength);
 550
 551                         #ifdef DEBUG
 552                         printf("query: %s;%s\n", queryName, params);
 553                         #endif
 554
 555                         if(!strcmp(queryName, "Supported")) {
 556                                 reply = strdup("PacketSize=3fff;qXfer:memory-map:read+");
 557                         } else if(!strcmp(queryName, "Xfer")) {
 558                                 char *type, *op, *annex, *s_addr, *s_length;
 559                                 char *tok = params;
 560
 561                                 type     = strsep(&tok, ":");
 562                                 op       = strsep(&tok, ":");
 563                                 annex    = strsep(&tok, ":");
 564                                 s_addr   = strsep(&tok, ",");
 565                                 s_length = tok;
 566
 567                                 unsigned addr = strtoul(s_addr, NULL, 16),
 568                                        length = strtoul(s_length, NULL, 16);
 569
 570                                 #ifdef DEBUG
 571                                 printf("Xfer: type:%s;op:%s;annex:%s;addr:%d;length:%d\n",
 572                                         type, op, annex, addr, length);
 573                                 #endif
 574
 575                                 const char* data = NULL;
 576
 577                                 if(!strcmp(type, "memory-map") && !strcmp(op, "read"))
 578                                         data = current_memory_map;
 579
 580                                 if(data) {
 581                                         unsigned data_length = strlen(data);
 582                                         if(addr + length > data_length)
 583                                                 length = data_length - addr;
 584
 585                                         if(length == 0) {
 586                                                 reply = strdup("l");
 587                                         } else {
 588                                                 reply = calloc(length + 2, 1);
 589                                                 reply[0] = 'm';
 590                                                 strncpy(&reply[1], data, length);
 591                                         }
 592                                 }
 593                         }
 594
 595                         if(reply == NULL)
 596                                 reply = strdup("");
 597
 598                         free(queryName);
 599
 600                         break;
 601                 }
 602
 603                 case 'v': {
 604                         char *params = NULL;
 605                         char *cmdName = strtok_r(packet, ":;", &params);
 606
 607                         cmdName++; // vCommand -> Command
 608
 609                         if(!strcmp(cmdName, "FlashErase")) {
 610                                 char *s_addr, *s_length;
 611                                 char *tok = params;
 612
 613                                 s_addr   = strsep(&tok, ",");
 614                                 s_length = tok;
 615
 616                                 unsigned addr = strtoul(s_addr, NULL, 16),
 617                                        length = strtoul(s_length, NULL, 16);
 618
 619                                 #ifdef DEBUG
 620                                 printf("FlashErase: addr:%08x,len:%04x\n",
 621                                         addr, length);
 622                                 #endif
 623
 624                                 if(flash_add_block(addr, length) < 0) {
 625                                         reply = strdup("E00");
 626                                 } else {
 627                                         reply = strdup("OK");
 628                                 }
 629                         } else if(!strcmp(cmdName, "FlashWrite")) {
 630                                 char *s_addr, *data;
 631                                 char *tok = params;
 632
 633                                 s_addr = strsep(&tok, ":");
 634                                 data   = tok;
 635
 636                                 unsigned addr = strtoul(s_addr, NULL, 16);
 637                                 unsigned data_length = status - (data - packet);
 638
 639                                 // Length of decoded data cannot be more than
 640                                 // encoded, as escapes are removed.
 641                                 // Additional byte is reserved for alignment fix.
 642                                 uint8_t *decoded = calloc(data_length + 1, 1);
 643                                 unsigned dec_index = 0;
 644                                 for(int i = 0; i < data_length; i++) {
 645                                         if(data[i] == 0x7d) {
 646                                                 i++;
 647                                                 decoded[dec_index++] = data[i] ^ 0x20;
 648                                         } else {
 649                                                 decoded[dec_index++] = data[i];
 650                                         }
 651                                 }
 652
 653                                 // Fix alignment
 654                                 if(dec_index % 2 != 0)
 655                                         dec_index++;
 656
 657                                 #ifdef DEBUG
 658                                 printf("binary packet %d -> %d\n", data_length, dec_index);
 659                                 #endif
 660
 661                                 if(flash_populate(addr, decoded, dec_index) < 0) {
 662                                         reply = strdup("E00");
 663                                 } else {
 664                                         reply = strdup("OK");
 665                                 }
 666                         } else if(!strcmp(cmdName, "FlashDone")) {
 667                                 if(flash_go(sl) < 0) {
 668                                         reply = strdup("E00");
 669                                 } else {
 670                                         reply = strdup("OK");
 671                                 }
 672                         } else if(!strcmp(cmdName, "Kill")) {
 673                                 attached = 0;
 674
 675                                 reply = strdup("OK");
 676                         }
 677
 678                         if(reply == NULL)
 679                                 reply = strdup("");
 680
 681                         break;
 682                 }
 683
 684                 case 'c':
 685                         stlink_run(sl);
 686
 687                         while(1) {
 688                                 int status = gdb_check_for_interrupt(client);
 689                                 if(status < 0) {
 690                                         fprintf(stderr, "cannot check for int: %d\n", status);
 691                                         return 1;
 692                                 }
 693
 694                                 if(status == 1) {
 695                                         stlink_force_debug(sl);
 696                                         break;
 697                                 }
 698
 699                                 stlink_status(sl);
 700                                 if(sl->core_stat == STLINK_CORE_HALTED) {
 701                                         break;
 702                                 }
 703
 704                                 usleep(100000);
 705                         }
 706
 707                         reply = strdup("S05"); // TRAP
 708                         break;
 709
 710                 case 's':
 711                         stlink_step(sl);
 712
 713                         reply = strdup("S05"); // TRAP
 714                         break;
 715
 716                 case '?':
 717                         if(attached) {
 718                                 reply = strdup("S05"); // TRAP
 719                         } else {
 720                                 /* Stub shall reply OK if not attached. */
 721                                 reply = strdup("OK");
 722                         }
 723                         break;
 724
 725                 case 'g':
 726                         stlink_read_all_regs(sl);
 727
 728                         reply = calloc(8 * 16 + 1, 1);
 729                         for(int i = 0; i < 16; i++)
 730                                 sprintf(&reply[i * 8], "%08x", htonl(sl->reg.r[i]));
 731
 732                         break;
 733
 734                 case 'p': {
 735                         unsigned id = strtoul(&packet[1], NULL, 16), reg = 0xDEADDEAD;
 736
 737                         if(id < 16) {
 738                                 stlink_read_reg(sl, id);
 739                                 reg = htonl(sl->reg.r[id]);
 740                         } else if(id == 0x19) {
 741                                 stlink_read_reg(sl, 16);
 742                                 reg = htonl(sl->reg.xpsr);
 743                         } else {
 744                                 reply = strdup("E00");
 745                         }
 746
 747                         reply = calloc(8 + 1, 1);
 748                         sprintf(reply, "%08x", reg);
 749
 750                         break;
 751                 }
 752
 753                 case 'P': {
 754                         char* s_reg = &packet[1];
 755                         char* s_value = strstr(&packet[1], "=") + 1;
 756
 757                         unsigned reg   = strtoul(s_reg,   NULL, 16);
 758                         unsigned value = strtoul(s_value, NULL, 16);
 759
 760                         if(reg < 16) {
 761                                 stlink_write_reg(sl, ntohl(value), reg);
 762                         } else if(reg == 0x19) {
 763                                 stlink_write_reg(sl, ntohl(value), 16);
 764                         } else {
 765                                 reply = strdup("E00");
 766                         }
 767
 768                         if(!reply) {
 769                                 reply = strdup("OK");
 770                         }
 771
 772                         break;
 773                 }
 774
 775                 case 'G':
 776                         for(int i = 0; i < 16; i++) {
 777                                 char str[9] = {0};
 778                                 strncpy(str, &packet[1 + i * 8], 8);
 779                                 uint32_t reg = strtoul(str, NULL, 16);
 780                                 stlink_write_reg(sl, ntohl(reg), i);
 781                         }
 782
 783                         reply = strdup("OK");
 784                         break;
 785
 786                 case 'm': {
 787                         char* s_start = &packet[1];
 788                         char* s_count = strstr(&packet[1], ",") + 1;
 789
 790                         stm32_addr_t start = strtoul(s_start, NULL, 16);
 791                         unsigned     count = strtoul(s_count, NULL, 16);
 792
 793                         unsigned adj_start = start % 4;
 794
 795                         stlink_read_mem32(sl, start - adj_start, (count % 4 == 0) ?
 796                                                 count : count + 4 - (count % 4));
 797
 798                         reply = calloc(count * 2 + 1, 1);
 799                         for(int i = 0; i < count; i++) {
 800                                 reply[i * 2 + 0] = hex[sl->q_buf[i + adj_start] >> 4];
 801                                 reply[i * 2 + 1] = hex[sl->q_buf[i + adj_start] & 0xf];
 802                         }
 803
 804                         break;
 805                 }
 806
 807                 case 'M': {
 808                         char* s_start = &packet[1];
 809                         char* s_count = strstr(&packet[1], ",") + 1;
 810                         char* hexdata = strstr(packet, ":") + 1;
 811
 812                         stm32_addr_t start = strtoul(s_start, NULL, 16);
 813                         unsigned     count = strtoul(s_count, NULL, 16);
 814
 815                         for(int i = 0; i < count; i ++) {
 816                                 char hex[3] = { hexdata[i*2], hexdata[i*2+1], 0 };
 817                                 uint8_t byte = strtoul(hex, NULL, 16);
 818                                 sl->q_buf[i] = byte;
 819                         }
 820
 821                         if((count % 4) == 0 && (start % 4) == 0) {
 822                                 stlink_write_mem32(sl, start, count);
 823                         } else {
 824                                 stlink_write_mem8(sl, start, count);
 825                         }
 826
 827                         reply = strdup("OK");
 828
 829                         break;
 830                 }
 831
 832                 case 'Z': {
 833                         char *endptr;
 834                         stm32_addr_t addr = strtoul(&packet[3], &endptr, 16);
 835                         stm32_addr_t len  = strtoul(&endptr[1], NULL, 16);
 836
 837                         switch (packet[1]) {
 838                                 case '1':
 839                                 if(update_code_breakpoint(sl, addr, 1) < 0) {
 840                                         reply = strdup("E00");
 841                                 } else {
 842                                         reply = strdup("OK");
 843                                 }
 844                                 break;
 845
 846                                 case '2':   // insert write watchpoint
 847                                 case '3':   // insert read  watchpoint
 848                                 case '4':   // insert access watchpoint
 849                                 {
 850                                         enum watchfun wf;
 851                                         if(packet[1] == '2') {
 852                                                 wf = WATCHWRITE;
 853                                         } else if(packet[1] == '3') {
 854                                                 wf = WATCHREAD;
 855                                         } else {
 856                                                 wf = WATCHACCESS;
 857                                                 if(add_data_watchpoint(sl, wf, addr, len) < 0) {
 858                                                         reply = strdup("E00");
 859                                                 } else {
 860                                                         reply = strdup("OK");
 861                                                         break;
 862                                                 }
 863                                 }
 864
 865                                 default:
 866                                 reply = strdup("");
 867                         }
 868                         break;
 869                 }
 870                 case 'z': {
 871                         char *endptr;
 872                         stm32_addr_t addr = strtoul(&packet[3], &endptr, 16);
 873                         stm32_addr_t len  = strtoul(&endptr[1], NULL, 16);
 874                         switch (packet[1]) {
 875                                 case '1': // remove breakpoint
 876                                 update_code_breakpoint(sl, addr, 0);
 877                                 reply = strdup("OK");
 878                                 break;
 879
 880                                 case '2' : // remove write watchpoint
 881                                 case '3' : // remove read watchpoint
 882                                 case '4' : // remove access watchpoint
 883                                 if(delete_data_watchpoint(sl, addr) < 0) {
 884                                         reply = strdup("E00");
 885                                 } else {
 886                                         reply = strdup("OK");
 887                                         break;
 888                                 }
 889
 890                                 default:
 891                                 reply = strdup("");
 892                         }
 893                         break;
 894                 }
 895
 896                 case '!': {
 897                         /*
 898                          * Enter extended mode which allows restarting.
 899                          * We do support that always.
 900                          */
 901
 902                         reply = strdup("OK");
 903
 904                         break;
 905                 }
 906
 907                 case 'R': {
 908                         /* Reset the core. */
 909
 910                         stlink_reset(sl);
 911                         init_code_breakpoints(sl);
 912                         init_data_watchpoints(sl);
 913
 914                         attached = 1;
 915
 916                         reply = strdup("OK");
 917
 918                         break;
 919                 }
 920
 921                 default:
 922                         reply = strdup("");
 923                 }
 924
 925                 if(reply) {
 926                         #ifdef DEBUG
 927                         printf("send: %s\n", reply);
 928                         #endif
 929
 930                         int result = gdb_send_packet(client, reply);
 931                         if(result != 0) {
 932                                 fprintf(stderr, "cannot send: %d\n", result);
 933                                 return 1;
 934                         }
 935
 936                         free(reply);
 937                 }
 938
 939                 free(packet);
 940         }
 941
 942         return 0;
 943 }