Questions tagged [acpi]

Advanced Configuration and Power Interface, a specification that provides an open standard for device configuration and power management by the operating system.

In computing, the Advanced Configuration and Power Interface (ACPI) specification provides an open standard for device configuration and by the operating system.

First released in December 1996, ACPI defines platform-independent interfaces for hardware discovery, configuration, power management and monitoring. With the intention of replacing Advanced Power Management, the MultiProcessor Specification and the Plug and Play BIOS Specification, the standard brings power management under the control of the operating system, as opposed to the previous BIOS-central system which relied on platform-specific firmware to determine power management and configuration policy. The specification is central to Operating System-directed configuration and Power Management (OSPM), a system implementing ACPI which removes device management responsibilities from legacy firmware interfaces.

The standard was originally developed by Intel, Microsoft and Toshiba, and was later joined by HP and Phoenix. As the ACPI technology gained wider adoption with many operating systems and processor architectures, the desire to improve the governance model of the specification has increased significantly. In October 2013, original developers of the ACPI standard agreed to transfer all assets to the Forum, where all future development will be taking place.3 The latest version of the standard is "Revision 6.2 Errata A", which was published by the UEFI Forum in September 2017.

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Access Laptop Embedded Fan Controller programmatically?

I want to access the embedded controller of my (windows) laptop to control the fan speed. Currently I am doing this manually using RW Everything - how can I access the embedded controller e.g. using C? Thanks for any hint! Please note: I am aware…
stefan.at.wpf
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Programmatically access CPU fan on a laptop? (Windows)

Is there a Windows standard way to do things such as "start fan", "decrease speed" or the like, from C/C++? I have a suspicion it might be ACPI, but I am a frail mortal and cannot read that kind of documentation. Edit: e.g. Windows 7 lets you select…
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Schedule machine to wake up

What's the best way to programmatically cause a Windows XP (or above) machine to wake up at a specific time. (Ideally a lot like how Media Center can start up automatically to record a particular TV program) I've got a Windows service (written in…
David Gardiner
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How can I obtain battery level inside a Linux kernel module?

I am trying to get the battery level inside a Linux kernel module (the module is inserted via modprobe). I would ideally like to use a kernel API call to get the battery information. I have searched on the web for solutions, and I have also explored…
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Difference between dts and ACPI

We can declare platform device information in dts file, rather than hard coding every data into operating system. Taking "arm" architecture as example. it supports dts and we will take dts from arch/arm/boot/dts/xx.dts. Convert this…
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How do I call ACPI control methods from C++ or C# on Windows?

I'm getting tired of waiting for HP to fix the switchable graphics driver for my laptop, but I think I can switch GPUs myself by calling ACPI methods. The switching works using vga_switcheroo in Linux, which is open source, so I know what methods I…
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IOMMU initialization without BIOS support

NOTE: if you have an AMD A55 chipset on a motherboard that support IOMMU, please send me a copy of your /sys/firmware/acpi/tables/DMAR (or whatever the name is that describes IOMMU). There is no risk of any sort for you. Thanks! Most motherboard…
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C#: How to wake up system which has been shutdown?

Is there any Win32 API for waking up a system that has been shut down, at a specific time? I have seen a program named Autopower On which is able to power the system on at a specified time.
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How to get the battery life of mac os x macbooks programatically?

What I wanted to do is take a log on battery percentage. I know the equivalent in linux is sysctl(hw.acpi.battery.life). However when I went through the man of sysctl in mac os x I did not find the equivalent code to find it. Can some one point out…
Vignesh
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How to deny shutdown when pressing the power button for a while?

On most newer computers you can shutdown the hard way by pressing the power button for a couple of seconds. But I want to prevent this completely. You're able to prevent some soft events like the sleep, suspend, hibernate and "Press power button"…
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Run a batch file on Windows 7 shutdown before closing programs (preferably on power button press)

I have a Windows 7 box with multiple VMWare Player machines that are started on boot. I use WMWare VIX and a batch file to shutdown the virtual machines like so: "C:\path\to\VMWare VIX\vmrun.exe" -T player stop "C:\path\to\machine.vmx" soft What…
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How to control power button press shutdown?

I'm working on a kiosk style application where I need to control the shutdown/restart of the PC when the power button is pressed. Thanks to this post, I'm about 90% of the way there. In control panel set the acpi power button press action to…
Mark
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After pm-suspend computer immediately wakes up. How to determine what caused it?

I am running a Debian-Jessy Server, that goes into S3 sleep mode after some hours network inactivity (I made a small bash script that checks it every two hours with crontab). Several seconds after suspending, it wakes up again. After a few hours,…
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Shutdown computer in MS-DOS using ACPI

I have MS-DOS 6.22 running on a Pentium based computer (motherboard supports ACPI), and would like to know if there was an assembly language routine I could use to shut down the computer, or is it a little harder than that (i.e. motherboard…
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How to decipher this ACPI Source Language code?

I used this .NET program to do a binary dump of the Windows Registry at HKLM/Hardware/ACPI/DSDT. Then, running Microsoft's ASL Compiler on that, I can get this ACPI Source Language: Scope(\_TZ_) { Name(TBSE, 0xaac) Name(CRT0, 0x0) …
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