1 /***************************************************************************
2 * Copyright (C) 2009 Zachary T Welch *
3 * zw@superlucidity.net *
5 * Copyright (C) 2007,2008,2009 Øyvind Harboe *
6 * oyvind.harboe@zylin.com *
8 * Copyright (C) 2009 SoftPLC Corporation *
12 * Copyright (C) 2005 by Dominic Rath *
13 * Dominic.Rath@gmx.de *
15 * This program is free software; you can redistribute it and/or modify *
16 * it under the terms of the GNU General Public License as published by *
17 * the Free Software Foundation; either version 2 of the License, or *
18 * (at your option) any later version. *
20 * This program is distributed in the hope that it will be useful, *
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
23 * GNU General Public License for more details. *
25 * You should have received a copy of the GNU General Public License *
26 * along with this program; if not, write to the *
27 * Free Software Foundation, Inc., *
28 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
29 ***************************************************************************/
35 #include "interface.h"
36 #include <transport/transport.h>
42 /* SVF and XSVF are higher level JTAG command sets (for boundary scan) */
44 #include "xsvf/xsvf.h"
46 /// The number of JTAG queue flushes (for profiling and debugging purposes).
47 static int jtag_flush_queue_count;
49 // Sleep this # of ms after flushing the queue
50 static int jtag_flush_queue_sleep = 0;
52 static void jtag_add_scan_check(struct jtag_tap *active,
53 void (*jtag_add_scan)(struct jtag_tap *active, int in_num_fields, const struct scan_field *in_fields, tap_state_t state),
54 int in_num_fields, struct scan_field *in_fields, tap_state_t state);
57 * The jtag_error variable is set when an error occurs while executing
58 * the queue. Application code may set this using jtag_set_error(),
59 * when an error occurs during processing that should be reported during
60 * jtag_execute_queue().
62 * The value is set and cleared, but never read by normal application code.
64 * This value is returned (and cleared) by jtag_execute_queue().
66 static int jtag_error = ERROR_OK;
68 static const char *jtag_event_strings[] =
70 [JTAG_TRST_ASSERTED] = "TAP reset",
71 [JTAG_TAP_EVENT_SETUP] = "TAP setup",
72 [JTAG_TAP_EVENT_ENABLE] = "TAP enabled",
73 [JTAG_TAP_EVENT_DISABLE] = "TAP disabled",
77 * JTAG adapters must initialize with TRST and SRST de-asserted
78 * (they're negative logic, so that means *high*). But some
79 * hardware doesn't necessarily work that way ... so set things
80 * up so that jtag_init() always forces that state.
82 static int jtag_trst = -1;
83 static int jtag_srst = -1;
86 * List all TAPs that have been created.
88 static struct jtag_tap *__jtag_all_taps = NULL;
90 * The number of TAPs in the __jtag_all_taps list, used to track the
91 * assigned chain position to new TAPs
93 static unsigned jtag_num_taps = 0;
95 static enum reset_types jtag_reset_config = RESET_NONE;
96 tap_state_t cmd_queue_cur_state = TAP_RESET;
98 static bool jtag_verify_capture_ir = true;
99 static int jtag_verify = 1;
101 /* how long the OpenOCD should wait before attempting JTAG communication after reset lines deasserted (in ms) */
102 static int adapter_nsrst_delay = 0; /* default to no nSRST delay */
103 static int jtag_ntrst_delay = 0; /* default to no nTRST delay */
104 static int adapter_nsrst_assert_width = 0; /* width of assertion */
105 static int jtag_ntrst_assert_width = 0; /* width of assertion */
108 * Contains a single callback along with a pointer that will be passed
109 * when an event occurs.
111 struct jtag_event_callback {
113 jtag_event_handler_t callback;
114 /// the private data to pass to the callback
116 /// the next callback
117 struct jtag_event_callback* next;
120 /* callbacks to inform high-level handlers about JTAG state changes */
121 static struct jtag_event_callback *jtag_event_callbacks;
124 static int speed_khz = 0;
125 /* speed to fallback to when RCLK is requested but not supported */
126 static int rclk_fallback_speed_khz = 0;
127 static enum {CLOCK_MODE_UNSELECTED, CLOCK_MODE_KHZ, CLOCK_MODE_RCLK} clock_mode;
128 static int jtag_speed = 0;
130 static struct jtag_interface *jtag = NULL;
133 const struct swd_driver *swd = NULL;
136 struct jtag_interface *jtag_interface = NULL;
138 void jtag_set_flush_queue_sleep(int ms)
140 jtag_flush_queue_sleep = ms;
143 void jtag_set_error(int error)
145 if ((error == ERROR_OK) || (jtag_error != ERROR_OK))
150 int jtag_error_clear(void)
152 int temp = jtag_error;
153 jtag_error = ERROR_OK;
159 static bool jtag_poll = 1;
161 bool is_jtag_poll_safe(void)
163 /* Polling can be disabled explicitly with set_enabled(false).
164 * It is also implicitly disabled while TRST is active and
165 * while SRST is gating the JTAG clock.
167 if (!jtag_poll || jtag_trst != 0)
169 return jtag_srst == 0 || (jtag_reset_config & RESET_SRST_NO_GATING);
172 bool jtag_poll_get_enabled(void)
177 void jtag_poll_set_enabled(bool value)
184 struct jtag_tap *jtag_all_taps(void)
186 return __jtag_all_taps;
189 unsigned jtag_tap_count(void)
191 return jtag_num_taps;
194 unsigned jtag_tap_count_enabled(void)
196 struct jtag_tap *t = jtag_all_taps();
207 /// Append a new TAP to the chain of all taps.
208 void jtag_tap_add(struct jtag_tap *t)
210 t->abs_chain_position = jtag_num_taps++;
212 struct jtag_tap **tap = &__jtag_all_taps;
214 tap = &(*tap)->next_tap;
218 /* returns a pointer to the n-th device in the scan chain */
219 struct jtag_tap *jtag_tap_by_position(unsigned n)
221 struct jtag_tap *t = jtag_all_taps();
229 struct jtag_tap *jtag_tap_by_string(const char *s)
231 /* try by name first */
232 struct jtag_tap *t = jtag_all_taps();
236 if (0 == strcmp(t->dotted_name, s))
241 /* no tap found by name, so try to parse the name as a number */
243 if (parse_uint(s, &n) != ERROR_OK)
246 /* FIXME remove this numeric fallback code late June 2010, along
247 * with all info in the User's Guide that TAPs have numeric IDs.
248 * Also update "scan_chain" output to not display the numbers.
250 t = jtag_tap_by_position(n);
252 LOG_WARNING("Specify TAP '%s' by name, not number %u",
258 struct jtag_tap* jtag_tap_next_enabled(struct jtag_tap* p)
260 p = p ? p->next_tap : jtag_all_taps();
270 const char *jtag_tap_name(const struct jtag_tap *tap)
272 return (tap == NULL) ? "(unknown)" : tap->dotted_name;
276 int jtag_register_event_callback(jtag_event_handler_t callback, void *priv)
278 struct jtag_event_callback **callbacks_p = &jtag_event_callbacks;
280 if (callback == NULL)
282 return ERROR_INVALID_ARGUMENTS;
287 while ((*callbacks_p)->next)
288 callbacks_p = &((*callbacks_p)->next);
289 callbacks_p = &((*callbacks_p)->next);
292 (*callbacks_p) = malloc(sizeof(struct jtag_event_callback));
293 (*callbacks_p)->callback = callback;
294 (*callbacks_p)->priv = priv;
295 (*callbacks_p)->next = NULL;
300 int jtag_unregister_event_callback(jtag_event_handler_t callback, void *priv)
302 struct jtag_event_callback **p = &jtag_event_callbacks, *temp;
304 if (callback == NULL)
306 return ERROR_INVALID_ARGUMENTS;
311 if (((*p)->priv != priv) || ((*p)->callback != callback))
325 int jtag_call_event_callbacks(enum jtag_event event)
327 struct jtag_event_callback *callback = jtag_event_callbacks;
329 LOG_DEBUG("jtag event: %s", jtag_event_strings[event]);
333 struct jtag_event_callback *next;
335 /* callback may remove itself */
336 next = callback->next;
337 callback->callback(event, callback->priv);
344 static void jtag_checks(void)
346 assert(jtag_trst == 0);
349 static void jtag_prelude(tap_state_t state)
353 assert(state != TAP_INVALID);
355 cmd_queue_cur_state = state;
358 void jtag_add_ir_scan_noverify(struct jtag_tap *active, const struct scan_field *in_fields,
363 int retval = interface_jtag_add_ir_scan(active, in_fields, state);
364 jtag_set_error(retval);
367 static void jtag_add_ir_scan_noverify_callback(struct jtag_tap *active, int dummy, const struct scan_field *in_fields,
370 jtag_add_ir_scan_noverify(active, in_fields, state);
373 void jtag_add_ir_scan(struct jtag_tap *active, struct scan_field *in_fields, tap_state_t state)
375 assert(state != TAP_RESET);
377 if (jtag_verify && jtag_verify_capture_ir)
379 /* 8 x 32 bit id's is enough for all invocations */
381 /* if we are to run a verification of the ir scan, we need to get the input back.
382 * We may have to allocate space if the caller didn't ask for the input back.
384 in_fields->check_value = active->expected;
385 in_fields->check_mask = active->expected_mask;
386 jtag_add_scan_check(active, jtag_add_ir_scan_noverify_callback, 1, in_fields, state);
389 jtag_add_ir_scan_noverify(active, in_fields, state);
393 void jtag_add_plain_ir_scan(int num_bits, const uint8_t *out_bits, uint8_t *in_bits,
396 assert(out_bits != NULL);
397 assert(state != TAP_RESET);
401 int retval = interface_jtag_add_plain_ir_scan(
402 num_bits, out_bits, in_bits, state);
403 jtag_set_error(retval);
406 static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
407 uint8_t *in_check_mask, int num_bits);
409 static int jtag_check_value_mask_callback(jtag_callback_data_t data0, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3)
411 return jtag_check_value_inner((uint8_t *)data0, (uint8_t *)data1, (uint8_t *)data2, (int)data3);
414 static void jtag_add_scan_check(struct jtag_tap *active, void (*jtag_add_scan)(struct jtag_tap *active, int in_num_fields, const struct scan_field *in_fields, tap_state_t state),
415 int in_num_fields, struct scan_field *in_fields, tap_state_t state)
417 for (int i = 0; i < in_num_fields; i++)
419 struct scan_field *field = &in_fields[i];
420 /* caller must provide in_buffer if needed for callback */
421 assert((field->check_value == NULL) || (field->in_value != NULL));
424 jtag_add_scan(active, in_num_fields, in_fields, state);
426 for (int i = 0; i < in_num_fields; i++)
428 if ((in_fields[i].check_value != NULL) && (in_fields[i].in_value != NULL))
430 /* this is synchronous for a minidriver */
431 jtag_add_callback4(jtag_check_value_mask_callback, (jtag_callback_data_t)in_fields[i].in_value,
432 (jtag_callback_data_t)in_fields[i].check_value,
433 (jtag_callback_data_t)in_fields[i].check_mask,
434 (jtag_callback_data_t)in_fields[i].num_bits);
439 void jtag_add_dr_scan_check(struct jtag_tap *active, int in_num_fields, struct scan_field *in_fields, tap_state_t state)
443 jtag_add_scan_check(active, jtag_add_dr_scan, in_num_fields, in_fields, state);
446 jtag_add_dr_scan(active, in_num_fields, in_fields, state);
451 void jtag_add_dr_scan(struct jtag_tap *active, int in_num_fields, const struct scan_field *in_fields,
454 assert(state != TAP_RESET);
459 retval = interface_jtag_add_dr_scan(active, in_num_fields, in_fields, state);
460 jtag_set_error(retval);
463 void jtag_add_plain_dr_scan(int num_bits, const uint8_t *out_bits, uint8_t *in_bits,
466 assert(out_bits != NULL);
467 assert(state != TAP_RESET);
472 retval = interface_jtag_add_plain_dr_scan(num_bits, out_bits, in_bits, state);
473 jtag_set_error(retval);
476 void jtag_add_tlr(void)
478 jtag_prelude(TAP_RESET);
479 jtag_set_error(interface_jtag_add_tlr());
481 /* NOTE: order here matches TRST path in jtag_add_reset() */
482 jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
483 jtag_notify_event(JTAG_TRST_ASSERTED);
487 * If supported by the underlying adapter, this clocks a raw bit sequence
488 * onto TMS for switching betwen JTAG and SWD modes.
490 * DO NOT use this to bypass the integrity checks and logging provided
491 * by the jtag_add_pathmove() and jtag_add_statemove() calls.
493 * @param nbits How many bits to clock out.
494 * @param seq The bit sequence. The LSB is bit 0 of seq[0].
495 * @param state The JTAG tap state to record on completion. Use
496 * TAP_INVALID to represent being in in SWD mode.
498 * @todo Update naming conventions to stop assuming everything is JTAG.
500 int jtag_add_tms_seq(unsigned nbits, const uint8_t *seq, enum tap_state state)
504 if (!(jtag->supported & DEBUG_CAP_TMS_SEQ))
505 return ERROR_JTAG_NOT_IMPLEMENTED;
508 cmd_queue_cur_state = state;
510 retval = interface_add_tms_seq(nbits, seq, state);
511 jtag_set_error(retval);
515 void jtag_add_pathmove(int num_states, const tap_state_t *path)
517 tap_state_t cur_state = cmd_queue_cur_state;
519 /* the last state has to be a stable state */
520 if (!tap_is_state_stable(path[num_states - 1]))
522 LOG_ERROR("BUG: TAP path doesn't finish in a stable state");
523 jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
527 for (int i = 0; i < num_states; i++)
529 if (path[i] == TAP_RESET)
531 LOG_ERROR("BUG: TAP_RESET is not a valid state for pathmove sequences");
532 jtag_set_error(ERROR_JTAG_STATE_INVALID);
536 if (tap_state_transition(cur_state, true) != path[i]
537 && tap_state_transition(cur_state, false) != path[i])
539 LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
540 tap_state_name(cur_state), tap_state_name(path[i]));
541 jtag_set_error(ERROR_JTAG_TRANSITION_INVALID);
549 jtag_set_error(interface_jtag_add_pathmove(num_states, path));
550 cmd_queue_cur_state = path[num_states - 1];
553 int jtag_add_statemove(tap_state_t goal_state)
555 tap_state_t cur_state = cmd_queue_cur_state;
557 if (goal_state != cur_state)
559 LOG_DEBUG("cur_state=%s goal_state=%s",
560 tap_state_name(cur_state),
561 tap_state_name(goal_state));
564 /* If goal is RESET, be paranoid and force that that transition
565 * (e.g. five TCK cycles, TMS high). Else trust "cur_state".
567 if (goal_state == TAP_RESET)
569 else if (goal_state == cur_state)
570 /* nothing to do */ ;
572 else if (tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state))
574 unsigned tms_bits = tap_get_tms_path(cur_state, goal_state);
575 unsigned tms_count = tap_get_tms_path_len(cur_state, goal_state);
576 tap_state_t moves[8];
577 assert(tms_count < ARRAY_SIZE(moves));
579 for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1)
581 bool bit = tms_bits & 1;
583 cur_state = tap_state_transition(cur_state, bit);
584 moves[i] = cur_state;
587 jtag_add_pathmove(tms_count, moves);
589 else if (tap_state_transition(cur_state, true) == goal_state
590 || tap_state_transition(cur_state, false) == goal_state)
592 jtag_add_pathmove(1, &goal_state);
601 void jtag_add_runtest(int num_cycles, tap_state_t state)
604 jtag_set_error(interface_jtag_add_runtest(num_cycles, state));
608 void jtag_add_clocks(int num_cycles)
610 if (!tap_is_state_stable(cmd_queue_cur_state))
612 LOG_ERROR("jtag_add_clocks() called with TAP in unstable state \"%s\"",
613 tap_state_name(cmd_queue_cur_state));
614 jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
621 jtag_set_error(interface_jtag_add_clocks(num_cycles));
625 void jtag_add_reset(int req_tlr_or_trst, int req_srst)
627 int trst_with_tlr = 0;
631 /* Without SRST, we must use target-specific JTAG operations
632 * on each target; callers should not be requesting SRST when
633 * that signal doesn't exist.
635 * RESET_SRST_PULLS_TRST is a board or chip level quirk, which
636 * can kick in even if the JTAG adapter can't drive TRST.
639 if (!(jtag_reset_config & RESET_HAS_SRST)) {
640 LOG_ERROR("BUG: can't assert SRST");
641 jtag_set_error(ERROR_FAIL);
644 if ((jtag_reset_config & RESET_SRST_PULLS_TRST) != 0
645 && !req_tlr_or_trst) {
646 LOG_ERROR("BUG: can't assert only SRST");
647 jtag_set_error(ERROR_FAIL);
653 /* JTAG reset (entry to TAP_RESET state) can always be achieved
654 * using TCK and TMS; that may go through a TAP_{IR,DR}UPDATE
655 * state first. TRST accelerates it, and bypasses those states.
657 * RESET_TRST_PULLS_SRST is a board or chip level quirk, which
658 * can kick in even if the JTAG adapter can't drive SRST.
660 if (req_tlr_or_trst) {
661 if (!(jtag_reset_config & RESET_HAS_TRST))
663 else if ((jtag_reset_config & RESET_TRST_PULLS_SRST) != 0
670 /* Maybe change TRST and/or SRST signal state */
671 if (jtag_srst != new_srst || jtag_trst != new_trst) {
674 retval = interface_jtag_add_reset(new_trst, new_srst);
675 if (retval != ERROR_OK)
676 jtag_set_error(retval);
678 retval = jtag_execute_queue();
680 if (retval != ERROR_OK) {
681 LOG_ERROR("TRST/SRST error");
686 /* SRST resets everything hooked up to that signal */
687 if (jtag_srst != new_srst) {
688 jtag_srst = new_srst;
691 LOG_DEBUG("SRST line asserted");
692 if (adapter_nsrst_assert_width)
693 jtag_add_sleep(adapter_nsrst_assert_width * 1000);
696 LOG_DEBUG("SRST line released");
697 if (adapter_nsrst_delay)
698 jtag_add_sleep(adapter_nsrst_delay * 1000);
702 /* Maybe enter the JTAG TAP_RESET state ...
703 * - using only TMS, TCK, and the JTAG state machine
704 * - or else more directly, using TRST
706 * TAP_RESET should be invisible to non-debug parts of the system.
709 LOG_DEBUG("JTAG reset with TLR instead of TRST");
712 } else if (jtag_trst != new_trst) {
713 jtag_trst = new_trst;
715 LOG_DEBUG("TRST line asserted");
716 tap_set_state(TAP_RESET);
717 if (jtag_ntrst_assert_width)
718 jtag_add_sleep(jtag_ntrst_assert_width * 1000);
720 LOG_DEBUG("TRST line released");
721 if (jtag_ntrst_delay)
722 jtag_add_sleep(jtag_ntrst_delay * 1000);
724 /* We just asserted nTRST, so we're now in TAP_RESET.
725 * Inform possible listeners about this, now that
726 * JTAG instructions and data can be shifted. This
727 * sequence must match jtag_add_tlr().
729 jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
730 jtag_notify_event(JTAG_TRST_ASSERTED);
735 void jtag_add_sleep(uint32_t us)
737 /// @todo Here, keep_alive() appears to be a layering violation!!!
739 jtag_set_error(interface_jtag_add_sleep(us));
742 static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
743 uint8_t *in_check_mask, int num_bits)
745 int retval = ERROR_OK;
749 compare_failed = buf_cmp_mask(captured, in_check_value, in_check_mask, num_bits);
751 compare_failed = buf_cmp(captured, in_check_value, num_bits);
753 if (compare_failed) {
754 char *captured_str, *in_check_value_str;
755 int bits = (num_bits > DEBUG_JTAG_IOZ)
759 /* NOTE: we've lost diagnostic context here -- 'which tap' */
761 captured_str = buf_to_str(captured, bits, 16);
762 in_check_value_str = buf_to_str(in_check_value, bits, 16);
764 LOG_WARNING("Bad value '%s' captured during DR or IR scan:",
766 LOG_WARNING(" check_value: 0x%s", in_check_value_str);
769 free(in_check_value_str);
772 char *in_check_mask_str;
774 in_check_mask_str = buf_to_str(in_check_mask, bits, 16);
775 LOG_WARNING(" check_mask: 0x%s", in_check_mask_str);
776 free(in_check_mask_str);
779 retval = ERROR_JTAG_QUEUE_FAILED;
784 void jtag_check_value_mask(struct scan_field *field, uint8_t *value, uint8_t *mask)
786 assert(field->in_value != NULL);
790 /* no checking to do */
794 jtag_execute_queue_noclear();
796 int retval = jtag_check_value_inner(field->in_value, value, mask, field->num_bits);
797 jtag_set_error(retval);
802 int default_interface_jtag_execute_queue(void)
806 LOG_ERROR("No JTAG interface configured yet. "
807 "Issue 'init' command in startup scripts "
808 "before communicating with targets.");
812 return jtag->execute_queue();
815 void jtag_execute_queue_noclear(void)
817 jtag_flush_queue_count++;
818 jtag_set_error(interface_jtag_execute_queue());
820 if (jtag_flush_queue_sleep > 0)
822 /* For debug purposes it can be useful to test performance
823 * or behavior when delaying after flushing the queue,
824 * e.g. to simulate long roundtrip times.
826 usleep(jtag_flush_queue_sleep * 1000);
830 int jtag_get_flush_queue_count(void)
832 return jtag_flush_queue_count;
835 int jtag_execute_queue(void)
837 jtag_execute_queue_noclear();
838 return jtag_error_clear();
841 static int jtag_reset_callback(enum jtag_event event, void *priv)
843 struct jtag_tap *tap = priv;
845 if (event == JTAG_TRST_ASSERTED)
847 tap->enabled = !tap->disabled_after_reset;
849 /* current instruction is either BYPASS or IDCODE */
850 buf_set_ones(tap->cur_instr, tap->ir_length);
857 /* sleep at least us microseconds. When we sleep more than 1000ms we
858 * do an alive sleep, i.e. keep GDB alive. Note that we could starve
859 * GDB if we slept for <1000ms many times.
861 void jtag_sleep(uint32_t us)
866 alive_sleep((us+999)/1000);
869 /* Maximum number of enabled JTAG devices we expect in the scan chain,
870 * plus one (to detect garbage at the end). Devices that don't support
871 * IDCODE take up fewer bits, possibly allowing a few more devices.
873 #define JTAG_MAX_CHAIN_SIZE 20
875 #define EXTRACT_MFG(X) (((X) & 0xffe) >> 1)
876 #define EXTRACT_PART(X) (((X) & 0xffff000) >> 12)
877 #define EXTRACT_VER(X) (((X) & 0xf0000000) >> 28)
879 /* A reserved manufacturer ID is used in END_OF_CHAIN_FLAG, so we
880 * know that no valid TAP will have it as an IDCODE value.
882 #define END_OF_CHAIN_FLAG 0x000000ff
884 /* a larger IR length than we ever expect to autoprobe */
885 #define JTAG_IRLEN_MAX 60
887 static int jtag_examine_chain_execute(uint8_t *idcode_buffer, unsigned num_idcode)
889 struct scan_field field = {
890 .num_bits = num_idcode * 32,
891 .out_value = idcode_buffer,
892 .in_value = idcode_buffer,
895 // initialize to the end of chain ID value
896 for (unsigned i = 0; i < JTAG_MAX_CHAIN_SIZE; i++)
897 buf_set_u32(idcode_buffer, i * 32, 32, END_OF_CHAIN_FLAG);
899 jtag_add_plain_dr_scan(field.num_bits, field.out_value, field.in_value, TAP_DRPAUSE);
901 return jtag_execute_queue();
904 static bool jtag_examine_chain_check(uint8_t *idcodes, unsigned count)
906 uint8_t zero_check = 0x0;
907 uint8_t one_check = 0xff;
909 for (unsigned i = 0; i < count * 4; i++)
911 zero_check |= idcodes[i];
912 one_check &= idcodes[i];
915 /* if there wasn't a single non-zero bit or if all bits were one,
916 * the scan is not valid. We wrote a mix of both values; either
918 * - There's a hardware issue (almost certainly):
919 * + all-zeroes can mean a target stuck in JTAG reset
920 * + all-ones tends to mean no target
921 * - The scan chain is WAY longer than we can handle, *AND* either
922 * + there are several hundreds of TAPs in bypass, or
923 * + at least a few dozen TAPs all have an all-ones IDCODE
925 if (zero_check == 0x00 || one_check == 0xff)
927 LOG_ERROR("JTAG scan chain interrogation failed: all %s",
928 (zero_check == 0x00) ? "zeroes" : "ones");
929 LOG_ERROR("Check JTAG interface, timings, target power, etc.");
935 static void jtag_examine_chain_display(enum log_levels level, const char *msg,
936 const char *name, uint32_t idcode)
938 log_printf_lf(level, __FILE__, __LINE__, __FUNCTION__,
939 "JTAG tap: %s %16.16s: 0x%08x "
940 "(mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
942 (unsigned int)idcode,
943 (unsigned int)EXTRACT_MFG(idcode),
944 (unsigned int)EXTRACT_PART(idcode),
945 (unsigned int)EXTRACT_VER(idcode));
948 static bool jtag_idcode_is_final(uint32_t idcode)
951 * Some devices, such as AVR8, will output all 1's instead
952 * of TDI input value at end of chain. Allow those values
953 * instead of failing.
955 return idcode == END_OF_CHAIN_FLAG || idcode == 0xFFFFFFFF;
959 * This helper checks that remaining bits in the examined chain data are
960 * all as expected, but a single JTAG device requires only 64 bits to be
961 * read back correctly. This can help identify and diagnose problems
962 * with the JTAG chain earlier, gives more helpful/explicit error messages.
963 * Returns TRUE iff garbage was found.
965 static bool jtag_examine_chain_end(uint8_t *idcodes, unsigned count, unsigned max)
967 bool triggered = false;
968 for (; count < max - 31; count += 32)
970 uint32_t idcode = buf_get_u32(idcodes, count, 32);
972 /* do not trigger the warning if the data looks good */
973 if (jtag_idcode_is_final(idcode))
975 LOG_WARNING("Unexpected idcode after end of chain: %d 0x%08x",
976 count, (unsigned int)idcode);
982 static bool jtag_examine_chain_match_tap(const struct jtag_tap *tap)
984 uint32_t idcode = tap->idcode;
986 /* ignore expected BYPASS codes; warn otherwise */
987 if (0 == tap->expected_ids_cnt && !idcode)
990 /* optionally ignore the JTAG version field */
991 uint32_t mask = tap->ignore_version ? ~(0xff << 24) : ~0;
995 /* Loop over the expected identification codes and test for a match */
996 unsigned ii, limit = tap->expected_ids_cnt;
998 for (ii = 0; ii < limit; ii++)
1000 uint32_t expected = tap->expected_ids[ii] & mask;
1002 if (idcode == expected)
1005 /* treat "-expected-id 0" as a "don't-warn" wildcard */
1006 if (0 == tap->expected_ids[ii])
1010 /* If none of the expected ids matched, warn */
1011 jtag_examine_chain_display(LOG_LVL_WARNING, "UNEXPECTED",
1012 tap->dotted_name, tap->idcode);
1013 for (ii = 0; ii < limit; ii++)
1017 snprintf(msg, sizeof(msg), "expected %u of %u", ii + 1, limit);
1018 jtag_examine_chain_display(LOG_LVL_ERROR, msg,
1019 tap->dotted_name, tap->expected_ids[ii]);
1024 /* Try to examine chain layout according to IEEE 1149.1 §12
1025 * This is called a "blind interrogation" of the scan chain.
1027 static int jtag_examine_chain(void)
1029 uint8_t idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
1033 bool autoprobe = false;
1035 /* DR scan to collect BYPASS or IDCODE register contents.
1036 * Then make sure the scan data has both ones and zeroes.
1038 LOG_DEBUG("DR scan interrogation for IDCODE/BYPASS");
1039 retval = jtag_examine_chain_execute(idcode_buffer, JTAG_MAX_CHAIN_SIZE);
1040 if (retval != ERROR_OK)
1042 if (!jtag_examine_chain_check(idcode_buffer, JTAG_MAX_CHAIN_SIZE))
1043 return ERROR_JTAG_INIT_FAILED;
1045 /* point at the 1st tap */
1046 struct jtag_tap *tap = jtag_tap_next_enabled(NULL);
1052 tap && bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;
1053 tap = jtag_tap_next_enabled(tap))
1055 uint32_t idcode = buf_get_u32(idcode_buffer, bit_count, 32);
1057 if ((idcode & 1) == 0)
1059 /* Zero for LSB indicates a device in bypass */
1060 LOG_INFO("TAP %s does not have IDCODE",
1063 tap->hasidcode = false;
1069 /* Friendly devices support IDCODE */
1070 tap->hasidcode = true;
1071 jtag_examine_chain_display(LOG_LVL_INFO,
1073 tap->dotted_name, idcode);
1077 tap->idcode = idcode;
1079 /* ensure the TAP ID matches what was expected */
1080 if (!jtag_examine_chain_match_tap(tap))
1081 retval = ERROR_JTAG_INIT_SOFT_FAIL;
1084 /* Fail if too many TAPs were enabled for us to verify them all. */
1086 LOG_ERROR("Too many TAPs enabled; '%s' ignored.",
1088 return ERROR_JTAG_INIT_FAILED;
1091 /* if autoprobing, the tap list is still empty ... populate it! */
1092 while (autoprobe && bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31) {
1096 /* Is there another TAP? */
1097 idcode = buf_get_u32(idcode_buffer, bit_count, 32);
1098 if (jtag_idcode_is_final(idcode))
1101 /* Default everything in this TAP except IR length.
1103 * REVISIT create a jtag_alloc(chip, tap) routine, and
1104 * share it with jim_newtap_cmd().
1106 tap = calloc(1, sizeof *tap);
1110 sprintf(buf, "auto%d", tapcount++);
1111 tap->chip = strdup(buf);
1112 tap->tapname = strdup("tap");
1114 sprintf(buf, "%s.%s", tap->chip, tap->tapname);
1115 tap->dotted_name = strdup(buf);
1117 /* tap->ir_length == 0 ... signifying irlen autoprobe */
1118 tap->ir_capture_mask = 0x03;
1119 tap->ir_capture_value = 0x01;
1121 tap->enabled = true;
1123 if ((idcode & 1) == 0) {
1125 tap->hasidcode = false;
1128 tap->hasidcode = true;
1129 tap->idcode = idcode;
1131 tap->expected_ids_cnt = 1;
1132 tap->expected_ids = malloc(sizeof(uint32_t));
1133 tap->expected_ids[0] = idcode;
1136 LOG_WARNING("AUTO %s - use \"jtag newtap "
1137 "%s %s -expected-id 0x%8.8" PRIx32 " ...\"",
1138 tap->dotted_name, tap->chip, tap->tapname,
1144 /* After those IDCODE or BYPASS register values should be
1145 * only the data we fed into the scan chain.
1147 if (jtag_examine_chain_end(idcode_buffer, bit_count,
1148 8 * sizeof(idcode_buffer))) {
1149 LOG_ERROR("double-check your JTAG setup (interface, "
1150 "speed, missing TAPs, ...)");
1151 return ERROR_JTAG_INIT_FAILED;
1154 /* Return success or, for backwards compatibility if only
1155 * some IDCODE values mismatched, a soft/continuable fault.
1161 * Validate the date loaded by entry to the Capture-IR state, to help
1162 * find errors related to scan chain configuration (wrong IR lengths)
1165 * Entry state can be anything. On non-error exit, all TAPs are in
1166 * bypass mode. On error exits, the scan chain is reset.
1168 static int jtag_validate_ircapture(void)
1170 struct jtag_tap *tap;
1171 int total_ir_length = 0;
1172 uint8_t *ir_test = NULL;
1173 struct scan_field field;
1178 /* when autoprobing, accomodate huge IR lengths */
1179 for (tap = NULL, total_ir_length = 0;
1180 (tap = jtag_tap_next_enabled(tap)) != NULL;
1181 total_ir_length += tap->ir_length) {
1182 if (tap->ir_length == 0)
1183 total_ir_length += JTAG_IRLEN_MAX;
1186 /* increase length to add 2 bit sentinel after scan */
1187 total_ir_length += 2;
1189 ir_test = malloc(DIV_ROUND_UP(total_ir_length, 8));
1190 if (ir_test == NULL)
1193 /* after this scan, all TAPs will capture BYPASS instructions */
1194 buf_set_ones(ir_test, total_ir_length);
1196 field.num_bits = total_ir_length;
1197 field.out_value = ir_test;
1198 field.in_value = ir_test;
1200 jtag_add_plain_ir_scan(field.num_bits, field.out_value, field.in_value, TAP_IDLE);
1202 LOG_DEBUG("IR capture validation scan");
1203 retval = jtag_execute_queue();
1204 if (retval != ERROR_OK)
1211 tap = jtag_tap_next_enabled(tap);
1216 /* If we're autoprobing, guess IR lengths. They must be at
1217 * least two bits. Guessing will fail if (a) any TAP does
1218 * not conform to the JTAG spec; or (b) when the upper bits
1219 * captured from some conforming TAP are nonzero. Or if
1220 * (c) an IR length is longer than 32 bits -- which is only
1221 * an implementation limit, which could someday be raised.
1223 * REVISIT optimization: if there's a *single* TAP we can
1224 * lift restrictions (a) and (b) by scanning a recognizable
1225 * pattern before the all-ones BYPASS. Check for where the
1226 * pattern starts in the result, instead of an 0...01 value.
1228 * REVISIT alternative approach: escape to some tcl code
1229 * which could provide more knowledge, based on IDCODE; and
1230 * only guess when that has no success.
1232 if (tap->ir_length == 0) {
1234 while ((val = buf_get_u32(ir_test, chain_pos,
1235 tap->ir_length + 1)) == 1
1236 && tap->ir_length <= 32) {
1239 LOG_WARNING("AUTO %s - use \"... -irlen %d\"",
1240 jtag_tap_name(tap), tap->ir_length);
1243 /* Validate the two LSBs, which must be 01 per JTAG spec.
1245 * Or ... more bits could be provided by TAP declaration.
1246 * Plus, some taps (notably in i.MX series chips) violate
1247 * this part of the JTAG spec, so their capture mask/value
1248 * attributes might disable this test.
1250 val = buf_get_u32(ir_test, chain_pos, tap->ir_length);
1251 if ((val & tap->ir_capture_mask) != tap->ir_capture_value) {
1252 LOG_ERROR("%s: IR capture error; saw 0x%0*x not 0x%0*x",
1254 (tap->ir_length + 7) / tap->ir_length,
1256 (tap->ir_length + 7) / tap->ir_length,
1257 (unsigned) tap->ir_capture_value);
1259 retval = ERROR_JTAG_INIT_FAILED;
1262 LOG_DEBUG("%s: IR capture 0x%0*x", jtag_tap_name(tap),
1263 (tap->ir_length + 7) / tap->ir_length, val);
1264 chain_pos += tap->ir_length;
1267 /* verify the '11' sentinel we wrote is returned at the end */
1268 val = buf_get_u32(ir_test, chain_pos, 2);
1271 char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
1273 LOG_ERROR("IR capture error at bit %d, saw 0x%s not 0x...3",
1276 retval = ERROR_JTAG_INIT_FAILED;
1281 if (retval != ERROR_OK) {
1283 jtag_execute_queue();
1289 void jtag_tap_init(struct jtag_tap *tap)
1291 unsigned ir_len_bits;
1292 unsigned ir_len_bytes;
1294 /* if we're autoprobing, cope with potentially huge ir_length */
1295 ir_len_bits = tap->ir_length ? : JTAG_IRLEN_MAX;
1296 ir_len_bytes = DIV_ROUND_UP(ir_len_bits, 8);
1298 tap->expected = calloc(1, ir_len_bytes);
1299 tap->expected_mask = calloc(1, ir_len_bytes);
1300 tap->cur_instr = malloc(ir_len_bytes);
1302 /// @todo cope better with ir_length bigger than 32 bits
1303 if (ir_len_bits > 32)
1306 buf_set_u32(tap->expected, 0, ir_len_bits, tap->ir_capture_value);
1307 buf_set_u32(tap->expected_mask, 0, ir_len_bits, tap->ir_capture_mask);
1309 // TAP will be in bypass mode after jtag_validate_ircapture()
1311 buf_set_ones(tap->cur_instr, tap->ir_length);
1313 // register the reset callback for the TAP
1314 jtag_register_event_callback(&jtag_reset_callback, tap);
1316 LOG_DEBUG("Created Tap: %s @ abs position %d, "
1317 "irlen %d, capture: 0x%x mask: 0x%x", tap->dotted_name,
1318 tap->abs_chain_position, tap->ir_length,
1319 (unsigned) tap->ir_capture_value,
1320 (unsigned) tap->ir_capture_mask);
1324 void jtag_tap_free(struct jtag_tap *tap)
1326 jtag_unregister_event_callback(&jtag_reset_callback, tap);
1328 /// @todo is anything missing? no memory leaks please
1329 free((void *)tap->expected);
1330 free((void *)tap->expected_ids);
1331 free((void *)tap->chip);
1332 free((void *)tap->tapname);
1333 free((void *)tap->dotted_name);
1338 * Do low-level setup like initializing registers, output signals,
1341 int adapter_init(struct command_context *cmd_ctx)
1346 if (!jtag_interface)
1348 /* nothing was previously specified by "interface" command */
1349 LOG_ERROR("Debug Adapter has to be specified, "
1350 "see \"interface\" command");
1351 return ERROR_JTAG_INVALID_INTERFACE;
1355 retval = jtag_interface->init();
1356 if (retval != ERROR_OK)
1360 jtag = jtag_interface;
1362 /* LEGACY SUPPORT ... adapter drivers must declare what
1363 * transports they allow. Until they all do so, assume
1364 * the legacy drivers are JTAG-only
1366 if (!transports_are_declared()) {
1367 LOG_ERROR("Adapter driver '%s' did not declare "
1368 "which transports it allows; assuming "
1369 "JTAG-only", jtag->name);
1370 retval = allow_transports(cmd_ctx, jtag_only);
1371 if (retval != ERROR_OK)
1375 if (CLOCK_MODE_UNSELECTED == clock_mode)
1377 LOG_ERROR("An adapter speed is not selected in the init script."
1378 " Insert a call to adapter_khz or jtag_rclk to proceed.");
1379 return ERROR_JTAG_INIT_FAILED;
1382 int requested_khz = jtag_get_speed_khz();
1383 int actual_khz = requested_khz;
1384 int jtag_speed_var = 0;
1385 retval = jtag_get_speed(&jtag_speed_var);
1386 if (retval != ERROR_OK)
1388 retval = jtag->speed(jtag_speed_var);
1389 if (retval != ERROR_OK)
1391 retval = jtag_get_speed_readable(&actual_khz);
1392 if (ERROR_OK != retval)
1393 LOG_INFO("adapter-specific clock speed value %d", jtag_speed_var);
1394 else if (actual_khz)
1396 /* Adaptive clocking -- JTAG-specific */
1397 if ((CLOCK_MODE_RCLK == clock_mode)
1398 || ((CLOCK_MODE_KHZ == clock_mode) && !requested_khz))
1400 LOG_INFO("RCLK (adaptive clock speed) not supported - fallback to %d kHz"
1404 LOG_INFO("clock speed %d kHz", actual_khz);
1407 LOG_INFO("RCLK (adaptive clock speed)");
1412 int jtag_init_inner(struct command_context *cmd_ctx)
1414 struct jtag_tap *tap;
1416 bool issue_setup = true;
1418 LOG_DEBUG("Init JTAG chain");
1420 tap = jtag_tap_next_enabled(NULL);
1422 /* Once JTAG itself is properly set up, and the scan chain
1423 * isn't absurdly large, IDCODE autoprobe should work fine.
1425 * But ... IRLEN autoprobe can fail even on systems which
1426 * are fully conformant to JTAG. Also, JTAG setup can be
1427 * quite finicky on some systems.
1429 * REVISIT: if TAP autoprobe works OK, then in many cases
1430 * we could escape to tcl code and set up targets based on
1431 * the TAP's IDCODE values.
1433 LOG_WARNING("There are no enabled taps. "
1434 "AUTO PROBING MIGHT NOT WORK!!");
1436 /* REVISIT default clock will often be too fast ... */
1440 if ((retval = jtag_execute_queue()) != ERROR_OK)
1443 /* Examine DR values first. This discovers problems which will
1444 * prevent communication ... hardware issues like TDO stuck, or
1445 * configuring the wrong number of (enabled) TAPs.
1447 retval = jtag_examine_chain();
1450 /* complete success */
1453 /* For backward compatibility reasons, try coping with
1454 * configuration errors involving only ID mismatches.
1455 * We might be able to talk to the devices.
1457 * Also the device might be powered down during startup.
1459 * After OpenOCD starts, we can try to power on the device
1462 LOG_ERROR("Trying to use configured scan chain anyway...");
1463 issue_setup = false;
1467 /* Now look at IR values. Problems here will prevent real
1468 * communication. They mostly mean that the IR length is
1469 * wrong ... or that the IR capture value is wrong. (The
1470 * latter is uncommon, but easily worked around: provide
1471 * ircapture/irmask values during TAP setup.)
1473 retval = jtag_validate_ircapture();
1474 if (retval != ERROR_OK)
1476 /* The target might be powered down. The user
1477 * can power it up and reset it after firing
1480 issue_setup = false;
1484 jtag_notify_event(JTAG_TAP_EVENT_SETUP);
1486 LOG_WARNING("Bypassing JTAG setup events due to errors");
1492 int adapter_quit(void)
1494 if (!jtag || !jtag->quit)
1497 // close the JTAG interface
1498 int result = jtag->quit();
1499 if (ERROR_OK != result)
1500 LOG_ERROR("failed: %d", result);
1506 int jtag_init_reset(struct command_context *cmd_ctx)
1510 if ((retval = adapter_init(cmd_ctx)) != ERROR_OK)
1513 LOG_DEBUG("Initializing with hard TRST+SRST reset");
1516 * This procedure is used by default when OpenOCD triggers a reset.
1517 * It's now done through an overridable Tcl "init_reset" wrapper.
1519 * This started out as a more powerful "get JTAG working" reset than
1520 * jtag_init_inner(), applying TRST because some chips won't activate
1521 * JTAG without a TRST cycle (presumed to be async, though some of
1522 * those chips synchronize JTAG activation using TCK).
1524 * But some chips only activate JTAG as part of an SRST cycle; SRST
1525 * got mixed in. So it became a hard reset routine, which got used
1526 * in more places, and which coped with JTAG reset being forced as
1527 * part of SRST (srst_pulls_trst).
1529 * And even more corner cases started to surface: TRST and/or SRST
1530 * assertion timings matter; some chips need other JTAG operations;
1531 * TRST/SRST sequences can need to be different from these, etc.
1533 * Systems should override that wrapper to support system-specific
1534 * requirements that this not-fully-generic code doesn't handle.
1536 * REVISIT once Tcl code can read the reset_config modes, this won't
1537 * need to be a C routine at all...
1539 jtag_add_reset(1, 0); /* TAP_RESET, using TMS+TCK or TRST */
1540 if (jtag_reset_config & RESET_HAS_SRST)
1542 jtag_add_reset(1, 1);
1543 if ((jtag_reset_config & RESET_SRST_PULLS_TRST) == 0)
1544 jtag_add_reset(0, 1);
1546 jtag_add_reset(0, 0);
1547 if ((retval = jtag_execute_queue()) != ERROR_OK)
1550 /* Check that we can communication on the JTAG chain + eventually we want to
1551 * be able to perform enumeration only after OpenOCD has started
1552 * telnet and GDB server
1554 * That would allow users to more easily perform any magic they need to before
1557 return jtag_init_inner(cmd_ctx);
1560 int jtag_init(struct command_context *cmd_ctx)
1564 if ((retval = adapter_init(cmd_ctx)) != ERROR_OK)
1567 /* guard against oddball hardware: force resets to be inactive */
1568 jtag_add_reset(0, 0);
1569 if ((retval = jtag_execute_queue()) != ERROR_OK)
1572 if (Jim_Eval_Named(cmd_ctx->interp, "jtag_init", __FILE__, __LINE__) != JIM_OK)
1578 unsigned jtag_get_speed_khz(void)
1583 static int adapter_khz_to_speed(unsigned khz, int* speed)
1585 LOG_DEBUG("convert khz to interface specific speed value");
1589 LOG_DEBUG("have interface set up");
1591 int retval = jtag->khz(jtag_get_speed_khz(), &speed_div1);
1592 if (ERROR_OK != retval)
1596 *speed = speed_div1;
1601 static int jtag_rclk_to_speed(unsigned fallback_speed_khz, int* speed)
1603 int retval = adapter_khz_to_speed(0, speed);
1604 if ((ERROR_OK != retval) && fallback_speed_khz)
1606 LOG_DEBUG("trying fallback speed...");
1607 retval = adapter_khz_to_speed(fallback_speed_khz, speed);
1612 static int jtag_set_speed(int speed)
1615 /* this command can be called during CONFIG,
1616 * in which case jtag isn't initialized */
1617 return jtag ? jtag->speed(speed) : ERROR_OK;
1620 int jtag_config_khz(unsigned khz)
1622 LOG_DEBUG("handle jtag khz");
1623 clock_mode = CLOCK_MODE_KHZ;
1625 int retval = adapter_khz_to_speed(khz, &speed);
1626 return (ERROR_OK != retval) ? retval : jtag_set_speed(speed);
1629 int jtag_config_rclk(unsigned fallback_speed_khz)
1631 LOG_DEBUG("handle jtag rclk");
1632 clock_mode = CLOCK_MODE_RCLK;
1633 rclk_fallback_speed_khz = fallback_speed_khz;
1635 int retval = jtag_rclk_to_speed(fallback_speed_khz, &speed);
1636 return (ERROR_OK != retval) ? retval : jtag_set_speed(speed);
1639 int jtag_get_speed(int *speed)
1643 case CLOCK_MODE_KHZ:
1644 adapter_khz_to_speed(jtag_get_speed_khz(), speed);
1646 case CLOCK_MODE_RCLK:
1647 jtag_rclk_to_speed(rclk_fallback_speed_khz, speed);
1650 LOG_ERROR("BUG: unknown jtag clock mode");
1656 int jtag_get_speed_readable(int *khz)
1658 int jtag_speed_var = 0;
1659 int retval = jtag_get_speed(&jtag_speed_var);
1660 if (retval != ERROR_OK)
1662 return jtag ? jtag->speed_div(jtag_speed_var, khz) : ERROR_OK;
1665 void jtag_set_verify(bool enable)
1667 jtag_verify = enable;
1670 bool jtag_will_verify()
1675 void jtag_set_verify_capture_ir(bool enable)
1677 jtag_verify_capture_ir = enable;
1680 bool jtag_will_verify_capture_ir()
1682 return jtag_verify_capture_ir;
1685 int jtag_power_dropout(int *dropout)
1689 /* TODO: as the jtag interface is not valid all
1690 * we can do at the moment is exit OpenOCD */
1691 LOG_ERROR("No Valid JTAG Interface Configured.");
1694 return jtag->power_dropout(dropout);
1697 int jtag_srst_asserted(int *srst_asserted)
1699 return jtag->srst_asserted(srst_asserted);
1702 enum reset_types jtag_get_reset_config(void)
1704 return jtag_reset_config;
1706 void jtag_set_reset_config(enum reset_types type)
1708 jtag_reset_config = type;
1711 int jtag_get_trst(void)
1715 int jtag_get_srst(void)
1720 void jtag_set_nsrst_delay(unsigned delay)
1722 adapter_nsrst_delay = delay;
1724 unsigned jtag_get_nsrst_delay(void)
1726 return adapter_nsrst_delay;
1728 void jtag_set_ntrst_delay(unsigned delay)
1730 jtag_ntrst_delay = delay;
1732 unsigned jtag_get_ntrst_delay(void)
1734 return jtag_ntrst_delay;
1738 void jtag_set_nsrst_assert_width(unsigned delay)
1740 adapter_nsrst_assert_width = delay;
1742 unsigned jtag_get_nsrst_assert_width(void)
1744 return adapter_nsrst_assert_width;
1746 void jtag_set_ntrst_assert_width(unsigned delay)
1748 jtag_ntrst_assert_width = delay;
1750 unsigned jtag_get_ntrst_assert_width(void)
1752 return jtag_ntrst_assert_width;
1755 static int jtag_select(struct command_context *ctx)
1759 /* NOTE: interface init must already have been done.
1760 * That works with only C code ... no Tcl glue required.
1763 retval = jtag_register_commands(ctx);
1765 if (retval != ERROR_OK)
1768 retval = svf_register_commands(ctx);
1770 if (retval != ERROR_OK)
1773 return xsvf_register_commands(ctx);
1776 static struct transport jtag_transport = {
1778 .select = jtag_select,
1782 static void jtag_constructor(void) __attribute__((constructor));
1783 static void jtag_constructor(void)
1785 transport_register(&jtag_transport);
1788 /** Returns true if the current debug session
1789 * is using JTAG as its transport.
1791 bool transport_is_jtag(void)
1793 return get_current_transport() == &jtag_transport;