gdb/target-memory.c

   1 /* Parts of target interface that deal with accessing memory and memory-like
   2    objects.
   3
   4    Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011
   5    Free Software Foundation, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "vec.h"
  24 #include "target.h"
  25 #include "memory-map.h"
  26
  27 #include "gdb_assert.h"
  28
  29 #include <stdio.h>
  30 #include <sys/time.h>
  31
  32 static int
  33 compare_block_starting_address (const void *a, const void *b)
  34 {
  35   const struct memory_write_request *a_req = a;
  36   const struct memory_write_request *b_req = b;
  37
  38   if (a_req->begin < b_req->begin)
  39     return -1;
  40   else if (a_req->begin == b_req->begin)
  41     return 0;
  42   else
  43     return 1;
  44 }
  45
  46 /* Adds to RESULT all memory write requests from BLOCK that are
  47    in [BEGIN, END) range.
  48
  49    If any memory request is only partially in the specified range,
  50    that part of the memory request will be added.  */
  51
  52 static void
  53 claim_memory (VEC(memory_write_request_s) *blocks,
  54               VEC(memory_write_request_s) **result,
  55               ULONGEST begin,
  56               ULONGEST end)
  57 {
  58   int i;
  59   ULONGEST claimed_begin;
  60   ULONGEST claimed_end;
  61   struct memory_write_request *r;
  62
  63   for (i = 0; VEC_iterate (memory_write_request_s, blocks, i, r); ++i)
  64     {
  65       /* If the request doesn't overlap [BEGIN, END), skip it.  We
  66          must handle END == 0 meaning the top of memory; we don't yet
  67          check for R->end == 0, which would also mean the top of
  68          memory, but there's an assertion in
  69          target_write_memory_blocks which checks for that.  */
  70
  71       if (begin >= r->end)
  72         continue;
  73       if (end != 0 && end <= r->begin)
  74         continue;
  75
  76       claimed_begin = max (begin, r->begin);
  77       if (end == 0)
  78         claimed_end = r->end;
  79       else
  80         claimed_end = min (end, r->end);
  81
  82       if (claimed_begin == r->begin && claimed_end == r->end)
  83         VEC_safe_push (memory_write_request_s, *result, r);
  84       else
  85         {
  86           struct memory_write_request *n =
  87             VEC_safe_push (memory_write_request_s, *result, NULL);
  88
  89           *n = *r;
  90           n->begin = claimed_begin;
  91           n->end = claimed_end;
  92           n->data += claimed_begin - r->begin;
  93         }
  94     }
  95 }
  96
  97 /* Given a vector of struct memory_write_request objects in BLOCKS,
  98    add memory requests for flash memory into FLASH_BLOCKS, and for
  99    regular memory to REGULAR_BLOCKS.  */
 100
 101 static void
 102 split_regular_and_flash_blocks (VEC(memory_write_request_s) *blocks,
 103                                 VEC(memory_write_request_s) **regular_blocks,
 104                                 VEC(memory_write_request_s) **flash_blocks)
 105 {
 106   struct mem_region *region;
 107   CORE_ADDR cur_address;
 108
 109   /* This implementation runs in O(length(regions)*length(blocks)) time.
 110      However, in most cases the number of blocks will be small, so this does
 111      not matter.
 112
 113      Note also that it's extremely unlikely that a memory write request
 114      will span more than one memory region, however for safety we handle
 115      such situations.  */
 116
 117   cur_address = 0;
 118   while (1)
 119     {
 120       VEC(memory_write_request_s) **r;
 121
 122       region = lookup_mem_region (cur_address);
 123       r = region->attrib.mode == MEM_FLASH ? flash_blocks : regular_blocks;
 124       cur_address = region->hi;
 125       claim_memory (blocks, r, region->lo, region->hi);
 126
 127       if (cur_address == 0)
 128         break;
 129     }
 130 }
 131
 132 /* Given an ADDRESS, if BEGIN is non-NULL this function sets *BEGIN
 133    to the start of the flash block containing the address.  Similarly,
 134    if END is non-NULL *END will be set to the address one past the end
 135    of the block containing the address.  */
 136
 137 static void
 138 block_boundaries (CORE_ADDR address, CORE_ADDR *begin, CORE_ADDR *end)
 139 {
 140   struct mem_region *region;
 141   unsigned blocksize;
 142
 143   region = lookup_mem_region (address);
 144   gdb_assert (region->attrib.mode == MEM_FLASH);
 145   blocksize = region->attrib.blocksize;
 146   if (begin)
 147     *begin = address / blocksize * blocksize;
 148   if (end)
 149     *end = (address + blocksize - 1) / blocksize * blocksize;
 150 }
 151
 152 /* Given the list of memory requests to be WRITTEN, this function
 153    returns write requests covering each group of flash blocks which must
 154    be erased.  */
 155
 156 static VEC(memory_write_request_s) *
 157 blocks_to_erase (VEC(memory_write_request_s) *written)
 158 {
 159   unsigned i;
 160   struct memory_write_request *ptr;
 161
 162   VEC(memory_write_request_s) *result = NULL;
 163
 164   for (i = 0; VEC_iterate (memory_write_request_s, written, i, ptr); ++i)
 165     {
 166       CORE_ADDR begin, end;
 167
 168       block_boundaries (ptr->begin, &begin, 0);
 169       block_boundaries (ptr->end - 1, 0, &end);
 170
 171       if (!VEC_empty (memory_write_request_s, result)
 172           && VEC_last (memory_write_request_s, result)->end >= begin)
 173         {
 174           VEC_last (memory_write_request_s, result)->end = end;
 175         }
 176       else
 177         {
 178           struct memory_write_request *n =
 179             VEC_safe_push (memory_write_request_s, result, NULL);
 180
 181           memset (n, 0, sizeof (struct memory_write_request));
 182           n->begin = begin;
 183           n->end = end;
 184         }
 185     }
 186
 187   return result;
 188 }
 189
 190 /* Given ERASED_BLOCKS, a list of blocks that will be erased with
 191    flash erase commands, and WRITTEN_BLOCKS, the list of memory
 192    addresses that will be written, compute the set of memory addresses
 193    that will be erased but not rewritten (e.g. padding within a block
 194    which is only partially filled by "load").  */
 195
 196 static VEC(memory_write_request_s) *
 197 compute_garbled_blocks (VEC(memory_write_request_s) *erased_blocks,
 198                         VEC(memory_write_request_s) *written_blocks)
 199 {
 200   VEC(memory_write_request_s) *result = NULL;
 201
 202   unsigned i, j;
 203   unsigned je = VEC_length (memory_write_request_s, written_blocks);
 204   struct memory_write_request *erased_p;
 205
 206   /* Look at each erased memory_write_request in turn, and
 207      see what part of it is subsequently written to.
 208
 209      This implementation is O(length(erased) * length(written)).  If
 210      the lists are sorted at this point it could be rewritten more
 211      efficiently, but the complexity is not generally worthwhile.  */
 212
 213   for (i = 0;
 214        VEC_iterate (memory_write_request_s, erased_blocks, i, erased_p);
 215        ++i)
 216     {
 217       /* Make a deep copy -- it will be modified inside the loop, but
 218          we don't want to modify original vector.  */
 219       struct memory_write_request erased = *erased_p;
 220
 221       for (j = 0; j != je;)
 222         {
 223           struct memory_write_request *written
 224             = VEC_index (memory_write_request_s,
 225                          written_blocks, j);
 226
 227           /* Now try various cases.  */
 228
 229           /* If WRITTEN is fully to the left of ERASED, check the next
 230              written memory_write_request.  */
 231           if (written->end <= erased.begin)
 232             {
 233               ++j;
 234               continue;
 235             }
 236
 237           /* If WRITTEN is fully to the right of ERASED, then ERASED
 238              is not written at all.  WRITTEN might affect other
 239              blocks.  */
 240           if (written->begin >= erased.end)
 241             {
 242               VEC_safe_push (memory_write_request_s, result, &erased);
 243               goto next_erased;
 244             }
 245
 246           /* If all of ERASED is completely written, we can move on to
 247              the next erased region.  */
 248           if (written->begin <= erased.begin
 249               && written->end >= erased.end)
 250             {
 251               goto next_erased;
 252             }
 253
 254           /* If there is an unwritten part at the beginning of ERASED,
 255              then we should record that part and try this inner loop
 256              again for the remainder.  */
 257           if (written->begin > erased.begin)
 258             {
 259               struct memory_write_request *n =
 260                 VEC_safe_push (memory_write_request_s, result, NULL);
 261
 262               memset (n, 0, sizeof (struct memory_write_request));
 263               n->begin = erased.begin;
 264               n->end = written->begin;
 265               erased.begin = written->begin;
 266               continue;
 267             }
 268
 269           /* If there is an unwritten part at the end of ERASED, we
 270              forget about the part that was written to and wait to see
 271              if the next write request writes more of ERASED.  We can't
 272              push it yet.  */
 273           if (written->end < erased.end)
 274             {
 275               erased.begin = written->end;
 276               ++j;
 277               continue;
 278             }
 279         }
 280
 281       /* If we ran out of write requests without doing anything about
 282          ERASED, then that means it's really erased.  */
 283       VEC_safe_push (memory_write_request_s, result, &erased);
 284
 285     next_erased:
 286       ;
 287     }
 288
 289   return result;
 290 }
 291
 292 static void
 293 cleanup_request_data (void *p)
 294 {
 295   VEC(memory_write_request_s) **v = p;
 296   struct memory_write_request *r;
 297   int i;
 298
 299   for (i = 0; VEC_iterate (memory_write_request_s, *v, i, r); ++i)
 300     xfree (r->data);
 301 }
 302
 303 static void
 304 cleanup_write_requests_vector (void *p)
 305 {
 306   VEC(memory_write_request_s) **v = p;
 307
 308   VEC_free (memory_write_request_s, *v);
 309 }
 310
 311 int
 312 target_write_memory_blocks (VEC(memory_write_request_s) *requests,
 313                             enum flash_preserve_mode preserve_flash_p,
 314                             void (*progress_cb) (ULONGEST, void *))
 315 {
 316   struct cleanup *back_to = make_cleanup (null_cleanup, NULL);
 317   VEC(memory_write_request_s) *blocks = VEC_copy (memory_write_request_s,
 318                                                   requests);
 319   unsigned i;
 320   int err = 0;
 321   struct memory_write_request *r;
 322   VEC(memory_write_request_s) *regular = NULL;
 323   VEC(memory_write_request_s) *flash = NULL;
 324   VEC(memory_write_request_s) *erased, *garbled;
 325
 326   /* END == 0 would represent wraparound: a write to the very last
 327      byte of the address space.  This file was not written with that
 328      possibility in mind.  This is fixable, but a lot of work for a
 329      rare problem; so for now, fail noisily here instead of obscurely
 330      later.  */
 331   for (i = 0; VEC_iterate (memory_write_request_s, requests, i, r); ++i)
 332     gdb_assert (r->end != 0);
 333
 334   make_cleanup (cleanup_write_requests_vector, &blocks);
 335
 336   /* Sort the blocks by their start address.  */
 337   qsort (VEC_address (memory_write_request_s, blocks),
 338          VEC_length (memory_write_request_s, blocks),
 339          sizeof (struct memory_write_request), compare_block_starting_address);
 340
 341   /* Split blocks into list of regular memory blocks,
 342      and list of flash memory blocks.  */
 343   make_cleanup (cleanup_write_requests_vector, &regular);
 344   make_cleanup (cleanup_write_requests_vector, &flash);
 345   split_regular_and_flash_blocks (blocks, &regular, &flash);
 346
 347   /* If a variable is added to forbid flash write, even during "load",
 348      it should be checked here.  Similarly, if this function is used
 349      for other situations besides "load" in which writing to flash
 350      is undesirable, that should be checked here.  */
 351
 352   /* Find flash blocks to erase.  */
 353   erased = blocks_to_erase (flash);
 354   make_cleanup (cleanup_write_requests_vector, &erased);
 355
 356   /* Find what flash regions will be erased, and not overwritten; then
 357      either preserve or discard the old contents.  */
 358   garbled = compute_garbled_blocks (erased, flash);
 359   make_cleanup (cleanup_request_data, &garbled);
 360   make_cleanup (cleanup_write_requests_vector, &garbled);
 361
 362   if (!VEC_empty (memory_write_request_s, garbled))
 363     {
 364       if (preserve_flash_p == flash_preserve)
 365         {
 366           struct memory_write_request *r;
 367
 368           /* Read in regions that must be preserved and add them to
 369              the list of blocks we read.  */
 370           for (i = 0; VEC_iterate (memory_write_request_s, garbled, i, r); ++i)
 371             {
 372               gdb_assert (r->data == NULL);
 373               r->data = xmalloc (r->end - r->begin);
 374               err = target_read_memory (r->begin, r->data, r->end - r->begin);
 375               if (err != 0)
 376                 goto out;
 377
 378               VEC_safe_push (memory_write_request_s, flash, r);
 379             }
 380
 381           qsort (VEC_address (memory_write_request_s, flash),
 382                  VEC_length (memory_write_request_s, flash),
 383                  sizeof (struct memory_write_request),
 384                  compare_block_starting_address);
 385         }
 386     }
 387
 388   /* We could coalesce adjacent memory blocks here, to reduce the
 389      number of write requests for small sections.  However, we would
 390      have to reallocate and copy the data pointers, which could be
 391      large; large sections are more common in loadable objects than
 392      large numbers of small sections (although the reverse can be true
 393      in object files).  So, we issue at least one write request per
 394      passed struct memory_write_request.  The remote stub will still
 395      have the opportunity to batch flash requests.  */
 396
 397   /* Write regular blocks.  */
 398   for (i = 0; VEC_iterate (memory_write_request_s, regular, i, r); ++i)
 399     {
 400       LONGEST len;
 401
 402       len = target_write_with_progress (current_target.beneath,
 403                                         TARGET_OBJECT_MEMORY, NULL,
 404                                         r->data, r->begin, r->end - r->begin,
 405                                         progress_cb, r->baton);
 406       if (len < (LONGEST) (r->end - r->begin))
 407         {
 408           /* Call error?  */
 409           err = -1;
 410           goto out;
 411         }
 412     }
 413
 414   if (!VEC_empty (memory_write_request_s, erased))
 415     {
 416       /* Erase all pages.  */
 417       for (i = 0; VEC_iterate (memory_write_request_s, erased, i, r); ++i)
 418         target_flash_erase (r->begin, r->end - r->begin);
 419
 420       /* Write flash data.  */
 421       for (i = 0; VEC_iterate (memory_write_request_s, flash, i, r); ++i)
 422         {
 423           LONGEST len;
 424
 425           len = target_write_with_progress (&current_target,
 426                                             TARGET_OBJECT_FLASH, NULL,
 427                                             r->data, r->begin,
 428                                             r->end - r->begin,
 429                                             progress_cb, r->baton);
 430           if (len < (LONGEST) (r->end - r->begin))
 431             error (_("Error writing data to flash"));
 432         }
 433
 434       target_flash_done ();
 435     }
 436
 437  out:
 438   do_cleanups (back_to);
 439
 440   return err;
 441 }