gdb/target-memory.c

   1 /* Parts of target interface that deal with accessing memory and memory-like
   2    objects.
   3
   4    Copyright (C) 2006-2014 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 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 "defs.h"
  22 #include "vec.h"
  23 #include "target.h"
  24 #include "memory-map.h"
  25
  26 #include <sys/time.h>
  27
  28 static int
  29 compare_block_starting_address (const void *a, const void *b)
  30 {
  31   const struct memory_write_request *a_req = a;
  32   const struct memory_write_request *b_req = b;
  33
  34   if (a_req->begin < b_req->begin)
  35     return -1;
  36   else if (a_req->begin == b_req->begin)
  37     return 0;
  38   else
  39     return 1;
  40 }
  41
  42 /* Adds to RESULT all memory write requests from BLOCK that are
  43    in [BEGIN, END) range.
  44
  45    If any memory request is only partially in the specified range,
  46    that part of the memory request will be added.  */
  47
  48 static void
  49 claim_memory (VEC(memory_write_request_s) *blocks,
  50               VEC(memory_write_request_s) **result,
  51               ULONGEST begin,
  52               ULONGEST end)
  53 {
  54   int i;
  55   ULONGEST claimed_begin;
  56   ULONGEST claimed_end;
  57   struct memory_write_request *r;
  58
  59   for (i = 0; VEC_iterate (memory_write_request_s, blocks, i, r); ++i)
  60     {
  61       /* If the request doesn't overlap [BEGIN, END), skip it.  We
  62          must handle END == 0 meaning the top of memory; we don't yet
  63          check for R->end == 0, which would also mean the top of
  64          memory, but there's an assertion in
  65          target_write_memory_blocks which checks for that.  */
  66
  67       if (begin >= r->end)
  68         continue;
  69       if (end != 0 && end <= r->begin)
  70         continue;
  71
  72       claimed_begin = max (begin, r->begin);
  73       if (end == 0)
  74         claimed_end = r->end;
  75       else
  76         claimed_end = min (end, r->end);
  77
  78       if (claimed_begin == r->begin && claimed_end == r->end)
  79         VEC_safe_push (memory_write_request_s, *result, r);
  80       else
  81         {
  82           struct memory_write_request *n =
  83             VEC_safe_push (memory_write_request_s, *result, NULL);
  84
  85           *n = *r;
  86           n->begin = claimed_begin;
  87           n->end = claimed_end;
  88           n->data += claimed_begin - r->begin;
  89         }
  90     }
  91 }
  92
  93 /* Given a vector of struct memory_write_request objects in BLOCKS,
  94    add memory requests for flash memory into FLASH_BLOCKS, and for
  95    regular memory to REGULAR_BLOCKS.  */
  96
  97 static void
  98 split_regular_and_flash_blocks (VEC(memory_write_request_s) *blocks,
  99                                 VEC(memory_write_request_s) **regular_blocks,
 100                                 VEC(memory_write_request_s) **flash_blocks)
 101 {
 102   struct mem_region *region;
 103   CORE_ADDR cur_address;
 104
 105   /* This implementation runs in O(length(regions)*length(blocks)) time.
 106      However, in most cases the number of blocks will be small, so this does
 107      not matter.
 108
 109      Note also that it's extremely unlikely that a memory write request
 110      will span more than one memory region, however for safety we handle
 111      such situations.  */
 112
 113   cur_address = 0;
 114   while (1)
 115     {
 116       VEC(memory_write_request_s) **r;
 117
 118       region = lookup_mem_region (cur_address);
 119       r = region->attrib.mode == MEM_FLASH ? flash_blocks : regular_blocks;
 120       cur_address = region->hi;
 121       claim_memory (blocks, r, region->lo, region->hi);
 122
 123       if (cur_address == 0)
 124         break;
 125     }
 126 }
 127
 128 /* Given an ADDRESS, if BEGIN is non-NULL this function sets *BEGIN
 129    to the start of the flash block containing the address.  Similarly,
 130    if END is non-NULL *END will be set to the address one past the end
 131    of the block containing the address.  */
 132
 133 static void
 134 block_boundaries (CORE_ADDR address, CORE_ADDR *begin, CORE_ADDR *end)
 135 {
 136   struct mem_region *region;
 137   unsigned blocksize;
 138
 139   region = lookup_mem_region (address);
 140   gdb_assert (region->attrib.mode == MEM_FLASH);
 141   blocksize = region->attrib.blocksize;
 142   if (begin)
 143     *begin = address / blocksize * blocksize;
 144   if (end)
 145     *end = (address + blocksize - 1) / blocksize * blocksize;
 146 }
 147
 148 /* Given the list of memory requests to be WRITTEN, this function
 149    returns write requests covering each group of flash blocks which must
 150    be erased.  */
 151
 152 static VEC(memory_write_request_s) *
 153 blocks_to_erase (VEC(memory_write_request_s) *written)
 154 {
 155   unsigned i;
 156   struct memory_write_request *ptr;
 157
 158   VEC(memory_write_request_s) *result = NULL;
 159
 160   for (i = 0; VEC_iterate (memory_write_request_s, written, i, ptr); ++i)
 161     {
 162       CORE_ADDR begin, end;
 163
 164       block_boundaries (ptr->begin, &begin, 0);
 165       block_boundaries (ptr->end - 1, 0, &end);
 166
 167       if (!VEC_empty (memory_write_request_s, result)
 168           && VEC_last (memory_write_request_s, result)->end >= begin)
 169         {
 170           VEC_last (memory_write_request_s, result)->end = end;
 171         }
 172       else
 173         {
 174           struct memory_write_request *n =
 175             VEC_safe_push (memory_write_request_s, result, NULL);
 176
 177           memset (n, 0, sizeof (struct memory_write_request));
 178           n->begin = begin;
 179           n->end = end;
 180         }
 181     }
 182
 183   return result;
 184 }
 185
 186 /* Given ERASED_BLOCKS, a list of blocks that will be erased with
 187    flash erase commands, and WRITTEN_BLOCKS, the list of memory
 188    addresses that will be written, compute the set of memory addresses
 189    that will be erased but not rewritten (e.g. padding within a block
 190    which is only partially filled by "load").  */
 191
 192 static VEC(memory_write_request_s) *
 193 compute_garbled_blocks (VEC(memory_write_request_s) *erased_blocks,
 194                         VEC(memory_write_request_s) *written_blocks)
 195 {
 196   VEC(memory_write_request_s) *result = NULL;
 197
 198   unsigned i, j;
 199   unsigned je = VEC_length (memory_write_request_s, written_blocks);
 200   struct memory_write_request *erased_p;
 201
 202   /* Look at each erased memory_write_request in turn, and
 203      see what part of it is subsequently written to.
 204
 205      This implementation is O(length(erased) * length(written)).  If
 206      the lists are sorted at this point it could be rewritten more
 207      efficiently, but the complexity is not generally worthwhile.  */
 208
 209   for (i = 0;
 210        VEC_iterate (memory_write_request_s, erased_blocks, i, erased_p);
 211        ++i)
 212     {
 213       /* Make a deep copy -- it will be modified inside the loop, but
 214          we don't want to modify original vector.  */
 215       struct memory_write_request erased = *erased_p;
 216
 217       for (j = 0; j != je;)
 218         {
 219           struct memory_write_request *written
 220             = VEC_index (memory_write_request_s,
 221                          written_blocks, j);
 222
 223           /* Now try various cases.  */
 224
 225           /* If WRITTEN is fully to the left of ERASED, check the next
 226              written memory_write_request.  */
 227           if (written->end <= erased.begin)
 228             {
 229               ++j;
 230               continue;
 231             }
 232
 233           /* If WRITTEN is fully to the right of ERASED, then ERASED
 234              is not written at all.  WRITTEN might affect other
 235              blocks.  */
 236           if (written->begin >= erased.end)
 237             {
 238               VEC_safe_push (memory_write_request_s, result, &erased);
 239               goto next_erased;
 240             }
 241
 242           /* If all of ERASED is completely written, we can move on to
 243              the next erased region.  */
 244           if (written->begin <= erased.begin
 245               && written->end >= erased.end)
 246             {
 247               goto next_erased;
 248             }
 249
 250           /* If there is an unwritten part at the beginning of ERASED,
 251              then we should record that part and try this inner loop
 252              again for the remainder.  */
 253           if (written->begin > erased.begin)
 254             {
 255               struct memory_write_request *n =
 256                 VEC_safe_push (memory_write_request_s, result, NULL);
 257
 258               memset (n, 0, sizeof (struct memory_write_request));
 259               n->begin = erased.begin;
 260               n->end = written->begin;
 261               erased.begin = written->begin;
 262               continue;
 263             }
 264
 265           /* If there is an unwritten part at the end of ERASED, we
 266              forget about the part that was written to and wait to see
 267              if the next write request writes more of ERASED.  We can't
 268              push it yet.  */
 269           if (written->end < erased.end)
 270             {
 271               erased.begin = written->end;
 272               ++j;
 273               continue;
 274             }
 275         }
 276
 277       /* If we ran out of write requests without doing anything about
 278          ERASED, then that means it's really erased.  */
 279       VEC_safe_push (memory_write_request_s, result, &erased);
 280
 281     next_erased:
 282       ;
 283     }
 284
 285   return result;
 286 }
 287
 288 static void
 289 cleanup_request_data (void *p)
 290 {
 291   VEC(memory_write_request_s) **v = p;
 292   struct memory_write_request *r;
 293   int i;
 294
 295   for (i = 0; VEC_iterate (memory_write_request_s, *v, i, r); ++i)
 296     xfree (r->data);
 297 }
 298
 299 static void
 300 cleanup_write_requests_vector (void *p)
 301 {
 302   VEC(memory_write_request_s) **v = p;
 303
 304   VEC_free (memory_write_request_s, *v);
 305 }
 306
 307 int
 308 target_write_memory_blocks (VEC(memory_write_request_s) *requests,
 309                             enum flash_preserve_mode preserve_flash_p,
 310                             void (*progress_cb) (ULONGEST, void *))
 311 {
 312   struct cleanup *back_to = make_cleanup (null_cleanup, NULL);
 313   VEC(memory_write_request_s) *blocks = VEC_copy (memory_write_request_s,
 314                                                   requests);
 315   unsigned i;
 316   int err = 0;
 317   struct memory_write_request *r;
 318   VEC(memory_write_request_s) *regular = NULL;
 319   VEC(memory_write_request_s) *flash = NULL;
 320   VEC(memory_write_request_s) *erased, *garbled;
 321
 322   /* END == 0 would represent wraparound: a write to the very last
 323      byte of the address space.  This file was not written with that
 324      possibility in mind.  This is fixable, but a lot of work for a
 325      rare problem; so for now, fail noisily here instead of obscurely
 326      later.  */
 327   for (i = 0; VEC_iterate (memory_write_request_s, requests, i, r); ++i)
 328     gdb_assert (r->end != 0);
 329
 330   make_cleanup (cleanup_write_requests_vector, &blocks);
 331
 332   /* Sort the blocks by their start address.  */
 333   qsort (VEC_address (memory_write_request_s, blocks),
 334          VEC_length (memory_write_request_s, blocks),
 335          sizeof (struct memory_write_request), compare_block_starting_address);
 336
 337   /* Split blocks into list of regular memory blocks,
 338      and list of flash memory blocks.  */
 339   make_cleanup (cleanup_write_requests_vector, &regular);
 340   make_cleanup (cleanup_write_requests_vector, &flash);
 341   split_regular_and_flash_blocks (blocks, &regular, &flash);
 342
 343   /* If a variable is added to forbid flash write, even during "load",
 344      it should be checked here.  Similarly, if this function is used
 345      for other situations besides "load" in which writing to flash
 346      is undesirable, that should be checked here.  */
 347
 348   /* Find flash blocks to erase.  */
 349   erased = blocks_to_erase (flash);
 350   make_cleanup (cleanup_write_requests_vector, &erased);
 351
 352   /* Find what flash regions will be erased, and not overwritten; then
 353      either preserve or discard the old contents.  */
 354   garbled = compute_garbled_blocks (erased, flash);
 355   make_cleanup (cleanup_request_data, &garbled);
 356   make_cleanup (cleanup_write_requests_vector, &garbled);
 357
 358   if (!VEC_empty (memory_write_request_s, garbled))
 359     {
 360       if (preserve_flash_p == flash_preserve)
 361         {
 362           struct memory_write_request *r;
 363
 364           /* Read in regions that must be preserved and add them to
 365              the list of blocks we read.  */
 366           for (i = 0; VEC_iterate (memory_write_request_s, garbled, i, r); ++i)
 367             {
 368               gdb_assert (r->data == NULL);
 369               r->data = xmalloc (r->end - r->begin);
 370               err = target_read_memory (r->begin, r->data, r->end - r->begin);
 371               if (err != 0)
 372                 goto out;
 373
 374               VEC_safe_push (memory_write_request_s, flash, r);
 375             }
 376
 377           qsort (VEC_address (memory_write_request_s, flash),
 378                  VEC_length (memory_write_request_s, flash),
 379                  sizeof (struct memory_write_request),
 380                  compare_block_starting_address);
 381         }
 382     }
 383
 384   /* We could coalesce adjacent memory blocks here, to reduce the
 385      number of write requests for small sections.  However, we would
 386      have to reallocate and copy the data pointers, which could be
 387      large; large sections are more common in loadable objects than
 388      large numbers of small sections (although the reverse can be true
 389      in object files).  So, we issue at least one write request per
 390      passed struct memory_write_request.  The remote stub will still
 391      have the opportunity to batch flash requests.  */
 392
 393   /* Write regular blocks.  */
 394   for (i = 0; VEC_iterate (memory_write_request_s, regular, i, r); ++i)
 395     {
 396       LONGEST len;
 397
 398       len = target_write_with_progress (current_target.beneath,
 399                                         TARGET_OBJECT_MEMORY, NULL,
 400                                         r->data, r->begin, r->end - r->begin,
 401                                         progress_cb, r->baton);
 402       if (len < (LONGEST) (r->end - r->begin))
 403         {
 404           /* Call error?  */
 405           err = -1;
 406           goto out;
 407         }
 408     }
 409
 410   if (!VEC_empty (memory_write_request_s, erased))
 411     {
 412       /* Erase all pages.  */
 413       for (i = 0; VEC_iterate (memory_write_request_s, erased, i, r); ++i)
 414         target_flash_erase (r->begin, r->end - r->begin);
 415
 416       /* Write flash data.  */
 417       for (i = 0; VEC_iterate (memory_write_request_s, flash, i, r); ++i)
 418         {
 419           LONGEST len;
 420
 421           len = target_write_with_progress (&current_target,
 422                                             TARGET_OBJECT_FLASH, NULL,
 423                                             r->data, r->begin,
 424                                             r->end - r->begin,
 425                                             progress_cb, r->baton);
 426           if (len < (LONGEST) (r->end - r->begin))
 427             error (_("Error writing data to flash"));
 428         }
 429
 430       target_flash_done ();
 431     }
 432
 433  out:
 434   do_cleanups (back_to);
 435
 436   return err;
 437 }