jtag_vpi.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/*
 * JTAG to VPI driver
 *
 * Copyright (C) 2013 Franck Jullien, <elec4fun@gmail.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 */
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <jtag/interface.h>
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
 
#ifndef _WIN32
#include <netinet/tcp.h>
#endif
 
#include "helper/replacements.h"
 
#define NO_TAP_SHIFT    0
#define TAP_SHIFT   1
 
#define DEFAULT_SERVER_ADDRESS  "127.0.0.1"
#define DEFAULT_SERVER_PORT 5555
 
#define XFERT_MAX_SIZE      512
 
#define CMD_RESET       0
#define CMD_TMS_SEQ     1
#define CMD_SCAN_CHAIN      2
#define CMD_SCAN_CHAIN_FLIP_TMS 3
#define CMD_STOP_SIMU       4
 
/* jtag_vpi server port and address to connect to */
static uint16_t server_port = DEFAULT_SERVER_PORT;
static char *server_address;
 
/* Send CMD_STOP_SIMU to server when OpenOCD exits? */
static bool stop_sim_on_exit;
 
static int sockfd;
 
/* One jtag_vpi "packet" as sent over a TCP channel. */
struct vpi_cmd {
    union {
        uint32_t cmd;
        unsigned char cmd_buf[4];
    };
    unsigned char buffer_out[XFERT_MAX_SIZE];
    unsigned char buffer_in[XFERT_MAX_SIZE];
    union {
        uint32_t length;
        unsigned char length_buf[4];
    };
    union {
        uint32_t nb_bits;
        unsigned char nb_bits_buf[4];
    };
};
 
static char *jtag_vpi_cmd_to_str(int cmd_num)
{
    switch (cmd_num) {
    case CMD_RESET:
        return "CMD_RESET";
    case CMD_TMS_SEQ:
        return "CMD_TMS_SEQ";
    case CMD_SCAN_CHAIN:
        return "CMD_SCAN_CHAIN";
    case CMD_SCAN_CHAIN_FLIP_TMS:
        return "CMD_SCAN_CHAIN_FLIP_TMS";
    case CMD_STOP_SIMU:
        return "CMD_STOP_SIMU";
    default:
        return "<unknown>";
    }
}
 
static int jtag_vpi_send_cmd(struct vpi_cmd *vpi)
{
    int retval;
 
    /* Optional low-level JTAG debug */
    if (LOG_LEVEL_IS(LOG_LVL_DEBUG_IO)) {
        if (vpi->nb_bits > 0) {
            /* command with a non-empty data payload */
            char *char_buf = buf_to_hex_str(vpi->buffer_out,
                    (vpi->nb_bits > DEBUG_JTAG_IOZ)
                        ? DEBUG_JTAG_IOZ
                        : vpi->nb_bits);
            LOG_DEBUG_IO("sending JTAG VPI cmd: cmd=%s, "
                    "length=%" PRIu32 ", "
                    "nb_bits=%" PRIu32 ", "
                    "buf_out=0x%s%s",
                    jtag_vpi_cmd_to_str(vpi->cmd),
                    vpi->length,
                    vpi->nb_bits,
                    char_buf,
                    (vpi->nb_bits > DEBUG_JTAG_IOZ) ? "(...)" : "");
            free(char_buf);
        } else {
            /* command without data payload */
            LOG_DEBUG_IO("sending JTAG VPI cmd: cmd=%s, "
                    "length=%" PRIu32 ", "
                    "nb_bits=%" PRIu32,
                    jtag_vpi_cmd_to_str(vpi->cmd),
                    vpi->length,
                    vpi->nb_bits);
        }
    }
 
    /* Use little endian when transmitting/receiving jtag_vpi cmds.
       The choice of little endian goes against usual networking conventions
       but is intentional to remain compatible with most older OpenOCD builds
       (i.e. builds on little-endian platforms). */
    h_u32_to_le(vpi->cmd_buf, vpi->cmd);
    h_u32_to_le(vpi->length_buf, vpi->length);
    h_u32_to_le(vpi->nb_bits_buf, vpi->nb_bits);
 
retry_write:
    retval = write_socket(sockfd, vpi, sizeof(struct vpi_cmd));
 
    if (retval < 0) {
        /* Account for the case when socket write is interrupted. */
#ifdef _WIN32
        int wsa_err = WSAGetLastError();
        if (wsa_err == WSAEINTR)
            goto retry_write;
#else
        if (errno == EINTR)
            goto retry_write;
#endif
        /* Otherwise this is an error using the socket, most likely fatal
           for the connection. B*/
        log_socket_error("jtag_vpi xmit");
        /* TODO: Clean way how adapter drivers can report fatal errors
           to upper layers of OpenOCD and let it perform an orderly shutdown? */
        exit(-1);
    } else if (retval < (int)sizeof(struct vpi_cmd)) {
        /* This means we could not send all data, which is most likely fatal
           for the jtag_vpi connection (the underlying TCP connection likely not
           usable anymore) */
        LOG_ERROR("jtag_vpi: Could not send all data through jtag_vpi connection.");
        exit(-1);
    }
 
    /* Otherwise the packet has been sent successfully. */
    return ERROR_OK;
}
 
static int jtag_vpi_receive_cmd(struct vpi_cmd *vpi)
{
    unsigned int bytes_buffered = 0;
    while (bytes_buffered < sizeof(struct vpi_cmd)) {
        int bytes_to_receive = sizeof(struct vpi_cmd) - bytes_buffered;
        int retval = read_socket(sockfd, ((char *)vpi) + bytes_buffered, bytes_to_receive);
        if (retval < 0) {
#ifdef _WIN32
            int wsa_err = WSAGetLastError();
            if (wsa_err == WSAEINTR) {
                /* socket read interrupted by WSACancelBlockingCall() */
                continue;
            }
#else
            if (errno == EINTR) {
                /* socket read interrupted by a signal */
                continue;
            }
#endif
            /* Otherwise, this is an error when accessing the socket. */
            log_socket_error("jtag_vpi recv");
            exit(-1);
        } else if (retval == 0) {
            /* Connection closed by the other side */
            LOG_ERROR("Connection prematurely closed by jtag_vpi server.");
            exit(-1);
        }
        /* Otherwise, we have successfully received some data */
        bytes_buffered += retval;
    }
 
    /* Use little endian when transmitting/receiving jtag_vpi cmds. */
    vpi->cmd = le_to_h_u32(vpi->cmd_buf);
    vpi->length = le_to_h_u32(vpi->length_buf);
    vpi->nb_bits = le_to_h_u32(vpi->nb_bits_buf);
 
    return ERROR_OK;
}
 
static int jtag_vpi_reset(int trst, int srst)
{
    struct vpi_cmd vpi;
    memset(&vpi, 0, sizeof(struct vpi_cmd));
 
    vpi.cmd = CMD_RESET;
    vpi.length = 0;
    return jtag_vpi_send_cmd(&vpi);
}
 
static int jtag_vpi_tms_seq(const uint8_t *bits, int nb_bits)
{
    struct vpi_cmd vpi;
    int nb_bytes;
 
    memset(&vpi, 0, sizeof(struct vpi_cmd));
    nb_bytes = DIV_ROUND_UP(nb_bits, 8);
 
    vpi.cmd = CMD_TMS_SEQ;
    memcpy(vpi.buffer_out, bits, nb_bytes);
    vpi.length = nb_bytes;
    vpi.nb_bits = nb_bits;
 
    return jtag_vpi_send_cmd(&vpi);
}
 
static int jtag_vpi_path_move(struct pathmove_command *cmd)
{
    uint8_t trans[DIV_ROUND_UP(cmd->num_states, 8)];
 
    memset(trans, 0, DIV_ROUND_UP(cmd->num_states, 8));
 
    for (unsigned int i = 0; i < cmd->num_states; i++) {
        if (tap_state_transition(tap_get_state(), true) == cmd->path[i])
            buf_set_u32(trans, i, 1, 1);
        tap_set_state(cmd->path[i]);
    }
 
    return jtag_vpi_tms_seq(trans, cmd->num_states);
}
 
static int jtag_vpi_tms(struct tms_command *cmd)
{
    return jtag_vpi_tms_seq(cmd->bits, cmd->num_bits);
}
 
static int jtag_vpi_state_move(enum tap_state state)
{
    if (tap_get_state() == state)
        return ERROR_OK;
 
    uint8_t tms_scan = tap_get_tms_path(tap_get_state(), state);
    int tms_len = tap_get_tms_path_len(tap_get_state(), state);
 
    int retval = jtag_vpi_tms_seq(&tms_scan, tms_len);
    if (retval != ERROR_OK)
        return retval;
 
    tap_set_state(state);
 
    return ERROR_OK;
}
 
static int jtag_vpi_queue_tdi_xfer(uint8_t *bits, int nb_bits, int tap_shift)
{
    struct vpi_cmd vpi;
    int nb_bytes = DIV_ROUND_UP(nb_bits, 8);
 
    memset(&vpi, 0, sizeof(struct vpi_cmd));
 
    vpi.cmd = tap_shift ? CMD_SCAN_CHAIN_FLIP_TMS : CMD_SCAN_CHAIN;
 
    if (bits)
        memcpy(vpi.buffer_out, bits, nb_bytes);
    else
        memset(vpi.buffer_out, 0xff, nb_bytes);
 
    vpi.length = nb_bytes;
    vpi.nb_bits = nb_bits;
 
    int retval = jtag_vpi_send_cmd(&vpi);
    if (retval != ERROR_OK)
        return retval;
 
    retval = jtag_vpi_receive_cmd(&vpi);
    if (retval != ERROR_OK)
        return retval;
 
    /* Optional low-level JTAG debug */
    if (LOG_LEVEL_IS(LOG_LVL_DEBUG_IO)) {
        char *char_buf = buf_to_hex_str(vpi.buffer_in,
                (nb_bits > DEBUG_JTAG_IOZ) ? DEBUG_JTAG_IOZ : nb_bits);
        LOG_DEBUG_IO("recvd JTAG VPI data: nb_bits=%d, buf_in=0x%s%s",
            nb_bits, char_buf, (nb_bits > DEBUG_JTAG_IOZ) ? "(...)" : "");
        free(char_buf);
    }
 
    if (bits)
        memcpy(bits, vpi.buffer_in, nb_bytes);
 
    return ERROR_OK;
}
 
static int jtag_vpi_queue_tdi(uint8_t *bits, int nb_bits, int tap_shift)
{
    int nb_xfer = DIV_ROUND_UP(nb_bits, XFERT_MAX_SIZE * 8);
    int retval;
 
    while (nb_xfer) {
        if (nb_xfer ==  1) {
            retval = jtag_vpi_queue_tdi_xfer(bits, nb_bits, tap_shift);
            if (retval != ERROR_OK)
                return retval;
        } else {
            retval = jtag_vpi_queue_tdi_xfer(bits, XFERT_MAX_SIZE * 8, NO_TAP_SHIFT);
            if (retval != ERROR_OK)
                return retval;
            nb_bits -= XFERT_MAX_SIZE * 8;
            if (bits)
                bits += XFERT_MAX_SIZE;
        }
 
        nb_xfer--;
    }
 
    return ERROR_OK;
}
 
static int jtag_vpi_clock_tms(int tms)
{
    const uint8_t tms_0 = 0;
    const uint8_t tms_1 = 1;
 
    return jtag_vpi_tms_seq(tms ? &tms_1 : &tms_0, 1);
}
 
static int jtag_vpi_scan(struct scan_command *cmd)
{
    int scan_bits;
    uint8_t *buf = NULL;
    int retval = ERROR_OK;
 
    scan_bits = jtag_build_buffer(cmd, &buf);
 
    if (cmd->ir_scan) {
        retval = jtag_vpi_state_move(TAP_IRSHIFT);
        if (retval != ERROR_OK)
            return retval;
    } else {
        retval = jtag_vpi_state_move(TAP_DRSHIFT);
        if (retval != ERROR_OK)
            return retval;
    }
 
    if (cmd->end_state == TAP_DRSHIFT) {
        retval = jtag_vpi_queue_tdi(buf, scan_bits, NO_TAP_SHIFT);
        if (retval != ERROR_OK)
            return retval;
    } else {
        retval = jtag_vpi_queue_tdi(buf, scan_bits, TAP_SHIFT);
        if (retval != ERROR_OK)
            return retval;
    }
 
    if (cmd->end_state != TAP_DRSHIFT) {
        /*
         * As our JTAG is in an unstable state (IREXIT1 or DREXIT1), move it
         * forward to a stable IRPAUSE or DRPAUSE.
         */
        retval = jtag_vpi_clock_tms(0);
        if (retval != ERROR_OK)
            return retval;
 
        if (cmd->ir_scan)
            tap_set_state(TAP_IRPAUSE);
        else
            tap_set_state(TAP_DRPAUSE);
    }
 
    retval = jtag_read_buffer(buf, cmd);
    if (retval != ERROR_OK)
        return retval;
 
    free(buf);
 
    if (cmd->end_state != TAP_DRSHIFT) {
        retval = jtag_vpi_state_move(cmd->end_state);
        if (retval != ERROR_OK)
            return retval;
    }
 
    return ERROR_OK;
}
 
static int jtag_vpi_runtest(unsigned int num_cycles, enum tap_state state)
{
    int retval;
 
    retval = jtag_vpi_state_move(TAP_IDLE);
    if (retval != ERROR_OK)
        return retval;
 
    retval = jtag_vpi_queue_tdi(NULL, num_cycles, NO_TAP_SHIFT);
    if (retval != ERROR_OK)
        return retval;
 
    return jtag_vpi_state_move(state);
}
 
static int jtag_vpi_stableclocks(unsigned int num_cycles)
{
    uint8_t tms_bits[4];
    unsigned int cycles_remain = num_cycles;
    int nb_bits;
    int retval;
    const unsigned int cycles_one_batch = sizeof(tms_bits) * 8;
 
    /* use TMS=1 in TAP RESET state, TMS=0 in all other stable states */
    memset(&tms_bits, (tap_get_state() == TAP_RESET) ? 0xff : 0x00, sizeof(tms_bits));
 
    /* send the TMS bits */
    while (cycles_remain > 0) {
        nb_bits = (cycles_remain < cycles_one_batch) ? cycles_remain : cycles_one_batch;
        retval = jtag_vpi_tms_seq(tms_bits, nb_bits);
        if (retval != ERROR_OK)
            return retval;
        cycles_remain -= nb_bits;
    }
 
    return ERROR_OK;
}
 
static int jtag_vpi_execute_queue(struct jtag_command *cmd_queue)
{
    struct jtag_command *cmd;
    int retval = ERROR_OK;
 
    for (cmd = cmd_queue; retval == ERROR_OK && cmd;
         cmd = cmd->next) {
        switch (cmd->type) {
        case JTAG_RESET:
            retval = jtag_vpi_reset(cmd->cmd.reset->trst, cmd->cmd.reset->srst);
            break;
        case JTAG_RUNTEST:
            retval = jtag_vpi_runtest(cmd->cmd.runtest->num_cycles,
                          cmd->cmd.runtest->end_state);
            break;
        case JTAG_STABLECLOCKS:
            retval = jtag_vpi_stableclocks(cmd->cmd.stableclocks->num_cycles);
            break;
        case JTAG_TLR_RESET:
            retval = jtag_vpi_state_move(cmd->cmd.statemove->end_state);
            break;
        case JTAG_PATHMOVE:
            retval = jtag_vpi_path_move(cmd->cmd.pathmove);
            break;
        case JTAG_TMS:
            retval = jtag_vpi_tms(cmd->cmd.tms);
            break;
        case JTAG_SLEEP:
            jtag_sleep(cmd->cmd.sleep->us);
            break;
        case JTAG_SCAN:
            retval = jtag_vpi_scan(cmd->cmd.scan);
            break;
        default:
            LOG_ERROR("BUG: unknown JTAG command type 0x%X",
                  cmd->type);
            retval = ERROR_FAIL;
            break;
        }
    }
 
    return retval;
}
 
static int jtag_vpi_init(void)
{
    if (!server_address)
        server_address = strdup(DEFAULT_SERVER_ADDRESS);
 
    const struct addrinfo hints = {
        .ai_family = AF_UNSPEC,
        .ai_socktype = SOCK_STREAM
    };
 
    char port_str[5 + 1];
    snprintf(port_str, sizeof(port_str), "%" PRIu16, server_port);
 
    struct addrinfo *result;
    int ret = getaddrinfo(server_address, port_str, &hints, &result);
 
    if (ret != 0) {
        LOG_ERROR("getaddrinfo: %s", gai_strerror(ret));
        return ERROR_FAIL;
    }
 
    struct addrinfo *rp;
    for (rp = result; rp ; rp = rp->ai_next) {
        sockfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
        if (sockfd == -1)
            continue;
 
        if (connect(sockfd, rp->ai_addr, rp->ai_addrlen) != -1)
            break;
 
        close(sockfd);
    }
 
    if (!rp) {
        LOG_ERROR("jtag_vpi: Can't connect to %s : %" PRIu16,
            server_address, server_port);
        freeaddrinfo(result);
        return ERROR_FAIL;
    }
 
    bool is_loopback = false;
    if (rp->ai_family == AF_INET) {
        struct sockaddr_in sa;
        memcpy(&sa, rp->ai_addr, sizeof(sa));
        is_loopback = (sa.sin_addr.s_addr == htonl(INADDR_LOOPBACK));
    } else if (rp->ai_family == AF_INET6) {
        struct sockaddr_in6 sa;
        memcpy(&sa, rp->ai_addr, sizeof(sa));
        is_loopback = IN6_IS_ADDR_LOOPBACK(&sa.sin6_addr);
    }
 
    if (is_loopback) {
        /* This increases performance dramatically for local
        * connections, which is the most likely arrangement
        * for a VPI connection. */
        LOG_DEBUG("Enabling TCP_NODELAY to enhance the speed of local connections");
 
        int flag = 1;
        setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, (char *)&flag,
            sizeof(int));
    }
 
    freeaddrinfo(result);
 
    LOG_INFO("jtag_vpi: Connection to %s : %" PRIu16 " successful",
        server_address, server_port);
 
    return ERROR_OK;
}
 
static int jtag_vpi_stop_simulation(void)
{
    struct vpi_cmd cmd;
    memset(&cmd, 0, sizeof(struct vpi_cmd));
    cmd.length = 0;
    cmd.nb_bits = 0;
    cmd.cmd = CMD_STOP_SIMU;
    return jtag_vpi_send_cmd(&cmd);
}
 
static int jtag_vpi_quit(void)
{
    if (stop_sim_on_exit) {
        if (jtag_vpi_stop_simulation() != ERROR_OK)
            LOG_WARNING("jtag_vpi: failed to send \"stop simulation\" command");
    }
    if (close_socket(sockfd) != 0) {
        LOG_WARNING("jtag_vpi: could not close jtag_vpi client socket");
        log_socket_error("jtag_vpi");
    }
    free(server_address);
    return ERROR_OK;
}
 
COMMAND_HANDLER(jtag_vpi_set_port)
{
    if (CMD_ARGC == 0)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    COMMAND_PARSE_NUMBER(u16, CMD_ARGV[0], server_port);
    LOG_INFO("jtag_vpi: server port set to %" PRIu16, server_port);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(jtag_vpi_set_address)
{
 
    if (CMD_ARGC == 0)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    free(server_address);
    server_address = strdup(CMD_ARGV[0]);
    LOG_INFO("jtag_vpi: server address set to %s", server_address);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(jtag_vpi_stop_sim_on_exit_handler)
{
    if (CMD_ARGC != 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    COMMAND_PARSE_ON_OFF(CMD_ARGV[0], stop_sim_on_exit);
    return ERROR_OK;
}
 
static const struct command_registration jtag_vpi_subcommand_handlers[] = {
    {
        .name = "set_port",
        .handler = &jtag_vpi_set_port,
        .mode = COMMAND_CONFIG,
        .help = "set the TCP port number of the jtag_vpi server (default: 5555)",
        .usage = "tcp_port_num",
    },
    {
        .name = "set_address",
        .handler = &jtag_vpi_set_address,
        .mode = COMMAND_CONFIG,
        .help = "set the hostname or IP address of the jtag_vpi server (default: 127.0.0.1)",
        .usage = "ipv4_addr",
    },
    {
        .name = "stop_sim_on_exit",
        .handler = &jtag_vpi_stop_sim_on_exit_handler,
        .mode = COMMAND_CONFIG,
        .help = "Configure if simulation stop command shall be sent "
            "before OpenOCD exits (default: off)",
        .usage = "<on|off>",
    },
    COMMAND_REGISTRATION_DONE
};
 
static const struct command_registration jtag_vpi_command_handlers[] = {
    {
        .name = "jtag_vpi",
        .mode = COMMAND_ANY,
        .help = "perform jtag_vpi management",
        .chain = jtag_vpi_subcommand_handlers,
        .usage = "",
    },
    COMMAND_REGISTRATION_DONE
};
 
static struct jtag_interface jtag_vpi_interface = {
    .supported = DEBUG_CAP_TMS_SEQ,
    .execute_queue = jtag_vpi_execute_queue,
};
 
struct adapter_driver jtag_vpi_adapter_driver = {
    .name = "jtag_vpi",
    .transport_ids = TRANSPORT_JTAG,
    .transport_preferred_id = TRANSPORT_JTAG,
    .commands = jtag_vpi_command_handlers,
 
    .init = jtag_vpi_init,
    .quit = jtag_vpi_quit,
 
    .jtag_ops = &jtag_vpi_interface,
};