[OpenOCD-devel] [PATCH]: 7d0e9a4 Get JTAG device serial string "raw".

[<ge...@op...>]

This is an automated email from Gerrit.

Kalle Raiskila (kra...@ik...) just uploaded a new patch set to Gerrit, which you can find at http://openocd.zylin.com/5129

-- gerrit

commit 7d0e9a47b380c9e3a7167680514458a5f989fa88
Author: Kalle Raiskila <kra...@ik...>
Date:   Mon Apr 22 15:13:39 2019 +0300

    Get JTAG device serial string "raw".
    
    This replaces using the utility function
    libusb_get_string_descriptor_ascii(), which mangles
    the string to 7-bit ASCII, causing problems on devices
    that use 8-bit serial data in their serial descriptor.
    
    The USB serial data still is 16 bit unicode in the devices, so
    we still discard half of it. But since that is how it has been
    done uptill this change, just continue ignoring the higher bytes.
    
    Change-Id: I81646baf2d0dc63578e6a9f947f5f644895c1361
    Signed-off-by: Kalle Raiskila <kra...@ik...>

diff --git a/src/jtag/drivers/libusb1_common.c b/src/jtag/drivers/libusb1_common.c
index d96ac76..dff4437 100644
--- a/src/jtag/drivers/libusb1_common.c
+++ b/src/jtag/drivers/libusb1_common.c
@@ -77,19 +77,43 @@ static bool string_descriptor_equal(libusb_device_handle *device, uint8_t str_in
 	int retval;
 	bool matched;
 	char desc_string[256+1]; /* Max size of string descriptor */
+	uint8_t tbuf[255];
+	uint16_t langid;
 
 	if (str_index == 0)
 		return false;
 
-	retval = libusb_get_string_descriptor_ascii(device, str_index,
-			(unsigned char *)desc_string, sizeof(desc_string)-1);
+
+	/* This replaces the old call to libusb_get_string_descriptor_ascii(), which would
+	 * mangle the reply to 7-bit ASCII, causing trouble on some (i.e. ST-Link) devices.
+	 * First, get the language codes the device has, then just use the first one.
+	 */
+	retval = libusb_get_string_descriptor(device, 0, 0, tbuf, sizeof(tbuf));
+	if (retval < 4) {
+		LOG_ERROR("Could not read language code descriptors from device");
+		return false;
+	}
+	langid = (uint16_t)(tbuf[2] | tbuf[3]<<8);
+	retval = libusb_get_string_descriptor(device, str_index, langid,
+		(unsigned char *)desc_string, sizeof(desc_string));
 	if (retval < 0) {
-		LOG_ERROR("libusb_get_string_descriptor_ascii() failed with %d", retval);
+		LOG_ERROR("libusb_get_string_descriptor() failed with %d", retval);
 		return false;
 	}
+	/* desc_string is now of the form: <size_in_bytes>, 3, 16-bit unicode characters...
+	 * Mangle this into a 8-bit character string, replacing any unicode character > 255
+	 * with '?'. This is how libusb_get_string_descriptor_ascii() did it.
+	 */
+	int desclen=desc_string[0];
+	int oi=0; /* Output index */
+	for(int i=2; i<desclen; i+=2)
+		if( desc_string[i+1] )
+			desc_string[oi++]='?';
+		else
+			desc_string[oi++]=desc_string[i];
 
 	/* Null terminate descriptor string in case it needs to be logged. */
-	desc_string[sizeof(desc_string)-1] = '\0';
+	desc_string[oi] = '\0';
 
 	matched = strncmp(string, desc_string, sizeof(desc_string)) == 0;
 	if (!matched)

--