The ACPI Component Architecture Project
The ACPI Component Architecture (ACPICA) project provides an operating system (OS)-independent reference implementation of the Advanced Configuration and Power Interface Specification (ACPI). It can be easily adapted to execute under any host OS. The ACPICA code is meant to be directly integrated into the host OS as a kernel-resident subsystem. Hosting the ACPICA subsystem requires no changes to the core ACPICA code. Instead, a small OS-specific interface layer is written specifically for each host OS in order to interface the ACPICA code to the native OS services.
The complexity of the ACPI specification leads to a lengthy and difficult implementation in operating system software. The primary purpose of the ACPI Component Architecture is to simplify ACPI implementations for operating system vendors (OSVs) by providing major portions of an ACPI implementation in OS-independent ACPI modules that can be easily integrated into any OS.
News
30 July 2009: The implementation of ACPI 4.0 support within ACPICA is complete with version 20090730.05 April 2010: ACPI 4.0a Specification is released. No ACPICA changes are required for ACPI 4.0a.
02 July 2010: iASL Data Table Compiler is released to simplify creation of non-AML ACPI tables (FADT, MADT, etc.)
09 December 2010: Major overhaul of the GPE support code. See the ACPICA Programmer Reference.
23 June 2011: Added AcpiHelp utility for ASL/AML operators, opcodes, and keywords.
16 August 2011: ACPICA git source repository moved to github.com.
23 November 2011: ACPI 5.0 Specification is released. The document can be obtained at the acpi.info website here
23 November 2011: Full support for ACPI 5.0 in ACPICA is released (version 20111123).