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cortex_a8/a9: fix some comments
[openocd/ellerodev.git] / src / target / arm_dpm.c
blob012316bf8ad78e65be79874d95fe79ecb4239ef8
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 "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 #include "arm_opcodes.h"
31
32
33 /**
34 * @file
35 * Implements various ARM DPM operations using architectural debug registers.
36 * These routines layer over core-specific communication methods to cope with
37 * implementation differences between cores like ARM1136 and Cortex-A8.
38 *
39 * The "Debug Programmers' Model" (DPM) for ARMv6 and ARMv7 is defined by
40 * Part C (Debug Architecture) of the ARM Architecture Reference Manual,
41 * ARMv7-A and ARMv7-R edition (ARM DDI 0406B). In OpenOCD, DPM operations
42 * are abstracted through internal programming interfaces to share code and
43 * to minimize needless differences in debug behavior between cores.
44 */
45
46 /*----------------------------------------------------------------------*/
47
48 /*
49 * Coprocessor support
50 */
51
52 /* Read coprocessor */
53 static int dpm_mrc(struct target *target, int cpnum,
54 uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
55 uint32_t *value)
56 {
57 struct arm *arm = target_to_arm(target);
58 struct arm_dpm *dpm = arm->dpm;
59 int retval;
60
61 retval = dpm->prepare(dpm);
62 if (retval != ERROR_OK)
63 return retval;
64
65 LOG_DEBUG("MRC p%d, %d, r0, c%d, c%d, %d", cpnum,
66 (int) op1, (int) CRn,
67 (int) CRm, (int) op2);
68
69 /* read coprocessor register into R0; return via DCC */
70 retval = dpm->instr_read_data_r0(dpm,
71 ARMV4_5_MRC(cpnum, op1, 0, CRn, CRm, op2),
72 value);
73
74 /* (void) */ dpm->finish(dpm);
75 return retval;
76 }
77
78 static int dpm_mcr(struct target *target, int cpnum,
79 uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
80 uint32_t value)
81 {
82 struct arm *arm = target_to_arm(target);
83 struct arm_dpm *dpm = arm->dpm;
84 int retval;
85
86 retval = dpm->prepare(dpm);
87 if (retval != ERROR_OK)
88 return retval;
89
90 LOG_DEBUG("MCR p%d, %d, r0, c%d, c%d, %d", cpnum,
91 (int) op1, (int) CRn,
92 (int) CRm, (int) op2);
93
94 /* read DCC into r0; then write coprocessor register from R0 */
95 retval = dpm->instr_write_data_r0(dpm,
96 ARMV4_5_MCR(cpnum, op1, 0, CRn, CRm, op2),
97 value);
98
99 /* (void) */ dpm->finish(dpm);
100 return retval;
101 }
102
103 /*----------------------------------------------------------------------*/
104
105 /*
106 * Register access utilities
107 */
108
109 /* Toggles between recorded core mode (USR, SVC, etc) and a temporary one.
110 * Routines *must* restore the original mode before returning!!
111 */
112 static int dpm_modeswitch(struct arm_dpm *dpm, enum arm_mode mode)
113 {
114 int retval;
115 uint32_t cpsr;
116
117 /* restore previous mode */
118 if (mode == ARM_MODE_ANY)
119 cpsr = buf_get_u32(dpm->arm->cpsr->value, 0, 32);
120
121 /* else force to the specified mode */
122 else
123 cpsr = mode;
124
125 retval = dpm->instr_write_data_r0(dpm, ARMV4_5_MSR_GP(0, 0xf, 0), cpsr);
126 if (retval != ERROR_OK)
127 return retval;
128
129 if (dpm->instr_cpsr_sync)
130 retval = dpm->instr_cpsr_sync(dpm);
131
132 return retval;
133 }
134
135 /* just read the register -- rely on the core mode being right */
136 static int dpm_read_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
137 {
138 uint32_t value;
139 int retval;
140
141 switch (regnum) {
142 case 0 ... 14:
143 /* return via DCC: "MCR p14, 0, Rnum, c0, c5, 0" */
144 retval = dpm->instr_read_data_dcc(dpm,
145 ARMV4_5_MCR(14, 0, regnum, 0, 5, 0),
146 &value);
147 break;
148 case 15: /* PC */
149 /* "MOV r0, pc"; then return via DCC */
150 retval = dpm->instr_read_data_r0(dpm, 0xe1a0000f, &value);
151
152 /* NOTE: this seems like a slightly awkward place to update
153 * this value ... but if the PC gets written (the only way
154 * to change what we compute), the arch spec says subsequent
155 * reads return values which are "unpredictable". So this
156 * is always right except in those broken-by-intent cases.
157 */
158 switch (dpm->arm->core_state) {
159 case ARM_STATE_ARM:
160 value -= 8;
161 break;
162 case ARM_STATE_THUMB:
163 case ARM_STATE_THUMB_EE:
164 value -= 4;
165 break;
166 case ARM_STATE_JAZELLE:
167 /* core-specific ... ? */
168 LOG_WARNING("Jazelle PC adjustment unknown");
169 break;
170 }
171 break;
172 default:
173 /* 16: "MRS r0, CPSR"; then return via DCC
174 * 17: "MRS r0, SPSR"; then return via DCC
175 */
176 retval = dpm->instr_read_data_r0(dpm,
177 ARMV4_5_MRS(0, regnum & 1),
178 &value);
179 break;
180 }
181
182 if (retval == ERROR_OK) {
183 buf_set_u32(r->value, 0, 32, value);
184 r->valid = true;
185 r->dirty = false;
186 LOG_DEBUG("READ: %s, %8.8x", r->name, (unsigned) value);
187 }
188
189 return retval;
190 }
191
192 /* just write the register -- rely on the core mode being right */
193 static int dpm_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
194 {
195 int retval;
196 uint32_t value = buf_get_u32(r->value, 0, 32);
197
198 switch (regnum) {
199 case 0 ... 14:
200 /* load register from DCC: "MRC p14, 0, Rnum, c0, c5, 0" */
201 retval = dpm->instr_write_data_dcc(dpm,
202 ARMV4_5_MRC(14, 0, regnum, 0, 5, 0),
203 value);
204 break;
205 case 15: /* PC */
206 /* read r0 from DCC; then "MOV pc, r0" */
207 retval = dpm->instr_write_data_r0(dpm, 0xe1a0f000, value);
208 break;
209 default:
210 /* 16: read r0 from DCC, then "MSR r0, CPSR_cxsf"
211 * 17: read r0 from DCC, then "MSR r0, SPSR_cxsf"
212 */
213 retval = dpm->instr_write_data_r0(dpm,
214 ARMV4_5_MSR_GP(0, 0xf, regnum & 1),
215 value);
216 if (retval != ERROR_OK)
217 return retval;
218
219 if (regnum == 16 && dpm->instr_cpsr_sync)
220 retval = dpm->instr_cpsr_sync(dpm);
221
222 break;
223 }
224
225 if (retval == ERROR_OK) {
226 r->dirty = false;
227 LOG_DEBUG("WRITE: %s, %8.8x", r->name, (unsigned) value);
228 }
229
230 return retval;
231 }
232
233 /**
234 * Read basic registers of the the current context: R0 to R15, and CPSR;
235 * sets the core mode (such as USR or IRQ) and state (such as ARM or Thumb).
236 * In normal operation this is called on entry to halting debug state,
237 * possibly after some other operations supporting restore of debug state
238 * or making sure the CPU is fully idle (drain write buffer, etc).
239 */
240 int arm_dpm_read_current_registers(struct arm_dpm *dpm)
241 {
242 struct arm *arm = dpm->arm;
243 uint32_t cpsr;
244 int retval;
245 struct reg *r;
246
247 retval = dpm->prepare(dpm);
248 if (retval != ERROR_OK)
249 return retval;
250
251 /* read R0 first (it's used for scratch), then CPSR */
252 r = arm->core_cache->reg_list + 0;
253 if (!r->valid) {
254 retval = dpm_read_reg(dpm, r, 0);
255 if (retval != ERROR_OK)
256 goto fail;
257 }
258 r->dirty = true;
259
260 retval = dpm->instr_read_data_r0(dpm, ARMV4_5_MRS(0, 0), &cpsr);
261 if (retval != ERROR_OK)
262 goto fail;
263
264 /* update core mode and state, plus shadow mapping for R8..R14 */
265 arm_set_cpsr(arm, cpsr);
266
267 /* REVISIT we can probably avoid reading R1..R14, saving time... */
268 for (unsigned i = 1; i < 16; i++) {
269 r = arm_reg_current(arm, i);
270 if (r->valid)
271 continue;
272
273 retval = dpm_read_reg(dpm, r, i);
274 if (retval != ERROR_OK)
275 goto fail;
276 }
277
278 /* NOTE: SPSR ignored (if it's even relevant). */
279
280 /* REVISIT the debugger can trigger various exceptions. See the
281 * ARMv7A architecture spec, section C5.7, for more info about
282 * what defenses are needed; v6 debug has the most issues.
283 */
284
285 fail:
286 /* (void) */ dpm->finish(dpm);
287 return retval;
288 }
289
290 /* Avoid needless I/O ... leave breakpoints and watchpoints alone
291 * unless they're removed, or need updating because of single-stepping
292 * or running debugger code.
293 */
294 static int dpm_maybe_update_bpwp(struct arm_dpm *dpm, bool bpwp,
295 struct dpm_bpwp *xp, int *set_p)
296 {
297 int retval = ERROR_OK;
298 bool disable;
299
300 if (!set_p) {
301 if (!xp->dirty)
302 goto done;
303 xp->dirty = false;
304 /* removed or startup; we must disable it */
305 disable = true;
306 } else if (bpwp) {
307 if (!xp->dirty)
308 goto done;
309 /* disabled, but we must set it */
310 xp->dirty = disable = false;
311 *set_p = true;
312 } else {
313 if (!*set_p)
314 goto done;
315 /* set, but we must temporarily disable it */
316 xp->dirty = disable = true;
317 *set_p = false;
318 }
319
320 if (disable)
321 retval = dpm->bpwp_disable(dpm, xp->number);
322 else
323 retval = dpm->bpwp_enable(dpm, xp->number,
324 xp->address, xp->control);
325
326 if (retval != ERROR_OK)
327 LOG_ERROR("%s: can't %s HW %spoint %d",
328 disable ? "disable" : "enable",
329 target_name(dpm->arm->target),
330 (xp->number < 16) ? "break" : "watch",
331 xp->number & 0xf);
332 done:
333 return retval;
334 }
335
336 static int dpm_add_breakpoint(struct target *target, struct breakpoint *bp);
337
338 /**
339 * Writes all modified core registers for all processor modes. In normal
340 * operation this is called on exit from halting debug state.
341 *
342 * @param dpm: represents the processor
343 * @param bpwp: true ensures breakpoints and watchpoints are set,
344 * false ensures they are cleared
345 */
346 int arm_dpm_write_dirty_registers(struct arm_dpm *dpm, bool bpwp)
347 {
348 struct arm *arm = dpm->arm;
349 struct reg_cache *cache = arm->core_cache;
350 int retval;
351 bool did_write;
352
353 retval = dpm->prepare(dpm);
354 if (retval != ERROR_OK)
355 goto done;
356
357 /* If we're managing hardware breakpoints for this core, enable
358 * or disable them as requested.
359 *
360 * REVISIT We don't yet manage them for ANY cores. Eventually
361 * we should be able to assume we handle them; but until then,
362 * cope with the hand-crafted breakpoint code.
363 */
364 if (arm->target->type->add_breakpoint == dpm_add_breakpoint) {
365 for (unsigned i = 0; i < dpm->nbp; i++) {
366 struct dpm_bp *dbp = dpm->dbp + i;
367 struct breakpoint *bp = dbp->bp;
368
369 retval = dpm_maybe_update_bpwp(dpm, bpwp, &dbp->bpwp,
370 bp ? &bp->set : NULL);
371 if (retval != ERROR_OK)
372 goto done;
373 }
374 }
375
376 /* enable/disable watchpoints */
377 for (unsigned i = 0; i < dpm->nwp; i++) {
378 struct dpm_wp *dwp = dpm->dwp + i;
379 struct watchpoint *wp = dwp->wp;
380
381 retval = dpm_maybe_update_bpwp(dpm, bpwp, &dwp->bpwp,
382 wp ? &wp->set : NULL);
383 if (retval != ERROR_OK)
384 goto done;
385 }
386
387 /* NOTE: writes to breakpoint and watchpoint registers might
388 * be queued, and need (efficient/batched) flushing later.
389 */
390
391 /* Scan the registers until we find one that's both dirty and
392 * eligible for flushing. Flush that and everything else that
393 * shares the same core mode setting. Typically this won't
394 * actually find anything to do...
395 */
396 do {
397 enum arm_mode mode = ARM_MODE_ANY;
398
399 did_write = false;
400
401 /* check everything except our scratch register R0 */
402 for (unsigned i = 1; i < cache->num_regs; i++) {
403 struct arm_reg *r;
404 unsigned regnum;
405
406 /* also skip PC, CPSR, and non-dirty */
407 if (i == 15)
408 continue;
409 if (arm->cpsr == cache->reg_list + i)
410 continue;
411 if (!cache->reg_list[i].dirty)
412 continue;
413
414 r = cache->reg_list[i].arch_info;
415 regnum = r->num;
416
417 /* may need to pick and set a mode */
418 if (!did_write) {
419 enum arm_mode tmode;
420
421 did_write = true;
422 mode = tmode = r->mode;
423
424 /* cope with special cases */
425 switch (regnum) {
426 case 8 ... 12:
427 /* r8..r12 "anything but FIQ" case;
428 * we "know" core mode is accurate
429 * since we haven't changed it yet
430 */
431 if (arm->core_mode == ARM_MODE_FIQ
432 && ARM_MODE_ANY
433 != mode)
434 tmode = ARM_MODE_USR;
435 break;
436 case 16:
437 /* SPSR */
438 regnum++;
439 break;
440 }
441
442 /* REVISIT error checks */
443 if (tmode != ARM_MODE_ANY)
444 {
445 retval = dpm_modeswitch(dpm, tmode);
446 if (retval != ERROR_OK)
447 goto done;
448 }
449 }
450 if (r->mode != mode)
451 continue;
452
453 retval = dpm_write_reg(dpm,
454 &cache->reg_list[i],
455 regnum);
456 if (retval != ERROR_OK)
457 goto done;
458 }
459
460 } while (did_write);
461
462 /* Restore original CPSR ... assuming either that we changed it,
463 * or it's dirty. Must write PC to ensure the return address is
464 * defined, and must not write it before CPSR.
465 */
466 retval = dpm_modeswitch(dpm, ARM_MODE_ANY);
467 if (retval != ERROR_OK)
468 goto done;
469 arm->cpsr->dirty = false;
470
471 retval = dpm_write_reg(dpm, arm->pc, 15);
472 if (retval != ERROR_OK)
473 goto done;
474 arm->pc->dirty = false;
475
476 /* flush R0 -- it's *very* dirty by now */
477 retval = dpm_write_reg(dpm, &cache->reg_list[0], 0);
478 if (retval != ERROR_OK)
479 goto done;
480 cache->reg_list[0].dirty = false;
481
482 /* (void) */ dpm->finish(dpm);
483 done:
484 return retval;
485 }
486
487 /* Returns ARM_MODE_ANY or temporary mode to use while reading the
488 * specified register ... works around flakiness from ARM core calls.
489 * Caller already filtered out SPSR access; mode is never MODE_SYS
490 * or MODE_ANY.
491 */
492 static enum arm_mode dpm_mapmode(struct arm *arm,
493 unsigned num, enum arm_mode mode)
494 {
495 enum arm_mode amode = arm->core_mode;
496
497 /* don't switch if the mode is already correct */
498 if (amode == ARM_MODE_SYS)
499 amode = ARM_MODE_USR;
500 if (mode == amode)
501 return ARM_MODE_ANY;
502
503 switch (num) {
504 /* don't switch for non-shadowed registers (r0..r7, r15/pc, cpsr) */
505 case 0 ... 7:
506 case 15:
507 case 16:
508 break;
509 /* r8..r12 aren't shadowed for anything except FIQ */
510 case 8 ... 12:
511 if (mode == ARM_MODE_FIQ)
512 return mode;
513 break;
514 /* r13/sp, and r14/lr are always shadowed */
515 case 13:
516 case 14:
517 return mode;
518 default:
519 LOG_WARNING("invalid register #%u", num);
520 break;
521 }
522 return ARM_MODE_ANY;
523 }
524
525
526 /*
527 * Standard ARM register accessors ... there are three methods
528 * in "struct arm", to support individual read/write and bulk read
529 * of registers.
530 */
531
532 static int arm_dpm_read_core_reg(struct target *target, struct reg *r,
533 int regnum, enum arm_mode mode)
534 {
535 struct arm_dpm *dpm = target_to_arm(target)->dpm;
536 int retval;
537
538 if (regnum < 0 || regnum > 16)
539 return ERROR_INVALID_ARGUMENTS;
540
541 if (regnum == 16) {
542 if (mode != ARM_MODE_ANY)
543 regnum = 17;
544 } else
545 mode = dpm_mapmode(dpm->arm, regnum, mode);
546
547 /* REVISIT what happens if we try to read SPSR in a core mode
548 * which has no such register?
549 */
550
551 retval = dpm->prepare(dpm);
552 if (retval != ERROR_OK)
553 return retval;
554
555 if (mode != ARM_MODE_ANY) {
556 retval = dpm_modeswitch(dpm, mode);
557 if (retval != ERROR_OK)
558 goto fail;
559 }
560
561 retval = dpm_read_reg(dpm, r, regnum);
562 if (retval != ERROR_OK)
563 goto fail;
564 /* always clean up, regardless of error */
565
566 if (mode != ARM_MODE_ANY)
567 /* (void) */ dpm_modeswitch(dpm, ARM_MODE_ANY);
568
569 fail:
570 /* (void) */ dpm->finish(dpm);
571 return retval;
572 }
573
574 static int arm_dpm_write_core_reg(struct target *target, struct reg *r,
575 int regnum, enum arm_mode mode, uint32_t value)
576 {
577 struct arm_dpm *dpm = target_to_arm(target)->dpm;
578 int retval;
579
580
581 if (regnum < 0 || regnum > 16)
582 return ERROR_INVALID_ARGUMENTS;
583
584 if (regnum == 16) {
585 if (mode != ARM_MODE_ANY)
586 regnum = 17;
587 } else
588 mode = dpm_mapmode(dpm->arm, regnum, mode);
589
590 /* REVISIT what happens if we try to write SPSR in a core mode
591 * which has no such register?
592 */
593
594 retval = dpm->prepare(dpm);
595 if (retval != ERROR_OK)
596 return retval;
597
598 if (mode != ARM_MODE_ANY) {
599 retval = dpm_modeswitch(dpm, mode);
600 if (retval != ERROR_OK)
601 goto fail;
602 }
603
604 retval = dpm_write_reg(dpm, r, regnum);
605 /* always clean up, regardless of error */
606
607 if (mode != ARM_MODE_ANY)
608 /* (void) */ dpm_modeswitch(dpm, ARM_MODE_ANY);
609
610 fail:
611 /* (void) */ dpm->finish(dpm);
612 return retval;
613 }
614
615 static int arm_dpm_full_context(struct target *target)
616 {
617 struct arm *arm = target_to_arm(target);
618 struct arm_dpm *dpm = arm->dpm;
619 struct reg_cache *cache = arm->core_cache;
620 int retval;
621 bool did_read;
622
623 retval = dpm->prepare(dpm);
624 if (retval != ERROR_OK)
625 goto done;
626
627 do {
628 enum arm_mode mode = ARM_MODE_ANY;
629
630 did_read = false;
631
632 /* We "know" arm_dpm_read_current_registers() was called so
633 * the unmapped registers (R0..R7, PC, AND CPSR) and some
634 * view of R8..R14 are current. We also "know" oddities of
635 * register mapping: special cases for R8..R12 and SPSR.
636 *
637 * Pick some mode with unread registers and read them all.
638 * Repeat until done.
639 */
640 for (unsigned i = 0; i < cache->num_regs; i++) {
641 struct arm_reg *r;
642
643 if (cache->reg_list[i].valid)
644 continue;
645 r = cache->reg_list[i].arch_info;
646
647 /* may need to pick a mode and set CPSR */
648 if (!did_read) {
649 did_read = true;
650 mode = r->mode;
651
652 /* For R8..R12 when we've entered debug
653 * state in FIQ mode... patch mode.
654 */
655 if (mode == ARM_MODE_ANY)
656 mode = ARM_MODE_USR;
657
658 /* REVISIT error checks */
659 retval = dpm_modeswitch(dpm, mode);
660 if (retval != ERROR_OK)
661 goto done;
662 }
663 if (r->mode != mode)
664 continue;
665
666 /* CPSR was read, so "R16" must mean SPSR */
667 retval = dpm_read_reg(dpm,
668 &cache->reg_list[i],
669 (r->num == 16) ? 17 : r->num);
670 if (retval != ERROR_OK)
671 goto done;
672 }
673
674 } while (did_read);
675
676 retval = dpm_modeswitch(dpm, ARM_MODE_ANY);
677 /* (void) */ dpm->finish(dpm);
678 done:
679 return retval;
680 }
681
682
683 /*----------------------------------------------------------------------*/
684
685 /*
686 * Breakpoint and Watchpoint support.
687 *
688 * Hardware {break,watch}points are usually left active, to minimize
689 * debug entry/exit costs. When they are set or cleared, it's done in
690 * batches. Also, DPM-conformant hardware can update debug registers
691 * regardless of whether the CPU is running or halted ... though that
692 * fact isn't currently leveraged.
693 */
694
695 static int dpm_bpwp_setup(struct arm_dpm *dpm, struct dpm_bpwp *xp,
696 uint32_t addr, uint32_t length)
697 {
698 uint32_t control;
699
700 control = (1 << 0) /* enable */
701 | (3 << 1); /* both user and privileged access */
702
703 /* Match 1, 2, or all 4 byte addresses in this word.
704 *
705 * FIXME: v7 hardware allows lengths up to 2 GB for BP and WP.
706 * Support larger length, when addr is suitably aligned. In
707 * particular, allow watchpoints on 8 byte "double" values.
708 *
709 * REVISIT allow watchpoints on unaligned 2-bit values; and on
710 * v7 hardware, unaligned 4-byte ones too.
711 */
712 switch (length) {
713 case 1:
714 control |= (1 << (addr & 3)) << 5;
715 break;
716 case 2:
717 /* require 2-byte alignment */
718 if (!(addr & 1)) {
719 control |= (3 << (addr & 2)) << 5;
720 break;
721 }
722 /* FALL THROUGH */
723 case 4:
724 /* require 4-byte alignment */
725 if (!(addr & 3)) {
726 control |= 0xf << 5;
727 break;
728 }
729 /* FALL THROUGH */
730 default:
731 LOG_ERROR("unsupported {break,watch}point length/alignment");
732 return ERROR_INVALID_ARGUMENTS;
733 }
734
735 /* other shared control bits:
736 * bits 15:14 == 0 ... both secure and nonsecure states (v6.1+ only)
737 * bit 20 == 0 ... not linked to a context ID
738 * bit 28:24 == 0 ... not ignoring N LSBs (v7 only)
739 */
740
741 xp->address = addr & ~3;
742 xp->control = control;
743 xp->dirty = true;
744
745 LOG_DEBUG("BPWP: addr %8.8" PRIx32 ", control %" PRIx32 ", number %d",
746 xp->address, control, xp->number);
747
748 /* hardware is updated in write_dirty_registers() */
749 return ERROR_OK;
750 }
751
752 static int dpm_add_breakpoint(struct target *target, struct breakpoint *bp)
753 {
754 struct arm *arm = target_to_arm(target);
755 struct arm_dpm *dpm = arm->dpm;
756 int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
757
758 if (bp->length < 2)
759 return ERROR_INVALID_ARGUMENTS;
760 if (!dpm->bpwp_enable)
761 return retval;
762
763 /* FIXME we need a generic solution for software breakpoints. */
764 if (bp->type == BKPT_SOFT)
765 LOG_DEBUG("using HW bkpt, not SW...");
766
767 for (unsigned i = 0; i < dpm->nbp; i++) {
768 if (!dpm->dbp[i].bp) {
769 retval = dpm_bpwp_setup(dpm, &dpm->dbp[i].bpwp,
770 bp->address, bp->length);
771 if (retval == ERROR_OK)
772 dpm->dbp[i].bp = bp;
773 break;
774 }
775 }
776
777 return retval;
778 }
779
780 static int dpm_remove_breakpoint(struct target *target, struct breakpoint *bp)
781 {
782 struct arm *arm = target_to_arm(target);
783 struct arm_dpm *dpm = arm->dpm;
784 int retval = ERROR_INVALID_ARGUMENTS;
785
786 for (unsigned i = 0; i < dpm->nbp; i++) {
787 if (dpm->dbp[i].bp == bp) {
788 dpm->dbp[i].bp = NULL;
789 dpm->dbp[i].bpwp.dirty = true;
790
791 /* hardware is updated in write_dirty_registers() */
792 retval = ERROR_OK;
793 break;
794 }
795 }
796
797 return retval;
798 }
799
800 static int dpm_watchpoint_setup(struct arm_dpm *dpm, unsigned index_t,
801 struct watchpoint *wp)
802 {
803 int retval;
804 struct dpm_wp *dwp = dpm->dwp + index_t;
805 uint32_t control;
806
807 /* this hardware doesn't support data value matching or masking */
808 if (wp->value || wp->mask != ~(uint32_t)0) {
809 LOG_DEBUG("watchpoint values and masking not supported");
810 return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
811 }
812
813 retval = dpm_bpwp_setup(dpm, &dwp->bpwp, wp->address, wp->length);
814 if (retval != ERROR_OK)
815 return retval;
816
817 control = dwp->bpwp.control;
818 switch (wp->rw) {
819 case WPT_READ:
820 control |= 1 << 3;
821 break;
822 case WPT_WRITE:
823 control |= 2 << 3;
824 break;
825 case WPT_ACCESS:
826 control |= 3 << 3;
827 break;
828 }
829 dwp->bpwp.control = control;
830
831 dpm->dwp[index_t].wp = wp;
832
833 return retval;
834 }
835
836 static int dpm_add_watchpoint(struct target *target, struct watchpoint *wp)
837 {
838 struct arm *arm = target_to_arm(target);
839 struct arm_dpm *dpm = arm->dpm;
840 int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
841
842 if (dpm->bpwp_enable) {
843 for (unsigned i = 0; i < dpm->nwp; i++) {
844 if (!dpm->dwp[i].wp) {
845 retval = dpm_watchpoint_setup(dpm, i, wp);
846 break;
847 }
848 }
849 }
850
851 return retval;
852 }
853
854 static int dpm_remove_watchpoint(struct target *target, struct watchpoint *wp)
855 {
856 struct arm *arm = target_to_arm(target);
857 struct arm_dpm *dpm = arm->dpm;
858 int retval = ERROR_INVALID_ARGUMENTS;
859
860 for (unsigned i = 0; i < dpm->nwp; i++) {
861 if (dpm->dwp[i].wp == wp) {
862 dpm->dwp[i].wp = NULL;
863 dpm->dwp[i].bpwp.dirty = true;
864
865 /* hardware is updated in write_dirty_registers() */
866 retval = ERROR_OK;
867 break;
868 }
869 }
870
871 return retval;
872 }
873
874 void arm_dpm_report_wfar(struct arm_dpm *dpm, uint32_t addr)
875 {
876 switch (dpm->arm->core_state) {
877 case ARM_STATE_ARM:
878 addr -= 8;
879 break;
880 case ARM_STATE_THUMB:
881 case ARM_STATE_THUMB_EE:
882 addr -= 4;
883 break;
884 case ARM_STATE_JAZELLE:
885 /* ?? */
886 break;
887 }
888 dpm->wp_pc = addr;
889 }
890
891 /*----------------------------------------------------------------------*/
892
893 /*
894 * Other debug and support utilities
895 */
896
897 void arm_dpm_report_dscr(struct arm_dpm *dpm, uint32_t dscr)
898 {
899 struct target *target = dpm->arm->target;
900
901 dpm->dscr = dscr;
902
903 /* Examine debug reason */
904 switch (DSCR_ENTRY(dscr)) {
905 case 6: /* Data abort (v6 only) */
906 case 7: /* Prefetch abort (v6 only) */
907 /* FALL THROUGH -- assume a v6 core in abort mode */
908 case 0: /* HALT request from debugger */
909 case 4: /* EDBGRQ */
910 target->debug_reason = DBG_REASON_DBGRQ;
911 break;
912 case 1: /* HW breakpoint */
913 case 3: /* SW BKPT */
914 case 5: /* vector catch */
915 target->debug_reason = DBG_REASON_BREAKPOINT;
916 break;
917 case 2: /* asynch watchpoint */
918 case 10: /* precise watchpoint */
919 target->debug_reason = DBG_REASON_WATCHPOINT;
920 break;
921 default:
922 target->debug_reason = DBG_REASON_UNDEFINED;
923 break;
924 }
925 }
926
927 /*----------------------------------------------------------------------*/
928
929 /*
930 * Setup and management support.
931 */
932
933 /**
934 * Hooks up this DPM to its associated target; call only once.
935 * Initially this only covers the register cache.
936 *
937 * Oh, and watchpoints. Yeah.
938 */
939 int arm_dpm_setup(struct arm_dpm *dpm)
940 {
941 struct arm *arm = dpm->arm;
942 struct target *target = arm->target;
943 struct reg_cache *cache;
944
945 arm->dpm = dpm;
946
947 /* register access setup */
948 arm->full_context = arm_dpm_full_context;
949 arm->read_core_reg = arm_dpm_read_core_reg;
950 arm->write_core_reg = arm_dpm_write_core_reg;
951
952 cache = arm_build_reg_cache(target, arm);
953 if (!cache)
954 return ERROR_FAIL;
955
956 *register_get_last_cache_p(&target->reg_cache) = cache;
957
958 /* coprocessor access setup */
959 arm->mrc = dpm_mrc;
960 arm->mcr = dpm_mcr;
961
962 /* breakpoint setup -- optional until it works everywhere */
963 if (!target->type->add_breakpoint) {
964 target->type->add_breakpoint = dpm_add_breakpoint;
965 target->type->remove_breakpoint = dpm_remove_breakpoint;
966 }
967
968 /* watchpoint setup */
969 target->type->add_watchpoint = dpm_add_watchpoint;
970 target->type->remove_watchpoint = dpm_remove_watchpoint;
971
972 /* FIXME add vector catch support */
973
974 dpm->nbp = 1 + ((dpm->didr >> 24) & 0xf);
975 dpm->dbp = calloc(dpm->nbp, sizeof *dpm->dbp);
976
977 dpm->nwp = 1 + ((dpm->didr >> 28) & 0xf);
978 dpm->dwp = calloc(dpm->nwp, sizeof *dpm->dwp);
979
980 if (!dpm->dbp || !dpm->dwp) {
981 free(dpm->dbp);
982 free(dpm->dwp);
983 return ERROR_FAIL;
984 }
985
986 LOG_INFO("%s: hardware has %d breakpoints, %d watchpoints",
987 target_name(target), dpm->nbp, dpm->nwp);
988
989 /* REVISIT ... and some of those breakpoints could match
990 * execution context IDs...
991 */
992
993 return ERROR_OK;
994 }
995
996 /**
997 * Reinitializes DPM state at the beginning of a new debug session
998 * or after a reset which may have affected the debug module.
999 */
1000 int arm_dpm_initialize(struct arm_dpm *dpm)
1001 {
1002 /* Disable all breakpoints and watchpoints at startup. */
1003 if (dpm->bpwp_disable) {
1004 unsigned i;
1005
1006 for (i = 0; i < dpm->nbp; i++) {
1007 dpm->dbp[i].bpwp.number = i;
1008 (void) dpm->bpwp_disable(dpm, i);
1009 }
1010 for (i = 0; i < dpm->nwp; i++) {
1011 dpm->dwp[i].bpwp.number = 16 + i;
1012 (void) dpm->bpwp_disable(dpm, 16 + i);
1013 }
1014 } else
1015 LOG_WARNING("%s: can't disable breakpoints and watchpoints",
1016 target_name(dpm->arm->target));
1017
1018 return ERROR_OK;
1019 }
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