gdb/remote-sim.c

   1 /* Generic remote debugging interface for simulators.
   2
   3    Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
   4    2002, 2004, 2005, 2006 Free Software Foundation, Inc.
   5
   6    Contributed by Cygnus Support.
   7    Steve Chamberlain (sac@cygnus.com).
   8
   9    This file is part of GDB.
  10
  11    This program is free software; you can redistribute it and/or modify
  12    it under the terms of the GNU General Public License as published by
  13    the Free Software Foundation; either version 2 of the License, or
  14    (at your option) any later version.
  15
  16    This program is distributed in the hope that it will be useful,
  17    but WITHOUT ANY WARRANTY; without even the implied warranty of
  18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19    GNU General Public License for more details.
  20
  21    You should have received a copy of the GNU General Public License
  22    along with this program; if not, write to the Free Software
  23    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24    Boston, MA 02110-1301, USA.  */
  25
  26 #include "defs.h"
  27 #include "inferior.h"
  28 #include "value.h"
  29 #include "gdb_string.h"
  30 #include <ctype.h>
  31 #include <fcntl.h>
  32 #include <signal.h>
  33 #include <setjmp.h>
  34 #include <errno.h>
  35 #include "terminal.h"
  36 #include "target.h"
  37 #include "gdbcore.h"
  38 #include "gdb/callback.h"
  39 #include "gdb/remote-sim.h"
  40 #include "remote-utils.h"
  41 #include "command.h"
  42 #include "regcache.h"
  43 #include "gdb_assert.h"
  44 #include "sim-regno.h"
  45 #include "arch-utils.h"
  46
  47 /* Prototypes */
  48
  49 extern void _initialize_remote_sim (void);
  50
  51 static void dump_mem (char *buf, int len);
  52
  53 static void init_callbacks (void);
  54
  55 static void end_callbacks (void);
  56
  57 static int gdb_os_write_stdout (host_callback *, const char *, int);
  58
  59 static void gdb_os_flush_stdout (host_callback *);
  60
  61 static int gdb_os_write_stderr (host_callback *, const char *, int);
  62
  63 static void gdb_os_flush_stderr (host_callback *);
  64
  65 static int gdb_os_poll_quit (host_callback *);
  66
  67 /* printf_filtered is depreciated */
  68 static void gdb_os_printf_filtered (host_callback *, const char *, ...);
  69
  70 static void gdb_os_vprintf_filtered (host_callback *, const char *, va_list);
  71
  72 static void gdb_os_evprintf_filtered (host_callback *, const char *, va_list);
  73
  74 static void gdb_os_error (host_callback *, const char *, ...);
  75
  76 static void gdbsim_fetch_register (int regno);
  77
  78 static void gdbsim_store_register (int regno);
  79
  80 static void gdbsim_kill (void);
  81
  82 static void gdbsim_load (char *prog, int fromtty);
  83
  84 static void gdbsim_open (char *args, int from_tty);
  85
  86 static void gdbsim_close (int quitting);
  87
  88 static void gdbsim_detach (char *args, int from_tty);
  89
  90 static void gdbsim_resume (ptid_t ptid, int step, enum target_signal siggnal);
  91
  92 static ptid_t gdbsim_wait (ptid_t ptid, struct target_waitstatus *status);
  93
  94 static void gdbsim_prepare_to_store (void);
  95
  96 static void gdbsim_files_info (struct target_ops *target);
  97
  98 static void gdbsim_mourn_inferior (void);
  99
 100 static void gdbsim_stop (void);
 101
 102 void simulator_command (char *args, int from_tty);
 103
 104 /* Naming convention:
 105
 106    sim_* are the interface to the simulator (see remote-sim.h).
 107    gdbsim_* are stuff which is internal to gdb.  */
 108
 109 /* Forward data declarations */
 110 extern struct target_ops gdbsim_ops;
 111
 112 static int program_loaded = 0;
 113
 114 /* We must keep track of whether the simulator has been opened or not because
 115    GDB can call a target's close routine twice, but sim_close doesn't allow
 116    this.  We also need to record the result of sim_open so we can pass it
 117    back to the other sim_foo routines.  */
 118 static SIM_DESC gdbsim_desc = 0;
 119
 120 static void
 121 dump_mem (char *buf, 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%lx", l[0]);
 130           if (len == 8)
 131             printf_filtered (" 0x%lx", l[1]);
 132           printf_filtered ("\n");
 133         }
 134       else
 135         {
 136           int i;
 137           printf_filtered ("\t");
 138           for (i = 0; i < len; i++)
 139             printf_filtered ("0x%x ", buf[i]);
 140           printf_filtered ("\n");
 141         }
 142     }
 143 }
 144
 145 static host_callback gdb_callback;
 146 static int callbacks_initialized = 0;
 147
 148 /* Initialize gdb_callback.  */
 149
 150 static void
 151 init_callbacks (void)
 152 {
 153   if (!callbacks_initialized)
 154     {
 155       gdb_callback = default_callback;
 156       gdb_callback.init (&gdb_callback);
 157       gdb_callback.write_stdout = gdb_os_write_stdout;
 158       gdb_callback.flush_stdout = gdb_os_flush_stdout;
 159       gdb_callback.write_stderr = gdb_os_write_stderr;
 160       gdb_callback.flush_stderr = gdb_os_flush_stderr;
 161       gdb_callback.printf_filtered = gdb_os_printf_filtered;
 162       gdb_callback.vprintf_filtered = gdb_os_vprintf_filtered;
 163       gdb_callback.evprintf_filtered = gdb_os_evprintf_filtered;
 164       gdb_callback.error = gdb_os_error;
 165       gdb_callback.poll_quit = gdb_os_poll_quit;
 166       gdb_callback.magic = HOST_CALLBACK_MAGIC;
 167       callbacks_initialized = 1;
 168     }
 169 }
 170
 171 /* Release callbacks (free resources used by them).  */
 172
 173 static void
 174 end_callbacks (void)
 175 {
 176   if (callbacks_initialized)
 177     {
 178       gdb_callback.shutdown (&gdb_callback);
 179       callbacks_initialized = 0;
 180     }
 181 }
 182
 183 /* GDB version of os_write_stdout callback.  */
 184
 185 static int
 186 gdb_os_write_stdout (host_callback *p, const char *buf, int len)
 187 {
 188   int i;
 189   char b[2];
 190
 191   ui_file_write (gdb_stdtarg, buf, len);
 192   return len;
 193 }
 194
 195 /* GDB version of os_flush_stdout callback.  */
 196
 197 static void
 198 gdb_os_flush_stdout (host_callback *p)
 199 {
 200   gdb_flush (gdb_stdtarg);
 201 }
 202
 203 /* GDB version of os_write_stderr callback.  */
 204
 205 static int
 206 gdb_os_write_stderr (host_callback *p, const char *buf, int len)
 207 {
 208   int i;
 209   char b[2];
 210
 211   for (i = 0; i < len; i++)
 212     {
 213       b[0] = buf[i];
 214       b[1] = 0;
 215       fputs_unfiltered (b, gdb_stdtargerr);
 216     }
 217   return len;
 218 }
 219
 220 /* GDB version of os_flush_stderr callback.  */
 221
 222 static void
 223 gdb_os_flush_stderr (host_callback *p)
 224 {
 225   gdb_flush (gdb_stdtargerr);
 226 }
 227
 228 /* GDB version of printf_filtered callback.  */
 229
 230 static void
 231 gdb_os_printf_filtered (host_callback * p, const char *format,...)
 232 {
 233   va_list args;
 234   va_start (args, format);
 235
 236   vfprintf_filtered (gdb_stdout, format, args);
 237
 238   va_end (args);
 239 }
 240
 241 /* GDB version of error vprintf_filtered.  */
 242
 243 static void
 244 gdb_os_vprintf_filtered (host_callback * p, const char *format, va_list ap)
 245 {
 246   vfprintf_filtered (gdb_stdout, format, ap);
 247 }
 248
 249 /* GDB version of error evprintf_filtered.  */
 250
 251 static void
 252 gdb_os_evprintf_filtered (host_callback * p, const char *format, va_list ap)
 253 {
 254   vfprintf_filtered (gdb_stderr, format, ap);
 255 }
 256
 257 /* GDB version of error callback.  */
 258
 259 static void
 260 gdb_os_error (host_callback * p, const char *format,...)
 261 {
 262   if (deprecated_error_hook)
 263     (*deprecated_error_hook) ();
 264   else
 265     {
 266       va_list args;
 267       va_start (args, format);
 268       verror (format, args);
 269       va_end (args);
 270     }
 271 }
 272
 273 int
 274 one2one_register_sim_regno (int regnum)
 275 {
 276   /* Only makes sense to supply raw registers.  */
 277   gdb_assert (regnum >= 0 && regnum < NUM_REGS);
 278   return regnum;
 279 }
 280
 281 static void
 282 gdbsim_fetch_register (int regno)
 283 {
 284   if (regno == -1)
 285     {
 286       for (regno = 0; regno < NUM_REGS; regno++)
 287         gdbsim_fetch_register (regno);
 288       return;
 289     }
 290
 291   switch (REGISTER_SIM_REGNO (regno))
 292     {
 293     case LEGACY_SIM_REGNO_IGNORE:
 294       break;
 295     case SIM_REGNO_DOES_NOT_EXIST:
 296       {
 297         /* For moment treat a `does not exist' register the same way
 298            as an ``unavailable'' register.  */
 299         char buf[MAX_REGISTER_SIZE];
 300         int nr_bytes;
 301         memset (buf, 0, MAX_REGISTER_SIZE);
 302         regcache_raw_supply (current_regcache, regno, buf);
 303         set_register_cached (regno, -1);
 304         break;
 305       }
 306     default:
 307       {
 308         static int warn_user = 1;
 309         char buf[MAX_REGISTER_SIZE];
 310         int nr_bytes;
 311         gdb_assert (regno >= 0 && regno < NUM_REGS);
 312         memset (buf, 0, MAX_REGISTER_SIZE);
 313         nr_bytes = sim_fetch_register (gdbsim_desc,
 314                                        REGISTER_SIM_REGNO (regno),
 315                                        buf, register_size (current_gdbarch, regno));
 316         if (nr_bytes > 0 && nr_bytes != register_size (current_gdbarch, regno) && warn_user)
 317           {
 318             fprintf_unfiltered (gdb_stderr,
 319                                 "Size of register %s (%d/%d) incorrect (%d instead of %d))",
 320                                 REGISTER_NAME (regno),
 321                                 regno, REGISTER_SIM_REGNO (regno),
 322                                 nr_bytes, register_size (current_gdbarch, regno));
 323             warn_user = 0;
 324           }
 325         /* FIXME: cagney/2002-05-27: Should check `nr_bytes == 0'
 326            indicating that GDB and the SIM have different ideas about
 327            which registers are fetchable.  */
 328         /* Else if (nr_bytes < 0): an old simulator, that doesn't
 329            think to return the register size.  Just assume all is ok.  */
 330         regcache_raw_supply (current_regcache, regno, buf);
 331         if (sr_get_debug ())
 332           {
 333             printf_filtered ("gdbsim_fetch_register: %d", regno);
 334             /* FIXME: We could print something more intelligible.  */
 335             dump_mem (buf, register_size (current_gdbarch, regno));
 336           }
 337         break;
 338       }
 339     }
 340 }
 341
 342
 343 static void
 344 gdbsim_store_register (int regno)
 345 {
 346   if (regno == -1)
 347     {
 348       for (regno = 0; regno < NUM_REGS; regno++)
 349         gdbsim_store_register (regno);
 350       return;
 351     }
 352   else if (REGISTER_SIM_REGNO (regno) >= 0)
 353     {
 354       char tmp[MAX_REGISTER_SIZE];
 355       int nr_bytes;
 356       deprecated_read_register_gen (regno, tmp);
 357       nr_bytes = sim_store_register (gdbsim_desc,
 358                                      REGISTER_SIM_REGNO (regno),
 359                                      tmp, register_size (current_gdbarch, regno));
 360       if (nr_bytes > 0 && nr_bytes != register_size (current_gdbarch, regno))
 361         internal_error (__FILE__, __LINE__,
 362                         _("Register size different to expected"));
 363       /* FIXME: cagney/2002-05-27: Should check `nr_bytes == 0'
 364          indicating that GDB and the SIM have different ideas about
 365          which registers are fetchable.  */
 366       if (sr_get_debug ())
 367         {
 368           printf_filtered ("gdbsim_store_register: %d", regno);
 369           /* FIXME: We could print something more intelligible.  */
 370           dump_mem (tmp, register_size (current_gdbarch, regno));
 371         }
 372     }
 373 }
 374
 375 /* Kill the running program.  This may involve closing any open files
 376    and releasing other resources acquired by the simulated program.  */
 377
 378 static void
 379 gdbsim_kill (void)
 380 {
 381   if (sr_get_debug ())
 382     printf_filtered ("gdbsim_kill\n");
 383
 384   /* There is no need to `kill' running simulator - the simulator is
 385      not running */
 386   inferior_ptid = null_ptid;
 387 }
 388
 389 /* Load an executable file into the target process.  This is expected to
 390    not only bring new code into the target process, but also to update
 391    GDB's symbol tables to match.  */
 392
 393 static void
 394 gdbsim_load (char *prog, int fromtty)
 395 {
 396   if (sr_get_debug ())
 397     printf_filtered ("gdbsim_load: prog \"%s\"\n", prog);
 398
 399   inferior_ptid = null_ptid;
 400
 401   /* FIXME: We will print two messages on error.
 402      Need error to either not print anything if passed NULL or need
 403      another routine that doesn't take any arguments.  */
 404   if (sim_load (gdbsim_desc, prog, NULL, fromtty) == SIM_RC_FAIL)
 405     error (_("unable to load program"));
 406
 407   /* FIXME: If a load command should reset the targets registers then
 408      a call to sim_create_inferior() should go here. */
 409
 410   program_loaded = 1;
 411 }
 412
 413
 414 /* Start an inferior process and set inferior_ptid to its pid.
 415    EXEC_FILE is the file to run.
 416    ARGS is a string containing the arguments to the program.
 417    ENV is the environment vector to pass.  Errors reported with error().
 418    On VxWorks and various standalone systems, we ignore exec_file.  */
 419 /* This is called not only when we first attach, but also when the
 420    user types "run" after having attached.  */
 421
 422 static void
 423 gdbsim_create_inferior (char *exec_file, char *args, char **env, int from_tty)
 424 {
 425   int len;
 426   char *arg_buf, **argv;
 427
 428   if (exec_file == 0 || exec_bfd == 0)
 429     warning (_("No executable file specified."));
 430   if (!program_loaded)
 431     warning (_("No program loaded."));
 432
 433   if (sr_get_debug ())
 434     printf_filtered ("gdbsim_create_inferior: exec_file \"%s\", args \"%s\"\n",
 435                      (exec_file ? exec_file : "(NULL)"),
 436                      args);
 437
 438   gdbsim_kill ();
 439   remove_breakpoints ();
 440   init_wait_for_inferior ();
 441
 442   if (exec_file != NULL)
 443     {
 444       len = strlen (exec_file) + 1 + strlen (args) + 1 + /*slop */ 10;
 445       arg_buf = (char *) alloca (len);
 446       arg_buf[0] = '\0';
 447       strcat (arg_buf, exec_file);
 448       strcat (arg_buf, " ");
 449       strcat (arg_buf, args);
 450       argv = buildargv (arg_buf);
 451       make_cleanup_freeargv (argv);
 452     }
 453   else
 454     argv = NULL;
 455   sim_create_inferior (gdbsim_desc, exec_bfd, argv, env);
 456
 457   inferior_ptid = pid_to_ptid (42);
 458   insert_breakpoints ();        /* Needed to get correct instruction in cache */
 459
 460   clear_proceed_status ();
 461 }
 462
 463 /* The open routine takes the rest of the parameters from the command,
 464    and (if successful) pushes a new target onto the stack.
 465    Targets should supply this routine, if only to provide an error message.  */
 466 /* Called when selecting the simulator. EG: (gdb) target sim name.  */
 467
 468 static void
 469 gdbsim_open (char *args, int from_tty)
 470 {
 471   int len;
 472   char *arg_buf;
 473   char **argv;
 474
 475   if (sr_get_debug ())
 476     printf_filtered ("gdbsim_open: args \"%s\"\n", args ? args : "(null)");
 477
 478   /* Remove current simulator if one exists.  Only do this if the simulator
 479      has been opened because sim_close requires it.
 480      This is important because the call to push_target below will cause
 481      sim_close to be called if the simulator is already open, but push_target
 482      is called after sim_open!  We can't move the call to push_target before
 483      the call to sim_open because sim_open may invoke `error'.  */
 484   if (gdbsim_desc != NULL)
 485     unpush_target (&gdbsim_ops);
 486
 487   len = (7 + 1                  /* gdbsim */
 488          + strlen (" -E little")
 489          + strlen (" --architecture=xxxxxxxxxx")
 490          + (args ? strlen (args) : 0)
 491          + 50) /* slack */ ;
 492   arg_buf = (char *) alloca (len);
 493   strcpy (arg_buf, "gdbsim");   /* 7 */
 494   /* Specify the byte order for the target when it is both selectable
 495      and explicitly specified by the user (not auto detected). */
 496   switch (selected_byte_order ())
 497     {
 498     case BFD_ENDIAN_BIG:
 499       strcat (arg_buf, " -E big");
 500       break;
 501     case BFD_ENDIAN_LITTLE:
 502       strcat (arg_buf, " -E little");
 503       break;
 504     case BFD_ENDIAN_UNKNOWN:
 505       break;
 506     }
 507   /* Specify the architecture of the target when it has been
 508      explicitly specified */
 509   if (selected_architecture_name () != NULL)
 510     {
 511       strcat (arg_buf, " --architecture=");
 512       strcat (arg_buf, selected_architecture_name ());
 513     }
 514   /* finally, any explicit args */
 515   if (args)
 516     {
 517       strcat (arg_buf, " ");    /* 1 */
 518       strcat (arg_buf, args);
 519     }
 520   argv = buildargv (arg_buf);
 521   if (argv == NULL)
 522     error (_("Insufficient memory available to allocate simulator arg list."));
 523   make_cleanup_freeargv (argv);
 524
 525   init_callbacks ();
 526   gdbsim_desc = sim_open (SIM_OPEN_DEBUG, &gdb_callback, exec_bfd, argv);
 527
 528   if (gdbsim_desc == 0)
 529     error (_("unable to create simulator instance"));
 530
 531   push_target (&gdbsim_ops);
 532   target_fetch_registers (-1);
 533   printf_filtered ("Connected to the simulator.\n");
 534 }
 535
 536 /* Does whatever cleanup is required for a target that we are no longer
 537    going to be calling.  Argument says whether we are quitting gdb and
 538    should not get hung in case of errors, or whether we want a clean
 539    termination even if it takes a while.  This routine is automatically
 540    always called just before a routine is popped off the target stack.
 541    Closing file descriptors and freeing memory are typical things it should
 542    do.  */
 543 /* Close out all files and local state before this target loses control. */
 544
 545 static void
 546 gdbsim_close (int quitting)
 547 {
 548   if (sr_get_debug ())
 549     printf_filtered ("gdbsim_close: quitting %d\n", quitting);
 550
 551   program_loaded = 0;
 552
 553   if (gdbsim_desc != NULL)
 554     {
 555       sim_close (gdbsim_desc, quitting);
 556       gdbsim_desc = NULL;
 557     }
 558
 559   end_callbacks ();
 560   generic_mourn_inferior ();
 561 }
 562
 563 /* Takes a program previously attached to and detaches it.
 564    The program may resume execution (some targets do, some don't) and will
 565    no longer stop on signals, etc.  We better not have left any breakpoints
 566    in the program or it'll die when it hits one.  ARGS is arguments
 567    typed by the user (e.g. a signal to send the process).  FROM_TTY
 568    says whether to be verbose or not.  */
 569 /* Terminate the open connection to the remote debugger.
 570    Use this when you want to detach and do something else with your gdb.  */
 571
 572 static void
 573 gdbsim_detach (char *args, int from_tty)
 574 {
 575   if (sr_get_debug ())
 576     printf_filtered ("gdbsim_detach: args \"%s\"\n", args);
 577
 578   pop_target ();                /* calls gdbsim_close to do the real work */
 579   if (from_tty)
 580     printf_filtered ("Ending simulator %s debugging\n", target_shortname);
 581 }
 582
 583 /* Resume execution of the target process.  STEP says whether to single-step
 584    or to run free; SIGGNAL is the signal value (e.g. SIGINT) to be given
 585    to the target, or zero for no signal.  */
 586
 587 static enum target_signal resume_siggnal;
 588 static int resume_step;
 589
 590 static void
 591 gdbsim_resume (ptid_t ptid, int step, enum target_signal siggnal)
 592 {
 593   if (PIDGET (inferior_ptid) != 42)
 594     error (_("The program is not being run."));
 595
 596   if (sr_get_debug ())
 597     printf_filtered ("gdbsim_resume: step %d, signal %d\n", step, siggnal);
 598
 599   resume_siggnal = siggnal;
 600   resume_step = step;
 601 }
 602
 603 /* Notify the simulator of an asynchronous request to stop.
 604
 605    The simulator shall ensure that the stop request is eventually
 606    delivered to the simulator.  If the call is made while the
 607    simulator is not running then the stop request is processed when
 608    the simulator is next resumed.
 609
 610    For simulators that do not support this operation, just abort */
 611
 612 static void
 613 gdbsim_stop (void)
 614 {
 615   if (!sim_stop (gdbsim_desc))
 616     {
 617       quit ();
 618     }
 619 }
 620
 621 /* GDB version of os_poll_quit callback.
 622    Taken from gdb/util.c - should be in a library.  */
 623
 624 static int
 625 gdb_os_poll_quit (host_callback *p)
 626 {
 627   if (deprecated_ui_loop_hook != NULL)
 628     deprecated_ui_loop_hook (0);
 629
 630   if (quit_flag)                /* gdb's idea of quit */
 631     {
 632       quit_flag = 0;            /* we've stolen it */
 633       return 1;
 634     }
 635   else if (immediate_quit)
 636     {
 637       return 1;
 638     }
 639   return 0;
 640 }
 641
 642 /* Wait for inferior process to do something.  Return pid of child,
 643    or -1 in case of error; store status through argument pointer STATUS,
 644    just as `wait' would. */
 645
 646 static void
 647 gdbsim_cntrl_c (int signo)
 648 {
 649   gdbsim_stop ();
 650 }
 651
 652 static ptid_t
 653 gdbsim_wait (ptid_t ptid, struct target_waitstatus *status)
 654 {
 655   static RETSIGTYPE (*prev_sigint) ();
 656   int sigrc = 0;
 657   enum sim_stop reason = sim_running;
 658
 659   if (sr_get_debug ())
 660     printf_filtered ("gdbsim_wait\n");
 661
 662 #if defined (HAVE_SIGACTION) && defined (SA_RESTART)
 663   {
 664     struct sigaction sa, osa;
 665     sa.sa_handler = gdbsim_cntrl_c;
 666     sigemptyset (&sa.sa_mask);
 667     sa.sa_flags = 0;
 668     sigaction (SIGINT, &sa, &osa);
 669     prev_sigint = osa.sa_handler;
 670   }
 671 #else
 672   prev_sigint = signal (SIGINT, gdbsim_cntrl_c);
 673 #endif
 674   sim_resume (gdbsim_desc, resume_step, resume_siggnal);
 675   signal (SIGINT, prev_sigint);
 676   resume_step = 0;
 677
 678   sim_stop_reason (gdbsim_desc, &reason, &sigrc);
 679
 680   switch (reason)
 681     {
 682     case sim_exited:
 683       status->kind = TARGET_WAITKIND_EXITED;
 684       status->value.integer = sigrc;
 685       break;
 686     case sim_stopped:
 687       switch (sigrc)
 688         {
 689         case TARGET_SIGNAL_ABRT:
 690           quit ();
 691           break;
 692         case TARGET_SIGNAL_INT:
 693         case TARGET_SIGNAL_TRAP:
 694         default:
 695           status->kind = TARGET_WAITKIND_STOPPED;
 696           status->value.sig = sigrc;
 697           break;
 698         }
 699       break;
 700     case sim_signalled:
 701       status->kind = TARGET_WAITKIND_SIGNALLED;
 702       status->value.sig = sigrc;
 703       break;
 704     case sim_running:
 705     case sim_polling:
 706       /* FIXME: Is this correct? */
 707       break;
 708     }
 709
 710   return inferior_ptid;
 711 }
 712
 713 /* Get ready to modify the registers array.  On machines which store
 714    individual registers, this doesn't need to do anything.  On machines
 715    which store all the registers in one fell swoop, this makes sure
 716    that registers contains all the registers from the program being
 717    debugged.  */
 718
 719 static void
 720 gdbsim_prepare_to_store (void)
 721 {
 722   /* Do nothing, since we can store individual regs */
 723 }
 724
 725 /* Transfer LEN bytes between GDB address MYADDR and target address
 726    MEMADDR.  If WRITE is non-zero, transfer them to the target,
 727    otherwise transfer them from the target.  TARGET is unused.
 728
 729    Returns the number of bytes transferred. */
 730
 731 static int
 732 gdbsim_xfer_inferior_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len,
 733                              int write, struct mem_attrib *attrib,
 734                              struct target_ops *target)
 735 {
 736   if (!program_loaded)
 737     error (_("No program loaded."));
 738
 739   if (sr_get_debug ())
 740     {
 741       /* FIXME: Send to something other than STDOUT? */
 742       printf_filtered ("gdbsim_xfer_inferior_memory: myaddr 0x");
 743       gdb_print_host_address (myaddr, gdb_stdout);
 744       printf_filtered (", memaddr 0x%s, len %d, write %d\n",
 745                        paddr_nz (memaddr), len, write);
 746       if (sr_get_debug () && write)
 747         dump_mem (myaddr, len);
 748     }
 749
 750   if (write)
 751     {
 752       len = sim_write (gdbsim_desc, memaddr, myaddr, len);
 753     }
 754   else
 755     {
 756       len = sim_read (gdbsim_desc, memaddr, myaddr, len);
 757       if (sr_get_debug () && len > 0)
 758         dump_mem (myaddr, len);
 759     }
 760   return len;
 761 }
 762
 763 static void
 764 gdbsim_files_info (struct target_ops *target)
 765 {
 766   char *file = "nothing";
 767
 768   if (exec_bfd)
 769     file = bfd_get_filename (exec_bfd);
 770
 771   if (sr_get_debug ())
 772     printf_filtered ("gdbsim_files_info: file \"%s\"\n", file);
 773
 774   if (exec_bfd)
 775     {
 776       printf_filtered ("\tAttached to %s running program %s\n",
 777                        target_shortname, file);
 778       sim_info (gdbsim_desc, 0);
 779     }
 780 }
 781
 782 /* Clear the simulator's notion of what the break points are.  */
 783
 784 static void
 785 gdbsim_mourn_inferior (void)
 786 {
 787   if (sr_get_debug ())
 788     printf_filtered ("gdbsim_mourn_inferior:\n");
 789
 790   remove_breakpoints ();
 791   generic_mourn_inferior ();
 792 }
 793
 794 static int
 795 gdbsim_insert_breakpoint (CORE_ADDR addr, bfd_byte *contents_cache)
 796 {
 797   return memory_insert_breakpoint (addr, contents_cache);
 798 }
 799
 800 static int
 801 gdbsim_remove_breakpoint (CORE_ADDR addr, bfd_byte *contents_cache)
 802 {
 803   return memory_remove_breakpoint (addr, contents_cache);
 804 }
 805
 806 /* Pass the command argument through to the simulator verbatim.  The
 807    simulator must do any command interpretation work.  */
 808
 809 void
 810 simulator_command (char *args, int from_tty)
 811 {
 812   if (gdbsim_desc == NULL)
 813     {
 814
 815       /* PREVIOUSLY: The user may give a command before the simulator
 816          is opened. [...] (??? assuming of course one wishes to
 817          continue to allow commands to be sent to unopened simulators,
 818          which isn't entirely unreasonable). */
 819
 820       /* The simulator is a builtin abstraction of a remote target.
 821          Consistent with that model, access to the simulator, via sim
 822          commands, is restricted to the period when the channel to the
 823          simulator is open. */
 824
 825       error (_("Not connected to the simulator target"));
 826     }
 827
 828   sim_do_command (gdbsim_desc, args);
 829
 830   /* Invalidate the register cache, in case the simulator command does
 831      something funny. */
 832   registers_changed ();
 833 }
 834
 835 /* Define the target subroutine names */
 836
 837 struct target_ops gdbsim_ops;
 838
 839 static void
 840 init_gdbsim_ops (void)
 841 {
 842   gdbsim_ops.to_shortname = "sim";
 843   gdbsim_ops.to_longname = "simulator";
 844   gdbsim_ops.to_doc = "Use the compiled-in simulator.";
 845   gdbsim_ops.to_open = gdbsim_open;
 846   gdbsim_ops.to_close = gdbsim_close;
 847   gdbsim_ops.to_detach = gdbsim_detach;
 848   gdbsim_ops.to_resume = gdbsim_resume;
 849   gdbsim_ops.to_wait = gdbsim_wait;
 850   gdbsim_ops.to_fetch_registers = gdbsim_fetch_register;
 851   gdbsim_ops.to_store_registers = gdbsim_store_register;
 852   gdbsim_ops.to_prepare_to_store = gdbsim_prepare_to_store;
 853   gdbsim_ops.deprecated_xfer_memory = gdbsim_xfer_inferior_memory;
 854   gdbsim_ops.to_files_info = gdbsim_files_info;
 855   gdbsim_ops.to_insert_breakpoint = gdbsim_insert_breakpoint;
 856   gdbsim_ops.to_remove_breakpoint = gdbsim_remove_breakpoint;
 857   gdbsim_ops.to_kill = gdbsim_kill;
 858   gdbsim_ops.to_load = gdbsim_load;
 859   gdbsim_ops.to_create_inferior = gdbsim_create_inferior;
 860   gdbsim_ops.to_mourn_inferior = gdbsim_mourn_inferior;
 861   gdbsim_ops.to_stop = gdbsim_stop;
 862   gdbsim_ops.to_stratum = process_stratum;
 863   gdbsim_ops.to_has_all_memory = 1;
 864   gdbsim_ops.to_has_memory = 1;
 865   gdbsim_ops.to_has_stack = 1;
 866   gdbsim_ops.to_has_registers = 1;
 867   gdbsim_ops.to_has_execution = 1;
 868   gdbsim_ops.to_magic = OPS_MAGIC;
 869
 870 #ifdef TARGET_REDEFINE_DEFAULT_OPS
 871   TARGET_REDEFINE_DEFAULT_OPS (&gdbsim_ops);
 872 #endif
 873 }
 874
 875 void
 876 _initialize_remote_sim (void)
 877 {
 878   init_gdbsim_ops ();
 879   add_target (&gdbsim_ops);
 880
 881   add_com ("sim", class_obscure, simulator_command,
 882            _("Send a command to the simulator."));
 883 }