X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=blobdiff_plain;f=src%2Fjtag%2Fcore.c;h=b61280cc0ce2bb349a1d23f3bb041b4aba62516c;hp=564b93f84940d546f35fd00135693467c3978f11;hb=3e90b63b1f54330de7ea3b6454ff5810ac861961;hpb=026559068d889660ad4545ee28b6561c82c39aea

diff --git a/src/jtag/core.c b/src/jtag/core.c
index 564b93f849..b61280cc0c 100644
--- a/src/jtag/core.c
+++ b/src/jtag/core.c
@@ -25,26 +25,38 @@
  *   You should have received a copy of the GNU General Public License     *
  *   along with this program; if not, write to the                         *
  *   Free Software Foundation, Inc.,                                       *
- *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
  ***************************************************************************/
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
 #include "jtag.h"
-#include "minidriver.h"
+#include "swd.h"
 #include "interface.h"
+#include <transport/transport.h>
 
 #ifdef HAVE_STRINGS_H
 #include <strings.h>
 #endif
 
+/* SVF and XSVF are higher level JTAG command sets (for boundary scan) */
+#include "svf/svf.h"
+#include "xsvf/xsvf.h"
 
-/// The number of JTAG queue flushes (for profiling and debugging purposes).
+/** The number of JTAG queue flushes (for profiling and debugging purposes). */
 static int jtag_flush_queue_count;
 
-static void jtag_add_scan_check(void (*jtag_add_scan)(int in_num_fields, const scan_field_t *in_fields, tap_state_t state),
-		int in_num_fields, scan_field_t *in_fields, tap_state_t state);
+/* Sleep this # of ms after flushing the queue */
+static int jtag_flush_queue_sleep;
+
+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),
+		int in_num_fields, struct scan_field *in_fields, tap_state_t state);
 
 /**
  * The jtag_error variable is set when an error occurs while executing
@@ -52,14 +64,13 @@ static void jtag_add_scan_check(void (*jtag_add_scan)(int in_num_fields, const s
  * when an error occurs during processing that should be reported during
  * jtag_execute_queue().
  *
- * Tts value may be checked with jtag_get_error() and cleared with
- * jtag_error_clear().  This value is returned (and cleared) by
- * jtag_execute_queue().
+ * The value is set and cleared, but never read by normal application code.
+ *
+ * This value is returned (and cleared) by jtag_execute_queue().
  */
 static int jtag_error = ERROR_OK;
 
-static const char *jtag_event_strings[] =
-{
+static const char *jtag_event_strings[] = {
 	[JTAG_TRST_ASSERTED] = "TAP reset",
 	[JTAG_TAP_EVENT_SETUP] = "TAP setup",
 	[JTAG_TAP_EVENT_ENABLE] = "TAP enabled",
@@ -78,47 +89,60 @@ static int jtag_srst = -1;
 /**
  * List all TAPs that have been created.
  */
-static jtag_tap_t *__jtag_all_taps = NULL;
+static struct jtag_tap *__jtag_all_taps;
 /**
  * The number of TAPs in the __jtag_all_taps list, used to track the
  * assigned chain position to new TAPs
  */
-static unsigned jtag_num_taps = 0;
+static unsigned jtag_num_taps;
 
 static enum reset_types jtag_reset_config = RESET_NONE;
-static tap_state_t cmd_queue_end_state = TAP_RESET;
 tap_state_t cmd_queue_cur_state = TAP_RESET;
 
 static bool jtag_verify_capture_ir = true;
 static int jtag_verify = 1;
 
-/* how long the OpenOCD should wait before attempting JTAG communication after reset lines deasserted (in ms) */
-static int jtag_nsrst_delay = 0; /* default to no nSRST delay */
-static int jtag_ntrst_delay = 0; /* default to no nTRST delay */
-static int jtag_nsrst_assert_width = 0; /* width of assertion */
-static int jtag_ntrst_assert_width = 0; /* width of assertion */
+/* how long the OpenOCD should wait before attempting JTAG communication after reset lines
+ *deasserted (in ms) */
+static int adapter_nsrst_delay;	/* default to no nSRST delay */
+static int jtag_ntrst_delay;/* default to no nTRST delay */
+static int adapter_nsrst_assert_width;	/* width of assertion */
+static int jtag_ntrst_assert_width;	/* width of assertion */
 
-typedef struct jtag_event_callback_s
-{
-	jtag_event_handler_t          callback;
-	void*                         priv;
-	struct jtag_event_callback_s* next;
-} jtag_event_callback_t;
+/**
+ * Contains a single callback along with a pointer that will be passed
+ * when an event occurs.
+ */
+struct jtag_event_callback {
+	/** a event callback */
+	jtag_event_handler_t callback;
+	/** the private data to pass to the callback */
+	void *priv;
+	/** the next callback */
+	struct jtag_event_callback *next;
+};
 
 /* callbacks to inform high-level handlers about JTAG state changes */
-static jtag_event_callback_t *jtag_event_callbacks;
+static struct jtag_event_callback *jtag_event_callbacks;
 
 /* speed in kHz*/
-static int speed_khz = 0;
+static int speed_khz;
 /* speed to fallback to when RCLK is requested but not supported */
-static int rclk_fallback_speed_khz = 0;
-static enum {CLOCK_MODE_SPEED, CLOCK_MODE_KHZ, CLOCK_MODE_RCLK} clock_mode;
-static int jtag_speed = 0;
+static int rclk_fallback_speed_khz;
+static enum {CLOCK_MODE_UNSELECTED, CLOCK_MODE_KHZ, CLOCK_MODE_RCLK} clock_mode;
+static int jtag_speed;
+
+static struct jtag_interface *jtag;
 
-static struct jtag_interface_s *jtag = NULL;
+const struct swd_driver *swd;
 
 /* configuration */
-jtag_interface_t *jtag_interface = NULL;
+struct jtag_interface *jtag_interface;
+
+void jtag_set_flush_queue_sleep(int ms)
+{
+	jtag_flush_queue_sleep = ms;
+}
 
 void jtag_set_error(int error)
 {
@@ -126,10 +150,7 @@ void jtag_set_error(int error)
 		return;
 	jtag_error = error;
 }
-int jtag_get_error(void)
-{
-	return jtag_error;
-}
+
 int jtag_error_clear(void)
 {
 	int temp = jtag_error;
@@ -164,7 +185,7 @@ void jtag_poll_set_enabled(bool value)
 
 /************/
 
-jtag_tap_t *jtag_all_taps(void)
+struct jtag_tap *jtag_all_taps(void)
 {
 	return __jtag_all_taps;
 };
@@ -176,10 +197,9 @@ unsigned jtag_tap_count(void)
 
 unsigned jtag_tap_count_enabled(void)
 {
-	jtag_tap_t *t = jtag_all_taps();
+	struct jtag_tap *t = jtag_all_taps();
 	unsigned n = 0;
-	while (t)
-	{
+	while (t) {
 		if (t->enabled)
 			n++;
 		t = t->next_tap;
@@ -187,21 +207,21 @@ unsigned jtag_tap_count_enabled(void)
 	return n;
 }
 
-/// Append a new TAP to the chain of all taps.
-void jtag_tap_add(struct jtag_tap_s *t)
+/** Append a new TAP to the chain of all taps. */
+void jtag_tap_add(struct jtag_tap *t)
 {
 	t->abs_chain_position = jtag_num_taps++;
 
-	jtag_tap_t **tap = &__jtag_all_taps;
+	struct jtag_tap **tap = &__jtag_all_taps;
 	while (*tap != NULL)
 		tap = &(*tap)->next_tap;
 	*tap = t;
 }
 
 /* returns a pointer to the n-th device in the scan chain */
-static inline jtag_tap_t *jtag_tap_by_position(unsigned n)
+struct jtag_tap *jtag_tap_by_position(unsigned n)
 {
-	jtag_tap_t *t = jtag_all_taps();
+	struct jtag_tap *t = jtag_all_taps();
 
 	while (t && n-- > 0)
 		t = t->next_tap;
@@ -209,13 +229,12 @@ static inline jtag_tap_t *jtag_tap_by_position(unsigned n)
 	return t;
 }
 
-jtag_tap_t *jtag_tap_by_string(const char *s)
+struct jtag_tap *jtag_tap_by_string(const char *s)
 {
 	/* try by name first */
-	jtag_tap_t *t = jtag_all_taps();
+	struct jtag_tap *t = jtag_all_taps();
 
-	while (t)
-	{
+	while (t) {
 		if (0 == strcmp(t->dotted_name, s))
 			return t;
 		t = t->next_tap;
@@ -238,22 +257,10 @@ jtag_tap_t *jtag_tap_by_string(const char *s)
 	return t;
 }
 
-jtag_tap_t *jtag_tap_by_jim_obj(Jim_Interp *interp, Jim_Obj *o)
-{
-	const char *cp = Jim_GetString(o, NULL);
-	jtag_tap_t *t = cp ? jtag_tap_by_string(cp) : NULL;
-	if (NULL == cp)
-		cp = "(unknown)";
-	if (NULL == t)
-		Jim_SetResult_sprintf(interp, "Tap '%s' could not be found", cp);
-	return t;
-}
-
-jtag_tap_t* jtag_tap_next_enabled(jtag_tap_t* p)
+struct jtag_tap *jtag_tap_next_enabled(struct jtag_tap *p)
 {
 	p = p ? p->next_tap : jtag_all_taps();
-	while (p)
-	{
+	while (p) {
 		if (p->enabled)
 			return p;
 		p = p->next_tap;
@@ -261,7 +268,7 @@ jtag_tap_t* jtag_tap_next_enabled(jtag_tap_t* p)
 	return NULL;
 }
 
-const char *jtag_tap_name(const jtag_tap_t *tap)
+const char *jtag_tap_name(const struct jtag_tap *tap)
 {
 	return (tap == NULL) ? "(unknown)" : tap->dotted_name;
 }
@@ -269,21 +276,18 @@ const char *jtag_tap_name(const jtag_tap_t *tap)
 
 int jtag_register_event_callback(jtag_event_handler_t callback, void *priv)
 {
-	jtag_event_callback_t **callbacks_p = &jtag_event_callbacks;
+	struct jtag_event_callback **callbacks_p = &jtag_event_callbacks;
 
 	if (callback == NULL)
-	{
-		return ERROR_INVALID_ARGUMENTS;
-	}
+		return ERROR_COMMAND_SYNTAX_ERROR;
 
-	if (*callbacks_p)
-	{
+	if (*callbacks_p) {
 		while ((*callbacks_p)->next)
 			callbacks_p = &((*callbacks_p)->next);
 		callbacks_p = &((*callbacks_p)->next);
 	}
 
-	(*callbacks_p) = malloc(sizeof(jtag_event_callback_t));
+	(*callbacks_p) = malloc(sizeof(struct jtag_event_callback));
 	(*callbacks_p)->callback = callback;
 	(*callbacks_p)->priv = priv;
 	(*callbacks_p)->next = NULL;
@@ -293,28 +297,20 @@ int jtag_register_event_callback(jtag_event_handler_t callback, void *priv)
 
 int jtag_unregister_event_callback(jtag_event_handler_t callback, void *priv)
 {
-	jtag_event_callback_t **callbacks_p;
-	jtag_event_callback_t **next;
+	struct jtag_event_callback **p = &jtag_event_callbacks, *temp;
 
 	if (callback == NULL)
-	{
-		return ERROR_INVALID_ARGUMENTS;
-	}
+		return ERROR_COMMAND_SYNTAX_ERROR;
 
-	for (callbacks_p = &jtag_event_callbacks;
-			*callbacks_p != NULL;
-			callbacks_p = next)
-	{
-		next = &((*callbacks_p)->next);
-
-		if ((*callbacks_p)->priv != priv)
+	while (*p) {
+		if (((*p)->priv != priv) || ((*p)->callback != callback)) {
+			p = &(*p)->next;
 			continue;
-
-		if ((*callbacks_p)->callback == callback)
-		{
-			free(*callbacks_p);
-			*callbacks_p = *next;
 		}
+
+		temp = *p;
+		*p = (*p)->next;
+		free(temp);
 	}
 
 	return ERROR_OK;
@@ -322,13 +318,12 @@ int jtag_unregister_event_callback(jtag_event_handler_t callback, void *priv)
 
 int jtag_call_event_callbacks(enum jtag_event event)
 {
-	jtag_event_callback_t *callback = jtag_event_callbacks;
+	struct jtag_event_callback *callback = jtag_event_callbacks;
 
 	LOG_DEBUG("jtag event: %s", jtag_event_strings[event]);
 
-	while (callback)
-	{
-		jtag_event_callback_t *next;
+	while (callback) {
+		struct jtag_event_callback *next;
 
 		/* callback may remove itself */
 		next = callback->next;
@@ -353,163 +348,129 @@ static void jtag_prelude(tap_state_t state)
 	cmd_queue_cur_state = state;
 }
 
-void jtag_alloc_in_value32(scan_field_t *field)
-{
-	interface_jtag_alloc_in_value32(field);
-}
-
-void jtag_add_ir_scan_noverify(int in_count, const scan_field_t *in_fields,
-		tap_state_t state)
+void jtag_add_ir_scan_noverify(struct jtag_tap *active, const struct scan_field *in_fields,
+	tap_state_t state)
 {
 	jtag_prelude(state);
 
-	int retval = interface_jtag_add_ir_scan(in_count, in_fields, state);
+	int retval = interface_jtag_add_ir_scan(active, in_fields, state);
 	jtag_set_error(retval);
 }
 
+static void jtag_add_ir_scan_noverify_callback(struct jtag_tap *active,
+	int dummy,
+	const struct scan_field *in_fields,
+	tap_state_t state)
+{
+	jtag_add_ir_scan_noverify(active, in_fields, state);
+}
 
-void jtag_add_ir_scan(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+/* If fields->in_value is filled out, then the captured IR value will be checked */
+void jtag_add_ir_scan(struct jtag_tap *active, struct scan_field *in_fields, tap_state_t state)
 {
 	assert(state != TAP_RESET);
 
-	if (jtag_verify && jtag_verify_capture_ir)
-	{
+	if (jtag_verify && jtag_verify_capture_ir) {
 		/* 8 x 32 bit id's is enough for all invocations */
 
-		for (int j = 0; j < in_num_fields; j++)
-		{
-			/* if we are to run a verification of the ir scan, we need to get the input back.
-			 * We may have to allocate space if the caller didn't ask for the input back.
-			 */
-			in_fields[j].check_value = in_fields[j].tap->expected;
-			in_fields[j].check_mask = in_fields[j].tap->expected_mask;
-		}
-		jtag_add_scan_check(jtag_add_ir_scan_noverify, in_num_fields, in_fields, state);
+		/* if we are to run a verification of the ir scan, we need to get the input back.
+		 * We may have to allocate space if the caller didn't ask for the input back.
+		 */
+		in_fields->check_value = active->expected;
+		in_fields->check_mask = active->expected_mask;
+		jtag_add_scan_check(active, jtag_add_ir_scan_noverify_callback, 1, in_fields,
+			state);
 	} else
-	{
-		jtag_add_ir_scan_noverify(in_num_fields, in_fields, state);
-	}
+		jtag_add_ir_scan_noverify(active, in_fields, state);
 }
 
-void jtag_add_plain_ir_scan(int in_num_fields, const scan_field_t *in_fields,
-		tap_state_t state)
+void jtag_add_plain_ir_scan(int num_bits, const uint8_t *out_bits, uint8_t *in_bits,
+	tap_state_t state)
 {
+	assert(out_bits != NULL);
 	assert(state != TAP_RESET);
 
 	jtag_prelude(state);
 
 	int retval = interface_jtag_add_plain_ir_scan(
-			in_num_fields, in_fields, state);
+			num_bits, out_bits, in_bits, state);
 	jtag_set_error(retval);
 }
 
-void jtag_add_callback(jtag_callback1_t f, jtag_callback_data_t data0)
-{
-	interface_jtag_add_callback(f, data0);
-}
-
-void jtag_add_callback4(jtag_callback_t f, jtag_callback_data_t data0,
-		jtag_callback_data_t data1, jtag_callback_data_t data2,
-		jtag_callback_data_t data3)
-{
-	interface_jtag_add_callback4(f, data0, data1, data2, data3);
-}
-
 static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
-		uint8_t *in_check_mask, int num_bits);
+				  uint8_t *in_check_mask, int num_bits);
 
-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)
+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)
 {
-	return jtag_check_value_inner((uint8_t *)data0, (uint8_t *)data1, (uint8_t *)data2, (int)data3);
+	return jtag_check_value_inner((uint8_t *)data0,
+		(uint8_t *)data1,
+		(uint8_t *)data2,
+		(int)data3);
 }
 
-static void jtag_add_scan_check(void (*jtag_add_scan)(int in_num_fields, const scan_field_t *in_fields, tap_state_t state),
-		int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+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),
+	int in_num_fields, struct scan_field *in_fields, tap_state_t state)
 {
-	for (int i = 0; i < in_num_fields; i++)
-	{
-		struct scan_field_s *field = &in_fields[i];
-		field->allocated = 0;
-		field->modified = 0;
-		if (field->check_value || field->in_value)
-			continue;
-		interface_jtag_add_scan_check_alloc(field);
-		field->modified = 1;
-	}
+	jtag_add_scan(active, in_num_fields, in_fields, state);
 
-	jtag_add_scan(in_num_fields, in_fields, state);
-
-	for (int i = 0; i < in_num_fields; i++)
-	{
-		if ((in_fields[i].check_value != NULL) && (in_fields[i].in_value != NULL))
-		{
+	for (int i = 0; i < in_num_fields; i++) {
+		if ((in_fields[i].check_value != NULL) && (in_fields[i].in_value != NULL)) {
 			/* this is synchronous for a minidriver */
-			jtag_add_callback4(jtag_check_value_mask_callback, (jtag_callback_data_t)in_fields[i].in_value,
+			jtag_add_callback4(jtag_check_value_mask_callback,
+				(jtag_callback_data_t)in_fields[i].in_value,
 				(jtag_callback_data_t)in_fields[i].check_value,
 				(jtag_callback_data_t)in_fields[i].check_mask,
 				(jtag_callback_data_t)in_fields[i].num_bits);
 		}
-		if (in_fields[i].allocated)
-		{
-			free(in_fields[i].in_value);
-		}
-		if (in_fields[i].modified)
-		{
-			in_fields[i].in_value = NULL;
-		}
 	}
 }
 
-void jtag_add_dr_scan_check(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+void jtag_add_dr_scan_check(struct jtag_tap *active,
+	int in_num_fields,
+	struct scan_field *in_fields,
+	tap_state_t state)
 {
 	if (jtag_verify)
-	{
-		jtag_add_scan_check(jtag_add_dr_scan, in_num_fields, in_fields, state);
-	} else
-	{
-		jtag_add_dr_scan(in_num_fields, in_fields, state);
-	}
+		jtag_add_scan_check(active, jtag_add_dr_scan, in_num_fields, in_fields, state);
+	else
+		jtag_add_dr_scan(active, in_num_fields, in_fields, state);
 }
 
 
-void jtag_add_dr_scan(int in_num_fields, const scan_field_t *in_fields,
-		tap_state_t state)
+void jtag_add_dr_scan(struct jtag_tap *active,
+	int in_num_fields,
+	const struct scan_field *in_fields,
+	tap_state_t state)
 {
 	assert(state != TAP_RESET);
 
 	jtag_prelude(state);
 
 	int retval;
-	retval = interface_jtag_add_dr_scan(in_num_fields, in_fields, state);
+	retval = interface_jtag_add_dr_scan(active, in_num_fields, in_fields, state);
 	jtag_set_error(retval);
 }
 
-void jtag_add_plain_dr_scan(int in_num_fields, const scan_field_t *in_fields,
-		tap_state_t state)
+void jtag_add_plain_dr_scan(int num_bits, const uint8_t *out_bits, uint8_t *in_bits,
+	tap_state_t state)
 {
+	assert(out_bits != NULL);
 	assert(state != TAP_RESET);
 
 	jtag_prelude(state);
 
 	int retval;
-	retval = interface_jtag_add_plain_dr_scan(in_num_fields, in_fields, state);
+	retval = interface_jtag_add_plain_dr_scan(num_bits, out_bits, in_bits, state);
 	jtag_set_error(retval);
 }
 
-void jtag_add_dr_out(jtag_tap_t* tap,
-		int num_fields, const int* num_bits, const uint32_t* value,
-		tap_state_t end_state)
-{
-	assert(end_state != TAP_RESET);
-	assert(end_state != TAP_INVALID);
-
-	cmd_queue_cur_state = end_state;
-
-	interface_jtag_add_dr_out(tap,
-			num_fields, num_bits, value,
-			end_state);
-}
-
 void jtag_add_tlr(void)
 {
 	jtag_prelude(TAP_RESET);
@@ -520,32 +481,57 @@ void jtag_add_tlr(void)
 	jtag_notify_event(JTAG_TRST_ASSERTED);
 }
 
+/**
+ * If supported by the underlying adapter, this clocks a raw bit sequence
+ * onto TMS for switching betwen JTAG and SWD modes.
+ *
+ * DO NOT use this to bypass the integrity checks and logging provided
+ * by the jtag_add_pathmove() and jtag_add_statemove() calls.
+ *
+ * @param nbits How many bits to clock out.
+ * @param seq The bit sequence.  The LSB is bit 0 of seq[0].
+ * @param state The JTAG tap state to record on completion.  Use
+ *	TAP_INVALID to represent being in in SWD mode.
+ *
+ * @todo Update naming conventions to stop assuming everything is JTAG.
+ */
+int jtag_add_tms_seq(unsigned nbits, const uint8_t *seq, enum tap_state state)
+{
+	int retval;
+
+	if (!(jtag->supported & DEBUG_CAP_TMS_SEQ))
+		return ERROR_JTAG_NOT_IMPLEMENTED;
+
+	jtag_checks();
+	cmd_queue_cur_state = state;
+
+	retval = interface_add_tms_seq(nbits, seq, state);
+	jtag_set_error(retval);
+	return retval;
+}
+
 void jtag_add_pathmove(int num_states, const tap_state_t *path)
 {
 	tap_state_t cur_state = cmd_queue_cur_state;
 
 	/* the last state has to be a stable state */
-	if (!tap_is_state_stable(path[num_states - 1]))
-	{
+	if (!tap_is_state_stable(path[num_states - 1])) {
 		LOG_ERROR("BUG: TAP path doesn't finish in a stable state");
 		jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
 		return;
 	}
 
-	for (int i = 0; i < num_states; i++)
-	{
-		if (path[i] == TAP_RESET)
-		{
+	for (int i = 0; i < num_states; i++) {
+		if (path[i] == TAP_RESET) {
 			LOG_ERROR("BUG: TAP_RESET is not a valid state for pathmove sequences");
 			jtag_set_error(ERROR_JTAG_STATE_INVALID);
 			return;
 		}
 
-		if (tap_state_transition(cur_state, true)  != path[i]
-		  && tap_state_transition(cur_state, false) != path[i])
-		{
+		if (tap_state_transition(cur_state, true) != path[i] &&
+				tap_state_transition(cur_state, false) != path[i]) {
 			LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
-					tap_state_name(cur_state), tap_state_name(path[i]));
+				tap_state_name(cur_state), tap_state_name(path[i]));
 			jtag_set_error(ERROR_JTAG_TRANSITION_INVALID);
 			return;
 		}
@@ -562,26 +548,27 @@ int jtag_add_statemove(tap_state_t goal_state)
 {
 	tap_state_t cur_state = cmd_queue_cur_state;
 
-	LOG_DEBUG("cur_state=%s goal_state=%s",
-		tap_state_name(cur_state),
-		tap_state_name(goal_state));
-
+	if (goal_state != cur_state) {
+		LOG_DEBUG("cur_state=%s goal_state=%s",
+			tap_state_name(cur_state),
+			tap_state_name(goal_state));
+	}
 
-	if (goal_state == cur_state)
-		;	/* nothing to do */
-	else if (goal_state == TAP_RESET)
-	{
+	/* If goal is RESET, be paranoid and force that that transition
+	 * (e.g. five TCK cycles, TMS high).  Else trust "cur_state".
+	 */
+	if (goal_state == TAP_RESET)
 		jtag_add_tlr();
-	}
-	else if (tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state))
-	{
+	else if (goal_state == cur_state)
+		/* nothing to do */;
+
+	else if (tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state)) {
 		unsigned tms_bits  = tap_get_tms_path(cur_state, goal_state);
 		unsigned tms_count = tap_get_tms_path_len(cur_state, goal_state);
 		tap_state_t moves[8];
-		assert(tms_count < DIM(moves));
+		assert(tms_count < ARRAY_SIZE(moves));
 
-		for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1)
-		{
+		for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1) {
 			bool bit = tms_bits & 1;
 
 			cur_state = tap_state_transition(cur_state, bit);
@@ -589,13 +576,9 @@ int jtag_add_statemove(tap_state_t goal_state)
 		}
 
 		jtag_add_pathmove(tms_count, moves);
-	}
-	else if (tap_state_transition(cur_state, true)  == goal_state
-		||   tap_state_transition(cur_state, false) == goal_state)
-	{
+	} else if (tap_state_transition(cur_state, true)  == goal_state
+			|| tap_state_transition(cur_state, false) == goal_state)
 		jtag_add_pathmove(1, &goal_state);
-	}
-
 	else
 		return ERROR_FAIL;
 
@@ -611,21 +594,59 @@ void jtag_add_runtest(int num_cycles, tap_state_t state)
 
 void jtag_add_clocks(int num_cycles)
 {
-	if (!tap_is_state_stable(cmd_queue_cur_state))
-	{
-		 LOG_ERROR("jtag_add_clocks() called with TAP in unstable state \"%s\"",
-				 tap_state_name(cmd_queue_cur_state));
-		 jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
-		 return;
+	if (!tap_is_state_stable(cmd_queue_cur_state)) {
+		LOG_ERROR("jtag_add_clocks() called with TAP in unstable state \"%s\"",
+			tap_state_name(cmd_queue_cur_state));
+		jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
+		return;
 	}
 
-	if (num_cycles > 0)
-	{
+	if (num_cycles > 0) {
 		jtag_checks();
 		jtag_set_error(interface_jtag_add_clocks(num_cycles));
 	}
 }
 
+void swd_add_reset(int req_srst)
+{
+	if (req_srst) {
+		if (!(jtag_reset_config & RESET_HAS_SRST)) {
+			LOG_ERROR("BUG: can't assert SRST");
+			jtag_set_error(ERROR_FAIL);
+			return;
+		}
+		req_srst = 1;
+	}
+
+	/* Maybe change SRST signal state */
+	if (jtag_srst != req_srst) {
+		int retval;
+
+		retval = interface_jtag_add_reset(0, req_srst);
+		if (retval != ERROR_OK)
+			jtag_set_error(retval);
+		else
+			retval = jtag_execute_queue();
+
+		if (retval != ERROR_OK) {
+			LOG_ERROR("TRST/SRST error");
+			return;
+		}
+
+		/* SRST resets everything hooked up to that signal */
+		jtag_srst = req_srst;
+		if (jtag_srst) {
+			LOG_DEBUG("SRST line asserted");
+			if (adapter_nsrst_assert_width)
+				jtag_add_sleep(adapter_nsrst_assert_width * 1000);
+		} else {
+			LOG_DEBUG("SRST line released");
+			if (adapter_nsrst_delay)
+				jtag_add_sleep(adapter_nsrst_delay * 1000);
+		}
+	}
+}
+
 void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 {
 	int trst_with_tlr = 0;
@@ -665,7 +686,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 		if (!(jtag_reset_config & RESET_HAS_TRST))
 			trst_with_tlr = 1;
 		else if ((jtag_reset_config & RESET_TRST_PULLS_SRST) != 0
-				&& !req_srst)
+			 && !req_srst)
 			trst_with_tlr = 1;
 		else
 			new_trst = 1;
@@ -682,7 +703,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 			retval = jtag_execute_queue();
 
 		if (retval != ERROR_OK) {
-			LOG_ERROR("TRST/SRST error %d", retval);
+			LOG_ERROR("TRST/SRST error");
 			return;
 		}
 	}
@@ -690,16 +711,14 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 	/* SRST resets everything hooked up to that signal */
 	if (jtag_srst != new_srst) {
 		jtag_srst = new_srst;
-		if (jtag_srst)
-		{
+		if (jtag_srst) {
 			LOG_DEBUG("SRST line asserted");
-			if (jtag_nsrst_assert_width)
-				jtag_add_sleep(jtag_nsrst_assert_width * 1000);
-		}
-		else {
+			if (adapter_nsrst_assert_width)
+				jtag_add_sleep(adapter_nsrst_assert_width * 1000);
+		} else {
 			LOG_DEBUG("SRST line released");
-			if (jtag_nsrst_delay)
-				jtag_add_sleep(jtag_nsrst_delay * 1000);
+			if (adapter_nsrst_delay)
+				jtag_add_sleep(adapter_nsrst_delay * 1000);
 		}
 	}
 
@@ -711,7 +730,6 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 	 */
 	if (trst_with_tlr) {
 		LOG_DEBUG("JTAG reset with TLR instead of TRST");
-		jtag_set_end_state(TAP_RESET);
 		jtag_add_tlr();
 
 	} else if (jtag_trst != new_trst) {
@@ -737,36 +755,18 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 	}
 }
 
-tap_state_t jtag_set_end_state(tap_state_t state)
-{
-	if ((state == TAP_DRSHIFT)||(state == TAP_IRSHIFT))
-	{
-		LOG_ERROR("BUG: TAP_DRSHIFT/IRSHIFT can't be end state. Calling code should use a larger scan field");
-	}
-
-	if (state != TAP_INVALID)
-		cmd_queue_end_state = state;
-	return cmd_queue_end_state;
-}
-
-tap_state_t jtag_get_end_state(void)
-{
-	return cmd_queue_end_state;
-}
-
 void jtag_add_sleep(uint32_t us)
 {
-	/// @todo Here, keep_alive() appears to be a layering violation!!!
+	/** @todo Here, keep_alive() appears to be a layering violation!!! */
 	keep_alive();
 	jtag_set_error(interface_jtag_add_sleep(us));
 }
 
 static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
-		uint8_t *in_check_mask, int num_bits)
+	uint8_t *in_check_mask, int num_bits)
 {
 	int retval = ERROR_OK;
-
-	int compare_failed = 0;
+	int compare_failed;
 
 	if (in_check_mask)
 		compare_failed = buf_cmp_mask(captured, in_check_value, in_check_mask, num_bits);
@@ -775,9 +775,7 @@ static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
 
 	if (compare_failed) {
 		char *captured_str, *in_check_value_str;
-		int bits = (num_bits > DEBUG_JTAG_IOZ)
-				? DEBUG_JTAG_IOZ
-				: num_bits;
+		int bits = (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits;
 
 		/* NOTE:  we've lost diagnostic context here -- 'which tap' */
 
@@ -785,7 +783,7 @@ static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
 		in_check_value_str = buf_to_str(in_check_value, bits, 16);
 
 		LOG_WARNING("Bad value '%s' captured during DR or IR scan:",
-				captured_str);
+			captured_str);
 		LOG_WARNING(" check_value: 0x%s", in_check_value_str);
 
 		free(captured_str);
@@ -804,12 +802,11 @@ static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
 	return retval;
 }
 
-void jtag_check_value_mask(scan_field_t *field, uint8_t *value, uint8_t *mask)
+void jtag_check_value_mask(struct scan_field *field, uint8_t *value, uint8_t *mask)
 {
 	assert(field->in_value != NULL);
 
-	if (value == NULL)
-	{
+	if (value == NULL) {
 		/* no checking to do */
 		return;
 	}
@@ -820,12 +817,9 @@ void jtag_check_value_mask(scan_field_t *field, uint8_t *value, uint8_t *mask)
 	jtag_set_error(retval);
 }
 
-
-
 int default_interface_jtag_execute_queue(void)
 {
-	if (NULL == jtag)
-	{
+	if (NULL == jtag) {
 		LOG_ERROR("No JTAG interface configured yet.  "
 			"Issue 'init' command in startup scripts "
 			"before communicating with targets.");
@@ -839,6 +833,14 @@ void jtag_execute_queue_noclear(void)
 {
 	jtag_flush_queue_count++;
 	jtag_set_error(interface_jtag_execute_queue());
+
+	if (jtag_flush_queue_sleep > 0) {
+		/* For debug purposes it can be useful to test performance
+		 * or behavior when delaying after flushing the queue,
+		 * e.g. to simulate long roundtrip times.
+		 */
+		usleep(jtag_flush_queue_sleep * 1000);
+	}
 }
 
 int jtag_get_flush_queue_count(void)
@@ -854,10 +856,9 @@ int jtag_execute_queue(void)
 
 static int jtag_reset_callback(enum jtag_event event, void *priv)
 {
-	jtag_tap_t *tap = priv;
+	struct jtag_tap *tap = priv;
 
-	if (event == JTAG_TRST_ASSERTED)
-	{
+	if (event == JTAG_TRST_ASSERTED) {
 		tap->enabled = !tap->disabled_after_reset;
 
 		/* current instruction is either BYPASS or IDCODE */
@@ -868,9 +869,16 @@ static int jtag_reset_callback(enum jtag_event event, void *priv)
 	return ERROR_OK;
 }
 
+/* sleep at least us microseconds. When we sleep more than 1000ms we
+ * do an alive sleep, i.e. keep GDB alive. Note that we could starve
+ * GDB if we slept for <1000ms many times.
+ */
 void jtag_sleep(uint32_t us)
 {
-	alive_sleep(us/1000);
+	if (us < 1000)
+		usleep(us);
+	else
+		alive_sleep((us+999)/1000);
 }
 
 /* Maximum number of enabled JTAG devices we expect in the scan chain,
@@ -886,22 +894,24 @@ void jtag_sleep(uint32_t us)
 /* A reserved manufacturer ID is used in END_OF_CHAIN_FLAG, so we
  * know that no valid TAP will have it as an IDCODE value.
  */
-#define END_OF_CHAIN_FLAG	0x000000ff
+#define END_OF_CHAIN_FLAG       0xffffffff
+
+/* a larger IR length than we ever expect to autoprobe */
+#define JTAG_IRLEN_MAX          60
 
 static int jtag_examine_chain_execute(uint8_t *idcode_buffer, unsigned num_idcode)
 {
-	scan_field_t field = {
-			.tap = NULL,
-			.num_bits = num_idcode * 32,
-			.out_value = idcode_buffer,
-			.in_value = idcode_buffer,
-		};
+	struct scan_field field = {
+		.num_bits = num_idcode * 32,
+		.out_value = idcode_buffer,
+		.in_value = idcode_buffer,
+	};
 
-	// initialize to the end of chain ID value
+	/* initialize to the end of chain ID value */
 	for (unsigned i = 0; i < JTAG_MAX_CHAIN_SIZE; i++)
 		buf_set_u32(idcode_buffer, i * 32, 32, END_OF_CHAIN_FLAG);
 
-	jtag_add_plain_dr_scan(1, &field, TAP_DRPAUSE);
+	jtag_add_plain_dr_scan(field.num_bits, field.out_value, field.in_value, TAP_DRPAUSE);
 	jtag_add_tlr();
 	return jtag_execute_queue();
 }
@@ -911,8 +921,7 @@ static bool jtag_examine_chain_check(uint8_t *idcodes, unsigned count)
 	uint8_t zero_check = 0x0;
 	uint8_t one_check = 0xff;
 
-	for (unsigned i = 0; i < count * 4; i++)
-	{
+	for (unsigned i = 0; i < count * 4; i++) {
 		zero_check |= idcodes[i];
 		one_check &= idcodes[i];
 	}
@@ -927,10 +936,9 @@ static bool jtag_examine_chain_check(uint8_t *idcodes, unsigned count)
 	 *     + there are several hundreds of TAPs in bypass, or
 	 *     + at least a few dozen TAPs all have an all-ones IDCODE
 	 */
-	if (zero_check == 0x00 || one_check == 0xff)
-	{
+	if (zero_check == 0x00 || one_check == 0xff) {
 		LOG_ERROR("JTAG scan chain interrogation failed: all %s",
-				(zero_check == 0x00) ? "zeroes" : "ones");
+			(zero_check == 0x00) ? "zeroes" : "ones");
 		LOG_ERROR("Check JTAG interface, timings, target power, etc.");
 		return false;
 	}
@@ -938,26 +946,26 @@ static bool jtag_examine_chain_check(uint8_t *idcodes, unsigned count)
 }
 
 static void jtag_examine_chain_display(enum log_levels level, const char *msg,
-		const char *name, uint32_t idcode)
+	const char *name, uint32_t idcode)
 {
-	log_printf_lf(level, __FILE__, __LINE__, __FUNCTION__,
-				  "JTAG tap: %s %16.16s: 0x%08x "
-				  "(mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
-				  name, msg,
-				  (unsigned int)idcode,
-				  (unsigned int)EXTRACT_MFG(idcode),
-				  (unsigned int)EXTRACT_PART(idcode),
-				  (unsigned int)EXTRACT_VER(idcode));
+	log_printf_lf(level, __FILE__, __LINE__, __func__,
+		"JTAG tap: %s %16.16s: 0x%08x "
+		"(mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
+		name, msg,
+		(unsigned int)idcode,
+		(unsigned int)EXTRACT_MFG(idcode),
+		(unsigned int)EXTRACT_PART(idcode),
+		(unsigned int)EXTRACT_VER(idcode));
 }
 
 static bool jtag_idcode_is_final(uint32_t idcode)
 {
 	/*
 	 * Some devices, such as AVR8, will output all 1's instead
-	 * of TDI input value at end of chain.  Allow those values
+	 * of TDI input value at end of chain. Allow those values
 	 * instead of failing.
 	 */
-	return idcode == END_OF_CHAIN_FLAG || idcode == 0xFFFFFFFF;
+	return idcode == END_OF_CHAIN_FLAG;
 }
 
 /**
@@ -970,31 +978,39 @@ static bool jtag_idcode_is_final(uint32_t idcode)
 static bool jtag_examine_chain_end(uint8_t *idcodes, unsigned count, unsigned max)
 {
 	bool triggered = false;
-	for (; count < max - 31; count += 32)
-	{
+	for (; count < max - 31; count += 32) {
 		uint32_t idcode = buf_get_u32(idcodes, count, 32);
 
 		/* do not trigger the warning if the data looks good */
 		if (jtag_idcode_is_final(idcode))
 			continue;
 		LOG_WARNING("Unexpected idcode after end of chain: %d 0x%08x",
-					count, (unsigned int)idcode);
+			count, (unsigned int)idcode);
 		triggered = true;
 	}
 	return triggered;
 }
 
-static bool jtag_examine_chain_match_tap(const struct jtag_tap_s *tap)
+static bool jtag_examine_chain_match_tap(const struct jtag_tap *tap)
 {
+	uint32_t idcode = tap->idcode;
+
 	/* ignore expected BYPASS codes; warn otherwise */
-	if (0 == tap->expected_ids_cnt && !tap->idcode)
+	if (0 == tap->expected_ids_cnt && !idcode)
 		return true;
 
+	/* optionally ignore the JTAG version field - bits 28-31 of IDCODE */
+	uint32_t mask = tap->ignore_version ? ~(0xf << 28) : ~0;
+
+	idcode &= mask;
+
 	/* Loop over the expected identification codes and test for a match */
-	uint8_t ii;
-	for (ii = 0; ii < tap->expected_ids_cnt; ii++)
-	{
-		if (tap->idcode == tap->expected_ids[ii])
+	unsigned ii, limit = tap->expected_ids_cnt;
+
+	for (ii = 0; ii < limit; ii++) {
+		uint32_t expected = tap->expected_ids[ii] & mask;
+
+		if (idcode == expected)
 			return true;
 
 		/* treat "-expected-id 0" as a "don't-warn" wildcard */
@@ -1004,14 +1020,13 @@ static bool jtag_examine_chain_match_tap(const struct jtag_tap_s *tap)
 
 	/* If none of the expected ids matched, warn */
 	jtag_examine_chain_display(LOG_LVL_WARNING, "UNEXPECTED",
-			tap->dotted_name, tap->idcode);
-	for (ii = 0; ii < tap->expected_ids_cnt; ii++)
-	{
+		tap->dotted_name, tap->idcode);
+	for (ii = 0; ii < limit; ii++) {
 		char msg[32];
-		snprintf(msg, sizeof(msg), "expected %hhu of %hhu",
-				ii + 1, tap->expected_ids_cnt);
+
+		snprintf(msg, sizeof(msg), "expected %u of %u", ii + 1, limit);
 		jtag_examine_chain_display(LOG_LVL_ERROR, msg,
-				tap->dotted_name, tap->expected_ids[ii]);
+			tap->dotted_name, tap->expected_ids[ii]);
 	}
 	return false;
 }
@@ -1024,6 +1039,8 @@ static int jtag_examine_chain(void)
 	uint8_t idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
 	unsigned bit_count;
 	int retval;
+	int tapcount = 0;
+	bool autoprobe = false;
 
 	/* DR scan to collect BYPASS or IDCODE register contents.
 	 * Then make sure the scan data has both ones and zeroes.
@@ -1036,36 +1053,30 @@ static int jtag_examine_chain(void)
 		return ERROR_JTAG_INIT_FAILED;
 
 	/* point at the 1st tap */
-	jtag_tap_t *tap = jtag_tap_next_enabled(NULL);
-	if (tap == NULL)
-	{
-		LOG_ERROR("JTAG: No taps enabled?");
-		return ERROR_JTAG_INIT_FAILED;
-	}
+	struct jtag_tap *tap = jtag_tap_next_enabled(NULL);
+
+	if (!tap)
+		autoprobe = true;
 
 	for (bit_count = 0;
-			tap && bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;
-			tap = jtag_tap_next_enabled(tap))
-	{
+	     tap && bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;
+	     tap = jtag_tap_next_enabled(tap)) {
 		uint32_t idcode = buf_get_u32(idcode_buffer, bit_count, 32);
 
-		if ((idcode & 1) == 0)
-		{
+		if ((idcode & 1) == 0) {
 			/* Zero for LSB indicates a device in bypass */
-			LOG_WARNING("TAP %s does not have IDCODE",
-					tap->dotted_name);
+			LOG_INFO("TAP %s does not have IDCODE",
+				tap->dotted_name);
 			idcode = 0;
 			tap->hasidcode = false;
 
 			bit_count += 1;
-		}
-		else
-		{
+		} else {
 			/* Friendly devices support IDCODE */
 			tap->hasidcode = true;
 			jtag_examine_chain_display(LOG_LVL_INFO,
-					"tap/device found",
-					tap->dotted_name, idcode);
+				"tap/device found",
+				tap->dotted_name, idcode);
 
 			bit_count += 32;
 		}
@@ -1079,17 +1090,70 @@ static int jtag_examine_chain(void)
 	/* Fail if too many TAPs were enabled for us to verify them all. */
 	if (tap) {
 		LOG_ERROR("Too many TAPs enabled; '%s' ignored.",
-				tap->dotted_name);
+			tap->dotted_name);
 		return ERROR_JTAG_INIT_FAILED;
 	}
 
+	/* if autoprobing, the tap list is still empty ... populate it! */
+	while (autoprobe && bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31) {
+		uint32_t idcode;
+		char buf[12];
+
+		/* Is there another TAP? */
+		idcode = buf_get_u32(idcode_buffer, bit_count, 32);
+		if (jtag_idcode_is_final(idcode))
+			break;
+
+		/* Default everything in this TAP except IR length.
+		 *
+		 * REVISIT create a jtag_alloc(chip, tap) routine, and
+		 * share it with jim_newtap_cmd().
+		 */
+		tap = calloc(1, sizeof *tap);
+		if (!tap)
+			return ERROR_FAIL;
+
+		sprintf(buf, "auto%d", tapcount++);
+		tap->chip = strdup(buf);
+		tap->tapname = strdup("tap");
+
+		sprintf(buf, "%s.%s", tap->chip, tap->tapname);
+		tap->dotted_name = strdup(buf);
+
+		/* tap->ir_length == 0 ... signifying irlen autoprobe */
+		tap->ir_capture_mask = 0x03;
+		tap->ir_capture_value = 0x01;
+
+		tap->enabled = true;
+
+		if ((idcode & 1) == 0) {
+			bit_count += 1;
+			tap->hasidcode = false;
+		} else {
+			bit_count += 32;
+			tap->hasidcode = true;
+			tap->idcode = idcode;
+
+			tap->expected_ids_cnt = 1;
+			tap->expected_ids = malloc(sizeof(uint32_t));
+			tap->expected_ids[0] = idcode;
+		}
+
+		LOG_WARNING("AUTO %s - use \"jtag newtap "
+			"%s %s -expected-id 0x%8.8" PRIx32 " ...\"",
+			tap->dotted_name, tap->chip, tap->tapname,
+			tap->idcode);
+
+		jtag_tap_init(tap);
+	}
+
 	/* After those IDCODE or BYPASS register values should be
 	 * only the data we fed into the scan chain.
 	 */
 	if (jtag_examine_chain_end(idcode_buffer, bit_count,
-			8 * sizeof(idcode_buffer))) {
+		    8 * sizeof(idcode_buffer))) {
 		LOG_ERROR("double-check your JTAG setup (interface, "
-				"speed, missing TAPs, ...)");
+			"speed, missing TAPs, ...)");
 		return ERROR_JTAG_INIT_FAILED;
 	}
 
@@ -1109,35 +1173,37 @@ static int jtag_examine_chain(void)
  */
 static int jtag_validate_ircapture(void)
 {
-	jtag_tap_t *tap;
+	struct jtag_tap *tap;
 	int total_ir_length = 0;
 	uint8_t *ir_test = NULL;
-	scan_field_t field;
-	int val;
+	struct scan_field field;
+	uint64_t val;
 	int chain_pos = 0;
 	int retval;
 
+	/* when autoprobing, accomodate huge IR lengths */
 	for (tap = NULL, total_ir_length = 0;
 			(tap = jtag_tap_next_enabled(tap)) != NULL;
-			total_ir_length += tap->ir_length)
-		continue;
+			total_ir_length += tap->ir_length) {
+		if (tap->ir_length == 0)
+			total_ir_length += JTAG_IRLEN_MAX;
+	}
 
 	/* increase length to add 2 bit sentinel after scan */
 	total_ir_length += 2;
 
-	ir_test = malloc(CEIL(total_ir_length, 8));
+	ir_test = malloc(DIV_ROUND_UP(total_ir_length, 8));
 	if (ir_test == NULL)
 		return ERROR_FAIL;
 
 	/* after this scan, all TAPs will capture BYPASS instructions */
 	buf_set_ones(ir_test, total_ir_length);
 
-	field.tap = NULL;
 	field.num_bits = total_ir_length;
 	field.out_value = ir_test;
 	field.in_value = ir_test;
 
-	jtag_add_plain_ir_scan(1, &field, TAP_IDLE);
+	jtag_add_plain_ir_scan(field.num_bits, field.out_value, field.in_value, TAP_IDLE);
 
 	LOG_DEBUG("IR capture validation scan");
 	retval = jtag_execute_queue();
@@ -1147,10 +1213,35 @@ static int jtag_validate_ircapture(void)
 	tap = NULL;
 	chain_pos = 0;
 
-	for (;;) {
+	for (;; ) {
 		tap = jtag_tap_next_enabled(tap);
-		if (tap == NULL) {
+		if (tap == NULL)
 			break;
+
+		/* If we're autoprobing, guess IR lengths.  They must be at
+		 * least two bits.  Guessing will fail if (a) any TAP does
+		 * not conform to the JTAG spec; or (b) when the upper bits
+		 * captured from some conforming TAP are nonzero.  Or if
+		 * (c) an IR length is longer than 32 bits -- which is only
+		 * an implementation limit, which could someday be raised.
+		 *
+		 * REVISIT optimization:  if there's a *single* TAP we can
+		 * lift restrictions (a) and (b) by scanning a recognizable
+		 * pattern before the all-ones BYPASS.  Check for where the
+		 * pattern starts in the result, instead of an 0...01 value.
+		 *
+		 * REVISIT alternative approach: escape to some tcl code
+		 * which could provide more knowledge, based on IDCODE; and
+		 * only guess when that has no success.
+		 */
+		if (tap->ir_length == 0) {
+			tap->ir_length = 2;
+			while ((val = buf_get_u64(ir_test, chain_pos, tap->ir_length + 1)) == 1
+					&& tap->ir_length <= 64) {
+				tap->ir_length++;
+			}
+			LOG_WARNING("AUTO %s - use \"... -irlen %d\"",
+				jtag_tap_name(tap), tap->ir_length);
 		}
 
 		/* Validate the two LSBs, which must be 01 per JTAG spec.
@@ -1160,31 +1251,28 @@ static int jtag_validate_ircapture(void)
 		 * this part of the JTAG spec, so their capture mask/value
 		 * attributes might disable this test.
 		 */
-		val = buf_get_u32(ir_test, chain_pos, tap->ir_length);
+		val = buf_get_u64(ir_test, chain_pos, tap->ir_length);
 		if ((val & tap->ir_capture_mask) != tap->ir_capture_value) {
-			LOG_ERROR("%s: IR capture error; saw 0x%0*x not 0x%0*x",
-					jtag_tap_name(tap),
-					(tap->ir_length + 7) / tap->ir_length,
-					val,
-					(tap->ir_length + 7) / tap->ir_length,
-					(unsigned) tap->ir_capture_value);
+			LOG_ERROR("%s: IR capture error; saw 0x%0*" PRIx64 " not 0x%0*" PRIx32,
+				jtag_tap_name(tap),
+				(tap->ir_length + 7) / tap->ir_length, val,
+				(tap->ir_length + 7) / tap->ir_length, tap->ir_capture_value);
 
 			retval = ERROR_JTAG_INIT_FAILED;
 			goto done;
 		}
-		LOG_DEBUG("%s: IR capture 0x%0*x", jtag_tap_name(tap),
-				(tap->ir_length + 7) / tap->ir_length, val);
+		LOG_DEBUG("%s: IR capture 0x%0*" PRIx64, jtag_tap_name(tap),
+			(tap->ir_length + 7) / tap->ir_length, val);
 		chain_pos += tap->ir_length;
 	}
 
 	/* verify the '11' sentinel we wrote is returned at the end */
-	val = buf_get_u32(ir_test, chain_pos, 2);
-	if (val != 0x3)
-	{
+	val = buf_get_u64(ir_test, chain_pos, 2);
+	if (val != 0x3) {
 		char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
 
 		LOG_ERROR("IR capture error at bit %d, saw 0x%s not 0x...3",
-				chain_pos, cbuf);
+			chain_pos, cbuf);
 		free(cbuf);
 		retval = ERROR_JTAG_INIT_FAILED;
 	}
@@ -1198,39 +1286,46 @@ done:
 	return retval;
 }
 
-
-void jtag_tap_init(jtag_tap_t *tap)
+void jtag_tap_init(struct jtag_tap *tap)
 {
-	assert(0 != tap->ir_length);
+	unsigned ir_len_bits;
+	unsigned ir_len_bytes;
 
-	/// @todo fix, this allocates one byte per bit for all three fields!
-	tap->expected = malloc(tap->ir_length);
-	tap->expected_mask = malloc(tap->ir_length);
-	tap->cur_instr = malloc(tap->ir_length);
+	/* if we're autoprobing, cope with potentially huge ir_length */
+	ir_len_bits = tap->ir_length ? : JTAG_IRLEN_MAX;
+	ir_len_bytes = DIV_ROUND_UP(ir_len_bits, 8);
 
-	/// @todo cope sanely with ir_length bigger than 32 bits
-	buf_set_u32(tap->expected, 0, tap->ir_length, tap->ir_capture_value);
-	buf_set_u32(tap->expected_mask, 0, tap->ir_length, tap->ir_capture_mask);
-	buf_set_ones(tap->cur_instr, tap->ir_length);
+	tap->expected = calloc(1, ir_len_bytes);
+	tap->expected_mask = calloc(1, ir_len_bytes);
+	tap->cur_instr = malloc(ir_len_bytes);
+
+	/** @todo cope better with ir_length bigger than 32 bits */
+	if (ir_len_bits > 32)
+		ir_len_bits = 32;
 
-	// place TAP in bypass mode
+	buf_set_u32(tap->expected, 0, ir_len_bits, tap->ir_capture_value);
+	buf_set_u32(tap->expected_mask, 0, ir_len_bits, tap->ir_capture_mask);
+
+	/* TAP will be in bypass mode after jtag_validate_ircapture() */
 	tap->bypass = 1;
-	// register the reset callback for the TAP
+	buf_set_ones(tap->cur_instr, tap->ir_length);
+
+	/* register the reset callback for the TAP */
 	jtag_register_event_callback(&jtag_reset_callback, tap);
+	jtag_tap_add(tap);
 
 	LOG_DEBUG("Created Tap: %s @ abs position %d, "
 			"irlen %d, capture: 0x%x mask: 0x%x", tap->dotted_name,
-				tap->abs_chain_position, tap->ir_length,
-				(unsigned) tap->ir_capture_value,
-				(unsigned) tap->ir_capture_mask);
-	jtag_tap_add(tap);
+			tap->abs_chain_position, tap->ir_length,
+			(unsigned) tap->ir_capture_value,
+			(unsigned) tap->ir_capture_mask);
 }
 
-void jtag_tap_free(jtag_tap_t *tap)
+void jtag_tap_free(struct jtag_tap *tap)
 {
 	jtag_unregister_event_callback(&jtag_reset_callback, tap);
 
-	/// @todo is anything missing? no memory leaks please
+	/** @todo is anything missing? no memory leaks please */
 	free((void *)tap->expected);
 	free((void *)tap->expected_ids);
 	free((void *)tap->chip);
@@ -1239,50 +1334,81 @@ void jtag_tap_free(jtag_tap_t *tap)
 	free(tap);
 }
 
-int jtag_interface_init(struct command_context_s *cmd_ctx)
+/**
+ * Do low-level setup like initializing registers, output signals,
+ * and clocking.
+ */
+int adapter_init(struct command_context *cmd_ctx)
 {
 	if (jtag)
 		return ERROR_OK;
 
-	if (!jtag_interface)
-	{
+	if (!jtag_interface) {
 		/* nothing was previously specified by "interface" command */
-		LOG_ERROR("JTAG interface has to be specified, see \"interface\" command");
+		LOG_ERROR("Debug Adapter has to be specified, "
+			"see \"interface\" command");
 		return ERROR_JTAG_INVALID_INTERFACE;
 	}
 
+	int retval;
+	retval = jtag_interface->init();
+	if (retval != ERROR_OK)
+		return retval;
 	jtag = jtag_interface;
-	if (jtag_interface->init() != ERROR_OK)
-	{
-		jtag = NULL;
+
+	/* LEGACY SUPPORT ... adapter drivers  must declare what
+	 * transports they allow.  Until they all do so, assume
+	 * the legacy drivers are JTAG-only
+	 */
+	if (!transports_are_declared()) {
+		LOG_ERROR("Adapter driver '%s' did not declare "
+			"which transports it allows; assuming "
+			"JTAG-only", jtag->name);
+		retval = allow_transports(cmd_ctx, jtag_only);
+		if (retval != ERROR_OK)
+			return retval;
+	}
+
+	if (jtag->speed == NULL) {
+		LOG_INFO("This adapter doesn't support configurable speed");
+		return ERROR_OK;
+	}
+
+	if (CLOCK_MODE_UNSELECTED == clock_mode) {
+		LOG_ERROR("An adapter speed is not selected in the init script."
+			" Insert a call to adapter_khz or jtag_rclk to proceed.");
 		return ERROR_JTAG_INIT_FAILED;
 	}
 
 	int requested_khz = jtag_get_speed_khz();
 	int actual_khz = requested_khz;
-	int retval = jtag_get_speed_readable(&actual_khz);
+	int jtag_speed_var = 0;
+	retval = jtag_get_speed(&jtag_speed_var);
+	if (retval != ERROR_OK)
+		return retval;
+	retval = jtag->speed(jtag_speed_var);
+	if (retval != ERROR_OK)
+		return retval;
+	retval = jtag_get_speed_readable(&actual_khz);
 	if (ERROR_OK != retval)
-		LOG_INFO("interface specific clock speed value %d", jtag_get_speed());
-	else if (actual_khz)
-	{
+		LOG_INFO("adapter-specific clock speed value %d", jtag_speed_var);
+	else if (actual_khz) {
+		/* Adaptive clocking -- JTAG-specific */
 		if ((CLOCK_MODE_RCLK == clock_mode)
-			|| ((CLOCK_MODE_KHZ == clock_mode) && !requested_khz))
-		{
+				|| ((CLOCK_MODE_KHZ == clock_mode) && !requested_khz)) {
 			LOG_INFO("RCLK (adaptive clock speed) not supported - fallback to %d kHz"
-				, actual_khz);
-		}
-		else
+			, actual_khz);
+		} else
 			LOG_INFO("clock speed %d kHz", actual_khz);
-	}
-	else
+	} else
 		LOG_INFO("RCLK (adaptive clock speed)");
 
 	return ERROR_OK;
 }
 
-int jtag_init_inner(struct command_context_s *cmd_ctx)
+int jtag_init_inner(struct command_context *cmd_ctx)
 {
-	jtag_tap_t *tap;
+	struct jtag_tap *tap;
 	int retval;
 	bool issue_setup = true;
 
@@ -1290,12 +1416,26 @@ int jtag_init_inner(struct command_context_s *cmd_ctx)
 
 	tap = jtag_tap_next_enabled(NULL);
 	if (tap == NULL) {
-		LOG_ERROR("There are no enabled taps?");
-		return ERROR_JTAG_INIT_FAILED;
+		/* Once JTAG itself is properly set up, and the scan chain
+		 * isn't absurdly large, IDCODE autoprobe should work fine.
+		 *
+		 * But ... IRLEN autoprobe can fail even on systems which
+		 * are fully conformant to JTAG.  Also, JTAG setup can be
+		 * quite finicky on some systems.
+		 *
+		 * REVISIT: if TAP autoprobe works OK, then in many cases
+		 * we could escape to tcl code and set up targets based on
+		 * the TAP's IDCODE values.
+		 */
+		LOG_WARNING("There are no enabled taps.  "
+			"AUTO PROBING MIGHT NOT WORK!!");
+
+		/* REVISIT default clock will often be too fast ... */
 	}
 
 	jtag_add_tlr();
-	if ((retval = jtag_execute_queue()) != ERROR_OK)
+	retval = jtag_execute_queue();
+	if (retval != ERROR_OK)
 		return retval;
 
 	/* Examine DR values first.  This discovers problems which will
@@ -1304,20 +1444,22 @@ int jtag_init_inner(struct command_context_s *cmd_ctx)
 	 */
 	retval = jtag_examine_chain();
 	switch (retval) {
-	case ERROR_OK:
-		/* complete success */
-		break;
-	case ERROR_JTAG_INIT_SOFT_FAIL:
-		/* For backward compatibility reasons, try coping with
-		 * configuration errors involving only ID mismatches.
-		 * We might be able to talk to the devices.
-		 */
-		LOG_ERROR("Trying to use configured scan chain anyway...");
-		issue_setup = false;
-		break;
-	default:
-		/* some hard error; already issued diagnostics */
-		return retval;
+		case ERROR_OK:
+			/* complete success */
+			break;
+		default:
+			/* For backward compatibility reasons, try coping with
+			 * configuration errors involving only ID mismatches.
+			 * We might be able to talk to the devices.
+			 *
+			 * Also the device might be powered down during startup.
+			 *
+			 * After OpenOCD starts, we can try to power on the device
+			 * and run a reset.
+			 */
+			LOG_ERROR("Trying to use configured scan chain anyway...");
+			issue_setup = false;
+			break;
 	}
 
 	/* Now look at IR values.  Problems here will prevent real
@@ -1327,8 +1469,13 @@ int jtag_init_inner(struct command_context_s *cmd_ctx)
 	 * ircapture/irmask values during TAP setup.)
 	 */
 	retval = jtag_validate_ircapture();
-	if (retval != ERROR_OK)
-		return retval;
+	if (retval != ERROR_OK) {
+		/* The target might be powered down. The user
+		 * can power it up and reset it after firing
+		 * up OpenOCD.
+		 */
+		issue_setup = false;
+	}
 
 	if (issue_setup)
 		jtag_notify_event(JTAG_TAP_EVENT_SETUP);
@@ -1339,12 +1486,12 @@ int jtag_init_inner(struct command_context_s *cmd_ctx)
 	return ERROR_OK;
 }
 
-int jtag_interface_quit(void)
+int adapter_quit(void)
 {
 	if (!jtag || !jtag->quit)
 		return ERROR_OK;
 
-	// close the JTAG interface
+	/* close the JTAG interface */
 	int result = jtag->quit();
 	if (ERROR_OK != result)
 		LOG_ERROR("failed: %d", result);
@@ -1352,12 +1499,25 @@ int jtag_interface_quit(void)
 	return ERROR_OK;
 }
 
-
-int jtag_init_reset(struct command_context_s *cmd_ctx)
+int swd_init_reset(struct command_context *cmd_ctx)
 {
-	int retval;
+	int retval = adapter_init(cmd_ctx);
+	if (retval != ERROR_OK)
+		return retval;
+
+	LOG_DEBUG("Initializing with hard SRST reset");
+
+	if (jtag_reset_config & RESET_HAS_SRST)
+		swd_add_reset(1);
+	swd_add_reset(0);
+	retval = jtag_execute_queue();
+	return retval;
+}
 
-	if ((retval = jtag_interface_init(cmd_ctx)) != ERROR_OK)
+int jtag_init_reset(struct command_context *cmd_ctx)
+{
+	int retval = adapter_init(cmd_ctx);
+	if (retval != ERROR_OK)
 		return retval;
 
 	LOG_DEBUG("Initializing with hard TRST+SRST reset");
@@ -1386,15 +1546,25 @@ int jtag_init_reset(struct command_context_s *cmd_ctx)
 	 * REVISIT once Tcl code can read the reset_config modes, this won't
 	 * need to be a C routine at all...
 	 */
-	jtag_add_reset(1, 0); /* TAP_RESET, using TMS+TCK or TRST */
-	if (jtag_reset_config & RESET_HAS_SRST)
-	{
+	jtag_add_reset(1, 0);	/* TAP_RESET, using TMS+TCK or TRST */
+	if (jtag_reset_config & RESET_HAS_SRST) {
 		jtag_add_reset(1, 1);
 		if ((jtag_reset_config & RESET_SRST_PULLS_TRST) == 0)
 			jtag_add_reset(0, 1);
 	}
-	jtag_add_reset(0, 0);
-	if ((retval = jtag_execute_queue()) != ERROR_OK)
+
+	/* some targets enable us to connect with srst asserted */
+	if (jtag_reset_config & RESET_CNCT_UNDER_SRST) {
+		if (jtag_reset_config & RESET_SRST_NO_GATING)
+			jtag_add_reset(0, 1);
+		else {
+			LOG_WARNING("\'srst_nogate\' reset_config option is required");
+			jtag_add_reset(0, 0);
+		}
+	} else
+		jtag_add_reset(0, 0);
+	retval = jtag_execute_queue();
+	if (retval != ERROR_OK)
 		return retval;
 
 	/* Check that we can communication on the JTAG chain + eventually we want to
@@ -1407,19 +1577,27 @@ int jtag_init_reset(struct command_context_s *cmd_ctx)
 	return jtag_init_inner(cmd_ctx);
 }
 
-int jtag_init(struct command_context_s *cmd_ctx)
+int jtag_init(struct command_context *cmd_ctx)
 {
-	int retval;
-
-	if ((retval = jtag_interface_init(cmd_ctx)) != ERROR_OK)
+	int retval = adapter_init(cmd_ctx);
+	if (retval != ERROR_OK)
 		return retval;
 
 	/* guard against oddball hardware: force resets to be inactive */
 	jtag_add_reset(0, 0);
-	if ((retval = jtag_execute_queue()) != ERROR_OK)
+
+	/* some targets enable us to connect with srst asserted */
+	if (jtag_reset_config & RESET_CNCT_UNDER_SRST) {
+		if (jtag_reset_config & RESET_SRST_NO_GATING)
+			jtag_add_reset(0, 1);
+		else
+			LOG_WARNING("\'srst_nogate\' reset_config option is required");
+	}
+	retval = jtag_execute_queue();
+	if (retval != ERROR_OK)
 		return retval;
 
-	if (Jim_Eval_Named(interp, "jtag_init", __FILE__, __LINE__) != JIM_OK)
+	if (Jim_Eval_Named(cmd_ctx->interp, "jtag_init", __FILE__, __LINE__) != JIM_OK)
 		return ERROR_FAIL;
 
 	return ERROR_OK;
@@ -1430,31 +1608,27 @@ unsigned jtag_get_speed_khz(void)
 	return speed_khz;
 }
 
-static int jtag_khz_to_speed(unsigned khz, int* speed)
+static int adapter_khz_to_speed(unsigned khz, int *speed)
 {
 	LOG_DEBUG("convert khz to interface specific speed value");
 	speed_khz = khz;
-	if (jtag != NULL)
-	{
+	if (jtag != NULL) {
 		LOG_DEBUG("have interface set up");
 		int speed_div1;
 		int retval = jtag->khz(jtag_get_speed_khz(), &speed_div1);
 		if (ERROR_OK != retval)
-		{
 			return retval;
-		}
 		*speed = speed_div1;
 	}
 	return ERROR_OK;
 }
 
-static int jtag_rclk_to_speed(unsigned fallback_speed_khz, int* speed)
+static int jtag_rclk_to_speed(unsigned fallback_speed_khz, int *speed)
 {
-	int retval = jtag_khz_to_speed(0, speed);
-	if ((ERROR_OK != retval) && fallback_speed_khz)
-	{
+	int retval = adapter_khz_to_speed(0, speed);
+	if ((ERROR_OK != retval) && fallback_speed_khz) {
 		LOG_DEBUG("trying fallback speed...");
-		retval = jtag_khz_to_speed(fallback_speed_khz, speed);
+		retval = adapter_khz_to_speed(fallback_speed_khz, speed);
 	}
 	return retval;
 }
@@ -1467,19 +1641,12 @@ static int jtag_set_speed(int speed)
 	return jtag ? jtag->speed(speed) : ERROR_OK;
 }
 
-int jtag_config_speed(int speed)
-{
-	LOG_DEBUG("handle jtag speed");
-	clock_mode = CLOCK_MODE_SPEED;
-	return jtag_set_speed(speed);
-}
-
 int jtag_config_khz(unsigned khz)
 {
 	LOG_DEBUG("handle jtag khz");
 	clock_mode = CLOCK_MODE_KHZ;
 	int speed = 0;
-	int retval = jtag_khz_to_speed(khz, &speed);
+	int retval = adapter_khz_to_speed(khz, &speed);
 	return (ERROR_OK != retval) ? retval : jtag_set_speed(speed);
 }
 
@@ -1493,31 +1660,29 @@ int jtag_config_rclk(unsigned fallback_speed_khz)
 	return (ERROR_OK != retval) ? retval : jtag_set_speed(speed);
 }
 
-int jtag_get_speed(void)
+int jtag_get_speed(int *speed)
 {
-	int speed;
-	switch(clock_mode)
-	{
-		case CLOCK_MODE_SPEED:
-			speed = jtag_speed;
-			break;
+	switch (clock_mode) {
 		case CLOCK_MODE_KHZ:
-			jtag_khz_to_speed(jtag_get_speed_khz(), &speed);
+			adapter_khz_to_speed(jtag_get_speed_khz(), speed);
 			break;
 		case CLOCK_MODE_RCLK:
-			jtag_rclk_to_speed(rclk_fallback_speed_khz, &speed);
+			jtag_rclk_to_speed(rclk_fallback_speed_khz, speed);
 			break;
 		default:
 			LOG_ERROR("BUG: unknown jtag clock mode");
-			speed = 0;
-			break;
+			return ERROR_FAIL;
 	}
-	return speed;
+	return ERROR_OK;
 }
 
 int jtag_get_speed_readable(int *khz)
 {
-	return jtag ? jtag->speed_div(jtag_get_speed(), khz) : ERROR_OK;
+	int jtag_speed_var = 0;
+	int retval = jtag_get_speed(&jtag_speed_var);
+	if (retval != ERROR_OK)
+		return retval;
+	return jtag ? jtag->speed_div(jtag_speed_var, khz) : ERROR_OK;
 }
 
 void jtag_set_verify(bool enable)
@@ -1542,6 +1707,12 @@ bool jtag_will_verify_capture_ir()
 
 int jtag_power_dropout(int *dropout)
 {
+	if (jtag == NULL) {
+		/* TODO: as the jtag interface is not valid all
+		 * we can do at the moment is exit OpenOCD */
+		LOG_ERROR("No Valid JTAG Interface Configured.");
+		exit(-1);
+	}
 	return jtag->power_dropout(dropout);
 }
 
@@ -1570,11 +1741,11 @@ int jtag_get_srst(void)
 
 void jtag_set_nsrst_delay(unsigned delay)
 {
-	jtag_nsrst_delay = delay;
+	adapter_nsrst_delay = delay;
 }
 unsigned jtag_get_nsrst_delay(void)
 {
-	return jtag_nsrst_delay;
+	return adapter_nsrst_delay;
 }
 void jtag_set_ntrst_delay(unsigned delay)
 {
@@ -1588,11 +1759,11 @@ unsigned jtag_get_ntrst_delay(void)
 
 void jtag_set_nsrst_assert_width(unsigned delay)
 {
-	jtag_nsrst_assert_width = delay;
+	adapter_nsrst_assert_width = delay;
 }
 unsigned jtag_get_nsrst_assert_width(void)
 {
-	return jtag_nsrst_assert_width;
+	return adapter_nsrst_assert_width;
 }
 void jtag_set_ntrst_assert_width(unsigned delay)
 {
@@ -1602,3 +1773,73 @@ unsigned jtag_get_ntrst_assert_width(void)
 {
 	return jtag_ntrst_assert_width;
 }
+
+static int jtag_select(struct command_context *ctx)
+{
+	int retval;
+
+	/* NOTE:  interface init must already have been done.
+	 * That works with only C code ... no Tcl glue required.
+	 */
+
+	retval = jtag_register_commands(ctx);
+
+	if (retval != ERROR_OK)
+		return retval;
+
+	retval = svf_register_commands(ctx);
+
+	if (retval != ERROR_OK)
+		return retval;
+
+	return xsvf_register_commands(ctx);
+}
+
+static struct transport jtag_transport = {
+	.name = "jtag",
+	.select = jtag_select,
+	.init = jtag_init,
+};
+
+static void jtag_constructor(void) __attribute__((constructor));
+static void jtag_constructor(void)
+{
+	transport_register(&jtag_transport);
+}
+
+/** Returns true if the current debug session
+ * is using JTAG as its transport.
+ */
+bool transport_is_jtag(void)
+{
+	return get_current_transport() == &jtag_transport;
+}
+
+void adapter_assert_reset(void)
+{
+	if (transport_is_jtag()) {
+		if (jtag_reset_config & RESET_SRST_PULLS_TRST)
+			jtag_add_reset(1, 1);
+		else
+			jtag_add_reset(0, 1);
+	} else if (transport_is_swd())
+		swd_add_reset(1);
+	else if (get_current_transport() != NULL)
+		LOG_ERROR("reset is not supported on %s",
+			get_current_transport()->name);
+	else
+		LOG_ERROR("transport is not selected");
+}
+
+void adapter_deassert_reset(void)
+{
+	if (transport_is_jtag())
+		jtag_add_reset(0, 0);
+	else if (transport_is_swd())
+		swd_add_reset(0);
+	else if (get_current_transport() != NULL)
+		LOG_ERROR("reset is not supported on %s",
+			get_current_transport()->name);
+	else
+		LOG_ERROR("transport is not selected");
+}