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. Alan Stern -- 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
