Power Management Status Diagnostics for Win2k "Secret Weapons"

I. Brief Description

About the setting and use of the advanced power management program APM (short for Advanced Power Management), and even the history and evolution of the process, a lot of information There are, so there is no need to repeat those content here. The only explanation is: APM refers to the management function. In the early days, there was no corresponding operation interface in the operating system. Later, especially from Windows 95, APM was applied to the microcomputer a lot, then 亟A corresponding operation interface is required to enable ordinary users to conveniently perform power management settings, which introduces ACPI (Power Management Advanced Configuration Interface). Most computers now support both APM and ACPI.

In Windows 2000, APM supports battery-powered management and can bring a running machine into a wait state to save power. Or resume using from the waiting state. Things like this are familiar to everyone and nothing new. Introduced here is a command line-based tool that allows you to diagnose advanced power management status on the command line and use these status information to help you identify and troubleshoot power management issues.

In windows2000, there are several ways to perform operations related to power management: A. BIOS settings. B. Registry settings. C. In the control panel, use the advanced power management configuration interface to set up. In fact, with the interface settings and to modify the registry settings, the effect of the two is the same as the same --- to facilitate those who do not have the ability to perform registry editing, the introduction of a graphical interface, namely advanced power management configuration Interface. Since advanced power management involves BIOS settings and registry settings, the power state diagnostics will list the power management related settings in the BIOS and the corresponding settings in the registry in the report file it generates.

Second, grammar and application

In the syntax of all supporting tools, the syntax of this tool is the simplest, there is only one command and two switches. The complete syntax is as follows:

apmstat [-v] [-? ]

Command and parameter description:

apmstat

Command file name, the part that must be used, cannot be omitted.

-v

Display settings related to power management: included in the BIOS and in the registry, information related to power management.

-?

Shows the syntax and help information used by the command.

Execution command should first call the so-called open command line console: cmd, after opening, type the command after the system prompt: apmstat –v and then press Enter. You can get the corresponding display information. The following is a screen report that I copied after executing the command on my own machine and displaying the result: (Chinese is added by me)

C:Program FilesSupport Tools>apmstat -v

This computer appears to have an APM legal HAL The APM of this computer has a legal hardware abstraction layer

This machine has an APM bios present that looks OK, and it is

not On the list of machines known to have APM problems. The BIOS settings related to APM are OK, and there is no problem with APM found in the list.

Check the power applet in the control panel to see if APM is enabled. You can detect the power management program in the control panel.

APM Registry Data Dump APM Registry Data Image

Major = 0001 Minor = 0002

InstallFlags = 0007

Code16Segment = f000 Code16Offset = 8560 DataSeg = Fdfc

Signature = APM

Valid = 0001

Detection Log Data: Data in the detected log file

44 45 54 4c 4f 47 31 00 00 00 00 00 00 00 00 00 00

DETLOG 1

C:Program FilesSupport Tools> (screen information ends here)

If you find a problem with power management, These reports will show up. Using the registry data image can be used as a reference for modifying the registry.

Third, related background information

The following is some background information about the power management program:

1. APM is disabled on the windows2000 server.

2. If Windows 2000 does not detect the battery during startup, it is generally considered to be working on a desktop computer. The power management program will automatically configure the default management scheme for the desktop computer.

3. APM can cause problems on desktop computers

Because the operating system introduces a power management program, there are also power management related items in the computer's BIOS settings. And the management projects of both parties can be set. For different computers, different settings will bring different results: some open power management will lead to system instability, only disable power management to solve the problem. Generally, in order to avoid the above-mentioned instability problem caused by the desktop computer to avoid the introduction of APM, the video card or other boards supplied by the third party need to be disabled in the BIOS of the computer. Of course, some computers can allow both to coexist and work well. Since this involves the compatibility of the BIOS, the motherboard, and the added board, the situation is ever-changing. What should be done, you only have to deal with it as appropriate.

4. The main part of APM:

APM BIOS

This refers to the APM (Power Management) related part placed in the BIOS.

Ntdetect.com (Startup Hardware Detector)

This is the part of the operating system that detects APMBIOS information, mainly in the BIOS. The APM part is now available. In fact, this part is related to the registry. From the screen information we intercepted above, it can be found that regardless of the state of the power management settings in the BIOS, it is reflected in the registry.

NtLdr

When the computer was in a dormant state, this part is responsible for recovering it from hibernation.

Ntapm.sys

This part is responsible for linking the operating system to the device driver. Since Windows is an event-triggered operating system, the implementation of power management must also be converted into a Triggerable event. Roughly speaking: This program notifies the operating system when a "management event" occurs.

The connection library file corresponding to the Hal.dll hardware abstraction layer.

Apmbatt.sys

The program for simulating a battery is actually a code that produces an analog battery status.

Power Options control panel program

Power Management Program in Control Panel. Open the control panel, there is a power management icon, double-click to open, you can set it up, this is called ACPI.

Biosinfo.inf

File to save BIOS information.

5. Use of ACPI

When using the control panel to set the power management, after changing the original state, you need to restart the machine to make the new settings take effect. If there is no power management item available in the Control Panel, it is likely that this is a computer that does not support power management.

If your computer uses a battery or UPS, the option to have a battery will appear in the Control Panel option. In fact, there is no battery at all on my own machine, but after opening the control panel, there are also options for the battery, but the related items are not set. See the control panel for details.