stlink_usb: remove gcc-specific constant
[openocd.git] / src / jtag / drivers / stlink_usb.c
index 087e7bfbfa71a0a5f116148626c50d8957730c67..1f3fbe2cdc7d7112b7e729084979505e95910902 100644 (file)
@@ -2,6 +2,9 @@
  *   Copyright (C) 2011-2012 by Mathias Kuester                            *
  *   Mathias Kuester <kesmtp@freenet.de>                                   *
  *                                                                         *
+ *   Copyright (C) 2012 by Spencer Oliver                                  *
+ *   spen@spen-soft.co.uk                                                  *
+ *                                                                         *
  *   This code is based on https://github.com/texane/stlink                *
  *                                                                         *
  *   This program is free software; you can redistribute it and/or modify  *
@@ -17,7 +20,7 @@
  *   You should have received a copy of the GNU General Public License     *
  *   along with this program; if not, write to the                         *
  *   Free Software Foundation, Inc.,                                       *
- *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
+ *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.           *
  ***************************************************************************/
 
 #ifdef HAVE_CONFIG_H
 /* project specific includes */
 #include <helper/binarybuffer.h>
 #include <jtag/interface.h>
-#include <jtag/stlink/stlink_layout.h>
-#include <jtag/stlink/stlink_transport.h>
-#include <jtag/stlink/stlink_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_common.h"
 
-#define ENDPOINT_IN    0x80
-#define ENDPOINT_OUT   0x00
+#define ENDPOINT_IN  0x80
+#define ENDPOINT_OUT 0x00
 
-#define STLINK_RX_EP   (1|ENDPOINT_IN)
-#define STLINK_TX_EP   (2|ENDPOINT_OUT)
-#define STLINK_CMD_SIZE        (16)
-#define STLINK_TX_SIZE (4*128)
-#define STLINK_RX_SIZE (4*128)
+#define STLINK_NULL_EP     0
+#define STLINK_RX_EP       (1|ENDPOINT_IN)
+#define STLINK_TX_EP       (2|ENDPOINT_OUT)
+#define STLINK_TRACE_EP    (3|ENDPOINT_IN)
+#define STLINK_SG_SIZE     (31)
+#define STLINK_DATA_SIZE   (4*128)
+#define STLINK_CMD_SIZE_V2 (16)
+#define STLINK_CMD_SIZE_V1 (10)
 
 enum stlink_jtag_api_version {
-       STLINK_JTAG_API_V1 = 0,
+       STLINK_JTAG_API_V1 = 1,
        STLINK_JTAG_API_V2,
 };
 
@@ -67,85 +75,112 @@ struct stlink_usb_handle_s {
        /** */
        struct libusb_transfer *trans;
        /** */
-       uint8_t txbuf[STLINK_TX_SIZE];
+       uint8_t cmdbuf[STLINK_SG_SIZE];
+       /** */
+       uint8_t cmdidx;
        /** */
-       uint8_t rxbuf[STLINK_RX_SIZE];
+       uint8_t direction;
        /** */
-       enum stlink_transports transport;
+       uint8_t databuf[STLINK_DATA_SIZE];
+       /** */
+       enum hl_transports transport;
        /** */
        struct stlink_usb_version version;
        /** */
        uint16_t vid;
        /** */
        uint16_t pid;
-       /** */
-       uint32_t sg_tag;
        /** this is the currently used jtag api */
        enum stlink_jtag_api_version jtag_api;
+       /** */
+       struct {
+               /** whether SWO tracing is enabled or not */
+               bool enabled;
+               /** trace data destination file */
+               FILE *output_f;
+               /** trace module source clock (for prescaler) */
+               uint32_t source_hz;
+               /** trace module clock prescaler */
+               uint32_t prescale;
+       } trace;
 };
 
-#define STLINK_DEBUG_ERR_OK                    0x80
-#define STLINK_DEBUG_ERR_FAULT                 0x81
-#define STLINK_CORE_RUNNING                    0x80
-#define STLINK_CORE_HALTED                     0x81
-#define STLINK_CORE_STAT_UNKNOWN               -1
-
-#define STLINK_GET_VERSION                     0xF1
-#define STLINK_DEBUG_COMMAND                   0xF2
-#define STLINK_DFU_COMMAND                     0xF3
-#define STLINK_SWIM_COMMAND                    0xF4
-#define STLINK_GET_CURRENT_MODE                        0xF5
-
-#define STLINK_DEV_DFU_MODE                    0x00
-#define STLINK_DEV_MASS_MODE                   0x01
-#define STLINK_DEV_DEBUG_MODE                  0x02
-#define STLINK_DEV_SWIM_MODE                   0x03
-#define STLINK_DEV_BOOTLOADER_MODE             0x04
-#define STLINK_DEV_UNKNOWN_MODE                        -1
-
-#define STLINK_DFU_EXIT                                0x07
-
-#define STLINK_SWIM_ENTER                      0x00
-#define STLINK_SWIM_EXIT                       0x01
-
-#define STLINK_DEBUG_ENTER_JTAG                        0x00
-#define STLINK_DEBUG_GETSTATUS                 0x01
-#define STLINK_DEBUG_FORCEDEBUG                        0x02
-#define STLINK_DEBUG_APIV1_RESETSYS            0x03
-#define STLINK_DEBUG_APIV1_READALLREGS         0x04
-#define STLINK_DEBUG_APIV1_READREG             0x05
-#define STLINK_DEBUG_APIV1_WRITEREG            0x06
-#define STLINK_DEBUG_READMEM_32BIT             0x07
-#define STLINK_DEBUG_WRITEMEM_32BIT            0x08
-#define STLINK_DEBUG_RUNCORE                   0x09
-#define STLINK_DEBUG_STEPCORE                  0x0a
-#define STLINK_DEBUG_APIV1_SETFP               0x0b
-#define STLINK_DEBUG_READMEM_8BIT              0x0c
-#define STLINK_DEBUG_WRITEMEM_8BIT             0x0d
-#define STLINK_DEBUG_APIV1_CLEARFP             0x0e
-#define STLINK_DEBUG_APIV1_WRITEDEBUGREG       0x0f
-#define STLINK_DEBUG_APIV1_SETWATCHPOINT       0x10
-
-#define STLINK_DEBUG_ENTER_JTAG                        0x00
-#define STLINK_DEBUG_ENTER_SWD                 0xa3
-
-#define STLINK_DEBUG_APIV1_ENTER               0x20
-#define STLINK_DEBUG_EXIT                      0x21
-#define STLINK_DEBUG_READCOREID                        0x22
-
-#define STLINK_DEBUG_APIV2_ENTER               0x30
-#define STLINK_DEBUG_APIV2_READ_IDCODES                0x31
-#define STLINK_DEBUG_APIV2_RESETSYS            0x32
-#define STLINK_DEBUG_APIV2_READREG             0x33
-#define STLINK_DEBUG_APIV2_WRITEREG            0x34
-
-#define STLINK_DEBUG_APIV2_READALLREGS         0x3A
-
-#define STLINK_DEBUG_APIV2_DRIVE_NRST          0x3C
-
-#define STLINK_DEBUG_APIV2_DRIVE_NRST_LOW      0x00
-#define STLINK_DEBUG_APIV2_DRIVE_NRST_HIGH     0x01
-#define STLINK_DEBUG_APIV2_DRIVE_NRST_PULSE    0x02
+#define STLINK_DEBUG_ERR_OK            0x80
+#define STLINK_DEBUG_ERR_FAULT         0x81
+#define STLINK_SWD_AP_WAIT             0x10
+#define STLINK_SWD_DP_WAIT             0x14
+
+#define STLINK_CORE_RUNNING            0x80
+#define STLINK_CORE_HALTED             0x81
+#define STLINK_CORE_STAT_UNKNOWN       -1
+
+#define STLINK_GET_VERSION             0xF1
+#define STLINK_DEBUG_COMMAND           0xF2
+#define STLINK_DFU_COMMAND             0xF3
+#define STLINK_SWIM_COMMAND            0xF4
+#define STLINK_GET_CURRENT_MODE        0xF5
+#define STLINK_GET_TARGET_VOLTAGE      0xF7
+
+#define STLINK_DEV_DFU_MODE            0x00
+#define STLINK_DEV_MASS_MODE           0x01
+#define STLINK_DEV_DEBUG_MODE          0x02
+#define STLINK_DEV_SWIM_MODE           0x03
+#define STLINK_DEV_BOOTLOADER_MODE     0x04
+#define STLINK_DEV_UNKNOWN_MODE        -1
+
+#define STLINK_DFU_EXIT                0x07
+
+#define STLINK_SWIM_ENTER              0x00
+#define STLINK_SWIM_EXIT               0x01
+
+#define STLINK_DEBUG_ENTER_JTAG            0x00
+#define STLINK_DEBUG_GETSTATUS             0x01
+#define STLINK_DEBUG_FORCEDEBUG            0x02
+#define STLINK_DEBUG_APIV1_RESETSYS        0x03
+#define STLINK_DEBUG_APIV1_READALLREGS     0x04
+#define STLINK_DEBUG_APIV1_READREG         0x05
+#define STLINK_DEBUG_APIV1_WRITEREG        0x06
+#define STLINK_DEBUG_READMEM_32BIT         0x07
+#define STLINK_DEBUG_WRITEMEM_32BIT        0x08
+#define STLINK_DEBUG_RUNCORE               0x09
+#define STLINK_DEBUG_STEPCORE              0x0a
+#define STLINK_DEBUG_APIV1_SETFP           0x0b
+#define STLINK_DEBUG_READMEM_8BIT          0x0c
+#define STLINK_DEBUG_WRITEMEM_8BIT         0x0d
+#define STLINK_DEBUG_APIV1_CLEARFP         0x0e
+#define STLINK_DEBUG_APIV1_WRITEDEBUGREG   0x0f
+#define STLINK_DEBUG_APIV1_SETWATCHPOINT   0x10
+
+#define STLINK_DEBUG_ENTER_JTAG            0x00
+#define STLINK_DEBUG_ENTER_SWD             0xa3
+
+#define STLINK_DEBUG_APIV1_ENTER           0x20
+#define STLINK_DEBUG_EXIT                  0x21
+#define STLINK_DEBUG_READCOREID            0x22
+
+#define STLINK_DEBUG_APIV2_ENTER           0x30
+#define STLINK_DEBUG_APIV2_READ_IDCODES    0x31
+#define STLINK_DEBUG_APIV2_RESETSYS        0x32
+#define STLINK_DEBUG_APIV2_READREG         0x33
+#define STLINK_DEBUG_APIV2_WRITEREG        0x34
+#define STLINK_DEBUG_APIV2_WRITEDEBUGREG   0x35
+#define STLINK_DEBUG_APIV2_READDEBUGREG    0x36
+
+#define STLINK_DEBUG_APIV2_READALLREGS     0x3A
+#define STLINK_DEBUG_APIV2_GETLASTRWSTATUS 0x3B
+#define STLINK_DEBUG_APIV2_DRIVE_NRST      0x3C
+
+#define STLINK_DEBUG_APIV2_START_TRACE_RX  0x40
+#define STLINK_DEBUG_APIV2_STOP_TRACE_RX   0x41
+#define STLINK_DEBUG_APIV2_GET_TRACE_NB    0x42
+
+#define STLINK_DEBUG_APIV2_DRIVE_NRST_LOW   0x00
+#define STLINK_DEBUG_APIV2_DRIVE_NRST_HIGH  0x01
+#define STLINK_DEBUG_APIV2_DRIVE_NRST_PULSE 0x02
+
+#define STLINK_TRACE_SIZE               1024
+#define STLINK_TRACE_MAX_HZ             2000000
+#define STLINK_TRACE_MIN_VERSION        13
 
 /** */
 enum stlink_mode {
@@ -157,57 +192,48 @@ enum stlink_mode {
        STLINK_MODE_DEBUG_SWIM
 };
 
-/** */
-static void stlink_usb_recv_v1_create_cmd(char *b, int s, uint32_t tag, uint32_t rxsize,
-                       uint8_t flag, uint8_t lun, uint8_t length)
-{
-       int i = 0;
-
-       memset(b, 0x00, s);
+#define REQUEST_SENSE        0x03
+#define REQUEST_SENSE_LENGTH 18
 
-       /* fill the send buffer */
-       strcpy(b, "USBC");
-       i += 4;
-
-       buf_set_u32(b+i, 0, 32, tag);
-       i += 4;
-       buf_set_u32(b+i, 0, 32, rxsize);
-       i += 4;
-       b[i++] = flag;
-       b[i++] = lun;
-       b[i++] = length;
-}
+static void stlink_usb_init_buffer(void *handle, uint8_t direction, uint32_t size);
 
 /** */
-static int stlink_usb_recv_v1_mass_storage_cmd(void *handle, const uint8_t *txbuf, int txsize, uint8_t *rxbuf,
-                   int rxsize)
+static int stlink_usb_xfer_v1_get_status(void *handle)
 {
-       char sg_buffer[31];
        struct stlink_usb_handle_s *h;
 
        assert(handle != NULL);
 
        h = (struct stlink_usb_handle_s *)handle;
-       h->sg_tag = (h->sg_tag + 1) & 1;
 
-       stlink_usb_recv_v1_create_cmd(sg_buffer, 31, h->sg_tag, rxsize, STLINK_TX_EP, 0x00, txsize);
+       /* read status */
+       memset(h->cmdbuf, 0, STLINK_SG_SIZE);
+
+       if (jtag_libusb_bulk_read(h->fd, STLINK_RX_EP, (char *)h->cmdbuf,
+                               13, 1000) != 13)
+               return ERROR_FAIL;
 
-       memcpy(sg_buffer+15, txbuf, 10);
+       uint32_t t1;
 
-       if (jtag_libusb_bulk_write(h->fd, STLINK_TX_EP, (char *)sg_buffer, 31,
-                                  1000) != 31) {
-               printf("send failed\n");
+       t1 = buf_get_u32(h->cmdbuf, 0, 32);
+
+       /* check for USBS */
+       if (t1 != 0x53425355)
+               return ERROR_FAIL;
+       /*
+        * CSW status:
+        * 0 success
+        * 1 command failure
+        * 2 phase error
+        */
+       if (h->cmdbuf[12] != 0)
                return ERROR_FAIL;
-       }
 
        return ERROR_OK;
 }
 
-#define REQUEST_SENSE          0x03
-#define REQUEST_SENSE_LENGTH   18
-
 /** */
-static int stlink_usb_recv_v1_get_status(void *handle, char *sg_buffer, int len)
+static int stlink_usb_xfer_rw(void *handle, int cmdsize, const uint8_t *buf, int size)
 {
        struct stlink_usb_handle_s *h;
 
@@ -215,102 +241,92 @@ static int stlink_usb_recv_v1_get_status(void *handle, char *sg_buffer, int len)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       /* read status */
-       memset(sg_buffer, 0x00, len);
-
-       if (jtag_libusb_bulk_read(h->fd, STLINK_RX_EP, (char *)sg_buffer,
-                               len, 1000) != len)
+       if (jtag_libusb_bulk_write(h->fd, STLINK_TX_EP, (char *)h->cmdbuf, cmdsize,
+                                  1000) != cmdsize) {
                return ERROR_FAIL;
+       }
 
-       uint32_t t1, t2;
-
-       t1 = buf_get_u32(sg_buffer+0, 0, 32);
-       t2 = buf_get_u32(sg_buffer+4, 0, 32);
-
-       /* check for USBS */
-       if (t1 != 0x53425355)
-               return ERROR_FAIL;
+       if (h->direction == STLINK_TX_EP && size) {
+               if (jtag_libusb_bulk_write(h->fd, STLINK_TX_EP, (char *)buf,
+                                         size, 1000) != size) {
+                       LOG_DEBUG("bulk write failed");
+                       return ERROR_FAIL;
+               }
+       } else if (h->direction == STLINK_RX_EP && size) {
+               if (jtag_libusb_bulk_read(h->fd, STLINK_RX_EP, (char *)buf,
+                                         size, 1000) != size) {
+                       LOG_DEBUG("bulk read failed");
+                       return ERROR_FAIL;
+               }
+       }
 
        return ERROR_OK;
 }
 
 /** */
-static int stlink_usb_recv_v1_get_sense(void *handle)
+static int stlink_usb_xfer_v1_get_sense(void *handle)
 {
+       int res;
        struct stlink_usb_handle_s *h;
-       char cdb[16];
-       char sg_buffer[31];
 
        assert(handle != NULL);
 
        h = (struct stlink_usb_handle_s *)handle;
-       h->sg_tag = (h->sg_tag + 1) & 1;
 
-       cdb[0] = REQUEST_SENSE;
-       cdb[4] = REQUEST_SENSE_LENGTH;
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 16);
 
-       stlink_usb_recv_v1_create_cmd(sg_buffer, 31, h->sg_tag, REQUEST_SENSE_LENGTH, STLINK_TX_EP,
-                       0x00, 16);
+       h->cmdbuf[h->cmdidx++] = REQUEST_SENSE;
+       h->cmdbuf[h->cmdidx++] = 0;
+       h->cmdbuf[h->cmdidx++] = 0;
+       h->cmdbuf[h->cmdidx++] = 0;
+       h->cmdbuf[h->cmdidx++] = REQUEST_SENSE_LENGTH;
 
-       memcpy(sg_buffer+15, cdb, 16);
+       res = stlink_usb_xfer_rw(handle, REQUEST_SENSE_LENGTH, h->databuf, 16);
 
-       if (jtag_libusb_bulk_write(h->fd, STLINK_TX_EP, (char *)sg_buffer, 16,
-                                  1000) != 16)
-               return ERROR_FAIL;
-
-       if (jtag_libusb_bulk_read(h->fd, STLINK_RX_EP, (char *)cdb,
-                                 16, 1000) != 16)
-               return ERROR_FAIL;
+       if (res != ERROR_OK)
+               return res;
 
-       if (stlink_usb_recv_v1_get_status(handle, sg_buffer, 13) != ERROR_OK)
-               return ERROR_FAIL;
-       /* check for sense */
-       if (sg_buffer[12] != 0)
+       if (stlink_usb_xfer_v1_get_status(handle) != ERROR_OK)
                return ERROR_FAIL;
 
-       /* if (sense[0] != 0x70 && sense[0] != 0x71) */
-
        return ERROR_OK;
 }
 
 /** */
-static int stlink_usb_recv_v1(void *handle, const uint8_t *txbuf, int txsize, uint8_t *rxbuf,
-                   int rxsize)
+static int stlink_usb_xfer(void *handle, const uint8_t *buf, int size)
 {
-       int err;
-       char sg_buffer[31];
+       int err, cmdsize = STLINK_CMD_SIZE_V2;
        struct stlink_usb_handle_s *h;
 
        assert(handle != NULL);
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       err = stlink_usb_recv_v1_mass_storage_cmd(handle, txbuf, txsize, rxbuf, rxsize);
+       if (h->version.stlink == 1)
+               cmdsize = STLINK_SG_SIZE;
+
+       err = stlink_usb_xfer_rw(handle, cmdsize, buf, size);
 
        if (err != ERROR_OK)
                return err;
 
-       if (rxsize && rxbuf) {
-               if (jtag_libusb_bulk_read(h->fd, STLINK_RX_EP, (char *)rxbuf,
-                                         rxsize, 1000) != rxsize) {
-                       LOG_DEBUG("jtag_libusb_bulk_read");
+       if (h->version.stlink == 1) {
+               if (stlink_usb_xfer_v1_get_status(handle) != ERROR_OK) {
+                       /* check csw status */
+                       if (h->cmdbuf[12] == 1) {
+                               LOG_DEBUG("get sense");
+                               if (stlink_usb_xfer_v1_get_sense(handle) != ERROR_OK)
+                                       return ERROR_FAIL;
+                       }
                        return ERROR_FAIL;
                }
        }
 
-       if (stlink_usb_recv_v1_get_status(handle, sg_buffer, 13) != ERROR_OK)
-               return ERROR_FAIL;
-       /* check for sense */
-       if (sg_buffer[12] == 1) {
-               LOG_DEBUG("get sense");
-               err = stlink_usb_recv_v1_get_sense(handle);
-       }
-       return err;
+       return ERROR_OK;
 }
 
 /** */
-static int stlink_usb_recv_v2(void *handle, const uint8_t *txbuf, int txsize, uint8_t *rxbuf,
-                   int rxsize)
+static int stlink_usb_read_trace(void *handle, const uint8_t *buf, int size)
 {
        struct stlink_usb_handle_s *h;
 
@@ -318,56 +334,52 @@ static int stlink_usb_recv_v2(void *handle, const uint8_t *txbuf, int txsize, ui
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       if (jtag_libusb_bulk_write(h->fd, STLINK_TX_EP, (char *)txbuf, txsize,
-                                  1000) != txsize) {
+       assert(h->version.stlink >= 2);
+
+       if (jtag_libusb_bulk_read(h->fd, STLINK_TRACE_EP, (char *)buf,
+                               size, 1000) != size) {
+               LOG_ERROR("bulk trace read failed");
                return ERROR_FAIL;
        }
-       if (rxsize && rxbuf) {
-               if (jtag_libusb_bulk_read(h->fd, STLINK_RX_EP, (char *)rxbuf,
-                                         rxsize, 1000) != rxsize) {
-                       return ERROR_FAIL;
-               }
-       }
+
        return ERROR_OK;
 }
 
 /** */
-static int stlink_usb_recv(void *handle, const uint8_t *txbuf, int txsize, uint8_t *rxbuf,
-                   int rxsize)
+static void stlink_usb_xfer_v1_create_cmd(void *handle, uint8_t direction, uint32_t size)
 {
        struct stlink_usb_handle_s *h;
 
-       assert(handle != NULL);
-
        h = (struct stlink_usb_handle_s *)handle;
 
-       if (h->version.stlink == 1) {
-               return stlink_usb_recv_v1(handle, txbuf, txsize, rxbuf, rxsize);
-       } else {
-               if (txsize < STLINK_CMD_SIZE)
-                       txsize = STLINK_CMD_SIZE;
-               return stlink_usb_recv_v2(handle, txbuf, txsize, rxbuf, rxsize);
-       }
-}
-
-/** */
-static int stlink_usb_send(void *handle, const uint8_t *cmd, int cmdsize, uint8_t *txbuf,
-                   int txsize)
-{
-       return stlink_usb_xfer(handle, cmd, cmdsize, STLINK_TX_EP, txbuf, txsize);
+       /* fill the send buffer */
+       strcpy((char *)h->cmdbuf, "USBC");
+       h->cmdidx += 4;
+       /* csw tag not used */
+       h->cmdidx += 4;
+       buf_set_u32(h->cmdbuf+h->cmdidx, 0, 32, size);
+       h->cmdidx += 4;
+       h->cmdbuf[h->cmdidx++] = (direction == STLINK_RX_EP ? ENDPOINT_IN : ENDPOINT_OUT);
+       h->cmdbuf[h->cmdidx++] = 0; /* lun */
+       h->cmdbuf[h->cmdidx++] = STLINK_CMD_SIZE_V1;
 }
 
 /** */
-static void stlink_usb_init_buffer(void *handle)
+static void stlink_usb_init_buffer(void *handle, uint8_t direction, uint32_t size)
 {
        struct stlink_usb_handle_s *h;
 
-       assert(handle != NULL);
-
        h = (struct stlink_usb_handle_s *)handle;
 
-       memset(h->txbuf, 0, STLINK_TX_SIZE);
-       memset(h->rxbuf, 0, STLINK_RX_SIZE);
+       h->direction = direction;
+
+       h->cmdidx = 0;
+
+       memset(h->cmdbuf, 0, STLINK_SG_SIZE);
+       memset(h->databuf, 0, STLINK_DATA_SIZE);
+
+       if (h->version.stlink == 1)
+               stlink_usb_xfer_v1_create_cmd(handle, direction, size);
 }
 
 static const char * const stlink_usb_error_msg[] = {
@@ -387,9 +399,9 @@ static int stlink_usb_error_check(void *handle)
 
        /* TODO: no error checking yet on api V1 */
        if (h->jtag_api == STLINK_JTAG_API_V1)
-               h->rxbuf[0] = STLINK_DEBUG_ERR_OK;
+               h->databuf[0] = STLINK_DEBUG_ERR_OK;
 
-       switch (h->rxbuf[0]) {
+       switch (h->databuf[0]) {
                case STLINK_DEBUG_ERR_OK:
                        res = ERROR_OK;
                        break;
@@ -401,7 +413,7 @@ static int stlink_usb_error_check(void *handle)
        }
 
        if (res != ERROR_OK)
-               LOG_DEBUG("status error: %d ('%s')", h->rxbuf[0], err_msg);
+               LOG_DEBUG("status error: %d ('%s')", h->databuf[0], err_msg);
 
        return res;
 }
@@ -417,33 +429,32 @@ static int stlink_usb_version(void *handle)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 6);
 
-       h->txbuf[0] = STLINK_GET_VERSION;
+       h->cmdbuf[h->cmdidx++] = STLINK_GET_VERSION;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 6);
+       res = stlink_usb_xfer(handle, h->databuf, 6);
 
        if (res != ERROR_OK)
                return res;
 
-       v = (h->rxbuf[0] << 8) | h->rxbuf[1];
+       v = (h->databuf[0] << 8) | h->databuf[1];
 
        h->version.stlink = (v >> 12) & 0x0f;
        h->version.jtag = (v >> 6) & 0x3f;
        h->version.swim = v & 0x3f;
-       h->vid = buf_get_u32(h->rxbuf, 16, 16);
-       h->pid = buf_get_u32(h->rxbuf, 32, 16);
+       h->vid = buf_get_u32(h->databuf, 16, 16);
+       h->pid = buf_get_u32(h->databuf, 32, 16);
 
        /* set the supported jtag api version
-        * V1 doesn't support API V2 at all
-        * V2 support API V2 since JTAG V13
+        * API V2 is supported since JTAG V11
         */
-       if ((h->version.stlink == 2) && (h->version.jtag > 12))
+       if (h->version.jtag >= 11)
                h->version.jtag_api_max = STLINK_JTAG_API_V2;
        else
                h->version.jtag_api_max = STLINK_JTAG_API_V1;
 
-       LOG_DEBUG("STLINK v%d JTAG v%d API v%d SWIM v%d VID %04X PID %04X",
+       LOG_INFO("STLINK v%d JTAG v%d API v%d SWIM v%d VID 0x%04X PID 0x%04X",
                h->version.stlink,
                h->version.jtag,
                (h->version.jtag_api_max == STLINK_JTAG_API_V1) ? 1 : 2,
@@ -454,6 +465,40 @@ static int stlink_usb_version(void *handle)
        return ERROR_OK;
 }
 
+static int stlink_usb_check_voltage(void *handle, float *target_voltage)
+{
+       struct stlink_usb_handle_s *h;
+       uint32_t adc_results[2];
+
+       h = (struct stlink_usb_handle_s *)handle;
+
+       /* only supported by stlink/v2 and for firmware >= 13 */
+       if (h->version.stlink == 1 || h->version.jtag < 13)
+               return ERROR_COMMAND_NOTFOUND;
+
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 8);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_GET_TARGET_VOLTAGE;
+
+       int result = stlink_usb_xfer(handle, h->databuf, 8);
+
+       if (result != ERROR_OK)
+               return result;
+
+       /* convert result */
+       adc_results[0] = le_to_h_u32(h->databuf);
+       adc_results[1] = le_to_h_u32(h->databuf + 4);
+
+       *target_voltage = 0;
+
+       if (adc_results[0])
+               *target_voltage = 2 * ((float)adc_results[1]) * (float)(1.2 / adc_results[0]);
+
+       LOG_INFO("Target voltage: %f", (double)*target_voltage);
+
+       return ERROR_OK;
+}
+
 /** */
 static int stlink_usb_current_mode(void *handle, uint8_t *mode)
 {
@@ -464,16 +509,16 @@ static int stlink_usb_current_mode(void *handle, uint8_t *mode)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
 
-       h->txbuf[0] = STLINK_GET_CURRENT_MODE;
+       h->cmdbuf[h->cmdidx++] = STLINK_GET_CURRENT_MODE;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 2);
+       res = stlink_usb_xfer(handle, h->databuf, 2);
 
        if (res != ERROR_OK)
                return res;
 
-       *mode = h->rxbuf[0];
+       *mode = h->databuf[0];
 
        return ERROR_OK;
 }
@@ -489,28 +534,35 @@ static int stlink_usb_mode_enter(void *handle, enum stlink_mode type)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       /* on api V2 we are able the read the latest command
+        * status
+        * TODO: we need the test on api V1 too
+        */
+       if (h->jtag_api == STLINK_JTAG_API_V2)
+               rx_size = 2;
+
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, rx_size);
 
        switch (type) {
                case STLINK_MODE_DEBUG_JTAG:
-                       h->txbuf[0] = STLINK_DEBUG_COMMAND;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
                        if (h->jtag_api == STLINK_JTAG_API_V1)
-                               h->txbuf[1] = STLINK_DEBUG_APIV1_ENTER;
+                               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_ENTER;
                        else
-                               h->txbuf[1] = STLINK_DEBUG_APIV2_ENTER;
-                       h->txbuf[2] = STLINK_DEBUG_ENTER_JTAG;
+                               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_ENTER;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_ENTER_JTAG;
                        break;
                case STLINK_MODE_DEBUG_SWD:
-                       h->txbuf[0] = STLINK_DEBUG_COMMAND;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
                        if (h->jtag_api == STLINK_JTAG_API_V1)
-                               h->txbuf[1] = STLINK_DEBUG_APIV1_ENTER;
+                               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_ENTER;
                        else
-                               h->txbuf[1] = STLINK_DEBUG_APIV2_ENTER;
-                       h->txbuf[2] = STLINK_DEBUG_ENTER_SWD;
+                               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_ENTER;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_ENTER_SWD;
                        break;
                case STLINK_MODE_DEBUG_SWIM:
-                       h->txbuf[0] = STLINK_SWIM_COMMAND;
-                       h->txbuf[1] = STLINK_SWIM_ENTER;
+                       h->cmdbuf[h->cmdidx++] = STLINK_SWIM_COMMAND;
+                       h->cmdbuf[h->cmdidx++] = STLINK_SWIM_ENTER;
                        break;
                case STLINK_MODE_DFU:
                case STLINK_MODE_MASS:
@@ -518,14 +570,7 @@ static int stlink_usb_mode_enter(void *handle, enum stlink_mode type)
                        return ERROR_FAIL;
        }
 
-       /* on api V2 we are able the read the latest command
-        * status
-        * TODO: we need the test on api V1 too
-        */
-       if (h->jtag_api == STLINK_JTAG_API_V2)
-               rx_size = 2;
-
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, rx_size);
+       res = stlink_usb_xfer(handle, h->databuf, rx_size);
 
        if (res != ERROR_OK)
                return res;
@@ -545,28 +590,28 @@ static int stlink_usb_mode_leave(void *handle, enum stlink_mode type)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_NULL_EP, 0);
 
        switch (type) {
                case STLINK_MODE_DEBUG_JTAG:
                case STLINK_MODE_DEBUG_SWD:
-                       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-                       h->txbuf[1] = STLINK_DEBUG_EXIT;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_EXIT;
                        break;
                case STLINK_MODE_DEBUG_SWIM:
-                       h->txbuf[0] = STLINK_SWIM_COMMAND;
-                       h->txbuf[1] = STLINK_SWIM_EXIT;
+                       h->cmdbuf[h->cmdidx++] = STLINK_SWIM_COMMAND;
+                       h->cmdbuf[h->cmdidx++] = STLINK_SWIM_EXIT;
                        break;
                case STLINK_MODE_DFU:
-                       h->txbuf[0] = STLINK_DFU_COMMAND;
-                       h->txbuf[1] = STLINK_DFU_EXIT;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DFU_COMMAND;
+                       h->cmdbuf[h->cmdidx++] = STLINK_DFU_EXIT;
                        break;
                case STLINK_MODE_MASS:
                default:
                        return ERROR_FAIL;
        }
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, 0, 0);
+       res = stlink_usb_xfer(handle, 0, 0);
 
        if (res != ERROR_OK)
                return res;
@@ -574,8 +619,10 @@ static int stlink_usb_mode_leave(void *handle, enum stlink_mode type)
        return ERROR_OK;
 }
 
+static int stlink_usb_assert_srst(void *handle, int srst);
+
 /** */
-static int stlink_usb_init_mode(void *handle)
+static int stlink_usb_init_mode(void *handle, bool connect_under_reset)
 {
        int res;
        uint8_t mode;
@@ -591,7 +638,7 @@ static int stlink_usb_init_mode(void *handle)
        if (res != ERROR_OK)
                return res;
 
-       LOG_DEBUG("MODE: %02X", mode);
+       LOG_DEBUG("MODE: 0x%02X", mode);
 
        /* try to exit current mode */
        switch (mode) {
@@ -623,17 +670,40 @@ static int stlink_usb_init_mode(void *handle)
        if (res != ERROR_OK)
                return res;
 
-       LOG_DEBUG("MODE: %02X", mode);
+       /* we check the target voltage here as an aid to debugging connection problems.
+        * the stlink requires the target Vdd to be connected for reliable debugging.
+        * this cmd is supported in all modes except DFU
+        */
+       if (mode != STLINK_DEV_DFU_MODE) {
+
+               float target_voltage;
+
+               /* check target voltage (if supported) */
+               res = stlink_usb_check_voltage(h, &target_voltage);
+
+               if (res != ERROR_OK) {
+                       if (res != ERROR_COMMAND_NOTFOUND)
+                               LOG_ERROR("voltage check failed");
+                       /* attempt to continue as it is not a catastrophic failure */
+               } else {
+                       /* check for a sensible target voltage, operating range is 1.65-5.5v
+                        * according to datasheet */
+                       if (target_voltage < 1.5)
+                               LOG_ERROR("target voltage may be too low for reliable debugging");
+               }
+       }
+
+       LOG_DEBUG("MODE: 0x%02X", mode);
 
        /* set selected mode */
        switch (h->transport) {
-               case STLINK_TRANSPORT_SWD:
+               case HL_TRANSPORT_SWD:
                        emode = STLINK_MODE_DEBUG_SWD;
                        break;
-               case STLINK_TRANSPORT_JTAG:
+               case HL_TRANSPORT_JTAG:
                        emode = STLINK_MODE_DEBUG_JTAG;
                        break;
-               case STLINK_TRANSPORT_SWIM:
+               case HL_TRANSPORT_SWIM:
                        emode = STLINK_MODE_DEBUG_SWIM;
                        break;
                default:
@@ -646,6 +716,12 @@ static int stlink_usb_init_mode(void *handle)
                return ERROR_FAIL;
        }
 
+       if (connect_under_reset) {
+               res = stlink_usb_assert_srst(handle, 0);
+               if (res != ERROR_OK)
+                       return res;
+       }
+
        res = stlink_usb_mode_enter(handle, emode);
 
        if (res != ERROR_OK)
@@ -656,7 +732,7 @@ static int stlink_usb_init_mode(void *handle)
        if (res != ERROR_OK)
                return res;
 
-       LOG_DEBUG("MODE: %02X", mode);
+       LOG_DEBUG("MODE: 0x%02X", mode);
 
        return ERROR_OK;
 }
@@ -671,23 +747,133 @@ static int stlink_usb_idcode(void *handle, uint32_t *idcode)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 4);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-       h->txbuf[1] = STLINK_DEBUG_READCOREID;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_READCOREID;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 4);
+       res = stlink_usb_xfer(handle, h->databuf, 4);
 
        if (res != ERROR_OK)
                return res;
 
-       *idcode = le_to_h_u32(h->rxbuf);
+       *idcode = le_to_h_u32(h->databuf);
 
-       LOG_DEBUG("IDCODE: %08X", *idcode);
+       LOG_DEBUG("IDCODE: 0x%08X", *idcode);
 
        return ERROR_OK;
 }
 
+static int stlink_usb_v2_read_debug_reg(void *handle, uint32_t addr, uint32_t *val)
+{
+       struct stlink_usb_handle_s *h;
+       int res;
+
+       assert(handle != NULL);
+
+       h = (struct stlink_usb_handle_s *)handle;
+
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 8);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_READDEBUGREG;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, addr);
+       h->cmdidx += 4;
+
+       res = stlink_usb_xfer(handle, h->databuf, 8);
+
+       if (res != ERROR_OK)
+               return res;
+
+       *val = le_to_h_u32(h->databuf + 4);
+
+       return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL;
+}
+
+static int stlink_usb_write_debug_reg(void *handle, uint32_t addr, uint32_t val)
+{
+       int res;
+       struct stlink_usb_handle_s *h;
+
+       assert(handle != NULL);
+
+       h = (struct stlink_usb_handle_s *)handle;
+
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       if (h->jtag_api == STLINK_JTAG_API_V1)
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_WRITEDEBUGREG;
+       else
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_WRITEDEBUGREG;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, addr);
+       h->cmdidx += 4;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, val);
+       h->cmdidx += 4;
+
+       res = stlink_usb_xfer(handle, h->databuf, 2);
+
+       if (res != ERROR_OK)
+               return res;
+
+       return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL;
+}
+
+/** */
+static void stlink_usb_trace_read(void *handle)
+{
+       struct stlink_usb_handle_s *h;
+
+       assert(handle != NULL);
+
+       h = (struct stlink_usb_handle_s *)handle;
+
+       if (h->trace.enabled && h->version.jtag >= STLINK_TRACE_MIN_VERSION) {
+               int res;
+
+               stlink_usb_init_buffer(handle, STLINK_RX_EP, 10);
+
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_GET_TRACE_NB;
+
+               res = stlink_usb_xfer(handle, h->databuf, 2);
+               if (res == ERROR_OK) {
+                       uint8_t buf[STLINK_TRACE_SIZE];
+                       size_t size = le_to_h_u16(h->databuf);
+
+                       if (size > 0) {
+                               size = size < sizeof(buf) ? size : sizeof(buf) - 1;
+
+                               res = stlink_usb_read_trace(handle, buf, size);
+                               if (res == ERROR_OK) {
+                                       /* Log retrieved trace output */
+                                       if (fwrite(buf, 1, size, h->trace.output_f) > 0)
+                                               fflush(h->trace.output_f);
+                               }
+                       }
+               }
+       }
+}
+
+static enum target_state stlink_usb_v2_get_status(void *handle)
+{
+       int result;
+       uint32_t status;
+
+       result = stlink_usb_v2_read_debug_reg(handle, DCB_DHCSR, &status);
+       if  (result != ERROR_OK)
+               return TARGET_UNKNOWN;
+
+       if (status & S_HALT)
+               return TARGET_HALTED;
+       else if (status & S_RESET_ST)
+               return TARGET_RESET;
+
+       stlink_usb_trace_read(handle);
+
+       return TARGET_RUNNING;
+}
+
 /** */
 static enum target_state stlink_usb_state(void *handle)
 {
@@ -699,21 +885,21 @@ static enum target_state stlink_usb_state(void *handle)
        h = (struct stlink_usb_handle_s *)handle;
 
        if (h->jtag_api == STLINK_JTAG_API_V2)
-               return TARGET_UNKNOWN;
+               return stlink_usb_v2_get_status(handle);
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-       h->txbuf[1] = STLINK_DEBUG_GETSTATUS;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_GETSTATUS;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 2);
+       res = stlink_usb_xfer(handle, h->databuf, 2);
 
        if (res != ERROR_OK)
                return TARGET_UNKNOWN;
 
-       if (h->rxbuf[0] == STLINK_CORE_RUNNING)
+       if (h->databuf[0] == STLINK_CORE_RUNNING)
                return TARGET_RUNNING;
-       if (h->rxbuf[0] == STLINK_CORE_HALTED)
+       if (h->databuf[0] == STLINK_CORE_HALTED)
                return TARGET_HALTED;
 
        return TARGET_UNKNOWN;
@@ -729,23 +915,179 @@ static int stlink_usb_reset(void *handle)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
 
        if (h->jtag_api == STLINK_JTAG_API_V1)
-               h->txbuf[1] = STLINK_DEBUG_APIV1_RESETSYS;
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_RESETSYS;
        else
-               h->txbuf[1] = STLINK_DEBUG_APIV2_RESETSYS;
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_RESETSYS;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 2);
+       res = stlink_usb_xfer(handle, h->databuf, 2);
 
        if (res != ERROR_OK)
                return res;
 
-       LOG_DEBUG("RESET: %08X", h->rxbuf[0]);
+       LOG_DEBUG("RESET: 0x%08X", h->databuf[0]);
 
-       return ERROR_OK;
+       /* the following is not a error under swd (using hardware srst), so return success */
+       if (h->databuf[0] == STLINK_SWD_AP_WAIT || h->databuf[0] == STLINK_SWD_DP_WAIT)
+               return ERROR_OK;
+
+       return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL;
+}
+
+static int stlink_usb_assert_srst(void *handle, int srst)
+{
+       int res;
+       struct stlink_usb_handle_s *h;
+
+       assert(handle != NULL);
+
+       h = (struct stlink_usb_handle_s *)handle;
+
+       if (h->jtag_api == STLINK_JTAG_API_V1)
+               return ERROR_COMMAND_NOTFOUND;
+
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_DRIVE_NRST;
+       h->cmdbuf[h->cmdidx++] = srst;
+
+       res = stlink_usb_xfer(handle, h->databuf, 2);
+
+       if (res != ERROR_OK)
+               return res;
+
+       return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL;
+}
+
+/** */
+static int stlink_configure_target_trace_port(void *handle)
+{
+       int res;
+       uint32_t reg;
+       struct stlink_usb_handle_s *h;
+
+       assert(handle != NULL);
+
+       h = (struct stlink_usb_handle_s *)handle;
+
+       /* configure the TPI */
+
+       /* enable the trace subsystem */
+       res = stlink_usb_v2_read_debug_reg(handle, DCB_DEMCR, &reg);
+       if (res != ERROR_OK)
+               goto out;
+       res = stlink_usb_write_debug_reg(handle, DCB_DEMCR, TRCENA|reg);
+       if (res != ERROR_OK)
+               goto out;
+       /* set the TPI clock prescaler */
+       res = stlink_usb_write_debug_reg(handle, TPI_ACPR, h->trace.prescale);
+       if (res != ERROR_OK)
+               goto out;
+       /* select the pin protocol.  The STLinkv2 only supports asynchronous
+        * UART emulation (NRZ) mode, so that's what we pick. */
+       res = stlink_usb_write_debug_reg(handle, TPI_SPPR, 0x02);
+       if (res != ERROR_OK)
+               goto out;
+       /* disable continuous formatting */
+       res = stlink_usb_write_debug_reg(handle, TPI_FFCR, (1<<8));
+       if (res != ERROR_OK)
+               goto out;
+
+       /* configure the ITM */
+
+       /* unlock access to the ITM registers */
+       res = stlink_usb_write_debug_reg(handle, ITM_LAR, 0xC5ACCE55);
+       if (res != ERROR_OK)
+               goto out;
+       /* enable trace with ATB ID 1 */
+       res = stlink_usb_write_debug_reg(handle, ITM_TCR, (1<<16)|(1<<0)|(1<<2));
+       if (res != ERROR_OK)
+               goto out;
+       /* trace privilege */
+       res = stlink_usb_write_debug_reg(handle, ITM_TPR, 1);
+       if (res != ERROR_OK)
+               goto out;
+       /* trace port enable (port 0) */
+       res = stlink_usb_write_debug_reg(handle, ITM_TER, (1<<0));
+       if (res != ERROR_OK)
+               goto out;
+
+       res = ERROR_OK;
+out:
+       return res;
+}
+
+/** */
+static void stlink_usb_trace_disable(void *handle)
+{
+       int res = ERROR_OK;
+       struct stlink_usb_handle_s *h;
+
+       assert(handle != NULL);
+
+       h = (struct stlink_usb_handle_s *)handle;
+
+       assert(h->version.jtag >= STLINK_TRACE_MIN_VERSION);
+
+       LOG_DEBUG("Tracing: disable\n");
+
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_STOP_TRACE_RX;
+       res = stlink_usb_xfer(handle, h->databuf, 2);
+
+       if (res == ERROR_OK)
+               h->trace.enabled = false;
+}
+
+
+/** */
+static int stlink_usb_trace_enable(void *handle)
+{
+       int res;
+       struct stlink_usb_handle_s *h;
+
+       assert(handle != NULL);
+
+       h = (struct stlink_usb_handle_s *)handle;
+
+       if (h->version.jtag >= STLINK_TRACE_MIN_VERSION) {
+               uint32_t trace_hz;
+
+               res = stlink_configure_target_trace_port(handle);
+               if (res != ERROR_OK)
+                       LOG_ERROR("Unable to configure tracing on target\n");
+
+               trace_hz = h->trace.prescale > 0 ?
+                       h->trace.source_hz / (h->trace.prescale + 1) :
+                       h->trace.source_hz;
+
+               stlink_usb_init_buffer(handle, STLINK_RX_EP, 10);
+
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_START_TRACE_RX;
+               h_u16_to_le(h->cmdbuf+h->cmdidx, (uint16_t)STLINK_TRACE_SIZE);
+               h->cmdidx += 2;
+               h_u32_to_le(h->cmdbuf+h->cmdidx, trace_hz);
+               h->cmdidx += 4;
+
+               res = stlink_usb_xfer(handle, h->databuf, 2);
+
+               if (res == ERROR_OK)  {
+                       h->trace.enabled = true;
+                       LOG_DEBUG("Tracing: recording at %uHz\n", trace_hz);
+               }
+       } else {
+               LOG_ERROR("Tracing is not supported by this version.");
+               res = ERROR_FAIL;
+       }
+
+       return res;
 }
 
 /** */
@@ -758,20 +1100,31 @@ static int stlink_usb_run(void *handle)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       if (h->jtag_api == STLINK_JTAG_API_V2)
-               return ERROR_FAIL;
+       if (h->jtag_api == STLINK_JTAG_API_V2) {
+               res = stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_DEBUGEN);
+
+               /* Try to start tracing, if requested */
+               if (res == ERROR_OK && h->trace.output_f) {
+                       if (stlink_usb_trace_enable(handle) == ERROR_OK)
+                               LOG_DEBUG("Tracing: enabled\n");
+                       else
+                               LOG_ERROR("Tracing: enable failed\n");
+               }
 
-       stlink_usb_init_buffer(handle);
+               return res;
+       }
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-       h->txbuf[1] = STLINK_DEBUG_RUNCORE;
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 2);
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_RUNCORE;
+
+       res = stlink_usb_xfer(handle, h->databuf, 2);
 
        if (res != ERROR_OK)
                return res;
 
-       return ERROR_OK;
+       return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL;
 }
 
 /** */
@@ -784,20 +1137,26 @@ static int stlink_usb_halt(void *handle)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       if (h->jtag_api == STLINK_JTAG_API_V2)
-               return ERROR_FAIL;
+       if (h->jtag_api == STLINK_JTAG_API_V2) {
+               res = stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_HALT|C_DEBUGEN);
 
-       stlink_usb_init_buffer(handle);
+               if (res == ERROR_OK && h->trace.enabled)
+                       stlink_usb_trace_disable(handle);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-       h->txbuf[1] = STLINK_DEBUG_FORCEDEBUG;
+               return res;
+       }
+
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_FORCEDEBUG;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 2);
+       res = stlink_usb_xfer(handle, h->databuf, 2);
 
        if (res != ERROR_OK)
                return res;
 
-       return ERROR_OK;
+       return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL;
 }
 
 /** */
@@ -810,20 +1169,25 @@ static int stlink_usb_step(void *handle)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       if (h->jtag_api == STLINK_JTAG_API_V2)
-               return ERROR_FAIL;
+       if (h->jtag_api == STLINK_JTAG_API_V2) {
+               /* TODO: this emulates the v1 api, it should really use a similar auto mask isr
+                * that the cortex-m3 currently does. */
+               stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_HALT|C_MASKINTS|C_DEBUGEN);
+               stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_STEP|C_MASKINTS|C_DEBUGEN);
+               return stlink_usb_write_debug_reg(handle, DCB_DHCSR, DBGKEY|C_HALT|C_DEBUGEN);
+       }
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-       h->txbuf[1] = STLINK_DEBUG_STEPCORE;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_STEPCORE;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 2);
+       res = stlink_usb_xfer(handle, h->databuf, 2);
 
        if (res != ERROR_OK)
                return res;
 
-       return ERROR_OK;
+       return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL;
 }
 
 /** */
@@ -836,15 +1200,15 @@ static int stlink_usb_read_regs(void *handle)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 84);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
        if (h->jtag_api == STLINK_JTAG_API_V1)
-               h->txbuf[1] = STLINK_DEBUG_APIV1_READALLREGS;
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_READALLREGS;
        else
-               h->txbuf[1] = STLINK_DEBUG_APIV2_READALLREGS;
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_READALLREGS;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 84);
+       res = stlink_usb_xfer(handle, h->databuf, 84);
 
        if (res != ERROR_OK)
                return res;
@@ -862,21 +1226,26 @@ static int stlink_usb_read_reg(void *handle, int num, uint32_t *val)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, h->jtag_api == STLINK_JTAG_API_V1 ? 4 : 8);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
        if (h->jtag_api == STLINK_JTAG_API_V1)
-               h->txbuf[1] = STLINK_DEBUG_APIV1_READREG;
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_READREG;
        else
-               h->txbuf[1] = STLINK_DEBUG_APIV2_READREG;
-       h->txbuf[2] = num;
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_READREG;
+       h->cmdbuf[h->cmdidx++] = num;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 4);
+       res = stlink_usb_xfer(handle, h->databuf, h->jtag_api == STLINK_JTAG_API_V1 ? 4 : 8);
 
        if (res != ERROR_OK)
                return res;
 
-       *val = le_to_h_u32(h->rxbuf);
+       if (h->jtag_api == STLINK_JTAG_API_V1)
+               *val = le_to_h_u32(h->databuf);
+       else {
+               *val = le_to_h_u32(h->databuf + 4);
+               return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL;
+       }
 
        return ERROR_OK;
 }
@@ -891,22 +1260,48 @@ static int stlink_usb_write_reg(void *handle, int num, uint32_t val)
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
        if (h->jtag_api == STLINK_JTAG_API_V1)
-               h->txbuf[1] = STLINK_DEBUG_APIV1_WRITEREG;
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV1_WRITEREG;
        else
-               h->txbuf[1] = STLINK_DEBUG_APIV2_WRITEREG;
-       h->txbuf[2] = num;
-       h_u32_to_le(h->txbuf + 3, val);
+               h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_WRITEREG;
+       h->cmdbuf[h->cmdidx++] = num;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, val);
+       h->cmdidx += 4;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, 2);
+       res = stlink_usb_xfer(handle, h->databuf, 2);
 
        if (res != ERROR_OK)
                return res;
 
-       return ERROR_OK;
+       return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : ERROR_FAIL;
+}
+
+static int stlink_usb_get_rw_status(void *handle)
+{
+       int res;
+       struct stlink_usb_handle_s *h;
+
+       assert(handle != NULL);
+
+       h = (struct stlink_usb_handle_s *)handle;
+
+       if (h->jtag_api == STLINK_JTAG_API_V1)
+               return ERROR_OK;
+
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, 2);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_APIV2_GETLASTRWSTATUS;
+
+       res = stlink_usb_xfer(handle, h->databuf, 2);
+
+       if (res != ERROR_OK)
+               return res;
+
+       return h->databuf[0] == STLINK_DEBUG_ERR_OK ? ERROR_OK : res;
 }
 
 /** */
@@ -921,25 +1316,27 @@ static int stlink_usb_read_mem8(void *handle, uint32_t addr, uint16_t len,
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, read_len);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-       h->txbuf[1] = STLINK_DEBUG_READMEM_8BIT;
-       h_u32_to_le(h->txbuf + 2, addr);
-       h_u16_to_le(h->txbuf + 2 + 4, len);
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_READMEM_8BIT;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, addr);
+       h->cmdidx += 4;
+       h_u16_to_le(h->cmdbuf+h->cmdidx, len);
+       h->cmdidx += 2;
 
        /* we need to fix read length for single bytes */
        if (read_len == 1)
                read_len++;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, read_len);
+       res = stlink_usb_xfer(handle, h->databuf, read_len);
 
        if (res != ERROR_OK)
                return res;
 
-       memcpy(buffer, h->rxbuf, len);
+       memcpy(buffer, h->databuf, len);
 
-       return ERROR_OK;
+       return stlink_usb_get_rw_status(handle);
 }
 
 /** */
@@ -953,24 +1350,26 @@ static int stlink_usb_write_mem8(void *handle, uint32_t addr, uint16_t len,
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
+       stlink_usb_init_buffer(handle, STLINK_TX_EP, len);
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-       h->txbuf[1] = STLINK_DEBUG_WRITEMEM_8BIT;
-       h_u32_to_le(h->txbuf + 2, addr);
-       h_u16_to_le(h->txbuf + 2 + 4, len);
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_WRITEMEM_8BIT;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, addr);
+       h->cmdidx += 4;
+       h_u16_to_le(h->cmdbuf+h->cmdidx, len);
+       h->cmdidx += 2;
 
-       res = stlink_usb_send(handle, h->txbuf, STLINK_CMD_SIZE, (uint8_t *) buffer, len);
+       res = stlink_usb_xfer(handle, buffer, len);
 
        if (res != ERROR_OK)
                return res;
 
-       return ERROR_OK;
+       return stlink_usb_get_rw_status(handle);
 }
 
 /** */
 static int stlink_usb_read_mem32(void *handle, uint32_t addr, uint16_t len,
-                         uint32_t *buffer)
+                         uint8_t *buffer)
 {
        int res;
        struct stlink_usb_handle_s *h;
@@ -979,28 +1378,30 @@ static int stlink_usb_read_mem32(void *handle, uint32_t addr, uint16_t len,
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
-
        len *= 4;
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-       h->txbuf[1] = STLINK_DEBUG_READMEM_32BIT;
-       h_u32_to_le(h->txbuf + 2, addr);
-       h_u16_to_le(h->txbuf + 2 + 4, len);
+       stlink_usb_init_buffer(handle, STLINK_RX_EP, len);
+
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_READMEM_32BIT;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, addr);
+       h->cmdidx += 4;
+       h_u16_to_le(h->cmdbuf+h->cmdidx, len);
+       h->cmdidx += 2;
 
-       res = stlink_usb_recv(handle, h->txbuf, STLINK_CMD_SIZE, h->rxbuf, len);
+       res = stlink_usb_xfer(handle, h->databuf, len);
 
        if (res != ERROR_OK)
                return res;
 
-       memcpy(buffer, h->rxbuf, len);
+       memcpy(buffer, h->databuf, len);
 
-       return ERROR_OK;
+       return stlink_usb_get_rw_status(handle);
 }
 
 /** */
 static int stlink_usb_write_mem32(void *handle, uint32_t addr, uint16_t len,
-                          const uint32_t *buffer)
+                          const uint8_t *buffer)
 {
        int res;
        struct stlink_usb_handle_s *h;
@@ -1009,32 +1410,50 @@ static int stlink_usb_write_mem32(void *handle, uint32_t addr, uint16_t len,
 
        h = (struct stlink_usb_handle_s *)handle;
 
-       stlink_usb_init_buffer(handle);
-
        len *= 4;
 
-       h->txbuf[0] = STLINK_DEBUG_COMMAND;
-       h->txbuf[1] = STLINK_DEBUG_WRITEMEM_32BIT;
-       h_u32_to_le(h->txbuf + 2, addr);
-       h_u16_to_le(h->txbuf + 2 + 4, len);
+       stlink_usb_init_buffer(handle, STLINK_TX_EP, len);
 
-       res = stlink_usb_send(handle, h->txbuf, STLINK_CMD_SIZE, (uint8_t *) buffer, len);
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_COMMAND;
+       h->cmdbuf[h->cmdidx++] = STLINK_DEBUG_WRITEMEM_32BIT;
+       h_u32_to_le(h->cmdbuf+h->cmdidx, addr);
+       h->cmdidx += 4;
+       h_u16_to_le(h->cmdbuf+h->cmdidx, len);
+       h->cmdidx += 2;
+
+       res = stlink_usb_xfer(handle, buffer, len);
 
        if (res != ERROR_OK)
                return res;
 
+       return stlink_usb_get_rw_status(handle);
+}
+
+/** */
+static int stlink_usb_close(void *fd)
+{
+       struct stlink_usb_handle_s *h;
+
+       h = (struct stlink_usb_handle_s *)fd;
+
+       if (h->fd)
+               jtag_libusb_close(h->fd);
+
+       free(fd);
+
        return ERROR_OK;
 }
 
 /** */
-static int stlink_usb_open(struct stlink_interface_param_s *param, void **fd)
+static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
 {
        int err;
        struct stlink_usb_handle_s *h;
+       enum stlink_jtag_api_version api;
 
        LOG_DEBUG("stlink_usb_open");
 
-       h = malloc(sizeof(struct stlink_usb_handle_s));
+       h = calloc(1, sizeof(struct stlink_usb_handle_s));
 
        if (h == 0) {
                LOG_DEBUG("malloc failed");
@@ -1043,22 +1462,25 @@ static int stlink_usb_open(struct stlink_interface_param_s *param, void **fd)
 
        h->transport = param->transport;
 
+       /* set max read/write buffer size in bytes */
+       param->max_buffer = 512;
+
        const uint16_t vids[] = { param->vid, 0 };
        const uint16_t pids[] = { param->pid, 0 };
 
-       LOG_DEBUG("transport: %d vid: %04x pid: %04x", param->transport,
+       LOG_DEBUG("transport: %d vid: 0x%04x pid: 0x%04x", param->transport,
                param->vid, param->pid);
 
        if (jtag_libusb_open(vids, pids, &h->fd) != ERROR_OK) {
                LOG_ERROR("open failed");
-               return ERROR_FAIL;
+               goto error_open;
        }
 
        jtag_libusb_set_configuration(h->fd, 0);
 
        if (jtag_libusb_claim_interface(h->fd, 0) != ERROR_OK) {
                LOG_DEBUG("claim interface failed");
-               return ERROR_FAIL;
+               goto error_open;
        }
 
        /* wrap version for first read */
@@ -1076,14 +1498,12 @@ static int stlink_usb_open(struct stlink_interface_param_s *param, void **fd)
 
        if (err != ERROR_OK) {
                LOG_ERROR("read version failed");
-               jtag_libusb_close(h->fd);
-               free(h);
-               return err;
+               goto error_open;
        }
 
        /* compare usb vid/pid */
        if ((param->vid != h->vid) || (param->pid != h->pid))
-               LOG_INFO("vid/pid are not identical: %04X/%04X %04X/%04X",
+               LOG_INFO("vid/pid are not identical: 0x%04X/0x%04X 0x%04X/0x%04X",
                        param->vid, param->pid,
                        h->vid, h->pid);
 
@@ -1091,12 +1511,12 @@ static int stlink_usb_open(struct stlink_interface_param_s *param, void **fd)
        err = ERROR_OK;
 
        switch (h->transport) {
-               case STLINK_TRANSPORT_SWD:
-               case STLINK_TRANSPORT_JTAG:
+               case HL_TRANSPORT_SWD:
+               case HL_TRANSPORT_JTAG:
                        if (h->version.jtag == 0)
                                err = ERROR_FAIL;
                        break;
-               case STLINK_TRANSPORT_SWIM:
+               case HL_TRANSPORT_SWIM:
                        if (h->version.swim == 0)
                                err = ERROR_FAIL;
                        break;
@@ -1107,37 +1527,52 @@ static int stlink_usb_open(struct stlink_interface_param_s *param, void **fd)
 
        if (err != ERROR_OK) {
                LOG_ERROR("mode (transport) not supported by device");
-               jtag_libusb_close(h->fd);
-               free(h);
-               return err;
+               goto error_open;
        }
 
-       /* set the used jtag api */
-       h->jtag_api = STLINK_JTAG_API_V1;
+       api = h->version.jtag_api_max;
+
+       /* check that user has not requested certain api version
+        * and if they have check it is supported */
+       if ((param->api != 0) && (param->api <= h->version.jtag_api_max)) {
+               api = param->api;
+               LOG_INFO("using stlink api v%d", api);
+       }
+
+       /* set the used jtag api, this will default to the newest supported version */
+       h->jtag_api = api;
+
+       if (h->jtag_api >= 2 && param->trace_f && param->trace_source_hz > 0) {
+               uint32_t prescale;
+
+               prescale = param->trace_source_hz > STLINK_TRACE_MAX_HZ ?
+                       (param->trace_source_hz / STLINK_TRACE_MAX_HZ) - 1 : 0;
+
+               h->trace.output_f = param->trace_f;
+               h->trace.source_hz = param->trace_source_hz;
+               h->trace.prescale = prescale;
+       }
 
        /* initialize the debug hardware */
-       err = stlink_usb_init_mode(h);
+       err = stlink_usb_init_mode(h, param->connect_under_reset);
 
        if (err != ERROR_OK) {
                LOG_ERROR("init mode failed");
-               jtag_libusb_close(h->fd);
-               free(h);
-               return err;
+               goto error_open;
        }
 
        *fd = h;
 
        return ERROR_OK;
-}
 
-/** */
-static int stlink_usb_close(void *fd)
-{
-       return ERROR_OK;
+error_open:
+       stlink_usb_close(h);
+
+       return ERROR_FAIL;
 }
 
 /** */
-struct stlink_layout_api_s stlink_usb_layout_api = {
+struct hl_layout_api_s stlink_usb_layout_api = {
        /** */
        .open = stlink_usb_open,
        /** */
@@ -1149,6 +1584,8 @@ struct stlink_layout_api_s stlink_usb_layout_api = {
        /** */
        .reset = stlink_usb_reset,
        /** */
+       .assert_srst = stlink_usb_assert_srst,
+       /** */
        .run = stlink_usb_run,
        /** */
        .halt = stlink_usb_halt,
@@ -1168,4 +1605,6 @@ struct stlink_layout_api_s stlink_usb_layout_api = {
        .read_mem32 = stlink_usb_read_mem32,
        /** */
        .write_mem32 = stlink_usb_write_mem32,
+       /** */
+       .write_debug_reg = stlink_usb_write_debug_reg
 };

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