4 * GDB RDP server stub - SH4 + ARM
6 * Copyright (c) 2009 Nathan Keynes.
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.
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.
27 #include <arpa/inet.h>
29 #include "dreamcast.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.
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 */
47 const gchar *peer_name;
53 void gdb_server_free( gpointer data )
55 struct gdb_server *server = (struct gdb_server *)data;
56 free((char *)server->peer_name);
61 int gdb_checksum( char *data, int length )
65 for( i=0; i<length; i++ )
71 void gdb_send_frame( struct gdb_server *server, char *data, int length )
74 snprintf( out, length+5, "$%.*s#%02x", length, data, gdb_checksum(data,length) );
75 write( server->fd, out, length+4 );
79 * Send bulk data (ie memory dump) as hex, with optional string prefix.
80 * Saves double copying when going through gdb_send_frame.
82 void gdb_send_hex_data( struct gdb_server *server, char *prefix, unsigned char *data, int datalen )
86 prefixlen = strlen(prefix);
87 int totallen = datalen*2 + prefixlen + 4;
93 if( prefix != NULL ) {
94 p += sprintf( p, "%s", prefix );
96 for( i=0; i<datalen; i++ ) {
97 p += sprintf( p, "%02x", data[i] );
100 sprintf( p, "%02x", gdb_checksum(out+1, datalen*2 + prefixlen) );
101 write( server->fd, out, totallen );
105 * Parse bulk hex data - buffer should be at least datalen/2 bytes long
107 size_t gdb_read_hex_data( struct gdb_server *server, unsigned char *buf, char *data, int datalen )
110 for( int i=0; i<datalen/2; i++ ) {
112 sscanf( p, "%02x", &v );
120 * Parse bulk binary-encoded data - $, #, 0x7D are encoded as 0x7d, char ^ 0x20.
121 * Buffer should be at least datalen bytes longs.
123 size_t gdb_read_binary_data( struct gdb_server *server, unsigned char *buf, char *data, int datalen )
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 ) {
131 *q++ = data[++i] ^ 0x20;
140 void gdb_printf_frame( struct gdb_server *server, char *msg, ... )
145 int len = vsnprintf( NULL, 0, msg, va );
147 vsnprintf( buf, len+1, msg, va);
149 gdb_send_frame( server, buf, len );
152 int gdb_print_registers( struct gdb_server *server, char *buf, int buflen, int firstreg, int regcount )
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);
160 sprintf( p, "00000000" );
162 sprintf( p, "%02x%02x%02x%02x", val[0], val[1], val[2], val[3] );
170 void gdb_set_registers( struct gdb_server *server, char *buf, int firstreg, int regcount )
174 for( i=firstreg; i < firstreg + regcount; i++ ) {
175 uint8_t *val = server->cpu->get_register(i);
176 unsigned int a,b,c,d;
178 sscanf( p, "%02x%02x%02x%02x", &a, &b, &c, &d );
189 * Send a 2-digit error code. There's no actual definition for any of the codes
190 * so they're more for our own amusement really.
192 void gdb_send_error( struct gdb_server *server, int error )
195 snprintf( out, 4, "E%02X", (error&0xFF) );
196 gdb_send_frame( server, out, 3 );
199 void gdb_server_handle_frame( struct gdb_server *server, int command, char *data, int length )
201 unsigned int tmp, tmp2, tmp3;
205 case '!': /* Enable extended mode */
206 gdb_send_frame( server, "OK", 2 );
208 case '?': /* Get stop reason - always return 5 (TRAP) */
209 gdb_send_frame( server, "S05", 3 );
211 case 'c': /* Continue */
213 gdb_send_frame( server, "S05", 3 );
215 case 'g': /* Read all general registers */
216 gdb_print_registers( server, buf, sizeof(buf), 0, server->cpu->num_gpr_regs );
217 gdb_send_frame( server, buf, strlen(buf) );
219 case 'G': /* Write all general registers */
220 if( length != server->cpu->num_gpr_regs*8 ) {
221 gdb_send_error( server, GDB_ERROR_FORMAT );
223 gdb_set_registers( server, data, 0, server->cpu->num_gpr_regs );
224 gdb_send_frame( server, "OK", 2 );
227 case 'H': /* Set thread - only thread 1 is supported here */
229 gdb_send_error( server, GDB_ERROR_FORMAT );
232 sscanf( data+1, "%d", &thread );
233 if( thread >= -1 && thread <= 1 ) {
234 gdb_send_frame( server, "OK", 2 );
236 gdb_send_error( server, GDB_ERROR_INVAL );
240 case 'k': /* kill - do nothing */
241 gdb_send_frame( server, "", 0 );
243 case 'm': /* Read memory */
244 if( sscanf( data, "%x,%x", &tmp, &tmp2 ) != 2 ) {
245 gdb_send_error( server, GDB_ERROR_FORMAT );
248 unsigned char mem[tmp2];
250 datalen = server->cpu->read_mem_vma(mem, tmp, tmp2);
252 datalen = server->cpu->read_mem_phys(mem, tmp, tmp2);
255 gdb_send_error( server, GDB_ERROR_INVAL );
257 gdb_send_hex_data( server, NULL, mem, datalen );
261 case 'M': /* Write memory */
262 if( sscanf( data, "%x,%x:%n", &tmp, &tmp2, &tmp3 ) != 2 ||
263 length-tmp3 != tmp2*2 ) {
264 gdb_send_error( server, GDB_ERROR_FORMAT );
267 unsigned char mem[tmp2];
268 len = gdb_read_hex_data( server, mem, data+tmp3, length-tmp3 );
270 gdb_send_error( server, GDB_ERROR_FORMAT );
273 len = server->cpu->write_mem_vma(tmp, mem, tmp2);
275 len = server->cpu->write_mem_phys(tmp, mem, tmp2);
278 gdb_send_error( server, GDB_ERROR_INVAL );
280 gdb_send_frame( server, "OK", 2 );
285 case 'p': /* Read single register */
286 if( sscanf( data, "%x", &tmp ) != 1 ) {
287 gdb_send_error( server, GDB_ERROR_FORMAT );
288 } else if( tmp >= server->cpu->num_gdb_regs ) {
289 gdb_send_error( server, GDB_ERROR_INVAL );
291 gdb_print_registers( server, buf, sizeof(buf), tmp, 1 );
292 gdb_send_frame( server, buf, 8 );
295 case 'P': /* Write single register. */
296 if( sscanf( data, "%x=%n", &tmp, &tmp2 ) != 1 ||
298 gdb_send_error( server, GDB_ERROR_FORMAT );
299 } else if( tmp >= server->cpu->num_gdb_regs ) {
300 gdb_send_error( server, GDB_ERROR_INVAL );
302 gdb_set_registers( server, data+tmp2, tmp, 1 );
303 gdb_send_frame( server, "OK", 2 );
306 case 'q': /* Query data */
307 if( strcmp( data, "C" ) == 0 ) {
308 gdb_send_frame( server, "QC1", 3 );
309 } else if( strcmp( data, "fThreadInfo" ) == 0 ) {
310 gdb_send_frame( server, "m1", 2 );
311 } else if( strcmp( data, "sThreadInfo" ) == 0 ) {
312 gdb_send_frame( server, "l", 1 );
313 } else if( strncmp( data, "Supported", 9 ) == 0 ) {
314 gdb_send_frame( server, "PacketSize=4000", 15 );
315 } else if( strcmp( data, "Symbol::" ) == 0 ) {
316 gdb_send_frame( server, "OK", 2 );
318 gdb_send_frame( server, "", 0 );
321 case 's': /* Single-step */
323 if( sscanf( data, "%x", &tmp ) != 1 ) {
324 gdb_send_error( server, GDB_ERROR_FORMAT );
326 *server->cpu->pc = tmp;
329 server->cpu->step_func();
330 gdb_send_frame( server, "S05", 3 );
332 case 'T': /* Thread alive */
333 if( sscanf( data, "%x", &tmp ) != 1 ) {
334 gdb_send_error( server, GDB_ERROR_FORMAT );
335 } else if( tmp != 1 ) {
336 gdb_send_error( server, GDB_ERROR_INVAL );
338 gdb_send_frame( server, "OK", 2 );
341 case 'v': /* Verbose */
342 /* Only current one is vCont, which we don't bother supporting
343 * at the moment, but don't warn about it either */
344 gdb_send_frame( server, "", 0 );
346 case 'X': /* Write memory binary */
347 if( sscanf( data, "%x,%x:%n", &tmp, &tmp2, &tmp3 ) != 2 ) {
348 gdb_send_error( server, GDB_ERROR_FORMAT );
350 unsigned char mem[length - tmp3];
351 size_t len = gdb_read_binary_data( server, mem, data + tmp3, length-tmp3 );
353 gdb_send_error( server, GDB_ERROR_FORMAT );
356 len = server->cpu->write_mem_vma(tmp, mem, tmp2);
358 len = server->cpu->write_mem_phys(tmp, mem, tmp2);
361 gdb_send_error( server, GDB_ERROR_INVAL );
363 gdb_send_frame( server, "OK", 2 );
368 case 'z': /* Remove Break/watchpoint */
369 if( sscanf( data, "%d,%x,%x", &tmp, &tmp2, &tmp3 ) != 3 ) {
370 gdb_send_error( server, GDB_ERROR_FORMAT );
372 if( tmp == 0 || tmp == 1 ) { /* soft break or hard break */
373 server->cpu->clear_breakpoint( tmp2, BREAK_KEEP );
374 gdb_send_frame( server, "OK", 2 );
376 gdb_send_frame( server, "", 0 );
380 case 'Z': /* Insert Break/watchpoint */
381 if( sscanf( data, "%d,%x,%x", &tmp, &tmp2, &tmp3 ) != 3 ) {
382 gdb_send_error( server, GDB_ERROR_FORMAT );
384 if( tmp == 0 || tmp == 1 ) { /* soft break or hard break */
385 server->cpu->set_breakpoint( tmp2, BREAK_KEEP );
386 gdb_send_frame( server, "OK", 2 );
388 gdb_send_frame( server, "", 0 );
393 /* Command unsupported */
394 WARN( "Received unknown GDB command '%c%s'", command, data );
395 gdb_send_frame( server, "", 0 );
402 * Decode out frames from the raw data stream. A frame takes the form of
404 * where data may not contain a '#' character, and checksum is a simple
405 * 8-bit modulo sum of all bytes in data, encoded as a 2-char hex number.
407 * The only other legal wire forms are
409 * indicating successful reception of the last message (ignored here), and
411 * indicating failed reception of the last message - need to resend.
413 void gdb_server_process_buffer( struct gdb_server *server )
415 int i, frame_start = -1, frame_len = -1;
416 for( i=0; i<server->buf_posn; i++ ) {
417 if( frame_start == -1 ) {
418 if( server->buf[i] == '$' ) {
420 } else if( server->buf[i] == '+' ) {
423 } else if( server->buf[i] == '-' ) {
424 /* Request retransmit */
425 } /* Anything else is noise */
426 } else if( server->buf[i] == '#' ) {
427 frame_len = i - frame_start - 1;
428 if( i+2 < server->buf_posn ) {
429 int calc_checksum = gdb_checksum( &server->buf[frame_start+1], frame_len );
430 int frame_checksum = 0;
431 sscanf( &server->buf[i+1], "%02x", &frame_checksum );
433 if( calc_checksum != frame_checksum ) {
434 WARN( "GDB frame checksum failure (expected %02X but was %02X)",
435 calc_checksum, frame_checksum );
436 write( server->fd, "-", 1 );
437 } else if( frame_len == 0 ) {
438 /* Empty frame - should never occur as a request */
439 WARN( "Empty GDB frame received" );
440 write( server->fd, "-", 1 );
442 /* We have a good frame */
443 write( server->fd, "+", 1 );
444 server->buf[i] = '\0';
445 gdb_server_handle_frame( server, server->buf[frame_start+1], &server->buf[frame_start+2], frame_len-1 );
452 if( frame_start == -1 ) {
453 server->buf_posn = 0; /* Consumed whole buffer */
454 } else if( frame_start > 0 ) {
455 memmove(&server->buf[0], &server->buf[frame_start], server->buf_posn - frame_start);
456 server->buf_posn -= frame_start;
460 gboolean gdb_server_data_callback( int fd, void *data )
462 struct gdb_server *server = (struct gdb_server *)data;
464 size_t len = read( fd, &server->buf[server->buf_posn], server->buf_size - server->buf_posn );
466 server->buf_posn += len;
467 gdb_server_process_buffer( server );
469 /* If we have an oversized packet, extend the buffer */
470 if( server->buf_posn > server->buf_size - BUFFER_SIZE_MARGIN &&
471 server->buf_size < MAX_BUFFER_SIZE ) {
472 server->buf_size <<= 1;
473 server->buf = realloc( server->buf, server->buf_size );
474 assert( server->buf != NULL );
478 INFO( "GDB disconnected" );
483 gboolean gdb_server_connect_callback( int fd, gpointer data )
485 struct sockaddr_in sin;
487 struct gdb_server *server = (struct gdb_server *)data;
488 int conn_fd = accept( fd, (struct sockaddr *)&sin, &sinlen);
489 if( conn_fd != -1 ) {
490 struct gdb_server *chan_serv = calloc( sizeof(struct gdb_server), 1 );
491 chan_serv->cpu = server->cpu;
492 chan_serv->mmu = server->mmu;
493 chan_serv->fd = conn_fd;
494 chan_serv->peer_name = g_strdup_printf("%s:%d", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port));
495 chan_serv->buf = malloc(1024);
496 chan_serv->buf_size = 1024;
497 chan_serv->buf_posn = 0;
498 io_register_tcp_listener( conn_fd, gdb_server_data_callback, chan_serv, gdb_server_free );
499 INFO( "GDB connected from %s", chan_serv->peer_name );
505 * Bind a network port for a GDB remote server for the specified cpu. The
506 * port is registered for the system network callback.
508 * @param interface network interface to bind to, or null for the default (all) interface
510 * @param cpu CPU to make available over the network port..
511 * @param mmu if TRUE, virtual memory is made available to GDB, otherwise GDB
512 * accesses physical memory.
513 * @return TRUE if the server was bound successfully.
515 gboolean gdb_init_server( const char *interface, int port, cpu_desc_t cpu, gboolean mmu )
517 int fd = io_create_server_socket( interface, port );
522 struct gdb_server *server = calloc( sizeof(struct gdb_server), 1 );
526 gboolean result = io_register_tcp_listener( fd, gdb_server_connect_callback, server, gdb_server_free ) != NULL;
527 INFO( "%s GDB server running on port %d", cpu->name, port );
.