Fix stm32l readmem32.
[fw/stlink] / gdbserver / 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
18 #include <stlink-common.h>
19
20 #include "gdb-remote.h"
21
22 #define FLASH_BASE 0x08000000
23 #define FLASH_PAGE (sl->flash_pgsz)
24 #define FLASH_PAGE_MASK (~((1 << 10) - 1))
25 #define FLASH_SIZE (FLASH_PAGE * 128)
26
27 static const char hex[] = "0123456789abcdef";
28
29 static const char* current_memory_map = NULL;
30
31 struct chip_params {
32         uint32_t chip_id;
33         char* description;
34         uint32_t max_flash_size, flash_pagesize;
35         uint32_t sram_size;
36         uint32_t bootrom_base, bootrom_size;
37 } const devices[] = {
38         { 0x412, "Low-density device",
39           0x8000,   0x400, 0x2800,  0x1ffff000, 0x800  }, // table 1, pm0063
40         { 0x410, "Medium-density device",
41           0x20000,  0x400, 0x5000,  0x1ffff000, 0x800  }, // table 2, pm0063
42         { 0x414, "High-density device",
43           0x80000,  0x800, 0x10000, 0x1ffff000, 0x800  },  // table 3 pm0063 
44           // This ignores the EEPROM! (and uses the page erase size,
45           // not the sector write protection...)
46         { 0x416, "EnergyLite device",
47           0x2000, 0x100, 0x4000, 0x1ff00000, 0x1000 },
48         { 0x418, "Connectivity line device",
49           0x40000,  0x800, 0x10000, 0x1fffb000, 0x4800 },
50         { 0x420, "Medium-density value line device",
51           0x20000,  0x400, 0x2000,  0x1ffff000, 0x800  },
52         { 0x428, "High-density value line device",
53           0x80000,  0x800, 0x8000,  0x1ffff000, 0x800  },
54         { 0x430, "XL-density device",   // pm0068
55           0x100000, 0x800, 0x18000, 0x1fffe000, 0x1800 },
56         { 0 }
57 };
58
59 int serve(stlink_t *sl, int port);
60 char* make_memory_map(const struct chip_params *params, uint32_t flash_size);
61
62 int main(int argc, char** argv) {
63         if(argc != 3) {
64                 fprintf(stderr, "Usage: %s <port> /dev/sgX\n", argv[0]);
65                 return 1;
66         }
67
68         // FIXME - hardcoded to usb....
69         stlink_t *sl =stlink_open_usb(argv[2], 10);
70         if (sl == NULL)
71                 return 1;
72
73         if(stlink_current_mode(sl) != STLINK_DEV_DEBUG_MODE)
74                 stlink_enter_swd_mode(sl);
75
76         uint32_t chip_id = stlink_chip_id(sl);
77         printf("Chip ID is %08x.\n", chip_id);
78
79         const struct chip_params* params = NULL;
80
81         for(int i = 0; i < sizeof(devices) / sizeof(devices[0]); i++) {
82                 if(devices[i].chip_id == (chip_id & 0xFFF)) {
83                         params = &devices[i];
84                         break;
85                 }
86         }
87
88         if(params == NULL) {
89                 fprintf(stderr, "Cannot recognize the connected device!\n");
90                 return 0;
91         }
92
93         printf("Device connected: %s\n", params->description);
94         printf("Device parameters: SRAM: 0x%x bytes, Flash: up to 0x%x bytes in pages of 0x%x bytes\n",
95                 params->sram_size, params->max_flash_size, params->flash_pagesize);
96
97         FLASH_PAGE = params->flash_pagesize;
98
99         uint32_t flash_size;
100
101         stlink_read_mem32(sl, 0x1FFFF7E0, 4);  // FIXME - that's never going to work!
102         flash_size = sl->q_buf[0] | (sl->q_buf[1] << 8);
103
104         printf("Flash size is %d KiB.\n", flash_size);
105         // memory map is in 1k blocks.
106         current_memory_map = make_memory_map(params, flash_size * 0x400);
107
108         int port = atoi(argv[1]);
109
110         while(serve(sl, port) == 0);
111
112         stlink_close(sl);
113
114         return 0;
115 }
116
117 static const char* const memory_map_template =
118   "<?xml version=\"1.0\"?>"
119   "<!DOCTYPE memory-map PUBLIC \"+//IDN gnu.org//DTD GDB Memory Map V1.0//EN\""
120   "     \"http://sourceware.org/gdb/gdb-memory-map.dtd\">"
121   "<memory-map>"
122   "  <memory type=\"rom\" start=\"0x00000000\" length=\"0x%x\"/>"       // code = sram, bootrom or flash; flash is bigger
123   "  <memory type=\"ram\" start=\"0x20000000\" length=\"0x%x\"/>"       // sram 8k
124   "  <memory type=\"flash\" start=\"0x08000000\" length=\"0x%x\">"
125   "    <property name=\"blocksize\">0x%x</property>"
126   "  </memory>"
127   "  <memory type=\"ram\" start=\"0x40000000\" length=\"0x1fffffff\"/>" // peripheral regs
128   "  <memory type=\"ram\" start=\"0xe0000000\" length=\"0x1fffffff\"/>" // cortex regs
129   "  <memory type=\"rom\" start=\"0x%08x\" length=\"0x%x\"/>"           // bootrom
130   "  <memory type=\"rom\" start=\"0x1ffff800\" length=\"0x8\"/>"        // option byte area
131   "</memory-map>";
132
133 char* make_memory_map(const struct chip_params *params, uint32_t flash_size) {
134         /* This will be freed in serve() */
135         char* map = malloc(4096);
136         map[0] = '\0';
137
138         snprintf(map, 4096, memory_map_template,
139                         flash_size,
140                         params->sram_size,
141                         flash_size, params->flash_pagesize,
142                         params->bootrom_base, params->bootrom_size);
143
144         return map;
145 }
146
147
148 /* 
149  * DWT_COMP0     0xE0001020
150  * DWT_MASK0     0xE0001024
151  * DWT_FUNCTION0 0xE0001028
152  * DWT_COMP1     0xE0001030
153  * DWT_MASK1     0xE0001034
154  * DWT_FUNCTION1 0xE0001038
155  * DWT_COMP2     0xE0001040
156  * DWT_MASK2     0xE0001044
157  * DWT_FUNCTION2 0xE0001048
158  * DWT_COMP3     0xE0001050
159  * DWT_MASK3     0xE0001054
160  * DWT_FUNCTION3 0xE0001058
161  */
162
163 #define DATA_WATCH_NUM 4
164
165 enum watchfun { WATCHDISABLED = 0, WATCHREAD = 5, WATCHWRITE = 6, WATCHACCESS = 7 };
166
167 struct code_hw_watchpoint {
168         stm32_addr_t addr;
169         uint8_t mask;
170         enum watchfun fun;
171 };
172
173 struct code_hw_watchpoint data_watches[DATA_WATCH_NUM];
174
175 static void init_data_watchpoints(stlink_t *sl) {
176         #ifdef DEBUG
177         printf("init watchpoints\n");
178         #endif
179
180         // set trcena in debug command to turn on dwt unit
181         stlink_read_mem32(sl, 0xE000EDFC, 4);
182         sl->q_buf[3] |= 1;
183         stlink_write_mem32(sl, 0xE000EDFC, 4);
184
185         // make sure all watchpoints are cleared
186         memset(sl->q_buf, 0, 4);
187         for(int i = 0; i < DATA_WATCH_NUM; i++) {
188                 data_watches[i].fun = WATCHDISABLED;
189                 stlink_write_mem32(sl, 0xe0001028 + i * 16, 4);
190         }
191 }
192
193 static int add_data_watchpoint(stlink_t *sl, enum watchfun wf, stm32_addr_t addr, unsigned int len)
194 {
195         int i = 0;
196         uint32_t mask;
197
198         // computer mask
199         // find a free watchpoint
200         // configure
201
202         mask = -1;
203         i = len;
204         while(i) {
205                 i >>= 1;
206                 mask++;
207         }
208
209         if((mask != -1) && (mask < 16)) {
210                 for(i = 0; i < DATA_WATCH_NUM; i++) {
211                         // is this an empty slot ?
212                         if(data_watches[i].fun == WATCHDISABLED) {
213                                 #ifdef DEBUG
214                                 printf("insert watchpoint %d addr %x wf %u mask %u len %d\n", i, addr, wf, mask, len);
215                                 #endif
216
217                                 data_watches[i].fun = wf;
218                                 data_watches[i].addr = addr;
219                                 data_watches[i].mask = mask;
220
221                                 // insert comparator address
222                                 sl->q_buf[0] = (addr & 0xff);
223                                 sl->q_buf[1] = ((addr >> 8) & 0xff);
224                                 sl->q_buf[2] = ((addr >> 16) & 0xff);
225                                 sl->q_buf[3] = ((addr >> 24)  & 0xff);
226
227                                 stlink_write_mem32(sl, 0xE0001020 + i * 16, 4);
228
229                                 // insert mask
230                                 memset(sl->q_buf, 0, 4);
231                                 sl->q_buf[0] = mask;
232                                 stlink_write_mem32(sl, 0xE0001024 + i * 16, 4);
233
234                                 // insert function
235                                 memset(sl->q_buf, 0, 4);
236                                 sl->q_buf[0] = wf;
237                                 stlink_write_mem32(sl, 0xE0001028 + i * 16, 4);
238
239                                 // just to make sure the matched bit is clear !
240                                 stlink_read_mem32(sl,  0xE0001028 + i * 16, 4);
241                                 return 0;
242                         }
243                 }
244         }
245
246         #ifdef DEBUG
247         printf("failure: add watchpoints addr %x wf %u len %u\n", addr, wf, len);
248         #endif
249         return -1;
250 }
251
252 static int delete_data_watchpoint(stlink_t *sl, stm32_addr_t addr)
253 {
254         int i;
255
256         for(i = 0 ; i < DATA_WATCH_NUM; i++) {
257                 if((data_watches[i].addr == addr) && (data_watches[i].fun != WATCHDISABLED)) {
258                         #ifdef DEBUG
259                         printf("delete watchpoint %d addr %x\n", i, addr);
260                         #endif
261
262                         memset(sl->q_buf, 0, 4);
263                         data_watches[i].fun = WATCHDISABLED;
264                         stlink_write_mem32(sl, 0xe0001028 + i * 16, 4);
265
266                         return 0;
267                 }
268         }
269
270         #ifdef DEBUG
271         printf("failure: delete watchpoint addr %x\n", addr);
272         #endif
273
274         return -1;
275 }
276
277 #define CODE_BREAK_NUM  6
278 #define CODE_BREAK_LOW  0x01
279 #define CODE_BREAK_HIGH 0x02
280
281 struct code_hw_breakpoint {
282         stm32_addr_t addr;
283         int          type;
284 };
285
286 struct code_hw_breakpoint code_breaks[CODE_BREAK_NUM];
287
288 static void init_code_breakpoints(stlink_t *sl) {
289         memset(sl->q_buf, 0, 4);
290         sl->q_buf[0] = 0x03; // KEY | ENABLE
291         stlink_write_mem32(sl, 0xe0002000, 4);
292
293         memset(sl->q_buf, 0, 4);
294         for(int i = 0; i < CODE_BREAK_NUM; i++) {
295                 code_breaks[i].type = 0;
296                 stlink_write_mem32(sl, 0xe0002008 + i * 4, 4);
297         }
298 }
299
300 static int update_code_breakpoint(stlink_t *sl, stm32_addr_t addr, int set) {
301         stm32_addr_t fpb_addr = addr & ~0x3;
302         int type = addr & 0x2 ? CODE_BREAK_HIGH : CODE_BREAK_LOW;
303
304         if(addr & 1) {
305                 fprintf(stderr, "update_code_breakpoint: unaligned address %08x\n", addr);
306                 return -1;
307         }
308
309         int id = -1;
310         for(int i = 0; i < CODE_BREAK_NUM; i++) {
311                 if(fpb_addr == code_breaks[i].addr ||
312                         (set && code_breaks[i].type == 0)) {
313                         id = i;
314                         break;
315                 }
316         }
317
318         if(id == -1) {
319                 if(set) return -1; // Free slot not found
320                 else    return 0;  // Breakpoint is already removed
321         }
322
323         struct code_hw_breakpoint* brk = &code_breaks[id];
324
325         brk->addr = fpb_addr;
326
327         if(set) brk->type |= type;
328         else    brk->type &= ~type;
329
330         memset(sl->q_buf, 0, 4);
331
332         if(brk->type == 0) {
333                 #ifdef DEBUG
334                 printf("clearing hw break %d\n", id);
335                 #endif
336
337                 stlink_write_mem32(sl, 0xe0002008 + id * 4, 4);
338         } else {
339                 sl->q_buf[0] = ( brk->addr        & 0xff) | 1;
340                 sl->q_buf[1] = ((brk->addr >> 8)  & 0xff);
341                 sl->q_buf[2] = ((brk->addr >> 16) & 0xff);
342                 sl->q_buf[3] = ((brk->addr >> 24) & 0xff) | (brk->type << 6);
343
344                 #ifdef DEBUG
345                 printf("setting hw break %d at %08x (%d)\n",
346                         id, brk->addr, brk->type);
347                 printf("reg %02x %02x %02x %02x\n",
348                         sl->q_buf[3], sl->q_buf[2], sl->q_buf[1], sl->q_buf[0]);
349                 #endif
350
351                 stlink_write_mem32(sl, 0xe0002008 + id * 4, 4);
352         }
353
354         return 0;
355 }
356
357
358 struct flash_block {
359         stm32_addr_t addr;
360         unsigned     length;
361         uint8_t*     data;
362
363         struct flash_block* next;
364 };
365
366 static struct flash_block* flash_root;
367
368 static int flash_add_block(stm32_addr_t addr, unsigned length, 
369                            stlink_t *sl) {
370         if(addr < FLASH_BASE || addr + length > FLASH_BASE + FLASH_SIZE) {
371                 fprintf(stderr, "flash_add_block: incorrect bounds\n");
372                 return -1;
373         }
374
375         if(addr % FLASH_PAGE != 0 || length % FLASH_PAGE != 0) {
376                 fprintf(stderr, "flash_add_block: unaligned block\n");
377                 return -1;
378         }
379
380         struct flash_block* new = malloc(sizeof(struct flash_block));
381         new->next = flash_root;
382
383         new->addr   = addr;
384         new->length = length;
385         new->data   = calloc(length, 1);
386
387         flash_root = new;
388
389         return 0;
390 }
391
392 static int flash_populate(stm32_addr_t addr, uint8_t* data, unsigned length) {
393         int fit_blocks = 0, fit_length = 0;
394
395         for(struct flash_block* fb = flash_root; fb; fb = fb->next) {
396                 /* Block: ------X------Y--------
397                  * Data:            a-----b
398                  *                a--b
399                  *            a-----------b
400                  * Block intersects with data, if:
401                  *  a < Y && b > x
402                  */
403
404                 unsigned X = fb->addr, Y = fb->addr + fb->length;
405                 unsigned a = addr, b = addr + length;
406                 if(a < Y && b > X) {
407                         // from start of the block
408                         unsigned start = (a > X ? a : X) - X;
409                         unsigned end   = (b > Y ? Y : b) - X;
410
411                         memcpy(fb->data + start, data, end - start);
412
413                         fit_blocks++;
414                         fit_length += end - start;
415                 }
416         }
417
418         if(fit_blocks == 0) {
419                 fprintf(stderr, "Unfit data block %08x -> %04x\n", addr, length);
420                 return -1;
421         }
422
423         if(fit_length != length) {
424                 fprintf(stderr, "warning: data block %08x -> %04x truncated to %04x\n",
425                         addr, length, fit_length);
426                 fprintf(stderr, "(this is not an error, just a GDB glitch)\n");
427         }
428
429         return 0;
430 }
431
432 static int flash_go(stlink_t *sl) {
433         int error = -1;
434
435         // Some kinds of clock settings do not allow writing to flash.
436         stlink_reset(sl);
437
438         for(struct flash_block* fb = flash_root; fb; fb = fb->next) {
439                 #ifdef DEBUG
440                 printf("flash_do: block %08x -> %04x\n", fb->addr, fb->length);
441                 #endif
442
443                 unsigned length = fb->length;
444                 for(stm32_addr_t page = fb->addr; page < fb->addr + fb->length; page += FLASH_PAGE) {
445                         #ifdef DEBUG
446                         printf("flash_do: page %08x\n", page);
447                         #endif
448
449                         stlink_erase_flash_page(sl, page);
450
451                         if(stlink_write_flash(sl, page, fb->data + (page - fb->addr),
452                                         length > FLASH_PAGE ? FLASH_PAGE : length) < 0)
453                                 goto error;
454                 }
455
456         }
457
458         stlink_reset(sl);
459
460         error = 0;
461
462 error:
463         for(struct flash_block* fb = flash_root, *next; fb; fb = next) {
464                 next = fb->next;
465                 free(fb->data);
466                 free(fb);
467         }
468
469         flash_root = NULL;
470
471         return error;
472 }
473
474 int serve(stlink_t *sl, int port) {
475         int sock = socket(AF_INET, SOCK_STREAM, 0);
476         if(sock < 0) {
477                 perror("socket");
478                 return 1;
479         }
480
481         unsigned int val = 1;
482         setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
483
484         struct sockaddr_in serv_addr = {0};
485         serv_addr.sin_family = AF_INET;
486         serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
487         serv_addr.sin_port = htons(port);
488
489         if(bind(sock, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) {
490                 perror("bind");
491                 return 1;
492         }
493
494         if(listen(sock, 5) < 0) {
495                 perror("listen");
496                 return 1;
497         }
498
499         stlink_force_debug(sl);
500         stlink_reset(sl);
501         init_code_breakpoints(sl);
502         init_data_watchpoints(sl);
503
504         printf("Listening at *:%d...\n", port);
505
506         int client = accept(sock, NULL, NULL);
507         if(client < 0) {
508                 perror("accept");
509                 return 1;
510         }
511
512         close(sock);
513
514         printf("GDB connected.\n");
515
516         /*
517          * To allow resetting the chip from GDB it is required to
518          * emulate attaching and detaching to target.
519          */
520         unsigned int attached = 1;
521
522         while(1) {
523                 char* packet;
524
525                 int status = gdb_recv_packet(client, &packet);
526                 if(status < 0) {
527                         fprintf(stderr, "cannot recv: %d\n", status);
528                         return 1;
529                 }
530
531                 #ifdef DEBUG
532                 printf("recv: %s\n", packet);
533                 #endif
534
535                 char* reply = NULL;
536                 reg regp;
537
538                 switch(packet[0]) {
539                 case 'q': {
540                         if(packet[1] == 'P' || packet[1] == 'C' || packet[1] == 'L') {
541                                 reply = strdup("");
542                                 break;
543                         }
544
545                         char *separator = strstr(packet, ":"), *params = "";
546                         if(separator == NULL) {
547                                 separator = packet + strlen(packet);
548                         } else {
549                                 params = separator + 1;
550                         }
551
552                         unsigned queryNameLength = (separator - &packet[1]);
553                         char* queryName = calloc(queryNameLength + 1, 1);
554                         strncpy(queryName, &packet[1], queryNameLength);
555
556                         #ifdef DEBUG
557                         printf("query: %s;%s\n", queryName, params);
558                         #endif
559
560                         if(!strcmp(queryName, "Supported")) {
561                                 reply = strdup("PacketSize=3fff;qXfer:memory-map:read+");
562                         } else if(!strcmp(queryName, "Xfer")) {
563                                 char *type, *op, *annex, *s_addr, *s_length;
564                                 char *tok = params;
565
566                                 type     = strsep(&tok, ":");
567                                 op       = strsep(&tok, ":");
568                                 annex    = strsep(&tok, ":");
569                                 s_addr   = strsep(&tok, ",");
570                                 s_length = tok;
571
572                                 unsigned addr = strtoul(s_addr, NULL, 16),
573                                        length = strtoul(s_length, NULL, 16);
574
575                                 #ifdef DEBUG
576                                 printf("Xfer: type:%s;op:%s;annex:%s;addr:%d;length:%d\n",
577                                         type, op, annex, addr, length);
578                                 #endif
579
580                                 const char* data = NULL;
581
582                                 if(!strcmp(type, "memory-map") && !strcmp(op, "read"))
583                                         data = current_memory_map;
584
585                                 if(data) {
586                                         unsigned data_length = strlen(data);
587                                         if(addr + length > data_length)
588                                                 length = data_length - addr;
589
590                                         if(length == 0) {
591                                                 reply = strdup("l");
592                                         } else {
593                                                 reply = calloc(length + 2, 1);
594                                                 reply[0] = 'm';
595                                                 strncpy(&reply[1], data, length);
596                                         }
597                                 }
598                         }
599
600                         if(reply == NULL)
601                                 reply = strdup("");
602
603                         free(queryName);
604
605                         break;
606                 }
607
608                 case 'v': {
609                         char *params = NULL;
610                         char *cmdName = strtok_r(packet, ":;", &params);
611
612                         cmdName++; // vCommand -> Command
613
614                         if(!strcmp(cmdName, "FlashErase")) {
615                                 char *s_addr, *s_length;
616                                 char *tok = params;
617
618                                 s_addr   = strsep(&tok, ",");
619                                 s_length = tok;
620
621                                 unsigned addr = strtoul(s_addr, NULL, 16),
622                                        length = strtoul(s_length, NULL, 16);
623
624                                 #ifdef DEBUG
625                                 printf("FlashErase: addr:%08x,len:%04x\n",
626                                         addr, length);
627                                 #endif
628
629                                 if(flash_add_block(addr, length, sl) < 0) {
630                                         reply = strdup("E00");
631                                 } else {
632                                         reply = strdup("OK");
633                                 }
634                         } else if(!strcmp(cmdName, "FlashWrite")) {
635                                 char *s_addr, *data;
636                                 char *tok = params;
637
638                                 s_addr = strsep(&tok, ":");
639                                 data   = tok;
640
641                                 unsigned addr = strtoul(s_addr, NULL, 16);
642                                 unsigned data_length = status - (data - packet);
643
644                                 // Length of decoded data cannot be more than
645                                 // encoded, as escapes are removed.
646                                 // Additional byte is reserved for alignment fix.
647                                 uint8_t *decoded = calloc(data_length + 1, 1);
648                                 unsigned dec_index = 0;
649                                 for(int i = 0; i < data_length; i++) {
650                                         if(data[i] == 0x7d) {
651                                                 i++;
652                                                 decoded[dec_index++] = data[i] ^ 0x20;
653                                         } else {
654                                                 decoded[dec_index++] = data[i];
655                                         }
656                                 }
657
658                                 // Fix alignment
659                                 if(dec_index % 2 != 0)
660                                         dec_index++;
661
662                                 #ifdef DEBUG
663                                 printf("binary packet %d -> %d\n", data_length, dec_index);
664                                 #endif
665
666                                 if(flash_populate(addr, decoded, dec_index) < 0) {
667                                         reply = strdup("E00");
668                                 } else {
669                                         reply = strdup("OK");
670                                 }
671                         } else if(!strcmp(cmdName, "FlashDone")) {
672                                 if(flash_go(sl) < 0) {
673                                         reply = strdup("E00");
674                                 } else {
675                                         reply = strdup("OK");
676                                 }
677                         } else if(!strcmp(cmdName, "Kill")) {
678                                 attached = 0;
679
680                                 reply = strdup("OK");
681                         }
682
683                         if(reply == NULL)
684                                 reply = strdup("");
685
686                         break;
687                 }
688
689                 case 'c':
690                         stlink_run(sl);
691
692                         while(1) {
693                                 int status = gdb_check_for_interrupt(client);
694                                 if(status < 0) {
695                                         fprintf(stderr, "cannot check for int: %d\n", status);
696                                         return 1;
697                                 }
698
699                                 if(status == 1) {
700                                         stlink_force_debug(sl);
701                                         break;
702                                 }
703
704                                 stlink_status(sl);
705                                 if(sl->core_stat == STLINK_CORE_HALTED) {
706                                         break;
707                                 }
708
709                                 usleep(100000);
710                         }
711
712                         reply = strdup("S05"); // TRAP
713                         break;
714
715                 case 's':
716                         stlink_step(sl);
717
718                         reply = strdup("S05"); // TRAP
719                         break;
720
721                 case '?':
722                         if(attached) {
723                                 reply = strdup("S05"); // TRAP
724                         } else {
725                                 /* Stub shall reply OK if not attached. */
726                                 reply = strdup("OK");
727                         }
728                         break;
729
730                 case 'g':
731                         stlink_read_all_regs(sl, &regp);
732
733                         reply = calloc(8 * 16 + 1, 1);
734                         for(int i = 0; i < 16; i++)
735                                 sprintf(&reply[i * 8], "%08x", htonl(regp.r[i]));
736
737                         break;
738
739                 case 'p': {
740                         unsigned id = strtoul(&packet[1], NULL, 16);
741                         unsigned myreg = 0xDEADDEAD;
742
743                         if(id < 16) {
744                                 stlink_read_reg(sl, id, &regp);
745                                 myreg = htonl(regp.r[id]);
746                         } else if(id == 0x19) {
747                                 stlink_read_reg(sl, 16, &regp);
748                                 myreg = htonl(regp.xpsr);
749                         } else {
750                                 reply = strdup("E00");
751                         }
752
753                         reply = calloc(8 + 1, 1);
754                         sprintf(reply, "%08x", myreg);
755
756                         break;
757                 }
758
759                 case 'P': {
760                         char* s_reg = &packet[1];
761                         char* s_value = strstr(&packet[1], "=") + 1;
762
763                         unsigned reg   = strtoul(s_reg,   NULL, 16);
764                         unsigned value = strtoul(s_value, NULL, 16);
765
766                         if(reg < 16) {
767                                 stlink_write_reg(sl, ntohl(value), reg);
768                         } else if(reg == 0x19) {
769                                 stlink_write_reg(sl, ntohl(value), 16);
770                         } else {
771                                 reply = strdup("E00");
772                         }
773
774                         if(!reply) {
775                                 reply = strdup("OK");
776                         }
777
778                         break;
779                 }
780
781                 case 'G':
782                         for(int i = 0; i < 16; i++) {
783                                 char str[9] = {0};
784                                 strncpy(str, &packet[1 + i * 8], 8);
785                                 uint32_t reg = strtoul(str, NULL, 16);
786                                 stlink_write_reg(sl, ntohl(reg), i);
787                         }
788
789                         reply = strdup("OK");
790                         break;
791
792                 case 'm': {
793                         char* s_start = &packet[1];
794                         char* s_count = strstr(&packet[1], ",") + 1;
795
796                         stm32_addr_t start = strtoul(s_start, NULL, 16);
797                         unsigned     count = strtoul(s_count, NULL, 16);
798
799                         unsigned adj_start = start % 4;
800
801                         stlink_read_mem32(sl, start - adj_start, (count % 4 == 0) ?
802                                                 count : count + 4 - (count % 4));
803
804                         reply = calloc(count * 2 + 1, 1);
805                         for(int i = 0; i < count; i++) {
806                                 reply[i * 2 + 0] = hex[sl->q_buf[i + adj_start] >> 4];
807                                 reply[i * 2 + 1] = hex[sl->q_buf[i + adj_start] & 0xf];
808                         }
809
810                         break;
811                 }
812
813                 case 'M': {
814                         char* s_start = &packet[1];
815                         char* s_count = strstr(&packet[1], ",") + 1;
816                         char* hexdata = strstr(packet, ":") + 1;
817
818                         stm32_addr_t start = strtoul(s_start, NULL, 16);
819                         unsigned     count = strtoul(s_count, NULL, 16);
820
821                         for(int i = 0; i < count; i ++) {
822                                 char hex[3] = { hexdata[i*2], hexdata[i*2+1], 0 };
823                                 uint8_t byte = strtoul(hex, NULL, 16);
824                                 sl->q_buf[i] = byte;
825                         }
826
827                         if((count % 4) == 0 && (start % 4) == 0) {
828                                 stlink_write_mem32(sl, start, count);
829                         } else {
830                                 stlink_write_mem8(sl, start, count);
831                         }
832
833                         reply = strdup("OK");
834
835                         break;
836                 }
837
838                 case 'Z': {
839                         char *endptr;
840                         stm32_addr_t addr = strtoul(&packet[3], &endptr, 16);
841                         stm32_addr_t len  = strtoul(&endptr[1], NULL, 16);
842
843                         switch (packet[1]) {
844                                 case '1':
845                                 if(update_code_breakpoint(sl, addr, 1) < 0) {
846                                         reply = strdup("E00");
847                                 } else {
848                                         reply = strdup("OK");
849                                 }
850                                 break;
851
852                                 case '2':   // insert write watchpoint
853                                 case '3':   // insert read  watchpoint
854                                 case '4':   // insert access watchpoint
855                                 {
856                                         enum watchfun wf;
857                                         if(packet[1] == '2') {
858                                                 wf = WATCHWRITE;
859                                         } else if(packet[1] == '3') {
860                                                 wf = WATCHREAD;
861                                         } else {
862                                                 wf = WATCHACCESS;
863                                                 if(add_data_watchpoint(sl, wf, addr, len) < 0) {
864                                                         reply = strdup("E00");
865                                                 } else {
866                                                         reply = strdup("OK");
867                                                         break;
868                                                 }
869                                         }
870                                 }
871
872                                 default:
873                                 reply = strdup("");
874                         }
875                         break;
876                 }
877                 case 'z': {
878                         char *endptr;
879                         stm32_addr_t addr = strtoul(&packet[3], &endptr, 16);
880                         //stm32_addr_t len  = strtoul(&endptr[1], NULL, 16);
881
882                         switch (packet[1]) {
883                                 case '1': // remove breakpoint
884                                 update_code_breakpoint(sl, addr, 0);
885                                 reply = strdup("OK");
886                                 break;
887
888                                 case '2' : // remove write watchpoint
889                                 case '3' : // remove read watchpoint
890                                 case '4' : // remove access watchpoint
891                                 if(delete_data_watchpoint(sl, addr) < 0) {
892                                         reply = strdup("E00");
893                                 } else {
894                                         reply = strdup("OK");
895                                         break;
896                                 }
897
898                                 default:
899                                 reply = strdup("");
900                         }
901                         break;
902                 }
903
904                 case '!': {
905                         /*
906                          * Enter extended mode which allows restarting.
907                          * We do support that always.
908                          */
909
910                         reply = strdup("OK");
911
912                         break;
913                 }
914
915                 case 'R': {
916                         /* Reset the core. */
917
918                         stlink_reset(sl);
919                         init_code_breakpoints(sl);
920                         init_data_watchpoints(sl);
921
922                         attached = 1;
923
924                         reply = strdup("OK");
925
926                         break;
927                 }
928
929                 default:
930                         reply = strdup("");
931                 }
932
933                 if(reply) {
934                         #ifdef DEBUG
935                         printf("send: %s\n", reply);
936                         #endif
937
938                         int result = gdb_send_packet(client, reply);
939                         if(result != 0) {
940                                 fprintf(stderr, "cannot send: %d\n", result);
941                                 return 1;
942                         }
943
944                         free(reply);
945                 }
946
947                 free(packet);
948         }
949
950         return 0;
951 }