X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=blobdiff_plain;f=src%2Fjtag%2Fjtag.c;h=0c74c4168bd3254e8e14cf282b61f53a1718ef3d;hp=c28858ee77d91a5b364123c8ba547a7a5c74bca8;hb=a28eaa85f73759bb189a46308642502c9fa5aa4b;hpb=bb36f541dd9f67a69471f29650e194a8a827ff95

diff --git a/src/jtag/jtag.c b/src/jtag/jtag.c
index c28858ee77..0c74c4168b 100644
--- a/src/jtag/jtag.c
+++ b/src/jtag/jtag.c
@@ -2,7 +2,7 @@
  *   Copyright (C) 2005 by Dominic Rath                                    *
  *   Dominic.Rath@gmx.de                                                   *
  *                                                                         *
- *   Copyright (C) 2007,2008 Øyvind Harboe                                      *
+ *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
  *   oyvind.harboe@zylin.com                                               *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
@@ -35,15 +35,15 @@
 #include "string.h"
 #include <unistd.h>
 
-/* 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 
+/* 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; 
+int jtag_error=ERROR_OK;
 
 
 char* tap_state_strings[16] =
 {
-	"tlr", 
+	"tlr",
 	"sds", "cd", "sd", "e1d", "pd", "e2d", "ud",
 	"rti",
 	"sis", "ci", "si", "e1i", "pi", "e2i", "ui"
@@ -66,7 +66,7 @@ static cmd_queue_page_t *cmd_queue_pages = NULL;
  * 3: Pause-DR
  * 4: Shift-IR
  * 5: Pause-IR
- * 
+ *
  * SD->SD and SI->SI have to be caught in interface specific code
  */
 u8 tap_move[6][6] =
@@ -122,9 +122,8 @@ int jtag_srst = 0;
 
 jtag_command_t *jtag_command_queue = NULL;
 jtag_command_t **last_comand_pointer = &jtag_command_queue;
-jtag_device_t *jtag_devices = NULL;
-int jtag_num_devices = 0;
-int jtag_ir_scan_size = 0;
+static jtag_tap_t *jtag_all_taps = NULL;
+
 enum reset_types jtag_reset_config = RESET_NONE;
 enum tap_state cmd_queue_end_state = TAP_TLR;
 enum tap_state cmd_queue_cur_state = TAP_TLR;
@@ -133,11 +132,11 @@ int jtag_verify_capture_ir = 1;
 
 /* how long the OpenOCD should wait before attempting JTAG communication after reset lines deasserted (in ms) */
 int jtag_nsrst_delay = 0; /* default to no nSRST delay */
-int jtag_ntrst_delay = 0; /* default to no nTRST delay */ 
+int jtag_ntrst_delay = 0; /* default to no nTRST delay */
 
 /* maximum number of JTAG devices expected in the chain
  */
-#define JTAG_MAX_CHAIN_SIZE 20 
+#define JTAG_MAX_CHAIN_SIZE 20
 
 /* callbacks to inform high-level handlers about JTAG state changes */
 jtag_event_callback_t *jtag_event_callbacks;
@@ -149,19 +148,19 @@ static int hasKHz = 0;
 
 /* jtag interfaces (parport, FTDI-USB, TI-USB, ...)
  */
- 
+
 #if BUILD_ECOSBOARD == 1
-	extern jtag_interface_t eCosBoard_interface;
+	extern jtag_interface_t zy1000_interface;
 #endif
- 
+
 #if BUILD_PARPORT == 1
 	extern jtag_interface_t parport_interface;
 #endif
-	 
+
 #if BUILD_DUMMY == 1
 	extern jtag_interface_t dummy_interface;
 #endif
-	
+
 #if BUILD_FT2232_FTD2XX == 1
 	extern jtag_interface_t ft2232_interface;
 #endif
@@ -200,7 +199,7 @@ static int hasKHz = 0;
 
 jtag_interface_t *jtag_interfaces[] = {
 #if BUILD_ECOSBOARD == 1
-	&eCosBoard_interface,
+	&zy1000_interface,
 #endif
 #if BUILD_PARPORT == 1
 	&parport_interface,
@@ -252,7 +251,7 @@ void jtag_add_runtest(int num_cycles, enum tap_state endstate);
 void jtag_add_end_state(enum tap_state endstate);
 void jtag_add_sleep(u32 us);
 int jtag_execute_queue(void);
-int jtag_cancel_queue(void);
+
 
 /* jtag commands */
 int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
@@ -273,39 +272,161 @@ int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *argv);
 
 int handle_verify_ircapture_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
 
+
+jtag_tap_t *jtag_AllTaps(void) 
+{ 
+  return jtag_all_taps; 
+};
+
+int 
+jtag_NumTotalTaps(void)
+{
+	jtag_tap_t *t;
+	int n;
+
+	n = 0;
+	t = jtag_AllTaps();
+	while(t){
+		n++;
+		t = t->next_tap;
+	}
+	return n;
+}
+
+int
+jtag_NumEnabledTaps(void)
+{
+	jtag_tap_t *t;
+	int n;
+
+	n = 0;
+	t = jtag_AllTaps();
+	while(t){
+		if( t->enabled ){
+			n++;
+		}
+		t = t->next_tap;
+	}
+	return n;
+}
+
+jtag_tap_t *
+jtag_NextEnabledTap( jtag_tap_t *p )
+{
+	if( p == NULL ){
+		// start at the head of list
+		p = jtag_AllTaps();
+	} else {
+		// start *after* this one
+		p = p->next_tap;
+	}
+	while( p ){
+		if( p->enabled ){
+			break;
+		} else {
+			p = p->next_tap;
+		}
+	}
+	return p;
+}
+
+jtag_tap_t *jtag_TapByString( const char *s )
+{
+	jtag_tap_t *t;
+	char *cp;
+
+	t = jtag_AllTaps();
+	// try name first
+	while(t){
+		if( 0 == strcmp( t->dotted_name, s ) ){
+			break;
+		} else {
+			t = t->next_tap;
+		}
+	}
+	// backup plan is by number
+	if( t == NULL ){
+		/* ok - is "s" a number? */
+		int n;
+		n = strtol( s, &cp, 0 );
+		if( (s != cp) && (*cp == 0) ){
+			/* Then it is... */
+			t = jtag_TapByAbsPosition(n);
+		}
+	}
+	return t;
+}
+
+jtag_tap_t *
+jtag_TapByJimObj( Jim_Interp *interp, Jim_Obj *o )
+{
+	jtag_tap_t *t;
+	const char *cp;
+
+	cp = Jim_GetString( o, NULL );
+	if(cp == NULL){
+		cp = "(unknown)";
+		t = NULL;
+	}  else {
+		t = jtag_TapByString( cp );
+	} 
+	if( t == NULL ){
+		Jim_SetResult_sprintf(interp,"Tap: %s is unknown", cp );
+	}
+	return t;
+}
+
+/* returns a pointer to the n-th device in the scan chain */
+jtag_tap_t *
+jtag_TapByAbsPosition( int n )
+{
+	int orig_n;
+	jtag_tap_t *t;
+
+	orig_n = n;
+	t = jtag_AllTaps();
+	
+	while( t && (n > 0)) {
+		n--;
+		t = t->next_tap;
+    }
+	return t;
+}
+
+
 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);
@@ -316,22 +437,22 @@ int jtag_unregister_event_callback(int (*callback)(enum jtag_event event, void *
 		}
 		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;
 }
 
@@ -342,35 +463,18 @@ int jtag_call_event_callbacks(enum jtag_event event)
 jtag_command_t** jtag_get_last_command_p(void)
 {
 /*	jtag_command_t *cmd = jtag_command_queue;
-	
+
 	if (cmd)
 		while (cmd->next)
 			cmd = cmd->next;
 	else
 		return &jtag_command_queue;
-	
+
 	return &cmd->next;*/
-	
+
 	return last_comand_pointer;
 }
 
-/* returns a pointer to the n-th device in the scan chain */
-jtag_device_t* jtag_get_device(int num)
-{
-	jtag_device_t *device = jtag_devices;
-	int i = 0;
-
-	while (device)
-	{
-		if (num == i)
-			return device;
-		device = device->next;
-		i++;
-	}
-	
-	LOG_ERROR("jtag device number %d not defined", num);
-	exit(-1);
-}
 
 void* cmd_queue_alloc(size_t size)
 {
@@ -396,7 +500,7 @@ void* cmd_queue_alloc(size_t size)
 
 	offset = (*p_page)->used;
 	(*p_page)->used += size;
-	
+
 	t=(u8 *)((*p_page)->address);
 	return t + offset;
 }
@@ -432,7 +536,7 @@ static void jtag_prelude1(void)
 static void jtag_prelude(enum tap_state state)
 {
 	jtag_prelude1();
-	
+
 	if (state != -1)
 		jtag_add_end_state(state);
 
@@ -442,24 +546,26 @@ static void jtag_prelude(enum tap_state state)
 void jtag_add_ir_scan(int num_fields, scan_field_t *fields, enum tap_state state)
 {
 	int retval;
-	
+
 	jtag_prelude(state);
-	
+
 	retval=interface_jtag_add_ir_scan(num_fields, fields, cmd_queue_end_state);
 	if (retval!=ERROR_OK)
 		jtag_error=retval;
 }
 
 int MINIDRIVER(interface_jtag_add_ir_scan)(int num_fields, scan_field_t *fields, enum tap_state state)
-{	
+{
 	jtag_command_t **last_cmd;
-	jtag_device_t *device;
-	int i, j;
+	jtag_tap_t *tap;
+	int j;
+	int x;
+	int nth_tap;
 	int scan_size = 0;
 
 
 	last_cmd = jtag_get_last_command_p();
-	
+
 	/* allocate memory for a new list member */
 	*last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
 	(*last_cmd)->next = NULL;
@@ -469,70 +575,78 @@ int MINIDRIVER(interface_jtag_add_ir_scan)(int num_fields, scan_field_t *fields,
 	/* allocate memory for ir scan command */
 	(*last_cmd)->cmd.scan = cmd_queue_alloc(sizeof(scan_command_t));
 	(*last_cmd)->cmd.scan->ir_scan = 1;
-	(*last_cmd)->cmd.scan->num_fields = jtag_num_devices;	/* one field per device */
-	(*last_cmd)->cmd.scan->fields = cmd_queue_alloc(jtag_num_devices * sizeof(scan_field_t));
+	x = jtag_NumEnabledTaps();
+	(*last_cmd)->cmd.scan->num_fields = x;	/* one field per device */
+	(*last_cmd)->cmd.scan->fields = cmd_queue_alloc(x  * sizeof(scan_field_t));
 	(*last_cmd)->cmd.scan->end_state = state;
 
-	for (i = 0; i < jtag_num_devices; i++)
-	{
+	nth_tap = -1;
+	tap = NULL;
+	for(;;){
 		int found = 0;
-		device = jtag_get_device(i);
-		scan_size = device->ir_length;
-		(*last_cmd)->cmd.scan->fields[i].device = i;
-		(*last_cmd)->cmd.scan->fields[i].num_bits = scan_size;
-		(*last_cmd)->cmd.scan->fields[i].in_value = NULL;
-		(*last_cmd)->cmd.scan->fields[i].in_handler = NULL;	/* disable verification by default */
+
+		// do this here so it is not forgotten
+		tap = jtag_NextEnabledTap(tap);
+		if( tap == NULL ){
+			break;
+		}
+		nth_tap++;
+		scan_size = tap->ir_length;
+		(*last_cmd)->cmd.scan->fields[nth_tap].tap = tap;
+		(*last_cmd)->cmd.scan->fields[nth_tap].num_bits = scan_size;
+		(*last_cmd)->cmd.scan->fields[nth_tap].in_value = NULL;
+		(*last_cmd)->cmd.scan->fields[nth_tap].in_handler = NULL;	/* disable verification by default */
 
 		/* search the list */
 		for (j = 0; j < num_fields; j++)
 		{
-			if (i == fields[j].device)
+			if (tap == fields[j].tap)
 			{
 				found = 1;
-				(*last_cmd)->cmd.scan->fields[i].out_value = buf_cpy(fields[j].out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
-				(*last_cmd)->cmd.scan->fields[i].out_mask = buf_cpy(fields[j].out_mask, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
-			
+				(*last_cmd)->cmd.scan->fields[nth_tap].out_value = buf_cpy(fields[j].out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
+				(*last_cmd)->cmd.scan->fields[nth_tap].out_mask = buf_cpy(fields[j].out_mask, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
+
 				if (jtag_verify_capture_ir)
 				{
 					if (fields[j].in_handler==NULL)
 					{
-						jtag_set_check_value((*last_cmd)->cmd.scan->fields+i, device->expected, device->expected_mask, NULL);
+						jtag_set_check_value((*last_cmd)->cmd.scan->fields+nth_tap, tap->expected, tap->expected_mask, NULL);
 					} else
 					{
-						(*last_cmd)->cmd.scan->fields[i].in_handler = fields[j].in_handler;
-						(*last_cmd)->cmd.scan->fields[i].in_handler_priv = fields[j].in_handler_priv;
-						(*last_cmd)->cmd.scan->fields[i].in_check_value = device->expected; 
-						(*last_cmd)->cmd.scan->fields[i].in_check_mask = device->expected_mask;
+						(*last_cmd)->cmd.scan->fields[nth_tap].in_handler = fields[j].in_handler;
+						(*last_cmd)->cmd.scan->fields[nth_tap].in_handler_priv = fields[j].in_handler_priv;
+						(*last_cmd)->cmd.scan->fields[nth_tap].in_check_value = tap->expected;
+						(*last_cmd)->cmd.scan->fields[nth_tap].in_check_mask = tap->expected_mask;
 					}
 				}
-				
-				device->bypass = 0;
+
+				tap->bypass = 0;
 				break;
 			}
 		}
-	
+
 		if (!found)
 		{
-			/* if a device isn't listed, set it to BYPASS */
-			(*last_cmd)->cmd.scan->fields[i].out_value = buf_set_ones(cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
-			(*last_cmd)->cmd.scan->fields[i].out_mask = NULL;
-			device->bypass = 1;
-			
+			/* if a tap isn't listed, set it to BYPASS */
+			(*last_cmd)->cmd.scan->fields[nth_tap].out_value = buf_set_ones(cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
+			(*last_cmd)->cmd.scan->fields[nth_tap].out_mask = NULL;
+			tap->bypass = 1;
+
 		}
-		
+
 		/* update device information */
-		buf_cpy((*last_cmd)->cmd.scan->fields[i].out_value, jtag_get_device(i)->cur_instr, scan_size);
+		buf_cpy((*last_cmd)->cmd.scan->fields[nth_tap].out_value, tap->cur_instr, scan_size);
 	}
-	
+
 	return ERROR_OK;
 }
 
 void jtag_add_plain_ir_scan(int num_fields, scan_field_t *fields, enum tap_state state)
 {
 	int retval;
-	
+
 	jtag_prelude(state);
-	
+
 	retval=interface_jtag_add_plain_ir_scan(num_fields, fields, cmd_queue_end_state);
 	if (retval!=ERROR_OK)
 		jtag_error=retval;
@@ -542,9 +656,9 @@ int MINIDRIVER(interface_jtag_add_plain_ir_scan)(int num_fields, scan_field_t *f
 {
 	int i;
 	jtag_command_t **last_cmd;
-	
+
 	last_cmd = jtag_get_last_command_p();
-	
+
 	/* allocate memory for a new list member */
 	*last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
 	(*last_cmd)->next = NULL;
@@ -558,11 +672,10 @@ int MINIDRIVER(interface_jtag_add_plain_ir_scan)(int num_fields, scan_field_t *f
 	(*last_cmd)->cmd.scan->fields = cmd_queue_alloc(num_fields * sizeof(scan_field_t));
 	(*last_cmd)->cmd.scan->end_state = state;
 
-	for (i = 0; i < num_fields; i++)
-	{
+	for( i = 0 ; i < num_fields ; i++ ){
 		int num_bits = fields[i].num_bits;
 		int num_bytes = CEIL(fields[i].num_bits, 8);
-		(*last_cmd)->cmd.scan->fields[i].device = fields[i].device;
+		(*last_cmd)->cmd.scan->fields[i].tap = fields[i].tap;
 		(*last_cmd)->cmd.scan->fields[i].num_bits = num_bits;
 		(*last_cmd)->cmd.scan->fields[i].out_value = buf_cpy(fields[i].out_value, cmd_queue_alloc(num_bytes), num_bits);
 		(*last_cmd)->cmd.scan->fields[i].out_mask = buf_cpy(fields[i].out_mask, cmd_queue_alloc(num_bytes), num_bits);
@@ -578,7 +691,7 @@ int MINIDRIVER(interface_jtag_add_plain_ir_scan)(int num_fields, scan_field_t *f
 void jtag_add_dr_scan(int num_fields, scan_field_t *fields, enum tap_state state)
 {
 	int retval;
-	
+
 	jtag_prelude(state);
 
 	retval=interface_jtag_add_dr_scan(num_fields, fields, cmd_queue_end_state);
@@ -588,27 +701,28 @@ void jtag_add_dr_scan(int num_fields, scan_field_t *fields, enum tap_state state
 
 int MINIDRIVER(interface_jtag_add_dr_scan)(int num_fields, scan_field_t *fields, enum tap_state state)
 {
-	int i, j;
+	int j;
+	int nth_tap;
 	int bypass_devices = 0;
 	int field_count = 0;
 	int scan_size;
 
 	jtag_command_t **last_cmd = jtag_get_last_command_p();
-	jtag_device_t *device = jtag_devices;
+	jtag_tap_t *tap;
 
 	/* count devices in bypass */
-	while (device)
-	{
-		if (device->bypass)
+	tap = NULL;
+	bypass_devices = 0;
+	for(;;){
+		tap = jtag_NextEnabledTap(tap);
+		if( tap == NULL ){
+			break;
+		}
+		if( tap->bypass ){
 			bypass_devices++;
-		device = device->next;
-	}
-	if (bypass_devices >= jtag_num_devices)
-	{
-		LOG_ERROR("all devices in bypass");
-		return ERROR_JTAG_DEVICE_ERROR;
+		}
 	}
-	
+
 	/* allocate memory for a new list member */
 	*last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
 	last_comand_pointer = &((*last_cmd)->next);
@@ -621,15 +735,21 @@ int MINIDRIVER(interface_jtag_add_dr_scan)(int num_fields, scan_field_t *fields,
 	(*last_cmd)->cmd.scan->num_fields = num_fields + bypass_devices;
 	(*last_cmd)->cmd.scan->fields = cmd_queue_alloc((num_fields + bypass_devices) * sizeof(scan_field_t));
 	(*last_cmd)->cmd.scan->end_state = state;
-	
-	for (i = 0; i < jtag_num_devices; i++)
-	{
+
+	tap = NULL;
+	nth_tap = -1;
+	for(;;){
+		nth_tap++;
+		tap = jtag_NextEnabledTap(tap);
+		if( tap == NULL ){
+			break;
+		}
 		int found = 0;
-		(*last_cmd)->cmd.scan->fields[field_count].device = i;
-	
+		(*last_cmd)->cmd.scan->fields[field_count].tap = tap;
+
 		for (j = 0; j < num_fields; j++)
 		{
-			if (i == fields[j].device)
+			if (tap == fields[j].tap)
 			{
 				found = 1;
 				scan_size = fields[j].num_bits;
@@ -647,12 +767,12 @@ int MINIDRIVER(interface_jtag_add_dr_scan)(int num_fields, scan_field_t *fields,
 		{
 #ifdef _DEBUG_JTAG_IO_
 			/* if a device isn't listed, the BYPASS register should be selected */
-			if (!jtag_get_device(i)->bypass)
+			if (! tap->bypass)
 			{
 				LOG_ERROR("BUG: no scan data for a device not in BYPASS");
 				exit(-1);
 			}
-#endif	
+#endif
 			/* program the scan field to 1 bit length, and ignore it's value */
 			(*last_cmd)->cmd.scan->fields[field_count].num_bits = 1;
 			(*last_cmd)->cmd.scan->fields[field_count].out_value = NULL;
@@ -667,7 +787,7 @@ int MINIDRIVER(interface_jtag_add_dr_scan)(int num_fields, scan_field_t *fields,
 		{
 #ifdef _DEBUG_JTAG_IO_
 			/* if a device is listed, the BYPASS register must not be selected */
-			if (jtag_get_device(i)->bypass)
+			if (tap->bypass)
 			{
 				LOG_ERROR("BUG: scan data for a device in BYPASS");
 				exit(-1);
@@ -678,27 +798,33 @@ int MINIDRIVER(interface_jtag_add_dr_scan)(int num_fields, scan_field_t *fields,
 	return ERROR_OK;
 }
 
-void MINIDRIVER(interface_jtag_add_dr_out)(int device_num, 
+void MINIDRIVER(interface_jtag_add_dr_out)(jtag_tap_t *target_tap,
 		int num_fields,
 		const int *num_bits,
 		const u32 *value,
 		enum tap_state end_state)
 {
-	int i;
+	int nth_tap;
 	int field_count = 0;
 	int scan_size;
 	int bypass_devices = 0;
 
 	jtag_command_t **last_cmd = jtag_get_last_command_p();
-	jtag_device_t *device = jtag_devices;
+	jtag_tap_t *tap;
+
 	/* count devices in bypass */
-	while (device)
-	{
-		if (device->bypass)
+	tap = NULL;
+	bypass_devices = 0;
+	for(;;){
+		tap = jtag_NextEnabledTap(tap);
+		if( tap == NULL ){
+			break;
+		}
+		if( tap->bypass ){
 			bypass_devices++;
-		device = device->next;
+		}
 	}
-	
+
 	/* allocate memory for a new list member */
 	*last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
 	last_comand_pointer = &((*last_cmd)->next);
@@ -711,17 +837,23 @@ void MINIDRIVER(interface_jtag_add_dr_out)(int device_num,
 	(*last_cmd)->cmd.scan->num_fields = num_fields + bypass_devices;
 	(*last_cmd)->cmd.scan->fields = cmd_queue_alloc((num_fields + bypass_devices) * sizeof(scan_field_t));
 	(*last_cmd)->cmd.scan->end_state = end_state;
-	
-	for (i = 0; i < jtag_num_devices; i++)
-	{
-		(*last_cmd)->cmd.scan->fields[field_count].device = i;
-	
-		if (i == device_num)
+
+	tap = NULL;
+	nth_tap = -1;
+	for(;;){
+		tap = jtag_NextEnabledTap(tap);
+		if( tap == NULL ){
+			break;
+		}
+		nth_tap++;
+		(*last_cmd)->cmd.scan->fields[field_count].tap = tap;
+
+		if (tap == target_tap)
 		{
 			int j;
 #ifdef _DEBUG_JTAG_IO_
 			/* if a device is listed, the BYPASS register must not be selected */
-			if (jtag_get_device(i)->bypass)
+			if (tap->bypass)
 			{
 				LOG_ERROR("BUG: scan data for a device in BYPASS");
 				exit(-1);
@@ -745,12 +877,12 @@ void MINIDRIVER(interface_jtag_add_dr_out)(int device_num,
 		{
 #ifdef _DEBUG_JTAG_IO_
 			/* if a device isn't listed, the BYPASS register should be selected */
-			if (!jtag_get_device(i)->bypass)
+			if (! tap->bypass)
 			{
 				LOG_ERROR("BUG: no scan data for a device not in BYPASS");
 				exit(-1);
 			}
-#endif	
+#endif
 			/* program the scan field to 1 bit length, and ignore it's value */
 			(*last_cmd)->cmd.scan->fields[field_count].num_bits = 1;
 			(*last_cmd)->cmd.scan->fields[field_count].out_value = NULL;
@@ -767,7 +899,7 @@ void MINIDRIVER(interface_jtag_add_dr_out)(int device_num,
 void jtag_add_plain_dr_scan(int num_fields, scan_field_t *fields, enum tap_state state)
 {
 	int retval;
-	
+
 	jtag_prelude(state);
 
 	retval=interface_jtag_add_plain_dr_scan(num_fields, fields, cmd_queue_end_state);
@@ -779,7 +911,7 @@ int MINIDRIVER(interface_jtag_add_plain_dr_scan)(int num_fields, scan_field_t *f
 {
 	int i;
 	jtag_command_t **last_cmd = jtag_get_last_command_p();
-	
+
 	/* allocate memory for a new list member */
 	*last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
 	last_comand_pointer = &((*last_cmd)->next);
@@ -792,12 +924,12 @@ int MINIDRIVER(interface_jtag_add_plain_dr_scan)(int num_fields, scan_field_t *f
 	(*last_cmd)->cmd.scan->num_fields = num_fields;
 	(*last_cmd)->cmd.scan->fields = cmd_queue_alloc(num_fields * sizeof(scan_field_t));
 	(*last_cmd)->cmd.scan->end_state = state;
-	
+
 	for (i = 0; i < num_fields; i++)
 	{
 		int num_bits = fields[i].num_bits;
 		int num_bytes = CEIL(fields[i].num_bits, 8);
-		(*last_cmd)->cmd.scan->fields[i].device = fields[i].device;
+		(*last_cmd)->cmd.scan->fields[i].tap = fields[i].tap;
 		(*last_cmd)->cmd.scan->fields[i].num_bits = num_bits;
 		(*last_cmd)->cmd.scan->fields[i].out_value = buf_cpy(fields[i].out_value, cmd_queue_alloc(num_bytes), num_bits);
 		(*last_cmd)->cmd.scan->fields[i].out_mask = buf_cpy(fields[i].out_mask, cmd_queue_alloc(num_bytes), num_bits);
@@ -811,10 +943,10 @@ int MINIDRIVER(interface_jtag_add_plain_dr_scan)(int num_fields, scan_field_t *f
 	return ERROR_OK;
 }
 
-void jtag_add_tlr()
+void jtag_add_tlr(void)
 {
 	jtag_prelude(TAP_TLR);
-	
+
 	int retval;
 	retval=interface_jtag_add_tlr();
 	if (retval!=ERROR_OK)
@@ -825,7 +957,7 @@ int MINIDRIVER(interface_jtag_add_tlr)()
 {
 	enum tap_state state = TAP_TLR;
 	jtag_command_t **last_cmd = jtag_get_last_command_p();
-	
+
 	/* allocate memory for a new list member */
 	*last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
 	last_comand_pointer = &((*last_cmd)->next);
@@ -834,8 +966,8 @@ int MINIDRIVER(interface_jtag_add_tlr)()
 
 	(*last_cmd)->cmd.statemove = cmd_queue_alloc(sizeof(statemove_command_t));
 	(*last_cmd)->cmd.statemove->end_state = state;
-	
-	
+
+
 	return ERROR_OK;
 }
 
@@ -867,9 +999,9 @@ void jtag_add_pathmove(int num_states, enum tap_state *path)
 		}
 		cur_state = path[i];
 	}
-	
+
 	jtag_prelude1();
-	
+
 
 	retval=interface_jtag_add_pathmove(num_states, path);
 	cmd_queue_cur_state = path[num_states - 1];
@@ -881,7 +1013,7 @@ int MINIDRIVER(interface_jtag_add_pathmove)(int num_states, enum tap_state *path
 {
 	jtag_command_t **last_cmd = jtag_get_last_command_p();
 	int i;
-	
+
 	/* allocate memory for a new list member */
 	*last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
 	last_comand_pointer = &((*last_cmd)->next);
@@ -891,17 +1023,17 @@ int MINIDRIVER(interface_jtag_add_pathmove)(int num_states, enum tap_state *path
 	(*last_cmd)->cmd.pathmove = cmd_queue_alloc(sizeof(pathmove_command_t));
 	(*last_cmd)->cmd.pathmove->num_states = num_states;
 	(*last_cmd)->cmd.pathmove->path = cmd_queue_alloc(sizeof(enum tap_state) * num_states);
-	
+
 	for (i = 0; i < num_states; i++)
 		(*last_cmd)->cmd.pathmove->path[i] = path[i];
-	
+
 	return ERROR_OK;
 }
 
 int MINIDRIVER(interface_jtag_add_runtest)(int num_cycles, enum tap_state state)
 {
 	jtag_command_t **last_cmd = jtag_get_last_command_p();
-	
+
 	/* allocate memory for a new list member */
 	*last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
 	(*last_cmd)->next = NULL;
@@ -911,16 +1043,16 @@ int MINIDRIVER(interface_jtag_add_runtest)(int num_cycles, enum tap_state state)
 	(*last_cmd)->cmd.runtest = cmd_queue_alloc(sizeof(runtest_command_t));
 	(*last_cmd)->cmd.runtest->num_cycles = num_cycles;
 	(*last_cmd)->cmd.runtest->end_state = state;
-	
+
 	return ERROR_OK;
 }
 
 void jtag_add_runtest(int num_cycles, enum tap_state state)
 {
 	int retval;
-	
+
 	jtag_prelude(state);
-	
+
 	/* executed by sw or hw fifo */
 	retval=interface_jtag_add_runtest(num_cycles, cmd_queue_end_state);
 	if (retval!=ERROR_OK)
@@ -931,12 +1063,12 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 {
 	int trst_with_tlr = 0;
 	int retval;
-	
+
 	/* 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_HAS_TRST)&&
 			((jtag_reset_config & RESET_SRST_PULLS_TRST)==0))
 	{
 		if (((req_tlr_or_trst&&!jtag_trst)||
@@ -948,7 +1080,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 			//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))
@@ -957,20 +1089,20 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 		jtag_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_error=ERROR_FAIL;
 		return;
 	}
-	
+
 	if (req_tlr_or_trst)
 	{
 		if (!trst_with_tlr && (jtag_reset_config & RESET_HAS_TRST))
@@ -984,7 +1116,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 	{
 		jtag_trst = 0;
 	}
-	
+
 	jtag_srst = req_srst;
 
 	retval = interface_jtag_add_reset(jtag_trst, jtag_srst);
@@ -1004,7 +1136,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 		if (jtag_nsrst_delay)
 			jtag_add_sleep(jtag_nsrst_delay * 1000);
 	}
-	
+
 	if (trst_with_tlr)
 	{
 		LOG_DEBUG("JTAG reset with TLR instead of TRST");
@@ -1013,7 +1145,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
 		jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
 		return;
 	}
-	
+
 	if (jtag_trst)
 	{
 		/* we just asserted nTRST, so we're now in Test-Logic-Reset,
@@ -1059,7 +1191,7 @@ void jtag_add_end_state(enum tap_state state)
 int MINIDRIVER(interface_jtag_add_sleep)(u32 us)
 {
 	jtag_command_t **last_cmd = jtag_get_last_command_p();
-	
+
 	/* allocate memory for a new list member */
 	*last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
 	(*last_cmd)->next = NULL;
@@ -1068,7 +1200,7 @@ int MINIDRIVER(interface_jtag_add_sleep)(u32 us)
 
 	(*last_cmd)->cmd.sleep = cmd_queue_alloc(sizeof(sleep_command_t));
 	(*last_cmd)->cmd.sleep->us = us;
-	
+
 	return ERROR_OK;
 }
 
@@ -1099,10 +1231,10 @@ int jtag_build_buffer(scan_command_t *cmd, u8 **buffer)
 {
 	int bit_count = 0;
 	int i;
-	
+
 	bit_count = jtag_scan_size(cmd);
 	*buffer = malloc(CEIL(bit_count, 8));
-	
+
 	bit_count = 0;
 
 	for (i = 0; i < cmd->num_fields; i++)
@@ -1118,7 +1250,7 @@ int jtag_build_buffer(scan_command_t *cmd, u8 **buffer)
 			free(char_buf);
 #endif
 		}
-		
+
 		bit_count += cmd->fields[i].num_bits;
 	}
 
@@ -1130,10 +1262,10 @@ int jtag_read_buffer(u8 *buffer, scan_command_t *cmd)
 	int i;
 	int bit_count = 0;
 	int retval;
-	
+
 	/* we return ERROR_OK, unless a check fails, or a handler reports a problem */
 	retval = ERROR_OK;
-	
+
 	for (i = 0; i < cmd->num_fields; i++)
 	{
 		/* if neither in_value nor in_handler
@@ -1143,7 +1275,7 @@ int jtag_read_buffer(u8 *buffer, scan_command_t *cmd)
 		{
 			int num_bits = cmd->fields[i].num_bits;
 			u8 *captured = buf_set_buf(buffer, bit_count, malloc(CEIL(num_bits, 8)), 0, num_bits);
-			
+
 #ifdef _DEBUG_JTAG_IO_
 			char *char_buf;
 
@@ -1151,11 +1283,11 @@ int jtag_read_buffer(u8 *buffer, scan_command_t *cmd)
 			LOG_DEBUG("fields[%i].in_value: 0x%s", i, char_buf);
 			free(char_buf);
 #endif
-			
+
 			if (cmd->fields[i].in_value)
 			{
 				buf_cpy(captured, cmd->fields[i].in_value, num_bits);
-				
+
 				if (cmd->fields[i].in_handler)
 				{
 					if (cmd->fields[i].in_handler(cmd->fields[i].in_value, cmd->fields[i].in_handler_priv, cmd->fields+i) != ERROR_OK)
@@ -1165,7 +1297,7 @@ int jtag_read_buffer(u8 *buffer, scan_command_t *cmd)
 					}
 				}
 			}
-			
+
 			/* no in_value specified, but a handler takes care of the scanned data */
 			if (cmd->fields[i].in_handler && (!cmd->fields[i].in_value))
 			{
@@ -1191,20 +1323,21 @@ int jtag_check_value(u8 *captured, void *priv, scan_field_t *field)
 {
 	int retval = ERROR_OK;
 	int num_bits = field->num_bits;
-	
+
 	int compare_failed = 0;
-	
+
 	if (field->in_check_mask)
 		compare_failed = buf_cmp_mask(captured, field->in_check_value, field->in_check_mask, num_bits);
 	else
 		compare_failed = buf_cmp(captured, field->in_check_value, num_bits);
-	
-	if (compare_failed)
-		{
+
+	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:",
+					(field->tap == NULL) ? "(unknown)" : field->tap->dotted_name );
 		if (compare_failed)
 		{
 			char *captured_char = buf_to_str(captured, (num_bits > 64) ? 64 : num_bits, 16);
@@ -1214,7 +1347,9 @@ int jtag_check_value(u8 *captured, void *priv, scan_field_t *field)
 			{
 				char *in_check_mask_char;
 				in_check_mask_char = buf_to_str(field->in_check_mask, (num_bits > 64) ? 64 : num_bits, 16);
-				LOG_WARNING("value captured during scan didn't pass the requested check: captured: 0x%s check_value: 0x%s check_mask: 0x%s", captured_char, in_check_value_char, in_check_mask_char);
+				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
@@ -1224,15 +1359,15 @@ int jtag_check_value(u8 *captured, void *priv, scan_field_t *field)
 
 			free(captured_char);
 			free(in_check_value_char);
-			
+
 			retval = ERROR_JTAG_QUEUE_FAILED;
 		}
-		
+
 	}
 	return retval;
 }
 
-/* 
+/*
   set up checking of this field using the in_handler. The values passed in must be valid until
   after jtag_execute() has completed.
  */
@@ -1251,7 +1386,7 @@ enum scan_type jtag_scan_type(scan_command_t *cmd)
 {
 	int i;
 	int type = 0;
-	
+
 	for (i = 0; i < cmd->num_fields; i++)
 	{
 		if (cmd->fields[i].in_value || cmd->fields[i].in_handler)
@@ -1266,15 +1401,15 @@ enum scan_type jtag_scan_type(scan_command_t *cmd)
 int MINIDRIVER(interface_jtag_execute_queue)(void)
 {
 	int retval;
-	
+
 	if (jtag==NULL)
 	{
 		LOG_ERROR("No JTAG interface configured yet. Issue 'init' command in startup scripts before communicating with targets.");
 		return ERROR_FAIL;
 	}
-	
+
 	retval = jtag->execute_queue();
-	
+
 	cmd_queue_free();
 
 	jtag_command_queue = NULL;
@@ -1296,29 +1431,29 @@ int jtag_execute_queue(void)
 
 int jtag_reset_callback(enum jtag_event event, void *priv)
 {
-	jtag_device_t *device = priv;
+	jtag_tap_t *tap = priv;
 
 	LOG_DEBUG("-");
-	
+
 	if (event == JTAG_TRST_ASSERTED)
 	{
-		buf_set_ones(device->cur_instr, device->ir_length);
-		device->bypass = 1;
+		buf_set_ones(tap->cur_instr, tap->ir_length);
+		tap->bypass = 1;
 	}
-	
+
 	return ERROR_OK;
 }
 
 void jtag_sleep(u32 us)
 {
-	usleep(us);
+	alive_sleep(us/1000);
 }
 
 /* Try to examine chain layout according to IEEE 1149.1 §12
  */
 int jtag_examine_chain(void)
 {
-	jtag_device_t *device = jtag_devices;
+	jtag_tap_t *tap;
 	scan_field_t field;
 	u8 idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
 	int i;
@@ -1326,8 +1461,8 @@ int jtag_examine_chain(void)
 	int device_count = 0;
 	u8 zero_check = 0x0;
 	u8 one_check = 0xff;
-	
-	field.device = 0;
+
+	field.tap = NULL;
 	field.num_bits = sizeof(idcode_buffer) * 8;
 	field.out_value = idcode_buffer;
 	field.out_mask = NULL;
@@ -1336,27 +1471,34 @@ int jtag_examine_chain(void)
 	field.in_check_mask = NULL;
 	field.in_handler = NULL;
 	field.in_handler_priv = NULL;
-	
+
 	for (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_TLR);
 	jtag_execute_queue();
-	
+
 	for (i = 0; i < JTAG_MAX_CHAIN_SIZE * 4; i++)
 	{
 		zero_check |= idcode_buffer[i];
 		one_check &= idcode_buffer[i];
 	}
-	
+
 	/* if there wasn't a single non-zero bit or if all bits were one, the scan isn't valid */
 	if ((zero_check == 0x00) || (one_check == 0xff))
 	{
 		LOG_ERROR("JTAG communication failure, check connection, JTAG interface, target power etc.");
 		return ERROR_JTAG_INIT_FAILED;
 	}
+
+	// point at the 1st tap
+	tap = jtag_NextEnabledTap(NULL);
+	if( tap == NULL ){
+		LOG_ERROR("JTAG: No taps enabled?");
+		return ERROR_JTAG_INIT_FAILED;
+	}
 	
 	for (bit_count = 0; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;)
 	{
@@ -1364,10 +1506,9 @@ int jtag_examine_chain(void)
 		if ((idcode & 1) == 0)
 		{
 			/* LSB must not be 0, this indicates a device in bypass */
-			device_count++;
-			
-			LOG_WARNING("Device was in bypass after TRST/TMS reset");
-			
+			LOG_WARNING("Tap/Device does not have IDCODE");
+			idcode=0;
+
 			bit_count += 1;
 		}
 		else
@@ -1375,22 +1516,22 @@ int jtag_examine_chain(void)
 			u32 manufacturer;
 			u32 part;
 			u32 version;
-			
+
 			if (idcode == 0x000000FF)
 			{
 				int unexpected=0;
-				/* End of chain (invalid manufacturer ID) 
-				 * 
+				/* End of chain (invalid manufacturer ID)
+				 *
 				 * The JTAG examine is the very first thing that happens
-				 * 
+				 *
 				 * A single JTAG device requires only 64 bits to be read back correctly.
-				 * 
+				 *
 				 * The code below adds a check that the rest of the data scanned (640 bits)
 				 * are all as expected. This helps diagnose/catch problems with the JTAG chain
-				 * 
+				 *
 				 * earlier and gives more helpful/explicit error messages.
 				 */
-				for (bit_count += 32; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;bit_count += 32) 
+				for (bit_count += 32; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;bit_count += 32)
 				{
 					idcode = buf_get_u32(idcode_buffer, bit_count, 32);
 					if (unexpected||(idcode != 0x000000FF))
@@ -1399,59 +1540,89 @@ int jtag_examine_chain(void)
 						unexpected = 1;
 					}
 				}
-				
+
 				break;
 			}
-			
-			if (device)
-			{
-				device->idcode = idcode;
-				device = device->next;
-			}
-			device_count++;
-			
-			manufacturer = (idcode & 0xffe) >> 1;
-			part = (idcode & 0xffff000) >> 12;
-			version = (idcode & 0xf0000000) >> 28;
 
-			LOG_INFO("JTAG device found: 0x%8.8x (Manufacturer: 0x%3.3x, Part: 0x%4.4x, Version: 0x%1.1x)", 
+#define EXTRACT_MFG(X)  (((X) & 0xffe) >> 1)
+			manufacturer = EXTRACT_MFG(idcode);
+#define EXTRACT_PART(X) (((X) & 0xffff000) >> 12)
+			part = EXTRACT_PART(idcode);
+#define EXTRACT_VER(X)  (((X) & 0xf0000000) >> 28)
+			version = EXTRACT_VER(idcode);
+
+			LOG_INFO("JTAG tap: %s tap/device found: 0x%8.8x (Manufacturer: 0x%3.3x, Part: 0x%4.4x, Version: 0x%1.1x)",
+					 ((tap != NULL) ? (tap->dotted_name) : "(not-named)"),
 				idcode, manufacturer, part, version);
-			
+
 			bit_count += 32;
 		}
+		if (tap)
+		{
+			tap->idcode = idcode;
+			if( tap->expected_id ){
+				if( tap->idcode != tap->expected_id ){
+					LOG_ERROR("ERROR: Tap: %s - Expected id: 0x%08x, Got: 0x%08x",
+							  tap->dotted_name,
+							  tap->expected_id,
+							  idcode );
+					LOG_ERROR("ERROR: expected: mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x",
+							  EXTRACT_MFG( tap->expected_id ),
+							  EXTRACT_PART( tap->expected_id ),
+							  EXTRACT_VER( tap->expected_id ) );
+					LOG_ERROR("ERROR:      got: mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x",
+							  EXTRACT_MFG( tap->idcode ),
+							  EXTRACT_PART( tap->idcode ),
+							  EXTRACT_VER( tap->idcode ) );
+				} else {
+					LOG_INFO("JTAG Tap/device matched");
+				}
+			} else {
+#if 0
+				LOG_INFO("JTAG TAP ID: 0x%08x - Unknown - please report (A) chipname and (B) idcode to the openocd project", 
+						 tap->idcode);
+#endif
+			}
+			tap = jtag_NextEnabledTap(tap);
+		}
+		device_count++;
 	}
-	
+
 	/* see if number of discovered devices matches configuration */
-	if (device_count != jtag_num_devices)
+	if (device_count != jtag_NumEnabledTaps())
 	{
-		LOG_ERROR("number of discovered devices in JTAG chain (%i) doesn't match configuration (%i)", 
-				device_count, jtag_num_devices);
+		LOG_ERROR("number of discovered devices in JTAG chain (%i) doesn't match (enabled) configuration (%i), total taps: %d",
+				  device_count, jtag_NumEnabledTaps(), jtag_NumTotalTaps());
 		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_device_t *device = jtag_devices;
+	jtag_tap_t *tap;
 	int total_ir_length = 0;
 	u8 *ir_test = NULL;
 	scan_field_t field;
 	int chain_pos = 0;
-	
-	while (device)
-	{
-		total_ir_length += device->ir_length;
-		device = device->next;
+
+	tap = NULL;
+	total_ir_length = 0;
+	for(;;){
+		tap = jtag_NextEnabledTap(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.device = 0;
+
+	field.tap = NULL;
 	field.num_bits = total_ir_length;
 	field.out_value = ir_test;
 	field.out_mask = NULL;
@@ -1460,13 +1631,19 @@ int jtag_validate_chain(void)
 	field.in_check_mask = NULL;
 	field.in_handler = NULL;
 	field.in_handler_priv = NULL;
-	
+
 	jtag_add_plain_ir_scan(1, &field, TAP_TLR);
 	jtag_execute_queue();
-	
-	device = jtag_devices;
-	while (device)
-	{
+
+	tap = NULL;
+	chain_pos = 0;
+	for(;;){
+		tap = jtag_NextEnabledTap(tap);
+		if( tap == NULL ){
+			break;
+		}
+		
+
 		if (buf_get_u32(ir_test, chain_pos, 2) != 0x1)
 		{
 			char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
@@ -1475,10 +1652,9 @@ int jtag_validate_chain(void)
 			free(ir_test);
 			return ERROR_JTAG_INIT_FAILED;
 		}
-		chain_pos += device->ir_length;
-		device = device->next;
+		chain_pos += tap->ir_length;
 	}
-	
+
 	if (buf_get_u32(ir_test, chain_pos, 2) != 0x3)
 	{
 		char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
@@ -1487,16 +1663,291 @@ int jtag_validate_chain(void)
 		free(ir_test);
 		return ERROR_JTAG_INIT_FAILED;
 	}
-	
+
 	free(ir_test);
+
+	return ERROR_OK;
+}
+
+
+static int
+jim_newtap_cmd( Jim_GetOptInfo *goi )
+{
+	jtag_tap_t *pTap;
+	jtag_tap_t **ppTap;
+	jim_wide w;
+	int x;
+	int e;
+	int reqbits;
+	Jim_Nvp *n;
+	char *cp;
+	const Jim_Nvp opts[] = {
+#define NTAP_OPT_IRLEN     0
+		{ .name = "-irlen"			,	.value = NTAP_OPT_IRLEN },
+#define NTAP_OPT_IRMASK    1
+		{ .name = "-irmask"			,	.value = NTAP_OPT_IRMASK },
+#define NTAP_OPT_IRCAPTURE 2
+		{ .name = "-ircapture"		,	.value = NTAP_OPT_IRCAPTURE },
+#define NTAP_OPT_ENABLED   3
+		{ .name = "-enable"			,   .value = NTAP_OPT_ENABLED },
+#define NTAP_OPT_DISABLED  4
+		{ .name = "-disable"		,   .value = NTAP_OPT_DISABLED },
+#define NTAP_OPT_EXPECTED_ID 5
+		{ .name = "-expected-id"	,   .value = NTAP_OPT_EXPECTED_ID },
+		{ .name = NULL				,   .value = -1 },
+	};
+
+		
+	pTap = malloc( sizeof(jtag_tap_t) );
+	memset( pTap, 0, sizeof(*pTap) );
+	if( !pTap ){
+		Jim_SetResult_sprintf( goi->interp, "no memory");
+		return JIM_ERR;
+	}
+	//
+	// we expect CHIP + TAP + OPTIONS
+	// 
+	if( goi->argc < 3 ){
+		Jim_SetResult_sprintf(goi->interp, "Missing CHIP TAP OPTIONS ....");
+		return JIM_ERR;
+	}
+	Jim_GetOpt_String( goi, &cp, NULL );
+	pTap->chip = strdup(cp);
+
+	Jim_GetOpt_String( goi, &cp, NULL );
+	pTap->tapname = strdup(cp);
+	
+	// name + dot + name + null
+	x = strlen(pTap->chip) + 1 + strlen(pTap->tapname) + 1;
+	cp = malloc( x );
+	sprintf( cp, "%s.%s", pTap->chip, pTap->tapname );
+	pTap->dotted_name = cp;
+
+	LOG_DEBUG("Creating New Tap, Chip: %s, Tap: %s, Dotted: %s, %d params", 
+			  pTap->chip, pTap->tapname, pTap->dotted_name, goi->argc);
+
 	
+	// default is enabled
+	pTap->enabled = 1;
+
+	// deal with options
+#define NTREQ_IRLEN      1
+#define NTREQ_IRCAPTURE  2
+#define NTREQ_IRMASK     4
+
+	// clear them as we find them
+	reqbits = (NTREQ_IRLEN | NTREQ_IRCAPTURE | NTREQ_IRMASK);
+	
+	while( goi->argc ){
+		e = Jim_GetOpt_Nvp( goi, opts, &n );
+		if( e != JIM_OK ){
+			Jim_GetOpt_NvpUnknown( goi, opts, 0 );
+			return e;
+		}
+		LOG_DEBUG("Processing option: %s", n->name );
+		switch( n->value ){
+		case NTAP_OPT_ENABLED:
+			pTap->enabled = 1;
+			break;
+		case NTAP_OPT_DISABLED:
+			pTap->enabled = 0;
+			break;
+		case NTAP_OPT_EXPECTED_ID:
+			e = Jim_GetOpt_Wide( goi, &w );
+			pTap->expected_id = w;
+			break;
+		case NTAP_OPT_IRLEN:
+		case NTAP_OPT_IRMASK:
+		case NTAP_OPT_IRCAPTURE:
+			e = Jim_GetOpt_Wide( goi, &w );
+			if( e != JIM_OK ){
+				Jim_SetResult_sprintf( goi->interp, "option: %s bad parameter", n->name );
+				return e;
+			}
+			if( (w < 0) || (w > 0xffff) ){
+				// wacky value
+				Jim_SetResult_sprintf( goi->interp, "option: %s - wacky value: %d (0x%x)", 
+									   n->name, (int)(w), (int)(w));
+				return JIM_ERR;
+			}
+			switch(n->value){
+			case NTAP_OPT_IRLEN:
+				pTap->ir_length = w;
+				reqbits &= (~(NTREQ_IRLEN));
+				break;
+			case NTAP_OPT_IRMASK:
+				pTap->ir_capture_mask = w;
+				reqbits &= (~(NTREQ_IRMASK));
+				break;
+			case NTAP_OPT_IRCAPTURE:
+				pTap->ir_capture_value = w;
+				reqbits &= (~(NTREQ_IRCAPTURE));
+				break;
+			}
+		} // switch(n->value)
+	} // while( goi->argc )
+
+	// Did we get all the options?
+	if( reqbits ){
+		// no 
+		Jim_SetResult_sprintf( goi->interp,
+							   "newtap: %s missing required parameters", 
+							   pTap->dotted_name);
+		// fixme: Tell user what is missing :-(
+		// no memory leaks pelase
+		free(((void *)(pTap->chip)));
+		free(((void *)(pTap->tapname)));
+		free(((void *)(pTap->dotted_name)));
+		free(((void *)(pTap)));
+		return JIM_ERR;
+	}
+
+	pTap->expected      = malloc( pTap->ir_length );
+	pTap->expected_mask = malloc( pTap->ir_length );
+	pTap->cur_instr     = malloc( pTap->ir_length );
+
+	buf_set_u32( pTap->expected,
+				 0,
+				 pTap->ir_length,
+				 pTap->ir_capture_value );
+	buf_set_u32( pTap->expected_mask,
+				 0, 
+				 pTap->ir_length,
+				 pTap->ir_capture_mask );
+	buf_set_ones( pTap->cur_instr, 
+				  pTap->ir_length );
+
+	pTap->bypass = 1;
+
+
+	jtag_register_event_callback(jtag_reset_callback, pTap );
+	
+	ppTap = &(jtag_all_taps);
+	while( (*ppTap) != NULL ){
+		ppTap = &((*ppTap)->next_tap);
+	}
+	*ppTap = pTap;
+	{ 
+		static int n_taps = 0;
+		pTap->abs_chain_position = n_taps++;
+	}
+	LOG_DEBUG( "Created Tap: %s @ abs position %d, irlen %d, capture: 0x%x mask: 0x%x",
+			   (*ppTap)->dotted_name,
+			   (*ppTap)->abs_chain_position,
+			   (*ppTap)->ir_length,
+			   (*ppTap)->ir_capture_value,
+			   (*ppTap)->ir_capture_mask );
+
+
 	return ERROR_OK;
 }
 
+
+static int
+jim_jtag_command( Jim_Interp *interp, int argc, Jim_Obj *const *argv )
+{
+	Jim_GetOptInfo goi;
+	int e;
+	Jim_Nvp *n;
+	struct command_context_s *context;
+
+	enum {
+		JTAG_CMD_INTERFACE,
+		JTAG_CMD_INIT_RESET,
+		JTAG_CMD_NEWTAP,
+		JTAG_CMD_TAPENABLE,
+		JTAG_CMD_TAPDISABLE,
+		JTAG_CMD_TAPISENABLED
+	};
+
+	const Jim_Nvp jtag_cmds[] = {
+		{ .name = "interface"     , .value = JTAG_CMD_INTERFACE },
+		{ .name = "arp_init-reset", .value = JTAG_CMD_INIT_RESET },
+		{ .name = "newtap"        , .value = JTAG_CMD_NEWTAP },
+		{ .name = "tapisenabled"     , .value = JTAG_CMD_TAPISENABLED },
+		{ .name = "tapenable"     , .value = JTAG_CMD_TAPENABLE },
+		{ .name = "tapdisable"    , .value = JTAG_CMD_TAPDISABLE },
+
+		{ .name = NULL, .value = -1 },
+	};
+
+	context = Jim_GetAssocData(interp, "context");
+	// go past the command
+	Jim_GetOpt_Setup( &goi, interp, argc-1, argv+1 );
+
+	e = Jim_GetOpt_Nvp( &goi, jtag_cmds, &n );
+	if( e != JIM_OK ){
+		Jim_GetOpt_NvpUnknown( &goi, jtag_cmds, 0 );
+		return e;
+	}
+		Jim_SetEmptyResult( goi.interp );
+	switch( n->value ){
+	case JTAG_CMD_INTERFACE:
+		// return the name of the interface
+		// TCL code might need to know the exact type...
+		// FUTURE: we allow this as a means to "set" the interface.
+		if( goi.argc != 0 ){
+			Jim_WrongNumArgs( goi.interp, 1, goi.argv-1, "(no params)");
+			return JIM_ERR;
+		}
+		Jim_SetResultString( goi.interp, jtag_interface->name, -1 );
+		return JIM_OK;
+	case JTAG_CMD_INIT_RESET:
+		if( goi.argc != 0 ){
+			Jim_WrongNumArgs( goi.interp, 1, goi.argv-1, "(no params)");
+			return JIM_ERR;
+		}
+		e = jtag_init_reset(context);
+		if( e != ERROR_OK ){
+			Jim_SetResult_sprintf( goi.interp, "error: %d", e);
+			return JIM_ERR;
+		}
+		return JIM_OK;
+	case JTAG_CMD_NEWTAP:
+		return jim_newtap_cmd( &goi );
+		break;
+	case JTAG_CMD_TAPISENABLED:
+	case JTAG_CMD_TAPENABLE:
+	case JTAG_CMD_TAPDISABLE:
+		if( goi.argc != 1 ){
+			Jim_SetResultString( goi.interp, "Too many parameters",-1 );
+			return JIM_ERR;
+		}
+		
+		{ 
+			jtag_tap_t *t;
+			t = jtag_TapByJimObj( goi.interp, goi.argv[0] );
+			if( t == NULL ){
+				return JIM_ERR;
+			}
+			switch( n->value ){
+			case JTAG_CMD_TAPISENABLED:
+				// below
+				break;
+			case JTAG_CMD_TAPENABLE:
+				e = 1;
+				t->enabled = e;
+				break;
+			case JTAG_CMD_TAPDISABLE:
+				e = 0;
+				t->enabled = e;
+				break;
+			}
+			Jim_SetResult( goi.interp, Jim_NewIntObj( goi.interp, e ) );
+			return JIM_OK;
+		}
+	}
+
+
+	return JIM_ERR;
+}
+
 int jtag_register_commands(struct command_context_s *cmd_ctx)
 {
+	register_jim( cmd_ctx, "jtag", jim_jtag_command, "perform jtag tap actions");
+
 	register_command(cmd_ctx, NULL, "interface", handle_interface_command,
-		COMMAND_CONFIG, NULL);
+		COMMAND_CONFIG, "try to configure interface");
 	register_command(cmd_ctx, NULL, "jtag_speed", handle_jtag_speed_command,
 		COMMAND_ANY, "set jtag speed (if supported)");
 	register_command(cmd_ctx, NULL, "jtag_khz", handle_jtag_khz_command,
@@ -1509,7 +1960,7 @@ int jtag_register_commands(struct command_context_s *cmd_ctx)
 		COMMAND_ANY, "jtag_nsrst_delay <ms> - delay after deasserting srst in ms");
 	register_command(cmd_ctx, NULL, "jtag_ntrst_delay", handle_jtag_ntrst_delay_command,
 		COMMAND_ANY, "jtag_ntrst_delay <ms> - delay after deasserting trst in ms");
-		
+
 	register_command(cmd_ctx, NULL, "scan_chain", handle_scan_chain_command,
 		COMMAND_EXEC, "print current scan chain configuration");
 
@@ -1532,7 +1983,7 @@ 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 */
@@ -1548,30 +1999,26 @@ int jtag_interface_init(struct command_context_s *cmd_ctx)
 	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)
 {
-	int validate_tries = 0;
-	jtag_device_t *device;
+	jtag_tap_t *tap;
 	int retval;
 
 	LOG_DEBUG("Init JTAG chain");
-	
-	device = jtag_devices;
-	jtag_ir_scan_size = 0;
-	jtag_num_devices = 0;
-	while (device != NULL)
-	{
-		jtag_ir_scan_size += device->ir_length;
-		jtag_num_devices++;
-		device = device->next;
+
+
+	tap = jtag_NextEnabledTap(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;
@@ -1581,19 +2028,12 @@ static int jtag_init_inner(struct command_context_s *cmd_ctx)
 	{
 		LOG_ERROR("trying to validate configured JTAG chain anyway...");
 	}
-	
-	while (jtag_validate_chain() != ERROR_OK)
+
+	if (jtag_validate_chain() != ERROR_OK)
 	{
-		validate_tries++;
-		
-		if (validate_tries > 5)
-		{
-			LOG_ERROR("Could not validate JTAG chain");
-			return ERROR_JTAG_INVALID_INTERFACE;
-		}
-		usleep(10000);
+		LOG_ERROR("Could not validate JTAG chain, continuing anyway...");
 	}
-	
+
 	return ERROR_OK;
 }
 
@@ -1607,19 +2047,19 @@ int jtag_init_reset(struct command_context_s *cmd_ctx)
 	LOG_DEBUG("Trying to bring the JTAG controller to life by asserting TRST / TLR");
 
 	/* Reset can happen after a power cycle.
-	 * 
+	 *
 	 * Ideally we would only assert TRST or run TLR 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 
+	 *
+	 * 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); /* TLR or TRST */
 	if (jtag_reset_config & RESET_HAS_SRST)
@@ -1631,11 +2071,11 @@ int jtag_init_reset(struct command_context_s *cmd_ctx)
 	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 
+	 * 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.
 	 */
@@ -1663,12 +2103,25 @@ static int default_khz(int khz, int *jtag_speed)
 static int default_speed_div(int speed, int *khz)
 {
 	LOG_ERROR("Translation from jtag_speed to khz not implemented");
-	return ERROR_FAIL;	
+	return ERROR_FAIL;
+}
+
+static int default_power_dropout(int *dropout)
+{
+	*dropout=0; /* by default we can't detect power dropout */
+	return ERROR_OK;
+}
+
+static int default_srst_asserted(int *srst_asserted)
+{
+	*srst_asserted=0; /* by default we can't detect srst asserted */
+	return ERROR_OK;
 }
 
 int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
 	int i;
+	int retval;
 
 	/* check whether the interface is already configured */
 	if (jtag_interface)
@@ -1687,11 +2140,13 @@ int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char
 	{
 		if (strcmp(args[0], jtag_interfaces[i]->name) == 0)
 		{
-			if (jtag_interfaces[i]->register_commands(cmd_ctx) != ERROR_OK)
-				exit(-1);
+			if ((retval = jtag_interfaces[i]->register_commands(cmd_ctx)) != ERROR_OK)
+			{
+				return retval;
+			}
 
 			jtag_interface = jtag_interfaces[i];
-			
+
 			if (jtag_interface->khz == NULL)
 			{
 				jtag_interface->khz = default_khz;
@@ -1700,6 +2155,15 @@ int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char
 			{
 				jtag_interface->speed_div = default_speed_div;
 			}
+			if (jtag_interface->power_dropout == NULL)
+			{
+				jtag_interface->power_dropout = default_power_dropout;
+			}
+			if (jtag_interface->srst_asserted == NULL)
+			{
+				jtag_interface->srst_asserted = default_srst_asserted;
+			}
+
 			return ERROR_OK;
 		}
 	}
@@ -1719,53 +2183,95 @@ int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char
 
 int handle_jtag_device_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
-	jtag_device_t **last_device_p = &jtag_devices;
-
-	if (*last_device_p)
-	{
-		while ((*last_device_p)->next)
-			last_device_p = &((*last_device_p)->next);
-		last_device_p = &((*last_device_p)->next);
-	}
-
-	if (argc < 3)
+	int e;
+	char buf[1024];
+	Jim_Obj *newargs[ 10 ];
+	//
+	// CONVERT SYNTAX
+	//
+	//   argv[-1] = command
+	//   argv[ 0] = ir length
+	//   argv[ 1] = ir capture
+	//   argv[ 2] = ir mask
+	//   argv[ 3] = not actually used by anything but in the docs
+	
+	if( argc < 4 ){
+		command_print( cmd_ctx, "OLD DEPRECATED SYNTAX: Please use the NEW syntax");
 		return ERROR_OK;
+	}
+	command_print( cmd_ctx, "OLD SYNTAX: DEPRECATED - translating to new syntax");
+	command_print( cmd_ctx, "jtag newtap CHIP TAP -irlen %s -ircapture %s -irvalue %s",
+				   args[0],
+				   args[1],
+				   args[2] );
+	command_print( cmd_ctx, "Example: STM32 has 2 taps, the cortexM3(len4) + boundryscan(len5)");
+	command_print( cmd_ctx, "jtag newtap stm32 cortexm3  ....., thus creating the tap: \"stm32.cortexm3\"");
+	command_print( cmd_ctx, "jtag newtap stm32 boundry  ....., and the tap: \"stm32.boundery\"");
+	command_print( cmd_ctx, "And then refer to the taps by the dotted name.");
+	
+
+
+	newargs[0] = Jim_NewStringObj( interp, "jtag", -1   );
+	newargs[1] = Jim_NewStringObj( interp, "newtap", -1 );
+	sprintf( buf, "chip%d", jtag_NumTotalTaps() );
+	newargs[2] = Jim_NewStringObj( interp, buf, -1 );
+	sprintf( buf, "tap%d", jtag_NumTotalTaps() );
+	newargs[3] = Jim_NewStringObj( interp, buf, -1  );
+	newargs[4] = Jim_NewStringObj( interp, "-irlen", -1  );
+	newargs[5] = Jim_NewStringObj( interp, args[0], -1  );
+	newargs[6] = Jim_NewStringObj( interp, "-ircapture", -1  );
+	newargs[7] = Jim_NewStringObj( interp, args[1], -1  );
+	newargs[8] = Jim_NewStringObj( interp, "-irmask", -1  );
+	newargs[9] = Jim_NewStringObj( interp, args[2], -1  );
+
+	command_print( cmd_ctx, "NEW COMMAND:");
+	sprintf( buf, "%s %s %s %s %s %s %s %s %s %s",
+			 Jim_GetString( newargs[0], NULL ),
+			 Jim_GetString( newargs[1], NULL ),
+			 Jim_GetString( newargs[2], NULL ),
+			 Jim_GetString( newargs[3], NULL ),
+			 Jim_GetString( newargs[4], NULL ),
+			 Jim_GetString( newargs[5], NULL ),
+			 Jim_GetString( newargs[6], NULL ),
+			 Jim_GetString( newargs[7], NULL ),
+			 Jim_GetString( newargs[8], NULL ),
+			 Jim_GetString( newargs[9], NULL ) );
 
-	*last_device_p = malloc(sizeof(jtag_device_t));
-	(*last_device_p)->ir_length = strtoul(args[0], NULL, 0);
-
-	(*last_device_p)->expected = malloc((*last_device_p)->ir_length);
-	buf_set_u32((*last_device_p)->expected, 0, (*last_device_p)->ir_length, strtoul(args[1], NULL, 0));
-	(*last_device_p)->expected_mask = malloc((*last_device_p)->ir_length);
-	buf_set_u32((*last_device_p)->expected_mask, 0, (*last_device_p)->ir_length, strtoul(args[2], NULL, 0));
+		
 
-	(*last_device_p)->cur_instr = malloc((*last_device_p)->ir_length);
-	(*last_device_p)->bypass = 1;
-	buf_set_ones((*last_device_p)->cur_instr, (*last_device_p)->ir_length);
-	
-	(*last_device_p)->next = NULL;
-	
-	jtag_register_event_callback(jtag_reset_callback, (*last_device_p));
-	
-	jtag_num_devices++;
-	
-	return ERROR_OK;
+	e = jim_jtag_command( interp, 10, newargs );
+	if( e != JIM_OK ){
+		command_print( cmd_ctx, "%s", Jim_GetString( Jim_GetResult(interp), NULL ) );
+	}
+	return e;
 }
 
+
 int handle_scan_chain_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
-	jtag_device_t *device = jtag_devices;
-	int device_count = 0;
-	
-	while (device)
-	{
+	jtag_tap_t *tap;
+
+	tap = jtag_all_taps;
+	command_print(cmd_ctx, "     TapName            | Enabled |   IdCode      Expected    IrLen IrCap  IrMask Instr     ");
+	command_print(cmd_ctx, "---|--------------------|---------|------------|------------|------|------|------|---------");
+
+	while( tap ){
 		u32 expected, expected_mask, cur_instr;
-		expected = buf_get_u32(device->expected, 0, device->ir_length);
-		expected_mask = buf_get_u32(device->expected_mask, 0, device->ir_length);
-		cur_instr = buf_get_u32(device->cur_instr, 0, device->ir_length);
-		command_print(cmd_ctx, "%i: idcode: 0x%8.8x ir length %i, ir capture 0x%x, ir mask 0x%x, current instruction 0x%x", device_count, device->idcode, device->ir_length, expected, expected_mask, cur_instr);
-		device = device->next;
-		device_count++;
+		expected = buf_get_u32(tap->expected, 0, tap->ir_length);
+		expected_mask = buf_get_u32(tap->expected_mask, 0, tap->ir_length);
+		cur_instr = buf_get_u32(tap->cur_instr, 0, tap->ir_length);
+		command_print(cmd_ctx,
+					  "%2d | %-18s |    %c    | 0x%08x | 0x%08x | 0x%02x | 0x%02x | 0x%02x | 0x%02x",
+					  tap->abs_chain_position,
+					  tap->dotted_name,
+					  tap->enabled ? 'Y' : 'n',
+					  tap->idcode, 
+					  tap->expected_id,
+					  tap->ir_length, 
+					  expected, 
+					  expected_mask, 
+					  cur_instr);
+		tap = tap->next_tap;
 	}
 
 	return ERROR_OK;
@@ -1775,7 +2281,7 @@ int handle_reset_config_command(struct command_context_s *cmd_ctx, char *cmd, ch
 {
 	if (argc < 1)
 		return ERROR_COMMAND_SYNTAX_ERROR;
-	
+
 	if (argc >= 1)
 	{
 		if (strcmp(args[0], "none") == 0)
@@ -1788,12 +2294,12 @@ int handle_reset_config_command(struct command_context_s *cmd_ctx, char *cmd, ch
 			jtag_reset_config = RESET_TRST_AND_SRST;
 		else
 		{
-			LOG_ERROR("invalid reset_config argument, defaulting to none");
+			LOG_ERROR("(1) invalid reset_config argument (%s), defaulting to none", args[0]);
 			jtag_reset_config = RESET_NONE;
 			return ERROR_INVALID_ARGUMENTS;
 		}
 	}
-	
+
 	if (argc >= 2)
 	{
 		if (strcmp(args[1], "separate") == 0)
@@ -1809,13 +2315,13 @@ int handle_reset_config_command(struct command_context_s *cmd_ctx, char *cmd, ch
 				jtag_reset_config |= RESET_SRST_PULLS_TRST | RESET_TRST_PULLS_SRST;
 			else
 			{
-				LOG_ERROR("invalid reset_config argument, defaulting to none");
+				LOG_ERROR("(2) invalid reset_config argument (%s), defaulting to none", args[1]);
 				jtag_reset_config = RESET_NONE;
 				return ERROR_INVALID_ARGUMENTS;
 			}
 		}
 	}
-	
+
 	if (argc >= 3)
 	{
 		if (strcmp(args[2], "trst_open_drain") == 0)
@@ -1824,7 +2330,7 @@ int handle_reset_config_command(struct command_context_s *cmd_ctx, char *cmd, ch
 			jtag_reset_config &= ~RESET_TRST_OPEN_DRAIN;
 		else
 		{
-			LOG_ERROR("invalid reset_config argument, defaulting to none");
+			LOG_ERROR("(3) invalid reset_config argument (%s) defaulting to none", args[2] );
 			jtag_reset_config = RESET_NONE;
 			return ERROR_INVALID_ARGUMENTS;
 		}
@@ -1838,12 +2344,12 @@ int handle_reset_config_command(struct command_context_s *cmd_ctx, char *cmd, ch
 			jtag_reset_config &= ~RESET_SRST_PUSH_PULL;
 		else
 		{
-			LOG_ERROR("invalid reset_config argument, defaulting to none");
+			LOG_ERROR("(4) invalid reset_config argument (%s), defaulting to none", args[3]);
 			jtag_reset_config = RESET_NONE;
 			return ERROR_INVALID_ARGUMENTS;
 		}
 	}
-	
+
 	return ERROR_OK;
 }
 
@@ -1858,7 +2364,7 @@ int handle_jtag_nsrst_delay_command(struct command_context_s *cmd_ctx, char *cmd
 	{
 		jtag_nsrst_delay = strtoul(args[0], NULL, 0);
 	}
-	
+
 	return ERROR_OK;
 }
 
@@ -1873,22 +2379,22 @@ int handle_jtag_ntrst_delay_command(struct command_context_s *cmd_ctx, char *cmd
 	{
 		jtag_ntrst_delay = strtoul(args[0], NULL, 0);
 	}
-	
+
 	return ERROR_OK;
 }
 
 int handle_jtag_speed_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
 	int retval=ERROR_OK;
-	
+
 	if (argc == 1)
 	{
 		LOG_DEBUG("handle jtag speed");
 
 		int cur_speed = 0;
 		cur_speed = jtag_speed = strtoul(args[0], NULL, 0);
-			
-		/* this command can be called during CONFIG, 
+
+		/* this command can be called during CONFIG,
 		 * in which case jtag isn't initialized */
 		if (jtag)
 		{
@@ -1901,7 +2407,7 @@ int handle_jtag_speed_command(struct command_context_s *cmd_ctx, char *cmd, char
 		return ERROR_COMMAND_SYNTAX_ERROR;
 	}
 	command_print(cmd_ctx, "jtag_speed: %d", jtag_speed);
-	
+
 	return retval;
 }
 
@@ -1909,7 +2415,7 @@ int handle_jtag_khz_command(struct command_context_s *cmd_ctx, char *cmd, char *
 {
 	int retval=ERROR_OK;
 	LOG_DEBUG("handle jtag khz");
-	
+
 	if(argc == 1)
 	{
 		speed_khz = strtoul(args[0], NULL, 0);
@@ -1923,9 +2429,9 @@ int handle_jtag_khz_command(struct command_context_s *cmd_ctx, char *cmd, char *
 				speed_khz = 0;
 				return retval;
 			}
-	
+
 			cur_speed = jtag_speed = speed_div1;
-	
+
 			retval=jtag->speed(cur_speed);
 		} else
 		{
@@ -1938,14 +2444,19 @@ int handle_jtag_khz_command(struct command_context_s *cmd_ctx, char *cmd, char *
 		return ERROR_COMMAND_SYNTAX_ERROR;
 	}
 
-	if (jtag!=NULL)	
+	if (jtag!=NULL)
 	{
-		int what_speed;
 		if ((retval=jtag->speed_div(jtag_speed, &speed_khz))!=ERROR_OK)
 			return retval;
 	}
-	
-	command_print(cmd_ctx, "jtag_khz: %d", speed_khz);
+
+	if (speed_khz==0)
+	{
+		command_print(cmd_ctx, "RCLK - adaptive");
+	} else
+	{
+		command_print(cmd_ctx, "%d kHz", speed_khz);
+	}
 	return retval;
 
 }
@@ -1970,7 +2481,7 @@ int handle_endstate_command(struct command_context_s *cmd_ctx, char *cmd, char *
 		}
 	}
 	command_print(cmd_ctx, "current endstate: %s", tap_state_strings[cmd_queue_end_state]);
-	
+
 	return ERROR_OK;
 }
 
@@ -1978,7 +2489,7 @@ int handle_jtag_reset_command(struct command_context_s *cmd_ctx, char *cmd, char
 {
 	int trst = -1;
 	int srst = -1;
-	
+
 	if (argc < 2)
 	{
 		return ERROR_COMMAND_SYNTAX_ERROR;
@@ -2029,19 +2540,25 @@ int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, char **a
 {
 	int i;
 	scan_field_t *fields;
-	
+	jtag_tap_t *tap;
+
 	if ((argc < 2) || (argc % 2))
 	{
 		return ERROR_COMMAND_SYNTAX_ERROR;
 	}
 
 	fields = malloc(sizeof(scan_field_t) * argc / 2);
-	
+
 	for (i = 0; i < argc / 2; i++)
 	{
-		int device = strtoul(args[i*2], NULL, 0);
-		int field_size = jtag_get_device(device)->ir_length;
-		fields[i].device = device;
+		tap = jtag_TapByString( args[i*2] );
+		if (tap==NULL)
+		{
+			command_print( cmd_ctx, "Tap: %s unknown", args[i*2] );
+			return ERROR_FAIL;
+		}
+		int field_size = tap->ir_length;
+		fields[i].tap = tap;
 		fields[i].out_value = malloc(CEIL(field_size, 8));
 		buf_set_u32(fields[i].out_value, 0, field_size, strtoul(args[i*2+1], NULL, 0));
 		fields[i].out_mask = NULL;
@@ -2069,7 +2586,7 @@ int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args)
 	int num_fields;
 	int field_count = 0;
 	int i, e;
-	long device;
+	jtag_tap_t *tap;
 
 	/* args[1] = device
 	 * args[2] = num_bits
@@ -2091,9 +2608,10 @@ int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args)
 			return e;
 	}
 
-	e = Jim_GetLong(interp, args[1], &device);
-	if (e != JIM_OK)
-		return e;
+	tap = jtag_TapByJimObj( interp, args[1] );
+	if( tap == NULL ){
+		return JIM_ERR;
+	}
 
 	num_fields=(argc-2)/2;
 	fields = malloc(sizeof(scan_field_t) * num_fields);
@@ -2105,8 +2623,9 @@ int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args)
 
 		Jim_GetLong(interp, args[i], &bits);
 		str = Jim_GetString(args[i+1], &len);
-		
-		fields[field_count].device = device;
+
+
+		fields[field_count].tap = tap;
 		fields[field_count].num_bits = bits;
 		fields[field_count].out_value = malloc(CEIL(bits, 8));
 		str_to_buf(str, len, fields[field_count].out_value, bits, 0);
@@ -2122,8 +2641,7 @@ int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args)
 	retval = jtag_execute_queue();
 	if (retval != ERROR_OK)
 	{
-		Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
-		Jim_AppendStrings(interp, Jim_GetResult(interp), "drscan: jtag execute failed", NULL);
+		Jim_SetResultString(interp, "drscan: jtag execute failed",-1);
 		return JIM_ERR;
 	}
 
@@ -2144,7 +2662,7 @@ int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args)
 	}
 
 	Jim_SetResult(interp, list);
-	
+
 	free(fields);
 
 	return JIM_OK;
@@ -2169,8 +2687,20 @@ int handle_verify_ircapture_command(struct command_context_s *cmd_ctx, char *cmd
 	{
 		return ERROR_COMMAND_SYNTAX_ERROR;
 	}
-	
+
 	command_print(cmd_ctx, "verify Capture-IR is %s", (jtag_verify_capture_ir) ? "enabled": "disabled");
-	
+
 	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);
+}
+