Split main jtag.c file into two layers:

- src/jtag/core.c: contains the low-level JTAG TAP and scanning routines.
- src/jtag/tcl.c: contains high-level JTAG TCL commands that use the core.
- Remove static keywords from routines in core.c, extern from tcl.c:
  - jtag, jtag_interface global variables
  - jtag_{examine,validate}_chain and jtag_tap_{init,free} functions
- Added myself to the copyright header in both of these files.
- Used 'svn cp' to add files, so versioning was preserved for both.


git-svn-id: svn://svn.berlios.de/openocd/trunk@2149 b42882b7-edfa-0310-969c-e2dbd0fdcd60

3 files changed, 1279 insertions, 1221 deletions

diff --git a/src/jtag/Makefile.am b/src/jtag/Makefile.am
index b798a28d..9896b8ec 100644
--- a/src/jtag/Makefile.am
+++ b/src/jtag/Makefile.am
@@ -124,7 +124,8 @@ ARMJTAGEWFILES =
 endif
 
 libjtag_la_SOURCES = \
-	jtag.c \
+	core.c \
+	tcl.c \
 	interface.c \
 	$(DRIVERFILES) \
 	$(BITBANGFILES) \
diff --git a/src/jtag/core.c b/src/jtag/core.c
new file mode 100644
index 00000000..eee20119
--- /dev/null
+++ b/src/jtag/core.c
@@ -0,0 +1,1268 @@
+/***************************************************************************
+ *   Copyright (C) 2005 by Dominic Rath                                    *
+ *   Dominic.Rath@gmx.de                                                   *
+ *                                                                         *
+ *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
+ *   oyvind.harboe@zylin.com                                               *
+ *                                                                         *
+ *   Copyright (C) 2009 SoftPLC Corporation                                *
+ *       http://softplc.com                                                *
+ *   dick@softplc.com                                                      *
+ *                                                                         *
+ *   Copyright (C) 2009 Zachary T Welch                                    *
+ *   zw@superlucidity.net                                                  *
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   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.             *
+ ***************************************************************************/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "jtag.h"
+#include "minidriver.h"
+#include "interface.h"
+
+#ifdef HAVE_STRINGS_H
+#include <strings.h>
+#endif
+
+
+/// 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);
+
+/* note that this is not marked as static as it must be available from outside jtag.c for those
+   that implement the jtag_xxx() minidriver layer
+*/
+int jtag_error=ERROR_OK;
+
+char* jtag_event_strings[] =
+{
+	"JTAG controller reset (RESET or TRST)"
+};
+
+const Jim_Nvp nvp_jtag_tap_event[] = {
+	{ .value = JTAG_TAP_EVENT_ENABLE,       .name = "tap-enable" },
+	{ .value = JTAG_TAP_EVENT_DISABLE,      .name = "tap-disable" },
+
+	{ .name = NULL, .value = -1 }
+};
+
+int jtag_trst = 0;
+int jtag_srst = 0;
+
+/**
+ * List all TAPs that have been created.
+ */
+static jtag_tap_t *__jtag_all_taps = NULL;
+/**
+ * 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;
+
+enum reset_types jtag_reset_config = RESET_NONE;
+tap_state_t cmd_queue_end_state = TAP_RESET;
+tap_state_t cmd_queue_cur_state = TAP_RESET;
+
+int jtag_verify_capture_ir = 1;
+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 */
+
+/* callbacks to inform high-level handlers about JTAG state changes */
+jtag_event_callback_t *jtag_event_callbacks;
+
+/* speed in kHz*/
+static int speed_khz = 0;
+/* flag if the kHz speed was defined */
+static bool hasKHz = false;
+
+struct jtag_interface_s *jtag = NULL;
+
+/* configuration */
+jtag_interface_t *jtag_interface = NULL;
+int jtag_speed = 0;
+
+jtag_tap_t *jtag_all_taps(void)
+{
+	return __jtag_all_taps;
+};
+
+unsigned jtag_tap_count(void)
+{
+	return jtag_num_taps;
+}
+
+unsigned jtag_tap_count_enabled(void)
+{
+	jtag_tap_t *t = jtag_all_taps();
+	unsigned n = 0;
+	while(t)
+	{
+		if (t->enabled)
+			n++;
+		t = t->next_tap;
+	}
+	return n;
+}
+
+/// Append a new TAP to the chain of all taps.
+void jtag_tap_add(struct jtag_tap_s *t)
+{
+	t->abs_chain_position = jtag_num_taps++;
+
+	jtag_tap_t **tap = &__jtag_all_taps;
+	while(*tap != NULL)
+		tap = &(*tap)->next_tap;
+	*tap = t;
+}
+
+jtag_tap_t *jtag_tap_by_string(const char *s)
+{
+	/* try by name first */
+	jtag_tap_t *t = jtag_all_taps();
+	while (t)
+	{
+		if (0 == strcmp(t->dotted_name, s))
+			return t;
+		t = t->next_tap;
+	}
+
+	/* no tap found by name, so try to parse the name as a number */
+	char *cp;
+	unsigned n = strtoul(s, &cp, 0);
+	if ((s == cp) || (*cp != 0))
+		return NULL;
+
+	return jtag_tap_by_position(n);
+}
+
+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;
+}
+
+/* returns a pointer to the n-th device in the scan chain */
+jtag_tap_t *jtag_tap_by_position(unsigned n)
+{
+	jtag_tap_t *t = jtag_all_taps();
+
+	while (t && n-- > 0)
+		t = t->next_tap;
+
+	return t;
+}
+
+const char *jtag_tap_name(const jtag_tap_t *tap)
+{
+	return (tap == NULL) ? "(unknown)" : tap->dotted_name;
+}
+
+
+int jtag_register_event_callback(int (*callback)(enum jtag_event event, void *priv), void *priv)
+{
+	jtag_event_callback_t **callbacks_p = &jtag_event_callbacks;
+
+	if (callback == NULL)
+	{
+		return ERROR_INVALID_ARGUMENTS;
+	}
+
+	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)->callback = callback;
+	(*callbacks_p)->priv = priv;
+	(*callbacks_p)->next = NULL;
+
+	return ERROR_OK;
+}
+
+int jtag_unregister_event_callback(int (*callback)(enum jtag_event event, void *priv))
+{
+	jtag_event_callback_t **callbacks_p = &jtag_event_callbacks;
+
+	if (callback == NULL)
+	{
+		return ERROR_INVALID_ARGUMENTS;
+	}
+
+	while (*callbacks_p)
+	{
+		jtag_event_callback_t **next = &((*callbacks_p)->next);
+		if ((*callbacks_p)->callback == callback)
+		{
+			free(*callbacks_p);
+			*callbacks_p = *next;
+		}
+		callbacks_p = next;
+	}
+
+	return ERROR_OK;
+}
+
+int jtag_call_event_callbacks(enum jtag_event event)
+{
+	jtag_event_callback_t *callback = jtag_event_callbacks;
+
+	LOG_DEBUG("jtag event: %s", jtag_event_strings[event]);
+
+	while (callback)
+	{
+		callback->callback(event, callback->priv);
+		callback = callback->next;
+	}
+
+	return ERROR_OK;
+}
+
+static void jtag_checks(void)
+{
+	assert(jtag_trst == 0);
+}
+
+static void jtag_prelude(tap_state_t state)
+{
+	jtag_checks();
+
+	assert(state!=TAP_INVALID);
+
+	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)
+{
+	jtag_prelude(state);
+
+	int retval = interface_jtag_add_ir_scan(in_count, in_fields, state);
+	jtag_set_error(retval);
+}
+
+
+void jtag_add_ir_scan(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+{
+	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);
+	} else
+	{
+		jtag_add_ir_scan_noverify(in_num_fields, in_fields, state);
+	}
+}
+
+void jtag_add_plain_ir_scan(int in_num_fields, const scan_field_t *in_fields,
+		tap_state_t state)
+{
+	jtag_prelude(state);
+
+	int retval = interface_jtag_add_plain_ir_scan(
+			in_num_fields, in_fields, state);
+	jtag_set_error(retval);
+}
+
+void jtag_add_callback(jtag_callback1_t f, u8 *in)
+{
+	interface_jtag_add_callback(f, in);
+}
+
+void jtag_add_callback4(jtag_callback_t f, u8 *in,
+		jtag_callback_data_t data1, jtag_callback_data_t data2,
+		jtag_callback_data_t data3)
+{
+	interface_jtag_add_callback4(f, in, data1, data2, data3);
+}
+
+int jtag_check_value_inner(u8 *captured, u8 *in_check_value, u8 *in_check_mask, int num_bits);
+
+static int jtag_check_value_mask_callback(u8 *in, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3)
+{
+	return jtag_check_value_inner(in, (u8 *)data1, (u8 *)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)
+{
+	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(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))
+		{
+			/* this is synchronous for a minidriver */
+			jtag_add_callback4(jtag_check_value_mask_callback, 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)
+{
+	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);
+	}
+}
+
+
+void jtag_add_dr_scan(int in_num_fields, const scan_field_t *in_fields,
+		tap_state_t state)
+{
+	jtag_prelude(state);
+
+	int retval;
+	retval = interface_jtag_add_dr_scan(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)
+{
+	jtag_prelude(state);
+
+	int retval;
+	retval = interface_jtag_add_plain_dr_scan(in_num_fields, in_fields, state);
+	jtag_set_error(retval);
+}
+
+void jtag_add_dr_out(jtag_tap_t* tap,
+		int num_fields, const int* num_bits, const u32* value,
+		tap_state_t end_state)
+{
+	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);
+	jtag_set_error(interface_jtag_add_tlr());
+	jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
+}
+
+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]))
+	{
+		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)
+		{
+			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])
+		{
+			LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
+					tap_state_name(cur_state), tap_state_name(path[i]));
+			jtag_set_error(ERROR_JTAG_TRANSITION_INVALID);
+			return;
+		}
+		cur_state = path[i];
+	}
+
+	jtag_checks();
+
+	jtag_set_error(interface_jtag_add_pathmove(num_states, path));
+	cmd_queue_cur_state = path[num_states - 1];
+}
+
+void jtag_add_runtest(int num_cycles, tap_state_t state)
+{
+	jtag_prelude(state);
+	jtag_set_error(interface_jtag_add_runtest(num_cycles, 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 (num_cycles > 0)
+	{
+		jtag_checks();
+		jtag_set_error(interface_jtag_add_clocks(num_cycles));
+	}
+}
+
+void jtag_add_reset(int req_tlr_or_trst, int req_srst)
+{
+	int trst_with_tlr = 0;
+
+	/* FIX!!! there are *many* different cases here. A better
+	 * approach is needed for legal combinations of transitions...
+	 */
+	if ((jtag_reset_config & RESET_HAS_SRST)&&
+			(jtag_reset_config & RESET_HAS_TRST)&&
+			((jtag_reset_config & RESET_SRST_PULLS_TRST)==0))
+	{
+		if (((req_tlr_or_trst&&!jtag_trst)||
+				(!req_tlr_or_trst&&jtag_trst))&&
+				((req_srst&&!jtag_srst)||
+						(!req_srst&&jtag_srst)))
+		{
+			/* FIX!!! srst_pulls_trst allows 1,1 => 0,0 transition.... */
+			//LOG_ERROR("BUG: transition of req_tlr_or_trst and req_srst in the same jtag_add_reset() call is undefined");
+		}
+	}
+
+	/* Make sure that jtag_reset_config allows the requested reset */
+	/* if SRST pulls TRST, we can't fulfill srst == 1 with trst == 0 */
+	if (((jtag_reset_config & RESET_SRST_PULLS_TRST) && (req_srst == 1)) && (!req_tlr_or_trst))
+	{
+		LOG_ERROR("BUG: requested reset would assert trst");
+		jtag_set_error(ERROR_FAIL);
+		return;
+	}
+
+	/* if TRST pulls SRST, we reset with TAP T-L-R */
+	if (((jtag_reset_config & RESET_TRST_PULLS_SRST) && (req_tlr_or_trst)) && (req_srst == 0))
+	{
+		trst_with_tlr = 1;
+	}
+
+	if (req_srst && !(jtag_reset_config & RESET_HAS_SRST))
+	{
+		LOG_ERROR("BUG: requested SRST assertion, but the current configuration doesn't support this");
+		jtag_set_error(ERROR_FAIL);
+		return;
+	}
+
+	if (req_tlr_or_trst)
+	{
+		if (!trst_with_tlr && (jtag_reset_config & RESET_HAS_TRST))
+		{
+			jtag_trst = 1;
+		} else
+		{
+			trst_with_tlr = 1;
+		}
+	} else
+	{
+		jtag_trst = 0;
+	}
+
+	jtag_srst = req_srst;
+
+	int retval = interface_jtag_add_reset(jtag_trst, jtag_srst);
+	if (retval != ERROR_OK)
+	{
+		jtag_set_error(retval);
+		return;
+	}
+	jtag_execute_queue();
+
+	if (jtag_srst)
+	{
+		LOG_DEBUG("SRST line asserted");
+	}
+	else
+	{
+		LOG_DEBUG("SRST line released");
+		if (jtag_nsrst_delay)
+			jtag_add_sleep(jtag_nsrst_delay * 1000);
+	}
+
+	if (trst_with_tlr)
+	{
+		LOG_DEBUG("JTAG reset with RESET instead of TRST");
+		jtag_set_end_state(TAP_RESET);
+		jtag_add_tlr();
+		return;
+	}
+
+	if (jtag_trst)
+	{
+		/* we just asserted nTRST, so we're now in Test-Logic-Reset,
+		 * and inform possible listeners about this
+		 */
+		LOG_DEBUG("TRST line asserted");
+		tap_set_state(TAP_RESET);
+		jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
+	}
+	else
+	{
+		if (jtag_ntrst_delay)
+			jtag_add_sleep(jtag_ntrst_delay * 1000);
+	}
+}
+
+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(u32 us)
+{
+	/// @todo Here, keep_alive() appears to be a layering violation!!!
+	keep_alive();
+	jtag_set_error(interface_jtag_add_sleep(us));
+}
+
+int jtag_check_value_inner(u8 *captured, u8 *in_check_value, u8 *in_check_mask, int num_bits)
+{
+	int retval = ERROR_OK;
+
+	int compare_failed = 0;
+
+	if (in_check_mask)
+		compare_failed = buf_cmp_mask(captured, in_check_value, in_check_mask, num_bits);
+	else
+		compare_failed = buf_cmp(captured, in_check_value, num_bits);
+
+	if (compare_failed){
+		/* An error handler could have caught the failing check
+		 * only report a problem when there wasn't a handler, or if the handler
+		 * acknowledged the error
+		 */
+		/*
+		LOG_WARNING("TAP %s:",
+					jtag_tap_name(field->tap));
+					*/
+		if (compare_failed)
+		{
+			char *captured_char = buf_to_str(captured, (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits, 16);
+			char *in_check_value_char = buf_to_str(in_check_value, (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits, 16);
+
+			if (in_check_mask)
+			{
+				char *in_check_mask_char;
+				in_check_mask_char = buf_to_str(in_check_mask, (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits, 16);
+				LOG_WARNING("value captured during scan didn't pass the requested check:");
+				LOG_WARNING("captured: 0x%s check_value: 0x%s check_mask: 0x%s",
+							captured_char, in_check_value_char, in_check_mask_char);
+				free(in_check_mask_char);
+			}
+			else
+			{
+				LOG_WARNING("value captured during scan didn't pass the requested check: captured: 0x%s check_value: 0x%s", captured_char, in_check_value_char);
+			}
+
+			free(captured_char);
+			free(in_check_value_char);
+
+			retval = ERROR_JTAG_QUEUE_FAILED;
+		}
+
+	}
+	return retval;
+}
+
+void jtag_check_value_mask(scan_field_t *field, u8 *value, u8 *mask)
+{
+	assert(field->in_value != NULL);
+
+	if (value==NULL)
+	{
+		/* no checking to do */
+		return;
+	}
+
+	jtag_execute_queue_noclear();
+
+	int retval=jtag_check_value_inner(field->in_value, value, mask, field->num_bits);
+	jtag_set_error(retval);
+}
+
+
+
+int default_interface_jtag_execute_queue(void)
+{
+	if (NULL == jtag)
+	{
+		LOG_ERROR("No JTAG interface configured yet.  "
+			"Issue 'init' command in startup scripts "
+			"before communicating with targets.");
+		return ERROR_FAIL;
+	}
+
+	return jtag->execute_queue();
+}
+
+void jtag_execute_queue_noclear(void)
+{
+	jtag_flush_queue_count++;
+	jtag_set_error(interface_jtag_execute_queue());
+}
+
+int jtag_get_flush_queue_count(void)
+{
+	return jtag_flush_queue_count;
+}
+
+int jtag_execute_queue(void)
+{
+	jtag_execute_queue_noclear();
+	return jtag_error_clear();
+}
+
+static int jtag_reset_callback(enum jtag_event event, void *priv)
+{
+	jtag_tap_t *tap = priv;
+
+	LOG_DEBUG("-");
+
+	if (event == JTAG_TRST_ASSERTED)
+	{
+		buf_set_ones(tap->cur_instr, tap->ir_length);
+		tap->bypass = 1;
+	}
+
+	return ERROR_OK;
+}
+
+void jtag_sleep(u32 us)
+{
+	alive_sleep(us/1000);
+}
+
+/// maximum number of JTAG devices expected in the chain
+#define JTAG_MAX_CHAIN_SIZE 20
+
+#define EXTRACT_MFG(X)  (((X) & 0xffe) >> 1)
+#define EXTRACT_PART(X) (((X) & 0xffff000) >> 12)
+#define EXTRACT_VER(X)  (((X) & 0xf0000000) >> 28)
+
+static int jtag_examine_chain_execute(u8 *idcode_buffer, unsigned num_idcode)
+{
+	scan_field_t field = {
+			.tap = NULL,
+			.num_bits = num_idcode * 32,
+			.out_value = idcode_buffer,
+			.in_value = idcode_buffer,
+		};
+
+	// 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, 0x000000FF);
+
+	jtag_add_plain_dr_scan(1, &field, TAP_RESET);
+	return jtag_execute_queue();
+}
+
+static bool jtag_examine_chain_check(u8 *idcodes, unsigned count)
+{
+	u8 zero_check = 0x0;
+	u8 one_check = 0xff;
+
+	for (unsigned i = 0; i < count * 4; i++)
+	{
+		zero_check |= idcodes[i];
+		one_check &= idcodes[i];
+	}
+
+	/* if there wasn't a single non-zero bit or if all bits were one,
+	 * the scan is not valid */
+	if (zero_check == 0x00 || one_check == 0xff)
+	{
+		LOG_ERROR("JTAG communication failure: check connection, "
+			"JTAG interface, target power etc.");
+		return false;
+	}
+	return true;
+}
+
+static void jtag_examine_chain_display(enum log_levels level, const char *msg,
+		const char *name, u32 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, idcode,
+		EXTRACT_MFG(idcode), EXTRACT_PART(idcode), EXTRACT_VER(idcode) );
+}
+
+static bool jtag_idcode_is_final(u32 idcode)
+{
+		return idcode == 0x000000FF || idcode == 0xFFFFFFFF;
+}
+
+/**
+ * This helper checks that remaining bits in the examined chain data are
+ * all as expected, but a single JTAG device requires only 64 bits to be
+ * read back correctly.  This can help identify and diagnose problems
+ * with the JTAG chain earlier, gives more helpful/explicit error messages.
+ */
+static void jtag_examine_chain_end(u8 *idcodes, unsigned count, unsigned max)
+{
+	bool triggered = false;
+	for ( ; count < max - 31; count += 32)
+	{
+		u32 idcode = buf_get_u32(idcodes, count, 32);
+		// do not trigger the warning if the data looks good
+		if (!triggered && jtag_idcode_is_final(idcode))
+			continue;
+		LOG_WARNING("Unexpected idcode after end of chain: %d 0x%08x",
+				count, idcode);
+		triggered = true;
+	}
+}
+
+static bool jtag_examine_chain_match_tap(const struct jtag_tap_s *tap)
+{
+	if (0 == tap->expected_ids_cnt)
+	{
+		/// @todo Enable LOG_INFO to ask for reports about unknown TAP IDs.
+#if 0
+		LOG_INFO("Uknown JTAG TAP ID: 0x%08x", tap->idcode)
+		LOG_INFO("Please report the chip name and reported ID code to the openocd project");
+#endif
+		return true;
+	}
+
+	/* Loop over the expected identification codes and test for a match */
+	u8 ii;
+	for (ii = 0; ii < tap->expected_ids_cnt; ii++)
+	{
+		if (tap->idcode == tap->expected_ids[ii])
+			break;
+	}
+
+	/* If none of the expected ids matched, log an error */
+	if (ii != tap->expected_ids_cnt)
+	{
+		LOG_INFO("JTAG Tap/device matched");
+		return true;
+	}
+	jtag_examine_chain_display(LOG_LVL_ERROR, "got",
+			tap->dotted_name, tap->idcode);
+	for (ii = 0; ii < tap->expected_ids_cnt; ii++)
+	{
+		char msg[32];
+		snprintf(msg, sizeof(msg), "expected %hhu of %hhu",
+				ii + 1, tap->expected_ids_cnt);
+		jtag_examine_chain_display(LOG_LVL_ERROR, msg,
+				tap->dotted_name, tap->expected_ids[ii]);
+	}
+	return false;
+}
+
+/* Try to examine chain layout according to IEEE 1149.1 §12
+ */
+int jtag_examine_chain(void)
+{
+	u8 idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
+	unsigned device_count = 0;
+
+	jtag_examine_chain_execute(idcode_buffer, JTAG_MAX_CHAIN_SIZE);
+
+	if (!jtag_examine_chain_check(idcode_buffer, JTAG_MAX_CHAIN_SIZE))
+		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;
+	}
+
+	for (unsigned bit_count = 0; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;)
+	{
+		u32 idcode = buf_get_u32(idcode_buffer, bit_count, 32);
+		if ((idcode & 1) == 0)
+		{
+			/* LSB must not be 0, this indicates a device in bypass */
+			LOG_WARNING("Tap/Device does not have IDCODE");
+			idcode = 0;
+
+			bit_count += 1;
+		}
+		else
+		{
+	 		/*
+			 * End of chain (invalid manufacturer ID) some devices, such
+			 * as AVR will output all 1's instead of TDI input value at
+			 * end of chain.
+			 */
+			if (jtag_idcode_is_final(idcode))
+			{
+				jtag_examine_chain_end(idcode_buffer,
+						bit_count + 32, JTAG_MAX_CHAIN_SIZE * 32);
+				break;
+			}
+
+			jtag_examine_chain_display(LOG_LVL_INFO, "tap/device found",
+					tap ? tap->dotted_name : "(not-named)",
+					idcode);
+
+			bit_count += 32;
+		}
+		device_count++;
+		if (!tap)
+			continue;
+
+		tap->idcode = idcode;
+
+		// ensure the TAP ID does matches what was expected
+ 		if (!jtag_examine_chain_match_tap(tap))
+			return ERROR_JTAG_INIT_FAILED;
+
+		tap = jtag_tap_next_enabled(tap);
+	}
+
+	/* see if number of discovered devices matches configuration */
+	if (device_count != jtag_tap_count_enabled())
+	{
+		LOG_ERROR("number of discovered devices in JTAG chain (%i) "
+				"does not match (enabled) configuration (%i), total taps: %d",
+				device_count, jtag_tap_count_enabled(), jtag_tap_count());
+		LOG_ERROR("check the config file and ensure proper JTAG communication"
+				" (connections, speed, ...)");
+		return ERROR_JTAG_INIT_FAILED;
+	}
+
+	return ERROR_OK;
+}
+
+int jtag_validate_chain(void)
+{
+	jtag_tap_t *tap;
+	int total_ir_length = 0;
+	u8 *ir_test = NULL;
+	scan_field_t field;
+	int chain_pos = 0;
+
+	tap = NULL;
+	total_ir_length = 0;
+	for(;;){
+		tap = jtag_tap_next_enabled(tap);
+		if( tap == NULL ){
+			break;
+		}
+		total_ir_length += tap->ir_length;
+	}
+
+	total_ir_length += 2;
+	ir_test = malloc(CEIL(total_ir_length, 8));
+	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_RESET);
+	jtag_execute_queue();
+
+	tap = NULL;
+	chain_pos = 0;
+	int val;
+	for(;;){
+		tap = jtag_tap_next_enabled(tap);
+		if( tap == NULL ){
+			break;
+		}
+
+		val = buf_get_u32(ir_test, chain_pos, 2);
+		if (val != 0x1)
+		{
+			char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
+			LOG_ERROR("Could not validate JTAG scan chain, IR mismatch, scan returned 0x%s. tap=%s pos=%d expected 0x1 got %0x", cbuf, jtag_tap_name(tap), chain_pos, val);
+			free(cbuf);
+			free(ir_test);
+			return ERROR_JTAG_INIT_FAILED;
+		}
+		chain_pos += tap->ir_length;
+	}
+
+	val = buf_get_u32(ir_test, chain_pos, 2);
+	if (val != 0x3)
+	{
+		char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
+		LOG_ERROR("Could not validate end of JTAG scan chain, IR mismatch, scan returned 0x%s. pos=%d expected 0x3 got %0x", cbuf, chain_pos, val);
+		free(cbuf);
+		free(ir_test);
+		return ERROR_JTAG_INIT_FAILED;
+	}
+
+	free(ir_test);
+
+	return ERROR_OK;
+}
+
+
+void jtag_tap_init(jtag_tap_t *tap)
+{
+	assert(0 != tap->ir_length);
+
+	tap->expected = malloc(tap->ir_length);
+	tap->expected_mask = malloc(tap->ir_length);
+	tap->cur_instr = malloc(tap->ir_length);
+
+	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);
+
+	// place TAP in bypass mode
+	tap->bypass = 1;
+	// register the reset callback for the TAP
+	jtag_register_event_callback(&jtag_reset_callback, 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,
+				tap->ir_capture_value, tap->ir_capture_mask);
+	jtag_tap_add(tap);
+}
+
+void jtag_tap_free(jtag_tap_t *tap)
+{
+	/// @todo is anything missing? no memory leaks please 
+	free((void *)tap->expected_ids);
+	free((void *)tap->chip);
+	free((void *)tap->tapname);
+	free((void *)tap->dotted_name);
+	free(tap);
+}
+
+int jtag_interface_init(struct command_context_s *cmd_ctx)
+{
+	if (jtag)
+		return ERROR_OK;
+
+	if (!jtag_interface)
+	{
+		/* nothing was previously specified by "interface" command */
+		LOG_ERROR("JTAG interface has to be specified, see \"interface\" command");
+		return ERROR_JTAG_INVALID_INTERFACE;
+	}
+	if(hasKHz)
+	{
+		jtag_interface->khz(jtag_get_speed_khz(), &jtag_speed);
+		hasKHz = false;
+	}
+
+	if (jtag_interface->init() != ERROR_OK)
+		return ERROR_JTAG_INIT_FAILED;
+
+	jtag = jtag_interface;
+	return ERROR_OK;
+}
+
+static int jtag_init_inner(struct command_context_s *cmd_ctx)
+{
+	jtag_tap_t *tap;
+	int retval;
+
+	LOG_DEBUG("Init JTAG chain");
+
+	tap = jtag_tap_next_enabled(NULL);
+	if( tap == NULL ){
+		LOG_ERROR("There are no enabled taps?");
+		return ERROR_JTAG_INIT_FAILED;
+	}
+
+	jtag_add_tlr();
+	if ((retval=jtag_execute_queue())!=ERROR_OK)
+		return retval;
+
+	/* examine chain first, as this could discover the real chain layout */
+	if (jtag_examine_chain() != ERROR_OK)
+	{
+		LOG_ERROR("trying to validate configured JTAG chain anyway...");
+	}
+
+	if (jtag_validate_chain() != ERROR_OK)
+	{
+		LOG_WARNING("Could not validate JTAG chain, continuing anyway...");
+	}
+
+	return ERROR_OK;
+}
+
+int jtag_interface_quit(void)
+{
+	if (!jtag || !jtag->quit)
+		return ERROR_OK;
+
+	// close the JTAG interface
+	int result = jtag->quit();
+	if (ERROR_OK != result)
+		LOG_ERROR("failed: %d", result);
+
+	return ERROR_OK;
+}
+
+
+int jtag_init_reset(struct command_context_s *cmd_ctx)
+{
+	int retval;
+
+	if ((retval=jtag_interface_init(cmd_ctx)) != ERROR_OK)
+		return retval;
+
+	LOG_DEBUG("Trying to bring the JTAG controller to life by asserting TRST / RESET");
+
+	/* Reset can happen after a power cycle.
+	 *
+	 * Ideally we would only assert TRST or run RESET before the target reset.
+	 *
+	 * However w/srst_pulls_trst, trst is asserted together with the target
+	 * reset whether we want it or not.
+	 *
+	 * NB! Some targets have JTAG circuitry disabled until a
+	 * trst & srst has been asserted.
+	 *
+	 * NB! here we assume nsrst/ntrst delay are sufficient!
+	 *
+	 * NB! order matters!!!! srst *can* disconnect JTAG circuitry
+	 *
+	 */
+	jtag_add_reset(1, 0); /* RESET 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)
+		return retval;
+
+	/* Check that we can communication on the JTAG chain + eventually we want to
+	 * be able to perform enumeration only after OpenOCD has started
+	 * telnet and GDB server
+	 *
+	 * That would allow users to more easily perform any magic they need to before
+	 * reset happens.
+	 */
+	return jtag_init_inner(cmd_ctx);
+}
+
+int jtag_init(struct command_context_s *cmd_ctx)
+{
+	int retval;
+	if ((retval=jtag_interface_init(cmd_ctx)) != ERROR_OK)
+		return retval;
+	if (jtag_init_inner(cmd_ctx)==ERROR_OK)
+	{
+		return ERROR_OK;
+	}
+	return jtag_init_reset(cmd_ctx);
+}
+
+void jtag_set_speed_khz(unsigned khz)
+{
+	speed_khz = khz;
+}
+unsigned jtag_get_speed_khz(void)
+{
+	return speed_khz;
+}
+
+void jtag_set_verify(bool enable)
+{
+	jtag_verify = enable;
+}
+
+bool jtag_will_verify()
+{
+	return jtag_verify;
+}
+
+
+int jtag_power_dropout(int *dropout)
+{
+	return jtag->power_dropout(dropout);
+}
+
+int jtag_srst_asserted(int *srst_asserted)
+{
+	return jtag->srst_asserted(srst_asserted);
+}
+
+void jtag_tap_handle_event( jtag_tap_t * tap, enum jtag_tap_event e)
+{
+	jtag_tap_event_action_t * jteap;
+	int done;
+
+	jteap = tap->event_action;
+
+	done = 0;
+	while (jteap) {
+		if (jteap->event == e) {
+			done = 1;
+			LOG_DEBUG( "JTAG tap: %s event: %d (%s) action: %s\n",
+					tap->dotted_name,
+					e,
+					Jim_Nvp_value2name_simple(nvp_jtag_tap_event, e)->name,
+					Jim_GetString(jteap->body, NULL) );
+			if (Jim_EvalObj(interp, jteap->body) != JIM_OK) {
+				Jim_PrintErrorMessage(interp);
+			}
+		}
+
+		jteap = jteap->next;
+	}
+
+	if (!done) {
+		LOG_DEBUG( "event %d %s - no action",
+				e,
+				Jim_Nvp_value2name_simple( nvp_jtag_tap_event, e)->name);
+	}
+}
+
+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 )
+		;	/* nothing to do */
+	else if( goal_state==TAP_RESET )
+	{
+		jtag_add_tlr();
+	}
+	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));
+
+		for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1)
+		{
+			bool bit = tms_bits & 1;
+
+			cur_state = tap_state_transition(cur_state, bit);
+			moves[i] = cur_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 )
+	{
+		jtag_add_pathmove(1, &goal_state);
+	}
+
+	else
+		return ERROR_FAIL;
+
+	return ERROR_OK;
+}
+
+void jtag_set_nsrst_delay(unsigned delay)
+{
+	jtag_nsrst_delay = delay;
+}
+unsigned jtag_get_nsrst_delay(void)
+{
+	return jtag_nsrst_delay;
+}
+void jtag_set_ntrst_delay(unsigned delay)
+{
+	jtag_ntrst_delay = delay;
+}
+unsigned jtag_get_ntrst_delay(void)
+{
+	return jtag_ntrst_delay;
+}
diff --git a/src/jtag/jtag.c b/src/jtag/tcl.c
index 3962fb2d..c3344b83 100644
--- a/src/jtag/jtag.c
+++ b/src/jtag/tcl.c
@@ -9,6 +9,9 @@
  *       http://softplc.com                                                *
  *   dick@softplc.com                                                      *
  *                                                                         *
+ *   Copyright (C) 2009 Zachary T Welch                                    *
+ *   zw@superlucidity.net                                                  *
+ *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
  *   it under the terms of the GNU General Public License as published by  *
  *   the Free Software Foundation; either version 2 of the License, or     *
@@ -36,59 +39,6 @@
 #include <strings.h>
 #endif
 
-
-/// 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);
-
-/* note that this is not marked as static as it must be available from outside jtag.c for those
-   that implement the jtag_xxx() minidriver layer
-*/
-int jtag_error=ERROR_OK;
-
-char* jtag_event_strings[] =
-{
-	"JTAG controller reset (RESET or TRST)"
-};
-
-const Jim_Nvp nvp_jtag_tap_event[] = {
-	{ .value = JTAG_TAP_EVENT_ENABLE,       .name = "tap-enable" },
-	{ .value = JTAG_TAP_EVENT_DISABLE,      .name = "tap-disable" },
-
-	{ .name = NULL, .value = -1 }
-};
-
-int jtag_trst = 0;
-int jtag_srst = 0;
-
-/**
- * List all TAPs that have been created.
- */
-static jtag_tap_t *__jtag_all_taps = NULL;
-/**
- * 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;
-
-enum reset_types jtag_reset_config = RESET_NONE;
-tap_state_t cmd_queue_end_state = TAP_RESET;
-tap_state_t cmd_queue_cur_state = TAP_RESET;
-
-int jtag_verify_capture_ir = 1;
-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 */
-
-/* callbacks to inform high-level handlers about JTAG state changes */
-jtag_event_callback_t *jtag_event_callbacks;
-
-/* speed in kHz*/
-static int speed_khz = 0;
 /* flag if the kHz speed was defined */
 static bool hasKHz = false;
 
@@ -216,11 +166,8 @@ jtag_interface_t *jtag_interfaces[] = {
 	NULL,
 };
 
-struct jtag_interface_s *jtag = NULL;
-
-/* configuration */
-static jtag_interface_t *jtag_interface = NULL;
-int jtag_speed = 0;
+extern struct jtag_interface_s *jtag;
+extern jtag_interface_t *jtag_interface;
 
 /* jtag commands */
 static int handle_interface_list_command(struct command_context_s *cmd_ctx,
@@ -245,888 +192,8 @@ static int handle_verify_ircapture_command(struct command_context_s *cmd_ctx, ch
 static int handle_verify_jtag_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
 static int handle_tms_sequence_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
 
-jtag_tap_t *jtag_all_taps(void)
-{
-	return __jtag_all_taps;
-};
-
-unsigned jtag_tap_count(void)
-{
-	return jtag_num_taps;
-}
-
-unsigned jtag_tap_count_enabled(void)
-{
-	jtag_tap_t *t = jtag_all_taps();
-	unsigned n = 0;
-	while(t)
-	{
-		if (t->enabled)
-			n++;
-		t = t->next_tap;
-	}
-	return n;
-}
-
-/// Append a new TAP to the chain of all taps.
-void jtag_tap_add(struct jtag_tap_s *t)
-{
-	t->abs_chain_position = jtag_num_taps++;
-
-	jtag_tap_t **tap = &__jtag_all_taps;
-	while(*tap != NULL)
-		tap = &(*tap)->next_tap;
-	*tap = t;
-}
-
-jtag_tap_t *jtag_tap_by_string(const char *s)
-{
-	/* try by name first */
-	jtag_tap_t *t = jtag_all_taps();
-	while (t)
-	{
-		if (0 == strcmp(t->dotted_name, s))
-			return t;
-		t = t->next_tap;
-	}
-
-	/* no tap found by name, so try to parse the name as a number */
-	char *cp;
-	unsigned n = strtoul(s, &cp, 0);
-	if ((s == cp) || (*cp != 0))
-		return NULL;
-
-	return jtag_tap_by_position(n);
-}
-
-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;
-}
-
-/* returns a pointer to the n-th device in the scan chain */
-jtag_tap_t *jtag_tap_by_position(unsigned n)
-{
-	jtag_tap_t *t = jtag_all_taps();
-
-	while (t && n-- > 0)
-		t = t->next_tap;
-
-	return t;
-}
-
-const char *jtag_tap_name(const jtag_tap_t *tap)
-{
-	return (tap == NULL) ? "(unknown)" : tap->dotted_name;
-}
-
-
-int jtag_register_event_callback(int (*callback)(enum jtag_event event, void *priv), void *priv)
-{
-	jtag_event_callback_t **callbacks_p = &jtag_event_callbacks;
-
-	if (callback == NULL)
-	{
-		return ERROR_INVALID_ARGUMENTS;
-	}
-
-	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)->callback = callback;
-	(*callbacks_p)->priv = priv;
-	(*callbacks_p)->next = NULL;
-
-	return ERROR_OK;
-}
-
-int jtag_unregister_event_callback(int (*callback)(enum jtag_event event, void *priv))
-{
-	jtag_event_callback_t **callbacks_p = &jtag_event_callbacks;
-
-	if (callback == NULL)
-	{
-		return ERROR_INVALID_ARGUMENTS;
-	}
-
-	while (*callbacks_p)
-	{
-		jtag_event_callback_t **next = &((*callbacks_p)->next);
-		if ((*callbacks_p)->callback == callback)
-		{
-			free(*callbacks_p);
-			*callbacks_p = *next;
-		}
-		callbacks_p = next;
-	}
-
-	return ERROR_OK;
-}
-
-int jtag_call_event_callbacks(enum jtag_event event)
-{
-	jtag_event_callback_t *callback = jtag_event_callbacks;
-
-	LOG_DEBUG("jtag event: %s", jtag_event_strings[event]);
-
-	while (callback)
-	{
-		callback->callback(event, callback->priv);
-		callback = callback->next;
-	}
-
-	return ERROR_OK;
-}
-
-static void jtag_checks(void)
-{
-	assert(jtag_trst == 0);
-}
-
-static void jtag_prelude(tap_state_t state)
-{
-	jtag_checks();
-
-	assert(state!=TAP_INVALID);
-
-	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)
-{
-	jtag_prelude(state);
-
-	int retval = interface_jtag_add_ir_scan(in_count, in_fields, state);
-	jtag_set_error(retval);
-}
-
-
-void jtag_add_ir_scan(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
-{
-	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);
-	} else
-	{
-		jtag_add_ir_scan_noverify(in_num_fields, in_fields, state);
-	}
-}
-
-void jtag_add_plain_ir_scan(int in_num_fields, const scan_field_t *in_fields,
-		tap_state_t state)
-{
-	jtag_prelude(state);
-
-	int retval = interface_jtag_add_plain_ir_scan(
-			in_num_fields, in_fields, state);
-	jtag_set_error(retval);
-}
-
-void jtag_add_callback(jtag_callback1_t f, u8 *in)
-{
-	interface_jtag_add_callback(f, in);
-}
-
-void jtag_add_callback4(jtag_callback_t f, u8 *in,
-		jtag_callback_data_t data1, jtag_callback_data_t data2,
-		jtag_callback_data_t data3)
-{
-	interface_jtag_add_callback4(f, in, data1, data2, data3);
-}
-
-int jtag_check_value_inner(u8 *captured, u8 *in_check_value, u8 *in_check_mask, int num_bits);
-
-static int jtag_check_value_mask_callback(u8 *in, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3)
-{
-	return jtag_check_value_inner(in, (u8 *)data1, (u8 *)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)
-{
-	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(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))
-		{
-			/* this is synchronous for a minidriver */
-			jtag_add_callback4(jtag_check_value_mask_callback, 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)
-{
-	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);
-	}
-}
-
-
-void jtag_add_dr_scan(int in_num_fields, const scan_field_t *in_fields,
-		tap_state_t state)
-{
-	jtag_prelude(state);
-
-	int retval;
-	retval = interface_jtag_add_dr_scan(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)
-{
-	jtag_prelude(state);
-
-	int retval;
-	retval = interface_jtag_add_plain_dr_scan(in_num_fields, in_fields, state);
-	jtag_set_error(retval);
-}
-
-void jtag_add_dr_out(jtag_tap_t* tap,
-		int num_fields, const int* num_bits, const u32* value,
-		tap_state_t end_state)
-{
-	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);
-	jtag_set_error(interface_jtag_add_tlr());
-	jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
-}
-
-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]))
-	{
-		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)
-		{
-			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])
-		{
-			LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
-					tap_state_name(cur_state), tap_state_name(path[i]));
-			jtag_set_error(ERROR_JTAG_TRANSITION_INVALID);
-			return;
-		}
-		cur_state = path[i];
-	}
-
-	jtag_checks();
-
-	jtag_set_error(interface_jtag_add_pathmove(num_states, path));
-	cmd_queue_cur_state = path[num_states - 1];
-}
-
-void jtag_add_runtest(int num_cycles, tap_state_t state)
-{
-	jtag_prelude(state);
-	jtag_set_error(interface_jtag_add_runtest(num_cycles, 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 (num_cycles > 0)
-	{
-		jtag_checks();
-		jtag_set_error(interface_jtag_add_clocks(num_cycles));
-	}
-}
-
-void jtag_add_reset(int req_tlr_or_trst, int req_srst)
-{
-	int trst_with_tlr = 0;
-
-	/* FIX!!! there are *many* different cases here. A better
-	 * approach is needed for legal combinations of transitions...
-	 */
-	if ((jtag_reset_config & RESET_HAS_SRST)&&
-			(jtag_reset_config & RESET_HAS_TRST)&&
-			((jtag_reset_config & RESET_SRST_PULLS_TRST)==0))
-	{
-		if (((req_tlr_or_trst&&!jtag_trst)||
-				(!req_tlr_or_trst&&jtag_trst))&&
-				((req_srst&&!jtag_srst)||
-						(!req_srst&&jtag_srst)))
-		{
-			/* FIX!!! srst_pulls_trst allows 1,1 => 0,0 transition.... */
-			//LOG_ERROR("BUG: transition of req_tlr_or_trst and req_srst in the same jtag_add_reset() call is undefined");
-		}
-	}
-
-	/* Make sure that jtag_reset_config allows the requested reset */
-	/* if SRST pulls TRST, we can't fulfill srst == 1 with trst == 0 */
-	if (((jtag_reset_config & RESET_SRST_PULLS_TRST) && (req_srst == 1)) && (!req_tlr_or_trst))
-	{
-		LOG_ERROR("BUG: requested reset would assert trst");
-		jtag_set_error(ERROR_FAIL);
-		return;
-	}
-
-	/* if TRST pulls SRST, we reset with TAP T-L-R */
-	if (((jtag_reset_config & RESET_TRST_PULLS_SRST) && (req_tlr_or_trst)) && (req_srst == 0))
-	{
-		trst_with_tlr = 1;
-	}
-
-	if (req_srst && !(jtag_reset_config & RESET_HAS_SRST))
-	{
-		LOG_ERROR("BUG: requested SRST assertion, but the current configuration doesn't support this");
-		jtag_set_error(ERROR_FAIL);
-		return;
-	}
-
-	if (req_tlr_or_trst)
-	{
-		if (!trst_with_tlr && (jtag_reset_config & RESET_HAS_TRST))
-		{
-			jtag_trst = 1;
-		} else
-		{
-			trst_with_tlr = 1;
-		}
-	} else
-	{
-		jtag_trst = 0;
-	}
-
-	jtag_srst = req_srst;
-
-	int retval = interface_jtag_add_reset(jtag_trst, jtag_srst);
-	if (retval != ERROR_OK)
-	{
-		jtag_set_error(retval);
-		return;
-	}
-	jtag_execute_queue();
-
-	if (jtag_srst)
-	{
-		LOG_DEBUG("SRST line asserted");
-	}
-	else
-	{
-		LOG_DEBUG("SRST line released");
-		if (jtag_nsrst_delay)
-			jtag_add_sleep(jtag_nsrst_delay * 1000);
-	}
-
-	if (trst_with_tlr)
-	{
-		LOG_DEBUG("JTAG reset with RESET instead of TRST");
-		jtag_set_end_state(TAP_RESET);
-		jtag_add_tlr();
-		return;
-	}
-
-	if (jtag_trst)
-	{
-		/* we just asserted nTRST, so we're now in Test-Logic-Reset,
-		 * and inform possible listeners about this
-		 */
-		LOG_DEBUG("TRST line asserted");
-		tap_set_state(TAP_RESET);
-		jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
-	}
-	else
-	{
-		if (jtag_ntrst_delay)
-			jtag_add_sleep(jtag_ntrst_delay * 1000);
-	}
-}
-
-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(u32 us)
-{
-	/// @todo Here, keep_alive() appears to be a layering violation!!!
-	keep_alive();
-	jtag_set_error(interface_jtag_add_sleep(us));
-}
-
-int jtag_check_value_inner(u8 *captured, u8 *in_check_value, u8 *in_check_mask, int num_bits)
-{
-	int retval = ERROR_OK;
-
-	int compare_failed = 0;
-
-	if (in_check_mask)
-		compare_failed = buf_cmp_mask(captured, in_check_value, in_check_mask, num_bits);
-	else
-		compare_failed = buf_cmp(captured, in_check_value, num_bits);
-
-	if (compare_failed){
-		/* An error handler could have caught the failing check
-		 * only report a problem when there wasn't a handler, or if the handler
-		 * acknowledged the error
-		 */
-		/*
-		LOG_WARNING("TAP %s:",
-					jtag_tap_name(field->tap));
-					*/
-		if (compare_failed)
-		{
-			char *captured_char = buf_to_str(captured, (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits, 16);
-			char *in_check_value_char = buf_to_str(in_check_value, (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits, 16);
-
-			if (in_check_mask)
-			{
-				char *in_check_mask_char;
-				in_check_mask_char = buf_to_str(in_check_mask, (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits, 16);
-				LOG_WARNING("value captured during scan didn't pass the requested check:");
-				LOG_WARNING("captured: 0x%s check_value: 0x%s check_mask: 0x%s",
-							captured_char, in_check_value_char, in_check_mask_char);
-				free(in_check_mask_char);
-			}
-			else
-			{
-				LOG_WARNING("value captured during scan didn't pass the requested check: captured: 0x%s check_value: 0x%s", captured_char, in_check_value_char);
-			}
-
-			free(captured_char);
-			free(in_check_value_char);
-
-			retval = ERROR_JTAG_QUEUE_FAILED;
-		}
-
-	}
-	return retval;
-}
-
-void jtag_check_value_mask(scan_field_t *field, u8 *value, u8 *mask)
-{
-	assert(field->in_value != NULL);
-
-	if (value==NULL)
-	{
-		/* no checking to do */
-		return;
-	}
-
-	jtag_execute_queue_noclear();
-
-	int retval=jtag_check_value_inner(field->in_value, value, mask, field->num_bits);
-	jtag_set_error(retval);
-}
-
-
-
-int default_interface_jtag_execute_queue(void)
-{
-	if (NULL == jtag)
-	{
-		LOG_ERROR("No JTAG interface configured yet.  "
-			"Issue 'init' command in startup scripts "
-			"before communicating with targets.");
-		return ERROR_FAIL;
-	}
-
-	return jtag->execute_queue();
-}
-
-void jtag_execute_queue_noclear(void)
-{
-	jtag_flush_queue_count++;
-	jtag_set_error(interface_jtag_execute_queue());
-}
-
-int jtag_get_flush_queue_count(void)
-{
-	return jtag_flush_queue_count;
-}
-
-int jtag_execute_queue(void)
-{
-	jtag_execute_queue_noclear();
-	return jtag_error_clear();
-}
-
-static int jtag_reset_callback(enum jtag_event event, void *priv)
-{
-	jtag_tap_t *tap = priv;
-
-	LOG_DEBUG("-");
-
-	if (event == JTAG_TRST_ASSERTED)
-	{
-		buf_set_ones(tap->cur_instr, tap->ir_length);
-		tap->bypass = 1;
-	}
-
-	return ERROR_OK;
-}
-
-void jtag_sleep(u32 us)
-{
-	alive_sleep(us/1000);
-}
-
-/// maximum number of JTAG devices expected in the chain
-#define JTAG_MAX_CHAIN_SIZE 20
-
-#define EXTRACT_MFG(X)  (((X) & 0xffe) >> 1)
-#define EXTRACT_PART(X) (((X) & 0xffff000) >> 12)
-#define EXTRACT_VER(X)  (((X) & 0xf0000000) >> 28)
-
-static int jtag_examine_chain_execute(u8 *idcode_buffer, unsigned num_idcode)
-{
-	scan_field_t field = {
-			.tap = NULL,
-			.num_bits = num_idcode * 32,
-			.out_value = idcode_buffer,
-			.in_value = idcode_buffer,
-		};
-
-	// 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, 0x000000FF);
-
-	jtag_add_plain_dr_scan(1, &field, TAP_RESET);
-	return jtag_execute_queue();
-}
-
-static bool jtag_examine_chain_check(u8 *idcodes, unsigned count)
-{
-	u8 zero_check = 0x0;
-	u8 one_check = 0xff;
-
-	for (unsigned i = 0; i < count * 4; i++)
-	{
-		zero_check |= idcodes[i];
-		one_check &= idcodes[i];
-	}
-
-	/* if there wasn't a single non-zero bit or if all bits were one,
-	 * the scan is not valid */
-	if (zero_check == 0x00 || one_check == 0xff)
-	{
-		LOG_ERROR("JTAG communication failure: check connection, "
-			"JTAG interface, target power etc.");
-		return false;
-	}
-	return true;
-}
-
-static void jtag_examine_chain_display(enum log_levels level, const char *msg,
-		const char *name, u32 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, idcode,
-		EXTRACT_MFG(idcode), EXTRACT_PART(idcode), EXTRACT_VER(idcode) );
-}
-
-static bool jtag_idcode_is_final(u32 idcode)
-{
-		return idcode == 0x000000FF || idcode == 0xFFFFFFFF;
-}
-
-/**
- * This helper checks that remaining bits in the examined chain data are
- * all as expected, but a single JTAG device requires only 64 bits to be
- * read back correctly.  This can help identify and diagnose problems
- * with the JTAG chain earlier, gives more helpful/explicit error messages.
- */
-static void jtag_examine_chain_end(u8 *idcodes, unsigned count, unsigned max)
-{
-	bool triggered = false;
-	for ( ; count < max - 31; count += 32)
-	{
-		u32 idcode = buf_get_u32(idcodes, count, 32);
-		// do not trigger the warning if the data looks good
-		if (!triggered && jtag_idcode_is_final(idcode))
-			continue;
-		LOG_WARNING("Unexpected idcode after end of chain: %d 0x%08x",
-				count, idcode);
-		triggered = true;
-	}
-}
-
-static bool jtag_examine_chain_match_tap(const struct jtag_tap_s *tap)
-{
-	if (0 == tap->expected_ids_cnt)
-	{
-		/// @todo Enable LOG_INFO to ask for reports about unknown TAP IDs.
-#if 0
-		LOG_INFO("Uknown JTAG TAP ID: 0x%08x", tap->idcode)
-		LOG_INFO("Please report the chip name and reported ID code to the openocd project");
-#endif
-		return true;
-	}
-
-	/* Loop over the expected identification codes and test for a match */
-	u8 ii;
-	for (ii = 0; ii < tap->expected_ids_cnt; ii++)
-	{
-		if (tap->idcode == tap->expected_ids[ii])
-			break;
-	}
-
-	/* If none of the expected ids matched, log an error */
-	if (ii != tap->expected_ids_cnt)
-	{
-		LOG_INFO("JTAG Tap/device matched");
-		return true;
-	}
-	jtag_examine_chain_display(LOG_LVL_ERROR, "got",
-			tap->dotted_name, tap->idcode);
-	for (ii = 0; ii < tap->expected_ids_cnt; ii++)
-	{
-		char msg[32];
-		snprintf(msg, sizeof(msg), "expected %hhu of %hhu",
-				ii + 1, tap->expected_ids_cnt);
-		jtag_examine_chain_display(LOG_LVL_ERROR, msg,
-				tap->dotted_name, tap->expected_ids[ii]);
-	}
-	return false;
-}
-
-/* Try to examine chain layout according to IEEE 1149.1 §12
- */
-static int jtag_examine_chain(void)
-{
-	u8 idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
-	unsigned device_count = 0;
-
-	jtag_examine_chain_execute(idcode_buffer, JTAG_MAX_CHAIN_SIZE);
-
-	if (!jtag_examine_chain_check(idcode_buffer, JTAG_MAX_CHAIN_SIZE))
-		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;
-	}
-
-	for (unsigned bit_count = 0; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;)
-	{
-		u32 idcode = buf_get_u32(idcode_buffer, bit_count, 32);
-		if ((idcode & 1) == 0)
-		{
-			/* LSB must not be 0, this indicates a device in bypass */
-			LOG_WARNING("Tap/Device does not have IDCODE");
-			idcode = 0;
-
-			bit_count += 1;
-		}
-		else
-		{
-	 		/*
-			 * End of chain (invalid manufacturer ID) some devices, such
-			 * as AVR will output all 1's instead of TDI input value at
-			 * end of chain.
-			 */
-			if (jtag_idcode_is_final(idcode))
-			{
-				jtag_examine_chain_end(idcode_buffer,
-						bit_count + 32, JTAG_MAX_CHAIN_SIZE * 32);
-				break;
-			}
-
-			jtag_examine_chain_display(LOG_LVL_INFO, "tap/device found",
-					tap ? tap->dotted_name : "(not-named)",
-					idcode);
-
-			bit_count += 32;
-		}
-		device_count++;
-		if (!tap)
-			continue;
-
-		tap->idcode = idcode;
-
-		// ensure the TAP ID does matches what was expected
- 		if (!jtag_examine_chain_match_tap(tap))
-			return ERROR_JTAG_INIT_FAILED;
-
-		tap = jtag_tap_next_enabled(tap);
-	}
-
-	/* see if number of discovered devices matches configuration */
-	if (device_count != jtag_tap_count_enabled())
-	{
-		LOG_ERROR("number of discovered devices in JTAG chain (%i) "
-				"does not match (enabled) configuration (%i), total taps: %d",
-				device_count, jtag_tap_count_enabled(), jtag_tap_count());
-		LOG_ERROR("check the config file and ensure proper JTAG communication"
-				" (connections, speed, ...)");
-		return ERROR_JTAG_INIT_FAILED;
-	}
-
-	return ERROR_OK;
-}
-
-static int jtag_validate_chain(void)
-{
-	jtag_tap_t *tap;
-	int total_ir_length = 0;
-	u8 *ir_test = NULL;
-	scan_field_t field;
-	int chain_pos = 0;
-
-	tap = NULL;
-	total_ir_length = 0;
-	for(;;){
-		tap = jtag_tap_next_enabled(tap);
-		if( tap == NULL ){
-			break;
-		}
-		total_ir_length += tap->ir_length;
-	}
-
-	total_ir_length += 2;
-	ir_test = malloc(CEIL(total_ir_length, 8));
-	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_RESET);
-	jtag_execute_queue();
-
-	tap = NULL;
-	chain_pos = 0;
-	int val;
-	for(;;){
-		tap = jtag_tap_next_enabled(tap);
-		if( tap == NULL ){
-			break;
-		}
-
-		val = buf_get_u32(ir_test, chain_pos, 2);
-		if (val != 0x1)
-		{
-			char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
-			LOG_ERROR("Could not validate JTAG scan chain, IR mismatch, scan returned 0x%s. tap=%s pos=%d expected 0x1 got %0x", cbuf, jtag_tap_name(tap), chain_pos, val);
-			free(cbuf);
-			free(ir_test);
-			return ERROR_JTAG_INIT_FAILED;
-		}
-		chain_pos += tap->ir_length;
-	}
-
-	val = buf_get_u32(ir_test, chain_pos, 2);
-	if (val != 0x3)
-	{
-		char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
-		LOG_ERROR("Could not validate end of JTAG scan chain, IR mismatch, scan returned 0x%s. pos=%d expected 0x3 got %0x", cbuf, chain_pos, val);
-		free(cbuf);
-		free(ir_test);
-		return ERROR_JTAG_INIT_FAILED;
-	}
-
-	free(ir_test);
-
-	return ERROR_OK;
-}
+extern int jtag_examine_chain(void);
+extern int jtag_validate_chain(void);
 
 enum jtag_tap_cfg_param {
 	JCFG_EVENT
@@ -1226,39 +293,8 @@ static int jtag_tap_configure_cmd( Jim_GetOptInfo *goi, jtag_tap_t * tap)
 }
 
 
-static void jtag_tap_init(jtag_tap_t *tap)
-{
-	assert(0 != tap->ir_length);
-
-	tap->expected = malloc(tap->ir_length);
-	tap->expected_mask = malloc(tap->ir_length);
-	tap->cur_instr = malloc(tap->ir_length);
-
-	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);
-
-	// place TAP in bypass mode
-	tap->bypass = 1;
-	// register the reset callback for the TAP
-	jtag_register_event_callback(&jtag_reset_callback, 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,
-				tap->ir_capture_value, tap->ir_capture_mask);
-	jtag_tap_add(tap);
-}
-
-static void jtag_tap_free(jtag_tap_t *tap)
-{
-	/// @todo is anything missing? no memory leaks please 
-	free((void *)tap->expected_ids);
-	free((void *)tap->chip);
-	free((void *)tap->tapname);
-	free((void *)tap->dotted_name);
-	free(tap);
-}
+extern void jtag_tap_init(jtag_tap_t *tap);
+extern void jtag_tap_free(jtag_tap_t *tap);
 
 static int jim_newtap_cmd( Jim_GetOptInfo *goi )
 {
@@ -1597,141 +633,6 @@ int jtag_register_commands(struct command_context_s *cmd_ctx)
 	return ERROR_OK;
 }
 
-int jtag_interface_init(struct command_context_s *cmd_ctx)
-{
-	if (jtag)
-		return ERROR_OK;
-
-	if (!jtag_interface)
-	{
-		/* nothing was previously specified by "interface" command */
-		LOG_ERROR("JTAG interface has to be specified, see \"interface\" command");
-		return ERROR_JTAG_INVALID_INTERFACE;
-	}
-	if(hasKHz)
-	{
-		jtag_interface->khz(jtag_get_speed_khz(), &jtag_speed);
-		hasKHz = false;
-	}
-
-	if (jtag_interface->init() != ERROR_OK)
-		return ERROR_JTAG_INIT_FAILED;
-
-	jtag = jtag_interface;
-	return ERROR_OK;
-}
-
-static int jtag_init_inner(struct command_context_s *cmd_ctx)
-{
-	jtag_tap_t *tap;
-	int retval;
-
-	LOG_DEBUG("Init JTAG chain");
-
-	tap = jtag_tap_next_enabled(NULL);
-	if( tap == NULL ){
-		LOG_ERROR("There are no enabled taps?");
-		return ERROR_JTAG_INIT_FAILED;
-	}
-
-	jtag_add_tlr();
-	if ((retval=jtag_execute_queue())!=ERROR_OK)
-		return retval;
-
-	/* examine chain first, as this could discover the real chain layout */
-	if (jtag_examine_chain() != ERROR_OK)
-	{
-		LOG_ERROR("trying to validate configured JTAG chain anyway...");
-	}
-
-	if (jtag_validate_chain() != ERROR_OK)
-	{
-		LOG_WARNING("Could not validate JTAG chain, continuing anyway...");
-	}
-
-	return ERROR_OK;
-}
-
-int jtag_interface_quit(void)
-{
-	if (!jtag || !jtag->quit)
-		return ERROR_OK;
-
-	// close the JTAG interface
-	int result = jtag->quit();
-	if (ERROR_OK != result)
-		LOG_ERROR("failed: %d", result);
-
-	return ERROR_OK;
-}
-
-
-int jtag_init_reset(struct command_context_s *cmd_ctx)
-{
-	int retval;
-
-	if ((retval=jtag_interface_init(cmd_ctx)) != ERROR_OK)
-		return retval;
-
-	LOG_DEBUG("Trying to bring the JTAG controller to life by asserting TRST / RESET");
-
-	/* Reset can happen after a power cycle.
-	 *
-	 * Ideally we would only assert TRST or run RESET before the target reset.
-	 *
-	 * However w/srst_pulls_trst, trst is asserted together with the target
-	 * reset whether we want it or not.
-	 *
-	 * NB! Some targets have JTAG circuitry disabled until a
-	 * trst & srst has been asserted.
-	 *
-	 * NB! here we assume nsrst/ntrst delay are sufficient!
-	 *
-	 * NB! order matters!!!! srst *can* disconnect JTAG circuitry
-	 *
-	 */
-	jtag_add_reset(1, 0); /* RESET 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)
-		return retval;
-
-	/* Check that we can communication on the JTAG chain + eventually we want to
-	 * be able to perform enumeration only after OpenOCD has started
-	 * telnet and GDB server
-	 *
-	 * That would allow users to more easily perform any magic they need to before
-	 * reset happens.
-	 */
-	return jtag_init_inner(cmd_ctx);
-}
-
-int jtag_init(struct command_context_s *cmd_ctx)
-{
-	int retval;
-	if ((retval=jtag_interface_init(cmd_ctx)) != ERROR_OK)
-		return retval;
-	if (jtag_init_inner(cmd_ctx)==ERROR_OK)
-	{
-		return ERROR_OK;
-	}
-	return jtag_init_reset(cmd_ctx);
-}
-
-void jtag_set_speed_khz(unsigned khz)
-{
-	speed_khz = khz;
-}
-unsigned jtag_get_speed_khz(void)
-{
-	return speed_khz;
-}
-
 static int default_khz(int khz, int *jtag_speed)
 {
 	LOG_ERROR("Translation from khz to jtag_speed not implemented");
@@ -2426,16 +1327,6 @@ static int handle_verify_ircapture_command(struct command_context_s *cmd_ctx, ch
 	return ERROR_OK;
 }
 
-void jtag_set_verify(bool enable)
-{
-	jtag_verify = enable;
-}
-
-bool jtag_will_verify()
-{
-	return jtag_verify;
-}
-
 static int handle_verify_jtag_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
 	if (argc > 1)
@@ -2457,48 +1348,6 @@ static int handle_verify_jtag_command(struct command_context_s *cmd_ctx, char *c
 	return ERROR_OK;
 }
 
-
-int jtag_power_dropout(int *dropout)
-{
-	return jtag->power_dropout(dropout);
-}
-
-int jtag_srst_asserted(int *srst_asserted)
-{
-	return jtag->srst_asserted(srst_asserted);
-}
-
-void jtag_tap_handle_event( jtag_tap_t * tap, enum jtag_tap_event e)
-{
-	jtag_tap_event_action_t * jteap;
-	int done;
-
-	jteap = tap->event_action;
-
-	done = 0;
-	while (jteap) {
-		if (jteap->event == e) {
-			done = 1;
-			LOG_DEBUG( "JTAG tap: %s event: %d (%s) action: %s\n",
-					tap->dotted_name,
-					e,
-					Jim_Nvp_value2name_simple(nvp_jtag_tap_event, e)->name,
-					Jim_GetString(jteap->body, NULL) );
-			if (Jim_EvalObj(interp, jteap->body) != JIM_OK) {
-				Jim_PrintErrorMessage(interp);
-			}
-		}
-
-		jteap = jteap->next;
-	}
-
-	if (!done) {
-		LOG_DEBUG( "event %d %s - no action",
-				e,
-				Jim_Nvp_value2name_simple( nvp_jtag_tap_event, e)->name);
-	}
-}
-
 static int handle_tms_sequence_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
 	if (argc > 1)
@@ -2523,63 +1372,3 @@ static int handle_tms_sequence_command(struct command_context_s *cmd_ctx, char *
 	return ERROR_OK;
 }
 
-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 )
-		;	/* nothing to do */
-	else if( goal_state==TAP_RESET )
-	{
-		jtag_add_tlr();
-	}
-	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));
-
-		for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1)
-		{
-			bool bit = tms_bits & 1;
-
-			cur_state = tap_state_transition(cur_state, bit);
-			moves[i] = cur_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 )
-	{
-		jtag_add_pathmove(1, &goal_state);
-	}
-
-	else
-		return ERROR_FAIL;
-
-	return ERROR_OK;
-}
-
-void jtag_set_nsrst_delay(unsigned delay)
-{
-	jtag_nsrst_delay = delay;
-}
-unsigned jtag_get_nsrst_delay(void)
-{
-	return jtag_nsrst_delay;
-}
-void jtag_set_ntrst_delay(unsigned delay)
-{
-	jtag_ntrst_delay = delay;
-}
-unsigned jtag_get_ntrst_delay(void)
-{
-	return jtag_ntrst_delay;
-}