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 "gdb_assert.h"
  27
  28 #include <stdio.h>
  29 #include <sys/time.h>
  30
  31 static int
  32 compare_block_starting_address (const void *a, const void *b)
  33 {
  34   const struct memory_write_request *a_req = a;
  35   const struct memory_write_request *b_req = b;
  36
  37   if (a_req->begin < b_req->begin)
  38     return -1;
  39   else if (a_req->begin == b_req->begin)
  40     return 0;
  41   else
  42     return 1;
  43 }
  44
  45 /* Adds to RESULT all memory write requests from BLOCK that are
  46    in [BEGIN, END) range.
  47
  48    If any memory request is only partially in the specified range,
  49    that part of the memory request will be added.  */
  50
  51 static void
  52 claim_memory (VEC(memory_write_request_s) *blocks,
  53               VEC(memory_write_request_s) **result,
  54               ULONGEST begin,
  55               ULONGEST end)
  56 {
  57   int i;
  58   ULONGEST claimed_begin;
  59   ULONGEST claimed_end;
  60   struct memory_write_request *r;
  61
  62   for (i = 0; VEC_iterate (memory_write_request_s, blocks, i, r); ++i)
  63     {
  64       /* If the request doesn't overlap [BEGIN, END), skip it.  We
  65          must handle END == 0 meaning the top of memory; we don't yet
  66          check for R->end == 0, which would also mean the top of
  67          memory, but there's an assertion in
  68          target_write_memory_blocks which checks for that.  */
  69
  70       if (begin >= r->end)
  71         continue;
  72       if (end != 0 && end <= r->begin)
  73         continue;
  74
  75       claimed_begin = max (begin, r->begin);
  76       if (end == 0)
  77         claimed_end = r->end;
  78       else
  79         claimed_end = min (end, r->end);
  80
  81       if (claimed_begin == r->begin && claimed_end == r->end)
  82         VEC_safe_push (memory_write_request_s, *result, r);
  83       else
  84         {
  85           struct memory_write_request *n =
  86             VEC_safe_push (memory_write_request_s, *result, NULL);
  87
  88           *n = *r;
  89           n->begin = claimed_begin;
  90           n->end = claimed_end;
  91           n->data += claimed_begin - r->begin;
  92         }
  93     }
  94 }
  95
  96 /* Given a vector of struct memory_write_request objects in BLOCKS,
  97    add memory requests for flash memory into FLASH_BLOCKS, and for
  98    regular memory to REGULAR_BLOCKS.  */
  99
 100 static void
 101 split_regular_and_flash_blocks (VEC(memory_write_request_s) *blocks,
 102                                 VEC(memory_write_request_s) **regular_blocks,
 103                                 VEC(memory_write_request_s) **flash_blocks)
 104 {
 105   struct mem_region *region;
 106   CORE_ADDR cur_address;
 107
 108   /* This implementation runs in O(length(regions)*length(blocks)) time.
 109      However, in most cases the number of blocks will be small, so this does
 110      not matter.
 111
 112      Note also that it's extremely unlikely that a memory write request
 113      will span more than one memory region, however for safety we handle
 114      such situations.  */
 115
 116   cur_address = 0;
 117   while (1)
 118     {
 119       VEC(memory_write_request_s) **r;
 120
 121       region = lookup_mem_region (cur_address);
 122       r = region->attrib.mode == MEM_FLASH ? flash_blocks : regular_blocks;
 123       cur_address = region->hi;
 124       claim_memory (blocks, r, region->lo, region->hi);
 125
 126       if (cur_address == 0)
 127         break;
 128     }
 129 }
 130
 131 /* Given an ADDRESS, if BEGIN is non-NULL this function sets *BEGIN
 132    to the start of the flash block containing the address.  Similarly,
 133    if END is non-NULL *END will be set to the address one past the end
 134    of the block containing the address.  */
 135
 136 static void
 137 block_boundaries (CORE_ADDR address, CORE_ADDR *begin, CORE_ADDR *end)
 138 {
 139   struct mem_region *region;
 140   unsigned blocksize;
 141
 142   region = lookup_mem_region (address);
 143   gdb_assert (region->attrib.mode == MEM_FLASH);
 144   blocksize = region->attrib.blocksize;
 145   if (begin)
 146     *begin = address / blocksize * blocksize;
 147   if (end)
 148     *end = (address + blocksize - 1) / blocksize * blocksize;
 149 }
 150
 151 /* Given the list of memory requests to be WRITTEN, this function
 152    returns write requests covering each group of flash blocks which must
 153    be erased.  */
 154
 155 static VEC(memory_write_request_s) *
 156 blocks_to_erase (VEC(memory_write_request_s) *written)
 157 {
 158   unsigned i;
 159   struct memory_write_request *ptr;
 160
 161   VEC(memory_write_request_s) *result = NULL;
 162
 163   for (i = 0; VEC_iterate (memory_write_request_s, written, i, ptr); ++i)
 164     {
 165       CORE_ADDR begin, end;
 166
 167       block_boundaries (ptr->begin, &begin, 0);
 168       block_boundaries (ptr->end - 1, 0, &end);
 169
 170       if (!VEC_empty (memory_write_request_s, result)
 171           && VEC_last (memory_write_request_s, result)->end >= begin)
 172         {
 173           VEC_last (memory_write_request_s, result)->end = end;
 174         }
 175       else
 176         {
 177           struct memory_write_request *n =
 178             VEC_safe_push (memory_write_request_s, result, NULL);
 179
 180           memset (n, 0, sizeof (struct memory_write_request));
 181           n->begin = begin;
 182           n->end = end;
 183         }
 184     }
 185
 186   return result;
 187 }
 188
 189 /* Given ERASED_BLOCKS, a list of blocks that will be erased with
 190    flash erase commands, and WRITTEN_BLOCKS, the list of memory
 191    addresses that will be written, compute the set of memory addresses
 192    that will be erased but not rewritten (e.g. padding within a block
 193    which is only partially filled by "load").  */
 194
 195 static VEC(memory_write_request_s) *
 196 compute_garbled_blocks (VEC(memory_write_request_s) *erased_blocks,
 197                         VEC(memory_write_request_s) *written_blocks)
 198 {
 199   VEC(memory_write_request_s) *result = NULL;
 200
 201   unsigned i, j;
 202   unsigned je = VEC_length (memory_write_request_s, written_blocks);
 203   struct memory_write_request *erased_p;
 204
 205   /* Look at each erased memory_write_request in turn, and
 206      see what part of it is subsequently written to.
 207
 208      This implementation is O(length(erased) * length(written)).  If
 209      the lists are sorted at this point it could be rewritten more
 210      efficiently, but the complexity is not generally worthwhile.  */
 211
 212   for (i = 0;
 213        VEC_iterate (memory_write_request_s, erased_blocks, i, erased_p);
 214        ++i)
 215     {
 216       /* Make a deep copy -- it will be modified inside the loop, but
 217          we don't want to modify original vector.  */
 218       struct memory_write_request erased = *erased_p;
 219
 220       for (j = 0; j != je;)
 221         {
 222           struct memory_write_request *written
 223             = VEC_index (memory_write_request_s,
 224                          written_blocks, j);
 225
 226           /* Now try various cases.  */
 227
 228           /* If WRITTEN is fully to the left of ERASED, check the next
 229              written memory_write_request.  */
 230           if (written->end <= erased.begin)
 231             {
 232               ++j;
 233               continue;
 234             }
 235
 236           /* If WRITTEN is fully to the right of ERASED, then ERASED
 237              is not written at all.  WRITTEN might affect other
 238              blocks.  */
 239           if (written->begin >= erased.end)
 240             {
 241               VEC_safe_push (memory_write_request_s, result, &erased);
 242               goto next_erased;
 243             }
 244
 245           /* If all of ERASED is completely written, we can move on to
 246              the next erased region.  */
 247           if (written->begin <= erased.begin
 248               && written->end >= erased.end)
 249             {
 250               goto next_erased;
 251             }
 252
 253           /* If there is an unwritten part at the beginning of ERASED,
 254              then we should record that part and try this inner loop
 255              again for the remainder.  */
 256           if (written->begin > erased.begin)
 257             {
 258               struct memory_write_request *n =
 259                 VEC_safe_push (memory_write_request_s, result, NULL);
 260
 261               memset (n, 0, sizeof (struct memory_write_request));
 262               n->begin = erased.begin;
 263               n->end = written->begin;
 264               erased.begin = written->begin;
 265               continue;
 266             }
 267
 268           /* If there is an unwritten part at the end of ERASED, we
 269              forget about the part that was written to and wait to see
 270              if the next write request writes more of ERASED.  We can't
 271              push it yet.  */
 272           if (written->end < erased.end)
 273             {
 274               erased.begin = written->end;
 275               ++j;
 276               continue;
 277             }
 278         }
 279
 280       /* If we ran out of write requests without doing anything about
 281          ERASED, then that means it's really erased.  */
 282       VEC_safe_push (memory_write_request_s, result, &erased);
 283
 284     next_erased:
 285       ;
 286     }
 287
 288   return result;
 289 }
 290
 291 static void
 292 cleanup_request_data (void *p)
 293 {
 294   VEC(memory_write_request_s) **v = p;
 295   struct memory_write_request *r;
 296   int i;
 297
 298   for (i = 0; VEC_iterate (memory_write_request_s, *v, i, r); ++i)
 299     xfree (r->data);
 300 }
 301
 302 static void
 303 cleanup_write_requests_vector (void *p)
 304 {
 305   VEC(memory_write_request_s) **v = p;
 306
 307   VEC_free (memory_write_request_s, *v);
 308 }
 309
 310 int
 311 target_write_memory_blocks (VEC(memory_write_request_s) *requests,
 312                             enum flash_preserve_mode preserve_flash_p,
 313                             void (*progress_cb) (ULONGEST, void *))
 314 {
 315   struct cleanup *back_to = make_cleanup (null_cleanup, NULL);
 316   VEC(memory_write_request_s) *blocks = VEC_copy (memory_write_request_s,
 317                                                   requests);
 318   unsigned i;
 319   int err = 0;
 320   struct memory_write_request *r;
 321   VEC(memory_write_request_s) *regular = NULL;
 322   VEC(memory_write_request_s) *flash = NULL;
 323   VEC(memory_write_request_s) *erased, *garbled;
 324
 325   /* END == 0 would represent wraparound: a write to the very last
 326      byte of the address space.  This file was not written with that
 327      possibility in mind.  This is fixable, but a lot of work for a
 328      rare problem; so for now, fail noisily here instead of obscurely
 329      later.  */
 330   for (i = 0; VEC_iterate (memory_write_request_s, requests, i, r); ++i)
 331     gdb_assert (r->end != 0);
 332
 333   make_cleanup (cleanup_write_requests_vector, &blocks);
 334
 335   /* Sort the blocks by their start address.  */
 336   qsort (VEC_address (memory_write_request_s, blocks),
 337          VEC_length (memory_write_request_s, blocks),
 338          sizeof (struct memory_write_request), compare_block_starting_address);
 339
 340   /* Split blocks into list of regular memory blocks,
 341      and list of flash memory blocks.  */
 342   make_cleanup (cleanup_write_requests_vector, &regular);
 343   make_cleanup (cleanup_write_requests_vector, &flash);
 344   split_regular_and_flash_blocks (blocks, &regular, &flash);
 345
 346   /* If a variable is added to forbid flash write, even during "load",
 347      it should be checked here.  Similarly, if this function is used
 348      for other situations besides "load" in which writing to flash
 349      is undesirable, that should be checked here.  */
 350
 351   /* Find flash blocks to erase.  */
 352   erased = blocks_to_erase (flash);
 353   make_cleanup (cleanup_write_requests_vector, &erased);
 354
 355   /* Find what flash regions will be erased, and not overwritten; then
 356      either preserve or discard the old contents.  */
 357   garbled = compute_garbled_blocks (erased, flash);
 358   make_cleanup (cleanup_request_data, &garbled);
 359   make_cleanup (cleanup_write_requests_vector, &garbled);
 360
 361   if (!VEC_empty (memory_write_request_s, garbled))
 362     {
 363       if (preserve_flash_p == flash_preserve)
 364         {
 365           struct memory_write_request *r;
 366
 367           /* Read in regions that must be preserved and add them to
 368              the list of blocks we read.  */
 369           for (i = 0; VEC_iterate (memory_write_request_s, garbled, i, r); ++i)
 370             {
 371               gdb_assert (r->data == NULL);
 372               r->data = xmalloc (r->end - r->begin);
 373               err = target_read_memory (r->begin, r->data, r->end - r->begin);
 374               if (err != 0)
 375                 goto out;
 376
 377               VEC_safe_push (memory_write_request_s, flash, r);
 378             }
 379
 380           qsort (VEC_address (memory_write_request_s, flash),
 381                  VEC_length (memory_write_request_s, flash),
 382                  sizeof (struct memory_write_request),
 383                  compare_block_starting_address);
 384         }
 385     }
 386
 387   /* We could coalesce adjacent memory blocks here, to reduce the
 388      number of write requests for small sections.  However, we would
 389      have to reallocate and copy the data pointers, which could be
 390      large; large sections are more common in loadable objects than
 391      large numbers of small sections (although the reverse can be true
 392      in object files).  So, we issue at least one write request per
 393      passed struct memory_write_request.  The remote stub will still
 394      have the opportunity to batch flash requests.  */
 395
 396   /* Write regular blocks.  */
 397   for (i = 0; VEC_iterate (memory_write_request_s, regular, i, r); ++i)
 398     {
 399       LONGEST len;
 400
 401       len = target_write_with_progress (current_target.beneath,
 402                                         TARGET_OBJECT_MEMORY, NULL,
 403                                         r->data, r->begin, r->end - r->begin,
 404                                         progress_cb, r->baton);
 405       if (len < (LONGEST) (r->end - r->begin))
 406         {
 407           /* Call error?  */
 408           err = -1;
 409           goto out;
 410         }
 411     }
 412
 413   if (!VEC_empty (memory_write_request_s, erased))
 414     {
 415       /* Erase all pages.  */
 416       for (i = 0; VEC_iterate (memory_write_request_s, erased, i, r); ++i)
 417         target_flash_erase (r->begin, r->end - r->begin);
 418
 419       /* Write flash data.  */
 420       for (i = 0; VEC_iterate (memory_write_request_s, flash, i, r); ++i)
 421         {
 422           LONGEST len;
 423
 424           len = target_write_with_progress (&current_target,
 425                                             TARGET_OBJECT_FLASH, NULL,
 426                                             r->data, r->begin,
 427                                             r->end - r->begin,
 428                                             progress_cb, r->baton);
 429           if (len < (LONGEST) (r->end - r->begin))
 430             error (_("Error writing data to flash"));
 431         }
 432
 433       target_flash_done ();
 434     }
 435
 436  out:
 437   do_cleanups (back_to);
 438
 439   return err;
 440 }