Oracle Solaris Modular Debugger Guide Kernel Debugging Modules USB Framework Debugging Support (uhci) USB Host Controller Walkers USB Host Controller Walkers uhci_qh Given the address of a USB UHCI controller Queue Head (QH) structure, iterate over the list of such structures. uhci_td Given the address of a USB UHCI controller Queue Head Descriptor (TD) structure, iterate over the list of such structures.