src/target/arm_dpm.c

   1 /*
   2  * Copyright (C) 2009 by David Brownell
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the
  16  * Free Software Foundation, Inc.,
  17  * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include "armv4_5.h"            /* REVISIT to become arm.h */
  25 #include "arm_dpm.h"
  26 #include <jtag/jtag.h>
  27 #include "register.h"
  28 #include "breakpoints.h"
  29 #include "target_type.h"
  30
  31
  32 /**
  33  * @file
  34  * Implements various ARM DPM operations using architectural debug registers.
  35  * These routines layer over core-specific communication methods to cope with
  36  * implementation differences between cores like ARM1136 and Cortex-A8.
  37  */
  38
  39 /*----------------------------------------------------------------------*/
  40
  41 /*
  42  * Coprocessor support
  43  */
  44
  45 /* Read coprocessor */
  46 static int dpm_mrc(struct target *target, int cpnum,
  47                 uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
  48                 uint32_t *value)
  49 {
  50         struct arm *arm = target_to_arm(target);
  51         struct arm_dpm *dpm = arm->dpm;
  52         int retval;
  53
  54         retval = dpm->prepare(dpm);
  55         if (retval != ERROR_OK)
  56                 return retval;
  57
  58         LOG_DEBUG("MRC p%d, %d, r0, c%d, c%d, %d", cpnum,
  59                         (int) op1, (int) CRn,
  60                         (int) CRm, (int) op2);
  61
  62         /* read coprocessor register into R0; return via DCC */
  63         retval = dpm->instr_read_data_r0(dpm,
  64                         ARMV4_5_MRC(cpnum, op1, 0, CRn, CRm, op2),
  65                         value);
  66
  67         /* (void) */ dpm->finish(dpm);
  68         return retval;
  69 }
  70
  71 static int dpm_mcr(struct target *target, int cpnum,
  72                 uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
  73                 uint32_t value)
  74 {
  75         struct arm *arm = target_to_arm(target);
  76         struct arm_dpm *dpm = arm->dpm;
  77         int retval;
  78
  79         retval = dpm->prepare(dpm);
  80         if (retval != ERROR_OK)
  81                 return retval;
  82
  83         LOG_DEBUG("MCR p%d, %d, r0, c%d, c%d, %d", cpnum,
  84                         (int) op1, (int) CRn,
  85                         (int) CRm, (int) op2);
  86
  87         /* read DCC into r0; then write coprocessor register from R0 */
  88         retval = dpm->instr_write_data_r0(dpm,
  89                         ARMV4_5_MCR(cpnum, op1, 0, CRn, CRm, op2),
  90                         value);
  91
  92         /* (void) */ dpm->finish(dpm);
  93         return retval;
  94 }
  95
  96 /*----------------------------------------------------------------------*/
  97
  98 /*
  99  * Register access utilities
 100  */
 101
 102 /* Toggles between recorded core mode (USR, SVC, etc) and a temporary one.
 103  * Routines *must* restore the original mode before returning!!
 104  */
 105 static int dpm_modeswitch(struct arm_dpm *dpm, enum armv4_5_mode mode)
 106 {
 107         int retval;
 108         uint32_t cpsr;
 109
 110         /* restore previous mode */
 111         if (mode == ARM_MODE_ANY)
 112                 cpsr = buf_get_u32(dpm->arm->cpsr->value, 0, 32);
 113
 114         /* else force to the specified mode */
 115         else
 116                 cpsr = mode;
 117
 118         retval = dpm->instr_write_data_r0(dpm, ARMV4_5_MSR_GP(0, 0xf, 0), cpsr);
 119
 120         if (dpm->instr_cpsr_sync)
 121                 retval = dpm->instr_cpsr_sync(dpm);
 122
 123         return retval;
 124 }
 125
 126 /* just read the register -- rely on the core mode being right */
 127 static int dpm_read_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
 128 {
 129         uint32_t value;
 130         int retval;
 131
 132         switch (regnum) {
 133         case 0 ... 14:
 134                 /* return via DCC:  "MCR p14, 0, Rnum, c0, c5, 0" */
 135                 retval = dpm->instr_read_data_dcc(dpm,
 136                                 ARMV4_5_MCR(14, 0, regnum, 0, 5, 0),
 137                                 &value);
 138                 break;
 139         case 15:        /* PC */
 140                 /* "MOV r0, pc"; then return via DCC */
 141                 retval = dpm->instr_read_data_r0(dpm, 0xe1a0000f, &value);
 142
 143                 /* NOTE: this seems like a slightly awkward place to update
 144                  * this value ... but if the PC gets written (the only way
 145                  * to change what we compute), the arch spec says subsequent
 146                  * reads return values which are "unpredictable".  So this
 147                  * is always right except in those broken-by-intent cases.
 148                  */
 149                 switch (dpm->arm->core_state) {
 150                 case ARM_STATE_ARM:
 151                         value -= 8;
 152                         break;
 153                 case ARM_STATE_THUMB:
 154                 case ARM_STATE_THUMB_EE:
 155                         value -= 4;
 156                         break;
 157                 case ARM_STATE_JAZELLE:
 158                         /* core-specific ... ? */
 159                         LOG_WARNING("Jazelle PC adjustment unknown");
 160                         break;
 161                 }
 162                 break;
 163         default:
 164                 /* 16: "MRS r0, CPSR"; then return via DCC
 165                  * 17: "MRS r0, SPSR"; then return via DCC
 166                  */
 167                 retval = dpm->instr_read_data_r0(dpm,
 168                                 ARMV4_5_MRS(0, regnum & 1),
 169                                 &value);
 170                 break;
 171         }
 172
 173         if (retval == ERROR_OK) {
 174                 buf_set_u32(r->value, 0, 32, value);
 175                 r->valid = true;
 176                 r->dirty = false;
 177                 LOG_DEBUG("READ: %s, %8.8x", r->name, (unsigned) value);
 178         }
 179
 180         return retval;
 181 }
 182
 183 /* just write the register -- rely on the core mode being right */
 184 static int dpm_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
 185 {
 186         int retval;
 187         uint32_t value = buf_get_u32(r->value, 0, 32);
 188
 189         switch (regnum) {
 190         case 0 ... 14:
 191                 /* load register from DCC:  "MRC p14, 0, Rnum, c0, c5, 0" */
 192                 retval = dpm->instr_write_data_dcc(dpm,
 193                                 ARMV4_5_MRC(14, 0, regnum, 0, 5, 0),
 194                                 value);
 195                 break;
 196         case 15:        /* PC */
 197                 /* read r0 from DCC; then "MOV pc, r0" */
 198                 retval = dpm->instr_write_data_r0(dpm, 0xe1a0f000, value);
 199                 break;
 200         default:
 201                 /* 16: read r0 from DCC, then "MSR r0, CPSR_cxsf"
 202                  * 17: read r0 from DCC, then "MSR r0, SPSR_cxsf"
 203                  */
 204                 retval = dpm->instr_write_data_r0(dpm,
 205                                 ARMV4_5_MSR_GP(0, 0xf, regnum & 1),
 206                                 value);
 207
 208                 if (regnum == 16 && dpm->instr_cpsr_sync)
 209                         retval = dpm->instr_cpsr_sync(dpm);
 210
 211                 break;
 212         }
 213
 214         if (retval == ERROR_OK) {
 215                 r->dirty = false;
 216                 LOG_DEBUG("WRITE: %s, %8.8x", r->name, (unsigned) value);
 217         }
 218
 219         return retval;
 220 }
 221
 222 /**
 223  * Read basic registers of the the current context:  R0 to R15, and CPSR;
 224  * sets the core mode (such as USR or IRQ) and state (such as ARM or Thumb).
 225  * In normal operation this is called on entry to halting debug state,
 226  * possibly after some other operations supporting restore of debug state
 227  * or making sure the CPU is fully idle (drain write buffer, etc).
 228  */
 229 int arm_dpm_read_current_registers(struct arm_dpm *dpm)
 230 {
 231         struct arm *arm = dpm->arm;
 232         uint32_t cpsr;
 233         int retval;
 234         struct reg *r;
 235
 236         retval = dpm->prepare(dpm);
 237         if (retval != ERROR_OK)
 238                 return retval;
 239
 240         /* read R0 first (it's used for scratch), then CPSR */
 241         r = arm->core_cache->reg_list + 0;
 242         if (!r->valid) {
 243                 retval = dpm_read_reg(dpm, r, 0);
 244                 if (retval != ERROR_OK)
 245                         goto fail;
 246         }
 247         r->dirty = true;
 248
 249         retval = dpm->instr_read_data_r0(dpm, ARMV4_5_MRS(0, 0), &cpsr);
 250         if (retval != ERROR_OK)
 251                 goto fail;
 252
 253         /* update core mode and state, plus shadow mapping for R8..R14 */
 254         arm_set_cpsr(arm, cpsr);
 255
 256         /* REVISIT we can probably avoid reading R1..R14, saving time... */
 257         for (unsigned i = 1; i < 16; i++) {
 258                 r = arm_reg_current(arm, i);
 259                 if (r->valid)
 260                         continue;
 261
 262                 retval = dpm_read_reg(dpm, r, i);
 263                 if (retval != ERROR_OK)
 264                         goto fail;
 265         }
 266
 267         /* NOTE: SPSR ignored (if it's even relevant). */
 268
 269         /* REVISIT the debugger can trigger various exceptions.  See the
 270          * ARMv7A architecture spec, section C5.7, for more info about
 271          * what defenses are needed; v6 debug has the most issues.
 272          */
 273
 274 fail:
 275         /* (void) */ dpm->finish(dpm);
 276         return retval;
 277 }
 278
 279 /**
 280  * Writes all modified core registers for all processor modes.  In normal
 281  * operation this is called on exit from halting debug state.
 282  *
 283  * @param dpm: represents the processor
 284  * @param bpwp: true ensures breakpoints and watchpoints are set,
 285  *      false ensures they are cleared
 286  */
 287 int arm_dpm_write_dirty_registers(struct arm_dpm *dpm, bool bpwp)
 288 {
 289         struct arm *arm = dpm->arm;
 290         struct reg_cache *cache = arm->core_cache;
 291         int retval;
 292         bool did_write;
 293
 294         retval = dpm->prepare(dpm);
 295         if (retval != ERROR_OK)
 296                 goto done;
 297
 298         /* enable/disable watchpoints */
 299         for (unsigned i = 0; i < dpm->nwp; i++) {
 300                 struct dpm_wp *dwp = dpm->dwp + i;
 301                 struct watchpoint *wp = dwp->wp;
 302                 bool disable;
 303
 304                 /* Avoid needless I/O ... leave watchpoints alone
 305                  * unless they're removed, or need updating because
 306                  * of single-stepping or running debugger code.
 307                  */
 308                 if (!wp) {
 309                         if (!dwp->dirty)
 310                                 continue;
 311                         dwp->dirty = false;
 312                         /* removed or startup; we must disable it */
 313                         disable = true;
 314                 } else if (bpwp) {
 315                         if (!dwp->dirty)
 316                                 continue;
 317                         /* disabled, but we must set it */
 318                         dwp->dirty = disable = false;
 319                         wp->set = true;
 320                 } else {
 321                         if (!wp->set)
 322                                 continue;
 323                         /* set, but we must temporarily disable it */
 324                         dwp->dirty = disable = true;
 325                         wp->set = false;
 326                 }
 327
 328                 if (disable)
 329                         retval = dpm->bpwp_disable(dpm, 16 + i);
 330                 else
 331                         retval = dpm->bpwp_enable(dpm, 16 + i,
 332                                         wp->address, dwp->control);
 333
 334                 if (retval != ERROR_OK)
 335                         LOG_ERROR("%s: can't %s HW watchpoint %d",
 336                                         target_name(arm->target),
 337                                         disable ? "disable" : "enable",
 338                                         i);
 339         }
 340
 341         /* NOTE:  writes to breakpoint and watchpoint registers might
 342          * be queued, and need (efficient/batched) flushing later.
 343          */
 344
 345         /* Scan the registers until we find one that's both dirty and
 346          * eligible for flushing.  Flush that and everything else that
 347          * shares the same core mode setting.  Typically this won't
 348          * actually find anything to do...
 349          */
 350         do {
 351                 enum armv4_5_mode mode = ARM_MODE_ANY;
 352
 353                 did_write = false;
 354
 355                 /* check everything except our scratch register R0 */
 356                 for (unsigned i = 1; i < cache->num_regs; i++) {
 357                         struct arm_reg *r;
 358                         unsigned regnum;
 359
 360                         /* also skip PC, CPSR, and non-dirty */
 361                         if (i == 15)
 362                                 continue;
 363                         if (arm->cpsr == cache->reg_list + i)
 364                                 continue;
 365                         if (!cache->reg_list[i].dirty)
 366                                 continue;
 367
 368                         r = cache->reg_list[i].arch_info;
 369                         regnum = r->num;
 370
 371                         /* may need to pick and set a mode */
 372                         if (!did_write) {
 373                                 enum armv4_5_mode tmode;
 374
 375                                 did_write = true;
 376                                 mode = tmode = r->mode;
 377
 378                                 /* cope with special cases */
 379                                 switch (regnum) {
 380                                 case 8 ... 12:
 381                                         /* r8..r12 "anything but FIQ" case;
 382                                          * we "know" core mode is accurate
 383                                          * since we haven't changed it yet
 384                                          */
 385                                         if (arm->core_mode == ARM_MODE_FIQ
 386                                                         && ARM_MODE_ANY
 387                                                                 != mode)
 388                                                 tmode = ARM_MODE_USR;
 389                                         break;
 390                                 case 16:
 391                                         /* SPSR */
 392                                         regnum++;
 393                                         break;
 394                                 }
 395
 396                                 /* REVISIT error checks */
 397                                 if (tmode != ARM_MODE_ANY)
 398                                         retval = dpm_modeswitch(dpm, tmode);
 399                         }
 400                         if (r->mode != mode)
 401                                 continue;
 402
 403                         retval = dpm_write_reg(dpm,
 404                                         &cache->reg_list[i],
 405                                         regnum);
 406
 407                 }
 408
 409         } while (did_write);
 410
 411         /* Restore original CPSR ... assuming either that we changed it,
 412          * or it's dirty.  Must write PC to ensure the return address is
 413          * defined, and must not write it before CPSR.
 414          */
 415         retval = dpm_modeswitch(dpm, ARM_MODE_ANY);
 416         arm->cpsr->dirty = false;
 417
 418         retval = dpm_write_reg(dpm, &cache->reg_list[15], 15);
 419         cache->reg_list[15].dirty = false;
 420
 421         /* flush R0 -- it's *very* dirty by now */
 422         retval = dpm_write_reg(dpm, &cache->reg_list[0], 0);
 423         cache->reg_list[0].dirty = false;
 424
 425         /* (void) */ dpm->finish(dpm);
 426 done:
 427         return retval;
 428 }
 429
 430 /* Returns ARM_MODE_ANY or temporary mode to use while reading the
 431  * specified register ... works around flakiness from ARM core calls.
 432  * Caller already filtered out SPSR access; mode is never MODE_SYS
 433  * or MODE_ANY.
 434  */
 435 static enum armv4_5_mode dpm_mapmode(struct arm *arm,
 436                 unsigned num, enum armv4_5_mode mode)
 437 {
 438         enum armv4_5_mode amode = arm->core_mode;
 439
 440         /* don't switch if the mode is already correct */
 441         if (amode == ARM_MODE_SYS)
 442                  amode = ARM_MODE_USR;
 443         if (mode == amode)
 444                 return ARM_MODE_ANY;
 445
 446         switch (num) {
 447         /* don't switch for non-shadowed registers (r0..r7, r15/pc, cpsr) */
 448         case 0 ... 7:
 449         case 15:
 450         case 16:
 451                 break;
 452         /* r8..r12 aren't shadowed for anything except FIQ */
 453         case 8 ... 12:
 454                 if (mode == ARM_MODE_FIQ)
 455                         return mode;
 456                 break;
 457         /* r13/sp, and r14/lr are always shadowed */
 458         case 13:
 459         case 14:
 460                 return mode;
 461         default:
 462                 LOG_WARNING("invalid register #%u", num);
 463                 break;
 464         }
 465         return ARM_MODE_ANY;
 466 }
 467
 468
 469 /*
 470  * Standard ARM register accessors ... there are three methods
 471  * in "struct arm", to support individual read/write and bulk read
 472  * of registers.
 473  */
 474
 475 static int arm_dpm_read_core_reg(struct target *target, struct reg *r,
 476                 int regnum, enum armv4_5_mode mode)
 477 {
 478         struct arm_dpm *dpm = target_to_arm(target)->dpm;
 479         int retval;
 480
 481         if (regnum < 0 || regnum > 16)
 482                 return ERROR_INVALID_ARGUMENTS;
 483
 484         if (regnum == 16) {
 485                 if (mode != ARM_MODE_ANY)
 486                         regnum = 17;
 487         } else
 488                 mode = dpm_mapmode(dpm->arm, regnum, mode);
 489
 490         /* REVISIT what happens if we try to read SPSR in a core mode
 491          * which has no such register?
 492          */
 493
 494         retval = dpm->prepare(dpm);
 495         if (retval != ERROR_OK)
 496                 return retval;
 497
 498         if (mode != ARM_MODE_ANY) {
 499                 retval = dpm_modeswitch(dpm, mode);
 500                 if (retval != ERROR_OK)
 501                         goto fail;
 502         }
 503
 504         retval = dpm_read_reg(dpm, r, regnum);
 505         /* always clean up, regardless of error */
 506
 507         if (mode != ARM_MODE_ANY)
 508                 /* (void) */ dpm_modeswitch(dpm, ARM_MODE_ANY);
 509
 510 fail:
 511         /* (void) */ dpm->finish(dpm);
 512         return retval;
 513 }
 514
 515 static int arm_dpm_write_core_reg(struct target *target, struct reg *r,
 516                 int regnum, enum armv4_5_mode mode, uint32_t value)
 517 {
 518         struct arm_dpm *dpm = target_to_arm(target)->dpm;
 519         int retval;
 520
 521
 522         if (regnum < 0 || regnum > 16)
 523                 return ERROR_INVALID_ARGUMENTS;
 524
 525         if (regnum == 16) {
 526                 if (mode != ARM_MODE_ANY)
 527                         regnum = 17;
 528         } else
 529                 mode = dpm_mapmode(dpm->arm, regnum, mode);
 530
 531         /* REVISIT what happens if we try to write SPSR in a core mode
 532          * which has no such register?
 533          */
 534
 535         retval = dpm->prepare(dpm);
 536         if (retval != ERROR_OK)
 537                 return retval;
 538
 539         if (mode != ARM_MODE_ANY) {
 540                 retval = dpm_modeswitch(dpm, mode);
 541                 if (retval != ERROR_OK)
 542                         goto fail;
 543         }
 544
 545         retval = dpm_write_reg(dpm, r, regnum);
 546         /* always clean up, regardless of error */
 547
 548         if (mode != ARM_MODE_ANY)
 549                 /* (void) */ dpm_modeswitch(dpm, ARM_MODE_ANY);
 550
 551 fail:
 552         /* (void) */ dpm->finish(dpm);
 553         return retval;
 554 }
 555
 556 static int arm_dpm_full_context(struct target *target)
 557 {
 558         struct arm *arm = target_to_arm(target);
 559         struct arm_dpm *dpm = arm->dpm;
 560         struct reg_cache *cache = arm->core_cache;
 561         int retval;
 562         bool did_read;
 563
 564         retval = dpm->prepare(dpm);
 565         if (retval != ERROR_OK)
 566                 goto done;
 567
 568         do {
 569                 enum armv4_5_mode mode = ARM_MODE_ANY;
 570
 571                 did_read = false;
 572
 573                 /* We "know" arm_dpm_read_current_registers() was called so
 574                  * the unmapped registers (R0..R7, PC, AND CPSR) and some
 575                  * view of R8..R14 are current.  We also "know" oddities of
 576                  * register mapping: special cases for R8..R12 and SPSR.
 577                  *
 578                  * Pick some mode with unread registers and read them all.
 579                  * Repeat until done.
 580                  */
 581                 for (unsigned i = 0; i < cache->num_regs; i++) {
 582                         struct arm_reg *r;
 583
 584                         if (cache->reg_list[i].valid)
 585                                 continue;
 586                         r = cache->reg_list[i].arch_info;
 587
 588                         /* may need to pick a mode and set CPSR */
 589                         if (!did_read) {
 590                                 did_read = true;
 591                                 mode = r->mode;
 592
 593                                 /* For R8..R12 when we've entered debug
 594                                  * state in FIQ mode... patch mode.
 595                                  */
 596                                 if (mode == ARM_MODE_ANY)
 597                                         mode = ARM_MODE_USR;
 598
 599                                 /* REVISIT error checks */
 600                                 retval = dpm_modeswitch(dpm, mode);
 601                         }
 602                         if (r->mode != mode)
 603                                 continue;
 604
 605                         /* CPSR was read, so "R16" must mean SPSR */
 606                         retval = dpm_read_reg(dpm,
 607                                         &cache->reg_list[i],
 608                                         (r->num == 16) ? 17 : r->num);
 609
 610                 }
 611
 612         } while (did_read);
 613
 614         retval = dpm_modeswitch(dpm, ARM_MODE_ANY);
 615         /* (void) */ dpm->finish(dpm);
 616 done:
 617         return retval;
 618 }
 619
 620
 621 /*----------------------------------------------------------------------*/
 622
 623 /*
 624  * Breakpoint and Watchpoint support.
 625  *
 626  * Hardware {break,watch}points are usually left active, to minimize
 627  * debug entry/exit costs.  When they are set or cleared, it's done in
 628  * batches.  Also, DPM-conformant hardware can update debug registers
 629  * regardless of whether the CPU is running or halted ... though that
 630  * fact isn't currently leveraged.
 631  */
 632
 633 static int dpm_watchpoint_setup(struct arm_dpm *dpm, unsigned index,
 634                 struct watchpoint *wp)
 635 {
 636         uint32_t addr = wp->address;
 637         uint32_t control;
 638
 639         /* this hardware doesn't support data value matching or masking */
 640         if (wp->value || wp->mask != ~(uint32_t)0) {
 641                 LOG_DEBUG("watchpoint values and masking not supported");
 642                 return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 643         }
 644
 645         control = (1 << 0)      /* enable */
 646                 | (3 << 1);     /* both user and privileged access */
 647
 648         switch (wp->rw) {
 649         case WPT_READ:
 650                 control |= 1 << 3;
 651                 break;
 652         case WPT_WRITE:
 653                 control |= 2 << 3;
 654                 break;
 655         case WPT_ACCESS:
 656                 control |= 3 << 3;
 657                 break;
 658         }
 659
 660         /* Match 1, 2, or all 4 byte addresses in this word.
 661          *
 662          * FIXME:  v7 hardware allows lengths up to 2 GB, and has eight
 663          * byte address select bits.  Support larger wp->length, if addr
 664          * is suitably aligned.
 665          */
 666         switch (wp->length) {
 667         case 1:
 668                 control |= (1 << (addr & 3)) << 5;
 669                 addr &= ~3;
 670                 break;
 671         case 2:
 672                 /* require 2-byte alignment */
 673                 if (!(addr & 1)) {
 674                         control |= (3 << (addr & 2)) << 5;
 675                         break;
 676                 }
 677                 /* FALL THROUGH */
 678         case 4:
 679                 /* require 4-byte alignment */
 680                 if (!(addr & 3)) {
 681                         control |= 0xf << 5;
 682                         break;
 683                 }
 684                 /* FALL THROUGH */
 685         default:
 686                 LOG_DEBUG("bad watchpoint length or alignment");
 687                 return ERROR_INVALID_ARGUMENTS;
 688         }
 689
 690         /* other control bits:
 691          * bits 9:12 == 0 ... only checking up to four byte addresses (v7 only)
 692          * bits 15:14 == 0 ... both secure and nonsecure states (v6.1+ only)
 693          * bit 20 == 0 ... not linked to a context ID
 694          * bit 28:24 == 0 ... not ignoring N LSBs (v7 only)
 695          */
 696
 697         dpm->dwp[index].wp = wp;
 698         dpm->dwp[index].control = control;
 699         dpm->dwp[index].dirty = true;
 700
 701         /* hardware is updated in write_dirty_registers() */
 702         return ERROR_OK;
 703 }
 704
 705
 706 static int dpm_add_watchpoint(struct target *target, struct watchpoint *wp)
 707 {
 708         struct arm *arm = target_to_arm(target);
 709         struct arm_dpm *dpm = arm->dpm;
 710         int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
 711
 712         if (dpm->bpwp_enable) {
 713                 for (unsigned i = 0; i < dpm->nwp; i++) {
 714                         if (!dpm->dwp[i].wp) {
 715                                 retval = dpm_watchpoint_setup(dpm, i, wp);
 716                                 break;
 717                         }
 718                 }
 719         }
 720
 721         return retval;
 722 }
 723
 724 static int dpm_remove_watchpoint(struct target *target, struct watchpoint *wp)
 725 {
 726         struct arm *arm = target_to_arm(target);
 727         struct arm_dpm *dpm = arm->dpm;
 728         int retval = ERROR_INVALID_ARGUMENTS;
 729
 730         for (unsigned i = 0; i < dpm->nwp; i++) {
 731                 if (dpm->dwp[i].wp == wp) {
 732                         dpm->dwp[i].wp = NULL;
 733                         dpm->dwp[i].dirty = true;
 734
 735                         /* hardware is updated in write_dirty_registers() */
 736                         retval = ERROR_OK;
 737                         break;
 738                 }
 739         }
 740
 741         return retval;
 742 }
 743
 744 void arm_dpm_report_wfar(struct arm_dpm *dpm, uint32_t addr)
 745 {
 746         switch (dpm->arm->core_state) {
 747         case ARM_STATE_ARM:
 748                 addr -= 8;
 749                 break;
 750         case ARM_STATE_THUMB:
 751         case ARM_STATE_THUMB_EE:
 752                 addr -= 4;
 753                 break;
 754         case ARM_STATE_JAZELLE:
 755                 /* ?? */
 756                 break;
 757         }
 758         dpm->wp_pc = addr;
 759 }
 760
 761 /*----------------------------------------------------------------------*/
 762
 763 /*
 764  * Other debug and support utilities
 765  */
 766
 767 void arm_dpm_report_dscr(struct arm_dpm *dpm, uint32_t dscr)
 768 {
 769         struct target *target = dpm->arm->target;
 770
 771         dpm->dscr = dscr;
 772
 773         /* Examine debug reason */
 774         switch (DSCR_ENTRY(dscr)) {
 775         case 6:         /* Data abort (v6 only) */
 776         case 7:         /* Prefetch abort (v6 only) */
 777                 /* FALL THROUGH -- assume a v6 core in abort mode */
 778         case 0:         /* HALT request from debugger */
 779         case 4:         /* EDBGRQ */
 780                 target->debug_reason = DBG_REASON_DBGRQ;
 781                 break;
 782         case 1:         /* HW breakpoint */
 783         case 3:         /* SW BKPT */
 784         case 5:         /* vector catch */
 785                 target->debug_reason = DBG_REASON_BREAKPOINT;
 786                 break;
 787         case 2:         /* asynch watchpoint */
 788         case 10:        /* precise watchpoint */
 789                 target->debug_reason = DBG_REASON_WATCHPOINT;
 790                 break;
 791         default:
 792                 target->debug_reason = DBG_REASON_UNDEFINED;
 793                 break;
 794         }
 795 }
 796
 797 /*----------------------------------------------------------------------*/
 798
 799 /*
 800  * Setup and management support.
 801  */
 802
 803 /**
 804  * Hooks up this DPM to its associated target; call only once.
 805  * Initially this only covers the register cache.
 806  *
 807  * Oh, and watchpoints.  Yeah.
 808  */
 809 int arm_dpm_setup(struct arm_dpm *dpm)
 810 {
 811         struct arm *arm = dpm->arm;
 812         struct target *target = arm->target;
 813         struct reg_cache *cache;
 814
 815         arm->dpm = dpm;
 816
 817         /* register access setup */
 818         arm->full_context = arm_dpm_full_context;
 819         arm->read_core_reg = arm_dpm_read_core_reg;
 820         arm->write_core_reg = arm_dpm_write_core_reg;
 821
 822         cache = armv4_5_build_reg_cache(target, arm);
 823         if (!cache)
 824                 return ERROR_FAIL;
 825
 826         *register_get_last_cache_p(&target->reg_cache) = cache;
 827
 828         /* coprocessor access setup */
 829         arm->mrc = dpm_mrc;
 830         arm->mcr = dpm_mcr;
 831
 832         /* breakpoint and watchpoint setup */
 833         target->type->add_watchpoint = dpm_add_watchpoint;
 834         target->type->remove_watchpoint = dpm_remove_watchpoint;
 835
 836         /* FIXME add breakpoint support */
 837         /* FIXME add vector catch support */
 838
 839         dpm->nbp = 1 + ((dpm->didr >> 24) & 0xf);
 840         dpm->dbp = calloc(dpm->nbp, sizeof *dpm->dbp);
 841
 842         dpm->nwp = 1 + ((dpm->didr >> 28) & 0xf);
 843         dpm->dwp = calloc(dpm->nwp, sizeof *dpm->dwp);
 844
 845         if (!dpm->dbp || !dpm->dwp) {
 846                 free(dpm->dbp);
 847                 free(dpm->dwp);
 848                 return ERROR_FAIL;
 849         }
 850
 851         LOG_INFO("%s: hardware has %d breakpoints, %d watchpoints",
 852                         target_name(target), dpm->nbp, dpm->nwp);
 853
 854         /* REVISIT ... and some of those breakpoints could match
 855          * execution context IDs...
 856          */
 857
 858         return ERROR_OK;
 859 }
 860
 861 /**
 862  * Reinitializes DPM state at the beginning of a new debug session
 863  * or after a reset which may have affected the debug module.
 864  */
 865 int arm_dpm_initialize(struct arm_dpm *dpm)
 866 {
 867         /* Disable all breakpoints and watchpoints at startup. */
 868         if (dpm->bpwp_disable) {
 869                 unsigned i;
 870
 871                 for (i = 0; i < dpm->nbp; i++)
 872                         (void) dpm->bpwp_disable(dpm, i);
 873                 for (i = 0; i < dpm->nwp; i++)
 874                         (void) dpm->bpwp_disable(dpm, 16 + i);
 875         } else
 876                 LOG_WARNING("%s: can't disable breakpoints and watchpoints",
 877                         target_name(dpm->arm->target));
 878
 879         return ERROR_OK;
 880 }