If I call device_create with a existing class the device lands up in /sys/devices/virtual. Using device_add I could populate the parent of the device and leave the class empty or provide a class and get the device to be created in the parent directory. What exactly is the significance of the" /sys/devices/virtual" directory? Is this meant to carry devices of a specific type say something that is divorced from actual hardware? Secondly a device created under /sys/devices/virtual has a uevent file that is populated like this. -bash-4.2$ cat uevent MAJOR=13 MINOR=63 DEVNAME=input/mice -bash-4.2$ A device in a specific PCI slot has something like this instead.. -bash-4.2$ cat /sys/devices/pci0000:00/0000:00:02.2/0000:03:00.3/net/eth1/uevent INTERFACE=eth1 IFINDEX=3 How is this file populated? Is it done by udev or is this done via a kernel call? Thanks S