jtag/tcl: fix a double free of jim object

[openocd.git] / src / jtag / tcl.c

/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2007-2010 Øyvind Harboe                                 *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2009 SoftPLC Corporation                                *
 *       http://softplc.com                                                *
 *   dick@softplc.com                                                      *
 *                                                                         *
 *   Copyright (C) 2009 Zachary T Welch                                    *
 *   zw@superlucidity.net                                                  *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "jtag.h"
#include "swd.h"
#include "minidriver.h"
#include "interface.h"
#include "interfaces.h"
#include "tcl.h"

#ifdef HAVE_STRINGS_H
#include <strings.h>
#endif

#include <helper/time_support.h>
#include "transport/transport.h"

/**
 * @file
 * Holds support for accessing JTAG-specific mechanisms from TCl scripts.
 */

static const Jim_Nvp nvp_jtag_tap_event[] = {
        { .value = JTAG_TRST_ASSERTED,          .name = "post-reset" },
        { .value = JTAG_TAP_EVENT_SETUP,        .name = "setup" },
        { .value = JTAG_TAP_EVENT_ENABLE,       .name = "tap-enable" },
        { .value = JTAG_TAP_EVENT_DISABLE,      .name = "tap-disable" },

        { .name = NULL, .value = -1 }
};

struct jtag_tap *jtag_tap_by_jim_obj(Jim_Interp *interp, Jim_Obj *o)
{
        const char *cp = Jim_GetString(o, NULL);
        struct jtag_tap *t = cp ? jtag_tap_by_string(cp) : NULL;
        if (NULL == cp)
                cp = "(unknown)";
        if (NULL == t)
                Jim_SetResultFormatted(interp, "Tap '%s' could not be found", cp);
        return t;
}

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 Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args)
{
        int retval;
        struct scan_field *fields;
        int num_fields;
        int field_count = 0;
        int i, e;
        struct jtag_tap *tap;
        tap_state_t endstate;

        /* args[1] = device
         * args[2] = num_bits
         * args[3] = hex string
         * ... repeat num bits and hex string ...
         *
         * .. optionally:
        *     args[N-2] = "-endstate"
         *     args[N-1] = statename
         */
        if ((argc < 4) || ((argc % 2) != 0)) {
                Jim_WrongNumArgs(interp, 1, args, "wrong arguments");
                return JIM_ERR;
        }

        endstate = TAP_IDLE;

        script_debug(interp, argc, args);

        /* validate arguments as numbers */
        e = JIM_OK;
        for (i = 2; i < argc; i += 2) {
                long bits;
                const char *cp;

                e = Jim_GetLong(interp, args[i], &bits);
                /* If valid - try next arg */
                if (e == JIM_OK)
                        continue;

                /* Not valid.. are we at the end? */
                if (((i + 2) != argc)) {
                        /* nope, then error */
                        return e;
                }

                /* 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);
                /* is it the magic? */
                if (0 == strcmp("-endstate", cp)) {
                        /* is the statename valid? */
                        cp = Jim_GetString(args[i + 1], NULL);

                        /* see if it is a valid state name */
                        endstate = tap_state_by_name(cp);
                        if (endstate < 0) {
                                /* update the error message */
                                Jim_SetResultFormatted(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 */
                                argc -= 2;
                        }
                }

                /* Still an error? */
                if (e != JIM_OK)
                        return e;       /* too bad */
        }       /* validate args */

        assert(e == JIM_OK);

        tap = jtag_tap_by_jim_obj(interp, args[1]);
        if (tap == NULL)
                return JIM_ERR;

        num_fields = (argc-2)/2;
        if (num_fields <= 0) {
                Jim_SetResultString(interp, "drscan: no scan fields supplied", -1);
                return JIM_ERR;
        }
        fields = malloc(sizeof(struct scan_field) * num_fields);
        for (i = 2; i < argc; i += 2) {
                long bits;
                int len;
                const char *str;

                Jim_GetLong(interp, args[i], &bits);
                str = Jim_GetString(args[i + 1], &len);

                fields[field_count].num_bits = bits;
                void *t = malloc(DIV_ROUND_UP(bits, 8));
                fields[field_count].out_value = t;
                str_to_buf(str, len, t, bits, 0);
                fields[field_count].in_value = t;
                field_count++;
        }

        jtag_add_dr_scan(tap, num_fields, fields, endstate);

        retval = jtag_execute_queue();
        if (retval != ERROR_OK) {
                Jim_SetResultString(interp, "drscan: jtag execute failed", -1);
                return JIM_ERR;
        }

        field_count = 0;
        Jim_Obj *list = Jim_NewListObj(interp, NULL, 0);
        for (i = 2; i < argc; i += 2) {
                long bits;
                char *str;

                Jim_GetLong(interp, args[i], &bits);
                str = buf_to_str(fields[field_count].in_value, bits, 16);
                free(fields[field_count].in_value);

                Jim_ListAppendElement(interp, list, Jim_NewStringObj(interp, str, strlen(str)));
                free(str);
                field_count++;
        }

        Jim_SetResult(interp, list);

        free(fields);

        return JIM_OK;
}


static int Jim_Command_pathmove(Jim_Interp *interp, int argc, Jim_Obj *const *args)
{
        tap_state_t states[8];

        if ((argc < 2) || ((size_t)argc > (ARRAY_SIZE(states) + 1))) {
                Jim_WrongNumArgs(interp, 1, args, "wrong arguments");
                return JIM_ERR;
        }

        script_debug(interp, argc, args);

        int i;
        for (i = 0; i < argc-1; i++) {
                const char *cp;
                cp = Jim_GetString(args[i + 1], NULL);
                states[i] = tap_state_by_name(cp);
                if (states[i] < 0) {
                        /* update the error message */
                        Jim_SetResultFormatted(interp, "endstate: %s invalid", cp);
                        return JIM_ERR;
                }
        }

        if ((jtag_add_statemove(states[0]) != ERROR_OK) || (jtag_execute_queue() != ERROR_OK)) {
                Jim_SetResultString(interp, "pathmove: jtag execute failed", -1);
                return JIM_ERR;
        }

        jtag_add_pathmove(argc - 2, states + 1);

        if (jtag_execute_queue() != ERROR_OK) {
                Jim_SetResultString(interp, "pathmove: failed", -1);
                return JIM_ERR;
        }

        return JIM_OK;
}


static int Jim_Command_flush_count(Jim_Interp *interp, int argc, Jim_Obj *const *args)
{
        script_debug(interp, argc, args);

        Jim_SetResult(interp, Jim_NewIntObj(interp, jtag_get_flush_queue_count()));

        return JIM_OK;
}

/* REVISIT Just what about these should "move" ... ?
 * These registrations, into the main JTAG table?
 *
 * There's a minor compatibility issue, these all show up twice;
 * that's not desirable:
 *  - jtag drscan ... NOT DOCUMENTED!
 *  - drscan ...
 *
 * The "irscan" command (for example) doesn't show twice.
 */
static const struct command_registration jtag_command_handlers_to_move[] = {
        {
                .name = "drscan",
                .mode = COMMAND_EXEC,
                .jim_handler = Jim_Command_drscan,
                .help = "Execute Data Register (DR) scan for one TAP.  "
                        "Other TAPs must be in BYPASS mode.",
                .usage = "tap_name [num_bits value]* ['-endstate' state_name]",
        },
        {
                .name = "flush_count",
                .mode = COMMAND_EXEC,
                .jim_handler = Jim_Command_flush_count,
                .help = "Returns the number of times the JTAG queue "
                        "has been flushed.",
        },
        {
                .name = "pathmove",
                .mode = COMMAND_EXEC,
                .jim_handler = Jim_Command_pathmove,
                .usage = "start_state state1 [state2 [state3 ...]]",
                .help = "Move JTAG state machine from current state "
                        "(start_state) to state1, then state2, state3, etc.",
        },
        COMMAND_REGISTRATION_DONE
};


enum jtag_tap_cfg_param {
        JCFG_EVENT,
        JCFG_IDCODE,
};

static Jim_Nvp nvp_config_opts[] = {
        { .name = "-event",      .value = JCFG_EVENT },
        { .name = "-idcode",     .value = JCFG_IDCODE },

        { .name = NULL,          .value = -1 }
};

static int jtag_tap_configure_event(Jim_GetOptInfo *goi, struct jtag_tap *tap)
{
        if (goi->argc == 0) {
                Jim_WrongNumArgs(goi->interp, goi->argc, goi->argv, "-event <event-name> ...");
                return JIM_ERR;
        }

        Jim_Nvp *n;
        int e = Jim_GetOpt_Nvp(goi, nvp_jtag_tap_event, &n);
        if (e != JIM_OK) {
                Jim_GetOpt_NvpUnknown(goi, nvp_jtag_tap_event, 1);
                return e;
        }

        if (goi->isconfigure) {
                if (goi->argc != 1) {
                        Jim_WrongNumArgs(goi->interp,
                                goi->argc,
                                goi->argv,
                                "-event <event-name> <event-body>");
                        return JIM_ERR;
                }
        } else {
                if (goi->argc != 0) {
                        Jim_WrongNumArgs(goi->interp, goi->argc, goi->argv, "-event <event-name>");
                        return JIM_ERR;
                }
        }

        struct jtag_tap_event_action *jteap  = tap->event_action;
        /* replace existing event body */
        bool found = false;
        while (jteap) {
                if (jteap->event == (enum jtag_event)n->value) {
                        found = true;
                        break;
                }
                jteap = jteap->next;
        }

        Jim_SetEmptyResult(goi->interp);

        if (goi->isconfigure) {
                if (!found)
                        jteap = calloc(1, sizeof(*jteap));
                else if (NULL != jteap->body)
                        Jim_DecrRefCount(goi->interp, jteap->body);

                jteap->interp = goi->interp;
                jteap->event = n->value;

                Jim_Obj *o;
                Jim_GetOpt_Obj(goi, &o);
                jteap->body = Jim_DuplicateObj(goi->interp, o);
                Jim_IncrRefCount(jteap->body);

                if (!found) {
                        /* add to head of event list */
                        jteap->next = tap->event_action;
                        tap->event_action = jteap;
                }
        } else if (found) {
                jteap->interp = goi->interp;
                Jim_SetResult(goi->interp,
                        Jim_DuplicateObj(goi->interp, jteap->body));
        }
        return JIM_OK;
}

static int jtag_tap_configure_cmd(Jim_GetOptInfo *goi, struct jtag_tap *tap)
{
        /* parse config or cget options */
        while (goi->argc > 0) {
                Jim_SetEmptyResult(goi->interp);

                Jim_Nvp *n;
                int e = Jim_GetOpt_Nvp(goi, nvp_config_opts, &n);
                if (e != JIM_OK) {
                        Jim_GetOpt_NvpUnknown(goi, nvp_config_opts, 0);
                        return e;
                }

                switch (n->value) {
                        case JCFG_EVENT:
                                e = jtag_tap_configure_event(goi, tap);
                                if (e != JIM_OK)
                                        return e;
                                break;
                        case JCFG_IDCODE:
                                if (goi->isconfigure) {
                                        Jim_SetResultFormatted(goi->interp,
                                                        "not settable: %s", n->name);
                                        return JIM_ERR;
                                } else {
                                        if (goi->argc != 0) {
                                                Jim_WrongNumArgs(goi->interp,
                                                                goi->argc, goi->argv,
                                                                "NO PARAMS");
                                                return JIM_ERR;
                                        }
                                }
                                Jim_SetResult(goi->interp, Jim_NewIntObj(goi->interp, tap->idcode));
                                break;
                        default:
                                Jim_SetResultFormatted(goi->interp, "unknown value: %s", n->name);
                                return JIM_ERR;
                }
        }

        return JIM_OK;
}

static int is_bad_irval(int ir_length, jim_wide w)
{
        jim_wide v = 1;

        v <<= ir_length;
        v -= 1;
        v = ~v;
        return (w & v) != 0;
}

static int jim_newtap_expected_id(Jim_Nvp *n, Jim_GetOptInfo *goi,
        struct jtag_tap *pTap)
{
        jim_wide w;
        int e = Jim_GetOpt_Wide(goi, &w);
        if (e != JIM_OK) {
                Jim_SetResultFormatted(goi->interp, "option: %s bad parameter", n->name);
                return e;
        }

        uint32_t *p = realloc(pTap->expected_ids,
                              (pTap->expected_ids_cnt + 1) * sizeof(uint32_t));
        if (!p) {
                Jim_SetResultFormatted(goi->interp, "no memory");
                return JIM_ERR;
        }

        pTap->expected_ids = p;
        pTap->expected_ids[pTap->expected_ids_cnt++] = w;

        return JIM_OK;
}

#define NTAP_OPT_IRLEN     0
#define NTAP_OPT_IRMASK    1
#define NTAP_OPT_IRCAPTURE 2
#define NTAP_OPT_ENABLED   3
#define NTAP_OPT_DISABLED  4
#define NTAP_OPT_EXPECTED_ID 5
#define NTAP_OPT_VERSION   6

static int jim_newtap_ir_param(Jim_Nvp *n, Jim_GetOptInfo *goi,
        struct jtag_tap *pTap)
{
        jim_wide w;
        int e = Jim_GetOpt_Wide(goi, &w);
        if (e != JIM_OK) {
                Jim_SetResultFormatted(goi->interp,
                        "option: %s bad parameter", n->name);
                return e;
        }
        switch (n->value) {
            case NTAP_OPT_IRLEN:
                    if (w > (jim_wide) (8 * sizeof(pTap->ir_capture_value))) {
                            LOG_WARNING("%s: huge IR length %d",
                                    pTap->dotted_name, (int) w);
                    }
                    pTap->ir_length = w;
                    break;
            case NTAP_OPT_IRMASK:
                    if (is_bad_irval(pTap->ir_length, w)) {
                            LOG_ERROR("%s: IR mask %x too big",
                                    pTap->dotted_name,
                                    (int) w);
                            return JIM_ERR;
                    }
                    if ((w & 3) != 3)
                            LOG_WARNING("%s: nonstandard IR mask", pTap->dotted_name);
                    pTap->ir_capture_mask = w;
                    break;
            case NTAP_OPT_IRCAPTURE:
                    if (is_bad_irval(pTap->ir_length, w)) {
                            LOG_ERROR("%s: IR capture %x too big",
                                    pTap->dotted_name, (int) w);
                            return JIM_ERR;
                    }
                    if ((w & 3) != 1)
                            LOG_WARNING("%s: nonstandard IR value",
                                    pTap->dotted_name);
                    pTap->ir_capture_value = w;
                    break;
            default:
                    return JIM_ERR;
        }
        return JIM_OK;
}

static int jim_newtap_cmd(Jim_GetOptInfo *goi)
{
        struct jtag_tap *pTap;
        int x;
        int e;
        Jim_Nvp *n;
        char *cp;
        const Jim_Nvp opts[] = {
                { .name = "-irlen",       .value = NTAP_OPT_IRLEN },
                { .name = "-irmask",       .value = NTAP_OPT_IRMASK },
                { .name = "-ircapture",       .value = NTAP_OPT_IRCAPTURE },
                { .name = "-enable",       .value = NTAP_OPT_ENABLED },
                { .name = "-disable",       .value = NTAP_OPT_DISABLED },
                { .name = "-expected-id",       .value = NTAP_OPT_EXPECTED_ID },
                { .name = "-ignore-version",       .value = NTAP_OPT_VERSION },
                { .name = NULL,       .value = -1 },
        };

        pTap = calloc(1, sizeof(struct jtag_tap));
        if (!pTap) {
                Jim_SetResultFormatted(goi->interp, "no memory");
                return JIM_ERR;
        }

        /*
         * we expect CHIP + TAP + OPTIONS
         * */
        if (goi->argc < 3) {
                Jim_SetResultFormatted(goi->interp, "Missing CHIP TAP OPTIONS ....");
                free(pTap);
                return JIM_ERR;
        }

        const char *tmp;
        Jim_GetOpt_String(goi, &tmp, NULL);
        pTap->chip = strdup(tmp);

        Jim_GetOpt_String(goi, &tmp, NULL);
        pTap->tapname = strdup(tmp);

        /* name + dot + name + null */
        x = strlen(pTap->chip) + 1 + strlen(pTap->tapname) + 1;
        cp = malloc(x);
        sprintf(cp, "%s.%s", pTap->chip, pTap->tapname);
        pTap->dotted_name = cp;

        LOG_DEBUG("Creating New Tap, Chip: %s, Tap: %s, Dotted: %s, %d params",
                pTap->chip, pTap->tapname, pTap->dotted_name, goi->argc);

        if (!transport_is_jtag()) {
                /* SWD doesn't require any JTAG tap parameters */
                pTap->enabled = true;
                jtag_tap_init(pTap);
                return JIM_OK;
        }

        /* IEEE specifies that the two LSBs of an IR scan are 01, so make
         * that the default.  The "-ircapture" and "-irmask" options are only
         * needed to cope with nonstandard TAPs, or to specify more bits.
         */
        pTap->ir_capture_mask = 0x03;
        pTap->ir_capture_value = 0x01;

        while (goi->argc) {
                e = Jim_GetOpt_Nvp(goi, opts, &n);
                if (e != JIM_OK) {
                        Jim_GetOpt_NvpUnknown(goi, opts, 0);
                        free(cp);
                        free(pTap);
                        return e;
                }
                LOG_DEBUG("Processing option: %s", n->name);
                switch (n->value) {
                    case NTAP_OPT_ENABLED:
                            pTap->disabled_after_reset = false;
                            break;
                    case NTAP_OPT_DISABLED:
                            pTap->disabled_after_reset = true;
                            break;
                    case NTAP_OPT_EXPECTED_ID:
                            e = jim_newtap_expected_id(n, goi, pTap);
                            if (JIM_OK != e) {
                                    free(cp);
                                    free(pTap);
                                    return e;
                            }
                            break;
                    case NTAP_OPT_IRLEN:
                    case NTAP_OPT_IRMASK:
                    case NTAP_OPT_IRCAPTURE:
                            e = jim_newtap_ir_param(n, goi, pTap);
                            if (JIM_OK != e) {
                                    free(cp);
                                    free(pTap);
                                    return e;
                            }
                            break;
                    case NTAP_OPT_VERSION:
                            pTap->ignore_version = true;
                            break;
                }       /* switch (n->value) */
        }       /* while (goi->argc) */

        /* default is enabled-after-reset */
        pTap->enabled = !pTap->disabled_after_reset;

        /* Did all the required option bits get cleared? */
        if (pTap->ir_length != 0) {
                jtag_tap_init(pTap);
                return JIM_OK;
        }

        Jim_SetResultFormatted(goi->interp,
                "newtap: %s missing IR length",
                pTap->dotted_name);
        jtag_tap_free(pTap);
        return JIM_ERR;
}

static void jtag_tap_handle_event(struct jtag_tap *tap, enum jtag_event e)
{
        struct jtag_tap_event_action *jteap;
        int retval;

        for (jteap = tap->event_action; jteap != NULL; jteap = jteap->next) {
                if (jteap->event != e)
                        continue;

                Jim_Nvp *nvp = Jim_Nvp_value2name_simple(nvp_jtag_tap_event, e);
                LOG_DEBUG("JTAG tap: %s event: %d (%s)\n\taction: %s",
                        tap->dotted_name, e, nvp->name,
                        Jim_GetString(jteap->body, NULL));

                retval = Jim_EvalObj(jteap->interp, jteap->body);
                if (retval == JIM_RETURN)
                        retval = jteap->interp->returnCode;

                if (retval != JIM_OK) {
                        Jim_MakeErrorMessage(jteap->interp);
                        LOG_USER("%s", Jim_GetString(Jim_GetResult(jteap->interp), NULL));
                        continue;
                }

                switch (e) {
                    case JTAG_TAP_EVENT_ENABLE:
                    case JTAG_TAP_EVENT_DISABLE:
                                /* NOTE:  we currently assume the handlers
                                 * can't fail.  Right here is where we should
                                 * really be verifying the scan chains ...
                                 */
                            tap->enabled = (e == JTAG_TAP_EVENT_ENABLE);
                            LOG_INFO("JTAG tap: %s %s", tap->dotted_name,
                                tap->enabled ? "enabled" : "disabled");
                            break;
                    default:
                            break;
                }
        }
}

static int jim_jtag_arp_init(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        Jim_GetOptInfo goi;
        Jim_GetOpt_Setup(&goi, interp, argc-1, argv + 1);
        if (goi.argc != 0) {
                Jim_WrongNumArgs(goi.interp, 1, goi.argv-1, "(no params)");
                return JIM_ERR;
        }
        struct command_context *context = current_command_context(interp);
        int e = jtag_init_inner(context);
        if (e != ERROR_OK) {
                Jim_Obj *eObj = Jim_NewIntObj(goi.interp, e);
                Jim_IncrRefCount(eObj);
                Jim_SetResultFormatted(goi.interp, "error: %#s", eObj);
                Jim_DecrRefCount(goi.interp, eObj);
                return JIM_ERR;
        }
        return JIM_OK;
}

static int jim_jtag_arp_init_reset(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        int e = ERROR_OK;
        Jim_GetOptInfo goi;
        Jim_GetOpt_Setup(&goi, interp, argc-1, argv + 1);
        if (goi.argc != 0) {
                Jim_WrongNumArgs(goi.interp, 1, goi.argv-1, "(no params)");
                return JIM_ERR;
        }
        struct command_context *context = current_command_context(interp);
        if (transport_is_jtag())
                e = jtag_init_reset(context);
        else if (transport_is_swd())
                e = swd_init_reset(context);

        if (e != ERROR_OK) {
                Jim_Obj *eObj = Jim_NewIntObj(goi.interp, e);
                Jim_IncrRefCount(eObj);
                Jim_SetResultFormatted(goi.interp, "error: %#s", eObj);
                Jim_DecrRefCount(goi.interp, eObj);
                return JIM_ERR;
        }
        return JIM_OK;
}

int jim_jtag_newtap(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        Jim_GetOptInfo goi;
        Jim_GetOpt_Setup(&goi, interp, argc-1, argv + 1);
        return jim_newtap_cmd(&goi);
}

static bool jtag_tap_enable(struct jtag_tap *t)
{
        if (t->enabled)
                return false;
        jtag_tap_handle_event(t, JTAG_TAP_EVENT_ENABLE);
        if (!t->enabled)
                return false;

        /* FIXME add JTAG sanity checks, w/o TLR
         *  - scan chain length grew by one (this)
         *  - IDs and IR lengths are as expected
         */
        jtag_call_event_callbacks(JTAG_TAP_EVENT_ENABLE);
        return true;
}
static bool jtag_tap_disable(struct jtag_tap *t)
{
        if (!t->enabled)
                return false;
        jtag_tap_handle_event(t, JTAG_TAP_EVENT_DISABLE);
        if (t->enabled)
                return false;

        /* FIXME add JTAG sanity checks, w/o TLR
         *  - scan chain length shrank by one (this)
         *  - IDs and IR lengths are as expected
         */
        jtag_call_event_callbacks(JTAG_TAP_EVENT_DISABLE);
        return true;
}

int jim_jtag_tap_enabler(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        const char *cmd_name = Jim_GetString(argv[0], NULL);
        Jim_GetOptInfo goi;
        Jim_GetOpt_Setup(&goi, interp, argc-1, argv + 1);
        if (goi.argc != 1) {
                Jim_SetResultFormatted(goi.interp, "usage: %s <name>", cmd_name);
                return JIM_ERR;
        }

        struct jtag_tap *t;

        t = jtag_tap_by_jim_obj(goi.interp, goi.argv[0]);
        if (t == NULL)
                return JIM_ERR;

        if (strcasecmp(cmd_name, "tapisenabled") == 0) {
                /* do nothing, just return the value */
        } else if (strcasecmp(cmd_name, "tapenable") == 0) {
                if (!jtag_tap_enable(t)) {
                        LOG_WARNING("failed to enable tap %s", t->dotted_name);
                        return JIM_ERR;
                }
        } else if (strcasecmp(cmd_name, "tapdisable") == 0) {
                if (!jtag_tap_disable(t)) {
                        LOG_WARNING("failed to disable tap %s", t->dotted_name);
                        return JIM_ERR;
                }
        } else {
                LOG_ERROR("command '%s' unknown", cmd_name);
                return JIM_ERR;
        }
        bool e = t->enabled;
        Jim_SetResult(goi.interp, Jim_NewIntObj(goi.interp, e));
        return JIM_OK;
}

int jim_jtag_configure(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        const char *cmd_name = Jim_GetString(argv[0], NULL);
        Jim_GetOptInfo goi;
        Jim_GetOpt_Setup(&goi, interp, argc-1, argv + 1);
        goi.isconfigure = !strcmp(cmd_name, "configure");
        if (goi.argc < 2 + goi.isconfigure) {
                Jim_WrongNumArgs(goi.interp, 0, NULL,
                        "<tap_name> <attribute> ...");
                return JIM_ERR;
        }

        struct jtag_tap *t;

        Jim_Obj *o;
        Jim_GetOpt_Obj(&goi, &o);
        t = jtag_tap_by_jim_obj(goi.interp, o);
        if (t == NULL)
                return JIM_ERR;

        return jtag_tap_configure_cmd(&goi, t);
}

static int jim_jtag_names(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        Jim_GetOptInfo goi;
        Jim_GetOpt_Setup(&goi, interp, argc-1, argv + 1);
        if (goi.argc != 0) {
                Jim_WrongNumArgs(goi.interp, 1, goi.argv, "Too many parameters");
                return JIM_ERR;
        }
        Jim_SetResult(goi.interp, Jim_NewListObj(goi.interp, NULL, 0));
        struct jtag_tap *tap;

        for (tap = jtag_all_taps(); tap; tap = tap->next_tap) {
                Jim_ListAppendElement(goi.interp,
                        Jim_GetResult(goi.interp),
                        Jim_NewStringObj(goi.interp,
                                tap->dotted_name, -1));
        }
        return JIM_OK;
}

COMMAND_HANDLER(handle_jtag_init_command)
{
        if (CMD_ARGC != 0)
                return ERROR_COMMAND_SYNTAX_ERROR;

        static bool jtag_initialized;
        if (jtag_initialized) {
                LOG_INFO("'jtag init' has already been called");
                return ERROR_OK;
        }
        jtag_initialized = true;

        LOG_DEBUG("Initializing jtag devices...");
        return jtag_init(CMD_CTX);
}

static const struct command_registration jtag_subcommand_handlers[] = {
        {
                .name = "init",
                .mode = COMMAND_ANY,
                .handler = handle_jtag_init_command,
                .help = "initialize jtag scan chain",
                .usage = ""
        },
        {
                .name = "arp_init",
                .mode = COMMAND_ANY,
                .jim_handler = jim_jtag_arp_init,
                .help = "Validates JTAG scan chain against the list of "
                        "declared TAPs using just the four standard JTAG "
                        "signals.",
        },
        {
                .name = "arp_init-reset",
                .mode = COMMAND_ANY,
                .jim_handler = jim_jtag_arp_init_reset,
                .help = "Uses TRST and SRST to try resetting everything on "
                        "the JTAG scan chain, then performs 'jtag arp_init'."
        },
        {
                .name = "newtap",
                .mode = COMMAND_CONFIG,
                .jim_handler = jim_jtag_newtap,
                .help = "Create a new TAP instance named basename.tap_type, "
                        "and appends it to the scan chain.",
                .usage = "basename tap_type '-irlen' count "
                        "['-enable'|'-disable'] "
                        "['-expected_id' number] "
                        "['-ignore-version'] "
                        "['-ircapture' number] "
                        "['-mask' number] ",
        },
        {
                .name = "tapisenabled",
                .mode = COMMAND_EXEC,
                .jim_handler = jim_jtag_tap_enabler,
                .help = "Returns a Tcl boolean (0/1) indicating whether "
                        "the TAP is enabled (1) or not (0).",
                .usage = "tap_name",
        },
        {
                .name = "tapenable",
                .mode = COMMAND_EXEC,
                .jim_handler = jim_jtag_tap_enabler,
                .help = "Try to enable the specified TAP using the "
                        "'tap-enable' TAP event.",
                .usage = "tap_name",
        },
        {
                .name = "tapdisable",
                .mode = COMMAND_EXEC,
                .jim_handler = jim_jtag_tap_enabler,
                .help = "Try to disable the specified TAP using the "
                        "'tap-disable' TAP event.",
                .usage = "tap_name",
        },
        {
                .name = "configure",
                .mode = COMMAND_ANY,
                .jim_handler = jim_jtag_configure,
                .help = "Provide a Tcl handler for the specified "
                        "TAP event.",
                .usage = "tap_name '-event' event_name handler",
        },
        {
                .name = "cget",
                .mode = COMMAND_EXEC,
                .jim_handler = jim_jtag_configure,
                .help = "Return any Tcl handler for the specified "
                        "TAP event.",
                .usage = "tap_name '-event' event_name",
        },
        {
                .name = "names",
                .mode = COMMAND_ANY,
                .jim_handler = jim_jtag_names,
                .help = "Returns list of all JTAG tap names.",
        },
        {
                .chain = jtag_command_handlers_to_move,
        },
        COMMAND_REGISTRATION_DONE
};

void jtag_notify_event(enum jtag_event event)
{
        struct jtag_tap *tap;

        for (tap = jtag_all_taps(); tap; tap = tap->next_tap)
                jtag_tap_handle_event(tap, event);
}


COMMAND_HANDLER(handle_scan_chain_command)
{
        struct jtag_tap *tap;
        char expected_id[12];

        tap = jtag_all_taps();
        command_print(CMD,
                "   TapName             Enabled  IdCode     Expected   IrLen IrCap IrMask");
        command_print(CMD,
                "-- ------------------- -------- ---------- ---------- ----- ----- ------");

        while (tap) {
                uint32_t expected, expected_mask, ii;

                snprintf(expected_id, sizeof(expected_id), "0x%08x",
                        (unsigned)((tap->expected_ids_cnt > 0)
                                   ? tap->expected_ids[0]
                                   : 0));
                if (tap->ignore_version)
                        expected_id[2] = '*';

                expected = buf_get_u32(tap->expected, 0, tap->ir_length);
                expected_mask = buf_get_u32(tap->expected_mask, 0, tap->ir_length);

                command_print(CMD,
                        "%2d %-18s     %c     0x%08x %s %5d 0x%02x  0x%02x",
                        tap->abs_chain_position,
                        tap->dotted_name,
                        tap->enabled ? 'Y' : 'n',
                        (unsigned int)(tap->idcode),
                        expected_id,
                        (unsigned int)(tap->ir_length),
                        (unsigned int)(expected),
                        (unsigned int)(expected_mask));

                for (ii = 1; ii < tap->expected_ids_cnt; ii++) {
                        snprintf(expected_id, sizeof(expected_id), "0x%08x",
                                (unsigned) tap->expected_ids[ii]);
                        if (tap->ignore_version)
                                expected_id[2] = '*';

                        command_print(CMD,
                                "                                           %s",
                                expected_id);
                }

                tap = tap->next_tap;
        }

        return ERROR_OK;
}

COMMAND_HANDLER(handle_jtag_ntrst_delay_command)
{
        if (CMD_ARGC > 1)
                return ERROR_COMMAND_SYNTAX_ERROR;
        if (CMD_ARGC == 1) {
                unsigned delay;
                COMMAND_PARSE_NUMBER(uint, CMD_ARGV[0], delay);

                jtag_set_ntrst_delay(delay);
        }
        command_print(CMD, "jtag_ntrst_delay: %u", jtag_get_ntrst_delay());
        return ERROR_OK;
}

COMMAND_HANDLER(handle_jtag_ntrst_assert_width_command)
{
        if (CMD_ARGC > 1)
                return ERROR_COMMAND_SYNTAX_ERROR;
        if (CMD_ARGC == 1) {
                unsigned delay;
                COMMAND_PARSE_NUMBER(uint, CMD_ARGV[0], delay);

                jtag_set_ntrst_assert_width(delay);
        }
        command_print(CMD, "jtag_ntrst_assert_width: %u", jtag_get_ntrst_assert_width());
        return ERROR_OK;
}

COMMAND_HANDLER(handle_jtag_rclk_command)
{
        if (CMD_ARGC > 1)
                return ERROR_COMMAND_SYNTAX_ERROR;

        int retval = ERROR_OK;
        if (CMD_ARGC == 1) {
                unsigned khz = 0;
                COMMAND_PARSE_NUMBER(uint, CMD_ARGV[0], khz);

                retval = jtag_config_rclk(khz);
                if (ERROR_OK != retval)
                        return retval;
        }

        int cur_khz = jtag_get_speed_khz();
        retval = jtag_get_speed_readable(&cur_khz);
        if (ERROR_OK != retval)
                return retval;

        if (cur_khz)
                command_print(CMD, "RCLK not supported - fallback to %d kHz", cur_khz);
        else
                command_print(CMD, "RCLK - adaptive");

        return retval;
}

COMMAND_HANDLER(handle_runtest_command)
{
        if (CMD_ARGC != 1)
                return ERROR_COMMAND_SYNTAX_ERROR;

        unsigned num_clocks;
        COMMAND_PARSE_NUMBER(uint, CMD_ARGV[0], num_clocks);

        jtag_add_runtest(num_clocks, TAP_IDLE);
        return jtag_execute_queue();
}

/*
 * 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.
 * Not surprisingly, this is the same constraint as SVF; the "irscan"
 * and "drscan" commands are a write-only subset of what SVF provides.
 */

COMMAND_HANDLER(handle_irscan_command)
{
        int i;
        struct scan_field *fields;
        struct jtag_tap *tap = NULL;
        tap_state_t endstate;

        if ((CMD_ARGC < 2) || (CMD_ARGC % 2))
                return ERROR_COMMAND_SYNTAX_ERROR;

        /* 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 (CMD_ARGC >= 4) {
                /* have at least one pair of numbers.
                 * is last pair the magic text? */
                if (strcmp("-endstate", CMD_ARGV[CMD_ARGC - 2]) == 0) {
                        endstate = tap_state_by_name(CMD_ARGV[CMD_ARGC - 1]);
                        if (endstate == TAP_INVALID)
                                return ERROR_COMMAND_SYNTAX_ERROR;
                        if (!scan_is_safe(endstate))
                                LOG_WARNING("unstable irscan endstate \"%s\"",
                                        CMD_ARGV[CMD_ARGC - 1]);
                        CMD_ARGC -= 2;
                }
        }

        int num_fields = CMD_ARGC / 2;
        if (num_fields > 1) {
                /* we really should be looking at plain_ir_scan if we want
                 * anything more fancy.
                 */
                LOG_ERROR("Specify a single value for tap");
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        fields = calloc(num_fields, sizeof(*fields));

        int retval;
        for (i = 0; i < num_fields; i++) {
                tap = jtag_tap_by_string(CMD_ARGV[i*2]);
                if (tap == NULL) {
                        free(fields);
                        command_print(CMD, "Tap: %s unknown", CMD_ARGV[i*2]);

                        return ERROR_FAIL;
                }
                uint64_t value;
                retval = parse_u64(CMD_ARGV[i * 2 + 1], &value);
                if (ERROR_OK != retval)
                        goto error_return;

                int field_size = tap->ir_length;
                fields[i].num_bits = field_size;
                uint8_t *v = calloc(1, DIV_ROUND_UP(field_size, 8));
                if (!v) {
                        LOG_ERROR("Out of memory");
                        goto error_return;
                }

                buf_set_u64(v, 0, field_size, value);
                fields[i].out_value = v;
                fields[i].in_value = NULL;
        }

        /* did we have an endstate? */
        jtag_add_ir_scan(tap, fields, endstate);

        retval = jtag_execute_queue();

error_return:
        for (i = 0; i < num_fields; i++) {
                if (NULL != fields[i].out_value)
                        free((void *)fields[i].out_value);
        }

        free(fields);

        return retval;
}

COMMAND_HANDLER(handle_verify_ircapture_command)
{
        if (CMD_ARGC > 1)
                return ERROR_COMMAND_SYNTAX_ERROR;

        if (CMD_ARGC == 1) {
                bool enable;
                COMMAND_PARSE_ENABLE(CMD_ARGV[0], enable);
                jtag_set_verify_capture_ir(enable);
        }

        const char *status = jtag_will_verify_capture_ir() ? "enabled" : "disabled";
        command_print(CMD, "verify Capture-IR is %s", status);

        return ERROR_OK;
}

COMMAND_HANDLER(handle_verify_jtag_command)
{
        if (CMD_ARGC > 1)
                return ERROR_COMMAND_SYNTAX_ERROR;

        if (CMD_ARGC == 1) {
                bool enable;
                COMMAND_PARSE_ENABLE(CMD_ARGV[0], enable);
                jtag_set_verify(enable);
        }

        const char *status = jtag_will_verify() ? "enabled" : "disabled";
        command_print(CMD, "verify jtag capture is %s", status);

        return ERROR_OK;
}

COMMAND_HANDLER(handle_tms_sequence_command)
{
        if (CMD_ARGC > 1)
                return ERROR_COMMAND_SYNTAX_ERROR;

        if (CMD_ARGC == 1) {
                bool use_new_table;
                if (strcmp(CMD_ARGV[0], "short") == 0)
                        use_new_table = true;
                else if (strcmp(CMD_ARGV[0], "long") == 0)
                        use_new_table = false;
                else
                        return ERROR_COMMAND_SYNTAX_ERROR;

                tap_use_new_tms_table(use_new_table);
        }

        command_print(CMD, "tms sequence is  %s",
                tap_uses_new_tms_table() ? "short" : "long");

        return ERROR_OK;
}

COMMAND_HANDLER(handle_jtag_flush_queue_sleep)
{
        if (CMD_ARGC != 1)
                return ERROR_COMMAND_SYNTAX_ERROR;

        int sleep_ms;
        COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], sleep_ms);

        jtag_set_flush_queue_sleep(sleep_ms);

        return ERROR_OK;
}

COMMAND_HANDLER(handle_wait_srst_deassert)
{
        if (CMD_ARGC != 1)
                return ERROR_COMMAND_SYNTAX_ERROR;

        int timeout_ms;
        COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], timeout_ms);
        if ((timeout_ms <= 0) || (timeout_ms > 100000)) {
                LOG_ERROR("Timeout must be an integer between 0 and 100000");
                return ERROR_FAIL;
        }

        LOG_USER("Waiting for srst assert + deassert for at most %dms", timeout_ms);
        int asserted_yet;
        int64_t then = timeval_ms();
        while (jtag_srst_asserted(&asserted_yet) == ERROR_OK) {
                if ((timeval_ms() - then) > timeout_ms) {
                        LOG_ERROR("Timed out");
                        return ERROR_FAIL;
                }
                if (asserted_yet)
                        break;
        }
        while (jtag_srst_asserted(&asserted_yet) == ERROR_OK) {
                if ((timeval_ms() - then) > timeout_ms) {
                        LOG_ERROR("Timed out");
                        return ERROR_FAIL;
                }
                if (!asserted_yet)
                        break;
        }

        return ERROR_OK;
}

static const struct command_registration jtag_command_handlers[] = {

        {
                .name = "jtag_flush_queue_sleep",
                .handler = handle_jtag_flush_queue_sleep,
                .mode = COMMAND_ANY,
                .help = "For debug purposes(simulate long delays of interface) "
                        "to test performance or change in behavior. Default 0ms.",
                .usage = "[sleep in ms]",
        },
        {
                .name = "jtag_rclk",
                .handler = handle_jtag_rclk_command,
                .mode = COMMAND_ANY,
                .help = "With an argument, change to to use adaptive clocking "
                        "if possible; else to use the fallback speed.  "
                        "With or without argument, display current setting.",
                .usage = "[fallback_speed_khz]",
        },
        {
                .name = "jtag_ntrst_delay",
                .handler = handle_jtag_ntrst_delay_command,
                .mode = COMMAND_ANY,
                .help = "delay after deasserting trst in ms",
                .usage = "[milliseconds]",
        },
        {
                .name = "jtag_ntrst_assert_width",
                .handler = handle_jtag_ntrst_assert_width_command,
                .mode = COMMAND_ANY,
                .help = "delay after asserting trst in ms",
                .usage = "[milliseconds]",
        },
        {
                .name = "scan_chain",
                .handler = handle_scan_chain_command,
                .mode = COMMAND_ANY,
                .help = "print current scan chain configuration",
                .usage = ""
        },
        {
                .name = "runtest",
                .handler = handle_runtest_command,
                .mode = COMMAND_EXEC,
                .help = "Move to Run-Test/Idle, and issue TCK for num_cycles.",
                .usage = "num_cycles"
        },
        {
                .name = "irscan",
                .handler = handle_irscan_command,
                .mode = COMMAND_EXEC,
                .help = "Execute Instruction Register (IR) scan.  The "
                        "specified opcodes are put into each TAP's IR, "
                        "and other TAPs are put in BYPASS.",
                .usage = "[tap_name instruction]* ['-endstate' state_name]",
        },
        {
                .name = "verify_ircapture",
                .handler = handle_verify_ircapture_command,
                .mode = COMMAND_ANY,
                .help = "Display or assign flag controlling whether to "
                        "verify values captured during Capture-IR.",
                .usage = "['enable'|'disable']",
        },
        {
                .name = "verify_jtag",
                .handler = handle_verify_jtag_command,
                .mode = COMMAND_ANY,
                .help = "Display or assign flag controlling whether to "
                        "verify values captured during IR and DR scans.",
                .usage = "['enable'|'disable']",
        },
        {
                .name = "tms_sequence",
                .handler = handle_tms_sequence_command,
                .mode = COMMAND_ANY,
                .help = "Display or change what style TMS sequences to use "
                        "for JTAG state transitions:  short (default) or "
                        "long.  Only for working around JTAG bugs.",
                /* Specifically for working around DRIVER bugs... */
                .usage = "['short'|'long']",
        },
        {
                .name = "wait_srst_deassert",
                .handler = handle_wait_srst_deassert,
                .mode = COMMAND_ANY,
                .help = "Wait for an SRST deassert. "
                        "Useful for cases where you need something to happen within ms "
                        "of an srst deassert. Timeout in ms ",
                .usage = "ms",
        },
        {
                .name = "jtag",
                .mode = COMMAND_ANY,
                .help = "perform jtag tap actions",
                .usage = "",

                .chain = jtag_subcommand_handlers,
        },
        {
                .chain = jtag_command_handlers_to_move,
        },
        COMMAND_REGISTRATION_DONE
};

int jtag_register_commands(struct command_context *cmd_ctx)
{
        return register_commands(cmd_ctx, NULL, jtag_command_handlers);
}