On Mon, Mar 3, 2014 at 6:18 PM, Andreas Fritiofson <andreas.fritiof...@gmail.com> wrote: > > On Mon, Mar 3, 2014 at 10:20 AM, Xiaofan Chen <xiaof...@gmail.com> wrote: >> >> On Mon, Mar 3, 2014 at 3:41 PM, Andreas Fritiofson >> <andreas.fritiof...@gmail.com> wrote: >> > On Mon, Mar 3, 2014 at 2:17 AM, Xiaofan Chen <xiaof...@gmail.com> wrote: >> >> Usually that means your device does not have a unique serial number. >> >> If the device has a unique serial number, Windows will not need to >> >> re-install the driver for your device. >> > >> > That might explain it, good to know, thanks! Will start adding serial >> > numbers to all firmwares, I guess. Actually, the *same* serial number >> > for >> > all devices sounds like the best option to reduce the Windows driver >> > hassle... :P >> > >> >> You can not do that, using the same serial number is worse than >> without serial number. The USB Specification allows either >> no serial number or *unique* serial number. > > > Can you point to the section in the spec that say so? I can't find anything > like that.
Hmm, sorry I could not find the requirement in the spec either. I think it is a Windows requirement. http://msdn.microsoft.com/en-us/library/windows/hardware/dn423379(v=vs.85).aspx *********** The USB device descriptor's iSerialNumber field indicates whether the device has a serial number and where the number is stored, as follows: iSerialNumber == 0x00 : The USB device has no serial number. iSerialNumber != 0x00 : The USB device has a serial number. The value assigned to iSerialNumber is the serial number's string index. If the device has a serial number, the serial number must uniquely identify each instance of the same device. For example, if two device descriptors have identical values for the idVendor, idProduct, and bcdDevicefields, the iSerialNumber field must be different, to distinguish one device from the other. Plug and Play requires that every byte in a USB serial number be valid. If a single byte is invalid, Windows discards the serial number and treats the device as if it had no serial number. The following byte values are not valid for USB serial numbers: 0x2C. Values less than 0x20. Values greater than 0x7F. For additional details on the iSerialNumber value, see section 9.6.1 of the USB 2.0 Specification. ********** More info: some USB class specification does require unique serial number http://community.silabs.com/t5/8-Bit-Discussion/requirements-for-USB-serial-number/td-p/78051 -- Xiaofan ------------------------------------------------------------------------------ Subversion Kills Productivity. Get off Subversion & Make the Move to Perforce. With Perforce, you get hassle-free workflows. Merge that actually works. Faster operations. Version large binaries. Built-in WAN optimization and the freedom to use Git, Perforce or both. Make the move to Perforce. http://pubads.g.doubleclick.net/gampad/clk?id=122218951&iu=/4140/ostg.clktrk _______________________________________________ OpenOCD-devel mailing list OpenOCD-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openocd-devel
