ti_icdi_usb.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *                                                                         *
 *   Copyright (C) 2012 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
/* project specific includes */
#include <helper/binarybuffer.h>
#include <jtag/adapter.h>
#include <jtag/interface.h>
#include <jtag/hla/hla_layout.h>
#include <jtag/hla/hla_transport.h>
#include <jtag/hla/hla_interface.h>
#include <target/target.h>
 
#include <target/cortex_m.h>
 
#include "libusb_helper.h"
 
#define ICDI_WRITE_ENDPOINT 0x02
#define ICDI_READ_ENDPOINT 0x83
 
#define ICDI_WRITE_TIMEOUT (LIBUSB_TIMEOUT_MS)
#define ICDI_READ_TIMEOUT (LIBUSB_TIMEOUT_MS)
#define ICDI_PACKET_SIZE 2048
 
#define PACKET_START "$"
#define PACKET_END "#"
 
struct icdi_usb_handle {
    struct libusb_device_handle *usb_dev;
 
    char *read_buffer;
    char *write_buffer;
    int max_packet;
    int read_count;
    uint32_t max_rw_packet; /* max X packet (read/write memory) transfers */
};
 
static int icdi_usb_read_mem(void *handle, uint32_t addr, uint32_t size,
        uint32_t count, uint8_t *buffer);
static int icdi_usb_write_mem(void *handle, uint32_t addr, uint32_t size,
        uint32_t count, const uint8_t *buffer);
 
static int remote_escape_output(const char *buffer, int len, char *out_buf, int *out_len, int out_maxlen)
{
    int input_index, output_index;
 
    output_index = 0;
 
    for (input_index = 0; input_index < len; input_index++) {
 
        char b = buffer[input_index];
 
        if (b == '$' || b == '#' || b == '}' || b == '*') {
            /* These must be escaped.  */
            if (output_index + 2 > out_maxlen)
                break;
            out_buf[output_index++] = '}';
            out_buf[output_index++] = b ^ 0x20;
        } else {
            if (output_index + 1 > out_maxlen)
                break;
            out_buf[output_index++] = b;
        }
    }
 
    *out_len = input_index;
    return output_index;
}
 
static int remote_unescape_input(const char *buffer, int len, char *out_buf, int out_maxlen)
{
    int input_index, output_index;
    int escaped;
 
    output_index = 0;
    escaped = 0;
 
    for (input_index = 0; input_index < len; input_index++) {
 
        char b = buffer[input_index];
 
        if (output_index + 1 > out_maxlen)
            LOG_ERROR("Received too much data from the target.");
 
        if (escaped) {
            out_buf[output_index++] = b ^ 0x20;
            escaped = 0;
        } else if (b == '}')
            escaped = 1;
        else
            out_buf[output_index++] = b;
    }
 
    if (escaped)
        LOG_ERROR("Unmatched escape character in target response.");
 
    return output_index;
}
 
static int icdi_send_packet(void *handle, int len)
{
    unsigned char cksum = 0;
    struct icdi_usb_handle *h = handle;
    int result, retry = 0;
    int transferred = 0;
 
    assert(handle);
 
    /* check we have a large enough buffer for checksum "#00" */
    if (len + 3 > h->max_packet) {
        LOG_ERROR("packet buffer too small");
        return ERROR_FAIL;
    }
 
    /* calculate checksum - offset start of packet */
    for (int i = 1; i < len; i++)
        cksum += h->write_buffer[i];
 
    len += sprintf(&h->write_buffer[len], PACKET_END "%02x", cksum);
 
#ifdef _DEBUG_USB_COMMS_
    char buffer[50];
    char ch = h->write_buffer[1];
    if (ch == 'x' || ch == 'X')
        LOG_DEBUG("writing packet: <binary>");
    else {
        memcpy(buffer, h->write_buffer, len >= 50 ? 50-1 : len);
        buffer[len] = 0;
        LOG_DEBUG("writing packet: %s", buffer);
    }
#endif
 
    while (1) {
 
        result = libusb_bulk_transfer(h->usb_dev, ICDI_WRITE_ENDPOINT, (unsigned char *)h->write_buffer, len,
                &transferred, ICDI_WRITE_TIMEOUT);
        if (result != 0 || transferred != len) {
            LOG_DEBUG("Error TX Data %d", result);
            return ERROR_FAIL;
        }
 
        /* check that the client got the message ok, or shall we resend */
        result = libusb_bulk_transfer(h->usb_dev, ICDI_READ_ENDPOINT, (unsigned char *)h->read_buffer, h->max_packet,
                    &transferred, ICDI_READ_TIMEOUT);
        if (result != 0 || transferred < 1) {
            LOG_DEBUG("Error RX Data %d", result);
            return ERROR_FAIL;
        }
 
#ifdef _DEBUG_USB_COMMS_
        LOG_DEBUG("received reply: '%c' : count %d", h->read_buffer[0], transferred);
#endif
 
        if (h->read_buffer[0] == '-') {
            LOG_DEBUG("Resending packet %d", ++retry);
        } else {
            if (h->read_buffer[0] != '+')
                LOG_DEBUG("Unexpected Reply from ICDI: %c", h->read_buffer[0]);
            break;
        }
 
        if (retry == 3) {
            LOG_DEBUG("maximum nack retries attempted");
            return ERROR_FAIL;
        }
    }
 
    retry = 0;
    h->read_count = transferred;
 
    while (1) {
 
        /* read reply from icdi */
        result = libusb_bulk_transfer(h->usb_dev, ICDI_READ_ENDPOINT, (unsigned char *)h->read_buffer + h->read_count,
                h->max_packet - h->read_count, &transferred, ICDI_READ_TIMEOUT);
 
#ifdef _DEBUG_USB_COMMS_
        LOG_DEBUG("received data: count %d", transferred);
#endif
 
        /* check for errors but retry for timeout */
        if (result != 0) {
 
            if (result == LIBUSB_ERROR_TIMEOUT) {
                LOG_DEBUG("Error RX timeout %d", result);
            } else {
                LOG_DEBUG("Error RX Data %d", result);
                return ERROR_FAIL;
            }
        }
 
        h->read_count += transferred;
 
        /* we need to make sure we have a full packet, including checksum */
        if (h->read_count > 5) {
 
            /* check that we have received an packet delimiter
             * we do not validate the checksum
             * reply should contain $...#AA - so we check for # */
            if (h->read_buffer[h->read_count - 3] == '#')
                return ERROR_OK;
        }
 
        if (retry++ == 3) {
            LOG_DEBUG("maximum data retries attempted");
            break;
        }
    }
 
    return ERROR_FAIL;
}
 
static int icdi_send_cmd(void *handle, const char *cmd)
{
    struct icdi_usb_handle *h = handle;
 
    int cmd_len = snprintf(h->write_buffer, h->max_packet, PACKET_START "%s", cmd);
    return icdi_send_packet(handle, cmd_len);
}
 
static int icdi_send_remote_cmd(void *handle, const char *data)
{
    struct icdi_usb_handle *h = handle;
 
    size_t cmd_len = sprintf(h->write_buffer, PACKET_START "qRcmd,");
    cmd_len += hexify(h->write_buffer + cmd_len, (const uint8_t *)data,
        strlen(data), h->max_packet - cmd_len);
 
    return icdi_send_packet(handle, cmd_len);
}
 
static int icdi_get_cmd_result(void *handle)
{
    struct icdi_usb_handle *h = handle;
    int offset = 0;
    char ch;
 
    assert(handle);
 
    do {
        ch = h->read_buffer[offset++];
        if (offset > h->read_count)
            return ERROR_FAIL;
    } while (ch != '$');
 
    if (memcmp("OK", h->read_buffer + offset, 2) == 0)
        return ERROR_OK;
 
    if (h->read_buffer[offset] == 'E') {
        /* get error code */
        uint8_t result;
        if (unhexify(&result, h->read_buffer + offset + 1, 1) != 1)
            return ERROR_FAIL;
        return result;
    }
 
    /* for now we assume everything else is ok */
    return ERROR_OK;
}
 
static int icdi_usb_idcode(void *handle, uint32_t *idcode)
{
    *idcode = 0;
    return ERROR_OK;
}
 
static int icdi_usb_write_debug_reg(void *handle, uint32_t addr, uint32_t val)
{
    uint8_t buf[4];
    /* REVISIT: There's no target pointer here so there's no way to use target_buffer_set_u32().
     * I guess all supported chips are little-endian anyway. */
    h_u32_to_le(buf, val);
    return icdi_usb_write_mem(handle, addr, 4, 1, buf);
}
 
static enum target_state icdi_usb_state(void *handle)
{
    int result;
    struct icdi_usb_handle *h = handle;
    uint32_t dhcsr;
    uint8_t buf[4];
 
    result = icdi_usb_read_mem(h, DCB_DHCSR, 4, 1, buf);
    if (result != ERROR_OK)
        return TARGET_UNKNOWN;
 
    /* REVISIT: There's no target pointer here so there's no way to use target_buffer_get_u32().
     * I guess all supported chips are little-endian anyway. */
    dhcsr = le_to_h_u32(buf);
    if (dhcsr & S_HALT)
        return TARGET_HALTED;
 
    return TARGET_RUNNING;
}
 
static int icdi_usb_version(void *handle)
{
    struct icdi_usb_handle *h = handle;
 
    char version[20];
 
    /* get info about icdi */
    int result = icdi_send_remote_cmd(handle, "version");
    if (result != ERROR_OK)
        return result;
 
    if (h->read_count < 8) {
        LOG_ERROR("Invalid Reply Received");
        return ERROR_FAIL;
    }
 
    /* convert reply */
    if (unhexify((uint8_t *)version, h->read_buffer + 2, 4) != 4) {
        LOG_WARNING("unable to get ICDI version");
        return ERROR_OK;
    }
 
    /* null terminate and print info */
    version[4] = 0;
 
    LOG_INFO("ICDI Firmware version: %s", version);
 
    return ERROR_OK;
}
 
static int icdi_usb_query(void *handle)
{
    int result;
 
    struct icdi_usb_handle *h = handle;
 
    result = icdi_send_cmd(handle, "qSupported");
    if (result != ERROR_OK)
        return result;
 
    /* check result */
    result = icdi_get_cmd_result(handle);
    if (result != ERROR_OK) {
        LOG_ERROR("query supported failed: 0x%x", result);
        return ERROR_FAIL;
    }
 
    /* from this we can get the max packet supported */
 
    /* query packet buffer size */
    char *offset = strstr(h->read_buffer, "PacketSize");
    if (offset) {
        char *separator;
        int max_packet;
 
        max_packet = strtol(offset + 11, &separator, 16);
        if (!max_packet)
            LOG_ERROR("invalid max packet, using defaults");
        else
            h->max_packet = max_packet;
        LOG_DEBUG("max packet supported : %i bytes", h->max_packet);
    }
 
 
    /* if required re allocate packet buffer */
    if (h->max_packet != ICDI_PACKET_SIZE) {
        h->read_buffer = realloc(h->read_buffer, h->max_packet);
        h->write_buffer = realloc(h->write_buffer, h->max_packet);
        if (!h->read_buffer || !h->write_buffer) {
            LOG_ERROR("unable to reallocate memory");
            return ERROR_FAIL;
        }
    }
 
    /* set extended mode */
    result = icdi_send_cmd(handle, "!");
    if (result != ERROR_OK)
        return result;
 
    /* check result */
    result = icdi_get_cmd_result(handle);
    if (result != ERROR_OK) {
        LOG_ERROR("unable to enable extended mode: 0x%x", result);
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int icdi_usb_reset(void *handle)
{
    /* we do this in hla_target.c */
    return ERROR_OK;
}
 
static int icdi_usb_assert_srst(void *handle, int srst)
{
    /* TODO not supported yet */
    return ERROR_COMMAND_NOTFOUND;
}
 
static int icdi_usb_run(void *handle)
{
    int result;
 
    /* resume target at current address */
    result = icdi_send_cmd(handle, "c");
    if (result != ERROR_OK)
        return result;
 
    /* check result */
    result = icdi_get_cmd_result(handle);
    if (result != ERROR_OK) {
        LOG_ERROR("continue failed: 0x%x", result);
        return ERROR_FAIL;
    }
 
    return result;
}
 
static int icdi_usb_halt(void *handle)
{
    int result;
 
    /* this query halts the target ?? */
    result = icdi_send_cmd(handle, "?");
    if (result != ERROR_OK)
        return result;
 
    /* check result */
    result = icdi_get_cmd_result(handle);
    if (result != ERROR_OK) {
        LOG_ERROR("halt failed: 0x%x", result);
        return ERROR_FAIL;
    }
 
    return result;
}
 
static int icdi_usb_step(void *handle)
{
    int result;
 
    /* step target at current address */
    result = icdi_send_cmd(handle, "s");
    if (result != ERROR_OK)
        return result;
 
    /* check result */
    result = icdi_get_cmd_result(handle);
    if (result != ERROR_OK) {
        LOG_ERROR("step failed: 0x%x", result);
        return ERROR_FAIL;
    }
 
    return result;
}
 
static int icdi_usb_read_regs(void *handle)
{
    /* currently unsupported */
    return ERROR_OK;
}
 
static int icdi_usb_read_reg(void *handle, unsigned int regsel, uint32_t *val)
{
    int result;
    struct icdi_usb_handle *h = handle;
    char cmd[10];
 
    snprintf(cmd, sizeof(cmd), "p%x", regsel);
    result = icdi_send_cmd(handle, cmd);
    if (result != ERROR_OK)
        return result;
 
    /* check result */
    result = icdi_get_cmd_result(handle);
    if (result != ERROR_OK) {
        LOG_ERROR("register read failed: 0x%x", result);
        return ERROR_FAIL;
    }
 
    /* convert result */
    uint8_t buf[4];
    if (unhexify(buf, h->read_buffer + 2, 4) != 4) {
        LOG_ERROR("failed to convert result");
        return ERROR_FAIL;
    }
    *val = le_to_h_u32(buf);
 
    return result;
}
 
static int icdi_usb_write_reg(void *handle, unsigned int regsel, uint32_t val)
{
    int result;
    char cmd[20];
    uint8_t buf[4];
    h_u32_to_le(buf, val);
 
    int cmd_len = snprintf(cmd, sizeof(cmd), "P%x=", regsel);
    hexify(cmd + cmd_len, buf, 4, sizeof(cmd));
 
    result = icdi_send_cmd(handle, cmd);
    if (result != ERROR_OK)
        return result;
 
    /* check result */
    result = icdi_get_cmd_result(handle);
    if (result != ERROR_OK) {
        LOG_ERROR("register write failed: 0x%x", result);
        return ERROR_FAIL;
    }
 
    return result;
}
 
static int icdi_usb_read_mem_int(void *handle, uint32_t addr, uint32_t len, uint8_t *buffer)
{
    int result;
    struct icdi_usb_handle *h = handle;
    char cmd[20];
 
    snprintf(cmd, sizeof(cmd), "x%" PRIx32 ",%" PRIx32, addr, len);
    result = icdi_send_cmd(handle, cmd);
    if (result != ERROR_OK)
        return result;
 
    /* check result */
    result = icdi_get_cmd_result(handle);
    if (result != ERROR_OK) {
        LOG_ERROR("memory read failed: 0x%x", result);
        return ERROR_FAIL;
    }
 
    /* unescape input */
    int read_len = remote_unescape_input(h->read_buffer + 5, h->read_count - 8, (char *)buffer, len);
    if (read_len != (int)len) {
        LOG_ERROR("read more bytes than expected: actual 0x%x expected 0x%" PRIx32, read_len, len);
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int icdi_usb_write_mem_int(void *handle, uint32_t addr, uint32_t len, const uint8_t *buffer)
{
    int result;
    struct icdi_usb_handle *h = handle;
 
    size_t cmd_len = snprintf(h->write_buffer, h->max_packet, PACKET_START "X%" PRIx32 ",%" PRIx32 ":", addr, len);
 
    int out_len;
    cmd_len += remote_escape_output((const char *)buffer, len, h->write_buffer + cmd_len,
            &out_len, h->max_packet - cmd_len);
 
    if (out_len < (int)len) {
        /* for now issue a error as we have no way of allocating a larger buffer */
        LOG_ERROR("memory buffer too small: requires 0x%x actual 0x%" PRIx32, out_len, len);
        return ERROR_FAIL;
    }
 
    result = icdi_send_packet(handle, cmd_len);
    if (result != ERROR_OK)
        return result;
 
    /* check result */
    result = icdi_get_cmd_result(handle);
    if (result != ERROR_OK) {
        LOG_ERROR("memory write failed: 0x%x", result);
        return ERROR_FAIL;
    }
 
    return ERROR_OK;
}
 
static int icdi_usb_read_mem(void *handle, uint32_t addr, uint32_t size,
        uint32_t count, uint8_t *buffer)
{
    int retval = ERROR_OK;
    struct icdi_usb_handle *h = handle;
    uint32_t bytes_remaining;
 
    /* calculate byte count */
    count *= size;
 
    while (count) {
 
        bytes_remaining = h->max_rw_packet;
        if (count < bytes_remaining)
            bytes_remaining = count;
 
        retval = icdi_usb_read_mem_int(handle, addr, bytes_remaining, buffer);
        if (retval != ERROR_OK)
            return retval;
 
        buffer += bytes_remaining;
        addr += bytes_remaining;
        count -= bytes_remaining;
    }
 
    return retval;
}
 
static int icdi_usb_write_mem(void *handle, uint32_t addr, uint32_t size,
        uint32_t count, const uint8_t *buffer)
{
    int retval = ERROR_OK;
    struct icdi_usb_handle *h = handle;
    uint32_t bytes_remaining;
 
    /* calculate byte count */
    count *= size;
 
    while (count) {
 
        bytes_remaining = h->max_rw_packet;
        if (count < bytes_remaining)
            bytes_remaining = count;
 
        retval = icdi_usb_write_mem_int(handle, addr, bytes_remaining, buffer);
        if (retval != ERROR_OK)
            return retval;
 
        buffer += bytes_remaining;
        addr += bytes_remaining;
        count -= bytes_remaining;
    }
 
    return retval;
}
 
static int icdi_usb_override_target(const char *targetname)
{
    return !strcmp(targetname, "cortex_m");
}
 
static int icdi_usb_close(void *handle)
{
    struct icdi_usb_handle *h = handle;
 
    if (!h)
        return ERROR_OK;
 
    if (h->usb_dev)
        jtag_libusb_close(h->usb_dev);
 
    free(h->read_buffer);
    free(h->write_buffer);
    free(handle);
    return ERROR_OK;
}
 
static int icdi_usb_open(struct hl_interface_param *param, void **fd)
{
    /* TODO: Convert remaining libusb_ calls to jtag_libusb_ */
    int retval;
    struct icdi_usb_handle *h;
 
    LOG_DEBUG("icdi_usb_open");
 
    h = calloc(1, sizeof(struct icdi_usb_handle));
 
    if (!h) {
        LOG_ERROR("unable to allocate memory");
        return ERROR_FAIL;
    }
 
    for (uint8_t i = 0; param->vid[i] && param->pid[i]; ++i)
        LOG_DEBUG("transport: %d vid: 0x%04x pid: 0x%04x serial: %s", param->transport,
            param->vid[i], param->pid[i], adapter_get_required_serial() ? adapter_get_required_serial() : "");
 
    /* TI (Stellaris) ICDI provides its serial number in the USB descriptor;
       no need to provide a callback here. */
    jtag_libusb_open(param->vid, param->pid, NULL, &h->usb_dev, NULL);
 
    if (!h->usb_dev) {
        LOG_ERROR("open failed");
        goto error_open;
    }
 
    if (libusb_claim_interface(h->usb_dev, 2)) {
        LOG_DEBUG("claim interface failed");
        goto error_open;
    }
 
    /* check if mode is supported */
    retval = ERROR_OK;
 
    switch (param->transport) {
#if 0
        /* TODO place holder as swd is not currently supported */
        case HL_TRANSPORT_SWD:
#endif
        case HL_TRANSPORT_JTAG:
            break;
        default:
            retval = ERROR_FAIL;
            break;
    }
 
    if (retval != ERROR_OK) {
        LOG_ERROR("mode (transport) not supported by device");
        goto error_open;
    }
 
    /* allocate buffer */
    h->read_buffer = malloc(ICDI_PACKET_SIZE);
    h->write_buffer = malloc(ICDI_PACKET_SIZE);
    h->max_packet = ICDI_PACKET_SIZE;
 
    if (!h->read_buffer || !h->write_buffer) {
        LOG_DEBUG("malloc failed");
        goto error_open;
    }
 
    /* query icdi version etc */
    retval = icdi_usb_version(h);
    if (retval != ERROR_OK)
        goto error_open;
 
    /* query icdi support */
    retval = icdi_usb_query(h);
    if (retval != ERROR_OK)
        goto error_open;
 
    *fd = h;
 
    /* set the max target read/write buffer in bytes
     * as we are using gdb binary packets to transfer memory we have to
     * reserve half the buffer for any possible escape chars plus
     * at least 64 bytes for the gdb packet header */
    h->max_rw_packet = (((h->max_packet - 64) / 4) * 4) / 2;
 
    return ERROR_OK;
 
error_open:
    icdi_usb_close(h);
 
    return ERROR_FAIL;
}
 
struct hl_layout_api icdi_usb_layout_api = {
    .open = icdi_usb_open,
    .close = icdi_usb_close,
    .idcode = icdi_usb_idcode,
    .state = icdi_usb_state,
    .reset = icdi_usb_reset,
    .assert_srst = icdi_usb_assert_srst,
    .run = icdi_usb_run,
    .halt = icdi_usb_halt,
    .step = icdi_usb_step,
    .read_regs = icdi_usb_read_regs,
    .read_reg = icdi_usb_read_reg,
    .write_reg = icdi_usb_write_reg,
    .read_mem = icdi_usb_read_mem,
    .write_mem = icdi_usb_write_mem,
    .write_debug_reg = icdi_usb_write_debug_reg,
    .override_target = icdi_usb_override_target,
    .custom_command = icdi_send_remote_cmd,
};