aarch64: introduce dpm extension for ARMv8
[openocd.git] / 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, see <http://www.gnu.org/licenses/>.
16 */
17
18 #ifdef HAVE_CONFIG_H
19 #include "config.h"
20 #endif
21
22 #include "arm.h"
23 #include "arm_dpm.h"
24 #include "armv8_dpm.h"
25 #include <jtag/jtag.h>
26 #include "register.h"
27 #include "breakpoints.h"
28 #include "target_type.h"
29 #include "arm_opcodes.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 * The "Debug Programmers' Model" (DPM) for ARMv6 and ARMv7 is defined by
39 * Part C (Debug Architecture) of the ARM Architecture Reference Manual,
40 * ARMv7-A and ARMv7-R edition (ARM DDI 0406B). In OpenOCD, DPM operations
41 * are abstracted through internal programming interfaces to share code and
42 * to minimize needless differences in debug behavior between cores.
43 */
44
45 /*----------------------------------------------------------------------*/
46
47 /*
48 * Coprocessor support
49 */
50
51 /* Read coprocessor */
52 static int dpm_mrc(struct target *target, int cpnum,
53 uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
54 uint32_t *value)
55 {
56 struct arm *arm = target_to_arm(target);
57 struct arm_dpm *dpm = arm->dpm;
58 int retval;
59
60 retval = dpm->prepare(dpm);
61 if (retval != ERROR_OK)
62 return retval;
63
64 LOG_DEBUG("MRC p%d, %d, r0, c%d, c%d, %d", cpnum,
65 (int) op1, (int) CRn,
66 (int) CRm, (int) op2);
67
68 /* read coprocessor register into R0; return via DCC */
69 retval = dpm->instr_read_data_r0(dpm,
70 ARMV4_5_MRC(cpnum, op1, 0, CRn, CRm, op2),
71 value);
72
73 /* (void) */ dpm->finish(dpm);
74 return retval;
75 }
76
77 static int dpm_mcr(struct target *target, int cpnum,
78 uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
79 uint32_t value)
80 {
81 struct arm *arm = target_to_arm(target);
82 struct arm_dpm *dpm = arm->dpm;
83 int retval;
84
85 retval = dpm->prepare(dpm);
86 if (retval != ERROR_OK)
87 return retval;
88
89 LOG_DEBUG("MCR p%d, %d, r0, c%d, c%d, %d", cpnum,
90 (int) op1, (int) CRn,
91 (int) CRm, (int) op2);
92
93 /* read DCC into r0; then write coprocessor register from R0 */
94 retval = dpm->instr_write_data_r0(dpm,
95 ARMV4_5_MCR(cpnum, op1, 0, CRn, CRm, op2),
96 value);
97
98 /* (void) */ dpm->finish(dpm);
99 return retval;
100 }
101
102 /*----------------------------------------------------------------------*/
103
104 /*
105 * Register access utilities
106 */
107
108 /* Toggles between recorded core mode (USR, SVC, etc) and a temporary one.
109 * Routines *must* restore the original mode before returning!!
110 */
111 int dpm_modeswitch(struct arm_dpm *dpm, enum arm_mode mode)
112 {
113 int retval;
114 uint32_t cpsr;
115
116 /* restore previous mode */
117 if (mode == ARM_MODE_ANY)
118 cpsr = buf_get_u32(dpm->arm->cpsr->value, 0, 32);
119
120 /* else force to the specified mode */
121 else
122 cpsr = mode;
123
124 retval = dpm->instr_write_data_r0(dpm, ARMV4_5_MSR_GP(0, 0xf, 0), cpsr);
125 if (retval != ERROR_OK)
126 return retval;
127
128 if (dpm->instr_cpsr_sync)
129 retval = dpm->instr_cpsr_sync(dpm);
130
131 return retval;
132 }
133
134 /* just read the register -- rely on the core mode being right */
135 static int dpm_read_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
136 {
137 uint32_t value;
138 int retval;
139
140 switch (regnum) {
141 case 0 ... 14:
142 /* return via DCC: "MCR p14, 0, Rnum, c0, c5, 0" */
143 retval = dpm->instr_read_data_dcc(dpm,
144 ARMV4_5_MCR(14, 0, regnum, 0, 5, 0),
145 &value);
146 break;
147 case 15:/* PC
148 * "MOV r0, pc"; then return via DCC */
149 retval = dpm->instr_read_data_r0(dpm, 0xe1a0000f, &value);
150
151 /* NOTE: this seems like a slightly awkward place to update
152 * this value ... but if the PC gets written (the only way
153 * to change what we compute), the arch spec says subsequent
154 * reads return values which are "unpredictable". So this
155 * is always right except in those broken-by-intent cases.
156 */
157 switch (dpm->arm->core_state) {
158 case ARM_STATE_ARM:
159 value -= 8;
160 break;
161 case ARM_STATE_THUMB:
162 case ARM_STATE_THUMB_EE:
163 value -= 4;
164 break;
165 case ARM_STATE_JAZELLE:
166 /* core-specific ... ? */
167 LOG_WARNING("Jazelle PC adjustment unknown");
168 break;
169 default:
170 LOG_WARNING("unknow core state");
171 break;
172 }
173 break;
174 default:
175 /* 16: "MRS r0, CPSR"; then return via DCC
176 * 17: "MRS r0, SPSR"; then return via DCC
177 */
178 retval = dpm->instr_read_data_r0(dpm,
179 ARMV4_5_MRS(0, regnum & 1),
180 &value);
181 break;
182 }
183
184 if (retval == ERROR_OK) {
185 buf_set_u32(r->value, 0, 32, value);
186 r->valid = true;
187 r->dirty = false;
188 LOG_DEBUG("READ: %s, %8.8x", r->name, (unsigned) value);
189 }
190
191 return retval;
192 }
193
194 /* just write the register -- rely on the core mode being right */
195 static int dpm_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
196 {
197 int retval;
198 uint32_t value = buf_get_u32(r->value, 0, 32);
199
200 switch (regnum) {
201 case 0 ... 14:
202 /* load register from DCC: "MRC p14, 0, Rnum, c0, c5, 0" */
203 retval = dpm->instr_write_data_dcc(dpm,
204 ARMV4_5_MRC(14, 0, regnum, 0, 5, 0),
205 value);
206 break;
207 case 15:/* PC
208 * read r0 from DCC; then "MOV pc, r0" */
209 retval = dpm->instr_write_data_r0(dpm, 0xe1a0f000, value);
210 break;
211 default:
212 /* 16: read r0 from DCC, then "MSR r0, CPSR_cxsf"
213 * 17: read r0 from DCC, then "MSR r0, SPSR_cxsf"
214 */
215 retval = dpm->instr_write_data_r0(dpm,
216 ARMV4_5_MSR_GP(0, 0xf, regnum & 1),
217 value);
218 if (retval != ERROR_OK)
219 return retval;
220
221 if (regnum == 16 && dpm->instr_cpsr_sync)
222 retval = dpm->instr_cpsr_sync(dpm);
223
224 break;
225 }
226
227 if (retval == ERROR_OK) {
228 r->dirty = false;
229 LOG_DEBUG("WRITE: %s, %8.8x", r->name, (unsigned) value);
230 }
231
232 return retval;
233 }
234
235 /**
236 * Write to program counter and switch the core state (arm/thumb) according to
237 * the address.
238 */
239 static int dpm_write_pc_core_state(struct arm_dpm *dpm, struct reg *r)
240 {
241 uint32_t value = buf_get_u32(r->value, 0, 32);
242
243 /* read r0 from DCC; then "BX r0" */
244 return dpm->instr_write_data_r0(dpm, ARMV4_5_BX(0), value);
245 }
246
247 /**
248 * Read basic registers of the the current context: R0 to R15, and CPSR;
249 * sets the core mode (such as USR or IRQ) and state (such as ARM or Thumb).
250 * In normal operation this is called on entry to halting debug state,
251 * possibly after some other operations supporting restore of debug state
252 * or making sure the CPU is fully idle (drain write buffer, etc).
253 */
254 int arm_dpm_read_current_registers(struct arm_dpm *dpm)
255 {
256 struct arm *arm = dpm->arm;
257 uint32_t cpsr;
258 int retval;
259 struct reg *r;
260
261 retval = dpm->prepare(dpm);
262 if (retval != ERROR_OK)
263 return retval;
264
265 /* read R0 first (it's used for scratch), then CPSR */
266 r = arm->core_cache->reg_list + 0;
267 if (!r->valid) {
268 retval = dpm_read_reg(dpm, r, 0);
269 if (retval != ERROR_OK)
270 goto fail;
271 }
272 r->dirty = true;
273
274 retval = dpm->instr_read_data_r0(dpm, ARMV4_5_MRS(0, 0), &cpsr);
275 if (retval != ERROR_OK)
276 goto fail;
277
278 /* update core mode and state, plus shadow mapping for R8..R14 */
279 arm_set_cpsr(arm, cpsr);
280
281 /* REVISIT we can probably avoid reading R1..R14, saving time... */
282 for (unsigned i = 1; i < 16; i++) {
283 r = arm_reg_current(arm, i);
284 if (r->valid)
285 continue;
286
287 retval = dpm_read_reg(dpm, r, i);
288 if (retval != ERROR_OK)
289 goto fail;
290 }
291
292 /* NOTE: SPSR ignored (if it's even relevant). */
293
294 /* REVISIT the debugger can trigger various exceptions. See the
295 * ARMv7A architecture spec, section C5.7, for more info about
296 * what defenses are needed; v6 debug has the most issues.
297 */
298
299 fail:
300 /* (void) */ dpm->finish(dpm);
301 return retval;
302 }
303
304 /* Avoid needless I/O ... leave breakpoints and watchpoints alone
305 * unless they're removed, or need updating because of single-stepping
306 * or running debugger code.
307 */
308 static int dpm_maybe_update_bpwp(struct arm_dpm *dpm, bool bpwp,
309 struct dpm_bpwp *xp, int *set_p)
310 {
311 int retval = ERROR_OK;
312 bool disable;
313
314 if (!set_p) {
315 if (!xp->dirty)
316 goto done;
317 xp->dirty = false;
318 /* removed or startup; we must disable it */
319 disable = true;
320 } else if (bpwp) {
321 if (!xp->dirty)
322 goto done;
323 /* disabled, but we must set it */
324 xp->dirty = disable = false;
325 *set_p = true;
326 } else {
327 if (!*set_p)
328 goto done;
329 /* set, but we must temporarily disable it */
330 xp->dirty = disable = true;
331 *set_p = false;
332 }
333
334 if (disable)
335 retval = dpm->bpwp_disable(dpm, xp->number);
336 else
337 retval = dpm->bpwp_enable(dpm, xp->number,
338 xp->address, xp->control);
339
340 if (retval != ERROR_OK)
341 LOG_ERROR("%s: can't %s HW %spoint %d",
342 disable ? "disable" : "enable",
343 target_name(dpm->arm->target),
344 (xp->number < 16) ? "break" : "watch",
345 xp->number & 0xf);
346 done:
347 return retval;
348 }
349
350 static int dpm_add_breakpoint(struct target *target, struct breakpoint *bp);
351
352 /**
353 * Writes all modified core registers for all processor modes. In normal
354 * operation this is called on exit from halting debug state.
355 *
356 * @param dpm: represents the processor
357 * @param bpwp: true ensures breakpoints and watchpoints are set,
358 * false ensures they are cleared
359 */
360 int arm_dpm_write_dirty_registers(struct arm_dpm *dpm, bool bpwp)
361 {
362 struct arm *arm = dpm->arm;
363 struct reg_cache *cache = arm->core_cache;
364 int retval;
365 bool did_write;
366
367 retval = dpm->prepare(dpm);
368 if (retval != ERROR_OK)
369 goto done;
370
371 /* If we're managing hardware breakpoints for this core, enable
372 * or disable them as requested.
373 *
374 * REVISIT We don't yet manage them for ANY cores. Eventually
375 * we should be able to assume we handle them; but until then,
376 * cope with the hand-crafted breakpoint code.
377 */
378 if (arm->target->type->add_breakpoint == dpm_add_breakpoint) {
379 for (unsigned i = 0; i < dpm->nbp; i++) {
380 struct dpm_bp *dbp = dpm->dbp + i;
381 struct breakpoint *bp = dbp->bp;
382
383 retval = dpm_maybe_update_bpwp(dpm, bpwp, &dbp->bpwp,
384 bp ? &bp->set : NULL);
385 if (retval != ERROR_OK)
386 goto done;
387 }
388 }
389
390 /* enable/disable watchpoints */
391 for (unsigned i = 0; i < dpm->nwp; i++) {
392 struct dpm_wp *dwp = dpm->dwp + i;
393 struct watchpoint *wp = dwp->wp;
394
395 retval = dpm_maybe_update_bpwp(dpm, bpwp, &dwp->bpwp,
396 wp ? &wp->set : NULL);
397 if (retval != ERROR_OK)
398 goto done;
399 }
400
401 /* NOTE: writes to breakpoint and watchpoint registers might
402 * be queued, and need (efficient/batched) flushing later.
403 */
404
405 /* Scan the registers until we find one that's both dirty and
406 * eligible for flushing. Flush that and everything else that
407 * shares the same core mode setting. Typically this won't
408 * actually find anything to do...
409 */
410 do {
411 enum arm_mode mode = ARM_MODE_ANY;
412
413 did_write = false;
414
415 /* check everything except our scratch register R0 */
416 for (unsigned i = 1; i < cache->num_regs; i++) {
417 struct arm_reg *r;
418 unsigned regnum;
419
420 /* also skip PC, CPSR, and non-dirty */
421 if (i == 15)
422 continue;
423 if (arm->cpsr == cache->reg_list + i)
424 continue;
425 if (!cache->reg_list[i].dirty)
426 continue;
427
428 r = cache->reg_list[i].arch_info;
429 regnum = r->num;
430
431 /* may need to pick and set a mode */
432 if (!did_write) {
433 enum arm_mode tmode;
434
435 did_write = true;
436 mode = tmode = r->mode;
437
438 /* cope with special cases */
439 switch (regnum) {
440 case 8 ... 12:
441 /* r8..r12 "anything but FIQ" case;
442 * we "know" core mode is accurate
443 * since we haven't changed it yet
444 */
445 if (arm->core_mode == ARM_MODE_FIQ
446 && ARM_MODE_ANY
447 != mode)
448 tmode = ARM_MODE_USR;
449 break;
450 case 16:
451 /* SPSR */
452 regnum++;
453 break;
454 }
455
456 /* REVISIT error checks */
457 if (tmode != ARM_MODE_ANY) {
458 retval = dpm_modeswitch(dpm, tmode);
459 if (retval != ERROR_OK)
460 goto done;
461 }
462 }
463 if (r->mode != mode)
464 continue;
465
466 retval = dpm_write_reg(dpm,
467 &cache->reg_list[i],
468 regnum);
469 if (retval != ERROR_OK)
470 goto done;
471 }
472
473 } while (did_write);
474
475 /* Restore original CPSR ... assuming either that we changed it,
476 * or it's dirty. Must write PC to ensure the return address is
477 * defined, and must not write it before CPSR.
478 */
479 retval = dpm_modeswitch(dpm, ARM_MODE_ANY);
480 if (retval != ERROR_OK)
481 goto done;
482 arm->cpsr->dirty = false;
483
484 /* restore the PC, make sure to also switch the core state
485 * to whatever it was set to with "arm core_state" command.
486 * target code will have set PC to an appropriate resume address.
487 */
488 retval = dpm_write_pc_core_state(dpm, arm->pc);
489 if (retval != ERROR_OK)
490 goto done;
491 /* on Cortex-A5 (as found on NXP VF610 SoC), BX instruction
492 * executed in debug state doesn't appear to set the PC,
493 * explicitly set it with a "MOV pc, r0". This doesn't influence
494 * CPSR on Cortex-A9 so it should be OK. Maybe due to different
495 * debug version?
496 */
497 retval = dpm_write_reg(dpm, arm->pc, 15);
498 if (retval != ERROR_OK)
499 goto done;
500 arm->pc->dirty = false;
501
502 /* flush R0 -- it's *very* dirty by now */
503 retval = dpm_write_reg(dpm, &cache->reg_list[0], 0);
504 if (retval != ERROR_OK)
505 goto done;
506 cache->reg_list[0].dirty = false;
507
508 /* (void) */ dpm->finish(dpm);
509 done:
510 return retval;
511 }
512
513 /* Returns ARM_MODE_ANY or temporary mode to use while reading the
514 * specified register ... works around flakiness from ARM core calls.
515 * Caller already filtered out SPSR access; mode is never MODE_SYS
516 * or MODE_ANY.
517 */
518 static enum arm_mode dpm_mapmode(struct arm *arm,
519 unsigned num, enum arm_mode mode)
520 {
521 enum arm_mode amode = arm->core_mode;
522
523 /* don't switch if the mode is already correct */
524 if (amode == ARM_MODE_SYS)
525 amode = ARM_MODE_USR;
526 if (mode == amode)
527 return ARM_MODE_ANY;
528
529 switch (num) {
530 /* don't switch for non-shadowed registers (r0..r7, r15/pc, cpsr) */
531 case 0 ... 7:
532 case 15:
533 case 16:
534 break;
535 /* r8..r12 aren't shadowed for anything except FIQ */
536 case 8 ... 12:
537 if (mode == ARM_MODE_FIQ)
538 return mode;
539 break;
540 /* r13/sp, and r14/lr are always shadowed */
541 case 13:
542 case 14:
543 return mode;
544 default:
545 LOG_WARNING("invalid register #%u", num);
546 break;
547 }
548 return ARM_MODE_ANY;
549 }
550
551
552 /*
553 * Standard ARM register accessors ... there are three methods
554 * in "struct arm", to support individual read/write and bulk read
555 * of registers.
556 */
557
558 static int arm_dpm_read_core_reg(struct target *target, struct reg *r,
559 int regnum, enum arm_mode mode)
560 {
561 struct arm_dpm *dpm = target_to_arm(target)->dpm;
562 int retval;
563
564 if (regnum < 0 || regnum > 16)
565 return ERROR_COMMAND_SYNTAX_ERROR;
566
567 if (regnum == 16) {
568 if (mode != ARM_MODE_ANY)
569 regnum = 17;
570 } else
571 mode = dpm_mapmode(dpm->arm, regnum, mode);
572
573 /* REVISIT what happens if we try to read SPSR in a core mode
574 * which has no such register?
575 */
576
577 retval = dpm->prepare(dpm);
578 if (retval != ERROR_OK)
579 return retval;
580
581 if (mode != ARM_MODE_ANY) {
582 retval = dpm_modeswitch(dpm, mode);
583 if (retval != ERROR_OK)
584 goto fail;
585 }
586
587 retval = dpm_read_reg(dpm, r, regnum);
588 if (retval != ERROR_OK)
589 goto fail;
590 /* always clean up, regardless of error */
591
592 if (mode != ARM_MODE_ANY)
593 /* (void) */ dpm_modeswitch(dpm, ARM_MODE_ANY);
594
595 fail:
596 /* (void) */ dpm->finish(dpm);
597 return retval;
598 }
599
600 static int arm_dpm_write_core_reg(struct target *target, struct reg *r,
601 int regnum, enum arm_mode mode, uint8_t *value)
602 {
603 struct arm_dpm *dpm = target_to_arm(target)->dpm;
604 int retval;
605
606
607 if (regnum < 0 || regnum > 16)
608 return ERROR_COMMAND_SYNTAX_ERROR;
609
610 if (regnum == 16) {
611 if (mode != ARM_MODE_ANY)
612 regnum = 17;
613 } else
614 mode = dpm_mapmode(dpm->arm, regnum, mode);
615
616 /* REVISIT what happens if we try to write SPSR in a core mode
617 * which has no such register?
618 */
619
620 retval = dpm->prepare(dpm);
621 if (retval != ERROR_OK)
622 return retval;
623
624 if (mode != ARM_MODE_ANY) {
625 retval = dpm_modeswitch(dpm, mode);
626 if (retval != ERROR_OK)
627 goto fail;
628 }
629
630 retval = dpm_write_reg(dpm, r, regnum);
631 /* always clean up, regardless of error */
632
633 if (mode != ARM_MODE_ANY)
634 /* (void) */ dpm_modeswitch(dpm, ARM_MODE_ANY);
635
636 fail:
637 /* (void) */ dpm->finish(dpm);
638 return retval;
639 }
640
641 static int arm_dpm_full_context(struct target *target)
642 {
643 struct arm *arm = target_to_arm(target);
644 struct arm_dpm *dpm = arm->dpm;
645 struct reg_cache *cache = arm->core_cache;
646 int retval;
647 bool did_read;
648
649 retval = dpm->prepare(dpm);
650 if (retval != ERROR_OK)
651 goto done;
652
653 do {
654 enum arm_mode mode = ARM_MODE_ANY;
655
656 did_read = false;
657
658 /* We "know" arm_dpm_read_current_registers() was called so
659 * the unmapped registers (R0..R7, PC, AND CPSR) and some
660 * view of R8..R14 are current. We also "know" oddities of
661 * register mapping: special cases for R8..R12 and SPSR.
662 *
663 * Pick some mode with unread registers and read them all.
664 * Repeat until done.
665 */
666 for (unsigned i = 0; i < cache->num_regs; i++) {
667 struct arm_reg *r;
668
669 if (cache->reg_list[i].valid)
670 continue;
671 r = cache->reg_list[i].arch_info;
672
673 /* may need to pick a mode and set CPSR */
674 if (!did_read) {
675 did_read = true;
676 mode = r->mode;
677
678 /* For regular (ARM_MODE_ANY) R8..R12
679 * in case we've entered debug state
680 * in FIQ mode we need to patch mode.
681 */
682 if (mode != ARM_MODE_ANY)
683 retval = dpm_modeswitch(dpm, mode);
684 else
685 retval = dpm_modeswitch(dpm, ARM_MODE_USR);
686
687 if (retval != ERROR_OK)
688 goto done;
689 }
690 if (r->mode != mode)
691 continue;
692
693 /* CPSR was read, so "R16" must mean SPSR */
694 retval = dpm_read_reg(dpm,
695 &cache->reg_list[i],
696 (r->num == 16) ? 17 : r->num);
697 if (retval != ERROR_OK)
698 goto done;
699 }
700
701 } while (did_read);
702
703 retval = dpm_modeswitch(dpm, ARM_MODE_ANY);
704 /* (void) */ dpm->finish(dpm);
705 done:
706 return retval;
707 }
708
709
710 /*----------------------------------------------------------------------*/
711
712 /*
713 * Breakpoint and Watchpoint support.
714 *
715 * Hardware {break,watch}points are usually left active, to minimize
716 * debug entry/exit costs. When they are set or cleared, it's done in
717 * batches. Also, DPM-conformant hardware can update debug registers
718 * regardless of whether the CPU is running or halted ... though that
719 * fact isn't currently leveraged.
720 */
721
722 static int dpm_bpwp_setup(struct arm_dpm *dpm, struct dpm_bpwp *xp,
723 uint32_t addr, uint32_t length)
724 {
725 uint32_t control;
726
727 control = (1 << 0) /* enable */
728 | (3 << 1); /* both user and privileged access */
729
730 /* Match 1, 2, or all 4 byte addresses in this word.
731 *
732 * FIXME: v7 hardware allows lengths up to 2 GB for BP and WP.
733 * Support larger length, when addr is suitably aligned. In
734 * particular, allow watchpoints on 8 byte "double" values.
735 *
736 * REVISIT allow watchpoints on unaligned 2-bit values; and on
737 * v7 hardware, unaligned 4-byte ones too.
738 */
739 switch (length) {
740 case 1:
741 control |= (1 << (addr & 3)) << 5;
742 break;
743 case 2:
744 /* require 2-byte alignment */
745 if (!(addr & 1)) {
746 control |= (3 << (addr & 2)) << 5;
747 break;
748 }
749 /* FALL THROUGH */
750 case 4:
751 /* require 4-byte alignment */
752 if (!(addr & 3)) {
753 control |= 0xf << 5;
754 break;
755 }
756 /* FALL THROUGH */
757 default:
758 LOG_ERROR("unsupported {break,watch}point length/alignment");
759 return ERROR_COMMAND_SYNTAX_ERROR;
760 }
761
762 /* other shared control bits:
763 * bits 15:14 == 0 ... both secure and nonsecure states (v6.1+ only)
764 * bit 20 == 0 ... not linked to a context ID
765 * bit 28:24 == 0 ... not ignoring N LSBs (v7 only)
766 */
767
768 xp->address = addr & ~3;
769 xp->control = control;
770 xp->dirty = true;
771
772 LOG_DEBUG("BPWP: addr %8.8" PRIx32 ", control %" PRIx32 ", number %d",
773 xp->address, control, xp->number);
774
775 /* hardware is updated in write_dirty_registers() */
776 return ERROR_OK;
777 }
778
779 static int dpm_add_breakpoint(struct target *target, struct breakpoint *bp)
780 {
781 struct arm *arm = target_to_arm(target);
782 struct arm_dpm *dpm = arm->dpm;
783 int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
784
785 if (bp->length < 2)
786 return ERROR_COMMAND_SYNTAX_ERROR;
787 if (!dpm->bpwp_enable)
788 return retval;
789
790 /* FIXME we need a generic solution for software breakpoints. */
791 if (bp->type == BKPT_SOFT)
792 LOG_DEBUG("using HW bkpt, not SW...");
793
794 for (unsigned i = 0; i < dpm->nbp; i++) {
795 if (!dpm->dbp[i].bp) {
796 retval = dpm_bpwp_setup(dpm, &dpm->dbp[i].bpwp,
797 bp->address, bp->length);
798 if (retval == ERROR_OK)
799 dpm->dbp[i].bp = bp;
800 break;
801 }
802 }
803
804 return retval;
805 }
806
807 static int dpm_remove_breakpoint(struct target *target, struct breakpoint *bp)
808 {
809 struct arm *arm = target_to_arm(target);
810 struct arm_dpm *dpm = arm->dpm;
811 int retval = ERROR_COMMAND_SYNTAX_ERROR;
812
813 for (unsigned i = 0; i < dpm->nbp; i++) {
814 if (dpm->dbp[i].bp == bp) {
815 dpm->dbp[i].bp = NULL;
816 dpm->dbp[i].bpwp.dirty = true;
817
818 /* hardware is updated in write_dirty_registers() */
819 retval = ERROR_OK;
820 break;
821 }
822 }
823
824 return retval;
825 }
826
827 static int dpm_watchpoint_setup(struct arm_dpm *dpm, unsigned index_t,
828 struct watchpoint *wp)
829 {
830 int retval;
831 struct dpm_wp *dwp = dpm->dwp + index_t;
832 uint32_t control;
833
834 /* this hardware doesn't support data value matching or masking */
835 if (wp->value || wp->mask != ~(uint32_t)0) {
836 LOG_DEBUG("watchpoint values and masking not supported");
837 return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
838 }
839
840 retval = dpm_bpwp_setup(dpm, &dwp->bpwp, wp->address, wp->length);
841 if (retval != ERROR_OK)
842 return retval;
843
844 control = dwp->bpwp.control;
845 switch (wp->rw) {
846 case WPT_READ:
847 control |= 1 << 3;
848 break;
849 case WPT_WRITE:
850 control |= 2 << 3;
851 break;
852 case WPT_ACCESS:
853 control |= 3 << 3;
854 break;
855 }
856 dwp->bpwp.control = control;
857
858 dpm->dwp[index_t].wp = wp;
859
860 return retval;
861 }
862
863 static int dpm_add_watchpoint(struct target *target, struct watchpoint *wp)
864 {
865 struct arm *arm = target_to_arm(target);
866 struct arm_dpm *dpm = arm->dpm;
867 int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
868
869 if (dpm->bpwp_enable) {
870 for (unsigned i = 0; i < dpm->nwp; i++) {
871 if (!dpm->dwp[i].wp) {
872 retval = dpm_watchpoint_setup(dpm, i, wp);
873 break;
874 }
875 }
876 }
877
878 return retval;
879 }
880
881 static int dpm_remove_watchpoint(struct target *target, struct watchpoint *wp)
882 {
883 struct arm *arm = target_to_arm(target);
884 struct arm_dpm *dpm = arm->dpm;
885 int retval = ERROR_COMMAND_SYNTAX_ERROR;
886
887 for (unsigned i = 0; i < dpm->nwp; i++) {
888 if (dpm->dwp[i].wp == wp) {
889 dpm->dwp[i].wp = NULL;
890 dpm->dwp[i].bpwp.dirty = true;
891
892 /* hardware is updated in write_dirty_registers() */
893 retval = ERROR_OK;
894 break;
895 }
896 }
897
898 return retval;
899 }
900
901 void arm_dpm_report_wfar(struct arm_dpm *dpm, uint32_t addr)
902 {
903 switch (dpm->arm->core_state) {
904 case ARM_STATE_ARM:
905 addr -= 8;
906 break;
907 case ARM_STATE_THUMB:
908 case ARM_STATE_THUMB_EE:
909 addr -= 4;
910 break;
911 case ARM_STATE_JAZELLE:
912 case ARM_STATE_AARCH64:
913 /* ?? */
914 break;
915 }
916 dpm->wp_pc = addr;
917 }
918
919 /*----------------------------------------------------------------------*/
920
921 /*
922 * Other debug and support utilities
923 */
924
925 void arm_dpm_report_dscr(struct arm_dpm *dpm, uint32_t dscr)
926 {
927 struct target *target = dpm->arm->target;
928
929 dpm->dscr = dscr;
930
931 /* Examine debug reason */
932 switch (DSCR_ENTRY(dscr)) {
933 case 6: /* Data abort (v6 only) */
934 case 7: /* Prefetch abort (v6 only) */
935 /* FALL THROUGH -- assume a v6 core in abort mode */
936 case 0: /* HALT request from debugger */
937 case 4: /* EDBGRQ */
938 target->debug_reason = DBG_REASON_DBGRQ;
939 break;
940 case 1: /* HW breakpoint */
941 case 3: /* SW BKPT */
942 case 5: /* vector catch */
943 target->debug_reason = DBG_REASON_BREAKPOINT;
944 break;
945 case 2: /* asynch watchpoint */
946 case 10:/* precise watchpoint */
947 target->debug_reason = DBG_REASON_WATCHPOINT;
948 break;
949 default:
950 target->debug_reason = DBG_REASON_UNDEFINED;
951 break;
952 }
953 }
954
955 /*----------------------------------------------------------------------*/
956
957 /*
958 * Setup and management support.
959 */
960
961 /**
962 * Hooks up this DPM to its associated target; call only once.
963 * Initially this only covers the register cache.
964 *
965 * Oh, and watchpoints. Yeah.
966 */
967 int arm_dpm_setup(struct arm_dpm *dpm)
968 {
969 struct arm *arm = dpm->arm;
970 struct target *target = arm->target;
971 struct reg_cache *cache = 0;
972
973 arm->dpm = dpm;
974
975 /* register access setup */
976 arm->full_context = arm_dpm_full_context;
977 arm->read_core_reg = arm_dpm_read_core_reg;
978 arm->write_core_reg = arm_dpm_write_core_reg;
979
980 if (arm->core_cache != NULL) {
981 cache = arm_build_reg_cache(target, arm);
982 if (!cache)
983 return ERROR_FAIL;
984
985 *register_get_last_cache_p(&target->reg_cache) = cache;
986 }
987
988 /* coprocessor access setup */
989 arm->mrc = dpm_mrc;
990 arm->mcr = dpm_mcr;
991
992 /* breakpoint setup -- optional until it works everywhere */
993 if (!target->type->add_breakpoint) {
994 target->type->add_breakpoint = dpm_add_breakpoint;
995 target->type->remove_breakpoint = dpm_remove_breakpoint;
996 }
997
998 /* watchpoint setup */
999 target->type->add_watchpoint = dpm_add_watchpoint;
1000 target->type->remove_watchpoint = dpm_remove_watchpoint;
1001
1002 /* FIXME add vector catch support */
1003
1004 dpm->nbp = 1 + ((dpm->didr >> 24) & 0xf);
1005 dpm->nwp = 1 + ((dpm->didr >> 28) & 0xf);
1006 dpm->dbp = calloc(dpm->nbp, sizeof *dpm->dbp);
1007 dpm->dwp = calloc(dpm->nwp, sizeof *dpm->dwp);
1008
1009 if (!dpm->dbp || !dpm->dwp) {
1010 free(dpm->dbp);
1011 free(dpm->dwp);
1012 return ERROR_FAIL;
1013 }
1014
1015 LOG_INFO("%s: hardware has %d breakpoints, %d watchpoints",
1016 target_name(target), dpm->nbp, dpm->nwp);
1017
1018 /* REVISIT ... and some of those breakpoints could match
1019 * execution context IDs...
1020 */
1021
1022 return ERROR_OK;
1023 }
1024
1025 /**
1026 * Reinitializes DPM state at the beginning of a new debug session
1027 * or after a reset which may have affected the debug module.
1028 */
1029 int arm_dpm_initialize(struct arm_dpm *dpm)
1030 {
1031 /* Disable all breakpoints and watchpoints at startup. */
1032 if (dpm->bpwp_disable) {
1033 unsigned i;
1034
1035 for (i = 0; i < dpm->nbp; i++) {
1036 dpm->dbp[i].bpwp.number = i;
1037 (void) dpm->bpwp_disable(dpm, i);
1038 }
1039 for (i = 0; i < dpm->nwp; i++) {
1040 dpm->dwp[i].bpwp.number = 16 + i;
1041 (void) dpm->bpwp_disable(dpm, 16 + i);
1042 }
1043 } else
1044 LOG_WARNING("%s: can't disable breakpoints and watchpoints",
1045 target_name(dpm->arm->target));
1046
1047 return ERROR_OK;
1048 }