Intel Extensible Firmware Interface, Specification

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Extensible Firmware Interface Specification
362 12/12/00 Version 1.02
Desktop Management Task Force (DMTF)
The DMTF is a standards organization comprised of companies from all areas of the
computer industry. Its purpose is to create the standards and infrastructure for cost-
effective management of PC systems.
Device Handle
A handle points to a list of one or more protocols that can respond to requests for services
for a given device referred to by the handle.
Device I/O Protocol
A protocol that is used during boot services to access memory and I/O. Also called the
EFI Device I/O Protocol .
Device Path
A variable-length binary data structure that is composed of variable-length generic device
path nodes and is used to define the programmatic path to a logical or physical device.
There are six major types of device paths:
Hardware Device Path , ACPI Device Path ,
Messaging Device Path , Media Device Path , BIOS Boot Specification Device Path ,
and End Of Hardware Device Path .
Device Path Instance
When an EFI Handle represents multiple devices, it is possible for a device path to
contain multiple device paths. An example of this would be a handle that represents
ConsoleOut and consists of both a VGA console and a serial output console. The handle
would send output to both devices and therefore has a device path that consists of two
complete device paths. Each of these paths is a device path instance.
Device Path Node
A variable-length generic data structure that is used to build a device path. Nodes are
distinguished by type, sub-type, length, and path-specific data. See
Device Path .
Device Path Protocol
A protocol that is used during boot services to provide the information needed to
construct and manage device paths. Also called the
EFI Device Path Protocol .
DHCP
See Dynamic Host Configuration Protocol .
Disk I/O Protocol
A protocol that is used during boot services to abstract Block I/O devices to allow non-
block sized I/O operations. Also called the
EFI Disk I/O Protocol .
DMI
See Desktop Management Interface .