Hi Alan, Alan Stern wrote: > On Sun, 4 Jan 2009, [ISO-8859-2] Németh Márton wrote: > >> I wonder if a software "USB loopback device" driver already exists, >> similar to the "lo" device in networking. > > Yes; the dummy_hcd driver acts very similar to a network loopback > interface. However USB is different from networking, because the two > ends of a connection are not symmetrical. USB works with a hosts and > devices, and dummy_hcd creates a virtual host controller together with > a virtual device controller. See > > http://www.linux-usb.org/gadget/ > > for more information. > >> This device would show up >> as a USB hardware device when it is asked to do so from the user >> space. Then the user space "simulator" would receive all USB packets >> which would normally be sent to the USB device and the "simulator" >> could react and send USB packets in the other direction. > > The "userspace simulator" is implemented by a separate driver called > gadgetfs. There is a sample userspace program to control it available > on the page mentioned above. Thanks for the hint, this looks like the closest what I was searching for. Regards, Márton Németh -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
