Intel Extensible Firmware Interface - Manual (Page 348)

Extensible Firmware Interface Specification
10-54 12/01/02 Version 1.10
Table 10-7 shows an example device path for a USB mouse that is behind a PCI to USB host
controller that is located at PCI device number 0x07 and PCI function 0x02. The PCI to USB host
controller is directly attached to a PCI root bridge. This device path consists of an ACPI Device
Path Node for the PCI Root Bridge, a PCI Device Path Node for the PCI to USB controller, a USB
Device Path Node, and a Device Path End Structure. The _HID and _UID of the first ACPI Device
Path Node must match the ACPI table description of the PCI Root Bridge. The shorthand notation
for this device path is:
ACPI(PNP0A03,0)/PCI(7|2)/USB(0,0)
Table 10-7. USB Mouse Device Path
Byte
Offset Byte
Length
Data
Description
0x00 0x01 0x02 Generic Device Path Header – Type ACPI Device Path
0x01 0x01 0x01 Sub type – ACPI Device Path
0x02 0x02 0x0C Length – 0x0C bytes
0x04 0x04 0x41D0,
0x0A03
_HID PNP0A03 – 0x41D0 represents a compressed string ‘PNP’ and is in
the low order bytes.
0x08 0x04 0x0000 _UID
0x0C 0x01 0x01 Generic Device Path Header – Type Hardware Device Path
0x0D 0x01 0x01 Sub type – PCI
0x0E 0x02 0x06 Length – 0x06 bytes
0x10 0x01 0x02 PCI Function
0x11 0x01 0x07 PCI Device
0x12 0x01 0x03 Generic Device Path Header – Type Messaging Device Path
0x13 0x01 0x05 Sub type – USB
0x14 0x02 0x06 Length – 0x06 bytes
0x16 0x01 0x00 USB Port Number
0x17 0x01 0x00 USB Endpoint Number
0x18 0x01 0xFF Generic Device Path Header – Type End of Hardware Device Path
0x19 0x01 0xFF Sub type – End of Entire Device Path
0x1A 0x02 0x04 Length – 0x04 bytes