jtag: cut down on usage of unintended modification of global end state

[openocd/genbsdl.git] / src / target / embeddedice.c

/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2007,2008,2009 Øyvind Harboe                            *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2008 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "embeddedice.h"
#include "register.h"

/**
 * @file
 *
 * This provides lowlevel glue to the EmbeddedICE (or EmbeddedICE-RT)
 * module found on scan chain 2 in ARM7, ARM9, and some other families
 * of ARM cores.  The module is called "EmbeddedICE-RT" if it has
 * monitor mode support.
 *
 * EmbeddedICE provides basic watchpoint/breakpoint hardware and a Debug
 * Communications Channel (DCC) used to read or write 32-bit words to
 * OpenOCD-aware code running on the target CPU.
 * Newer modules also include vector catch hardware.  Some versions
 * support hardware single-stepping, "monitor mode" debug (which is not
 * currently supported by OpenOCD), or extended reporting on why the
 * core entered debug mode.
 */

/*
 * From:  ARM9E-S TRM, DDI 0165, table C-4 (and similar, for other cores)
 */
static const struct {
        char            *name;
        unsigned short  addr;
        unsigned short  width;
} eice_regs[] = {
        [EICE_DBG_CTRL] = {
                .name =         "debug_ctrl",
                .addr =         0,
                /* width is assigned based on EICE version */
        },
        [EICE_DBG_STAT] = {
                .name =         "debug_status",
                .addr =         1,
                /* width is assigned based on EICE version */
        },
        [EICE_COMMS_CTRL] = {
                .name =         "comms_ctrl",
                .addr =         4,
                .width =        6,
        },
        [EICE_COMMS_DATA] = {
                .name =         "comms_data",
                .addr =         5,
                .width =        32,
        },
        [EICE_W0_ADDR_VALUE] = {
                .name =         "watch_0_addr_value",
                .addr =         8,
                .width =        32,
        },
        [EICE_W0_ADDR_MASK] = {
                .name =         "watch_0_addr_mask",
                .addr =         9,
                .width =        32,
        },
        [EICE_W0_DATA_VALUE ] = {
                .name =         "watch_0_data_value",
                .addr =         10,
                .width =        32,
        },
        [EICE_W0_DATA_MASK] = {
                .name =         "watch_0_data_mask",
                .addr =         11,
                .width =        32,
        },
        [EICE_W0_CONTROL_VALUE] = {
                .name =         "watch_0_control_value",
                .addr =         12,
                .width =        9,
        },
        [EICE_W0_CONTROL_MASK] = {
                .name =         "watch_0_control_mask",
                .addr =         13,
                .width =        8,
        },
        [EICE_W1_ADDR_VALUE] = {
                .name =         "watch_1_addr_value",
                .addr =         16,
                .width =        32,
        },
        [EICE_W1_ADDR_MASK] = {
                .name =         "watch_1_addr_mask",
                .addr =         17,
                .width =        32,
        },
        [EICE_W1_DATA_VALUE] = {
                .name =         "watch_1_data_value",
                .addr =         18,
                .width =        32,
        },
        [EICE_W1_DATA_MASK] = {
                .name =         "watch_1_data_mask",
                .addr =         19,
                .width =        32,
        },
        [EICE_W1_CONTROL_VALUE] = {
                .name =         "watch_1_control_value",
                .addr =         20,
                .width =        9,
        },
        [EICE_W1_CONTROL_MASK] = {
                .name =         "watch_1_control_mask",
                .addr =         21,
                .width =        8,
        },
        /* vector_catch isn't always present */
        [EICE_VEC_CATCH] = {
                .name =         "vector_catch",
                .addr =         2,
                .width =        8,
        },
};


static int embeddedice_get_reg(struct reg *reg)
{
        int retval;

        if ((retval = embeddedice_read_reg(reg)) != ERROR_OK)
                LOG_ERROR("error queueing EmbeddedICE register read");
        else if ((retval = jtag_execute_queue()) != ERROR_OK)
                LOG_ERROR("EmbeddedICE register read failed");

        return retval;
}

static const struct reg_arch_type eice_reg_type = {
        .get = embeddedice_get_reg,
        .set = embeddedice_set_reg_w_exec,
};

/**
 * Probe EmbeddedICE module and set up local records of its registers.
 * Different versions of the modules have different capabilities, such as
 * hardware support for vector_catch, single stepping, and monitor mode.
 */
struct reg_cache *
embeddedice_build_reg_cache(struct target *target, struct arm7_9_common *arm7_9)
{
        int retval;
        struct reg_cache *reg_cache = malloc(sizeof(struct reg_cache));
        struct reg *reg_list = NULL;
        struct embeddedice_reg *arch_info = NULL;
        struct arm_jtag *jtag_info = &arm7_9->jtag_info;
        int num_regs = ARRAY_SIZE(eice_regs);
        int i;
        int eice_version = 0;

        /* vector_catch isn't always present */
        if (!arm7_9->has_vector_catch)
                num_regs--;

        /* the actual registers are kept in two arrays */
        reg_list = calloc(num_regs, sizeof(struct reg));
        arch_info = calloc(num_regs, sizeof(struct embeddedice_reg));

        /* fill in values for the reg cache */
        reg_cache->name = "EmbeddedICE registers";
        reg_cache->next = NULL;
        reg_cache->reg_list = reg_list;
        reg_cache->num_regs = num_regs;

        /* FIXME the second watchpoint unit on Feroceon and Dragonite
         * seems not to work ... we should have a way to not set up
         * its four registers here!
         */

        /* set up registers */
        for (i = 0; i < num_regs; i++)
        {
                reg_list[i].name = eice_regs[i].name;
                reg_list[i].size = eice_regs[i].width;
                reg_list[i].dirty = 0;
                reg_list[i].valid = 0;
                reg_list[i].value = calloc(1, 4);
                reg_list[i].arch_info = &arch_info[i];
                reg_list[i].type = &eice_reg_type;
                arch_info[i].addr = eice_regs[i].addr;
                arch_info[i].jtag_info = jtag_info;
        }

        /* identify EmbeddedICE version by reading DCC control register */
        embeddedice_read_reg(&reg_list[EICE_COMMS_CTRL]);
        if ((retval = jtag_execute_queue()) != ERROR_OK)
        {
                for (i = 0; i < num_regs; i++)
                {
                        free(reg_list[i].value);
                }
                free(reg_list);
                free(reg_cache);
                free(arch_info);
                return NULL;
        }

        eice_version = buf_get_u32(reg_list[EICE_COMMS_CTRL].value, 28, 4);
        LOG_INFO("Embedded ICE version %d", eice_version);

        switch (eice_version)
        {
                case 1:
                        /* ARM7TDMI r3, ARM7TDMI-S r3
                         *
                         * REVISIT docs say ARM7TDMI-S r4 uses version 1 but
                         * that it has 6-bit CTRL and 5-bit STAT... doc bug?
                         * ARM7TDMI r4 docs say EICE v4.
                         */
                        reg_list[EICE_DBG_CTRL].size = 3;
                        reg_list[EICE_DBG_STAT].size = 5;
                        break;
                case 2:
                        /* ARM9TDMI */
                        reg_list[EICE_DBG_CTRL].size = 4;
                        reg_list[EICE_DBG_STAT].size = 5;
                        arm7_9->has_single_step = 1;
                        break;
                case 3:
                        LOG_ERROR("EmbeddedICE v%d handling might be broken",
                                        eice_version);
                        reg_list[EICE_DBG_CTRL].size = 6;
                        reg_list[EICE_DBG_STAT].size = 5;
                        arm7_9->has_single_step = 1;
                        arm7_9->has_monitor_mode = 1;
                        break;
                case 4:
                        /* ARM7TDMI r4 */
                        reg_list[EICE_DBG_CTRL].size = 6;
                        reg_list[EICE_DBG_STAT].size = 5;
                        arm7_9->has_monitor_mode = 1;
                        break;
                case 5:
                        /* ARM9E-S rev 1 */
                        reg_list[EICE_DBG_CTRL].size = 6;
                        reg_list[EICE_DBG_STAT].size = 5;
                        arm7_9->has_single_step = 1;
                        arm7_9->has_monitor_mode = 1;
                        break;
                case 6:
                        /* ARM7EJ-S, ARM9E-S rev 2, ARM9EJ-S */
                        reg_list[EICE_DBG_CTRL].size = 6;
                        reg_list[EICE_DBG_STAT].size = 10;
                        /* DBG_STAT has MOE bits */
                        arm7_9->has_monitor_mode = 1;
                        break;
                case 7:
                        LOG_ERROR("EmbeddedICE v%d handling might be broken",
                                        eice_version);
                        reg_list[EICE_DBG_CTRL].size = 6;
                        reg_list[EICE_DBG_STAT].size = 5;
                        arm7_9->has_monitor_mode = 1;
                        break;
                default:
                        /*
                         * The Feroceon implementation has the version number
                         * in some unusual bits.  Let feroceon.c validate it
                         * and do the appropriate setup itself.
                         */
                        if (strcmp(target_type_name(target), "feroceon") == 0 ||
                            strcmp(target_type_name(target), "dragonite") == 0)
                                break;
                        LOG_ERROR("unknown EmbeddedICE version "
                                "(comms ctrl: 0x%8.8" PRIx32 ")",
                                buf_get_u32(reg_list[EICE_COMMS_CTRL].value, 0, 32));
        }

        /* On Feroceon and Dragonite the second unit is seemingly missing. */
        LOG_INFO("%s: hardware has %d breakpoint/watchpoint unit%s",
                        target_name(target), arm7_9->wp_available_max,
                        (arm7_9->wp_available_max != 1) ? "s" : "");

        return reg_cache;
}

/**
 * Initialize EmbeddedICE module, if needed.
 */
int embeddedice_setup(struct target *target)
{
        int retval;
        struct arm7_9_common *arm7_9 = target_to_arm7_9(target);

        /* Explicitly disable monitor mode.  For now we only support halting
         * debug ... we don't know how to talk with a resident debug monitor
         * that manages break requests.  ARM's "Angel Debug Monitor" is one
         * common example of such code.
         */
        if (arm7_9->has_monitor_mode)
        {
                struct reg *dbg_ctrl = &arm7_9->eice_cache->reg_list[EICE_DBG_CTRL];

                embeddedice_read_reg(dbg_ctrl);
                if ((retval = jtag_execute_queue()) != ERROR_OK)
                        return retval;
                buf_set_u32(dbg_ctrl->value, 4, 1, 0);
                embeddedice_set_reg_w_exec(dbg_ctrl, dbg_ctrl->value);
        }
        return jtag_execute_queue();
}

/**
 * Queue a read for an EmbeddedICE register into the register cache,
 * optionally checking the value read.
 * Note that at this level, all registers are 32 bits wide.
 */
int embeddedice_read_reg_w_check(struct reg *reg,
                uint8_t *check_value, uint8_t *check_mask)
{
        struct embeddedice_reg *ice_reg = reg->arch_info;
        uint8_t reg_addr = ice_reg->addr & 0x1f;
        struct scan_field fields[3];
        uint8_t field1_out[1];
        uint8_t field2_out[1];

        jtag_set_end_state(TAP_IDLE);
        arm_jtag_scann(ice_reg->jtag_info, 0x2);

        arm_jtag_set_instr(ice_reg->jtag_info, ice_reg->jtag_info->intest_instr, NULL);

        /* bits 31:0 -- data (ignored here) */
        fields[0].num_bits = 32;
        fields[0].out_value = reg->value;
        fields[0].in_value = NULL;
        fields[0].check_value = NULL;
        fields[0].check_mask = NULL;

        /* bits 36:32 -- register */
        fields[1].num_bits = 5;
        fields[1].out_value = field1_out;
        fields[1].out_value[0] = reg_addr;
        fields[1].in_value = NULL;
        fields[1].check_value = NULL;
        fields[1].check_mask = NULL;

        /* bit 37 -- 0/read */
        fields[2].num_bits = 1;
        fields[2].out_value = field2_out;
        fields[2].out_value[0] = 0;
        fields[2].in_value = NULL;
        fields[2].check_value = NULL;
        fields[2].check_mask = NULL;

        /* traverse Update-DR, setting address for the next read */
        jtag_add_dr_scan(ice_reg->jtag_info->tap, 3, fields, TAP_IDLE);

        /* bits 31:0 -- the data we're reading (and maybe checking) */
        fields[0].in_value = reg->value;
        fields[0].check_value = check_value;
        fields[0].check_mask = check_mask;

        /* when reading the DCC data register, leaving the address field set to
         * EICE_COMMS_DATA would read the register twice
         * reading the control register is safe
         */
        fields[1].out_value[0] = eice_regs[EICE_COMMS_CTRL].addr;

        /* traverse Update-DR, reading but with no other side effects */
        jtag_add_dr_scan_check(ice_reg->jtag_info->tap, 3, fields, TAP_IDLE);

        return ERROR_OK;
}

/**
 * Receive a block of size 32-bit words from the DCC.
 * We assume the target is always going to be fast enough (relative to
 * the JTAG clock) that the debugger won't need to poll the handshake
 * bit.  The JTAG clock is usually at least six times slower than the
 * functional clock, so the 50+ JTAG clocks needed to receive the word
 * allow hundreds of instruction cycles (per word) in the target.
 */
int embeddedice_receive(struct arm_jtag *jtag_info, uint32_t *data, uint32_t size)
{
        struct scan_field fields[3];
        uint8_t field1_out[1];
        uint8_t field2_out[1];

        jtag_set_end_state(TAP_IDLE);
        arm_jtag_scann(jtag_info, 0x2);
        arm_jtag_set_instr(jtag_info, jtag_info->intest_instr, NULL);

        fields[0].num_bits = 32;
        fields[0].out_value = NULL;
        fields[0].in_value = NULL;

        fields[1].num_bits = 5;
        fields[1].out_value = field1_out;
        fields[1].out_value[0] = eice_regs[EICE_COMMS_DATA].addr;
        fields[1].in_value = NULL;

        fields[2].num_bits = 1;
        fields[2].out_value = field2_out;
        fields[2].out_value[0] = 0;
        fields[2].in_value = NULL;

        jtag_add_dr_scan(jtag_info->tap, 3, fields, TAP_IDLE);

        while (size > 0)
        {
                /* when reading the last item, set the register address to the DCC control reg,
                 * to avoid reading additional data from the DCC data reg
                 */
                if (size == 1)
                        fields[1].out_value[0] = eice_regs[EICE_COMMS_CTRL].addr;

                fields[0].in_value = (uint8_t *)data;
                jtag_add_dr_scan(jtag_info->tap, 3, fields, TAP_IDLE);
                jtag_add_callback(arm_le_to_h_u32, (jtag_callback_data_t)data);

                data++;
                size--;
        }

        return jtag_execute_queue();
}

/**
 * Queue a read for an EmbeddedICE register into the register cache,
 * not checking the value read.
 */
int embeddedice_read_reg(struct reg *reg)
{
        return embeddedice_read_reg_w_check(reg, NULL, NULL);
}

/**
 * Queue a write for an EmbeddedICE register, updating the register cache.
 * Uses embeddedice_write_reg().
 */
void embeddedice_set_reg(struct reg *reg, uint32_t value)
{
        embeddedice_write_reg(reg, value);

        buf_set_u32(reg->value, 0, reg->size, value);
        reg->valid = 1;
        reg->dirty = 0;

}

/**
 * Write an EmbeddedICE register, updating the register cache.
 * Uses embeddedice_set_reg(); not queued.
 */
int embeddedice_set_reg_w_exec(struct reg *reg, uint8_t *buf)
{
        int retval;

        embeddedice_set_reg(reg, buf_get_u32(buf, 0, reg->size));
        if ((retval = jtag_execute_queue()) != ERROR_OK)
                LOG_ERROR("register write failed");
        return retval;
}

/**
 * Queue a write for an EmbeddedICE register, bypassing the register cache.
 */
void embeddedice_write_reg(struct reg *reg, uint32_t value)
{
        struct embeddedice_reg *ice_reg = reg->arch_info;

        LOG_DEBUG("%i: 0x%8.8" PRIx32 "", ice_reg->addr, value);

        jtag_set_end_state(TAP_IDLE);
        arm_jtag_scann(ice_reg->jtag_info, 0x2);

        arm_jtag_set_instr(ice_reg->jtag_info, ice_reg->jtag_info->intest_instr, NULL);

        uint8_t reg_addr = ice_reg->addr & 0x1f;
        embeddedice_write_reg_inner(ice_reg->jtag_info->tap, reg_addr, value);
}

/**
 * Queue a write for an EmbeddedICE register, using cached value.
 * Uses embeddedice_write_reg().
 */
void embeddedice_store_reg(struct reg *reg)
{
        embeddedice_write_reg(reg, buf_get_u32(reg->value, 0, reg->size));
}

/**
 * Send a block of size 32-bit words to the DCC.
 * We assume the target is always going to be fast enough (relative to
 * the JTAG clock) that the debugger won't need to poll the handshake
 * bit.  The JTAG clock is usually at least six times slower than the
 * functional clock, so the 50+ JTAG clocks needed to receive the word
 * allow hundreds of instruction cycles (per word) in the target.
 */
int embeddedice_send(struct arm_jtag *jtag_info, uint32_t *data, uint32_t size)
{
        struct scan_field fields[3];
        uint8_t field0_out[4];
        uint8_t field1_out[1];
        uint8_t field2_out[1];

        jtag_set_end_state(TAP_IDLE);
        arm_jtag_scann(jtag_info, 0x2);
        arm_jtag_set_instr(jtag_info, jtag_info->intest_instr, NULL);

        fields[0].num_bits = 32;
        fields[0].out_value = field0_out;
        fields[0].in_value = NULL;

        fields[1].num_bits = 5;
        fields[1].out_value = field1_out;
        fields[1].out_value[0] = eice_regs[EICE_COMMS_DATA].addr;
        fields[1].in_value = NULL;

        fields[2].num_bits = 1;
        fields[2].out_value = field2_out;
        fields[2].out_value[0] = 1;

        fields[2].in_value = NULL;

        while (size > 0)
        {
                buf_set_u32(fields[0].out_value, 0, 32, *data);
                jtag_add_dr_scan(jtag_info->tap, 3, fields, TAP_IDLE);

                data++;
                size--;
        }

        /* call to jtag_execute_queue() intentionally omitted */
        return ERROR_OK;
}

/**
 * Poll DCC control register until read or write handshake completes.
 */
int embeddedice_handshake(struct arm_jtag *jtag_info, int hsbit, uint32_t timeout)
{
        struct scan_field fields[3];
        uint8_t field0_in[4];
        uint8_t field1_out[1];
        uint8_t field2_out[1];
        int retval;
        uint32_t hsact;
        struct timeval lap;
        struct timeval now;

        if (hsbit == EICE_COMM_CTRL_WBIT)
                hsact = 1;
        else if (hsbit == EICE_COMM_CTRL_RBIT)
                hsact = 0;
        else
                return ERROR_INVALID_ARGUMENTS;

        jtag_set_end_state(TAP_IDLE);
        arm_jtag_scann(jtag_info, 0x2);
        arm_jtag_set_instr(jtag_info, jtag_info->intest_instr, NULL);

        fields[0].num_bits = 32;
        fields[0].out_value = NULL;
        fields[0].in_value = field0_in;

        fields[1].num_bits = 5;
        fields[1].out_value = field1_out;
        fields[1].out_value[0] = eice_regs[EICE_COMMS_DATA].addr;
        fields[1].in_value = NULL;

        fields[2].num_bits = 1;
        fields[2].out_value = field2_out;
        fields[2].out_value[0] = 0;
        fields[2].in_value = NULL;

        jtag_add_dr_scan(jtag_info->tap, 3, fields, TAP_IDLE);
        gettimeofday(&lap, NULL);
        do {
                jtag_add_dr_scan(jtag_info->tap, 3, fields, TAP_IDLE);
                if ((retval = jtag_execute_queue()) != ERROR_OK)
                        return retval;

                if (buf_get_u32(field0_in, hsbit, 1) == hsact)
                        return ERROR_OK;

                gettimeofday(&now, NULL);
        } while ((uint32_t)((now.tv_sec - lap.tv_sec) * 1000
                        + (now.tv_usec - lap.tv_usec) / 1000) <= timeout);

        return ERROR_TARGET_TIMEOUT;
}

#ifndef HAVE_JTAG_MINIDRIVER_H
/**
 * This is an inner loop of the open loop DCC write of data to target
 */
void embeddedice_write_dcc(struct jtag_tap *tap,
                int reg_addr, uint8_t *buffer, int little, int count)
{
        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
/* provided by minidriver */
#endif