mips: load code in buffer mode

[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.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
 ***************************************************************************/

/* This file supports the zy1000 debugger:
 *
 * http://www.ultsol.com/index.php/component/content/article/8/33-zylin-zy1000-jtag-probe
 *
 * 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 <pthread.h>

#include <target/embeddedice.h>
#include <jtag/minidriver.h>
#include <jtag/interface.h>
#include <time.h>
#include <helper/time_support.h>

#include <netinet/tcp.h>

/* Assume we're connecting to a revc w/60MHz clock. */
#define ZYLIN_KHZ 60000

/* The software needs to check if it's in RCLK mode or not */
static bool zy1000_rclk;

static int zy1000_khz(int khz, int *jtag_speed)
{
        if (khz == 0)
                *jtag_speed = 0;
        else {
                int speed;
                /* Round speed up to nearest divisor.
                 *
                 * E.g. 16000kHz
                 * (64000 + 15999) / 16000 = 4
                 * (4 + 1) / 2 = 2
                 * 2 * 2 = 4
                 *
                 * 64000 / 4 = 16000
                 *
                 * E.g. 15999
                 * (64000 + 15998) / 15999 = 5
                 * (5 + 1) / 2 = 3
                 * 3 * 2 = 6
                 *
                 * 64000 / 6 = 10666
                 *
                 */
                speed = (ZYLIN_KHZ + (khz - 1)) / khz;
                speed = (speed + 1) / 2;
                speed *= 2;
                if (speed > 8190) {
                        /* maximum dividend */
                        speed = 8190;
                }
                *jtag_speed = speed;
        }
        return ERROR_OK;
}

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

        return ERROR_OK;
}

static bool readPowerDropout(void)
{
        uint32_t 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)
{
        uint32_t 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;
}

/* Wait for SRST to assert or deassert */
static void waitSRST(bool asserted)
{
        bool first = true;
        long long start = 0;
        long total = 0;
        const char *mode = asserted ? "assert" : "deassert";

        for (;; ) {
                bool srstAsserted = readSRST();
                if ((asserted && srstAsserted) || (!asserted && !srstAsserted)) {
                        if (total > 1)
                                LOG_USER("SRST took %dms to %s", (int)total, mode);
                        break;
                }

                if (first) {
                        first = false;
                        start = timeval_ms();
                }

                total = timeval_ms() - start;

                keep_alive();

                if (total > 5000) {
                        LOG_ERROR("SRST took too long to %s: %dms", mode, (int)total);
                        break;
                }
        }
}

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);

                waitSRST(true);
        }

        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 && ((jtag_get_reset_config() & RESET_TRST_PULLS_SRST) == 0)) ||
                        (!srst && !trst && (jtag_get_reset_config() & RESET_TRST_PULLS_SRST)))
                waitSRST(false);
}

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

        zy1000_rclk = false;

        if (speed == 0) {
                /*0 means RCLK*/
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x10, 0x100);
                zy1000_rclk = true;
                LOG_DEBUG("jtag_speed using RCLK");
        } else {
                if (speed > 8190 || speed < 2) {
                        LOG_USER(
                                "valid ZY1000 jtag_speed=[8190,2]. With divisor is %dkHz / even values between 8190-2, i.e. min %dHz, max %dMHz",
                                ZYLIN_KHZ,
                                (ZYLIN_KHZ * 1000) / 8190,
                                ZYLIN_KHZ / (2 * 1000));
                        return ERROR_COMMAND_SYNTAX_ERROR;
                }

                int khz;
                speed &= ~1;
                zy1000_speed_div(speed, &khz);
                LOG_USER("jtag_speed %d => JTAG clk=%d kHz", speed, khz);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x14, 0x100);
                ZY1000_POKE(ZY1000_JTAG_BASE + 0x1c, speed);
        }
        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_COMMAND_SYNTAX_ERROR;
        }

        return ERROR_OK;
}

#if !BUILD_ZY1000_MASTER
static char *tcp_server = "notspecified";
static int jim_zy1000_server(Jim_Interp *interp, int argc, Jim_Obj * const *argv)
{
        if (argc != 2)
                return JIM_ERR;

        tcp_server = strdup(Jim_GetString(argv[1], NULL));

        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;
        }

        bool dropout = readPowerDropout();

        Jim_SetResult(interp, Jim_NewIntObj(interp, dropout));

        return JIM_OK;
}

int zy1000_quit(void)
{

        return ERROR_OK;
}

int interface_jtag_execute_queue(void)
{
        uint32_t empty;

        waitIdle();

        /* We must make sure to write data read back to memory location before we return
         * from this fn
         */
        zy1000_flush_readqueue();

        /* and handle any callbacks... */
        zy1000_flush_callbackqueue();

        if (zy1000_rclk) {
                /* Only check for errors when using RCLK to speed up
                 * jtag over TCP/IP
                 */
                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 void writeShiftValue(uint8_t *data, int bits);

/* here we shuffle N bits out/in */
static inline void scanBits(const uint8_t *out_value,
        uint8_t *in_value,
        int num_bits,
        bool pause_now,
        tap_state_t shiftState,
        tap_state_t end_state)
{
        tap_state_t pause_state = shiftState;
        for (int j = 0; j < num_bits; j += 32) {
                int k = num_bits - j;
                if (k > 32) {
                        k = 32;
                        /* we have more to shift out */
                } else if (pause_now) {
                        /* this was the last to shift out this time */
                        pause_state = end_state;
                }

                /* we have (num_bits + 7)/8 bytes of bits to toggle out. */
                /* bits are pushed out LSB to MSB */
                uint32_t value;
                value = 0;
                if (out_value != NULL) {
                        for (int l = 0; l < k; l += 8)
                                value |= 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 (in_value != NULL)
                        writeShiftValue(in_value + (j/8), k);
        }
}

static inline void scanFields(int num_fields,
        const struct scan_field *fields,
        tap_state_t shiftState,
        tap_state_t end_state)
{
        for (int i = 0; i < num_fields; i++) {
                scanBits(fields[i].out_value,
                        fields[i].in_value,
                        fields[i].num_bits,
                        (i == num_fields-1),
                        shiftState,
                        end_state);
        }
}

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;
        tap_state_t pause_state = TAP_IRSHIFT;

        for (tap = jtag_tap_next_enabled(NULL); tap != NULL; tap = nextTap) {
                nextTap = jtag_tap_next_enabled(tap);
                if (nextTap == NULL)
                        pause_state = state;
                scan_size = tap->ir_length;

                /* search the list */
                if (tap == active) {
                        scanFields(1, fields, TAP_IRSHIFT, pause_state);
                        /* 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_state, scan_size, 0xffffffff);

                        /* Optimization code will check what the cur_instr is set to, so
                         * we must set it to bypass value.
                         */
                        buf_set_ones(tap->cur_instr, tap->ir_length);

                        tap->bypass = 1;
                }
        }

        return ERROR_OK;
}

int interface_jtag_add_plain_ir_scan(int num_bits,
        const uint8_t *out_bits,
        uint8_t *in_bits,
        tap_state_t state)
{
        scanBits(out_bits, in_bits, num_bits, true, TAP_IRSHIFT, 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;
        tap_state_t pause_state = TAP_DRSHIFT;
        for (tap = jtag_tap_next_enabled(NULL); tap != NULL; tap = nextTap) {
                nextTap = jtag_tap_next_enabled(tap);
                if (nextTap == NULL)
                        pause_state = state;

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

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

int interface_jtag_add_plain_dr_scan(int num_bits,
        const uint8_t *out_bits,
        uint8_t *in_bits,
        tap_state_t state)
{
        scanBits(out_bits, in_bits, num_bits, true, TAP_DRSHIFT, 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_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 < (int)((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);
}

static void jtag_pre_post_bits(struct jtag_tap *tap, int *pre, int *post)
{
        /* 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++;
                }
        }
        *pre = pre_bits;
        *post = post_bits;
}

void embeddedice_write_dcc(struct jtag_tap *tap,
        int reg_addr,
        const uint8_t *buffer,
        int little,
        int count)
{
#if 0
        int i;
        for (i = 0; i < count; i++) {
                embeddedice_write_reg_inner(tap, reg_addr, fast_target_buffer_get_u32(buffer,
                                little));
                buffer += 4;
        }
#else
        int pre_bits;
        int post_bits;
        jtag_pre_post_bits(tap, &pre_bits, &post_bits);

        if ((pre_bits > 32) || (post_bits + 6 > 32)) {
                int i;
                for (i = 0; i < count; i++) {
                        embeddedice_write_reg_inner(tap, reg_addr,
                                fast_target_buffer_get_u32(buffer, little));
                        buffer += 4;
                }
        } else {
                int i;
                for (i = 0; i < count; i++) {
                        /* Fewer pokes means we get to use the FIFO more efficiently */
                        shiftValueInner(TAP_DRSHIFT, TAP_DRSHIFT, pre_bits, 0);
                        shiftValueInner(TAP_DRSHIFT, TAP_DRSHIFT, 32,
                                fast_target_buffer_get_u32(buffer, little));
                        /* Danger! here we need to exit into the TAP_IDLE state to make
                         * DCC pick up this value.
                         */
                        shiftValueInner(TAP_DRSHIFT, TAP_IDLE, 6 + post_bits,
                                (reg_addr | (1 << 5)));
                        buffer += 4;
                }
        }
#endif
}

int arm11_run_instr_data_to_core_noack_inner(struct jtag_tap *tap,
        uint32_t opcode,
        const uint32_t *data,
        size_t count)
{
        /* bypass bits before and after */
        int pre_bits;
        int post_bits;
        jtag_pre_post_bits(tap, &pre_bits, &post_bits);
        post_bits += 2;

        if ((pre_bits > 32) || (post_bits > 32)) {
                int arm11_run_instr_data_to_core_noack_inner_default(struct jtag_tap *,
                                uint32_t, const uint32_t *, size_t);
                return arm11_run_instr_data_to_core_noack_inner_default(tap, opcode, data, count);
        } else {
                static const uint8_t zero;

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

                while (--count > 0) {
#if 1
                        /* Danger! This code doesn't update cmd_queue_cur_state, so
                         * invoking jtag_add_pathmove() before jtag_add_dr_scan() after
                         * this loop would fail!
                         */
                        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);
                        /* minimum 2 bits */
                        shiftValueInner(TAP_DRSHIFT, TAP_DRPAUSE, post_bits, 0);

                        /* copy & paste from arm11_dbgtap.c */
                        /* TAP_DREXIT2, TAP_DRUPDATE, TAP_IDLE, TAP_IDLE, TAP_IDLE, TAP_DRSELECT,
                         * TAP_DRCAPTURE, TAP_DRSHIFT */
                        /* KLUDGE! we have to flush the fifo or the Nios CPU locks up.
                         * This is probably a bug in the Avalon bus(cross clocking bridge?)
                         * or in the jtag registers module.
                         */
                        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 */
                        ZY1000_POKE(ZY1000_JTAG_BASE + 0x20, TAP_DRSHIFT);
                        waitIdle();
#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
                        };

                        struct scan_field fields[2] = {
                                        { .num_bits = 32, .out_value = t },
                                        { .num_bits = 2, .out_value = &zero },
                        };
                        t += 4;

                        jtag_add_dr_scan(tap,
                                2,
                                fields,
                                TAP_IDLE);

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

                struct scan_field fields[2] = {
                                { .num_bits = 32, .out_value = t },
                                { .num_bits = 2, .out_value = &zero },
                };

                /* This will happen on the last iteration updating cmd_queue_cur_state
                 * so we don't have to track it during the common code path
                 */
                jtag_add_dr_scan(tap,
                        2,
                        fields,
                        TAP_IDLE);

                return jtag_execute_queue();
        }
}

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)",
        },
#if !BUILD_ZY1000_MASTER
        {
                .name = "zy1000_server",
                .mode = COMMAND_ANY,
                .jim_handler = jim_zy1000_server,
                .help = "Tcpip address for ZY1000 server.",
                .usage = "address",
        },
#endif
        {
                .name = "powerstatus",
                .mode = COMMAND_ANY,
                .jim_handler = zylinjtag_Jim_Command_powerstatus,
                .help = "Returns power status of target",
        },
        COMMAND_REGISTRATION_DONE
};

#if !BUILD_ZY1000_MASTER

static int tcp_ip = -1;

/* Write large packets if we can */
static size_t out_pos;
static uint8_t out_buffer[16384];
static size_t in_pos;
static size_t in_write;
static uint8_t in_buffer[16384];

static bool flush_writes(void)
{
        bool ok = (write(tcp_ip, out_buffer, out_pos) == (int)out_pos);
        out_pos = 0;
        return ok;
}

static bool writeLong(uint32_t l)
{
        int i;
        for (i = 0; i < 4; i++) {
                uint8_t c = (l >> (i*8))&0xff;
                out_buffer[out_pos++] = c;
                if (out_pos >= sizeof(out_buffer)) {
                        if (!flush_writes())
                                return false;
                }
        }
        return true;
}

static bool readLong(uint32_t *out_data)
{
        uint32_t data = 0;
        int i;
        for (i = 0; i < 4; i++) {
                uint8_t c;
                if (in_pos == in_write) {
                        /* If we have some data that we can send, send them before
                         * we wait for more data
                         */
                        if (out_pos > 0) {
                                if (!flush_writes())
                                        return false;
                        }

                        /* read more */
                        int t;
                        t = read(tcp_ip, in_buffer, sizeof(in_buffer));
                        if (t < 1)
                                return false;
                        in_write = (size_t) t;
                        in_pos = 0;
                }
                c = in_buffer[in_pos++];

                data |= (c << (i*8));
        }
        *out_data = data;
        return true;
}

enum ZY1000_CMD {
        ZY1000_CMD_POKE = 0x0,
        ZY1000_CMD_PEEK = 0x8,
        ZY1000_CMD_SLEEP = 0x1,
        ZY1000_CMD_WAITIDLE = 2
};

#include <sys/socket.h> /* for socket(), connect(), send(), and recv() */
#include <arpa/inet.h>  /* for sockaddr_in and inet_addr() */

/* We initialize this late since we need to know the server address
 * first.
 */
static void tcpip_open(void)
{
        if (tcp_ip >= 0)
                return;

        struct sockaddr_in echoServAddr;/* Echo server address */

        /* Create a reliable, stream socket using TCP */
        tcp_ip = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
        if (tcp_ip < 0) {
                fprintf(stderr, "Failed to connect to zy1000 server\n");
                exit(-1);
        }

        /* Construct the server address structure */
        memset(&echoServAddr, 0, sizeof(echoServAddr)); /* Zero out structure */
        echoServAddr.sin_family = AF_INET;      /* Internet address family */
        echoServAddr.sin_addr.s_addr = inet_addr(tcp_server);   /* Server IP address */
        echoServAddr.sin_port = htons(7777);    /* Server port */

        /* Establish the connection to the echo server */
        if (connect(tcp_ip, (struct sockaddr *) &echoServAddr, sizeof(echoServAddr)) < 0) {
                fprintf(stderr, "Failed to connect to zy1000 server\n");
                exit(-1);
        }

        int flag = 1;
        setsockopt(tcp_ip,      /* socket affected */
                IPPROTO_TCP,                    /* set option at TCP level */
                TCP_NODELAY,                    /* name of option */
                (char *)&flag,                  /* the cast is historical cruft */
                sizeof(int));                   /* length of option value */

}

/* send a poke */
void zy1000_tcpout(uint32_t address, uint32_t data)
{
        tcpip_open();
        if (!writeLong((ZY1000_CMD_POKE << 24) | address) || !writeLong(data)) {
                fprintf(stderr, "Could not write to zy1000 server\n");
                exit(-1);
        }
}

/* By sending the wait to the server, we avoid a readback
 * of status. Radically improves performance for this operation
 * with long ping times.
 */
void waitIdle(void)
{
        tcpip_open();
        if (!writeLong((ZY1000_CMD_WAITIDLE << 24))) {
                fprintf(stderr, "Could not write to zy1000 server\n");
                exit(-1);
        }
}

uint32_t zy1000_tcpin(uint32_t address)
{
        tcpip_open();

        zy1000_flush_readqueue();

        uint32_t data;
        if (!writeLong((ZY1000_CMD_PEEK << 24) | address) || !readLong(&data)) {
                fprintf(stderr, "Could not read from zy1000 server\n");
                exit(-1);
        }
        return data;
}

int interface_jtag_add_sleep(uint32_t us)
{
        tcpip_open();
        if (!writeLong((ZY1000_CMD_SLEEP << 24)) || !writeLong(us)) {
                fprintf(stderr, "Could not read from zy1000 server\n");
                exit(-1);
        }
        return ERROR_OK;
}

/* queue a readback */
#define readqueue_size 16384
static struct {
        uint8_t *dest;
        int bits;
} readqueue[readqueue_size];

static int readqueue_pos;

/* flush the readqueue, this means reading any data that
 * we're expecting and store them into the final position
 */
void zy1000_flush_readqueue(void)
{
        if (readqueue_pos == 0) {
                /* simply debugging by allowing easy breakpoints when there
                 * is something to do. */
                return;
        }
        int i;
        tcpip_open();
        for (i = 0; i < readqueue_pos; i++) {
                uint32_t value;
                if (!readLong(&value)) {
                        fprintf(stderr, "Could not read from zy1000 server\n");
                        exit(-1);
                }

                uint8_t *in_value = readqueue[i].dest;
                int k = readqueue[i].bits;

                /* we're shifting in data to MSB, shift data to be aligned for returning the value */
                value >>= 32-k;

                for (int l = 0; l < k; l += 8)
                        in_value[l/8] = (value >> l)&0xff;
        }
        readqueue_pos = 0;
}

/* By queuing the callback's we avoid flushing the
 * read queue until jtag_execute_queue(). This can
 * reduce latency dramatically for cases where
 * callbacks are used extensively.
*/
#define callbackqueue_size 128
static struct callbackentry {
        jtag_callback_t callback;
        jtag_callback_data_t data0;
        jtag_callback_data_t data1;
        jtag_callback_data_t data2;
        jtag_callback_data_t data3;
} callbackqueue[callbackqueue_size];

static int callbackqueue_pos;

void zy1000_jtag_add_callback4(jtag_callback_t callback,
        jtag_callback_data_t data0,
        jtag_callback_data_t data1,
        jtag_callback_data_t data2,
        jtag_callback_data_t data3)
{
        if (callbackqueue_pos >= callbackqueue_size)
                zy1000_flush_callbackqueue();

        callbackqueue[callbackqueue_pos].callback = callback;
        callbackqueue[callbackqueue_pos].data0 = data0;
        callbackqueue[callbackqueue_pos].data1 = data1;
        callbackqueue[callbackqueue_pos].data2 = data2;
        callbackqueue[callbackqueue_pos].data3 = data3;
        callbackqueue_pos++;

        /* KLUDGE!
         * make callbacks synchronous for now as minidriver requires callback
         * to be synchronous.
         *
         * We can get away with making read and writes asynchronous so we
         * don't completely kill performance.
         */
        zy1000_flush_callbackqueue();
}

static int zy1000_jtag_convert_to_callback4(jtag_callback_data_t data0,
        jtag_callback_data_t data1,
        jtag_callback_data_t data2,
        jtag_callback_data_t data3)
{
        ((jtag_callback1_t)data1)(data0);
        return ERROR_OK;
}

void zy1000_jtag_add_callback(jtag_callback1_t callback, jtag_callback_data_t data0)
{
        zy1000_jtag_add_callback4(zy1000_jtag_convert_to_callback4,
                data0,
                (jtag_callback_data_t)callback,
                0,
                0);
}

void zy1000_flush_callbackqueue(void)
{
        /* we have to flush the read queue so we have access to
         the data the callbacks will use
        */
        zy1000_flush_readqueue();
        int i;
        for (i = 0; i < callbackqueue_pos; i++) {
                struct callbackentry *entry = &callbackqueue[i];
                jtag_set_error(entry->callback(entry->data0, entry->data1, entry->data2,
                                entry->data3));
        }
        callbackqueue_pos = 0;
}

static void writeShiftValue(uint8_t *data, int bits)
{
        waitIdle();

        if (!writeLong((ZY1000_CMD_PEEK << 24) | (ZY1000_JTAG_BASE + 0xc))) {
                fprintf(stderr, "Could not read from zy1000 server\n");
                exit(-1);
        }

        if (readqueue_pos >= readqueue_size)
                zy1000_flush_readqueue();

        readqueue[readqueue_pos].dest = data;
        readqueue[readqueue_pos].bits = bits;
        readqueue_pos++;

        /* KLUDGE!!! minidriver requires readqueue to be synchronous */
        zy1000_flush_readqueue();
}

#else

static void writeShiftValue(uint8_t *data, int bits)
{
        uint32_t value;
        waitIdle();
        ZY1000_PEEK(ZY1000_JTAG_BASE + 0xc, value);
        VERBOSE(LOG_INFO("getShiftValue %08x", value));

        /* data in, LSB to MSB */
        /* we're shifting in data to MSB, shift data to be aligned for returning the value */
        value >>= 32 - bits;

        for (int l = 0; l < bits; l += 8)
                data[l/8] = (value >> l)&0xff;
}

#endif

#if BUILD_ZY1000_MASTER

#ifdef WATCHDOG_BASE
/* If we connect to port 8888 we must send a char every 10s or the board resets itself */
static void watchdog_server(cyg_addrword_t data)
{
        int so_reuseaddr_option = 1;

        int fd = socket(AF_INET, SOCK_STREAM, 0);
        if (fd == -1) {
                LOG_ERROR("error creating socket: %s", strerror(errno));
                exit(-1);
        }

        setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (void *) &so_reuseaddr_option,
                sizeof(int));

        struct sockaddr_in sin;
        unsigned int address_size;
        address_size = sizeof(sin);
        memset(&sin, 0, sizeof(sin));
        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = INADDR_ANY;
        sin.sin_port = htons(8888);

        if (bind(fd, (struct sockaddr *) &sin, sizeof(sin)) == -1) {
                LOG_ERROR("couldn't bind to socket: %s", strerror(errno));
                exit(-1);
        }

        if (listen(fd, 1) == -1) {
                LOG_ERROR("couldn't listen on socket: %s", strerror(errno));
                exit(-1);
        }


        for (;; ) {
                int watchdog_ip = accept(fd, (struct sockaddr *) &sin, &address_size);

                /* Start watchdog, must be reset every 10 seconds. */
                HAL_WRITE_UINT32(WATCHDOG_BASE + 4, 4);

                if (watchdog_ip < 0) {
                        LOG_ERROR("couldn't open watchdog socket: %s", strerror(errno));
                        exit(-1);
                }

                int flag = 1;
                setsockopt(watchdog_ip, /* socket affected */
                        IPPROTO_TCP,                    /* set option at TCP level */
                        TCP_NODELAY,                    /* name of option */
                        (char *)&flag,                  /* the cast is historical cruft */
                        sizeof(int));                   /* length of option value */


                char buf;
                for (;; ) {
                        if (read(watchdog_ip, &buf, 1) == 1) {
                                /* Reset timer */
                                HAL_WRITE_UINT32(WATCHDOG_BASE + 8, 0x1234);
                                /* Echo so we can telnet in and see that resetting works */
                                write(watchdog_ip, &buf, 1);
                        } else {
                                /* Stop tickling the watchdog, the CPU will reset in < 10 seconds
                                 * now.
                                 */
                                return;
                        }

                }

                /* Never reached */
        }
}
#endif

#endif

#if BUILD_ZY1000_MASTER
int interface_jtag_add_sleep(uint32_t us)
{
        jtag_sleep(us);
        return ERROR_OK;
}
#endif

#if BUILD_ZY1000_MASTER
volatile void *zy1000_jtag_master;
#include <sys/mman.h>
#endif

int zy1000_init(void)
{
#if BUILD_ZY1000_MASTER
        int fd = open("/dev/mem", O_RDWR | O_SYNC);
        if (fd == -1) {
                LOG_ERROR("No access to /dev/mem");
                return ERROR_FAIL;
        }
#ifndef REGISTERS_BASE
#define REGISTERS_BASE 0x9002000
#define REGISTERS_SPAN 128
#endif

        zy1000_jtag_master = mmap(0,
                        REGISTERS_SPAN,
                        PROT_READ | PROT_WRITE,
                        MAP_SHARED,
                        fd,
                        REGISTERS_BASE);

        if (zy1000_jtag_master == (void *) -1) {
                close(fd);
                LOG_ERROR("No access to /dev/mem");
                return ERROR_FAIL;
        }
#endif

        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);

        return ERROR_OK;
}

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,
};