- retired variable stuff.

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

/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "replacements.h"

#include "jtag.h"

#include "command.h"
#include "log.h"

#include "stdlib.h"
#include "string.h"
#include <unistd.h>

#include "openocd_tcl.h"


/* note that this is not marked as static as it must be available from outside jtag.c for those 
   that implement the jtag_xxx() minidriver layer 
*/
int jtag_error=ERROR_OK; 


char* tap_state_strings[16] =
{
        "tlr", 
        "sds", "cd", "sd", "e1d", "pd", "e2d", "ud",
        "rti",
        "sis", "ci", "si", "e1i", "pi", "e2i", "ui"
};

typedef struct cmd_queue_page_s
{
        void *address;
        size_t used;
        struct cmd_queue_page_s *next;
} cmd_queue_page_t;

#define CMD_QUEUE_PAGE_SIZE (1024 * 1024)
static cmd_queue_page_t *cmd_queue_pages = NULL;

/* tap_move[i][j]: tap movement command to go from state i to state j
 * 0: Test-Logic-Reset
 * 1: Run-Test/Idle
 * 2: Shift-DR
 * 3: Pause-DR
 * 4: Shift-IR
 * 5: Pause-IR
 * 
 * SD->SD and SI->SI have to be caught in interface specific code
 */
u8 tap_move[6][6] =
{
/*        TLR   RTI   SD    PD    SI    PI             */
        {0x7f, 0x00, 0x17, 0x0a, 0x1b, 0x16},   /* TLR */
        {0x7f, 0x00, 0x25, 0x05, 0x2b, 0x0b},   /* RTI */
        {0x7f, 0x31, 0x00, 0x01, 0x0f, 0x2f},   /* SD  */
        {0x7f, 0x30, 0x20, 0x17, 0x1e, 0x2f},   /* PD  */
        {0x7f, 0x31, 0x07, 0x17, 0x00, 0x01},   /* SI  */
        {0x7f, 0x30, 0x1c, 0x17, 0x20, 0x2f}    /* PI  */
};

int tap_move_map[16] = {
        0, -1, -1,  2, -1,  3, -1, -1,
        1, -1, -1,  4, -1,  5, -1, -1
};

tap_transition_t tap_transitions[16] =
{
        {TAP_TLR, TAP_RTI},             /* TLR */
        {TAP_SIS, TAP_CD},              /* SDS */
        {TAP_E1D, TAP_SD},              /* CD  */
        {TAP_E1D, TAP_SD},              /* SD  */
        {TAP_UD,  TAP_PD},              /* E1D */
        {TAP_E2D, TAP_PD},              /* PD  */
        {TAP_UD,  TAP_SD},              /* E2D */
        {TAP_SDS, TAP_RTI},             /* UD  */
        {TAP_SDS, TAP_RTI},             /* RTI */
        {TAP_TLR, TAP_CI},              /* SIS */
        {TAP_E1I, TAP_SI},              /* CI  */
        {TAP_E1I, TAP_SI},              /* SI  */
        {TAP_UI,  TAP_PI},              /* E1I */
        {TAP_E2I, TAP_PI},              /* PI  */
        {TAP_UI,  TAP_SI},              /* E2I */
        {TAP_SDS, TAP_RTI}              /* UI  */
};

char* jtag_event_strings[] =
{
        "JTAG controller reset (TLR or TRST)"
};

/* kludge!!!! these are just global variables that the
 * interface use internally. They really belong
 * inside the drivers, but we don't want to break
 * linking the drivers!!!!
 */
enum tap_state end_state = TAP_TLR;
enum tap_state cur_state = TAP_TLR;
int jtag_trst = 0;
int jtag_srst = 0;

jtag_command_t *jtag_command_queue = NULL;
jtag_command_t **last_comand_pointer = &jtag_command_queue;
jtag_device_t *jtag_devices = NULL;
int jtag_num_devices = 0;
int jtag_ir_scan_size = 0;
enum reset_types jtag_reset_config = RESET_NONE;
enum tap_state cmd_queue_end_state = TAP_TLR;
enum tap_state cmd_queue_cur_state = TAP_TLR;

int jtag_verify_capture_ir = 1;

/* how long the OpenOCD should wait before attempting JTAG communication after reset lines deasserted (in ms) */
int jtag_nsrst_delay = 0; /* default to no nSRST delay */
int jtag_ntrst_delay = 0; /* default to no nTRST delay */ 

/* maximum number of JTAG devices expected in the chain
 */
#define JTAG_MAX_CHAIN_SIZE 20 

/* callbacks to inform high-level handlers about JTAG state changes */
jtag_event_callback_t *jtag_event_callbacks;

/* speed in kHz*/
static int speed1 = 0, speed2 = 0;
/* flag if the kHz speed was defined */
static int hasKHz = 0;

/* jtag interfaces (parport, FTDI-USB, TI-USB, ...)
 */
 
#if BUILD_ECOSBOARD == 1
        extern jtag_interface_t eCosBoard_interface;
#endif
 
#if BUILD_PARPORT == 1
        extern jtag_interface_t parport_interface;
#endif
         
#if BUILD_DUMMY == 1
        extern jtag_interface_t dummy_interface;
#endif
        
#if BUILD_FT2232_FTD2XX == 1
        extern jtag_interface_t ft2232_interface;
#endif

#if BUILD_FT2232_LIBFTDI == 1
        extern jtag_interface_t ft2232_interface;
#endif

#if BUILD_AMTJTAGACCEL == 1
        extern jtag_interface_t amt_jtagaccel_interface;
#endif

#if BUILD_EP93XX == 1
        extern jtag_interface_t ep93xx_interface;
#endif

#if BUILD_AT91RM9200 == 1
        extern jtag_interface_t at91rm9200_interface;
#endif

#if BUILD_GW16012 == 1
        extern jtag_interface_t gw16012_interface;
#endif

#if BUILD_PRESTO_LIBFTDI == 1 || BUILD_PRESTO_FTD2XX == 1
        extern jtag_interface_t presto_interface;
#endif

#if BUILD_USBPROG == 1
        extern jtag_interface_t usbprog_interface;
#endif

#if BUILD_JLINK == 1
        extern jtag_interface_t jlink_interface;
#endif

jtag_interface_t *jtag_interfaces[] = {
#if BUILD_ECOSBOARD == 1
        &eCosBoard_interface,
#endif
#if BUILD_PARPORT == 1
        &parport_interface,
#endif
#if BUILD_DUMMY == 1
        &dummy_interface,
#endif
#if BUILD_FT2232_FTD2XX == 1
        &ft2232_interface,
#endif
#if BUILD_FT2232_LIBFTDI == 1
        &ft2232_interface,
#endif
#if BUILD_AMTJTAGACCEL == 1
        &amt_jtagaccel_interface,
#endif
#if BUILD_EP93XX == 1
        &ep93xx_interface,
#endif
#if BUILD_AT91RM9200 == 1
        &at91rm9200_interface,
#endif
#if BUILD_GW16012 == 1
        &gw16012_interface,
#endif
#if BUILD_PRESTO_LIBFTDI == 1 || BUILD_PRESTO_FTD2XX == 1
        &presto_interface,
#endif
#if BUILD_USBPROG == 1
        &usbprog_interface,
#endif
#if BUILD_JLINK == 1
        &jlink_interface,
#endif
        NULL,
};

jtag_interface_t *jtag = NULL;

/* configuration */
jtag_interface_t *jtag_interface = NULL;
int jtag_speed = 0;
int jtag_speed_post_reset = 0;


/* forward declarations */
void jtag_add_pathmove(int num_states, enum tap_state *path);
void jtag_add_runtest(int num_cycles, enum tap_state endstate);
void jtag_add_end_state(enum tap_state endstate);
void jtag_add_sleep(u32 us);
int jtag_execute_queue(void);
int jtag_cancel_queue(void);

/* jtag commands */
int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int handle_jtag_speed_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int handle_jtag_khz_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int handle_jtag_device_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int handle_reset_config_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int handle_jtag_nsrst_delay_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int handle_jtag_ntrst_delay_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);

int handle_scan_chain_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);

int handle_endstate_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int handle_jtag_reset_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int handle_runtest_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *argv);

int handle_verify_ircapture_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);

int jtag_register_event_callback(int (*callback)(enum jtag_event event, void *priv), void *priv)
{
        jtag_event_callback_t **callbacks_p = &jtag_event_callbacks;
        
        if (callback == NULL)
        {
                return ERROR_INVALID_ARGUMENTS;
        }
        
        if (*callbacks_p)
        {
                while ((*callbacks_p)->next)
                        callbacks_p = &((*callbacks_p)->next);
                callbacks_p = &((*callbacks_p)->next);
        }
        
        (*callbacks_p) = malloc(sizeof(jtag_event_callback_t));
        (*callbacks_p)->callback = callback;
        (*callbacks_p)->priv = priv;
        (*callbacks_p)->next = NULL;
        
        return ERROR_OK;
}

int jtag_unregister_event_callback(int (*callback)(enum jtag_event event, void *priv))
{
        jtag_event_callback_t **callbacks_p = &jtag_event_callbacks;
        
        if (callback == NULL)
        {
                return ERROR_INVALID_ARGUMENTS;
        }
                
        while (*callbacks_p)
        {
                jtag_event_callback_t **next = &((*callbacks_p)->next);
                if ((*callbacks_p)->callback == callback)
                {
                        free(*callbacks_p);
                        *callbacks_p = *next;
                }
                callbacks_p = next;
        }
        
        return ERROR_OK;
}

int jtag_call_event_callbacks(enum jtag_event event)
{
        jtag_event_callback_t *callback = jtag_event_callbacks;
        
        LOG_DEBUG("jtag event: %s", jtag_event_strings[event]);
        
        while (callback)
        {
                callback->callback(event, callback->priv);
                callback = callback->next;
        }
        
        return ERROR_OK;
}

/* returns a pointer to the pointer of the last command in queue
 * this may be a pointer to the root pointer (jtag_command_queue)
 * or to the next member of the last but one command
 */
jtag_command_t** jtag_get_last_command_p(void)
{
/*      jtag_command_t *cmd = jtag_command_queue;
        
        if (cmd)
                while (cmd->next)
                        cmd = cmd->next;
        else
                return &jtag_command_queue;
        
        return &cmd->next;*/
        
        return last_comand_pointer;
}

/* returns a pointer to the n-th device in the scan chain */
jtag_device_t* jtag_get_device(int num)
{
        jtag_device_t *device = jtag_devices;
        int i = 0;

        while (device)
        {
                if (num == i)
                        return device;
                device = device->next;
                i++;
        }
        
        LOG_ERROR("jtag device number %d not defined", num);
        exit(-1);
}

void* cmd_queue_alloc(size_t size)
{
        cmd_queue_page_t **p_page = &cmd_queue_pages;
        int offset;
        u8 *t;

        if (*p_page)
        {
                while ((*p_page)->next)
                        p_page = &((*p_page)->next);
                if (CMD_QUEUE_PAGE_SIZE - (*p_page)->used < size)
                        p_page = &((*p_page)->next);
        }

        if (!*p_page)
        {
                *p_page = malloc(sizeof(cmd_queue_page_t));
                (*p_page)->used = 0;
                (*p_page)->address = malloc(CMD_QUEUE_PAGE_SIZE);
                (*p_page)->next = NULL;
        }

        offset = (*p_page)->used;
        (*p_page)->used += size;
        
        t=(u8 *)((*p_page)->address);
        return t + offset;
}

void cmd_queue_free()
{
        cmd_queue_page_t *page = cmd_queue_pages;

        while (page)
        {
                cmd_queue_page_t *last = page;
                free(page->address);
                page = page->next;
                free(last);
        }

        cmd_queue_pages = NULL;
}

static void jtag_prelude1()
{
        if (jtag_trst == 1)
        {
                LOG_WARNING("JTAG command queued, while TRST is low (TAP in reset)");
                jtag_error=ERROR_JTAG_TRST_ASSERTED;
                return;
        }

        if (cmd_queue_end_state == TAP_TLR)
                jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
}

static void jtag_prelude(enum tap_state state)
{
        jtag_prelude1();
        
        if (state != -1)
                jtag_add_end_state(state);

        cmd_queue_cur_state = cmd_queue_end_state;
}

void jtag_add_ir_scan(int num_fields, scan_field_t *fields, enum tap_state state)
{
        int retval;
        
        jtag_prelude(state);
        
        retval=interface_jtag_add_ir_scan(num_fields, fields, cmd_queue_end_state);
        if (retval!=ERROR_OK)
                jtag_error=retval;
}

int MINIDRIVER(interface_jtag_add_ir_scan)(int num_fields, scan_field_t *fields, enum tap_state state)
{       
        jtag_command_t **last_cmd;
        jtag_device_t *device;
        int i, j;
        int scan_size = 0;


        last_cmd = jtag_get_last_command_p();
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        (*last_cmd)->next = NULL;
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->type = JTAG_SCAN;

        /* allocate memory for ir scan command */
        (*last_cmd)->cmd.scan = cmd_queue_alloc(sizeof(scan_command_t));
        (*last_cmd)->cmd.scan->ir_scan = 1;
        (*last_cmd)->cmd.scan->num_fields = jtag_num_devices;   /* one field per device */
        (*last_cmd)->cmd.scan->fields = cmd_queue_alloc(jtag_num_devices * sizeof(scan_field_t));
        (*last_cmd)->cmd.scan->end_state = state;

        for (i = 0; i < jtag_num_devices; i++)
        {
                int found = 0;
                device = jtag_get_device(i);
                scan_size = device->ir_length;
                (*last_cmd)->cmd.scan->fields[i].device = i;
                (*last_cmd)->cmd.scan->fields[i].num_bits = scan_size;
                (*last_cmd)->cmd.scan->fields[i].in_value = NULL;
                (*last_cmd)->cmd.scan->fields[i].in_handler = NULL;     /* disable verification by default */

                /* search the list */
                for (j = 0; j < num_fields; j++)
                {
                        if (i == fields[j].device)
                        {
                                found = 1;
                                (*last_cmd)->cmd.scan->fields[i].out_value = buf_cpy(fields[j].out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
                                (*last_cmd)->cmd.scan->fields[i].out_mask = buf_cpy(fields[j].out_mask, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
                        
                                if (jtag_verify_capture_ir)
                                {
                                        if (fields[j].in_handler==NULL)
                                        {
                                                jtag_set_check_value((*last_cmd)->cmd.scan->fields+i, device->expected, device->expected_mask, NULL);
                                        } else
                                        {
                                                (*last_cmd)->cmd.scan->fields[i].in_handler = fields[j].in_handler;
                                                (*last_cmd)->cmd.scan->fields[i].in_handler_priv = fields[j].in_handler_priv;
                                                (*last_cmd)->cmd.scan->fields[i].in_check_value = device->expected; 
                                                (*last_cmd)->cmd.scan->fields[i].in_check_mask = device->expected_mask;
                                        }
                                }
                                
                                device->bypass = 0;
                                break;
                        }
                }
        
                if (!found)
                {
                        /* if a device isn't listed, set it to BYPASS */
                        (*last_cmd)->cmd.scan->fields[i].out_value = buf_set_ones(cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
                        (*last_cmd)->cmd.scan->fields[i].out_mask = NULL;
                        device->bypass = 1;
                        
                }
                
                /* update device information */
                buf_cpy((*last_cmd)->cmd.scan->fields[i].out_value, jtag_get_device(i)->cur_instr, scan_size);
        }
        
        return ERROR_OK;
}

void jtag_add_plain_ir_scan(int num_fields, scan_field_t *fields, enum tap_state state)
{
        int retval;
        
        jtag_prelude(state);
        
        retval=interface_jtag_add_plain_ir_scan(num_fields, fields, cmd_queue_end_state);
        if (retval!=ERROR_OK)
                jtag_error=retval;
}

int MINIDRIVER(interface_jtag_add_plain_ir_scan)(int num_fields, scan_field_t *fields, enum tap_state state)
{
        int i;
        jtag_command_t **last_cmd;
        
        last_cmd = jtag_get_last_command_p();
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        (*last_cmd)->next = NULL;
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->type = JTAG_SCAN;

        /* allocate memory for ir scan command */
        (*last_cmd)->cmd.scan = cmd_queue_alloc(sizeof(scan_command_t));
        (*last_cmd)->cmd.scan->ir_scan = 1;
        (*last_cmd)->cmd.scan->num_fields = num_fields;
        (*last_cmd)->cmd.scan->fields = cmd_queue_alloc(num_fields * sizeof(scan_field_t));
        (*last_cmd)->cmd.scan->end_state = state;

        for (i = 0; i < num_fields; i++)
        {
                int num_bits = fields[i].num_bits;
                int num_bytes = CEIL(fields[i].num_bits, 8);
                (*last_cmd)->cmd.scan->fields[i].device = fields[i].device;
                (*last_cmd)->cmd.scan->fields[i].num_bits = num_bits;
                (*last_cmd)->cmd.scan->fields[i].out_value = buf_cpy(fields[i].out_value, cmd_queue_alloc(num_bytes), num_bits);
                (*last_cmd)->cmd.scan->fields[i].out_mask = buf_cpy(fields[i].out_mask, cmd_queue_alloc(num_bytes), num_bits);
                (*last_cmd)->cmd.scan->fields[i].in_value = fields[i].in_value;
                (*last_cmd)->cmd.scan->fields[i].in_check_value = fields[i].in_check_value;
                (*last_cmd)->cmd.scan->fields[i].in_check_mask = fields[i].in_check_mask;
                (*last_cmd)->cmd.scan->fields[i].in_handler = NULL;
                (*last_cmd)->cmd.scan->fields[i].in_handler_priv = NULL;
        }
        return ERROR_OK;
}

void jtag_add_dr_scan(int num_fields, scan_field_t *fields, enum tap_state state)
{
        int retval;
        
        jtag_prelude(state);

        retval=interface_jtag_add_dr_scan(num_fields, fields, cmd_queue_end_state);
        if (retval!=ERROR_OK)
                jtag_error=retval;
}

int MINIDRIVER(interface_jtag_add_dr_scan)(int num_fields, scan_field_t *fields, enum tap_state state)
{
        int i, j;
        int bypass_devices = 0;
        int field_count = 0;
        int scan_size;

        jtag_command_t **last_cmd = jtag_get_last_command_p();
        jtag_device_t *device = jtag_devices;

        /* count devices in bypass */
        while (device)
        {
                if (device->bypass)
                        bypass_devices++;
                device = device->next;
        }
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->next = NULL;
        (*last_cmd)->type = JTAG_SCAN;

        /* allocate memory for dr scan command */
        (*last_cmd)->cmd.scan = cmd_queue_alloc(sizeof(scan_command_t));
        (*last_cmd)->cmd.scan->ir_scan = 0;
        (*last_cmd)->cmd.scan->num_fields = num_fields + bypass_devices;
        (*last_cmd)->cmd.scan->fields = cmd_queue_alloc((num_fields + bypass_devices) * sizeof(scan_field_t));
        (*last_cmd)->cmd.scan->end_state = state;
        
        for (i = 0; i < jtag_num_devices; i++)
        {
                int found = 0;
                (*last_cmd)->cmd.scan->fields[field_count].device = i;
        
                for (j = 0; j < num_fields; j++)
                {
                        if (i == fields[j].device)
                        {
                                found = 1;
                                scan_size = fields[j].num_bits;
                                (*last_cmd)->cmd.scan->fields[field_count].num_bits = scan_size;
                                (*last_cmd)->cmd.scan->fields[field_count].out_value = buf_cpy(fields[j].out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
                                (*last_cmd)->cmd.scan->fields[field_count].out_mask = buf_cpy(fields[j].out_mask, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
                                (*last_cmd)->cmd.scan->fields[field_count].in_value = fields[j].in_value;
                                (*last_cmd)->cmd.scan->fields[field_count].in_check_value = fields[j].in_check_value;
                                (*last_cmd)->cmd.scan->fields[field_count].in_check_mask = fields[j].in_check_mask;
                                (*last_cmd)->cmd.scan->fields[field_count].in_handler = fields[j].in_handler;
                                (*last_cmd)->cmd.scan->fields[field_count++].in_handler_priv = fields[j].in_handler_priv;
                        }
                }
                if (!found)
                {
#ifdef _DEBUG_JTAG_IO_
                        /* if a device isn't listed, the BYPASS register should be selected */
                        if (!jtag_get_device(i)->bypass)
                        {
                                LOG_ERROR("BUG: no scan data for a device not in BYPASS");
                                exit(-1);
                        }
#endif  
                        /* program the scan field to 1 bit length, and ignore it's value */
                        (*last_cmd)->cmd.scan->fields[field_count].num_bits = 1;
                        (*last_cmd)->cmd.scan->fields[field_count].out_value = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].out_mask = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].in_value = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].in_check_value = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].in_check_mask = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].in_handler = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count++].in_handler_priv = NULL;
                }
                else
                {
#ifdef _DEBUG_JTAG_IO_
                        /* if a device is listed, the BYPASS register must not be selected */
                        if (jtag_get_device(i)->bypass)
                        {
                                LOG_ERROR("BUG: scan data for a device in BYPASS");
                                exit(-1);
                        }
#endif
                }
        }
        return ERROR_OK;
}

void MINIDRIVER(interface_jtag_add_dr_out)(int device_num, 
                int num_fields,
                const int *num_bits,
                const u32 *value,
                enum tap_state end_state)
{
        int i;
        int field_count = 0;
        int scan_size;
        int bypass_devices = 0;

        jtag_command_t **last_cmd = jtag_get_last_command_p();
        jtag_device_t *device = jtag_devices;
        /* count devices in bypass */
        while (device)
        {
                if (device->bypass)
                        bypass_devices++;
                device = device->next;
        }
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->next = NULL;
        (*last_cmd)->type = JTAG_SCAN;

        /* allocate memory for dr scan command */
        (*last_cmd)->cmd.scan = cmd_queue_alloc(sizeof(scan_command_t));
        (*last_cmd)->cmd.scan->ir_scan = 0;
        (*last_cmd)->cmd.scan->num_fields = num_fields + bypass_devices;
        (*last_cmd)->cmd.scan->fields = cmd_queue_alloc((num_fields + bypass_devices) * sizeof(scan_field_t));
        (*last_cmd)->cmd.scan->end_state = end_state;
        
        for (i = 0; i < jtag_num_devices; i++)
        {
                (*last_cmd)->cmd.scan->fields[field_count].device = i;
        
                if (i == device_num)
                {
                        int j;
#ifdef _DEBUG_JTAG_IO_
                        /* if a device is listed, the BYPASS register must not be selected */
                        if (jtag_get_device(i)->bypass)
                        {
                                LOG_ERROR("BUG: scan data for a device in BYPASS");
                                exit(-1);
                        }
#endif
                        for (j = 0; j < num_fields; j++)
                        {
                                u8 out_value[4];
                                scan_size = num_bits[j];
                                buf_set_u32(out_value, 0, scan_size, value[j]);
                                (*last_cmd)->cmd.scan->fields[field_count].num_bits = scan_size;
                                (*last_cmd)->cmd.scan->fields[field_count].out_value = buf_cpy(out_value, cmd_queue_alloc(CEIL(scan_size, 8)), scan_size);
                                (*last_cmd)->cmd.scan->fields[field_count].out_mask = NULL;
                                (*last_cmd)->cmd.scan->fields[field_count].in_value = NULL;
                                (*last_cmd)->cmd.scan->fields[field_count].in_check_value = NULL;
                                (*last_cmd)->cmd.scan->fields[field_count].in_check_mask = NULL;
                                (*last_cmd)->cmd.scan->fields[field_count].in_handler = NULL;
                                (*last_cmd)->cmd.scan->fields[field_count++].in_handler_priv = NULL;
                        }
                } else
                {
#ifdef _DEBUG_JTAG_IO_
                        /* if a device isn't listed, the BYPASS register should be selected */
                        if (!jtag_get_device(i)->bypass)
                        {
                                LOG_ERROR("BUG: no scan data for a device not in BYPASS");
                                exit(-1);
                        }
#endif  
                        /* program the scan field to 1 bit length, and ignore it's value */
                        (*last_cmd)->cmd.scan->fields[field_count].num_bits = 1;
                        (*last_cmd)->cmd.scan->fields[field_count].out_value = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].out_mask = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].in_value = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].in_check_value = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].in_check_mask = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count].in_handler = NULL;
                        (*last_cmd)->cmd.scan->fields[field_count++].in_handler_priv = NULL;
                }
        }
}




void jtag_add_plain_dr_scan(int num_fields, scan_field_t *fields, enum tap_state state)
{
        int retval;
        
        jtag_prelude(state);

        retval=interface_jtag_add_plain_dr_scan(num_fields, fields, cmd_queue_end_state);
        if (retval!=ERROR_OK)
                jtag_error=retval;
}

int MINIDRIVER(interface_jtag_add_plain_dr_scan)(int num_fields, scan_field_t *fields, enum tap_state state)
{
        int i;
        jtag_command_t **last_cmd = jtag_get_last_command_p();
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->next = NULL;
        (*last_cmd)->type = JTAG_SCAN;

        /* allocate memory for scan command */
        (*last_cmd)->cmd.scan = cmd_queue_alloc(sizeof(scan_command_t));
        (*last_cmd)->cmd.scan->ir_scan = 0;
        (*last_cmd)->cmd.scan->num_fields = num_fields;
        (*last_cmd)->cmd.scan->fields = cmd_queue_alloc(num_fields * sizeof(scan_field_t));
        (*last_cmd)->cmd.scan->end_state = state;
        
        for (i = 0; i < num_fields; i++)
        {
                int num_bits = fields[i].num_bits;
                int num_bytes = CEIL(fields[i].num_bits, 8);
                (*last_cmd)->cmd.scan->fields[i].device = fields[i].device;
                (*last_cmd)->cmd.scan->fields[i].num_bits = num_bits;
                (*last_cmd)->cmd.scan->fields[i].out_value = buf_cpy(fields[i].out_value, cmd_queue_alloc(num_bytes), num_bits);
                (*last_cmd)->cmd.scan->fields[i].out_mask = buf_cpy(fields[i].out_mask, cmd_queue_alloc(num_bytes), num_bits);
                (*last_cmd)->cmd.scan->fields[i].in_value = fields[i].in_value;
                (*last_cmd)->cmd.scan->fields[i].in_check_value = fields[i].in_check_value;
                (*last_cmd)->cmd.scan->fields[i].in_check_mask = fields[i].in_check_mask;
                (*last_cmd)->cmd.scan->fields[i].in_handler = fields[i].in_handler;
                (*last_cmd)->cmd.scan->fields[i].in_handler_priv = fields[i].in_handler_priv;
        }

        return ERROR_OK;
}

void jtag_add_tlr()
{
        jtag_prelude(TAP_TLR);
        
        int retval;
        retval=interface_jtag_add_tlr();
        if (retval!=ERROR_OK)
                jtag_error=retval;
}

int MINIDRIVER(interface_jtag_add_tlr)()
{
        enum tap_state state = TAP_TLR;
        jtag_command_t **last_cmd = jtag_get_last_command_p();
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->next = NULL;
        (*last_cmd)->type = JTAG_STATEMOVE;

        (*last_cmd)->cmd.statemove = cmd_queue_alloc(sizeof(statemove_command_t));
        (*last_cmd)->cmd.statemove->end_state = state;
        
        
        return ERROR_OK;
}

void jtag_add_pathmove(int num_states, enum tap_state *path)
{
        enum tap_state cur_state=cmd_queue_cur_state;
        int i;
        int retval;

        /* the last state has to be a stable state */
        if (tap_move_map[path[num_states - 1]] == -1)
        {
                LOG_ERROR("BUG: TAP path doesn't finish in a stable state");
                exit(-1);
        }

        for (i=0; i<num_states; i++)
        {
                if ((tap_transitions[cur_state].low != path[i])&&
                                (tap_transitions[cur_state].high != path[i]))
                {
                        LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_strings[cur_state], tap_state_strings[path[i]]);
                        exit(-1);
                }
                cur_state = path[i];
        }
        
        jtag_prelude1();
        
        cmd_queue_cur_state = path[num_states - 1];

        retval=interface_jtag_add_pathmove(num_states, path);
        if (retval!=ERROR_OK)
                jtag_error=retval;
}


int MINIDRIVER(interface_jtag_add_pathmove)(int num_states, enum tap_state *path)
{
        jtag_command_t **last_cmd = jtag_get_last_command_p();
        int i;
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->next = NULL;
        (*last_cmd)->type = JTAG_PATHMOVE;

        (*last_cmd)->cmd.pathmove = cmd_queue_alloc(sizeof(pathmove_command_t));
        (*last_cmd)->cmd.pathmove->num_states = num_states;
        (*last_cmd)->cmd.pathmove->path = cmd_queue_alloc(sizeof(enum tap_state) * num_states);
        
        for (i = 0; i < num_states; i++)
                (*last_cmd)->cmd.pathmove->path[i] = path[i];
        
        return ERROR_OK;
}

int MINIDRIVER(interface_jtag_add_runtest)(int num_cycles, enum tap_state state)
{
        jtag_command_t **last_cmd = jtag_get_last_command_p();
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        (*last_cmd)->next = NULL;
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->type = JTAG_RUNTEST;

        (*last_cmd)->cmd.runtest = cmd_queue_alloc(sizeof(runtest_command_t));
        (*last_cmd)->cmd.runtest->num_cycles = num_cycles;
        (*last_cmd)->cmd.runtest->end_state = state;
        
        return ERROR_OK;
}

void jtag_add_runtest(int num_cycles, enum tap_state state)
{
        int retval;
        
        jtag_prelude(state);
        
        /* executed by sw or hw fifo */
        retval=interface_jtag_add_runtest(num_cycles, cmd_queue_end_state);
        if (retval!=ERROR_OK)
                jtag_error=retval;
}

void jtag_add_reset(int req_tlr_or_trst, int req_srst)
{
        int trst_with_tlr = 0;
        int retval;
        
        /* FIX!!! there are *many* different cases here. A better
         * approach is needed for legal combinations of transitions...
         */
        if ((jtag_reset_config & RESET_HAS_SRST)&&
                        (jtag_reset_config & RESET_HAS_TRST)&& 
                        ((jtag_reset_config & RESET_SRST_PULLS_TRST)==0))
        {
                if (((req_tlr_or_trst&&!jtag_trst)||
                                (!req_tlr_or_trst&&jtag_trst))&&
                                ((req_srst&&!jtag_srst)||
                                                (!req_srst&&jtag_srst)))
                {
                        /* FIX!!! srst_pulls_trst allows 1,1 => 0,0 transition.... */
                        //LOG_ERROR("BUG: transition of req_tlr_or_trst and req_srst in the same jtag_add_reset() call is undefined");
                }
        }
        
        /* Make sure that jtag_reset_config allows the requested reset */
        /* if SRST pulls TRST, we can't fulfill srst == 1 with trst == 0 */
        if (((jtag_reset_config & RESET_SRST_PULLS_TRST) && (req_srst == 1)) && (!req_tlr_or_trst))
        {
                LOG_ERROR("BUG: requested reset would assert trst");
                jtag_error=ERROR_FAIL;
                return;
        }
                
        /* if TRST pulls SRST, we reset with TAP T-L-R */
        if (((jtag_reset_config & RESET_TRST_PULLS_SRST) && (req_tlr_or_trst)) && (req_srst == 0))
        {
                trst_with_tlr = 1;
        }
        
        if (req_srst && !(jtag_reset_config & RESET_HAS_SRST))
        {
                LOG_ERROR("BUG: requested SRST assertion, but the current configuration doesn't support this");
                jtag_error=ERROR_FAIL;
                return;
        }
        
        if (req_tlr_or_trst)
        {
                if (!trst_with_tlr && (jtag_reset_config & RESET_HAS_TRST))
                {
                        jtag_trst = 1;
                } else
                {
                        trst_with_tlr = 1;
                }
        } else
        {
                jtag_trst = 0;
        }
        
        jtag_srst = req_srst;

        retval = interface_jtag_add_reset(jtag_trst, jtag_srst);
        if (retval!=ERROR_OK)
        {
                jtag_error=retval;
                return;
        }

        if (jtag_srst)
        {
                LOG_DEBUG("SRST line asserted");
        }
        else
        {
                LOG_DEBUG("SRST line released");
                if (jtag_nsrst_delay)
                        jtag_add_sleep(jtag_nsrst_delay * 1000);
        }
        
        if (trst_with_tlr)
        {
                LOG_DEBUG("JTAG reset with TLR instead of TRST");
                jtag_add_end_state(TAP_TLR);
                jtag_add_tlr();
                jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
                return;
        }
        
        if (jtag_trst)
        {
                /* we just asserted nTRST, so we're now in Test-Logic-Reset,
                 * and inform possible listeners about this
                 */
                LOG_DEBUG("TRST line asserted");
                cmd_queue_cur_state = TAP_TLR;
                jtag_call_event_callbacks(JTAG_TRST_ASSERTED);
        }
        else
        {
                if (jtag_ntrst_delay)
                        jtag_add_sleep(jtag_ntrst_delay * 1000);
        }
}

int MINIDRIVER(interface_jtag_add_reset)(int req_trst, int req_srst)
{
        jtag_command_t **last_cmd = jtag_get_last_command_p();

        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        (*last_cmd)->next = NULL;
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->type = JTAG_RESET;

        (*last_cmd)->cmd.reset = cmd_queue_alloc(sizeof(reset_command_t));
        (*last_cmd)->cmd.reset->trst = req_trst;
        (*last_cmd)->cmd.reset->srst = req_srst;

        
        return ERROR_OK;
}

void jtag_add_end_state(enum tap_state state)
{
        cmd_queue_end_state = state;
        if ((cmd_queue_end_state == TAP_SD)||(cmd_queue_end_state == TAP_SD))
        {
                LOG_ERROR("BUG: TAP_SD/SI can't be end state. Calling code should use a larger scan field");
        }
}

int MINIDRIVER(interface_jtag_add_sleep)(u32 us)
{
        jtag_command_t **last_cmd = jtag_get_last_command_p();
        
        /* allocate memory for a new list member */
        *last_cmd = cmd_queue_alloc(sizeof(jtag_command_t));
        (*last_cmd)->next = NULL;
        last_comand_pointer = &((*last_cmd)->next);
        (*last_cmd)->type = JTAG_SLEEP;

        (*last_cmd)->cmd.sleep = cmd_queue_alloc(sizeof(sleep_command_t));
        (*last_cmd)->cmd.sleep->us = us;
        
        return ERROR_OK;
}

void jtag_add_sleep(u32 us)
{
        int retval=interface_jtag_add_sleep(us);
        if (retval!=ERROR_OK)
                jtag_error=retval;
        return;
}

int jtag_scan_size(scan_command_t *cmd)
{
        int bit_count = 0;
        int i;

        /* count bits in scan command */
        for (i = 0; i < cmd->num_fields; i++)
        {
                bit_count += cmd->fields[i].num_bits;
        }

        return bit_count;
}

int jtag_build_buffer(scan_command_t *cmd, u8 **buffer)
{
        int bit_count = 0;
        int i;
        
        bit_count = jtag_scan_size(cmd);
        *buffer = malloc(CEIL(bit_count, 8));
        
        bit_count = 0;

        for (i = 0; i < cmd->num_fields; i++)
        {
                if (cmd->fields[i].out_value)
                {
#ifdef _DEBUG_JTAG_IO_
                        char* char_buf = buf_to_str(cmd->fields[i].out_value, (cmd->fields[i].num_bits > 64) ? 64 : cmd->fields[i].num_bits, 16);
#endif
                        buf_set_buf(cmd->fields[i].out_value, 0, *buffer, bit_count, cmd->fields[i].num_bits);
#ifdef _DEBUG_JTAG_IO_
                        LOG_DEBUG("fields[%i].out_value: 0x%s", i, char_buf);
                        free(char_buf);
#endif
                }
                
                bit_count += cmd->fields[i].num_bits;
        }

        return bit_count;

}

int jtag_read_buffer(u8 *buffer, scan_command_t *cmd)
{
        int i;
        int bit_count = 0;
        int retval;
        
        /* we return ERROR_OK, unless a check fails, or a handler reports a problem */
        retval = ERROR_OK;
        
        for (i = 0; i < cmd->num_fields; i++)
        {
                /* if neither in_value nor in_handler
                 * are specified we don't have to examine this field
                 */
                if (cmd->fields[i].in_value || cmd->fields[i].in_handler)
                {
                        int num_bits = cmd->fields[i].num_bits;
                        u8 *captured = buf_set_buf(buffer, bit_count, malloc(CEIL(num_bits, 8)), 0, num_bits);
                        
#ifdef _DEBUG_JTAG_IO_
                        char *char_buf;

                        char_buf = buf_to_str(captured, (num_bits > 64) ? 64 : num_bits, 16);
                        LOG_DEBUG("fields[%i].in_value: 0x%s", i, char_buf);
                        free(char_buf);
#endif
                        
                        if (cmd->fields[i].in_value)
                        {
                                buf_cpy(captured, cmd->fields[i].in_value, num_bits);
                                
                                if (cmd->fields[i].in_handler)
                                {
                                        if (cmd->fields[i].in_handler(cmd->fields[i].in_value, cmd->fields[i].in_handler_priv, cmd->fields+i) != ERROR_OK)
                                        {
                                                LOG_WARNING("in_handler reported a failed check");
                                                retval = ERROR_JTAG_QUEUE_FAILED;
                                        }
                                }
                        }
                        
                        /* no in_value specified, but a handler takes care of the scanned data */
                        if (cmd->fields[i].in_handler && (!cmd->fields[i].in_value))
                        {
                                if (cmd->fields[i].in_handler(captured, cmd->fields[i].in_handler_priv, cmd->fields+i) != ERROR_OK)
                                {
                                        /* We're going to call the error:handler later, but if the in_handler
                                         * reported an error we report this failure upstream
                                         */
                                        LOG_WARNING("in_handler reported a failed check");
                                        retval = ERROR_JTAG_QUEUE_FAILED;
                                }
                        }

                        free(captured);
                }
                bit_count += cmd->fields[i].num_bits;
        }

        return retval;
}

int jtag_check_value(u8 *captured, void *priv, scan_field_t *field)
{
        int retval = ERROR_OK;
        int num_bits = field->num_bits;
        
        int compare_failed = 0;
        
        if (field->in_check_mask)
                compare_failed = buf_cmp_mask(captured, field->in_check_value, field->in_check_mask, num_bits);
        else
                compare_failed = buf_cmp(captured, field->in_check_value, num_bits);
        
        if (compare_failed)
                {
                /* An error handler could have caught the failing check
                 * only report a problem when there wasn't a handler, or if the handler
                 * acknowledged the error
                 */ 
                if (compare_failed)
                {
                        char *captured_char = buf_to_str(captured, (num_bits > 64) ? 64 : num_bits, 16);
                        char *in_check_value_char = buf_to_str(field->in_check_value, (num_bits > 64) ? 64 : num_bits, 16);

                        if (field->in_check_mask)
                        {
                                char *in_check_mask_char;
                                in_check_mask_char = buf_to_str(field->in_check_mask, (num_bits > 64) ? 64 : num_bits, 16);
                                LOG_WARNING("value captured during scan didn't pass the requested check: captured: 0x%s check_value: 0x%s check_mask: 0x%s", captured_char, in_check_value_char, in_check_mask_char);
                                free(in_check_mask_char);
                        }
                        else
                        {
                                LOG_WARNING("value captured during scan didn't pass the requested check: captured: 0x%s check_value: 0x%s", captured_char, in_check_value_char);
                        }

                        free(captured_char);
                        free(in_check_value_char);
                        
                        retval = ERROR_JTAG_QUEUE_FAILED;
                }
                
        }
        return retval;
}

/* 
  set up checking of this field using the in_handler. The values passed in must be valid until
  after jtag_execute() has completed.
 */
void jtag_set_check_value(scan_field_t *field, u8 *value, u8 *mask, error_handler_t *in_error_handler)
{
        if (value)
                field->in_handler = jtag_check_value;
        else
                field->in_handler = NULL;       /* No check, e.g. embeddedice uses value==NULL to indicate no check */
        field->in_handler_priv = NULL;
        field->in_check_value = value;
        field->in_check_mask = mask;
}

enum scan_type jtag_scan_type(scan_command_t *cmd)
{
        int i;
        int type = 0;
        
        for (i = 0; i < cmd->num_fields; i++)
        {
                if (cmd->fields[i].in_value || cmd->fields[i].in_handler)
                        type |= SCAN_IN;
                if (cmd->fields[i].out_value)
                        type |= SCAN_OUT;
        }

        return type;
}

int MINIDRIVER(interface_jtag_execute_queue)(void)
{
        int retval;
        
        if (jtag==NULL)
        {
                LOG_ERROR("No JTAG interface configured yet. Issue 'init' command in startup scripts before communicating with targets.");
                return ERROR_FAIL;
        }
        
        retval = jtag->execute_queue();
        
        cmd_queue_free();

        jtag_command_queue = NULL;
        last_comand_pointer = &jtag_command_queue;

        return retval;
}

int jtag_execute_queue(void)
{
        int retval=interface_jtag_execute_queue();
        if (retval==ERROR_OK)
        {
                retval=jtag_error;
        }
        jtag_error=ERROR_OK;
        return retval;
}

int jtag_reset_callback(enum jtag_event event, void *priv)
{
        jtag_device_t *device = priv;

        LOG_DEBUG("-");
        
        if (event == JTAG_TRST_ASSERTED)
        {
                buf_set_ones(device->cur_instr, device->ir_length);
                device->bypass = 1;
        }
        
        return ERROR_OK;
}

void jtag_sleep(u32 us)
{
        usleep(us);
}

/* Try to examine chain layout according to IEEE 1149.1 §12
 */
int jtag_examine_chain()
{
        jtag_device_t *device = jtag_devices;
        scan_field_t field;
        u8 idcode_buffer[JTAG_MAX_CHAIN_SIZE * 4];
        int i;
        int bit_count;
        int device_count = 0;
        u8 zero_check = 0x0;
        u8 one_check = 0xff;
        
        field.device = 0;
        field.num_bits = sizeof(idcode_buffer) * 8;
        field.out_value = idcode_buffer;
        field.out_mask = NULL;
        field.in_value = idcode_buffer;
        field.in_check_value = NULL;
        field.in_check_mask = NULL;
        field.in_handler = NULL;
        field.in_handler_priv = NULL;
        
        for (i = 0; i < JTAG_MAX_CHAIN_SIZE; i++)
        {
                buf_set_u32(idcode_buffer, i * 32, 32, 0x000000FF);
        }
        
        jtag_add_plain_dr_scan(1, &field, TAP_TLR);
        jtag_execute_queue();
        
        for (i = 0; i < JTAG_MAX_CHAIN_SIZE * 4; i++)
        {
                zero_check |= idcode_buffer[i];
                one_check &= idcode_buffer[i];
        }
        
        /* if there wasn't a single non-zero bit or if all bits were one, the scan isn't valid */
        if ((zero_check == 0x00) || (one_check == 0xff))
        {
                LOG_ERROR("JTAG communication failure, check connection, JTAG interface, target power etc.");
                return ERROR_JTAG_INIT_FAILED;
        }
        
        for (bit_count = 0; bit_count < (JTAG_MAX_CHAIN_SIZE * 32) - 31;)
        {
                u32 idcode = buf_get_u32(idcode_buffer, bit_count, 32);
                if ((idcode & 1) == 0)
                {
                        /* LSB must not be 0, this indicates a device in bypass */
                        device_count++;
                        
                        bit_count += 1;
                }
                else
                {
                        u32 manufacturer;
                        u32 part;
                        u32 version;
                        
                        if (idcode == 0x000000FF)
                        {
                                /* End of chain (invalid manufacturer ID) */
                                break;
                        }
                        
                        if (device)
                        {
                                device->idcode = idcode;
                                device = device->next;
                        }
                        device_count++;
                        
                        manufacturer = (idcode & 0xffe) >> 1;
                        part = (idcode & 0xffff000) >> 12;
                        version = (idcode & 0xf0000000) >> 28;

                        LOG_INFO("JTAG device found: 0x%8.8x (Manufacturer: 0x%3.3x, Part: 0x%4.4x, Version: 0x%1.1x)", 
                                idcode, manufacturer, part, version);
                        
                        bit_count += 32;
                }
        }
        
        /* see if number of discovered devices matches configuration */
        if (device_count != jtag_num_devices)
        {
                LOG_ERROR("number of discovered devices in JTAG chain (%i) doesn't match configuration (%i)", 
                                device_count, jtag_num_devices);
                LOG_ERROR("check the config file and ensure proper JTAG communication (connections, speed, ...)");
                return ERROR_JTAG_INIT_FAILED;
        }
        
        return ERROR_OK;
}

int jtag_validate_chain()
{
        jtag_device_t *device = jtag_devices;
        int total_ir_length = 0;
        u8 *ir_test = NULL;
        scan_field_t field;
        int chain_pos = 0;
        
        while (device)
        {
                total_ir_length += device->ir_length;
                device = device->next;
        }
        
        total_ir_length += 2;
        ir_test = malloc(CEIL(total_ir_length, 8));
        buf_set_ones(ir_test, total_ir_length);
        
        field.device = 0;
        field.num_bits = total_ir_length;
        field.out_value = ir_test;
        field.out_mask = NULL;
        field.in_value = ir_test;
        field.in_check_value = NULL;
        field.in_check_mask = NULL;
        field.in_handler = NULL;
        field.in_handler_priv = NULL;
        
        jtag_add_plain_ir_scan(1, &field, TAP_TLR);
        jtag_execute_queue();
        
        device = jtag_devices;
        while (device)
        {
                if (buf_get_u32(ir_test, chain_pos, 2) != 0x1)
                {
                        char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
                        LOG_ERROR("Error validating JTAG scan chain, IR mismatch, scan returned 0x%s", cbuf);
                        free(cbuf);
                        free(ir_test);
                        return ERROR_JTAG_INIT_FAILED;
                }
                chain_pos += device->ir_length;
                device = device->next;
        }
        
        if (buf_get_u32(ir_test, chain_pos, 2) != 0x3)
        {
                char *cbuf = buf_to_str(ir_test, total_ir_length, 16);
                LOG_ERROR("Error validating JTAG scan chain, IR mismatch, scan returned 0x%s", cbuf);
                free(cbuf);
                free(ir_test);
                return ERROR_JTAG_INIT_FAILED;
        }
        
        free(ir_test);
        
        return ERROR_OK;
}

int jtag_register_commands(struct command_context_s *cmd_ctx)
{
        register_command(cmd_ctx, NULL, "interface", handle_interface_command,
                COMMAND_CONFIG, NULL);
        register_command(cmd_ctx, NULL, "jtag_speed", handle_jtag_speed_command,
                COMMAND_ANY, "set jtag speed (if supported) <reset speed> [<post reset speed, default value is reset speed>]");
        register_command(cmd_ctx, NULL, "jtag_khz", handle_jtag_khz_command,
                COMMAND_ANY, "same as jtag_speed, except it takes maximum khz as arguments. 0 KHz = RTCK.");
        register_command(cmd_ctx, NULL, "jtag_device", handle_jtag_device_command,
                COMMAND_CONFIG, "jtag_device <ir_length> <ir_expected> <ir_mask>");
        register_command(cmd_ctx, NULL, "reset_config", handle_reset_config_command,
                COMMAND_CONFIG, NULL);
        register_command(cmd_ctx, NULL, "jtag_nsrst_delay", handle_jtag_nsrst_delay_command,
                COMMAND_ANY, "jtag_nsrst_delay <ms> - delay after deasserting srst in ms");
        register_command(cmd_ctx, NULL, "jtag_ntrst_delay", handle_jtag_ntrst_delay_command,
                COMMAND_ANY, "jtag_ntrst_delay <ms> - delay after deasserting trst in ms");
                
        register_command(cmd_ctx, NULL, "scan_chain", handle_scan_chain_command,
                COMMAND_EXEC, "print current scan chain configuration");

        register_command(cmd_ctx, NULL, "endstate", handle_endstate_command,
                COMMAND_EXEC, "finish JTAG operations in <tap_state>");
        register_command(cmd_ctx, NULL, "jtag_reset", handle_jtag_reset_command,
                COMMAND_EXEC, "toggle reset lines <trst> <srst>");
        register_command(cmd_ctx, NULL, "runtest", handle_runtest_command,
                COMMAND_EXEC, "move to Run-Test/Idle, and execute <num_cycles>");
        register_command(cmd_ctx, NULL, "irscan", handle_irscan_command,
                COMMAND_EXEC, "execute IR scan <device> <instr> [dev2] [instr2] ...");
        
        add_jim("drscan", Jim_Command_drscan, "execute DR scan <device> <num_bits> <value> <num_bits1> <value2> ...");

        register_command(cmd_ctx, NULL, "verify_ircapture", handle_verify_ircapture_command,
                COMMAND_ANY, "verify value captured during Capture-IR <enable|disable>");
        return ERROR_OK;
}

int jtag_interface_init(struct command_context_s *cmd_ctx)
{
        if (jtag)
                return ERROR_OK;
        
        if (!jtag_interface)
        {
                /* nothing was previously specified by "interface" command */
                LOG_ERROR("JTAG interface has to be specified, see \"interface\" command");
                return ERROR_JTAG_INVALID_INTERFACE;
        }
        if(hasKHz)
        {
                /*stay on "reset speed"*/
                jtag_interface->khz(speed1, &jtag_speed);
                jtag_interface->khz(speed2, &jtag_speed_post_reset);
                hasKHz = 0;
        }

        if (jtag_interface->init() != ERROR_OK)
                return ERROR_JTAG_INIT_FAILED;

        
        
        jtag = jtag_interface;
        return ERROR_OK;
}

static int jtag_init_inner(struct command_context_s *cmd_ctx)
{
        int validate_tries = 0;
        jtag_device_t *device;
        int retval;

        LOG_DEBUG("Init JTAG chain");
        
        device = jtag_devices;
        jtag_ir_scan_size = 0;
        jtag_num_devices = 0;
        while (device != NULL)
        {
                jtag_ir_scan_size += device->ir_length;
                jtag_num_devices++;
                device = device->next;
        }
        
        jtag_add_tlr();
        if ((retval=jtag_execute_queue())!=ERROR_OK)
                return retval;

        /* examine chain first, as this could discover the real chain layout */
        if (jtag_examine_chain() != ERROR_OK)
        {
                LOG_ERROR("trying to validate configured JTAG chain anyway...");
        }
        
        while (jtag_validate_chain() != ERROR_OK)
        {
                validate_tries++;
                
                if (validate_tries > 5)
                {
                        LOG_ERROR("Could not validate JTAG chain, exit");
                        return ERROR_JTAG_INVALID_INTERFACE;
                }
                usleep(10000);
        }
        
        return ERROR_OK;
}

int jtag_init_reset(struct command_context_s *cmd_ctx)
{
        int retval;

        if ((retval=jtag_interface_init(cmd_ctx)) != ERROR_OK)
                return retval;

        LOG_DEBUG("Trying to bring the JTAG controller to life by asserting TRST / TLR");

        /* Reset can happen after a power cycle.
         * 
         * Ideally we would only assert TRST or run TLR before the target reset.
         * 
         * However w/srst_pulls_trst, trst is asserted together with the target
         * reset whether we want it or not.
         * 
         * NB! Some targets have JTAG circuitry disabled until a 
         * trst & srst has been asserted.
         * 
         * NB! here we assume nsrst/ntrst delay are sufficient!
         * 
         * NB! order matters!!!! srst *can* disconnect JTAG circuitry
         * 
         */
        jtag_add_reset(1, 0); /* TLR or TRST */
        if (jtag_reset_config & RESET_HAS_SRST)
        {
                jtag_add_reset(1, 1);
                if ((jtag_reset_config & RESET_SRST_PULLS_TRST)==0)
                        jtag_add_reset(0, 1);
        }
        jtag_add_reset(0, 0);
        if ((retval = jtag_execute_queue()) != ERROR_OK)
                return retval;
        
        /* Check that we can communication on the JTAG chain + eventually we want to
         * be able to perform enumeration only after OpenOCD has started 
         * telnet and GDB server
         * 
         * That would allow users to more easily perform any magic they need to before
         * reset happens.
         */
        return jtag_init_inner(cmd_ctx);
}

int jtag_init(struct command_context_s *cmd_ctx)
{
        int retval;
        if ((retval=jtag_interface_init(cmd_ctx)) != ERROR_OK)
                return retval;
        if (jtag_init_inner(cmd_ctx)==ERROR_OK)
        {
                return ERROR_OK;
        }
        return jtag_init_reset(cmd_ctx);
}


static int default_khz(int khz, int *jtag_speed)
{
        LOG_ERROR("Translation from khz to jtag_speed not implemented");
        return ERROR_FAIL;
}

static int default_speed_div(int speed, int *khz)
{
        return ERROR_FAIL;      
}

int handle_interface_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        int i;

        /* check whether the interface is already configured */
        if (jtag_interface)
        {
                LOG_WARNING("Interface already configured, ignoring");
                return ERROR_OK;
        }

        /* interface name is a mandatory argument */
        if (argc < 1 || args[0][0] == '\0')
        {
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        for (i=0; jtag_interfaces[i]; i++)
        {
                if (strcmp(args[0], jtag_interfaces[i]->name) == 0)
                {
                        if (jtag_interfaces[i]->register_commands(cmd_ctx) != ERROR_OK)
                                exit(-1);

                        jtag_interface = jtag_interfaces[i];
                        
                        if (jtag_interface->khz == NULL)
                        {
                                jtag_interface->khz = default_khz;
                        }
                        if (jtag_interface->speed_div == NULL)
                        {
                                jtag_interface->speed_div = default_speed_div;
                        }
                        return ERROR_OK;
                }
        }

        /* no valid interface was found (i.e. the configuration option,
         * didn't match one of the compiled-in interfaces
         */
        LOG_ERROR("No valid jtag interface found (%s)", args[0]);
        LOG_ERROR("compiled-in jtag interfaces:");
        for (i = 0; jtag_interfaces[i]; i++)
        {
                LOG_ERROR("%i: %s", i, jtag_interfaces[i]->name);
        }

        return ERROR_JTAG_INVALID_INTERFACE;
}

int handle_jtag_device_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        jtag_device_t **last_device_p = &jtag_devices;

        if (*last_device_p)
        {
                while ((*last_device_p)->next)
                        last_device_p = &((*last_device_p)->next);
                last_device_p = &((*last_device_p)->next);
        }

        if (argc < 3)
                return ERROR_OK;

        *last_device_p = malloc(sizeof(jtag_device_t));
        (*last_device_p)->ir_length = strtoul(args[0], NULL, 0);

        (*last_device_p)->expected = malloc((*last_device_p)->ir_length);
        buf_set_u32((*last_device_p)->expected, 0, (*last_device_p)->ir_length, strtoul(args[1], NULL, 0));
        (*last_device_p)->expected_mask = malloc((*last_device_p)->ir_length);
        buf_set_u32((*last_device_p)->expected_mask, 0, (*last_device_p)->ir_length, strtoul(args[2], NULL, 0));

        (*last_device_p)->cur_instr = malloc((*last_device_p)->ir_length);
        (*last_device_p)->bypass = 1;
        buf_set_ones((*last_device_p)->cur_instr, (*last_device_p)->ir_length);
        
        (*last_device_p)->next = NULL;
        
        jtag_register_event_callback(jtag_reset_callback, (*last_device_p));
        
        jtag_num_devices++;
        
        return ERROR_OK;
}

int handle_scan_chain_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        jtag_device_t *device = jtag_devices;
        int device_count = 0;
        
        while (device)
        {
                u32 expected, expected_mask, cur_instr;
                expected = buf_get_u32(device->expected, 0, device->ir_length);
                expected_mask = buf_get_u32(device->expected_mask, 0, device->ir_length);
                cur_instr = buf_get_u32(device->cur_instr, 0, device->ir_length);
                command_print(cmd_ctx, "%i: idcode: 0x%8.8x ir length %i, ir capture 0x%x, ir mask 0x%x, current instruction 0x%x", device_count, device->idcode, device->ir_length, expected, expected_mask, cur_instr);
                device = device->next;
                device_count++;
        }

        return ERROR_OK;
}

int handle_reset_config_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        if (argc < 1)
                return ERROR_COMMAND_SYNTAX_ERROR;
        
        if (argc >= 1)
        {
                if (strcmp(args[0], "none") == 0)
                        jtag_reset_config = RESET_NONE;
                else if (strcmp(args[0], "trst_only") == 0)
                        jtag_reset_config = RESET_HAS_TRST;
                else if (strcmp(args[0], "srst_only") == 0)
                        jtag_reset_config = RESET_HAS_SRST;
                else if (strcmp(args[0], "trst_and_srst") == 0)
                        jtag_reset_config = RESET_TRST_AND_SRST;
                else
                {
                        LOG_ERROR("invalid reset_config argument, defaulting to none");
                        jtag_reset_config = RESET_NONE;
                        return ERROR_INVALID_ARGUMENTS;
                }
        }
        
        if (argc >= 2)
        {
                if (strcmp(args[1], "separate") == 0)
                {
                        /* seperate reset lines - default */
                } else
                {
                        if (strcmp(args[1], "srst_pulls_trst") == 0)
                                jtag_reset_config |= RESET_SRST_PULLS_TRST;
                        else if (strcmp(args[1], "trst_pulls_srst") == 0)
                                jtag_reset_config |= RESET_TRST_PULLS_SRST;
                        else if (strcmp(args[1], "combined") == 0)
                                jtag_reset_config |= RESET_SRST_PULLS_TRST | RESET_TRST_PULLS_SRST;
                        else
                        {
                                LOG_ERROR("invalid reset_config argument, defaulting to none");
                                jtag_reset_config = RESET_NONE;
                                return ERROR_INVALID_ARGUMENTS;
                        }
                }
        }
        
        if (argc >= 3)
        {
                if (strcmp(args[2], "trst_open_drain") == 0)
                        jtag_reset_config |= RESET_TRST_OPEN_DRAIN;
                else if (strcmp(args[2], "trst_push_pull") == 0)
                        jtag_reset_config &= ~RESET_TRST_OPEN_DRAIN;
                else
                {
                        LOG_ERROR("invalid reset_config argument, defaulting to none");
                        jtag_reset_config = RESET_NONE;
                        return ERROR_INVALID_ARGUMENTS;
                }
        }

        if (argc >= 4)
        {
                if (strcmp(args[3], "srst_push_pull") == 0)
                        jtag_reset_config |= RESET_SRST_PUSH_PULL;
                else if (strcmp(args[3], "srst_open_drain") == 0)
                        jtag_reset_config &= ~RESET_SRST_PUSH_PULL;
                else
                {
                        LOG_ERROR("invalid reset_config argument, defaulting to none");
                        jtag_reset_config = RESET_NONE;
                        return ERROR_INVALID_ARGUMENTS;
                }
        }
        
        return ERROR_OK;
}

int handle_jtag_nsrst_delay_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        if (argc < 1)
        {
                LOG_ERROR("jtag_nsrst_delay <ms> command takes one required argument");
                exit(-1);
        }
        else
        {
                jtag_nsrst_delay = strtoul(args[0], NULL, 0);
        }
        
        return ERROR_OK;
}

int handle_jtag_ntrst_delay_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        if (argc < 1)
        {
                LOG_ERROR("jtag_ntrst_delay <ms> command takes one required argument");
                exit(-1);
        }
        else
        {
                jtag_ntrst_delay = strtoul(args[0], NULL, 0);
        }
        
        return ERROR_OK;
}

int handle_jtag_speed_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        int cur_speed = 0;
        
        if (argc != 0)
        {
                if ((argc<1) || (argc>2))
                        return ERROR_COMMAND_SYNTAX_ERROR;
                
                LOG_DEBUG("handle jtag speed");
                
                if (argc >= 1)
                        cur_speed = jtag_speed = jtag_speed_post_reset = strtoul(args[0], NULL, 0);
                if (argc == 2)
                        cur_speed = jtag_speed_post_reset = strtoul(args[1], NULL, 0);
                        
                /* this command can be called during CONFIG, 
                 * in which case jtag isn't initialized */
                if (jtag)
                {
                        jtag->speed_div(jtag_speed, &speed1);
                        jtag->speed_div(jtag_speed_post_reset, &speed2);
                        jtag->speed(cur_speed);
                }
        }               
        command_print(cmd_ctx, "jtag_speed: %d, %d", jtag_speed, jtag_speed_post_reset);
        
        return ERROR_OK;
}

int handle_jtag_khz_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        LOG_DEBUG("handle jtag khz");
        
        if (argc>2)
                return ERROR_COMMAND_SYNTAX_ERROR;

        if(argc != 0)
        {
                
                if (argc >= 1)
                        speed1 = speed2 = strtoul(args[0], NULL, 0);
                if (argc == 2)
                        speed2 = strtoul(args[1], NULL, 0);
        
                if (jtag != NULL)
                {
                        int cur_speed = 0;
                        LOG_DEBUG("have interface set up");
                        int speed_div1, speed_div2;
                        if (jtag->khz(speed1, &speed_div1)!=ERROR_OK)
                        {
                                speed1 = speed2 = 0;
                                return ERROR_OK;
                        }
                        if (jtag->khz(speed2, &speed_div2)!=ERROR_OK)
                        {
                                speed1 = speed2 = 0;
                                return ERROR_OK;
                        }
        
                        if (argc >= 1)
                                cur_speed = jtag_speed = jtag_speed_post_reset = speed_div1;
                        if (argc == 2)
                                cur_speed = jtag_speed_post_reset = speed_div2;
        
                        jtag->speed(cur_speed);
                } else
                {
                        hasKHz = 1;
                }
        }
        command_print(cmd_ctx, "jtag_khz: %d, %d", speed1, speed2);
        
        return ERROR_OK;
}


int handle_endstate_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        enum tap_state state;

        if (argc < 1)
        {
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
        else
        {
                for (state = 0; state < 16; state++)
                {
                        if (strcmp(args[0], tap_state_strings[state]) == 0)
                        {
                                jtag_add_end_state(state);
                                jtag_execute_queue();
                        }
                }
        }
        command_print(cmd_ctx, "current endstate: %s", tap_state_strings[cmd_queue_end_state]);
        
        return ERROR_OK;
}

int handle_jtag_reset_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        int trst = -1;
        int srst = -1;
        
        if (argc < 2)
        {
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        if (args[0][0] == '1')
                trst = 1;
        else if (args[0][0] == '0')
                trst = 0;
        else
        {
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        if (args[1][0] == '1')
                srst = 1;
        else if (args[1][0] == '0')
                srst = 0;
        else
        {
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        if (jtag_interface_init(cmd_ctx) != ERROR_OK)
                return ERROR_JTAG_INIT_FAILED;

        jtag_add_reset(trst, srst);
        jtag_execute_queue();

        return ERROR_OK;
}

int handle_runtest_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        if (argc < 1)
        {
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        jtag_add_runtest(strtol(args[0], NULL, 0), -1);
        jtag_execute_queue();

        return ERROR_OK;

}


int handle_irscan_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        int i;
        scan_field_t *fields;
        
        if ((argc < 2) || (argc % 2))
        {
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        fields = malloc(sizeof(scan_field_t) * argc / 2);
        
        for (i = 0; i < argc / 2; i++)
        {
                int device = strtoul(args[i*2], NULL, 0);
                int field_size = jtag_get_device(device)->ir_length;
                fields[i].device = device;
                fields[i].out_value = malloc(CEIL(field_size, 8));
                buf_set_u32(fields[i].out_value, 0, field_size, strtoul(args[i*2+1], NULL, 0));
                fields[i].out_mask = NULL;
                fields[i].in_value = NULL;
                fields[i].in_check_mask = NULL;
                fields[i].in_handler = NULL;
                fields[i].in_handler_priv = NULL;
        }

        jtag_add_ir_scan(argc / 2, fields, -1);
        jtag_execute_queue();

        for (i = 0; i < argc / 2; i++)
                free(fields[i].out_value);

        free (fields);

        return ERROR_OK;
}

/* FIX!!! this command is busted for > 32 bits */
int Jim_Command_drscan(Jim_Interp *interp, int argc, Jim_Obj *const *args)
{
        int retval;
        scan_field_t *fields;
        int num_fields;
        int field_count = 0;
        int i, j;
        
        if ((argc < 4) || ((argc % 2)!=0))
        {
                return JIM_ERR;
        }

        for (i = 2; i < argc; i+=2)
        {
                long bits;
                Jim_GetLong(interp, args[i], &bits);
                if ((bits<=0)||(bits>32))
                {
//                      LOG_ERROR("minimum 1/maximum 32 bit fields - patches gratefully accepted!");
                        return JIM_ERR;
                }
        }
        long device;
        Jim_GetLong(interp, args[1], &device);
        num_fields=(argc-2)/2;

        fields = malloc(sizeof(scan_field_t) * num_fields);

        for (i = 2; i < argc; i+=2)
        {
                long bits;
                Jim_GetLong(interp, args[i], &bits);
                long val;
                Jim_GetLong(interp, args[i+1], &val);
                
                fields[field_count].device = device;
                fields[field_count].num_bits = bits;
                fields[field_count].out_value = malloc(CEIL(bits, 8));
                buf_set_u32(fields[field_count].out_value, 0, bits, val);
                fields[field_count].out_mask = NULL;
                fields[field_count].in_value = fields[field_count].out_value;
                fields[field_count].in_check_mask = NULL;
                fields[field_count].in_check_value = NULL;
                fields[field_count].in_handler = NULL;
                fields[field_count++].in_handler_priv = NULL;
        }

        jtag_add_dr_scan(num_fields, fields, -1);
        retval=jtag_execute_queue();
        
        field_count=0;
        Jim_Obj *list=Jim_NewListObj(interp, NULL, 0);
        for (i = 2; i < argc; i+=2)
        {
                long bits;
                Jim_GetLong(interp, args[i], &bits);
                
                u32 val = buf_get_u32(fields[field_count].in_value, 0, bits);

                Jim_ListAppendElement(interp, list, Jim_NewIntObj(interp, val));
                
                free(fields[field_count].out_value);
                field_count++;
        }
        
        Jim_SetResult(interp, list);
        
        free(fields);

        return retval?JIM_OK:JIM_ERR;
}

int handle_verify_ircapture_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
{
        if (argc == 1)
        {
                if (strcmp(args[0], "enable") == 0)
                {
                        jtag_verify_capture_ir = 1;
                }
                else if (strcmp(args[0], "disable") == 0)
                {
                        jtag_verify_capture_ir = 0;
                } else
                {
                        return ERROR_COMMAND_SYNTAX_ERROR;
                }
        } else if (argc != 0)
        {
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
        
        command_print(cmd_ctx, "verify Capture-IR is %s", (jtag_verify_capture_ir) ? "enabled": "disabled");
        
        return ERROR_OK;
}