The Advanced Configuration and Power Interface (ACPI) specification was developed to establish industry
common interfaces enabling robust operating system (OS)-directed motherboard device configuration
and power management of both devices and entire systems. ACPI is the key element in Operating
System-directed configuration and Power Management (OSPM).
ACPI evolved the existing pre-ACPI collection of power management BIOS code, Advanced Power
Management (APM) application programming interfaces (APIs, PNPBIOS APIs, Multiprocessor
Specification (MPS) tables and so on into a well-defined power management and configuration interface
specification. ACPI provides the means for an orderly transition from existing (legacy) hardware to ACPI
hardware, and it allows for both ACPI and legacy mechanisms to exist in a single machine and to be used
as needed.
Further, system architectures being built at the time of the original ACPI specification’s inception,
stretched the limits of historical “Plug and Play” interfaces. ACPI evolved existing motherboard
configuration interfaces to support advanced architectures in a more robust, and potentially more
efficient manner.
The interfaces and OSPM concepts defined within this specification are suitable to all classes of
computers including (but not limited to) desktop, mobile, workstation, and server machines. From a
power management perspective, OSPM/ACPI promotes the concept that systems should conserve
energy by transitioning unused devices into lower power states including placing the entire system in a
low-power state (sleeping state) when possible.
This document describes ACPI hardware interfaces, ACPI software interfaces and ACPI data structures
that, when implemented, enable support for robust OS-directed configuration and power management
(OSPM)
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ACPI
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