ACPI Methods exposure in OS

I w开发者_Go百科ant to write a ACPI method for windows Operating System, as a part of my college project and I am new to this assembly level programming.

I want to know whether ACPI Method will be in BIOS or it can be present in OS and ACPI driver is able to execute that?

ALso how exactly the ACPI Methods are exposed to OS from BIOS of the Current ACPI Methods?

Honestly it sounds like you haven't done ANY research at all. The first result in google returned a wikipedia page that answers your first question:

"...the standard brings power management into operating system control (OSPM), as opposed to the previous BIOS central system, which relied on platform-specific firmware to determine power management and configuration policy..."

"The OSPM implementation must expose an ACPI-compatible environment to device drivers, which exposes certain system, device and processor states."

http://en.wikipedia.org/wiki/Advanced_Configuration_and_Power_Interface

The APIs for the OSPM in Windows are not documented as well as the rest of the Windows API, but atleast there's something...: http://msdn.microsoft.com/en-us/library/ff536161%28v=vs.85%29.aspx

good luck! :)