ACPI Extensions for Display Adapters: Introduction

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).