Extensible Firmware Interface Specification
340 12/12/00 Version 1.02
The EFI Device Path for the PCI IDE controller would contain entries for the following things:
• Root PCI Bridge. ACPI Device Path _HID PNP0A03, _UID 0. ACPI name space \_SB\PCI0
• PCI IDE controller. PCI Device Path with device and function of the IDE controller. ACPI
name space \_SB\PCI0\IDE0
• ATA Address. ATA Messaging Device Path for Primary bus and Master device. ACPI name
space \_SB\PCI0\IDE0\PRIM\MAST
• End Device Path
Table C-2. IDE Disk Device Path
Byte
Offset
Byte
Length Data Description
0 1 0x02 Generic Device Path Header – Type ACPI Device Path
1 1 0x01 Sub type – ACPI Device Path
2 2 0x0C Length
4 4 0x41D0,
0x0A03
_HID PNP0A03 – 0x41D0 represents a compressed string ‘PNP’ and is in
the low order bytes
8 4 0x0000 _UID
C 1 0x01 Generic Device Path Header – Type Hardware Device Path
D 1 0x01 Sub type PCI Device Path
E 2 0x06 Length
10 1 0x01 PCI Function
11 1 0x10 PCI Device
12 1 0x03 Generic Device Path Header – Messaging Device Path
13 1 0x01 Sub type – ATAPI Device Path
14 2 0x06 Length
16 1 0x00 Primary =0, Secondary = 1
17 1 0x00 Master = 0, Slave = 1
18 2 0x0000 LUN
1A 1 0xFF Generic Device Path Header – Type End Device Path
1B 1 0xFF Sub type – End Device Path
1C 2 0x04 Length