jtag/core.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2009 Zachary T Welch                                    *
 *   zw@superlucidity.net                                                  *
 *                                                                         *
 *   Copyright (C) 2007,2008,2009 Øyvind Harboe                            *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2009 SoftPLC Corporation                                *
 *       http://softplc.com                                                *
 *   dick@softplc.com                                                      *
 *                                                                         *
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include "adapter.h"
#include "jtag.h"
#include "swd.h"
#include "interface.h"
#include <transport/transport.h>
#include <helper/jep106.h>
#include "helper/system.h"
 
#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif
 
/* SVF and XSVF are higher level JTAG command sets (for boundary scan) */
#include "svf/svf.h"
#include "xsvf/xsvf.h"
 
/* ipdbg are utilities to debug IP-cores. It uses JTAG for transport. */
#include "server/ipdbg.h"
 
static int jtag_flush_queue_count;
 
/* Sleep this # of ms after flushing the queue */
static int jtag_flush_queue_sleep;
 
static void jtag_add_scan_check(struct jtag_tap *active,
        void (*jtag_add_scan)(struct jtag_tap *active,
        int in_num_fields,
        const struct scan_field *in_fields,
        tap_state_t state),
        int in_num_fields, struct scan_field *in_fields, tap_state_t state);
 
static int jtag_error = ERROR_OK;
 
static const char *jtag_event_strings[] = {
    [JTAG_TRST_ASSERTED] = "TAP reset",
    [JTAG_TAP_EVENT_SETUP] = "TAP setup",
    [JTAG_TAP_EVENT_ENABLE] = "TAP enabled",
    [JTAG_TAP_EVENT_DISABLE] = "TAP disabled",
};
 
/*
 * JTAG adapters must initialize with TRST and SRST de-asserted
 * (they're negative logic, so that means *high*).  But some
 * hardware doesn't necessarily work that way ... so set things
 * up so that jtag_init() always forces that state.
 */
static int jtag_trst = -1;
static int jtag_srst = -1;
 
static struct jtag_tap *__jtag_all_taps;
 
static enum reset_types jtag_reset_config = RESET_NONE;
tap_state_t cmd_queue_cur_state = TAP_RESET;
 
static bool jtag_verify_capture_ir = true;
static int jtag_verify = 1;
 
/* how long the OpenOCD should wait before attempting JTAG communication after reset lines
 *deasserted (in ms) */
static int adapter_nsrst_delay; /* default to no nSRST delay */
static int jtag_ntrst_delay;/* default to no nTRST delay */
static int adapter_nsrst_assert_width;  /* width of assertion */
static int jtag_ntrst_assert_width; /* width of assertion */
 
struct jtag_event_callback {
    jtag_event_handler_t callback;
    void *priv;
    struct jtag_event_callback *next;
};
 
/* callbacks to inform high-level handlers about JTAG state changes */
static struct jtag_event_callback *jtag_event_callbacks;
 
extern struct adapter_driver *adapter_driver;
 
void jtag_set_flush_queue_sleep(int ms)
{
    jtag_flush_queue_sleep = ms;
}
 
void jtag_set_error(int error)
{
    if ((error == ERROR_OK) || (jtag_error != ERROR_OK))
        return;
    jtag_error = error;
}
 
int jtag_error_clear(void)
{
    int temp = jtag_error;
    jtag_error = ERROR_OK;
    return temp;
}
 
/************/
 
static bool jtag_poll = true;
static bool jtag_poll_en = true;
 
bool is_jtag_poll_safe(void)
{
    /* Polling can be disabled explicitly with set_enabled(false).
     * It can also be masked with mask().
     * It is also implicitly disabled while TRST is active and
     * while SRST is gating the JTAG clock.
     */
    if (!jtag_poll_en)
        return false;
 
    if (!transport_is_jtag())
        return jtag_poll;
 
    if (!jtag_poll || jtag_trst != 0)
        return false;
    return jtag_srst == 0 || (jtag_reset_config & RESET_SRST_NO_GATING);
}
 
bool jtag_poll_get_enabled(void)
{
    return jtag_poll;
}
 
void jtag_poll_set_enabled(bool value)
{
    jtag_poll = value;
}
 
bool jtag_poll_mask(void)
{
    bool retval = jtag_poll_en;
    jtag_poll_en = false;
    return retval;
}
 
void jtag_poll_unmask(bool saved)
{
    jtag_poll_en = saved;
}
 
/************/
 
struct jtag_tap *jtag_all_taps(void)
{
    return __jtag_all_taps;
};
 
unsigned jtag_tap_count(void)
{
    struct jtag_tap *t = jtag_all_taps();
    unsigned n = 0;
    while (t) {
        n++;
        t = t->next_tap;
    }
    return n;
}
 
unsigned jtag_tap_count_enabled(void)
{
    struct jtag_tap *t = jtag_all_taps();
    unsigned n = 0;
    while (t) {
        if (t->enabled)
            n++;
        t = t->next_tap;
    }
    return n;
}
 
static void jtag_tap_add(struct jtag_tap *t)
{
    unsigned jtag_num_taps = 0;
 
    struct jtag_tap **tap = &__jtag_all_taps;
    while (*tap) {
        jtag_num_taps++;
        tap = &(*tap)->next_tap;
    }
    *tap = t;
    t->abs_chain_position = jtag_num_taps;
}
 
/* returns a pointer to the n-th device in the scan chain */
struct jtag_tap *jtag_tap_by_position(unsigned n)
{
    struct jtag_tap *t = jtag_all_taps();
 
    while (t && n-- > 0)
        t = t->next_tap;
 
    return t;
}
 
struct jtag_tap *jtag_tap_by_string(const char *s)
{
    /* try by name first */
    struct jtag_tap *t = jtag_all_taps();
 
    while (t) {
        if (strcmp(t->dotted_name, s) == 0)
            return t;
        t = t->next_tap;
    }
 
    /* no tap found by name, so try to parse the name as a number */
    unsigned n;
    if (parse_uint(s, &n) != ERROR_OK)
        return NULL;
 
    /* FIXME remove this numeric fallback code late June 2010, along
     * with all info in the User's Guide that TAPs have numeric IDs.
     * Also update "scan_chain" output to not display the numbers.
     */
    t = jtag_tap_by_position(n);
    if (t)
        LOG_WARNING("Specify TAP '%s' by name, not number %u",
            t->dotted_name, n);
 
    return t;
}
 
struct jtag_tap *jtag_tap_next_enabled(struct jtag_tap *p)
{
    p = p ? p->next_tap : jtag_all_taps();
    while (p) {
        if (p->enabled)
            return p;
        p = p->next_tap;
    }
    return NULL;
}
 
const char *jtag_tap_name(const struct jtag_tap *tap)
{
    return (!tap) ? "(unknown)" : tap->dotted_name;
}
 
 
int jtag_register_event_callback(jtag_event_handler_t callback, void *priv)
{
    struct jtag_event_callback **callbacks_p = &jtag_event_callbacks;
 
    if (!callback)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    if (*callbacks_p) {
        while ((*callbacks_p)->next)
            callbacks_p = &((*callbacks_p)->next);
        callbacks_p = &((*callbacks_p)->next);
    }
 
    (*callbacks_p) = malloc(sizeof(struct jtag_event_callback));
    (*callbacks_p)->callback = callback;
    (*callbacks_p)->priv = priv;
    (*callbacks_p)->next = NULL;
 
    return ERROR_OK;
}
 
int jtag_unregister_event_callback(jtag_event_handler_t callback, void *priv)
{
    struct jtag_event_callback **p = &jtag_event_callbacks, *temp;
 
    if (!callback)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    while (*p) {
        if (((*p)->priv != priv) || ((*p)->callback != callback)) {
            p = &(*p)->next;
            continue;
        }
 
        temp = *p;
        *p = (*p)->next;
        free(temp);
    }
 
    return ERROR_OK;
}
 
int jtag_call_event_callbacks(enum jtag_event event)
{
    struct jtag_event_callback *callback = jtag_event_callbacks;
 
    LOG_DEBUG("jtag event: %s", jtag_event_strings[event]);
 
    while (callback) {
        struct jtag_event_callback *next;
 
        /* callback may remove itself */
        next = callback->next;
        callback->callback(event, callback->priv);
        callback = next;
    }
 
    return ERROR_OK;
}
 
static void jtag_checks(void)
{
    assert(jtag_trst == 0);
}
 
static void jtag_prelude(tap_state_t state)
{
    jtag_checks();
 
    assert(state != TAP_INVALID);
 
    cmd_queue_cur_state = state;
}
 
void jtag_add_ir_scan_noverify(struct jtag_tap *active, const struct scan_field *in_fields,
    tap_state_t state)
{
    jtag_prelude(state);
 
    int retval = interface_jtag_add_ir_scan(active, in_fields, state);
    jtag_set_error(retval);
}
 
static void jtag_add_ir_scan_noverify_callback(struct jtag_tap *active,
    int dummy,
    const struct scan_field *in_fields,
    tap_state_t state)
{
    jtag_add_ir_scan_noverify(active, in_fields, state);
}
 
/* If fields->in_value is filled out, then the captured IR value will be checked */
void jtag_add_ir_scan(struct jtag_tap *active, struct scan_field *in_fields, tap_state_t state)
{
    assert(state != TAP_RESET);
 
    if (jtag_verify && jtag_verify_capture_ir) {
        /* 8 x 32 bit id's is enough for all invocations */
 
        /* if we are to run a verification of the ir scan, we need to get the input back.
         * We may have to allocate space if the caller didn't ask for the input back.
         */
        in_fields->check_value = active->expected;
        in_fields->check_mask = active->expected_mask;
        jtag_add_scan_check(active, jtag_add_ir_scan_noverify_callback, 1, in_fields,
            state);
    } else
        jtag_add_ir_scan_noverify(active, in_fields, state);
}
 
void jtag_add_plain_ir_scan(int num_bits, const uint8_t *out_bits, uint8_t *in_bits,
    tap_state_t state)
{
    assert(out_bits);
    assert(state != TAP_RESET);
 
    jtag_prelude(state);
 
    int retval = interface_jtag_add_plain_ir_scan(
            num_bits, out_bits, in_bits, state);
    jtag_set_error(retval);
}
 
static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
                  uint8_t *in_check_mask, int num_bits);
 
static int jtag_check_value_mask_callback(jtag_callback_data_t data0,
    jtag_callback_data_t data1,
    jtag_callback_data_t data2,
    jtag_callback_data_t data3)
{
    return jtag_check_value_inner((uint8_t *)data0,
        (uint8_t *)data1,
        (uint8_t *)data2,
        (int)data3);
}
 
static void jtag_add_scan_check(struct jtag_tap *active, void (*jtag_add_scan)(
        struct jtag_tap *active,
        int in_num_fields,
        const struct scan_field *in_fields,
        tap_state_t state),
    int in_num_fields, struct scan_field *in_fields, tap_state_t state)
{
    jtag_add_scan(active, in_num_fields, in_fields, state);
 
    for (int i = 0; i < in_num_fields; i++) {
        if ((in_fields[i].check_value) && (in_fields[i].in_value)) {
            jtag_add_callback4(jtag_check_value_mask_callback,
                (jtag_callback_data_t)in_fields[i].in_value,
                (jtag_callback_data_t)in_fields[i].check_value,
                (jtag_callback_data_t)in_fields[i].check_mask,
                (jtag_callback_data_t)in_fields[i].num_bits);
        }
    }
}
 
void jtag_add_dr_scan_check(struct jtag_tap *active,
    int in_num_fields,
    struct scan_field *in_fields,
    tap_state_t state)
{
    if (jtag_verify)
        jtag_add_scan_check(active, jtag_add_dr_scan, in_num_fields, in_fields, state);
    else
        jtag_add_dr_scan(active, in_num_fields, in_fields, state);
}
 
 
void jtag_add_dr_scan(struct jtag_tap *active,
    int in_num_fields,
    const struct scan_field *in_fields,
    tap_state_t state)
{
    assert(state != TAP_RESET);
 
    jtag_prelude(state);
 
    int retval;
    retval = interface_jtag_add_dr_scan(active, in_num_fields, in_fields, state);
    jtag_set_error(retval);
}
 
void jtag_add_plain_dr_scan(int num_bits, const uint8_t *out_bits, uint8_t *in_bits,
    tap_state_t state)
{
    assert(out_bits);
    assert(state != TAP_RESET);
 
    jtag_prelude(state);
 
    int retval;
    retval = interface_jtag_add_plain_dr_scan(num_bits, out_bits, in_bits, state);
    jtag_set_error(retval);
}
 
void jtag_add_tlr(void)
{
    jtag_prelude(TAP_RESET);
    jtag_set_error(interface_jtag_add_tlr());
 
    /* NOTE: order here matches TRST path in jtag_add_reset() */
    jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
    jtag_notify_event(JTAG_TRST_ASSERTED);
}
 
int jtag_add_tms_seq(unsigned nbits, const uint8_t *seq, enum tap_state state)
{
    int retval;
 
    if (!(adapter_driver->jtag_ops->supported & DEBUG_CAP_TMS_SEQ))
        return ERROR_JTAG_NOT_IMPLEMENTED;
 
    jtag_checks();
    cmd_queue_cur_state = state;
 
    retval = interface_add_tms_seq(nbits, seq, state);
    jtag_set_error(retval);
    return retval;
}
 
void jtag_add_pathmove(int num_states, const tap_state_t *path)
{
    tap_state_t cur_state = cmd_queue_cur_state;
 
    /* the last state has to be a stable state */
    if (!tap_is_state_stable(path[num_states - 1])) {
        LOG_ERROR("BUG: TAP path doesn't finish in a stable state");
        jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
        return;
    }
 
    for (int i = 0; i < num_states; i++) {
        if (path[i] == TAP_RESET) {
            LOG_ERROR("BUG: TAP_RESET is not a valid state for pathmove sequences");
            jtag_set_error(ERROR_JTAG_STATE_INVALID);
            return;
        }
 
        if (tap_state_transition(cur_state, true) != path[i] &&
                tap_state_transition(cur_state, false) != path[i]) {
            LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition",
                tap_state_name(cur_state), tap_state_name(path[i]));
            jtag_set_error(ERROR_JTAG_TRANSITION_INVALID);
            return;
        }
        cur_state = path[i];
    }
 
    jtag_checks();
 
    jtag_set_error(interface_jtag_add_pathmove(num_states, path));
    cmd_queue_cur_state = path[num_states - 1];
}
 
int jtag_add_statemove(tap_state_t goal_state)
{
    tap_state_t cur_state = cmd_queue_cur_state;
 
    if (goal_state != cur_state) {
        LOG_DEBUG("cur_state=%s goal_state=%s",
            tap_state_name(cur_state),
            tap_state_name(goal_state));
    }
 
    /* If goal is RESET, be paranoid and force that that transition
     * (e.g. five TCK cycles, TMS high).  Else trust "cur_state".
     */
    if (goal_state == TAP_RESET)
        jtag_add_tlr();
    else if (goal_state == cur_state)
        /* nothing to do */;
 
    else if (tap_is_state_stable(cur_state) && tap_is_state_stable(goal_state)) {
        unsigned tms_bits  = tap_get_tms_path(cur_state, goal_state);
        unsigned tms_count = tap_get_tms_path_len(cur_state, goal_state);
        tap_state_t moves[8];
        assert(tms_count < ARRAY_SIZE(moves));
 
        for (unsigned i = 0; i < tms_count; i++, tms_bits >>= 1) {
            bool bit = tms_bits & 1;
 
            cur_state = tap_state_transition(cur_state, bit);
            moves[i] = cur_state;
        }
 
        jtag_add_pathmove(tms_count, moves);
    } else if (tap_state_transition(cur_state, true)  == goal_state
            || tap_state_transition(cur_state, false) == goal_state)
        jtag_add_pathmove(1, &goal_state);
    else
        return ERROR_FAIL;
 
    return ERROR_OK;
}
 
void jtag_add_runtest(int num_cycles, tap_state_t state)
{
    jtag_prelude(state);
    jtag_set_error(interface_jtag_add_runtest(num_cycles, state));
}
 
 
void jtag_add_clocks(int num_cycles)
{
    if (!tap_is_state_stable(cmd_queue_cur_state)) {
        LOG_ERROR("jtag_add_clocks() called with TAP in unstable state \"%s\"",
            tap_state_name(cmd_queue_cur_state));
        jtag_set_error(ERROR_JTAG_NOT_STABLE_STATE);
        return;
    }
 
    if (num_cycles > 0) {
        jtag_checks();
        jtag_set_error(interface_jtag_add_clocks(num_cycles));
    }
}
 
static int adapter_system_reset(int req_srst)
{
    int retval;
 
    if (req_srst) {
        if (!(jtag_reset_config & RESET_HAS_SRST)) {
            LOG_ERROR("BUG: can't assert SRST");
            return ERROR_FAIL;
        }
        req_srst = 1;
    }
 
    /* Maybe change SRST signal state */
    if (jtag_srst != req_srst) {
        retval = adapter_driver->reset(0, req_srst);
        if (retval != ERROR_OK) {
            LOG_ERROR("SRST error");
            return ERROR_FAIL;
        }
        jtag_srst = req_srst;
 
        if (req_srst) {
            LOG_DEBUG("SRST line asserted");
            if (adapter_nsrst_assert_width)
                jtag_sleep(adapter_nsrst_assert_width * 1000);
        } else {
            LOG_DEBUG("SRST line released");
            if (adapter_nsrst_delay)
                jtag_sleep(adapter_nsrst_delay * 1000);
        }
    }
 
    return ERROR_OK;
}
 
static void legacy_jtag_add_reset(int req_tlr_or_trst, int req_srst)
{
    int trst_with_tlr = 0;
    int new_srst = 0;
    int new_trst = 0;
 
    /* Without SRST, we must use target-specific JTAG operations
     * on each target; callers should not be requesting SRST when
     * that signal doesn't exist.
     *
     * RESET_SRST_PULLS_TRST is a board or chip level quirk, which
     * can kick in even if the JTAG adapter can't drive TRST.
     */
    if (req_srst) {
        if (!(jtag_reset_config & RESET_HAS_SRST)) {
            LOG_ERROR("BUG: can't assert SRST");
            jtag_set_error(ERROR_FAIL);
            return;
        }
        if ((jtag_reset_config & RESET_SRST_PULLS_TRST) != 0
                && !req_tlr_or_trst) {
            LOG_ERROR("BUG: can't assert only SRST");
            jtag_set_error(ERROR_FAIL);
            return;
        }
        new_srst = 1;
    }
 
    /* JTAG reset (entry to TAP_RESET state) can always be achieved
     * using TCK and TMS; that may go through a TAP_{IR,DR}UPDATE
     * state first.  TRST accelerates it, and bypasses those states.
     *
     * RESET_TRST_PULLS_SRST is a board or chip level quirk, which
     * can kick in even if the JTAG adapter can't drive SRST.
     */
    if (req_tlr_or_trst) {
        if (!(jtag_reset_config & RESET_HAS_TRST))
            trst_with_tlr = 1;
        else if ((jtag_reset_config & RESET_TRST_PULLS_SRST) != 0
             && !req_srst)
            trst_with_tlr = 1;
        else
            new_trst = 1;
    }
 
    /* Maybe change TRST and/or SRST signal state */
    if (jtag_srst != new_srst || jtag_trst != new_trst) {
        int retval;
 
        retval = interface_jtag_add_reset(new_trst, new_srst);
        if (retval != ERROR_OK)
            jtag_set_error(retval);
        else
            retval = jtag_execute_queue();
 
        if (retval != ERROR_OK) {
            LOG_ERROR("TRST/SRST error");
            return;
        }
    }
 
    /* SRST resets everything hooked up to that signal */
    if (jtag_srst != new_srst) {
        jtag_srst = new_srst;
        if (jtag_srst) {
            LOG_DEBUG("SRST line asserted");
            if (adapter_nsrst_assert_width)
                jtag_add_sleep(adapter_nsrst_assert_width * 1000);
        } else {
            LOG_DEBUG("SRST line released");
            if (adapter_nsrst_delay)
                jtag_add_sleep(adapter_nsrst_delay * 1000);
        }
    }
 
    /* Maybe enter the JTAG TAP_RESET state ...
     *  - using only TMS, TCK, and the JTAG state machine
     *  - or else more directly, using TRST
     *
     * TAP_RESET should be invisible to non-debug parts of the system.
     */
    if (trst_with_tlr) {
        LOG_DEBUG("JTAG reset with TLR instead of TRST");
        jtag_add_tlr();
 
    } else if (jtag_trst != new_trst) {
        jtag_trst = new_trst;
        if (jtag_trst) {
            LOG_DEBUG("TRST line asserted");
            tap_set_state(TAP_RESET);
            if (jtag_ntrst_assert_width)
                jtag_add_sleep(jtag_ntrst_assert_width * 1000);
        } else {
            LOG_DEBUG("TRST line released");
            if (jtag_ntrst_delay)
                jtag_add_sleep(jtag_ntrst_delay * 1000);
 
            /* We just asserted nTRST, so we're now in TAP_RESET.
             * Inform possible listeners about this, now that
             * JTAG instructions and data can be shifted.  This
             * sequence must match jtag_add_tlr().
             */
            jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
            jtag_notify_event(JTAG_TRST_ASSERTED);
        }
    }
}
 
/* FIXME: name is misleading; we do not plan to "add" reset into jtag queue */
void jtag_add_reset(int req_tlr_or_trst, int req_srst)
{
    int retval;
    int trst_with_tlr = 0;
    int new_srst = 0;
    int new_trst = 0;
 
    if (!adapter_driver->reset) {
        legacy_jtag_add_reset(req_tlr_or_trst, req_srst);
        return;
    }
 
    /* Without SRST, we must use target-specific JTAG operations
     * on each target; callers should not be requesting SRST when
     * that signal doesn't exist.
     *
     * RESET_SRST_PULLS_TRST is a board or chip level quirk, which
     * can kick in even if the JTAG adapter can't drive TRST.
     */
    if (req_srst) {
        if (!(jtag_reset_config & RESET_HAS_SRST)) {
            LOG_ERROR("BUG: can't assert SRST");
            jtag_set_error(ERROR_FAIL);
            return;
        }
        if ((jtag_reset_config & RESET_SRST_PULLS_TRST) != 0
                && !req_tlr_or_trst) {
            LOG_ERROR("BUG: can't assert only SRST");
            jtag_set_error(ERROR_FAIL);
            return;
        }
        new_srst = 1;
    }
 
    /* JTAG reset (entry to TAP_RESET state) can always be achieved
     * using TCK and TMS; that may go through a TAP_{IR,DR}UPDATE
     * state first.  TRST accelerates it, and bypasses those states.
     *
     * RESET_TRST_PULLS_SRST is a board or chip level quirk, which
     * can kick in even if the JTAG adapter can't drive SRST.
     */
    if (req_tlr_or_trst) {
        if (!(jtag_reset_config & RESET_HAS_TRST))
            trst_with_tlr = 1;
        else if ((jtag_reset_config & RESET_TRST_PULLS_SRST) != 0
             && !req_srst)
            trst_with_tlr = 1;
        else
            new_trst = 1;
    }
 
    /* Maybe change TRST and/or SRST signal state */
    if (jtag_srst != new_srst || jtag_trst != new_trst) {
        /* guarantee jtag queue empty before changing reset status */
        jtag_execute_queue();
 
        retval = adapter_driver->reset(new_trst, new_srst);
        if (retval != ERROR_OK) {
            jtag_set_error(retval);
            LOG_ERROR("TRST/SRST error");
            return;
        }
    }
 
    /* SRST resets everything hooked up to that signal */
    if (jtag_srst != new_srst) {
        jtag_srst = new_srst;
        if (jtag_srst) {
            LOG_DEBUG("SRST line asserted");
            if (adapter_nsrst_assert_width)
                jtag_add_sleep(adapter_nsrst_assert_width * 1000);
        } else {
            LOG_DEBUG("SRST line released");
            if (adapter_nsrst_delay)
                jtag_add_sleep(adapter_nsrst_delay * 1000);
        }
    }
 
    /* Maybe enter the JTAG TAP_RESET state ...
     *  - using only TMS, TCK, and the JTAG state machine
     *  - or else more directly, using TRST
     *
     * TAP_RESET should be invisible to non-debug parts of the system.
     */
    if (trst_with_tlr) {
        LOG_DEBUG("JTAG reset with TLR instead of TRST");
        jtag_add_tlr();
        jtag_execute_queue();
 
    } else if (jtag_trst != new_trst) {
        jtag_trst = new_trst;
        if (jtag_trst) {
            LOG_DEBUG("TRST line asserted");
            tap_set_state(TAP_RESET);
            if (jtag_ntrst_assert_width)
                jtag_add_sleep(jtag_ntrst_assert_width * 1000);
        } else {
            LOG_DEBUG("TRST line released");
            if (jtag_ntrst_delay)
                jtag_add_sleep(jtag_ntrst_delay * 1000);
 
            /* We just asserted nTRST, so we're now in TAP_RESET.
             * Inform possible listeners about this, now that
             * JTAG instructions and data can be shifted.  This
             * sequence must match jtag_add_tlr().
             */
            jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
            jtag_notify_event(JTAG_TRST_ASSERTED);
        }
    }
}
 
void jtag_add_sleep(uint32_t us)
{
    keep_alive();
    jtag_set_error(interface_jtag_add_sleep(us));
}
 
static int jtag_check_value_inner(uint8_t *captured, uint8_t *in_check_value,
    uint8_t *in_check_mask, int num_bits)
{
    int retval = ERROR_OK;
    int compare_failed;
 
    if (in_check_mask)
        compare_failed = buf_cmp_mask(captured, in_check_value, in_check_mask, num_bits);
    else
        compare_failed = buf_cmp(captured, in_check_value, num_bits);
 
    if (compare_failed) {
        char *captured_str, *in_check_value_str;
        int bits = (num_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : num_bits;
 
        /* NOTE:  we've lost diagnostic context here -- 'which tap' */
 
        captured_str = buf_to_hex_str(captured, bits);
        in_check_value_str = buf_to_hex_str(in_check_value, bits);
 
        LOG_WARNING("Bad value '%s' captured during DR or IR scan:",
            captured_str);
        LOG_WARNING(" check_value: 0x%s", in_check_value_str);
 
        free(captured_str);
        free(in_check_value_str);
 
        if (in_check_mask) {
            char *in_check_mask_str;
 
            in_check_mask_str = buf_to_hex_str(in_check_mask, bits);
            LOG_WARNING(" check_mask: 0x%s", in_check_mask_str);
            free(in_check_mask_str);
        }
 
        retval = ERROR_JTAG_QUEUE_FAILED;
    }
    return retval;
}
 
void jtag_check_value_mask(struct scan_field *field, uint8_t *value, uint8_t *mask)
{
    assert(field->in_value);
 
    if (!value) {
        /* no checking to do */
        return;
    }
 
    jtag_execute_queue_noclear();
 
    int retval = jtag_check_value_inner(field->in_value, value, mask, field->num_bits);
    jtag_set_error(retval);
}
 
int default_interface_jtag_execute_queue(void)
{
    if (!is_adapter_initialized()) {
        LOG_ERROR("No JTAG interface configured yet.  "
            "Issue 'init' command in startup scripts "
            "before communicating with targets.");
        return ERROR_FAIL;
    }
 
    if (!transport_is_jtag()) {
        /*
         * FIXME: This should not happen!
         * There could be old code that queues jtag commands with non jtag interfaces so, for
         * the moment simply highlight it by log an error and return on empty execute_queue.
         * We should fix it quitting with assert(0) because it is an internal error.
         * The fix can be applied immediately after next release (v0.11.0 ?)
         */
        LOG_ERROR("JTAG API jtag_execute_queue() called on non JTAG interface");
        if (!adapter_driver->jtag_ops || !adapter_driver->jtag_ops->execute_queue)
            return ERROR_OK;
    }
 
    struct jtag_command *cmd = jtag_command_queue_get();
    int result = adapter_driver->jtag_ops->execute_queue(cmd);
 
    while (debug_level >= LOG_LVL_DEBUG_IO && cmd) {
        switch (cmd->type) {
            case JTAG_SCAN:
                LOG_DEBUG_IO("JTAG %s SCAN to %s",
                        cmd->cmd.scan->ir_scan ? "IR" : "DR",
                        tap_state_name(cmd->cmd.scan->end_state));
                for (int i = 0; i < cmd->cmd.scan->num_fields; i++) {
                    struct scan_field *field = cmd->cmd.scan->fields + i;
                    if (field->out_value) {
                        char *str = buf_to_hex_str(field->out_value, field->num_bits);
                        LOG_DEBUG_IO("  %db out: %s", field->num_bits, str);
                        free(str);
                    }
                    if (field->in_value) {
                        char *str = buf_to_hex_str(field->in_value, field->num_bits);
                        LOG_DEBUG_IO("  %db  in: %s", field->num_bits, str);
                        free(str);
                    }
                }
                break;
            case JTAG_TLR_RESET:
                LOG_DEBUG_IO("JTAG TLR RESET to %s",
                        tap_state_name(cmd->cmd.statemove->end_state));
                break;
            case JTAG_RUNTEST:
                LOG_DEBUG_IO("JTAG RUNTEST %d cycles to %s",
                        cmd->cmd.runtest->num_cycles,
                        tap_state_name(cmd->cmd.runtest->end_state));
                break;
            case JTAG_RESET:
                {
                    const char *reset_str[3] = {
                        "leave", "deassert", "assert"
                    };
                    LOG_DEBUG_IO("JTAG RESET %s TRST, %s SRST",
                            reset_str[cmd->cmd.reset->trst + 1],
                            reset_str[cmd->cmd.reset->srst + 1]);
                }
                break;
            case JTAG_PATHMOVE:
                LOG_DEBUG_IO("JTAG PATHMOVE (TODO)");
                break;
            case JTAG_SLEEP:
                LOG_DEBUG_IO("JTAG SLEEP (TODO)");
                break;
            case JTAG_STABLECLOCKS:
                LOG_DEBUG_IO("JTAG STABLECLOCKS (TODO)");
                break;
            case JTAG_TMS:
                LOG_DEBUG_IO("JTAG TMS (TODO)");
                break;
            default:
                LOG_ERROR("Unknown JTAG command: %d", cmd->type);
                break;
        }
        cmd = cmd->next;
    }
 
    return result;
}
 
void jtag_execute_queue_noclear(void)
{
    jtag_flush_queue_count++;
    jtag_set_error(interface_jtag_execute_queue());
 
    if (jtag_flush_queue_sleep > 0) {
        /* For debug purposes it can be useful to test performance
         * or behavior when delaying after flushing the queue,
         * e.g. to simulate long roundtrip times.
         */
        usleep(jtag_flush_queue_sleep * 1000);
    }
}
 
int jtag_get_flush_queue_count(void)
{
    return jtag_flush_queue_count;
}
 
int jtag_execute_queue(void)
{
    jtag_execute_queue_noclear();
    return jtag_error_clear();
}
 
static int jtag_reset_callback(enum jtag_event event, void *priv)
{
    struct jtag_tap *tap = priv;
 
    if (event == JTAG_TRST_ASSERTED) {
        tap->enabled = !tap->disabled_after_reset;
 
        /* current instruction is either BYPASS or IDCODE */
        buf_set_ones(tap->cur_instr, tap->ir_length);
        tap->bypass = true;
    }
 
    return ERROR_OK;
}
 
/* sleep at least us microseconds. When we sleep more than 1000ms we
 * do an alive sleep, i.e. keep GDB alive. Note that we could starve
 * GDB if we slept for <1000ms many times.
 */
void jtag_sleep(uint32_t us)
{
    if (us < 1000)
        usleep(us);
    else
        alive_sleep((us+999)/1000);
}
 
#define JTAG_MAX_AUTO_TAPS 20
 
#define EXTRACT_MFG(X)  (((X) & 0xffe) >> 1)
#define EXTRACT_PART(X) (((X) & 0xffff000) >> 12)
#define EXTRACT_VER(X)  (((X) & 0xf0000000) >> 28)
 
/* A reserved manufacturer ID is used in END_OF_CHAIN_FLAG, so we
 * know that no valid TAP will have it as an IDCODE value.
 */
#define END_OF_CHAIN_FLAG       0xffffffff
 
/* a larger IR length than we ever expect to autoprobe */
#define JTAG_IRLEN_MAX          60
 
static int jtag_examine_chain_execute(uint8_t *idcode_buffer, unsigned num_idcode)
{
    struct scan_field field = {
        .num_bits = num_idcode * 32,
        .out_value = idcode_buffer,
        .in_value = idcode_buffer,
    };
 
    /* initialize to the end of chain ID value */
    for (unsigned i = 0; i < num_idcode; i++)
        buf_set_u32(idcode_buffer, i * 32, 32, END_OF_CHAIN_FLAG);
 
    jtag_add_plain_dr_scan(field.num_bits, field.out_value, field.in_value, TAP_DRPAUSE);
    jtag_add_tlr();
    return jtag_execute_queue();
}
 
static bool jtag_examine_chain_check(uint8_t *idcodes, unsigned count)
{
    uint8_t zero_check = 0x0;
    uint8_t one_check = 0xff;
 
    for (unsigned i = 0; i < count * 4; i++) {
        zero_check |= idcodes[i];
        one_check &= idcodes[i];
    }
 
    /* if there wasn't a single non-zero bit or if all bits were one,
     * the scan is not valid.  We wrote a mix of both values; either
     *
     *  - There's a hardware issue (almost certainly):
     *     + all-zeroes can mean a target stuck in JTAG reset
     *     + all-ones tends to mean no target
     *  - The scan chain is WAY longer than we can handle, *AND* either
     *     + there are several hundreds of TAPs in bypass, or
     *     + at least a few dozen TAPs all have an all-ones IDCODE
     */
    if (zero_check == 0x00 || one_check == 0xff) {
        LOG_ERROR("JTAG scan chain interrogation failed: all %s",
            (zero_check == 0x00) ? "zeroes" : "ones");
        LOG_ERROR("Check JTAG interface, timings, target power, etc.");
        return false;
    }
    return true;
}
 
static void jtag_examine_chain_display(enum log_levels level, const char *msg,
    const char *name, uint32_t idcode)
{
    log_printf_lf(level, __FILE__, __LINE__, __func__,
        "JTAG tap: %s %16.16s: 0x%08x "
        "(mfg: 0x%3.3x (%s), part: 0x%4.4x, ver: 0x%1.1x)",
        name, msg,
        (unsigned int)idcode,
        (unsigned int)EXTRACT_MFG(idcode),
        jep106_manufacturer(EXTRACT_MFG(idcode)),
        (unsigned int)EXTRACT_PART(idcode),
        (unsigned int)EXTRACT_VER(idcode));
}
 
static bool jtag_idcode_is_final(uint32_t idcode)
{
    /*
     * Some devices, such as AVR8, will output all 1's instead
     * of TDI input value at end of chain. Allow those values
     * instead of failing.
     */
    return idcode == END_OF_CHAIN_FLAG;
}
 
static bool jtag_examine_chain_end(uint8_t *idcodes, unsigned count, unsigned max)
{
    bool triggered = false;
    for (; count < max - 31; count += 32) {
        uint32_t idcode = buf_get_u32(idcodes, count, 32);
 
        /* do not trigger the warning if the data looks good */
        if (jtag_idcode_is_final(idcode))
            continue;
        LOG_WARNING("Unexpected idcode after end of chain: %d 0x%08x",
            count, (unsigned int)idcode);
        triggered = true;
    }
    return triggered;
}
 
static bool jtag_examine_chain_match_tap(const struct jtag_tap *tap)
{
 
    if (tap->expected_ids_cnt == 0 || !tap->has_idcode)
        return true;
 
    /* optionally ignore the JTAG version field - bits 28-31 of IDCODE */
    uint32_t mask = tap->ignore_version ? ~(0xfU << 28) : ~0U;
    uint32_t idcode = tap->idcode & mask;
 
    /* Loop over the expected identification codes and test for a match */
    for (unsigned ii = 0; ii < tap->expected_ids_cnt; ii++) {
        uint32_t expected = tap->expected_ids[ii] & mask;
 
        if (idcode == expected)
            return true;
 
        /* treat "-expected-id 0" as a "don't-warn" wildcard */
        if (tap->expected_ids[ii] == 0)
            return true;
    }
 
    /* If none of the expected ids matched, warn */
    jtag_examine_chain_display(LOG_LVL_WARNING, "UNEXPECTED",
        tap->dotted_name, tap->idcode);
    for (unsigned ii = 0; ii < tap->expected_ids_cnt; ii++) {
        char msg[32];
 
        snprintf(msg, sizeof(msg), "expected %u of %u", ii + 1, tap->expected_ids_cnt);
        jtag_examine_chain_display(LOG_LVL_ERROR, msg,
            tap->dotted_name, tap->expected_ids[ii]);
    }
    return false;
}
 
/* Try to examine chain layout according to IEEE 1149.1 §12
 * This is called a "blind interrogation" of the scan chain.
 */
static int jtag_examine_chain(void)
{
    int retval;
    unsigned max_taps = jtag_tap_count();
 
    /* Autoprobe up to this many. */
    if (max_taps < JTAG_MAX_AUTO_TAPS)
        max_taps = JTAG_MAX_AUTO_TAPS;
 
    /* Add room for end-of-chain marker. */
    max_taps++;
 
    uint8_t *idcode_buffer = calloc(4, max_taps);
    if (!idcode_buffer)
        return ERROR_JTAG_INIT_FAILED;
 
    /* DR scan to collect BYPASS or IDCODE register contents.
     * Then make sure the scan data has both ones and zeroes.
     */
    LOG_DEBUG("DR scan interrogation for IDCODE/BYPASS");
    retval = jtag_examine_chain_execute(idcode_buffer, max_taps);
    if (retval != ERROR_OK)
        goto out;
    if (!jtag_examine_chain_check(idcode_buffer, max_taps)) {
        retval = ERROR_JTAG_INIT_FAILED;
        goto out;
    }
 
    /* Point at the 1st predefined tap, if any */
    struct jtag_tap *tap = jtag_tap_next_enabled(NULL);
 
    unsigned bit_count = 0;
    unsigned autocount = 0;
    for (unsigned i = 0; i < max_taps; i++) {
        assert(bit_count < max_taps * 32);
        uint32_t idcode = buf_get_u32(idcode_buffer, bit_count, 32);
 
        /* No predefined TAP? Auto-probe. */
        if (!tap) {
            /* Is there another TAP? */
            if (jtag_idcode_is_final(idcode))
                break;
 
            /* Default everything in this TAP except IR length.
             *
             * REVISIT create a jtag_alloc(chip, tap) routine, and
             * share it with jim_newtap_cmd().
             */
            tap = calloc(1, sizeof(*tap));
            if (!tap) {
                retval = ERROR_FAIL;
                goto out;
            }
 
            tap->chip = alloc_printf("auto%u", autocount++);
            tap->tapname = strdup("tap");
            tap->dotted_name = alloc_printf("%s.%s", tap->chip, tap->tapname);
 
            tap->ir_length = 0; /* ... signifying irlen autoprobe */
            tap->ir_capture_mask = 0x03;
            tap->ir_capture_value = 0x01;
 
            tap->enabled = true;
 
            jtag_tap_init(tap);
        }
 
        if ((idcode & 1) == 0 && !tap->ignore_bypass) {
            /* Zero for LSB indicates a device in bypass */
            LOG_INFO("TAP %s does not have valid IDCODE (idcode=0x%" PRIx32 ")",
                    tap->dotted_name, idcode);
            tap->has_idcode = false;
            tap->idcode = 0;
 
            bit_count += 1;
        } else {
            /* Friendly devices support IDCODE */
            tap->has_idcode = true;
            tap->idcode = idcode;
            jtag_examine_chain_display(LOG_LVL_INFO, "tap/device found", tap->dotted_name, idcode);
 
            bit_count += 32;
        }
 
        /* ensure the TAP ID matches what was expected */
        if (!jtag_examine_chain_match_tap(tap))
            retval = ERROR_JTAG_INIT_SOFT_FAIL;
 
        tap = jtag_tap_next_enabled(tap);
    }
 
    /* After those IDCODE or BYPASS register values should be
     * only the data we fed into the scan chain.
     */
    if (jtag_examine_chain_end(idcode_buffer, bit_count, max_taps * 32)) {
        LOG_ERROR("double-check your JTAG setup (interface, speed, ...)");
        retval = ERROR_JTAG_INIT_FAILED;
        goto out;
    }
 
    /* Return success or, for backwards compatibility if only
     * some IDCODE values mismatched, a soft/continuable fault.
     */
out:
    free(idcode_buffer);
    return retval;
}
 
/*
 * Validate the date loaded by entry to the Capture-IR state, to help
 * find errors related to scan chain configuration (wrong IR lengths)
 * or communication.
 *
 * Entry state can be anything.  On non-error exit, all TAPs are in
 * bypass mode.  On error exits, the scan chain is reset.
 */
static int jtag_validate_ircapture(void)
{
    struct jtag_tap *tap;
    uint8_t *ir_test = NULL;
    struct scan_field field;
    int chain_pos = 0;
    int retval;
 
    /* when autoprobing, accommodate huge IR lengths */
    int total_ir_length = 0;
    for (tap = jtag_tap_next_enabled(NULL); tap; tap = jtag_tap_next_enabled(tap)) {
        if (tap->ir_length == 0)
            total_ir_length += JTAG_IRLEN_MAX;
        else
            total_ir_length += tap->ir_length;
    }
 
    /* increase length to add 2 bit sentinel after scan */
    total_ir_length += 2;
 
    ir_test = malloc(DIV_ROUND_UP(total_ir_length, 8));
    if (!ir_test)
        return ERROR_FAIL;
 
    /* after this scan, all TAPs will capture BYPASS instructions */
    buf_set_ones(ir_test, total_ir_length);
 
    field.num_bits = total_ir_length;
    field.out_value = ir_test;
    field.in_value = ir_test;
 
    jtag_add_plain_ir_scan(field.num_bits, field.out_value, field.in_value, TAP_IDLE);
 
    LOG_DEBUG("IR capture validation scan");
    retval = jtag_execute_queue();
    if (retval != ERROR_OK)
        goto done;
 
    tap = NULL;
    chain_pos = 0;
 
    for (;; ) {
        tap = jtag_tap_next_enabled(tap);
        if (!tap)
            break;
 
        /* If we're autoprobing, guess IR lengths.  They must be at
         * least two bits.  Guessing will fail if (a) any TAP does
         * not conform to the JTAG spec; or (b) when the upper bits
         * captured from some conforming TAP are nonzero.  Or if
         * (c) an IR length is longer than JTAG_IRLEN_MAX bits,
         * an implementation limit, which could someday be raised.
         *
         * REVISIT optimization:  if there's a *single* TAP we can
         * lift restrictions (a) and (b) by scanning a recognizable
         * pattern before the all-ones BYPASS.  Check for where the
         * pattern starts in the result, instead of an 0...01 value.
         *
         * REVISIT alternative approach: escape to some tcl code
         * which could provide more knowledge, based on IDCODE; and
         * only guess when that has no success.
         */
        if (tap->ir_length == 0) {
            tap->ir_length = 2;
            while (buf_get_u64(ir_test, chain_pos, tap->ir_length + 1) == 1
                    && tap->ir_length < JTAG_IRLEN_MAX) {
                tap->ir_length++;
            }
            LOG_WARNING("AUTO %s - use \"jtag newtap %s %s -irlen %d "
                    "-expected-id 0x%08" PRIx32 "\"",
                    tap->dotted_name, tap->chip, tap->tapname, tap->ir_length, tap->idcode);
        }
 
        /* Validate the two LSBs, which must be 01 per JTAG spec.
         *
         * Or ... more bits could be provided by TAP declaration.
         * Plus, some taps (notably in i.MX series chips) violate
         * this part of the JTAG spec, so their capture mask/value
         * attributes might disable this test.
         */
        uint64_t val = buf_get_u64(ir_test, chain_pos, tap->ir_length);
        if ((val & tap->ir_capture_mask) != tap->ir_capture_value) {
            LOG_ERROR("%s: IR capture error; saw 0x%0*" PRIx64 " not 0x%0*" PRIx32,
                jtag_tap_name(tap),
                (tap->ir_length + 7) / tap->ir_length, val,
                (tap->ir_length + 7) / tap->ir_length, tap->ir_capture_value);
 
            retval = ERROR_JTAG_INIT_FAILED;
            goto done;
        }
        LOG_DEBUG("%s: IR capture 0x%0*" PRIx64, jtag_tap_name(tap),
            (tap->ir_length + 7) / tap->ir_length, val);
        chain_pos += tap->ir_length;
    }
 
    /* verify the '11' sentinel we wrote is returned at the end */
    uint64_t val = buf_get_u64(ir_test, chain_pos, 2);
    if (val != 0x3) {
        char *cbuf = buf_to_hex_str(ir_test, total_ir_length);
 
        LOG_ERROR("IR capture error at bit %d, saw 0x%s not 0x...3",
            chain_pos, cbuf);
        free(cbuf);
        retval = ERROR_JTAG_INIT_FAILED;
    }
 
done:
    free(ir_test);
    if (retval != ERROR_OK) {
        jtag_add_tlr();
        jtag_execute_queue();
    }
    return retval;
}
 
void jtag_tap_init(struct jtag_tap *tap)
{
    unsigned ir_len_bits;
    unsigned ir_len_bytes;
 
    /* if we're autoprobing, cope with potentially huge ir_length */
    ir_len_bits = tap->ir_length ? tap->ir_length : JTAG_IRLEN_MAX;
    ir_len_bytes = DIV_ROUND_UP(ir_len_bits, 8);
 
    tap->expected = calloc(1, ir_len_bytes);
    tap->expected_mask = calloc(1, ir_len_bytes);
    tap->cur_instr = malloc(ir_len_bytes);
 
    if (ir_len_bits > 32)
        ir_len_bits = 32;
 
    buf_set_u32(tap->expected, 0, ir_len_bits, tap->ir_capture_value);
    buf_set_u32(tap->expected_mask, 0, ir_len_bits, tap->ir_capture_mask);
 
    /* TAP will be in bypass mode after jtag_validate_ircapture() */
    tap->bypass = true;
    buf_set_ones(tap->cur_instr, tap->ir_length);
 
    /* register the reset callback for the TAP */
    jtag_register_event_callback(&jtag_reset_callback, tap);
    jtag_tap_add(tap);
 
    LOG_DEBUG("Created Tap: %s @ abs position %d, "
            "irlen %d, capture: 0x%x mask: 0x%x", tap->dotted_name,
            tap->abs_chain_position, tap->ir_length,
            (unsigned) tap->ir_capture_value,
            (unsigned) tap->ir_capture_mask);
}
 
void jtag_tap_free(struct jtag_tap *tap)
{
    jtag_unregister_event_callback(&jtag_reset_callback, tap);
 
    struct jtag_tap_event_action *jteap = tap->event_action;
    while (jteap) {
        struct jtag_tap_event_action *next = jteap->next;
        Jim_DecrRefCount(jteap->interp, jteap->body);
        free(jteap);
        jteap = next;
    }
 
    free(tap->expected);
    free(tap->expected_mask);
    free(tap->expected_ids);
    free(tap->cur_instr);
    free(tap->chip);
    free(tap->tapname);
    free(tap->dotted_name);
    free(tap);
}
 
int jtag_init_inner(struct command_context *cmd_ctx)
{
    struct jtag_tap *tap;
    int retval;
    bool issue_setup = true;
 
    LOG_DEBUG("Init JTAG chain");
 
    tap = jtag_tap_next_enabled(NULL);
    if (!tap) {
        /* Once JTAG itself is properly set up, and the scan chain
         * isn't absurdly large, IDCODE autoprobe should work fine.
         *
         * But ... IRLEN autoprobe can fail even on systems which
         * are fully conformant to JTAG.  Also, JTAG setup can be
         * quite finicky on some systems.
         *
         * REVISIT: if TAP autoprobe works OK, then in many cases
         * we could escape to tcl code and set up targets based on
         * the TAP's IDCODE values.
         */
        LOG_WARNING("There are no enabled taps.  "
            "AUTO PROBING MIGHT NOT WORK!!");
 
        /* REVISIT default clock will often be too fast ... */
    }
 
    jtag_add_tlr();
    retval = jtag_execute_queue();
    if (retval != ERROR_OK)
        return retval;
 
    /* Examine DR values first.  This discovers problems which will
     * prevent communication ... hardware issues like TDO stuck, or
     * configuring the wrong number of (enabled) TAPs.
     */
    retval = jtag_examine_chain();
    switch (retval) {
        case ERROR_OK:
            /* complete success */
            break;
        default:
            /* For backward compatibility reasons, try coping with
             * configuration errors involving only ID mismatches.
             * We might be able to talk to the devices.
             *
             * Also the device might be powered down during startup.
             *
             * After OpenOCD starts, we can try to power on the device
             * and run a reset.
             */
            LOG_ERROR("Trying to use configured scan chain anyway...");
            issue_setup = false;
            break;
    }
 
    /* Now look at IR values.  Problems here will prevent real
     * communication.  They mostly mean that the IR length is
     * wrong ... or that the IR capture value is wrong.  (The
     * latter is uncommon, but easily worked around:  provide
     * ircapture/irmask values during TAP setup.)
     */
    retval = jtag_validate_ircapture();
    if (retval != ERROR_OK) {
        /* The target might be powered down. The user
         * can power it up and reset it after firing
         * up OpenOCD.
         */
        issue_setup = false;
    }
 
    if (issue_setup)
        jtag_notify_event(JTAG_TAP_EVENT_SETUP);
    else
        LOG_WARNING("Bypassing JTAG setup events due to errors");
 
 
    return ERROR_OK;
}
 
int swd_init_reset(struct command_context *cmd_ctx)
{
    int retval, retval1;
 
    retval = adapter_init(cmd_ctx);
    if (retval != ERROR_OK)
        return retval;
 
    LOG_DEBUG("Initializing with hard SRST reset");
 
    if (jtag_reset_config & RESET_HAS_SRST)
        retval = adapter_system_reset(1);
    retval1 = adapter_system_reset(0);
 
    return (retval == ERROR_OK) ? retval1 : retval;
}
 
int jtag_init_reset(struct command_context *cmd_ctx)
{
    int retval = adapter_init(cmd_ctx);
    if (retval != ERROR_OK)
        return retval;
 
    LOG_DEBUG("Initializing with hard TRST+SRST reset");
 
    /*
     * This procedure is used by default when OpenOCD triggers a reset.
     * It's now done through an overridable Tcl "init_reset" wrapper.
     *
     * This started out as a more powerful "get JTAG working" reset than
     * jtag_init_inner(), applying TRST because some chips won't activate
     * JTAG without a TRST cycle (presumed to be async, though some of
     * those chips synchronize JTAG activation using TCK).
     *
     * But some chips only activate JTAG as part of an SRST cycle; SRST
     * got mixed in.  So it became a hard reset routine, which got used
     * in more places, and which coped with JTAG reset being forced as
     * part of SRST (srst_pulls_trst).
     *
     * And even more corner cases started to surface:  TRST and/or SRST
     * assertion timings matter; some chips need other JTAG operations;
     * TRST/SRST sequences can need to be different from these, etc.
     *
     * Systems should override that wrapper to support system-specific
     * requirements that this not-fully-generic code doesn't handle.
     *
     * REVISIT once Tcl code can read the reset_config modes, this won't
     * need to be a C routine at all...
     */
    if (jtag_reset_config & RESET_HAS_SRST) {
        jtag_add_reset(1, 1);
        if ((jtag_reset_config & RESET_SRST_PULLS_TRST) == 0)
            jtag_add_reset(0, 1);
    } else {
        jtag_add_reset(1, 0);   /* TAP_RESET, using TMS+TCK or TRST */
    }
 
    /* some targets enable us to connect with srst asserted */
    if (jtag_reset_config & RESET_CNCT_UNDER_SRST) {
        if (jtag_reset_config & RESET_SRST_NO_GATING)
            jtag_add_reset(0, 1);
        else {
            LOG_WARNING("\'srst_nogate\' reset_config option is required");
            jtag_add_reset(0, 0);
        }
    } else
        jtag_add_reset(0, 0);
    retval = jtag_execute_queue();
    if (retval != ERROR_OK)
        return retval;
 
    /* Check that we can communication on the JTAG chain + eventually we want to
     * be able to perform enumeration only after OpenOCD has started
     * telnet and GDB server
     *
     * That would allow users to more easily perform any magic they need to before
     * reset happens.
     */
    return jtag_init_inner(cmd_ctx);
}
 
int jtag_init(struct command_context *cmd_ctx)
{
    int retval = adapter_init(cmd_ctx);
    if (retval != ERROR_OK)
        return retval;
 
    /* guard against oddball hardware: force resets to be inactive */
    jtag_add_reset(0, 0);
 
    /* some targets enable us to connect with srst asserted */
    if (jtag_reset_config & RESET_CNCT_UNDER_SRST) {
        if (jtag_reset_config & RESET_SRST_NO_GATING)
            jtag_add_reset(0, 1);
        else
            LOG_WARNING("\'srst_nogate\' reset_config option is required");
    }
    retval = jtag_execute_queue();
    if (retval != ERROR_OK)
        return retval;
 
    if (Jim_Eval_Named(cmd_ctx->interp, "jtag_init", __FILE__, __LINE__) != JIM_OK)
        return ERROR_FAIL;
 
    return ERROR_OK;
}
 
void jtag_set_verify(bool enable)
{
    jtag_verify = enable;
}
 
bool jtag_will_verify(void)
{
    return jtag_verify;
}
 
void jtag_set_verify_capture_ir(bool enable)
{
    jtag_verify_capture_ir = enable;
}
 
bool jtag_will_verify_capture_ir(void)
{
    return jtag_verify_capture_ir;
}
 
int jtag_power_dropout(int *dropout)
{
    if (!is_adapter_initialized()) {
        /* TODO: as the jtag interface is not valid all
         * we can do at the moment is exit OpenOCD */
        LOG_ERROR("No Valid JTAG Interface Configured.");
        exit(-1);
    }
    if (adapter_driver->power_dropout)
        return adapter_driver->power_dropout(dropout);
 
    *dropout = 0; /* by default we can't detect power dropout */
    return ERROR_OK;
}
 
int jtag_srst_asserted(int *srst_asserted)
{
    if (adapter_driver->srst_asserted)
        return adapter_driver->srst_asserted(srst_asserted);
 
    *srst_asserted = 0; /* by default we can't detect srst asserted */
    return ERROR_OK;
}
 
enum reset_types jtag_get_reset_config(void)
{
    return jtag_reset_config;
}
void jtag_set_reset_config(enum reset_types type)
{
    jtag_reset_config = type;
}
 
int jtag_get_trst(void)
{
    return jtag_trst == 1;
}
int jtag_get_srst(void)
{
    return jtag_srst == 1;
}
 
void jtag_set_nsrst_delay(unsigned delay)
{
    adapter_nsrst_delay = delay;
}
unsigned jtag_get_nsrst_delay(void)
{
    return adapter_nsrst_delay;
}
void jtag_set_ntrst_delay(unsigned delay)
{
    jtag_ntrst_delay = delay;
}
unsigned jtag_get_ntrst_delay(void)
{
    return jtag_ntrst_delay;
}
 
 
void jtag_set_nsrst_assert_width(unsigned delay)
{
    adapter_nsrst_assert_width = delay;
}
unsigned jtag_get_nsrst_assert_width(void)
{
    return adapter_nsrst_assert_width;
}
void jtag_set_ntrst_assert_width(unsigned delay)
{
    jtag_ntrst_assert_width = delay;
}
unsigned jtag_get_ntrst_assert_width(void)
{
    return jtag_ntrst_assert_width;
}
 
static int jtag_select(struct command_context *ctx)
{
    int retval;
 
    /* NOTE:  interface init must already have been done.
     * That works with only C code ... no Tcl glue required.
     */
 
    retval = jtag_register_commands(ctx);
 
    if (retval != ERROR_OK)
        return retval;
 
    retval = svf_register_commands(ctx);
 
    if (retval != ERROR_OK)
        return retval;
 
    retval = xsvf_register_commands(ctx);
 
    if (retval != ERROR_OK)
        return retval;
 
    return ipdbg_register_commands(ctx);
}
 
static struct transport jtag_transport = {
    .name = "jtag",
    .select = jtag_select,
    .init = jtag_init,
};
 
static void jtag_constructor(void) __attribute__((constructor));
static void jtag_constructor(void)
{
    transport_register(&jtag_transport);
}
 
bool transport_is_jtag(void)
{
    return get_current_transport() == &jtag_transport;
}
 
int adapter_resets(int trst, int srst)
{
    if (!get_current_transport()) {
        LOG_ERROR("transport is not selected");
        return ERROR_FAIL;
    }
 
    if (transport_is_jtag()) {
        if (srst == SRST_ASSERT && !(jtag_reset_config & RESET_HAS_SRST)) {
            LOG_ERROR("adapter has no srst signal");
            return ERROR_FAIL;
        }
 
        /* adapters without trst signal will eventually use tlr sequence */
        jtag_add_reset(trst, srst);
        /*
         * The jtag queue is still used for reset by some adapter. Flush it!
         * FIXME: To be removed when all adapter drivers will be updated!
         */
        jtag_execute_queue();
        return ERROR_OK;
    } else if (transport_is_swd() || transport_is_hla() ||
               transport_is_dapdirect_swd() || transport_is_dapdirect_jtag() ||
               transport_is_swim()) {
        if (trst == TRST_ASSERT) {
            LOG_ERROR("transport %s has no trst signal",
                get_current_transport()->name);
            return ERROR_FAIL;
        }
 
        if (srst == SRST_ASSERT && !(jtag_reset_config & RESET_HAS_SRST)) {
            LOG_ERROR("adapter has no srst signal");
            return ERROR_FAIL;
        }
        adapter_system_reset(srst);
        return ERROR_OK;
    }
 
    if (trst == TRST_DEASSERT && srst == SRST_DEASSERT)
        return ERROR_OK;
 
    LOG_ERROR("reset is not supported on transport %s",
        get_current_transport()->name);
 
    return ERROR_FAIL;
}
 
int adapter_assert_reset(void)
{
    if (transport_is_jtag()) {
        if (jtag_reset_config & RESET_SRST_PULLS_TRST)
            jtag_add_reset(1, 1);
        else
            jtag_add_reset(0, 1);
        return ERROR_OK;
    } else if (transport_is_swd() || transport_is_hla() ||
               transport_is_dapdirect_jtag() || transport_is_dapdirect_swd() ||
               transport_is_swim())
        return adapter_system_reset(1);
    else if (get_current_transport())
        LOG_ERROR("reset is not supported on %s",
            get_current_transport()->name);
    else
        LOG_ERROR("transport is not selected");
    return ERROR_FAIL;
}
 
int adapter_deassert_reset(void)
{
    if (transport_is_jtag()) {
        jtag_add_reset(0, 0);
        return ERROR_OK;
    } else if (transport_is_swd() || transport_is_hla() ||
               transport_is_dapdirect_jtag() || transport_is_dapdirect_swd() ||
               transport_is_swim())
        return adapter_system_reset(0);
    else if (get_current_transport())
        LOG_ERROR("reset is not supported on %s",
            get_current_transport()->name);
    else
        LOG_ERROR("transport is not selected");
    return ERROR_FAIL;
}
 
int adapter_config_trace(bool enabled, enum tpiu_pin_protocol pin_protocol,
        uint32_t port_size, unsigned int *trace_freq,
        unsigned int traceclkin_freq, uint16_t *prescaler)
{
    if (adapter_driver->config_trace) {
        return adapter_driver->config_trace(enabled, pin_protocol, port_size, trace_freq,
            traceclkin_freq, prescaler);
    } else if (enabled) {
        LOG_ERROR("The selected interface does not support tracing");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
int adapter_poll_trace(uint8_t *buf, size_t *size)
{
    if (adapter_driver->poll_trace)
        return adapter_driver->poll_trace(buf, size);
 
    return ERROR_FAIL;
}