arc.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2013-2015,2019-2020 Synopsys, Inc.                      *
 *   Frank Dols <frank.dols@synopsys.com>                                  *
 *   Mischa Jonker <mischa.jonker@synopsys.com>                            *
 *   Anton Kolesov <anton.kolesov@synopsys.com>                            *
 *   Evgeniy Didin <didin@synopsys.com>                                    *
 ***************************************************************************/
 
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include "arc.h"
 
 
 
/*
 * ARC architecture specific details.
 *
 * ARC has two types of registers:
 *  1) core registers(e.g. r0,r1..) [is_core = true]
 *  2) Auxiliary registers [is_core = false]..
 *
 * Auxiliary registers at the same time can be divided into
 * read-only BCR(build configuration regs, e.g. isa_config, mpu_build) and
 * R/RW non-BCR ("control" register, e.g. pc, status32_t, debug).
 *
 * The way of accessing to Core and AUX registers differs on Jtag level.
 * BCR/non-BCR describes if the register is immutable and that reading
 * unexisting register is safe RAZ, rather then an error.
 * Note, core registers cannot be BCR.
 *
 * In arc/cpu/ tcl files all registers are defined as core, non-BCR aux
 * and BCR aux, in "add-reg" command they are passed to three lists
 * respectively:  core_reg_descriptions, aux_reg_descriptions,
 * bcr_reg_descriptions.
 *
 * Due to the specifics of accessing to BCR/non-BCR registers there are two
 * register caches:
 *  1) core_and_aux_cache - includes registers described in
 *     core_reg_descriptions and aux_reg_descriptions lists.
 *     Used during save/restore context step.
 *  2) bcr_cache - includes registers described bcr_reg_descriptions.
 *     Currently used internally during configure step.
 */
 
 
static int arc_remove_watchpoint(struct target *target,
    struct watchpoint *watchpoint);
static int arc_enable_watchpoints(struct target *target);
static int arc_enable_breakpoints(struct target *target);
static int arc_unset_breakpoint(struct target *target,
        struct breakpoint *breakpoint);
static int arc_set_breakpoint(struct target *target,
        struct breakpoint *breakpoint);
static int arc_single_step_core(struct target *target);
 
void arc_reg_data_type_add(struct target *target,
        struct arc_reg_data_type *data_type)
{
    LOG_TARGET_DEBUG(target, "Adding %s reg_data_type", data_type->data_type.id);
    struct arc_common *arc = target_to_arc(target);
    assert(arc);
 
    list_add_tail(&data_type->list, &arc->reg_data_types);
}
 
struct reg *arc_reg_get_by_name(struct reg_cache *first,
        const char *name, bool search_all)
{
    unsigned int i;
    struct reg_cache *cache = first;
 
    while (cache) {
        for (i = 0; i < cache->num_regs; i++) {
            if (!strcmp(cache->reg_list[i].name, name))
                return &(cache->reg_list[i]);
        }
 
        if (search_all)
            cache = cache->next;
        else
            break;
    }
 
    return NULL;
}
 
static int arc_reset_caches_states(struct target *target)
{
    struct arc_common *arc = target_to_arc(target);
 
    LOG_TARGET_DEBUG(target, "Resetting internal variables of caches states");
 
    /* Reset caches states. */
    arc->dcache_flushed = false;
    arc->l2cache_flushed = false;
    arc->icache_invalidated = false;
    arc->dcache_invalidated = false;
    arc->l2cache_invalidated = false;
 
    return ERROR_OK;
}
 
/* Initialize arc_common structure, which passes to openocd target instance */
static int arc_init_arch_info(struct target *target, struct arc_common *arc,
    struct jtag_tap *tap)
{
    arc->common_magic = ARC_COMMON_MAGIC;
    target->arch_info = arc;
 
    arc->jtag_info.tap = tap;
 
    /* The only allowed ir_length is 4 for ARC jtag. */
    if (tap->ir_length != 4) {
        LOG_TARGET_ERROR(target, "ARC jtag instruction length should be equal to 4");
        return ERROR_FAIL;
    }
 
    /* On most ARC targets there is a dcache, so we enable its flushing
     * by default. If there no dcache, there will be no error, just a slight
     * performance penalty from unnecessary JTAG operations. */
    arc->has_dcache = true;
    arc->has_icache = true;
    /* L2$ is not available in a target by default. */
    arc->has_l2cache = false;
    arc_reset_caches_states(target);
 
    /* Add standard GDB data types */
    INIT_LIST_HEAD(&arc->reg_data_types);
    struct arc_reg_data_type *std_types = calloc(ARRAY_SIZE(standard_gdb_types),
        sizeof(*std_types));
 
    if (!std_types) {
        LOG_TARGET_ERROR(target, "Unable to allocate memory");
        return ERROR_FAIL;
    }
 
    for (unsigned int i = 0; i < ARRAY_SIZE(standard_gdb_types); i++) {
        std_types[i].data_type.type = standard_gdb_types[i].type;
        std_types[i].data_type.id = standard_gdb_types[i].id;
        arc_reg_data_type_add(target, &(std_types[i]));
    }
 
    /* Fields related to target descriptions */
    INIT_LIST_HEAD(&arc->core_reg_descriptions);
    INIT_LIST_HEAD(&arc->aux_reg_descriptions);
    INIT_LIST_HEAD(&arc->bcr_reg_descriptions);
    arc->num_regs = 0;
    arc->num_core_regs = 0;
    arc->num_aux_regs = 0;
    arc->num_bcr_regs = 0;
    arc->last_general_reg = ULONG_MAX;
    arc->pc_index_in_cache = ULONG_MAX;
    arc->debug_index_in_cache = ULONG_MAX;
 
    return ERROR_OK;
}
 
int arc_reg_add(struct target *target, struct arc_reg_desc *arc_reg,
        const char * const type_name, const size_t type_name_len)
{
    assert(target);
    assert(arc_reg);
 
    struct arc_common *arc = target_to_arc(target);
    assert(arc);
 
    /* Find register type */
    {
        struct arc_reg_data_type *type;
        list_for_each_entry(type, &arc->reg_data_types, list)
            if (!strncmp(type->data_type.id, type_name, type_name_len)) {
                arc_reg->data_type = &(type->data_type);
                break;
            }
 
        if (!arc_reg->data_type)
            return ERROR_ARC_REGTYPE_NOT_FOUND;
    }
 
    if (arc_reg->is_core) {
        list_add_tail(&arc_reg->list, &arc->core_reg_descriptions);
        arc->num_core_regs += 1;
    } else if (arc_reg->is_bcr) {
        list_add_tail(&arc_reg->list, &arc->bcr_reg_descriptions);
        arc->num_bcr_regs += 1;
    } else {
        list_add_tail(&arc_reg->list, &arc->aux_reg_descriptions);
        arc->num_aux_regs += 1;
    }
    arc->num_regs += 1;
 
    LOG_TARGET_DEBUG(target,
            "added register {name=%s, num=0x%" PRIx32 ", type=%s%s%s%s}",
            arc_reg->name, arc_reg->arch_num, arc_reg->data_type->id,
            arc_reg->is_core ? ", core" : "",  arc_reg->is_bcr ? ", bcr" : "",
            arc_reg->is_general ? ", general" : ""
        );
 
    return ERROR_OK;
}
 
/* Reading core or aux register */
static int arc_get_register(struct reg *reg)
{
    assert(reg);
 
    struct arc_reg_desc *desc = reg->arch_info;
    struct target *target = desc->target;
    struct arc_common *arc = target_to_arc(target);
 
    uint32_t value;
 
    if (reg->valid) {
        LOG_TARGET_DEBUG(target, "Get register (cached) gdb_num=%" PRIu32 ", name=%s, value=0x%" PRIx32,
                reg->number, desc->name, target_buffer_get_u32(target, reg->value));
        return ERROR_OK;
    }
 
    if (desc->is_core) {
        /* Accessing to R61/R62 registers causes Jtag hang */
        if (desc->arch_num == ARC_R61 || desc->arch_num == ARC_R62) {
            LOG_TARGET_ERROR(target, "It is forbidden to read core registers 61 and 62");
            return ERROR_FAIL;
        }
        CHECK_RETVAL(arc_jtag_read_core_reg_one(&arc->jtag_info, desc->arch_num,
                    &value));
    } else {
        CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, desc->arch_num,
            &value));
    }
 
    target_buffer_set_u32(target, reg->value, value);
 
    /* If target is unhalted all register reads should be uncached. */
    if (target->state == TARGET_HALTED)
        reg->valid = true;
    else
        reg->valid = false;
 
    reg->dirty = false;
 
    LOG_TARGET_DEBUG(target, "Get register gdb_num=%" PRIu32 ", name=%s, value=0x%" PRIx32,
            reg->number, desc->name, value);
 
 
    return ERROR_OK;
}
 
/* Writing core or aux register */
static int arc_set_register(struct reg *reg, uint8_t *buf)
{
    struct arc_reg_desc *desc = reg->arch_info;
    struct target *target = desc->target;
    uint32_t value = target_buffer_get_u32(target, buf);
    /* Unlike "get" function "set" is supported only if target
    * is in halt mode. Async writes are not supported yet. */
    if (target->state != TARGET_HALTED)
        return ERROR_TARGET_NOT_HALTED;
 
    /* Accessing to R61/R62 registers causes Jtag hang */
    if (desc->is_core && (desc->arch_num == ARC_R61 ||
            desc->arch_num == ARC_R62)) {
        LOG_TARGET_ERROR(target, "It is forbidden to write core registers 61 and 62");
        return ERROR_FAIL;
    }
    target_buffer_set_u32(target, reg->value, value);
 
    LOG_TARGET_DEBUG(target, "Set register gdb_num=%" PRIu32 ", name=%s, value=0x%08" PRIx32,
            reg->number, desc->name, value);
 
    reg->valid = true;
    reg->dirty = true;
 
    return ERROR_OK;
}
 
static const struct reg_arch_type arc_reg_type = {
    .get = arc_get_register,
    .set = arc_set_register,
};
 
/* GDB register groups. For now we support only general and "empty" */
static const char * const reg_group_general = "general";
static const char * const reg_group_other = "";
 
/* Common code to initialize `struct reg` for different registers: core, aux, bcr. */
static int arc_init_reg(struct target *target, struct reg *reg,
            struct arc_reg_desc *reg_desc, unsigned long number)
{
    assert(target);
    assert(reg);
    assert(reg_desc);
 
    struct arc_common *arc = target_to_arc(target);
 
    /* Initialize struct reg */
    reg->name = reg_desc->name;
    reg->size = 32; /* All register in ARC are 32-bit */
    reg->value = reg_desc->reg_value;
    reg->type = &arc_reg_type;
    reg->arch_info = reg_desc;
    reg->caller_save = true; /* @todo should be configurable. */
    reg->reg_data_type = reg_desc->data_type;
    reg->feature = &reg_desc->feature;
 
    reg->feature->name = reg_desc->gdb_xml_feature;
 
    /* reg->number is used by OpenOCD as value for @regnum. Thus when setting
     * value of a register GDB will use it as a number of register in
     * P-packet. OpenOCD gdbserver will then use number of register in
     * P-packet as an array index in the reg_list returned by
     * arc_regs_get_gdb_reg_list. So to ensure that registers are assigned
     * correctly it would be required to either sort registers in
     * arc_regs_get_gdb_reg_list or to assign numbers sequentially here and
     * according to how registers will be sorted in
     * arc_regs_get_gdb_reg_list. Second options is much more simpler. */
    reg->number = number;
 
    if (reg_desc->is_general) {
        arc->last_general_reg = reg->number;
        reg->group = reg_group_general;
    } else {
        reg->group = reg_group_other;
    }
 
    return ERROR_OK;
}
 
/* Building aux/core reg_cache */
static int arc_build_reg_cache(struct target *target)
{
    unsigned long i = 0;
    struct arc_reg_desc *reg_desc;
    /* get pointers to arch-specific information */
    struct arc_common *arc = target_to_arc(target);
    const unsigned long num_regs = arc->num_core_regs + arc->num_aux_regs;
    struct reg_cache **cache_p = register_get_last_cache_p(&target->reg_cache);
    struct reg_cache *cache = calloc(1, sizeof(*cache));
    struct reg *reg_list = calloc(num_regs, sizeof(*reg_list));
 
    if (!cache || !reg_list)  {
        LOG_TARGET_ERROR(target, "Not enough memory");
        goto fail;
    }
 
    /* Build the process context cache */
    cache->name = "arc registers";
    cache->next = NULL;
    cache->reg_list = reg_list;
    cache->num_regs = num_regs;
    arc->core_and_aux_cache = cache;
    (*cache_p) = cache;
 
    if (list_empty(&arc->core_reg_descriptions)) {
        LOG_TARGET_ERROR(target, "No core registers were defined");
        goto fail;
    }
 
    list_for_each_entry(reg_desc, &arc->core_reg_descriptions, list) {
        CHECK_RETVAL(arc_init_reg(target, &reg_list[i], reg_desc, i));
 
        LOG_TARGET_DEBUG(target, "reg n=%3li name=%3s group=%s feature=%s", i,
            reg_list[i].name, reg_list[i].group,
            reg_list[i].feature->name);
 
        i += 1;
    }
 
    if (list_empty(&arc->aux_reg_descriptions)) {
        LOG_TARGET_ERROR(target, "No aux registers were defined");
        goto fail;
    }
 
    list_for_each_entry(reg_desc, &arc->aux_reg_descriptions, list) {
        CHECK_RETVAL(arc_init_reg(target, &reg_list[i], reg_desc, i));
 
        LOG_TARGET_DEBUG(target, "reg n=%3li name=%3s group=%s feature=%s", i,
            reg_list[i].name, reg_list[i].group,
            reg_list[i].feature->name);
 
        /* PC and DEBUG are essential so we search for them. */
        if (!strcmp("pc", reg_desc->name)) {
            if (arc->pc_index_in_cache != ULONG_MAX) {
                LOG_TARGET_ERROR(target, "Double definition of PC in configuration");
                goto fail;
            }
            arc->pc_index_in_cache = i;
        } else if (!strcmp("debug", reg_desc->name)) {
            if (arc->debug_index_in_cache != ULONG_MAX) {
                LOG_TARGET_ERROR(target, "Double definition of DEBUG in configuration");
                goto fail;
            }
            arc->debug_index_in_cache = i;
        }
        i += 1;
    }
 
    if (arc->pc_index_in_cache == ULONG_MAX
            || arc->debug_index_in_cache == ULONG_MAX) {
        LOG_TARGET_ERROR(target, "`pc' and `debug' registers must be present in target description");
        goto fail;
    }
 
    assert(i == (arc->num_core_regs + arc->num_aux_regs));
 
    arc->core_aux_cache_built = true;
 
    return ERROR_OK;
 
fail:
    free(cache);
    free(reg_list);
 
    return ERROR_FAIL;
}
 
/* Build bcr reg_cache.
 * This function must be called only after arc_build_reg_cache */
static int arc_build_bcr_reg_cache(struct target *target)
{
    /* get pointers to arch-specific information */
    struct arc_common *arc = target_to_arc(target);
    const unsigned long num_regs = arc->num_bcr_regs;
    struct reg_cache **cache_p = register_get_last_cache_p(&target->reg_cache);
    struct reg_cache *cache = malloc(sizeof(*cache));
    struct reg *reg_list = calloc(num_regs, sizeof(*reg_list));
 
    struct arc_reg_desc *reg_desc;
    unsigned long i = 0;
    unsigned long gdb_regnum = arc->core_and_aux_cache->num_regs;
 
    if (!cache || !reg_list)  {
        LOG_TARGET_ERROR(target, "Unable to allocate memory");
        goto fail;
    }
 
    /* Build the process context cache */
    cache->name = "arc.bcr";
    cache->next = NULL;
    cache->reg_list = reg_list;
    cache->num_regs = num_regs;
    arc->bcr_cache = cache;
    (*cache_p) = cache;
 
    if (list_empty(&arc->bcr_reg_descriptions)) {
        LOG_TARGET_ERROR(target, "No BCR registers are defined");
        goto fail;
    }
 
    list_for_each_entry(reg_desc, &arc->bcr_reg_descriptions, list) {
        CHECK_RETVAL(arc_init_reg(target, &reg_list[i], reg_desc, gdb_regnum));
        /* BCRs always semantically, they are just read-as-zero, if there is
         * not real register. */
        reg_list[i].exist = true;
 
        LOG_TARGET_DEBUG(target, "reg n=%3li name=%3s group=%s feature=%s", i,
            reg_list[i].name, reg_list[i].group,
            reg_list[i].feature->name);
        i += 1;
        gdb_regnum += 1;
    }
 
    assert(i == arc->num_bcr_regs);
 
    arc->bcr_cache_built = true;
 
 
    return ERROR_OK;
fail:
    free(cache);
    free(reg_list);
 
    return ERROR_FAIL;
}
 
 
static int arc_get_gdb_reg_list(struct target *target, struct reg **reg_list[],
    int *reg_list_size, enum target_register_class reg_class)
{
    assert(target->reg_cache);
    struct arc_common *arc = target_to_arc(target);
 
    /* get pointers to arch-specific information storage */
    *reg_list_size = arc->num_regs;
    *reg_list = calloc(*reg_list_size, sizeof(struct reg *));
 
    if (!*reg_list) {
        LOG_TARGET_ERROR(target, "Unable to allocate memory");
        return ERROR_FAIL;
    }
 
    /* OpenOCD gdb_server API seems to be inconsistent here: when it generates
     * XML tdesc it filters out !exist registers, however when creating a
     * g-packet it doesn't do so. REG_CLASS_ALL is used in first case, and
     * REG_CLASS_GENERAL used in the latter one. Due to this we had to filter
     * out !exist register for "general", but not for "all". Attempts to filter out
     * !exist for "all" as well will cause a failed check in OpenOCD GDB
     * server. */
    if (reg_class == REG_CLASS_ALL) {
        unsigned long i = 0;
        struct reg_cache *reg_cache = target->reg_cache;
        while (reg_cache) {
            for (unsigned int j = 0; j < reg_cache->num_regs; j++, i++)
                (*reg_list)[i] =  &reg_cache->reg_list[j];
            reg_cache = reg_cache->next;
        }
        assert(i == arc->num_regs);
        LOG_TARGET_DEBUG(target, "REG_CLASS_ALL: number of regs=%i", *reg_list_size);
    } else {
        unsigned long i = 0;
        unsigned long gdb_reg_number = 0;
        struct reg_cache *reg_cache = target->reg_cache;
        while (reg_cache) {
            for (unsigned int j = 0;
                 j < reg_cache->num_regs && gdb_reg_number <= arc->last_general_reg;
                 j++) {
                if (reg_cache->reg_list[j].exist) {
                    (*reg_list)[i] =  &reg_cache->reg_list[j];
                    i++;
                }
                gdb_reg_number += 1;
            }
            reg_cache = reg_cache->next;
        }
        *reg_list_size = i;
        LOG_TARGET_DEBUG(target, "REG_CLASS_GENERAL: number of regs=%i", *reg_list_size);
    }
 
    return ERROR_OK;
}
 
/* Reading field of struct_type register */
int arc_reg_get_field(struct target *target, const char *reg_name,
        const char *field_name, uint32_t *value_ptr)
{
    struct reg_data_type_struct_field *field;
 
    LOG_TARGET_DEBUG(target, "getting register field (reg_name=%s, field_name=%s)", reg_name, field_name);
 
    /* Get register */
    struct reg *reg = arc_reg_get_by_name(target->reg_cache, reg_name, true);
 
    if (!reg) {
        LOG_TARGET_ERROR(target, "Requested register `%s' doesn't exist", reg_name);
        return ERROR_ARC_REGISTER_NOT_FOUND;
    }
 
    if (reg->reg_data_type->type != REG_TYPE_ARCH_DEFINED
        || reg->reg_data_type->type_class != REG_TYPE_CLASS_STRUCT)
        return ERROR_ARC_REGISTER_IS_NOT_STRUCT;
 
    /* Get field in a register */
    struct reg_data_type_struct *reg_struct =
        reg->reg_data_type->reg_type_struct;
    for (field = reg_struct->fields;
         field;
         field = field->next) {
        if (!strcmp(field->name, field_name))
            break;
    }
 
    if (!field)
        return ERROR_ARC_REGISTER_FIELD_NOT_FOUND;
 
    if (!field->use_bitfields)
        return ERROR_ARC_FIELD_IS_NOT_BITFIELD;
 
    if (!reg->valid)
        CHECK_RETVAL(reg->type->get(reg));
 
    /* First do endianness-safe read of register value
     * then convert it to binary buffer for further
     * field extraction */
 
    *value_ptr = buf_get_u32(reg->value, field->bitfield->start,
        field->bitfield->end - field->bitfield->start + 1);
 
    return ERROR_OK;
}
 
static int arc_get_register_value(struct target *target, const char *reg_name,
        uint32_t *value_ptr)
{
    LOG_TARGET_DEBUG(target, "reg_name=%s", reg_name);
 
    struct reg *reg = arc_reg_get_by_name(target->reg_cache, reg_name, true);
 
    if (!reg)
        return ERROR_ARC_REGISTER_NOT_FOUND;
 
    if (!reg->valid)
        CHECK_RETVAL(reg->type->get(reg));
 
    *value_ptr = target_buffer_get_u32(target, reg->value);
 
    return ERROR_OK;
}
 
static int arc_set_register_value(struct target *target, const char *reg_name,
        uint32_t value)
{
    LOG_TARGET_DEBUG(target, "reg_name=%s value=0x%08" PRIx32, reg_name, value);
 
    if (!(target && reg_name)) {
        LOG_TARGET_ERROR(target, "Arguments cannot be NULL");
        return ERROR_FAIL;
    }
 
    struct reg *reg = arc_reg_get_by_name(target->reg_cache, reg_name, true);
 
    if (!reg)
        return ERROR_ARC_REGISTER_NOT_FOUND;
 
    uint8_t value_buf[4];
    buf_set_u32(value_buf, 0, 32, value);
    CHECK_RETVAL(reg->type->set(reg, value_buf));
 
    return ERROR_OK;
}
 
/* Configure DCCM's */
static int arc_configure_dccm(struct target  *target)
{
    struct arc_common *arc = target_to_arc(target);
 
    uint32_t dccm_build_version, dccm_build_size0, dccm_build_size1;
    CHECK_RETVAL(arc_reg_get_field(target, "dccm_build", "version",
        &dccm_build_version));
    CHECK_RETVAL(arc_reg_get_field(target, "dccm_build", "size0",
        &dccm_build_size0));
    CHECK_RETVAL(arc_reg_get_field(target, "dccm_build", "size1",
        &dccm_build_size1));
    /* There is no yet support of configurable number of cycles,
     * So there is no difference between v3 and v4 */
    if ((dccm_build_version == 3 || dccm_build_version == 4) && dccm_build_size0 > 0) {
        CHECK_RETVAL(arc_get_register_value(target, "aux_dccm", &(arc->dccm_start)));
        uint32_t dccm_size = 0x100;
        dccm_size <<= dccm_build_size0;
        if (dccm_build_size0 == 0xF)
            dccm_size <<= dccm_build_size1;
        arc->dccm_end = arc->dccm_start + dccm_size;
        LOG_TARGET_DEBUG(target, "DCCM detected start=0x%" PRIx32 " end=0x%" PRIx32,
                arc->dccm_start, arc->dccm_end);
 
    }
    return ERROR_OK;
}
 
 
/* Configure ICCM's */
 
static int arc_configure_iccm(struct target  *target)
{
    struct arc_common *arc = target_to_arc(target);
 
    /* ICCM0 */
    uint32_t iccm_build_version, iccm_build_size00, iccm_build_size01;
    uint32_t aux_iccm = 0;
    CHECK_RETVAL(arc_reg_get_field(target, "iccm_build", "version",
        &iccm_build_version));
    CHECK_RETVAL(arc_reg_get_field(target, "iccm_build", "iccm0_size0",
        &iccm_build_size00));
    CHECK_RETVAL(arc_reg_get_field(target, "iccm_build", "iccm0_size1",
        &iccm_build_size01));
    if (iccm_build_version == 4 && iccm_build_size00 > 0) {
        CHECK_RETVAL(arc_get_register_value(target, "aux_iccm", &aux_iccm));
        uint32_t iccm0_size = 0x100;
        iccm0_size <<= iccm_build_size00;
        if (iccm_build_size00 == 0xF)
            iccm0_size <<= iccm_build_size01;
        /* iccm0 start is located in highest 4 bits of aux_iccm */
        arc->iccm0_start = aux_iccm & 0xF0000000;
        arc->iccm0_end = arc->iccm0_start + iccm0_size;
        LOG_TARGET_DEBUG(target, "ICCM0 detected start=0x%" PRIx32 " end=0x%" PRIx32,
                arc->iccm0_start, arc->iccm0_end);
    }
 
    /* ICCM1 */
    uint32_t iccm_build_size10, iccm_build_size11;
    CHECK_RETVAL(arc_reg_get_field(target, "iccm_build", "iccm1_size0",
        &iccm_build_size10));
    CHECK_RETVAL(arc_reg_get_field(target, "iccm_build", "iccm1_size1",
        &iccm_build_size11));
    if (iccm_build_version == 4 && iccm_build_size10 > 0) {
        /* Use value read for ICCM0 */
        if (!aux_iccm)
            CHECK_RETVAL(arc_get_register_value(target, "aux_iccm", &aux_iccm));
        uint32_t iccm1_size = 0x100;
        iccm1_size <<= iccm_build_size10;
        if (iccm_build_size10 == 0xF)
            iccm1_size <<= iccm_build_size11;
        arc->iccm1_start = aux_iccm & 0x0F000000;
        arc->iccm1_end = arc->iccm1_start + iccm1_size;
        LOG_TARGET_DEBUG(target, "ICCM1 detected start=0x%" PRIx32 " end=0x%" PRIx32,
                arc->iccm1_start, arc->iccm1_end);
    }
    return ERROR_OK;
}
 
/* Configure some core features, depending on BCRs. */
static int arc_configure(struct target *target)
{
    LOG_TARGET_DEBUG(target, "Configuring ARC ICCM and DCCM");
 
    /* Configuring DCCM if DCCM_BUILD and AUX_DCCM are known registers. */
    if (arc_reg_get_by_name(target->reg_cache, "dccm_build", true)
            && arc_reg_get_by_name(target->reg_cache, "aux_dccm", true))
        CHECK_RETVAL(arc_configure_dccm(target));
 
    /* Configuring ICCM if ICCM_BUILD and AUX_ICCM are known registers. */
    if (arc_reg_get_by_name(target->reg_cache, "iccm_build", true)
            && arc_reg_get_by_name(target->reg_cache, "aux_iccm", true))
        CHECK_RETVAL(arc_configure_iccm(target));
 
    return ERROR_OK;
}
 
/* arc_examine is function, which is used for all arc targets*/
static int arc_examine(struct target *target)
{
    uint32_t status;
    struct arc_common *arc = target_to_arc(target);
 
    CHECK_RETVAL(arc_jtag_startup(&arc->jtag_info));
 
    if (!target_was_examined(target)) {
        CHECK_RETVAL(arc_jtag_status(&arc->jtag_info, &status));
        if (status & ARC_JTAG_STAT_RU)
            target->state = TARGET_RUNNING;
        else
            target->state = TARGET_HALTED;
 
        /* Read BCRs and configure optional registers. */
        CHECK_RETVAL(arc_configure(target));
    }
 
    return ERROR_OK;
}
 
static int arc_exit_debug(struct target *target)
{
    uint32_t value;
    struct arc_common *arc = target_to_arc(target);
 
    /* Do read-modify-write sequence, or DEBUG.UB will be reset unintentionally. */
    CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_DEBUG_REG, &value));
    value |= SET_CORE_FORCE_HALT; /* set the HALT bit */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DEBUG_REG, value));
    alive_sleep(1);
 
    target->state = TARGET_HALTED;
    CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_HALTED));
 
    if (LOG_LEVEL_IS(LOG_LVL_DEBUG)) {
        LOG_TARGET_DEBUG(target, "core stopped (halted) debug-reg: 0x%08" PRIx32, value);
        CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_STATUS32_REG, &value));
        LOG_TARGET_DEBUG(target, "core STATUS32: 0x%08" PRIx32, value);
    }
 
    return ERROR_OK;
}
 
static int arc_halt(struct target *target)
{
    uint32_t value, irq_state;
    struct arc_common *arc = target_to_arc(target);
 
    LOG_TARGET_DEBUG(target, "target->state: %s", target_state_name(target));
 
    if (target->state == TARGET_HALTED) {
        LOG_TARGET_DEBUG(target, "target was already halted");
        return ERROR_OK;
    }
 
    if (target->state == TARGET_UNKNOWN)
        LOG_TARGET_WARNING(target, "target was in unknown state when halt was requested");
 
    if (target->state == TARGET_RESET) {
        if ((jtag_get_reset_config() & RESET_SRST_PULLS_TRST) && jtag_get_srst()) {
            LOG_TARGET_ERROR(target, "can't request a halt while in reset if nSRST pulls nTRST");
            return ERROR_TARGET_FAILURE;
        } else {
            target->debug_reason = DBG_REASON_DBGRQ;
        }
    }
 
    /* Break (stop) processor.
     * Do read-modify-write sequence, or DEBUG.UB will be reset unintentionally.
     * We do not use here arc_get/set_core_reg functions here because they imply
     * that the processor is already halted. */
    CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_DEBUG_REG, &value));
    value |= SET_CORE_FORCE_HALT; /* set the HALT bit */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DEBUG_REG, value));
    alive_sleep(1);
 
    /* Save current IRQ state */
    CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_STATUS32_REG, &irq_state));
 
    if (irq_state & AUX_STATUS32_REG_IE_BIT)
        arc->irq_state = 1;
    else
        arc->irq_state = 0;
 
    /* update state and notify gdb*/
    target->state = TARGET_HALTED;
    CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_HALTED));
 
    /* some more debug information */
    if (LOG_LEVEL_IS(LOG_LVL_DEBUG)) {
        LOG_TARGET_DEBUG(target, "core stopped (halted) DEGUB-REG: 0x%08" PRIx32, value);
        CHECK_RETVAL(arc_get_register_value(target, "status32", &value));
        LOG_TARGET_DEBUG(target, "core STATUS32: 0x%08" PRIx32, value);
    }
 
    return ERROR_OK;
}
 
static int arc_save_context(struct target *target)
{
    int retval = ERROR_OK;
    unsigned int i;
    struct arc_common *arc = target_to_arc(target);
    struct reg *reg_list = arc->core_and_aux_cache->reg_list;
 
    LOG_TARGET_DEBUG(target, "Saving aux and core registers values");
    assert(reg_list);
 
    /* It is assumed that there is at least one AUX register in the list, for
     * example PC. */
    const uint32_t core_regs_size = arc->num_core_regs * sizeof(uint32_t);
    /* last_general_reg is inclusive number. To get count of registers it is
     * required to do +1. */
    const uint32_t regs_to_scan =
        MIN(arc->last_general_reg + 1, arc->num_regs);
    const uint32_t aux_regs_size = arc->num_aux_regs * sizeof(uint32_t);
    uint32_t *core_values = malloc(core_regs_size);
    uint32_t *aux_values = malloc(aux_regs_size);
    uint32_t *core_addrs = malloc(core_regs_size);
    uint32_t *aux_addrs = malloc(aux_regs_size);
    unsigned int core_cnt = 0;
    unsigned int aux_cnt = 0;
 
    if (!core_values || !core_addrs || !aux_values || !aux_addrs)  {
        LOG_TARGET_ERROR(target, "Unable to allocate memory");
        retval = ERROR_FAIL;
        goto exit;
    }
 
    memset(core_values, 0xff, core_regs_size);
    memset(core_addrs, 0xff, core_regs_size);
    memset(aux_values, 0xff, aux_regs_size);
    memset(aux_addrs, 0xff, aux_regs_size);
 
    for (i = 0; i < MIN(arc->num_core_regs, regs_to_scan); i++) {
        struct reg *reg = reg_list + i;
        struct arc_reg_desc *arc_reg = reg->arch_info;
        if (!reg->valid && reg->exist)
            core_addrs[core_cnt++] = arc_reg->arch_num;
    }
 
    for (i = arc->num_core_regs; i < regs_to_scan; i++) {
        struct reg *reg = reg_list + i;
        struct arc_reg_desc *arc_reg = reg->arch_info;
        if (!reg->valid && reg->exist)
            aux_addrs[aux_cnt++] = arc_reg->arch_num;
    }
 
    /* Read data from target. */
    if (core_cnt > 0) {
        retval = arc_jtag_read_core_reg(&arc->jtag_info, core_addrs, core_cnt, core_values);
        if (retval != ERROR_OK) {
            LOG_TARGET_ERROR(target, "Attempt to read core registers failed");
            retval = ERROR_FAIL;
            goto exit;
        }
    }
    if (aux_cnt > 0) {
        retval = arc_jtag_read_aux_reg(&arc->jtag_info, aux_addrs, aux_cnt, aux_values);
        if (retval != ERROR_OK) {
            LOG_TARGET_ERROR(target, "Attempt to read aux registers failed");
            retval = ERROR_FAIL;
            goto exit;
        }
    }
 
    /* Parse core regs */
    core_cnt = 0;
    for (i = 0; i < MIN(arc->num_core_regs, regs_to_scan); i++) {
        struct reg *reg = reg_list + i;
        struct arc_reg_desc *arc_reg = reg->arch_info;
        if (!reg->valid && reg->exist) {
            target_buffer_set_u32(target, reg->value, core_values[core_cnt]);
            reg->valid = true;
            reg->dirty = false;
            LOG_TARGET_DEBUG(target, "Get core register regnum=%u, name=%s, value=0x%08" PRIx32,
                i, arc_reg->name, core_values[core_cnt]);
            core_cnt++;
        }
    }
 
    /* Parse aux regs */
    aux_cnt = 0;
    for (i = arc->num_core_regs; i < regs_to_scan; i++) {
        struct reg *reg = reg_list + i;
        struct arc_reg_desc *arc_reg = reg->arch_info;
        if (!reg->valid && reg->exist) {
            target_buffer_set_u32(target, reg->value, aux_values[aux_cnt]);
            reg->valid = true;
            reg->dirty = false;
            LOG_TARGET_DEBUG(target, "Get aux register regnum=%u, name=%s, value=0x%08" PRIx32,
                i, arc_reg->name, aux_values[aux_cnt]);
            aux_cnt++;
        }
    }
 
exit:
    free(core_values);
    free(core_addrs);
    free(aux_values);
    free(aux_addrs);
 
    return retval;
}
 
static int get_current_actionpoint(struct target *target,
        struct arc_actionpoint **actionpoint)
{
    assert(target);
    assert(actionpoint);
 
    uint32_t debug_ah;
    /* Check if actionpoint caused halt */
    CHECK_RETVAL(arc_reg_get_field(target, "debug", "ah",
                &debug_ah));
 
    if (debug_ah) {
        struct arc_common *arc = target_to_arc(target);
        unsigned int ap;
        uint32_t debug_asr;
        CHECK_RETVAL(arc_reg_get_field(target, "debug",
                    "asr", &debug_asr));
 
        for (ap = 0; debug_asr > 1; debug_asr >>= 1)
            ap += 1;
 
        assert(ap < arc->actionpoints_num);
 
        *actionpoint = &(arc->actionpoints_list[ap]);
    } else {
        *actionpoint = NULL;
    }
 
    return ERROR_OK;
}
 
static int arc_examine_debug_reason(struct target *target)
{
    uint32_t debug_bh;
 
    /* Only check for reason if don't know it already. */
    /* BTW After singlestep at this point core is not marked as halted, so
     * reading from memory to get current instruction wouldn't work anyway.  */
    if (target->debug_reason == DBG_REASON_DBGRQ ||
        target->debug_reason == DBG_REASON_SINGLESTEP) {
        return ERROR_OK;
    }
 
    CHECK_RETVAL(arc_reg_get_field(target, "debug", "bh",
                &debug_bh));
 
    if (debug_bh) {
        /* DEBUG.BH is set if core halted due to BRK instruction.  */
        target->debug_reason = DBG_REASON_BREAKPOINT;
    } else {
        struct arc_actionpoint *actionpoint = NULL;
        CHECK_RETVAL(get_current_actionpoint(target, &actionpoint));
 
        if (actionpoint) {
            if (!actionpoint->used)
                LOG_TARGET_WARNING(target, "Target halted by an unused actionpoint");
 
            if (actionpoint->type == ARC_AP_BREAKPOINT)
                target->debug_reason = DBG_REASON_BREAKPOINT;
            else if (actionpoint->type == ARC_AP_WATCHPOINT)
                target->debug_reason = DBG_REASON_WATCHPOINT;
            else
                LOG_TARGET_WARNING(target, "Unknown type of actionpoint");
        }
    }
 
    return ERROR_OK;
}
 
static int arc_debug_entry(struct target *target)
{
    CHECK_RETVAL(arc_save_context(target));
 
    /* TODO: reset internal indicators of caches states, otherwise D$/I$
     * will not be flushed/invalidated when required. */
    CHECK_RETVAL(arc_reset_caches_states(target));
    CHECK_RETVAL(arc_examine_debug_reason(target));
 
    return ERROR_OK;
}
 
static int arc_poll(struct target *target)
{
    uint32_t status, value;
    struct arc_common *arc = target_to_arc(target);
 
    /* gdb calls continuously through this arc_poll() function  */
    CHECK_RETVAL(arc_jtag_status(&arc->jtag_info, &status));
 
    /* check for processor halted */
    if (status & ARC_JTAG_STAT_RU) {
        if (target->state != TARGET_RUNNING) {
            LOG_TARGET_WARNING(target, "target is still running");
            target->state = TARGET_RUNNING;
        }
        return ERROR_OK;
    }
    /* In some cases JTAG status register indicates that
     *  processor is in halt mode, but processor is still running.
     *  We check halt bit of AUX STATUS32 register for setting correct state. */
    if ((target->state == TARGET_RUNNING) || (target->state == TARGET_RESET)) {
        CHECK_RETVAL(arc_get_register_value(target, "status32", &value));
        if (value & AUX_STATUS32_REG_HALT_BIT) {
            LOG_TARGET_DEBUG(target, "ARC core in halt or reset state");
            /* Save context if target was not in reset state */
            if (target->state == TARGET_RUNNING)
                CHECK_RETVAL(arc_debug_entry(target));
            target->state = TARGET_HALTED;
            CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_HALTED));
        } else {
            LOG_TARGET_DEBUG(target, "Discrepancy of STATUS32[0] HALT bit and ARC_JTAG_STAT_RU, "
                        "target is still running");
        }
    } else if (target->state == TARGET_DEBUG_RUNNING) {
        target->state = TARGET_HALTED;
        LOG_TARGET_DEBUG(target, "ARC core is in debug running mode");
 
        CHECK_RETVAL(arc_debug_entry(target));
 
        CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_DEBUG_HALTED));
    }
 
    return ERROR_OK;
}
 
static int arc_assert_reset(struct target *target)
{
    struct arc_common *arc = target_to_arc(target);
    enum reset_types jtag_reset_config = jtag_get_reset_config();
    bool srst_asserted = false;
 
    LOG_TARGET_DEBUG(target, "target->state: %s", target_state_name(target));
 
    if (target_has_event_action(target, TARGET_EVENT_RESET_ASSERT)) {
        /* allow scripts to override the reset event */
 
        target_handle_event(target, TARGET_EVENT_RESET_ASSERT);
        register_cache_invalidate(arc->core_and_aux_cache);
         /* An ARC target might be in halt state after reset, so
         * if script requested processor to resume, then it must
         * be manually started to ensure that this request
         * is satisfied. */
        if (target->state == TARGET_HALTED && !target->reset_halt) {
            /* Resume the target and continue from the current
             * PC register value. */
            LOG_TARGET_DEBUG(target, "Starting CPU execution after reset");
            CHECK_RETVAL(target_resume(target, true, 0, false, false));
        }
        target->state = TARGET_RESET;
 
        return ERROR_OK;
    }
 
    /* some cores support connecting while srst is asserted
     * use that mode if it has been configured */
    if (!(jtag_reset_config & RESET_SRST_PULLS_TRST) &&
            (jtag_reset_config & RESET_SRST_NO_GATING)) {
        jtag_add_reset(0, 1);
        srst_asserted = true;
    }
 
    if (jtag_reset_config & RESET_HAS_SRST) {
        /* should issue a srst only, but we may have to assert trst as well */
        if (jtag_reset_config & RESET_SRST_PULLS_TRST)
            jtag_add_reset(1, 1);
        else if (!srst_asserted)
            jtag_add_reset(0, 1);
    }
 
    target->state = TARGET_RESET;
    jtag_add_sleep(50000);
 
    register_cache_invalidate(arc->core_and_aux_cache);
 
    if (target->reset_halt)
        CHECK_RETVAL(target_halt(target));
 
    return ERROR_OK;
}
 
static int arc_deassert_reset(struct target *target)
{
    LOG_TARGET_DEBUG(target, "target->state: %s", target_state_name(target));
 
    /* deassert reset lines */
    jtag_add_reset(0, 0);
 
    return ERROR_OK;
}
 
static int arc_arch_state(struct target *target)
{
    uint32_t pc_value;
 
    if (!LOG_LEVEL_IS(LOG_LVL_DEBUG))
        return ERROR_OK;
 
    CHECK_RETVAL(arc_get_register_value(target, "pc", &pc_value));
 
    LOG_TARGET_DEBUG(target, "target state: %s;  PC at: 0x%08" PRIx32,
        target_state_name(target),
        pc_value);
 
    return ERROR_OK;
}
 
static int arc_restore_context(struct target *target)
{
    int retval = ERROR_OK;
    unsigned int i;
    struct arc_common *arc = target_to_arc(target);
    struct reg *reg_list = arc->core_and_aux_cache->reg_list;
 
    LOG_TARGET_DEBUG(target, "Restoring registers values");
    assert(reg_list);
 
    const uint32_t core_regs_size = arc->num_core_regs  * sizeof(uint32_t);
    const uint32_t aux_regs_size =  arc->num_aux_regs * sizeof(uint32_t);
    uint32_t *core_values = malloc(core_regs_size);
    uint32_t *aux_values = malloc(aux_regs_size);
    uint32_t *core_addrs = malloc(core_regs_size);
    uint32_t *aux_addrs = malloc(aux_regs_size);
    unsigned int core_cnt = 0;
    unsigned int aux_cnt = 0;
 
    if (!core_values || !core_addrs || !aux_values || !aux_addrs)  {
        LOG_TARGET_ERROR(target, "Unable to allocate memory");
        retval = ERROR_FAIL;
        goto exit;
    }
 
    memset(core_values, 0xff, core_regs_size);
    memset(core_addrs, 0xff, core_regs_size);
    memset(aux_values, 0xff, aux_regs_size);
    memset(aux_addrs, 0xff, aux_regs_size);
 
    for (i = 0; i < arc->num_core_regs; i++) {
        struct reg *reg = &(reg_list[i]);
        struct arc_reg_desc *arc_reg = reg->arch_info;
        if (reg->valid && reg->exist && reg->dirty) {
            LOG_TARGET_DEBUG(target, "Will write regnum=%u", i);
            core_addrs[core_cnt] = arc_reg->arch_num;
            core_values[core_cnt] = target_buffer_get_u32(target, reg->value);
            core_cnt += 1;
        }
    }
 
    for (i = 0; i < arc->num_aux_regs; i++) {
        struct reg *reg = &(reg_list[arc->num_core_regs + i]);
        struct arc_reg_desc *arc_reg = reg->arch_info;
        if (reg->valid && reg->exist && reg->dirty) {
            LOG_TARGET_DEBUG(target, "Will write regnum=%lu", arc->num_core_regs + i);
            aux_addrs[aux_cnt] = arc_reg->arch_num;
            aux_values[aux_cnt] = target_buffer_get_u32(target, reg->value);
            aux_cnt += 1;
        }
    }
 
    /* Write data to target.
     * Check before write, if aux and core count is greater than 0. */
    if (core_cnt > 0) {
        retval = arc_jtag_write_core_reg(&arc->jtag_info, core_addrs, core_cnt, core_values);
        if (retval != ERROR_OK) {
            LOG_TARGET_ERROR(target, "Attempt to write to core registers failed");
            retval = ERROR_FAIL;
            goto exit;
        }
    }
 
    if (aux_cnt > 0) {
        retval = arc_jtag_write_aux_reg(&arc->jtag_info, aux_addrs, aux_cnt, aux_values);
        if (retval != ERROR_OK) {
            LOG_TARGET_ERROR(target, "Attempt to write to aux registers failed");
            retval = ERROR_FAIL;
            goto exit;
        }
    }
 
exit:
    free(core_values);
    free(core_addrs);
    free(aux_values);
    free(aux_addrs);
 
    return retval;
}
 
static int arc_enable_interrupts(struct target *target, bool enable)
{
    uint32_t value;
 
    struct arc_common *arc = target_to_arc(target);
 
    CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_STATUS32_REG, &value));
 
    if (enable) {
        /* enable interrupts */
        value |= SET_CORE_ENABLE_INTERRUPTS;
        CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_STATUS32_REG, value));
        LOG_TARGET_DEBUG(target, "interrupts enabled");
    } else {
        /* disable interrupts */
        value &= ~SET_CORE_ENABLE_INTERRUPTS;
        CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_STATUS32_REG, value));
        LOG_TARGET_DEBUG(target, "interrupts disabled");
    }
 
    return ERROR_OK;
}
 
static int arc_resume(struct target *target, bool current, target_addr_t address,
        bool handle_breakpoints, bool debug_execution)
{
    struct arc_common *arc = target_to_arc(target);
    uint32_t resume_pc = 0;
    uint32_t value;
    struct reg *pc = &arc->core_and_aux_cache->reg_list[arc->pc_index_in_cache];
 
    LOG_TARGET_DEBUG(target, "current:%i, address:0x%08" TARGET_PRIxADDR ", handle_breakpoints:%i,"
        " debug_execution:%i", current, address, handle_breakpoints, debug_execution);
 
    /* We need to reset ARC cache variables so caches
     * would be invalidated and actual data
     * would be fetched from memory. */
    CHECK_RETVAL(arc_reset_caches_states(target));
 
    if (target->state != TARGET_HALTED) {
        LOG_TARGET_ERROR(target, "not halted");
        return ERROR_TARGET_NOT_HALTED;
    }
 
    if (!debug_execution) {
        /* (gdb) continue = execute until we hit break/watch-point */
        target_free_all_working_areas(target);
        CHECK_RETVAL(arc_enable_breakpoints(target));
        CHECK_RETVAL(arc_enable_watchpoints(target));
    }
 
    /* current = true: continue on current PC, otherwise continue at <address> */
    if (!current) {
        target_buffer_set_u32(target, pc->value, address);
        pc->dirty = true;
        pc->valid = true;
        LOG_TARGET_DEBUG(target, "Changing the value of current PC to 0x%08" TARGET_PRIxADDR, address);
    }
 
    if (!current)
        resume_pc = address;
    else
        resume_pc = target_buffer_get_u32(target, pc->value);
 
    CHECK_RETVAL(arc_restore_context(target));
 
    LOG_TARGET_DEBUG(target, "Target resumes from PC=0x%" PRIx32 ", pc.dirty=%i, pc.valid=%i",
        resume_pc, pc->dirty, pc->valid);
 
    /* check if GDB tells to set our PC where to continue from */
    if (pc->valid && resume_pc == target_buffer_get_u32(target, pc->value)) {
        value = target_buffer_get_u32(target, pc->value);
        LOG_TARGET_DEBUG(target, "resume Core (when start-core) with PC @:0x%08" PRIx32, value);
        CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_PC_REG, value));
    }
 
    /* the front-end may request us not to handle breakpoints here */
    if (handle_breakpoints) {
        /* Single step past breakpoint at current address */
        struct breakpoint *breakpoint = breakpoint_find(target, resume_pc);
        if (breakpoint) {
            LOG_TARGET_DEBUG(target, "skipping past breakpoint at 0x%08" TARGET_PRIxADDR,
                breakpoint->address);
            CHECK_RETVAL(arc_unset_breakpoint(target, breakpoint));
            CHECK_RETVAL(arc_single_step_core(target));
            CHECK_RETVAL(arc_set_breakpoint(target, breakpoint));
        }
    }
 
    /* Restore IRQ state if not in debug_execution*/
    if (!debug_execution)
        CHECK_RETVAL(arc_enable_interrupts(target, arc->irq_state));
    else
        CHECK_RETVAL(arc_enable_interrupts(target, !debug_execution));
 
    target->debug_reason = DBG_REASON_NOTHALTED;
 
    /* ready to get us going again */
    target->state = TARGET_RUNNING;
    CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_STATUS32_REG, &value));
    value &= ~SET_CORE_HALT_BIT;        /* clear the HALT bit */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_STATUS32_REG, value));
    LOG_TARGET_DEBUG(target, "Core started to run");
 
    /* registers are now invalid */
    register_cache_invalidate(arc->core_and_aux_cache);
 
    if (!debug_execution) {
        target->state = TARGET_RUNNING;
        CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_RESUMED));
        LOG_TARGET_DEBUG(target, "target resumed at 0x%08" PRIx32, resume_pc);
    } else {
        target->state = TARGET_DEBUG_RUNNING;
        CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_DEBUG_RESUMED));
        LOG_TARGET_DEBUG(target, "target debug resumed at 0x%08" PRIx32, resume_pc);
    }
 
    return ERROR_OK;
}
 
static int arc_init_target(struct command_context *cmd_ctx, struct target *target)
{
    CHECK_RETVAL(arc_build_reg_cache(target));
    CHECK_RETVAL(arc_build_bcr_reg_cache(target));
    target->debug_reason = DBG_REASON_DBGRQ;
    return ERROR_OK;
}
 
static void arc_free_reg_cache(struct reg_cache *cache)
{
    free(cache->reg_list);
    free(cache);
}
 
static void arc_deinit_target(struct target *target)
{
    struct arc_common *arc = target_to_arc(target);
 
    LOG_TARGET_DEBUG(target, "deinitialization of target");
    if (arc->core_aux_cache_built)
        arc_free_reg_cache(arc->core_and_aux_cache);
    if (arc->bcr_cache_built)
        arc_free_reg_cache(arc->bcr_cache);
 
    struct arc_reg_data_type *type, *n;
    struct arc_reg_desc *desc, *k;
 
    /* Free arc-specific reg_data_types allocations*/
    list_for_each_entry_safe_reverse(type, n, &arc->reg_data_types, list) {
        if (type->data_type.type_class == REG_TYPE_CLASS_STRUCT) {
            free(type->reg_type_struct_field);
            free(type->bitfields);
            free(type);
        }   else if (type->data_type.type_class == REG_TYPE_CLASS_FLAGS) {
            free(type->reg_type_flags_field);
            free(type->bitfields);
            free(type);
        }
    }
 
    /* Free standard_gdb_types reg_data_types allocations */
    type = list_first_entry(&arc->reg_data_types, struct arc_reg_data_type, list);
    free(type);
 
    list_for_each_entry_safe(desc, k, &arc->aux_reg_descriptions, list)
        free_reg_desc(desc);
 
    list_for_each_entry_safe(desc, k, &arc->core_reg_descriptions, list)
        free_reg_desc(desc);
 
    list_for_each_entry_safe(desc, k, &arc->bcr_reg_descriptions, list)
        free_reg_desc(desc);
 
    free(arc->actionpoints_list);
    free(arc);
}
 
 
static int arc_target_create(struct target *target)
{
    struct arc_common *arc = calloc(1, sizeof(*arc));
 
    if (!arc) {
        LOG_TARGET_ERROR(target, "Unable to allocate memory");
        return ERROR_FAIL;
    }
 
    LOG_TARGET_DEBUG(target, "Entering");
    CHECK_RETVAL(arc_init_arch_info(target, arc, target->tap));
 
    return ERROR_OK;
}
 
static int arc_write_instruction_u32(struct target *target, uint32_t address,
    uint32_t instr)
{
    uint8_t value_buf[4];
    if (!target_was_examined(target)) {
        LOG_TARGET_ERROR(target, "Target not examined yet");
        return ERROR_FAIL;
    }
 
    LOG_TARGET_DEBUG(target, "Address: 0x%08" PRIx32 ", value: 0x%08" PRIx32, address,
        instr);
 
    if (target->endianness == TARGET_LITTLE_ENDIAN)
        arc_h_u32_to_me(value_buf, instr);
    else
        h_u32_to_be(value_buf, instr);
 
    CHECK_RETVAL(target_write_buffer(target, address, 4, value_buf));
 
    return ERROR_OK;
}
 
static int arc_read_instruction_u32(struct target *target, uint32_t address,
        uint32_t *value)
{
    uint8_t value_buf[4];
 
    if (!target_was_examined(target)) {
        LOG_TARGET_ERROR(target, "Target not examined yet");
        return ERROR_FAIL;
    }
 
    *value = 0;
    CHECK_RETVAL(target_read_buffer(target, address, 4, value_buf));
 
    if (target->endianness == TARGET_LITTLE_ENDIAN)
        *value = arc_me_to_h_u32(value_buf);
    else
        *value = be_to_h_u32(value_buf);
 
    LOG_TARGET_DEBUG(target, "Address: 0x%08" PRIx32 ", value: 0x%08" PRIx32, address,
        *value);
 
    return ERROR_OK;
}
 
/* Actionpoint mechanism allows to setup HW breakpoints
 * and watchpoints. Each actionpoint is controlled by
 * 3 aux registers: Actionpoint(AP) match mask(AP_AMM), AP match value(AP_AMV)
 * and AP control(AC).
 * This function is for setting/unsetting actionpoints:
 * at - actionpoint target: trigger on mem/reg access
 * tt - transaction type : trigger on r/w. */
static int arc_configure_actionpoint(struct target *target, uint32_t ap_num,
    uint32_t match_value, uint32_t control_tt, uint32_t control_at)
{
    struct arc_common *arc = target_to_arc(target);
 
    if (control_tt != AP_AC_TT_DISABLE) {
 
        if (arc->actionpoints_num_avail < 1) {
            LOG_TARGET_ERROR(target, "No free actionpoints, maximum amount is %u",
                    arc->actionpoints_num);
            return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
        }
 
        /* Names of register to set - 24 chars should be enough. Looks a little
         * bit out-of-place for C code, but makes it aligned to the bigger
         * concept of "ARC registers are defined in TCL" as far as possible.
         */
        char ap_amv_reg_name[24], ap_amm_reg_name[24], ap_ac_reg_name[24];
        snprintf(ap_amv_reg_name, 24, "ap_amv%" PRIu32, ap_num);
        snprintf(ap_amm_reg_name, 24, "ap_amm%" PRIu32, ap_num);
        snprintf(ap_ac_reg_name, 24, "ap_ac%" PRIu32, ap_num);
        CHECK_RETVAL(arc_set_register_value(target, ap_amv_reg_name,
                     match_value));
        CHECK_RETVAL(arc_set_register_value(target, ap_amm_reg_name, 0));
        CHECK_RETVAL(arc_set_register_value(target, ap_ac_reg_name,
                     control_tt | control_at));
        arc->actionpoints_num_avail--;
    } else {
        char ap_ac_reg_name[24];
        snprintf(ap_ac_reg_name, 24, "ap_ac%" PRIu32, ap_num);
        CHECK_RETVAL(arc_set_register_value(target, ap_ac_reg_name,
                     AP_AC_TT_DISABLE));
        arc->actionpoints_num_avail++;
    }
 
    return ERROR_OK;
}
 
static int arc_set_breakpoint(struct target *target,
        struct breakpoint *breakpoint)
{
    if (breakpoint->is_set) {
        LOG_TARGET_WARNING(target, "breakpoint already set");
        return ERROR_OK;
    }
 
    if (breakpoint->type == BKPT_SOFT) {
        LOG_TARGET_DEBUG(target, "bpid: %" PRIu32, breakpoint->unique_id);
 
        if (breakpoint->length == 4) {
            uint32_t verify = 0xffffffff;
 
            CHECK_RETVAL(target_read_buffer(target, breakpoint->address, breakpoint->length,
                    breakpoint->orig_instr));
 
            CHECK_RETVAL(arc_write_instruction_u32(target, breakpoint->address,
                    ARC_SDBBP_32));
 
            CHECK_RETVAL(arc_read_instruction_u32(target, breakpoint->address, &verify));
 
            if (verify != ARC_SDBBP_32) {
                LOG_TARGET_ERROR(target, "Unable to set 32bit breakpoint at address @0x%" TARGET_PRIxADDR
                        " - check that memory is read/writable", breakpoint->address);
                return ERROR_FAIL;
            }
        } else if (breakpoint->length == 2) {
            uint16_t verify = 0xffff;
 
            CHECK_RETVAL(target_read_buffer(target, breakpoint->address, breakpoint->length,
                    breakpoint->orig_instr));
            CHECK_RETVAL(target_write_u16(target, breakpoint->address, ARC_SDBBP_16));
 
            CHECK_RETVAL(target_read_u16(target, breakpoint->address, &verify));
            if (verify != ARC_SDBBP_16) {
                LOG_TARGET_ERROR(target, "Unable to set 16bit breakpoint at address @0x%" TARGET_PRIxADDR
                        " - check that memory is read/writable", breakpoint->address);
                return ERROR_FAIL;
            }
        } else {
            LOG_TARGET_ERROR(target, "Invalid breakpoint length: target supports only 2 or 4");
            return ERROR_COMMAND_ARGUMENT_INVALID;
        }
 
        breakpoint->is_set = true;
    } else if (breakpoint->type == BKPT_HARD) {
        struct arc_common *arc = target_to_arc(target);
        struct arc_actionpoint *ap_list = arc->actionpoints_list;
        unsigned int bp_num;
 
        for (bp_num = 0; bp_num < arc->actionpoints_num; bp_num++) {
            if (!ap_list[bp_num].used)
                break;
        }
 
        if (bp_num >= arc->actionpoints_num) {
            LOG_TARGET_ERROR(target, "No free actionpoints, maximum amount is %u",
                    arc->actionpoints_num);
            return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
        }
 
        int retval = arc_configure_actionpoint(target, bp_num,
                breakpoint->address, AP_AC_TT_READWRITE, AP_AC_AT_INST_ADDR);
 
        if (retval == ERROR_OK) {
            breakpoint_hw_set(breakpoint, bp_num);
            ap_list[bp_num].used = 1;
            ap_list[bp_num].bp_value = breakpoint->address;
            ap_list[bp_num].type = ARC_AP_BREAKPOINT;
 
            LOG_TARGET_DEBUG(target, "bpid: %" PRIu32 ", bp_num %u bp_value 0x%" PRIx32,
                    breakpoint->unique_id, bp_num, ap_list[bp_num].bp_value);
        }
 
    } else {
        LOG_TARGET_ERROR(target, "setting unknown breakpoint type");
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int arc_unset_breakpoint(struct target *target,
        struct breakpoint *breakpoint)
{
    int retval = ERROR_OK;
 
    if (!breakpoint->is_set) {
        LOG_TARGET_WARNING(target, "breakpoint not set");
        return ERROR_OK;
    }
 
    if (breakpoint->type == BKPT_SOFT) {
        /* restore original instruction (kept in target endianness) */
        LOG_TARGET_DEBUG(target, "bpid: %" PRIu32, breakpoint->unique_id);
        if (breakpoint->length == 4) {
            uint32_t current_instr;
 
            /* check that user program has not modified breakpoint instruction */
            CHECK_RETVAL(arc_read_instruction_u32(target, breakpoint->address, &current_instr));
 
            if (current_instr == ARC_SDBBP_32) {
                retval = target_write_buffer(target, breakpoint->address,
                    breakpoint->length, breakpoint->orig_instr);
                if (retval != ERROR_OK)
                    return retval;
            } else {
                LOG_TARGET_WARNING(target, "Software breakpoint @0x%" TARGET_PRIxADDR
                    " has been overwritten outside of debugger."
                    "Expected: @0x%x, got: @0x%" PRIx32,
                    breakpoint->address, ARC_SDBBP_32, current_instr);
            }
        } else if (breakpoint->length == 2) {
            uint16_t current_instr;
 
            /* check that user program has not modified breakpoint instruction */
            CHECK_RETVAL(target_read_u16(target, breakpoint->address, &current_instr));
            if (current_instr == ARC_SDBBP_16) {
                retval = target_write_buffer(target, breakpoint->address,
                    breakpoint->length, breakpoint->orig_instr);
                if (retval != ERROR_OK)
                    return retval;
            } else {
                LOG_TARGET_WARNING(target, "Software breakpoint @0x%" TARGET_PRIxADDR
                    " has been overwritten outside of debugger. "
                    "Expected: 0x%04x, got: 0x%04" PRIx16,
                    breakpoint->address, ARC_SDBBP_16, current_instr);
            }
        } else {
            LOG_TARGET_ERROR(target, "Invalid breakpoint length: target supports only 2 or 4");
            return ERROR_COMMAND_ARGUMENT_INVALID;
        }
        breakpoint->is_set = false;
 
    } else if (breakpoint->type == BKPT_HARD) {
        struct arc_common *arc = target_to_arc(target);
        struct arc_actionpoint *ap_list = arc->actionpoints_list;
        unsigned int bp_num = breakpoint->number;
 
        if (bp_num >= arc->actionpoints_num) {
            LOG_TARGET_DEBUG(target, "Invalid actionpoint ID: %u in breakpoint: %" PRIu32,
                      bp_num, breakpoint->unique_id);
            return ERROR_OK;
        }
 
        retval = arc_configure_actionpoint(target, bp_num,
                        breakpoint->address, AP_AC_TT_DISABLE, AP_AC_AT_INST_ADDR);
 
        if (retval == ERROR_OK) {
            breakpoint->is_set = false;
            ap_list[bp_num].used = 0;
            ap_list[bp_num].bp_value = 0;
 
            LOG_TARGET_DEBUG(target, "bpid: %" PRIu32 " - released actionpoint ID: %u",
                    breakpoint->unique_id, bp_num);
        }
    } else {
        LOG_TARGET_ERROR(target, "unsetting unknown breakpoint type");
        return ERROR_FAIL;
    }
 
    return retval;
}
 
static int arc_enable_breakpoints(struct target *target)
{
    struct breakpoint *breakpoint = target->breakpoints;
 
    /* set any pending breakpoints */
    while (breakpoint) {
        if (!breakpoint->is_set)
            CHECK_RETVAL(arc_set_breakpoint(target, breakpoint));
        breakpoint = breakpoint->next;
    }
 
    return ERROR_OK;
}
 
static int arc_add_breakpoint(struct target *target, struct breakpoint *breakpoint)
{
    if (target->state == TARGET_HALTED) {
        return arc_set_breakpoint(target, breakpoint);
 
    } else {
        LOG_TARGET_ERROR(target, "not halted (add breakpoint)");
        return ERROR_TARGET_NOT_HALTED;
    }
}
 
static int arc_remove_breakpoint(struct target *target,
    struct breakpoint *breakpoint)
{
    if (target->state == TARGET_HALTED) {
        if (breakpoint->is_set)
            CHECK_RETVAL(arc_unset_breakpoint(target, breakpoint));
    } else {
        LOG_TARGET_ERROR(target, "not halted (remove breakpoint)");
        return ERROR_TARGET_NOT_HALTED;
    }
 
    return ERROR_OK;
}
 
static void arc_reset_actionpoints(struct target *target)
{
    struct arc_common *arc = target_to_arc(target);
    struct arc_actionpoint *ap_list = arc->actionpoints_list;
    struct breakpoint *next_b;
    struct watchpoint *next_w;
 
    while (target->breakpoints) {
        next_b = target->breakpoints->next;
        arc_remove_breakpoint(target, target->breakpoints);
        free(target->breakpoints->orig_instr);
        free(target->breakpoints);
        target->breakpoints = next_b;
    }
    while (target->watchpoints) {
        next_w = target->watchpoints->next;
        arc_remove_watchpoint(target, target->watchpoints);
        free(target->watchpoints);
        target->watchpoints = next_w;
    }
    for (unsigned int i = 0; i < arc->actionpoints_num; i++) {
        if ((ap_list[i].used) && (ap_list[i].reg_address))
            arc_remove_auxreg_actionpoint(target, ap_list[i].reg_address);
    }
}
 
int arc_set_actionpoints_num(struct target *target, uint32_t ap_num)
{
    LOG_TARGET_DEBUG(target, "actionpoints=%" PRIu32, ap_num);
    struct arc_common *arc = target_to_arc(target);
 
    /* Make sure that there are no enabled actionpoints in target. */
    arc_reset_actionpoints(target);
 
    /* Assume that all points have been removed from target.  */
    free(arc->actionpoints_list);
 
    arc->actionpoints_num_avail = ap_num;
    arc->actionpoints_num = ap_num;
    /* calloc can be safely called when ncount == 0.  */
    arc->actionpoints_list = calloc(ap_num, sizeof(struct arc_actionpoint));
 
    if (!arc->actionpoints_list) {
        LOG_TARGET_ERROR(target, "Unable to allocate memory");
        return ERROR_FAIL;
    }
    return ERROR_OK;
}
 
 
int arc_add_auxreg_actionpoint(struct target *target,
    uint32_t auxreg_addr, uint32_t transaction)
{
    unsigned int ap_num = 0;
    int retval = ERROR_OK;
 
    if (target->state != TARGET_HALTED)
        return ERROR_TARGET_NOT_HALTED;
 
    struct arc_common *arc = target_to_arc(target);
    struct arc_actionpoint *ap_list = arc->actionpoints_list;
 
    while (ap_list[ap_num].used)
        ap_num++;
 
    if (ap_num >= arc->actionpoints_num) {
        LOG_TARGET_ERROR(target, "No actionpoint free, maximum amount is %u",
                arc->actionpoints_num);
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    retval =  arc_configure_actionpoint(target, ap_num,
            auxreg_addr, transaction, AP_AC_AT_AUXREG_ADDR);
 
    if (retval == ERROR_OK) {
        ap_list[ap_num].used = 1;
        ap_list[ap_num].reg_address = auxreg_addr;
    }
 
    return retval;
}
 
int arc_remove_auxreg_actionpoint(struct target *target, uint32_t auxreg_addr)
{
    int retval = ERROR_OK;
    bool ap_found = false;
    unsigned int ap_num = 0;
 
    if (target->state != TARGET_HALTED)
        return ERROR_TARGET_NOT_HALTED;
 
    struct arc_common *arc = target_to_arc(target);
    struct arc_actionpoint *ap_list = arc->actionpoints_list;
 
    while ((ap_list[ap_num].used) && (ap_num < arc->actionpoints_num)) {
        if (ap_list[ap_num].reg_address == auxreg_addr) {
            ap_found = true;
            break;
        }
        ap_num++;
    }
 
    if (ap_found) {
        retval =  arc_configure_actionpoint(target, ap_num,
                auxreg_addr, AP_AC_TT_DISABLE, AP_AC_AT_AUXREG_ADDR);
 
        if (retval == ERROR_OK) {
            ap_list[ap_num].used = 0;
            ap_list[ap_num].bp_value = 0;
        }
    } else {
        LOG_TARGET_ERROR(target, "Register actionpoint not found");
    }
    return retval;
}
 
 
static int arc_set_watchpoint(struct target *target,
        struct watchpoint *watchpoint)
{
    unsigned int wp_num;
    struct arc_common *arc = target_to_arc(target);
    struct arc_actionpoint *ap_list = arc->actionpoints_list;
 
    if (watchpoint->is_set) {
        LOG_TARGET_WARNING(target, "watchpoint already set");
        return ERROR_OK;
    }
 
    for (wp_num = 0; wp_num < arc->actionpoints_num; wp_num++) {
        if (!ap_list[wp_num].used)
            break;
    }
 
    if (wp_num >= arc->actionpoints_num) {
        LOG_TARGET_ERROR(target, "No free actionpoints, maximum amount is %u",
                arc->actionpoints_num);
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    if (watchpoint->length != 4) {
        LOG_TARGET_ERROR(target, "Only watchpoints of length 4 are supported");
        return ERROR_TARGET_UNALIGNED_ACCESS;
    }
 
    int enable = AP_AC_TT_DISABLE;
    switch (watchpoint->rw) {
    case WPT_READ:
        enable = AP_AC_TT_READ;
        break;
    case WPT_WRITE:
        enable = AP_AC_TT_WRITE;
        break;
    case WPT_ACCESS:
        enable = AP_AC_TT_READWRITE;
        break;
    default:
        LOG_TARGET_ERROR(target, "BUG: watchpoint->rw neither read, write nor access");
        return ERROR_FAIL;
    }
 
    int retval =  arc_configure_actionpoint(target, wp_num,
                    watchpoint->address, enable, AP_AC_AT_MEMORY_ADDR);
 
    if (retval == ERROR_OK) {
        watchpoint_set(watchpoint, wp_num);
        ap_list[wp_num].used = 1;
        ap_list[wp_num].bp_value = watchpoint->address;
        ap_list[wp_num].type = ARC_AP_WATCHPOINT;
 
        LOG_TARGET_DEBUG(target, "wpid: %" PRIu32 ", wp_num %u wp_value 0x%" PRIx32,
                watchpoint->unique_id, wp_num, ap_list[wp_num].bp_value);
    }
 
    return retval;
}
 
static int arc_unset_watchpoint(struct target *target,
        struct watchpoint *watchpoint)
{
    /* get pointers to arch-specific information */
    struct arc_common *arc = target_to_arc(target);
    struct arc_actionpoint *ap_list = arc->actionpoints_list;
 
    if (!watchpoint->is_set) {
        LOG_TARGET_WARNING(target, "watchpoint not set");
        return ERROR_OK;
    }
 
    unsigned int wp_num = watchpoint->number;
    if (wp_num >= arc->actionpoints_num) {
        LOG_TARGET_DEBUG(target, "Invalid actionpoint ID: %u in watchpoint: %" PRIu32,
                wp_num, watchpoint->unique_id);
        return ERROR_OK;
    }
 
    int retval =  arc_configure_actionpoint(target, wp_num,
                watchpoint->address, AP_AC_TT_DISABLE, AP_AC_AT_MEMORY_ADDR);
 
    if (retval == ERROR_OK) {
        watchpoint->is_set = false;
        ap_list[wp_num].used = 0;
        ap_list[wp_num].bp_value = 0;
 
        LOG_TARGET_DEBUG(target, "wpid: %" PRIu32 " - releasing actionpoint ID: %u",
                watchpoint->unique_id, wp_num);
    }
 
    return retval;
}
 
static int arc_enable_watchpoints(struct target *target)
{
    struct watchpoint *watchpoint = target->watchpoints;
 
    /* set any pending watchpoints */
    while (watchpoint) {
        if (!watchpoint->is_set)
            CHECK_RETVAL(arc_set_watchpoint(target, watchpoint));
        watchpoint = watchpoint->next;
    }
 
    return ERROR_OK;
}
 
static int arc_add_watchpoint(struct target *target,
    struct watchpoint *watchpoint)
{
    if (target->state != TARGET_HALTED) {
        LOG_TARGET_ERROR(target, "not halted");
        return ERROR_TARGET_NOT_HALTED;
    }
 
    CHECK_RETVAL(arc_set_watchpoint(target, watchpoint));
 
    return ERROR_OK;
}
 
static int arc_remove_watchpoint(struct target *target,
    struct watchpoint *watchpoint)
{
    if (target->state != TARGET_HALTED) {
        LOG_TARGET_ERROR(target, "not halted");
        return ERROR_TARGET_NOT_HALTED;
    }
 
    if (watchpoint->is_set)
        CHECK_RETVAL(arc_unset_watchpoint(target, watchpoint));
 
    return ERROR_OK;
}
 
static int arc_hit_watchpoint(struct target *target, struct watchpoint **hit_watchpoint)
{
    assert(target);
    assert(hit_watchpoint);
 
    struct arc_actionpoint *actionpoint = NULL;
    CHECK_RETVAL(get_current_actionpoint(target, &actionpoint));
 
    if (actionpoint) {
        if (!actionpoint->used)
            LOG_TARGET_WARNING(target, "Target halted by unused actionpoint");
 
        /* If this check fails - that is some sort of an error in OpenOCD. */
        if (actionpoint->type != ARC_AP_WATCHPOINT)
            LOG_TARGET_WARNING(target, "Target halted by breakpoint, but is treated as a watchpoint");
 
        for (struct watchpoint *watchpoint = target->watchpoints;
                watchpoint;
                watchpoint = watchpoint->next) {
            if (actionpoint->bp_value == watchpoint->address) {
                *hit_watchpoint = watchpoint;
                LOG_TARGET_DEBUG(target, "Hit watchpoint, wpid: %" PRIu32 ", watchpoint num: %u",
                            watchpoint->unique_id, watchpoint->number);
                return ERROR_OK;
            }
        }
    }
 
    return ERROR_FAIL;
}
 
/* Helper function which switches core to single_step mode by
 * doing aux r/w operations.  */
static int arc_config_step(struct target *target, bool enable_step)
{
    uint32_t value;
 
    struct arc_common *arc = target_to_arc(target);
 
    /* enable core debug step mode */
    if (enable_step) {
        CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_STATUS32_REG,
            &value));
        value &= ~SET_CORE_AE_BIT; /* clear the AE bit */
        CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_STATUS32_REG,
            value));
        LOG_TARGET_DEBUG(target, " [status32:0x%08" PRIx32 "]", value);
 
        /* Doing read-modify-write, because DEBUG might contain manually set
         * bits like UB or ED, which should be preserved.  */
        CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info,
                    AUX_DEBUG_REG, &value));
        value |= SET_CORE_SINGLE_INSTR_STEP; /* set the IS bit */
        CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DEBUG_REG,
            value));
        LOG_TARGET_DEBUG(target, "core debug step mode enabled [debug-reg:0x%08" PRIx32 "]", value);
 
    } else {    /* disable core debug step mode */
        CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_DEBUG_REG,
            &value));
        value &= ~SET_CORE_SINGLE_INSTR_STEP; /* clear the IS bit */
        CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DEBUG_REG,
            value));
        LOG_TARGET_DEBUG(target, "core debug step mode disabled");
    }
 
    return ERROR_OK;
}
 
static int arc_single_step_core(struct target *target)
{
    CHECK_RETVAL(arc_debug_entry(target));
 
    /* disable interrupts while stepping */
    CHECK_RETVAL(arc_enable_interrupts(target, false));
 
    /* configure single step mode */
    CHECK_RETVAL(arc_config_step(target, true));
 
    /* exit debug mode */
    CHECK_RETVAL(arc_exit_debug(target));
 
    return ERROR_OK;
}
 
static int arc_step(struct target *target, bool current, target_addr_t address,
    bool handle_breakpoints)
{
    /* get pointers to arch-specific information */
    struct arc_common *arc = target_to_arc(target);
    struct breakpoint *breakpoint = NULL;
    struct reg *pc = &(arc->core_and_aux_cache->reg_list[arc->pc_index_in_cache]);
 
    if (target->state != TARGET_HALTED) {
        LOG_TARGET_ERROR(target, "not halted");
        return ERROR_TARGET_NOT_HALTED;
    }
 
    /* current = true: continue on current pc, otherwise continue at <address> */
    if (!current) {
        buf_set_u32(pc->value, 0, 32, address);
        pc->dirty = true;
        pc->valid = true;
    }
 
    LOG_TARGET_DEBUG(target, "Target steps one instruction from PC=0x%" PRIx32,
        buf_get_u32(pc->value, 0, 32));
 
    /* the front-end may request us not to handle breakpoints */
    if (handle_breakpoints) {
        breakpoint = breakpoint_find(target, buf_get_u32(pc->value, 0, 32));
        if (breakpoint)
            CHECK_RETVAL(arc_unset_breakpoint(target, breakpoint));
    }
 
    /* restore context */
    CHECK_RETVAL(arc_restore_context(target));
 
    target->debug_reason = DBG_REASON_SINGLESTEP;
 
    CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_RESUMED));
 
    /* disable interrupts while stepping */
    CHECK_RETVAL(arc_enable_interrupts(target, false));
 
    /* do a single step */
    CHECK_RETVAL(arc_config_step(target, true));
 
    /* make sure we done our step */
    alive_sleep(1);
 
    /* registers are now invalid */
    register_cache_invalidate(arc->core_and_aux_cache);
 
    if (breakpoint)
        CHECK_RETVAL(arc_set_breakpoint(target, breakpoint));
 
    LOG_TARGET_DEBUG(target, "target stepped");
 
    target->state = TARGET_HALTED;
 
    /* Saving context */
    CHECK_RETVAL(arc_debug_entry(target));
    CHECK_RETVAL(target_call_event_callbacks(target, TARGET_EVENT_HALTED));
 
    return ERROR_OK;
}
 
 
/* This function invalidates icache. */
static int arc_icache_invalidate(struct target *target)
{
    uint32_t value;
 
    struct arc_common *arc = target_to_arc(target);
 
    /* Don't waste time if already done. */
    if (!arc->has_icache || arc->icache_invalidated)
        return ERROR_OK;
 
    LOG_TARGET_DEBUG(target, "Invalidating I$");
 
    value = IC_IVIC_INVALIDATE; /* invalidate I$ */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_IC_IVIC_REG, value));
 
    arc->icache_invalidated = true;
 
    return ERROR_OK;
}
 
/* This function invalidates dcache */
static int arc_dcache_invalidate(struct target *target)
{
    uint32_t value, dc_ctrl_value;
 
    struct arc_common *arc = target_to_arc(target);
 
    if (!arc->has_dcache || arc->dcache_invalidated)
        return ERROR_OK;
 
    LOG_TARGET_DEBUG(target, "Invalidating D$");
 
    CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_DC_CTRL_REG, &value));
    dc_ctrl_value = value;
    value &= ~DC_CTRL_IM;
 
    /* set DC_CTRL invalidate mode to invalidate-only (no flushing!!) */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DC_CTRL_REG, value));
    value = DC_IVDC_INVALIDATE; /* invalidate D$ */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DC_IVDC_REG, value));
 
    /* restore DC_CTRL invalidate mode */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DC_CTRL_REG, dc_ctrl_value));
 
    arc->dcache_invalidated = true;
 
    return ERROR_OK;
}
 
/* This function invalidates l2 cache. */
static int arc_l2cache_invalidate(struct target *target)
{
    uint32_t value, slc_ctrl_value;
 
    struct arc_common *arc = target_to_arc(target);
 
    if (!arc->has_l2cache || arc->l2cache_invalidated)
        return ERROR_OK;
 
    LOG_TARGET_DEBUG(target, "Invalidating L2$");
 
    CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, SLC_AUX_CACHE_CTRL, &value));
    slc_ctrl_value = value;
    value &= ~L2_CTRL_IM;
 
    /* set L2_CTRL invalidate mode to invalidate-only (no flushing!!) */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, SLC_AUX_CACHE_CTRL, value));
    /* invalidate L2$ */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, SLC_AUX_CACHE_INV, L2_INV_IV));
 
    /* Wait until invalidate operation ends */
    do {
        LOG_TARGET_DEBUG(target, "Waiting for invalidation end");
        CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, SLC_AUX_CACHE_CTRL, &value));
    } while (value & L2_CTRL_BS);
 
    /* restore L2_CTRL invalidate mode */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, SLC_AUX_CACHE_CTRL, slc_ctrl_value));
 
    arc->l2cache_invalidated = true;
 
    return ERROR_OK;
}
 
 
int arc_cache_invalidate(struct target *target)
{
    CHECK_RETVAL(arc_icache_invalidate(target));
    CHECK_RETVAL(arc_dcache_invalidate(target));
    CHECK_RETVAL(arc_l2cache_invalidate(target));
 
    return ERROR_OK;
}
 
/* Flush data cache. This function is cheap to call and return quickly if D$
 * already has been flushed since target had been halted. JTAG debugger reads
 * values directly from memory, bypassing cache, so if there are unflushed
 * lines debugger will read invalid values, which will cause a lot of troubles.
 * */
static int arc_dcache_flush(struct target *target)
{
    uint32_t value, dc_ctrl_value;
    bool has_to_set_dc_ctrl_im;
 
    struct arc_common *arc = target_to_arc(target);
 
    /* Don't waste time if already done. */
    if (!arc->has_dcache || arc->dcache_flushed)
        return ERROR_OK;
 
    LOG_TARGET_DEBUG(target, "Flushing D$");
 
    /* Store current value of DC_CTRL */
    CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, AUX_DC_CTRL_REG, &dc_ctrl_value));
 
    /* Set DC_CTRL invalidate mode to flush (if not already set) */
    has_to_set_dc_ctrl_im = (dc_ctrl_value & DC_CTRL_IM) == 0;
    if (has_to_set_dc_ctrl_im) {
        value = dc_ctrl_value | DC_CTRL_IM;
        CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DC_CTRL_REG, value));
    }
 
    /* Flush D$ */
    value = DC_IVDC_INVALIDATE;
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DC_IVDC_REG, value));
 
    /* Restore DC_CTRL invalidate mode (even of flush failed) */
    if (has_to_set_dc_ctrl_im)
        CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, AUX_DC_CTRL_REG, dc_ctrl_value));
 
    arc->dcache_flushed = true;
 
    return ERROR_OK;
}
 
/* This function flushes l2cache. */
static int arc_l2cache_flush(struct target *target)
{
    uint32_t value;
 
    struct arc_common *arc = target_to_arc(target);
 
    /* Don't waste time if already done. */
    if (!arc->has_l2cache || arc->l2cache_flushed)
        return ERROR_OK;
 
    LOG_TARGET_DEBUG(target, "Flushing L2$");
 
    /* Flush L2 cache */
    CHECK_RETVAL(arc_jtag_write_aux_reg_one(&arc->jtag_info, SLC_AUX_CACHE_FLUSH, L2_FLUSH_FL));
 
    /* Wait until flush operation ends */
    do {
        LOG_TARGET_DEBUG(target, "Waiting for flushing end");
        CHECK_RETVAL(arc_jtag_read_aux_reg_one(&arc->jtag_info, SLC_AUX_CACHE_CTRL, &value));
    } while (value & L2_CTRL_BS);
 
    arc->l2cache_flushed = true;
 
    return ERROR_OK;
}
 
int arc_cache_flush(struct target *target)
{
    CHECK_RETVAL(arc_dcache_flush(target));
    CHECK_RETVAL(arc_l2cache_flush(target));
 
    return ERROR_OK;
}
 
/* ARC v2 target */
struct target_type arcv2_target = {
    .name = "arcv2",
 
    .poll = arc_poll,
 
    .arch_state = arc_arch_state,
 
    /* TODO That seems like something similar to metaware hostlink, so perhaps
     * we can exploit this in the future. */
    .target_request_data = NULL,
 
    .halt = arc_halt,
    .resume = arc_resume,
    .step = arc_step,
 
    .assert_reset = arc_assert_reset,
    .deassert_reset = arc_deassert_reset,
 
    /* TODO Implement soft_reset_halt */
    .soft_reset_halt = NULL,
 
    .get_gdb_reg_list = arc_get_gdb_reg_list,
 
    .read_memory = arc_mem_read,
    .write_memory = arc_mem_write,
    .checksum_memory = NULL,
    .blank_check_memory = NULL,
 
    .add_breakpoint = arc_add_breakpoint,
    .add_context_breakpoint = NULL,
    .add_hybrid_breakpoint = NULL,
    .remove_breakpoint = arc_remove_breakpoint,
    .add_watchpoint = arc_add_watchpoint,
    .remove_watchpoint = arc_remove_watchpoint,
    .hit_watchpoint = arc_hit_watchpoint,
 
    .run_algorithm = NULL,
    .start_algorithm = NULL,
    .wait_algorithm = NULL,
 
    .commands = arc_monitor_command_handlers,
 
    .target_create = arc_target_create,
    .init_target = arc_init_target,
    .deinit_target = arc_deinit_target,
    .examine = arc_examine,
 
    .virt2phys = NULL,
    .read_phys_memory = NULL,
    .write_phys_memory = NULL,
    .mmu = NULL,
};