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 #define FLASH_BASE 0x08000000
  21 #define FLASH_PAGE (sl->flash_pgsz)
  22 #define FLASH_PAGE_MASK (~((1 << 10) - 1))
  23 #define FLASH_SIZE (FLASH_PAGE * 128)
  24
  25 static const char hex[] = "0123456789abcdef";
  26
  27 static const char* current_memory_map = NULL;
  28
  29 struct chip_params {
  30         uint32_t chip_id;
  31         char* description;
  32         uint32_t max_flash_size, flash_pagesize;
  33         uint32_t sram_size;
  34         uint32_t bootrom_base, bootrom_size;
  35 } const devices[] = {
  36         { 0x412, "Low-density device",
  37           0x8000,   0x400, 0x2800,  0x1ffff000, 0x800  },
  38         { 0x410, "Medium-density device",
  39           0x20000,  0x400, 0x5000,  0x1ffff000, 0x800  },
  40         { 0x414, "High-density device",
  41           0x80000,  0x800, 0x10000, 0x1ffff000, 0x800  },
  42         { 0x418, "Connectivity line device",
  43           0x40000,  0x800, 0x10000, 0x1fffb000, 0x4800 },
  44         { 0x420, "Medium-density value line device",
  45           0x20000,  0x400, 0x2000,  0x1ffff000, 0x800  },
  46         { 0x428, "High-density value line device",
  47           0x80000,  0x800, 0x8000,  0x1ffff000, 0x800  },
  48         { 0x430, "XL-density device",
  49           0x100000, 0x800, 0x18000, 0x1fffe000, 0x1800 },
  50         { 0 }
  51 };
  52
  53 int serve(struct stlink* sl, int port);
  54 char* make_memory_map(const struct chip_params *params, uint32_t flash_size);
  55
  56 int main(int argc, char** argv) {
  57
  58         struct stlink *sl = NULL;
  59
  60         switch(argc) {
  61
  62                 default: {
  63                         fprintf(stderr, "Usage: %s <port> [/dev/sgX] \n", argv[0]);
  64                         return 1;
  65                 }
  66
  67                 case 3 : {
  68                         sl = stlink_quirk_open(argv[2], 0);
  69                         if(sl == NULL) return 1;
  70                         break;
  71                 }
  72
  73                 case 2 : { // Search ST-LINK (from /dev/sg0 to /dev/sg99)
  74                         const int DevNumMax = 99;
  75                         int ExistDevCount = 0;
  76
  77                         for(int DevNum = 0; DevNum <= DevNumMax; DevNum++)
  78                         {
  79                                 if(DevNum < 10) {
  80                                         char DevName[] = "/dev/sgX";
  81                                         const int X_index = 7;
  82                                         DevName[X_index] = DevNum + '0';
  83                                         if ( !access(DevName, F_OK) ) {
  84                                                 sl = stlink_quirk_open(DevName, 0);
  85                                                 ExistDevCount++;
  86                                         }
  87                                 }
  88                                 else if(DevNum < 100) {
  89                                         char DevName[] = "/dev/sgXY";
  90                                         const int X_index = 7;
  91                                         const int Y_index = 8;
  92                                         DevName[X_index] = DevNum/10 + '0';
  93                                         DevName[Y_index] = DevNum%10 + '0';
  94                                         if ( !access(DevName, F_OK) ) {
  95                                                 sl = stlink_quirk_open(DevName, 0);
  96                                                 ExistDevCount++;
  97                                         }
  98                                 }
  99                                 if(sl != NULL) break;
 100                         }
 101
 102                         if(sl == NULL) {
 103                                 fprintf(stdout, "\nNumber of /dev/sgX devices found: %i \n",
 104                                                 ExistDevCount);
 105                                 fprintf(stderr, "ST-LINK not found\n");
 106                                 return 1;
 107                         }
 108                         break;
 109                 }
 110         }
 111
 112         if(stlink_current_mode(sl) != STLINK_DEV_DEBUG_MODE)
 113                 stlink_enter_swd_mode(sl);
 114
 115         uint32_t chip_id;
 116
 117         stlink_read_mem32(sl, 0xE0042000, 4);
 118         chip_id = sl->q_buf[0] | (sl->q_buf[1] << 8) | (sl->q_buf[2] << 16) |
 119                 (sl->q_buf[3] << 24);
 120
 121         printf("Chip ID is %08x.\n", chip_id);
 122
 123         const struct chip_params* params = NULL;
 124
 125         for(int i = 0; i < sizeof(devices) / sizeof(devices[0]); i++) {
 126                 if(devices[i].chip_id == (chip_id & 0xFFF)) {
 127                         params = &devices[i];
 128                         break;
 129                 }
 130         }
 131
 132         if(params == NULL) {
 133                 fprintf(stderr, "Cannot recognize the connected device!\n");
 134                 return 0;
 135         }
 136
 137         printf("Device connected: %s\n", params->description);
 138         printf("Device parameters: SRAM: 0x%x bytes, Flash: up to 0x%x bytes in pages of 0x%x bytes\n",
 139                 params->sram_size, params->max_flash_size, params->flash_pagesize);
 140
 141         FLASH_PAGE = params->flash_pagesize;
 142
 143         uint32_t flash_size;
 144
 145         stlink_read_mem32(sl, 0x1FFFF7E0, 4);
 146         flash_size = sl->q_buf[0] | (sl->q_buf[1] << 8);
 147
 148         printf("Flash size is %d KiB.\n", flash_size);
 149         // memory map is in 1k blocks.
 150         current_memory_map = make_memory_map(params, flash_size * 0x400);
 151
 152         int port = atoi(argv[1]);
 153
 154         while(serve(sl, port) == 0);
 155
 156         stlink_close(sl);
 157
 158         return 0;
 159 }
 160
 161 static const char* const memory_map_template =
 162   "<?xml version=\"1.0\"?>"
 163   "<!DOCTYPE memory-map PUBLIC \"+//IDN gnu.org//DTD GDB Memory Map V1.0//EN\""
 164   "     \"http://sourceware.org/gdb/gdb-memory-map.dtd\">"
 165   "<memory-map>"
 166   "  <memory type=\"rom\" start=\"0x00000000\" length=\"0x%x\"/>"       // code = sram, bootrom or flash; flash is bigger
 167   "  <memory type=\"ram\" start=\"0x20000000\" length=\"0x%x\"/>"       // sram 8k
 168   "  <memory type=\"flash\" start=\"0x08000000\" length=\"0x%x\">"
 169   "    <property name=\"blocksize\">0x%x</property>"
 170   "  </memory>"
 171   "  <memory type=\"ram\" start=\"0x40000000\" length=\"0x1fffffff\"/>" // peripheral regs
 172   "  <memory type=\"ram\" start=\"0xe0000000\" length=\"0x1fffffff\"/>" // cortex regs
 173   "  <memory type=\"rom\" start=\"0x%08x\" length=\"0x%x\"/>"           // bootrom
 174   "  <memory type=\"rom\" start=\"0x1ffff800\" length=\"0x8\"/>"        // option byte area
 175   "</memory-map>";
 176
 177 char* make_memory_map(const struct chip_params *params, uint32_t flash_size) {
 178         /* This will be freed in serve() */
 179         char* map = malloc(4096);
 180         map[0] = '\0';
 181
 182         snprintf(map, 4096, memory_map_template,
 183                         flash_size,
 184                         params->sram_size,
 185                         flash_size, params->flash_pagesize,
 186                         params->bootrom_base, params->bootrom_size);
 187
 188         return map;
 189 }
 190
 191
 192 /*
 193  * DWT_COMP0     0xE0001020
 194  * DWT_MASK0     0xE0001024
 195  * DWT_FUNCTION0 0xE0001028
 196  * DWT_COMP1     0xE0001030
 197  * DWT_MASK1     0xE0001034
 198  * DWT_FUNCTION1 0xE0001038
 199  * DWT_COMP2     0xE0001040
 200  * DWT_MASK2     0xE0001044
 201  * DWT_FUNCTION2 0xE0001048
 202  * DWT_COMP3     0xE0001050
 203  * DWT_MASK3     0xE0001054
 204  * DWT_FUNCTION3 0xE0001058
 205  */
 206
 207 #define DATA_WATCH_NUM 4
 208
 209 enum watchfun { WATCHDISABLED = 0, WATCHREAD = 5, WATCHWRITE = 6, WATCHACCESS = 7 };
 210
 211 struct code_hw_watchpoint {
 212         stm32_addr_t addr;
 213         uint8_t mask;
 214         enum watchfun fun;
 215 };
 216
 217 struct code_hw_watchpoint data_watches[DATA_WATCH_NUM];
 218
 219 static void init_data_watchpoints(struct stlink *sl) {
 220         int i;
 221
 222         #ifdef DEBUG
 223         printf("init watchpoints\n");
 224         #endif
 225
 226         // set trcena in debug command to turn on dwt unit
 227         stlink_read_mem32(sl, 0xE000EDFC, 4);
 228         sl->q_buf[3] |= 1;
 229         stlink_write_mem32(sl, 0xE000EDFC, 4);
 230
 231         // make sure all watchpoints are cleared
 232         memset(sl->q_buf, 0, 4);
 233         for(int i = 0; i < DATA_WATCH_NUM; i++) {
 234                 data_watches[i].fun = WATCHDISABLED;
 235                 stlink_write_mem32(sl, 0xe0001028 + i * 16, 4);
 236         }
 237 }
 238
 239 static int add_data_watchpoint(struct stlink* sl, enum watchfun wf, stm32_addr_t addr, unsigned int len)
 240 {
 241         int i = 0;
 242         uint32_t mask, temp;
 243
 244         // computer mask
 245         // find a free watchpoint
 246         // configure
 247
 248         mask = -1;
 249         i = len;
 250         while(i) {
 251                 i >>= 1;
 252                 mask++;
 253         }
 254
 255         if((mask != -1) && (mask < 16)) {
 256                 for(i = 0; i < DATA_WATCH_NUM; i++) {
 257                         // is this an empty slot ?
 258                         if(data_watches[i].fun == WATCHDISABLED) {
 259                                 #ifdef DEBUG
 260                                 printf("insert watchpoint %d addr %x wf %u mask %u len %d\n", i, addr, wf, mask, len);
 261                                 #endif
 262
 263                                 data_watches[i].fun = wf;
 264                                 data_watches[i].addr = addr;
 265                                 data_watches[i].mask = mask;
 266
 267                                 // insert comparator address
 268                                 sl->q_buf[0] = (addr & 0xff);
 269                                 sl->q_buf[1] = ((addr >> 8) & 0xff);
 270                                 sl->q_buf[2] = ((addr >> 16) & 0xff);
 271                                 sl->q_buf[3] = ((addr >> 24)  & 0xff);
 272
 273                                 stlink_write_mem32(sl, 0xE0001020 + i * 16, 4);
 274
 275                                 // insert mask
 276                                 memset(sl->q_buf, 0, 4);
 277                                 sl->q_buf[0] = mask;
 278                                 stlink_write_mem32(sl, 0xE0001024 + i * 16, 4);
 279
 280                                 // insert function
 281                                 memset(sl->q_buf, 0, 4);
 282                                 sl->q_buf[0] = wf;
 283                                 stlink_write_mem32(sl, 0xE0001028 + i * 16, 4);
 284
 285                                 // just to make sure the matched bit is clear !
 286                                 stlink_read_mem32(sl,  0xE0001028 + i * 16, 4);
 287                                 return 0;
 288                         }
 289                 }
 290         }
 291
 292         #ifdef DEBUG
 293         printf("failure: add watchpoints addr %x wf %u len %u\n", addr, wf, len);
 294         #endif
 295         return -1;
 296 }
 297
 298 static int delete_data_watchpoint(struct stlink* sl, stm32_addr_t addr)
 299 {
 300         int i;
 301
 302         for(i = 0 ; i < DATA_WATCH_NUM; i++) {
 303                 if((data_watches[i].addr == addr) && (data_watches[i].fun != WATCHDISABLED)) {
 304                         #ifdef DEBUG
 305                         printf("delete watchpoint %d addr %x\n", i, addr);
 306                         #endif
 307
 308                         memset(sl->q_buf, 0, 4);
 309                         data_watches[i].fun = WATCHDISABLED;
 310                         stlink_write_mem32(sl, 0xe0001028 + i * 16, 4);
 311
 312                         return 0;
 313                 }
 314         }
 315
 316         #ifdef DEBUG
 317         printf("failure: delete watchpoint addr %x\n", addr);
 318         #endif
 319
 320         return -1;
 321 }
 322
 323 #define CODE_BREAK_NUM  6
 324 #define CODE_BREAK_LOW  0x01
 325 #define CODE_BREAK_HIGH 0x02
 326
 327 struct code_hw_breakpoint {
 328         stm32_addr_t addr;
 329         int          type;
 330 };
 331
 332 struct code_hw_breakpoint code_breaks[CODE_BREAK_NUM];
 333
 334 static void init_code_breakpoints(struct stlink* sl) {
 335         memset(sl->q_buf, 0, 4);
 336         sl->q_buf[0] = 0x03; // KEY | ENABLE
 337         stlink_write_mem32(sl, 0xe0002000, 4);
 338
 339         memset(sl->q_buf, 0, 4);
 340         for(int i = 0; i < CODE_BREAK_NUM; i++) {
 341                 code_breaks[i].type = 0;
 342                 stlink_write_mem32(sl, 0xe0002008 + i * 4, 4);
 343         }
 344 }
 345
 346 static int update_code_breakpoint(struct stlink* sl, stm32_addr_t addr, int set) {
 347         stm32_addr_t fpb_addr = addr & ~0x3;
 348         int type = addr & 0x2 ? CODE_BREAK_HIGH : CODE_BREAK_LOW;
 349
 350         if(addr & 1) {
 351                 fprintf(stderr, "update_code_breakpoint: unaligned address %08x\n", addr);
 352                 return -1;
 353         }
 354
 355         int id = -1;
 356         for(int i = 0; i < CODE_BREAK_NUM; i++) {
 357                 if(fpb_addr == code_breaks[i].addr ||
 358                         (set && code_breaks[i].type == 0)) {
 359                         id = i;
 360                         break;
 361                 }
 362         }
 363
 364         if(id == -1) {
 365                 if(set) return -1; // Free slot not found
 366                 else    return 0;  // Breakpoint is already removed
 367         }
 368
 369         struct code_hw_breakpoint* brk = &code_breaks[id];
 370
 371         brk->addr = fpb_addr;
 372
 373         if(set) brk->type |= type;
 374         else    brk->type &= ~type;
 375
 376         memset(sl->q_buf, 0, 4);
 377
 378         if(brk->type == 0) {
 379                 #ifdef DEBUG
 380                 printf("clearing hw break %d\n", id);
 381                 #endif
 382
 383                 stlink_write_mem32(sl, 0xe0002008 + id * 4, 4);
 384         } else {
 385                 sl->q_buf[0] = ( brk->addr        & 0xff) | 1;
 386                 sl->q_buf[1] = ((brk->addr >> 8)  & 0xff);
 387                 sl->q_buf[2] = ((brk->addr >> 16) & 0xff);
 388                 sl->q_buf[3] = ((brk->addr >> 24) & 0xff) | (brk->type << 6);
 389
 390                 #ifdef DEBUG
 391                 printf("setting hw break %d at %08x (%d)\n",
 392                         id, brk->addr, brk->type);
 393                 printf("reg %02x %02x %02x %02x\n",
 394                         sl->q_buf[3], sl->q_buf[2], sl->q_buf[1], sl->q_buf[0]);
 395                 #endif
 396
 397                 stlink_write_mem32(sl, 0xe0002008 + id * 4, 4);
 398         }
 399
 400         return 0;
 401 }
 402
 403
 404 struct flash_block {
 405         stm32_addr_t addr;
 406         unsigned     length;
 407         uint8_t*     data;
 408
 409         struct flash_block* next;
 410 };
 411
 412 static struct flash_block* flash_root;
 413
 414 static int flash_add_block(stm32_addr_t addr, unsigned length,
 415                            struct stlink* sl) {
 416         if(addr < FLASH_BASE || addr + length > FLASH_BASE + FLASH_SIZE) {
 417                 fprintf(stderr, "flash_add_block: incorrect bounds\n");
 418                 return -1;
 419         }
 420
 421         if(addr % FLASH_PAGE != 0 || length % FLASH_PAGE != 0) {
 422                 fprintf(stderr, "flash_add_block: unaligned block\n");
 423                 return -1;
 424         }
 425
 426         struct flash_block* new = malloc(sizeof(struct flash_block));
 427         new->next = flash_root;
 428
 429         new->addr   = addr;
 430         new->length = length;
 431         new->data   = calloc(length, 1);
 432
 433         flash_root = new;
 434
 435         return 0;
 436 }
 437
 438 static int flash_populate(stm32_addr_t addr, uint8_t* data, unsigned length) {
 439         int fit_blocks = 0, fit_length = 0;
 440
 441         for(struct flash_block* fb = flash_root; fb; fb = fb->next) {
 442                 /* Block: ------X------Y--------
 443                  * Data:            a-----b
 444                  *                a--b
 445                  *            a-----------b
 446                  * Block intersects with data, if:
 447                  *  a < Y && b > x
 448                  */
 449
 450                 unsigned X = fb->addr, Y = fb->addr + fb->length;
 451                 unsigned a = addr, b = addr + length;
 452                 if(a < Y && b > X) {
 453                         // from start of the block
 454                         unsigned start = (a > X ? a : X) - X;
 455                         unsigned end   = (b > Y ? Y : b) - X;
 456
 457                         memcpy(fb->data + start, data, end - start);
 458
 459                         fit_blocks++;
 460                         fit_length += end - start;
 461                 }
 462         }
 463
 464         if(fit_blocks == 0) {
 465                 fprintf(stderr, "Unfit data block %08x -> %04x\n", addr, length);
 466                 return -1;
 467         }
 468
 469         if(fit_length != length) {
 470                 fprintf(stderr, "warning: data block %08x -> %04x truncated to %04x\n",
 471                         addr, length, fit_length);
 472                 fprintf(stderr, "(this is not an error, just a GDB glitch)\n");
 473         }
 474
 475         return 0;
 476 }
 477
 478 static int flash_go(struct stlink* sl) {
 479         int error = -1;
 480
 481         // Some kinds of clock settings do not allow writing to flash.
 482         stlink_reset(sl);
 483
 484         for(struct flash_block* fb = flash_root; fb; fb = fb->next) {
 485                 #ifdef DEBUG
 486                 printf("flash_do: block %08x -> %04x\n", fb->addr, fb->length);
 487                 #endif
 488
 489                 unsigned length = fb->length;
 490                 for(stm32_addr_t page = fb->addr; page < fb->addr + fb->length; page += FLASH_PAGE) {
 491                         #ifdef DEBUG
 492                         printf("flash_do: page %08x\n", page);
 493                         #endif
 494
 495                         stlink_erase_flash_page(sl, page);
 496
 497                         if(stlink_write_flash(sl, page, fb->data + (page - fb->addr),
 498                                         length > FLASH_PAGE ? FLASH_PAGE : length) < 0)
 499                                 goto error;
 500                 }
 501
 502         }
 503
 504         stlink_reset(sl);
 505
 506         error = 0;
 507
 508 error:
 509         for(struct flash_block* fb = flash_root, *next; fb; fb = next) {
 510                 next = fb->next;
 511                 free(fb->data);
 512                 free(fb);
 513         }
 514
 515         flash_root = NULL;
 516
 517         return error;
 518 }
 519
 520 int serve(struct stlink* sl, int port) {
 521         int sock = socket(AF_INET, SOCK_STREAM, 0);
 522         if(sock < 0) {
 523                 perror("socket");
 524                 return 1;
 525         }
 526
 527         unsigned int val = 1;
 528         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 529
 530         struct sockaddr_in serv_addr = {0};
 531         serv_addr.sin_family = AF_INET;
 532         serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
 533         serv_addr.sin_port = htons(port);
 534
 535         if(bind(sock, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
 536                 perror("bind");
 537                 return 1;
 538         }
 539
 540         if(listen(sock, 5) < 0) {
 541                 perror("listen");
 542                 return 1;
 543         }
 544
 545         stlink_force_debug(sl);
 546         stlink_reset(sl);
 547         init_code_breakpoints(sl);
 548         init_data_watchpoints(sl);
 549
 550         printf("Listening at *:%d...\n", port);
 551
 552         int client = accept(sock, NULL, NULL);
 553         if(client < 0) {
 554                 perror("accept");
 555                 return 1;
 556         }
 557
 558         close(sock);
 559
 560         printf("GDB connected.\n");
 561
 562         /*
 563          * To allow resetting the chip from GDB it is required to
 564          * emulate attaching and detaching to target.
 565          */
 566         unsigned int attached = 1;
 567
 568         while(1) {
 569                 char* packet;
 570
 571                 int status = gdb_recv_packet(client, &packet);
 572                 if(status < 0) {
 573                         fprintf(stderr, "cannot recv: %d\n", status);
 574                         return 1;
 575                 }
 576
 577                 #ifdef DEBUG
 578                 printf("recv: %s\n", packet);
 579                 #endif
 580
 581                 char* reply = NULL;
 582
 583                 switch(packet[0]) {
 584                 case 'q': {
 585                         if(packet[1] == 'P' || packet[1] == 'C' || packet[1] == 'L') {
 586                                 reply = strdup("");
 587                                 break;
 588                         }
 589
 590                         char *separator = strstr(packet, ":"), *params = "";
 591                         if(separator == NULL) {
 592                                 separator = packet + strlen(packet);
 593                         } else {
 594                                 params = separator + 1;
 595                         }
 596
 597                         unsigned queryNameLength = (separator - &packet[1]);
 598                         char* queryName = calloc(queryNameLength + 1, 1);
 599                         strncpy(queryName, &packet[1], queryNameLength);
 600
 601                         #ifdef DEBUG
 602                         printf("query: %s;%s\n", queryName, params);
 603                         #endif
 604
 605                         if(!strcmp(queryName, "Supported")) {
 606                                 reply = strdup("PacketSize=3fff;qXfer:memory-map:read+");
 607                         } else if(!strcmp(queryName, "Xfer")) {
 608                                 char *type, *op, *annex, *s_addr, *s_length;
 609                                 char *tok = params;
 610
 611                                 type     = strsep(&tok, ":");
 612                                 op       = strsep(&tok, ":");
 613                                 annex    = strsep(&tok, ":");
 614                                 s_addr   = strsep(&tok, ",");
 615                                 s_length = tok;
 616
 617                                 unsigned addr = strtoul(s_addr, NULL, 16),
 618                                        length = strtoul(s_length, NULL, 16);
 619
 620                                 #ifdef DEBUG
 621                                 printf("Xfer: type:%s;op:%s;annex:%s;addr:%d;length:%d\n",
 622                                         type, op, annex, addr, length);
 623                                 #endif
 624
 625                                 const char* data = NULL;
 626
 627                                 if(!strcmp(type, "memory-map") && !strcmp(op, "read"))
 628                                         data = current_memory_map;
 629
 630                                 if(data) {
 631                                         unsigned data_length = strlen(data);
 632                                         if(addr + length > data_length)
 633                                                 length = data_length - addr;
 634
 635                                         if(length == 0) {
 636                                                 reply = strdup("l");
 637                                         } else {
 638                                                 reply = calloc(length + 2, 1);
 639                                                 reply[0] = 'm';
 640                                                 strncpy(&reply[1], data, length);
 641                                         }
 642                                 }
 643                         }
 644
 645                         if(reply == NULL)
 646                                 reply = strdup("");
 647
 648                         free(queryName);
 649
 650                         break;
 651                 }
 652
 653                 case 'v': {
 654                         char *params = NULL;
 655                         char *cmdName = strtok_r(packet, ":;", &params);
 656
 657                         cmdName++; // vCommand -> Command
 658
 659                         if(!strcmp(cmdName, "FlashErase")) {
 660                                 char *s_addr, *s_length;
 661                                 char *tok = params;
 662
 663                                 s_addr   = strsep(&tok, ",");
 664                                 s_length = tok;
 665
 666                                 unsigned addr = strtoul(s_addr, NULL, 16),
 667                                        length = strtoul(s_length, NULL, 16);
 668
 669                                 #ifdef DEBUG
 670                                 printf("FlashErase: addr:%08x,len:%04x\n",
 671                                         addr, length);
 672                                 #endif
 673
 674                                 if(flash_add_block(addr, length, sl) < 0) {
 675                                         reply = strdup("E00");
 676                                 } else {
 677                                         reply = strdup("OK");
 678                                 }
 679                         } else if(!strcmp(cmdName, "FlashWrite")) {
 680                                 char *s_addr, *data;
 681                                 char *tok = params;
 682
 683                                 s_addr = strsep(&tok, ":");
 684                                 data   = tok;
 685
 686                                 unsigned addr = strtoul(s_addr, NULL, 16);
 687                                 unsigned data_length = status - (data - packet);
 688
 689                                 // Length of decoded data cannot be more than
 690                                 // encoded, as escapes are removed.
 691                                 // Additional byte is reserved for alignment fix.
 692                                 uint8_t *decoded = calloc(data_length + 1, 1);
 693                                 unsigned dec_index = 0;
 694                                 for(int i = 0; i < data_length; i++) {
 695                                         if(data[i] == 0x7d) {
 696                                                 i++;
 697                                                 decoded[dec_index++] = data[i] ^ 0x20;
 698                                         } else {
 699                                                 decoded[dec_index++] = data[i];
 700                                         }
 701                                 }
 702
 703                                 // Fix alignment
 704                                 if(dec_index % 2 != 0)
 705                                         dec_index++;
 706
 707                                 #ifdef DEBUG
 708                                 printf("binary packet %d -> %d\n", data_length, dec_index);
 709                                 #endif
 710
 711                                 if(flash_populate(addr, decoded, dec_index) < 0) {
 712                                         reply = strdup("E00");
 713                                 } else {
 714                                         reply = strdup("OK");
 715                                 }
 716                         } else if(!strcmp(cmdName, "FlashDone")) {
 717                                 if(flash_go(sl) < 0) {
 718                                         reply = strdup("E00");
 719                                 } else {
 720                                         reply = strdup("OK");
 721                                 }
 722                         } else if(!strcmp(cmdName, "Kill")) {
 723                                 attached = 0;
 724
 725                                 reply = strdup("OK");
 726                         }
 727
 728                         if(reply == NULL)
 729                                 reply = strdup("");
 730
 731                         break;
 732                 }
 733
 734                 case 'c':
 735                         stlink_run(sl);
 736
 737                         while(1) {
 738                                 int status = gdb_check_for_interrupt(client);
 739                                 if(status < 0) {
 740                                         fprintf(stderr, "cannot check for int: %d\n", status);
 741                                         return 1;
 742                                 }
 743
 744                                 if(status == 1) {
 745                                         stlink_force_debug(sl);
 746                                         break;
 747                                 }
 748
 749                                 stlink_status(sl);
 750                                 if(sl->core_stat == STLINK_CORE_HALTED) {
 751                                         break;
 752                                 }
 753
 754                                 usleep(100000);
 755                         }
 756
 757                         reply = strdup("S05"); // TRAP
 758                         break;
 759
 760                 case 's':
 761                         stlink_step(sl);
 762
 763                         reply = strdup("S05"); // TRAP
 764                         break;
 765
 766                 case '?':
 767                         if(attached) {
 768                                 reply = strdup("S05"); // TRAP
 769                         } else {
 770                                 /* Stub shall reply OK if not attached. */
 771                                 reply = strdup("OK");
 772                         }
 773                         break;
 774
 775                 case 'g':
 776                         stlink_read_all_regs(sl);
 777
 778                         reply = calloc(8 * 16 + 1, 1);
 779                         for(int i = 0; i < 16; i++)
 780                                 sprintf(&reply[i * 8], "%08x", htonl(sl->reg.r[i]));
 781
 782                         break;
 783
 784                 case 'p': {
 785                         unsigned id = strtoul(&packet[1], NULL, 16), reg = 0xDEADDEAD;
 786
 787                         if(id < 16) {
 788                                 stlink_read_reg(sl, id);
 789                                 reg = htonl(sl->reg.r[id]);
 790                         } else if(id == 0x19) {
 791                                 stlink_read_reg(sl, 16);
 792                                 reg = htonl(sl->reg.xpsr);
 793                         } else {
 794                                 reply = strdup("E00");
 795                         }
 796
 797                         reply = calloc(8 + 1, 1);
 798                         sprintf(reply, "%08x", reg);
 799
 800                         break;
 801                 }
 802
 803                 case 'P': {
 804                         char* s_reg = &packet[1];
 805                         char* s_value = strstr(&packet[1], "=") + 1;
 806
 807                         unsigned reg   = strtoul(s_reg,   NULL, 16);
 808                         unsigned value = strtoul(s_value, NULL, 16);
 809
 810                         if(reg < 16) {
 811                                 stlink_write_reg(sl, ntohl(value), reg);
 812                         } else if(reg == 0x19) {
 813                                 stlink_write_reg(sl, ntohl(value), 16);
 814                         } else {
 815                                 reply = strdup("E00");
 816                         }
 817
 818                         if(!reply) {
 819                                 reply = strdup("OK");
 820                         }
 821
 822                         break;
 823                 }
 824
 825                 case 'G':
 826                         for(int i = 0; i < 16; i++) {
 827                                 char str[9] = {0};
 828                                 strncpy(str, &packet[1 + i * 8], 8);
 829                                 uint32_t reg = strtoul(str, NULL, 16);
 830                                 stlink_write_reg(sl, ntohl(reg), i);
 831                         }
 832
 833                         reply = strdup("OK");
 834                         break;
 835
 836                 case 'm': {
 837                         char* s_start = &packet[1];
 838                         char* s_count = strstr(&packet[1], ",") + 1;
 839
 840                         stm32_addr_t start = strtoul(s_start, NULL, 16);
 841                         unsigned     count = strtoul(s_count, NULL, 16);
 842
 843                         unsigned adj_start = start % 4;
 844
 845                         stlink_read_mem32(sl, start - adj_start, (count % 4 == 0) ?
 846                                                 count : count + 4 - (count % 4));
 847
 848                         reply = calloc(count * 2 + 1, 1);
 849                         for(int i = 0; i < count; i++) {
 850                                 reply[i * 2 + 0] = hex[sl->q_buf[i + adj_start] >> 4];
 851                                 reply[i * 2 + 1] = hex[sl->q_buf[i + adj_start] & 0xf];
 852                         }
 853
 854                         break;
 855                 }
 856
 857                 case 'M': {
 858                         char* s_start = &packet[1];
 859                         char* s_count = strstr(&packet[1], ",") + 1;
 860                         char* hexdata = strstr(packet, ":") + 1;
 861
 862                         stm32_addr_t start = strtoul(s_start, NULL, 16);
 863                         unsigned     count = strtoul(s_count, NULL, 16);
 864
 865                         for(int i = 0; i < count; i ++) {
 866                                 char hex[3] = { hexdata[i*2], hexdata[i*2+1], 0 };
 867                                 uint8_t byte = strtoul(hex, NULL, 16);
 868                                 sl->q_buf[i] = byte;
 869                         }
 870
 871                         if((count % 4) == 0 && (start % 4) == 0) {
 872                                 stlink_write_mem32(sl, start, count);
 873                         } else {
 874                                 stlink_write_mem8(sl, start, count);
 875                         }
 876
 877                         reply = strdup("OK");
 878
 879                         break;
 880                 }
 881
 882                 case 'Z': {
 883                         char *endptr;
 884                         stm32_addr_t addr = strtoul(&packet[3], &endptr, 16);
 885                         stm32_addr_t len  = strtoul(&endptr[1], NULL, 16);
 886
 887                         switch (packet[1]) {
 888                                 case '1':
 889                                 if(update_code_breakpoint(sl, addr, 1) < 0) {
 890                                         reply = strdup("E00");
 891                                 } else {
 892                                         reply = strdup("OK");
 893                                 }
 894                                 break;
 895
 896                                 case '2':   // insert write watchpoint
 897                                 case '3':   // insert read  watchpoint
 898                                 case '4':   // insert access watchpoint
 899                                 {
 900                                         enum watchfun wf;
 901                                         if(packet[1] == '2') {
 902                                                 wf = WATCHWRITE;
 903                                         } else if(packet[1] == '3') {
 904                                                 wf = WATCHREAD;
 905                                         } else {
 906                                                 wf = WATCHACCESS;
 907                                                 if(add_data_watchpoint(sl, wf, addr, len) < 0) {
 908                                                         reply = strdup("E00");
 909                                                 } else {
 910                                                         reply = strdup("OK");
 911                                                         break;
 912                                                 }
 913                                         }
 914                                 }
 915
 916                                 default:
 917                                 reply = strdup("");
 918                         }
 919                         break;
 920                 }
 921                 case 'z': {
 922                         char *endptr;
 923                         stm32_addr_t addr = strtoul(&packet[3], &endptr, 16);
 924                         stm32_addr_t len  = strtoul(&endptr[1], NULL, 16);
 925
 926                         switch (packet[1]) {
 927                                 case '1': // remove breakpoint
 928                                 update_code_breakpoint(sl, addr, 0);
 929                                 reply = strdup("OK");
 930                                 break;
 931
 932                                 case '2' : // remove write watchpoint
 933                                 case '3' : // remove read watchpoint
 934                                 case '4' : // remove access watchpoint
 935                                 if(delete_data_watchpoint(sl, addr) < 0) {
 936                                         reply = strdup("E00");
 937                                 } else {
 938                                         reply = strdup("OK");
 939                                         break;
 940                                 }
 941
 942                                 default:
 943                                 reply = strdup("");
 944                         }
 945                         break;
 946                 }
 947
 948                 case '!': {
 949                         /*
 950                          * Enter extended mode which allows restarting.
 951                          * We do support that always.
 952                          */
 953
 954                         reply = strdup("OK");
 955
 956                         break;
 957                 }
 958
 959                 case 'R': {
 960                         /* Reset the core. */
 961
 962                         stlink_reset(sl);
 963                         init_code_breakpoints(sl);
 964                         init_data_watchpoints(sl);
 965
 966                         attached = 1;
 967
 968                         reply = strdup("OK");
 969
 970                         break;
 971                 }
 972
 973                 default:
 974                         reply = strdup("");
 975                 }
 976
 977                 if(reply) {
 978                         #ifdef DEBUG
 979                         printf("send: %s\n", reply);
 980                         #endif
 981
 982                         int result = gdb_send_packet(client, reply);
 983                         if(result != 0) {
 984                                 fprintf(stderr, "cannot send: %d\n", result);
 985                                 return 1;
 986                         }
 987
 988                         free(reply);
 989                 }
 990
 991                 free(packet);
 992         }
 993
 994         return 0;
 995 }