lxdream 0.9.1| filename | src/gdbserver.c |
| changeset | 998:1754a8c6a9cf |
| next | 1020:04e622ab1635 |
| author | nkeynes |
| date | Tue Mar 24 11:15:57 2009 +0000 (14 years ago) |
| permissions | -rw-r--r-- |
| last change | Add preliminary implementation of the GDB remote debugging server - attaches to either or both the SH4 and ARM |
| view | annotate | diff | log | raw |
1 /**
2 * $Id: gdbserver.c 1018 2009-03-19 12:29:06Z nkeynes $
3 *
4 * GDB RDP server stub - SH4 + ARM
5 *
6 * Copyright (c) 2009 Nathan Keynes.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
20 #include <errno.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <stdarg.h>
24 #include <string.h>
25 #include <unistd.h>
26 #include <glib.h>
27 #include <arpa/inet.h>
28 #include "lxdream.h"
29 #include "dreamcast.h"
30 #include "netutil.h"
31 #include "cpu.h"
33 #define DEFAULT_BUFFER_SIZE 1024
34 #define BUFFER_SIZE_MARGIN 32
35 #define MAX_BUFFER_SIZE 65536
37 /* These are just local interpretations - they're not interpreted by GDB
38 * in any way shape or form.
39 */
40 #define GDB_ERROR_FORMAT 1 /* Badly formatted command */
41 #define GDB_ERROR_INVAL 2 /* Invalid data */
42 #define GDB_ERROR_FAIL 3 /* Command failed */
43 struct gdb_server {
44 cpu_desc_t cpu;
45 gboolean mmu;
46 int fd;
47 const gchar *peer_name;
48 char *buf;
49 int buf_size;
50 int buf_posn;
51 };
53 void gdb_server_free( gpointer data )
54 {
55 struct gdb_server *server = (struct gdb_server *)data;
56 free((char *)server->peer_name);
57 free(server->buf);
58 free(data);
59 }
61 int gdb_checksum( char *data, int length )
62 {
63 int i;
64 int result = 0;
65 for( i=0; i<length; i++ )
66 result += data[i];
67 result &= 0xFF;
68 return result;
69 }
71 void gdb_send_frame( struct gdb_server *server, char *data, int length )
72 {
73 char out[length+5];
74 snprintf( out, length+5, "$%.*s#%02x", length, data, gdb_checksum(data,length) );
75 write( server->fd, out, length+4 );
76 }
78 /**
79 * Send bulk data (ie memory dump) as hex, with optional string prefix.
80 * Saves double copying when going through gdb_send_frame.
81 */
82 void gdb_send_hex_data( struct gdb_server *server, char *prefix, unsigned char *data, int datalen )
83 {
84 int prefixlen = 0;
85 if( prefix != NULL )
86 prefixlen = strlen(prefix);
87 int totallen = datalen*2 + prefixlen + 4;
88 char out[totallen+1];
89 char *p = &out[1];
90 int i;
92 out[0] = '$';
93 if( prefix != NULL ) {
94 p += sprintf( p, "%s", prefix );
95 }
96 for( i=0; i<datalen; i++ ) {
97 p += sprintf( p, "%02x", data[i] );
98 }
99 *p++ = '#';
100 sprintf( p, "%02x", gdb_checksum(out+1, datalen*2 + prefixlen) );
101 write( server->fd, out, totallen );
102 }
104 /**
105 * Parse bulk hex data - buffer should be at least datalen/2 bytes long
106 */
107 size_t gdb_read_hex_data( struct gdb_server *server, unsigned char *buf, unsigned char *data, int datalen )
108 {
109 char *p = data;
110 for( int i=0; i<datalen/2; i++ ) {
111 int v;
112 sscanf( p, "%02x", &v );
113 buf[i] = v;
114 p += 2;
115 }
116 return datalen/2;
117 }
119 /**
120 * Parse bulk binary-encoded data - $, #, 0x7D are encoded as 0x7d, char ^ 0x20.
121 * Buffer should be at least datalen bytes longs.
122 */
123 size_t gdb_read_binary_data( struct gdb_server *server, unsigned char *buf, unsigned char *data, int datalen )
124 {
125 unsigned char *q = buf;
126 for( int i=0, j=0; i<datalen; i++ ) {
127 if( data[i] == 0x7D ) {
128 if( i == datalen-1 ) {
129 return -1;
130 } else {
131 *q++ = data[++i] ^ 0x20;
132 }
133 } else {
134 *q++ = data[i];
135 }
136 }
137 return q - buf;
138 }
140 void gdb_printf_frame( struct gdb_server *server, char *msg, ... )
141 {
142 va_list va;
144 va_start(va,msg);
145 int len = vsnprintf( NULL, 0, msg, va );
146 char buf[len+1];
147 vsnprintf( buf, len+1, msg, va);
148 va_end(va);
149 gdb_send_frame( server, buf, len );
150 }
152 int gdb_print_registers( struct gdb_server *server, char *buf, int buflen, int firstreg, int regcount )
153 {
154 int i;
155 char *p = buf;
156 char *endp = buf + (buflen-8);
157 for( i=firstreg; i < firstreg + regcount && p < endp; i++ ) {
158 uint8_t *val = server->cpu->get_register(i);
159 if( val == NULL ) {
160 sprintf( p, "00000000" );
161 } else {
162 sprintf( p, "%02x%02x%02x%02x", val[0], val[1], val[2], val[3] );
163 }
164 p += 8;
165 }
167 return i - firstreg;
168 }
170 void gdb_set_registers( struct gdb_server *server, char *buf, int firstreg, int regcount )
171 {
172 int i;
173 char *p = buf;
174 for( i=firstreg; i < firstreg + regcount; i++ ) {
175 uint8_t *val = server->cpu->get_register(i);
176 if( val != NULL ) {
177 sscanf( p, "%02x%02x%02x%02x", val, val+1, val+2, val+3 );
178 }
179 p += 8;
180 }
181 }
183 /**
184 * Send a 2-digit error code. There's no actual definition for any of the codes
185 * so they're more for our own amusement really.
186 */
187 void gdb_send_error( struct gdb_server *server, int error )
188 {
189 char out[4];
190 snprintf( out, 4, "E%02X", (error&0xFF) );
191 gdb_send_frame( server, out, 3 );
192 }
194 void gdb_server_handle_frame( struct gdb_server *server, int command, char *data, int length )
195 {
196 unsigned int tmp, tmp2, tmp3;
197 char buf[512];
199 switch( command ) {
200 case '!': /* Enable extended mode */
201 gdb_send_frame( server, "OK", 2 );
202 break;
203 case '?': /* Get stop reason - always return 5 (TRAP) */
204 gdb_send_frame( server, "S05", 3 );
205 break;
206 case 'c': /* Continue */
207 dreamcast_run();
208 gdb_send_frame( server, "S05", 3 );
209 break;
210 case 'g': /* Read all general registers */
211 gdb_print_registers( server, buf, sizeof(buf), 0, server->cpu->num_gpr_regs );
212 gdb_send_frame( server, buf, strlen(buf) );
213 break;
214 case 'G': /* Write all general registers */
215 if( length != server->cpu->num_gpr_regs*8 ) {
216 gdb_send_error( server, GDB_ERROR_FORMAT );
217 } else {
218 gdb_set_registers( server, data, 0, server->cpu->num_gpr_regs );
219 gdb_send_frame( server, "OK", 2 );
220 }
221 break;
222 case 'H': /* Set thread - only thread 1 is supported here */
223 if( length < 2 ) {
224 gdb_send_error( server, GDB_ERROR_FORMAT );
225 } else {
226 int thread;
227 sscanf( data+1, "%d", &thread );
228 if( thread >= -1 && thread <= 1 ) {
229 gdb_send_frame( server, "OK", 2 );
230 } else {
231 gdb_send_error( server, GDB_ERROR_INVAL );
232 }
233 }
234 break;
235 case 'k': /* kill - do nothing */
236 gdb_send_frame( server, "", 0 );
237 break;
238 case 'm': /* Read memory */
239 if( sscanf( data, "%x,%x", &tmp, &tmp2 ) != 2 ) {
240 gdb_send_error( server, GDB_ERROR_FORMAT );
241 } else {
242 size_t datalen;
243 char mem[tmp2];
244 if( server->mmu ) {
245 datalen = server->cpu->read_mem_vma(mem, tmp, tmp2);
246 } else {
247 datalen = server->cpu->read_mem_phys(mem, tmp, tmp2);
248 }
249 if( datalen == 0 ) {
250 gdb_send_error( server, GDB_ERROR_INVAL );
251 } else {
252 gdb_send_hex_data( server, NULL, mem, datalen );
253 }
254 }
255 break;
256 case 'M': /* Write memory */
257 if( sscanf( data, "%x,%x:%n", &tmp, &tmp2, &tmp3 ) != 2 ||
258 length-tmp3 != tmp2*2 ) {
259 gdb_send_error( server, GDB_ERROR_FORMAT );
260 } else {
261 size_t len;
262 char mem[tmp2];
263 len = gdb_read_hex_data( server, mem, data+tmp3, length-tmp3 );
264 if( len != tmp2 ) {
265 gdb_send_error( server, GDB_ERROR_FORMAT );
266 } else {
267 if( server->mmu ) {
268 len = server->cpu->write_mem_vma(tmp, mem, tmp2);
269 } else {
270 len = server->cpu->write_mem_phys(tmp, mem, tmp2);
271 }
272 if( len != tmp2 ) {
273 gdb_send_error( server, GDB_ERROR_INVAL );
274 } else {
275 gdb_send_frame( server, "OK", 2 );
276 }
277 }
278 }
279 break;
280 case 'p': /* Read single register */
281 if( sscanf( data, "%x", &tmp ) != 1 ) {
282 gdb_send_error( server, GDB_ERROR_FORMAT );
283 } else if( tmp >= server->cpu->num_gdb_regs ) {
284 gdb_send_error( server, GDB_ERROR_INVAL );
285 } else {
286 gdb_print_registers( server, buf, sizeof(buf), tmp, 1 );
287 gdb_send_frame( server, buf, 8 );
288 }
289 break;
290 case 'P': /* Write single register. */
291 if( sscanf( data, "%x=%n", &tmp, &tmp2 ) != 1 ||
292 length-tmp2 != 8) {
293 gdb_send_error( server, GDB_ERROR_FORMAT );
294 } else if( tmp >= server->cpu->num_gdb_regs ) {
295 gdb_send_error( server, GDB_ERROR_INVAL );
296 } else {
297 gdb_set_registers( server, data+tmp2, tmp, 1 );
298 gdb_send_frame( server, "OK", 2 );
299 }
300 break;
301 case 'q': /* Query data */
302 if( strcmp( data, "C" ) == 0 ) {
303 gdb_send_frame( server, "QC1", 3 );
304 } else if( strcmp( data, "fThreadInfo" ) == 0 ) {
305 gdb_send_frame( server, "m1", 2 );
306 } else if( strcmp( data, "sThreadInfo" ) == 0 ) {
307 gdb_send_frame( server, "l", 1 );
308 } else if( strncmp( data, "Supported", 9 ) == 0 ) {
309 gdb_send_frame( server, "PacketSize=4000", 15 );
310 } else if( strcmp( data, "Symbol::" ) == 0 ) {
311 gdb_send_frame( server, "OK", 2 );
312 } else {
313 gdb_send_frame( server, "", 0 );
314 }
315 break;
316 case 's': /* Single-step */
317 if( length != 0 ) {
318 if( sscanf( data, "%x", &tmp ) != 1 ) {
319 gdb_send_error( server, GDB_ERROR_FORMAT );
320 } else {
321 *server->cpu->pc = tmp;
322 }
323 }
324 server->cpu->step_func();
325 gdb_send_frame( server, "S05", 3 );
326 break;
327 case 'T': /* Thread alive */
328 if( sscanf( data, "%x", &tmp ) != 1 ) {
329 gdb_send_error( server, GDB_ERROR_FORMAT );
330 } else if( tmp != 1 ) {
331 gdb_send_error( server, GDB_ERROR_INVAL );
332 } else {
333 gdb_send_frame( server, "OK", 2 );
334 }
335 break;
336 case 'v': /* Verbose */
337 /* Only current one is vCont, which we don't bother supporting
338 * at the moment, but don't warn about it either */
339 gdb_send_frame( server, "", 0 );
340 break;
341 case 'X': /* Write memory binary */
342 if( sscanf( data, "%x,%x:%n", &tmp, &tmp2, &tmp3 ) != 2 ) {
343 gdb_send_error( server, GDB_ERROR_FORMAT );
344 } else {
345 char mem[length - tmp3];
346 size_t len = gdb_read_binary_data( server, mem, data + tmp3, length-tmp3 );
347 if( len != tmp2 ) {
348 gdb_send_error( server, GDB_ERROR_FORMAT );
349 } else {
350 if( server->mmu ) {
351 len = server->cpu->write_mem_vma(tmp, mem, tmp2);
352 } else {
353 len = server->cpu->write_mem_phys(tmp, mem, tmp2);
354 }
355 if( len != tmp2 ) {
356 gdb_send_error( server, GDB_ERROR_INVAL );
357 } else {
358 gdb_send_frame( server, "OK", 2 );
359 }
360 }
361 }
362 break;
363 case 'z': /* Remove Break/watchpoint */
364 if( sscanf( data, "%d,%x,%x", &tmp, &tmp2, &tmp3 ) != 3 ) {
365 gdb_send_error( server, GDB_ERROR_FORMAT );
366 } else {
367 if( tmp == 0 || tmp == 1 ) { /* soft break or hard break */
368 server->cpu->clear_breakpoint( tmp2, BREAK_KEEP );
369 gdb_send_frame( server, "OK", 2 );
370 } else {
371 gdb_send_frame( server, "", 0 );
372 }
373 }
374 break;
375 case 'Z': /* Insert Break/watchpoint */
376 if( sscanf( data, "%d,%x,%x", &tmp, &tmp2, &tmp3 ) != 3 ) {
377 gdb_send_error( server, GDB_ERROR_FORMAT );
378 } else {
379 if( tmp == 0 || tmp == 1 ) { /* soft break or hard break */
380 server->cpu->set_breakpoint( tmp2, BREAK_KEEP );
381 gdb_send_frame( server, "OK", 2 );
382 } else {
383 gdb_send_frame( server, "", 0 );
384 }
385 }
386 break;
387 default:
388 /* Command unsupported */
389 WARN( "Received unknown GDB command '%c%s'", command, data );
390 gdb_send_frame( server, "", 0 );
391 break;
392 }
394 }
396 /**
397 * Decode out frames from the raw data stream. A frame takes the form of
398 * $<data>#<checksum>
399 * where data may not contain a '#' character, and checksum is a simple
400 * 8-bit modulo sum of all bytes in data, encoded as a 2-char hex number.
401 *
402 * The only other legal wire forms are
403 * +
404 * indicating successful reception of the last message (ignored here), and
405 * -
406 * indicating failed reception of the last message - need to resend.
407 */
408 void gdb_server_process_buffer( struct gdb_server *server )
409 {
410 int i, frame_start = -1, frame_len = -1;
411 for( i=0; i<server->buf_posn; i++ ) {
412 if( frame_start == -1 ) {
413 if( server->buf[i] == '$' ) {
414 frame_start = i;
415 } else if( server->buf[i] == '+' ) {
416 /* Success */
417 continue;
418 } else if( server->buf[i] == '-' ) {
419 /* Request retransmit */
420 } /* Anything else is noise */
421 } else if( server->buf[i] == '#' ) {
422 frame_len = i - frame_start - 1;
423 if( i+2 < server->buf_posn ) {
424 int calc_checksum = gdb_checksum( &server->buf[frame_start+1], frame_len );
425 int frame_checksum = 0;
426 sscanf( &server->buf[i+1], "%02x", &frame_checksum );
428 if( calc_checksum != frame_checksum ) {
429 WARN( "GDB frame checksum failure (expected %02X but was %02X)",
430 calc_checksum, frame_checksum );
431 write( server->fd, "-", 1 );
432 } else if( frame_len == 0 ) {
433 /* Empty frame - should never occur as a request */
434 WARN( "Empty GDB frame received" );
435 write( server->fd, "-", 1 );
436 } else {
437 /* We have a good frame */
438 write( server->fd, "+", 1 );
439 server->buf[i] = '\0';
440 gdb_server_handle_frame( server, server->buf[frame_start+1], &server->buf[frame_start+2], frame_len-1 );
441 }
442 i+=2;
443 frame_start = -1;
444 }
445 }
446 }
447 if( frame_start == -1 ) {
448 server->buf_posn = 0; /* Consumed whole buffer */
449 } else if( frame_start > 0 ) {
450 memmove(&server->buf[0], &server->buf[frame_start], server->buf_posn - frame_start);
451 server->buf_posn -= frame_start;
452 }
453 }
455 gboolean gdb_server_data_callback( int fd, void *data )
456 {
457 struct gdb_server *server = (struct gdb_server *)data;
459 size_t len = read( fd, &server->buf[server->buf_posn], server->buf_size - server->buf_posn );
460 if( len > 0 ) {
461 server->buf_posn += len;
462 gdb_server_process_buffer( server );
464 /* If we have an oversized packet, extend the buffer */
465 if( server->buf_posn > server->buf_size - BUFFER_SIZE_MARGIN &&
466 server->buf_size < MAX_BUFFER_SIZE ) {
467 server->buf_size <<= 1;
468 server->buf = realloc( server->buf, server->buf_size );
469 assert( server->buf != NULL );
470 }
471 return TRUE;
472 } else {
473 INFO( "GDB disconnected" );
474 return FALSE;
475 }
476 }
478 gboolean gdb_server_connect_callback( int fd, gpointer data )
479 {
480 struct sockaddr_in sin;
481 socklen_t sinlen;
482 struct gdb_server *server = (struct gdb_server *)data;
483 int conn_fd = accept( fd, (struct sockaddr *)&sin, &sinlen);
484 if( conn_fd != -1 ) {
485 struct gdb_server *chan_serv = calloc( sizeof(struct gdb_server), 1 );
486 chan_serv->cpu = server->cpu;
487 chan_serv->mmu = server->mmu;
488 chan_serv->fd = conn_fd;
489 chan_serv->peer_name = g_strdup_printf("%s:%d", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
490 chan_serv->buf = malloc(1024);
491 chan_serv->buf_size = 1024;
492 chan_serv->buf_posn = 0;
493 net_register_tcp_listener( conn_fd, gdb_server_data_callback, chan_serv, gdb_server_free );
494 INFO( "GDB connected from %s", chan_serv->peer_name );
495 }
496 return TRUE;
497 }
499 /**
500 * Bind a network port for a GDB remote server for the specified cpu. The
501 * port is registered for the system network callback.
502 *
503 * @param interface network interface to bind to, or null for the default (all) interface
504 * @param port
505 * @param cpu CPU to make available over the network port..
506 * @param mmu if TRUE, virtual memory is made available to GDB, otherwise GDB
507 * accesses physical memory.
508 * @return TRUE if the server was bound successfully.
509 */
510 gboolean gdb_init_server( const char *interface, int port, cpu_desc_t cpu, gboolean mmu )
511 {
512 int fd = net_create_server_socket( interface, port );
513 if( fd == -1 ) {
514 return FALSE;
515 }
517 struct gdb_server *server = calloc( sizeof(struct gdb_server), 1 );
518 server->cpu = cpu;
519 server->mmu = mmu;
520 server->fd = fd;
521 net_register_tcp_listener( fd, gdb_server_connect_callback, server, gdb_server_free );
522 INFO( "%s GDB server running on port %d", cpu->name, port );
523 }
.