Advanced Configuration and Power Interface Specification

Advanced Configuration and Power Interface Specification
6
Device Configuration
This section specifies the objects OSPM uses to configure devices. There are three types of
configuration objects:
• Device identification objects associate platform devices with Plug and Play IDs.
• Device configuration objects declare and configure hardware resources and characteristics for
devices enumerated via ACPI.
• Device insertion and removal objects provide mechanisms for handling dynamic insertion and
removal of devices.
This section also defines the ACPI device–resource descriptor formats. Device–resource descriptors
are used as parameters by some of the device configuration objects.
6.1 Device Identification Objects
Device identification objects associate each platform device with a Plug and Play device ID for each
device. All the device identification objects are listed in the table below:
Table 6-138 Device Identification Objects
Object Description
_ADR Object that evaluates to a device’s address on its parent bus.
_CID Object that evaluates to a device’s Plug and Play-compatible ID list.
_CLS Object that evaluates to a package of coded device-class information.
_DDN Object that associates a logical software name (for example, COM1) with a device.
_HID Object that evaluates to a device’s Plug and Play hardware ID.
_HRV Object that evaluates to an integer hardware revision number.
_MLS Object that provides a human readable description of a device in multiple languages.
_PLD Object that provides physical location description information.
_SUB Object that evaluates to a device's Plug and Play subsystem ID.
_SUN Object that evaluates to the slot-unique ID number for a slot.
_STR Object that contains a Unicode identifier for a device.
_UID Object that specifies a device’s unique persistent ID, or a control method that generates it.
For any device that is not on an enumerable type of bus (for example, an ISA bus), OSPM
enumerates the devices’ Plug and Play ID(s) and the ACPI BIOS must supply an _HID object (plus
an optional _CID object) for each device to enable OSPM to do that. For devices on an enumerable
type of bus, such as a PCI bus, the ACPI system must identify which device on the enumerable bus
is identified by a particular Plug and Play ID; the ACPI BIOS must supply an _ADR object for each
device to enable this. A device object must contain either an _HID object or an _ADR object, but can
contain both.
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