ACPI Extensions for Display Adapters: IntroductionΒΆ

This section of the document describes a number of specialized ACPI methods to support motherboard graphics devices.

In many cases, system manufacturers need to add special support to handle multiple output devices such as panels and TV-out capabilities, as well as special power management features. This is particularly true for notebook manufacturers. The methods described here have been designed to enable interaction between the platform firmware, video driver, and OS to smoothly support these features.

Systems containing a built-in display adapter are required to implement the ACPI Extensions for Display Adapters.

Table B-1: Video Extension Object Requirements

Method

Description

Requirement

_DOS

Enable/Disable output switching

Required if system supports display switching or LCD brightness levels

_DOD

Enumerate all devices attached to display adapter

Required if integrated controller supports output switching

_ROM

Get ROM Data

Required if ROM image is stored in proprietary format

_GPD

Get POST Device

Required if _VPO is implemented

_SPD

Set POST Device

Required if _VPO is implemented

_VPO

Video POST Options

Required if system supports changing post VGA device

_ADR

Return the unique ID for this device

Required

_BCL

Query list of brightness control levels supported

Required if embedded LCD supports brightness control

_BCM

Set the brightness level

Required if _BCL is implemented

_DDC

Return the EDID for this device

Required if embedded LCD does not support return of EDID via standard interface

_DCS

Return status of output device

Required if the system supports display switching (via hotkey)

_DGS

Query graphics state

Required if the system supports display switching (via hotkey

_DSS

Device state set

Required if the system supports display switching (via hotkey).