aboutsummaryrefslogtreecommitdiff
path: root/gdb/remote-sim.c
blob: ba9695f7008d3b42c3dc56223386222371a856d7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
/* Generic remote debugging interface for simulators.
   Copyright 1993, 1994, 1996, 1997 Free Software Foundation, Inc.
   Contributed by Cygnus Support.
   Steve Chamberlain (sac@cygnus.com).

This file is part of GDB.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "inferior.h"
#include "wait.h"
#include "value.h"
#include "gdb_string.h"
#include <ctype.h>
#include <fcntl.h>
#include <signal.h>
#include <setjmp.h>
#include <errno.h>
#include "terminal.h"
#include "target.h"
#include "gdbcore.h"
#include "callback.h"
#include "remote-sim.h"
#include "remote-utils.h"
#include "command.h"

/* Prototypes */

static void dump_mem PARAMS ((char *buf, int len));

static void init_callbacks PARAMS ((void));

static void end_callbacks PARAMS ((void));

static int gdb_os_write_stdout PARAMS ((host_callback *, const char *, int));

static void gdb_os_flush_stdout PARAMS ((host_callback *));

static int gdb_os_write_stderr PARAMS ((host_callback *, const char *, int));

static void gdb_os_flush_stderr PARAMS ((host_callback *));

static int gdb_os_poll_quit PARAMS ((host_callback *));

/* printf_filtered is depreciated */
static void gdb_os_printf_filtered PARAMS ((host_callback *, const char *, ...));

static void gdb_os_vprintf_filtered PARAMS ((host_callback *, const char *, va_list));

static void gdb_os_evprintf_filtered PARAMS ((host_callback *, const char *, va_list));

static void gdb_os_error PARAMS ((host_callback *, const char *, ...));

static void gdbsim_fetch_register PARAMS ((int regno));

static void gdbsim_store_register PARAMS ((int regno));

static void gdbsim_kill PARAMS ((void));

static void gdbsim_load PARAMS ((char *prog, int fromtty));

static void gdbsim_create_inferior PARAMS ((char *exec_file, char *args, char **env));

static void gdbsim_open PARAMS ((char *args, int from_tty));

static void gdbsim_close PARAMS ((int quitting));

static void gdbsim_detach PARAMS ((char *args, int from_tty));

static void gdbsim_resume PARAMS ((int pid, int step, enum target_signal siggnal));

static int gdbsim_wait PARAMS ((int pid, struct target_waitstatus *status));

static void gdbsim_prepare_to_store PARAMS ((void));

static int gdbsim_xfer_inferior_memory PARAMS ((CORE_ADDR memaddr,
						char *myaddr, int len,
						int write,
						struct target_ops *target));

static void gdbsim_files_info PARAMS ((struct target_ops *target));

static void gdbsim_mourn_inferior PARAMS ((void));

static void gdbsim_stop PARAMS ((void));

static void simulator_command PARAMS ((char *args, int from_tty));

/* Naming convention:

   sim_* are the interface to the simulator (see remote-sim.h).
   gdbsim_* are stuff which is internal to gdb.  */

/* Forward data declarations */
extern struct target_ops gdbsim_ops;

static int program_loaded = 0;

/* We must keep track of whether the simulator has been opened or not because
   GDB can call a target's close routine twice, but sim_close doesn't allow
   this.  We also need to record the result of sim_open so we can pass it
   back to the other sim_foo routines.  */
static SIM_DESC gdbsim_desc = 0;

static void
dump_mem (buf, len)
     char *buf;
     int len;
{
  if (len <= 8)
    {
      if (len == 8 || len == 4)
	{
	  long l[2];
	  memcpy (l, buf, len);
	  printf_filtered ("\t0x%x", l[0]);
	  printf_filtered (len == 8 ? " 0x%x\n" : "\n", l[1]);
	}
      else
	{
	  int i;
	  printf_filtered ("\t");
	  for (i = 0; i < len; i++)
	    printf_filtered ("0x%x ", buf[i]);
	  printf_filtered ("\n");
	}
    }
}

static host_callback gdb_callback;
static int callbacks_initialized = 0;

/* Initialize gdb_callback.  */

static void
init_callbacks ()
{
  if (! callbacks_initialized)
    {
      gdb_callback = default_callback;
      gdb_callback.init (&gdb_callback);
      gdb_callback.write_stdout = gdb_os_write_stdout;
      gdb_callback.flush_stdout = gdb_os_flush_stdout;
      gdb_callback.write_stderr = gdb_os_write_stderr;
      gdb_callback.flush_stderr = gdb_os_flush_stderr;
      gdb_callback.printf_filtered = gdb_os_printf_filtered;
      gdb_callback.vprintf_filtered = gdb_os_vprintf_filtered;
      gdb_callback.evprintf_filtered = gdb_os_evprintf_filtered;
      gdb_callback.error = gdb_os_error;
      gdb_callback.poll_quit = gdb_os_poll_quit;
      gdb_callback.magic = HOST_CALLBACK_MAGIC;
      callbacks_initialized = 1;
    }
}

/* Release callbacks (free resources used by them).  */

static void
end_callbacks ()
{
  if (callbacks_initialized)
    {
      gdb_callback.shutdown (&gdb_callback);
      callbacks_initialized = 0;
    }
}

/* GDB version of os_write_stdout callback.  */

static int 
gdb_os_write_stdout (p, buf, len)
     host_callback *p;
     const char *buf;
     int len;
{
  int i;
  char b[2];

  for (i = 0; i < len; i++) 
    {
      b[0] = buf[i];
      b[1] = 0;
      if (target_output_hook)
	target_output_hook (b);
      else
	fputs_filtered (b, gdb_stdout);
    }
  return len;
}

/* GDB version of os_flush_stdout callback.  */

static void
gdb_os_flush_stdout (p)
     host_callback *p;
{
  gdb_flush (gdb_stdout);
}

/* GDB version of os_write_stderr callback.  */

static int 
gdb_os_write_stderr (p, buf, len)
     host_callback *p;
     const char *buf;
     int len;
{
  int i;
  char b[2];

  for (i = 0; i < len; i++) 
    {
      b[0] = buf[i];
      b[1] = 0;
      if (target_output_hook)
	target_output_hook (b);
      else
	fputs_filtered (b, gdb_stderr);
    }
  return len;
}

/* GDB version of os_flush_stderr callback.  */

static void
gdb_os_flush_stderr (p)
     host_callback *p;
{
  gdb_flush (gdb_stderr);
}

/* GDB version of printf_filtered callback.  */

/* VARARGS */
static void
#ifdef ANSI_PROTOTYPES
gdb_os_printf_filtered (host_callback *p, const char *format, ...)
#else
gdb_os_printf_filtered (p, va_alist)
     host_callback *p;
     va_dcl
#endif
{
  va_list args;
#ifdef ANSI_PROTOTYPES
  va_start (args, format);
#else
  char *format;

  va_start (args);
  format = va_arg (args, char *);
#endif

  vfprintf_filtered (gdb_stdout, format, args);

  va_end (args);
}

/* GDB version of error vprintf_filtered.  */

/* VARARGS */
static void
#ifdef ANSI_PROTOTYPES
gdb_os_vprintf_filtered (host_callback *p, const char *format, va_list ap)
#else
gdb_os_vprintf_filtered (p, format, ap)
     host_callback *p;
     char *format;
     va_list ap;
#endif
{
  vfprintf_filtered (gdb_stdout, format, ap);
}

/* GDB version of error evprintf_filtered.  */

/* VARARGS */
static void
#ifdef ANSI_PROTOTYPES
gdb_os_evprintf_filtered (host_callback *p, const char *format, va_list ap)
#else
gdb_os_evprintf_filtered (p, format, ap)
     host_callback *p;
     char *format;
     va_list ap;
#endif
{
  vfprintf_filtered (gdb_stderr, format, ap);
}

/* GDB version of error callback.  */

/* VARARGS */
static void
#ifdef ANSI_PROTOTYPES
gdb_os_error (host_callback *p, const char *format, ...)
#else
gdb_os_error (p, va_alist)
     host_callback *p;
     va_dcl
#endif
{
  if (error_hook)
    (*error_hook) ();
  else 
    {
      va_list args;
#ifdef ANSI_PROTOTYPES
      va_start (args, format);
#else
      char *format;

      va_start (args);
      format = va_arg (args, char *);
#endif

      error_begin ();
      vfprintf_filtered (gdb_stderr, format, args);
      fprintf_filtered (gdb_stderr, "\n");
      va_end (args);
      return_to_top_level (RETURN_ERROR);
    }
}

static void
gdbsim_fetch_register (regno)
int regno;
{
  if (regno == -1) 
    {
      for (regno = 0; regno < NUM_REGS; regno++)
	gdbsim_fetch_register (regno);
    }
  else
    {
      char buf[MAX_REGISTER_RAW_SIZE];

      sim_fetch_register (gdbsim_desc, regno, buf);
      supply_register (regno, buf);
      if (sr_get_debug ())
	{
	  printf_filtered ("gdbsim_fetch_register: %d", regno);
	  /* FIXME: We could print something more intelligible.  */
	  dump_mem (buf, REGISTER_RAW_SIZE (regno));
	}
    }
}


static void
gdbsim_store_register (regno)
int regno;
{
  if (regno  == -1) 
    {
      for (regno = 0; regno < NUM_REGS; regno++)
	gdbsim_store_register (regno);
    }
  else
    {
      /* FIXME: Until read_register() returns LONGEST, we have this.  */
      char tmp[MAX_REGISTER_RAW_SIZE];
      read_register_gen (regno, tmp);
      sim_store_register (gdbsim_desc, regno, tmp);
      if (sr_get_debug ())
	{
	  printf_filtered ("gdbsim_store_register: %d", regno);
	  /* FIXME: We could print something more intelligible.  */
	  dump_mem (tmp, REGISTER_RAW_SIZE (regno));
	}
    }
}

/* Kill the running program.  This may involve closing any open files
   and releasing other resources acquired by the simulated program.  */

static void
gdbsim_kill ()
{
  if (sr_get_debug ())
    printf_filtered ("gdbsim_kill\n");

  /* There is no need to `kill' running simulator - the simulator is
     not running */
  inferior_pid = 0;
}

/* Load an executable file into the target process.  This is expected to
   not only bring new code into the target process, but also to update
   GDB's symbol tables to match.  */

static void
gdbsim_load (prog, fromtty)
     char *prog;
     int fromtty;
{
  if (sr_get_debug ())
    printf_filtered ("gdbsim_load: prog \"%s\"\n", prog);

  inferior_pid = 0;

  /* FIXME: We will print two messages on error.
     Need error to either not print anything if passed NULL or need
     another routine that doesn't take any arguments.  */
  if (sim_load (gdbsim_desc, prog, NULL, fromtty) == SIM_RC_FAIL)
    error ("unable to load program");

  program_loaded = 1;
}


/* Start an inferior process and set inferior_pid to its pid.
   EXEC_FILE is the file to run.
   ARGS is a string containing the arguments to the program.
   ENV is the environment vector to pass.  Errors reported with error().
   On VxWorks and various standalone systems, we ignore exec_file.  */
/* This is called not only when we first attach, but also when the
   user types "run" after having attached.  */

static void
gdbsim_create_inferior (exec_file, args, env)
     char *exec_file;
     char *args;
     char **env;
{
  int len;
  char *arg_buf,**argv;
  CORE_ADDR entry_pt;

  if (! program_loaded)
    error ("No program loaded.");

  if (sr_get_debug ())
    printf_filtered ("gdbsim_create_inferior: exec_file \"%s\", args \"%s\"\n",
      exec_file, args);

  if (exec_file == 0 || exec_bfd == 0)
   error ("No exec file specified.");

  entry_pt = (CORE_ADDR) bfd_get_start_address (exec_bfd);

  gdbsim_kill ();	 
  remove_breakpoints ();
  init_wait_for_inferior ();

  len = strlen (exec_file) + 1 + strlen (args) + 1 + /*slop*/ 10;
  arg_buf = (char *) alloca (len);
  arg_buf[0] = '\0';
  strcat (arg_buf, exec_file);
  strcat (arg_buf, " ");
  strcat (arg_buf, args);
  argv = buildargv (arg_buf);
  make_cleanup (freeargv, (char *) argv);
  sim_create_inferior (gdbsim_desc, argv, env);

  inferior_pid = 42;
  insert_breakpoints ();	/* Needed to get correct instruction in cache */
  proceed (entry_pt, TARGET_SIGNAL_DEFAULT, 0);
}

/* The open routine takes the rest of the parameters from the command,
   and (if successful) pushes a new target onto the stack.
   Targets should supply this routine, if only to provide an error message.  */
/* Called when selecting the simulator. EG: (gdb) target sim name.  */

static void
gdbsim_open (args, from_tty)
     char *args;
     int from_tty;
{
  int len;
  char *arg_buf;
  char **argv;

  if (sr_get_debug ())
    printf_filtered ("gdbsim_open: args \"%s\"\n", args ? args : "(null)");

  /* Remove current simulator if one exists.  Only do this if the simulator
     has been opened because sim_close requires it.
     This is important because the call to push_target below will cause
     sim_close to be called if the simulator is already open, but push_target
     is called after sim_open!  We can't move the call to push_target before
     the call to sim_open because sim_open may invoke `error'.  */
  if (gdbsim_desc != NULL)
    unpush_target (&gdbsim_ops);

  len = 7 + 1 + (args ? strlen (args) : 0) + 50;
  arg_buf = (char *) alloca (len);
  sprintf (arg_buf, "gdbsim%s%s",
	   args ? " " : "", args ? args : "");
#ifdef TARGET_BYTE_ORDER_SELECTABLE
  /* Since GDB always closes the target and updates byte-order when
     opening a new file, TARGET_BYTE_ORDER is normally correct. */
  if (TARGET_BYTE_ORDER == BIG_ENDIAN)
    strcat (arg_buf, " -E big");
  else
    strcat (arg_buf, " -E little");
#endif
  argv = buildargv (arg_buf);
  if (argv == NULL)
    error ("Insufficient memory available to allocate simulator arg list.");
  make_cleanup (freeargv, (char *) argv);

  init_callbacks ();
  gdbsim_desc = sim_open (SIM_OPEN_DEBUG, &gdb_callback, argv);

  if (gdbsim_desc == 0)
    error ("unable to create simulator instance");

  push_target (&gdbsim_ops);
  target_fetch_registers (-1);
  printf_filtered ("Connected to the simulator.\n");
}

/* Does whatever cleanup is required for a target that we are no longer
   going to be calling.  Argument says whether we are quitting gdb and
   should not get hung in case of errors, or whether we want a clean
   termination even if it takes a while.  This routine is automatically
   always called just before a routine is popped off the target stack.
   Closing file descriptors and freeing memory are typical things it should
   do.  */
/* Close out all files and local state before this target loses control. */

static void
gdbsim_close (quitting)
     int quitting;
{
  if (sr_get_debug ())
    printf_filtered ("gdbsim_close: quitting %d\n", quitting);

  program_loaded = 0;

  if (gdbsim_desc != NULL)
    {
      sim_close (gdbsim_desc, quitting);
      gdbsim_desc = NULL;
    }

  end_callbacks ();
}

/* Takes a program previously attached to and detaches it.
   The program may resume execution (some targets do, some don't) and will
   no longer stop on signals, etc.  We better not have left any breakpoints
   in the program or it'll die when it hits one.  ARGS is arguments
   typed by the user (e.g. a signal to send the process).  FROM_TTY
   says whether to be verbose or not.  */
/* Terminate the open connection to the remote debugger.
   Use this when you want to detach and do something else with your gdb.  */

static void
gdbsim_detach (args,from_tty)
     char *args;
     int from_tty;
{
  if (sr_get_debug ())
    printf_filtered ("gdbsim_detach: args \"%s\"\n", args);

  pop_target ();		/* calls gdbsim_close to do the real work */
  if (from_tty)
    printf_filtered ("Ending simulator %s debugging\n", target_shortname);
}
 
/* Resume execution of the target process.  STEP says whether to single-step
   or to run free; SIGGNAL is the signal value (e.g. SIGINT) to be given
   to the target, or zero for no signal.  */

static enum target_signal resume_siggnal;
static int resume_step;

static void
gdbsim_resume (pid, step, siggnal)
     int pid, step;
     enum target_signal siggnal;
{
  if (inferior_pid != 42)
    error ("The program is not being run.");

  if (sr_get_debug ())
    printf_filtered ("gdbsim_resume: step %d, signal %d\n", step, siggnal);

  resume_siggnal = siggnal;
  resume_step = step;
}

/* Notify the simulator of an asynchronous request to stop.
   
   The simulator shall ensure that the stop request is eventually
   delivered to the simulator.  If the call is made while the
   simulator is not running then the stop request is processed when
   the simulator is next resumed.

   For simulators that do not support this operation, just abort */

static void
gdbsim_stop ()
{
  if (! sim_stop (gdbsim_desc))
    {
      quit ();
    }
}

/* GDB version of os_poll_quit callback.
   Taken from gdb/util.c - should be in a library */

static int
gdb_os_poll_quit (p)
     host_callback *p;
{
  notice_quit ();
  if (quit_flag) /* gdb's idea of quit */
    {
      quit_flag = 0; /* we've stolen it */
      return 1;
    }
  else if (immediate_quit)
    {
      return 1;
    }
  return 0;
}

/* Wait for inferior process to do something.  Return pid of child,
   or -1 in case of error; store status through argument pointer STATUS,
   just as `wait' would. */

static void
gdbsim_cntrl_c (int signo)
{
  gdbsim_stop ();
}

static int
gdbsim_wait (pid, status)
     int pid;
     struct target_waitstatus *status;
{
  static RETSIGTYPE (*prev_sigint) ();
  int sigrc = 0;
  enum sim_stop reason = sim_running;

  if (sr_get_debug ())
    printf_filtered ("gdbsim_wait\n");

  prev_sigint = signal (SIGINT, gdbsim_cntrl_c);
  sim_resume (gdbsim_desc, resume_step,
	      target_signal_to_host (resume_siggnal));
  signal (SIGINT, prev_sigint);
  resume_step = 0;

  sim_stop_reason (gdbsim_desc, &reason, &sigrc);

  switch (reason)
    {
    case sim_exited:
      status->kind = TARGET_WAITKIND_EXITED;
      status->value.integer = sigrc;
      break;
    case sim_stopped:
      switch (sigrc)
	{
	case SIGABRT:
	  quit ();
	  break;
	case SIGINT:
	case SIGTRAP:
	default:
	  status->kind = TARGET_WAITKIND_STOPPED;
	  /* The signal in sigrc is a host signal.  That probably
	     should be fixed.  */
	  status->value.sig = target_signal_from_host (sigrc);
	  break;
	}
      break;
    case sim_signalled:
      status->kind = TARGET_WAITKIND_SIGNALLED;
      /* The signal in sigrc is a host signal.  That probably
	 should be fixed.  */
      status->value.sig = target_signal_from_host (sigrc);
      break;
    case sim_running:
    case sim_polling:
      /* FIXME: Is this correct? */
      break;
    }

  return inferior_pid;
}

/* Get ready to modify the registers array.  On machines which store
   individual registers, this doesn't need to do anything.  On machines
   which store all the registers in one fell swoop, this makes sure
   that registers contains all the registers from the program being
   debugged.  */

static void
gdbsim_prepare_to_store ()
{
  /* Do nothing, since we can store individual regs */
}

static int
gdbsim_xfer_inferior_memory (memaddr, myaddr, len, write, target)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
     int write;
     struct target_ops *target;			/* ignored */
{
  if (! program_loaded)
    error ("No program loaded.");

  if (sr_get_debug ())
    {
      printf_filtered ("gdbsim_xfer_inferior_memory: myaddr 0x%x, memaddr 0x%x, len %d, write %d\n",
		       myaddr, memaddr, len, write);
      if (sr_get_debug () && write)
	dump_mem(myaddr, len);
    }

  if (write)
    {
      len = sim_write (gdbsim_desc, memaddr, myaddr, len);
    }
  else 
    {
      len = sim_read (gdbsim_desc, memaddr, myaddr, len);
      if (sr_get_debug () && len > 0)
	dump_mem(myaddr, len);
    } 
  return len;
}

static void
gdbsim_files_info (target)
     struct target_ops *target;
{
  char *file = "nothing";

  if (exec_bfd)
    file = bfd_get_filename (exec_bfd);

  if (sr_get_debug ())
    printf_filtered ("gdbsim_files_info: file \"%s\"\n", file);

  if (exec_bfd)
    {
      printf_filtered ("\tAttached to %s running program %s\n",
		       target_shortname, file);
      sim_info (gdbsim_desc, 0);
    }
}

/* Clear the simulator's notion of what the break points are.  */

static void
gdbsim_mourn_inferior () 
{ 
  if (sr_get_debug ())
    printf_filtered ("gdbsim_mourn_inferior:\n");

  remove_breakpoints ();
  generic_mourn_inferior ();
}

/* Pass the command argument through to the simulator verbatim.  The
   simulator must do any command interpretation work.  */

static void
simulator_command (args, from_tty)
     char *args;
     int from_tty;
{
  if (gdbsim_desc == NULL)
    {

      /* PREVIOUSLY: The user may give a command before the simulator
         is opened. [...] (??? assuming of course one wishes to
         continue to allow commands to be sent to unopened simulators,
         which isn't entirely unreasonable). */

      /* The simulator is a builtin abstraction of a remote target.
         Consistent with that model, access to the simulator, via sim
         commands, is restricted to the period when the channel to the
         simulator is open. */

      error ("Not connected to the simulator target");
    }

  sim_do_command (gdbsim_desc, args);
}

/* Define the target subroutine names */

struct target_ops gdbsim_ops = {
  "sim",			/* to_shortname */
  "simulator",			/* to_longname */
  "Use the compiled-in simulator.",  /* to_doc */
  gdbsim_open,			/* to_open */
  gdbsim_close,			/* to_close */
  NULL,				/* to_attach */
  gdbsim_detach,		/* to_detach */
  gdbsim_resume,		/* to_resume */
  gdbsim_wait,			/* to_wait */
  gdbsim_fetch_register,	/* to_fetch_registers */
  gdbsim_store_register,	/* to_store_registers */
  gdbsim_prepare_to_store,	/* to_prepare_to_store */
  gdbsim_xfer_inferior_memory,	/* to_xfer_memory */
  gdbsim_files_info,		/* to_files_info */
  memory_insert_breakpoint,	/* to_insert_breakpoint */
  memory_remove_breakpoint,	/* to_remove_breakpoint */
  NULL,				/* to_terminal_init */
  NULL,				/* to_terminal_inferior */
  NULL,				/* to_terminal_ours_for_output */
  NULL,				/* to_terminal_ours */
  NULL,				/* to_terminal_info */
  gdbsim_kill,			/* to_kill */
  gdbsim_load,			/* to_load */
  NULL,				/* to_lookup_symbol */
  gdbsim_create_inferior,	/* to_create_inferior */ 
  gdbsim_mourn_inferior,	/* to_mourn_inferior */
  0,				/* to_can_run */
  0,				/* to_notice_signals */
  0,				/* to_thread_alive */
  gdbsim_stop,			/* to_stop */
  process_stratum,		/* to_stratum */
  NULL,				/* to_next */
  1,				/* to_has_all_memory */
  1,				/* to_has_memory */
  1,				/* to_has_stack */
  1,				/* to_has_registers */
  1,				/* to_has_execution */
  NULL,				/* sections */
  NULL,				/* sections_end */
  OPS_MAGIC,			/* to_magic */
};

void
_initialize_remote_sim ()
{
  add_target (&gdbsim_ops);

  add_com ("sim <command>", class_obscure, simulator_command,
	   "Send a command to the simulator."); 
}