Why do the virtual root hubs for XHCI and EHCI have bProtocol set to 0? https://github.com/aros-development-team/AROS/blob/master/rom/usb/pciusbhc/xhci/pcixhci_commands.c#L150 According to the USB spec, a value of 0 there means that the hub only supports full speed and low speed.