A few days ago, version 4.0 of the Advanced Configuration and Power Interface (ACPI) specification was released, weighing in at a hefty 727 pages
... there are still flaws in many implementations.
Intel is now developing the Simple Firmware Interface (SFI) especially for small and low spec devices like Mobile Internet Devices (MIDs) with Atom processors, and is particularly targeting the Linux operating system... SFI can be implemented in addition to, or as an alternative to ACPI, in the firmware either within a classic BIOS, (U)EFI, or with alternative firmware like OpenFirmware.
Version 0.6 has been released as a draft and there is a reference implementation for the 2.6.32 kernel."
Everything should be made as simple as possible, but not simpler. -- Albert Einstein