gdb/remote-sim.c

   1 /* Generic remote debugging interface for simulators.
   2    Copyright 1993, 1994, 1996, 1997 Free Software Foundation, Inc.
   3    Contributed by Cygnus Support.
   4    Steve Chamberlain (sac@cygnus.com).
   5
   6 This file is part of GDB.
   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
  18 You should have received a copy of the GNU General Public License
  19 along with this program; if not, write to the Free Software
  20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 #include "defs.h"
  23 #include "inferior.h"
  24 #include "wait.h"
  25 #include "value.h"
  26 #include "gdb_string.h"
  27 #include <ctype.h>
  28 #include <fcntl.h>
  29 #include <signal.h>
  30 #include <setjmp.h>
  31 #include <errno.h>
  32 #include "terminal.h"
  33 #include "target.h"
  34 #include "gdbcore.h"
  35 #include "callback.h"
  36 #include "remote-sim.h"
  37 #include "remote-utils.h"
  38 #include "command.h"
  39
  40 /* Prototypes */
  41
  42 static void dump_mem PARAMS ((char *buf, int len));
  43
  44 static void init_callbacks PARAMS ((void));
  45
  46 static void end_callbacks PARAMS ((void));
  47
  48 static int gdb_os_write_stdout PARAMS ((host_callback *, const char *, int));
  49
  50 static void gdb_os_flush_stdout PARAMS ((host_callback *));
  51
  52 static int gdb_os_write_stderr PARAMS ((host_callback *, const char *, int));
  53
  54 static void gdb_os_flush_stderr PARAMS ((host_callback *));
  55
  56 static int gdb_os_poll_quit PARAMS ((host_callback *));
  57
  58 /* printf_filtered is depreciated */
  59 static void gdb_os_printf_filtered PARAMS ((host_callback *, const char *, ...));
  60
  61 static void gdb_os_vprintf_filtered PARAMS ((host_callback *, const char *, va_list));
  62
  63 static void gdb_os_evprintf_filtered PARAMS ((host_callback *, const char *, va_list));
  64
  65 static void gdb_os_error PARAMS ((host_callback *, const char *, ...));
  66
  67 static void gdbsim_fetch_register PARAMS ((int regno));
  68
  69 static void gdbsim_store_register PARAMS ((int regno));
  70
  71 static void gdbsim_kill PARAMS ((void));
  72
  73 static void gdbsim_load PARAMS ((char *prog, int fromtty));
  74
  75 static void gdbsim_create_inferior PARAMS ((char *exec_file, char *args, char **env));
  76
  77 static void gdbsim_open PARAMS ((char *args, int from_tty));
  78
  79 static void gdbsim_close PARAMS ((int quitting));
  80
  81 static void gdbsim_detach PARAMS ((char *args, int from_tty));
  82
  83 static void gdbsim_resume PARAMS ((int pid, int step, enum target_signal siggnal));
  84
  85 static int gdbsim_wait PARAMS ((int pid, struct target_waitstatus *status));
  86
  87 static void gdbsim_prepare_to_store PARAMS ((void));
  88
  89 static int gdbsim_xfer_inferior_memory PARAMS ((CORE_ADDR memaddr,
  90                                                 char *myaddr, int len,
  91                                                 int write,
  92                                                 struct target_ops *target));
  93
  94 static void gdbsim_files_info PARAMS ((struct target_ops *target));
  95
  96 static void gdbsim_mourn_inferior PARAMS ((void));
  97
  98 static void gdbsim_stop PARAMS ((void));
  99
 100 static void simulator_command PARAMS ((char *args, int from_tty));
 101
 102 /* Naming convention:
 103
 104    sim_* are the interface to the simulator (see remote-sim.h).
 105    gdbsim_* are stuff which is internal to gdb.  */
 106
 107 /* Forward data declarations */
 108 extern struct target_ops gdbsim_ops;
 109
 110 static int program_loaded = 0;
 111
 112 /* We must keep track of whether the simulator has been opened or not because
 113    GDB can call a target's close routine twice, but sim_close doesn't allow
 114    this.  We also need to record the result of sim_open so we can pass it
 115    back to the other sim_foo routines.  */
 116 static SIM_DESC gdbsim_desc = 0;
 117
 118 static void
 119 dump_mem (buf, len)
 120      char *buf;
 121      int len;
 122 {
 123   if (len <= 8)
 124     {
 125       if (len == 8 || len == 4)
 126         {
 127           long l[2];
 128           memcpy (l, buf, len);
 129           printf_filtered ("\t0x%x", l[0]);
 130           printf_filtered (len == 8 ? " 0x%x\n" : "\n", l[1]);
 131         }
 132       else
 133         {
 134           int i;
 135           printf_filtered ("\t");
 136           for (i = 0; i < len; i++)
 137             printf_filtered ("0x%x ", buf[i]);
 138           printf_filtered ("\n");
 139         }
 140     }
 141 }
 142
 143 static host_callback gdb_callback;
 144 static int callbacks_initialized = 0;
 145
 146 /* Initialize gdb_callback.  */
 147
 148 static void
 149 init_callbacks ()
 150 {
 151   if (! callbacks_initialized)
 152     {
 153       gdb_callback = default_callback;
 154       gdb_callback.init (&gdb_callback);
 155       gdb_callback.write_stdout = gdb_os_write_stdout;
 156       gdb_callback.flush_stdout = gdb_os_flush_stdout;
 157       gdb_callback.write_stderr = gdb_os_write_stderr;
 158       gdb_callback.flush_stderr = gdb_os_flush_stderr;
 159       gdb_callback.printf_filtered = gdb_os_printf_filtered;
 160       gdb_callback.vprintf_filtered = gdb_os_vprintf_filtered;
 161       gdb_callback.evprintf_filtered = gdb_os_evprintf_filtered;
 162       gdb_callback.error = gdb_os_error;
 163       gdb_callback.poll_quit = gdb_os_poll_quit;
 164       gdb_callback.magic = HOST_CALLBACK_MAGIC;
 165       callbacks_initialized = 1;
 166     }
 167 }
 168
 169 /* Release callbacks (free resources used by them).  */
 170
 171 static void
 172 end_callbacks ()
 173 {
 174   if (callbacks_initialized)
 175     {
 176       gdb_callback.shutdown (&gdb_callback);
 177       callbacks_initialized = 0;
 178     }
 179 }
 180
 181 /* GDB version of os_write_stdout callback.  */
 182
 183 static int
 184 gdb_os_write_stdout (p, buf, len)
 185      host_callback *p;
 186      const char *buf;
 187      int len;
 188 {
 189   int i;
 190   char b[2];
 191
 192   for (i = 0; i < len; i++)
 193     {
 194       b[0] = buf[i];
 195       b[1] = 0;
 196       if (target_output_hook)
 197         target_output_hook (b);
 198       else
 199         fputs_filtered (b, gdb_stdout);
 200     }
 201   return len;
 202 }
 203
 204 /* GDB version of os_flush_stdout callback.  */
 205
 206 static void
 207 gdb_os_flush_stdout (p)
 208      host_callback *p;
 209 {
 210   gdb_flush (gdb_stdout);
 211 }
 212
 213 /* GDB version of os_write_stderr callback.  */
 214
 215 static int
 216 gdb_os_write_stderr (p, buf, len)
 217      host_callback *p;
 218      const char *buf;
 219      int len;
 220 {
 221   int i;
 222   char b[2];
 223
 224   for (i = 0; i < len; i++)
 225     {
 226       b[0] = buf[i];
 227       b[1] = 0;
 228       if (target_output_hook)
 229         target_output_hook (b);
 230       else
 231         fputs_filtered (b, gdb_stderr);
 232     }
 233   return len;
 234 }
 235
 236 /* GDB version of os_flush_stderr callback.  */
 237
 238 static void
 239 gdb_os_flush_stderr (p)
 240      host_callback *p;
 241 {
 242   gdb_flush (gdb_stderr);
 243 }
 244
 245 /* GDB version of printf_filtered callback.  */
 246
 247 /* VARARGS */
 248 static void
 249 #ifdef ANSI_PROTOTYPES
 250 gdb_os_printf_filtered (host_callback *p, const char *format, ...)
 251 #else
 252 gdb_os_printf_filtered (p, va_alist)
 253      host_callback *p;
 254      va_dcl
 255 #endif
 256 {
 257   va_list args;
 258 #ifdef ANSI_PROTOTYPES
 259   va_start (args, format);
 260 #else
 261   char *format;
 262
 263   va_start (args);
 264   format = va_arg (args, char *);
 265 #endif
 266
 267   vfprintf_filtered (gdb_stdout, format, args);
 268
 269   va_end (args);
 270 }
 271
 272 /* GDB version of error vprintf_filtered.  */
 273
 274 /* VARARGS */
 275 static void
 276 #ifdef ANSI_PROTOTYPES
 277 gdb_os_vprintf_filtered (host_callback *p, const char *format, va_list ap)
 278 #else
 279 gdb_os_vprintf_filtered (p, format, ap)
 280      host_callback *p;
 281      char *format;
 282      va_list ap;
 283 #endif
 284 {
 285   vfprintf_filtered (gdb_stdout, format, ap);
 286 }
 287
 288 /* GDB version of error evprintf_filtered.  */
 289
 290 /* VARARGS */
 291 static void
 292 #ifdef ANSI_PROTOTYPES
 293 gdb_os_evprintf_filtered (host_callback *p, const char *format, va_list ap)
 294 #else
 295 gdb_os_evprintf_filtered (p, format, ap)
 296      host_callback *p;
 297      char *format;
 298      va_list ap;
 299 #endif
 300 {
 301   vfprintf_filtered (gdb_stderr, format, ap);
 302 }
 303
 304 /* GDB version of error callback.  */
 305
 306 /* VARARGS */
 307 static void
 308 #ifdef ANSI_PROTOTYPES
 309 gdb_os_error (host_callback *p, const char *format, ...)
 310 #else
 311 gdb_os_error (p, va_alist)
 312      host_callback *p;
 313      va_dcl
 314 #endif
 315 {
 316   if (error_hook)
 317     (*error_hook) ();
 318   else
 319     {
 320       va_list args;
 321 #ifdef ANSI_PROTOTYPES
 322       va_start (args, format);
 323 #else
 324       char *format;
 325
 326       va_start (args);
 327       format = va_arg (args, char *);
 328 #endif
 329
 330       error_begin ();
 331       vfprintf_filtered (gdb_stderr, format, args);
 332       fprintf_filtered (gdb_stderr, "\n");
 333       va_end (args);
 334       return_to_top_level (RETURN_ERROR);
 335     }
 336 }
 337
 338 static void
 339 gdbsim_fetch_register (regno)
 340 int regno;
 341 {
 342   if (regno == -1)
 343     {
 344       for (regno = 0; regno < NUM_REGS; regno++)
 345         gdbsim_fetch_register (regno);
 346     }
 347   else if (reg_names[regno] != NULL && *reg_names[regno] != '\0')
 348     {
 349       char buf[MAX_REGISTER_RAW_SIZE];
 350
 351       sim_fetch_register (gdbsim_desc, regno, buf);
 352       supply_register (regno, buf);
 353       if (sr_get_debug ())
 354         {
 355           printf_filtered ("gdbsim_fetch_register: %d", regno);
 356           /* FIXME: We could print something more intelligible.  */
 357           dump_mem (buf, REGISTER_RAW_SIZE (regno));
 358         }
 359     }
 360 }
 361
 362
 363 static void
 364 gdbsim_store_register (regno)
 365 int regno;
 366 {
 367   if (regno  == -1)
 368     {
 369       for (regno = 0; regno < NUM_REGS; regno++)
 370         gdbsim_store_register (regno);
 371     }
 372   else if (reg_names[regno] != NULL && *reg_names[regno] != '\0')
 373     {
 374       /* FIXME: Until read_register() returns LONGEST, we have this.  */
 375       char tmp[MAX_REGISTER_RAW_SIZE];
 376       read_register_gen (regno, tmp);
 377       sim_store_register (gdbsim_desc, regno, tmp);
 378       if (sr_get_debug ())
 379         {
 380           printf_filtered ("gdbsim_store_register: %d", regno);
 381           /* FIXME: We could print something more intelligible.  */
 382           dump_mem (tmp, REGISTER_RAW_SIZE (regno));
 383         }
 384     }
 385 }
 386
 387 /* Kill the running program.  This may involve closing any open files
 388    and releasing other resources acquired by the simulated program.  */
 389
 390 static void
 391 gdbsim_kill ()
 392 {
 393   if (sr_get_debug ())
 394     printf_filtered ("gdbsim_kill\n");
 395
 396   /* There is no need to `kill' running simulator - the simulator is
 397      not running */
 398   inferior_pid = 0;
 399 }
 400
 401 /* Load an executable file into the target process.  This is expected to
 402    not only bring new code into the target process, but also to update
 403    GDB's symbol tables to match.  */
 404
 405 static void
 406 gdbsim_load (prog, fromtty)
 407      char *prog;
 408      int fromtty;
 409 {
 410   if (sr_get_debug ())
 411     printf_filtered ("gdbsim_load: prog \"%s\"\n", prog);
 412
 413   inferior_pid = 0;
 414
 415   /* FIXME: We will print two messages on error.
 416      Need error to either not print anything if passed NULL or need
 417      another routine that doesn't take any arguments.  */
 418   if (sim_load (gdbsim_desc, prog, NULL, fromtty) == SIM_RC_FAIL)
 419     error ("unable to load program");
 420
 421   /* FIXME: If a load command should reset the targets registers then
 422      a call to sim_create_inferior() should go here. */
 423
 424   program_loaded = 1;
 425 }
 426
 427
 428 /* Start an inferior process and set inferior_pid to its pid.
 429    EXEC_FILE is the file to run.
 430    ARGS is a string containing the arguments to the program.
 431    ENV is the environment vector to pass.  Errors reported with error().
 432    On VxWorks and various standalone systems, we ignore exec_file.  */
 433 /* This is called not only when we first attach, but also when the
 434    user types "run" after having attached.  */
 435
 436 static void
 437 gdbsim_create_inferior (exec_file, args, env)
 438      char *exec_file;
 439      char *args;
 440      char **env;
 441 {
 442   int len;
 443   char *arg_buf,**argv;
 444
 445   if (exec_file == 0 || exec_bfd == 0)
 446     warning ("No exec file specified.");
 447   if (! program_loaded)
 448     warning ("No program loaded.");
 449
 450   if (sr_get_debug ())
 451     printf_filtered ("gdbsim_create_inferior: exec_file \"%s\", args \"%s\"\n",
 452                      (exec_file ? exec_file: "(NULL)"),
 453                      args);
 454
 455   gdbsim_kill ();
 456   remove_breakpoints ();
 457   init_wait_for_inferior ();
 458
 459   if (exec_file != NULL)
 460     {
 461       len = strlen (exec_file) + 1 + strlen (args) + 1 + /*slop*/ 10;
 462       arg_buf = (char *) alloca (len);
 463       arg_buf[0] = '\0';
 464       strcat (arg_buf, exec_file);
 465       strcat (arg_buf, " ");
 466       strcat (arg_buf, args);
 467       argv = buildargv (arg_buf);
 468       make_cleanup (freeargv, (char *) argv);
 469     }
 470   else
 471     argv = NULL;
 472   sim_create_inferior (gdbsim_desc, exec_bfd, argv, env);
 473
 474   inferior_pid = 42;
 475   insert_breakpoints (); /* Needed to get correct instruction in cache */
 476
 477   /* NB: Entry point already set by sim_create_inferior. */
 478   proceed ((CORE_ADDR)-1, TARGET_SIGNAL_DEFAULT, 0);
 479 }
 480
 481 /* The open routine takes the rest of the parameters from the command,
 482    and (if successful) pushes a new target onto the stack.
 483    Targets should supply this routine, if only to provide an error message.  */
 484 /* Called when selecting the simulator. EG: (gdb) target sim name.  */
 485
 486 static void
 487 gdbsim_open (args, from_tty)
 488      char *args;
 489      int from_tty;
 490 {
 491   int len;
 492   char *arg_buf;
 493   char **argv;
 494
 495   if (sr_get_debug ())
 496     printf_filtered ("gdbsim_open: args \"%s\"\n", args ? args : "(null)");
 497
 498   /* Remove current simulator if one exists.  Only do this if the simulator
 499      has been opened because sim_close requires it.
 500      This is important because the call to push_target below will cause
 501      sim_close to be called if the simulator is already open, but push_target
 502      is called after sim_open!  We can't move the call to push_target before
 503      the call to sim_open because sim_open may invoke `error'.  */
 504   if (gdbsim_desc != NULL)
 505     unpush_target (&gdbsim_ops);
 506
 507   len = (7 + 1 /* gdbsim */
 508          + strlen (" -E little")
 509          + strlen (" --architecture=xxxxxxxxxx")
 510          + (args ? strlen (args) : 0)
 511          + 50) /* slack */;
 512   arg_buf = (char *) alloca (len);
 513   strcpy (arg_buf, "gdbsim"); /* 7 */
 514   /* Specify the byte order for the target when it is both selectable
 515      and explicitly specified by the user (not auto detected). */
 516 #ifdef TARGET_BYTE_ORDER_SELECTABLE
 517   if (!target_byte_order_auto)
 518     {
 519       switch (TARGET_BYTE_ORDER)
 520         {
 521         case BIG_ENDIAN:
 522           strcat (arg_buf, " -E big");
 523           break;
 524         case LITTLE_ENDIAN:
 525           strcat (arg_buf, " -E little");
 526           break;
 527         default:
 528           fatal ("Value of TARGET_BYTE_ORDER unknown");
 529         }
 530     }
 531 #endif
 532   /* Specify the architecture of the target when it has been
 533      explicitly specified */
 534   if (!target_architecture_auto)
 535     {
 536       strcat (arg_buf, " --architecture=");
 537       strcat (arg_buf, target_architecture->printable_name);
 538     }
 539   /* finally, any explicit args */
 540   if (args)
 541     {
 542       strcat (arg_buf, " "); /* 1 */
 543       strcat (arg_buf, args);
 544     }
 545   argv = buildargv (arg_buf);
 546   if (argv == NULL)
 547     error ("Insufficient memory available to allocate simulator arg list.");
 548   make_cleanup (freeargv, (char *) argv);
 549
 550   init_callbacks ();
 551   gdbsim_desc = sim_open (SIM_OPEN_DEBUG, &gdb_callback, exec_bfd, argv);
 552
 553   if (gdbsim_desc == 0)
 554     error ("unable to create simulator instance");
 555
 556   push_target (&gdbsim_ops);
 557   target_fetch_registers (-1);
 558   printf_filtered ("Connected to the simulator.\n");
 559 }
 560
 561 /* Does whatever cleanup is required for a target that we are no longer
 562    going to be calling.  Argument says whether we are quitting gdb and
 563    should not get hung in case of errors, or whether we want a clean
 564    termination even if it takes a while.  This routine is automatically
 565    always called just before a routine is popped off the target stack.
 566    Closing file descriptors and freeing memory are typical things it should
 567    do.  */
 568 /* Close out all files and local state before this target loses control. */
 569
 570 static void
 571 gdbsim_close (quitting)
 572      int quitting;
 573 {
 574   if (sr_get_debug ())
 575     printf_filtered ("gdbsim_close: quitting %d\n", quitting);
 576
 577   program_loaded = 0;
 578
 579   if (gdbsim_desc != NULL)
 580     {
 581       sim_close (gdbsim_desc, quitting);
 582       gdbsim_desc = NULL;
 583     }
 584
 585   end_callbacks ();
 586 }
 587
 588 /* Takes a program previously attached to and detaches it.
 589    The program may resume execution (some targets do, some don't) and will
 590    no longer stop on signals, etc.  We better not have left any breakpoints
 591    in the program or it'll die when it hits one.  ARGS is arguments
 592    typed by the user (e.g. a signal to send the process).  FROM_TTY
 593    says whether to be verbose or not.  */
 594 /* Terminate the open connection to the remote debugger.
 595    Use this when you want to detach and do something else with your gdb.  */
 596
 597 static void
 598 gdbsim_detach (args,from_tty)
 599      char *args;
 600      int from_tty;
 601 {
 602   if (sr_get_debug ())
 603     printf_filtered ("gdbsim_detach: args \"%s\"\n", args);
 604
 605   pop_target ();                /* calls gdbsim_close to do the real work */
 606   if (from_tty)
 607     printf_filtered ("Ending simulator %s debugging\n", target_shortname);
 608 }
 609
 610 /* Resume execution of the target process.  STEP says whether to single-step
 611    or to run free; SIGGNAL is the signal value (e.g. SIGINT) to be given
 612    to the target, or zero for no signal.  */
 613
 614 static enum target_signal resume_siggnal;
 615 static int resume_step;
 616
 617 static void
 618 gdbsim_resume (pid, step, siggnal)
 619      int pid, step;
 620      enum target_signal siggnal;
 621 {
 622   if (inferior_pid != 42)
 623     error ("The program is not being run.");
 624
 625   if (sr_get_debug ())
 626     printf_filtered ("gdbsim_resume: step %d, signal %d\n", step, siggnal);
 627
 628   resume_siggnal = siggnal;
 629   resume_step = step;
 630 }
 631
 632 /* Notify the simulator of an asynchronous request to stop.
 633
 634    The simulator shall ensure that the stop request is eventually
 635    delivered to the simulator.  If the call is made while the
 636    simulator is not running then the stop request is processed when
 637    the simulator is next resumed.
 638
 639    For simulators that do not support this operation, just abort */
 640
 641 static void
 642 gdbsim_stop ()
 643 {
 644   if (! sim_stop (gdbsim_desc))
 645     {
 646       quit ();
 647     }
 648 }
 649
 650 /* GDB version of os_poll_quit callback.
 651    Taken from gdb/util.c - should be in a library */
 652
 653 static int
 654 gdb_os_poll_quit (p)
 655      host_callback *p;
 656 {
 657   notice_quit ();
 658   if (quit_flag) /* gdb's idea of quit */
 659     {
 660       quit_flag = 0; /* we've stolen it */
 661       return 1;
 662     }
 663   else if (immediate_quit)
 664     {
 665       return 1;
 666     }
 667   return 0;
 668 }
 669
 670 /* Wait for inferior process to do something.  Return pid of child,
 671    or -1 in case of error; store status through argument pointer STATUS,
 672    just as `wait' would. */
 673
 674 static void
 675 gdbsim_cntrl_c (signo)
 676      int signo;
 677 {
 678   gdbsim_stop ();
 679 }
 680
 681 static int
 682 gdbsim_wait (pid, status)
 683      int pid;
 684      struct target_waitstatus *status;
 685 {
 686   static RETSIGTYPE (*prev_sigint) ();
 687   int sigrc = 0;
 688   enum sim_stop reason = sim_running;
 689
 690   if (sr_get_debug ())
 691     printf_filtered ("gdbsim_wait\n");
 692
 693 #if defined (HAVE_SIGACTION) && defined (SA_RESTART)
 694   {
 695     struct sigaction sa, osa;
 696     sa.sa_handler = gdbsim_cntrl_c;
 697     sigemptyset (&sa.sa_mask);
 698     sa.sa_flags = 0;
 699     sigaction (SIGINT, &sa, &osa);
 700     prev_sigint = osa.sa_handler;
 701   }
 702 #else
 703   prev_sigint = signal (SIGINT, gdbsim_cntrl_c);
 704 #endif
 705   sim_resume (gdbsim_desc, resume_step,
 706               target_signal_to_host (resume_siggnal));
 707   signal (SIGINT, prev_sigint);
 708   resume_step = 0;
 709
 710   sim_stop_reason (gdbsim_desc, &reason, &sigrc);
 711
 712   switch (reason)
 713     {
 714     case sim_exited:
 715       status->kind = TARGET_WAITKIND_EXITED;
 716       status->value.integer = sigrc;
 717       break;
 718     case sim_stopped:
 719       switch (sigrc)
 720         {
 721         case SIGABRT:
 722           quit ();
 723           break;
 724         case SIGINT:
 725         case SIGTRAP:
 726         default:
 727           status->kind = TARGET_WAITKIND_STOPPED;
 728           /* The signal in sigrc is a host signal.  That probably
 729              should be fixed.  */
 730           status->value.sig = target_signal_from_host (sigrc);
 731           break;
 732         }
 733       break;
 734     case sim_signalled:
 735       status->kind = TARGET_WAITKIND_SIGNALLED;
 736       /* The signal in sigrc is a host signal.  That probably
 737          should be fixed.  */
 738       status->value.sig = target_signal_from_host (sigrc);
 739       break;
 740     case sim_running:
 741     case sim_polling:
 742       /* FIXME: Is this correct? */
 743       break;
 744     }
 745
 746   return inferior_pid;
 747 }
 748
 749 /* Get ready to modify the registers array.  On machines which store
 750    individual registers, this doesn't need to do anything.  On machines
 751    which store all the registers in one fell swoop, this makes sure
 752    that registers contains all the registers from the program being
 753    debugged.  */
 754
 755 static void
 756 gdbsim_prepare_to_store ()
 757 {
 758   /* Do nothing, since we can store individual regs */
 759 }
 760
 761 static int
 762 gdbsim_xfer_inferior_memory (memaddr, myaddr, len, write, target)
 763      CORE_ADDR memaddr;
 764      char *myaddr;
 765      int len;
 766      int write;
 767      struct target_ops *target;                 /* ignored */
 768 {
 769   if (! program_loaded)
 770     error ("No program loaded.");
 771
 772   if (sr_get_debug ())
 773     {
 774       printf_filtered ("gdbsim_xfer_inferior_memory: myaddr 0x%x, memaddr 0x%x, len %d, write %d\n",
 775                        myaddr, memaddr, len, write);
 776       if (sr_get_debug () && write)
 777         dump_mem(myaddr, len);
 778     }
 779
 780   if (write)
 781     {
 782       len = sim_write (gdbsim_desc, memaddr, myaddr, len);
 783     }
 784   else
 785     {
 786       len = sim_read (gdbsim_desc, memaddr, myaddr, len);
 787       if (sr_get_debug () && len > 0)
 788         dump_mem(myaddr, len);
 789     }
 790   return len;
 791 }
 792
 793 static void
 794 gdbsim_files_info (target)
 795      struct target_ops *target;
 796 {
 797   char *file = "nothing";
 798
 799   if (exec_bfd)
 800     file = bfd_get_filename (exec_bfd);
 801
 802   if (sr_get_debug ())
 803     printf_filtered ("gdbsim_files_info: file \"%s\"\n", file);
 804
 805   if (exec_bfd)
 806     {
 807       printf_filtered ("\tAttached to %s running program %s\n",
 808                        target_shortname, file);
 809       sim_info (gdbsim_desc, 0);
 810     }
 811 }
 812
 813 /* Clear the simulator's notion of what the break points are.  */
 814
 815 static void
 816 gdbsim_mourn_inferior ()
 817 {
 818   if (sr_get_debug ())
 819     printf_filtered ("gdbsim_mourn_inferior:\n");
 820
 821   remove_breakpoints ();
 822   generic_mourn_inferior ();
 823 }
 824
 825 static int
 826 gdbsim_insert_breakpoint (addr, contents_cache)
 827      CORE_ADDR addr;
 828      char *contents_cache;
 829 {
 830 #ifdef SIM_HAS_BREAKPOINTS
 831   SIM_RC retcode;
 832
 833   retcode = sim_set_breakpoint (gdbsim_desc, addr);
 834
 835   switch (retcode)
 836     {
 837     case SIM_RC_OK:
 838       return 0;
 839     case SIM_RC_INSUFFICIENT_RESOURCES:
 840       return ENOMEM;
 841     default:
 842       return EIO;
 843     }
 844 #else
 845   return memory_insert_breakpoint (addr, contents_cache);
 846 #endif
 847 }
 848
 849 static int
 850 gdbsim_remove_breakpoint (addr, contents_cache)
 851      CORE_ADDR addr;
 852      char *contents_cache;
 853 {
 854 #ifdef SIM_HAS_BREAKPOINTS
 855   SIM_RC retcode;
 856
 857   retcode = sim_clear_breakpoint (gdbsim_desc, addr);
 858
 859   switch (retcode)
 860     {
 861     case SIM_RC_OK:
 862     case SIM_RC_UNKNOWN_BREAKPOINT:
 863       return 0;
 864     case SIM_RC_INSUFFICIENT_RESOURCES:
 865       return ENOMEM;
 866     default:
 867       return EIO;
 868     }
 869 #else
 870   return memory_remove_breakpoint (addr, contents_cache);
 871 #endif
 872 }
 873
 874 /* Pass the command argument through to the simulator verbatim.  The
 875    simulator must do any command interpretation work.  */
 876
 877 static void
 878 simulator_command (args, from_tty)
 879      char *args;
 880      int from_tty;
 881 {
 882   if (gdbsim_desc == NULL)
 883     {
 884
 885       /* PREVIOUSLY: The user may give a command before the simulator
 886          is opened. [...] (??? assuming of course one wishes to
 887          continue to allow commands to be sent to unopened simulators,
 888          which isn't entirely unreasonable). */
 889
 890       /* The simulator is a builtin abstraction of a remote target.
 891          Consistent with that model, access to the simulator, via sim
 892          commands, is restricted to the period when the channel to the
 893          simulator is open. */
 894
 895       error ("Not connected to the simulator target");
 896     }
 897
 898   sim_do_command (gdbsim_desc, args);
 899 }
 900
 901 /* Define the target subroutine names */
 902
 903 struct target_ops gdbsim_ops = {
 904   "sim",                        /* to_shortname */
 905   "simulator",                  /* to_longname */
 906   "Use the compiled-in simulator.",  /* to_doc */
 907   gdbsim_open,                  /* to_open */
 908   gdbsim_close,                 /* to_close */
 909   NULL,                         /* to_attach */
 910   gdbsim_detach,                /* to_detach */
 911   gdbsim_resume,                /* to_resume */
 912   gdbsim_wait,                  /* to_wait */
 913   gdbsim_fetch_register,        /* to_fetch_registers */
 914   gdbsim_store_register,        /* to_store_registers */
 915   gdbsim_prepare_to_store,      /* to_prepare_to_store */
 916   gdbsim_xfer_inferior_memory,  /* to_xfer_memory */
 917   gdbsim_files_info,            /* to_files_info */
 918   gdbsim_insert_breakpoint,     /* to_insert_breakpoint */
 919   gdbsim_remove_breakpoint,     /* to_remove_breakpoint */
 920   NULL,                         /* to_terminal_init */
 921   NULL,                         /* to_terminal_inferior */
 922   NULL,                         /* to_terminal_ours_for_output */
 923   NULL,                         /* to_terminal_ours */
 924   NULL,                         /* to_terminal_info */
 925   gdbsim_kill,                  /* to_kill */
 926   gdbsim_load,                  /* to_load */
 927   NULL,                         /* to_lookup_symbol */
 928   gdbsim_create_inferior,       /* to_create_inferior */
 929   gdbsim_mourn_inferior,        /* to_mourn_inferior */
 930   0,                            /* to_can_run */
 931   0,                            /* to_notice_signals */
 932   0,                            /* to_thread_alive */
 933   gdbsim_stop,                  /* to_stop */
 934   process_stratum,              /* to_stratum */
 935   NULL,                         /* to_next */
 936   1,                            /* to_has_all_memory */
 937   1,                            /* to_has_memory */
 938   1,                            /* to_has_stack */
 939   1,                            /* to_has_registers */
 940   1,                            /* to_has_execution */
 941   NULL,                         /* sections */
 942   NULL,                         /* sections_end */
 943   OPS_MAGIC,                    /* to_magic */
 944 };
 945
 946 void
 947 _initialize_remote_sim ()
 948 {
 949   add_target (&gdbsim_ops);
 950
 951   add_com ("sim <command>", class_obscure, simulator_command,
 952            "Send a command to the simulator.");
 953 }