xref: /openbmc/qemu/target/riscv/debug.c (revision 954a6c4f)
1 /*
2  * QEMU RISC-V Native Debug Support
3  *
4  * Copyright (c) 2022 Wind River Systems, Inc.
5  *
6  * Author:
7  *   Bin Meng <bin.meng@windriver.com>
8  *
9  * This provides the native debug support via the Trigger Module, as defined
10  * in the RISC-V Debug Specification:
11  * https://github.com/riscv/riscv-debug-spec/raw/master/riscv-debug-stable.pdf
12  *
13  * This program is free software; you can redistribute it and/or modify it
14  * under the terms and conditions of the GNU General Public License,
15  * version 2 or later, as published by the Free Software Foundation.
16  *
17  * This program is distributed in the hope it will be useful, but WITHOUT
18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
20  * more details.
21  *
22  * You should have received a copy of the GNU General Public License along with
23  * this program.  If not, see <http://www.gnu.org/licenses/>.
24  */
25 
26 #include "qemu/osdep.h"
27 #include "qemu/log.h"
28 #include "qapi/error.h"
29 #include "cpu.h"
30 #include "trace.h"
31 #include "exec/exec-all.h"
32 
33 /*
34  * The following M-mode trigger CSRs are implemented:
35  *
36  * - tselect
37  * - tdata1
38  * - tdata2
39  * - tdata3
40  * - tinfo
41  *
42  * The following triggers are initialized by default:
43  *
44  * Index | Type |          tdata mapping | Description
45  * ------+------+------------------------+------------
46  *     0 |    2 |         tdata1, tdata2 | Address / Data Match
47  *     1 |    2 |         tdata1, tdata2 | Address / Data Match
48  */
49 
50 /* tdata availability of a trigger */
51 typedef bool tdata_avail[TDATA_NUM];
52 
53 static tdata_avail tdata_mapping[TRIGGER_TYPE_NUM] = {
54     [TRIGGER_TYPE_NO_EXIST] = { false, false, false },
55     [TRIGGER_TYPE_AD_MATCH] = { true, true, true },
56     [TRIGGER_TYPE_INST_CNT] = { true, false, true },
57     [TRIGGER_TYPE_INT] = { true, true, true },
58     [TRIGGER_TYPE_EXCP] = { true, true, true },
59     [TRIGGER_TYPE_AD_MATCH6] = { true, true, true },
60     [TRIGGER_TYPE_EXT_SRC] = { true, false, false },
61     [TRIGGER_TYPE_UNAVAIL] = { true, true, true }
62 };
63 
64 /* only breakpoint size 1/2/4/8 supported */
65 static int access_size[SIZE_NUM] = {
66     [SIZE_ANY] = 0,
67     [SIZE_1B]  = 1,
68     [SIZE_2B]  = 2,
69     [SIZE_4B]  = 4,
70     [SIZE_6B]  = -1,
71     [SIZE_8B]  = 8,
72     [6 ... 15] = -1,
73 };
74 
75 static inline target_ulong extract_trigger_type(CPURISCVState *env,
76                                                 target_ulong tdata1)
77 {
78     switch (riscv_cpu_mxl(env)) {
79     case MXL_RV32:
80         return extract32(tdata1, 28, 4);
81     case MXL_RV64:
82     case MXL_RV128:
83         return extract64(tdata1, 60, 4);
84     default:
85         g_assert_not_reached();
86     }
87 }
88 
89 static inline target_ulong get_trigger_type(CPURISCVState *env,
90                                             target_ulong trigger_index)
91 {
92     return extract_trigger_type(env, env->tdata1[trigger_index]);
93 }
94 
95 static trigger_action_t get_trigger_action(CPURISCVState *env,
96                                            target_ulong trigger_index)
97 {
98     target_ulong tdata1 = env->tdata1[trigger_index];
99     int trigger_type = get_trigger_type(env, trigger_index);
100     trigger_action_t action = DBG_ACTION_NONE;
101 
102     switch (trigger_type) {
103     case TRIGGER_TYPE_AD_MATCH:
104         action = (tdata1 & TYPE2_ACTION) >> 12;
105         break;
106     case TRIGGER_TYPE_AD_MATCH6:
107         action = (tdata1 & TYPE6_ACTION) >> 12;
108         break;
109     case TRIGGER_TYPE_INST_CNT:
110     case TRIGGER_TYPE_INT:
111     case TRIGGER_TYPE_EXCP:
112     case TRIGGER_TYPE_EXT_SRC:
113         qemu_log_mask(LOG_UNIMP, "trigger type: %d is not supported\n",
114                       trigger_type);
115         break;
116     case TRIGGER_TYPE_NO_EXIST:
117     case TRIGGER_TYPE_UNAVAIL:
118         qemu_log_mask(LOG_GUEST_ERROR, "trigger type: %d does not exit\n",
119                       trigger_type);
120         break;
121     default:
122         g_assert_not_reached();
123     }
124 
125     return action;
126 }
127 
128 static inline target_ulong build_tdata1(CPURISCVState *env,
129                                         trigger_type_t type,
130                                         bool dmode, target_ulong data)
131 {
132     target_ulong tdata1;
133 
134     switch (riscv_cpu_mxl(env)) {
135     case MXL_RV32:
136         tdata1 = RV32_TYPE(type) |
137                  (dmode ? RV32_DMODE : 0) |
138                  (data & RV32_DATA_MASK);
139         break;
140     case MXL_RV64:
141     case MXL_RV128:
142         tdata1 = RV64_TYPE(type) |
143                  (dmode ? RV64_DMODE : 0) |
144                  (data & RV64_DATA_MASK);
145         break;
146     default:
147         g_assert_not_reached();
148     }
149 
150     return tdata1;
151 }
152 
153 bool tdata_available(CPURISCVState *env, int tdata_index)
154 {
155     int trigger_type = get_trigger_type(env, env->trigger_cur);
156 
157     if (unlikely(tdata_index >= TDATA_NUM)) {
158         return false;
159     }
160 
161     return tdata_mapping[trigger_type][tdata_index];
162 }
163 
164 target_ulong tselect_csr_read(CPURISCVState *env)
165 {
166     return env->trigger_cur;
167 }
168 
169 void tselect_csr_write(CPURISCVState *env, target_ulong val)
170 {
171     if (val < RV_MAX_TRIGGERS) {
172         env->trigger_cur = val;
173     }
174 }
175 
176 static target_ulong tdata1_validate(CPURISCVState *env, target_ulong val,
177                                     trigger_type_t t)
178 {
179     uint32_t type, dmode;
180     target_ulong tdata1;
181 
182     switch (riscv_cpu_mxl(env)) {
183     case MXL_RV32:
184         type = extract32(val, 28, 4);
185         dmode = extract32(val, 27, 1);
186         tdata1 = RV32_TYPE(t);
187         break;
188     case MXL_RV64:
189     case MXL_RV128:
190         type = extract64(val, 60, 4);
191         dmode = extract64(val, 59, 1);
192         tdata1 = RV64_TYPE(t);
193         break;
194     default:
195         g_assert_not_reached();
196     }
197 
198     if (type != t) {
199         qemu_log_mask(LOG_GUEST_ERROR,
200                       "ignoring type write to tdata1 register\n");
201     }
202 
203     if (dmode != 0) {
204         qemu_log_mask(LOG_UNIMP, "debug mode is not supported\n");
205     }
206 
207     return tdata1;
208 }
209 
210 static inline void warn_always_zero_bit(target_ulong val, target_ulong mask,
211                                         const char *msg)
212 {
213     if (val & mask) {
214         qemu_log_mask(LOG_UNIMP, "%s bit is always zero\n", msg);
215     }
216 }
217 
218 static void do_trigger_action(CPURISCVState *env, target_ulong trigger_index)
219 {
220     trigger_action_t action = get_trigger_action(env, trigger_index);
221 
222     switch (action) {
223     case DBG_ACTION_NONE:
224         break;
225     case DBG_ACTION_BP:
226         riscv_raise_exception(env, RISCV_EXCP_BREAKPOINT, 0);
227         break;
228     case DBG_ACTION_DBG_MODE:
229     case DBG_ACTION_TRACE0:
230     case DBG_ACTION_TRACE1:
231     case DBG_ACTION_TRACE2:
232     case DBG_ACTION_TRACE3:
233     case DBG_ACTION_EXT_DBG0:
234     case DBG_ACTION_EXT_DBG1:
235         qemu_log_mask(LOG_UNIMP, "action: %d is not supported\n", action);
236         break;
237     default:
238         g_assert_not_reached();
239     }
240 }
241 
242 /* type 2 trigger */
243 
244 static uint32_t type2_breakpoint_size(CPURISCVState *env, target_ulong ctrl)
245 {
246     uint32_t sizelo, sizehi = 0;
247 
248     if (riscv_cpu_mxl(env) == MXL_RV64) {
249         sizehi = extract32(ctrl, 21, 2);
250     }
251     sizelo = extract32(ctrl, 16, 2);
252     return (sizehi << 2) | sizelo;
253 }
254 
255 static inline bool type2_breakpoint_enabled(target_ulong ctrl)
256 {
257     bool mode = !!(ctrl & (TYPE2_U | TYPE2_S | TYPE2_M));
258     bool rwx = !!(ctrl & (TYPE2_LOAD | TYPE2_STORE | TYPE2_EXEC));
259 
260     return mode && rwx;
261 }
262 
263 static target_ulong type2_mcontrol_validate(CPURISCVState *env,
264                                             target_ulong ctrl)
265 {
266     target_ulong val;
267     uint32_t size;
268 
269     /* validate the generic part first */
270     val = tdata1_validate(env, ctrl, TRIGGER_TYPE_AD_MATCH);
271 
272     /* validate unimplemented (always zero) bits */
273     warn_always_zero_bit(ctrl, TYPE2_MATCH, "match");
274     warn_always_zero_bit(ctrl, TYPE2_CHAIN, "chain");
275     warn_always_zero_bit(ctrl, TYPE2_ACTION, "action");
276     warn_always_zero_bit(ctrl, TYPE2_TIMING, "timing");
277     warn_always_zero_bit(ctrl, TYPE2_SELECT, "select");
278     warn_always_zero_bit(ctrl, TYPE2_HIT, "hit");
279 
280     /* validate size encoding */
281     size = type2_breakpoint_size(env, ctrl);
282     if (access_size[size] == -1) {
283         qemu_log_mask(LOG_UNIMP, "access size %d is not supported, using SIZE_ANY\n",
284                       size);
285     } else {
286         val |= (ctrl & TYPE2_SIZELO);
287         if (riscv_cpu_mxl(env) == MXL_RV64) {
288             val |= (ctrl & TYPE2_SIZEHI);
289         }
290     }
291 
292     /* keep the mode and attribute bits */
293     val |= (ctrl & (TYPE2_U | TYPE2_S | TYPE2_M |
294                     TYPE2_LOAD | TYPE2_STORE | TYPE2_EXEC));
295 
296     return val;
297 }
298 
299 static void type2_breakpoint_insert(CPURISCVState *env, target_ulong index)
300 {
301     target_ulong ctrl = env->tdata1[index];
302     target_ulong addr = env->tdata2[index];
303     bool enabled = type2_breakpoint_enabled(ctrl);
304     CPUState *cs = env_cpu(env);
305     int flags = BP_CPU | BP_STOP_BEFORE_ACCESS;
306     uint32_t size;
307 
308     if (!enabled) {
309         return;
310     }
311 
312     if (ctrl & TYPE2_EXEC) {
313         cpu_breakpoint_insert(cs, addr, flags, &env->cpu_breakpoint[index]);
314     }
315 
316     if (ctrl & TYPE2_LOAD) {
317         flags |= BP_MEM_READ;
318     }
319     if (ctrl & TYPE2_STORE) {
320         flags |= BP_MEM_WRITE;
321     }
322 
323     if (flags & BP_MEM_ACCESS) {
324         size = type2_breakpoint_size(env, ctrl);
325         if (size != 0) {
326             cpu_watchpoint_insert(cs, addr, size, flags,
327                                   &env->cpu_watchpoint[index]);
328         } else {
329             cpu_watchpoint_insert(cs, addr, 8, flags,
330                                   &env->cpu_watchpoint[index]);
331         }
332     }
333 }
334 
335 static void type2_breakpoint_remove(CPURISCVState *env, target_ulong index)
336 {
337     CPUState *cs = env_cpu(env);
338 
339     if (env->cpu_breakpoint[index]) {
340         cpu_breakpoint_remove_by_ref(cs, env->cpu_breakpoint[index]);
341         env->cpu_breakpoint[index] = NULL;
342     }
343 
344     if (env->cpu_watchpoint[index]) {
345         cpu_watchpoint_remove_by_ref(cs, env->cpu_watchpoint[index]);
346         env->cpu_watchpoint[index] = NULL;
347     }
348 }
349 
350 static void type2_reg_write(CPURISCVState *env, target_ulong index,
351                             int tdata_index, target_ulong val)
352 {
353     target_ulong new_val;
354 
355     switch (tdata_index) {
356     case TDATA1:
357         new_val = type2_mcontrol_validate(env, val);
358         if (new_val != env->tdata1[index]) {
359             env->tdata1[index] = new_val;
360             type2_breakpoint_remove(env, index);
361             type2_breakpoint_insert(env, index);
362         }
363         break;
364     case TDATA2:
365         if (val != env->tdata2[index]) {
366             env->tdata2[index] = val;
367             type2_breakpoint_remove(env, index);
368             type2_breakpoint_insert(env, index);
369         }
370         break;
371     case TDATA3:
372         qemu_log_mask(LOG_UNIMP,
373                       "tdata3 is not supported for type 2 trigger\n");
374         break;
375     default:
376         g_assert_not_reached();
377     }
378 
379     return;
380 }
381 
382 /* type 6 trigger */
383 
384 static inline bool type6_breakpoint_enabled(target_ulong ctrl)
385 {
386     bool mode = !!(ctrl & (TYPE6_VU | TYPE6_VS | TYPE6_U | TYPE6_S | TYPE6_M));
387     bool rwx = !!(ctrl & (TYPE6_LOAD | TYPE6_STORE | TYPE6_EXEC));
388 
389     return mode && rwx;
390 }
391 
392 static target_ulong type6_mcontrol6_validate(CPURISCVState *env,
393                                              target_ulong ctrl)
394 {
395     target_ulong val;
396     uint32_t size;
397 
398     /* validate the generic part first */
399     val = tdata1_validate(env, ctrl, TRIGGER_TYPE_AD_MATCH6);
400 
401     /* validate unimplemented (always zero) bits */
402     warn_always_zero_bit(ctrl, TYPE6_MATCH, "match");
403     warn_always_zero_bit(ctrl, TYPE6_CHAIN, "chain");
404     warn_always_zero_bit(ctrl, TYPE6_ACTION, "action");
405     warn_always_zero_bit(ctrl, TYPE6_TIMING, "timing");
406     warn_always_zero_bit(ctrl, TYPE6_SELECT, "select");
407     warn_always_zero_bit(ctrl, TYPE6_HIT, "hit");
408 
409     /* validate size encoding */
410     size = extract32(ctrl, 16, 4);
411     if (access_size[size] == -1) {
412         qemu_log_mask(LOG_UNIMP, "access size %d is not supported, using SIZE_ANY\n",
413                       size);
414     } else {
415         val |= (ctrl & TYPE6_SIZE);
416     }
417 
418     /* keep the mode and attribute bits */
419     val |= (ctrl & (TYPE6_VU | TYPE6_VS | TYPE6_U | TYPE6_S | TYPE6_M |
420                     TYPE6_LOAD | TYPE6_STORE | TYPE6_EXEC));
421 
422     return val;
423 }
424 
425 static void type6_breakpoint_insert(CPURISCVState *env, target_ulong index)
426 {
427     target_ulong ctrl = env->tdata1[index];
428     target_ulong addr = env->tdata2[index];
429     bool enabled = type6_breakpoint_enabled(ctrl);
430     CPUState *cs = env_cpu(env);
431     int flags = BP_CPU | BP_STOP_BEFORE_ACCESS;
432     uint32_t size;
433 
434     if (!enabled) {
435         return;
436     }
437 
438     if (ctrl & TYPE6_EXEC) {
439         cpu_breakpoint_insert(cs, addr, flags, &env->cpu_breakpoint[index]);
440     }
441 
442     if (ctrl & TYPE6_LOAD) {
443         flags |= BP_MEM_READ;
444     }
445 
446     if (ctrl & TYPE6_STORE) {
447         flags |= BP_MEM_WRITE;
448     }
449 
450     if (flags & BP_MEM_ACCESS) {
451         size = extract32(ctrl, 16, 4);
452         if (size != 0) {
453             cpu_watchpoint_insert(cs, addr, size, flags,
454                                   &env->cpu_watchpoint[index]);
455         } else {
456             cpu_watchpoint_insert(cs, addr, 8, flags,
457                                   &env->cpu_watchpoint[index]);
458         }
459     }
460 }
461 
462 static void type6_breakpoint_remove(CPURISCVState *env, target_ulong index)
463 {
464     type2_breakpoint_remove(env, index);
465 }
466 
467 static void type6_reg_write(CPURISCVState *env, target_ulong index,
468                             int tdata_index, target_ulong val)
469 {
470     target_ulong new_val;
471 
472     switch (tdata_index) {
473     case TDATA1:
474         new_val = type6_mcontrol6_validate(env, val);
475         if (new_val != env->tdata1[index]) {
476             env->tdata1[index] = new_val;
477             type6_breakpoint_remove(env, index);
478             type6_breakpoint_insert(env, index);
479         }
480         break;
481     case TDATA2:
482         if (val != env->tdata2[index]) {
483             env->tdata2[index] = val;
484             type6_breakpoint_remove(env, index);
485             type6_breakpoint_insert(env, index);
486         }
487         break;
488     case TDATA3:
489         qemu_log_mask(LOG_UNIMP,
490                       "tdata3 is not supported for type 6 trigger\n");
491         break;
492     default:
493         g_assert_not_reached();
494     }
495 
496     return;
497 }
498 
499 target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index)
500 {
501     switch (tdata_index) {
502     case TDATA1:
503         return env->tdata1[env->trigger_cur];
504     case TDATA2:
505         return env->tdata2[env->trigger_cur];
506     case TDATA3:
507         return env->tdata3[env->trigger_cur];
508     default:
509         g_assert_not_reached();
510     }
511 }
512 
513 void tdata_csr_write(CPURISCVState *env, int tdata_index, target_ulong val)
514 {
515     int trigger_type;
516 
517     if (tdata_index == TDATA1) {
518         trigger_type = extract_trigger_type(env, val);
519     } else {
520         trigger_type = get_trigger_type(env, env->trigger_cur);
521     }
522 
523     switch (trigger_type) {
524     case TRIGGER_TYPE_AD_MATCH:
525         type2_reg_write(env, env->trigger_cur, tdata_index, val);
526         break;
527     case TRIGGER_TYPE_AD_MATCH6:
528         type6_reg_write(env, env->trigger_cur, tdata_index, val);
529         break;
530     case TRIGGER_TYPE_INST_CNT:
531     case TRIGGER_TYPE_INT:
532     case TRIGGER_TYPE_EXCP:
533     case TRIGGER_TYPE_EXT_SRC:
534         qemu_log_mask(LOG_UNIMP, "trigger type: %d is not supported\n",
535                       trigger_type);
536         break;
537     case TRIGGER_TYPE_NO_EXIST:
538     case TRIGGER_TYPE_UNAVAIL:
539         qemu_log_mask(LOG_GUEST_ERROR, "trigger type: %d does not exit\n",
540                       trigger_type);
541         break;
542     default:
543         g_assert_not_reached();
544     }
545 }
546 
547 target_ulong tinfo_csr_read(CPURISCVState *env)
548 {
549     /* assume all triggers support the same types of triggers */
550     return BIT(TRIGGER_TYPE_AD_MATCH) |
551            BIT(TRIGGER_TYPE_AD_MATCH6);
552 }
553 
554 void riscv_cpu_debug_excp_handler(CPUState *cs)
555 {
556     RISCVCPU *cpu = RISCV_CPU(cs);
557     CPURISCVState *env = &cpu->env;
558 
559     if (cs->watchpoint_hit) {
560         if (cs->watchpoint_hit->flags & BP_CPU) {
561             cs->watchpoint_hit = NULL;
562             do_trigger_action(env, DBG_ACTION_BP);
563         }
564     } else {
565         if (cpu_breakpoint_test(cs, env->pc, BP_CPU)) {
566             do_trigger_action(env, DBG_ACTION_BP);
567         }
568     }
569 }
570 
571 bool riscv_cpu_debug_check_breakpoint(CPUState *cs)
572 {
573     RISCVCPU *cpu = RISCV_CPU(cs);
574     CPURISCVState *env = &cpu->env;
575     CPUBreakpoint *bp;
576     target_ulong ctrl;
577     target_ulong pc;
578     int trigger_type;
579     int i;
580 
581     QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
582         for (i = 0; i < RV_MAX_TRIGGERS; i++) {
583             trigger_type = get_trigger_type(env, i);
584 
585             switch (trigger_type) {
586             case TRIGGER_TYPE_AD_MATCH:
587                 /* type 2 trigger cannot be fired in VU/VS mode */
588                 if (riscv_cpu_virt_enabled(env)) {
589                     return false;
590                 }
591 
592                 ctrl = env->tdata1[i];
593                 pc = env->tdata2[i];
594 
595                 if ((ctrl & TYPE2_EXEC) && (bp->pc == pc)) {
596                     /* check U/S/M bit against current privilege level */
597                     if ((ctrl >> 3) & BIT(env->priv)) {
598                         return true;
599                     }
600                 }
601                 break;
602             case TRIGGER_TYPE_AD_MATCH6:
603                 ctrl = env->tdata1[i];
604                 pc = env->tdata2[i];
605 
606                 if ((ctrl & TYPE6_EXEC) && (bp->pc == pc)) {
607                     if (riscv_cpu_virt_enabled(env)) {
608                         /* check VU/VS bit against current privilege level */
609                         if ((ctrl >> 23) & BIT(env->priv)) {
610                             return true;
611                         }
612                     } else {
613                         /* check U/S/M bit against current privilege level */
614                         if ((ctrl >> 3) & BIT(env->priv)) {
615                             return true;
616                         }
617                     }
618                 }
619                 break;
620             default:
621                 /* other trigger types are not supported or irrelevant */
622                 break;
623             }
624         }
625     }
626 
627     return false;
628 }
629 
630 bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp)
631 {
632     RISCVCPU *cpu = RISCV_CPU(cs);
633     CPURISCVState *env = &cpu->env;
634     target_ulong ctrl;
635     target_ulong addr;
636     int trigger_type;
637     int flags;
638     int i;
639 
640     for (i = 0; i < RV_MAX_TRIGGERS; i++) {
641         trigger_type = get_trigger_type(env, i);
642 
643         switch (trigger_type) {
644         case TRIGGER_TYPE_AD_MATCH:
645             /* type 2 trigger cannot be fired in VU/VS mode */
646             if (riscv_cpu_virt_enabled(env)) {
647                 return false;
648             }
649 
650             ctrl = env->tdata1[i];
651             addr = env->tdata2[i];
652             flags = 0;
653 
654             if (ctrl & TYPE2_LOAD) {
655                 flags |= BP_MEM_READ;
656             }
657             if (ctrl & TYPE2_STORE) {
658                 flags |= BP_MEM_WRITE;
659             }
660 
661             if ((wp->flags & flags) && (wp->vaddr == addr)) {
662                 /* check U/S/M bit against current privilege level */
663                 if ((ctrl >> 3) & BIT(env->priv)) {
664                     return true;
665                 }
666             }
667             break;
668         case TRIGGER_TYPE_AD_MATCH6:
669             ctrl = env->tdata1[i];
670             addr = env->tdata2[i];
671             flags = 0;
672 
673             if (ctrl & TYPE6_LOAD) {
674                 flags |= BP_MEM_READ;
675             }
676             if (ctrl & TYPE6_STORE) {
677                 flags |= BP_MEM_WRITE;
678             }
679 
680             if ((wp->flags & flags) && (wp->vaddr == addr)) {
681                 if (riscv_cpu_virt_enabled(env)) {
682                     /* check VU/VS bit against current privilege level */
683                     if ((ctrl >> 23) & BIT(env->priv)) {
684                         return true;
685                     }
686                 } else {
687                     /* check U/S/M bit against current privilege level */
688                     if ((ctrl >> 3) & BIT(env->priv)) {
689                         return true;
690                     }
691                 }
692             }
693             break;
694         default:
695             /* other trigger types are not supported */
696             break;
697         }
698     }
699 
700     return false;
701 }
702 
703 void riscv_trigger_init(CPURISCVState *env)
704 {
705     target_ulong tdata1 = build_tdata1(env, TRIGGER_TYPE_AD_MATCH, 0, 0);
706     int i;
707 
708     /* init to type 2 triggers */
709     for (i = 0; i < RV_MAX_TRIGGERS; i++) {
710         /*
711          * type = TRIGGER_TYPE_AD_MATCH
712          * dmode = 0 (both debug and M-mode can write tdata)
713          * maskmax = 0 (unimplemented, always 0)
714          * sizehi = 0 (match against any size, RV64 only)
715          * hit = 0 (unimplemented, always 0)
716          * select = 0 (always 0, perform match on address)
717          * timing = 0 (always 0, trigger before instruction)
718          * sizelo = 0 (match against any size)
719          * action = 0 (always 0, raise a breakpoint exception)
720          * chain = 0 (unimplemented, always 0)
721          * match = 0 (always 0, when any compare value equals tdata2)
722          */
723         env->tdata1[i] = tdata1;
724         env->tdata2[i] = 0;
725         env->tdata3[i] = 0;
726         env->cpu_breakpoint[i] = NULL;
727         env->cpu_watchpoint[i] = NULL;
728     }
729 }
730