This book belongs to series FYSOS, about creating own operating system.
Learn to program the four major USB
controllers, UHCI, OHCI, EHCI, and the new xHCI, and communicate with
devices attached to their root hubs, without operating system
intervention. This book teachs you how to communicate with the bare
hardware to request the device descriptors and then send and received
data from various USB devices including USB external Hubs.