225 lines
4.1 KiB
HTML
225 lines
4.1 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
|
|
<HTML
|
|
><HEAD
|
|
><TITLE
|
|
>About ACPI</TITLE
|
|
><META
|
|
NAME="GENERATOR"
|
|
CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
|
|
REL="HOME"
|
|
TITLE="ACPI: Advanced Configuration and Power Interface"
|
|
HREF="index.html"><LINK
|
|
REL="PREVIOUS"
|
|
TITLE="Translations"
|
|
HREF="translations.html"><LINK
|
|
REL="NEXT"
|
|
TITLE="Why switch?"
|
|
HREF="apmtoacpi.html"></HEAD
|
|
><BODY
|
|
CLASS="sect1"
|
|
BGCOLOR="#FFFFFF"
|
|
TEXT="#000000"
|
|
LINK="#0000FF"
|
|
VLINK="#840084"
|
|
ALINK="#0000FF"
|
|
><DIV
|
|
CLASS="NAVHEADER"
|
|
><TABLE
|
|
SUMMARY="Header navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TH
|
|
COLSPAN="3"
|
|
ALIGN="center"
|
|
>ACPI: Advanced Configuration and Power Interface</TH
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="left"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="translations.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="80%"
|
|
ALIGN="center"
|
|
VALIGN="bottom"
|
|
></TD
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="right"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="apmtoacpi.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
></TABLE
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"></DIV
|
|
><DIV
|
|
CLASS="sect1"
|
|
><H1
|
|
CLASS="sect1"
|
|
><A
|
|
NAME="aboutacpi"
|
|
></A
|
|
>4. About ACPI</H1
|
|
><P
|
|
>In the world of power management ACPI is relatively new to the game.
|
|
It was first released in 1996 by
|
|
Compaq/Hewlett-Packard, Intel, Microsoft, Phoenix and Toshiba. These
|
|
developers aimed to replace the previous industry standard for power
|
|
management. Their <A
|
|
HREF="http://www.acpi.info"
|
|
TARGET="_top"
|
|
>ACPI.info</A
|
|
> site
|
|
contains the official specifications, a list of companies that support ACPI
|
|
and a number of other goodies. This is definitely not required reading, but
|
|
may be of some interest to the insanely curious.</P
|
|
><P
|
|
>ACPI allows control of power management from within the
|
|
operating system. The previous industry standard for power management, Advanced
|
|
Power Management (APM), is controlled at the BIOS level. APM is activated
|
|
when the system becomes idle--the longer the system idles, the less power it
|
|
consumes (e.g. screen saver vs. sleep vs. suspend).
|
|
In APM, the operating system has no knowledge of when the system will
|
|
change power states.</P
|
|
><P
|
|
>ACPI can typically be configured from within the operating system.
|
|
This is unlike APM where configuration often involves rebooting and
|
|
entering the BIOS configuration screens to set parameters.</P
|
|
><P
|
|
>ACPI has several different software components:</P
|
|
><P
|
|
></P
|
|
><UL
|
|
><LI
|
|
><P
|
|
>a subsystem which controls hardware states and
|
|
functions that may have previously been in the BIOS configuration</P
|
|
><P
|
|
>These states include:</P
|
|
><P
|
|
></P
|
|
><UL
|
|
><LI
|
|
><P
|
|
>thermal control</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
>motherboard configuration</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
>power states (sleep, suspend)</P
|
|
></LI
|
|
></UL
|
|
></LI
|
|
><LI
|
|
><P
|
|
>a policy manager, which is software that sits on top of
|
|
the operating system and allows user input on the system
|
|
policies</P
|
|
></LI
|
|
><LI
|
|
><P
|
|
>the ACPI also has device drivers that control/monitor devices such as a
|
|
laptop battery, SMBus (communication/transmission path) and EC (embedded controller).</P
|
|
></LI
|
|
></UL
|
|
><P
|
|
>If you would like more information on power management in laptops, check out
|
|
the resources on <A
|
|
HREF="http://www.tuxmobil.org"
|
|
TARGET="_top"
|
|
>tuxmobil.org</A
|
|
>.
|
|
Specifically: <A
|
|
HREF="http://tuxmobil.org/apm_linux.html"
|
|
TARGET="_top"
|
|
>Power Management
|
|
with Linux - APM, ACPI, PMU</A
|
|
> and the <A
|
|
HREF="http://tuxmobil.org/Mobile-Guide.db/mobile-guide-p2c1-hardware-in-detail.html"
|
|
TARGET="_top"
|
|
>Hardware in Detail</A
|
|
> section of the
|
|
<A
|
|
HREF="http://tuxmobil.org/Mobile-Guide.db/Mobile-Guide.html"
|
|
TARGET="_top"
|
|
>Linux
|
|
Mobile Guide</A
|
|
>.</P
|
|
></DIV
|
|
><DIV
|
|
CLASS="NAVFOOTER"
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"><TABLE
|
|
SUMMARY="Footer navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="translations.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="index.html"
|
|
ACCESSKEY="H"
|
|
>Home</A
|
|
></TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="apmtoacpi.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
>Translations</TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
> </TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
>Why switch?</TD
|
|
></TR
|
|
></TABLE
|
|
></DIV
|
|
></BODY
|
|
></HTML
|
|
> |