jtag: jtag_add_ir_scan() now takes a single field

[openocd.git] / src / jtag / zy1000 / zy1000.c

/***************************************************************************
 *   Copyright (C) 2007-2010 by Øyvind Harboe                              *
 *                                                                         *
 *   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.             *
 ***************************************************************************/

/* This file supports the zy1000 debugger: http://www.zylin.com/zy1000.html
 *
 * The zy1000 is a standalone debugger that has a web interface and
 * requires no drivers on the developer host as all communication
 * is via TCP/IP. The zy1000 gets it performance(~400-700kBytes/s
 * DCC downloads @ 16MHz target) as it has an FPGA to hardware
 * accelerate the JTAG commands, while offering *very* low latency
 * between OpenOCD and the FPGA registers.
 *
 * The disadvantage of the zy1000 is that it has a feeble CPU compared to
 * a PC(ca. 50-500 DMIPS depending on how one counts it), whereas a PC
 * is on the order of 10000 DMIPS(i.e. at a factor of 20-200).
 *
 * The zy1000 revc hardware is using an Altera Nios CPU, whereas the
 * revb is using ARM7 + Xilinx.
 *
 * See Zylin web pages or contact Zylin for more information.
 *
 * The reason this code is in OpenOCD rather than OpenOCD linked with the
 * ZY1000 code is that OpenOCD is the long road towards getting
 * libopenocd into place. libopenocd will support both low performance,
 * low latency systems(embedded) and high performance high latency
 * systems(PCs).
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <target/embeddedice.h>
#include <jtag/minidriver.h>
#include <jtag/interface.h>
#include "zy1000_version.h"

#include <cyg/hal/hal_io.h>             // low level i/o
#include <cyg/hal/hal_diag.h>

#include <time.h>

#ifdef CYGPKG_HAL_NIOS2
#include <cyg/hal/io.h>
#include <cyg/firmwareutil/firmwareutil.h>
#endif

#define ZYLIN_VERSION GIT_ZY1000_VERSION
#define ZYLIN_DATE __DATE__
#define ZYLIN_TIME __TIME__
#define ZYLIN_OPENOCD GIT_OPENOCD_VERSION
#define ZYLIN_OPENOCD_VERSION "ZY1000 " ZYLIN_VERSION " " ZYLIN_DATE


static int zy1000_khz(int khz, int *jtag_speed)
{
        if (khz == 0)
        {
                *jtag_speed = 0;
        }
        else
        {
                *jtag_speed = 64000/khz;
        }
        return ERROR_OK;
}

static int zy1000_speed_div(int speed, int *khz)
{
        if (speed == 0)
        {
                *khz = 0;
        }
        else
        {
                *khz = 64000/speed;
        }

        return ERROR_OK;
}

static bool readPowerDropout(void)
{
        cyg_uint32 state;
        // sample and clear power dropout
        ZY1000_POKE(ZY1000_JTAG_BASE + 0x10, 0x80);
        ZY1000_PEEK(ZY1000_JTAG_BASE + 0x10, state);
        bool powerDropout;
        powerDropout = (state & 0x80) != 0;
        return powerDropout;
}


static bool readSRST(void)
{
        cyg_uint32 state;
        // sample and clear SRST sensing
        ZY1000_POKE(ZY1000_JTAG_BASE + 0x10, 0x00000040);
        ZY1000_PEEK(ZY1000_JTAG_BASE + 0x10, state);
        bool srstAsserted;
        srstAsserted = (state & 0x40) != 0;
        return srstAsserted;
}

static int zy1000_srst_asserted(int *srst_asserted)
{
        *srst_asserted = readSRST();
        return ERROR_OK;
}

static int zy1000_power_dropout(int *dropout)
{
        *dropout = readPowerDropout();
        return ERROR_OK;
}

void zy1000_reset(int trst, int srst)
{
        LOG_DEBUG("zy1000 trst=%d, srst=%d", trst, srst);

        /* flush the JTAG FIFO. Not flushing the queue before messing with
         * reset has such interesting bugs as causing hard to reproduce
         * RCLK bugs as RCLK will stop responding when TRST is asserted
         */
        waitIdle();

        if (!srst)
        {
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x14, 0x00000001);
        }
        else
        {
                /* Danger!!! if clk != 0 when in
                 * idle in TAP_IDLE, reset halt on str912 will fail.
                 */
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x10, 0x00000001);
        }

        if (!trst)
        {
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x14, 0x00000002);
        }
        else
        {
                /* assert reset */
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x10, 0x00000002);
        }

        if (trst||(srst && (jtag_get_reset_config() & RESET_SRST_PULLS_TRST)))
        {
                /* we're now in the RESET state until trst is deasserted */
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x20, TAP_RESET);
        } else
        {
                /* We'll get RCLK failure when we assert TRST, so clear any false positives here */
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x14, 0x400);
        }

        /* wait for srst to float back up */
        if (!srst)
        {
                int i;
                for (i = 0; i < 1000; i++)
                {
                        // We don't want to sense our own reset, so we clear here.
                        // There is of course a timing hole where we could loose
                        // a "real" reset.
                        if (!readSRST())
                                break;

                        /* wait 1ms */
                        alive_sleep(1);
                }

                if (i == 1000)
                {
                        LOG_USER("SRST didn't deassert after %dms", i);
                } else if (i > 1)
                {
                        LOG_USER("SRST took %dms to deassert", i);
                }
        }
}

int zy1000_speed(int speed)
{
        /* flush JTAG master FIFO before setting speed */
        waitIdle();

        if (speed == 0)
        {
                /*0 means RCLK*/
                speed = 0;
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x10, 0x100);
                LOG_DEBUG("jtag_speed using RCLK");
        }
        else
        {
                if (speed > 8190 || speed < 2)
                {
                        LOG_USER("valid ZY1000 jtag_speed=[8190,2]. Divisor is 64MHz / even values between 8190-2, i.e. min 7814Hz, max 32MHz");
                        return ERROR_INVALID_ARGUMENTS;
                }

                LOG_USER("jtag_speed %d => JTAG clk=%f", speed, 64.0/(float)speed);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x14, 0x100);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x1c, speed&~1);
        }
        return ERROR_OK;
}

static bool savePower;


static void setPower(bool power)
{
        savePower = power;
        if (power)
        {
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x14, 0x8);
        } else
        {
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x10, 0x8);
        }
}

COMMAND_HANDLER(handle_power_command)
{
        switch (CMD_ARGC)
        {
        case 1: {
                bool enable;
                COMMAND_PARSE_ON_OFF(CMD_ARGV[0], enable);
                setPower(enable);
                // fall through
        }
        case 0:
                LOG_INFO("Target power %s", savePower ? "on" : "off");
                break;
        default:
                return ERROR_INVALID_ARGUMENTS;
        }

        return ERROR_OK;
}


/* Give TELNET a way to find out what version this is */
static int jim_zy1000_version(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        if ((argc < 1) || (argc > 3))
                return JIM_ERR;
        const char *version_str = NULL;

        if (argc == 1)
        {
                version_str = ZYLIN_OPENOCD_VERSION;
        } else
        {
                const char *str = Jim_GetString(argv[1], NULL);
                const char *str2 = NULL;
                if (argc > 2)
                        str2 = Jim_GetString(argv[2], NULL);
                if (strcmp("openocd", str) == 0)
                {
                        version_str = ZYLIN_OPENOCD;
                }
                else if (strcmp("zy1000", str) == 0)
                {
                        version_str = ZYLIN_VERSION;
                }
                else if (strcmp("date", str) == 0)
                {
                        version_str = ZYLIN_DATE;
                }
                else if (strcmp("time", str) == 0)
                {
                        version_str = ZYLIN_TIME;
                }
                else if (strcmp("pcb", str) == 0)
                {
#ifdef CYGPKG_HAL_NIOS2
                        version_str="c";
#else
                        version_str="b";
#endif
                }
#ifdef CYGPKG_HAL_NIOS2
                else if (strcmp("fpga", str) == 0)
                {

                        /* return a list of 32 bit integers to describe the expected
                         * and actual FPGA
                         */
                        static char *fpga_id = "0x12345678 0x12345678 0x12345678 0x12345678";
                        cyg_uint32 id, timestamp;
                        HAL_READ_UINT32(SYSID_BASE, id);
                        HAL_READ_UINT32(SYSID_BASE+4, timestamp);
                        sprintf(fpga_id, "0x%08x 0x%08x 0x%08x 0x%08x", id, timestamp, SYSID_ID, SYSID_TIMESTAMP);
                        version_str = fpga_id;
                        if ((argc>2) && (strcmp("time", str2) == 0))
                        {
                            time_t last_mod = timestamp;
                            char * t = ctime (&last_mod) ;
                            t[strlen(t)-1] = 0;
                            version_str = t;
                        }
                }
#endif

                else
                {
                        return JIM_ERR;
                }
        }

        Jim_SetResult(interp, Jim_NewStringObj(interp, version_str, -1));

        return JIM_OK;
}


#ifdef CYGPKG_HAL_NIOS2


struct info_forward
{
        void *data;
        struct cyg_upgrade_info *upgraded_file;
};

static void report_info(void *data, const char * format, va_list args)
{
        char *s = alloc_vprintf(format, args);
        LOG_USER_N("%s", s);
        free(s);
}

struct cyg_upgrade_info firmware_info =
{
                (cyg_uint8 *)0x84000000,
                "/ram/firmware.phi",
                "Firmware",
                0x0300000,
                0x1f00000 -
                0x0300000,
                "ZylinNiosFirmware\n",
                report_info,
};

static int jim_zy1000_writefirmware(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
        if (argc != 2)
                return JIM_ERR;

        int length;
        const char *str = Jim_GetString(argv[1], &length);

        /* */
        int tmpFile;
        if ((tmpFile = open(firmware_info.file, O_RDWR | O_CREAT | O_TRUNC)) <= 0)
        {
                return JIM_ERR;
        }
        bool success;
        success = write(tmpFile, str, length) == length;
        close(tmpFile);
        if (!success)
                return JIM_ERR;

        if (!cyg_firmware_upgrade(NULL, firmware_info))
                return JIM_ERR;

        return JIM_OK;
}
#endif

static int
zylinjtag_Jim_Command_powerstatus(Jim_Interp *interp,
                                                                   int argc,
                Jim_Obj * const *argv)
{
        if (argc != 1)
        {
                Jim_WrongNumArgs(interp, 1, argv, "powerstatus");
                return JIM_ERR;
        }

        cyg_uint32 status;
        ZY1000_PEEK(ZY1000_JTAG_BASE + 0x10, status);

        Jim_SetResult(interp, Jim_NewIntObj(interp, (status&0x80) != 0));

        return JIM_OK;
}




int zy1000_init(void)
{
        LOG_USER("%s", ZYLIN_OPENOCD_VERSION);

        ZY1000_POKE(ZY1000_JTAG_BASE + 0x10, 0x30); // Turn on LED1 & LED2

        setPower(true); // on by default


         /* deassert resets. Important to avoid infinite loop waiting for SRST to deassert */
        zy1000_reset(0, 0);
        zy1000_speed(jtag_get_speed());

        return ERROR_OK;
}

int zy1000_quit(void)
{

        return ERROR_OK;
}



int interface_jtag_execute_queue(void)
{
        cyg_uint32 empty;

        waitIdle();
        ZY1000_PEEK(ZY1000_JTAG_BASE + 0x10, empty);
        /* clear JTAG error register */
        ZY1000_POKE(ZY1000_JTAG_BASE + 0x14, 0x400);

        if ((empty&0x400) != 0)
        {
                LOG_WARNING("RCLK timeout");
                /* the error is informative only as we don't want to break the firmware if there
                 * is a false positive.
                 */
//              return ERROR_FAIL;
        }
        return ERROR_OK;
}





static cyg_uint32 getShiftValue(void)
{
        cyg_uint32 value;
        waitIdle();
        ZY1000_PEEK(ZY1000_JTAG_BASE + 0xc, value);
        VERBOSE(LOG_INFO("getShiftValue %08x", value));
        return value;
}
#if 0
static cyg_uint32 getShiftValueFlip(void)
{
        cyg_uint32 value;
        waitIdle();
        ZY1000_PEEK(ZY1000_JTAG_BASE + 0x18, value);
        VERBOSE(LOG_INFO("getShiftValue %08x (flipped)", value));
        return value;
}
#endif

#if 0
static void shiftValueInnerFlip(const tap_state_t state, const tap_state_t endState, int repeat, cyg_uint32 value)
{
        VERBOSE(LOG_INFO("shiftValueInner %s %s %d %08x (flipped)", tap_state_name(state), tap_state_name(endState), repeat, value));
        cyg_uint32 a,b;
        a = state;
        b = endState;
        ZY1000_POKE(ZY1000_JTAG_BASE + 0xc, value);
        ZY1000_POKE(ZY1000_JTAG_BASE + 0x8, (1 << 15) | (repeat << 8) | (a << 4) | b);
        VERBOSE(getShiftValueFlip());
}
#endif

static void gotoEndState(tap_state_t end_state)
{
        setCurrentState(end_state);
}

static __inline void scanFields(int num_fields, const struct scan_field *fields, tap_state_t shiftState, int pause)
{
        int i;
        int j;
        int k;

        for (i = 0; i < num_fields; i++)
        {
                cyg_uint32 value;

                uint8_t *inBuffer = NULL;


                // figure out where to store the input data
                int num_bits = fields[i].num_bits;
                if (fields[i].in_value != NULL)
                {
                        inBuffer = fields[i].in_value;
                }

                // here we shuffle N bits out/in
                j = 0;
                while (j < num_bits)
                {
                        tap_state_t pause_state;
                        int l;
                        k = num_bits-j;
                        pause_state = (shiftState == TAP_DRSHIFT)?TAP_DRSHIFT:TAP_IRSHIFT;
                        if (k > 32)
                        {
                                k = 32;
                                /* we have more to shift out */
                        } else if (pause&&(i == num_fields-1))
                        {
                                /* this was the last to shift out this time */
                                pause_state = (shiftState==TAP_DRSHIFT)?TAP_DRPAUSE:TAP_IRPAUSE;
                        }

                        // we have (num_bits + 7)/8 bytes of bits to toggle out.
                        // bits are pushed out LSB to MSB
                        value = 0;
                        if (fields[i].out_value != NULL)
                        {
                                for (l = 0; l < k; l += 8)
                                {
                                        value|=fields[i].out_value[(j + l)/8]<<l;
                                }
                        }
                        /* mask away unused bits for easier debugging */
                        if (k < 32)
                        {
                                value&=~(((uint32_t)0xffffffff) << k);
                        } else
                        {
                                /* Shifting by >= 32 is not defined by the C standard
                                 * and will in fact shift by &0x1f bits on nios */
                        }

                        shiftValueInner(shiftState, pause_state, k, value);

                        if (inBuffer != NULL)
                        {
                                // data in, LSB to MSB
                                value = getShiftValue();
                                // we're shifting in data to MSB, shift data to be aligned for returning the value
                                value >>= 32-k;

                                for (l = 0; l < k; l += 8)
                                {
                                        inBuffer[(j + l)/8]=(value >> l)&0xff;
                                }
                        }
                        j += k;
                }
        }
}

int interface_jtag_add_ir_scan(struct jtag_tap *active, const struct scan_field *fields, tap_state_t state)
{
        int scan_size = 0;
        struct jtag_tap *tap, *nextTap;

        for (tap = jtag_tap_next_enabled(NULL); tap!= NULL; tap = nextTap)
        {
                nextTap = jtag_tap_next_enabled(tap);
                bool pause = (nextTap==NULL);
                scan_size = tap->ir_length;

                /* search the list */
                if (tap == active)
                {
                        scanFields(1, fields, TAP_IRSHIFT, pause);
                        /* update device information */
                        buf_cpy(fields[0].out_value, tap->cur_instr, scan_size);

                        tap->bypass = 0;
                } else
                {
                        /* if a device isn't listed, set it to BYPASS */
                        assert(scan_size <= 32);
                        shiftValueInner(TAP_IRSHIFT, pause?TAP_IRPAUSE:TAP_IRSHIFT, scan_size, 0xffffffff);

                        tap->bypass = 1;
                }
        }
        gotoEndState(state);

        return ERROR_OK;
}





int interface_jtag_add_plain_ir_scan(int num_fields, const struct scan_field *fields, tap_state_t state)
{
        scanFields(num_fields, fields, TAP_IRSHIFT, 1);
        gotoEndState(state);

        return ERROR_OK;
}

int interface_jtag_add_dr_scan(struct jtag_tap *active, int num_fields, const struct scan_field *fields, tap_state_t state)
{
        struct jtag_tap *tap, *nextTap;
        for (tap = jtag_tap_next_enabled(NULL); tap!= NULL; tap = nextTap)
        {
                nextTap = jtag_tap_next_enabled(tap);
                bool pause = (nextTap==NULL);

                /* Find a range of fields to write to this tap */
                if (tap == active)
                {
                        assert(!tap->bypass);

                        scanFields(num_fields, fields, TAP_DRSHIFT, pause);
                } else
                {
                        /* Shift out a 0 for disabled tap's */
                        assert(tap->bypass);
                        shiftValueInner(TAP_DRSHIFT, pause?TAP_DRPAUSE:TAP_DRSHIFT, 1, 0);
                }
        }
        gotoEndState(state);
        return ERROR_OK;
}

int interface_jtag_add_plain_dr_scan(int num_fields, const struct scan_field *fields, tap_state_t state)
{
        scanFields(num_fields, fields, TAP_DRSHIFT, 1);
        gotoEndState(state);
        return ERROR_OK;
}

int interface_jtag_add_tlr()
{
        setCurrentState(TAP_RESET);
        return ERROR_OK;
}


int interface_jtag_add_reset(int req_trst, int req_srst)
{
        zy1000_reset(req_trst, req_srst);
        return ERROR_OK;
}

static int zy1000_jtag_add_clocks(int num_cycles, tap_state_t state, tap_state_t clockstate)
{
        /* num_cycles can be 0 */
        setCurrentState(clockstate);

        /* execute num_cycles, 32 at the time. */
        int i;
        for (i = 0; i < num_cycles; i += 32)
        {
                int num;
                num = 32;
                if (num_cycles-i < num)
                {
                        num = num_cycles-i;
                }
                shiftValueInner(clockstate, clockstate, num, 0);
        }

#if !TEST_MANUAL()
        /* finish in end_state */
        setCurrentState(state);
#else
        tap_state_t t = TAP_IDLE;
        /* test manual drive code on any target */
        int tms;
        uint8_t tms_scan = tap_get_tms_path(t, state);
        int tms_count = tap_get_tms_path_len(tap_get_state(), tap_get_end_state());

        for (i = 0; i < tms_count; i++)
        {
                tms = (tms_scan >> i) & 1;
                waitIdle();
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28,  tms);
        }
        waitIdle();
        ZY1000_POKE(ZY1000_JTAG_BASE + 0x20, state);
#endif

        return ERROR_OK;
}

int interface_jtag_add_runtest(int num_cycles, tap_state_t state)
{
        return zy1000_jtag_add_clocks(num_cycles, state, TAP_IDLE);
}

int interface_jtag_add_clocks(int num_cycles)
{
        return zy1000_jtag_add_clocks(num_cycles, cmd_queue_cur_state, cmd_queue_cur_state);
}

int interface_jtag_add_sleep(uint32_t us)
{
        jtag_sleep(us);
        return ERROR_OK;
}

int interface_add_tms_seq(unsigned num_bits, const uint8_t *seq, enum tap_state state)
{
        /*wait for the fifo to be empty*/
        waitIdle();

        for (unsigned i = 0; i < num_bits; i++)
        {
                int tms;

                if (((seq[i/8] >> (i % 8)) & 1) == 0)
                {
                        tms = 0;
                }
                else
                {
                        tms = 1;
                }

                waitIdle();
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28, tms);
        }

        waitIdle();
        if (state != TAP_INVALID)
        {
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x20, state);
        } else
        {
                /* this would be normal if we are switching to SWD mode */
        }
        return ERROR_OK;
}

int interface_jtag_add_pathmove(int num_states, const tap_state_t *path)
{
        int state_count;
        int tms = 0;

        state_count = 0;

        tap_state_t cur_state = cmd_queue_cur_state;

        uint8_t seq[16];
        memset(seq, 0, sizeof(seq));
        assert(num_states < (sizeof(seq) * 8));

        while (num_states)
        {
                if (tap_state_transition(cur_state, false) == path[state_count])
                {
                        tms = 0;
                }
                else if (tap_state_transition(cur_state, true) == path[state_count])
                {
                        tms = 1;
                }
                else
                {
                        LOG_ERROR("BUG: %s -> %s isn't a valid TAP transition", tap_state_name(cur_state), tap_state_name(path[state_count]));
                        exit(-1);
                }

                seq[state_count/8] = seq[state_count/8] | (tms << (state_count % 8));

                cur_state = path[state_count];
                state_count++;
                num_states--;
        }

        return interface_add_tms_seq(state_count, seq, cur_state);
}

void embeddedice_write_dcc(struct jtag_tap *tap, int reg_addr, uint8_t *buffer, int little, int count)
{
//      static int const reg_addr = 0x5;
        tap_state_t end_state = jtag_get_end_state();
        if (jtag_tap_next_enabled(jtag_tap_next_enabled(NULL)) == NULL)
        {
                /* better performance via code duplication */
                if (little)
                {
                        int i;
                        for (i = 0; i < count; i++)
                        {
                                shiftValueInner(TAP_DRSHIFT, TAP_DRSHIFT, 32, fast_target_buffer_get_u32(buffer, 1));
                                shiftValueInner(TAP_DRSHIFT, end_state, 6, reg_addr | (1 << 5));
                                buffer += 4;
                        }
                } else
                {
                        int i;
                        for (i = 0; i < count; i++)
                        {
                                shiftValueInner(TAP_DRSHIFT, TAP_DRSHIFT, 32, fast_target_buffer_get_u32(buffer, 0));
                                shiftValueInner(TAP_DRSHIFT, end_state, 6, reg_addr | (1 << 5));
                                buffer += 4;
                        }
                }
        }
        else
        {
                int i;
                for (i = 0; i < count; i++)
                {
                        embeddedice_write_reg_inner(tap, reg_addr, fast_target_buffer_get_u32(buffer, little));
                        buffer += 4;
                }
        }
}



int arm11_run_instr_data_to_core_noack_inner(struct jtag_tap * tap, uint32_t opcode, uint32_t * data, size_t count)
{
#if 0
        int arm11_run_instr_data_to_core_noack_inner_default(struct jtag_tap * tap, uint32_t opcode, uint32_t * data, size_t count);
        return arm11_run_instr_data_to_core_noack_inner_default(tap, opcode, data, count);
#else
        static const int bits[] = {32, 2};
        uint32_t values[] = {0, 0};

        /* FIX!!!!!! the target_write_memory() API started this nasty problem
         * with unaligned uint32_t * pointers... */
        const uint8_t *t = (const uint8_t *)data;


        /* bypass bits before and after */
        int pre_bits = 0;
        int post_bits = 0;

        bool found = false;
        struct jtag_tap *cur_tap, *nextTap;
        for (cur_tap = jtag_tap_next_enabled(NULL); cur_tap!= NULL; cur_tap = nextTap)
        {
                nextTap = jtag_tap_next_enabled(cur_tap);
                if (cur_tap == tap)
                {
                        found = true;
                } else
                {
                        if (found)
                        {
                                post_bits++;
                        } else
                        {
                                pre_bits++;
                        }
                }
        }

        post_bits+=2;


        while (--count > 0)
        {
                shiftValueInner(TAP_DRSHIFT, TAP_DRSHIFT, pre_bits, 0);

                uint32_t value;
                value = *t++;
                value |= (*t++<<8);
                value |= (*t++<<16);
                value |= (*t++<<24);

                shiftValueInner(TAP_DRSHIFT, TAP_DRSHIFT, 32, value);
                shiftValueInner(TAP_DRSHIFT, TAP_DRPAUSE, post_bits, 0);

#if 1
                /* copy & paste from arm11_dbgtap.c */
                //TAP_DREXIT2, TAP_DRUPDATE, TAP_IDLE, TAP_IDLE, TAP_IDLE, TAP_DRSELECT, TAP_DRCAPTURE, TAP_DRSHIFT

                waitIdle();
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28, 1);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28, 1);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28, 0);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28, 0);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28, 0);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28, 1);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28, 0);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x28, 0);
                /* we don't have to wait for the queue to empty here. waitIdle();        */
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x20, TAP_DRSHIFT);
#else
                static const tap_state_t arm11_MOVE_DRPAUSE_IDLE_DRPAUSE_with_delay[] =
                {
                        TAP_DREXIT2, TAP_DRUPDATE, TAP_IDLE, TAP_IDLE, TAP_IDLE, TAP_DRSELECT, TAP_DRCAPTURE, TAP_DRSHIFT
                };

                jtag_add_pathmove(ARRAY_SIZE(arm11_MOVE_DRPAUSE_IDLE_DRPAUSE_with_delay),
                        arm11_MOVE_DRPAUSE_IDLE_DRPAUSE_with_delay);
#endif
        }

        values[0] = *t++;
        values[0] |= (*t++<<8);
        values[0] |= (*t++<<16);
        values[0] |= (*t++<<24);

        /* This will happen on the last iteration updating the current tap state
         * so we don't have to track it during the common code path */
        jtag_add_dr_out(tap,
                2,
                bits,
                values,
                TAP_IDLE);

        return jtag_execute_queue();
#endif
}


static const struct command_registration zy1000_commands[] = {
        {
                .name = "power",
                .handler = handle_power_command,
                .mode = COMMAND_ANY,
                .help = "Turn power switch to target on/off. "
                        "With no arguments, prints status.",
                .usage = "('on'|'off)",
        },
        {
                .name = "zy1000_version",
                .mode = COMMAND_ANY,
                .jim_handler = jim_zy1000_version,
                .help = "Print version info for zy1000.",
                .usage = "['openocd'|'zy1000'|'date'|'time'|'pcb'|'fpga']",
        },
        {
                .name = "powerstatus",
                .mode = COMMAND_ANY,
                .jim_handler = zylinjtag_Jim_Command_powerstatus,
                .help = "Returns power status of target",
        },
#ifdef CYGPKG_HAL_NIOS2
        {
                .name = "updatezy1000firmware",
                .mode = COMMAND_ANY,
                .jim_handler = jim_zy1000_writefirmware,
                .help = "writes firmware to flash",
                /* .usage = "some_string", */
        },
#endif
        COMMAND_REGISTRATION_DONE
};



struct jtag_interface zy1000_interface =
{
        .name = "ZY1000",
        .supported = DEBUG_CAP_TMS_SEQ,
        .execute_queue = NULL,
        .speed = zy1000_speed,
        .commands = zy1000_commands,
        .init = zy1000_init,
        .quit = zy1000_quit,
        .khz = zy1000_khz,
        .speed_div = zy1000_speed_div,
        .power_dropout = zy1000_power_dropout,
        .srst_asserted = zy1000_srst_asserted,
};