Hi, probably what you are saying is so important that solves my doubt about a my misunderstanding about USB protocol and my idea to use the usbdump is totally wrong and no more usefull.
Foundamentally my goal is only understand if, pluging a usb device, a direct writing operation can or not occur from the processor into the usb device. So, please, let me ask another question to exclude all my misunderstanding. You wrote: “A processor runs on the USB device replying to this protocol. There is no direct hardware access. You need to ask the manufacturer which USB request returns the counter you are asking for”. 1- If "there is no direct hardware access", this means that the processor can only do read-only accesses to the USB device. Is it correct ? yes/no: 2- Speaking of “which USB request returns the counter” do you mean that the counter increment occurs "internally" following a request of the processor, excluding a direct writing operation of the processor into the usb device ?. Is it correct ? yes/no: If so, your reply solves my limited knowledges of the usb protocol. Thanks in advance. Regards -----Messaggio originale----- Da: Hans Petter Selasky [mailto:h...@selasky.org] Inviato: martedì 20 marzo 2018 08:32 A: Vincenzo Di Salvo Oggetto: Re: R: usb's quirks ... how to sniff bios'es messages addressed to usb rom chip On 03/19/18 21:13, Vincenzo Di Salvo wrote: > Thanks. > > I have read the usbdump man page ... and I know that is wireshark is able to > sniff usb traffic. > > My problem is how to detect the bit that increment the counter (always that > the chip of the usb drive allows a such action). > Hi, I think you misunderstand what USB is. USB is a protocol. A processor runs on the USB device replying to this protocol. There is no direct hardware access. You need to ask the manufacturer which USB request returns the counter you are asking for. --HPS > Again: I kindly contact you to know if someone of the list has already done > this test, if he can address me on the right street among the numerous > informations shown by wireshark or usbdump. > > Tutorials weblink are appreciated (if they exist). > > Regards. > > Vincenzo. --- Questa email è stata esaminata alla ricerca di virus da AVG. http://www.avg.com _______________________________________________ freebsd-usb@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"
