adi_v5_swd: Improve SWD support

[openocd.git] / src / target / arm_adi_v5.c

/***************************************************************************
 *   Copyright (C) 2006 by Magnus Lundin                                   *
 *   lundin@mlu.mine.nu                                                    *
 *                                                                         *
 *   Copyright (C) 2008 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 *                                                                         *
 *   Copyright (C) 2009-2010 by Oyvind Harboe                              *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2009-2010 by David Brownell                             *
 *                                                                         *
 *   Copyright (C) 2013 by Andreas Fritiofson                              *
 *   andreas.fritiofson@gmail.com                                          *
 *                                                                         *
 *   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.           *
 ***************************************************************************/

/**
 * @file
 * This file implements support for the ARM Debug Interface version 5 (ADIv5)
 * debugging architecture.  Compared with previous versions, this includes
 * a low pin-count Serial Wire Debug (SWD) alternative to JTAG for message
 * transport, and focusses on memory mapped resources as defined by the
 * CoreSight architecture.
 *
 * A key concept in ADIv5 is the Debug Access Port, or DAP.  A DAP has two
 * basic components:  a Debug Port (DP) transporting messages to and from a
 * debugger, and an Access Port (AP) accessing resources.  Three types of DP
 * are defined.  One uses only JTAG for communication, and is called JTAG-DP.
 * One uses only SWD for communication, and is called SW-DP.  The third can
 * use either SWD or JTAG, and is called SWJ-DP.  The most common type of AP
 * is used to access memory mapped resources and is called a MEM-AP.  Also a
 * JTAG-AP is also defined, bridging to JTAG resources; those are uncommon.
 *
 * This programming interface allows DAP pipelined operations through a
 * transaction queue.  This primarily affects AP operations (such as using
 * a MEM-AP to access memory or registers).  If the current transaction has
 * not finished by the time the next one must begin, and the ORUNDETECT bit
 * is set in the DP_CTRL_STAT register, the SSTICKYORUN status is set and
 * further AP operations will fail.  There are two basic methods to avoid
 * such overrun errors.  One involves polling for status instead of using
 * transaction piplining.  The other involves adding delays to ensure the
 * AP has enough time to complete one operation before starting the next
 * one.  (For JTAG these delays are controlled by memaccess_tck.)
 */

/*
 * Relevant specifications from ARM include:
 *
 * ARM(tm) Debug Interface v5 Architecture Specification    ARM IHI 0031A
 * CoreSight(tm) v1.0 Architecture Specification            ARM IHI 0029B
 *
 * CoreSight(tm) DAP-Lite TRM, ARM DDI 0316D
 * Cortex-M3(tm) TRM, ARM DDI 0337G
 */

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

#include "jtag/interface.h"
#include "arm.h"
#include "arm_adi_v5.h"
#include <helper/time_support.h>

/* ARM ADI Specification requires at least 10 bits used for TAR autoincrement  */

/*
        uint32_t tar_block_size(uint32_t address)
        Return the largest block starting at address that does not cross a tar block size alignment boundary
*/
static uint32_t max_tar_block_size(uint32_t tar_autoincr_block, uint32_t address)
{
        return tar_autoincr_block - ((tar_autoincr_block - 1) & address);
}

/***************************************************************************
 *                                                                         *
 * DP and MEM-AP  register access  through APACC and DPACC                 *
 *                                                                         *
***************************************************************************/

/**
 * Select one of the APs connected to the specified DAP.  The
 * selection is implicitly used with future AP transactions.
 * This is a NOP if the specified AP is already selected.
 *
 * @param dap The DAP
 * @param apsel Number of the AP to (implicitly) use with further
 *      transactions.  This normally identifies a MEM-AP.
 */
void dap_ap_select(struct adiv5_dap *dap, uint8_t ap)
{
        uint32_t new_ap = (ap << 24) & 0xFF000000;

        if (new_ap != dap->ap_current) {
                dap->ap_current = new_ap;
                /* Switching AP invalidates cached values.
                 * Values MUST BE UPDATED BEFORE AP ACCESS.
                 */
                dap->ap_bank_value = -1;
                dap->ap_csw_value = -1;
                dap->ap_tar_value = -1;
        }
}

static int dap_setup_accessport_csw(struct adiv5_dap *dap, uint32_t csw)
{
        csw = csw | CSW_DBGSWENABLE | CSW_MASTER_DEBUG | CSW_HPROT |
                dap->apcsw[dap->ap_current >> 24];

        if (csw != dap->ap_csw_value) {
                /* LOG_DEBUG("DAP: Set CSW %x",csw); */
                int retval = dap_queue_ap_write(dap, AP_REG_CSW, csw);
                if (retval != ERROR_OK)
                        return retval;
                dap->ap_csw_value = csw;
        }
        return ERROR_OK;
}

static int dap_setup_accessport_tar(struct adiv5_dap *dap, uint32_t tar)
{
        if (tar != dap->ap_tar_value || dap->ap_csw_value & CSW_ADDRINC_MASK) {
                /* LOG_DEBUG("DAP: Set TAR %x",tar); */
                int retval = dap_queue_ap_write(dap, AP_REG_TAR, tar);
                if (retval != ERROR_OK)
                        return retval;
                dap->ap_tar_value = tar;
        }
        return ERROR_OK;
}

/**
 * Queue transactions setting up transfer parameters for the
 * currently selected MEM-AP.
 *
 * Subsequent transfers using registers like AP_REG_DRW or AP_REG_BD2
 * initiate data reads or writes using memory or peripheral addresses.
 * If the CSW is configured for it, the TAR may be automatically
 * incremented after each transfer.
 *
 * @todo Rename to reflect it being specifically a MEM-AP function.
 *
 * @param dap The DAP connected to the MEM-AP.
 * @param csw MEM-AP Control/Status Word (CSW) register to assign.  If this
 *      matches the cached value, the register is not changed.
 * @param tar MEM-AP Transfer Address Register (TAR) to assign.  If this
 *      matches the cached address, the register is not changed.
 *
 * @return ERROR_OK if the transaction was properly queued, else a fault code.
 */
int dap_setup_accessport(struct adiv5_dap *dap, uint32_t csw, uint32_t tar)
{
        int retval;
        retval = dap_setup_accessport_csw(dap, csw);
        if (retval != ERROR_OK)
                return retval;
        retval = dap_setup_accessport_tar(dap, tar);
        if (retval != ERROR_OK)
                return retval;
        return ERROR_OK;
}

/**
 * Asynchronous (queued) read of a word from memory or a system register.
 *
 * @param dap The DAP connected to the MEM-AP performing the read.
 * @param address Address of the 32-bit word to read; it must be
 *      readable by the currently selected MEM-AP.
 * @param value points to where the word will be stored when the
 *      transaction queue is flushed (assuming no errors).
 *
 * @return ERROR_OK for success.  Otherwise a fault code.
 */
int mem_ap_read_u32(struct adiv5_dap *dap, uint32_t address,
                uint32_t *value)
{
        int retval;

        /* Use banked addressing (REG_BDx) to avoid some link traffic
         * (updating TAR) when reading several consecutive addresses.
         */
        retval = dap_setup_accessport(dap, CSW_32BIT | CSW_ADDRINC_OFF,
                        address & 0xFFFFFFF0);
        if (retval != ERROR_OK)
                return retval;

        return dap_queue_ap_read(dap, AP_REG_BD0 | (address & 0xC), value);
}

/**
 * Synchronous read of a word from memory or a system register.
 * As a side effect, this flushes any queued transactions.
 *
 * @param dap The DAP connected to the MEM-AP performing the read.
 * @param address Address of the 32-bit word to read; it must be
 *      readable by the currently selected MEM-AP.
 * @param value points to where the result will be stored.
 *
 * @return ERROR_OK for success; *value holds the result.
 * Otherwise a fault code.
 */
int mem_ap_read_atomic_u32(struct adiv5_dap *dap, uint32_t address,
                uint32_t *value)
{
        int retval;

        retval = mem_ap_read_u32(dap, address, value);
        if (retval != ERROR_OK)
                return retval;

        return dap_run(dap);
}

/**
 * Asynchronous (queued) write of a word to memory or a system register.
 *
 * @param dap The DAP connected to the MEM-AP.
 * @param address Address to be written; it must be writable by
 *      the currently selected MEM-AP.
 * @param value Word that will be written to the address when transaction
 *      queue is flushed (assuming no errors).
 *
 * @return ERROR_OK for success.  Otherwise a fault code.
 */
int mem_ap_write_u32(struct adiv5_dap *dap, uint32_t address,
                uint32_t value)
{
        int retval;

        /* Use banked addressing (REG_BDx) to avoid some link traffic
         * (updating TAR) when writing several consecutive addresses.
         */
        retval = dap_setup_accessport(dap, CSW_32BIT | CSW_ADDRINC_OFF,
                        address & 0xFFFFFFF0);
        if (retval != ERROR_OK)
                return retval;

        return dap_queue_ap_write(dap, AP_REG_BD0 | (address & 0xC),
                        value);
}

/**
 * Synchronous write of a word to memory or a system register.
 * As a side effect, this flushes any queued transactions.
 *
 * @param dap The DAP connected to the MEM-AP.
 * @param address Address to be written; it must be writable by
 *      the currently selected MEM-AP.
 * @param value Word that will be written.
 *
 * @return ERROR_OK for success; the data was written.  Otherwise a fault code.
 */
int mem_ap_write_atomic_u32(struct adiv5_dap *dap, uint32_t address,
                uint32_t value)
{
        int retval = mem_ap_write_u32(dap, address, value);

        if (retval != ERROR_OK)
                return retval;

        return dap_run(dap);
}

/**
 * Synchronous write of a block of memory, using a specific access size.
 *
 * @param dap The DAP connected to the MEM-AP.
 * @param buffer The data buffer to write. No particular alignment is assumed.
 * @param size Which access size to use, in bytes. 1, 2 or 4.
 * @param count The number of writes to do (in size units, not bytes).
 * @param address Address to be written; it must be writable by the currently selected MEM-AP.
 * @param addrinc Whether the target address should be increased for each write or not. This
 *  should normally be true, except when writing to e.g. a FIFO.
 * @return ERROR_OK on success, otherwise an error code.
 */
int mem_ap_write(struct adiv5_dap *dap, const uint8_t *buffer, uint32_t size, uint32_t count,
                uint32_t address, bool addrinc)
{
        size_t nbytes = size * count;
        const uint32_t csw_addrincr = addrinc ? CSW_ADDRINC_SINGLE : CSW_ADDRINC_OFF;
        uint32_t csw_size;
        uint32_t addr_xor;
        int retval;

        /* TI BE-32 Quirks mode:
         * Writes on big-endian TMS570 behave very strangely. Observed behavior:
         *   size   write address   bytes written in order
         *   4      TAR ^ 0         (val >> 24), (val >> 16), (val >> 8), (val)
         *   2      TAR ^ 2         (val >> 8), (val)
         *   1      TAR ^ 3         (val)
         * For example, if you attempt to write a single byte to address 0, the processor
         * will actually write a byte to address 3.
         *
         * To make writes of size < 4 work as expected, we xor a value with the address before
         * setting the TAP, and we set the TAP after every transfer rather then relying on
         * address increment. */

        if (size == 4) {
                csw_size = CSW_32BIT;
                addr_xor = 0;
        } else if (size == 2) {
                csw_size = CSW_16BIT;
                addr_xor = dap->ti_be_32_quirks ? 2 : 0;
        } else if (size == 1) {
                csw_size = CSW_8BIT;
                addr_xor = dap->ti_be_32_quirks ? 3 : 0;
        } else {
                return ERROR_TARGET_UNALIGNED_ACCESS;
        }

        if (dap->unaligned_access_bad && (address % size != 0))
                return ERROR_TARGET_UNALIGNED_ACCESS;

        retval = dap_setup_accessport_tar(dap, address ^ addr_xor);
        if (retval != ERROR_OK)
                return retval;

        while (nbytes > 0) {
                uint32_t this_size = size;

                /* Select packed transfer if possible */
                if (addrinc && dap->packed_transfers && nbytes >= 4
                                && max_tar_block_size(dap->tar_autoincr_block, address) >= 4) {
                        this_size = 4;
                        retval = dap_setup_accessport_csw(dap, csw_size | CSW_ADDRINC_PACKED);
                } else {
                        retval = dap_setup_accessport_csw(dap, csw_size | csw_addrincr);
                }

                if (retval != ERROR_OK)
                        break;

                /* How many source bytes each transfer will consume, and their location in the DRW,
                 * depends on the type of transfer and alignment. See ARM document IHI0031C. */
                uint32_t outvalue = 0;
                if (dap->ti_be_32_quirks) {
                        switch (this_size) {
                        case 4:
                                outvalue |= (uint32_t)*buffer++ << 8 * (3 ^ (address++ & 3) ^ addr_xor);
                                outvalue |= (uint32_t)*buffer++ << 8 * (3 ^ (address++ & 3) ^ addr_xor);
                                outvalue |= (uint32_t)*buffer++ << 8 * (3 ^ (address++ & 3) ^ addr_xor);
                                outvalue |= (uint32_t)*buffer++ << 8 * (3 ^ (address++ & 3) ^ addr_xor);
                                break;
                        case 2:
                                outvalue |= (uint32_t)*buffer++ << 8 * (1 ^ (address++ & 3) ^ addr_xor);
                                outvalue |= (uint32_t)*buffer++ << 8 * (1 ^ (address++ & 3) ^ addr_xor);
                                break;
                        case 1:
                                outvalue |= (uint32_t)*buffer++ << 8 * (0 ^ (address++ & 3) ^ addr_xor);
                                break;
                        }
                } else {
                        switch (this_size) {
                        case 4:
                                outvalue |= (uint32_t)*buffer++ << 8 * (address++ & 3);
                                outvalue |= (uint32_t)*buffer++ << 8 * (address++ & 3);
                        case 2:
                                outvalue |= (uint32_t)*buffer++ << 8 * (address++ & 3);
                        case 1:
                                outvalue |= (uint32_t)*buffer++ << 8 * (address++ & 3);
                        }
                }

                nbytes -= this_size;

                retval = dap_queue_ap_write(dap, AP_REG_DRW, outvalue);
                if (retval != ERROR_OK)
                        break;

                /* Rewrite TAR if it wrapped or we're xoring addresses */
                if (addrinc && (addr_xor || (address % dap->tar_autoincr_block < size && nbytes > 0))) {
                        retval = dap_setup_accessport_tar(dap, address ^ addr_xor);
                        if (retval != ERROR_OK)
                                break;
                }
        }

        /* REVISIT: Might want to have a queued version of this function that does not run. */
        if (retval == ERROR_OK)
                retval = dap_run(dap);

        if (retval != ERROR_OK) {
                uint32_t tar;
                if (dap_queue_ap_read(dap, AP_REG_TAR, &tar) == ERROR_OK
                                && dap_run(dap) == ERROR_OK)
                        LOG_ERROR("Failed to write memory at 0x%08"PRIx32, tar);
                else
                        LOG_ERROR("Failed to write memory and, additionally, failed to find out where");
        }

        return retval;
}

/**
 * Synchronous read of a block of memory, using a specific access size.
 *
 * @param dap The DAP connected to the MEM-AP.
 * @param buffer The data buffer to receive the data. No particular alignment is assumed.
 * @param size Which access size to use, in bytes. 1, 2 or 4.
 * @param count The number of reads to do (in size units, not bytes).
 * @param address Address to be read; it must be readable by the currently selected MEM-AP.
 * @param addrinc Whether the target address should be increased after each read or not. This
 *  should normally be true, except when reading from e.g. a FIFO.
 * @return ERROR_OK on success, otherwise an error code.
 */
int mem_ap_read(struct adiv5_dap *dap, uint8_t *buffer, uint32_t size, uint32_t count,
                uint32_t adr, bool addrinc)
{
        size_t nbytes = size * count;
        const uint32_t csw_addrincr = addrinc ? CSW_ADDRINC_SINGLE : CSW_ADDRINC_OFF;
        uint32_t csw_size;
        uint32_t address = adr;
        int retval;

        /* TI BE-32 Quirks mode:
         * Reads on big-endian TMS570 behave strangely differently than writes.
         * They read from the physical address requested, but with DRW byte-reversed.
         * For example, a byte read from address 0 will place the result in the high bytes of DRW.
         * Also, packed 8-bit and 16-bit transfers seem to sometimes return garbage in some bytes,
         * so avoid them. */

        if (size == 4)
                csw_size = CSW_32BIT;
        else if (size == 2)
                csw_size = CSW_16BIT;
        else if (size == 1)
                csw_size = CSW_8BIT;
        else
                return ERROR_TARGET_UNALIGNED_ACCESS;

        if (dap->unaligned_access_bad && (adr % size != 0))
                return ERROR_TARGET_UNALIGNED_ACCESS;

        /* Allocate buffer to hold the sequence of DRW reads that will be made. This is a significant
         * over-allocation if packed transfers are going to be used, but determining the real need at
         * this point would be messy. */
        uint32_t *read_buf = malloc(count * sizeof(uint32_t));
        uint32_t *read_ptr = read_buf;
        if (read_buf == NULL) {
                LOG_ERROR("Failed to allocate read buffer");
                return ERROR_FAIL;
        }

        retval = dap_setup_accessport_tar(dap, address);
        if (retval != ERROR_OK) {
                free(read_buf);
                return retval;
        }

        /* Queue up all reads. Each read will store the entire DRW word in the read buffer. How many
         * useful bytes it contains, and their location in the word, depends on the type of transfer
         * and alignment. */
        while (nbytes > 0) {
                uint32_t this_size = size;

                /* Select packed transfer if possible */
                if (addrinc && dap->packed_transfers && nbytes >= 4
                                && max_tar_block_size(dap->tar_autoincr_block, address) >= 4) {
                        this_size = 4;
                        retval = dap_setup_accessport_csw(dap, csw_size | CSW_ADDRINC_PACKED);
                } else {
                        retval = dap_setup_accessport_csw(dap, csw_size | csw_addrincr);
                }
                if (retval != ERROR_OK)
                        break;

                retval = dap_queue_ap_read(dap, AP_REG_DRW, read_ptr++);
                if (retval != ERROR_OK)
                        break;

                nbytes -= this_size;
                address += this_size;

                /* Rewrite TAR if it wrapped */
                if (addrinc && address % dap->tar_autoincr_block < size && nbytes > 0) {
                        retval = dap_setup_accessport_tar(dap, address);
                        if (retval != ERROR_OK)
                                break;
                }
        }

        if (retval == ERROR_OK)
                retval = dap_run(dap);

        /* Restore state */
        address = adr;
        nbytes = size * count;
        read_ptr = read_buf;

        /* If something failed, read TAR to find out how much data was successfully read, so we can
         * at least give the caller what we have. */
        if (retval != ERROR_OK) {
                uint32_t tar;
                if (dap_queue_ap_read(dap, AP_REG_TAR, &tar) == ERROR_OK
                                && dap_run(dap) == ERROR_OK) {
                        LOG_ERROR("Failed to read memory at 0x%08"PRIx32, tar);
                        if (nbytes > tar - address)
                                nbytes = tar - address;
                } else {
                        LOG_ERROR("Failed to read memory and, additionally, failed to find out where");
                        nbytes = 0;
                }
        }

        /* Replay loop to populate caller's buffer from the correct word and byte lane */
        while (nbytes > 0) {
                uint32_t this_size = size;

                if (addrinc && dap->packed_transfers && nbytes >= 4
                                && max_tar_block_size(dap->tar_autoincr_block, address) >= 4) {
                        this_size = 4;
                }

                if (dap->ti_be_32_quirks) {
                        switch (this_size) {
                        case 4:
                                *buffer++ = *read_ptr >> 8 * (3 - (address++ & 3));
                                *buffer++ = *read_ptr >> 8 * (3 - (address++ & 3));
                        case 2:
                                *buffer++ = *read_ptr >> 8 * (3 - (address++ & 3));
                        case 1:
                                *buffer++ = *read_ptr >> 8 * (3 - (address++ & 3));
                        }
                } else {
                        switch (this_size) {
                        case 4:
                                *buffer++ = *read_ptr >> 8 * (address++ & 3);
                                *buffer++ = *read_ptr >> 8 * (address++ & 3);
                        case 2:
                                *buffer++ = *read_ptr >> 8 * (address++ & 3);
                        case 1:
                                *buffer++ = *read_ptr >> 8 * (address++ & 3);
                        }
                }

                read_ptr++;
                nbytes -= this_size;
        }

        free(read_buf);
        return retval;
}

/*--------------------------------------------------------------------*/
/*          Wrapping function with selection of AP                    */
/*--------------------------------------------------------------------*/
int mem_ap_sel_read_u32(struct adiv5_dap *swjdp, uint8_t ap,
                uint32_t address, uint32_t *value)
{
        dap_ap_select(swjdp, ap);
        return mem_ap_read_u32(swjdp, address, value);
}

int mem_ap_sel_write_u32(struct adiv5_dap *swjdp, uint8_t ap,
                uint32_t address, uint32_t value)
{
        dap_ap_select(swjdp, ap);
        return mem_ap_write_u32(swjdp, address, value);
}

int mem_ap_sel_read_atomic_u32(struct adiv5_dap *swjdp, uint8_t ap,
                uint32_t address, uint32_t *value)
{
        dap_ap_select(swjdp, ap);
        return mem_ap_read_atomic_u32(swjdp, address, value);
}

int mem_ap_sel_write_atomic_u32(struct adiv5_dap *swjdp, uint8_t ap,
                uint32_t address, uint32_t value)
{
        dap_ap_select(swjdp, ap);
        return mem_ap_write_atomic_u32(swjdp, address, value);
}

int mem_ap_sel_read_buf(struct adiv5_dap *swjdp, uint8_t ap,
                uint8_t *buffer, uint32_t size, uint32_t count, uint32_t address)
{
        dap_ap_select(swjdp, ap);
        return mem_ap_read(swjdp, buffer, size, count, address, true);
}

int mem_ap_sel_write_buf(struct adiv5_dap *swjdp, uint8_t ap,
                const uint8_t *buffer, uint32_t size, uint32_t count, uint32_t address)
{
        dap_ap_select(swjdp, ap);
        return mem_ap_write(swjdp, buffer, size, count, address, true);
}

int mem_ap_sel_read_buf_noincr(struct adiv5_dap *swjdp, uint8_t ap,
                uint8_t *buffer, uint32_t size, uint32_t count, uint32_t address)
{
        dap_ap_select(swjdp, ap);
        return mem_ap_read(swjdp, buffer, size, count, address, false);
}

int mem_ap_sel_write_buf_noincr(struct adiv5_dap *swjdp, uint8_t ap,
                const uint8_t *buffer, uint32_t size, uint32_t count, uint32_t address)
{
        dap_ap_select(swjdp, ap);
        return mem_ap_write(swjdp, buffer, size, count, address, false);
}

/*--------------------------------------------------------------------------*/


#define DAP_POWER_DOMAIN_TIMEOUT (10)

/* FIXME don't import ... just initialize as
 * part of DAP transport setup
*/
extern const struct dap_ops jtag_dp_ops;

/*--------------------------------------------------------------------------*/

/**
 * Initialize a DAP.  This sets up the power domains, prepares the DP
 * for further use, and arranges to use AP #0 for all AP operations
 * until dap_ap-select() changes that policy.
 *
 * @param dap The DAP being initialized.
 *
 * @todo Rename this.  We also need an initialization scheme which account
 * for SWD transports not just JTAG; that will need to address differences
 * in layering.  (JTAG is useful without any debug target; but not SWD.)
 * And this may not even use an AHB-AP ... e.g. DAP-Lite uses an APB-AP.
 */
int ahbap_debugport_init(struct adiv5_dap *dap)
{
        int retval;

        LOG_DEBUG(" ");

        /* JTAG-DP or SWJ-DP, in JTAG mode
         * ... for SWD mode this is patched as part
         * of link switchover
         */
        if (!dap->ops)
                dap->ops = &jtag_dp_ops;

        /* Default MEM-AP setup.
         *
         * REVISIT AP #0 may be an inappropriate default for this.
         * Should we probe, or take a hint from the caller?
         * Presumably we can ignore the possibility of multiple APs.
         */
        dap->ap_current = !0;
        dap_ap_select(dap, 0);

        /* DP initialization */

        dap->dp_bank_value = 0;

        retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
        if (retval != ERROR_OK)
                return retval;

        retval = dap_queue_dp_write(dap, DP_CTRL_STAT, SSTICKYERR);
        if (retval != ERROR_OK)
                return retval;

        retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
        if (retval != ERROR_OK)
                return retval;

        dap->dp_ctrl_stat = CDBGPWRUPREQ | CSYSPWRUPREQ;
        retval = dap_queue_dp_write(dap, DP_CTRL_STAT, dap->dp_ctrl_stat);
        if (retval != ERROR_OK)
                return retval;

        /* Check that we have debug power domains activated */
        LOG_DEBUG("DAP: wait CDBGPWRUPACK");
        retval = dap_dp_poll_register(dap, DP_CTRL_STAT,
                                      CDBGPWRUPACK, CDBGPWRUPACK,
                                      DAP_POWER_DOMAIN_TIMEOUT);
        if (retval != ERROR_OK)
                return retval;

        LOG_DEBUG("DAP: wait CSYSPWRUPACK");
        retval = dap_dp_poll_register(dap, DP_CTRL_STAT,
                                      CSYSPWRUPACK, CSYSPWRUPACK,
                                      DAP_POWER_DOMAIN_TIMEOUT);
        if (retval != ERROR_OK)
                return retval;

        retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
        if (retval != ERROR_OK)
                return retval;
        /* With debug power on we can activate OVERRUN checking */
        dap->dp_ctrl_stat = CDBGPWRUPREQ | CSYSPWRUPREQ | CORUNDETECT;
        retval = dap_queue_dp_write(dap, DP_CTRL_STAT, dap->dp_ctrl_stat);
        if (retval != ERROR_OK)
                return retval;
        retval = dap_queue_dp_read(dap, DP_CTRL_STAT, NULL);
        if (retval != ERROR_OK)
                return retval;

        /* check that we support packed transfers */
        uint32_t csw, cfg;

        retval = dap_setup_accessport(dap, CSW_8BIT | CSW_ADDRINC_PACKED, 0);
        if (retval != ERROR_OK)
                return retval;

        retval = dap_queue_ap_read(dap, AP_REG_CSW, &csw);
        if (retval != ERROR_OK)
                return retval;

        retval = dap_queue_ap_read(dap, AP_REG_CFG, &cfg);
        if (retval != ERROR_OK)
                return retval;

        retval = dap_run(dap);
        if (retval != ERROR_OK)
                return retval;

        if (csw & CSW_ADDRINC_PACKED)
                dap->packed_transfers = true;
        else
                dap->packed_transfers = false;

        /* Packed transfers on TI BE-32 processors do not work correctly in
         * many cases. */
        if (dap->ti_be_32_quirks)
                dap->packed_transfers = false;

        LOG_DEBUG("MEM_AP Packed Transfers: %s",
                        dap->packed_transfers ? "enabled" : "disabled");

        /* The ARM ADI spec leaves implementation-defined whether unaligned
         * memory accesses work, only work partially, or cause a sticky error.
         * On TI BE-32 processors, reads seem to return garbage in some bytes
         * and unaligned writes seem to cause a sticky error.
         * TODO: it would be nice to have a way to detect whether unaligned
         * operations are supported on other processors. */
        dap->unaligned_access_bad = dap->ti_be_32_quirks;

        LOG_DEBUG("MEM_AP CFG: large data %d, long address %d, big-endian %d",
                        !!(cfg & 0x04), !!(cfg & 0x02), !!(cfg & 0x01));

        return ERROR_OK;
}

/* CID interpretation -- see ARM IHI 0029B section 3
 * and ARM IHI 0031A table 13-3.
 */
static const char *class_description[16] = {
        "Reserved", "ROM table", "Reserved", "Reserved",
        "Reserved", "Reserved", "Reserved", "Reserved",
        "Reserved", "CoreSight component", "Reserved", "Peripheral Test Block",
        "Reserved", "OptimoDE DESS",
        "Generic IP component", "PrimeCell or System component"
};

static bool is_dap_cid_ok(uint32_t cid3, uint32_t cid2, uint32_t cid1, uint32_t cid0)
{
        return cid3 == 0xb1 && cid2 == 0x05
                        && ((cid1 & 0x0f) == 0) && cid0 == 0x0d;
}

/*
 * This function checks the ID for each access port to find the requested Access Port type
 */
int dap_find_ap(struct adiv5_dap *dap, enum ap_type type_to_find, uint8_t *ap_num_out)
{
        int ap;

        /* Maximum AP number is 255 since the SELECT register is 8 bits */
        for (ap = 0; ap <= 255; ap++) {

                /* read the IDR register of the Access Port */
                uint32_t id_val = 0;
                dap_ap_select(dap, ap);

                int retval = dap_queue_ap_read(dap, AP_REG_IDR, &id_val);
                if (retval != ERROR_OK)
                        return retval;

                retval = dap_run(dap);

                /* IDR bits:
                 * 31-28 : Revision
                 * 27-24 : JEDEC bank (0x4 for ARM)
                 * 23-17 : JEDEC code (0x3B for ARM)
                 * 16    : Mem-AP
                 * 15-8  : Reserved
                 *  7-0  : AP Identity (1=AHB-AP 2=APB-AP 0x10=JTAG-AP)
                 */

                /* Reading register for a non-existant AP should not cause an error,
                 * but just to be sure, try to continue searching if an error does happen.
                 */
                if ((retval == ERROR_OK) &&                  /* Register read success */
                        ((id_val & 0x0FFF0000) == 0x04770000) && /* Jedec codes match */
                        ((id_val & 0xFF) == type_to_find)) {     /* type matches*/

                        LOG_DEBUG("Found %s at AP index: %d (IDR=0x%08" PRIX32 ")",
                                                (type_to_find == AP_TYPE_AHB_AP)  ? "AHB-AP"  :
                                                (type_to_find == AP_TYPE_APB_AP)  ? "APB-AP"  :
                                                (type_to_find == AP_TYPE_JTAG_AP) ? "JTAG-AP" : "Unknown",
                                                ap, id_val);

                        *ap_num_out = ap;
                        return ERROR_OK;
                }
        }

        LOG_DEBUG("No %s found",
                                (type_to_find == AP_TYPE_AHB_AP)  ? "AHB-AP"  :
                                (type_to_find == AP_TYPE_APB_AP)  ? "APB-AP"  :
                                (type_to_find == AP_TYPE_JTAG_AP) ? "JTAG-AP" : "Unknown");
        return ERROR_FAIL;
}

int dap_get_debugbase(struct adiv5_dap *dap, int ap,
                        uint32_t *out_dbgbase, uint32_t *out_apid)
{
        uint32_t ap_old;
        int retval;
        uint32_t dbgbase, apid;

        /* AP address is in bits 31:24 of DP_SELECT */
        if (ap >= 256)
                return ERROR_COMMAND_SYNTAX_ERROR;

        ap_old = dap->ap_current;
        dap_ap_select(dap, ap);

        retval = dap_queue_ap_read(dap, AP_REG_BASE, &dbgbase);
        if (retval != ERROR_OK)
                return retval;
        retval = dap_queue_ap_read(dap, AP_REG_IDR, &apid);
        if (retval != ERROR_OK)
                return retval;
        retval = dap_run(dap);
        if (retval != ERROR_OK)
                return retval;

        /* Excavate the device ID code */
        struct jtag_tap *tap = dap->jtag_info->tap;
        while (tap != NULL) {
                if (tap->hasidcode)
                        break;
                tap = tap->next_tap;
        }
        if (tap == NULL || !tap->hasidcode)
                return ERROR_OK;

        dap_ap_select(dap, ap_old);

        /* The asignment happens only here to prevent modification of these
         * values before they are certain. */
        *out_dbgbase = dbgbase;
        *out_apid = apid;

        return ERROR_OK;
}

int dap_lookup_cs_component(struct adiv5_dap *dap, int ap,
                        uint32_t dbgbase, uint8_t type, uint32_t *addr)
{
        uint32_t ap_old;
        uint32_t romentry, entry_offset = 0, component_base, devtype;
        int retval = ERROR_FAIL;

        if (ap >= 256)
                return ERROR_COMMAND_SYNTAX_ERROR;

        ap_old = dap->ap_current;
        dap_ap_select(dap, ap);

        do {
                retval = mem_ap_read_atomic_u32(dap, (dbgbase&0xFFFFF000) |
                                                entry_offset, &romentry);
                if (retval != ERROR_OK)
                        return retval;

                component_base = (dbgbase & 0xFFFFF000)
                        + (romentry & 0xFFFFF000);

                if (romentry & 0x1) {
                        retval = mem_ap_read_atomic_u32(dap,
                                        (component_base & 0xfffff000) | 0xfcc,
                                        &devtype);
                        if (retval != ERROR_OK)
                                return retval;
                        if ((devtype & 0xff) == type) {
                                *addr = component_base;
                                retval = ERROR_OK;
                                break;
                        }
                }
                entry_offset += 4;
        } while (romentry > 0);

        dap_ap_select(dap, ap_old);

        return retval;
}

static int dap_rom_display(struct command_context *cmd_ctx,
                                struct adiv5_dap *dap, int ap, uint32_t dbgbase, int depth)
{
        int retval;
        uint32_t cid0, cid1, cid2, cid3, memtype, romentry;
        uint16_t entry_offset;
        char tabs[7] = "";

        if (depth > 16) {
                command_print(cmd_ctx, "\tTables too deep");
                return ERROR_FAIL;
        }

        if (depth)
                snprintf(tabs, sizeof(tabs), "[L%02d] ", depth);

        /* bit 16 of apid indicates a memory access port */
        if (dbgbase & 0x02)
                command_print(cmd_ctx, "\t%sValid ROM table present", tabs);
        else
                command_print(cmd_ctx, "\t%sROM table in legacy format", tabs);

        /* Now we read ROM table ID registers, ref. ARM IHI 0029B sec  */
        retval = mem_ap_read_u32(dap, (dbgbase&0xFFFFF000) | 0xFF0, &cid0);
        if (retval != ERROR_OK)
                return retval;
        retval = mem_ap_read_u32(dap, (dbgbase&0xFFFFF000) | 0xFF4, &cid1);
        if (retval != ERROR_OK)
                return retval;
        retval = mem_ap_read_u32(dap, (dbgbase&0xFFFFF000) | 0xFF8, &cid2);
        if (retval != ERROR_OK)
                return retval;
        retval = mem_ap_read_u32(dap, (dbgbase&0xFFFFF000) | 0xFFC, &cid3);
        if (retval != ERROR_OK)
                return retval;
        retval = mem_ap_read_u32(dap, (dbgbase&0xFFFFF000) | 0xFCC, &memtype);
        if (retval != ERROR_OK)
                return retval;
        retval = dap_run(dap);
        if (retval != ERROR_OK)
                return retval;

        if (!is_dap_cid_ok(cid3, cid2, cid1, cid0))
                command_print(cmd_ctx, "\t%sCID3 0x%02x"
                                ", CID2 0x%02x"
                                ", CID1 0x%02x"
                                ", CID0 0x%02x",
                                tabs,
                                (unsigned)cid3, (unsigned)cid2,
                                (unsigned)cid1, (unsigned)cid0);
        if (memtype & 0x01)
                command_print(cmd_ctx, "\t%sMEMTYPE system memory present on bus", tabs);
        else
                command_print(cmd_ctx, "\t%sMEMTYPE system memory not present: dedicated debug bus", tabs);

        /* Now we read ROM table entries from dbgbase&0xFFFFF000) | 0x000 until we get 0x00000000 */
        for (entry_offset = 0; ; entry_offset += 4) {
                retval = mem_ap_read_atomic_u32(dap, (dbgbase&0xFFFFF000) | entry_offset, &romentry);
                if (retval != ERROR_OK)
                        return retval;
                command_print(cmd_ctx, "\t%sROMTABLE[0x%x] = 0x%" PRIx32 "",
                                tabs, entry_offset, romentry);
                if (romentry & 0x01) {
                        uint32_t c_cid0, c_cid1, c_cid2, c_cid3;
                        uint32_t c_pid0, c_pid1, c_pid2, c_pid3, c_pid4;
                        uint32_t component_base;
                        unsigned part_num;
                        char *type, *full;

                        component_base = (dbgbase & 0xFFFFF000) + (romentry & 0xFFFFF000);

                        /* IDs are in last 4K section */
                        retval = mem_ap_read_atomic_u32(dap, component_base + 0xFE0, &c_pid0);
                        if (retval != ERROR_OK) {
                                command_print(cmd_ctx, "\t%s\tCan't read component with base address 0x%" PRIx32
                                              ", the corresponding core might be turned off", tabs, component_base);
                                continue;
                        }
                        c_pid0 &= 0xff;
                        retval = mem_ap_read_atomic_u32(dap, component_base + 0xFE4, &c_pid1);
                        if (retval != ERROR_OK)
                                return retval;
                        c_pid1 &= 0xff;
                        retval = mem_ap_read_atomic_u32(dap, component_base + 0xFE8, &c_pid2);
                        if (retval != ERROR_OK)
                                return retval;
                        c_pid2 &= 0xff;
                        retval = mem_ap_read_atomic_u32(dap, component_base + 0xFEC, &c_pid3);
                        if (retval != ERROR_OK)
                                return retval;
                        c_pid3 &= 0xff;
                        retval = mem_ap_read_atomic_u32(dap, component_base + 0xFD0, &c_pid4);
                        if (retval != ERROR_OK)
                                return retval;
                        c_pid4 &= 0xff;

                        retval = mem_ap_read_atomic_u32(dap, component_base + 0xFF0, &c_cid0);
                        if (retval != ERROR_OK)
                                return retval;
                        c_cid0 &= 0xff;
                        retval = mem_ap_read_atomic_u32(dap, component_base + 0xFF4, &c_cid1);
                        if (retval != ERROR_OK)
                                return retval;
                        c_cid1 &= 0xff;
                        retval = mem_ap_read_atomic_u32(dap, component_base + 0xFF8, &c_cid2);
                        if (retval != ERROR_OK)
                                return retval;
                        c_cid2 &= 0xff;
                        retval = mem_ap_read_atomic_u32(dap, component_base + 0xFFC, &c_cid3);
                        if (retval != ERROR_OK)
                                return retval;
                        c_cid3 &= 0xff;

                        command_print(cmd_ctx, "\t\tComponent base address 0x%" PRIx32 ", "
                                      "start address 0x%" PRIx32, component_base,
                                      /* component may take multiple 4K pages */
                                      (uint32_t)(component_base - 0x1000*(c_pid4 >> 4)));
                        command_print(cmd_ctx, "\t\tComponent class is 0x%" PRIx8 ", %s",
                                        (uint8_t)((c_cid1 >> 4) & 0xf),
                                        /* See ARM IHI 0029B Table 3-3 */
                                        class_description[(c_cid1 >> 4) & 0xf]);

                        /* CoreSight component? */
                        if (((c_cid1 >> 4) & 0x0f) == 9) {
                                uint32_t devtype;
                                unsigned minor;
                                char *major = "Reserved", *subtype = "Reserved";

                                retval = mem_ap_read_atomic_u32(dap,
                                                (component_base & 0xfffff000) | 0xfcc,
                                                &devtype);
                                if (retval != ERROR_OK)
                                        return retval;
                                minor = (devtype >> 4) & 0x0f;
                                switch (devtype & 0x0f) {
                                case 0:
                                        major = "Miscellaneous";
                                        switch (minor) {
                                        case 0:
                                                subtype = "other";
                                                break;
                                        case 4:
                                                subtype = "Validation component";
                                                break;
                                        }
                                        break;
                                case 1:
                                        major = "Trace Sink";
                                        switch (minor) {
                                        case 0:
                                                subtype = "other";
                                                break;
                                        case 1:
                                                subtype = "Port";
                                                break;
                                        case 2:
                                                subtype = "Buffer";
                                                break;
                                        case 3:
                                                subtype = "Router";
                                                break;
                                        }
                                        break;
                                case 2:
                                        major = "Trace Link";
                                        switch (minor) {
                                        case 0:
                                                subtype = "other";
                                                break;
                                        case 1:
                                                subtype = "Funnel, router";
                                                break;
                                        case 2:
                                                subtype = "Filter";
                                                break;
                                        case 3:
                                                subtype = "FIFO, buffer";
                                                break;
                                        }
                                        break;
                                case 3:
                                        major = "Trace Source";
                                        switch (minor) {
                                        case 0:
                                                subtype = "other";
                                                break;
                                        case 1:
                                                subtype = "Processor";
                                                break;
                                        case 2:
                                                subtype = "DSP";
                                                break;
                                        case 3:
                                                subtype = "Engine/Coprocessor";
                                                break;
                                        case 4:
                                                subtype = "Bus";
                                                break;
                                        case 6:
                                                subtype = "Software";
                                                break;
                                        }
                                        break;
                                case 4:
                                        major = "Debug Control";
                                        switch (minor) {
                                        case 0:
                                                subtype = "other";
                                                break;
                                        case 1:
                                                subtype = "Trigger Matrix";
                                                break;
                                        case 2:
                                                subtype = "Debug Auth";
                                                break;
                                        case 3:
                                                subtype = "Power Requestor";
                                                break;
                                        }
                                        break;
                                case 5:
                                        major = "Debug Logic";
                                        switch (minor) {
                                        case 0:
                                                subtype = "other";
                                                break;
                                        case 1:
                                                subtype = "Processor";
                                                break;
                                        case 2:
                                                subtype = "DSP";
                                                break;
                                        case 3:
                                                subtype = "Engine/Coprocessor";
                                                break;
                                        case 4:
                                                subtype = "Bus";
                                                break;
                                        case 5:
                                                subtype = "Memory";
                                                break;
                                        }
                                        break;
                                case 6:
                                        major = "Perfomance Monitor";
                                        switch (minor) {
                                        case 0:
                                                subtype = "other";
                                                break;
                                        case 1:
                                                subtype = "Processor";
                                                break;
                                        case 2:
                                                subtype = "DSP";
                                                break;
                                        case 3:
                                                subtype = "Engine/Coprocessor";
                                                break;
                                        case 4:
                                                subtype = "Bus";
                                                break;
                                        case 5:
                                                subtype = "Memory";
                                                break;
                                        }
                                        break;
                                }
                                command_print(cmd_ctx, "\t\tType is 0x%02" PRIx8 ", %s, %s",
                                                (uint8_t)(devtype & 0xff),
                                                major, subtype);
                                /* REVISIT also show 0xfc8 DevId */
                        }

                        if (!is_dap_cid_ok(cid3, cid2, cid1, cid0))
                                command_print(cmd_ctx,
                                                "\t\tCID3 0%02x"
                                                ", CID2 0%02x"
                                                ", CID1 0%02x"
                                                ", CID0 0%02x",
                                                (int)c_cid3,
                                                (int)c_cid2,
                                                (int)c_cid1,
                                                (int)c_cid0);
                        command_print(cmd_ctx,
                                "\t\tPeripheral ID[4..0] = hex "
                                "%02x %02x %02x %02x %02x",
                                (int)c_pid4, (int)c_pid3, (int)c_pid2,
                                (int)c_pid1, (int)c_pid0);

                        /* Part number interpretations are from Cortex
                         * core specs, the CoreSight components TRM
                         * (ARM DDI 0314H), CoreSight System Design
                         * Guide (ARM DGI 0012D) and ETM specs; also
                         * from chip observation (e.g. TI SDTI).
                         */
                        part_num = (c_pid0 & 0xff);
                        part_num |= (c_pid1 & 0x0f) << 8;
                        switch (part_num) {
                        case 0x000:
                                type = "Cortex-M3 NVIC";
                                full = "(Interrupt Controller)";
                                break;
                        case 0x001:
                                type = "Cortex-M3 ITM";
                                full = "(Instrumentation Trace Module)";
                                break;
                        case 0x002:
                                type = "Cortex-M3 DWT";
                                full = "(Data Watchpoint and Trace)";
                                break;
                        case 0x003:
                                type = "Cortex-M3 FBP";
                                full = "(Flash Patch and Breakpoint)";
                                break;
                        case 0x00c:
                                type = "Cortex-M4 SCS";
                                full = "(System Control Space)";
                                break;
                        case 0x00d:
                                type = "CoreSight ETM11";
                                full = "(Embedded Trace)";
                                break;
                        /* case 0x113: what? */
                        case 0x120:             /* from OMAP3 memmap */
                                type = "TI SDTI";
                                full = "(System Debug Trace Interface)";
                                break;
                        case 0x343:             /* from OMAP3 memmap */
                                type = "TI DAPCTL";
                                full = "";
                                break;
                        case 0x906:
                                type = "Coresight CTI";
                                full = "(Cross Trigger)";
                                break;
                        case 0x907:
                                type = "Coresight ETB";
                                full = "(Trace Buffer)";
                                break;
                        case 0x908:
                                type = "Coresight CSTF";
                                full = "(Trace Funnel)";
                                break;
                        case 0x910:
                                type = "CoreSight ETM9";
                                full = "(Embedded Trace)";
                                break;
                        case 0x912:
                                type = "Coresight TPIU";
                                full = "(Trace Port Interface Unit)";
                                break;
                        case 0x913:
                                type = "Coresight ITM";
                                full = "(Instrumentation Trace Macrocell)";
                                break;
                        case 0x917:
                                type = "Coresight HTM";
                                full = "(AHB Trace Macrocell)";
                                break;
                        case 0x920:
                                type = "CoreSight ETM11";
                                full = "(Embedded Trace)";
                                break;
                        case 0x921:
                                type = "Cortex-A8 ETM";
                                full = "(Embedded Trace)";
                                break;
                        case 0x922:
                                type = "Cortex-A8 CTI";
                                full = "(Cross Trigger)";
                                break;
                        case 0x923:
                                type = "Cortex-M3 TPIU";
                                full = "(Trace Port Interface Unit)";
                                break;
                        case 0x924:
                                type = "Cortex-M3 ETM";
                                full = "(Embedded Trace)";
                                break;
                        case 0x925:
                                type = "Cortex-M4 ETM";
                                full = "(Embedded Trace)";
                                break;
                        case 0x930:
                                type = "Cortex-R4 ETM";
                                full = "(Embedded Trace)";
                                break;
                        case 0x950:
                                type = "CoreSight Component";
                                full = "(unidentified Cortex-A9 component)";
                                break;
                        case 0x962:
                                type = "CoreSight STM";
                                full = "(System Trace Macrocell)";
                                break;
                        case 0x9a0:
                                type = "CoreSight PMU";
                                full = "(Performance Monitoring Unit)";
                                break;
                        case 0x9a1:
                                type = "Cortex-M4 TPUI";
                                full = "(Trace Port Interface Unit)";
                                break;
                        case 0xc08:
                                type = "Cortex-A8 Debug";
                                full = "(Debug Unit)";
                                break;
                        case 0xc09:
                                type = "Cortex-A9 Debug";
                                full = "(Debug Unit)";
                                break;
                        default:
                                type = "-*- unrecognized -*-";
                                full = "";
                                break;
                        }
                        command_print(cmd_ctx, "\t\tPart is %s %s",
                                        type, full);

                        /* ROM Table? */
                        if (((c_cid1 >> 4) & 0x0f) == 1) {
                                retval = dap_rom_display(cmd_ctx, dap, ap, component_base, depth + 1);
                                if (retval != ERROR_OK)
                                        return retval;
                        }
                } else {
                        if (romentry)
                                command_print(cmd_ctx, "\t\tComponent not present");
                        else
                                break;
                }
        }
        command_print(cmd_ctx, "\t%s\tEnd of ROM table", tabs);
        return ERROR_OK;
}

static int dap_info_command(struct command_context *cmd_ctx,
                struct adiv5_dap *dap, int ap)
{
        int retval;
        uint32_t dbgbase = 0, apid = 0; /* Silence gcc by initializing */
        int romtable_present = 0;
        uint8_t mem_ap;
        uint32_t ap_old;

        retval = dap_get_debugbase(dap, ap, &dbgbase, &apid);
        if (retval != ERROR_OK)
                return retval;

        ap_old = dap->ap_current;
        dap_ap_select(dap, ap);

        /* Now we read ROM table ID registers, ref. ARM IHI 0029B sec  */
        mem_ap = ((apid&0x10000) && ((apid&0x0F) != 0));
        command_print(cmd_ctx, "AP ID register 0x%8.8" PRIx32, apid);
        if (apid) {
                switch (apid&0x0F) {
                        case 0:
                                command_print(cmd_ctx, "\tType is JTAG-AP");
                                break;
                        case 1:
                                command_print(cmd_ctx, "\tType is MEM-AP AHB");
                                break;
                        case 2:
                                command_print(cmd_ctx, "\tType is MEM-AP APB");
                                break;
                        default:
                                command_print(cmd_ctx, "\tUnknown AP type");
                                break;
                }

                /* NOTE: a MEM-AP may have a single CoreSight component that's
                 * not a ROM table ... or have no such components at all.
                 */
                if (mem_ap)
                        command_print(cmd_ctx, "AP BASE 0x%8.8" PRIx32, dbgbase);
        } else
                command_print(cmd_ctx, "No AP found at this ap 0x%x", ap);

        romtable_present = ((mem_ap) && (dbgbase != 0xFFFFFFFF));
        if (romtable_present) {
                dap_rom_display(cmd_ctx, dap, ap, dbgbase, 0);
        } else
                command_print(cmd_ctx, "\tNo ROM table present");
        dap_ap_select(dap, ap_old);

        return ERROR_OK;
}

COMMAND_HANDLER(handle_dap_info_command)
{
        struct target *target = get_current_target(CMD_CTX);
        struct arm *arm = target_to_arm(target);
        struct adiv5_dap *dap = arm->dap;
        uint32_t apsel;

        switch (CMD_ARGC) {
        case 0:
                apsel = dap->apsel;
                break;
        case 1:
                COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], apsel);
                break;
        default:
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        return dap_info_command(CMD_CTX, dap, apsel);
}

COMMAND_HANDLER(dap_baseaddr_command)
{
        struct target *target = get_current_target(CMD_CTX);
        struct arm *arm = target_to_arm(target);
        struct adiv5_dap *dap = arm->dap;

        uint32_t apsel, baseaddr;
        int retval;

        switch (CMD_ARGC) {
        case 0:
                apsel = dap->apsel;
                break;
        case 1:
                COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], apsel);
                /* AP address is in bits 31:24 of DP_SELECT */
                if (apsel >= 256)
                        return ERROR_COMMAND_SYNTAX_ERROR;
                break;
        default:
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        dap_ap_select(dap, apsel);

        /* NOTE:  assumes we're talking to a MEM-AP, which
         * has a base address.  There are other kinds of AP,
         * though they're not common for now.  This should
         * use the ID register to verify it's a MEM-AP.
         */
        retval = dap_queue_ap_read(dap, AP_REG_BASE, &baseaddr);
        if (retval != ERROR_OK)
                return retval;
        retval = dap_run(dap);
        if (retval != ERROR_OK)
                return retval;

        command_print(CMD_CTX, "0x%8.8" PRIx32, baseaddr);

        return retval;
}

COMMAND_HANDLER(dap_memaccess_command)
{
        struct target *target = get_current_target(CMD_CTX);
        struct arm *arm = target_to_arm(target);
        struct adiv5_dap *dap = arm->dap;

        uint32_t memaccess_tck;

        switch (CMD_ARGC) {
        case 0:
                memaccess_tck = dap->memaccess_tck;
                break;
        case 1:
                COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], memaccess_tck);
                break;
        default:
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
        dap->memaccess_tck = memaccess_tck;

        command_print(CMD_CTX, "memory bus access delay set to %" PRIi32 " tck",
                        dap->memaccess_tck);

        return ERROR_OK;
}

COMMAND_HANDLER(dap_apsel_command)
{
        struct target *target = get_current_target(CMD_CTX);
        struct arm *arm = target_to_arm(target);
        struct adiv5_dap *dap = arm->dap;

        uint32_t apsel, apid;
        int retval;

        switch (CMD_ARGC) {
        case 0:
                apsel = 0;
                break;
        case 1:
                COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], apsel);
                /* AP address is in bits 31:24 of DP_SELECT */
                if (apsel >= 256)
                        return ERROR_COMMAND_SYNTAX_ERROR;
                break;
        default:
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        dap->apsel = apsel;
        dap_ap_select(dap, apsel);

        retval = dap_queue_ap_read(dap, AP_REG_IDR, &apid);
        if (retval != ERROR_OK)
                return retval;
        retval = dap_run(dap);
        if (retval != ERROR_OK)
                return retval;

        command_print(CMD_CTX, "ap %" PRIi32 " selected, identification register 0x%8.8" PRIx32,
                        apsel, apid);

        return retval;
}

COMMAND_HANDLER(dap_apcsw_command)
{
        struct target *target = get_current_target(CMD_CTX);
        struct arm *arm = target_to_arm(target);
        struct adiv5_dap *dap = arm->dap;

        uint32_t apcsw = dap->apcsw[dap->apsel], sprot = 0;

        switch (CMD_ARGC) {
        case 0:
                command_print(CMD_CTX, "apsel %" PRIi32 " selected, csw 0x%8.8" PRIx32,
                        (dap->apsel), apcsw);
                break;
        case 1:
                COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], sprot);
                /* AP address is in bits 31:24 of DP_SELECT */
                if (sprot > 1)
                        return ERROR_COMMAND_SYNTAX_ERROR;
                if (sprot)
                        apcsw |= CSW_SPROT;
                else
                        apcsw &= ~CSW_SPROT;
                break;
        default:
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
        dap->apcsw[dap->apsel] = apcsw;

        return 0;
}



COMMAND_HANDLER(dap_apid_command)
{
        struct target *target = get_current_target(CMD_CTX);
        struct arm *arm = target_to_arm(target);
        struct adiv5_dap *dap = arm->dap;

        uint32_t apsel, apid;
        int retval;

        switch (CMD_ARGC) {
        case 0:
                apsel = dap->apsel;
                break;
        case 1:
                COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], apsel);
                /* AP address is in bits 31:24 of DP_SELECT */
                if (apsel >= 256)
                        return ERROR_COMMAND_SYNTAX_ERROR;
                break;
        default:
                return ERROR_COMMAND_SYNTAX_ERROR;
        }

        dap_ap_select(dap, apsel);

        retval = dap_queue_ap_read(dap, AP_REG_IDR, &apid);
        if (retval != ERROR_OK)
                return retval;
        retval = dap_run(dap);
        if (retval != ERROR_OK)
                return retval;

        command_print(CMD_CTX, "0x%8.8" PRIx32, apid);

        return retval;
}

COMMAND_HANDLER(dap_ti_be_32_quirks_command)
{
        struct target *target = get_current_target(CMD_CTX);
        struct arm *arm = target_to_arm(target);
        struct adiv5_dap *dap = arm->dap;

        uint32_t enable = dap->ti_be_32_quirks;

        switch (CMD_ARGC) {
        case 0:
                break;
        case 1:
                COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], enable);
                if (enable > 1)
                        return ERROR_COMMAND_SYNTAX_ERROR;
                break;
        default:
                return ERROR_COMMAND_SYNTAX_ERROR;
        }
        dap->ti_be_32_quirks = enable;
        command_print(CMD_CTX, "TI BE-32 quirks mode %s",
                enable ? "enabled" : "disabled");

        return 0;
}

static const struct command_registration dap_commands[] = {
        {
                .name = "info",
                .handler = handle_dap_info_command,
                .mode = COMMAND_EXEC,
                .help = "display ROM table for MEM-AP "
                        "(default currently selected AP)",
                .usage = "[ap_num]",
        },
        {
                .name = "apsel",
                .handler = dap_apsel_command,
                .mode = COMMAND_EXEC,
                .help = "Set the currently selected AP (default 0) "
                        "and display the result",
                .usage = "[ap_num]",
        },
        {
                .name = "apcsw",
                .handler = dap_apcsw_command,
                .mode = COMMAND_EXEC,
                .help = "Set csw access bit ",
                .usage = "[sprot]",
        },

        {
                .name = "apid",
                .handler = dap_apid_command,
                .mode = COMMAND_EXEC,
                .help = "return ID register from AP "
                        "(default currently selected AP)",
                .usage = "[ap_num]",
        },
        {
                .name = "baseaddr",
                .handler = dap_baseaddr_command,
                .mode = COMMAND_EXEC,
                .help = "return debug base address from MEM-AP "
                        "(default currently selected AP)",
                .usage = "[ap_num]",
        },
        {
                .name = "memaccess",
                .handler = dap_memaccess_command,
                .mode = COMMAND_EXEC,
                .help = "set/get number of extra tck for MEM-AP memory "
                        "bus access [0-255]",
                .usage = "[cycles]",
        },
        {
                .name = "ti_be_32_quirks",
                .handler = dap_ti_be_32_quirks_command,
                .mode = COMMAND_CONFIG,
                .help = "set/get quirks mode for TI TMS450/TMS570 processors",
                .usage = "[enable]",
        },
        COMMAND_REGISTRATION_DONE
};

const struct command_registration dap_command_handlers[] = {
        {
                .name = "dap",
                .mode = COMMAND_EXEC,
                .help = "DAP command group",
                .usage = "",
                .chain = dap_commands,
        },
        COMMAND_REGISTRATION_DONE
};