gdb/memattr.c

   1 /* Memory attributes support, for GDB.
   2
   3    Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
   4    Free Software Foundation, Inc.
   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., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #include "defs.h"
  24 #include "command.h"
  25 #include "gdbcmd.h"
  26 #include "memattr.h"
  27 #include "target.h"
  28 #include "value.h"
  29 #include "language.h"
  30 #include "vec.h"
  31 #include "gdb_string.h"
  32
  33 const struct mem_attrib default_mem_attrib =
  34 {
  35   MEM_RW,                       /* mode */
  36   MEM_WIDTH_UNSPECIFIED,
  37   0,                            /* hwbreak */
  38   0,                            /* cache */
  39   0,                            /* verify */
  40   -1 /* Flash blocksize not specified.  */
  41 };
  42
  43 const struct mem_attrib unknown_mem_attrib =
  44 {
  45   MEM_NONE,                     /* mode */
  46   MEM_WIDTH_UNSPECIFIED,
  47   0,                            /* hwbreak */
  48   0,                            /* cache */
  49   0,                            /* verify */
  50   -1 /* Flash blocksize not specified.  */
  51 };
  52
  53
  54 VEC(mem_region_s) *mem_region_list, *target_mem_region_list;
  55 static int mem_number = 0;
  56
  57 /* If this flag is set, the memory region list should be automatically
  58    updated from the target.  If it is clear, the list is user-controlled
  59    and should be left alone.  */
  60 static int mem_use_target = 1;
  61
  62 /* If this flag is set, we have tried to fetch the target memory regions
  63    since the last time it was invalidated.  If that list is still
  64    empty, then the target can't supply memory regions.  */
  65 static int target_mem_regions_valid;
  66
  67 /* If this flag is set, gdb will assume that memory ranges not
  68    specified by the memory map have type MEM_NONE, and will
  69    emit errors on all accesses to that memory.  */
  70 static int inaccessible_by_default = 0;
  71
  72 static void
  73 show_inaccessible_by_default (struct ui_file *file, int from_tty,
  74                               struct cmd_list_element *c,
  75                               const char *value)
  76 {
  77   if (inaccessible_by_default)
  78     fprintf_filtered (file, _("\
  79 Unknown memory addresses will be treated as inaccessible.\n"));
  80   else
  81     fprintf_filtered (file, _("\
  82 Unknown memory addresses will be treated as RAM.\n"));
  83 }
  84
  85
  86 /* Predicate function which returns true if LHS should sort before RHS
  87    in a list of memory regions, useful for VEC_lower_bound.  */
  88
  89 static int
  90 mem_region_lessthan (const struct mem_region *lhs,
  91                      const struct mem_region *rhs)
  92 {
  93   return lhs->lo < rhs->lo;
  94 }
  95
  96 /* A helper function suitable for qsort, used to sort a
  97    VEC(mem_region_s) by starting address.  */
  98
  99 int
 100 mem_region_cmp (const void *untyped_lhs, const void *untyped_rhs)
 101 {
 102   const struct mem_region *lhs = untyped_lhs;
 103   const struct mem_region *rhs = untyped_rhs;
 104
 105   if (lhs->lo < rhs->lo)
 106     return -1;
 107   else if (lhs->lo == rhs->lo)
 108     return 0;
 109   else
 110     return 1;
 111 }
 112
 113 /* Allocate a new memory region, with default settings.  */
 114
 115 void
 116 mem_region_init (struct mem_region *new)
 117 {
 118   memset (new, 0, sizeof (struct mem_region));
 119   new->enabled_p = 1;
 120   new->attrib = default_mem_attrib;
 121 }
 122
 123 /* This function should be called before any command which would
 124    modify the memory region list.  It will handle switching from
 125    a target-provided list to a local list, if necessary.  */
 126
 127 static void
 128 require_user_regions (int from_tty)
 129 {
 130   struct mem_region *m;
 131   int ix, length;
 132
 133   /* If we're already using a user-provided list, nothing to do.  */
 134   if (!mem_use_target)
 135     return;
 136
 137   /* Switch to a user-provided list (possibly a copy of the current
 138      one).  */
 139   mem_use_target = 0;
 140
 141   /* If we don't have a target-provided region list yet, then
 142      no need to warn.  */
 143   if (mem_region_list == NULL)
 144     return;
 145
 146   /* Otherwise, let the user know how to get back.  */
 147   if (from_tty)
 148     warning (_("Switching to manual control of memory regions; use "
 149                "\"mem auto\" to fetch regions from the target again."));
 150
 151   /* And create a new list for the user to modify.  */
 152   length = VEC_length (mem_region_s, target_mem_region_list);
 153   mem_region_list = VEC_alloc (mem_region_s, length);
 154   for (ix = 0; VEC_iterate (mem_region_s, target_mem_region_list, ix, m); ix++)
 155     VEC_quick_push (mem_region_s, mem_region_list, m);
 156 }
 157
 158 /* This function should be called before any command which would
 159    read the memory region list, other than those which call
 160    require_user_regions.  It will handle fetching the
 161    target-provided list, if necessary.  */
 162
 163 static void
 164 require_target_regions (void)
 165 {
 166   if (mem_use_target && !target_mem_regions_valid)
 167     {
 168       target_mem_regions_valid = 1;
 169       target_mem_region_list = target_memory_map ();
 170       mem_region_list = target_mem_region_list;
 171     }
 172 }
 173
 174 static void
 175 create_mem_region (CORE_ADDR lo, CORE_ADDR hi,
 176                    const struct mem_attrib *attrib)
 177 {
 178   struct mem_region new;
 179   int i, ix;
 180
 181   /* lo == hi is a useless empty region */
 182   if (lo >= hi && hi != 0)
 183     {
 184       printf_unfiltered (_("invalid memory region: low >= high\n"));
 185       return;
 186     }
 187
 188   mem_region_init (&new);
 189   new.lo = lo;
 190   new.hi = hi;
 191
 192   ix = VEC_lower_bound (mem_region_s, mem_region_list, &new,
 193                         mem_region_lessthan);
 194
 195   /* Check for an overlapping memory region.  We only need to check
 196      in the vicinity - at most one before and one after the
 197      insertion point.  */
 198   for (i = ix - 1; i < ix + 1; i++)
 199     {
 200       struct mem_region *n;
 201
 202       if (i < 0)
 203         continue;
 204       if (i >= VEC_length (mem_region_s, mem_region_list))
 205         continue;
 206
 207       n = VEC_index (mem_region_s, mem_region_list, i);
 208
 209       if ((lo >= n->lo && (lo < n->hi || n->hi == 0))
 210           || (hi > n->lo && (hi <= n->hi || n->hi == 0))
 211           || (lo <= n->lo && (hi >= n->hi || hi == 0)))
 212         {
 213           printf_unfiltered (_("overlapping memory region\n"));
 214           return;
 215         }
 216     }
 217
 218   new.number = ++mem_number;
 219   new.attrib = *attrib;
 220   VEC_safe_insert (mem_region_s, mem_region_list, ix, &new);
 221 }
 222
 223 /*
 224  * Look up the memory region cooresponding to ADDR.
 225  */
 226 struct mem_region *
 227 lookup_mem_region (CORE_ADDR addr)
 228 {
 229   static struct mem_region region;
 230   struct mem_region *m;
 231   CORE_ADDR lo;
 232   CORE_ADDR hi;
 233   int ix;
 234
 235   require_target_regions ();
 236
 237   /* First we initialize LO and HI so that they describe the entire
 238      memory space.  As we process the memory region chain, they are
 239      redefined to describe the minimal region containing ADDR.  LO
 240      and HI are used in the case where no memory region is defined
 241      that contains ADDR.  If a memory region is disabled, it is
 242      treated as if it does not exist.  The initial values for LO
 243      and HI represent the bottom and top of memory.  */
 244
 245   lo = 0;
 246   hi = 0;
 247
 248   /* Either find memory range containing ADDRESS, or set LO and HI
 249      to the nearest boundaries of an existing memory range.
 250
 251      If we ever want to support a huge list of memory regions, this
 252      check should be replaced with a binary search (probably using
 253      VEC_lower_bound).  */
 254   for (ix = 0; VEC_iterate (mem_region_s, mem_region_list, ix, m); ix++)
 255     {
 256       if (m->enabled_p == 1)
 257         {
 258           /* If the address is in the memory region, return that memory range.  */
 259           if (addr >= m->lo && (addr < m->hi || m->hi == 0))
 260             return m;
 261
 262           /* This (correctly) won't match if m->hi == 0, representing
 263              the top of the address space, because CORE_ADDR is unsigned;
 264              no value of LO is less than zero.  */
 265           if (addr >= m->hi && lo < m->hi)
 266             lo = m->hi;
 267
 268           /* This will never set HI to zero; if we're here and ADDR
 269              is at or below M, and the region starts at zero, then ADDR
 270              would have been in the region.  */
 271           if (addr <= m->lo && (hi == 0 || hi > m->lo))
 272             hi = m->lo;
 273         }
 274     }
 275
 276   /* Because no region was found, we must cons up one based on what
 277      was learned above.  */
 278   region.lo = lo;
 279   region.hi = hi;
 280
 281   /* When no memory map is defined at all, we always return
 282      'default_mem_attrib', so that we do not make all memory
 283      inaccessible for targets that don't provide a memory map.  */
 284   if (inaccessible_by_default && !VEC_empty (mem_region_s, mem_region_list))
 285     region.attrib = unknown_mem_attrib;
 286   else
 287     region.attrib = default_mem_attrib;
 288
 289   return &region;
 290 }
 291
 292 /* Invalidate any memory regions fetched from the target.  */
 293
 294 void
 295 invalidate_target_mem_regions (void)
 296 {
 297   struct mem_region *m;
 298   int ix;
 299
 300   if (!target_mem_regions_valid)
 301     return;
 302
 303   target_mem_regions_valid = 0;
 304   VEC_free (mem_region_s, target_mem_region_list);
 305   if (mem_use_target)
 306     mem_region_list = NULL;
 307 }
 308
 309 /* Clear memory region list */
 310
 311 static void
 312 mem_clear (void)
 313 {
 314   VEC_free (mem_region_s, mem_region_list);
 315 }
 316 \f
 317
 318 static void
 319 mem_command (char *args, int from_tty)
 320 {
 321   CORE_ADDR lo, hi;
 322   char *tok;
 323   struct mem_attrib attrib;
 324
 325   if (!args)
 326     error_no_arg (_("No mem"));
 327
 328   /* For "mem auto", switch back to using a target provided list.  */
 329   if (strcmp (args, "auto") == 0)
 330     {
 331       if (mem_use_target)
 332         return;
 333
 334       if (mem_region_list != target_mem_region_list)
 335         {
 336           mem_clear ();
 337           mem_region_list = target_mem_region_list;
 338         }
 339
 340       mem_use_target = 1;
 341       return;
 342     }
 343
 344   require_user_regions (from_tty);
 345
 346   tok = strtok (args, " \t");
 347   if (!tok)
 348     error (_("no lo address"));
 349   lo = parse_and_eval_address (tok);
 350
 351   tok = strtok (NULL, " \t");
 352   if (!tok)
 353     error (_("no hi address"));
 354   hi = parse_and_eval_address (tok);
 355
 356   attrib = default_mem_attrib;
 357   while ((tok = strtok (NULL, " \t")) != NULL)
 358     {
 359       if (strcmp (tok, "rw") == 0)
 360         attrib.mode = MEM_RW;
 361       else if (strcmp (tok, "ro") == 0)
 362         attrib.mode = MEM_RO;
 363       else if (strcmp (tok, "wo") == 0)
 364         attrib.mode = MEM_WO;
 365
 366       else if (strcmp (tok, "8") == 0)
 367         attrib.width = MEM_WIDTH_8;
 368       else if (strcmp (tok, "16") == 0)
 369         {
 370           if ((lo % 2 != 0) || (hi % 2 != 0))
 371             error (_("region bounds not 16 bit aligned"));
 372           attrib.width = MEM_WIDTH_16;
 373         }
 374       else if (strcmp (tok, "32") == 0)
 375         {
 376           if ((lo % 4 != 0) || (hi % 4 != 0))
 377             error (_("region bounds not 32 bit aligned"));
 378           attrib.width = MEM_WIDTH_32;
 379         }
 380       else if (strcmp (tok, "64") == 0)
 381         {
 382           if ((lo % 8 != 0) || (hi % 8 != 0))
 383             error (_("region bounds not 64 bit aligned"));
 384           attrib.width = MEM_WIDTH_64;
 385         }
 386
 387 #if 0
 388       else if (strcmp (tok, "hwbreak") == 0)
 389         attrib.hwbreak = 1;
 390       else if (strcmp (tok, "swbreak") == 0)
 391         attrib.hwbreak = 0;
 392 #endif
 393
 394       else if (strcmp (tok, "cache") == 0)
 395         attrib.cache = 1;
 396       else if (strcmp (tok, "nocache") == 0)
 397         attrib.cache = 0;
 398
 399 #if 0
 400       else if (strcmp (tok, "verify") == 0)
 401         attrib.verify = 1;
 402       else if (strcmp (tok, "noverify") == 0)
 403         attrib.verify = 0;
 404 #endif
 405
 406       else
 407         error (_("unknown attribute: %s"), tok);
 408     }
 409
 410   create_mem_region (lo, hi, &attrib);
 411 }
 412 \f
 413
 414 static void
 415 mem_info_command (char *args, int from_tty)
 416 {
 417   struct mem_region *m;
 418   struct mem_attrib *attrib;
 419   int ix;
 420
 421   if (mem_use_target)
 422     printf_filtered (_("Using memory regions provided by the target.\n"));
 423   else
 424     printf_filtered (_("Using user-defined memory regions.\n"));
 425
 426   require_target_regions ();
 427
 428   if (!mem_region_list)
 429     {
 430       printf_unfiltered (_("There are no memory regions defined.\n"));
 431       return;
 432     }
 433
 434   printf_filtered ("Num ");
 435   printf_filtered ("Enb ");
 436   printf_filtered ("Low Addr   ");
 437   if (TARGET_ADDR_BIT > 32)
 438     printf_filtered ("        ");
 439   printf_filtered ("High Addr  ");
 440   if (TARGET_ADDR_BIT > 32)
 441     printf_filtered ("        ");
 442   printf_filtered ("Attrs ");
 443   printf_filtered ("\n");
 444
 445   for (ix = 0; VEC_iterate (mem_region_s, mem_region_list, ix, m); ix++)
 446     {
 447       char *tmp;
 448       printf_filtered ("%-3d %-3c\t",
 449                        m->number,
 450                        m->enabled_p ? 'y' : 'n');
 451       if (TARGET_ADDR_BIT <= 32)
 452         tmp = hex_string_custom ((unsigned long) m->lo, 8);
 453       else
 454         tmp = hex_string_custom ((unsigned long) m->lo, 16);
 455
 456       printf_filtered ("%s ", tmp);
 457
 458       if (TARGET_ADDR_BIT <= 32)
 459         {
 460         if (m->hi == 0)
 461           tmp = "0x100000000";
 462         else
 463           tmp = hex_string_custom ((unsigned long) m->hi, 8);
 464         }
 465       else
 466         {
 467         if (m->hi == 0)
 468           tmp = "0x10000000000000000";
 469         else
 470           tmp = hex_string_custom ((unsigned long) m->hi, 16);
 471         }
 472
 473       printf_filtered ("%s ", tmp);
 474
 475       /* Print a token for each attribute.
 476
 477        * FIXME: Should we output a comma after each token?  It may
 478        * make it easier for users to read, but we'd lose the ability
 479        * to cut-and-paste the list of attributes when defining a new
 480        * region.  Perhaps that is not important.
 481        *
 482        * FIXME: If more attributes are added to GDB, the output may
 483        * become cluttered and difficult for users to read.  At that
 484        * time, we may want to consider printing tokens only if they
 485        * are different from the default attribute.  */
 486
 487       attrib = &m->attrib;
 488       switch (attrib->mode)
 489         {
 490         case MEM_RW:
 491           printf_filtered ("rw ");
 492           break;
 493         case MEM_RO:
 494           printf_filtered ("ro ");
 495           break;
 496         case MEM_WO:
 497           printf_filtered ("wo ");
 498           break;
 499         case MEM_FLASH:
 500           printf_filtered ("flash blocksize 0x%x ", attrib->blocksize);
 501           break;
 502         }
 503
 504       switch (attrib->width)
 505         {
 506         case MEM_WIDTH_8:
 507           printf_filtered ("8 ");
 508           break;
 509         case MEM_WIDTH_16:
 510           printf_filtered ("16 ");
 511           break;
 512         case MEM_WIDTH_32:
 513           printf_filtered ("32 ");
 514           break;
 515         case MEM_WIDTH_64:
 516           printf_filtered ("64 ");
 517           break;
 518         case MEM_WIDTH_UNSPECIFIED:
 519           break;
 520         }
 521
 522 #if 0
 523       if (attrib->hwbreak)
 524         printf_filtered ("hwbreak");
 525       else
 526         printf_filtered ("swbreak");
 527 #endif
 528
 529       if (attrib->cache)
 530         printf_filtered ("cache ");
 531       else
 532         printf_filtered ("nocache ");
 533
 534 #if 0
 535       if (attrib->verify)
 536         printf_filtered ("verify ");
 537       else
 538         printf_filtered ("noverify ");
 539 #endif
 540
 541       printf_filtered ("\n");
 542
 543       gdb_flush (gdb_stdout);
 544     }
 545 }
 546 \f
 547
 548 /* Enable the memory region number NUM. */
 549
 550 static void
 551 mem_enable (int num)
 552 {
 553   struct mem_region *m;
 554   int ix;
 555
 556   for (ix = 0; VEC_iterate (mem_region_s, mem_region_list, ix, m); ix++)
 557     if (m->number == num)
 558       {
 559         m->enabled_p = 1;
 560         return;
 561       }
 562   printf_unfiltered (_("No memory region number %d.\n"), num);
 563 }
 564
 565 static void
 566 mem_enable_command (char *args, int from_tty)
 567 {
 568   char *p = args;
 569   char *p1;
 570   int num;
 571   struct mem_region *m;
 572   int ix;
 573
 574   require_user_regions (from_tty);
 575
 576   dcache_invalidate (target_dcache);
 577
 578   if (p == 0)
 579     {
 580       for (ix = 0; VEC_iterate (mem_region_s, mem_region_list, ix, m); ix++)
 581         m->enabled_p = 1;
 582     }
 583   else
 584     while (*p)
 585       {
 586         p1 = p;
 587         while (*p1 >= '0' && *p1 <= '9')
 588           p1++;
 589         if (*p1 && *p1 != ' ' && *p1 != '\t')
 590           error (_("Arguments must be memory region numbers."));
 591
 592         num = atoi (p);
 593         mem_enable (num);
 594
 595         p = p1;
 596         while (*p == ' ' || *p == '\t')
 597           p++;
 598       }
 599 }
 600 \f
 601
 602 /* Disable the memory region number NUM. */
 603
 604 static void
 605 mem_disable (int num)
 606 {
 607   struct mem_region *m;
 608   int ix;
 609
 610   for (ix = 0; VEC_iterate (mem_region_s, mem_region_list, ix, m); ix++)
 611     if (m->number == num)
 612       {
 613         m->enabled_p = 0;
 614         return;
 615       }
 616   printf_unfiltered (_("No memory region number %d.\n"), num);
 617 }
 618
 619 static void
 620 mem_disable_command (char *args, int from_tty)
 621 {
 622   char *p = args;
 623   char *p1;
 624   int num;
 625   struct mem_region *m;
 626   int ix;
 627
 628   require_user_regions (from_tty);
 629
 630   dcache_invalidate (target_dcache);
 631
 632   if (p == 0)
 633     {
 634       for (ix = 0; VEC_iterate (mem_region_s, mem_region_list, ix, m); ix++)
 635         m->enabled_p = 0;
 636     }
 637   else
 638     while (*p)
 639       {
 640         p1 = p;
 641         while (*p1 >= '0' && *p1 <= '9')
 642           p1++;
 643         if (*p1 && *p1 != ' ' && *p1 != '\t')
 644           error (_("Arguments must be memory region numbers."));
 645
 646         num = atoi (p);
 647         mem_disable (num);
 648
 649         p = p1;
 650         while (*p == ' ' || *p == '\t')
 651           p++;
 652       }
 653 }
 654
 655 /* Delete the memory region number NUM. */
 656
 657 static void
 658 mem_delete (int num)
 659 {
 660   struct mem_region *m1, *m;
 661   int ix;
 662
 663   if (!mem_region_list)
 664     {
 665       printf_unfiltered (_("No memory region number %d.\n"), num);
 666       return;
 667     }
 668
 669   for (ix = 0; VEC_iterate (mem_region_s, mem_region_list, ix, m); ix++)
 670     if (m->number == num)
 671       break;
 672
 673   if (m == NULL)
 674     {
 675       printf_unfiltered (_("No memory region number %d.\n"), num);
 676       return;
 677     }
 678
 679   VEC_ordered_remove (mem_region_s, mem_region_list, ix);
 680 }
 681
 682 static void
 683 mem_delete_command (char *args, int from_tty)
 684 {
 685   char *p = args;
 686   char *p1;
 687   int num;
 688
 689   require_user_regions (from_tty);
 690
 691   dcache_invalidate (target_dcache);
 692
 693   if (p == 0)
 694     {
 695       if (query ("Delete all memory regions? "))
 696         mem_clear ();
 697       dont_repeat ();
 698       return;
 699     }
 700
 701   while (*p)
 702     {
 703       p1 = p;
 704       while (*p1 >= '0' && *p1 <= '9')
 705         p1++;
 706       if (*p1 && *p1 != ' ' && *p1 != '\t')
 707         error (_("Arguments must be memory region numbers."));
 708
 709       num = atoi (p);
 710       mem_delete (num);
 711
 712       p = p1;
 713       while (*p == ' ' || *p == '\t')
 714         p++;
 715     }
 716
 717   dont_repeat ();
 718 }
 719
 720 static void
 721 dummy_cmd (char *args, int from_tty)
 722 {
 723 }
 724 \f
 725 extern initialize_file_ftype _initialize_mem; /* -Wmissing-prototype */
 726
 727 static struct cmd_list_element *mem_set_cmdlist;
 728 static struct cmd_list_element *mem_show_cmdlist;
 729
 730 void
 731 _initialize_mem (void)
 732 {
 733   add_com ("mem", class_vars, mem_command, _("\
 734 Define attributes for memory region or reset memory region handling to\n\
 735 target-based.\n\
 736 Usage: mem auto\n\
 737        mem <lo addr> <hi addr> [<mode> <width> <cache>], \n\
 738 where <mode>  may be rw (read/write), ro (read-only) or wo (write-only), \n\
 739       <width> may be 8, 16, 32, or 64, and \n\
 740       <cache> may be cache or nocache"));
 741
 742   add_cmd ("mem", class_vars, mem_enable_command, _("\
 743 Enable memory region.\n\
 744 Arguments are the code numbers of the memory regions to enable.\n\
 745 Usage: enable mem <code number>\n\
 746 Do \"info mem\" to see current list of code numbers."), &enablelist);
 747
 748   add_cmd ("mem", class_vars, mem_disable_command, _("\
 749 Disable memory region.\n\
 750 Arguments are the code numbers of the memory regions to disable.\n\
 751 Usage: disable mem <code number>\n\
 752 Do \"info mem\" to see current list of code numbers."), &disablelist);
 753
 754   add_cmd ("mem", class_vars, mem_delete_command, _("\
 755 Delete memory region.\n\
 756 Arguments are the code numbers of the memory regions to delete.\n\
 757 Usage: delete mem <code number>\n\
 758 Do \"info mem\" to see current list of code numbers."), &deletelist);
 759
 760   add_info ("mem", mem_info_command,
 761             _("Memory region attributes"));
 762
 763   add_prefix_cmd ("mem", class_vars, dummy_cmd, _("\
 764 Memory regions settings"),
 765                   &mem_set_cmdlist, "set mem ",
 766                   0/* allow-unknown */, &setlist);
 767   add_prefix_cmd ("mem", class_vars, dummy_cmd, _("\
 768 Memory regions settings"),
 769                   &mem_show_cmdlist, "show mem  ",
 770                   0/* allow-unknown */, &showlist);
 771
 772   add_setshow_boolean_cmd ("inaccessible-by-default", no_class,
 773                                   &inaccessible_by_default, _("\
 774 Set handling of unknown memory regions."), _("\
 775 Show handling of unknown memory regions."), _("\
 776 If on, and some memory map is defined, debugger will emit errors on\n\
 777 accesses to memory not defined in the memory map. If off, accesses to all\n\
 778 memory addresses will be allowed."),
 779                                 NULL,
 780                                 show_inaccessible_by_default,
 781                                 &mem_set_cmdlist,
 782                                 &mem_show_cmdlist);
 783 }