sim/rl78/gdb-if.c

   1 /* gdb-if.c -- sim interface to GDB.
   2
   3 Copyright (C) 2011-2022 Free Software Foundation, Inc.
   4 Contributed by Red Hat, Inc.
   5
   6 This file is part of the GNU simulators.
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  20
  21 /* This must come before any other includes.  */
  22 #include "defs.h"
  23
  24 #include <stdio.h>
  25 #include <assert.h>
  26 #include <signal.h>
  27 #include <string.h>
  28 #include <ctype.h>
  29 #include <stdlib.h>
  30
  31 #include "ansidecl.h"
  32 #include "libiberty.h"
  33 #include "sim/callback.h"
  34 #include "sim/sim.h"
  35 #include "gdb/signals.h"
  36 #include "gdb/sim-rl78.h"
  37
  38 #include "cpu.h"
  39 #include "mem.h"
  40 #include "load.h"
  41 #include "trace.h"
  42
  43 /* Ideally, we'd wrap up all the minisim's data structures in an
  44    object and pass that around.  However, neither GDB nor run needs
  45    that ability.
  46
  47    So we just have one instance, that lives in global variables, and
  48    each time we open it, we re-initialize it.  */
  49
  50 struct sim_state
  51 {
  52   const char *message;
  53 };
  54
  55 static struct sim_state the_minisim = {
  56   "This is the sole rl78 minisim instance."
  57 };
  58
  59 static int is_open;
  60
  61 static struct host_callback_struct *host_callbacks;
  62
  63 /* Open an instance of the sim.  For this sim, only one instance
  64    is permitted.  If sim_open() is called multiple times, the sim
  65    will be reset.  */
  66
  67 SIM_DESC
  68 sim_open (SIM_OPEN_KIND kind,
  69           struct host_callback_struct *callback,
  70           struct bfd *abfd, char * const *argv)
  71 {
  72   if (is_open)
  73     fprintf (stderr, "rl78 minisim: re-opened sim\n");
  74
  75   /* The 'run' interface doesn't use this function, so we don't care
  76      about KIND; it's always SIM_OPEN_DEBUG.  */
  77   if (kind != SIM_OPEN_DEBUG)
  78     fprintf (stderr, "rl78 minisim: sim_open KIND != SIM_OPEN_DEBUG: %d\n",
  79              kind);
  80
  81   /* We use this for the load command.  Perhaps someday, it'll be used
  82      for syscalls too.  */
  83   host_callbacks = callback;
  84
  85   /* We don't expect any command-line arguments.  */
  86
  87   init_cpu ();
  88   trace = 0;
  89
  90   sim_disasm_init (abfd);
  91   is_open = 1;
  92
  93   while (argv != NULL && *argv != NULL)
  94     {
  95       if (strcmp (*argv, "g10") == 0 || strcmp (*argv, "-Mg10") == 0)
  96         {
  97           fprintf (stderr, "rl78 g10 support enabled.\n");
  98           rl78_g10_mode = 1;
  99           g13_multiply = 0;
 100           g14_multiply = 0;
 101           mem_set_mirror (0, 0xf8000, 4096);
 102           break;
 103         }
 104       if (strcmp (*argv, "g13") == 0 || strcmp (*argv, "-Mg13") == 0)
 105         {
 106           fprintf (stderr, "rl78 g13 support enabled.\n");
 107           rl78_g10_mode = 0;
 108           g13_multiply = 1;
 109           g14_multiply = 0;
 110           break;
 111         }
 112       if (strcmp (*argv, "g14") == 0 || strcmp (*argv, "-Mg14") == 0)
 113         {
 114           fprintf (stderr, "rl78 g14 support enabled.\n");
 115           rl78_g10_mode = 0;
 116           g13_multiply = 0;
 117           g14_multiply = 1;
 118           break;
 119         }
 120       argv++;
 121     }
 122
 123   return &the_minisim;
 124 }
 125
 126 /* Verify the sim descriptor.  Just print a message if the descriptor
 127    doesn't match.  Nothing bad will happen if the descriptor doesn't
 128    match because all of the state is global.  But if it doesn't
 129    match, that means there's a problem with the caller.  */
 130
 131 static void
 132 check_desc (SIM_DESC sd)
 133 {
 134   if (sd != &the_minisim)
 135     fprintf (stderr, "rl78 minisim: desc != &the_minisim\n");
 136 }
 137
 138 /* Close the sim.  */
 139
 140 void
 141 sim_close (SIM_DESC sd, int quitting)
 142 {
 143   check_desc (sd);
 144
 145   /* Not much to do.  At least free up our memory.  */
 146   init_mem ();
 147
 148   is_open = 0;
 149 }
 150
 151 /* Open the program to run; print a message if the program cannot
 152    be opened.  */
 153
 154 static bfd *
 155 open_objfile (const char *filename)
 156 {
 157   bfd *prog = bfd_openr (filename, 0);
 158
 159   if (!prog)
 160     {
 161       fprintf (stderr, "Can't read %s\n", filename);
 162       return 0;
 163     }
 164
 165   if (!bfd_check_format (prog, bfd_object))
 166     {
 167       fprintf (stderr, "%s not a rl78 program\n", filename);
 168       return 0;
 169     }
 170
 171   return prog;
 172 }
 173
 174 /* Load a program.  */
 175
 176 SIM_RC
 177 sim_load (SIM_DESC sd, const char *prog, struct bfd *abfd, int from_tty)
 178 {
 179   check_desc (sd);
 180
 181   if (!abfd)
 182     abfd = open_objfile (prog);
 183   if (!abfd)
 184     return SIM_RC_FAIL;
 185
 186   rl78_load (abfd, host_callbacks, "sim");
 187
 188   return SIM_RC_OK;
 189 }
 190
 191 /* Create inferior.  */
 192
 193 SIM_RC
 194 sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
 195                      char * const *argv, char * const *env)
 196 {
 197   check_desc (sd);
 198
 199   if (abfd)
 200     rl78_load (abfd, 0, "sim");
 201
 202   return SIM_RC_OK;
 203 }
 204
 205 /* Read memory.  */
 206
 207 int
 208 sim_read (SIM_DESC sd, SIM_ADDR mem, unsigned char *buf, int length)
 209 {
 210   check_desc (sd);
 211
 212   if (mem >= MEM_SIZE)
 213     return 0;
 214   else if (mem + length > MEM_SIZE)
 215     length = MEM_SIZE - mem;
 216
 217   mem_get_blk (mem, buf, length);
 218   return length;
 219 }
 220
 221 /* Write memory.  */
 222
 223 int
 224 sim_write (SIM_DESC sd, SIM_ADDR mem, const unsigned char *buf, int length)
 225 {
 226   check_desc (sd);
 227
 228   if (mem >= MEM_SIZE)
 229     return 0;
 230   else if (mem + length > MEM_SIZE)
 231     length = MEM_SIZE - mem;
 232
 233   mem_put_blk (mem, buf, length);
 234   return length;
 235 }
 236
 237 /* Read the LENGTH bytes at BUF as an little-endian value.  */
 238
 239 static SI
 240 get_le (unsigned char *buf, int length)
 241 {
 242   SI acc = 0;
 243
 244   while (--length >= 0)
 245     acc = (acc << 8) + buf[length];
 246
 247   return acc;
 248 }
 249
 250 /* Store VAL as a little-endian value in the LENGTH bytes at BUF.  */
 251
 252 static void
 253 put_le (unsigned char *buf, int length, SI val)
 254 {
 255   int i;
 256
 257   for (i = 0; i < length; i++)
 258     {
 259       buf[i] = val & 0xff;
 260       val >>= 8;
 261     }
 262 }
 263
 264 /* Verify that REGNO is in the proper range.  Return 0 if not and
 265    something non-zero if so.  */
 266
 267 static int
 268 check_regno (enum sim_rl78_regnum regno)
 269 {
 270   return 0 <= regno && regno < sim_rl78_num_regs;
 271 }
 272
 273 /* Return the size of the register REGNO.  */
 274
 275 static size_t
 276 reg_size (enum sim_rl78_regnum regno)
 277 {
 278   size_t size;
 279
 280   if (regno == sim_rl78_pc_regnum)
 281     size = 4;
 282   else
 283     size = 1;
 284
 285   return size;
 286 }
 287
 288 /* Return the register address associated with the register specified by
 289    REGNO.  */
 290
 291 static unsigned long
 292 reg_addr (enum sim_rl78_regnum regno)
 293 {
 294   if (sim_rl78_bank0_r0_regnum <= regno
 295       && regno <= sim_rl78_bank0_r7_regnum)
 296     return 0xffef8 + (regno - sim_rl78_bank0_r0_regnum);
 297   else if (sim_rl78_bank1_r0_regnum <= regno
 298            && regno <= sim_rl78_bank1_r7_regnum)
 299     return 0xffef0 + (regno - sim_rl78_bank1_r0_regnum);
 300   else if (sim_rl78_bank2_r0_regnum <= regno
 301            && regno <= sim_rl78_bank2_r7_regnum)
 302     return 0xffee8 + (regno - sim_rl78_bank2_r0_regnum);
 303   else if (sim_rl78_bank3_r0_regnum <= regno
 304            && regno <= sim_rl78_bank3_r7_regnum)
 305     return 0xffee0 + (regno - sim_rl78_bank3_r0_regnum);
 306   else if (regno == sim_rl78_psw_regnum)
 307     return 0xffffa;
 308   else if (regno == sim_rl78_es_regnum)
 309     return 0xffffd;
 310   else if (regno == sim_rl78_cs_regnum)
 311     return 0xffffc;
 312   /* Note: We can't handle PC here because it's not memory mapped.  */
 313   else if (regno == sim_rl78_spl_regnum)
 314     return 0xffff8;
 315   else if (regno == sim_rl78_sph_regnum)
 316     return 0xffff9;
 317   else if (regno == sim_rl78_pmc_regnum)
 318     return 0xffffe;
 319   else if (regno == sim_rl78_mem_regnum)
 320     return 0xfffff;
 321
 322   return 0;
 323 }
 324
 325 /* Fetch the contents of the register specified by REGNO, placing the
 326    contents in BUF.  The length LENGTH must match the sim's internal
 327    notion of the register's size.  */
 328
 329 int
 330 sim_fetch_register (SIM_DESC sd, int regno, unsigned char *buf, int length)
 331 {
 332   size_t size;
 333   SI val;
 334
 335   check_desc (sd);
 336
 337   if (!check_regno (regno))
 338     return 0;
 339
 340   size = reg_size (regno);
 341
 342   if (length != size)
 343     return 0;
 344
 345   if (regno == sim_rl78_pc_regnum)
 346     val = pc;
 347   else
 348     val = memory[reg_addr (regno)];
 349
 350   put_le (buf, length, val);
 351
 352   return size;
 353 }
 354
 355 /* Store the value stored in BUF to the register REGNO.  The length
 356    LENGTH must match the sim's internal notion of the register size.  */
 357
 358 int
 359 sim_store_register (SIM_DESC sd, int regno, unsigned char *buf, int length)
 360 {
 361   size_t size;
 362   SI val;
 363
 364   check_desc (sd);
 365
 366   if (!check_regno (regno))
 367     return -1;
 368
 369   size = reg_size (regno);
 370
 371   if (length != size)
 372     return -1;
 373
 374   val = get_le (buf, length);
 375
 376   if (regno == sim_rl78_pc_regnum)
 377     {
 378       pc = val;
 379
 380       /* The rl78 program counter is 20 bits wide.  Ensure that GDB
 381          hasn't picked up any stray bits.  This has occurred when performing
 382          a GDB "return" command in which the return address is obtained
 383          from a 32-bit container on the stack.  */
 384       assert ((pc & ~0x0fffff) == 0);
 385     }
 386   else
 387     memory[reg_addr (regno)] = val;
 388   return size;
 389 }
 390
 391 /* Print out message associated with "info target".  */
 392
 393 void
 394 sim_info (SIM_DESC sd, int verbose)
 395 {
 396   check_desc (sd);
 397
 398   printf ("The rl78 minisim doesn't collect any statistics.\n");
 399 }
 400
 401 static volatile int stop;
 402 static enum sim_stop reason;
 403 int siggnal;
 404
 405
 406 /* Given a signal number used by the rl78 bsp (that is, newlib),
 407    return the corresponding signal numbers.  */
 408
 409 static int
 410 rl78_signal_to_target (int sig)
 411 {
 412   switch (sig)
 413     {
 414     case 4:
 415       return GDB_SIGNAL_ILL;
 416
 417     case 5:
 418       return GDB_SIGNAL_TRAP;
 419
 420     case 10:
 421       return GDB_SIGNAL_BUS;
 422
 423     case 11:
 424       return GDB_SIGNAL_SEGV;
 425
 426     case 24:
 427       return GDB_SIGNAL_XCPU;
 428       break;
 429
 430     case 2:
 431       return GDB_SIGNAL_INT;
 432
 433     case 8:
 434       return GDB_SIGNAL_FPE;
 435       break;
 436
 437     case 6:
 438       return GDB_SIGNAL_ABRT;
 439     }
 440
 441   return 0;
 442 }
 443
 444
 445 /* Take a step return code RC and set up the variables consulted by
 446    sim_stop_reason appropriately.  */
 447
 448 static void
 449 handle_step (int rc)
 450 {
 451   if (RL78_STEPPED (rc) || RL78_HIT_BREAK (rc))
 452     {
 453       reason = sim_stopped;
 454       siggnal = GDB_SIGNAL_TRAP;
 455     }
 456   else if (RL78_STOPPED (rc))
 457     {
 458       reason = sim_stopped;
 459       siggnal = rl78_signal_to_target (RL78_STOP_SIG (rc));
 460     }
 461   else
 462     {
 463       assert (RL78_EXITED (rc));
 464       reason = sim_exited;
 465       siggnal = RL78_EXIT_STATUS (rc);
 466     }
 467 }
 468
 469
 470 /* Resume execution after a stop.  */
 471
 472 void
 473 sim_resume (SIM_DESC sd, int step, int sig_to_deliver)
 474 {
 475   int rc;
 476
 477   check_desc (sd);
 478
 479   if (sig_to_deliver != 0)
 480     {
 481       fprintf (stderr,
 482                "Warning: the rl78 minisim does not implement "
 483                "signal delivery yet.\n" "Resuming with no signal.\n");
 484     }
 485
 486       /* We don't clear 'stop' here, because then we would miss
 487          interrupts that arrived on the way here.  Instead, we clear
 488          the flag in sim_stop_reason, after GDB has disabled the
 489          interrupt signal handler.  */
 490   for (;;)
 491     {
 492       if (stop)
 493         {
 494           stop = 0;
 495           reason = sim_stopped;
 496           siggnal = GDB_SIGNAL_INT;
 497           break;
 498         }
 499
 500       rc = setjmp (decode_jmp_buf);
 501       if (rc == 0)
 502         rc = decode_opcode ();
 503
 504       if (!RL78_STEPPED (rc) || step)
 505         {
 506           handle_step (rc);
 507           break;
 508         }
 509     }
 510 }
 511
 512 /* Stop the sim.  */
 513
 514 int
 515 sim_stop (SIM_DESC sd)
 516 {
 517   stop = 1;
 518
 519   return 1;
 520 }
 521
 522 /* Fetch the stop reason and signal.  */
 523
 524 void
 525 sim_stop_reason (SIM_DESC sd, enum sim_stop *reason_p, int *sigrc_p)
 526 {
 527   check_desc (sd);
 528
 529   *reason_p = reason;
 530   *sigrc_p = siggnal;
 531 }
 532
 533 /* Execute the sim-specific command associated with GDB's "sim ..."
 534    command.  */
 535
 536 void
 537 sim_do_command (SIM_DESC sd, const char *cmd)
 538 {
 539   const char *arg;
 540   char **argv = buildargv (cmd);
 541
 542   check_desc (sd);
 543
 544   cmd = arg = "";
 545   if (argv != NULL)
 546     {
 547       if (argv[0] != NULL)
 548         cmd = argv[0];
 549       if (argv[1] != NULL)
 550         arg = argv[1];
 551     }
 552
 553   if (strcmp (cmd, "trace") == 0)
 554     {
 555       if (strcmp (arg, "on") == 0)
 556         trace = 1;
 557       else if (strcmp (arg, "off") == 0)
 558         trace = 0;
 559       else
 560         printf ("The 'sim trace' command expects 'on' or 'off' "
 561                 "as an argument.\n");
 562     }
 563   else if (strcmp (cmd, "verbose") == 0)
 564     {
 565       if (strcmp (arg, "on") == 0)
 566         verbose = 1;
 567       else if (strcmp (arg, "noisy") == 0)
 568         verbose = 2;
 569       else if (strcmp (arg, "off") == 0)
 570         verbose = 0;
 571       else
 572         printf ("The 'sim verbose' command expects 'on', 'noisy', or 'off'"
 573                 " as an argument.\n");
 574     }
 575   else
 576     printf ("The 'sim' command expects either 'trace' or 'verbose'"
 577             " as a subcommand.\n");
 578
 579   freeargv (argv);
 580 }
 581
 582 /* Stub for command completion.  */
 583
 584 char **
 585 sim_complete_command (SIM_DESC sd, const char *text, const char *word)
 586 {
 587     return NULL;
 588 }
 589
 590 char *
 591 sim_memory_map (SIM_DESC sd)
 592 {
 593   return NULL;
 594 }