Specifications

Version 2.0

211

2. Use certain algorithm to sort all the condensed device paths

3. Adding/Removing controller(s) would change the index (hardware

configuration change)

CSD(Connection Specific Descriptor): A string of numbers and characters, which

identifies how the device connects to parent controller.

1. Specify the connection of device

2. use one or several numbers or characters to describe each media and

messaging device path node in device path to specify the connection

A.2.5 Example (USB Devices)

Hardware Configuration (USB part)

4 UHC

7 USB devices: 4 Hard disks, 3 hub

Other hardware are ignored when mapping usb subsystem

Device Path (controllers are underlined)

acpi(pnp0a03,0)/pci(1d,0)/usb(0,1)/usb(1,1)/HD(Part4, sigxxx)

acpi(pnp0a03,0)/pci(1d,3)/usb(0,1)/usb(5,1)/HD(Part2, sigxxx)

acpi(pnp0a03,0)/pci(1d,1)/usb(1,0)/HD(Part3, sigxxx)

acpi(pnp0a03,0)/pci(1d,2)/usb(1,0)/ usb(2,0)/HD(Part1, sigxxx)

Steps to determine the consistent mapping for devices:

1. Determine the MTD

2. Determine the HI

3. Determine the CSD

4. Make the final mapping

A.2.5.1 Step 1: Determine MTD

MTD for all devices:

• hd is defined for harddisk.

• cd is defined for CD-ROM.

• fp is defined for floppy.

• f is defined for unknown device.

…

More names will be added according to the evolution of UEFI specification

Formatted: Bullets and Numbering