sim/rx/gdb-if.c

   1 /* gdb-if.c -- sim interface to GDB.
   2
   3 Copyright (C) 2008-2020 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 #include "config.h"
  22 #include <stdio.h>
  23 #include <assert.h>
  24 #include <signal.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include <stdlib.h>
  28
  29 #include "ansidecl.h"
  30 #include "gdb/callback.h"
  31 #include "gdb/remote-sim.h"
  32 #include "gdb/signals.h"
  33 #include "gdb/sim-rx.h"
  34
  35 #include "cpu.h"
  36 #include "mem.h"
  37 #include "load.h"
  38 #include "syscalls.h"
  39 #include "err.h"
  40 #include "trace.h"
  41
  42 /* Ideally, we'd wrap up all the minisim's data structures in an
  43    object and pass that around.  However, neither GDB nor run needs
  44    that ability.
  45
  46    So we just have one instance, that lives in global variables, and
  47    each time we open it, we re-initialize it.  */
  48 struct sim_state
  49 {
  50   const char *message;
  51 };
  52
  53 static struct sim_state the_minisim = {
  54   "This is the sole rx minisim instance.  See libsim.a's global variables."
  55 };
  56
  57 static int rx_sim_is_open;
  58
  59 SIM_DESC
  60 sim_open (SIM_OPEN_KIND kind,
  61           struct host_callback_struct *callback,
  62           struct bfd *abfd, char * const *argv)
  63 {
  64   if (rx_sim_is_open)
  65     fprintf (stderr, "rx minisim: re-opened sim\n");
  66
  67   /* The 'run' interface doesn't use this function, so we don't care
  68      about KIND; it's always SIM_OPEN_DEBUG.  */
  69   if (kind != SIM_OPEN_DEBUG)
  70     fprintf (stderr, "rx minisim: sim_open KIND != SIM_OPEN_DEBUG: %d\n",
  71              kind);
  72
  73   set_callbacks (callback);
  74
  75   /* We don't expect any command-line arguments.  */
  76
  77   init_mem ();
  78   init_regs ();
  79   execution_error_init_debugger ();
  80
  81   sim_disasm_init (abfd);
  82   rx_sim_is_open = 1;
  83   return &the_minisim;
  84 }
  85
  86 static void
  87 check_desc (SIM_DESC sd)
  88 {
  89   if (sd != &the_minisim)
  90     fprintf (stderr, "rx minisim: desc != &the_minisim\n");
  91 }
  92
  93 void
  94 sim_close (SIM_DESC sd, int quitting)
  95 {
  96   check_desc (sd);
  97
  98   /* Not much to do.  At least free up our memory.  */
  99   init_mem ();
 100
 101   rx_sim_is_open = 0;
 102 }
 103
 104 static bfd *
 105 open_objfile (const char *filename)
 106 {
 107   bfd *prog = bfd_openr (filename, 0);
 108
 109   if (!prog)
 110     {
 111       fprintf (stderr, "Can't read %s\n", filename);
 112       return 0;
 113     }
 114
 115   if (!bfd_check_format (prog, bfd_object))
 116     {
 117       fprintf (stderr, "%s not a rx program\n", filename);
 118       return 0;
 119     }
 120
 121   return prog;
 122 }
 123
 124 static struct swap_list
 125 {
 126   bfd_vma start, end;
 127   struct swap_list *next;
 128 } *swap_list = NULL;
 129
 130 static void
 131 free_swap_list (void)
 132 {
 133   while (swap_list)
 134     {
 135       struct swap_list *next = swap_list->next;
 136       free (swap_list);
 137       swap_list = next;
 138     }
 139 }
 140
 141 /* When running in big endian mode, we must do an additional
 142    byte swap of memory areas used to hold instructions.  See
 143    the comment preceding rx_load in load.c to see why this is
 144    so.
 145
 146    Construct a list of memory areas that must be byte swapped.
 147    This list will be consulted when either reading or writing
 148    memory.  */
 149
 150 static void
 151 build_swap_list (struct bfd *abfd)
 152 {
 153   asection *s;
 154   free_swap_list ();
 155
 156   /* Nothing to do when in little endian mode.  */
 157   if (!rx_big_endian)
 158     return;
 159
 160   for (s = abfd->sections; s; s = s->next)
 161     {
 162       if ((s->flags & SEC_LOAD) && (s->flags & SEC_CODE))
 163         {
 164           struct swap_list *sl;
 165           bfd_size_type size;
 166
 167           size = bfd_section_size (s);
 168           if (size <= 0)
 169             continue;
 170
 171           sl = malloc (sizeof (struct swap_list));
 172           assert (sl != NULL);
 173           sl->next = swap_list;
 174           sl->start = bfd_section_lma (s);
 175           sl->end = sl->start + size;
 176           swap_list = sl;
 177         }
 178     }
 179 }
 180
 181 static int
 182 addr_in_swap_list (bfd_vma addr)
 183 {
 184   struct swap_list *s;
 185
 186   for (s = swap_list; s; s = s->next)
 187     {
 188       if (s->start <= addr && addr < s->end)
 189         return 1;
 190     }
 191   return 0;
 192 }
 193
 194 SIM_RC
 195 sim_load (SIM_DESC sd, const char *prog, struct bfd *abfd, int from_tty)
 196 {
 197   check_desc (sd);
 198
 199   if (!abfd)
 200     abfd = open_objfile (prog);
 201   if (!abfd)
 202     return SIM_RC_FAIL;
 203
 204   rx_load (abfd, get_callbacks ());
 205   build_swap_list (abfd);
 206
 207   return SIM_RC_OK;
 208 }
 209
 210 SIM_RC
 211 sim_create_inferior (SIM_DESC sd, struct bfd *abfd,
 212                      char * const *argv, char * const *env)
 213 {
 214   check_desc (sd);
 215
 216   if (abfd)
 217     {
 218       rx_load (abfd, NULL);
 219       build_swap_list (abfd);
 220     }
 221
 222   return SIM_RC_OK;
 223 }
 224
 225 int
 226 sim_read (SIM_DESC sd, SIM_ADDR mem, unsigned char *buf, int length)
 227 {
 228   int i;
 229
 230   check_desc (sd);
 231
 232   if (mem == 0)
 233     return 0;
 234
 235   execution_error_clear_last_error ();
 236
 237   for (i = 0; i < length; i++)
 238     {
 239       bfd_vma addr = mem + i;
 240       int do_swap = addr_in_swap_list (addr);
 241       buf[i] = mem_get_qi (addr ^ (do_swap ? 3 : 0));
 242
 243       if (execution_error_get_last_error () != SIM_ERR_NONE)
 244         return i;
 245     }
 246
 247   return length;
 248 }
 249
 250 int
 251 sim_write (SIM_DESC sd, SIM_ADDR mem, const unsigned char *buf, int length)
 252 {
 253   int i;
 254
 255   check_desc (sd);
 256
 257   execution_error_clear_last_error ();
 258
 259   for (i = 0; i < length; i++)
 260     {
 261       bfd_vma addr = mem + i;
 262       int do_swap = addr_in_swap_list (addr);
 263       mem_put_qi (addr ^ (do_swap ? 3 : 0), buf[i]);
 264
 265       if (execution_error_get_last_error () != SIM_ERR_NONE)
 266         return i;
 267     }
 268
 269   return length;
 270 }
 271
 272 /* Read the LENGTH bytes at BUF as an little-endian value.  */
 273 static DI
 274 get_le (unsigned char *buf, int length)
 275 {
 276   DI acc = 0;
 277   while (--length >= 0)
 278     acc = (acc << 8) + buf[length];
 279
 280   return acc;
 281 }
 282
 283 /* Read the LENGTH bytes at BUF as a big-endian value.  */
 284 static DI
 285 get_be (unsigned char *buf, int length)
 286 {
 287   DI acc = 0;
 288   while (length-- > 0)
 289     acc = (acc << 8) + *buf++;
 290
 291   return acc;
 292 }
 293
 294 /* Store VAL as a little-endian value in the LENGTH bytes at BUF.  */
 295 static void
 296 put_le (unsigned char *buf, int length, DI val)
 297 {
 298   int i;
 299
 300   for (i = 0; i < length; i++)
 301     {
 302       buf[i] = val & 0xff;
 303       val >>= 8;
 304     }
 305 }
 306
 307 /* Store VAL as a big-endian value in the LENGTH bytes at BUF.  */
 308 static void
 309 put_be (unsigned char *buf, int length, DI val)
 310 {
 311   int i;
 312
 313   for (i = length-1; i >= 0; i--)
 314     {
 315       buf[i] = val & 0xff;
 316       val >>= 8;
 317     }
 318 }
 319
 320
 321 static int
 322 check_regno (enum sim_rx_regnum regno)
 323 {
 324   return 0 <= regno && regno < sim_rx_num_regs;
 325 }
 326
 327 static size_t
 328 reg_size (enum sim_rx_regnum regno)
 329 {
 330   size_t size;
 331
 332   switch (regno)
 333     {
 334     case sim_rx_r0_regnum:
 335       size = sizeof (regs.r[0]);
 336       break;
 337     case sim_rx_r1_regnum:
 338       size = sizeof (regs.r[1]);
 339       break;
 340     case sim_rx_r2_regnum:
 341       size = sizeof (regs.r[2]);
 342       break;
 343     case sim_rx_r3_regnum:
 344       size = sizeof (regs.r[3]);
 345       break;
 346     case sim_rx_r4_regnum:
 347       size = sizeof (regs.r[4]);
 348       break;
 349     case sim_rx_r5_regnum:
 350       size = sizeof (regs.r[5]);
 351       break;
 352     case sim_rx_r6_regnum:
 353       size = sizeof (regs.r[6]);
 354       break;
 355     case sim_rx_r7_regnum:
 356       size = sizeof (regs.r[7]);
 357       break;
 358     case sim_rx_r8_regnum:
 359       size = sizeof (regs.r[8]);
 360       break;
 361     case sim_rx_r9_regnum:
 362       size = sizeof (regs.r[9]);
 363       break;
 364     case sim_rx_r10_regnum:
 365       size = sizeof (regs.r[10]);
 366       break;
 367     case sim_rx_r11_regnum:
 368       size = sizeof (regs.r[11]);
 369       break;
 370     case sim_rx_r12_regnum:
 371       size = sizeof (regs.r[12]);
 372       break;
 373     case sim_rx_r13_regnum:
 374       size = sizeof (regs.r[13]);
 375       break;
 376     case sim_rx_r14_regnum:
 377       size = sizeof (regs.r[14]);
 378       break;
 379     case sim_rx_r15_regnum:
 380       size = sizeof (regs.r[15]);
 381       break;
 382     case sim_rx_isp_regnum:
 383       size = sizeof (regs.r_isp);
 384       break;
 385     case sim_rx_usp_regnum:
 386       size = sizeof (regs.r_usp);
 387       break;
 388     case sim_rx_intb_regnum:
 389       size = sizeof (regs.r_intb);
 390       break;
 391     case sim_rx_pc_regnum:
 392       size = sizeof (regs.r_pc);
 393       break;
 394     case sim_rx_ps_regnum:
 395       size = sizeof (regs.r_psw);
 396       break;
 397     case sim_rx_bpc_regnum:
 398       size = sizeof (regs.r_bpc);
 399       break;
 400     case sim_rx_bpsw_regnum:
 401       size = sizeof (regs.r_bpsw);
 402       break;
 403     case sim_rx_fintv_regnum:
 404       size = sizeof (regs.r_fintv);
 405       break;
 406     case sim_rx_fpsw_regnum:
 407       size = sizeof (regs.r_fpsw);
 408       break;
 409     case sim_rx_acc_regnum:
 410       size = sizeof (regs.r_acc);
 411       break;
 412     default:
 413       size = 0;
 414       break;
 415     }
 416   return size;
 417 }
 418
 419 int
 420 sim_fetch_register (SIM_DESC sd, int regno, unsigned char *buf, int length)
 421 {
 422   size_t size;
 423   DI val;
 424
 425   check_desc (sd);
 426
 427   if (!check_regno (regno))
 428     return 0;
 429
 430   size = reg_size (regno);
 431
 432   if (length != size)
 433     return 0;
 434
 435   switch (regno)
 436     {
 437     case sim_rx_r0_regnum:
 438       val = get_reg (0);
 439       break;
 440     case sim_rx_r1_regnum:
 441       val = get_reg (1);
 442       break;
 443     case sim_rx_r2_regnum:
 444       val = get_reg (2);
 445       break;
 446     case sim_rx_r3_regnum:
 447       val = get_reg (3);
 448       break;
 449     case sim_rx_r4_regnum:
 450       val = get_reg (4);
 451       break;
 452     case sim_rx_r5_regnum:
 453       val = get_reg (5);
 454       break;
 455     case sim_rx_r6_regnum:
 456       val = get_reg (6);
 457       break;
 458     case sim_rx_r7_regnum:
 459       val = get_reg (7);
 460       break;
 461     case sim_rx_r8_regnum:
 462       val = get_reg (8);
 463       break;
 464     case sim_rx_r9_regnum:
 465       val = get_reg (9);
 466       break;
 467     case sim_rx_r10_regnum:
 468       val = get_reg (10);
 469       break;
 470     case sim_rx_r11_regnum:
 471       val = get_reg (11);
 472       break;
 473     case sim_rx_r12_regnum:
 474       val = get_reg (12);
 475       break;
 476     case sim_rx_r13_regnum:
 477       val = get_reg (13);
 478       break;
 479     case sim_rx_r14_regnum:
 480       val = get_reg (14);
 481       break;
 482     case sim_rx_r15_regnum:
 483       val = get_reg (15);
 484       break;
 485     case sim_rx_isp_regnum:
 486       val = get_reg (isp);
 487       break;
 488     case sim_rx_usp_regnum:
 489       val = get_reg (usp);
 490       break;
 491     case sim_rx_intb_regnum:
 492       val = get_reg (intb);
 493       break;
 494     case sim_rx_pc_regnum:
 495       val = get_reg (pc);
 496       break;
 497     case sim_rx_ps_regnum:
 498       val = get_reg (psw);
 499       break;
 500     case sim_rx_bpc_regnum:
 501       val = get_reg (bpc);
 502       break;
 503     case sim_rx_bpsw_regnum:
 504       val = get_reg (bpsw);
 505       break;
 506     case sim_rx_fintv_regnum:
 507       val = get_reg (fintv);
 508       break;
 509     case sim_rx_fpsw_regnum:
 510       val = get_reg (fpsw);
 511       break;
 512     case sim_rx_acc_regnum:
 513       val = ((DI) get_reg (acchi) << 32) | get_reg (acclo);
 514       break;
 515     default:
 516       fprintf (stderr, "rx minisim: unrecognized register number: %d\n",
 517                regno);
 518       return -1;
 519     }
 520
 521   if (rx_big_endian)
 522     put_be (buf, length, val);
 523   else
 524     put_le (buf, length, val);
 525
 526   return size;
 527 }
 528
 529 int
 530 sim_store_register (SIM_DESC sd, int regno, unsigned char *buf, int length)
 531 {
 532   size_t size;
 533   DI val;
 534
 535   check_desc (sd);
 536
 537   if (!check_regno (regno))
 538     return -1;
 539
 540   size = reg_size (regno);
 541
 542   if (length != size)
 543     return -1;
 544
 545   if (rx_big_endian)
 546     val = get_be (buf, length);
 547   else
 548     val = get_le (buf, length);
 549
 550   switch (regno)
 551     {
 552     case sim_rx_r0_regnum:
 553       put_reg (0, val);
 554       break;
 555     case sim_rx_r1_regnum:
 556       put_reg (1, val);
 557       break;
 558     case sim_rx_r2_regnum:
 559       put_reg (2, val);
 560       break;
 561     case sim_rx_r3_regnum:
 562       put_reg (3, val);
 563       break;
 564     case sim_rx_r4_regnum:
 565       put_reg (4, val);
 566       break;
 567     case sim_rx_r5_regnum:
 568       put_reg (5, val);
 569       break;
 570     case sim_rx_r6_regnum:
 571       put_reg (6, val);
 572       break;
 573     case sim_rx_r7_regnum:
 574       put_reg (7, val);
 575       break;
 576     case sim_rx_r8_regnum:
 577       put_reg (8, val);
 578       break;
 579     case sim_rx_r9_regnum:
 580       put_reg (9, val);
 581       break;
 582     case sim_rx_r10_regnum:
 583       put_reg (10, val);
 584       break;
 585     case sim_rx_r11_regnum:
 586       put_reg (11, val);
 587       break;
 588     case sim_rx_r12_regnum:
 589       put_reg (12, val);
 590       break;
 591     case sim_rx_r13_regnum:
 592       put_reg (13, val);
 593       break;
 594     case sim_rx_r14_regnum:
 595       put_reg (14, val);
 596       break;
 597     case sim_rx_r15_regnum:
 598       put_reg (15, val);
 599       break;
 600     case sim_rx_isp_regnum:
 601       put_reg (isp, val);
 602       break;
 603     case sim_rx_usp_regnum:
 604       put_reg (usp, val);
 605       break;
 606     case sim_rx_intb_regnum:
 607       put_reg (intb, val);
 608       break;
 609     case sim_rx_pc_regnum:
 610       put_reg (pc, val);
 611       break;
 612     case sim_rx_ps_regnum:
 613       put_reg (psw, val);
 614       break;
 615     case sim_rx_bpc_regnum:
 616       put_reg (bpc, val);
 617       break;
 618     case sim_rx_bpsw_regnum:
 619       put_reg (bpsw, val);
 620       break;
 621     case sim_rx_fintv_regnum:
 622       put_reg (fintv, val);
 623       break;
 624     case sim_rx_fpsw_regnum:
 625       put_reg (fpsw, val);
 626       break;
 627     case sim_rx_acc_regnum:
 628       put_reg (acclo, val & 0xffffffff);
 629       put_reg (acchi, (val >> 32) & 0xffffffff);
 630       break;
 631     default:
 632       fprintf (stderr, "rx minisim: unrecognized register number: %d\n",
 633                regno);
 634       return 0;
 635     }
 636
 637   return size;
 638 }
 639
 640 void
 641 sim_info (SIM_DESC sd, int verbose)
 642 {
 643   check_desc (sd);
 644
 645   printf ("The rx minisim doesn't collect any statistics.\n");
 646 }
 647
 648 static volatile int stop;
 649 static enum sim_stop reason;
 650 int siggnal;
 651
 652
 653 /* Given a signal number used by the RX bsp (that is, newlib),
 654    return a target signal number used by GDB.  */
 655 static int
 656 rx_signal_to_gdb_signal (int rx)
 657 {
 658   switch (rx)
 659     {
 660     case 4:
 661       return GDB_SIGNAL_ILL;
 662
 663     case 5:
 664       return GDB_SIGNAL_TRAP;
 665
 666     case 10:
 667       return GDB_SIGNAL_BUS;
 668
 669     case 11:
 670       return GDB_SIGNAL_SEGV;
 671
 672     case 24:
 673       return GDB_SIGNAL_XCPU;
 674
 675     case 2:
 676       return GDB_SIGNAL_INT;
 677
 678     case 8:
 679       return GDB_SIGNAL_FPE;
 680
 681     case 6:
 682       return GDB_SIGNAL_ABRT;
 683     }
 684
 685   return 0;
 686 }
 687
 688
 689 /* Take a step return code RC and set up the variables consulted by
 690    sim_stop_reason appropriately.  */
 691 void
 692 handle_step (int rc)
 693 {
 694   if (execution_error_get_last_error () != SIM_ERR_NONE)
 695     {
 696       reason = sim_stopped;
 697       siggnal = GDB_SIGNAL_SEGV;
 698     }
 699   if (RX_STEPPED (rc) || RX_HIT_BREAK (rc))
 700     {
 701       reason = sim_stopped;
 702       siggnal = GDB_SIGNAL_TRAP;
 703     }
 704   else if (RX_STOPPED (rc))
 705     {
 706       reason = sim_stopped;
 707       siggnal = rx_signal_to_gdb_signal (RX_STOP_SIG (rc));
 708     }
 709   else
 710     {
 711       assert (RX_EXITED (rc));
 712       reason = sim_exited;
 713       siggnal = RX_EXIT_STATUS (rc);
 714     }
 715 }
 716
 717
 718 void
 719 sim_resume (SIM_DESC sd, int step, int sig_to_deliver)
 720 {
 721   int rc;
 722
 723   check_desc (sd);
 724
 725   if (sig_to_deliver != 0)
 726     {
 727       fprintf (stderr,
 728                "Warning: the rx minisim does not implement "
 729                "signal delivery yet.\n" "Resuming with no signal.\n");
 730     }
 731
 732   execution_error_clear_last_error ();
 733
 734   if (step)
 735     {
 736       rc = setjmp (decode_jmp_buf);
 737       if (rc == 0)
 738         rc = decode_opcode ();
 739       handle_step (rc);
 740     }
 741   else
 742     {
 743       /* We don't clear 'stop' here, because then we would miss
 744          interrupts that arrived on the way here.  Instead, we clear
 745          the flag in sim_stop_reason, after GDB has disabled the
 746          interrupt signal handler.  */
 747       for (;;)
 748         {
 749           if (stop)
 750             {
 751               stop = 0;
 752               reason = sim_stopped;
 753               siggnal = GDB_SIGNAL_INT;
 754               break;
 755             }
 756
 757           rc = setjmp (decode_jmp_buf);
 758           if (rc == 0)
 759             rc = decode_opcode ();
 760
 761           if (execution_error_get_last_error () != SIM_ERR_NONE)
 762             {
 763               reason = sim_stopped;
 764               siggnal = GDB_SIGNAL_SEGV;
 765               break;
 766             }
 767
 768           if (!RX_STEPPED (rc))
 769             {
 770               handle_step (rc);
 771               break;
 772             }
 773         }
 774     }
 775 }
 776
 777 int
 778 sim_stop (SIM_DESC sd)
 779 {
 780   stop = 1;
 781
 782   return 1;
 783 }
 784
 785 void
 786 sim_stop_reason (SIM_DESC sd, enum sim_stop *reason_p, int *sigrc_p)
 787 {
 788   check_desc (sd);
 789
 790   *reason_p = reason;
 791   *sigrc_p = siggnal;
 792 }
 793
 794 void
 795 sim_do_command (SIM_DESC sd, const char *cmd)
 796 {
 797   const char *args;
 798   char *p = strdup (cmd);
 799
 800   check_desc (sd);
 801
 802   /* Skip leading whitespace.  */
 803   while (isspace (*p))
 804     p++;
 805
 806   /* Find the extent of the command word.  */
 807   for (p = cmd; *p; p++)
 808     if (isspace (*p))
 809       break;
 810
 811   /* Null-terminate the command word, and record the start of any
 812      further arguments.  */
 813   if (*p)
 814     {
 815       *p = '\0';
 816       args = p + 1;
 817       while (isspace (*args))
 818         args++;
 819     }
 820   else
 821     args = p;
 822
 823   if (strcmp (cmd, "trace") == 0)
 824     {
 825       if (strcmp (args, "on") == 0)
 826         trace = 1;
 827       else if (strcmp (args, "off") == 0)
 828         trace = 0;
 829       else
 830         printf ("The 'sim trace' command expects 'on' or 'off' "
 831                 "as an argument.\n");
 832     }
 833   else if (strcmp (cmd, "verbose") == 0)
 834     {
 835       if (strcmp (args, "on") == 0)
 836         verbose = 1;
 837       else if (strcmp (args, "noisy") == 0)
 838         verbose = 2;
 839       else if (strcmp (args, "off") == 0)
 840         verbose = 0;
 841       else
 842         printf ("The 'sim verbose' command expects 'on', 'noisy', or 'off'"
 843                 " as an argument.\n");
 844     }
 845   else
 846     printf ("The 'sim' command expects either 'trace' or 'verbose'"
 847             " as a subcommand.\n");
 848
 849   free (p);
 850 }
 851
 852 char **
 853 sim_complete_command (SIM_DESC sd, const char *text, const char *word)
 854 {
 855   return NULL;
 856 }