riscv.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
#include <assert.h>
#include <stdlib.h>
#include <time.h>
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <helper/log.h>
#include <helper/time_support.h>
#include "target/target.h"
#include "target/algorithm.h"
#include "target/target_type.h"
#include <target/smp.h>
#include "jtag/jtag.h"
#include "target/register.h"
#include "target/breakpoints.h"
#include "riscv.h"
#include "gdb_regs.h"
#include "rtos/rtos.h"
#include "debug_defines.h"
#include <helper/bits.h>
 
#define get_field(reg, mask) (((reg) & (mask)) / ((mask) & ~((mask) << 1)))
#define set_field(reg, mask, val) (((reg) & ~(mask)) | (((val) * ((mask) & ~((mask) << 1))) & (mask)))
 
/* Constants for legacy SiFive hardware breakpoints. */
#define CSR_BPCONTROL_X         (1<<0)
#define CSR_BPCONTROL_W         (1<<1)
#define CSR_BPCONTROL_R         (1<<2)
#define CSR_BPCONTROL_U         (1<<3)
#define CSR_BPCONTROL_S         (1<<4)
#define CSR_BPCONTROL_H         (1<<5)
#define CSR_BPCONTROL_M         (1<<6)
#define CSR_BPCONTROL_BPMATCH   (0xf<<7)
#define CSR_BPCONTROL_BPACTION  (0xff<<11)
 
#define DEBUG_ROM_START         0x800
#define DEBUG_ROM_RESUME    (DEBUG_ROM_START + 4)
#define DEBUG_ROM_EXCEPTION (DEBUG_ROM_START + 8)
#define DEBUG_RAM_START         0x400
 
#define SETHALTNOT              0x10c
 
/*** JTAG registers. ***/
 
#define DTMCONTROL                  0x10
#define DTMCONTROL_DBUS_RESET       (1<<16)
#define DTMCONTROL_IDLE             (7<<10)
#define DTMCONTROL_ADDRBITS         (0xf<<4)
#define DTMCONTROL_VERSION          (0xf)
 
#define DBUS                        0x11
#define DBUS_OP_START               0
#define DBUS_OP_SIZE                2
typedef enum {
    DBUS_OP_NOP = 0,
    DBUS_OP_READ = 1,
    DBUS_OP_WRITE = 2
} dbus_op_t;
typedef enum {
    DBUS_STATUS_SUCCESS = 0,
    DBUS_STATUS_FAILED = 2,
    DBUS_STATUS_BUSY = 3
} dbus_status_t;
#define DBUS_DATA_START             2
#define DBUS_DATA_SIZE              34
#define DBUS_ADDRESS_START          36
 
typedef enum slot {
    SLOT0,
    SLOT1,
    SLOT_LAST,
} slot_t;
 
/*** Debug Bus registers. ***/
 
#define DMCONTROL               0x10
#define DMCONTROL_INTERRUPT     (((uint64_t)1)<<33)
#define DMCONTROL_HALTNOT       (((uint64_t)1)<<32)
#define DMCONTROL_BUSERROR      (7<<19)
#define DMCONTROL_SERIAL        (3<<16)
#define DMCONTROL_AUTOINCREMENT (1<<15)
#define DMCONTROL_ACCESS        (7<<12)
#define DMCONTROL_HARTID        (0x3ff<<2)
#define DMCONTROL_NDRESET       (1<<1)
#define DMCONTROL_FULLRESET     1
 
#define DMINFO                  0x11
#define DMINFO_ABUSSIZE         (0x7fU<<25)
#define DMINFO_SERIALCOUNT      (0xf<<21)
#define DMINFO_ACCESS128        (1<<20)
#define DMINFO_ACCESS64         (1<<19)
#define DMINFO_ACCESS32         (1<<18)
#define DMINFO_ACCESS16         (1<<17)
#define DMINFO_ACCESS8          (1<<16)
#define DMINFO_DRAMSIZE         (0x3f<<10)
#define DMINFO_AUTHENTICATED    (1<<5)
#define DMINFO_AUTHBUSY         (1<<4)
#define DMINFO_AUTHTYPE         (3<<2)
#define DMINFO_VERSION          3
 
/*** Info about the core being debugged. ***/
 
#define DBUS_ADDRESS_UNKNOWN    0xffff
 
#define MAX_HWBPS           16
#define DRAM_CACHE_SIZE     16
 
static uint8_t ir_dtmcontrol[4] = {DTMCONTROL};
struct scan_field select_dtmcontrol = {
    .in_value = NULL,
    .out_value = ir_dtmcontrol
};
static uint8_t ir_dbus[4] = {DBUS};
struct scan_field select_dbus = {
    .in_value = NULL,
    .out_value = ir_dbus
};
static uint8_t ir_idcode[4] = {0x1};
struct scan_field select_idcode = {
    .in_value = NULL,
    .out_value = ir_idcode
};
 
static bscan_tunnel_type_t bscan_tunnel_type;
int bscan_tunnel_ir_width; /* if zero, then tunneling is not present/active */
 
static const uint8_t bscan_zero[4] = {0};
static const uint8_t bscan_one[4] = {1};
 
static uint8_t ir_user4[4];
static struct scan_field select_user4 = {
    .in_value = NULL,
    .out_value = ir_user4
};
 
 
static uint8_t bscan_tunneled_ir_width[4] = {5};  /* overridden by assignment in riscv_init_target */
static struct scan_field _bscan_tunnel_data_register_select_dmi[] = {
        {
            .num_bits = 3,
            .out_value = bscan_zero,
            .in_value = NULL,
        },
        {
            .num_bits = 5, /* initialized in riscv_init_target to ir width of DM */
            .out_value = ir_dbus,
            .in_value = NULL,
        },
        {
            .num_bits = 7,
            .out_value = bscan_tunneled_ir_width,
            .in_value = NULL,
        },
        {
            .num_bits = 1,
            .out_value = bscan_zero,
            .in_value = NULL,
        }
};
 
static struct scan_field _bscan_tunnel_nested_tap_select_dmi[] = {
        {
            .num_bits = 1,
            .out_value = bscan_zero,
            .in_value = NULL,
        },
        {
            .num_bits = 7,
            .out_value = bscan_tunneled_ir_width,
            .in_value = NULL,
        },
        {
            .num_bits = 0, /* initialized in riscv_init_target to ir width of DM */
            .out_value = ir_dbus,
            .in_value = NULL,
        },
        {
            .num_bits = 3,
            .out_value = bscan_zero,
            .in_value = NULL,
        }
};
static struct scan_field *bscan_tunnel_nested_tap_select_dmi = _bscan_tunnel_nested_tap_select_dmi;
static uint32_t bscan_tunnel_nested_tap_select_dmi_num_fields = ARRAY_SIZE(_bscan_tunnel_nested_tap_select_dmi);
 
static struct scan_field *bscan_tunnel_data_register_select_dmi = _bscan_tunnel_data_register_select_dmi;
static uint32_t bscan_tunnel_data_register_select_dmi_num_fields = ARRAY_SIZE(_bscan_tunnel_data_register_select_dmi);
 
struct trigger {
    uint64_t address;
    uint32_t length;
    uint64_t mask;
    uint64_t value;
    bool read, write, execute;
    int unique_id;
};
 
/* Wall-clock timeout for a command/access. Settable via RISC-V Target commands.*/
int riscv_command_timeout_sec = DEFAULT_COMMAND_TIMEOUT_SEC;
 
/* Wall-clock timeout after reset. Settable via RISC-V Target commands.*/
int riscv_reset_timeout_sec = DEFAULT_RESET_TIMEOUT_SEC;
 
static bool riscv_enable_virt2phys = true;
bool riscv_ebreakm = true;
bool riscv_ebreaks = true;
bool riscv_ebreaku = true;
 
bool riscv_enable_virtual;
 
static enum {
    RO_NORMAL,
    RO_REVERSED
} resume_order;
 
static const virt2phys_info_t sv32 = {
    .name = "Sv32",
    .va_bits = 32,
    .level = 2,
    .pte_shift = 2,
    .vpn_shift = {12, 22},
    .vpn_mask = {0x3ff, 0x3ff},
    .pte_ppn_shift = {10, 20},
    .pte_ppn_mask = {0x3ff, 0xfff},
    .pa_ppn_shift = {12, 22},
    .pa_ppn_mask = {0x3ff, 0xfff},
};
 
static const virt2phys_info_t sv39 = {
    .name = "Sv39",
    .va_bits = 39,
    .level = 3,
    .pte_shift = 3,
    .vpn_shift = {12, 21, 30},
    .vpn_mask = {0x1ff, 0x1ff, 0x1ff},
    .pte_ppn_shift = {10, 19, 28},
    .pte_ppn_mask = {0x1ff, 0x1ff, 0x3ffffff},
    .pa_ppn_shift = {12, 21, 30},
    .pa_ppn_mask = {0x1ff, 0x1ff, 0x3ffffff},
};
 
static const virt2phys_info_t sv48 = {
    .name = "Sv48",
    .va_bits = 48,
    .level = 4,
    .pte_shift = 3,
    .vpn_shift = {12, 21, 30, 39},
    .vpn_mask = {0x1ff, 0x1ff, 0x1ff, 0x1ff},
    .pte_ppn_shift = {10, 19, 28, 37},
    .pte_ppn_mask = {0x1ff, 0x1ff, 0x1ff, 0x1ffff},
    .pa_ppn_shift = {12, 21, 30, 39},
    .pa_ppn_mask = {0x1ff, 0x1ff, 0x1ff, 0x1ffff},
};
 
static enum riscv_halt_reason riscv_halt_reason(struct target *target, int hartid);
static void riscv_info_init(struct target *target, struct riscv_info *r);
static void riscv_invalidate_register_cache(struct target *target);
static int riscv_step_rtos_hart(struct target *target);
 
static void riscv_sample_buf_maybe_add_timestamp(struct target *target, bool before)
{
    RISCV_INFO(r);
    uint32_t now = timeval_ms() & 0xffffffff;
    if (r->sample_buf.used + 5 < r->sample_buf.size) {
        if (before)
            r->sample_buf.buf[r->sample_buf.used++] = RISCV_SAMPLE_BUF_TIMESTAMP_BEFORE;
        else
            r->sample_buf.buf[r->sample_buf.used++] = RISCV_SAMPLE_BUF_TIMESTAMP_AFTER;
        r->sample_buf.buf[r->sample_buf.used++] = now & 0xff;
        r->sample_buf.buf[r->sample_buf.used++] = (now >> 8) & 0xff;
        r->sample_buf.buf[r->sample_buf.used++] = (now >> 16) & 0xff;
        r->sample_buf.buf[r->sample_buf.used++] = (now >> 24) & 0xff;
    }
}
 
static int riscv_resume_go_all_harts(struct target *target);
 
void select_dmi_via_bscan(struct target *target)
{
    jtag_add_ir_scan(target->tap, &select_user4, TAP_IDLE);
    if (bscan_tunnel_type == BSCAN_TUNNEL_DATA_REGISTER)
        jtag_add_dr_scan(target->tap, bscan_tunnel_data_register_select_dmi_num_fields,
                                        bscan_tunnel_data_register_select_dmi, TAP_IDLE);
    else /* BSCAN_TUNNEL_NESTED_TAP */
        jtag_add_dr_scan(target->tap, bscan_tunnel_nested_tap_select_dmi_num_fields,
                                        bscan_tunnel_nested_tap_select_dmi, TAP_IDLE);
}
 
uint32_t dtmcontrol_scan_via_bscan(struct target *target, uint32_t out)
{
    /* On BSCAN TAP: Select IR=USER4, issue tunneled IR scan via BSCAN TAP's DR */
    uint8_t tunneled_ir_width[4] = {bscan_tunnel_ir_width};
    uint8_t tunneled_dr_width[4] = {32};
    uint8_t out_value[5] = {0};
    uint8_t in_value[5] = {0};
 
    buf_set_u32(out_value, 0, 32, out);
    struct scan_field tunneled_ir[4] = {};
    struct scan_field tunneled_dr[4] = {};
 
    if (bscan_tunnel_type == BSCAN_TUNNEL_DATA_REGISTER) {
        tunneled_ir[0].num_bits = 3;
        tunneled_ir[0].out_value = bscan_zero;
        tunneled_ir[0].in_value = NULL;
        tunneled_ir[1].num_bits = bscan_tunnel_ir_width;
        tunneled_ir[1].out_value = ir_dtmcontrol;
        tunneled_ir[1].in_value = NULL;
        tunneled_ir[2].num_bits = 7;
        tunneled_ir[2].out_value = tunneled_ir_width;
        tunneled_ir[2].in_value = NULL;
        tunneled_ir[3].num_bits = 1;
        tunneled_ir[3].out_value = bscan_zero;
        tunneled_ir[3].in_value = NULL;
 
        tunneled_dr[0].num_bits = 3;
        tunneled_dr[0].out_value = bscan_zero;
        tunneled_dr[0].in_value = NULL;
        tunneled_dr[1].num_bits = 32 + 1;
        tunneled_dr[1].out_value = out_value;
        tunneled_dr[1].in_value = in_value;
        tunneled_dr[2].num_bits = 7;
        tunneled_dr[2].out_value = tunneled_dr_width;
        tunneled_dr[2].in_value = NULL;
        tunneled_dr[3].num_bits = 1;
        tunneled_dr[3].out_value = bscan_one;
        tunneled_dr[3].in_value = NULL;
    } else {
        /* BSCAN_TUNNEL_NESTED_TAP */
        tunneled_ir[3].num_bits = 3;
        tunneled_ir[3].out_value = bscan_zero;
        tunneled_ir[3].in_value = NULL;
        tunneled_ir[2].num_bits = bscan_tunnel_ir_width;
        tunneled_ir[2].out_value = ir_dtmcontrol;
        tunneled_ir[1].in_value = NULL;
        tunneled_ir[1].num_bits = 7;
        tunneled_ir[1].out_value = tunneled_ir_width;
        tunneled_ir[2].in_value = NULL;
        tunneled_ir[0].num_bits = 1;
        tunneled_ir[0].out_value = bscan_zero;
        tunneled_ir[0].in_value = NULL;
 
        tunneled_dr[3].num_bits = 3;
        tunneled_dr[3].out_value = bscan_zero;
        tunneled_dr[3].in_value = NULL;
        tunneled_dr[2].num_bits = 32 + 1;
        tunneled_dr[2].out_value = out_value;
        tunneled_dr[2].in_value = in_value;
        tunneled_dr[1].num_bits = 7;
        tunneled_dr[1].out_value = tunneled_dr_width;
        tunneled_dr[1].in_value = NULL;
        tunneled_dr[0].num_bits = 1;
        tunneled_dr[0].out_value = bscan_one;
        tunneled_dr[0].in_value = NULL;
    }
    jtag_add_ir_scan(target->tap, &select_user4, TAP_IDLE);
    jtag_add_dr_scan(target->tap, ARRAY_SIZE(tunneled_ir), tunneled_ir, TAP_IDLE);
    jtag_add_dr_scan(target->tap, ARRAY_SIZE(tunneled_dr), tunneled_dr, TAP_IDLE);
    select_dmi_via_bscan(target);
 
    int retval = jtag_execute_queue();
    if (retval != ERROR_OK) {
        LOG_ERROR("failed jtag scan: %d", retval);
        return retval;
    }
    /* Note the starting offset is bit 1, not bit 0.  In BSCAN tunnel, there is a one-bit TCK skew between
       output and input */
    uint32_t in = buf_get_u32(in_value, 1, 32);
    LOG_DEBUG("DTMCS: 0x%x -> 0x%x", out, in);
 
    return in;
}
 
static uint32_t dtmcontrol_scan(struct target *target, uint32_t out)
{
    struct scan_field field;
    uint8_t in_value[4];
    uint8_t out_value[4] = { 0 };
 
    if (bscan_tunnel_ir_width != 0)
        return dtmcontrol_scan_via_bscan(target, out);
 
 
    buf_set_u32(out_value, 0, 32, out);
 
    jtag_add_ir_scan(target->tap, &select_dtmcontrol, TAP_IDLE);
 
    field.num_bits = 32;
    field.out_value = out_value;
    field.in_value = in_value;
    jtag_add_dr_scan(target->tap, 1, &field, TAP_IDLE);
 
    /* Always return to dbus. */
    jtag_add_ir_scan(target->tap, &select_dbus, TAP_IDLE);
 
    int retval = jtag_execute_queue();
    if (retval != ERROR_OK) {
        LOG_ERROR("failed jtag scan: %d", retval);
        return retval;
    }
 
    uint32_t in = buf_get_u32(field.in_value, 0, 32);
    LOG_DEBUG("DTMCONTROL: 0x%x -> 0x%x", out, in);
 
    return in;
}
 
static struct target_type *get_target_type(struct target *target)
{
    if (!target->arch_info) {
        LOG_ERROR("Target has not been initialized");
        return NULL;
    }
 
    RISCV_INFO(info);
    switch (info->dtm_version) {
        case 0:
            return &riscv011_target;
        case 1:
            return &riscv013_target;
        default:
            LOG_ERROR("Unsupported DTM version: %d", info->dtm_version);
            return NULL;
    }
}
 
static int riscv_create_target(struct target *target, Jim_Interp *interp)
{
    LOG_DEBUG("riscv_create_target()");
    target->arch_info = calloc(1, sizeof(struct riscv_info));
    if (!target->arch_info) {
        LOG_ERROR("Failed to allocate RISC-V target structure.");
        return ERROR_FAIL;
    }
    riscv_info_init(target, target->arch_info);
    return ERROR_OK;
}
 
static int riscv_init_target(struct command_context *cmd_ctx,
        struct target *target)
{
    LOG_DEBUG("riscv_init_target()");
    RISCV_INFO(info);
    info->cmd_ctx = cmd_ctx;
 
    select_dtmcontrol.num_bits = target->tap->ir_length;
    select_dbus.num_bits = target->tap->ir_length;
    select_idcode.num_bits = target->tap->ir_length;
 
    if (bscan_tunnel_ir_width != 0) {
        assert(target->tap->ir_length >= 6);
        uint32_t ir_user4_raw = 0x23 << (target->tap->ir_length - 6);
        h_u32_to_le(ir_user4, ir_user4_raw);
        select_user4.num_bits = target->tap->ir_length;
        bscan_tunneled_ir_width[0] = bscan_tunnel_ir_width;
        if (bscan_tunnel_type == BSCAN_TUNNEL_DATA_REGISTER)
            bscan_tunnel_data_register_select_dmi[1].num_bits = bscan_tunnel_ir_width;
        else /* BSCAN_TUNNEL_NESTED_TAP */
            bscan_tunnel_nested_tap_select_dmi[2].num_bits = bscan_tunnel_ir_width;
    }
 
    riscv_semihosting_init(target);
 
    target->debug_reason = DBG_REASON_DBGRQ;
 
    return ERROR_OK;
}
 
static void riscv_free_registers(struct target *target)
{
    /* Free the shared structure use for most registers. */
    if (target->reg_cache) {
        if (target->reg_cache->reg_list) {
            free(target->reg_cache->reg_list[0].arch_info);
            /* Free the ones we allocated separately. */
            for (unsigned int i = GDB_REGNO_COUNT; i < target->reg_cache->num_regs; i++)
                free(target->reg_cache->reg_list[i].arch_info);
            for (unsigned int i = 0; i < target->reg_cache->num_regs; i++)
                free(target->reg_cache->reg_list[i].value);
            free(target->reg_cache->reg_list);
        }
        free(target->reg_cache);
    }
}
 
static void riscv_deinit_target(struct target *target)
{
    LOG_DEBUG("riscv_deinit_target()");
 
    struct riscv_info *info = target->arch_info;
    struct target_type *tt = get_target_type(target);
 
    if (tt && info && info->version_specific)
        tt->deinit_target(target);
 
    riscv_free_registers(target);
 
    if (!info)
        return;
 
    range_list_t *entry, *tmp;
    list_for_each_entry_safe(entry, tmp, &info->expose_csr, list) {
        free(entry->name);
        free(entry);
    }
 
    list_for_each_entry_safe(entry, tmp, &info->expose_custom, list) {
        free(entry->name);
        free(entry);
    }
 
    free(info->reg_names);
    free(target->arch_info);
 
    target->arch_info = NULL;
}
 
static void trigger_from_breakpoint(struct trigger *trigger,
        const struct breakpoint *breakpoint)
{
    trigger->address = breakpoint->address;
    trigger->length = breakpoint->length;
    trigger->mask = ~0LL;
    trigger->read = false;
    trigger->write = false;
    trigger->execute = true;
    /* unique_id is unique across both breakpoints and watchpoints. */
    trigger->unique_id = breakpoint->unique_id;
}
 
static int maybe_add_trigger_t1(struct target *target,
        struct trigger *trigger, uint64_t tdata1)
{
    RISCV_INFO(r);
 
    const uint32_t bpcontrol_x = 1<<0;
    const uint32_t bpcontrol_w = 1<<1;
    const uint32_t bpcontrol_r = 1<<2;
    const uint32_t bpcontrol_u = 1<<3;
    const uint32_t bpcontrol_s = 1<<4;
    const uint32_t bpcontrol_h = 1<<5;
    const uint32_t bpcontrol_m = 1<<6;
    const uint32_t bpcontrol_bpmatch = 0xf << 7;
    const uint32_t bpcontrol_bpaction = 0xff << 11;
 
    if (tdata1 & (bpcontrol_r | bpcontrol_w | bpcontrol_x)) {
        /* Trigger is already in use, presumably by user code. */
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    tdata1 = set_field(tdata1, bpcontrol_r, trigger->read);
    tdata1 = set_field(tdata1, bpcontrol_w, trigger->write);
    tdata1 = set_field(tdata1, bpcontrol_x, trigger->execute);
    tdata1 = set_field(tdata1, bpcontrol_u,
            !!(r->misa & BIT('U' - 'A')));
    tdata1 = set_field(tdata1, bpcontrol_s,
            !!(r->misa & BIT('S' - 'A')));
    tdata1 = set_field(tdata1, bpcontrol_h,
            !!(r->misa & BIT('H' - 'A')));
    tdata1 |= bpcontrol_m;
    tdata1 = set_field(tdata1, bpcontrol_bpmatch, 0); /* exact match */
    tdata1 = set_field(tdata1, bpcontrol_bpaction, 0); /* cause bp exception */
 
    riscv_set_register(target, GDB_REGNO_TDATA1, tdata1);
 
    riscv_reg_t tdata1_rb;
    if (riscv_get_register(target, &tdata1_rb, GDB_REGNO_TDATA1) != ERROR_OK)
        return ERROR_FAIL;
    LOG_DEBUG("tdata1=0x%" PRIx64, tdata1_rb);
 
    if (tdata1 != tdata1_rb) {
        LOG_DEBUG("Trigger doesn't support what we need; After writing 0x%"
                PRIx64 " to tdata1 it contains 0x%" PRIx64,
                tdata1, tdata1_rb);
        riscv_set_register(target, GDB_REGNO_TDATA1, 0);
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    riscv_set_register(target, GDB_REGNO_TDATA2, trigger->address);
 
    return ERROR_OK;
}
 
static int maybe_add_trigger_t2(struct target *target,
        struct trigger *trigger, uint64_t tdata1)
{
    RISCV_INFO(r);
 
    /* tselect is already set */
    if (tdata1 & (MCONTROL_EXECUTE | MCONTROL_STORE | MCONTROL_LOAD)) {
        /* Trigger is already in use, presumably by user code. */
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    /* address/data match trigger */
    tdata1 |= MCONTROL_DMODE(riscv_xlen(target));
    tdata1 = set_field(tdata1, MCONTROL_ACTION,
            MCONTROL_ACTION_DEBUG_MODE);
    tdata1 = set_field(tdata1, MCONTROL_MATCH, MCONTROL_MATCH_EQUAL);
    tdata1 |= MCONTROL_M;
    if (r->misa & (1 << ('S' - 'A')))
        tdata1 |= MCONTROL_S;
    if (r->misa & (1 << ('U' - 'A')))
        tdata1 |= MCONTROL_U;
 
    if (trigger->execute)
        tdata1 |= MCONTROL_EXECUTE;
    if (trigger->read)
        tdata1 |= MCONTROL_LOAD;
    if (trigger->write)
        tdata1 |= MCONTROL_STORE;
 
    riscv_set_register(target, GDB_REGNO_TDATA1, tdata1);
 
    uint64_t tdata1_rb;
    int result = riscv_get_register(target, &tdata1_rb, GDB_REGNO_TDATA1);
    if (result != ERROR_OK)
        return result;
    LOG_DEBUG("tdata1=0x%" PRIx64, tdata1_rb);
 
    if (tdata1 != tdata1_rb) {
        LOG_DEBUG("Trigger doesn't support what we need; After writing 0x%"
                PRIx64 " to tdata1 it contains 0x%" PRIx64,
                tdata1, tdata1_rb);
        riscv_set_register(target, GDB_REGNO_TDATA1, 0);
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    riscv_set_register(target, GDB_REGNO_TDATA2, trigger->address);
 
    return ERROR_OK;
}
 
static int maybe_add_trigger_t6(struct target *target,
        struct trigger *trigger, uint64_t tdata1)
{
    RISCV_INFO(r);
 
    /* tselect is already set */
    if (tdata1 & (CSR_MCONTROL6_EXECUTE | CSR_MCONTROL6_STORE | CSR_MCONTROL6_LOAD)) {
        /* Trigger is already in use, presumably by user code. */
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    /* address/data match trigger */
    tdata1 |= MCONTROL_DMODE(riscv_xlen(target));
    tdata1 = set_field(tdata1, CSR_MCONTROL6_ACTION,
            MCONTROL_ACTION_DEBUG_MODE);
    tdata1 = set_field(tdata1, CSR_MCONTROL6_MATCH, MCONTROL_MATCH_EQUAL);
    tdata1 |= CSR_MCONTROL6_M;
    if (r->misa & (1 << ('H' - 'A')))
        tdata1 |= CSR_MCONTROL6_VS | CSR_MCONTROL6_VU;
    if (r->misa & (1 << ('S' - 'A')))
        tdata1 |= CSR_MCONTROL6_S;
    if (r->misa & (1 << ('U' - 'A')))
        tdata1 |= CSR_MCONTROL6_U;
 
    if (trigger->execute)
        tdata1 |= CSR_MCONTROL6_EXECUTE;
    if (trigger->read)
        tdata1 |= CSR_MCONTROL6_LOAD;
    if (trigger->write)
        tdata1 |= CSR_MCONTROL6_STORE;
 
    riscv_set_register(target, GDB_REGNO_TDATA1, tdata1);
 
    uint64_t tdata1_rb;
    int result = riscv_get_register(target, &tdata1_rb, GDB_REGNO_TDATA1);
    if (result != ERROR_OK)
        return result;
    LOG_DEBUG("tdata1=0x%" PRIx64, tdata1_rb);
 
    if (tdata1 != tdata1_rb) {
        LOG_DEBUG("Trigger doesn't support what we need; After writing 0x%"
                PRIx64 " to tdata1 it contains 0x%" PRIx64,
                tdata1, tdata1_rb);
        riscv_set_register(target, GDB_REGNO_TDATA1, 0);
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    riscv_set_register(target, GDB_REGNO_TDATA2, trigger->address);
 
    return ERROR_OK;
}
 
static int add_trigger(struct target *target, struct trigger *trigger)
{
    RISCV_INFO(r);
 
    if (riscv_enumerate_triggers(target) != ERROR_OK)
        return ERROR_FAIL;
 
    riscv_reg_t tselect;
    if (riscv_get_register(target, &tselect, GDB_REGNO_TSELECT) != ERROR_OK)
        return ERROR_FAIL;
 
    unsigned int i;
    for (i = 0; i < r->trigger_count; i++) {
        if (r->trigger_unique_id[i] != -1)
            continue;
 
        riscv_set_register(target, GDB_REGNO_TSELECT, i);
 
        uint64_t tdata1;
        int result = riscv_get_register(target, &tdata1, GDB_REGNO_TDATA1);
        if (result != ERROR_OK)
            return result;
        int type = get_field(tdata1, MCONTROL_TYPE(riscv_xlen(target)));
 
        switch (type) {
            case 1:
                result = maybe_add_trigger_t1(target, trigger, tdata1);
                break;
            case 2:
                result = maybe_add_trigger_t2(target, trigger, tdata1);
                break;
            case 6:
                result = maybe_add_trigger_t6(target, trigger, tdata1);
                break;
            default:
                LOG_DEBUG("trigger %d has unknown type %d", i, type);
                continue;
        }
 
        if (result != ERROR_OK)
            continue;
 
        LOG_DEBUG("[%d] Using trigger %d (type %d) for bp %d", target->coreid,
                i, type, trigger->unique_id);
        r->trigger_unique_id[i] = trigger->unique_id;
        break;
    }
 
    riscv_set_register(target, GDB_REGNO_TSELECT, tselect);
 
    if (i >= r->trigger_count) {
        LOG_ERROR("Couldn't find an available hardware trigger.");
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    return ERROR_OK;
}
 
static int write_by_given_size(struct target *target, target_addr_t address,
        uint32_t size, uint8_t *buffer, uint32_t access_size)
{
    assert(size == 1 || size == 2 || size == 4 || size == 8);
    assert(access_size == 1 || access_size == 2 || access_size == 4 || access_size == 8);
 
    if (access_size <= size && address % access_size == 0)
        /* Can do the memory access directly without a helper buffer. */
        return target_write_memory(target, address, access_size, size / access_size, buffer);
 
    unsigned int offset_head = address % access_size;
    unsigned int n_blocks = ((size + offset_head) <= access_size) ? 1 : 2;
    uint8_t helper_buf[n_blocks * access_size];
 
    /* Read from memory */
    if (target_read_memory(target, address - offset_head, access_size, n_blocks, helper_buf) != ERROR_OK)
        return ERROR_FAIL;
 
    /* Modify and write back */
    memcpy(helper_buf + offset_head, buffer, size);
    return target_write_memory(target, address - offset_head, access_size, n_blocks, helper_buf);
}
 
static int read_by_given_size(struct target *target, target_addr_t address,
    uint32_t size, uint8_t *buffer, uint32_t access_size)
{
    assert(size == 1 || size == 2 || size == 4 || size == 8);
    assert(access_size == 1 || access_size == 2 || access_size == 4 || access_size == 8);
 
    if (access_size <= size && address % access_size == 0)
        /* Can do the memory access directly without a helper buffer. */
        return target_read_memory(target, address, access_size, size / access_size, buffer);
 
    unsigned int offset_head = address % access_size;
    unsigned int n_blocks = ((size + offset_head) <= access_size) ? 1 : 2;
    uint8_t helper_buf[n_blocks * access_size];
 
    /* Read from memory */
    if (target_read_memory(target, address - offset_head, access_size, n_blocks, helper_buf) != ERROR_OK)
        return ERROR_FAIL;
 
    /* Pick the requested portion from the buffer */
    memcpy(buffer, helper_buf + offset_head, size);
    return ERROR_OK;
}
 
int riscv_write_by_any_size(struct target *target, target_addr_t address, uint32_t size, uint8_t *buffer)
{
    assert(size == 1 || size == 2 ||  size == 4 || size == 8);
 
    /* Find access size that correspond to data size and the alignment. */
    unsigned int preferred_size = size;
    while (address % preferred_size != 0)
        preferred_size /= 2;
 
    /* First try the preferred (most natural) access size. */
    if (write_by_given_size(target, address, size, buffer, preferred_size) == ERROR_OK)
        return ERROR_OK;
 
    /* On failure, try other access sizes.
       Minimize the number of accesses by trying first the largest size. */
    for (unsigned int access_size = 8; access_size > 0; access_size /= 2) {
        if (access_size == preferred_size)
            /* Already tried this size. */
            continue;
 
        if (write_by_given_size(target, address, size, buffer, access_size) == ERROR_OK)
            return ERROR_OK;
    }
 
    /* No access attempt succeeded. */
    return ERROR_FAIL;
}
 
int riscv_read_by_any_size(struct target *target, target_addr_t address, uint32_t size, uint8_t *buffer)
{
    assert(size == 1 || size == 2 ||  size == 4 || size == 8);
 
    /* Find access size that correspond to data size and the alignment. */
    unsigned int preferred_size = size;
    while (address % preferred_size != 0)
        preferred_size /= 2;
 
    /* First try the preferred (most natural) access size. */
    if (read_by_given_size(target, address, size, buffer, preferred_size) == ERROR_OK)
        return ERROR_OK;
 
    /* On failure, try other access sizes.
       Minimize the number of accesses by trying first the largest size. */
    for (unsigned int access_size = 8; access_size > 0; access_size /= 2) {
        if (access_size == preferred_size)
            /* Already tried this size. */
            continue;
 
        if (read_by_given_size(target, address, size, buffer, access_size) == ERROR_OK)
            return ERROR_OK;
    }
 
    /* No access attempt succeeded. */
    return ERROR_FAIL;
}
 
static int riscv_add_breakpoint(struct target *target, struct breakpoint *breakpoint)
{
    LOG_DEBUG("[%d] @0x%" TARGET_PRIxADDR, target->coreid, breakpoint->address);
    assert(breakpoint);
    if (breakpoint->type == BKPT_SOFT) {
        if (!(breakpoint->length == 4 || breakpoint->length == 2)) {
            LOG_ERROR("Invalid breakpoint length %d", breakpoint->length);
            return ERROR_FAIL;
        }
 
        if (0 != (breakpoint->address % 2)) {
            LOG_ERROR("Invalid breakpoint alignment for address 0x%" TARGET_PRIxADDR, breakpoint->address);
            return ERROR_FAIL;
        }
 
        /* Read the original instruction. */
        if (riscv_read_by_any_size(
                target, breakpoint->address, breakpoint->length, breakpoint->orig_instr) != ERROR_OK) {
            LOG_ERROR("Failed to read original instruction at 0x%" TARGET_PRIxADDR,
                    breakpoint->address);
            return ERROR_FAIL;
        }
 
        uint8_t buff[4] = { 0 };
        buf_set_u32(buff, 0, breakpoint->length * CHAR_BIT, breakpoint->length == 4 ? ebreak() : ebreak_c());
        /* Write the ebreak instruction. */
        if (riscv_write_by_any_size(target, breakpoint->address, breakpoint->length, buff) != ERROR_OK) {
            LOG_ERROR("Failed to write %d-byte breakpoint instruction at 0x%"
                    TARGET_PRIxADDR, breakpoint->length, breakpoint->address);
            return ERROR_FAIL;
        }
 
    } else if (breakpoint->type == BKPT_HARD) {
        struct trigger trigger;
        trigger_from_breakpoint(&trigger, breakpoint);
        int const result = add_trigger(target, &trigger);
        if (result != ERROR_OK)
            return result;
    } else {
        LOG_INFO("OpenOCD only supports hardware and software breakpoints.");
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    breakpoint->is_set = true;
    return ERROR_OK;
}
 
static int remove_trigger(struct target *target, struct trigger *trigger)
{
    RISCV_INFO(r);
 
    if (riscv_enumerate_triggers(target) != ERROR_OK)
        return ERROR_FAIL;
 
    unsigned int i;
    for (i = 0; i < r->trigger_count; i++) {
        if (r->trigger_unique_id[i] == trigger->unique_id)
            break;
    }
    if (i >= r->trigger_count) {
        LOG_ERROR("Couldn't find the hardware resources used by hardware "
                "trigger.");
        return ERROR_FAIL;
    }
    LOG_DEBUG("[%d] Stop using resource %d for bp %d", target->coreid, i,
            trigger->unique_id);
 
    riscv_reg_t tselect;
    int result = riscv_get_register(target, &tselect, GDB_REGNO_TSELECT);
    if (result != ERROR_OK)
        return result;
    riscv_set_register(target, GDB_REGNO_TSELECT, i);
    riscv_set_register(target, GDB_REGNO_TDATA1, 0);
    riscv_set_register(target, GDB_REGNO_TSELECT, tselect);
    r->trigger_unique_id[i] = -1;
 
    return ERROR_OK;
}
 
static int riscv_remove_breakpoint(struct target *target,
        struct breakpoint *breakpoint)
{
    if (breakpoint->type == BKPT_SOFT) {
        /* Write the original instruction. */
        if (riscv_write_by_any_size(
                target, breakpoint->address, breakpoint->length, breakpoint->orig_instr) != ERROR_OK) {
            LOG_ERROR("Failed to restore instruction for %d-byte breakpoint at "
                    "0x%" TARGET_PRIxADDR, breakpoint->length, breakpoint->address);
            return ERROR_FAIL;
        }
 
    } else if (breakpoint->type == BKPT_HARD) {
        struct trigger trigger;
        trigger_from_breakpoint(&trigger, breakpoint);
        int result = remove_trigger(target, &trigger);
        if (result != ERROR_OK)
            return result;
 
    } else {
        LOG_INFO("OpenOCD only supports hardware and software breakpoints.");
        return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
    }
 
    breakpoint->is_set = false;
 
    return ERROR_OK;
}
 
static void trigger_from_watchpoint(struct trigger *trigger,
        const struct watchpoint *watchpoint)
{
    trigger->address = watchpoint->address;
    trigger->length = watchpoint->length;
    trigger->mask = watchpoint->mask;
    trigger->value = watchpoint->value;
    trigger->read = (watchpoint->rw == WPT_READ || watchpoint->rw == WPT_ACCESS);
    trigger->write = (watchpoint->rw == WPT_WRITE || watchpoint->rw == WPT_ACCESS);
    trigger->execute = false;
    /* unique_id is unique across both breakpoints and watchpoints. */
    trigger->unique_id = watchpoint->unique_id;
}
 
int riscv_add_watchpoint(struct target *target, struct watchpoint *watchpoint)
{
    struct trigger trigger;
    trigger_from_watchpoint(&trigger, watchpoint);
 
    int result = add_trigger(target, &trigger);
    if (result != ERROR_OK)
        return result;
    watchpoint->is_set = true;
 
    return ERROR_OK;
}
 
int riscv_remove_watchpoint(struct target *target,
        struct watchpoint *watchpoint)
{
    LOG_DEBUG("[%d] @0x%" TARGET_PRIxADDR, target->coreid, watchpoint->address);
 
    struct trigger trigger;
    trigger_from_watchpoint(&trigger, watchpoint);
 
    int result = remove_trigger(target, &trigger);
    if (result != ERROR_OK)
        return result;
    watchpoint->is_set = false;
 
    return ERROR_OK;
}
 
/* Sets *hit_watchpoint to the first watchpoint identified as causing the
 * current halt.
 *
 * The GDB server uses this information to tell GDB what data address has
 * been hit, which enables GDB to print the hit variable along with its old
 * and new value. */
static int riscv_hit_watchpoint(struct target *target, struct watchpoint **hit_watchpoint)
{
    struct watchpoint *wp = target->watchpoints;
 
    LOG_DEBUG("Current hartid = %d", riscv_current_hartid(target));
 
    /*TODO instead of disassembling the instruction that we think caused the
     * trigger, check the hit bit of each watchpoint first. The hit bit is
     * simpler and more reliable to check but as it is optional and relatively
     * new, not all hardware will implement it  */
    riscv_reg_t dpc;
    riscv_get_register(target, &dpc, GDB_REGNO_DPC);
    const uint8_t length = 4;
    LOG_DEBUG("dpc is 0x%" PRIx64, dpc);
 
    /* fetch the instruction at dpc */
    uint8_t buffer[length];
    if (target_read_buffer(target, dpc, length, buffer) != ERROR_OK) {
        LOG_ERROR("Failed to read instruction at dpc 0x%" PRIx64, dpc);
        return ERROR_FAIL;
    }
 
    uint32_t instruction = 0;
 
    for (int i = 0; i < length; i++) {
        LOG_DEBUG("Next byte is %x", buffer[i]);
        instruction += (buffer[i] << 8 * i);
    }
    LOG_DEBUG("Full instruction is %x", instruction);
 
    /* find out which memory address is accessed by the instruction at dpc */
    /* opcode is first 7 bits of the instruction */
    uint8_t opcode = instruction & 0x7F;
    uint32_t rs1;
    int16_t imm;
    riscv_reg_t mem_addr;
 
    if (opcode == MATCH_LB || opcode == MATCH_SB) {
        rs1 = (instruction & 0xf8000) >> 15;
        riscv_get_register(target, &mem_addr, rs1);
 
        if (opcode == MATCH_SB) {
            LOG_DEBUG("%x is store instruction", instruction);
            imm = ((instruction & 0xf80) >> 7) | ((instruction & 0xfe000000) >> 20);
        } else {
            LOG_DEBUG("%x is load instruction", instruction);
            imm = (instruction & 0xfff00000) >> 20;
        }
        /* sign extend 12-bit imm to 16-bits */
        if (imm & (1 << 11))
            imm |= 0xf000;
        mem_addr += imm;
        LOG_DEBUG("memory address=0x%" PRIx64, mem_addr);
    } else {
        LOG_DEBUG("%x is not a RV32I load or store", instruction);
        return ERROR_FAIL;
    }
 
    while (wp) {
        /*TODO support length/mask */
        if (wp->address == mem_addr) {
            *hit_watchpoint = wp;
            LOG_DEBUG("Hit address=%" TARGET_PRIxADDR, wp->address);
            return ERROR_OK;
        }
        wp = wp->next;
    }
 
    /* No match found - either we hit a watchpoint caused by an instruction that
     * this function does not yet disassemble, or we hit a breakpoint.
     *
     * OpenOCD will behave as if this function had never been implemented i.e.
     * report the halt to GDB with no address information. */
    return ERROR_FAIL;
}
 
static int oldriscv_step(struct target *target, bool current, uint32_t address,
        bool handle_breakpoints)
{
    struct target_type *tt = get_target_type(target);
    return tt->step(target, current, address, handle_breakpoints);
}
 
static int old_or_new_riscv_step(struct target *target, bool current,
        target_addr_t address, bool handle_breakpoints)
{
    RISCV_INFO(r);
    LOG_DEBUG("handle_breakpoints=%d", handle_breakpoints);
    if (!r->is_halted)
        return oldriscv_step(target, current, address, handle_breakpoints);
    else
        return riscv_openocd_step(target, current, address, handle_breakpoints);
}
 
static int riscv_examine(struct target *target)
{
    LOG_DEBUG("riscv_examine()");
    if (target_was_examined(target)) {
        LOG_DEBUG("Target was already examined.");
        return ERROR_OK;
    }
 
    /* Don't need to select dbus, since the first thing we do is read dtmcontrol. */
 
    RISCV_INFO(info);
    uint32_t dtmcontrol = dtmcontrol_scan(target, 0);
    LOG_DEBUG("dtmcontrol=0x%x", dtmcontrol);
    info->dtm_version = get_field(dtmcontrol, DTMCONTROL_VERSION);
    LOG_DEBUG("  version=0x%x", info->dtm_version);
 
    struct target_type *tt = get_target_type(target);
    if (!tt)
        return ERROR_FAIL;
 
    int result = tt->init_target(info->cmd_ctx, target);
    if (result != ERROR_OK)
        return result;
 
    return tt->examine(target);
}
 
static int oldriscv_poll(struct target *target)
{
    struct target_type *tt = get_target_type(target);
    return tt->poll(target);
}
 
static int old_or_new_riscv_poll(struct target *target)
{
    RISCV_INFO(r);
    if (!r->is_halted)
        return oldriscv_poll(target);
    else
        return riscv_openocd_poll(target);
}
 
int riscv_select_current_hart(struct target *target)
{
    return riscv_set_current_hartid(target, target->coreid);
}
 
static int halt_prep(struct target *target)
{
    RISCV_INFO(r);
 
    LOG_DEBUG("[%s] prep hart, debug_reason=%d", target_name(target),
                target->debug_reason);
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
    if (riscv_is_halted(target)) {
        LOG_DEBUG("[%s] Hart is already halted (reason=%d).",
                target_name(target), target->debug_reason);
    } else {
        if (r->halt_prep(target) != ERROR_OK)
            return ERROR_FAIL;
        r->prepped = true;
    }
 
    return ERROR_OK;
}
 
static int riscv_halt_go_all_harts(struct target *target)
{
    RISCV_INFO(r);
 
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
    if (riscv_is_halted(target)) {
        LOG_DEBUG("[%s] Hart is already halted.", target_name(target));
    } else {
        if (r->halt_go(target) != ERROR_OK)
            return ERROR_FAIL;
    }
 
    riscv_invalidate_register_cache(target);
 
    return ERROR_OK;
}
 
static int halt_go(struct target *target)
{
    RISCV_INFO(r);
    int result;
    if (!r->is_halted) {
        struct target_type *tt = get_target_type(target);
        result = tt->halt(target);
    } else {
        result = riscv_halt_go_all_harts(target);
    }
    target->state = TARGET_HALTED;
    if (target->debug_reason == DBG_REASON_NOTHALTED)
        target->debug_reason = DBG_REASON_DBGRQ;
 
    return result;
}
 
static int halt_finish(struct target *target)
{
    return target_call_event_callbacks(target, TARGET_EVENT_HALTED);
}
 
int riscv_halt(struct target *target)
{
    RISCV_INFO(r);
 
    if (!r->is_halted) {
        struct target_type *tt = get_target_type(target);
        return tt->halt(target);
    }
 
    LOG_DEBUG("[%d] halting all harts", target->coreid);
 
    int result = ERROR_OK;
    if (target->smp) {
        struct target_list *tlist;
        foreach_smp_target(tlist, target->smp_targets) {
            struct target *t = tlist->target;
            if (halt_prep(t) != ERROR_OK)
                result = ERROR_FAIL;
        }
 
        foreach_smp_target(tlist, target->smp_targets) {
            struct target *t = tlist->target;
            struct riscv_info *i = riscv_info(t);
            if (i->prepped) {
                if (halt_go(t) != ERROR_OK)
                    result = ERROR_FAIL;
            }
        }
 
        foreach_smp_target(tlist, target->smp_targets) {
            struct target *t = tlist->target;
            if (halt_finish(t) != ERROR_OK)
                return ERROR_FAIL;
        }
 
    } else {
        if (halt_prep(target) != ERROR_OK)
            result = ERROR_FAIL;
        if (halt_go(target) != ERROR_OK)
            result = ERROR_FAIL;
        if (halt_finish(target) != ERROR_OK)
            return ERROR_FAIL;
    }
 
    return result;
}
 
static int riscv_assert_reset(struct target *target)
{
    LOG_DEBUG("[%d]", target->coreid);
    struct target_type *tt = get_target_type(target);
    riscv_invalidate_register_cache(target);
    return tt->assert_reset(target);
}
 
static int riscv_deassert_reset(struct target *target)
{
    LOG_DEBUG("[%d]", target->coreid);
    struct target_type *tt = get_target_type(target);
    return tt->deassert_reset(target);
}
 
static int riscv_resume_prep_all_harts(struct target *target)
{
    RISCV_INFO(r);
 
    LOG_DEBUG("[%s] prep hart", target_name(target));
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
    if (riscv_is_halted(target)) {
        if (r->resume_prep(target) != ERROR_OK)
            return ERROR_FAIL;
    } else {
        LOG_DEBUG("[%s] hart requested resume, but was already resumed",
                target_name(target));
    }
 
    LOG_DEBUG("[%s] mark as prepped", target_name(target));
    r->prepped = true;
 
    return ERROR_OK;
}
 
/* state must be riscv_reg_t state[RISCV_MAX_HWBPS] = {0}; */
static int disable_triggers(struct target *target, riscv_reg_t *state)
{
    RISCV_INFO(r);
 
    LOG_DEBUG("deal with triggers");
 
    if (riscv_enumerate_triggers(target) != ERROR_OK)
        return ERROR_FAIL;
 
    if (r->manual_hwbp_set) {
        /* Look at every trigger that may have been set. */
        riscv_reg_t tselect;
        if (riscv_get_register(target, &tselect, GDB_REGNO_TSELECT) != ERROR_OK)
            return ERROR_FAIL;
        for (unsigned int t = 0; t < r->trigger_count; t++) {
            if (riscv_set_register(target, GDB_REGNO_TSELECT, t) != ERROR_OK)
                return ERROR_FAIL;
            riscv_reg_t tdata1;
            if (riscv_get_register(target, &tdata1, GDB_REGNO_TDATA1) != ERROR_OK)
                return ERROR_FAIL;
            if (tdata1 & MCONTROL_DMODE(riscv_xlen(target))) {
                state[t] = tdata1;
                if (riscv_set_register(target, GDB_REGNO_TDATA1, 0) != ERROR_OK)
                    return ERROR_FAIL;
            }
        }
        if (riscv_set_register(target, GDB_REGNO_TSELECT, tselect) != ERROR_OK)
            return ERROR_FAIL;
 
    } else {
        /* Just go through the triggers we manage. */
        struct watchpoint *watchpoint = target->watchpoints;
        int i = 0;
        while (watchpoint) {
            LOG_DEBUG("watchpoint %d: set=%d", i, watchpoint->is_set);
            state[i] = watchpoint->is_set;
            if (watchpoint->is_set) {
                if (riscv_remove_watchpoint(target, watchpoint) != ERROR_OK)
                    return ERROR_FAIL;
            }
            watchpoint = watchpoint->next;
            i++;
        }
    }
 
    return ERROR_OK;
}
 
static int enable_triggers(struct target *target, riscv_reg_t *state)
{
    RISCV_INFO(r);
 
    if (r->manual_hwbp_set) {
        /* Look at every trigger that may have been set. */
        riscv_reg_t tselect;
        if (riscv_get_register(target, &tselect, GDB_REGNO_TSELECT) != ERROR_OK)
            return ERROR_FAIL;
        for (unsigned int t = 0; t < r->trigger_count; t++) {
            if (state[t] != 0) {
                if (riscv_set_register(target, GDB_REGNO_TSELECT, t) != ERROR_OK)
                    return ERROR_FAIL;
                if (riscv_set_register(target, GDB_REGNO_TDATA1, state[t]) != ERROR_OK)
                    return ERROR_FAIL;
            }
        }
        if (riscv_set_register(target, GDB_REGNO_TSELECT, tselect) != ERROR_OK)
            return ERROR_FAIL;
 
    } else {
        struct watchpoint *watchpoint = target->watchpoints;
        int i = 0;
        while (watchpoint) {
            LOG_DEBUG("watchpoint %d: cleared=%" PRId64, i, state[i]);
            if (state[i]) {
                if (riscv_add_watchpoint(target, watchpoint) != ERROR_OK)
                    return ERROR_FAIL;
            }
            watchpoint = watchpoint->next;
            i++;
        }
    }
 
    return ERROR_OK;
}
 
static int resume_prep(struct target *target, bool current,
        target_addr_t address, bool handle_breakpoints, bool debug_execution)
{
    RISCV_INFO(r);
    LOG_DEBUG("[%d]", target->coreid);
 
    if (!current)
        riscv_set_register(target, GDB_REGNO_PC, address);
 
    if (target->debug_reason == DBG_REASON_WATCHPOINT) {
        /* To be able to run off a trigger, disable all the triggers, step, and
         * then resume as usual. */
        riscv_reg_t trigger_state[RISCV_MAX_HWBPS] = {0};
 
        if (disable_triggers(target, trigger_state) != ERROR_OK)
            return ERROR_FAIL;
 
        if (old_or_new_riscv_step(target, true, 0, false) != ERROR_OK)
            return ERROR_FAIL;
 
        if (enable_triggers(target, trigger_state) != ERROR_OK)
            return ERROR_FAIL;
    }
 
    if (r->is_halted) {
        if (riscv_resume_prep_all_harts(target) != ERROR_OK)
            return ERROR_FAIL;
    }
 
    LOG_DEBUG("[%d] mark as prepped", target->coreid);
    r->prepped = true;
 
    return ERROR_OK;
}
 
static int resume_go(struct target *target, bool current,
        target_addr_t address, bool handle_breakpoints, bool debug_execution)
{
    RISCV_INFO(r);
    int result;
    if (!r->is_halted) {
        struct target_type *tt = get_target_type(target);
        result = tt->resume(target, current, address, handle_breakpoints,
                debug_execution);
    } else {
        result = riscv_resume_go_all_harts(target);
    }
 
    return result;
}
 
static int resume_finish(struct target *target)
{
    register_cache_invalidate(target->reg_cache);
 
    target->state = TARGET_RUNNING;
    target->debug_reason = DBG_REASON_NOTHALTED;
    return target_call_event_callbacks(target, TARGET_EVENT_RESUMED);
}
 
static int riscv_resume(
        struct target *target,
        bool current,
        target_addr_t address,
        bool handle_breakpoints,
        bool debug_execution,
        bool single_hart)
{
    LOG_DEBUG("handle_breakpoints=%d", handle_breakpoints);
    int result = ERROR_OK;
    if (target->smp && !single_hart) {
        struct target_list *tlist;
        foreach_smp_target_direction(resume_order == RO_NORMAL,
                                     tlist, target->smp_targets) {
            struct target *t = tlist->target;
            if (resume_prep(t, current, address, handle_breakpoints,
                        debug_execution) != ERROR_OK)
                result = ERROR_FAIL;
        }
 
        foreach_smp_target_direction(resume_order == RO_NORMAL,
                                     tlist, target->smp_targets) {
            struct target *t = tlist->target;
            struct riscv_info *i = riscv_info(t);
            if (i->prepped) {
                if (resume_go(t, current, address, handle_breakpoints,
                            debug_execution) != ERROR_OK)
                    result = ERROR_FAIL;
            }
        }
 
        foreach_smp_target_direction(resume_order == RO_NORMAL,
                                     tlist, target->smp_targets) {
            struct target *t = tlist->target;
            if (resume_finish(t) != ERROR_OK)
                return ERROR_FAIL;
        }
 
    } else {
        if (resume_prep(target, current, address, handle_breakpoints,
                    debug_execution) != ERROR_OK)
            result = ERROR_FAIL;
        if (resume_go(target, current, address, handle_breakpoints,
                    debug_execution) != ERROR_OK)
            result = ERROR_FAIL;
        if (resume_finish(target) != ERROR_OK)
            return ERROR_FAIL;
    }
 
    return result;
}
 
static int riscv_target_resume(struct target *target, bool current,
        target_addr_t address, bool handle_breakpoints, bool debug_execution)
{
    return riscv_resume(target, current, address, handle_breakpoints,
            debug_execution, false);
}
 
static int riscv_mmu(struct target *target, int *enabled)
{
    if (!riscv_enable_virt2phys) {
        *enabled = 0;
        return ERROR_OK;
    }
 
    /* Don't use MMU in explicit or effective M (machine) mode */
    riscv_reg_t priv;
    if (riscv_get_register(target, &priv, GDB_REGNO_PRIV) != ERROR_OK) {
        LOG_ERROR("Failed to read priv register.");
        return ERROR_FAIL;
    }
 
    riscv_reg_t mstatus;
    if (riscv_get_register(target, &mstatus, GDB_REGNO_MSTATUS) != ERROR_OK) {
        LOG_ERROR("Failed to read mstatus register.");
        return ERROR_FAIL;
    }
 
    if ((get_field(mstatus, MSTATUS_MPRV) ? get_field(mstatus, MSTATUS_MPP) : priv) == PRV_M) {
        LOG_DEBUG("SATP/MMU ignored in Machine mode (mstatus=0x%" PRIx64 ").", mstatus);
        *enabled = 0;
        return ERROR_OK;
    }
 
    riscv_reg_t satp;
    if (riscv_get_register(target, &satp, GDB_REGNO_SATP) != ERROR_OK) {
        LOG_DEBUG("Couldn't read SATP.");
        /* If we can't read SATP, then there must not be an MMU. */
        *enabled = 0;
        return ERROR_OK;
    }
 
    if (get_field(satp, RISCV_SATP_MODE(riscv_xlen(target))) == SATP_MODE_OFF) {
        LOG_DEBUG("MMU is disabled.");
        *enabled = 0;
    } else {
        LOG_DEBUG("MMU is enabled.");
        *enabled = 1;
    }
 
    return ERROR_OK;
}
 
static int riscv_address_translate(struct target *target,
        target_addr_t virtual, target_addr_t *physical)
{
    RISCV_INFO(r);
    riscv_reg_t satp_value;
    int mode;
    uint64_t ppn_value;
    target_addr_t table_address;
    const virt2phys_info_t *info;
    uint64_t pte = 0;
    int i;
 
    int result = riscv_get_register(target, &satp_value, GDB_REGNO_SATP);
    if (result != ERROR_OK)
        return result;
 
    unsigned int xlen = riscv_xlen(target);
    mode = get_field(satp_value, RISCV_SATP_MODE(xlen));
    switch (mode) {
        case SATP_MODE_SV32:
            info = &sv32;
            break;
        case SATP_MODE_SV39:
            info = &sv39;
            break;
        case SATP_MODE_SV48:
            info = &sv48;
            break;
        case SATP_MODE_OFF:
            LOG_ERROR("No translation or protection." \
                      " (satp: 0x%" PRIx64 ")", satp_value);
            return ERROR_FAIL;
        default:
            LOG_ERROR("The translation mode is not supported." \
                      " (satp: 0x%" PRIx64 ")", satp_value);
            return ERROR_FAIL;
    }
    LOG_DEBUG("virtual=0x%" TARGET_PRIxADDR "; mode=%s", virtual, info->name);
 
    /* verify bits xlen-1:va_bits-1 are all equal */
    assert(xlen >= info->va_bits);
    target_addr_t mask = ((target_addr_t)1 << (xlen - (info->va_bits - 1))) - 1;
    target_addr_t masked_msbs = (virtual >> (info->va_bits - 1)) & mask;
    if (masked_msbs != 0 && masked_msbs != mask) {
        LOG_ERROR("Virtual address 0x%" TARGET_PRIxADDR " is not sign-extended "
                "for %s mode.", virtual, info->name);
        return ERROR_FAIL;
    }
 
    ppn_value = get_field(satp_value, RISCV_SATP_PPN(xlen));
    table_address = ppn_value << RISCV_PGSHIFT;
    i = info->level - 1;
    while (i >= 0) {
        uint64_t vpn = virtual >> info->vpn_shift[i];
        vpn &= info->vpn_mask[i];
        target_addr_t pte_address = table_address +
                                    (vpn << info->pte_shift);
        uint8_t buffer[8];
        assert(info->pte_shift <= 3);
        int retval = r->read_memory(target, pte_address,
                4, (1 << info->pte_shift) / 4, buffer, 4);
        if (retval != ERROR_OK)
            return ERROR_FAIL;
 
        if (info->pte_shift == 2)
            pte = buf_get_u32(buffer, 0, 32);
        else
            pte = buf_get_u64(buffer, 0, 64);
 
        LOG_DEBUG("i=%d; PTE @0x%" TARGET_PRIxADDR " = 0x%" PRIx64, i,
                pte_address, pte);
 
        if (!(pte & PTE_V) || (!(pte & PTE_R) && (pte & PTE_W)))
            return ERROR_FAIL;
 
        if ((pte & PTE_R) || (pte & PTE_X)) /* Found leaf PTE. */
            break;
 
        i--;
        if (i < 0)
            break;
        ppn_value = pte >> PTE_PPN_SHIFT;
        table_address = ppn_value << RISCV_PGSHIFT;
    }
 
    if (i < 0) {
        LOG_ERROR("Couldn't find the PTE.");
        return ERROR_FAIL;
    }
 
    /* Make sure to clear out the high bits that may be set. */
    *physical = virtual & (((target_addr_t)1 << info->va_bits) - 1);
 
    while (i < info->level) {
        ppn_value = pte >> info->pte_ppn_shift[i];
        ppn_value &= info->pte_ppn_mask[i];
        *physical &= ~(((target_addr_t)info->pa_ppn_mask[i]) <<
                info->pa_ppn_shift[i]);
        *physical |= (ppn_value << info->pa_ppn_shift[i]);
        i++;
    }
    LOG_DEBUG("0x%" TARGET_PRIxADDR " -> 0x%" TARGET_PRIxADDR, virtual,
            *physical);
 
    return ERROR_OK;
}
 
static int riscv_virt2phys(struct target *target, target_addr_t virtual, target_addr_t *physical)
{
    int enabled;
    if (riscv_mmu(target, &enabled) == ERROR_OK) {
        if (!enabled)
            return ERROR_FAIL;
 
        if (riscv_address_translate(target, virtual, physical) == ERROR_OK)
            return ERROR_OK;
    }
 
    return ERROR_FAIL;
}
 
static int riscv_read_phys_memory(struct target *target, target_addr_t phys_address,
            uint32_t size, uint32_t count, uint8_t *buffer)
{
    RISCV_INFO(r);
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
    return r->read_memory(target, phys_address, size, count, buffer, size);
}
 
static int riscv_read_memory(struct target *target, target_addr_t address,
        uint32_t size, uint32_t count, uint8_t *buffer)
{
    if (count == 0) {
        LOG_WARNING("0-length read from 0x%" TARGET_PRIxADDR, address);
        return ERROR_OK;
    }
 
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
 
    target_addr_t physical_addr;
    if (target->type->virt2phys(target, address, &physical_addr) == ERROR_OK)
        address = physical_addr;
 
    RISCV_INFO(r);
    return r->read_memory(target, address, size, count, buffer, size);
}
 
static int riscv_write_phys_memory(struct target *target, target_addr_t phys_address,
            uint32_t size, uint32_t count, const uint8_t *buffer)
{
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
    struct target_type *tt = get_target_type(target);
    return tt->write_memory(target, phys_address, size, count, buffer);
}
 
static int riscv_write_memory(struct target *target, target_addr_t address,
        uint32_t size, uint32_t count, const uint8_t *buffer)
{
    if (count == 0) {
        LOG_WARNING("0-length write to 0x%" TARGET_PRIxADDR, address);
        return ERROR_OK;
    }
 
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
 
    target_addr_t physical_addr;
    if (target->type->virt2phys(target, address, &physical_addr) == ERROR_OK)
        address = physical_addr;
 
    struct target_type *tt = get_target_type(target);
    return tt->write_memory(target, address, size, count, buffer);
}
 
static const char *riscv_get_gdb_arch(const struct target *target)
{
    switch (riscv_xlen(target)) {
        case 32:
            return "riscv:rv32";
        case 64:
            return "riscv:rv64";
    }
    LOG_ERROR("Unsupported xlen: %d", riscv_xlen(target));
    return NULL;
}
 
static int riscv_get_gdb_reg_list_internal(struct target *target,
        struct reg **reg_list[], int *reg_list_size,
        enum target_register_class reg_class, bool read)
{
    RISCV_INFO(r);
    LOG_DEBUG("[%s] {%d} reg_class=%d, read=%d",
            target_name(target), r->current_hartid, reg_class, read);
 
    if (!target->reg_cache) {
        LOG_ERROR("Target not initialized. Return ERROR_FAIL.");
        return ERROR_FAIL;
    }
 
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
 
    switch (reg_class) {
        case REG_CLASS_GENERAL:
            *reg_list_size = 33;
            break;
        case REG_CLASS_ALL:
            *reg_list_size = target->reg_cache->num_regs;
            break;
        default:
            LOG_ERROR("Unsupported reg_class: %d", reg_class);
            return ERROR_FAIL;
    }
 
    *reg_list = calloc(*reg_list_size, sizeof(struct reg *));
    if (!*reg_list)
        return ERROR_FAIL;
 
    for (int i = 0; i < *reg_list_size; i++) {
        assert(!target->reg_cache->reg_list[i].valid ||
                target->reg_cache->reg_list[i].size > 0);
        (*reg_list)[i] = &target->reg_cache->reg_list[i];
        if (read &&
                target->reg_cache->reg_list[i].exist &&
                !target->reg_cache->reg_list[i].valid) {
            if (target->reg_cache->reg_list[i].type->get(
                        &target->reg_cache->reg_list[i]) != ERROR_OK)
                return ERROR_FAIL;
        }
    }
 
    return ERROR_OK;
}
 
static int riscv_get_gdb_reg_list_noread(struct target *target,
        struct reg **reg_list[], int *reg_list_size,
        enum target_register_class reg_class)
{
    return riscv_get_gdb_reg_list_internal(target, reg_list, reg_list_size,
            reg_class, false);
}
 
static int riscv_get_gdb_reg_list(struct target *target,
        struct reg **reg_list[], int *reg_list_size,
        enum target_register_class reg_class)
{
    return riscv_get_gdb_reg_list_internal(target, reg_list, reg_list_size,
            reg_class, true);
}
 
static int riscv_arch_state(struct target *target)
{
    struct target_type *tt = get_target_type(target);
    return tt->arch_state(target);
}
 
/* Algorithm must end with a software breakpoint instruction. */
static int riscv_run_algorithm(struct target *target, int num_mem_params,
        struct mem_param *mem_params, int num_reg_params,
        struct reg_param *reg_params, target_addr_t entry_point,
        target_addr_t exit_point, unsigned int timeout_ms, void *arch_info)
{
    RISCV_INFO(info);
 
    if (num_mem_params > 0) {
        LOG_ERROR("Memory parameters are not supported for RISC-V algorithms.");
        return ERROR_FAIL;
    }
 
    if (target->state != TARGET_HALTED) {
        LOG_TARGET_ERROR(target, "not halted (run target algo)");
        return ERROR_TARGET_NOT_HALTED;
    }
 
    /* Save registers */
    struct reg *reg_pc = register_get_by_name(target->reg_cache, "pc", true);
    if (!reg_pc || reg_pc->type->get(reg_pc) != ERROR_OK)
        return ERROR_FAIL;
    uint64_t saved_pc = buf_get_u64(reg_pc->value, 0, reg_pc->size);
    LOG_DEBUG("saved_pc=0x%" PRIx64, saved_pc);
 
    uint64_t saved_regs[32];
    for (int i = 0; i < num_reg_params; i++) {
        LOG_DEBUG("save %s", reg_params[i].reg_name);
        struct reg *r = register_get_by_name(target->reg_cache, reg_params[i].reg_name, false);
        if (!r) {
            LOG_ERROR("Couldn't find register named '%s'", reg_params[i].reg_name);
            return ERROR_FAIL;
        }
 
        if (r->size != reg_params[i].size) {
            LOG_ERROR("Register %s is %d bits instead of %d bits.",
                    reg_params[i].reg_name, r->size, reg_params[i].size);
            return ERROR_FAIL;
        }
 
        if (r->number > GDB_REGNO_XPR31) {
            LOG_ERROR("Only GPRs can be use as argument registers.");
            return ERROR_FAIL;
        }
 
        if (r->type->get(r) != ERROR_OK)
            return ERROR_FAIL;
        saved_regs[r->number] = buf_get_u64(r->value, 0, r->size);
 
        if (reg_params[i].direction == PARAM_OUT || reg_params[i].direction == PARAM_IN_OUT) {
            if (r->type->set(r, reg_params[i].value) != ERROR_OK)
                return ERROR_FAIL;
        }
    }
 
 
    /* Disable Interrupts before attempting to run the algorithm. */
    uint64_t current_mstatus;
    uint8_t mstatus_bytes[8] = { 0 };
 
    LOG_DEBUG("Disabling Interrupts");
    struct reg *reg_mstatus = register_get_by_name(target->reg_cache,
            "mstatus", true);
    if (!reg_mstatus) {
        LOG_ERROR("Couldn't find mstatus!");
        return ERROR_FAIL;
    }
 
    reg_mstatus->type->get(reg_mstatus);
    current_mstatus = buf_get_u64(reg_mstatus->value, 0, reg_mstatus->size);
    uint64_t ie_mask = MSTATUS_MIE | MSTATUS_HIE | MSTATUS_SIE | MSTATUS_UIE;
    buf_set_u64(mstatus_bytes, 0, info->xlen, set_field(current_mstatus,
                ie_mask, 0));
 
    reg_mstatus->type->set(reg_mstatus, mstatus_bytes);
 
    /* Run algorithm */
    LOG_DEBUG("resume at 0x%" TARGET_PRIxADDR, entry_point);
    if (riscv_resume(target, false, entry_point, false, false, true) != ERROR_OK)
        return ERROR_FAIL;
 
    int64_t start = timeval_ms();
    while (target->state != TARGET_HALTED) {
        LOG_DEBUG("poll()");
        int64_t now = timeval_ms();
        if (now - start > timeout_ms) {
            LOG_ERROR("Algorithm timed out after %" PRId64 " ms.", now - start);
            riscv_halt(target);
            old_or_new_riscv_poll(target);
            enum gdb_regno regnums[] = {
                GDB_REGNO_RA, GDB_REGNO_SP, GDB_REGNO_GP, GDB_REGNO_TP,
                GDB_REGNO_T0, GDB_REGNO_T1, GDB_REGNO_T2, GDB_REGNO_FP,
                GDB_REGNO_S1, GDB_REGNO_A0, GDB_REGNO_A1, GDB_REGNO_A2,
                GDB_REGNO_A3, GDB_REGNO_A4, GDB_REGNO_A5, GDB_REGNO_A6,
                GDB_REGNO_A7, GDB_REGNO_S2, GDB_REGNO_S3, GDB_REGNO_S4,
                GDB_REGNO_S5, GDB_REGNO_S6, GDB_REGNO_S7, GDB_REGNO_S8,
                GDB_REGNO_S9, GDB_REGNO_S10, GDB_REGNO_S11, GDB_REGNO_T3,
                GDB_REGNO_T4, GDB_REGNO_T5, GDB_REGNO_T6,
                GDB_REGNO_PC,
                GDB_REGNO_MSTATUS, GDB_REGNO_MEPC, GDB_REGNO_MCAUSE,
            };
            for (unsigned int i = 0; i < ARRAY_SIZE(regnums); i++) {
                enum gdb_regno regno = regnums[i];
                riscv_reg_t reg_value;
                if (riscv_get_register(target, &reg_value, regno) != ERROR_OK)
                    break;
                LOG_ERROR("%s = 0x%" PRIx64, gdb_regno_name(regno), reg_value);
            }
            return ERROR_TARGET_TIMEOUT;
        }
 
        int result = old_or_new_riscv_poll(target);
        if (result != ERROR_OK)
            return result;
    }
 
    /* The current hart id might have been changed in poll(). */
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
 
    if (reg_pc->type->get(reg_pc) != ERROR_OK)
        return ERROR_FAIL;
    uint64_t final_pc = buf_get_u64(reg_pc->value, 0, reg_pc->size);
    if (exit_point && final_pc != exit_point) {
        LOG_ERROR("PC ended up at 0x%" PRIx64 " instead of 0x%"
                TARGET_PRIxADDR, final_pc, exit_point);
        return ERROR_FAIL;
    }
 
    /* Restore Interrupts */
    LOG_DEBUG("Restoring Interrupts");
    buf_set_u64(mstatus_bytes, 0, info->xlen, current_mstatus);
    reg_mstatus->type->set(reg_mstatus, mstatus_bytes);
 
    /* Restore registers */
    uint8_t buf[8] = { 0 };
    buf_set_u64(buf, 0, info->xlen, saved_pc);
    if (reg_pc->type->set(reg_pc, buf) != ERROR_OK)
        return ERROR_FAIL;
 
    for (int i = 0; i < num_reg_params; i++) {
        if (reg_params[i].direction == PARAM_IN ||
                reg_params[i].direction == PARAM_IN_OUT) {
            struct reg *r = register_get_by_name(target->reg_cache, reg_params[i].reg_name, false);
            if (r->type->get(r) != ERROR_OK) {
                LOG_ERROR("get(%s) failed", r->name);
                return ERROR_FAIL;
            }
            buf_cpy(r->value, reg_params[i].value, reg_params[i].size);
        }
        LOG_DEBUG("restore %s", reg_params[i].reg_name);
        struct reg *r = register_get_by_name(target->reg_cache, reg_params[i].reg_name, false);
        buf_set_u64(buf, 0, info->xlen, saved_regs[r->number]);
        if (r->type->set(r, buf) != ERROR_OK) {
            LOG_ERROR("set(%s) failed", r->name);
            return ERROR_FAIL;
        }
    }
 
    return ERROR_OK;
}
 
static int riscv_checksum_memory(struct target *target,
        target_addr_t address, uint32_t count,
        uint32_t *checksum)
{
    struct working_area *crc_algorithm;
    struct reg_param reg_params[2];
    int retval;
 
    LOG_DEBUG("address=0x%" TARGET_PRIxADDR "; count=0x%" PRIx32, address, count);
 
    static const uint8_t riscv32_crc_code[] = {
#include "../../../contrib/loaders/checksum/riscv32_crc.inc"
    };
    static const uint8_t riscv64_crc_code[] = {
#include "../../../contrib/loaders/checksum/riscv64_crc.inc"
    };
 
    static const uint8_t *crc_code;
 
    unsigned int xlen = riscv_xlen(target);
    unsigned int crc_code_size;
    if (xlen == 32) {
        crc_code = riscv32_crc_code;
        crc_code_size = sizeof(riscv32_crc_code);
    } else {
        crc_code = riscv64_crc_code;
        crc_code_size = sizeof(riscv64_crc_code);
    }
 
    if (count < crc_code_size * 4) {
        /* Don't use the algorithm for relatively small buffers. It's faster
         * just to read the memory.  target_checksum_memory() will take care of
         * that if we fail. */
        return ERROR_FAIL;
    }
 
    retval = target_alloc_working_area(target, crc_code_size, &crc_algorithm);
    if (retval != ERROR_OK)
        return retval;
 
    if (crc_algorithm->address + crc_algorithm->size > address &&
            crc_algorithm->address < address + count) {
        /* Region to checksum overlaps with the work area we've been assigned.
         * Bail. (Would be better to manually checksum what we read there, and
         * use the algorithm for the rest.) */
        target_free_working_area(target, crc_algorithm);
        return ERROR_FAIL;
    }
 
    retval = target_write_buffer(target, crc_algorithm->address, crc_code_size,
            crc_code);
    if (retval != ERROR_OK) {
        LOG_ERROR("Failed to write code to " TARGET_ADDR_FMT ": %d",
                crc_algorithm->address, retval);
        target_free_working_area(target, crc_algorithm);
        return retval;
    }
 
    init_reg_param(&reg_params[0], "a0", xlen, PARAM_IN_OUT);
    init_reg_param(&reg_params[1], "a1", xlen, PARAM_OUT);
    buf_set_u64(reg_params[0].value, 0, xlen, address);
    buf_set_u64(reg_params[1].value, 0, xlen, count);
 
    /* 20 second timeout/megabyte */
    unsigned int timeout = 20000 * (1 + (count / (1024 * 1024)));
 
    retval = target_run_algorithm(target, 0, NULL, 2, reg_params,
            crc_algorithm->address,
            0,  /* Leave exit point unspecified because we don't know. */
            timeout, NULL);
 
    if (retval == ERROR_OK)
        *checksum = buf_get_u32(reg_params[0].value, 0, 32);
    else
        LOG_ERROR("error executing RISC-V CRC algorithm");
 
    destroy_reg_param(&reg_params[0]);
    destroy_reg_param(&reg_params[1]);
 
    target_free_working_area(target, crc_algorithm);
 
    LOG_DEBUG("checksum=0x%" PRIx32 ", result=%d", *checksum, retval);
 
    return retval;
}
 
/*** OpenOCD Helper Functions ***/
 
enum riscv_poll_hart {
    RPH_NO_CHANGE,
    RPH_DISCOVERED_HALTED,
    RPH_DISCOVERED_RUNNING,
    RPH_ERROR
};
static enum riscv_poll_hart riscv_poll_hart(struct target *target, int hartid)
{
    RISCV_INFO(r);
    if (riscv_set_current_hartid(target, hartid) != ERROR_OK)
        return RPH_ERROR;
 
    LOG_DEBUG("polling hart %d, target->state=%d", hartid, target->state);
 
    /* If OpenOCD thinks we're running but this hart is halted then it's time
     * to raise an event. */
    bool halted = riscv_is_halted(target);
    if (target->state != TARGET_HALTED && halted) {
        LOG_DEBUG("  triggered a halt");
        r->on_halt(target);
        return RPH_DISCOVERED_HALTED;
    } else if (target->state != TARGET_RUNNING && !halted) {
        LOG_DEBUG("  triggered running");
        target->state = TARGET_RUNNING;
        target->debug_reason = DBG_REASON_NOTHALTED;
        return RPH_DISCOVERED_RUNNING;
    }
 
    return RPH_NO_CHANGE;
}
 
static int set_debug_reason(struct target *target, enum riscv_halt_reason halt_reason)
{
    switch (halt_reason) {
        case RISCV_HALT_BREAKPOINT:
            target->debug_reason = DBG_REASON_BREAKPOINT;
            break;
        case RISCV_HALT_TRIGGER:
            target->debug_reason = DBG_REASON_WATCHPOINT;
            break;
        case RISCV_HALT_INTERRUPT:
        case RISCV_HALT_GROUP:
            target->debug_reason = DBG_REASON_DBGRQ;
            break;
        case RISCV_HALT_SINGLESTEP:
            target->debug_reason = DBG_REASON_SINGLESTEP;
            break;
        case RISCV_HALT_UNKNOWN:
            target->debug_reason = DBG_REASON_UNDEFINED;
            break;
        case RISCV_HALT_ERROR:
            return ERROR_FAIL;
    }
    LOG_DEBUG("[%s] debug_reason=%d", target_name(target), target->debug_reason);
    return ERROR_OK;
}
 
static int sample_memory(struct target *target)
{
    RISCV_INFO(r);
 
    if (!r->sample_buf.buf || !r->sample_config.enabled)
        return ERROR_OK;
 
    LOG_DEBUG("buf used/size: %d/%d", r->sample_buf.used, r->sample_buf.size);
 
    uint64_t start = timeval_ms();
    riscv_sample_buf_maybe_add_timestamp(target, true);
    int result = ERROR_OK;
    if (r->sample_memory) {
        result = r->sample_memory(target, &r->sample_buf, &r->sample_config,
                                      start + TARGET_DEFAULT_POLLING_INTERVAL);
        if (result != ERROR_NOT_IMPLEMENTED)
            goto exit;
    }
 
    /* Default slow path. */
    while (timeval_ms() - start < TARGET_DEFAULT_POLLING_INTERVAL) {
        for (unsigned int i = 0; i < ARRAY_SIZE(r->sample_config.bucket); i++) {
            if (r->sample_config.bucket[i].enabled &&
                    r->sample_buf.used + 1 + r->sample_config.bucket[i].size_bytes < r->sample_buf.size) {
                assert(i < RISCV_SAMPLE_BUF_TIMESTAMP_BEFORE);
                r->sample_buf.buf[r->sample_buf.used] = i;
                result = riscv_read_phys_memory(
                    target, r->sample_config.bucket[i].address,
                    r->sample_config.bucket[i].size_bytes, 1,
                    r->sample_buf.buf + r->sample_buf.used + 1);
                if (result == ERROR_OK)
                    r->sample_buf.used += 1 + r->sample_config.bucket[i].size_bytes;
                else
                    goto exit;
            }
        }
    }
 
exit:
    riscv_sample_buf_maybe_add_timestamp(target, false);
    if (result != ERROR_OK) {
        LOG_INFO("Turning off memory sampling because it failed.");
        r->sample_config.enabled = false;
    }
    return result;
}
 
/*** OpenOCD Interface ***/
int riscv_openocd_poll(struct target *target)
{
    LOG_DEBUG("polling all harts");
    int halted_hart = -1;
 
    if (target->smp) {
        unsigned int should_remain_halted = 0;
        unsigned int should_resume = 0;
        struct target_list *list;
        foreach_smp_target(list, target->smp_targets) {
            struct target *t = list->target;
            struct riscv_info *r = riscv_info(t);
            enum riscv_poll_hart out = riscv_poll_hart(t, r->current_hartid);
            switch (out) {
            case RPH_NO_CHANGE:
                break;
            case RPH_DISCOVERED_RUNNING:
                t->state = TARGET_RUNNING;
                t->debug_reason = DBG_REASON_NOTHALTED;
                break;
            case RPH_DISCOVERED_HALTED:
                t->state = TARGET_HALTED;
                enum riscv_halt_reason halt_reason =
                    riscv_halt_reason(t, r->current_hartid);
                if (set_debug_reason(t, halt_reason) != ERROR_OK)
                    return ERROR_FAIL;
 
                if (halt_reason == RISCV_HALT_BREAKPOINT) {
                    int retval;
                    switch (riscv_semihosting(t, &retval)) {
                    case SEMIHOSTING_NONE:
                    case SEMIHOSTING_WAITING:
                        /* This hart should remain halted. */
                        should_remain_halted++;
                        break;
                    case SEMIHOSTING_HANDLED:
                        /* This hart should be resumed, along with any other
                             * harts that halted due to haltgroups. */
                        should_resume++;
                        break;
                    case SEMIHOSTING_ERROR:
                        return retval;
                    }
                } else if (halt_reason != RISCV_HALT_GROUP) {
                    should_remain_halted++;
                }
                break;
 
            case RPH_ERROR:
                return ERROR_FAIL;
            }
        }
 
        LOG_DEBUG("should_remain_halted=%d, should_resume=%d",
                  should_remain_halted, should_resume);
        if (should_remain_halted && should_resume) {
            LOG_WARNING("%d harts should remain halted, and %d should resume.",
                        should_remain_halted, should_resume);
        }
        if (should_remain_halted) {
            LOG_DEBUG("halt all");
            riscv_halt(target);
        } else if (should_resume) {
            LOG_DEBUG("resume all");
            riscv_resume(target, true, 0, false, false, false);
        }
 
        /* Sample memory if any target is running. */
        foreach_smp_target(list, target->smp_targets) {
            struct target *t = list->target;
            if (t->state == TARGET_RUNNING) {
                sample_memory(target);
                break;
            }
        }
 
        return ERROR_OK;
 
    } else {
        enum riscv_poll_hart out = riscv_poll_hart(target,
                riscv_current_hartid(target));
        if (out == RPH_NO_CHANGE || out == RPH_DISCOVERED_RUNNING) {
            if (target->state == TARGET_RUNNING)
                sample_memory(target);
            return ERROR_OK;
        } else if (out == RPH_ERROR) {
            return ERROR_FAIL;
        }
 
        halted_hart = riscv_current_hartid(target);
        LOG_DEBUG("  hart %d halted", halted_hart);
 
        enum riscv_halt_reason halt_reason = riscv_halt_reason(target, halted_hart);
        if (set_debug_reason(target, halt_reason) != ERROR_OK)
            return ERROR_FAIL;
        target->state = TARGET_HALTED;
    }
 
    if (target->debug_reason == DBG_REASON_BREAKPOINT) {
        int retval;
        switch (riscv_semihosting(target, &retval)) {
            case SEMIHOSTING_NONE:
            case SEMIHOSTING_WAITING:
                target_call_event_callbacks(target, TARGET_EVENT_HALTED);
                break;
            case SEMIHOSTING_HANDLED:
                if (riscv_resume(target, true, 0, false, false, false) != ERROR_OK)
                    return ERROR_FAIL;
                break;
            case SEMIHOSTING_ERROR:
                return retval;
        }
    } else {
        target_call_event_callbacks(target, TARGET_EVENT_HALTED);
    }
 
    return ERROR_OK;
}
 
int riscv_openocd_step(struct target *target, bool current,
        target_addr_t address, bool handle_breakpoints)
{
    LOG_DEBUG("stepping rtos hart");
 
    if (!current)
        riscv_set_register(target, GDB_REGNO_PC, address);
 
    riscv_reg_t trigger_state[RISCV_MAX_HWBPS] = {0};
    if (disable_triggers(target, trigger_state) != ERROR_OK)
        return ERROR_FAIL;
 
    int out = riscv_step_rtos_hart(target);
    if (out != ERROR_OK) {
        LOG_ERROR("unable to step rtos hart");
        return out;
    }
 
    register_cache_invalidate(target->reg_cache);
 
    if (enable_triggers(target, trigger_state) != ERROR_OK)
        return ERROR_FAIL;
 
    target->state = TARGET_RUNNING;
    target_call_event_callbacks(target, TARGET_EVENT_RESUMED);
    target->state = TARGET_HALTED;
    target->debug_reason = DBG_REASON_SINGLESTEP;
    target_call_event_callbacks(target, TARGET_EVENT_HALTED);
    return out;
}
 
/* Command Handlers */
COMMAND_HANDLER(riscv_set_command_timeout_sec)
{
    if (CMD_ARGC != 1) {
        LOG_ERROR("Command takes exactly 1 parameter");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
    int timeout = atoi(CMD_ARGV[0]);
    if (timeout <= 0) {
        LOG_ERROR("%s is not a valid integer argument for command.", CMD_ARGV[0]);
        return ERROR_FAIL;
    }
 
    riscv_command_timeout_sec = timeout;
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_set_reset_timeout_sec)
{
    if (CMD_ARGC != 1) {
        LOG_ERROR("Command takes exactly 1 parameter");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
    int timeout = atoi(CMD_ARGV[0]);
    if (timeout <= 0) {
        LOG_ERROR("%s is not a valid integer argument for command.", CMD_ARGV[0]);
        return ERROR_FAIL;
    }
 
    riscv_reset_timeout_sec = timeout;
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_set_mem_access)
{
    struct target *target = get_current_target(CMD_CTX);
    RISCV_INFO(r);
    int progbuf_cnt = 0;
    int sysbus_cnt = 0;
    int abstract_cnt = 0;
 
    if (CMD_ARGC < 1 || CMD_ARGC > RISCV_NUM_MEM_ACCESS_METHODS) {
        LOG_ERROR("Command takes 1 to %d parameters", RISCV_NUM_MEM_ACCESS_METHODS);
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    /* Check argument validity */
    for (unsigned int i = 0; i < CMD_ARGC; i++) {
        if (strcmp("progbuf", CMD_ARGV[i]) == 0) {
            progbuf_cnt++;
        } else if (strcmp("sysbus", CMD_ARGV[i]) == 0) {
            sysbus_cnt++;
        } else if (strcmp("abstract", CMD_ARGV[i]) == 0) {
            abstract_cnt++;
        } else {
            LOG_ERROR("Unknown argument '%s'. "
                "Must be one of: 'progbuf', 'sysbus' or 'abstract'.", CMD_ARGV[i]);
            return ERROR_COMMAND_SYNTAX_ERROR;
        }
    }
    if (progbuf_cnt > 1 || sysbus_cnt > 1 || abstract_cnt > 1) {
        LOG_ERROR("Syntax error - duplicate arguments to `riscv set_mem_access`.");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    /* Args are valid, store them */
    for (unsigned int i = 0; i < RISCV_NUM_MEM_ACCESS_METHODS; i++)
        r->mem_access_methods[i] = RISCV_MEM_ACCESS_UNSPECIFIED;
    for (unsigned int i = 0; i < CMD_ARGC; i++) {
        if (strcmp("progbuf", CMD_ARGV[i]) == 0)
            r->mem_access_methods[i] = RISCV_MEM_ACCESS_PROGBUF;
        else if (strcmp("sysbus", CMD_ARGV[i]) == 0)
            r->mem_access_methods[i] = RISCV_MEM_ACCESS_SYSBUS;
        else if (strcmp("abstract", CMD_ARGV[i]) == 0)
            r->mem_access_methods[i] = RISCV_MEM_ACCESS_ABSTRACT;
    }
 
    /* Reset warning flags */
    r->mem_access_progbuf_warn = true;
    r->mem_access_sysbus_warn = true;
    r->mem_access_abstract_warn = true;
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_set_enable_virtual)
{
    if (CMD_ARGC != 1) {
        LOG_ERROR("Command takes exactly 1 parameter");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
    COMMAND_PARSE_ON_OFF(CMD_ARGV[0], riscv_enable_virtual);
    return ERROR_OK;
}
 
static int parse_ranges(struct list_head *ranges, const char *tcl_arg, const char *reg_type, unsigned int max_val)
{
    char *args = strdup(tcl_arg);
    if (!args)
        return ERROR_FAIL;
 
    /* For backward compatibility, allow multiple parameters within one TCL argument, separated by ',' */
    char *arg = strtok(args, ",");
    while (arg) {
        unsigned int low = 0;
        unsigned int high = 0;
        char *name = NULL;
 
        char *dash = strchr(arg, '-');
        char *equals = strchr(arg, '=');
        unsigned int pos;
 
        if (!dash && !equals) {
            /* Expecting single register number. */
            if (sscanf(arg, "%u%n", &low, &pos) != 1 || pos != strlen(arg)) {
                LOG_ERROR("Failed to parse single register number from '%s'.", arg);
                free(args);
                return ERROR_COMMAND_SYNTAX_ERROR;
            }
        } else if (dash && !equals) {
            /* Expecting register range - two numbers separated by a dash: ##-## */
            *dash = 0;
            dash++;
            if (sscanf(arg, "%u%n", &low, &pos) != 1 || pos != strlen(arg)) {
                LOG_ERROR("Failed to parse single register number from '%s'.", arg);
                free(args);
                return ERROR_COMMAND_SYNTAX_ERROR;
            }
            if (sscanf(dash, "%u%n", &high, &pos) != 1 || pos != strlen(dash)) {
                LOG_ERROR("Failed to parse single register number from '%s'.", dash);
                free(args);
                return ERROR_COMMAND_SYNTAX_ERROR;
            }
            if (high < low) {
                LOG_ERROR("Incorrect range encountered [%u, %u].", low, high);
                free(args);
                return ERROR_FAIL;
            }
        } else if (!dash && equals) {
            /* Expecting single register number with textual name specified: ##=name */
            *equals = 0;
            equals++;
            if (sscanf(arg, "%u%n", &low, &pos) != 1 || pos != strlen(arg)) {
                LOG_ERROR("Failed to parse single register number from '%s'.", arg);
                free(args);
                return ERROR_COMMAND_SYNTAX_ERROR;
            }
 
            name = calloc(1, strlen(equals) + strlen(reg_type) + 2);
            if (!name) {
                LOG_ERROR("Failed to allocate register name.");
                free(args);
                return ERROR_FAIL;
            }
 
            /* Register prefix: "csr_" or "custom_" */
            strcpy(name, reg_type);
            name[strlen(reg_type)] = '_';
 
            if (sscanf(equals, "%[_a-zA-Z0-9]%n", name + strlen(reg_type) + 1, &pos) != 1 || pos != strlen(equals)) {
                LOG_ERROR("Failed to parse register name from '%s'.", equals);
                free(args);
                free(name);
                return ERROR_COMMAND_SYNTAX_ERROR;
            }
        } else {
            LOG_ERROR("Invalid argument '%s'.", arg);
            free(args);
            return ERROR_COMMAND_SYNTAX_ERROR;
        }
 
        high = high > low ? high : low;
 
        if (high > max_val) {
            LOG_ERROR("Cannot expose %s register number %u, maximum allowed value is %u.", reg_type, high, max_val);
            free(name);
            free(args);
            return ERROR_FAIL;
        }
 
        /* Check for overlap, name uniqueness. */
        range_list_t *entry;
        list_for_each_entry(entry, ranges, list) {
            if ((entry->low <= high) && (low <= entry->high)) {
                if (low == high)
                    LOG_WARNING("Duplicate %s register number - "
                            "Register %u has already been exposed previously", reg_type, low);
                else
                    LOG_WARNING("Overlapping register ranges - Register range starting from %u overlaps "
                            "with already exposed register/range at %u.", low, entry->low);
            }
 
            if (entry->name && name && (strcasecmp(entry->name, name) == 0)) {
                LOG_ERROR("Duplicate register name \"%s\" found.", name);
                free(name);
                free(args);
                return ERROR_FAIL;
            }
        }
 
        range_list_t *range = calloc(1, sizeof(range_list_t));
        if (!range) {
            LOG_ERROR("Failed to allocate range list.");
            free(name);
            free(args);
            return ERROR_FAIL;
        }
 
        range->low = low;
        range->high = high;
        range->name = name;
        list_add(&range->list, ranges);
 
        arg = strtok(NULL, ",");
    }
 
    free(args);
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_set_expose_csrs)
{
    if (CMD_ARGC == 0) {
        LOG_ERROR("Command expects parameters");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    struct target *target = get_current_target(CMD_CTX);
    RISCV_INFO(info);
    int ret = ERROR_OK;
 
    for (unsigned int i = 0; i < CMD_ARGC; i++) {
        ret = parse_ranges(&info->expose_csr, CMD_ARGV[i], "csr", 0xfff);
        if (ret != ERROR_OK)
            break;
    }
 
    return ret;
}
 
COMMAND_HANDLER(riscv_set_expose_custom)
{
    if (CMD_ARGC == 0) {
        LOG_ERROR("Command expects parameters");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    struct target *target = get_current_target(CMD_CTX);
    RISCV_INFO(info);
    int ret = ERROR_OK;
 
    for (unsigned int i = 0; i < CMD_ARGC; i++) {
        ret = parse_ranges(&info->expose_custom, CMD_ARGV[i], "custom", 0x3fff);
        if (ret != ERROR_OK)
            break;
    }
 
    return ret;
}
 
COMMAND_HANDLER(riscv_authdata_read)
{
    unsigned int index = 0;
    if (CMD_ARGC == 0) {
        /* nop */
    } else if (CMD_ARGC == 1) {
        COMMAND_PARSE_NUMBER(uint, CMD_ARGV[0], index);
    } else {
        LOG_ERROR("Command takes at most one parameter");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    struct target *target = get_current_target(CMD_CTX);
    if (!target) {
        LOG_ERROR("target is NULL!");
        return ERROR_FAIL;
    }
 
    RISCV_INFO(r);
    if (!r) {
        LOG_ERROR("riscv_info is NULL!");
        return ERROR_FAIL;
    }
 
    if (r->authdata_read) {
        uint32_t value;
        if (r->authdata_read(target, &value, index) != ERROR_OK)
            return ERROR_FAIL;
        command_print_sameline(CMD, "0x%08" PRIx32, value);
        return ERROR_OK;
    } else {
        LOG_ERROR("authdata_read is not implemented for this target.");
        return ERROR_FAIL;
    }
}
 
COMMAND_HANDLER(riscv_authdata_write)
{
    uint32_t value;
    unsigned int index = 0;
 
    if (CMD_ARGC == 0 || CMD_ARGC > 2)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    if (CMD_ARGC == 1) {
        COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], value);
    } else {
        COMMAND_PARSE_NUMBER(uint, CMD_ARGV[0], index);
        COMMAND_PARSE_NUMBER(u32, CMD_ARGV[1], value);
    }
 
    struct target *target = get_current_target(CMD_CTX);
    RISCV_INFO(r);
 
    if (!r->authdata_write) {
        LOG_ERROR("authdata_write is not implemented for this target.");
        return ERROR_FAIL;
    }
 
    return r->authdata_write(target, value, index);
}
 
COMMAND_HANDLER(riscv_dmi_read)
{
    if (CMD_ARGC != 1) {
        LOG_ERROR("Command takes 1 parameter");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    struct target *target = get_current_target(CMD_CTX);
    if (!target) {
        LOG_ERROR("target is NULL!");
        return ERROR_FAIL;
    }
 
    RISCV_INFO(r);
    if (!r) {
        LOG_ERROR("riscv_info is NULL!");
        return ERROR_FAIL;
    }
 
    if (r->dmi_read) {
        uint32_t address, value;
        COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], address);
        if (r->dmi_read(target, &value, address) != ERROR_OK)
            return ERROR_FAIL;
        command_print(CMD, "0x%" PRIx32, value);
        return ERROR_OK;
    } else {
        LOG_ERROR("dmi_read is not implemented for this target.");
        return ERROR_FAIL;
    }
}
 
 
COMMAND_HANDLER(riscv_dmi_write)
{
    if (CMD_ARGC != 2) {
        LOG_ERROR("Command takes exactly 2 arguments");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    struct target *target = get_current_target(CMD_CTX);
    RISCV_INFO(r);
 
    uint32_t address, value;
    COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], address);
    COMMAND_PARSE_NUMBER(u32, CMD_ARGV[1], value);
 
    if (r->dmi_write) {
        return r->dmi_write(target, address, value);
    } else {
        LOG_ERROR("dmi_write is not implemented for this target.");
        return ERROR_FAIL;
    }
}
 
COMMAND_HANDLER(riscv_reset_delays)
{
    int wait = 0;
 
    if (CMD_ARGC > 1) {
        LOG_ERROR("Command takes at most one argument");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    if (CMD_ARGC == 1)
        COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], wait);
 
    struct target *target = get_current_target(CMD_CTX);
    RISCV_INFO(r);
    r->reset_delays_wait = wait;
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_set_ir)
{
    if (CMD_ARGC != 2) {
        LOG_ERROR("Command takes exactly 2 arguments");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    uint32_t value;
    COMMAND_PARSE_NUMBER(u32, CMD_ARGV[1], value);
 
    if (!strcmp(CMD_ARGV[0], "idcode"))
        buf_set_u32(ir_idcode, 0, 32, value);
    else if (!strcmp(CMD_ARGV[0], "dtmcs"))
        buf_set_u32(ir_dtmcontrol, 0, 32, value);
    else if (!strcmp(CMD_ARGV[0], "dmi"))
        buf_set_u32(ir_dbus, 0, 32, value);
    else
        return ERROR_FAIL;
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_resume_order)
{
    if (CMD_ARGC > 1) {
        LOG_ERROR("Command takes at most one argument");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
 
    if (!strcmp(CMD_ARGV[0], "normal")) {
        resume_order = RO_NORMAL;
    } else if (!strcmp(CMD_ARGV[0], "reversed")) {
        resume_order = RO_REVERSED;
    } else {
        LOG_ERROR("Unsupported resume order: %s", CMD_ARGV[0]);
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_use_bscan_tunnel)
{
    int irwidth = 0;
    int tunnel_type = BSCAN_TUNNEL_NESTED_TAP;
 
    if (CMD_ARGC > 2) {
        LOG_ERROR("Command takes at most two arguments");
        return ERROR_COMMAND_SYNTAX_ERROR;
    } else if (CMD_ARGC == 1) {
        COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], irwidth);
    } else if (CMD_ARGC == 2) {
        COMMAND_PARSE_NUMBER(int, CMD_ARGV[0], irwidth);
        COMMAND_PARSE_NUMBER(int, CMD_ARGV[1], tunnel_type);
    }
    if (tunnel_type == BSCAN_TUNNEL_NESTED_TAP)
        LOG_INFO("Nested Tap based Bscan Tunnel Selected");
    else if (tunnel_type == BSCAN_TUNNEL_DATA_REGISTER)
        LOG_INFO("Simple Register based Bscan Tunnel Selected");
    else
        LOG_INFO("Invalid Tunnel type selected ! : selecting default Nested Tap Type");
 
    bscan_tunnel_type = tunnel_type;
    bscan_tunnel_ir_width = irwidth;
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_set_enable_virt2phys)
{
    if (CMD_ARGC != 1) {
        LOG_ERROR("Command takes exactly 1 parameter");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
    COMMAND_PARSE_ON_OFF(CMD_ARGV[0], riscv_enable_virt2phys);
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_set_ebreakm)
{
    if (CMD_ARGC != 1) {
        LOG_ERROR("Command takes exactly 1 parameter");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
    COMMAND_PARSE_ON_OFF(CMD_ARGV[0], riscv_ebreakm);
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_set_ebreaks)
{
    if (CMD_ARGC != 1) {
        LOG_ERROR("Command takes exactly 1 parameter");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
    COMMAND_PARSE_ON_OFF(CMD_ARGV[0], riscv_ebreaks);
    return ERROR_OK;
}
 
COMMAND_HANDLER(riscv_set_ebreaku)
{
    if (CMD_ARGC != 1) {
        LOG_ERROR("Command takes exactly 1 parameter");
        return ERROR_COMMAND_SYNTAX_ERROR;
    }
    COMMAND_PARSE_ON_OFF(CMD_ARGV[0], riscv_ebreaku);
    return ERROR_OK;
}
 
COMMAND_HELPER(riscv_print_info_line, const char *section, const char *key,
               unsigned int value)
{
    char full_key[80];
    snprintf(full_key, sizeof(full_key), "%s.%s", section, key);
    command_print(CMD, "%-21s %3d", full_key, value);
    return 0;
}
 
COMMAND_HANDLER(handle_info)
{
    struct target *target = get_current_target(CMD_CTX);
    RISCV_INFO(r);
 
    /* This output format can be fed directly into TCL's "array set". */
 
    riscv_print_info_line(CMD, "hart", "xlen", riscv_xlen(target));
    riscv_enumerate_triggers(target);
    riscv_print_info_line(CMD, "hart", "trigger_count",
                          r->trigger_count);
 
    if (r->print_info)
        return CALL_COMMAND_HANDLER(r->print_info, target);
 
    return 0;
}
 
static const struct command_registration riscv_exec_command_handlers[] = {
    {
        .name = "info",
        .handler = handle_info,
        .mode = COMMAND_EXEC,
        .usage = "",
        .help = "Displays some information OpenOCD detected about the target."
    },
    {
        .name = "set_command_timeout_sec",
        .handler = riscv_set_command_timeout_sec,
        .mode = COMMAND_ANY,
        .usage = "[sec]",
        .help = "Set the wall-clock timeout (in seconds) for individual commands"
    },
    {
        .name = "set_reset_timeout_sec",
        .handler = riscv_set_reset_timeout_sec,
        .mode = COMMAND_ANY,
        .usage = "[sec]",
        .help = "Set the wall-clock timeout (in seconds) after reset is deasserted"
    },
    {
        .name = "set_mem_access",
        .handler = riscv_set_mem_access,
        .mode = COMMAND_ANY,
        .usage = "method1 [method2] [method3]",
        .help = "Set which memory access methods shall be used and in which order "
            "of priority. Method can be one of: 'progbuf', 'sysbus' or 'abstract'."
    },
    {
        .name = "set_enable_virtual",
        .handler = riscv_set_enable_virtual,
        .mode = COMMAND_ANY,
        .usage = "on|off",
        .help = "When on, memory accesses are performed on physical or virtual "
                "memory depending on the current system configuration. "
                "When off (default), all memory accessses are performed on physical memory."
    },
    {
        .name = "expose_csrs",
        .handler = riscv_set_expose_csrs,
        .mode = COMMAND_CONFIG,
        .usage = "n0[-m0|=name0][,n1[-m1|=name1]]...",
        .help = "Configure a list of inclusive ranges for CSRs to expose in "
                "addition to the standard ones. This must be executed before "
                "`init`."
    },
    {
        .name = "expose_custom",
        .handler = riscv_set_expose_custom,
        .mode = COMMAND_CONFIG,
        .usage = "n0[-m0|=name0][,n1[-m1|=name1]]...",
        .help = "Configure a list of inclusive ranges for custom registers to "
            "expose. custom0 is accessed as abstract register number 0xc000, "
            "etc. This must be executed before `init`."
    },
    {
        .name = "authdata_read",
        .handler = riscv_authdata_read,
        .usage = "[index]",
        .mode = COMMAND_ANY,
        .help = "Return the 32-bit value read from authdata or authdata0 "
                "(index=0), or authdata1 (index=1)."
    },
    {
        .name = "authdata_write",
        .handler = riscv_authdata_write,
        .mode = COMMAND_ANY,
        .usage = "[index] value",
        .help = "Write the 32-bit value to authdata or authdata0 (index=0), "
                "or authdata1 (index=1)."
    },
    {
        .name = "dmi_read",
        .handler = riscv_dmi_read,
        .mode = COMMAND_ANY,
        .usage = "address",
        .help = "Perform a 32-bit DMI read at address, returning the value."
    },
    {
        .name = "dmi_write",
        .handler = riscv_dmi_write,
        .mode = COMMAND_ANY,
        .usage = "address value",
        .help = "Perform a 32-bit DMI write of value at address."
    },
    {
        .name = "reset_delays",
        .handler = riscv_reset_delays,
        .mode = COMMAND_ANY,
        .usage = "[wait]",
        .help = "OpenOCD learns how many Run-Test/Idle cycles are required "
            "between scans to avoid encountering the target being busy. This "
            "command resets those learned values after `wait` scans. It's only "
            "useful for testing OpenOCD itself."
    },
    {
        .name = "resume_order",
        .handler = riscv_resume_order,
        .mode = COMMAND_ANY,
        .usage = "normal|reversed",
        .help = "Choose the order that harts are resumed in when `hasel` is not "
            "supported. Normal order is from lowest hart index to highest. "
            "Reversed order is from highest hart index to lowest."
    },
    {
        .name = "set_ir",
        .handler = riscv_set_ir,
        .mode = COMMAND_ANY,
        .usage = "[idcode|dtmcs|dmi] value",
        .help = "Set IR value for specified JTAG register."
    },
    {
        .name = "use_bscan_tunnel",
        .handler = riscv_use_bscan_tunnel,
        .mode = COMMAND_ANY,
        .usage = "value [type]",
        .help = "Enable or disable use of a BSCAN tunnel to reach DM.  Supply "
            "the width of the DM transport TAP's instruction register to "
            "enable.  Supply a value of 0 to disable. Pass A second argument "
            "(optional) to indicate Bscan Tunnel Type {0:(default) NESTED_TAP , "
            "1: DATA_REGISTER}"
    },
    {
        .name = "set_enable_virt2phys",
        .handler = riscv_set_enable_virt2phys,
        .mode = COMMAND_ANY,
        .usage = "on|off",
        .help = "When on (default), enable translation from virtual address to "
            "physical address."
    },
    {
        .name = "set_ebreakm",
        .handler = riscv_set_ebreakm,
        .mode = COMMAND_ANY,
        .usage = "on|off",
        .help = "Control dcsr.ebreakm. When off, M-mode ebreak instructions "
            "don't trap to OpenOCD. Defaults to on."
    },
    {
        .name = "set_ebreaks",
        .handler = riscv_set_ebreaks,
        .mode = COMMAND_ANY,
        .usage = "on|off",
        .help = "Control dcsr.ebreaks. When off, S-mode ebreak instructions "
            "don't trap to OpenOCD. Defaults to on."
    },
    {
        .name = "set_ebreaku",
        .handler = riscv_set_ebreaku,
        .mode = COMMAND_ANY,
        .usage = "on|off",
        .help = "Control dcsr.ebreaku. When off, U-mode ebreak instructions "
            "don't trap to OpenOCD. Defaults to on."
    },
    COMMAND_REGISTRATION_DONE
};
 
/*
 * To be noted that RISC-V targets use the same semihosting commands as
 * ARM targets.
 *
 * The main reason is compatibility with existing tools. For example the
 * Eclipse OpenOCD/SEGGER J-Link/QEMU plug-ins have several widgets to
 * configure semihosting, which generate commands like `arm semihosting
 * enable`.
 * A secondary reason is the fact that the protocol used is exactly the
 * one specified by ARM. If RISC-V will ever define its own semihosting
 * protocol, then a command like `riscv semihosting enable` will make
 * sense, but for now all semihosting commands are prefixed with `arm`.
 */
 
static const struct command_registration riscv_command_handlers[] = {
    {
        .name = "riscv",
        .mode = COMMAND_ANY,
        .help = "RISC-V Command Group",
        .usage = "",
        .chain = riscv_exec_command_handlers
    },
    {
        .name = "arm",
        .mode = COMMAND_ANY,
        .help = "ARM Command Group",
        .usage = "",
        .chain = semihosting_common_handlers
    },
    {
        .chain = smp_command_handlers
    },
    COMMAND_REGISTRATION_DONE
};
 
static unsigned int riscv_xlen_nonconst(struct target *target)
{
    return riscv_xlen(target);
}
 
static unsigned int riscv_data_bits(struct target *target)
{
    RISCV_INFO(r);
    if (r->data_bits)
        return r->data_bits(target);
    return riscv_xlen(target);
}
 
struct target_type riscv_target = {
    .name = "riscv",
 
    .target_create = riscv_create_target,
    .init_target = riscv_init_target,
    .deinit_target = riscv_deinit_target,
    .examine = riscv_examine,
 
    /* poll current target status */
    .poll = old_or_new_riscv_poll,
 
    .halt = riscv_halt,
    .resume = riscv_target_resume,
    .step = old_or_new_riscv_step,
 
    .assert_reset = riscv_assert_reset,
    .deassert_reset = riscv_deassert_reset,
 
    .read_memory = riscv_read_memory,
    .write_memory = riscv_write_memory,
    .read_phys_memory = riscv_read_phys_memory,
    .write_phys_memory = riscv_write_phys_memory,
 
    .checksum_memory = riscv_checksum_memory,
 
    .mmu = riscv_mmu,
    .virt2phys = riscv_virt2phys,
 
    .get_gdb_arch = riscv_get_gdb_arch,
    .get_gdb_reg_list = riscv_get_gdb_reg_list,
    .get_gdb_reg_list_noread = riscv_get_gdb_reg_list_noread,
 
    .add_breakpoint = riscv_add_breakpoint,
    .remove_breakpoint = riscv_remove_breakpoint,
 
    .add_watchpoint = riscv_add_watchpoint,
    .remove_watchpoint = riscv_remove_watchpoint,
    .hit_watchpoint = riscv_hit_watchpoint,
 
    .arch_state = riscv_arch_state,
 
    .run_algorithm = riscv_run_algorithm,
 
    .commands = riscv_command_handlers,
 
    .address_bits = riscv_xlen_nonconst,
    .data_bits = riscv_data_bits
};
 
/*** RISC-V Interface ***/
 
/* Initializes the shared RISC-V structure. */
static void riscv_info_init(struct target *target, struct riscv_info *r)
{
    memset(r, 0, sizeof(*r));
 
    r->common_magic = RISCV_COMMON_MAGIC;
 
    r->dtm_version = 1;
    r->current_hartid = target->coreid;
    r->version_specific = NULL;
 
    memset(r->trigger_unique_id, 0xff, sizeof(r->trigger_unique_id));
 
    r->xlen = -1;
 
    r->mem_access_methods[0] = RISCV_MEM_ACCESS_PROGBUF;
    r->mem_access_methods[1] = RISCV_MEM_ACCESS_SYSBUS;
    r->mem_access_methods[2] = RISCV_MEM_ACCESS_ABSTRACT;
 
    r->mem_access_progbuf_warn = true;
    r->mem_access_sysbus_warn = true;
    r->mem_access_abstract_warn = true;
 
    INIT_LIST_HEAD(&r->expose_csr);
    INIT_LIST_HEAD(&r->expose_custom);
}
 
static int riscv_resume_go_all_harts(struct target *target)
{
    RISCV_INFO(r);
 
    LOG_DEBUG("[%s] resuming hart", target_name(target));
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
    if (riscv_is_halted(target)) {
        if (r->resume_go(target) != ERROR_OK)
            return ERROR_FAIL;
    } else {
        LOG_DEBUG("[%s] hart requested resume, but was already resumed",
                target_name(target));
    }
 
    riscv_invalidate_register_cache(target);
    return ERROR_OK;
}
 
/* Steps the hart that's currently selected in the RTOS, or if there is no RTOS
 * then the only hart. */
static int riscv_step_rtos_hart(struct target *target)
{
    RISCV_INFO(r);
    if (riscv_select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
    LOG_DEBUG("[%s] stepping", target_name(target));
 
    if (!riscv_is_halted(target)) {
        LOG_ERROR("Hart isn't halted before single step!");
        return ERROR_FAIL;
    }
    riscv_invalidate_register_cache(target);
    r->on_step(target);
    if (r->step_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
    riscv_invalidate_register_cache(target);
    r->on_halt(target);
    if (!riscv_is_halted(target)) {
        LOG_ERROR("Hart was not halted after single step!");
        return ERROR_FAIL;
    }
    return ERROR_OK;
}
 
bool riscv_supports_extension(struct target *target, char letter)
{
    RISCV_INFO(r);
    unsigned int num;
    if (letter >= 'a' && letter <= 'z')
        num = letter - 'a';
    else if (letter >= 'A' && letter <= 'Z')
        num = letter - 'A';
    else
        return false;
    return r->misa & BIT(num);
}
 
unsigned int riscv_xlen(const struct target *target)
{
    RISCV_INFO(r);
    return r->xlen;
}
 
int riscv_set_current_hartid(struct target *target, int hartid)
{
    RISCV_INFO(r);
    if (!r->select_current_hart)
        return ERROR_OK;
 
    int previous_hartid = riscv_current_hartid(target);
    r->current_hartid = hartid;
    LOG_DEBUG("setting hartid to %d, was %d", hartid, previous_hartid);
    if (r->select_current_hart(target) != ERROR_OK)
        return ERROR_FAIL;
 
    return ERROR_OK;
}
 
/* Invalidates the register cache. */
static void riscv_invalidate_register_cache(struct target *target)
{
    LOG_DEBUG("[%d]", target->coreid);
    register_cache_invalidate(target->reg_cache);
    for (size_t i = 0; i < target->reg_cache->num_regs; ++i) {
        struct reg *reg = &target->reg_cache->reg_list[i];
        reg->valid = false;
    }
}
 
int riscv_current_hartid(const struct target *target)
{
    RISCV_INFO(r);
    return r->current_hartid;
}
 
int riscv_count_harts(struct target *target)
{
    if (!target)
        return 1;
    RISCV_INFO(r);
    if (!r || !r->hart_count)
        return 1;
    return r->hart_count(target);
}
 
static bool gdb_regno_cacheable(enum gdb_regno regno, bool write)
{
    /* GPRs, FPRs, vector registers are just normal data stores. */
    if (regno <= GDB_REGNO_XPR31 ||
            (regno >= GDB_REGNO_FPR0 && regno <= GDB_REGNO_FPR31) ||
            (regno >= GDB_REGNO_V0 && regno <= GDB_REGNO_V31))
        return true;
 
    /* Most CSRs won't change value on us, but we can't assume it about arbitrary
     * CSRs. */
    switch (regno) {
        case GDB_REGNO_DPC:
            return true;
 
        case GDB_REGNO_VSTART:
        case GDB_REGNO_VXSAT:
        case GDB_REGNO_VXRM:
        case GDB_REGNO_VLENB:
        case GDB_REGNO_VL:
        case GDB_REGNO_VTYPE:
        case GDB_REGNO_MISA:
        case GDB_REGNO_DCSR:
        case GDB_REGNO_DSCRATCH0:
        case GDB_REGNO_MSTATUS:
        case GDB_REGNO_MEPC:
        case GDB_REGNO_MCAUSE:
        case GDB_REGNO_SATP:
            /*
             * WARL registers might not contain the value we just wrote, but
             * these ones won't spontaneously change their value either. *
             */
            return !write;
 
        case GDB_REGNO_TSELECT: /* I think this should be above, but then it doesn't work. */
        case GDB_REGNO_TDATA1:  /* Changes value when tselect is changed. */
        case GDB_REGNO_TDATA2:  /* Changse value when tselect is changed. */
        default:
            return false;
    }
}
 
int riscv_set_register(struct target *target, enum gdb_regno regid, riscv_reg_t value)
{
    RISCV_INFO(r);
    LOG_DEBUG("[%s] %s <- %" PRIx64, target_name(target), gdb_regno_name(regid), value);
    assert(r->set_register);
 
    keep_alive();
 
    /* TODO: Hack to deal with gdb that thinks these registers still exist. */
    if (regid > GDB_REGNO_XPR15 && regid <= GDB_REGNO_XPR31 && value == 0 &&
            riscv_supports_extension(target, 'E'))
        return ERROR_OK;
 
    struct reg *reg = &target->reg_cache->reg_list[regid];
    buf_set_u64(reg->value, 0, reg->size, value);
 
    int result = r->set_register(target, regid, value);
    if (result == ERROR_OK)
        reg->valid = gdb_regno_cacheable(regid, true);
    else
        reg->valid = false;
    LOG_DEBUG("[%s] wrote 0x%" PRIx64 " to %s valid=%d",
              target_name(target), value, reg->name, reg->valid);
    return result;
}
 
int riscv_get_register(struct target *target, riscv_reg_t *value,
        enum gdb_regno regid)
{
    RISCV_INFO(r);
 
    keep_alive();
 
    struct reg *reg = &target->reg_cache->reg_list[regid];
    if (!reg->exist) {
        LOG_DEBUG("[%s] %s does not exist.",
                  target_name(target), gdb_regno_name(regid));
        return ERROR_FAIL;
    }
 
    if (reg && reg->valid) {
        *value = buf_get_u64(reg->value, 0, reg->size);
        LOG_DEBUG("[%s] %s: %" PRIx64 " (cached)", target_name(target),
                  gdb_regno_name(regid), *value);
        return ERROR_OK;
    }
 
    /* TODO: Hack to deal with gdb that thinks these registers still exist. */
    if (regid > GDB_REGNO_XPR15 && regid <= GDB_REGNO_XPR31 &&
            riscv_supports_extension(target, 'E')) {
        *value = 0;
        return ERROR_OK;
    }
 
    int result = r->get_register(target, value, regid);
 
    if (result == ERROR_OK)
        reg->valid = gdb_regno_cacheable(regid, false);
 
    LOG_DEBUG("[%s] %s: %" PRIx64, target_name(target),
            gdb_regno_name(regid), *value);
    return result;
}
 
bool riscv_is_halted(struct target *target)
{
    RISCV_INFO(r);
    assert(r->is_halted);
    return r->is_halted(target);
}
 
static enum riscv_halt_reason riscv_halt_reason(struct target *target, int hartid)
{
    RISCV_INFO(r);
    if (riscv_set_current_hartid(target, hartid) != ERROR_OK)
        return RISCV_HALT_ERROR;
    if (!riscv_is_halted(target)) {
        LOG_ERROR("Hart is not halted!");
        return RISCV_HALT_UNKNOWN;
    }
    return r->halt_reason(target);
}
 
size_t riscv_debug_buffer_size(struct target *target)
{
    RISCV_INFO(r);
    return r->debug_buffer_size;
}
 
int riscv_write_debug_buffer(struct target *target, int index, riscv_insn_t insn)
{
    RISCV_INFO(r);
    r->write_debug_buffer(target, index, insn);
    return ERROR_OK;
}
 
riscv_insn_t riscv_read_debug_buffer(struct target *target, int index)
{
    RISCV_INFO(r);
    return r->read_debug_buffer(target, index);
}
 
int riscv_execute_debug_buffer(struct target *target)
{
    RISCV_INFO(r);
    return r->execute_debug_buffer(target);
}
 
void riscv_fill_dmi_write_u64(struct target *target, char *buf, int a, uint64_t d)
{
    RISCV_INFO(r);
    r->fill_dmi_write_u64(target, buf, a, d);
}
 
void riscv_fill_dmi_read_u64(struct target *target, char *buf, int a)
{
    RISCV_INFO(r);
    r->fill_dmi_read_u64(target, buf, a);
}
 
void riscv_fill_dmi_nop_u64(struct target *target, char *buf)
{
    RISCV_INFO(r);
    r->fill_dmi_nop_u64(target, buf);
}
 
int riscv_dmi_write_u64_bits(struct target *target)
{
    RISCV_INFO(r);
    return r->dmi_write_u64_bits(target);
}
 
int riscv_enumerate_triggers(struct target *target)
{
    RISCV_INFO(r);
 
    if (r->triggers_enumerated)
        return ERROR_OK;
 
    r->triggers_enumerated = true;  /* At the very least we tried. */
 
    riscv_reg_t tselect;
    int result = riscv_get_register(target, &tselect, GDB_REGNO_TSELECT);
    /* If tselect is not readable, the trigger module is likely not
        * implemented. There are no triggers to enumerate then and no error
        * should be thrown. */
    if (result != ERROR_OK) {
        LOG_DEBUG("[%s] Cannot access tselect register. "
                "Assuming that triggers are not implemented.", target_name(target));
        r->trigger_count = 0;
        return ERROR_OK;
    }
 
    for (unsigned int t = 0; t < RISCV_MAX_TRIGGERS; ++t) {
        r->trigger_count = t;
 
        /* If we can't write tselect, then this hart does not support triggers. */
        if (riscv_set_register(target, GDB_REGNO_TSELECT, t) != ERROR_OK)
            break;
        uint64_t tselect_rb;
        result = riscv_get_register(target, &tselect_rb, GDB_REGNO_TSELECT);
        if (result != ERROR_OK)
            return result;
        /* Mask off the top bit, which is used as tdrmode in old
            * implementations. */
        tselect_rb &= ~(1ULL << (riscv_xlen(target) - 1));
        if (tselect_rb != t)
            break;
        uint64_t tdata1;
        result = riscv_get_register(target, &tdata1, GDB_REGNO_TDATA1);
        if (result != ERROR_OK)
            return result;
 
        int type = get_field(tdata1, MCONTROL_TYPE(riscv_xlen(target)));
        if (type == 0)
            break;
        switch (type) {
            case 1:
                /* On these older cores we don't support software using
                    * triggers. */
                riscv_set_register(target, GDB_REGNO_TDATA1, 0);
                break;
            case 2:
                if (tdata1 & MCONTROL_DMODE(riscv_xlen(target)))
                    riscv_set_register(target, GDB_REGNO_TDATA1, 0);
                break;
            case 6:
                if (tdata1 & MCONTROL_DMODE(riscv_xlen(target)))
                    riscv_set_register(target, GDB_REGNO_TDATA1, 0);
                break;
        }
    }
 
    riscv_set_register(target, GDB_REGNO_TSELECT, tselect);
 
    LOG_INFO("[%s] Found %d triggers", target_name(target), r->trigger_count);
 
    return ERROR_OK;
}
 
const char *gdb_regno_name(enum gdb_regno regno)
{
    static char buf[32];
 
    switch (regno) {
        case GDB_REGNO_ZERO:
            return "zero";
        case GDB_REGNO_RA:
            return "ra";
        case GDB_REGNO_SP:
            return "sp";
        case GDB_REGNO_GP:
            return "gp";
        case GDB_REGNO_TP:
            return "tp";
        case GDB_REGNO_T0:
            return "t0";
        case GDB_REGNO_T1:
            return "t1";
        case GDB_REGNO_T2:
            return "t2";
        case GDB_REGNO_S0:
            return "s0";
        case GDB_REGNO_S1:
            return "s1";
        case GDB_REGNO_A0:
            return "a0";
        case GDB_REGNO_A1:
            return "a1";
        case GDB_REGNO_A2:
            return "a2";
        case GDB_REGNO_A3:
            return "a3";
        case GDB_REGNO_A4:
            return "a4";
        case GDB_REGNO_A5:
            return "a5";
        case GDB_REGNO_A6:
            return "a6";
        case GDB_REGNO_A7:
            return "a7";
        case GDB_REGNO_S2:
            return "s2";
        case GDB_REGNO_S3:
            return "s3";
        case GDB_REGNO_S4:
            return "s4";
        case GDB_REGNO_S5:
            return "s5";
        case GDB_REGNO_S6:
            return "s6";
        case GDB_REGNO_S7:
            return "s7";
        case GDB_REGNO_S8:
            return "s8";
        case GDB_REGNO_S9:
            return "s9";
        case GDB_REGNO_S10:
            return "s10";
        case GDB_REGNO_S11:
            return "s11";
        case GDB_REGNO_T3:
            return "t3";
        case GDB_REGNO_T4:
            return "t4";
        case GDB_REGNO_T5:
            return "t5";
        case GDB_REGNO_T6:
            return "t6";
        case GDB_REGNO_PC:
            return "pc";
        case GDB_REGNO_FPR0:
            return "fpr0";
        case GDB_REGNO_FPR31:
            return "fpr31";
        case GDB_REGNO_CSR0:
            return "csr0";
        case GDB_REGNO_TSELECT:
            return "tselect";
        case GDB_REGNO_TDATA1:
            return "tdata1";
        case GDB_REGNO_TDATA2:
            return "tdata2";
        case GDB_REGNO_MISA:
            return "misa";
        case GDB_REGNO_DPC:
            return "dpc";
        case GDB_REGNO_DCSR:
            return "dcsr";
        case GDB_REGNO_DSCRATCH0:
            return "dscratch0";
        case GDB_REGNO_MSTATUS:
            return "mstatus";
        case GDB_REGNO_MEPC:
            return "mepc";
        case GDB_REGNO_MCAUSE:
            return "mcause";
        case GDB_REGNO_PRIV:
            return "priv";
        case GDB_REGNO_SATP:
            return "satp";
        case GDB_REGNO_VTYPE:
            return "vtype";
        case GDB_REGNO_VL:
            return "vl";
        case GDB_REGNO_V0:
            return "v0";
        case GDB_REGNO_V1:
            return "v1";
        case GDB_REGNO_V2:
            return "v2";
        case GDB_REGNO_V3:
            return "v3";
        case GDB_REGNO_V4:
            return "v4";
        case GDB_REGNO_V5:
            return "v5";
        case GDB_REGNO_V6:
            return "v6";
        case GDB_REGNO_V7:
            return "v7";
        case GDB_REGNO_V8:
            return "v8";
        case GDB_REGNO_V9:
            return "v9";
        case GDB_REGNO_V10:
            return "v10";
        case GDB_REGNO_V11:
            return "v11";
        case GDB_REGNO_V12:
            return "v12";
        case GDB_REGNO_V13:
            return "v13";
        case GDB_REGNO_V14:
            return "v14";
        case GDB_REGNO_V15:
            return "v15";
        case GDB_REGNO_V16:
            return "v16";
        case GDB_REGNO_V17:
            return "v17";
        case GDB_REGNO_V18:
            return "v18";
        case GDB_REGNO_V19:
            return "v19";
        case GDB_REGNO_V20:
            return "v20";
        case GDB_REGNO_V21:
            return "v21";
        case GDB_REGNO_V22:
            return "v22";
        case GDB_REGNO_V23:
            return "v23";
        case GDB_REGNO_V24:
            return "v24";
        case GDB_REGNO_V25:
            return "v25";
        case GDB_REGNO_V26:
            return "v26";
        case GDB_REGNO_V27:
            return "v27";
        case GDB_REGNO_V28:
            return "v28";
        case GDB_REGNO_V29:
            return "v29";
        case GDB_REGNO_V30:
            return "v30";
        case GDB_REGNO_V31:
            return "v31";
        default:
            if (regno <= GDB_REGNO_XPR31)
                sprintf(buf, "x%d", regno - GDB_REGNO_ZERO);
            else if (regno >= GDB_REGNO_CSR0 && regno <= GDB_REGNO_CSR4095)
                sprintf(buf, "csr%d", regno - GDB_REGNO_CSR0);
            else if (regno >= GDB_REGNO_FPR0 && regno <= GDB_REGNO_FPR31)
                sprintf(buf, "f%d", regno - GDB_REGNO_FPR0);
            else
                sprintf(buf, "gdb_regno_%d", regno);
            return buf;
    }
}
 
static int register_get(struct reg *reg)
{
    riscv_reg_info_t *reg_info = reg->arch_info;
    struct target *target = reg_info->target;
    RISCV_INFO(r);
 
    if (reg->number >= GDB_REGNO_V0 && reg->number <= GDB_REGNO_V31) {
        if (!r->get_register_buf) {
            LOG_ERROR("Reading register %s not supported on this RISC-V target.",
                    gdb_regno_name(reg->number));
            return ERROR_FAIL;
        }
 
        if (r->get_register_buf(target, reg->value, reg->number) != ERROR_OK)
            return ERROR_FAIL;
    } else {
        uint64_t value;
        int result = riscv_get_register(target, &value, reg->number);
        if (result != ERROR_OK)
            return result;
        buf_set_u64(reg->value, 0, reg->size, value);
    }
    reg->valid = gdb_regno_cacheable(reg->number, false);
    char *str = buf_to_hex_str(reg->value, reg->size);
    LOG_DEBUG("[%s] read 0x%s from %s (valid=%d)", target_name(target),
            str, reg->name, reg->valid);
    free(str);
    return ERROR_OK;
}
 
static int register_set(struct reg *reg, uint8_t *buf)
{
    riscv_reg_info_t *reg_info = reg->arch_info;
    struct target *target = reg_info->target;
    RISCV_INFO(r);
 
    char *str = buf_to_hex_str(buf, reg->size);
    LOG_DEBUG("[%s] write 0x%s to %s (valid=%d)", target_name(target),
            str, reg->name, reg->valid);
    free(str);
 
    /* Exit early for writing x0, which on the hardware would be ignored, and we
     * don't want to update our cache. */
    if (reg->number == GDB_REGNO_ZERO)
        return ERROR_OK;
 
    memcpy(reg->value, buf, DIV_ROUND_UP(reg->size, 8));
    reg->valid = gdb_regno_cacheable(reg->number, true);
 
    if (reg->number == GDB_REGNO_TDATA1 ||
            reg->number == GDB_REGNO_TDATA2) {
        r->manual_hwbp_set = true;
        /* When enumerating triggers, we clear any triggers with DMODE set,
         * assuming they were left over from a previous debug session. So make
         * sure that is done before a user might be setting their own triggers.
         */
        if (riscv_enumerate_triggers(target) != ERROR_OK)
            return ERROR_FAIL;
    }
 
    if (reg->number >= GDB_REGNO_V0 && reg->number <= GDB_REGNO_V31) {
        if (!r->set_register_buf) {
            LOG_ERROR("Writing register %s not supported on this RISC-V target.",
                    gdb_regno_name(reg->number));
            return ERROR_FAIL;
        }
 
        if (r->set_register_buf(target, reg->number, reg->value) != ERROR_OK)
            return ERROR_FAIL;
    } else {
        uint64_t value = buf_get_u64(buf, 0, reg->size);
        if (riscv_set_register(target, reg->number, value) != ERROR_OK)
            return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static struct reg_arch_type riscv_reg_arch_type = {
    .get = register_get,
    .set = register_set
};
 
struct csr_info {
    unsigned int number;
    const char *name;
};
 
static int cmp_csr_info(const void *p1, const void *p2)
{
    return (int) (((struct csr_info *)p1)->number) - (int) (((struct csr_info *)p2)->number);
}
 
int riscv_init_registers(struct target *target)
{
    RISCV_INFO(info);
 
    riscv_free_registers(target);
 
    target->reg_cache = calloc(1, sizeof(*target->reg_cache));
    if (!target->reg_cache)
        return ERROR_FAIL;
    target->reg_cache->name = "RISC-V Registers";
    target->reg_cache->num_regs = GDB_REGNO_COUNT;
 
    if (!list_empty(&info->expose_custom)) {
        range_list_t *entry;
        list_for_each_entry(entry, &info->expose_custom, list)
            target->reg_cache->num_regs += entry->high - entry->low + 1;
    }
 
    LOG_DEBUG("create register cache for %d registers",
            target->reg_cache->num_regs);
 
    target->reg_cache->reg_list =
        calloc(target->reg_cache->num_regs, sizeof(struct reg));
    if (!target->reg_cache->reg_list)
        return ERROR_FAIL;
 
    const unsigned int max_reg_name_len = 12;
    free(info->reg_names);
    info->reg_names =
        calloc(target->reg_cache->num_regs, max_reg_name_len);
    if (!info->reg_names)
        return ERROR_FAIL;
    char *reg_name = info->reg_names;
 
    static struct reg_feature feature_cpu = {
        .name = "org.gnu.gdb.riscv.cpu"
    };
    static struct reg_feature feature_fpu = {
        .name = "org.gnu.gdb.riscv.fpu"
    };
    static struct reg_feature feature_csr = {
        .name = "org.gnu.gdb.riscv.csr"
    };
    static struct reg_feature feature_vector = {
        .name = "org.gnu.gdb.riscv.vector"
    };
    static struct reg_feature feature_virtual = {
        .name = "org.gnu.gdb.riscv.virtual"
    };
    static struct reg_feature feature_custom = {
        .name = "org.gnu.gdb.riscv.custom"
    };
 
    /* These types are built into gdb. */
    static struct reg_data_type type_ieee_single = { .type = REG_TYPE_IEEE_SINGLE, .id = "ieee_single" };
    static struct reg_data_type type_ieee_double = { .type = REG_TYPE_IEEE_DOUBLE, .id = "ieee_double" };
    static struct reg_data_type_union_field single_double_fields[] = {
        {"float", &type_ieee_single, single_double_fields + 1},
        {"double", &type_ieee_double, NULL},
    };
    static struct reg_data_type_union single_double_union = {
        .fields = single_double_fields
    };
    static struct reg_data_type type_ieee_single_double = {
        .type = REG_TYPE_ARCH_DEFINED,
        .id = "FPU_FD",
        .type_class = REG_TYPE_CLASS_UNION,
        { .reg_type_union = &single_double_union }
    };
    static struct reg_data_type type_uint8 = { .type = REG_TYPE_UINT8, .id = "uint8" };
    static struct reg_data_type type_uint16 = { .type = REG_TYPE_UINT16, .id = "uint16" };
    static struct reg_data_type type_uint32 = { .type = REG_TYPE_UINT32, .id = "uint32" };
    static struct reg_data_type type_uint64 = { .type = REG_TYPE_UINT64, .id = "uint64" };
    static struct reg_data_type type_uint128 = { .type = REG_TYPE_UINT128, .id = "uint128" };
 
    /* This is roughly the XML we want:
     * <vector id="bytes" type="uint8" count="16"/>
     * <vector id="shorts" type="uint16" count="8"/>
     * <vector id="words" type="uint32" count="4"/>
     * <vector id="longs" type="uint64" count="2"/>
     * <vector id="quads" type="uint128" count="1"/>
     * <union id="riscv_vector_type">
     *   <field name="b" type="bytes"/>
     *   <field name="s" type="shorts"/>
     *   <field name="w" type="words"/>
     *   <field name="l" type="longs"/>
     *   <field name="q" type="quads"/>
     * </union>
     */
 
    info->vector_uint8.type = &type_uint8;
    info->vector_uint8.count = info->vlenb;
    info->type_uint8_vector.type = REG_TYPE_ARCH_DEFINED;
    info->type_uint8_vector.id = "bytes";
    info->type_uint8_vector.type_class = REG_TYPE_CLASS_VECTOR;
    info->type_uint8_vector.reg_type_vector = &info->vector_uint8;
 
    info->vector_uint16.type = &type_uint16;
    info->vector_uint16.count = info->vlenb / 2;
    info->type_uint16_vector.type = REG_TYPE_ARCH_DEFINED;
    info->type_uint16_vector.id = "shorts";
    info->type_uint16_vector.type_class = REG_TYPE_CLASS_VECTOR;
    info->type_uint16_vector.reg_type_vector = &info->vector_uint16;
 
    info->vector_uint32.type = &type_uint32;
    info->vector_uint32.count = info->vlenb / 4;
    info->type_uint32_vector.type = REG_TYPE_ARCH_DEFINED;
    info->type_uint32_vector.id = "words";
    info->type_uint32_vector.type_class = REG_TYPE_CLASS_VECTOR;
    info->type_uint32_vector.reg_type_vector = &info->vector_uint32;
 
    info->vector_uint64.type = &type_uint64;
    info->vector_uint64.count = info->vlenb / 8;
    info->type_uint64_vector.type = REG_TYPE_ARCH_DEFINED;
    info->type_uint64_vector.id = "longs";
    info->type_uint64_vector.type_class = REG_TYPE_CLASS_VECTOR;
    info->type_uint64_vector.reg_type_vector = &info->vector_uint64;
 
    info->vector_uint128.type = &type_uint128;
    info->vector_uint128.count = info->vlenb / 16;
    info->type_uint128_vector.type = REG_TYPE_ARCH_DEFINED;
    info->type_uint128_vector.id = "quads";
    info->type_uint128_vector.type_class = REG_TYPE_CLASS_VECTOR;
    info->type_uint128_vector.reg_type_vector = &info->vector_uint128;
 
    info->vector_fields[0].name = "b";
    info->vector_fields[0].type = &info->type_uint8_vector;
    if (info->vlenb >= 2) {
        info->vector_fields[0].next = info->vector_fields + 1;
        info->vector_fields[1].name = "s";
        info->vector_fields[1].type = &info->type_uint16_vector;
    } else {
        info->vector_fields[0].next = NULL;
    }
    if (info->vlenb >= 4) {
        info->vector_fields[1].next = info->vector_fields + 2;
        info->vector_fields[2].name = "w";
        info->vector_fields[2].type = &info->type_uint32_vector;
    } else {
        info->vector_fields[1].next = NULL;
    }
    if (info->vlenb >= 8) {
        info->vector_fields[2].next = info->vector_fields + 3;
        info->vector_fields[3].name = "l";
        info->vector_fields[3].type = &info->type_uint64_vector;
    } else {
        info->vector_fields[2].next = NULL;
    }
    if (info->vlenb >= 16) {
        info->vector_fields[3].next = info->vector_fields + 4;
        info->vector_fields[4].name = "q";
        info->vector_fields[4].type = &info->type_uint128_vector;
    } else {
        info->vector_fields[3].next = NULL;
    }
    info->vector_fields[4].next = NULL;
 
    info->vector_union.fields = info->vector_fields;
 
    info->type_vector.type = REG_TYPE_ARCH_DEFINED;
    info->type_vector.id = "riscv_vector";
    info->type_vector.type_class = REG_TYPE_CLASS_UNION;
    info->type_vector.reg_type_union = &info->vector_union;
 
    struct csr_info csr_info[] = {
#define DECLARE_CSR(name, number) { number, #name },
#include "encoding.h"
#undef DECLARE_CSR
    };
    /* encoding.h does not contain the registers in sorted order. */
    qsort(csr_info, ARRAY_SIZE(csr_info), sizeof(*csr_info), cmp_csr_info);
    unsigned int csr_info_index = 0;
 
    int custom_within_range = 0;
 
    riscv_reg_info_t *shared_reg_info = calloc(1, sizeof(riscv_reg_info_t));
    if (!shared_reg_info)
        return ERROR_FAIL;
    shared_reg_info->target = target;
 
    /* When gdb requests register N, gdb_get_register_packet() assumes that this
     * is register at index N in reg_list. So if there are certain registers
     * that don't exist, we need to leave holes in the list (or renumber, but
     * it would be nice not to have yet another set of numbers to translate
     * between). */
    for (uint32_t number = 0; number < target->reg_cache->num_regs; number++) {
        struct reg *r = &target->reg_cache->reg_list[number];
        r->dirty = false;
        r->valid = false;
        r->exist = true;
        r->type = &riscv_reg_arch_type;
        r->arch_info = shared_reg_info;
        r->number = number;
        r->size = riscv_xlen(target);
        /* r->size is set in riscv_invalidate_register_cache, maybe because the
         * target is in theory allowed to change XLEN on us. But I expect a lot
         * of other things to break in that case as well. */
        if (number <= GDB_REGNO_XPR31) {
            r->exist = number <= GDB_REGNO_XPR15 ||
                !riscv_supports_extension(target, 'E');
            /* TODO: For now we fake that all GPRs exist because otherwise gdb
             * doesn't work. */
            r->exist = true;
            r->caller_save = true;
            switch (number) {
                case GDB_REGNO_ZERO:
                    r->name = "zero";
                    break;
                case GDB_REGNO_RA:
                    r->name = "ra";
                    break;
                case GDB_REGNO_SP:
                    r->name = "sp";
                    break;
                case GDB_REGNO_GP:
                    r->name = "gp";
                    break;
                case GDB_REGNO_TP:
                    r->name = "tp";
                    break;
                case GDB_REGNO_T0:
                    r->name = "t0";
                    break;
                case GDB_REGNO_T1:
                    r->name = "t1";
                    break;
                case GDB_REGNO_T2:
                    r->name = "t2";
                    break;
                case GDB_REGNO_FP:
                    r->name = "fp";
                    break;
                case GDB_REGNO_S1:
                    r->name = "s1";
                    break;
                case GDB_REGNO_A0:
                    r->name = "a0";
                    break;
                case GDB_REGNO_A1:
                    r->name = "a1";
                    break;
                case GDB_REGNO_A2:
                    r->name = "a2";
                    break;
                case GDB_REGNO_A3:
                    r->name = "a3";
                    break;
                case GDB_REGNO_A4:
                    r->name = "a4";
                    break;
                case GDB_REGNO_A5:
                    r->name = "a5";
                    break;
                case GDB_REGNO_A6:
                    r->name = "a6";
                    break;
                case GDB_REGNO_A7:
                    r->name = "a7";
                    break;
                case GDB_REGNO_S2:
                    r->name = "s2";
                    break;
                case GDB_REGNO_S3:
                    r->name = "s3";
                    break;
                case GDB_REGNO_S4:
                    r->name = "s4";
                    break;
                case GDB_REGNO_S5:
                    r->name = "s5";
                    break;
                case GDB_REGNO_S6:
                    r->name = "s6";
                    break;
                case GDB_REGNO_S7:
                    r->name = "s7";
                    break;
                case GDB_REGNO_S8:
                    r->name = "s8";
                    break;
                case GDB_REGNO_S9:
                    r->name = "s9";
                    break;
                case GDB_REGNO_S10:
                    r->name = "s10";
                    break;
                case GDB_REGNO_S11:
                    r->name = "s11";
                    break;
                case GDB_REGNO_T3:
                    r->name = "t3";
                    break;
                case GDB_REGNO_T4:
                    r->name = "t4";
                    break;
                case GDB_REGNO_T5:
                    r->name = "t5";
                    break;
                case GDB_REGNO_T6:
                    r->name = "t6";
                    break;
            }
            r->group = "general";
            r->feature = &feature_cpu;
        } else if (number == GDB_REGNO_PC) {
            r->caller_save = true;
            sprintf(reg_name, "pc");
            r->group = "general";
            r->feature = &feature_cpu;
        } else if (number >= GDB_REGNO_FPR0 && number <= GDB_REGNO_FPR31) {
            r->caller_save = true;
            if (riscv_supports_extension(target, 'D')) {
                r->size = 64;
                if (riscv_supports_extension(target, 'F'))
                    r->reg_data_type = &type_ieee_single_double;
                else
                    r->reg_data_type = &type_ieee_double;
            } else if (riscv_supports_extension(target, 'F')) {
                r->reg_data_type = &type_ieee_single;
                r->size = 32;
            } else {
                r->exist = false;
            }
            switch (number) {
                case GDB_REGNO_FT0:
                    r->name = "ft0";
                    break;
                case GDB_REGNO_FT1:
                    r->name = "ft1";
                    break;
                case GDB_REGNO_FT2:
                    r->name = "ft2";
                    break;
                case GDB_REGNO_FT3:
                    r->name = "ft3";
                    break;
                case GDB_REGNO_FT4:
                    r->name = "ft4";
                    break;
                case GDB_REGNO_FT5:
                    r->name = "ft5";
                    break;
                case GDB_REGNO_FT6:
                    r->name = "ft6";
                    break;
                case GDB_REGNO_FT7:
                    r->name = "ft7";
                    break;
                case GDB_REGNO_FS0:
                    r->name = "fs0";
                    break;
                case GDB_REGNO_FS1:
                    r->name = "fs1";
                    break;
                case GDB_REGNO_FA0:
                    r->name = "fa0";
                    break;
                case GDB_REGNO_FA1:
                    r->name = "fa1";
                    break;
                case GDB_REGNO_FA2:
                    r->name = "fa2";
                    break;
                case GDB_REGNO_FA3:
                    r->name = "fa3";
                    break;
                case GDB_REGNO_FA4:
                    r->name = "fa4";
                    break;
                case GDB_REGNO_FA5:
                    r->name = "fa5";
                    break;
                case GDB_REGNO_FA6:
                    r->name = "fa6";
                    break;
                case GDB_REGNO_FA7:
                    r->name = "fa7";
                    break;
                case GDB_REGNO_FS2:
                    r->name = "fs2";
                    break;
                case GDB_REGNO_FS3:
                    r->name = "fs3";
                    break;
                case GDB_REGNO_FS4:
                    r->name = "fs4";
                    break;
                case GDB_REGNO_FS5:
                    r->name = "fs5";
                    break;
                case GDB_REGNO_FS6:
                    r->name = "fs6";
                    break;
                case GDB_REGNO_FS7:
                    r->name = "fs7";
                    break;
                case GDB_REGNO_FS8:
                    r->name = "fs8";
                    break;
                case GDB_REGNO_FS9:
                    r->name = "fs9";
                    break;
                case GDB_REGNO_FS10:
                    r->name = "fs10";
                    break;
                case GDB_REGNO_FS11:
                    r->name = "fs11";
                    break;
                case GDB_REGNO_FT8:
                    r->name = "ft8";
                    break;
                case GDB_REGNO_FT9:
                    r->name = "ft9";
                    break;
                case GDB_REGNO_FT10:
                    r->name = "ft10";
                    break;
                case GDB_REGNO_FT11:
                    r->name = "ft11";
                    break;
            }
            r->group = "float";
            r->feature = &feature_fpu;
        } else if (number >= GDB_REGNO_CSR0 && number <= GDB_REGNO_CSR4095) {
            r->group = "csr";
            r->feature = &feature_csr;
            unsigned int csr_number = number - GDB_REGNO_CSR0;
 
            while (csr_info[csr_info_index].number < csr_number &&
                    csr_info_index < ARRAY_SIZE(csr_info) - 1) {
                csr_info_index++;
            }
            if (csr_info[csr_info_index].number == csr_number) {
                r->name = csr_info[csr_info_index].name;
            } else {
                sprintf(reg_name, "csr%d", csr_number);
                /* Assume unnamed registers don't exist, unless we have some
                 * configuration that tells us otherwise. That's important
                 * because eg. Eclipse crashes if a target has too many
                 * registers, and apparently has no way of only showing a
                 * subset of registers in any case. */
                r->exist = false;
            }
 
            switch (csr_number) {
                case CSR_FFLAGS:
                case CSR_FRM:
                case CSR_FCSR:
                    r->exist = riscv_supports_extension(target, 'F');
                    r->group = "float";
                    r->feature = &feature_fpu;
                    break;
                case CSR_SSTATUS:
                case CSR_STVEC:
                case CSR_SIP:
                case CSR_SIE:
                case CSR_SCOUNTEREN:
                case CSR_SSCRATCH:
                case CSR_SEPC:
                case CSR_SCAUSE:
                case CSR_STVAL:
                case CSR_SATP:
                    r->exist = riscv_supports_extension(target, 'S');
                    break;
                case CSR_MEDELEG:
                case CSR_MIDELEG:
                    /* "In systems with only M-mode, or with both M-mode and
                     * U-mode but without U-mode trap support, the medeleg and
                     * mideleg registers should not exist." */
                    r->exist = riscv_supports_extension(target, 'S') ||
                        riscv_supports_extension(target, 'N');
                    break;
 
                case CSR_PMPCFG1:
                case CSR_PMPCFG3:
                case CSR_CYCLEH:
                case CSR_TIMEH:
                case CSR_INSTRETH:
                case CSR_HPMCOUNTER3H:
                case CSR_HPMCOUNTER4H:
                case CSR_HPMCOUNTER5H:
                case CSR_HPMCOUNTER6H:
                case CSR_HPMCOUNTER7H:
                case CSR_HPMCOUNTER8H:
                case CSR_HPMCOUNTER9H:
                case CSR_HPMCOUNTER10H:
                case CSR_HPMCOUNTER11H:
                case CSR_HPMCOUNTER12H:
                case CSR_HPMCOUNTER13H:
                case CSR_HPMCOUNTER14H:
                case CSR_HPMCOUNTER15H:
                case CSR_HPMCOUNTER16H:
                case CSR_HPMCOUNTER17H:
                case CSR_HPMCOUNTER18H:
                case CSR_HPMCOUNTER19H:
                case CSR_HPMCOUNTER20H:
                case CSR_HPMCOUNTER21H:
                case CSR_HPMCOUNTER22H:
                case CSR_HPMCOUNTER23H:
                case CSR_HPMCOUNTER24H:
                case CSR_HPMCOUNTER25H:
                case CSR_HPMCOUNTER26H:
                case CSR_HPMCOUNTER27H:
                case CSR_HPMCOUNTER28H:
                case CSR_HPMCOUNTER29H:
                case CSR_HPMCOUNTER30H:
                case CSR_HPMCOUNTER31H:
                case CSR_MCYCLEH:
                case CSR_MINSTRETH:
                case CSR_MHPMCOUNTER3H:
                case CSR_MHPMCOUNTER4H:
                case CSR_MHPMCOUNTER5H:
                case CSR_MHPMCOUNTER6H:
                case CSR_MHPMCOUNTER7H:
                case CSR_MHPMCOUNTER8H:
                case CSR_MHPMCOUNTER9H:
                case CSR_MHPMCOUNTER10H:
                case CSR_MHPMCOUNTER11H:
                case CSR_MHPMCOUNTER12H:
                case CSR_MHPMCOUNTER13H:
                case CSR_MHPMCOUNTER14H:
                case CSR_MHPMCOUNTER15H:
                case CSR_MHPMCOUNTER16H:
                case CSR_MHPMCOUNTER17H:
                case CSR_MHPMCOUNTER18H:
                case CSR_MHPMCOUNTER19H:
                case CSR_MHPMCOUNTER20H:
                case CSR_MHPMCOUNTER21H:
                case CSR_MHPMCOUNTER22H:
                case CSR_MHPMCOUNTER23H:
                case CSR_MHPMCOUNTER24H:
                case CSR_MHPMCOUNTER25H:
                case CSR_MHPMCOUNTER26H:
                case CSR_MHPMCOUNTER27H:
                case CSR_MHPMCOUNTER28H:
                case CSR_MHPMCOUNTER29H:
                case CSR_MHPMCOUNTER30H:
                case CSR_MHPMCOUNTER31H:
                    r->exist = riscv_xlen(target) == 32;
                    break;
 
                case CSR_VSTART:
                case CSR_VXSAT:
                case CSR_VXRM:
                case CSR_VL:
                case CSR_VTYPE:
                case CSR_VLENB:
                    r->exist = riscv_supports_extension(target, 'V');
                    break;
            }
 
            if (!r->exist && !list_empty(&info->expose_csr)) {
                range_list_t *entry;
                list_for_each_entry(entry, &info->expose_csr, list)
                    if ((entry->low <= csr_number) && (csr_number <= entry->high)) {
                        if (entry->name) {
                            *reg_name = 0;
                            r->name = entry->name;
                        }
 
                        LOG_DEBUG("Exposing additional CSR %d (name=%s)",
                                csr_number, entry->name ? entry->name : reg_name);
 
                        r->exist = true;
                        break;
                    }
            }
 
        } else if (number == GDB_REGNO_PRIV) {
            sprintf(reg_name, "priv");
            r->group = "general";
            r->feature = &feature_virtual;
            r->size = 8;
 
        } else if (number >= GDB_REGNO_V0 && number <= GDB_REGNO_V31) {
            r->caller_save = false;
            r->exist = riscv_supports_extension(target, 'V') && info->vlenb;
            r->size = info->vlenb * 8;
            sprintf(reg_name, "v%d", number - GDB_REGNO_V0);
            r->group = "vector";
            r->feature = &feature_vector;
            r->reg_data_type = &info->type_vector;
 
        } else if (number >= GDB_REGNO_COUNT) {
            /* Custom registers. */
            assert(!list_empty(&info->expose_custom));
 
            range_list_t *range = list_first_entry(&info->expose_custom, range_list_t, list);
 
            unsigned int custom_number = range->low + custom_within_range;
 
            r->group = "custom";
            r->feature = &feature_custom;
            r->arch_info = calloc(1, sizeof(riscv_reg_info_t));
            if (!r->arch_info)
                return ERROR_FAIL;
            ((riscv_reg_info_t *) r->arch_info)->target = target;
            ((riscv_reg_info_t *) r->arch_info)->custom_number = custom_number;
            sprintf(reg_name, "custom%d", custom_number);
 
            if (range->name) {
                *reg_name = 0;
                r->name = range->name;
            }
 
            LOG_DEBUG("Exposing additional custom register %d (name=%s)",
                    number, range->name ? range->name : reg_name);
 
            custom_within_range++;
            if (custom_within_range > range->high - range->low) {
                custom_within_range = 0;
                list_rotate_left(&info->expose_custom);
            }
        }
 
        if (reg_name[0]) {
            r->name = reg_name;
            reg_name += strlen(reg_name) + 1;
            assert(reg_name < info->reg_names + target->reg_cache->num_regs *
                    max_reg_name_len);
        }
        r->value = calloc(1, DIV_ROUND_UP(r->size, 8));
    }
 
    return ERROR_OK;
}
 
 
void riscv_add_bscan_tunneled_scan(struct target *target, struct scan_field *field,
                    riscv_bscan_tunneled_scan_context_t *ctxt)
{
    jtag_add_ir_scan(target->tap, &select_user4, TAP_IDLE);
 
    memset(ctxt->tunneled_dr, 0, sizeof(ctxt->tunneled_dr));
    if (bscan_tunnel_type == BSCAN_TUNNEL_DATA_REGISTER) {
        ctxt->tunneled_dr[3].num_bits = 1;
        ctxt->tunneled_dr[3].out_value = bscan_one;
        ctxt->tunneled_dr[2].num_bits = 7;
        ctxt->tunneled_dr_width = field->num_bits;
        ctxt->tunneled_dr[2].out_value = &ctxt->tunneled_dr_width;
        /* for BSCAN tunnel, there is a one-TCK skew between shift in and shift out, so
           scanning num_bits + 1, and then will right shift the input field after executing the queues */
 
        ctxt->tunneled_dr[1].num_bits = field->num_bits + 1;
        ctxt->tunneled_dr[1].out_value = field->out_value;
        ctxt->tunneled_dr[1].in_value = field->in_value;
 
        ctxt->tunneled_dr[0].num_bits = 3;
        ctxt->tunneled_dr[0].out_value = bscan_zero;
    } else {
        /* BSCAN_TUNNEL_NESTED_TAP */
        ctxt->tunneled_dr[0].num_bits = 1;
        ctxt->tunneled_dr[0].out_value = bscan_one;
        ctxt->tunneled_dr[1].num_bits = 7;
        ctxt->tunneled_dr_width = field->num_bits;
        ctxt->tunneled_dr[1].out_value = &ctxt->tunneled_dr_width;
        /* for BSCAN tunnel, there is a one-TCK skew between shift in and shift out, so
           scanning num_bits + 1, and then will right shift the input field after executing the queues */
        ctxt->tunneled_dr[2].num_bits = field->num_bits + 1;
        ctxt->tunneled_dr[2].out_value = field->out_value;
        ctxt->tunneled_dr[2].in_value = field->in_value;
        ctxt->tunneled_dr[3].num_bits = 3;
        ctxt->tunneled_dr[3].out_value = bscan_zero;
    }
    jtag_add_dr_scan(target->tap, ARRAY_SIZE(ctxt->tunneled_dr), ctxt->tunneled_dr, TAP_IDLE);
}