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stlink: workaround serial bug with old ST-Link DFU 

Old ST-LINK DFU returns an incorrect serial in the USB descriptor
 example for the following serial "57FF72067265575742132067"
  - the correct descriptor serial is:
    0x32, 0x03, 0x35, 0x00, 0x37, 0x00, 0x46, 0x00, 0x46, 0x00 ...
    this contains the length (0x32 = 50), the type (0x3 = DT_STRING)
    and the serial in unicode format.
    the serial part is: 0x0035, 0x0037, 0x0046, 0x0046 ... >>  57FF ...
    this format could be read correctly by 'libusb_get_string_descriptor_ascii'
    so this case is managed by libusb_helper::string_descriptor_equal
  - the buggy DFU is not doing any unicode conversion and returns a raw
    serial data in the descriptor:
    0x1a, 0x03, 0x57, 0x00, 0xFF, 0x00, 0x72, 0x00 ...
            >>    57          FF          72       ...
    based on the length (0x1a = 26) we could easily decide if we have to fixup the serial
    and then we have just to convert the raw data into printable characters using sprintf

example for an old ST-LINK/V2 standalone:
  before : 'W?rreWWB g'
  after  : '57FF72067265575742132067'
  => same as the displayed value in STM32CubeProgrammer

tested using these commands
  using the buggy serial
    -c "hla_serial \x57\x3f\x72\x06\x72\x65\x57\x57\x42\x13\x20\x67"
  using the computed serial
    -c "hla_serial 57FF72067265575742132067"

Change-Id: I1213818257663eeb8e76f419087d3127d0524842
Signed-off-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>
Reviewed-on: http://openocd.zylin.com/5396
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
This commit is contained in:
Tarek BOCHKATI 2020-03-07 17:20:24 +01:00 committed by Oleksij Rempel
parent 6ecccc8895
commit 4b4389a2d6
1 changed files with 82 additions and 1 deletions
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83
src/jtag/drivers/stlink_usb.c
View File

@ -47,6 +47,8 @@
#define USE_LIBUSB_ASYNCIO
#endif
#define STLINK_SERIAL_LEN 24
#define ENDPOINT_IN 0x80
#define ENDPOINT_OUT 0x00
@ -2745,6 +2747,85 @@ static int stlink_usb_close(void *handle)
return ERROR_OK;
}
/* Compute ST-Link serial number from the device descriptor
* this function will help to work-around a bug in old ST-Link/V2 DFU
* the buggy DFU returns an incorrect serial in the USB descriptor
* example for the following serial "57FF72067265575742132067"
* - the correct descriptor serial is:
* 0x32, 0x03, 0x35, 0x00, 0x37, 0x00, 0x46, 0x00, 0x46, 0x00, 0x37, 0x00, 0x32, 0x00 ...
* this contains the length (0x32 = 50), the type (0x3 = DT_STRING) and the serial in unicode format
* the serial part is: 0x0035, 0x0037, 0x0046, 0x0046, 0x0037, 0x0032 ... >> 57FF72 ...
* this format could be read correctly by 'libusb_get_string_descriptor_ascii'
* so this case is managed by libusb_helper::string_descriptor_equal
* - the buggy DFU is not doing any unicode conversion and returns a raw serial data in the descriptor
* 0x1a, 0x03, 0x57, 0x00, 0xFF, 0x00, 0x72, 0x00 ...
* >> 57 FF 72 ...
* based on the length (0x1a = 26) we could easily decide if we have to fixup the serial
* and then we have just to convert the raw data into printable characters using sprintf
*/
char *stlink_usb_get_alternate_serial(libusb_device_handle *device,
struct libusb_device_descriptor *dev_desc)
{
int usb_retval;
unsigned char desc_serial[(STLINK_SERIAL_LEN + 1) * 2];
if (dev_desc->iSerialNumber == 0)
return NULL;
/* get the LANGID from String Descriptor Zero */
usb_retval = libusb_get_string_descriptor(device, 0, 0, desc_serial,
sizeof(desc_serial));
if (usb_retval < LIBUSB_SUCCESS) {
LOG_ERROR("libusb_get_string_descriptor() failed: %s(%d)",
libusb_error_name(usb_retval), usb_retval);
return NULL;
} else if (usb_retval < 4) {
/* the size should be least 4 bytes to contain a minimum of 1 supported LANGID */
LOG_ERROR("could not get the LANGID");
return NULL;
}
uint32_t langid = desc_serial[2] | (desc_serial[3] << 8);
/* get the serial */
usb_retval = libusb_get_string_descriptor(device, dev_desc->iSerialNumber,
langid, desc_serial, sizeof(desc_serial));
unsigned char len = desc_serial[0];
if (usb_retval < LIBUSB_SUCCESS) {
LOG_ERROR("libusb_get_string_descriptor() failed: %s(%d)",
libusb_error_name(usb_retval), usb_retval);
return NULL;
} else if (desc_serial[1] != LIBUSB_DT_STRING || len > usb_retval) {
LOG_ERROR("invalid string in ST-LINK USB serial descriptor");
return NULL;
}
if (len == ((STLINK_SERIAL_LEN + 1) * 2)) {
/* good ST-Link adapter, this case is managed by
* libusb::libusb_get_string_descriptor_ascii */
return NULL;
} else if (len != ((STLINK_SERIAL_LEN / 2 + 1) * 2)) {
LOG_ERROR("unexpected serial length (%d) in descriptor", len);
return NULL;
}
/* else (len == 26) => buggy ST-Link */
char *alternate_serial = malloc((STLINK_SERIAL_LEN + 1) * sizeof(char));
if (alternate_serial == NULL)
return NULL;
for (unsigned int i = 0; i < STLINK_SERIAL_LEN; i += 2)
sprintf(alternate_serial + i, "%02X", desc_serial[i + 2]);
alternate_serial[STLINK_SERIAL_LEN] = '\0';
return alternate_serial;
}
/** */
static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
{
@ -2779,7 +2860,7 @@ static int stlink_usb_open(struct hl_interface_param_s *param, void **fd)
*/
do {
if (jtag_libusb_open(param->vid, param->pid, param->serial,
&h->fd, NULL) != ERROR_OK) {
&h->fd, stlink_usb_get_alternate_serial) != ERROR_OK) {
LOG_ERROR("open failed");
goto error_open;
}