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