gdb/remote-sim.c

   1 /* Generic remote debugging interface for simulators.
   2    Copyright 1993, 1994 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., 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 /* Kill the running program.  This may involve closing any open files
 123    and releasing other resources acquired by the simulated program.  */
 124
 125 static void
 126 gdbsim_kill ()
 127 {
 128   if (sr_get_debug ())
 129     printf_filtered ("gdbsim_kill\n");
 130
 131   sim_kill ();  /* close fd's, remove mappings */
 132   inferior_pid = 0;
 133 }
 134
 135 /* Load an executable file into the target process.  This is expected to
 136    not only bring new code into the target process, but also to update
 137    GDB's symbol tables to match.  */
 138
 139 static void
 140 gdbsim_load (prog, fromtty)
 141      char *prog;
 142      int fromtty;
 143 {
 144   if (sr_get_debug ())
 145     printf_filtered ("gdbsim_load: prog \"%s\"\n", prog);
 146
 147   inferior_pid = 0;
 148
 149   /* This must be done before calling gr_load_image.  */
 150   program_loaded = 1;
 151
 152   if (sim_load (prog, fromtty) != 0)
 153     gr_load_image (prog, fromtty);
 154 }
 155
 156
 157 /* Start an inferior process and set inferior_pid to its pid.
 158    EXEC_FILE is the file to run.
 159    ALLARGS is a string containing the arguments to the program.
 160    ENV is the environment vector to pass.  Errors reported with error().
 161    On VxWorks and various standalone systems, we ignore exec_file.  */
 162 /* This is called not only when we first attach, but also when the
 163    user types "run" after having attached.  */
 164
 165 static void
 166 gdbsim_create_inferior (exec_file, args, env)
 167      char *exec_file;
 168      char *args;
 169      char **env;
 170 {
 171   int len;
 172   char *arg_buf,**argv;
 173   CORE_ADDR entry_pt;
 174
 175   if (! program_loaded)
 176     error ("No program loaded.");
 177
 178   if (sr_get_debug ())
 179     printf_filtered ("gdbsim_create_inferior: exec_file \"%s\", args \"%s\"\n",
 180       exec_file, args);
 181
 182   if (exec_file == 0 || exec_bfd == 0)
 183    error ("No exec file specified.");
 184
 185   entry_pt = (CORE_ADDR) bfd_get_start_address (exec_bfd);
 186
 187   gdbsim_kill (NULL, NULL);
 188   remove_breakpoints ();
 189   init_wait_for_inferior ();
 190
 191   len = 5 + strlen (exec_file) + 1 + strlen (args) + 1 + /*slop*/ 10;
 192   arg_buf = (char *) alloca (len);
 193   arg_buf[0] = '\0';
 194   strcat (arg_buf, exec_file);
 195   strcat (arg_buf, " ");
 196   strcat (arg_buf, args);
 197   argv = buildargv (arg_buf);
 198   make_cleanup (freeargv, (char *) argv);
 199   sim_create_inferior (entry_pt, argv, env);
 200
 201   inferior_pid = 42;
 202   insert_breakpoints ();        /* Needed to get correct instruction in cache */
 203   proceed (entry_pt, TARGET_SIGNAL_DEFAULT, 0);
 204 }
 205
 206 /* The open routine takes the rest of the parameters from the command,
 207    and (if successful) pushes a new target onto the stack.
 208    Targets should supply this routine, if only to provide an error message.  */
 209 /* Called when selecting the simulator. EG: (gdb) target sim name.  */
 210
 211 static void
 212 gdbsim_open (args, from_tty)
 213      char *args;
 214      int from_tty;
 215 {
 216   if (sr_get_debug ())
 217     printf_filtered ("gdbsim_open: args \"%s\"\n", args ? args : "(null)");
 218
 219   sim_open (args);
 220
 221   push_target (&gdbsim_ops);
 222   target_fetch_registers (-1);
 223
 224   printf_filtered ("Connected to the simulator.\n");
 225 }
 226
 227 /* Does whatever cleanup is required for a target that we are no longer
 228    going to be calling.  Argument says whether we are quitting gdb and
 229    should not get hung in case of errors, or whether we want a clean
 230    termination even if it takes a while.  This routine is automatically
 231    always called just before a routine is popped off the target stack.
 232    Closing file descriptors and freeing memory are typical things it should
 233    do.  */
 234 /* Close out all files and local state before this target loses control. */
 235
 236 static void
 237 gdbsim_close (quitting)
 238      int quitting;
 239 {
 240   if (sr_get_debug ())
 241     printf_filtered ("gdbsim_close: quitting %d\n", quitting);
 242
 243   program_loaded = 0;
 244
 245   sim_close (quitting);
 246 }
 247
 248 /* Takes a program previously attached to and detaches it.
 249    The program may resume execution (some targets do, some don't) and will
 250    no longer stop on signals, etc.  We better not have left any breakpoints
 251    in the program or it'll die when it hits one.  ARGS is arguments
 252    typed by the user (e.g. a signal to send the process).  FROM_TTY
 253    says whether to be verbose or not.  */
 254 /* Terminate the open connection to the remote debugger.
 255    Use this when you want to detach and do something else with your gdb.  */
 256
 257 static void
 258 gdbsim_detach (args,from_tty)
 259      char *args;
 260      int from_tty;
 261 {
 262   if (sr_get_debug ())
 263     printf_filtered ("gdbsim_detach: args \"%s\"\n", args);
 264
 265   pop_target ();                /* calls gdbsim_close to do the real work */
 266   if (from_tty)
 267     printf_filtered ("Ending simulator %s debugging\n", target_shortname);
 268 }
 269
 270 /* Resume execution of the target process.  STEP says whether to single-step
 271    or to run free; SIGGNAL is the signal value (e.g. SIGINT) to be given
 272    to the target, or zero for no signal.  */
 273
 274 static void
 275 gdbsim_resume (pid, step, siggnal)
 276      int pid, step;
 277      enum target_signal siggnal;
 278 {
 279   if (sr_get_debug ())
 280     printf_filtered ("gdbsim_resume: step %d, signal %d\n", step, siggnal);
 281
 282   sim_resume (step, target_signal_to_host (siggnal));
 283 }
 284
 285 /* Wait for inferior process to do something.  Return pid of child,
 286    or -1 in case of error; store status through argument pointer STATUS,
 287    just as `wait' would.  */
 288
 289 static int
 290 gdbsim_wait (pid, status)
 291      int pid;
 292      struct target_waitstatus *status;
 293 {
 294   int sigrc;
 295   enum sim_stop reason;
 296
 297   if (sr_get_debug ())
 298     printf_filtered ("gdbsim_wait\n");
 299
 300   sim_stop_reason (&reason, &sigrc);
 301   switch (reason)
 302     {
 303     case sim_exited:
 304       status->kind = TARGET_WAITKIND_EXITED;
 305       status->value.integer = sigrc;
 306       break;
 307     case sim_stopped:
 308       status->kind = TARGET_WAITKIND_STOPPED;
 309       /* The signal in sigrc is a host signal.  That probably
 310          should be fixed.  */
 311       status->value.sig = target_signal_from_host (sigrc);
 312       break;
 313     case sim_signalled:
 314       status->kind = TARGET_WAITKIND_SIGNALLED;
 315       /* The signal in sigrc is a host signal.  That probably
 316          should be fixed.  */
 317       status->value.sig = target_signal_from_host (sigrc);
 318       break;
 319     }
 320
 321   return inferior_pid;
 322 }
 323
 324 /* Get ready to modify the registers array.  On machines which store
 325    individual registers, this doesn't need to do anything.  On machines
 326    which store all the registers in one fell swoop, this makes sure
 327    that registers contains all the registers from the program being
 328    debugged.  */
 329
 330 static void
 331 gdbsim_prepare_to_store ()
 332 {
 333   /* Do nothing, since we can store individual regs */
 334 }
 335
 336 static int
 337 gdbsim_xfer_inferior_memory (memaddr, myaddr, len, write, target)
 338      CORE_ADDR memaddr;
 339      char *myaddr;
 340      int len;
 341      int write;
 342      struct target_ops *target;                 /* ignored */
 343 {
 344   if (! program_loaded)
 345     error ("No program loaded.");
 346
 347   if (sr_get_debug ())
 348     {
 349       printf_filtered ("gdbsim_xfer_inferior_memory: myaddr 0x%x, memaddr 0x%x, len %d, write %d\n",
 350                        myaddr, memaddr, len, write);
 351       if (sr_get_debug () && write)
 352         dump_mem(myaddr, len);
 353     }
 354
 355   if (write)
 356     {
 357       len = sim_write (memaddr, myaddr, len);
 358     }
 359   else
 360     {
 361       len = sim_read (memaddr, myaddr, len);
 362       if (sr_get_debug () && len > 0)
 363         dump_mem(myaddr, len);
 364     }
 365   return len;
 366 }
 367
 368 static void
 369 gdbsim_files_info (target)
 370      struct target_ops *target;
 371 {
 372   char *file = "nothing";
 373
 374   if (exec_bfd)
 375     file = bfd_get_filename (exec_bfd);
 376
 377   if (sr_get_debug ())
 378     printf_filtered ("gdbsim_files_info: file \"%s\"\n", file);
 379
 380   if (exec_bfd)
 381     {
 382       printf_filtered ("\tAttached to %s running program %s\n",
 383                        target_shortname, file);
 384       sim_info (0);
 385     }
 386 }
 387
 388 /* Clear the sims notion of what the break points are.  */
 389
 390 static void
 391 gdbsim_mourn_inferior ()
 392 {
 393   if (sr_get_debug ())
 394     printf_filtered ("gdbsim_mourn_inferior:\n");
 395
 396   remove_breakpoints ();
 397   generic_mourn_inferior ();
 398 }
 399
 400 /* Define the target subroutine names */
 401
 402 struct target_ops gdbsim_ops =
 403 {
 404   "sim", "simulator",
 405   "Use the simulator",
 406   gdbsim_open, gdbsim_close,
 407   0, gdbsim_detach, gdbsim_resume, gdbsim_wait, /* attach */
 408   gdbsim_fetch_register, gdbsim_store_register,
 409   gdbsim_prepare_to_store,
 410   gdbsim_xfer_inferior_memory,
 411   gdbsim_files_info,
 412   memory_insert_breakpoint,
 413   memory_remove_breakpoint,
 414   0, 0, 0, 0, 0,                /* Terminal handling */
 415   gdbsim_kill,                  /* kill */
 416   gdbsim_load,                  /* load */
 417   0,                            /* lookup_symbol */
 418   gdbsim_create_inferior,       /* create_inferior */
 419   gdbsim_mourn_inferior,        /* mourn_inferior */
 420   0,                            /* can_run */
 421   0,                            /* notice_signals */
 422   0,                            /* to_stop */
 423   process_stratum, 0,           /* next */
 424   1, 1, 1, 1, 1,                /* all mem, mem, stack, regs, exec */
 425   0, 0,                         /* Section pointers */
 426   OPS_MAGIC,                    /* Always the last thing */
 427 };
 428
 429 void
 430 _initialize_remote_sim ()
 431 {
 432   add_target (&gdbsim_ops);
 433 }