The Advanced Configuration and Power Interface (ACPI) is an open framework that let’s the operating system manage the power of your device.
This process is better known as Operating System-directed configuration and Power Management (OSPM) which runs the gamut across computers including laptops, desktops, servers and even mobile devices.
The OSPM provides a means for systems to ration power by transitioning dormant components into low power states whenever possible. I think it’s important that the OS plays a pivotal role in apportioning power states because it makes it easy for software vendors to bake power management functionality into their software.
ACPI is really just a bunch of static tables and runtime control methods that lets the firmware report power management stuff to the OS.
ACPI is also completely independent of the CPU so this is a huge plus because it liberates ACPI from a single architecture.
The only really “issue” I’ve discovered with the ACPI is that it only has a small coterie of adopters.
Microsoft, Intel, HP, Phoenix and Toshiba were the original promoters but there was a need to take the standard to the next level, a need that couldn’t be actualized unless there was a governing body out there that could champion the task.
And now… ladies and gentleman, I introduce to you: UEFI.
UEFI takes the stage and bows.
UEFI currently has 250 members including contributors from the Linux Foundation and ARM. Under the auspices of the UEFI forum, we now have a permanent home for the ACPI specification. Furthermore, since UEFI espouses the zeitgeist of open collaboration, I’m expecting the efforts of various Linux distro’s to coalesce with the Linux upstream community.
Let’s face it, BIOS code is convoluted and rigid but under the guidance of the UEFI forum, the entire standard becomes more malleable and therefore affords flexible implementation of features in the future.
5.0 is the latest iteration of the standard; you can peruse the intricacies of the document but the bottom line is that more spec contributors can collaborate on future development. I see real synergies forming from this UEFI press release.
You can read the official presser on the UEFI site.