Intel Extensible Firmware Interface - Manual (Page 540)

Extensible Firmware Interface Specification
13-20 12/01/02 Version 1.10
Table 13-3 shows an example device path for channel #3 of a four channel PCI SCSI controller that
is located behind a PCI to PCI bridge at PCI device number 0x07 and PCI function 0x00. The PCI
to PCI bridge is directly attached to a PCI root bridge, and it is at PCI device number 0x05 and PCI
function 0x00. This device path consists of an ACPI Device Path Node, two PCI Device Path
Nodes, a Controller Node, and a Device Path End Structure. The _HID and _UID must match the
ACPI table description of the PCI Root Bridge. The shorthand notation of the device paths for all
four of the SCSI channels are listed below. Table 2-3 shows the last device path listed.
ACPI(PNP0A03,0)/PCI(5|0)/PCI(7|0)/Controller(0) .
ACPI(PNP0A03,0)/PCI(5|0)/PCI(7|0)/Controller(1) .
ACPI(PNP0A03,0)/PCI(5|0)/PCI(7|0)/Controller(2) .
ACPI(PNP0A03,0)/PCI(5|0)/PCI(7|0)/Controller(3) .
Table 13-3. Channel #3 of a PCI SCSI Controller behind a PCI Bridge
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 0x00 PCI Function
0x11 0x01 0x05 PCI Device
0x12 0x01 0x01 Generic Device Path Header – Type Hardware Device Path
0x13 0x01 0x01 Sub type – PCI
0x14 0x02 0x06 Length – 0x06 bytes
0x16 0x01 0x00 PCI Function
0x17 0x01 0x07 PCI Device
0x18 0x01 0x01 Generic Device Path Header – Type Hardware Device Path
0x19 0x01 0x05 Sub type – Controller
0x1A 0x02 0x08 Length – 0x08 bytes
0x1C 0x04 0x0003 Controller Number
0x20 0x01 0xFF Generic Device Path Header – Type End of Hardware Device Path
0x21 0x01 0xFF Sub type – End of Entire Device Path
0x22 0x02 0x04 Length – 0x04 bytes