OS Driver, BIOS Active Clause Samples

OS Driver, BIOS Active. By examining the contents of the HcControl register, the OS driver knows there is an active BIOS driver if the InterruptRouting bit is not set and the HostControllerFunctionalState is not USBRESET. If the HostControllerFunctionalState is USBOPERATIONAL, then the OS driver should proceed directly to the setup of the HC. Otherwise, the OS driver should set the HostControllerFunctionalState to USBRESUME and wait the minimum time specified in the USB Specification for assertion of resume on the USB before it proceeds to the setup of the HC.