gdb/remote-sim.c

   1 /* Generic remote debugging interface for simulators.
   2    Copyright 1993 Free Software Foundation, Inc.
   3    Contributed by Cygnus Support.
   4    Steve Chamberlain (sac@cygnus.com) and Doug Evans (dje@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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  21
  22 #include "defs.h"
  23 #include "inferior.h"
  24 #include "wait.h"
  25 #include "value.h"
  26 #include <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 "remote-sim.h"
  36 #include "remote-utils.h"
  37
  38 /* Naming convention:
  39
  40    sim_* are the interface to the simulator (see remote-sim.h).
  41
  42    gdbsim_* are stuff which is internal to gdb.  */
  43
  44 /* Forward data declarations */
  45 extern struct target_ops gdbsim_ops;
  46
  47 static int program_loaded = 0;
  48
  49 static void
  50 dump_mem (buf, len)
  51      char *buf;
  52      int len;
  53 {
  54   if (len <= 8)
  55     {
  56       if (len == 8 || len == 4)
  57         {
  58           long l[2];
  59           memcpy (l, buf, len);
  60           printf_filtered ("\t0x%x", l[0]);
  61           printf_filtered (len == 8 ? " 0x%x\n" : "\n", l[1]);
  62         }
  63       else
  64         {
  65           int i;
  66           printf_filtered ("\t");
  67           for (i = 0; i < len; i++)
  68             printf_filtered ("0x%x ", buf[i]);
  69           printf_filtered ("\n");
  70         }
  71     }
  72 }
  73
  74 static void
  75 gdbsim_fetch_register (regno)
  76 int regno;
  77 {
  78   if (regno == -1)
  79     {
  80       for (regno = 0; regno < NUM_REGS; regno++)
  81         gdbsim_fetch_register (regno);
  82     }
  83   else
  84     {
  85       char buf[MAX_REGISTER_RAW_SIZE];
  86
  87       sim_fetch_register (regno, buf);
  88       supply_register (regno, buf);
  89       if (sr_get_debug ())
  90         {
  91           printf_filtered ("gdbsim_fetch_register: %d", regno);
  92           /* FIXME: We could print something more intelligible.  */
  93           dump_mem (buf, REGISTER_RAW_SIZE (regno));
  94         }
  95     }
  96 }
  97
  98 static void
  99 gdbsim_store_register (regno)
 100 int regno;
 101 {
 102   if (regno  == -1)
 103     {
 104       for (regno = 0; regno < NUM_REGS; regno++)
 105         gdbsim_store_register (regno);
 106     }
 107   else
 108     {
 109       /* FIXME: Until read_register() returns LONGEST, we have this.  */
 110       char tmp[MAX_REGISTER_RAW_SIZE];
 111       read_register_gen (regno, tmp);
 112       sim_store_register (regno, tmp);
 113       if (sr_get_debug ())
 114         {
 115           printf_filtered ("gdbsim_store_register: %d", regno);
 116           /* FIXME: We could print something more intelligible.  */
 117           dump_mem (tmp, REGISTER_RAW_SIZE (regno));
 118         }
 119     }
 120 }
 121
 122 static void
 123 gdbsim_kill ()
 124 {
 125   if (sr_get_debug ())
 126     printf_filtered ("gdbsim_kill\n");
 127
 128   sim_kill ();  /* close fd's, remove mappings */
 129   inferior_pid = 0;
 130 }
 131
 132 /* Load an executable file into the target process.  This is expected to
 133    not only bring new code into the target process, but also to update
 134    GDB's symbol tables to match.  */
 135
 136 static void
 137 gdbsim_load (prog, fromtty)
 138      char *prog;
 139      int fromtty;
 140 {
 141   if (sr_get_debug ())
 142     printf_filtered ("gdbsim_load: prog \"%s\"\n", prog);
 143
 144   inferior_pid = 0;
 145   program_loaded = 1;
 146   gr_load_image (prog, fromtty);
 147 }
 148
 149
 150 /* Start an inferior process and set inferior_pid to its pid.
 151    EXEC_FILE is the file to run.
 152    ALLARGS is a string containing the arguments to the program.
 153    ENV is the environment vector to pass.  Errors reported with error().
 154    On VxWorks and various standalone systems, we ignore exec_file.  */
 155 /* This is called not only when we first attach, but also when the
 156    user types "run" after having attached.  */
 157
 158 static void
 159 gdbsim_create_inferior (exec_file, args, env)
 160      char *exec_file;
 161      char *args;
 162      char **env;
 163 {
 164   int len,entry_pt;
 165   char *arg_buf,**argv;
 166
 167   if (! program_loaded)
 168     error ("No program loaded.");
 169
 170   if (sr_get_debug ())
 171     printf_filtered ("gdbsim_create_inferior: exec_file \"%s\", args \"%s\"\n",
 172       exec_file, args);
 173
 174   if (exec_file == 0 || exec_bfd == 0)
 175    error ("No exec file specified.");
 176
 177   entry_pt = (int) bfd_get_start_address (exec_bfd);
 178
 179   gdbsim_kill (NULL, NULL);
 180   remove_breakpoints ();
 181   init_wait_for_inferior ();
 182
 183   len = 5 + strlen (exec_file) + 1 + strlen (args) + 1 + /*slop*/ 10;
 184   arg_buf = (char *) alloca (len);
 185   arg_buf[0] = '\0';
 186   strcat (arg_buf, exec_file);
 187   strcat (arg_buf, " ");
 188   strcat (arg_buf, args);
 189   argv = buildargv (arg_buf);
 190   make_cleanup (freeargv, (char *) argv);
 191   /* FIXME: remote-sim.h says targets that don't support this return
 192      non-zero.  Perhaps distinguish between "not supported" and other errors?
 193      Or maybe that can be the only error.  */
 194   if (sim_set_args (argv, env) != 0)
 195     return;
 196
 197   inferior_pid = 42;
 198   insert_breakpoints ();        /* Needed to get correct instruction in cache */
 199   proceed (entry_pt, -1, 0);
 200 }
 201
 202 /* The open routine takes the rest of the parameters from the command,
 203    and (if successful) pushes a new target onto the stack.
 204    Targets should supply this routine, if only to provide an error message.  */
 205 /* Called when selecting the simulator. EG: (gdb) target sim name.  */
 206
 207 static void
 208 gdbsim_open (args, from_tty)
 209      char *args;
 210      int from_tty;
 211 {
 212   if (sr_get_debug ())
 213     printf_filtered ("gdbsim_open: args \"%s\"\n", args);
 214
 215   if (sim_open (args) != 0)
 216     {
 217       /* FIXME: This is totally bogus.  sim_open should have a way to
 218          tell us what the error was, so we can tell the user.  */
 219       error ("Unable to initialize simulator (insufficient memory?).");
 220       return;
 221     }
 222
 223   push_target (&gdbsim_ops);
 224   target_fetch_registers (-1);
 225
 226   printf_filtered ("Connected to the simulator.\n");
 227 }
 228
 229 /* Does whatever cleanup is required for a target that we are no longer
 230    going to be calling.  Argument says whether we are quitting gdb and
 231    should not get hung in case of errors, or whether we want a clean
 232    termination even if it takes a while.  This routine is automatically
 233    always called just before a routine is popped off the target stack.
 234    Closing file descriptors and freeing memory are typical things it should
 235    do.  */
 236 /* Close out all files and local state before this target loses control. */
 237
 238 static void
 239 gdbsim_close (quitting)
 240      int quitting;
 241 {
 242   if (sr_get_debug ())
 243     printf_filtered ("gdbsim_close: quitting %d\n", quitting);
 244
 245   program_loaded = 0;
 246
 247   /* FIXME: Need to call sim_close() to close all files and
 248      delete all mappings. */
 249 }
 250
 251 /* Takes a program previously attached to and detaches it.
 252    The program may resume execution (some targets do, some don't) and will
 253    no longer stop on signals, etc.  We better not have left any breakpoints
 254    in the program or it'll die when it hits one.  ARGS is arguments
 255    typed by the user (e.g. a signal to send the process).  FROM_TTY
 256    says whether to be verbose or not.  */
 257 /* Terminate the open connection to the remote debugger.
 258    Use this when you want to detach and do something else with your gdb.  */
 259
 260 static void
 261 gdbsim_detach (args,from_tty)
 262      char *args;
 263      int from_tty;
 264 {
 265   if (sr_get_debug ())
 266     printf_filtered ("gdbsim_detach: args \"%s\"\n", args);
 267
 268   pop_target ();                /* calls gdbsim_close to do the real work */
 269   if (from_tty)
 270     printf_filtered ("Ending simulator %s debugging\n", target_shortname);
 271 }
 272
 273 /* Resume execution of the target process.  STEP says whether to single-step
 274    or to run free; SIGGNAL is the signal value (e.g. SIGINT) to be given
 275    to the target, or zero for no signal.  */
 276
 277 static void
 278 gdbsim_resume (pid, step, siggnal)
 279      int pid, step, siggnal;
 280 {
 281   if (sr_get_debug ())
 282     printf_filtered ("gdbsim_resume: step %d, signal %d\n", step, siggnal);
 283
 284   sim_resume (step, siggnal);
 285 }
 286
 287 /* Wait for inferior process to do something.  Return pid of child,
 288    or -1 in case of error; store status through argument pointer STATUS,
 289    just as `wait' would.  */
 290
 291 static int
 292 gdbsim_wait (pid, status)
 293      int pid;
 294      WAITTYPE *status;
 295 {
 296   int sigrc;
 297   enum sim_stop reason;
 298
 299   if (sr_get_debug ())
 300     printf_filtered ("gdbsim_wait: ");
 301   sim_stop_reason (&reason, &sigrc);
 302   if (reason == sim_exited)
 303     WSETEXIT (*status, sigrc);
 304   else
 305     WSETSTOP (*status, sigrc);
 306   if (sr_get_debug ())
 307     printf_filtered ("status %d\n", *status);
 308   return inferior_pid;
 309 }
 310
 311 /* Get ready to modify the registers array.  On machines which store
 312    individual registers, this doesn't need to do anything.  On machines
 313    which store all the registers in one fell swoop, this makes sure
 314    that registers contains all the registers from the program being
 315    debugged.  */
 316
 317 static void
 318 gdbsim_prepare_to_store ()
 319 {
 320   /* Do nothing, since we can store individual regs */
 321 }
 322
 323 static int
 324 gdbsim_xfer_inferior_memory (memaddr, myaddr, len, write, target)
 325      CORE_ADDR memaddr;
 326      char *myaddr;
 327      int len;
 328      int write;
 329      struct target_ops *target;                 /* ignored */
 330 {
 331   if (! program_loaded)
 332     error ("No program loaded.");
 333
 334   if (sr_get_debug ())
 335     {
 336       printf_filtered ("gdbsim_xfer_inferior_memory: myaddr 0x%x, memaddr 0x%x, len %d, write %d\n",
 337                        myaddr, memaddr, len, write);
 338       if (sr_get_debug () && write)
 339         dump_mem(myaddr, len);
 340     }
 341
 342   if (write)
 343     {
 344       len = sim_write (memaddr, myaddr, len);
 345     }
 346   else
 347     {
 348       len = sim_read (memaddr, myaddr, len);
 349       if (sr_get_debug () && len > 0)
 350         dump_mem(myaddr, len);
 351     }
 352   return len;
 353 }
 354
 355 static void
 356 gdbsim_files_info (target)
 357      struct target_ops *target;
 358 {
 359   char *file = "nothing";
 360
 361   if (exec_bfd)
 362     file = bfd_get_filename (exec_bfd);
 363
 364   if (sr_get_debug ())
 365     printf_filtered ("gdbsim_files_info: file \"%s\"\n", file);
 366
 367   if (exec_bfd)
 368     {
 369       printf_filtered ("\tAttached to %s running program %s\n",
 370                        target_shortname, file);
 371       sim_info (printf_filtered, 0);
 372     }
 373 }
 374
 375 /* Clear the sims notion of what the break points are.  */
 376
 377 static void
 378 gdbsim_mourn_inferior ()
 379 {
 380   if (sr_get_debug ())
 381     printf_filtered ("gdbsim_mourn_inferior:\n");
 382
 383   remove_breakpoints ();
 384   generic_mourn_inferior ();
 385 }
 386
 387 /* Define the target subroutine names */
 388
 389 struct target_ops gdbsim_ops =
 390 {
 391   "sim", "simulator",
 392   "Use the simulator",
 393   gdbsim_open, gdbsim_close,
 394   0, gdbsim_detach, gdbsim_resume, gdbsim_wait, /* attach */
 395   gdbsim_fetch_register, gdbsim_store_register,
 396   gdbsim_prepare_to_store,
 397   gdbsim_xfer_inferior_memory,
 398   gdbsim_files_info,
 399   0, 0,                         /* Breakpoints */
 400   0, 0, 0, 0, 0,                /* Terminal handling */
 401   gdbsim_kill,                  /* kill */
 402   gdbsim_load,
 403   0,                            /* lookup_symbol */
 404   gdbsim_create_inferior,               /* create_inferior */
 405   gdbsim_mourn_inferior,                /* mourn_inferior */
 406   0,                            /* can_run */
 407   0,                            /* notice_signals */
 408   process_stratum, 0,           /* next */
 409   1, 1, 1, 1, 1,                /* all mem, mem, stack, regs, exec */
 410   0, 0,                         /* Section pointers */
 411   OPS_MAGIC,                    /* Always the last thing */
 412 };
 413
 414 void
 415 _initialize_remote_sim ()
 416 {
 417   add_target (&gdbsim_ops);
 418 }