Method and device for advanced configuration and power interface (ACPI) sleep-state support using CPU-only reset

摘要

A mechanism for firmware to gain control from the operating system of an Advanced Configuration and Power Interface (ACPI)-compliant computing device during sleep-state transitions even if the computing device lacks a dedicated means for such a change to occur is discussed. Embodiments of the present invention report a CPU-only reset register in place of a sleep control register for an ACPI-compliant computing device in which an operating system is attempting a sleep-state transition. A CPU reset value is substituted for a sleep type value in a sleep-state object and written to the CPU-only reset register that was reported instead of the sleep control register thereby triggering a CPU-only reset. Firmware code operating at a known CPU reset vector may perform specified processing and then authorize a transition to the originally requested sleep-state.

主权项

1. A computer-implemented method for providing Advanced Configuration and Power Interface (ACPI) sleep-state support in a computing device equipped with a central processing unit (CPU), comprising:
triggering a CPU-only reset for the computing device as a result of an operating system for the computing device determining to enter a specified sleep-state, the CPU-only reset triggered for the computing device instead of the computing device immediately entering into the specified sleep-state, the CPU-only reset using an I/O address of a CPU reset register that populates an ACPI-defined tables in place of an I/O address of a sleep control register; executing firmware code based on the triggered CPU-only reset; and entering the specified sleep-state at an end of execution of the firmware code.