Advanced Configuration and Power Interface (ACPI) Specification

Version 6.4

January 2021

Acknowledgments

The material contained herein is not a license, either expressly or impliedly, to any intellectual property owned or controlled by any of the authors or developers of this material or to any contribution thereto. The material contained herein is provided on an “AS IS” basis and, to the maximum extent permitted by applicable law, this information is provided AS IS AND WITH ALL FAULTS, and the authors and developers of this material hereby disclaim all other warranties and conditions, either express, implied or statutory, including, but not limited to, any (if any) implied warranties, duties or conditions of merchantability, of fitness for a particular purpose, of accuracy or completeness of responses, of results, of workmanlike effort, of lack of viruses and of lack of negligence, all with regard to this material and any contribution thereto. Designers must not rely on the absence or characteristics of any features or instructions marked “reserved” or “undefined.” The Unified EFI Forum, Inc. reserves any features or instructions so marked for future definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them. ALSO, THERE IS NO WARRANTY OR CONDITION OF TITLE, QUIET ENJOYMENT, QUIET POSSESSION, CORRESPONDENCE TO DESCRIPTION OR NON-INFRINGEMENT WITH REGARD TO THE SPECIFICATION AND ANY CONTRIBUTION THERETO.

IN NO EVENT WILL ANY AUTHOR OR DEVELOPER OF THIS MATERIAL OR ANY CONTRIBUTION THERETO BE LIABLE TO ANY OTHER PARTY FOR THE COST OF PROCURING SUBSTITUTE GOODS OR SERVICES, LOST PROFITS, LOSS OF USE, LOSS OF DATA, OR ANY INCIDENTAL, CONSEQUENTIAL, DIRECT, INDIRECT, OR SPECIAL DAMAGES WHETHER UNDER CONTRACT, TORT, WARRANTY, OR OTHERWISE, ARISING IN ANY WAY OUT OF THIS OR ANY OTHER AGREEMENT RELATING TO THIS DOCUMENT, WHETHER OR NOT SUCH PARTY HAD ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.

Copyright © 2021, Unified Extensible Firmware Interface (UEFI) Forum, Inc. All Rights Reserved. The UEFI Forum is the owner of all rights and title in and to this work, including all copyright rights that may exist, and all rights to use and reproduce this work. Further to such rights, permission is hereby granted to any person implementing this specification to maintain an electronic version of this work accessible by its internal personnel, and to print a copy of this specification in hard copy form, in whole or in part, in each case solely for use by that person in connection with the implementation of this Specification, provided no modification is made to the Specification.

• List of Tables
• List of Figures
• Revision History
• Overview

• 1. Introduction
  • 1.1. Principal Goals
  • 1.2. Power Management Rationale
  • 1.3. Legacy Support
  • 1.4. OEM Implementation Strategy
  • 1.5. Power and Sleep Buttons
  • 1.6. ACPI Specification and the Structure of ACPI
  • 1.7. OS and Platform Compliance
    • 1.7.1. Platform Implementations of ACPI-defined Interfaces
      • 1.7.1.1. Recommended Features and Interface Descriptions for Design Guides
      • 1.7.1.2. Terminology Examples for Design Guides
    • 1.7.2. OSPM Implementations
    • 1.7.3. OS Requirements
  • 1.8. Target Audience
  • 1.9. Document Organization
    • 1.9.1. ACPI Introduction and Overview
    • 1.9.2. Programming Models
    • 1.9.3. Implementation Details
    • 1.9.4. Technical Reference
    • 1.9.5. Revsion Numbers
  • 1.10. Related Documents
• 2. Definition of Terms
  • 2.1. General ACPI Terminology
  • 2.2. Global System State Definitions
  • 2.3. Device Power State Definitions
    • 2.3.1. Device Performance States
  • 2.4. Sleeping and Soft-off State Definitions
  • 2.5. Processor Power State Definitions
  • 2.6. Device and Processor Performance State Definitions
• 3. ACPI Concepts
  • 3.1. System Power Management
  • 3.2. Power States
    • 3.2.1. Power Button
    • 3.2.2. Platform Power Management Characteristics
      • 3.2.2.1. Mobile PC
      • 3.2.2.2. Desktop PCs
      • 3.2.2.3. Multiprocessor and Server PCs
  • 3.3. Device Power Management
    • 3.3.1. Device Power Management Model
    • 3.3.2. Power Management Standards
    • 3.3.3. Device Power States
    • 3.3.4. Device Power State Definitions
  • 3.4. Controlling Device Power
    • 3.4.1. Getting Device Power Capabilities
    • 3.4.2. Setting Device Power States
    • 3.4.3. Getting Device Power Status
    • 3.4.4. Waking the System
    • 3.4.5. Example: Modem Device Power Management
      • 3.4.5.1. Obtaining the Modem Capabilities
      • 3.4.5.2. Setting the Modem Power State
      • 3.4.5.3. Obtaining the Modem Power Status
      • 3.4.5.4. Waking the System
  • 3.5. Processor Power Management
  • 3.6. Device and Processor Performance States
  • 3.7. Configuration and “Plug and Play”
    • 3.7.1. Device Configuration Example: Configuring the Modem
    • 3.7.2. NUMA Nodes
  • 3.8. System Events
  • 3.9. Battery Management
    • 3.9.1. Battery Communications
    • 3.9.2. Battery Capacity
    • 3.9.3. Battery Gas Gauge
    • 3.9.4. Low Battery Levels
      • 3.9.4.1. Emergency Shutdown
    • 3.9.5. Battery Calibration
    • 3.9.6. Battery Charge Limiting
  • 3.10. Thermal Management Concepts
    • 3.10.1. Active and Passive Cooling Modes
    • 3.10.2. Performance vs. Energy Conservation
    • 3.10.3. Acoustics (Noise)
    • 3.10.4. Multiple Thermal Zones
  • 3.11. Flexible Platform Architecture Support
    • 3.11.1. Hardware-reduced ACPI
      • 3.11.1.1. Interrupt-based Wake Events
    • 3.11.2. Low-Power Idle
      • 3.11.2.1. Low Power S0 Idle Capable Flag
    • 3.11.3. Connection Resources
      • 3.11.3.1. Supported Platforms
• 4. ACPI Hardware Specification
  • 4.1. Hardware-Reduced ACPI
    • 4.1.1. Hardware-Reduced Events
      • 4.1.1.1. GPIO-Signaled Events or Interrupt Signaled Events
      • 4.1.1.2. Interrupt-based Wake Events
  • 4.2. Fixed Hardware Programming Model
  • 4.3. Generic Hardware Programming Model
  • 4.4. Diagram Legend
  • 4.5. Register Bit Notation
  • 4.6. The ACPI Hardware Model
    • 4.6.1. Hardware Reserved Bits
    • 4.6.2. Hardware Ignored Bits
    • 4.6.3. Hardware Write-Only Bits
    • 4.6.4. Cross Device Dependencies
      • 4.6.4.1. Example 1: Related Device Interference
      • 4.6.4.2. Example 2: Unrelated Device Interference
  • 4.7. ACPI Hardware Features
  • 4.8. ACPI Register Model
    • 4.8.1. ACPI Register Summary
      • 4.8.1.1. PM1 Event Registers
      • 4.8.1.2. PM1 Control Registers
      • 4.8.1.3. PM2 Control Register
      • 4.8.1.4. PM Timer Register
      • 4.8.1.5. Processor Control Block (P_BLK)
      • 4.8.1.6. General-Purpose Event Registers
    • 4.8.2. Fixed Hardware Features
    • 4.8.3. Power Management Timer
      • 4.8.3.1. Console Buttons
      • 4.8.3.2. Sleeping/Wake Control
      • 4.8.3.3. Real Time Clock Alarm
      • 4.8.3.4. Legacy/ACPI Select and the SCI Interrupt
      • 4.8.3.5. Processor Control
    • 4.8.4. Fixed Hardware Registers
      • 4.8.4.1. PM1 Event Grouping
      • 4.8.4.2. PM1 Control Grouping
      • 4.8.4.3. Power Management Timer (PM_TMR)
      • 4.8.4.4. PM2 Control (PM2_CNT)
      • 4.8.4.5. Processor Register Block (P_BLK)
      • 4.8.4.6. Reset Register
      • 4.8.4.7. Sleep Control and Status Registers
    • 4.8.5. Generic Hardware Registers
      • 4.8.5.1. General-Purpose Event Register Blocks
      • 4.8.5.2. Example Generic Devices
• 5. ACPI Software Programming Model
  • 5.1. Overview of the System Description Table Architecture
    • 5.1.1. Address Space Translation
  • 5.2. ACPI System Description Tables
    • 5.2.1. Reserved Bits and Fields
      • 5.2.1.1. Reserved Bits and Software Components
      • 5.2.1.2. Reserved Values and Software Components
      • 5.2.1.3. Reserved Hardware Bits and Software Components
      • 5.2.1.4. Ignored Hardware Bits and Software Components
    • 5.2.2. Compatibility
    • 5.2.3. Address Format
      • 5.2.3.1. Functional Fixed Hardware
      • 5.2.3.2. Generic Address Structure
    • 5.2.4. Universally Unique Identifiers (UUIDs)
    • 5.2.5. Root System Description Pointer (RSDP)
      • 5.2.5.1. Finding the RSDP on IA-PC Systems
      • 5.2.5.2. Finding the RSDP on UEFI Enabled Systems
      • 5.2.5.3. Root System Description Pointer (RSDP) Structure
    • 5.2.6. System Description Table Header
    • 5.2.7. Root System Description Table (RSDT)
    • 5.2.8. Extended System Description Table (XSDT)
    • 5.2.9. Fixed ACPI Description Table (FADT)
      • 5.2.9.1. Preferred PM Profile System Types
      • 5.2.9.2. System Type Attributes
      • 5.2.9.3. IA-PC Boot Architecture Flags
      • 5.2.9.4. ARM Architecture Boot Flags
    • 5.2.10. Firmware ACPI Control Structure (FACS)
      • 5.2.10.1. Global Lock
    • 5.2.11. Definition Blocks
      • 5.2.11.1. Differentiated System Description Table (DSDT)
      • 5.2.11.2. Secondary System Description Table (SSDT)
      • 5.2.11.3. Persistent System Description Table (PSDT)
    • 5.2.12. Multiple APIC Description Table (MADT)
      • 5.2.12.1. MADT Processor Local APIC / SAPIC Structure Entry Order
      • 5.2.12.2. Processor Local APIC Structure
      • 5.2.12.3. I/O APIC Structure
      • 5.2.12.4. Platforms with APIC and Dual 8259 Support
      • 5.2.12.5. Interrupt Source Override Structure
      • 5.2.12.6. Non-Maskable Interrupt (NMI) Source Structure
      • 5.2.12.7. Local APIC NMI Structure
      • 5.2.12.8. Local APIC Address Override Structure
      • 5.2.12.9. I/O SAPIC Structure
      • 5.2.12.10. Local SAPIC Structure
      • 5.2.12.11. Platform Interrupt Source Structure
      • 5.2.12.12. Processor Local x2APIC Structure
      • 5.2.12.13. Local x2APIC NMI Structure
      • 5.2.12.14. GIC CPU Interface (GICC) Structure
      • 5.2.12.15. GIC Distributor (GICD) Structure
      • 5.2.12.16. GIC MSI Frame Structure
      • 5.2.12.17. GIC Redistributor (GICR) Structure
      • 5.2.12.18. GIC Interrupt Translation Service (ITS) Structure
      • 5.2.12.19. Multiprocessor Wakeup Structure
    • 5.2.13. Global System Interrupts
    • 5.2.14. Smart Battery Table (SBST)
    • 5.2.15. Embedded Controller Boot Resources Table (ECDT)
    • 5.2.16. System Resource Affinity Table (SRAT)
      • 5.2.16.1. Processor Local APIC/SAPIC Affinity Structure
      • 5.2.16.2. Memory Affinity Structure
      • 5.2.16.3. Processor Local x2APIC Affinity Structure
      • 5.2.16.4. GICC Affinity Structure
      • 5.2.16.5. GIC Interrupt Translation Service (ITS) Affinity Structure
      • 5.2.16.6. Generic Initiator Affinity Structure
    • 5.2.17. System Locality Information Table (SLIT)
    • 5.2.18. Corrected Platform Error Polling Table (CPEP)
      • 5.2.18.1. Corrected Platform Error Polling Processor Structure
    • 5.2.19. Maximum System Characteristics Table (MSCT)
      • 5.2.19.1. Maximum Proximity Domain Information Structure
    • 5.2.20. ACPI RAS Feature Table (RASF)
      • 5.2.20.1. RASF PCC Sub Channel Identifier
      • 5.2.20.2. Using PCC registers
      • 5.2.20.3. RASF Communication Channel
      • 5.2.20.4. Platform RAS Capabilities
      • 5.2.20.5. Parameter Block
    • 5.2.21. Memory Power State Table (MPST)
      • 5.2.21.1. MPST PCC Sub Channel
      • 5.2.21.2. Memory Power State
      • 5.2.21.3. Action Sequence
      • 5.2.21.4. Memory Power Node
      • 5.2.21.5. Memory Power State Structure
      • 5.2.21.6. Memory Power State Characteristics structure
      • 5.2.21.7. Autonomous Memory Power Management
      • 5.2.21.8. Handling BIOS Reserved Memory
      • 5.2.21.9. Interaction with NUMA processor and memory affinity tables
      • 5.2.21.10. Interaction with Memory Hot Plug
      • 5.2.21.11. OS Memory Allocation Considerations
      • 5.2.21.12. Platform Memory Topology Table (PMTT)
    • 5.2.22. Boot Graphics Resource Table (BGRT)
      • 5.2.22.1. Version
      • 5.2.22.2. Status
      • 5.2.22.3. Image Type
      • 5.2.22.4. Image Address
      • 5.2.22.5. Image Offset
    • 5.2.23. Firmware Performance Data Table (FPDT)
      • 5.2.23.1. Performance Record Format
      • 5.2.23.2. FPDT Performance Record Types
      • 5.2.23.3. Runtime Performance Record Types
      • 5.2.23.4. Firmware Basic Boot Performance Table Pointer Record
      • 5.2.23.5. S3 Performance Table Pointer Record
      • 5.2.23.6. Firmware Basic Boot Performance Table
      • 5.2.23.7. Firmware Basic Boot Performance Data Record
      • 5.2.23.8. S3 Performance Table
    • 5.2.24. Generic Timer Description Table (GTDT)
      • 5.2.24.1. GT Block Structure
      • 5.2.24.2. Arm Generic Watchdog Structure
    • 5.2.25. NVDIMM Firmware Interface Table (NFIT)
      • 5.2.25.1. Overview
      • 5.2.25.2. System Physical Address (SPA) Range Structure
      • 5.2.25.3. NVDIMM Region Mapping Structure
      • 5.2.25.4. Interleave Structure
      • 5.2.25.5. SMBIOS Management Information Structure
      • 5.2.25.6. NVDIMM Control Region Structure
      • 5.2.25.7. NVDIMM Block Data Window Region Structure
      • 5.2.25.8. Flush Hint Address Structure
      • 5.2.25.9. Platform Capabilities Structure
      • 5.2.25.10. NVDIMM Representation Format
    • 5.2.26. Secure Devices (SDEV) ACPI Table
      • 5.2.26.1. Secure Device Structures
    • 5.2.27. Heterogeneous Memory Attribute Table (HMAT)
      • 5.2.27.1. HMAT Overview
      • 5.2.27.2. Memory Side Cache Overview
      • 5.2.27.3. Memory Proximity Domain Attributes Structure
      • 5.2.27.4. System Locality Latency and Bandwidth Information Structure
      • 5.2.27.5. Memory Side Cache Information Structure
    • 5.2.28. Platform Debug Trigger Table (PDTT)
      • 5.2.28.1. PDTT PCC Sub Channel
      • 5.2.28.2. PDTT PCC Trigger Order
      • 5.2.28.3. Example: OS Invoking Multiple Debug Triggers
    • 5.2.29. Processor Properties Topology Table (PPTT)
      • 5.2.29.1. Processor hierarchy node structure (Type 0)
      • 5.2.29.2. Cache Type Structure - Type 1
    • 5.2.30. Platform Health Assessment Table (PHAT)
      • 5.2.30.1. Platform Health Assessment Record Format
      • 5.2.30.2. Platform Health Assessment Record Type Format
      • 5.2.30.3. Firmware Version Data Record Structure
      • 5.2.30.4. Firmware Health Data Record Structure
  • 5.3. ACPI Namespace
    • 5.3.1. Predefined Root Namespaces
    • 5.3.2. Objects
  • 5.4. Definition Block Encoding
    • 5.4.1. AML Encoding
    • 5.4.2. Definition Block Loading
  • 5.5. Control Methods and the ACPI Source Language (ASL)
    • 5.5.1. ASL Statements
    • 5.5.2. Control Method Execution
      • 5.5.2.1. Arguments
      • 5.5.2.2. Method Calling Convention
      • 5.5.2.3. Local Variables and Locally Created Data Objects
      • 5.5.2.4. Access to Operation Regions
  • 5.6. ACPI Event Programming Model
    • 5.6.1. ACPI Event Programming Model Components
    • 5.6.2. Types of ACPI Events
    • 5.6.3. Fixed Event Handling
    • 5.6.4. General-Purpose Event Handling
      • 5.6.4.1. _Exx, _Lxx, and _Qxx Methods for GPE Processing
      • 5.6.4.2. GPE Wake Events
    • 5.6.5. GPIO-signaled ACPI Events
      • 5.6.5.1. Declaring GPIO Controller Devices
      • 5.6.5.2. _AEI Object for GPIO-signaled Events
      • 5.6.5.3. The Event (_EVT) Method for Handling GPIO-signaled Events
    • 5.6.6. Device Object Notifications
    • 5.6.7. Device Class-Specific Objects
    • 5.6.8. Predefined ACPI Names for Objects, Methods, and Resources
    • 5.6.9. Interrupt-signaled ACPI events
      • 5.6.9.1. Declaring Generic Event Device
      • 5.6.9.2. _CRS Object for Interrupt-signaled Events
      • 5.6.9.3. The Event (_EVT) Method for Handling Interrupt-signaled Events
      • 5.6.9.4. GED Wake Events
    • 5.6.10. Managing a Wake Event Using Device _PRW Objects
  • 5.7. Predefined Objects
    • 5.7.1. \_GL (Global Lock Mutex)
    • 5.7.2. \_OSI (Operating System Interfaces)
      • 5.7.2.1. _OSI Examples
    • 5.7.3. \_OS (OS Name Object)
    • 5.7.4. \_REV (Revision Data Object)
    • 5.7.5. \_DLM (DeviceLock Mutex)
  • 5.8. System Configuration Objects
    • 5.8.1. \_PIC Method
• 6. Device Configuration
  • 6.1. Device Identification Objects
    • 6.1.1. _ADR (Address)
    • 6.1.2. _CID (Compatible ID)
    • 6.1.3. _CLS (Class Code)
    • 6.1.4. _DDN (DOS Device Name)
    • 6.1.5. _HID (Hardware ID)
    • 6.1.6. _HRV (Hardware Revision)
    • 6.1.7. _MLS (Multiple Language String)
    • 6.1.8. _PLD (Physical Location of Device)
    • 6.1.9. _SUB (Subsystem ID)
    • 6.1.10. _STR (String)
    • 6.1.11. _SUN (Slot User Number)
    • 6.1.12. _UID (Unique ID)
  • 6.2. Device Configuration Objects
    • 6.2.1. _CDM (Clock Domain)
    • 6.2.2. _CRS (Current Resource Settings)
    • 6.2.3. _DIS (Disable)
    • 6.2.4. _DMA (Direct Memory Access)
    • 6.2.5. _DSD (Device Specific Data)
    • 6.2.6. _FIX (Fixed Register Resource Provider)
    • 6.2.7. _GSB (Global System Interrupt Base)
    • 6.2.8. _HPP (Hot Plug Parameters)
    • 6.2.9. _HPX (Hot Plug Parameter Extensions)
      • 6.2.9.1. PCI Setting Record (Type 0)
      • 6.2.9.2. PCI-X Setting Record (Type 1)
      • 6.2.9.3. PCI Express Setting Record (Type 2)
      • 6.2.9.4. PCI Express Descriptor Setting Record (Type 3)
      • 6.2.9.5. _HPX Example
    • 6.2.10. _MAT (Multiple APIC Table Entry)
    • 6.2.11. _OSC (Operating System Capabilities)
      • 6.2.11.1. Rules for Evaluating _OSC
      • 6.2.11.2. Platform-Wide OSPM Capabilities
      • 6.2.11.3. Operating System Capabilities (_OSC) for USB
    • 6.2.12. _PRS (Possible Resource Settings)
    • 6.2.13. _PRT (PCI Routing Table)
      • 6.2.13.1. Example: Using _PRT to Describe PCI IRQ Routing
    • 6.2.14. _PXM (Proximity)
    • 6.2.15. _SLI (System Locality Information)
    • 6.2.16. _SRS (Set Resource Settings)
    • 6.2.17. _CCA (Cache Coherency Attribute)
      • 6.2.17.1. _CCA Example ASL:
    • 6.2.18. _HMA(Heterogeneous Memory Attributes)
  • 6.3. Device Insertion, Removal, and Status Objects
    • 6.3.1. _EDL (Eject Device List)
    • 6.3.2. _EJD (Ejection Dependent Device)
    • 6.3.3. _EJx (Eject)
    • 6.3.4. _LCK (Lock)
    • 6.3.5. _OST (OSPM Status Indication)
      • 6.3.5.1. Processing Sequence for Graceful Shutdown Request:
      • 6.3.5.2. Processing Sequence for Error Disconnect Recover
    • 6.3.6. _RMV (Remove)
    • 6.3.7. _STA (Device Status)
  • 6.4. Resource Data Types for ACPI
    • 6.4.1. ASL Macros for Resource Descriptors
    • 6.4.2. Small Resource Data Type
      • 6.4.2.1. IRQ Descriptor
      • 6.4.2.2. DMA Descriptor
      • 6.4.2.3. Start Dependent Functions Descriptor
      • 6.4.2.4. End Dependent Functions Descriptor
      • 6.4.2.5. I/O Port Descriptor
      • 6.4.2.6. Fixed Location I/O Port Descriptor
      • 6.4.2.7. Fixed DMA Descriptor
      • 6.4.2.8. Vendor-Defined Descriptor, Type 0
      • 6.4.2.9. End Tag
    • 6.4.3. Large Resource Data Type
      • 6.4.3.1. 24-Bit Memory Range Descriptor
      • 6.4.3.2. Vendor-Defined Descriptor, Type 1
      • 6.4.3.3. 32-Bit Memory Range Descriptor
      • 6.4.3.4. 32-Bit Fixed Memory Range Descriptor
      • 6.4.3.5. Address Space Resource Descriptors
      • 6.4.3.6. Extended Interrupt Descriptor
      • 6.4.3.7. Generic Register Descriptor
      • 6.4.3.8. Connection Descriptors
      • 6.4.3.9. Pin Function Descriptor
      • 6.4.3.10. Pin Configuration Descriptor
      • 6.4.3.11. Pin Group Descriptor
      • 6.4.3.12. Pin Group Function Descriptor
      • 6.4.3.13. Pin Group Configuration Descriptor
  • 6.5. Other Objects and Control Methods
    • 6.5.1. _INI (Init)
    • 6.5.2. _DCK (Dock)
    • 6.5.3. _BDN (BIOS Dock Name)
    • 6.5.4. _REG (Region)
    • 6.5.5. _BBN (Base Bus Number)
    • 6.5.6. _SEG (Segment)
    • 6.5.7. _GLK (Global Lock)
    • 6.5.8. _DEP (Operation Region Dependencies)
    • 6.5.9. _FIT (Firmware Interface Table)
    • 6.5.10. NVDIMM Label Methods
      • 6.5.10.1. _LSI (Label Storage Information)
      • 6.5.10.2. _LSR (Label Storage Read)
      • 6.5.10.3. _LSW (Label Storage Write)
    • 6.5.11. _CBR (CXL Host Bridge Register Info)
• 7. Power and Performance Management
  • 7.1. Power Resource Objects and the Power Management Models
  • 7.2. Declaring a Power Resource Object
    • 7.2.1. Defined Methods for a Power Resource
    • 7.2.2. _OFF
    • 7.2.3. _ON
    • 7.2.4. _STA (Power Resource Status)
    • 7.2.5. Passive Power Resources
  • 7.3. Device Power Management Objects
    • 7.3.1. _DSW (Device Sleep Wake)
    • 7.3.2. _PS0 (Power State 0)
    • 7.3.3. _PS1 (Power State 1)
    • 7.3.4. _PS2 (Power State 2)
    • 7.3.5. _PS3 (Power State 3)
    • 7.3.6. _PSC (Power State Current)
    • 7.3.7. _PSE (Power State for Enumeration)
    • 7.3.8. _PR0 (Power Resources for D0)
    • 7.3.9. _PR1 (Power Resources for D1)
    • 7.3.10. _PR2 (Power Resources for D2)
    • 7.3.11. _PR3 (Power Resources for D3hot)
    • 7.3.12. _PRE (Power Resources for Enumeration)
    • 7.3.13. _PRW (Power Resources for Wake)
    • 7.3.14. _PSW (Power State Wake)
    • 7.3.15. _IRC (In Rush Current)
    • 7.3.16. _S1D (S1 Device State)
    • 7.3.17. _S2D (S2 Device State)
    • 7.3.18. _S3D (S3 Device State)
    • 7.3.19. _S4D (S4 Device State)
    • 7.3.20. _S0W (S0 Device Wake State)
    • 7.3.21. _S1W (S1 Device Wake State)
    • 7.3.22. _S2W (S2 Device Wake State)
    • 7.3.23. _S3W (S3 Device Wake State)
    • 7.3.24. _S4W (S4 Device Wake State)
    • 7.3.25. _RST (Device Reset)
    • 7.3.26. _PRR (Power Resource for Reset)
  • 7.4. OEM-Supplied System-Level Control Methods
    • 7.4.1. \_PTS (Prepare To Sleep)
    • 7.4.2. \_Sx (System States)
      • 7.4.2.1. System \_S0 State (Working)
      • 7.4.2.2. System \_S1 State (Sleeping with Processor Context Maintained)
      • 7.4.2.3. System \_S2 State
      • 7.4.2.4. System \_S3 State
      • 7.4.2.5. System \_S4 State
      • 7.4.2.6. System \_S5 State (Soft Off)
    • 7.4.3. \_SWS (System Wake Source)
    • 7.4.4. \_TTS (Transition To State)
    • 7.4.5. \_WAK (System Wake)
  • 7.5. OSPM usage of _PTS, _TTS, and _WAK
• 8. Processor Configuration and Control
  • 8.1. Processor Power States
    • 8.1.1. Processor Power State C0
    • 8.1.2. Processor Power State C1
    • 8.1.3. Processor Power State C2
    • 8.1.4. Processor Power State C3
    • 8.1.5. Additional Processor Power States
  • 8.2. Flushing Caches
  • 8.3. Power, Performance, and Throttling State Dependencies
  • 8.4. Declaring Processors
    • 8.4.1. _PDC (Processor Driver Capabilities)
    • 8.4.2. Processor Power State Control
      • 8.4.2.1. _CST (C States)
      • 8.4.2.2. _CSD (C-State Dependency)
    • 8.4.3. Processor Hierarchy
      • 8.4.3.1. Processor Container Device
    • 8.4.4. Lower Power Idle States
      • 8.4.4.1. Hierarchical Idle States
      • 8.4.4.2. Idle State Coordination
      • 8.4.4.3. _LPI (Low Power Idle States)
      • 8.4.4.4. _RDI (Resource Dependencies for Idle)
      • 8.4.4.5. Compatibility
    • 8.4.5. Processor Throttling Controls
      • 8.4.5.1. _PTC (Processor Throttling Control)
      • 8.4.5.2. _TSS (Throttling Supported States)
      • 8.4.5.3. _TPC (Throttling Present Capabilities)
      • 8.4.5.4. _TSD (T-State Dependency)
      • 8.4.5.5. _TDL (T-state Depth Limit)
    • 8.4.6. Processor Performance Control
      • 8.4.6.1. _PCT (Performance Control)
      • 8.4.6.2. _PSS (Performance Supported States)
      • 8.4.6.3. _PPC (Performance Present Capabilities)
      • 8.4.6.4. Processor Performance Control Example
      • 8.4.6.5. _PSD (P-State Dependency)
      • 8.4.6.6. _PDL (P-state Depth Limit)
    • 8.4.7. Collaborative Processor Performance Control
      • 8.4.7.1. _CPC (Continuous Performance Control)
    • 8.4.8. _PPE (Polling for Platform Errors)
  • 8.5. Processor Aggregator Device
    • 8.5.1. Logical Processor Idling
      • 8.5.1.1. _PUR (Processor Utilization Request)
    • 8.5.2. OSPM _OST Evaluation
• 9. ACPI-Defined Devices and Device-Specific Objects
  • 9.1. Device Object Name Collision
    • 9.1.1. _DSM (Device Specific Method)
  • 9.2. \_SI System Indicators
    • 9.2.1. _SST (System Status)
    • 9.2.2. _MSG (Message)
    • 9.2.3. _BLT (Battery Level Threshold)
  • 9.3. Ambient Light Sensor Device
    • 9.3.1. Overview
    • 9.3.2. _ALI (Ambient Light Illuminance)
    • 9.3.3. _ALT (Ambient Light Temperature)
    • 9.3.4. _ALC (Ambient Light Color Chromaticity)
    • 9.3.5. _ALR (Ambient Light Response)
    • 9.3.6. _ALP (Ambient Light Polling)
    • 9.3.7. Ambient Light Sensor Events
    • 9.3.8. Relationship to Backlight Control Methods
  • 9.4. Battery Device
  • 9.5. Control Method Lid Device
    • 9.5.1. _LID
  • 9.6. Control Method Power and Sleep Button Devices
  • 9.7. Embedded Controller Device
  • 9.8. Generic Container Device
  • 9.9. ATA Controller Devices
    • 9.9.1. Objects for Both ATA and SATA Controllers
      • 9.9.1.1. _GTF (Get Task File)
    • 9.9.2. IDE Controller Device
      • 9.9.2.1. IDE Controller-specific Objects
    • 9.9.3. Serial ATA (SATA) Controller Device
      • 9.9.3.1. Definitions
      • 9.9.3.2. Overview
      • 9.9.3.3. SATA controller-specific control methods
  • 9.10. Floppy Controller Device Objects
    • 9.10.1. _FDE (Floppy Disk Enumerate)
    • 9.10.2. _FDI (Floppy Disk Information)
    • 9.10.3. _FDM (Floppy Disk Drive Mode)
  • 9.11. GPE Block Device
    • 9.11.1. Matching Control Methods for Events in a GPE Block Device
  • 9.12. Module Device
  • 9.13. Memory Devices
    • 9.13.1. Address Decoding
    • 9.13.2. Memory Bandwidth Monitoring and Reporting
      • 9.13.2.1. _MBM (Memory Bandwidth Monitoring Data)
      • 9.13.2.2. _MSM (Memory Set Monitoring)
    • 9.13.3. _OSC Definition for Memory Device
    • 9.13.4. Example: Memory Device
  • 9.14. _UPC (USB Port Capabilities)
    • 9.14.1. USB 2.0 Host Controllers and _UPC and _PLD
  • 9.15. PC/AT RTC/CMOS Devices
    • 9.15.1. PC/AT-compatible RTC/CMOS Devices (PNP0B00)
    • 9.15.2. Intel PIIX4-compatible RTC/CMOS Devices (PNP0B01)
    • 9.15.3. Dallas Semiconductor-compatible RTC/CMOS Devices (PNP0B02)
  • 9.16. User Presence Detection Device
    • 9.16.1. _UPD (User Presence Detect)
    • 9.16.2. _UPP (User Presence Polling)
    • 9.16.3. User Presence Sensor Events
  • 9.17. I/O APIC Device
  • 9.18. Time and Alarm Device
    • 9.18.1. Overview
    • 9.18.2. _GCP (Get Capability)
    • 9.18.3. _GRT (Get Real Time)
    • 9.18.4. _SRT (Set Real Time)
    • 9.18.5. _GWS (Get Wake alarm status)
    • 9.18.6. _CWS (Clear Wake alarm status)
    • 9.18.7. _STP (Set Expired Timer Wake Policy)
    • 9.18.8. _STV (Set Timer Value)
    • 9.18.9. _TIP (Expired Timer Wake Policy)
    • 9.18.10. _TIV (Timer Values)
    • 9.18.11. ACPI Wakeup Alarm Events
    • 9.18.12. Relationship to Real Time Clock Alarm
    • 9.18.13. Time and Alarm device as a replacement to the RTC
    • 9.18.14. Relationship to UEFI time source
    • 9.18.15. Example ASL code
  • 9.19. Generic Buttons Device
    • 9.19.1. Button Interrupts
    • 9.19.2. Button Usages and Collections
    • 9.19.3. Generic Buttons Device Example
  • 9.20. NVDIMM Devices
    • 9.20.1. Overview
    • 9.20.2. NVDIMM Root Device
    • 9.20.3. NVDIMM Device
    • 9.20.4. Example
    • 9.20.5. Loading NVDIMM drivers
    • 9.20.6. Hot Plug Support
    • 9.20.7. NVDIMM Root Device _DSMs
      • 9.20.7.1. Input Parameters:
      • 9.20.7.2. Address Range Scrubbing (ARS) Overview
      • 9.20.7.3. Address Range Scrub (ARS) Error Injection Overview
      • 9.20.7.4. Function Index 1 - Query ARS Capabilities
      • 9.20.7.5. Function Index 2 - Start ARS
      • 9.20.7.6. Function Index 3 - Query ARS Status
      • 9.20.7.7. Function Index 4 - Clear Uncorrectable Error
      • 9.20.7.8. Function Index 5 - Translate SPA
      • 9.20.7.9. Function Index 7 - ARS Error Inject
      • 9.20.7.10. Function Index 8 - ARS Error Inject Clear
      • 9.20.7.11. Function Index 9 - ARS Error Inject Status Query
      • 9.20.7.12. Function Index 0xA - Query ARS Error Inject Capabilities
    • 9.20.8. NVDIMM Device Methods
      • 9.20.8.1. _NCH (Get NVDIMM Current Health Information)
      • 9.20.8.2. _NBS (Get NVDIMM Boot Status)
      • 9.20.8.3. _NIC (Get NVDIMM Health Error Injection Capabilities)
      • 9.20.8.4. _NIH (NVDIMM Inject/Clear Health Errors)
      • 9.20.8.5. _NIG (Get NVDIMM Inject Health Error Status)
• 10. Power Source and Power Meter Devices
  • 10.1. Smart Battery Subsystems
    • 10.1.1. ACPI Smart Battery Status Change Notification Requirements
      • 10.1.1.1. Smart Battery Charger
      • 10.1.1.2. Smart Battery Charger with optional System Manager or Selector
      • 10.1.1.3. Smart Battery System Manager
      • 10.1.1.4. Smart Battery Selector
    • 10.1.2. Smart Battery Objects
    • 10.1.3. _SBS (Smart Battery Subsystem)
      • 10.1.3.1. Example: Single Smart Battery Subsystem
      • 10.1.3.2. Multiple Smart Battery Subsystem: Example
  • 10.2. Control Method Batteries
    • 10.2.1. Battery Events
    • 10.2.2. Battery Control Methods
      • 10.2.2.1. _BCT (Battery Charge Time)
      • 10.2.2.2. _BIF (Battery Information)
      • 10.2.2.3. _BIX (Battery Information Extended)
      • 10.2.2.4. _BMA (Battery Measurement Averaging Interval)
      • 10.2.2.5. _BMC (Battery Maintenance Control)
      • 10.2.2.6. _BMD (Battery Maintenance Data)
      • 10.2.2.7. _BMS (Battery Measurement Sampling Time)
      • 10.2.2.8. _BPC (Battery Power Characteristics)
      • 10.2.2.9. _BPS (Battery Power State)
      • 10.2.2.10. _BPT (Battery Power Threshold)
      • 10.2.2.11. _BST (Battery Status)
      • 10.2.2.12. _BTH (Battery Throttle Limit)
      • 10.2.2.13. _BTM (Battery Time)
      • 10.2.2.14. _BTP (Battery Trip Point)
      • 10.2.2.15. _OSC Definition for Control Method Battery
  • 10.3. AC Adapters and Power Source Objects
    • 10.3.1. _PSR (Power Source)
    • 10.3.2. _PCL (Power Consumer List)
    • 10.3.3. _PIF (Power Source Information)
    • 10.3.4. _PRL (Power Source Redundancy List)
  • 10.4. Power Meters
    • 10.4.1. _PMC (Power Meter Capabilities)
    • 10.4.2. _PTP (Power Trip Points)
    • 10.4.3. _PMM (Power Meter Measurement)
    • 10.4.4. _PAI (Power Averaging Interval)
    • 10.4.5. _GAI (Get Averaging Interval)
    • 10.4.6. _SHL (Set Hardware Limit)
    • 10.4.7. _GHL (Get Hardware Limit)
    • 10.4.8. _PMD (Power Metered Devices)
  • 10.5. Wireless Power Controllers
    • 10.5.1. Wireless Power Calibration Device
    • 10.5.2. Wireless Power Calibration (_WPC)
    • 10.5.3. Wireless Power Polling (_WPP)
  • 10.6. Wireless Power Calibration Event
  • 10.7. Example: Power Source and Power Meter Namespace
• 11. Thermal Management
  • 11.1. Thermal Control
    • 11.1.1. Active, Passive, and Critical Policies
    • 11.1.2. Dynamically Changing Cooling Temperature Trip Points
      • 11.1.2.1. OSPM Change of Cooling Policy
      • 11.1.2.2. Resetting Cooling Temperatures to Adjust to Bay Device Insertion or Removal
      • 11.1.2.3. Resetting Cooling Temperatures to Implement Hysteresis
    • 11.1.3. Detecting Temperature Changes
      • 11.1.3.1. Temperature Change Notifications
      • 11.1.3.2. Polling
    • 11.1.4. Active Cooling
    • 11.1.5. Passive Cooling
      • 11.1.5.1. Processor Clock Throttling
    • 11.1.6. Critical Shutdown
  • 11.2. Cooling Preferences
    • 11.2.1. Evaluating Thermal Device Lists
    • 11.2.2. Evaluating Device Thermal Relationship Information
    • 11.2.3. Fan Device Notifications
  • 11.3. Fan Device
    • 11.3.1. Fan Objects
      • 11.3.1.1. _FIF (Fan Information)
      • 11.3.1.2. _FPS (Fan Performance States)
      • 11.3.1.3. _FSL (Fan Set Level)
      • 11.3.1.4. _FST (Fan Status)
  • 11.4. Thermal Objects
    • 11.4.1. _ACx (Active Cooling)
    • 11.4.2. _ALx (Active List)
    • 11.4.3. _ART (Active Cooling Relationship Table)
    • 11.4.4. _CRT (Critical Temperature)
    • 11.4.5. _CR3 (Warm/Standby Temperature)
    • 11.4.6. _DTI (Device Temperature Indication)
    • 11.4.7. _HOT (Hot Temperature)
    • 11.4.8. _MTL (Minimum Throttle Limit)
    • 11.4.9. _NTT (Notification Temperature Threshold)
    • 11.4.10. _PSL (Passive List)
    • 11.4.11. _PSV (Passive)
    • 11.4.12. _RTV (Relative Temperature Values)
    • 11.4.13. _SCP (Set Cooling Policy)
    • 11.4.14. _STR (String)
    • 11.4.15. _TC1 (Thermal Constant 1)
    • 11.4.16. _TC2 (Thermal Constant 2)
    • 11.4.17. _TFP (Thermal fast Sampling Period)
    • 11.4.18. _TMP (Temperature)
    • 11.4.19. _TPT (Trip Point Temperature)
    • 11.4.20. _TRT (Thermal Relationship Table)
    • 11.4.21. _TSN (Thermal Sensor Device)
    • 11.4.22. _TSP (Thermal Sampling Period)
    • 11.4.23. _TST (Temperature Sensor Threshold)
    • 11.4.24. _TZD (Thermal Zone Devices)
    • 11.4.25. _TZM (Thermal Zone Member)
    • 11.4.26. _TZP (Thermal Zone Polling)
  • 11.5. Native OS Device Driver Thermal Interfaces
  • 11.6. Thermal Zone Interface Requirements
  • 11.7. Thermal Zone Examples
    • 11.7.1. Example: The Basic Thermal Zone
    • 11.7.2. Example: Multiple-Speed Fans
    • 11.7.3. Example: Thermal Zone with Multiple Devices
• 12. ACPI Embedded Controller Interface Specification
  • 12.1. Embedded Controller Interface Description
  • 12.2. Embedded Controller Register Descriptions
    • 12.2.1. Embedded Controller Status, EC_SC (R)
    • 12.2.2. Embedded Controller Command, EC_SC (W)
    • 12.2.3. Embedded Controller Data, EC_DATA (R/W)
  • 12.3. Embedded Controller Command Set
    • 12.3.1. Read Embedded Controller, RD_EC (0x80)
    • 12.3.2. Write Embedded Controller, WR_EC (0x81)
    • 12.3.3. Burst Enable Embedded Controller, BE_EC (0x82)
    • 12.3.4. Burst Disable Embedded Controller, BD_EC (0x83)
    • 12.3.5. Query Embedded Controller, QR_EC (0x84)
  • 12.4. SMBus Host Controller Notification Header (Optional), OS_SMB_EVT
  • 12.5. Embedded Controller Firmware
  • 12.6. Interrupt Model
    • 12.6.1. Event Interrupt Model
    • 12.6.2. Command Interrupt Model
  • 12.7. Embedded Controller Interfacing Algorithms
  • 12.8. Embedded Controller Description Information
  • 12.9. SMBus Host Controller Interface via Embedded Controller
    • 12.9.1. Register Description
      • 12.9.1.1. Status Register, SMB_STS
      • 12.9.1.2. Protocol Register, SMB_PRTCL
      • 12.9.1.3. Address Register, SMB_ADDR
      • 12.9.1.4. Command Register, SMB_CMD
      • 12.9.1.5. Data Register Array, SMB_DATA[i], i=0-31
      • 12.9.1.6. Block Count Register, SMB_BCNT
      • 12.9.1.7. Alarm Address Register, SMB_ALRM_ADDR
      • 12.9.1.8. Alarm Data Registers, SMB_ALRM_DATA[0], SMB_ALRM_DATA[1]
    • 12.9.2. Protocol Description
      • 12.9.2.1. Write Quick
      • 12.9.2.2. Read Quick
      • 12.9.2.3. Send Byte
      • 12.9.2.4. Receive Byte
      • 12.9.2.5. Write Byte
      • 12.9.2.6. Read Byte
      • 12.9.2.7. Write Word
      • 12.9.2.8. Read Word
      • 12.9.2.9. Write Block
      • 12.9.2.10. Read Block
      • 12.9.2.11. Process Call
      • 12.9.2.12. Block Write-Block Read Process Call
      • 12.9.2.13. SMBus Register Set
  • 12.10. SMBus Devices
    • 12.10.1. SMBus Device Access Restrictions
    • 12.10.2. SMBus Device Command Access Restriction
  • 12.11. Defining an Embedded Controller Device in ACPI Namespace
    • 12.11.1. Example: EC Definition ASL Code
  • 12.12. Defining an EC SMBus Host Controller in ACPI Namespace
    • 12.12.1. Example: EC SMBus Host Controller ASL-Code
• 13. ACPI System Management Bus Interface Specification
  • 13.1. SMBus Overview
    • 13.1.1. SMBus Slave Addresses
    • 13.1.2. SMBus Protocols
    • 13.1.3. SMBus Status Codes
    • 13.1.4. SMBus Command Values
  • 13.2. Accessing the SMBus from ASL Code
    • 13.2.1. Declaring SMBus Host Controller Objects
    • 13.2.2. Declaring SMBus Devices
    • 13.2.3. Declaring SMBus Operation Regions
    • 13.2.4. Declaring SMBus Fields
    • 13.2.5. Declaring and Using an SMBus Data Buffer
  • 13.3. Using the SMBus Protocols
    • 13.3.1. Read/Write Quick (SMBQuick)
    • 13.3.2. Send/Receive Byte (SMBSendReceive)
    • 13.3.3. Read/Write Byte (SMBByte)
    • 13.3.4. Read/Write Word (SMBWord)
    • 13.3.5. Read/Write Block (SMBBlock)
    • 13.3.6. Word Process Call (SMBProcessCall)
    • 13.3.7. Block Process Call (SMBBlockProcessCall)
• 14. Platform Communications Channel (PCC)
  • 14.1. Platform Communications Channel Table
    • 14.1.1. Platform Communications Channel Global Flags
    • 14.1.2. Platform Communications Channel Subspace Structures
    • 14.1.3. Generic Communications Subspace Structure (type 0)
    • 14.1.4. HW-Reduced Communications Subspace Structure (type 1)
    • 14.1.5. HW-Reduced Communications Subspace Structure (type 2)
    • 14.1.6. Extended PCC subspaces (types 3 and 4)
    • 14.1.7. HW Registers based Communications Subspace Structure (Type 5)
  • 14.2. Generic Communications Channel Shared Memory Region
    • 14.2.1. Generic Communications Channel Command Field
    • 14.2.2. Generic Communications Channel Status Field
  • 14.3. Extended PCC Subspace Shared Memory Region
  • 14.4. Reduced PCC Subspace Shared Memory Region
  • 14.5. Doorbell Protocol
  • 14.6. Platform Notification
    • 14.6.1. Platform Notification for Subspace Types 0, 1 and 2
    • 14.6.2. Platform Notification for slave PCC subspaces (type 4)
  • 14.7. Referencing the PCC address space
• 15. System Address Map Interfaces
  • 15.1. INT 15H, E820H - Query System Address Map
  • 15.2. E820 Assumptions and Limitations
  • 15.3. UEFI GetMemoryMap() Boot Services Function
  • 15.4. UEFI Assumptions and Limitations
  • 15.5. Example Address Map
  • 15.6. Example: Operating System Usage
• 16. Waking and Sleeping
  • 16.1. Sleeping States
    • 16.1.1. S1 Sleeping State
      • 16.1.1.1. Example 1: S1 Sleeping State Implementation
      • 16.1.1.2. Example 2: S1 Sleeping State Implementation
    • 16.1.2. S2 Sleeping State
      • 16.1.2.1. Example: S2 Sleeping State Implementation
    • 16.1.3. S3 Sleeping State
      • 16.1.3.1. Example: S3 Sleeping State Implementation
    • 16.1.4. S4 Sleeping State
      • 16.1.4.1. Operating System-Initiated S4 Transition
      • 16.1.4.2. The S4BIOS Transition
    • 16.1.5. S5 Soft Off State
    • 16.1.6. Transitioning from the Working to the Sleeping State
    • 16.1.7. Transitioning from the Working to the Soft Off State
  • 16.2. Flushing Caches
  • 16.3. Initialization
    • 16.3.1. Placing the System in ACPI Mode
    • 16.3.2. Platform Boot Firmware Initialization of Memory
    • 16.3.3. OS Loading
    • 16.3.4. Exiting ACPI Mode
• 17. Non-Uniform Memory Access (NUMA) Architecture Platforms
  • 17.1. NUMA Node
  • 17.2. System Locality
    • 17.2.1. System Resource Affinity Table Definition
    • 17.2.2. System Resource Affinity Update
  • 17.3. System Locality Distance Information
    • 17.3.1. Online Hot Plug
    • 17.3.2. Impact to Existing Localities
  • 17.4. Heterogeneous Memory Attributes Information
    • 17.4.1. Online Hot Plug
    • 17.4.2. Impact to Existing Localities
• 18. ACPI Platform Error Interfaces (APEI)
  • 18.1. Hardware Errors and Error Sources
  • 18.2. Relationship between OSPM and System Firmware
  • 18.3. Error Source Discovery
    • 18.3.1. Boot Error Source
    • 18.3.2. ACPI Error Source
      • 18.3.2.1. IA-32 Architecture Machine Check Exception
      • 18.3.2.2. IA-32 Architecture Corrected Machine Check
      • 18.3.2.3. IA-32 Architecture Non-Maskable Interrupt
      • 18.3.2.4. PCI Express Root Port AER Structure
      • 18.3.2.5. PCI Express Device AER Structure
      • 18.3.2.6. PCI Express/PCI-X Bridge AER Structure
      • 18.3.2.7. Generic Hardware Error Source
      • 18.3.2.8. Generic Hardware Error Source version 2 (GHESv2 - Type 10)
      • 18.3.2.9. Hardware Error Notification
      • 18.3.2.10. IA-32 Architecture Deferred Machine Check
  • 18.4. Firmware First Error Handling
    • 18.4.1. Example: Firmware First Handling Using NMI Notification
  • 18.5. Error Serialization
    • 18.5.1. Serialization Action Table
      • 18.5.1.1. Serialization Actions
      • 18.5.1.2. Serialization Instruction Entries
      • 18.5.1.3. Error Record Serialization Information
    • 18.5.2. Operations
      • 18.5.2.1. Writing
      • 18.5.2.2. Reading
      • 18.5.2.3. Clearing
      • 18.5.2.4. Usage
  • 18.6. Error Injection
    • 18.6.1. Error Injection Table (EINJ)
    • 18.6.2. Injection Instruction Entries
    • 18.6.3. Injection Instructions
    • 18.6.4. Error Types
    • 18.6.5. Trigger Action Table
    • 18.6.6. Error Injection Operation
  • 18.7. GHES_ASSIST Error Reporting
    • 18.7.1. GHES_ASSIST on Machine Check Architecture
• 19. ACPI Source Language (ASL) Reference
  • 19.1. ASL 2.0 Symbolic Operators and Expressions
  • 19.2. ASL Language Grammar
    • 19.2.1. ASL Grammar Notation
    • 19.2.2. ASL Name and Pathname Terms
    • 19.2.3. ASL Root and Secondary Terms
    • 19.2.4. ASL Data and Constant Terms
    • 19.2.5. ASL Opcode Terms
    • 19.2.6. ASL Primary (Terminal) Terms
    • 19.2.7. ASL Parameter Keyword Terms
    • 19.2.8. ASL Resource Template Terms
  • 19.3. ASL Concepts
    • 19.3.1. ASL Names
      • 19.3.1.1. _T_x Reserved Object Names
    • 19.3.2. ASL Literal Constants
      • 19.3.2.1. Integers
      • 19.3.2.2. Strings
    • 19.3.3. ASL Resource Templates
    • 19.3.4. ASL Macros
    • 19.3.5. ASL Data Types
      • 19.3.5.1. Data Type Conversion Overview
      • 19.3.5.2. Explicit Data Type Conversions
      • 19.3.5.3. Implicit Data Type Conversions
      • 19.3.5.4. Implicit Source Operand Conversion
      • 19.3.5.5. Implicit Result Object Conversion
      • 19.3.5.6. Data Types and Type Conversions
      • 19.3.5.7. Data Type Conversion Rules
      • 19.3.5.8. Rules for Storing and Copying Objects
  • 19.4. ASL Operators Summary
  • 19.5. ASL Operator Summary by Type
  • 19.6. ASL Operator Reference
    • 19.6.1. AccessAs (Change Field Unit Access)
    • 19.6.2. Acquire (Acquire a Mutex)
    • 19.6.3. Add (Integer Add)
    • 19.6.4. Alias (Declare Name Alias)
    • 19.6.5. And (Integer Bitwise And)
    • 19.6.6. Argx (Method Argument Data Objects)
    • 19.6.7. BankField (Declare Bank/Data Field)
    • 19.6.8. Break (Break from While)
    • 19.6.9. BreakPoint (Execution Break Point)
    • 19.6.10. Buffer (Declare Buffer Object)
    • 19.6.11. Case (Expression for Conditional Execution)
    • 19.6.12. Concatenate (Concatenate Data)
    • 19.6.13. ConcatenateResTemplate (Concatenate Resource Templates)
    • 19.6.14. CondRefOf (Create Object Reference Conditionally)
    • 19.6.15. Connection (Declare Field Connection Attributes)
    • 19.6.16. Continue (Continue Innermost Enclosing While)
    • 19.6.17. CopyObject (Copy and Store Object)
    • 19.6.18. CreateBitField (Create 1-Bit Buffer Field)
    • 19.6.19. CreateByteField (Create 8-Bit Buffer Field)
    • 19.6.20. CreateDWordField (Create 32-Bit Buffer Field)
    • 19.6.21. CreateField (Create Arbitrary Length Buffer Field)
    • 19.6.22. CreateQWordField (Create 64-Bit Buffer Field)
    • 19.6.23. CreateWordField (Create 16-Bit Buffer Field)
    • 19.6.24. CSI2Bus (CSI-2 Serial Bus Connection Resource Descriptor Macro)
    • 19.6.25. DataTableRegion (Create Data Table Operation Region)
    • 19.6.26. Debug (Debugger Output)
    • 19.6.27. Decrement (Integer Decrement)
    • 19.6.28. Default (Default Execution Path in Switch)
    • 19.6.29. DefinitionBlock (Declare Definition Block)
    • 19.6.30. DerefOf (Dereference an Object Reference)
    • 19.6.31. Device (Declare Device Package)
    • 19.6.32. Divide (Integer Divide)
    • 19.6.33. DMA (DMA Resource Descriptor Macro)
    • 19.6.34. DWordIO (DWord IO Resource Descriptor Macro)
    • 19.6.35. DWordMemory (DWord Memory Resource Descriptor Macro)
    • 19.6.36. DWordSpace (DWord Space Resource Descriptor Macro)
    • 19.6.37. EISAID (EISA ID String To Integer Conversion Macro)
    • 19.6.38. Else (Alternate Execution)
    • 19.6.39. ElseIf (Alternate/Conditional Execution)
    • 19.6.40. EndDependentFn (End Dependent Function Resource Descriptor Macro)
    • 19.6.41. Event (Declare Event Synchronization Object)
    • 19.6.42. ExtendedIO (Extended IO Resource Descriptor Macro)
    • 19.6.43. ExtendedMemory (Extended Memory Resource Descriptor Macro)
    • 19.6.44. ExtendedSpace (Extended Address Space Resource Descriptor Macro)
    • 19.6.45. External (Declare External Objects)
    • 19.6.46. Fatal (Fatal Error Check)
    • 19.6.47. Field (Declare Field Objects)
    • 19.6.48. FindSetLeftBit (Find First Set Left Bit)
    • 19.6.49. FindSetRightBit (Find First Set Right Bit)
    • 19.6.50. FixedDMA (DMA Resource Descriptor Macro)
    • 19.6.51. FixedIO (Fixed IO Resource Descriptor Macro)
    • 19.6.52. For (Conditional Loop)
    • 19.6.53. Fprintf (Create and Store formatted string)
    • 19.6.54. FromBCD (Convert BCD To Integer)
    • 19.6.55. Function (Declare Control Method)
    • 19.6.56. GpioInt (GPIO Interrupt Connection Resource Descriptor Macro)
    • 19.6.57. GpioIo (GPIO Connection IO Resource Descriptor Macro)
    • 19.6.58. I2CSerialBusV2 (I2C Serial Bus Connection Resource Descriptor (Version 2) Macro)
    • 19.6.59. If (Conditional Execution)
    • 19.6.60. Include (Include Additional ASL File)
    • 19.6.61. Increment (Integer Increment)
    • 19.6.62. Index (Indexed Reference To Member Object)
      • 19.6.62.1. Index with Packages
      • 19.6.62.2. Index with Buffers
      • 19.6.62.3. Index with Strings
    • 19.6.63. IndexField (Declare Index/Data Fields)
    • 19.6.64. Interrupt (Interrupt Resource Descriptor Macro)
    • 19.6.65. IO (IO Resource Descriptor Macro)
    • 19.6.66. IRQ (Interrupt Resource Descriptor Macro)
    • 19.6.67. IRQNoFlags (Interrupt Resource Descriptor Macro)
    • 19.6.68. LAnd (Logical And)
    • 19.6.69. LEqual (Logical Equal)
    • 19.6.70. LGreater (Logical Greater)
    • 19.6.71. LGreaterEqual (Logical Greater Than Or Equal)
    • 19.6.72. LLess (Logical Less)
    • 19.6.73. LLessEqual (Logical Less Than Or Equal)
    • 19.6.74. LNot (Logical Not)
    • 19.6.75. LNotEqual (Logical Not Equal)
    • 19.6.76. Load (Load Definition Block)
    • 19.6.77. LoadTable (Load Definition Block From XSDT)
    • 19.6.78. Localx (Method Local Data Objects)
    • 19.6.79. LOr (Logical Or)
    • 19.6.80. Match (Find Object Match)
    • 19.6.81. Memory24 (Memory Resource Descriptor Macro)
    • 19.6.82. Memory32 (Memory Resource Descriptor Macro)
    • 19.6.83. Memory32Fixed (Memory Resource Descriptor Macro)
    • 19.6.84. Method (Declare Control Method)
    • 19.6.85. Mid (Extract Portion of Buffer or String)
    • 19.6.86. Mod (Integer Modulo)
    • 19.6.87. Multiply (Integer Multiply)
    • 19.6.88. Mutex (Declare Synchronization/Mutex Object)
    • 19.6.89. Name (Declare Named Object)
    • 19.6.90. NAnd (Integer Bitwise Nand)
    • 19.6.91. NoOp Code (No Operation)
    • 19.6.92. NOr (Integer Bitwise Nor)
    • 19.6.93. Not (Integer Bitwise Not)
    • 19.6.94. Notify (Notify Object of Event)
    • 19.6.95. Offset (Change Current Field Unit Offset)
    • 19.6.96. ObjectType (Get Object Type)
    • 19.6.97. One (Constant One Integer)
    • 19.6.98. Ones (Constant Ones Integer)
    • 19.6.99. OperationRegion (Declare Operation Region)
    • 19.6.100. Or (Integer Bitwise Or)
    • 19.6.101. Package (Declare Package Object)
    • 19.6.102. PinConfig (Pin Configuration Descriptor Macro)
    • 19.6.103. PinFunction (Pin Function Descriptor Macro)
    • 19.6.104. PinGroup (Pin Group Descriptor Macro)
    • 19.6.105. PinGroupConfig (Pin Group Configuration Descriptor Macro)
    • 19.6.106. PinGroupFunction (Pin Group Function Configuration Descriptor Macro)
    • 19.6.107. PowerResource (Declare Power Resource)
    • 19.6.108. Printf (Create and Store formatted string)
    • 19.6.109. QWordIO (QWord IO Resource Descriptor Macro)
    • 19.6.110. QWordMemory (QWord Memory Resource Descriptor Macro)
    • 19.6.111. QWordSpace (QWord Space Resource Descriptor Macro)
    • 19.6.112. RawDataBuffer (Raw Data Buffer)
    • 19.6.113. RefOf (Create Object Reference)
    • 19.6.114. Register (Generic Register Resource Descriptor Macro)
    • 19.6.115. Release (Release a Mutex Synchronization Object)
    • 19.6.116. Reset (Reset an Event Synchronization Object)
    • 19.6.117. ResourceTemplate (Resource To Buffer Conversion Macro)
    • 19.6.118. Return (Return from Method Execution)
    • 19.6.119. Revision (Constant Revision Integer)
    • 19.6.120. Scope (Open Named Scope)
    • 19.6.121. ShiftLeft (Integer Shift Left)
    • 19.6.122. ShiftRight (Integer Shift Right)
    • 19.6.123. Signal (Signal a Synchronization Event)
    • 19.6.124. SizeOf (Get Data Object Size)
    • 19.6.125. Sleep (Milliseconds Sleep)
    • 19.6.126. SPISerialBusV2 (SPI Serial Bus Connection Resource Descriptor (Version 2) Macro)
    • 19.6.127. Stall (Stall for a Short Time)
    • 19.6.128. StartDependentFn (Start Dependent Function Resource Descriptor Macro)
    • 19.6.129. StartDependentFnNoPri (Start Dependent Function Resource Descriptor Macro)
    • 19.6.130. Store (Store an Object)
    • 19.6.131. Subtract (Integer Subtract)
    • 19.6.132. Switch (Select Code To Execute Based On Expression)
    • 19.6.133. ThermalZone (Declare Thermal Zone)
    • 19.6.134. Timer (Get 64-Bit Timer Value)
    • 19.6.135. ToBCD (Convert Integer to BCD)
    • 19.6.136. ToBuffer (Convert Data to Buffer)
    • 19.6.137. ToDecimalString (Convert Data to Decimal String)
    • 19.6.138. ToHexString (Convert Data to Hexadecimal String)
    • 19.6.139. ToInteger (Convert Data to Integer)
    • 19.6.140. ToPLD (Creates a _PLD Buffer Object)
    • 19.6.141. ToString (Convert Buffer To String)
    • 19.6.142. ToUUID (Convert String to UUID Macro)
    • 19.6.143. UARTSerialBusV2 (UART Serial Bus Connection Resource Descriptor Version 2 Macro)
    • 19.6.144. Unicode (String To Unicode Conversion Macro)
    • 19.6.145. VendorLong (Long Vendor Resource Descriptor)
    • 19.6.146. VendorShort (Short Vendor Resource Descriptor)
    • 19.6.147. Wait (Wait for a Synchronization Event)
    • 19.6.148. While (Conditional Loop)
    • 19.6.149. WordBusNumber (Word Bus Number Resource Descriptor Macro)
    • 19.6.150. WordIO (Word IO Resource Descriptor Macro)
    • 19.6.151. WordSpace (Word Space Resource Descriptor Macro)
    • 19.6.152. XOr (Integer Bitwise Xor)
    • 19.6.153. Zero (Constant Zero Integer)
• 20. ACPI Machine Language (AML) Specification
  • 20.1. Notation Conventions
  • 20.2. AML Grammar Definition
    • 20.2.1. Table and Table Header Encoding
    • 20.2.2. Name Objects Encoding
    • 20.2.3. Data Objects Encoding
    • 20.2.4. Package Length Encoding
    • 20.2.5. Term Objects Encoding
      • 20.2.5.1. Namespace Modifier Objects Encoding
      • 20.2.5.2. Named Objects Encoding
      • 20.2.5.3. Statement Opcodes Encoding
      • 20.2.5.4. Expression Opcodes Encoding
    • 20.2.6. Miscellaneous Objects Encoding
      • 20.2.6.1. Arg Objects Encoding
      • 20.2.6.2. Local Objects Encoding
      • 20.2.6.3. Debug Objects Encoding
  • 20.3. AML Byte Stream Byte Values
  • 20.4. AML Encoding of Names in the Namespace
• 21. ACPI Data Tables and Table Definition Language
  • 21.1. Types of ACPI Data Tables
  • 21.2. ACPI Table Definition Language Specification
    • 21.2.1. Overview of the Table Definition Language (TDL)
    • 21.2.2. TDL Grammar Specification
    • 21.2.3. Data Types
      • 21.2.3.1. Integers
      • 21.2.3.2. Integer Expressions
      • 21.2.3.3. Flags
      • 21.2.3.4. Strings
      • 21.2.3.5. Buffers
    • 21.2.4. Fields Set Automatically by the Compiler
    • 21.2.5. Special Fields
    • 21.2.6. TDL Generic Data Types
    • 21.2.7. Defining a Known ACPI Table in TDL
    • 21.2.8. Defining an Unknown or New ACPI table in TDL
    • 21.2.9. Table Definition Language Examples
      • 21.2.9.1. ECDT Disassembler Output
      • 21.2.9.2. ECDT Definition with Field Comments
    • 21.2.10. Minimal ECDT Definition
      • 21.2.10.1. Generic ACPI Table Definition

• Appendix A: Device Class Specifications
  • Overview
  • Device Power States
    • Bus Power Management
    • Display Power Management
    • PCMCIA/PCCARD/CardBus Power Management
    • PCI Power Management
    • USB Power Management
    • Device Classes
  • Default Device Class
    • Default Power Management Policy
    • Default Wake Events
    • Default Minimum Power Capabilities
  • Audio Device Class
    • Audio Device Power State Definitions
    • Audio Device Power Management Policy
    • Audio Device Wake Events
    • Audio Device Minimum Power Capabilities
  • COM Port Device Class
    • COM Port Power State Definitions
    • COM Power Power Management Policy
    • COM Port Wake Events
    • COM Port Minimum Power Capabilities
  • Display Device Class
    • Display Device Power State Definitions
    • Display Device Power Management Policy
    • Display Device Wake Events
    • Display Device Minimum Power Capabilities
    • Display Device Performance States
  • Input Device Class
    • Input Device Power State Definitions
    • Input Device Power Management Policy
    • Input Device Wake Events
    • Input Device Minimum Power Capabilities
  • Modem Device Class
    • Technology Overview
    • Modem Device Power State Definitions
    • Modem Device Power Management Policy
    • Modem Device Wake Events
    • Modem Device Minimum Power Capabilities
  • Network Device Class
    • Network Device Power State Definitions
    • Network Device Power Management Policy
    • Network Device Wake Events
    • Network Device Minimum Power Capabilities
  • PC Card Controller Device Class
    • PC Card Controller Device Power State Definitions
    • PC Card Controller Device Power Management Policy
    • PC Card Controller Wake Events
    • PC Card Controller Minimum Power Capabilities
  • Storage Device Class
    • Storage Device Power State Definitions
    • Storage Device Power Management Policy
    • Storage Device Wake Events
    • Storage Device Minimum Power Capabilities
• Appendix B: Video Extensions
  • ACPI Extensions for Display Adapters: Introduction
  • Video Extension Definitions
  • ACPI Namespace
  • Display-specific Methods
    • _DOS (Enable/Disable Output Switching)
    • _DOD (Enumerate All Devices Attached to the Display Adapter)
    • _ROM (Get ROM Data)
    • _GPD (Get POST Device)
    • _SPD (Set POST Device)
    • _VPO (Video POST Options)
  • Notifications for Display Devices
  • Output Device-specific Methods
    • _ADR (Return the Unique ID for this Device)
    • _BCL (Query List of Brightness Control Levels Supported)
    • _BCM (Set the Brightness Level)
    • _BQC (Brightness Query Current level)
    • _DDC (Return the EDID for this Device)
    • _DCS (Return the Status of Output Device)
    • _DGS (Query Graphics State)
    • _DSS (Device Set State)
  • Notifications Specific to Output Devices
  • Notes on State Changes
• Appendix C: Deprecated Content