gdb/remote-sim.c

   1 /* Generic remote debugging interface for simulators.
   2
   3    Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
   4    2004, 2005, 2006, 2007, 2008 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 3 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, see <http://www.gnu.org/licenses/>.  */
  23
  24 #include "defs.h"
  25 #include "inferior.h"
  26 #include "value.h"
  27 #include "gdb_string.h"
  28 #include <ctype.h>
  29 #include <fcntl.h>
  30 #include <signal.h>
  31 #include <setjmp.h>
  32 #include <errno.h>
  33 #include "terminal.h"
  34 #include "target.h"
  35 #include "gdbcore.h"
  36 #include "gdb/callback.h"
  37 #include "gdb/remote-sim.h"
  38 #include "command.h"
  39 #include "regcache.h"
  40 #include "gdb_assert.h"
  41 #include "sim-regno.h"
  42 #include "arch-utils.h"
  43 #include "readline/readline.h"
  44 #include "gdbthread.h"
  45
  46 /* Prototypes */
  47
  48 extern void _initialize_remote_sim (void);
  49
  50 static void dump_mem (char *buf, int len);
  51
  52 static void init_callbacks (void);
  53
  54 static void end_callbacks (void);
  55
  56 static int gdb_os_write_stdout (host_callback *, const char *, int);
  57
  58 static void gdb_os_flush_stdout (host_callback *);
  59
  60 static int gdb_os_write_stderr (host_callback *, const char *, int);
  61
  62 static void gdb_os_flush_stderr (host_callback *);
  63
  64 static int gdb_os_poll_quit (host_callback *);
  65
  66 /* printf_filtered is depreciated */
  67 static void gdb_os_printf_filtered (host_callback *, const char *, ...);
  68
  69 static void gdb_os_vprintf_filtered (host_callback *, const char *, va_list);
  70
  71 static void gdb_os_evprintf_filtered (host_callback *, const char *, va_list);
  72
  73 static void gdb_os_error (host_callback *, const char *, ...);
  74
  75 static void gdbsim_fetch_register (struct regcache *regcache, int regno);
  76
  77 static void gdbsim_store_register (struct regcache *regcache, int regno);
  78
  79 static void gdbsim_kill (void);
  80
  81 static void gdbsim_load (char *prog, int fromtty);
  82
  83 static void gdbsim_open (char *args, int from_tty);
  84
  85 static void gdbsim_close (int quitting);
  86
  87 static void gdbsim_detach (char *args, int from_tty);
  88
  89 static void gdbsim_resume (ptid_t ptid, int step, enum target_signal siggnal);
  90
  91 static ptid_t gdbsim_wait (ptid_t ptid, struct target_waitstatus *status);
  92
  93 static void gdbsim_prepare_to_store (struct regcache *regcache);
  94
  95 static void gdbsim_files_info (struct target_ops *target);
  96
  97 static void gdbsim_mourn_inferior (void);
  98
  99 static void gdbsim_stop (ptid_t ptid);
 100
 101 void simulator_command (char *args, int from_tty);
 102
 103 /* Naming convention:
 104
 105    sim_* are the interface to the simulator (see remote-sim.h).
 106    gdbsim_* are stuff which is internal to gdb.  */
 107
 108 /* Forward data declarations */
 109 extern struct target_ops gdbsim_ops;
 110
 111 static int program_loaded = 0;
 112
 113 /* We must keep track of whether the simulator has been opened or not because
 114    GDB can call a target's close routine twice, but sim_close doesn't allow
 115    this.  We also need to record the result of sim_open so we can pass it
 116    back to the other sim_foo routines.  */
 117 static SIM_DESC gdbsim_desc = 0;
 118
 119 /* This is the ptid we use while we're connected to the simulator.
 120    Its value is arbitrary, as the simulator target don't have a notion
 121    or processes or threads, but we need something non-null to place in
 122    inferior_ptid.  */
 123 static ptid_t remote_sim_ptid;
 124
 125 static void
 126 dump_mem (char *buf, int len)
 127 {
 128   if (len <= 8)
 129     {
 130       if (len == 8 || len == 4)
 131         {
 132           long l[2];
 133           memcpy (l, buf, len);
 134           printf_filtered ("\t0x%lx", l[0]);
 135           if (len == 8)
 136             printf_filtered (" 0x%lx", l[1]);
 137           printf_filtered ("\n");
 138         }
 139       else
 140         {
 141           int i;
 142           printf_filtered ("\t");
 143           for (i = 0; i < len; i++)
 144             printf_filtered ("0x%x ", buf[i]);
 145           printf_filtered ("\n");
 146         }
 147     }
 148 }
 149
 150 static host_callback gdb_callback;
 151 static int callbacks_initialized = 0;
 152
 153 /* Initialize gdb_callback.  */
 154
 155 static void
 156 init_callbacks (void)
 157 {
 158   if (!callbacks_initialized)
 159     {
 160       gdb_callback = default_callback;
 161       gdb_callback.init (&gdb_callback);
 162       gdb_callback.write_stdout = gdb_os_write_stdout;
 163       gdb_callback.flush_stdout = gdb_os_flush_stdout;
 164       gdb_callback.write_stderr = gdb_os_write_stderr;
 165       gdb_callback.flush_stderr = gdb_os_flush_stderr;
 166       gdb_callback.printf_filtered = gdb_os_printf_filtered;
 167       gdb_callback.vprintf_filtered = gdb_os_vprintf_filtered;
 168       gdb_callback.evprintf_filtered = gdb_os_evprintf_filtered;
 169       gdb_callback.error = gdb_os_error;
 170       gdb_callback.poll_quit = gdb_os_poll_quit;
 171       gdb_callback.magic = HOST_CALLBACK_MAGIC;
 172       callbacks_initialized = 1;
 173     }
 174 }
 175
 176 /* Release callbacks (free resources used by them).  */
 177
 178 static void
 179 end_callbacks (void)
 180 {
 181   if (callbacks_initialized)
 182     {
 183       gdb_callback.shutdown (&gdb_callback);
 184       callbacks_initialized = 0;
 185     }
 186 }
 187
 188 /* GDB version of os_write_stdout callback.  */
 189
 190 static int
 191 gdb_os_write_stdout (host_callback *p, const char *buf, int len)
 192 {
 193   int i;
 194   char b[2];
 195
 196   ui_file_write (gdb_stdtarg, buf, len);
 197   return len;
 198 }
 199
 200 /* GDB version of os_flush_stdout callback.  */
 201
 202 static void
 203 gdb_os_flush_stdout (host_callback *p)
 204 {
 205   gdb_flush (gdb_stdtarg);
 206 }
 207
 208 /* GDB version of os_write_stderr callback.  */
 209
 210 static int
 211 gdb_os_write_stderr (host_callback *p, const char *buf, int len)
 212 {
 213   int i;
 214   char b[2];
 215
 216   for (i = 0; i < len; i++)
 217     {
 218       b[0] = buf[i];
 219       b[1] = 0;
 220       fputs_unfiltered (b, gdb_stdtargerr);
 221     }
 222   return len;
 223 }
 224
 225 /* GDB version of os_flush_stderr callback.  */
 226
 227 static void
 228 gdb_os_flush_stderr (host_callback *p)
 229 {
 230   gdb_flush (gdb_stdtargerr);
 231 }
 232
 233 /* GDB version of printf_filtered callback.  */
 234
 235 static void
 236 gdb_os_printf_filtered (host_callback * p, const char *format,...)
 237 {
 238   va_list args;
 239   va_start (args, format);
 240
 241   vfprintf_filtered (gdb_stdout, format, args);
 242
 243   va_end (args);
 244 }
 245
 246 /* GDB version of error vprintf_filtered.  */
 247
 248 static void
 249 gdb_os_vprintf_filtered (host_callback * p, const char *format, va_list ap)
 250 {
 251   vfprintf_filtered (gdb_stdout, format, ap);
 252 }
 253
 254 /* GDB version of error evprintf_filtered.  */
 255
 256 static void
 257 gdb_os_evprintf_filtered (host_callback * p, const char *format, va_list ap)
 258 {
 259   vfprintf_filtered (gdb_stderr, format, ap);
 260 }
 261
 262 /* GDB version of error callback.  */
 263
 264 static void
 265 gdb_os_error (host_callback * p, const char *format,...)
 266 {
 267   if (deprecated_error_hook)
 268     (*deprecated_error_hook) ();
 269   else
 270     {
 271       va_list args;
 272       va_start (args, format);
 273       verror (format, args);
 274       va_end (args);
 275     }
 276 }
 277
 278 int
 279 one2one_register_sim_regno (struct gdbarch *gdbarch, int regnum)
 280 {
 281   /* Only makes sense to supply raw registers.  */
 282   gdb_assert (regnum >= 0 && regnum < gdbarch_num_regs (gdbarch));
 283   return regnum;
 284 }
 285
 286 static void
 287 gdbsim_fetch_register (struct regcache *regcache, int regno)
 288 {
 289   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 290   if (regno == -1)
 291     {
 292       for (regno = 0; regno < gdbarch_num_regs (gdbarch); regno++)
 293         gdbsim_fetch_register (regcache, regno);
 294       return;
 295     }
 296
 297   switch (gdbarch_register_sim_regno (gdbarch, regno))
 298     {
 299     case LEGACY_SIM_REGNO_IGNORE:
 300       break;
 301     case SIM_REGNO_DOES_NOT_EXIST:
 302       {
 303         /* For moment treat a `does not exist' register the same way
 304            as an ``unavailable'' register.  */
 305         char buf[MAX_REGISTER_SIZE];
 306         int nr_bytes;
 307         memset (buf, 0, MAX_REGISTER_SIZE);
 308         regcache_raw_supply (regcache, regno, buf);
 309         break;
 310       }
 311
 312     default:
 313       {
 314         static int warn_user = 1;
 315         char buf[MAX_REGISTER_SIZE];
 316         int nr_bytes;
 317         gdb_assert (regno >= 0 && regno < gdbarch_num_regs (gdbarch));
 318         memset (buf, 0, MAX_REGISTER_SIZE);
 319         nr_bytes = sim_fetch_register (gdbsim_desc,
 320                                        gdbarch_register_sim_regno
 321                                          (gdbarch, regno),
 322                                        buf,
 323                                        register_size (gdbarch, regno));
 324         if (nr_bytes > 0
 325             && nr_bytes != register_size (gdbarch, regno) && warn_user)
 326           {
 327             fprintf_unfiltered (gdb_stderr,
 328                                 "Size of register %s (%d/%d) incorrect (%d instead of %d))",
 329                                 gdbarch_register_name (gdbarch, regno),
 330                                 regno,
 331                                 gdbarch_register_sim_regno
 332                                   (gdbarch, regno),
 333                                 nr_bytes, register_size (gdbarch, regno));
 334             warn_user = 0;
 335           }
 336         /* FIXME: cagney/2002-05-27: Should check `nr_bytes == 0'
 337            indicating that GDB and the SIM have different ideas about
 338            which registers are fetchable.  */
 339         /* Else if (nr_bytes < 0): an old simulator, that doesn't
 340            think to return the register size.  Just assume all is ok.  */
 341         regcache_raw_supply (regcache, regno, buf);
 342         if (remote_debug)
 343           {
 344             printf_filtered ("gdbsim_fetch_register: %d", regno);
 345             /* FIXME: We could print something more intelligible.  */
 346             dump_mem (buf, register_size (gdbarch, regno));
 347           }
 348         break;
 349       }
 350     }
 351 }
 352
 353
 354 static void
 355 gdbsim_store_register (struct regcache *regcache, int regno)
 356 {
 357   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 358   if (regno == -1)
 359     {
 360       for (regno = 0; regno < gdbarch_num_regs (gdbarch); regno++)
 361         gdbsim_store_register (regcache, regno);
 362       return;
 363     }
 364   else if (gdbarch_register_sim_regno (gdbarch, regno) >= 0)
 365     {
 366       char tmp[MAX_REGISTER_SIZE];
 367       int nr_bytes;
 368       regcache_cooked_read (regcache, regno, tmp);
 369       nr_bytes = sim_store_register (gdbsim_desc,
 370                                      gdbarch_register_sim_regno
 371                                        (gdbarch, regno),
 372                                      tmp, register_size (gdbarch, regno));
 373       if (nr_bytes > 0 && nr_bytes != register_size (gdbarch, regno))
 374         internal_error (__FILE__, __LINE__,
 375                         _("Register size different to expected"));
 376       /* FIXME: cagney/2002-05-27: Should check `nr_bytes == 0'
 377          indicating that GDB and the SIM have different ideas about
 378          which registers are fetchable.  */
 379       if (remote_debug)
 380         {
 381           printf_filtered ("gdbsim_store_register: %d", regno);
 382           /* FIXME: We could print something more intelligible.  */
 383           dump_mem (tmp, register_size (gdbarch, regno));
 384         }
 385     }
 386 }
 387
 388 /* Kill the running program.  This may involve closing any open files
 389    and releasing other resources acquired by the simulated program.  */
 390
 391 static void
 392 gdbsim_kill (void)
 393 {
 394   if (remote_debug)
 395     printf_filtered ("gdbsim_kill\n");
 396
 397   /* There is no need to `kill' running simulator - the simulator is
 398      not running.  Mourning it is enough.  */
 399   target_mourn_inferior ();
 400 }
 401
 402 /* Load an executable file into the target process.  This is expected to
 403    not only bring new code into the target process, but also to update
 404    GDB's symbol tables to match.  */
 405
 406 static void
 407 gdbsim_load (char *args, int fromtty)
 408 {
 409   char **argv;
 410   char *prog;
 411
 412   if (args == NULL)
 413       error_no_arg (_("program to load"));
 414
 415   argv = gdb_buildargv (args);
 416   make_cleanup_freeargv (argv);
 417
 418   prog = tilde_expand (argv[0]);
 419
 420   if (argv[1] != NULL)
 421     error (_("GDB sim does not yet support a load offset."));
 422
 423   if (remote_debug)
 424     printf_filtered ("gdbsim_load: prog \"%s\"\n", prog);
 425
 426   /* FIXME: We will print two messages on error.
 427      Need error to either not print anything if passed NULL or need
 428      another routine that doesn't take any arguments.  */
 429   if (sim_load (gdbsim_desc, prog, NULL, fromtty) == SIM_RC_FAIL)
 430     error (_("unable to load program"));
 431
 432   /* FIXME: If a load command should reset the targets registers then
 433      a call to sim_create_inferior() should go here. */
 434
 435   program_loaded = 1;
 436 }
 437
 438
 439 /* Start an inferior process and set inferior_ptid to its pid.
 440    EXEC_FILE is the file to run.
 441    ARGS is a string containing the arguments to the program.
 442    ENV is the environment vector to pass.  Errors reported with error().
 443    On VxWorks and various standalone systems, we ignore exec_file.  */
 444 /* This is called not only when we first attach, but also when the
 445    user types "run" after having attached.  */
 446
 447 static void
 448 gdbsim_create_inferior (char *exec_file, char *args, char **env, int from_tty)
 449 {
 450   int len;
 451   char *arg_buf, **argv;
 452
 453   if (exec_file == 0 || exec_bfd == 0)
 454     warning (_("No executable file specified."));
 455   if (!program_loaded)
 456     warning (_("No program loaded."));
 457
 458   if (remote_debug)
 459     printf_filtered ("gdbsim_create_inferior: exec_file \"%s\", args \"%s\"\n",
 460                      (exec_file ? exec_file : "(NULL)"),
 461                      args);
 462
 463   if (ptid_equal (inferior_ptid, remote_sim_ptid))
 464     gdbsim_kill ();
 465   remove_breakpoints ();
 466   init_wait_for_inferior ();
 467
 468   if (exec_file != NULL)
 469     {
 470       len = strlen (exec_file) + 1 + strlen (args) + 1 + /*slop */ 10;
 471       arg_buf = (char *) alloca (len);
 472       arg_buf[0] = '\0';
 473       strcat (arg_buf, exec_file);
 474       strcat (arg_buf, " ");
 475       strcat (arg_buf, args);
 476       argv = gdb_buildargv (arg_buf);
 477       make_cleanup_freeargv (argv);
 478     }
 479   else
 480     argv = NULL;
 481   sim_create_inferior (gdbsim_desc, exec_bfd, argv, env);
 482
 483   inferior_ptid = remote_sim_ptid;
 484   add_inferior_silent (ptid_get_pid (inferior_ptid));
 485   add_thread_silent (inferior_ptid);
 486
 487   target_mark_running (&gdbsim_ops);
 488   insert_breakpoints ();        /* Needed to get correct instruction in cache */
 489
 490   clear_proceed_status ();
 491 }
 492
 493 /* The open routine takes the rest of the parameters from the command,
 494    and (if successful) pushes a new target onto the stack.
 495    Targets should supply this routine, if only to provide an error message.  */
 496 /* Called when selecting the simulator. EG: (gdb) target sim name.  */
 497
 498 static void
 499 gdbsim_open (char *args, int from_tty)
 500 {
 501   int len;
 502   char *arg_buf;
 503   char **argv;
 504
 505   if (remote_debug)
 506     printf_filtered ("gdbsim_open: args \"%s\"\n", args ? args : "(null)");
 507
 508   /* Remove current simulator if one exists.  Only do this if the simulator
 509      has been opened because sim_close requires it.
 510      This is important because the call to push_target below will cause
 511      sim_close to be called if the simulator is already open, but push_target
 512      is called after sim_open!  We can't move the call to push_target before
 513      the call to sim_open because sim_open may invoke `error'.  */
 514   if (gdbsim_desc != NULL)
 515     unpush_target (&gdbsim_ops);
 516
 517   len = (7 + 1                  /* gdbsim */
 518          + strlen (" -E little")
 519          + strlen (" --architecture=xxxxxxxxxx")
 520          + (args ? strlen (args) : 0)
 521          + 50) /* slack */ ;
 522   arg_buf = (char *) alloca (len);
 523   strcpy (arg_buf, "gdbsim");   /* 7 */
 524   /* Specify the byte order for the target when it is explicitly
 525      specified by the user (not auto detected). */
 526   switch (selected_byte_order ())
 527     {
 528     case BFD_ENDIAN_BIG:
 529       strcat (arg_buf, " -E big");
 530       break;
 531     case BFD_ENDIAN_LITTLE:
 532       strcat (arg_buf, " -E little");
 533       break;
 534     case BFD_ENDIAN_UNKNOWN:
 535       break;
 536     }
 537   /* Specify the architecture of the target when it has been
 538      explicitly specified */
 539   if (selected_architecture_name () != NULL)
 540     {
 541       strcat (arg_buf, " --architecture=");
 542       strcat (arg_buf, selected_architecture_name ());
 543     }
 544   /* finally, any explicit args */
 545   if (args)
 546     {
 547       strcat (arg_buf, " ");    /* 1 */
 548       strcat (arg_buf, args);
 549     }
 550   argv = gdb_buildargv (arg_buf);
 551   make_cleanup_freeargv (argv);
 552
 553   init_callbacks ();
 554   gdbsim_desc = sim_open (SIM_OPEN_DEBUG, &gdb_callback, exec_bfd, argv);
 555
 556   if (gdbsim_desc == 0)
 557     error (_("unable to create simulator instance"));
 558
 559   push_target (&gdbsim_ops);
 560   printf_filtered ("Connected to the simulator.\n");
 561
 562   /* There's nothing running after "target sim" or "load"; not until
 563      "run".  */
 564   inferior_ptid = null_ptid;
 565   target_mark_exited (&gdbsim_ops);
 566 }
 567
 568 /* Does whatever cleanup is required for a target that we are no longer
 569    going to be calling.  Argument says whether we are quitting gdb and
 570    should not get hung in case of errors, or whether we want a clean
 571    termination even if it takes a while.  This routine is automatically
 572    always called just before a routine is popped off the target stack.
 573    Closing file descriptors and freeing memory are typical things it should
 574    do.  */
 575 /* Close out all files and local state before this target loses control. */
 576
 577 static void
 578 gdbsim_close (int quitting)
 579 {
 580   if (remote_debug)
 581     printf_filtered ("gdbsim_close: quitting %d\n", quitting);
 582
 583   program_loaded = 0;
 584
 585   if (gdbsim_desc != NULL)
 586     {
 587       sim_close (gdbsim_desc, quitting);
 588       gdbsim_desc = NULL;
 589     }
 590
 591   end_callbacks ();
 592   generic_mourn_inferior ();
 593   delete_thread_silent (remote_sim_ptid);
 594   delete_inferior_silent (ptid_get_pid (remote_sim_ptid));
 595 }
 596
 597 /* Takes a program previously attached to and detaches it.
 598    The program may resume execution (some targets do, some don't) and will
 599    no longer stop on signals, etc.  We better not have left any breakpoints
 600    in the program or it'll die when it hits one.  ARGS is arguments
 601    typed by the user (e.g. a signal to send the process).  FROM_TTY
 602    says whether to be verbose or not.  */
 603 /* Terminate the open connection to the remote debugger.
 604    Use this when you want to detach and do something else with your gdb.  */
 605
 606 static void
 607 gdbsim_detach (char *args, int from_tty)
 608 {
 609   if (remote_debug)
 610     printf_filtered ("gdbsim_detach: args \"%s\"\n", args);
 611
 612   pop_target ();                /* calls gdbsim_close to do the real work */
 613   if (from_tty)
 614     printf_filtered ("Ending simulator %s debugging\n", target_shortname);
 615 }
 616
 617 /* Resume execution of the target process.  STEP says whether to single-step
 618    or to run free; SIGGNAL is the signal value (e.g. SIGINT) to be given
 619    to the target, or zero for no signal.  */
 620
 621 static enum target_signal resume_siggnal;
 622 static int resume_step;
 623
 624 static void
 625 gdbsim_resume (ptid_t ptid, int step, enum target_signal siggnal)
 626 {
 627   if (!ptid_equal (inferior_ptid, remote_sim_ptid))
 628     error (_("The program is not being run."));
 629
 630   if (remote_debug)
 631     printf_filtered ("gdbsim_resume: step %d, signal %d\n", step, siggnal);
 632
 633   resume_siggnal = siggnal;
 634   resume_step = step;
 635 }
 636
 637 /* Notify the simulator of an asynchronous request to stop.
 638
 639    The simulator shall ensure that the stop request is eventually
 640    delivered to the simulator.  If the call is made while the
 641    simulator is not running then the stop request is processed when
 642    the simulator is next resumed.
 643
 644    For simulators that do not support this operation, just abort */
 645
 646 static void
 647 gdbsim_stop (ptid_t ptid)
 648 {
 649   if (!sim_stop (gdbsim_desc))
 650     {
 651       quit ();
 652     }
 653 }
 654
 655 /* GDB version of os_poll_quit callback.
 656    Taken from gdb/util.c - should be in a library.  */
 657
 658 static int
 659 gdb_os_poll_quit (host_callback *p)
 660 {
 661   if (deprecated_ui_loop_hook != NULL)
 662     deprecated_ui_loop_hook (0);
 663
 664   if (quit_flag)                /* gdb's idea of quit */
 665     {
 666       quit_flag = 0;            /* we've stolen it */
 667       return 1;
 668     }
 669   else if (immediate_quit)
 670     {
 671       return 1;
 672     }
 673   return 0;
 674 }
 675
 676 /* Wait for inferior process to do something.  Return pid of child,
 677    or -1 in case of error; store status through argument pointer STATUS,
 678    just as `wait' would. */
 679
 680 static void
 681 gdbsim_cntrl_c (int signo)
 682 {
 683   gdbsim_stop (remote_sim_ptid);
 684 }
 685
 686 static ptid_t
 687 gdbsim_wait (ptid_t ptid, struct target_waitstatus *status)
 688 {
 689   static RETSIGTYPE (*prev_sigint) ();
 690   int sigrc = 0;
 691   enum sim_stop reason = sim_running;
 692
 693   if (remote_debug)
 694     printf_filtered ("gdbsim_wait\n");
 695
 696 #if defined (HAVE_SIGACTION) && defined (SA_RESTART)
 697   {
 698     struct sigaction sa, osa;
 699     sa.sa_handler = gdbsim_cntrl_c;
 700     sigemptyset (&sa.sa_mask);
 701     sa.sa_flags = 0;
 702     sigaction (SIGINT, &sa, &osa);
 703     prev_sigint = osa.sa_handler;
 704   }
 705 #else
 706   prev_sigint = signal (SIGINT, gdbsim_cntrl_c);
 707 #endif
 708   sim_resume (gdbsim_desc, resume_step, resume_siggnal);
 709   signal (SIGINT, prev_sigint);
 710   resume_step = 0;
 711
 712   sim_stop_reason (gdbsim_desc, &reason, &sigrc);
 713
 714   switch (reason)
 715     {
 716     case sim_exited:
 717       status->kind = TARGET_WAITKIND_EXITED;
 718       status->value.integer = sigrc;
 719       break;
 720     case sim_stopped:
 721       switch (sigrc)
 722         {
 723         case TARGET_SIGNAL_ABRT:
 724           quit ();
 725           break;
 726         case TARGET_SIGNAL_INT:
 727         case TARGET_SIGNAL_TRAP:
 728         default:
 729           status->kind = TARGET_WAITKIND_STOPPED;
 730           status->value.sig = sigrc;
 731           break;
 732         }
 733       break;
 734     case sim_signalled:
 735       status->kind = TARGET_WAITKIND_SIGNALLED;
 736       status->value.sig = sigrc;
 737       break;
 738     case sim_running:
 739     case sim_polling:
 740       /* FIXME: Is this correct? */
 741       break;
 742     }
 743
 744   return inferior_ptid;
 745 }
 746
 747 /* Get ready to modify the registers array.  On machines which store
 748    individual registers, this doesn't need to do anything.  On machines
 749    which store all the registers in one fell swoop, this makes sure
 750    that registers contains all the registers from the program being
 751    debugged.  */
 752
 753 static void
 754 gdbsim_prepare_to_store (struct regcache *regcache)
 755 {
 756   /* Do nothing, since we can store individual regs */
 757 }
 758
 759 /* Transfer LEN bytes between GDB address MYADDR and target address
 760    MEMADDR.  If WRITE is non-zero, transfer them to the target,
 761    otherwise transfer them from the target.  TARGET is unused.
 762
 763    Returns the number of bytes transferred. */
 764
 765 static int
 766 gdbsim_xfer_inferior_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len,
 767                              int write, struct mem_attrib *attrib,
 768                              struct target_ops *target)
 769 {
 770   /* If no program is running yet, then ignore the simulator for
 771      memory.  Pass the request down to the next target, hopefully
 772      an exec file.  */
 773   if (!target_has_execution)
 774     return 0;
 775
 776   if (!program_loaded)
 777     error (_("No program loaded."));
 778
 779   if (remote_debug)
 780     {
 781       /* FIXME: Send to something other than STDOUT? */
 782       printf_filtered ("gdbsim_xfer_inferior_memory: myaddr 0x");
 783       gdb_print_host_address (myaddr, gdb_stdout);
 784       printf_filtered (", memaddr 0x%s, len %d, write %d\n",
 785                        paddr_nz (memaddr), len, write);
 786       if (remote_debug && write)
 787         dump_mem (myaddr, len);
 788     }
 789
 790   if (write)
 791     {
 792       len = sim_write (gdbsim_desc, memaddr, myaddr, len);
 793     }
 794   else
 795     {
 796       len = sim_read (gdbsim_desc, memaddr, myaddr, len);
 797       if (remote_debug && len > 0)
 798         dump_mem (myaddr, len);
 799     }
 800   return len;
 801 }
 802
 803 static void
 804 gdbsim_files_info (struct target_ops *target)
 805 {
 806   char *file = "nothing";
 807
 808   if (exec_bfd)
 809     file = bfd_get_filename (exec_bfd);
 810
 811   if (remote_debug)
 812     printf_filtered ("gdbsim_files_info: file \"%s\"\n", file);
 813
 814   if (exec_bfd)
 815     {
 816       printf_filtered ("\tAttached to %s running program %s\n",
 817                        target_shortname, file);
 818       sim_info (gdbsim_desc, 0);
 819     }
 820 }
 821
 822 /* Clear the simulator's notion of what the break points are.  */
 823
 824 static void
 825 gdbsim_mourn_inferior (void)
 826 {
 827   if (remote_debug)
 828     printf_filtered ("gdbsim_mourn_inferior:\n");
 829
 830   remove_breakpoints ();
 831   target_mark_exited (&gdbsim_ops);
 832   generic_mourn_inferior ();
 833   delete_thread_silent (remote_sim_ptid);
 834 }
 835
 836 /* Pass the command argument through to the simulator verbatim.  The
 837    simulator must do any command interpretation work.  */
 838
 839 void
 840 simulator_command (char *args, int from_tty)
 841 {
 842   if (gdbsim_desc == NULL)
 843     {
 844
 845       /* PREVIOUSLY: The user may give a command before the simulator
 846          is opened. [...] (??? assuming of course one wishes to
 847          continue to allow commands to be sent to unopened simulators,
 848          which isn't entirely unreasonable). */
 849
 850       /* The simulator is a builtin abstraction of a remote target.
 851          Consistent with that model, access to the simulator, via sim
 852          commands, is restricted to the period when the channel to the
 853          simulator is open. */
 854
 855       error (_("Not connected to the simulator target"));
 856     }
 857
 858   sim_do_command (gdbsim_desc, args);
 859
 860   /* Invalidate the register cache, in case the simulator command does
 861      something funny. */
 862   registers_changed ();
 863 }
 864
 865 /* Check to see if a thread is still alive.  */
 866
 867 static int
 868 gdbsim_thread_alive (ptid_t ptid)
 869 {
 870   if (ptid_equal (ptid, remote_sim_ptid))
 871     /* The simulators' task is always alive.  */
 872     return 1;
 873
 874   return 0;
 875 }
 876
 877 /* Convert a thread ID to a string.  Returns the string in a static
 878    buffer.  */
 879
 880 static char *
 881 gdbsim_pid_to_str (ptid_t ptid)
 882 {
 883   static char buf[64];
 884
 885   if (ptid_equal (remote_sim_ptid, ptid))
 886     {
 887       xsnprintf (buf, sizeof buf, "Thread <main>");
 888       return buf;
 889     }
 890
 891   return normal_pid_to_str (ptid);
 892 }
 893
 894 /* Define the target subroutine names */
 895
 896 struct target_ops gdbsim_ops;
 897
 898 static void
 899 init_gdbsim_ops (void)
 900 {
 901   gdbsim_ops.to_shortname = "sim";
 902   gdbsim_ops.to_longname = "simulator";
 903   gdbsim_ops.to_doc = "Use the compiled-in simulator.";
 904   gdbsim_ops.to_open = gdbsim_open;
 905   gdbsim_ops.to_close = gdbsim_close;
 906   gdbsim_ops.to_detach = gdbsim_detach;
 907   gdbsim_ops.to_resume = gdbsim_resume;
 908   gdbsim_ops.to_wait = gdbsim_wait;
 909   gdbsim_ops.to_fetch_registers = gdbsim_fetch_register;
 910   gdbsim_ops.to_store_registers = gdbsim_store_register;
 911   gdbsim_ops.to_prepare_to_store = gdbsim_prepare_to_store;
 912   gdbsim_ops.deprecated_xfer_memory = gdbsim_xfer_inferior_memory;
 913   gdbsim_ops.to_files_info = gdbsim_files_info;
 914   gdbsim_ops.to_insert_breakpoint = memory_insert_breakpoint;
 915   gdbsim_ops.to_remove_breakpoint = memory_remove_breakpoint;
 916   gdbsim_ops.to_kill = gdbsim_kill;
 917   gdbsim_ops.to_load = gdbsim_load;
 918   gdbsim_ops.to_create_inferior = gdbsim_create_inferior;
 919   gdbsim_ops.to_mourn_inferior = gdbsim_mourn_inferior;
 920   gdbsim_ops.to_stop = gdbsim_stop;
 921   gdbsim_ops.to_thread_alive = gdbsim_thread_alive;
 922   gdbsim_ops.to_pid_to_str = gdbsim_pid_to_str;
 923   gdbsim_ops.to_stratum = process_stratum;
 924   gdbsim_ops.to_has_all_memory = 1;
 925   gdbsim_ops.to_has_memory = 1;
 926   gdbsim_ops.to_has_stack = 1;
 927   gdbsim_ops.to_has_registers = 1;
 928   gdbsim_ops.to_has_execution = 1;
 929   gdbsim_ops.to_magic = OPS_MAGIC;
 930 }
 931
 932 void
 933 _initialize_remote_sim (void)
 934 {
 935   init_gdbsim_ops ();
 936   add_target (&gdbsim_ops);
 937
 938   add_com ("sim", class_obscure, simulator_command,
 939            _("Send a command to the simulator."));
 940
 941   /* Yes, 42000 is arbitrary.  The only sense out of it, is that it
 942      isn't 0.  */
 943   remote_sim_ptid = ptid_build (42000, 0, 42000);
 944 }