ACPICA. Most of these are still works in progress. Support exists for:
- Fixed feature and control method power, lid and sleep buttons.
- Detection of ISA PnP devices using ACPI namespace.
- Detection of PCI root busses using ACPI namespace.
- CPU throttling and sleep states (incomplete)
- Thermal monitoring and cooling control (incomplete)
- Interface to platform embedded controllers (mostly complete)
- ACPI timer (incomplete)
- Simple userland control of sleep states.
- Shutdown and poweroff.