Factoring of jtag_examine_chain for maintainability:
[fw/openocd] / src / jtag / jtag.c
index 3da409c457627ca42dddfb5ddd1fa442d123af12..ca4eb6849319a1feb9263df2ea723ff5a43a72ff 100644 (file)
@@ -6,7 +6,7 @@
  *   oyvind.harboe@zylin.com                                               *
  *                                                                         *
  *   Copyright (C) 2009 SoftPLC Corporation                                *
- *      http://softplc.com                                                    *
+ *       http://softplc.com                                                *
  *   dick@softplc.com                                                      *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
 #endif
 
 #include "jtag.h"
+#include "minidriver.h"
+#include "interface.h"
 
 #ifdef HAVE_STRINGS_H
 #include <strings.h>
 #endif
 
 
-int jtag_flush_queue_count; /* count # of flushes for profiling / debugging purposes */
+/// The number of JTAG queue flushes (for profiling and debugging purposes).
+static int jtag_flush_queue_count;
 
-static void jtag_add_scan_check(void (*jtag_add_scan)(int in_num_fields, scan_field_t *in_fields, tap_state_t state),
+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
@@ -45,16 +48,6 @@ static void jtag_add_scan_check(void (*jtag_add_scan)(int in_num_fields, scan_fi
 */
 int jtag_error=ERROR_OK;
 
-typedef struct cmd_queue_page_s
-{
-       void *address;
-       size_t used;
-       struct cmd_queue_page_s *next;
-} cmd_queue_page_t;
-
-#define CMD_QUEUE_PAGE_SIZE (1024 * 1024)
-static cmd_queue_page_t *cmd_queue_pages = NULL;
-
 char* jtag_event_strings[] =
 {
        "JTAG controller reset (RESET or TRST)"
@@ -70,27 +63,15 @@ const Jim_Nvp nvp_jtag_tap_event[] = {
 int jtag_trst = 0;
 int jtag_srst = 0;
 
-#ifndef HAVE_JTAG_MINIDRIVER_H
-struct jtag_callback_entry
-{
-       struct jtag_callback_entry *next;
-
-       jtag_callback_t callback;
-       u8 *in;
-       jtag_callback_data_t data1;
-       jtag_callback_data_t data2;
-       jtag_callback_data_t data3;
-};
-
-
-static struct jtag_callback_entry *jtag_callback_queue_head = NULL;
-static struct jtag_callback_entry *jtag_callback_queue_tail = NULL;
-#endif
-
-
-jtag_command_t *jtag_command_queue = NULL;
-jtag_command_t **last_command_pointer = &jtag_command_queue;
-static jtag_tap_t *jtag_all_taps = NULL;
+/**
+ * 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 int jtag_num_taps = 0;
 
 enum reset_types jtag_reset_config = RESET_NONE;
 tap_state_t cmd_queue_end_state = TAP_RESET;
@@ -103,17 +84,13 @@ int jtag_verify = 1;
 static int jtag_nsrst_delay = 0; /* default to no nSRST delay */
 static 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
-
 /* 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 int hasKHz = 0;
+static bool hasKHz = false;
 
 /* jtag interfaces (parport, FTDI-USB, TI-USB, ...)
  */
@@ -227,20 +204,12 @@ jtag_interface_t *jtag_interfaces[] = {
        NULL,
 };
 
-jtag_interface_t *jtag = NULL;
+struct jtag_interface_s *jtag = NULL;
 
 /* configuration */
 static jtag_interface_t *jtag_interface = NULL;
 int jtag_speed = 0;
 
-/* forward declarations */
-//void jtag_add_pathmove(int num_states, tap_state_t *path);
-//void jtag_add_runtest(int num_cycles, tap_state_t endstate);
-//void jtag_add_end_state(tap_state_t endstate);
-//void jtag_add_sleep(u32 us);
-//int jtag_execute_queue(void);
-static tap_state_t tap_state_by_name(const char *name);
-
 /* jtag commands */
 static int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
 static int handle_jtag_speed_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
@@ -263,32 +232,23 @@ 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_AllTaps(void)
+jtag_tap_t *jtag_all_taps(void)
 {
-       return jtag_all_taps;
+       return __jtag_all_taps;
 };
 
-int jtag_NumTotalTaps(void)
+int jtag_tap_count(void)
 {
-       jtag_tap_t *t;
-       int n;
-
-       n = 0;
-       t = jtag_AllTaps();
-       while(t){
-               n++;
-               t = t->next_tap;
-       }
-       return n;
+       return jtag_num_taps;
 }
 
-int jtag_NumEnabledTaps(void)
+int jtag_tap_count_enabled(void)
 {
        jtag_tap_t *t;
        int n;
 
        n = 0;
-       t = jtag_AllTaps();
+       t = jtag_all_taps();
        while(t){
                if( t->enabled ){
                        n++;
@@ -298,12 +258,23 @@ int jtag_NumEnabledTaps(void)
        return n;
 }
 
-jtag_tap_t *jtag_TapByString( const char *s )
+/// Append a new TAP to the chain of all taps.
+static 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 )
 {
        jtag_tap_t *t;
        char *cp;
 
-       t = jtag_AllTaps();
+       t = jtag_all_taps();
        /* try name first */
        while(t){
                if( 0 == strcmp( t->dotted_name, s ) ){
@@ -319,13 +290,13 @@ jtag_tap_t *jtag_TapByString( const char *s )
                n = strtol( s, &cp, 0 );
                if( (s != cp) && (*cp == 0) ){
                        /* Then it is... */
-                       t = jtag_TapByAbsPosition(n);
+                       t = jtag_tap_by_abs_position(n);
                }
        }
        return t;
 }
 
-jtag_tap_t * jtag_TapByJimObj( Jim_Interp *interp, Jim_Obj *o )
+jtag_tap_t * jtag_tap_by_jim_obj( Jim_Interp *interp, Jim_Obj *o )
 {
        jtag_tap_t *t;
        const char *cp;
@@ -335,7 +306,7 @@ jtag_tap_t * jtag_TapByJimObj( Jim_Interp *interp, Jim_Obj *o )
                cp = "(unknown)";
                t = NULL;
        }  else {
-               t = jtag_TapByString( cp );
+               t = jtag_tap_by_string( cp );
        }
        if( t == NULL ){
                Jim_SetResult_sprintf(interp,"Tap: %s is unknown", cp );
@@ -344,13 +315,13 @@ jtag_tap_t * jtag_TapByJimObj( Jim_Interp *interp, Jim_Obj *o )
 }
 
 /* returns a pointer to the n-th device in the scan chain */
-jtag_tap_t * jtag_TapByAbsPosition( int n )
+jtag_tap_t * jtag_tap_by_abs_position( int n )
 {
        int orig_n;
        jtag_tap_t *t;
 
        orig_n = n;
-       t = jtag_AllTaps();
+       t = jtag_all_taps();
 
        while( t && (n > 0)) {
                n--;
@@ -359,6 +330,12 @@ jtag_tap_t * jtag_TapByAbsPosition( int n )
        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;
@@ -421,161 +398,54 @@ int jtag_call_event_callbacks(enum jtag_event event)
        return ERROR_OK;
 }
 
-/* returns a pointer to the pointer of the last command in queue
- * this may be a pointer to the root pointer (jtag_command_queue)
- * or to the next member of the last but one command
- */
-jtag_command_t** jtag_get_last_command_p(void)
+static void jtag_checks(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_command_pointer;
+       assert(jtag_trst == 0);
 }
 
-
-void jtag_queue_command(jtag_command_t * cmd)
-{
-       jtag_command_t **last_cmd;
-
-       last_cmd = jtag_get_last_command_p();
-
-       *last_cmd = cmd;
-
-       (*last_cmd)->next = NULL;
-
-       last_command_pointer = &((*last_cmd)->next);
-}
-
-
-void* cmd_queue_alloc(size_t size)
-{
-       cmd_queue_page_t **p_page = &cmd_queue_pages;
-       int offset;
-       u8 *t;
-
-       /*
-        * WARNING:
-        *    We align/round the *SIZE* per below
-        *    so that all pointers returned by
-        *    this function are reasonably well
-        *    aligned.
-        *
-        * If we did not, then an "odd-length" request would cause the
-        * *next* allocation to be at an *odd* address, and because
-        * this function has the same type of api as malloc() - we
-        * must also return pointers that have the same type of
-        * alignment.
-        *
-        * What I do not/have is a reasonable portable means
-        * to align by...
-        *
-        * The solution here, is based on these suggestions.
-        * http://gcc.gnu.org/ml/gcc-help/2008-12/msg00041.html
-        *
-        */
-       union worse_case_align {
-               int i;
-               long l;
-               float f;
-               void *v;
-       };
-#define ALIGN_SIZE  (sizeof(union worse_case_align))
-
-       /* The alignment process. */
-       size = (size + ALIGN_SIZE -1) & (~(ALIGN_SIZE-1));
-       /* Done... */
-
-       if (*p_page)
-       {
-               while ((*p_page)->next)
-                       p_page = &((*p_page)->next);
-               if (CMD_QUEUE_PAGE_SIZE - (*p_page)->used < size)
-                       p_page = &((*p_page)->next);
-       }
-
-       if (!*p_page)
-       {
-               *p_page = malloc(sizeof(cmd_queue_page_t));
-               (*p_page)->used = 0;
-               (*p_page)->address = malloc(CMD_QUEUE_PAGE_SIZE);
-               (*p_page)->next = NULL;
-       }
-
-       offset = (*p_page)->used;
-       (*p_page)->used += size;
-
-       t=(u8 *)((*p_page)->address);
-       return t + offset;
-}
-
-void cmd_queue_free(void)
+static void jtag_prelude(tap_state_t state)
 {
-       cmd_queue_page_t *page = cmd_queue_pages;
+       jtag_checks();
 
-       while (page)
-       {
-               cmd_queue_page_t *last = page;
-               free(page->address);
-               page = page->next;
-               free(last);
-       }
+       assert(state!=TAP_INVALID);
 
-       cmd_queue_pages = NULL;
+       cmd_queue_cur_state = state;
 }
 
-static void jtag_prelude1(void)
-{
-       if (jtag_trst == 1)
-       {
-               LOG_WARNING("JTAG command queued, while TRST is low (TAP in reset)");
-               jtag_error=ERROR_JTAG_TRST_ASSERTED;
-               return;
-       }
-
-       if (cmd_queue_end_state == TAP_RESET)
-               jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
-}
-
-static void jtag_prelude(tap_state_t state)
+void jtag_alloc_in_value32(scan_field_t *field)
 {
-       jtag_prelude1();
-
-       if (state != TAP_INVALID)
-               jtag_add_end_state(state);
-
-       cmd_queue_cur_state = cmd_queue_end_state;
+       interface_jtag_alloc_in_value32(field);
 }
 
-void jtag_add_ir_scan_noverify(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+void jtag_add_ir_scan_noverify(int in_num_fields, const scan_field_t *in_fields, tap_state_t state)
 {
        int retval;
        jtag_prelude(state);
 
-       retval=interface_jtag_add_ir_scan(in_num_fields, in_fields, cmd_queue_end_state);
+       retval=interface_jtag_add_ir_scan(in_num_fields, in_fields, state);
        if (retval!=ERROR_OK)
                jtag_error=retval;
 
 }
 
 
+/**
+ * Generate an IR SCAN with a list of scan fields with one entry for each enabled TAP.
+ *
+ * If the input field list contains an instruction value for a TAP then that is used
+ * otherwise the TAP is set to bypass.
+ *
+ * TAPs for which no fields are passed are marked as bypassed for subsequent DR SCANs.
+ *
+ */
 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 invoations */
+               /* 8 x 32 bit id's is enough for all invocations */
 
                for (int j = 0; j < in_num_fields; j++)
                {
-                       in_fields[j].check_value=NULL;
-                       in_fields[j].check_mask=NULL;
                        /* 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.
                         */
@@ -590,133 +460,34 @@ void jtag_add_ir_scan(int in_num_fields, scan_field_t *in_fields, tap_state_t st
 }
 
 /**
- * Generate a list of scan fields with one entry for each TAP.
+ * Duplicate the scan fields passed into the function into an IR SCAN command
  *
- * If the input field list contains an instruction value for a TAP then that is used
- * otherwise the TAP is set to bypass.
+ * This function assumes that the caller handles extra fields for bypassed TAPs
  *
  */
-int MINIDRIVER(interface_jtag_add_ir_scan)(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
-{
-       jtag_tap_t *tap;
-       int nth_tap;
-
-       int num_taps = jtag_NumEnabledTaps();
-
-       jtag_command_t * cmd    = cmd_queue_alloc(sizeof(jtag_command_t));
-       scan_command_t * scan   = cmd_queue_alloc(sizeof(scan_command_t));
-
-       jtag_queue_command(cmd);
-
-       cmd->type                               = JTAG_SCAN;
-       cmd->cmd.scan                   = scan;
-
-       scan->ir_scan                   = true;
-       scan->num_fields                = num_taps;     /* one field per device */
-       scan->fields                    = cmd_queue_alloc(num_taps  * sizeof(scan_field_t));
-       scan->end_state                 = state;
-
-       nth_tap = -1;
-       tap = NULL;
-       for(;;){
-               int found = 0;
-
-               /* do this here so it is not forgotten */
-               tap = jtag_NextEnabledTap(tap);
-               if( tap == NULL ){
-                       break;
-               }
-               nth_tap++;
-
-               assert(nth_tap < num_taps);
-
-               size_t scan_size                                = tap->ir_length;
-               scan->fields[nth_tap].tap               = tap;
-               scan->fields[nth_tap].num_bits  = scan_size;
-               scan->fields[nth_tap].in_value  = NULL; /* do not collect input for tap's in bypass */
-
-               /* search the list */
-               for (int j = 0; j < in_num_fields; j++)
-               {
-                       if (tap == in_fields[j].tap)
-                       {
-                               found = 1;
-                               scan->fields[nth_tap].in_value  = in_fields[j].in_value;
-                               scan->fields[nth_tap].out_value = buf_cpy(in_fields[j].out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
-
-                               tap->bypass = 0;
-                               break;
-                       }
-               }
-
-               if (!found)
-               {
-                       /* if a tap isn't listed, set it to BYPASS */
-                       scan->fields[nth_tap].out_value = buf_set_ones(cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
-                       tap->bypass = 1;
-               }
-
-               /* update device information */
-               buf_cpy(scan->fields[nth_tap].out_value, tap->cur_instr, scan_size);
-       }
-
-       assert(nth_tap == (num_taps - 1));
-
-       return ERROR_OK;
-}
-
-void jtag_add_plain_ir_scan(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+void jtag_add_plain_ir_scan(int in_num_fields, const scan_field_t *in_fields, tap_state_t state)
 {
        int retval;
 
        jtag_prelude(state);
 
-       retval=interface_jtag_add_plain_ir_scan(in_num_fields, in_fields, cmd_queue_end_state);
+       retval=interface_jtag_add_plain_ir_scan(in_num_fields, in_fields, state);
        if (retval!=ERROR_OK)
                jtag_error=retval;
 }
 
-int MINIDRIVER(interface_jtag_add_plain_ir_scan)(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+void jtag_add_callback(jtag_callback1_t f, u8 *in)
 {
-
-       jtag_command_t * cmd    = cmd_queue_alloc(sizeof(jtag_command_t));
-       scan_command_t * scan   = cmd_queue_alloc(sizeof(scan_command_t));
-       
-       jtag_queue_command(cmd);
-
-       cmd->type                               = JTAG_SCAN;
-       cmd->cmd.scan                   = scan;
-
-       scan->ir_scan                   = true;
-       scan->num_fields                = in_num_fields;
-       scan->fields                    = cmd_queue_alloc(in_num_fields * sizeof(scan_field_t));
-       scan->end_state                 = state;
-
-       for (int i = 0; i < in_num_fields; i++)
-       {
-               int num_bits = in_fields[i].num_bits;
-               int num_bytes = CEIL(in_fields[i].num_bits, 8);
-               scan->fields[i].tap = in_fields[i].tap;
-               scan->fields[i].num_bits = num_bits;
-               scan->fields[i].out_value = buf_cpy(in_fields[i].out_value, cmd_queue_alloc(num_bytes), num_bits);
-               scan->fields[i].in_value = in_fields[i].in_value;
-       }
-
-       return ERROR_OK;
+       interface_jtag_add_callback(f, in);
 }
 
-void jtag_add_dr_scan(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+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)
 {
-       int retval;
-
-       jtag_prelude(state);
-
-       retval=interface_jtag_add_dr_scan(in_num_fields, in_fields, cmd_queue_end_state);
-       if (retval!=ERROR_OK)
-               jtag_error=retval;
+       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)
@@ -724,31 +495,18 @@ static int jtag_check_value_mask_callback(u8 *in, jtag_callback_data_t data1, jt
        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, scan_field_t *in_fields, tap_state_t state),
+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++)
        {
-               in_fields[i].allocated = 0;
-               in_fields[i].modified = 0;
-               if ((in_fields[i].check_value != NULL) && (in_fields[i].in_value == NULL))
-               {
-                       in_fields[i].modified = 1;
-                       /* we need storage space... */
-#ifdef HAVE_JTAG_MINIDRIVER_H
-                       if (in_fields[i].num_bits <= 32)
-                       {
-                               /* This is enough space and we're executing this synchronously */
-                               in_fields[i].in_value = in_fields[i].intmp;
-                       } else
-                       {
-                               in_fields[i].in_value = (u8 *)malloc(CEIL(in_fields[i].num_bits, 8));
-                               in_fields[i].allocated = 1;
-                       }
-#else
-                       in_fields[i].in_value = (u8 *)cmd_queue_alloc(CEIL(in_fields[i].num_bits, 8));
-#endif
-               }
+               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);
@@ -785,226 +543,57 @@ void jtag_add_dr_scan_check(int in_num_fields, scan_field_t *in_fields, tap_stat
        }
 }
 
-int MINIDRIVER(interface_jtag_add_dr_scan)(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
-{
-       int j;
-       int nth_tap;
-       int bypass_devices = 0;
-       int field_count = 0;
-
-       jtag_tap_t *tap;
 
-       /* count devices in bypass */
-       tap = NULL;
-       bypass_devices = 0;
-       for(;;){
-               tap = jtag_NextEnabledTap(tap);
-               if( tap == NULL ){
-                       break;
-               }
-               if( tap->bypass ){
-                       bypass_devices++;
-               }
-       }
-
-       jtag_command_t * cmd    = cmd_queue_alloc(sizeof(jtag_command_t));
-       scan_command_t * scan   = cmd_queue_alloc(sizeof(scan_command_t));
-       
-       jtag_queue_command(cmd);
-       
-       cmd->type                               = JTAG_SCAN;
-       cmd->cmd.scan                   = scan;
-
-       scan->ir_scan                   = false;
-       scan->num_fields                = in_num_fields + bypass_devices;
-       scan->fields                    = cmd_queue_alloc((in_num_fields + bypass_devices) * sizeof(scan_field_t));
-       scan->end_state                 = state;
-
-       tap = NULL;
-       nth_tap = -1;
-       for(;;){
-               nth_tap++;
-               tap = jtag_NextEnabledTap(tap);
-               if( tap == NULL ){
-                       break;
-               }
-               int found = 0;
-               scan->fields[field_count].tap = tap;
-
-               for (j = 0; j < in_num_fields; j++)
-               {
-                       if (tap == in_fields[j].tap)
-                       {
-                               found = 1;
-                               size_t scan_size = in_fields[j].num_bits;
-                               scan->fields[field_count].num_bits      = scan_size;
-                               scan->fields[field_count].out_value     = buf_cpy(in_fields[j].out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
-                               scan->fields[field_count].in_value      = in_fields[j].in_value;
-                               field_count++;
-                       }
-               }
-               if (!found)
-               {
-#ifdef _DEBUG_JTAG_IO_
-                       /* if a device isn't listed, the BYPASS register should be selected */
-                       if (! tap->bypass)
-                       {
-                               LOG_ERROR("BUG: no scan data for a device not in BYPASS");
-                               exit(-1);
-                       }
-#endif
-                       /* program the scan field to 1 bit length, and ignore it's value */
-                       scan->fields[field_count].num_bits              = 1;
-                       scan->fields[field_count].out_value             = NULL;
-                       scan->fields[field_count].in_value              = NULL;
-                       field_count++;
-               }
-               else
-               {
-#ifdef _DEBUG_JTAG_IO_
-                       /* if a device is listed, the BYPASS register must not be selected */
-                       if (tap->bypass)
-                       {
-                               LOG_ERROR("BUG: scan data for a device in BYPASS");
-                               exit(-1);
-                       }
-#endif
-               }
-       }
-
-       /* field_count represents the true number of fields setup*/
-       scan->num_fields = field_count;
-       return ERROR_OK;
-}
-
-void MINIDRIVER(interface_jtag_add_dr_out)(jtag_tap_t *target_tap,
-               int in_num_fields,
-               const int *num_bits,
-               const u32 *value,
-               tap_state_t end_state)
+/**
+ * Generate a DR SCAN using the fields passed to the function
+ *
+ * For not bypassed TAPs the function checks in_fields and uses fields specified there.
+ * For bypassed TAPs the function generates a dummy 1bit field.
+ *
+ * The bypass status of TAPs is set by jtag_add_ir_scan().
+ *
+ */
+void jtag_add_dr_scan(int in_num_fields, const scan_field_t *in_fields, tap_state_t state)
 {
-       int nth_tap;
-       int field_count = 0;
-       int scan_size;
-       int bypass_devices = 0;
-
-       jtag_tap_t *tap;
-
-       /* count devices in bypass */
-       tap = NULL;
-       bypass_devices = 0;
-       for(;;){
-               tap = jtag_NextEnabledTap(tap);
-               if( tap == NULL ){
-                       break;
-               }
-               if( tap->bypass ){
-                       bypass_devices++;
-               }
-       }
-
-       /* allocate memory for a new list member */
-       jtag_command_t * cmd = cmd_queue_alloc(sizeof(jtag_command_t));
+       int retval;
 
-       jtag_queue_command(cmd);
+       jtag_prelude(state);
 
-       cmd->type = JTAG_SCAN;
+       retval=interface_jtag_add_dr_scan(in_num_fields, in_fields, state);
+       if (retval!=ERROR_OK)
+               jtag_error=retval;
+}
 
-       /* allocate memory for dr scan command */
-       cmd->cmd.scan = cmd_queue_alloc(sizeof(scan_command_t));
-       cmd->cmd.scan->ir_scan = false;
-       cmd->cmd.scan->num_fields = in_num_fields + bypass_devices;
-       cmd->cmd.scan->fields = cmd_queue_alloc((in_num_fields + bypass_devices) * sizeof(scan_field_t));
-       cmd->cmd.scan->end_state = end_state;
 
-       tap = NULL;
-       nth_tap = -1;
-       for(;;){
-               tap = jtag_NextEnabledTap(tap);
-               if( tap == NULL ){
-                       break;
-               }
-               nth_tap++;
-               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 (tap->bypass)
-                       {
-                               LOG_ERROR("BUG: scan data for a device in BYPASS");
-                               exit(-1);
-                       }
-#endif
-                       for (j = 0; j < in_num_fields; j++)
-                       {
-                               u8 out_value[4];
-                               scan_size = num_bits[j];
-                               buf_set_u32(out_value, 0, scan_size, value[j]);
-                               cmd->cmd.scan->fields[field_count].num_bits = scan_size;
-                               cmd->cmd.scan->fields[field_count].out_value = buf_cpy(out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
-                               cmd->cmd.scan->fields[field_count].in_value = NULL;
-                               field_count++;
-                       }
-               } else
-               {
-#ifdef _DEBUG_JTAG_IO_
-                       /* if a device isn't listed, the BYPASS register should be selected */
-                       if (! tap->bypass)
-                       {
-                               LOG_ERROR("BUG: no scan data for a device not in BYPASS");
-                               exit(-1);
-                       }
-#endif
-                       /* program the scan field to 1 bit length, and ignore it's value */
-                       cmd->cmd.scan->fields[field_count].num_bits = 1;
-                       cmd->cmd.scan->fields[field_count].out_value = NULL;
-                       cmd->cmd.scan->fields[field_count].in_value = NULL;
-                       field_count++;
-               }
-       }
-}
-
-void jtag_add_plain_dr_scan(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+/**
+ * Duplicate the scan fields passed into the function into a DR SCAN command
+ *
+ * This function assumes that the caller handles extra fields for bypassed TAPs
+ *
+ */
+void jtag_add_plain_dr_scan(int in_num_fields, const scan_field_t *in_fields, tap_state_t state)
 {
        int retval;
 
        jtag_prelude(state);
 
-       retval=interface_jtag_add_plain_dr_scan(in_num_fields, in_fields, cmd_queue_end_state);
+       retval=interface_jtag_add_plain_dr_scan(in_num_fields, in_fields, state);
        if (retval!=ERROR_OK)
                jtag_error=retval;
 }
 
-int MINIDRIVER(interface_jtag_add_plain_dr_scan)(int in_num_fields, scan_field_t *in_fields, tap_state_t state)
+void jtag_add_dr_out(jtag_tap_t* tap,
+               int num_fields, const int* num_bits, const u32* value,
+               tap_state_t end_state)
 {
-       /* allocate memory for a new list member */
-       jtag_command_t * cmd = cmd_queue_alloc(sizeof(jtag_command_t));
+       assert(end_state != TAP_INVALID);
 
-       jtag_queue_command(cmd);
+       cmd_queue_cur_state = end_state;
 
-       cmd->type = JTAG_SCAN;
-
-       /* allocate memory for scan command */
-       cmd->cmd.scan = cmd_queue_alloc(sizeof(scan_command_t));
-       cmd->cmd.scan->ir_scan = false;
-       cmd->cmd.scan->num_fields = in_num_fields;
-       cmd->cmd.scan->fields = cmd_queue_alloc(in_num_fields * sizeof(scan_field_t));
-       cmd->cmd.scan->end_state = state;
-
-       for (int i = 0; i < in_num_fields; i++)
-       {
-               int num_bits = in_fields[i].num_bits;
-               int num_bytes = CEIL(in_fields[i].num_bits, 8);
-               cmd->cmd.scan->fields[i].tap = in_fields[i].tap;
-               cmd->cmd.scan->fields[i].num_bits = num_bits;
-               cmd->cmd.scan->fields[i].out_value = buf_cpy(in_fields[i].out_value, cmd_queue_alloc(num_bytes), num_bits);
-               cmd->cmd.scan->fields[i].in_value = in_fields[i].in_value;
-       }
-
-       return ERROR_OK;
+       interface_jtag_add_dr_out(tap,
+                       num_fields, num_bits, value,
+                       end_state);
 }
 
 void jtag_add_tlr(void)
@@ -1015,26 +604,11 @@ void jtag_add_tlr(void)
        retval=interface_jtag_add_tlr();
        if (retval!=ERROR_OK)
                jtag_error=retval;
+       
+       jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
 }
 
-int MINIDRIVER(interface_jtag_add_tlr)(void)
-{
-       tap_state_t state = TAP_RESET;
-
-       /* allocate memory for a new list member */
-       jtag_command_t * cmd = cmd_queue_alloc(sizeof(jtag_command_t));
-
-       jtag_queue_command(cmd);
-
-       cmd->type = JTAG_STATEMOVE;
-
-       cmd->cmd.statemove = cmd_queue_alloc(sizeof(statemove_command_t));
-       cmd->cmd.statemove->end_state = state;
-
-       return ERROR_OK;
-}
-
-void jtag_add_pathmove(int num_states, tap_state_t *path)
+void jtag_add_pathmove(int num_states, const tap_state_t *path)
 {
        tap_state_t cur_state = cmd_queue_cur_state;
        int i;
@@ -1064,7 +638,7 @@ void jtag_add_pathmove(int num_states, tap_state_t *path)
                cur_state = path[i];
        }
 
-       jtag_prelude1();
+       jtag_checks();
 
        retval = interface_jtag_add_pathmove(num_states, path);
        cmd_queue_cur_state = path[num_states - 1];
@@ -1072,41 +646,6 @@ void jtag_add_pathmove(int num_states, tap_state_t *path)
                jtag_error=retval;
 }
 
-int MINIDRIVER(interface_jtag_add_pathmove)(int num_states, tap_state_t *path)
-{
-       /* allocate memory for a new list member */
-       jtag_command_t * cmd = cmd_queue_alloc(sizeof(jtag_command_t));
-
-       jtag_queue_command(cmd);
-
-       cmd->type = JTAG_PATHMOVE;
-
-       cmd->cmd.pathmove = cmd_queue_alloc(sizeof(pathmove_command_t));
-       cmd->cmd.pathmove->num_states = num_states;
-       cmd->cmd.pathmove->path = cmd_queue_alloc(sizeof(tap_state_t) * num_states);
-
-       for (int i = 0; i < num_states; i++)
-               cmd->cmd.pathmove->path[i] = path[i];
-
-       return ERROR_OK;
-}
-
-int MINIDRIVER(interface_jtag_add_runtest)(int num_cycles, tap_state_t state)
-{
-       /* allocate memory for a new list member */
-       jtag_command_t * cmd = cmd_queue_alloc(sizeof(jtag_command_t));
-
-       jtag_queue_command(cmd);
-
-       cmd->type = JTAG_RUNTEST;
-
-       cmd->cmd.runtest = cmd_queue_alloc(sizeof(runtest_command_t));
-       cmd->cmd.runtest->num_cycles = num_cycles;
-       cmd->cmd.runtest->end_state = state;
-
-       return ERROR_OK;
-}
-
 void jtag_add_runtest(int num_cycles, tap_state_t state)
 {
        int retval;
@@ -1114,27 +653,12 @@ void jtag_add_runtest(int num_cycles, tap_state_t state)
        jtag_prelude(state);
 
        /* executed by sw or hw fifo */
-       retval=interface_jtag_add_runtest(num_cycles, cmd_queue_end_state);
+       retval=interface_jtag_add_runtest(num_cycles, state);
        if (retval!=ERROR_OK)
                jtag_error=retval;
 }
 
 
-int MINIDRIVER(interface_jtag_add_clocks)( int num_cycles )
-{
-       /* allocate memory for a new list member */
-       jtag_command_t * cmd = cmd_queue_alloc(sizeof(jtag_command_t));
-
-       jtag_queue_command(cmd);
-
-       cmd->type = JTAG_STABLECLOCKS;
-
-       cmd->cmd.stableclocks = cmd_queue_alloc(sizeof(stableclocks_command_t));
-       cmd->cmd.stableclocks->num_cycles = num_cycles;
-
-       return ERROR_OK;
-}
-
 void jtag_add_clocks( int num_cycles )
 {
        int retval;
@@ -1149,7 +673,7 @@ void jtag_add_clocks( int num_cycles )
 
        if( num_cycles > 0 )
        {
-               jtag_prelude1();
+               jtag_checks();
 
                retval = interface_jtag_add_clocks(num_cycles);
                if (retval != ERROR_OK)
@@ -1223,6 +747,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
                jtag_error=retval;
                return;
        }
+       jtag_execute_queue();
 
        if (jtag_srst)
        {
@@ -1238,9 +763,8 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
        if (trst_with_tlr)
        {
                LOG_DEBUG("JTAG reset with RESET instead of TRST");
-               jtag_add_end_state(TAP_RESET);
+               jtag_set_end_state(TAP_RESET);
                jtag_add_tlr();
-               jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
                return;
        }
 
@@ -1250,7 +774,7 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
                 * and inform possible listeners about this
                 */
                LOG_DEBUG("TRST line asserted");
-               cmd_queue_cur_state = TAP_RESET;
+               tap_set_state(TAP_RESET);
                jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
        }
        else
@@ -1260,44 +784,21 @@ void jtag_add_reset(int req_tlr_or_trst, int req_srst)
        }
 }
 
-int MINIDRIVER(interface_jtag_add_reset)(int req_trst, int req_srst)
+tap_state_t jtag_set_end_state(tap_state_t state)
 {
-       /* allocate memory for a new list member */
-       jtag_command_t * cmd = cmd_queue_alloc(sizeof(jtag_command_t));
-
-       jtag_queue_command(cmd);
-
-       cmd->type = JTAG_RESET;
-
-       cmd->cmd.reset = cmd_queue_alloc(sizeof(reset_command_t));
-       cmd->cmd.reset->trst = req_trst;
-       cmd->cmd.reset->srst = req_srst;
-
-       return ERROR_OK;
-}
-
-void jtag_add_end_state(tap_state_t state)
-{
-       cmd_queue_end_state = state;
-       if ((cmd_queue_end_state == TAP_DRSHIFT)||(cmd_queue_end_state == TAP_IRSHIFT))
+       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;
 }
 
-int MINIDRIVER(interface_jtag_add_sleep)(u32 us)
+tap_state_t jtag_get_end_state(void)
 {
-       /* allocate memory for a new list member */
-       jtag_command_t * cmd = cmd_queue_alloc(sizeof(jtag_command_t));
-
-       jtag_queue_command(cmd);
-
-       cmd->type = JTAG_SLEEP;
-
-       cmd->cmd.sleep = cmd_queue_alloc(sizeof(sleep_command_t));
-       cmd->cmd.sleep->us = us;
-
-       return ERROR_OK;
+       return cmd_queue_end_state;
 }
 
 void jtag_add_sleep(u32 us)
@@ -1309,107 +810,6 @@ void jtag_add_sleep(u32 us)
        return;
 }
 
-int jtag_scan_size(scan_command_t *cmd)
-{
-       int bit_count = 0;
-       int i;
-
-       /* count bits in scan command */
-       for (i = 0; i < cmd->num_fields; i++)
-       {
-               bit_count += cmd->fields[i].num_bits;
-       }
-
-       return bit_count;
-}
-
-int jtag_build_buffer(scan_command_t *cmd, u8 **buffer)
-{
-       int bit_count = 0;
-       int i;
-
-       bit_count = jtag_scan_size(cmd);
-       *buffer = calloc(1,CEIL(bit_count, 8));
-
-       bit_count = 0;
-
-#ifdef _DEBUG_JTAG_IO_
-       LOG_DEBUG("%s num_fields: %i", cmd->ir_scan ? "IRSCAN" : "DRSCAN", cmd->num_fields);
-#endif
-
-       for (i = 0; i < cmd->num_fields; i++)
-       {
-               if (cmd->fields[i].out_value)
-               {
-#ifdef _DEBUG_JTAG_IO_
-                       char* char_buf = buf_to_str(cmd->fields[i].out_value, (cmd->fields[i].num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : cmd->fields[i].num_bits, 16);
-#endif
-                       buf_set_buf(cmd->fields[i].out_value, 0, *buffer, bit_count, cmd->fields[i].num_bits);
-#ifdef _DEBUG_JTAG_IO_
-                       LOG_DEBUG("fields[%i].out_value[%i]: 0x%s", i, cmd->fields[i].num_bits, char_buf);
-                       free(char_buf);
-#endif
-               }
-               else
-               {
-#ifdef _DEBUG_JTAG_IO_
-                       LOG_DEBUG("fields[%i].out_value[%i]: NULL", i, cmd->fields[i].num_bits);
-#endif
-               }
-
-               bit_count += cmd->fields[i].num_bits;
-       }
-
-#ifdef _DEBUG_JTAG_IO_
-       //LOG_DEBUG("bit_count totalling: %i",  bit_count );
-#endif
-
-       return bit_count;
-}
-
-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
-                * are specified we don't have to examine this field
-                */
-               if (cmd->fields[i].in_value)
-               {
-                       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 = buf_to_str(captured, (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits, 16);
-                       LOG_DEBUG("fields[%i].in_value[%i]: 0x%s", i, num_bits, char_buf);
-                       free(char_buf);
-#endif
-
-                       if (cmd->fields[i].in_value)
-                       {
-                               buf_cpy(captured, cmd->fields[i].in_value, num_bits);
-                       }
-
-                       free(captured);
-               }
-               bit_count += cmd->fields[i].num_bits;
-       }
-
-       return retval;
-}
-
-static const char *jtag_tap_name(jtag_tap_t *tap)
-{
-       return (tap == NULL) ? "(unknown)" : tap->dotted_name;
-}
-
 int jtag_check_value_inner(u8 *captured, u8 *in_check_value, u8 *in_check_mask, int num_bits)
 {
        int retval = ERROR_OK;
@@ -1477,96 +877,18 @@ void jtag_check_value_mask(scan_field_t *field, u8 *value, u8 *mask)
 
 
 
-enum scan_type jtag_scan_type(scan_command_t *cmd)
+int default_interface_jtag_execute_queue(void)
 {
-       int i;
-       int type = 0;
-
-       for (i = 0; i < cmd->num_fields; i++)
+       if (NULL == jtag)
        {
-               if (cmd->fields[i].in_value)
-                       type |= SCAN_IN;
-               if (cmd->fields[i].out_value)
-                       type |= SCAN_OUT;
-       }
-
-       return type;
-}
-
-
-#ifndef HAVE_JTAG_MINIDRIVER_H
-/* add callback to end of queue */
-void jtag_add_callback4(jtag_callback_t callback, u8 *in, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3)
-{
-       struct jtag_callback_entry *entry=cmd_queue_alloc(sizeof(struct jtag_callback_entry));
-
-       entry->next=NULL;
-       entry->callback=callback;
-       entry->in=in;
-       entry->data1=data1;
-       entry->data2=data2;
-       entry->data3=data3;
-
-       if (jtag_callback_queue_head==NULL)
-       {
-               jtag_callback_queue_head=entry;
-               jtag_callback_queue_tail=entry;
-       } else
-       {
-               jtag_callback_queue_tail->next=entry;
-               jtag_callback_queue_tail=entry;
-       }
-}
-
-
-static int jtag_convert_to_callback4(u8 *in, jtag_callback_data_t data1, jtag_callback_data_t data2, jtag_callback_data_t data3)
-{
-       ((jtag_callback1_t)data1)(in);
-       return ERROR_OK;
-}
-
-void jtag_add_callback(jtag_callback1_t callback, u8 *in)
-{
-       jtag_add_callback4(jtag_convert_to_callback4, in, (jtag_callback_data_t)callback, 0, 0);
-}
-#endif
-
-#ifndef HAVE_JTAG_MINIDRIVER_H
-
-int 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.");
+               LOG_ERROR("No JTAG interface configured yet.  "
+                       "Issue 'init' command in startup scripts "
+                       "before communicating with targets.");
                return ERROR_FAIL;
        }
 
-       retval = jtag->execute_queue();
-
-       if (retval == ERROR_OK)
-       {
-               struct jtag_callback_entry *entry;
-               for (entry=jtag_callback_queue_head; entry!=NULL; entry=entry->next)
-               {
-                       retval=entry->callback(entry->in, entry->data1, entry->data2, entry->data3);
-                       if (retval!=ERROR_OK)
-                               break;
-               }
-       }
-
-       cmd_queue_free();
-
-       jtag_callback_queue_head = NULL;
-       jtag_callback_queue_tail = NULL;
-
-       jtag_command_queue = NULL;
-       last_command_pointer = &jtag_command_queue;
-
-       return retval;
+       return jtag->execute_queue();
 }
-#endif
 
 void jtag_execute_queue_noclear(void)
 {
@@ -1583,6 +905,11 @@ void jtag_execute_queue_noclear(void)
        }
 }
 
+int jtag_get_flush_queue_count(void)
+{
+       return jtag_flush_queue_count;
+}
+
 int jtag_execute_queue(void)
 {
        int retval;
@@ -1592,7 +919,7 @@ int jtag_execute_queue(void)
        return retval;
 }
 
-int jtag_reset_callback(enum jtag_event event, void *priv)
+static int jtag_reset_callback(enum jtag_event event, void *priv)
 {
        jtag_tap_t *tap = priv;
 
@@ -1612,9 +939,16 @@ 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)
+
 /* Try to examine chain layout according to IEEE 1149.1 Â§12
  */
-int jtag_examine_chain(void)
+static int jtag_examine_chain(void)
 {
        jtag_tap_t *tap;
        scan_field_t field;
@@ -1656,7 +990,7 @@ int jtag_examine_chain(void)
        }
 
        /* point at the 1st tap */
-       tap = jtag_NextEnabledTap(NULL);
+       tap = jtag_tap_next_enabled(NULL);
        if( tap == NULL ){
                LOG_ERROR("JTAG: No taps enabled?");
                return ERROR_JTAG_INIT_FAILED;
@@ -1708,11 +1042,8 @@ int jtag_examine_chain(void)
                                break;
                        }
 
-#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)",
@@ -1721,58 +1052,58 @@ int jtag_examine_chain(void)
 
                        bit_count += 32;
                }
-               if (tap)
-               {
-                       tap->idcode = idcode;
+               device_count++;
+               if (!tap)
+                       continue;
 
-                       if (tap->expected_ids_cnt > 0) {
-                               /* 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;
-                                       }
+               tap->idcode = idcode;
+
+               if (tap->expected_ids_cnt > 0) {
+                       /* 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_ERROR("JTAG tap: %s             got: 0x%08x (mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
+                       /* If none of the expected ids matched, log an error */
+                       if (ii == tap->expected_ids_cnt) {
+                               LOG_ERROR("JTAG tap: %s             got: 0x%08x (mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
+                                                 tap->dotted_name,
+                                                 idcode,
+                                                 EXTRACT_MFG( tap->idcode ),
+                                                 EXTRACT_PART( tap->idcode ),
+                                                 EXTRACT_VER( tap->idcode ) );
+                               for (ii = 0; ii < tap->expected_ids_cnt; ii++) {
+                                       LOG_ERROR("JTAG tap: %s expected %hhu of %hhu: 0x%08x (mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
                                                          tap->dotted_name,
-                                                         idcode,
-                                                         EXTRACT_MFG( tap->idcode ),
-                                                         EXTRACT_PART( tap->idcode ),
-                                                         EXTRACT_VER( tap->idcode ) );
-                                       for (ii = 0; ii < tap->expected_ids_cnt; ii++) {
-                                               LOG_ERROR("JTAG tap: %s expected %hhu of %hhu: 0x%08x (mfg: 0x%3.3x, part: 0x%4.4x, ver: 0x%1.1x)",
-                                                                 tap->dotted_name,
-                                                                 ii + 1,
-                                                                 tap->expected_ids_cnt,
-                                                                 tap->expected_ids[ii],
-                                                                 EXTRACT_MFG( tap->expected_ids[ii] ),
-                                                                 EXTRACT_PART( tap->expected_ids[ii] ),
-                                                                 EXTRACT_VER( tap->expected_ids[ii] ) );
-                                       }
-
-                                       return ERROR_JTAG_INIT_FAILED;
-                               } else {
-                                       LOG_INFO("JTAG Tap/device matched");
+                                                         ii + 1,
+                                                         tap->expected_ids_cnt,
+                                                         tap->expected_ids[ii],
+                                                         EXTRACT_MFG( tap->expected_ids[ii] ),
+                                                         EXTRACT_PART( tap->expected_ids[ii] ),
+                                                         EXTRACT_VER( tap->expected_ids[ii] ) );
                                }
+
+                               return ERROR_JTAG_INIT_FAILED;
                        } 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);
+                       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++;
+               tap = jtag_tap_next_enabled(tap);
        }
 
        /* see if number of discovered devices matches configuration */
-       if (device_count != jtag_NumEnabledTaps())
+       if (device_count != jtag_tap_count_enabled())
        {
                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());
+                                 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;
        }
@@ -1780,7 +1111,7 @@ int jtag_examine_chain(void)
        return ERROR_OK;
 }
 
-int jtag_validate_chain(void)
+static int jtag_validate_chain(void)
 {
        jtag_tap_t *tap;
        int total_ir_length = 0;
@@ -1791,7 +1122,7 @@ int jtag_validate_chain(void)
        tap = NULL;
        total_ir_length = 0;
        for(;;){
-               tap = jtag_NextEnabledTap(tap);
+               tap = jtag_tap_next_enabled(tap);
                if( tap == NULL ){
                        break;
                }
@@ -1815,7 +1146,7 @@ int jtag_validate_chain(void)
        chain_pos = 0;
        int val;
        for(;;){
-               tap = jtag_NextEnabledTap(tap);
+               tap = jtag_tap_next_enabled(tap);
                if( tap == NULL ){
                        break;
                }
@@ -1944,10 +1275,44 @@ static int jtag_tap_configure_cmd( Jim_GetOptInfo *goi, jtag_tap_t * tap)
        return JIM_OK;
 }
 
+
+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);
+}
+
 static int jim_newtap_cmd( Jim_GetOptInfo *goi )
 {
        jtag_tap_t *pTap;
-       jtag_tap_t **ppTap;
        jim_wide w;
        int x;
        int e;
@@ -2079,58 +1444,18 @@ static int jim_newtap_cmd( Jim_GetOptInfo *goi )
                } /* 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);
-               /* TODO: Tell user what is missing :-( */
-               /* no memory leaks pelase */
-               free(((void *)(pTap->expected_ids)));
-               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;
+       /* Did all the required option bits get cleared? */
+       if (0 == reqbits)
        {
-               static int n_taps = 0;
-               pTap->abs_chain_position = n_taps++;
+               jtag_tap_init(pTap);
+               return ERROR_OK;
        }
-       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;
+       Jim_SetResult_sprintf(goi->interp,
+                       "newtap: %s missing required parameters",
+                       pTap->dotted_name);
+       jtag_tap_free(pTap);
+       return JIM_ERR;
 }
 
 static int jim_jtag_command( Jim_Interp *interp, int argc, Jim_Obj *const *argv )
@@ -2210,7 +1535,7 @@ static int jim_jtag_command( Jim_Interp *interp, int argc, Jim_Obj *const *argv
 
                {
                        jtag_tap_t *t;
-                       t = jtag_TapByJimObj( goi.interp, goi.argv[0] );
+                       t = jtag_tap_by_jim_obj( goi.interp, goi.argv[0] );
                        if( t == NULL ){
                                return JIM_ERR;
                        }
@@ -2244,7 +1569,7 @@ static int jim_jtag_command( Jim_Interp *interp, int argc, Jim_Obj *const *argv
                        jtag_tap_t *t;
 
                        Jim_GetOpt_Obj(&goi, &o);
-                       t = jtag_TapByJimObj( goi.interp, o );
+                       t = jtag_tap_by_jim_obj( goi.interp, o );
                        if( t == NULL ){
                                return JIM_ERR;
                        }
@@ -2264,7 +1589,7 @@ static int jim_jtag_command( Jim_Interp *interp, int argc, Jim_Obj *const *argv
                        jtag_tap_t *t;
 
                        Jim_GetOpt_Obj(&goi, &o);
-                       t = jtag_TapByJimObj( goi.interp, o );
+                       t = jtag_tap_by_jim_obj( goi.interp, o );
                        if( t == NULL ){
                                return JIM_ERR;
                        }
@@ -2284,11 +1609,12 @@ int jtag_register_commands(struct command_context_s *cmd_ctx)
        register_command(cmd_ctx, NULL, "interface", handle_interface_command,
                COMMAND_CONFIG, "try to configure interface");
        register_command(cmd_ctx, NULL, "jtag_speed", handle_jtag_speed_command,
-               COMMAND_ANY, "set jtag speed (if supported)");
+               COMMAND_ANY, "(DEPRECATED) set jtag speed (if supported)");
        register_command(cmd_ctx, NULL, "jtag_khz", handle_jtag_khz_command,
-               COMMAND_ANY, "same as jtag_speed, except it takes maximum khz as arguments. 0 KHz = RTCK.");
+               COMMAND_ANY, "set maximum jtag speed (if supported); "
+               "parameter is maximum khz, or 0 for adaptive clocking (RTCK).");
        register_command(cmd_ctx, NULL, "jtag_device", handle_jtag_device_command,
-               COMMAND_CONFIG, "jtag_device <ir_length> <ir_expected> <ir_mask>");
+               COMMAND_CONFIG, "(DEPRECATED) jtag_device <ir_length> <ir_expected> <ir_mask>");
        register_command(cmd_ctx, NULL, "reset_config", handle_reset_config_command,
                COMMAND_ANY,
                "[none/trst_only/srst_only/trst_and_srst] [srst_pulls_trst/trst_pulls_srst] [combined/separate] [trst_push_pull/trst_open_drain] [srst_push_pull/srst_open_drain]");
@@ -2333,8 +1659,8 @@ int jtag_interface_init(struct command_context_s *cmd_ctx)
        }
        if(hasKHz)
        {
-               jtag_interface->khz(speed_khz, &jtag_speed);
-               hasKHz = 0;
+               jtag_interface->khz(jtag_get_speed_khz(), &jtag_speed);
+               hasKHz = false;
        }
 
        if (jtag_interface->init() != ERROR_OK)
@@ -2351,7 +1677,7 @@ static int jtag_init_inner(struct command_context_s *cmd_ctx)
 
        LOG_DEBUG("Init JTAG chain");
 
-       tap = jtag_NextEnabledTap(NULL);
+       tap = jtag_tap_next_enabled(NULL);
        if( tap == NULL ){
                LOG_ERROR("There are no enabled taps?");
                return ERROR_JTAG_INIT_FAILED;
@@ -2367,14 +1693,28 @@ static int jtag_init_inner(struct command_context_s *cmd_ctx)
                LOG_ERROR("trying to validate configured JTAG chain anyway...");
        }
 
-       if (jtag_validate_chain() != ERROR_OK)
-       {
-               LOG_WARNING("Could not validate JTAG chain, continuing 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;
@@ -2432,6 +1772,15 @@ int jtag_init(struct command_context_s *cmd_ctx)
        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");
@@ -2549,9 +1898,9 @@ static int handle_jtag_device_command(struct command_context_s *cmd_ctx, char *c
 
        newargs[0] = Jim_NewStringObj( interp, "jtag", -1   );
        newargs[1] = Jim_NewStringObj( interp, "newtap", -1 );
-       sprintf( buf, "chip%d", jtag_NumTotalTaps() );
+       sprintf( buf, "chip%d", jtag_tap_count() );
        newargs[2] = Jim_NewStringObj( interp, buf, -1 );
-       sprintf( buf, "tap%d", jtag_NumTotalTaps() );
+       sprintf( buf, "tap%d", jtag_tap_count() );
        newargs[3] = Jim_NewStringObj( interp, buf, -1  );
        newargs[4] = Jim_NewStringObj( interp, "-irlen", -1  );
        newargs[5] = Jim_NewStringObj( interp, args[0], -1  );
@@ -2584,7 +1933,7 @@ static int handle_scan_chain_command(struct command_context_s *cmd_ctx, char *cm
 {
        jtag_tap_t *tap;
 
-       tap = jtag_all_taps;
+       tap = jtag_all_taps();
        command_print(cmd_ctx, "     TapName            | Enabled |   IdCode      Expected    IrLen IrCap  IrMask Instr     ");
        command_print(cmd_ctx, "---|--------------------|---------|------------|------------|------|------|------|---------");
 
@@ -2619,77 +1968,111 @@ static int handle_scan_chain_command(struct command_context_s *cmd_ctx, char *cm
 
 static int handle_reset_config_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
+       int new_cfg = 0;
+       int mask = 0;
+
        if (argc < 1)
                return ERROR_COMMAND_SYNTAX_ERROR;
 
-       if (argc >= 1)
-       {
-               if (strcmp(args[0], "none") == 0)
-                       jtag_reset_config = RESET_NONE;
-               else if (strcmp(args[0], "trst_only") == 0)
-                       jtag_reset_config = RESET_HAS_TRST;
-               else if (strcmp(args[0], "srst_only") == 0)
-                       jtag_reset_config = RESET_HAS_SRST;
-               else if (strcmp(args[0], "trst_and_srst") == 0)
-                       jtag_reset_config = RESET_TRST_AND_SRST;
+       /* Original versions cared about the order of these tokens:
+        *   reset_config signals [combination [trst_type [srst_type]]]
+        * They also clobbered the previous configuration even on error.
+        *
+        * Here we don't care about the order, and only change values
+        * which have been explicitly specified.
+        */
+       for (; argc; argc--, args++) {
+               int tmp = 0;
+               int m;
+
+               /* signals */
+               m = RESET_HAS_TRST | RESET_HAS_SRST;
+               if (strcmp(*args, "none") == 0)
+                       tmp = RESET_NONE;
+               else if (strcmp(*args, "trst_only") == 0)
+                       tmp = RESET_HAS_TRST;
+               else if (strcmp(*args, "srst_only") == 0)
+                       tmp = RESET_HAS_SRST;
+               else if (strcmp(*args, "trst_and_srst") == 0)
+                       tmp = RESET_HAS_TRST | RESET_HAS_SRST;
                else
-               {
-                       LOG_ERROR("(1) invalid reset_config argument (%s), defaulting to none", args[0]);
-                       jtag_reset_config = RESET_NONE;
+                       m = 0;
+               if (mask & m) {
+                       LOG_ERROR("extra reset_config %s spec (%s)",
+                                       "signal", *args);
                        return ERROR_INVALID_ARGUMENTS;
                }
-       }
-
-       if (argc >= 2)
-       {
-               if (strcmp(args[1], "separate") == 0)
-               {
-                       /* seperate reset lines - default */
-               } else
-               {
-                       if (strcmp(args[1], "srst_pulls_trst") == 0)
-                               jtag_reset_config |= RESET_SRST_PULLS_TRST;
-                       else if (strcmp(args[1], "trst_pulls_srst") == 0)
-                               jtag_reset_config |= RESET_TRST_PULLS_SRST;
-                       else if (strcmp(args[1], "combined") == 0)
-                               jtag_reset_config |= RESET_SRST_PULLS_TRST | RESET_TRST_PULLS_SRST;
-                       else
-                       {
-                               LOG_ERROR("(2) invalid reset_config argument (%s), defaulting to none", args[1]);
-                               jtag_reset_config = RESET_NONE;
-                               return ERROR_INVALID_ARGUMENTS;
-                       }
+               if (m)
+                       goto next;
+
+               /* combination (options for broken wiring) */
+               m = RESET_SRST_PULLS_TRST | RESET_TRST_PULLS_SRST;
+               if (strcmp(*args, "separate") == 0)
+                       /* separate reset lines - default */;
+               else if (strcmp(*args, "srst_pulls_trst") == 0)
+                       tmp |= RESET_SRST_PULLS_TRST;
+               else if (strcmp(*args, "trst_pulls_srst") == 0)
+                       tmp |= RESET_TRST_PULLS_SRST;
+               else if (strcmp(*args, "combined") == 0)
+                       tmp |= RESET_SRST_PULLS_TRST | RESET_TRST_PULLS_SRST;
+               else
+                       m = 0;
+               if (mask & m) {
+                       LOG_ERROR("extra reset_config %s spec (%s)",
+                                       "combination", *args);
+                       return ERROR_INVALID_ARGUMENTS;
                }
-       }
+               if (m)
+                       goto next;
 
-       if (argc >= 3)
-       {
-               if (strcmp(args[2], "trst_open_drain") == 0)
-                       jtag_reset_config |= RESET_TRST_OPEN_DRAIN;
-               else if (strcmp(args[2], "trst_push_pull") == 0)
-                       jtag_reset_config &= ~RESET_TRST_OPEN_DRAIN;
+               /* trst_type (NOP without HAS_TRST) */
+               m = RESET_TRST_OPEN_DRAIN;
+               if (strcmp(*args, "trst_open_drain") == 0)
+                       tmp |= RESET_TRST_OPEN_DRAIN;
+               else if (strcmp(*args, "trst_push_pull") == 0)
+                       /* push/pull from adapter - default */;
                else
-               {
-                       LOG_ERROR("(3) invalid reset_config argument (%s) defaulting to none", args[2] );
-                       jtag_reset_config = RESET_NONE;
+                       m = 0;
+               if (mask & m) {
+                       LOG_ERROR("extra reset_config %s spec (%s)",
+                                       "trst_type", *args);
                        return ERROR_INVALID_ARGUMENTS;
                }
-       }
+               if (m)
+                       goto next;
 
-       if (argc >= 4)
-       {
-               if (strcmp(args[3], "srst_push_pull") == 0)
-                       jtag_reset_config |= RESET_SRST_PUSH_PULL;
-               else if (strcmp(args[3], "srst_open_drain") == 0)
-                       jtag_reset_config &= ~RESET_SRST_PUSH_PULL;
+               /* srst_type (NOP without HAS_SRST) */
+               m |= RESET_SRST_PUSH_PULL;
+               if (strcmp(*args, "srst_push_pull") == 0)
+                       tmp |= RESET_SRST_PUSH_PULL;
+               else if (strcmp(*args, "srst_open_drain") == 0)
+                       /* open drain from adapter - default */;
                else
-               {
-                       LOG_ERROR("(4) invalid reset_config argument (%s), defaulting to none", args[3]);
-                       jtag_reset_config = RESET_NONE;
+                       m = 0;
+               if (mask & m) {
+                       LOG_ERROR("extra reset_config %s spec (%s)",
+                                       "srst_type", *args);
                        return ERROR_INVALID_ARGUMENTS;
                }
+               if (m)
+                       goto next;
+
+               /* caller provided nonsense; fail */
+               LOG_ERROR("unknown reset_config flag (%s)", *args);
+               return ERROR_INVALID_ARGUMENTS;
+
+next:
+               /* Remember the bits which were specified (mask)
+                * and their new values (new_cfg).
+                */
+               mask |= m;
+               new_cfg |= tmp;
        }
 
+       /* clear previous values of those bits, save new values */
+       jtag_reset_config &= ~mask;
+       jtag_reset_config |= new_cfg;
+
        return ERROR_OK;
 }
 
@@ -2702,7 +2085,7 @@ static int handle_jtag_nsrst_delay_command(struct command_context_s *cmd_ctx, ch
        }
        else
        {
-               jtag_nsrst_delay = strtoul(args[0], NULL, 0);
+               jtag_set_nsrst_delay(strtoul(args[0], NULL, 0));
        }
 
        return ERROR_OK;
@@ -2717,12 +2100,13 @@ static int handle_jtag_ntrst_delay_command(struct command_context_s *cmd_ctx, ch
        }
        else
        {
-               jtag_ntrst_delay = strtoul(args[0], NULL, 0);
+               jtag_set_ntrst_delay(strtoul(args[0], NULL, 0));
        }
 
        return ERROR_OK;
 }
 
+
 static int handle_jtag_speed_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
        int retval=ERROR_OK;
@@ -2756,17 +2140,17 @@ static int handle_jtag_khz_command(struct command_context_s *cmd_ctx, char *cmd,
        int retval=ERROR_OK;
        LOG_DEBUG("handle jtag khz");
 
+       int cur_speed = 0;
        if(argc == 1)
        {
-               speed_khz = strtoul(args[0], NULL, 0);
+               jtag_set_speed_khz(strtoul(args[0], NULL, 0));
                if (jtag != NULL)
                {
-                       int cur_speed = 0;
                        LOG_DEBUG("have interface set up");
                        int speed_div1;
-                       if ((retval=jtag->khz(speed_khz, &speed_div1))!=ERROR_OK)
+                       if ((retval=jtag->khz(jtag_get_speed_khz(), &speed_div1))!=ERROR_OK)
                        {
-                               speed_khz = 0;
+                               jtag_set_speed_khz(0);
                                return retval;
                        }
 
@@ -2775,7 +2159,7 @@ static int handle_jtag_khz_command(struct command_context_s *cmd_ctx, char *cmd,
                        retval=jtag->speed(cur_speed);
                } else
                {
-                       hasKHz = 1;
+                       hasKHz = true;
                }
        } else if (argc==0)
        {
@@ -2783,43 +2167,38 @@ static int handle_jtag_khz_command(struct command_context_s *cmd_ctx, char *cmd,
        {
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
+       cur_speed = jtag_get_speed_khz();
 
        if (jtag!=NULL)
        {
-               if ((retval=jtag->speed_div(jtag_speed, &speed_khz))!=ERROR_OK)
+               if ((retval=jtag->speed_div(jtag_speed, &cur_speed))!=ERROR_OK)
                        return retval;
        }
 
-       if (speed_khz==0)
-       {
+       if (cur_speed)
+               command_print(cmd_ctx, "%d kHz", cur_speed);
+       else
                command_print(cmd_ctx, "RCLK - adaptive");
-       } else
-       {
-               command_print(cmd_ctx, "%d kHz", speed_khz);
-       }
        return retval;
 
 }
 
 static int handle_endstate_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
-       tap_state_t state;
-
        if (argc < 1)
-       {
                return ERROR_COMMAND_SYNTAX_ERROR;
-       }
-       else
+
+       tap_state_t state = tap_state_by_name(args[0]);
+       if (state < 0)
        {
-               state = tap_state_by_name( args[0] );
-               if( state < 0 ){
-                       command_print( cmd_ctx, "Invalid state name: %s\n", args[0] );
-                       return ERROR_COMMAND_SYNTAX_ERROR;
-               }
-               jtag_add_end_state(state);
-               jtag_execute_queue();
+               command_print( cmd_ctx, "Invalid state name: %s\n", args[0] );
+               return ERROR_COMMAND_SYNTAX_ERROR;
        }
-       command_print(cmd_ctx, "current endstate: %s", tap_state_name(cmd_queue_end_state));
+       jtag_set_end_state(state);
+       jtag_execute_queue();
+
+       command_print(cmd_ctx, "current endstate: %s",
+                       tap_state_name(cmd_queue_end_state));
 
        return ERROR_OK;
 }
@@ -2868,13 +2247,33 @@ static int handle_runtest_command(struct command_context_s *cmd_ctx, char *cmd,
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
 
-       jtag_add_runtest(strtol(args[0], NULL, 0), TAP_INVALID);
+       jtag_add_runtest(strtol(args[0], NULL, 0), jtag_get_end_state());
        jtag_execute_queue();
 
        return ERROR_OK;
 
 }
 
+/*
+ * For "irscan" or "drscan" commands, the "end" (really, "next") state
+ * should be stable ... and *NOT* a shift state, otherwise free-running
+ * jtag clocks could change the values latched by the update state.
+ */
+static bool scan_is_safe(tap_state_t state)
+{
+       switch (state)
+       {
+       case TAP_RESET:
+       case TAP_IDLE:
+       case TAP_DRPAUSE:
+       case TAP_IRPAUSE:
+               return true;
+       default:
+               return false;
+       }
+}
+
+
 static int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
        int i;
@@ -2887,11 +2286,12 @@ static int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, c
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
 
-       /* optional "-endstate" */
-       /*          "statename" */
-       /* at the end of the arguments. */
-       /* assume none. */
-       endstate = cmd_queue_end_state;
+       /* optional "-endstate" "statename" at the end of the arguments,
+        * so that e.g. IRPAUSE can let us load the data register before
+        * entering RUN/IDLE to execute the instruction we load here.
+        */
+       endstate = TAP_IDLE;
+
        if( argc >= 4 ){
                /* have at least one pair of numbers. */
                /* is last pair the magic text? */
@@ -2908,6 +2308,9 @@ static int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, c
                        if( endstate >= TAP_NUM_STATES ){
                                return ERROR_COMMAND_SYNTAX_ERROR;
                        } else {
+                               if (!scan_is_safe(endstate))
+                                       LOG_WARNING("irscan with unsafe "
+                                                       "endstate \"%s\"", cpA);
                                /* found - remove the last 2 args */
                                argc -= 2;
                        }
@@ -2920,7 +2323,7 @@ static int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, c
 
        for (i = 0; i < num_fields; i++)
        {
-               tap = jtag_TapByString( args[i*2] );
+               tap = jtag_tap_by_string( args[i*2] );
                if (tap==NULL)
                {
                        command_print( cmd_ctx, "Tap: %s unknown", args[i*2] );
@@ -2972,8 +2375,8 @@ static int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args
                return JIM_ERR;
        }
 
-       /* assume no endstate */
-       endstate = cmd_queue_end_state;
+       endstate = TAP_IDLE;
+
        /* validate arguments as numbers */
        e = JIM_OK;
        for (i = 2; i < argc; i+=2)
@@ -2993,7 +2396,10 @@ static int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args
                        return e;
                }
 
-               /* it could be: "-endstate FOO" */
+               /* it could be: "-endstate FOO"
+                * e.g. DRPAUSE so we can issue more instructions
+                * before entering RUN/IDLE and executing them.
+                */
 
                /* get arg as a string. */
                cp = Jim_GetString( args[i], NULL );
@@ -3008,6 +2414,10 @@ static int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args
                                /* update the error message */
                                Jim_SetResult_sprintf(interp,"endstate: %s invalid", cp );
                        } else {
+                               if (!scan_is_safe(endstate))
+                                       LOG_WARNING("drscan with unsafe "
+                                                       "endstate \"%s\"", cp);
+
                                /* valid - so clear the error */
                                e = JIM_OK;
                                /* and remove the last 2 args */
@@ -3021,7 +2431,7 @@ static int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args
                }
        } /* validate args */
 
-       tap = jtag_TapByJimObj( interp, args[1] );
+       tap = jtag_tap_by_jim_obj( interp, args[1] );
        if( tap == NULL ){
                return JIM_ERR;
        }
@@ -3080,7 +2490,7 @@ static int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args
 
 static int Jim_Command_flush_count(Jim_Interp *interp, int argc, Jim_Obj *const *args)
 {
-       Jim_SetResult(interp, Jim_NewIntObj(interp, jtag_flush_queue_count));
+       Jim_SetResult(interp, Jim_NewIntObj(interp, jtag_get_flush_queue_count()));
 
        return JIM_OK;
 }
@@ -3111,27 +2521,33 @@ 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)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
        if (argc == 1)
        {
                if (strcmp(args[0], "enable") == 0)
-               {
-                       jtag_verify = 1;
-               }
+                       jtag_set_verify(true);
                else if (strcmp(args[0], "disable") == 0)
-               {
-                       jtag_verify = 0;
-               } else
-               {
+                       jtag_set_verify(false);
+               else
                        return ERROR_COMMAND_SYNTAX_ERROR;
-               }
-       } else if (argc != 0)
-       {
-               return ERROR_COMMAND_SYNTAX_ERROR;
        }
 
-       command_print(cmd_ctx, "verify jtag capture is %s", (jtag_verify) ? "enabled": "disabled");
+       const char *status = jtag_will_verify() ? "enabled": "disabled";
+       command_print(cmd_ctx, "verify jtag capture is %s", status);
 
        return ERROR_OK;
 }
@@ -3178,464 +2594,122 @@ void jtag_tap_handle_event( jtag_tap_t * tap, enum jtag_tap_event e)
        }
 }
 
-/*-----<Cable Helper API>---------------------------------------*/
-
-/*  these Cable Helper API functions are all documented in the jtag.h header file,
-       using a Doxygen format.  And since Doxygen's configuration file "Doxyfile",
-       is setup to prefer its docs in the header file, no documentation is here, for
-       if it were, it would have to be doubly maintained.
-*/
-
-/**
- * @see tap_set_state() and tap_get_state() accessors.
- * Actual name is not important since accessors hide it.
- */
-static tap_state_t state_follower = TAP_RESET;
-
-void tap_set_state_impl( tap_state_t new_state )
-{
-       /* this is the state we think the TAPs are in now, was cur_state */
-       state_follower = new_state;
-}
-
-tap_state_t tap_get_state()
-{
-       return state_follower;
-}
-
-/**
- * @see tap_set_end_state() and tap_get_end_state() accessors.
- * Actual name is not important because accessors hide it.
- */
-static tap_state_t end_state_follower = TAP_RESET;
-
-void tap_set_end_state( tap_state_t new_end_state )
-{
-       /* this is the state we think the TAPs will be in at completion of the
-          current TAP operation, was end_state
-       */
-       end_state_follower = new_end_state;
-}
-
-tap_state_t tap_get_end_state()
-{
-       return end_state_follower;
-}
-
-
-int tap_move_ndx( tap_state_t astate )
+static int handle_tms_sequence_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 {
-       /* given a stable state, return the index into the tms_seqs[] array within tap_get_tms_path() */
-
-       int ndx;
+       if (argc > 1)
+               return ERROR_COMMAND_SYNTAX_ERROR;
 
-       switch( astate )
+       if (argc == 1)
        {
-       case TAP_RESET:         ndx = 0;                        break;
-       case TAP_DRSHIFT:       ndx = 2;                        break;
-       case TAP_DRPAUSE:       ndx = 3;                        break;
-       case TAP_IDLE:          ndx = 1;                        break;
-       case TAP_IRSHIFT:       ndx = 4;                        break;
-       case TAP_IRPAUSE:       ndx = 5;                        break;
-       default:
-               LOG_ERROR( "fatal: unstable state \"%s\" used in tap_move_ndx()", tap_state_name(astate) );
-               exit(1);
-       }
-
-       return ndx;
-}
+               bool use_new_table;
+               if (strcmp(args[0], "short") == 0)
+                       use_new_table = true;
+               else if (strcmp(args[0], "long") == 0)
+                       use_new_table = false;
+               else
+                       return ERROR_COMMAND_SYNTAX_ERROR;
 
+               tap_use_new_tms_table(use_new_table);
+       }
 
-/* tap_move[i][j]: tap movement command to go from state i to state j
- * 0: Test-Logic-Reset
- * 1: Run-Test/Idle
- * 2: Shift-DR
- * 3: Pause-DR
- * 4: Shift-IR
- * 5: Pause-IR
- *
- * DRSHIFT->DRSHIFT and IRSHIFT->IRSHIFT have to be caught in interface specific code
- */
-struct tms_sequences
-{
-       u8      bits;
-       u8      bit_count;
+       command_print(cmd_ctx, "tms sequence is  %s",
+                       tap_uses_new_tms_table() ? "short": "long");
 
-};
+       return ERROR_OK;
+}
 
-/*
- * These macros allow us to specify TMS state transitions by bits rather than hex bytes.
- * Read the bits from LSBit first to MSBit last (right-to-left).
+/**
+ * Function jtag_add_statemove
+ * moves from the current state to the goal \a state. This needs
+ * to be handled according to the xsvf spec, see the XSTATE command
+ * description.
  */
-#define HEX__(n) 0x##n##LU
-
-#define B8__(x) \
-        (((x) & 0x0000000FLU)?(1<<0):0) \
-       +(((x) & 0x000000F0LU)?(1<<1):0) \
-       +(((x) & 0x00000F00LU)?(1<<2):0) \
-       +(((x) & 0x0000F000LU)?(1<<3):0) \
-       +(((x) & 0x000F0000LU)?(1<<4):0) \
-       +(((x) & 0x00F00000LU)?(1<<5):0) \
-       +(((x) & 0x0F000000LU)?(1<<6):0) \
-       +(((x) & 0xF0000000LU)?(1<<7):0)
-
-#define B8(bits,count)         { ((u8)B8__(HEX__(bits))), (count) }
-
-static const struct tms_sequences old_tms_seqs[6][6] =         /*  [from_state_ndx][to_state_ndx] */
-{
-       /* value clocked to TMS to move from one of six stable states to another.
-        * N.B. OOCD clocks TMS from LSB first, so read these right-to-left.
-        * N.B. These values are tightly bound to the table in tap_get_tms_path_len().
-        * N.B. Reset only needs to be 0b11111, but in JLink an even byte of 1's is more stable.
-        *              These extra ones cause no TAP state problem, because we go into reset and stay in reset.
-        */
-
-
-
-       /* to state: */
-       /*      RESET                   IDLE                    DRSHIFT                 DRPAUSE                 IRSHIFT                 IRPAUSE         */              /* from state: */
-       {       B8(1111111,7),  B8(0000000,7),  B8(0010111,7),  B8(0001010,7),  B8(0011011,7),  B8(0010110,7) },        /* RESET */
-       {       B8(1111111,7),  B8(0000000,7),  B8(0100101,7),  B8(0000101,7),  B8(0101011,7),  B8(0001011,7) },        /* IDLE */
-       {       B8(1111111,7),  B8(0110001,7),  B8(0000000,7),  B8(0000001,7),  B8(0001111,7),  B8(0101111,7) },        /* DRSHIFT */
-       {       B8(1111111,7),  B8(0110000,7),  B8(0100000,7),  B8(0010111,7),  B8(0011110,7),  B8(0101111,7) },        /* DRPAUSE */
-       {       B8(1111111,7),  B8(0110001,7),  B8(0000111,7),  B8(0010111,7),  B8(0000000,7),  B8(0000001,7) },        /* IRSHIFT */
-       {       B8(1111111,7),  B8(0110000,7),  B8(0011100,7),  B8(0010111,7),  B8(0011110,7),  B8(0101111,7) },        /* IRPAUSE */
-};
-
-
-
-static const struct tms_sequences short_tms_seqs[6][6] =               /*  [from_state_ndx][to_state_ndx] */
+int jtag_add_statemove(tap_state_t goal_state)
 {
-       /*      this is the table submitted by Jeff Williams on 3/30/2009 with this comment:
+       int retval = ERROR_OK;
 
-               OK, I added Peter's version of the state table, and it works OK for
-               me on MC1322x. I've recreated the jlink portion of patch with this
-               new state table. His changes to my state table are pretty minor in
-               terms of total transitions, but Peter feels that his version fixes
-               some long-standing problems.
-               Jeff
+       tap_state_t moves[8];
+       tap_state_t cur_state = cmd_queue_cur_state;
+       int i;
+       int tms_bits;
+       int     tms_count;
 
-               I added the bit count into the table, reduced RESET column to 7 bits from 8.
-               Dick
+       LOG_DEBUG( "cur_state=%s goal_state=%s",
+               tap_state_name(cur_state),
+               tap_state_name(goal_state) );
 
-               state specific comments:
-               ------------------------
-               *->RESET                   tried the 5 bit reset and it gave me problems, 7 bits seems to
-                                          work better on ARM9 with ft2232 driver.  (Dick)
 
-               RESET->DRSHIFT add 1 extra clock cycles in the RESET state before advancing.
-                                               needed on ARM9 with ft2232 driver.  (Dick)
+       /*      From the XSVF spec, pertaining to XSTATE:
 
-               RESET->IRSHIFT add 1 extra clock cycles in the RESET state before advancing.
-                                               needed on ARM9 with ft2232 driver.  (Dick)
+               For special states known as stable states (Test-Logic-Reset,
+               Run-Test/Idle, Pause-DR, Pause- IR), an XSVF interpreter follows
+               predefined TAP state paths when the starting state is a stable state and
+               when the XSTATE specifies a new stable state (see the STATE command in
+               the [Ref 5] for the TAP state paths between stable states). For
+               non-stable states, XSTATE should specify a state that is only one TAP
+               state transition distance from the current TAP state to avoid undefined
+               TAP state paths. A sequence of multiple XSTATE commands can be issued to
+               transition the TAP through a specific state path.
        */
 
-       /* to state: */
-       /*      RESET                   IDLE                            DRSHIFT                 DRPAUSE                 IRSHIFT                 IRPAUSE */                      /* from state: */
-       {       B8(1111111,7),  B8(0000000,7),  B8(00101,5),            B8(01010,5),    B8(001101,6),   B8(010110,6) },         /* RESET */
-       {       B8(1111111,7),  B8(0000000,7),  B8(001,3),                      B8(0101,4),             B8(0011,4),     B8(01011,5) },          /* IDLE */
-       {       B8(1111111,7),  B8(011,3),              B8(00111,5),            B8(01,2),               B8(001111,6),   B8(0101111,7) },                /* DRSHIFT */
-       {       B8(1111111,7),  B8(011,3),              B8(01,2),               B8(0,1),                B8(001111,6),   B8(0101111,7) },                /* DRPAUSE */
-       {       B8(1111111,7),  B8(011,3),              B8(00111,5),            B8(010111,6),   B8(001111,6),   B8(01,2) },                     /* IRSHIFT */
-       {       B8(1111111,7),  B8(011,3),              B8(00111,5),            B8(010111,6),   B8(01,2),               B8(0,1) }                       /* IRPAUSE */
+       if (goal_state==cur_state )
+               ;       /* nothing to do */
 
-};
-
-typedef const struct tms_sequences tms_table[6][6];
-
-static tms_table *tms_seqs=&short_tms_seqs;
-
-int tap_get_tms_path( tap_state_t from, tap_state_t to )
-{
-       return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bits;
-}
-
-
-int tap_get_tms_path_len( tap_state_t from, tap_state_t to )
-{
-       return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bit_count;
-}
-
-
-bool tap_is_state_stable(tap_state_t astate)
-{
-       bool is_stable;
-
-       /*      A switch() is used because it is symbol dependent
-               (not value dependent like an array), and can also check bounds.
-       */
-       switch( astate )
+       else if( goal_state==TAP_RESET )
        {
-       case TAP_RESET:
-       case TAP_IDLE:
-       case TAP_DRSHIFT:
-       case TAP_DRPAUSE:
-       case TAP_IRSHIFT:
-       case TAP_IRPAUSE:
-               is_stable = true;
-               break;
-       default:
-               is_stable = false;
+               jtag_add_tlr();
        }
 
-       return is_stable;
-}
-
-tap_state_t tap_state_transition(tap_state_t cur_state, bool tms)
-{
-       tap_state_t new_state;
-
-       /*      A switch is used because it is symbol dependent and not value dependent
-               like an array.  Also it can check for out of range conditions.
-       */
-
-       if (tms)
-       {
-               switch (cur_state)
-               {
-               case TAP_RESET:
-                       new_state = cur_state;
-                       break;
-               case TAP_IDLE:
-               case TAP_DRUPDATE:
-               case TAP_IRUPDATE:
-                       new_state = TAP_DRSELECT;
-                       break;
-               case TAP_DRSELECT:
-                       new_state = TAP_IRSELECT;
-                       break;
-               case TAP_DRCAPTURE:
-               case TAP_DRSHIFT:
-                       new_state = TAP_DREXIT1;
-                       break;
-               case TAP_DREXIT1:
-               case TAP_DREXIT2:
-                       new_state = TAP_DRUPDATE;
-                       break;
-               case TAP_DRPAUSE:
-                       new_state = TAP_DREXIT2;
-                       break;
-               case TAP_IRSELECT:
-                       new_state = TAP_RESET;
-                       break;
-               case TAP_IRCAPTURE:
-               case TAP_IRSHIFT:
-                       new_state = TAP_IREXIT1;
-                       break;
-               case TAP_IREXIT1:
-               case TAP_IREXIT2:
-                       new_state = TAP_IRUPDATE;
-                       break;
-               case TAP_IRPAUSE:
-                       new_state = TAP_IREXIT2;
-                       break;
-               default:
-                       LOG_ERROR( "fatal: invalid argument cur_state=%d", cur_state );
-                       exit(1);
-                       break;
-               }
-       }
-       else
+       else if( tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state) )
        {
-               switch (cur_state)
-               {
-               case TAP_RESET:
-               case TAP_IDLE:
-               case TAP_DRUPDATE:
-               case TAP_IRUPDATE:
-                       new_state = TAP_IDLE;
-                       break;
-               case TAP_DRSELECT:
-                       new_state = TAP_DRCAPTURE;
-                       break;
-               case TAP_DRCAPTURE:
-               case TAP_DRSHIFT:
-               case TAP_DREXIT2:
-                       new_state = TAP_DRSHIFT;
-                       break;
-               case TAP_DREXIT1:
-               case TAP_DRPAUSE:
-                       new_state = TAP_DRPAUSE;
-                       break;
-               case TAP_IRSELECT:
-                       new_state = TAP_IRCAPTURE;
-                       break;
-               case TAP_IRCAPTURE:
-               case TAP_IRSHIFT:
-               case TAP_IREXIT2:
-                       new_state = TAP_IRSHIFT;
-                       break;
-               case TAP_IREXIT1:
-               case TAP_IRPAUSE:
-                       new_state = TAP_IRPAUSE;
-                       break;
-               default:
-                       LOG_ERROR( "fatal: invalid argument cur_state=%d", cur_state );
-                       exit(1);
-                       break;
-               }
-       }
-
-       return new_state;
-}
-
-const char* tap_state_name(tap_state_t state)
-{
-       const char* ret;
+               /*      note: unless tms_bits holds a path that agrees with [Ref 5] in above
+                       spec, then this code is not fully conformant to the xsvf spec.  This
+                       puts a burden on tap_get_tms_path() function from the xsvf spec.
+                       If in doubt, you should confirm that that burden is being met.
+               */
 
-       switch( state )
-       {
-       case TAP_RESET:         ret = "RESET";                  break;
-       case TAP_IDLE:          ret = "RUN/IDLE";               break;
-       case TAP_DRSELECT:      ret = "DRSELECT";               break;
-       case TAP_DRCAPTURE: ret = "DRCAPTURE";          break;
-       case TAP_DRSHIFT:       ret = "DRSHIFT";                        break;
-       case TAP_DREXIT1:       ret = "DREXIT1";                        break;
-       case TAP_DRPAUSE:       ret = "DRPAUSE";                        break;
-       case TAP_DREXIT2:       ret = "DREXIT2";                        break;
-       case TAP_DRUPDATE:      ret = "DRUPDATE";               break;
-       case TAP_IRSELECT:      ret = "IRSELECT";               break;
-       case TAP_IRCAPTURE: ret = "IRCAPTURE";          break;
-       case TAP_IRSHIFT:       ret = "IRSHIFT";                        break;
-       case TAP_IREXIT1:       ret = "IREXIT1";                        break;
-       case TAP_IRPAUSE:       ret = "IRPAUSE";                        break;
-       case TAP_IREXIT2:       ret = "IREXIT2";                        break;
-       case TAP_IRUPDATE:      ret = "IRUPDATE";               break;
-       default:                                ret = "???";
-       }
+               tms_bits  = tap_get_tms_path(cur_state, goal_state);
+               tms_count = tap_get_tms_path_len(cur_state, goal_state);
 
-       return ret;
-}
+               assert( (unsigned) tms_count < DIM(moves) );
 
-static tap_state_t tap_state_by_name( const char *name )
-{
-       tap_state_t x;
+               for (i=0;   i<tms_count;   i++, tms_bits>>=1)
+               {
+                       bool bit = tms_bits & 1;
 
-       for( x = 0 ; x < TAP_NUM_STATES ; x++ ){
-               /* be nice to the human */
-               if( 0 == strcasecmp( name, tap_state_name(x) ) ){
-                       return x;
+                       cur_state = tap_state_transition(cur_state, bit);
+                       moves[i] = cur_state;
                }
-       }
-       /* not found */
-       return TAP_INVALID;
-}
-
-#ifdef _DEBUG_JTAG_IO_
-
-#define JTAG_DEBUG_STATE_APPEND(buf, len, bit) \
-               do { buf[len] = bit ? '1' : '0'; } while(0)
-#define JTAG_DEBUG_STATE_PRINT(a, b, astr, bstr) \
-               DEBUG_JTAG_IO("TAP/SM: %9s -> %5s\tTMS: %s\tTDI: %s", \
-                       tap_state_name(a), tap_state_name(b), astr, bstr)
-
-tap_state_t jtag_debug_state_machine(const void *tms_buf, const void *tdi_buf,
-               unsigned tap_bits, tap_state_t next_state)
-{
-       const u8 *tms_buffer;
-       const u8 *tdi_buffer;
-       unsigned tap_bytes;
-       unsigned cur_byte;
-       unsigned cur_bit;
-
-       unsigned tap_out_bits;
-       char tms_str[33];
-       char tdi_str[33];
-
-       tap_state_t last_state;
 
-       // set startstate (and possibly last, if tap_bits == 0)
-       last_state = next_state;
-       DEBUG_JTAG_IO("TAP/SM: START state: %s", tap_state_name(next_state));
-
-       tms_buffer = (const u8 *)tms_buf;
-       tdi_buffer = (const u8 *)tdi_buf;
-
-       tap_bytes = TAP_SCAN_BYTES(tap_bits);
-       DEBUG_JTAG_IO("TAP/SM: TMS bits: %u (bytes: %u)", tap_bits, tap_bytes);
+               jtag_add_pathmove(tms_count, moves);
+       }
 
-       tap_out_bits = 0;
-       for(cur_byte = 0; cur_byte < tap_bytes; cur_byte++)
+       /*      else state must be immediately reachable in one clock cycle, and does not
+               need to be a stable state.
+       */
+       else if( tap_state_transition(cur_state, true)  == goal_state
+               ||   tap_state_transition(cur_state, false) == goal_state )
        {
-               for(cur_bit = 0; cur_bit < 8; cur_bit++)
-               {
-                       // make sure we do not run off the end of the buffers
-                       unsigned tap_bit = cur_byte * 8 + cur_bit;
-                       if (tap_bit == tap_bits)
-                               break;
-
-                       // check and save TMS bit
-                       tap_bit = !!(tms_buffer[cur_byte] & (1 << cur_bit));
-                       JTAG_DEBUG_STATE_APPEND(tms_str, tap_out_bits, tap_bit);
-
-                       // use TMS bit to find the next TAP state
-                       next_state = tap_state_transition(last_state, tap_bit);
-
-                       // check and store TDI bit
-                       tap_bit = !!(tdi_buffer[cur_byte] & (1 << cur_bit));
-                       JTAG_DEBUG_STATE_APPEND(tdi_str, tap_out_bits, tap_bit);
-
-                       // increment TAP bits
-                       tap_out_bits++;
-
-                       // Only show TDO bits on state transitions, or
-                       // after some number of bits in the same state.
-                       if ((next_state == last_state) && (tap_out_bits < 32))
-                               continue;
-
-                       // terminate strings and display state transition
-                       tms_str[tap_out_bits] = tdi_str[tap_out_bits] = 0;
-                       JTAG_DEBUG_STATE_PRINT(last_state, next_state, tms_str, tdi_str);
-
-                       // reset state
-                       last_state = next_state;
-                       tap_out_bits = 0;
-               }
+               /* move a single state */
+               moves[0] = goal_state;
+               jtag_add_pathmove( 1, moves );
        }
 
-       if (tap_out_bits)
+       else
        {
-               // terminate strings and display state transition
-               tms_str[tap_out_bits] = tdi_str[tap_out_bits] = 0;
-               JTAG_DEBUG_STATE_PRINT(last_state, next_state, tms_str, tdi_str);
+               retval = ERROR_FAIL;
        }
 
-       DEBUG_JTAG_IO("TAP/SM: FINAL state: %s", tap_state_name(next_state));
-
-       return next_state;
+       return retval;
 }
-#endif // _DEBUG_JTAG_IO_
 
-#ifndef HAVE_JTAG_MINIDRIVER_H
-void jtag_alloc_in_value32(scan_field_t *field)
+void jtag_set_nsrst_delay(unsigned delay)
 {
-       field->in_value=(u8 *)cmd_queue_alloc(4);
+       jtag_nsrst_delay = delay;
 }
-#endif
-
-static int handle_tms_sequence_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+void jtag_set_ntrst_delay(unsigned delay)
 {
-       if (argc == 1)
-       {
-               if (strcmp(args[0], "short") == 0)
-               {
-                       tms_seqs=&short_tms_seqs;
-               }
-               else if (strcmp(args[0], "long") == 0)
-               {
-                       tms_seqs=&old_tms_seqs;
-               } else
-               {
-                       return ERROR_COMMAND_SYNTAX_ERROR;
-               }
-       } else if (argc != 0)
-       {
-               return ERROR_COMMAND_SYNTAX_ERROR;
-       }
-
-       command_print(cmd_ctx, "tms sequence is  %s", (tms_seqs==&short_tms_seqs) ? "short": "long");
-
-       return ERROR_OK;
+       jtag_ntrst_delay = delay;
 }
 
-/*-----</Cable Helper API>--------------------------------------*/
+