Disks are attached to particular bus types:
type spec = bus_type * int * intA specification for a device number. There are more valid specifications than valid device numbers because of hardware and/or protocol limits.
make spec validates a given device number specification spec and returns a device number
val of_string : bool -> string -> tof_string hvm name returns the interface which best matches the name by applying the policy: first check if it is a disk_number, else fall back to a linux_device for backwards compatability
val to_debug_string : t -> stringto_debug_string i returns a pretty-printed interface
val to_linux_device : t -> stringto_linux_device i returns a possible linux string representation of interface i
val of_linux_device : string -> tof_linux_device x returns the interface corresponding to string x
val to_xenstore_key : t -> xenstore_keyto_xenstore_key i returns the xenstore key from interface i
val of_xenstore_key : xenstore_key -> tof_xenstore_key key returns an interface from a xenstore key
val to_disk_number : t -> disk_numberto_disk_number i returns the corresponding non-negative disk number
val of_disk_number : bool -> disk_number -> tof_disk_number hvm n returns the interface corresponding to disk number n which depends on whether the guest is hvm or not.