Debugging information listing the percent of total usage for each sleep state. The values are reset when hw.acpi.cpu.cx_lowest is modified.
Lowest Cx state to use for idling the CPU. A scheduling algorithm will select states between C1 and this setting as system load dictates. To enable ACPI CPU idling control, machdep.cpu_idle_hlt must be set to 1.
List of supported CPU idle states and their transition latency in microseconds. Each state has a type (e.g., C2). C1 is equivalent to the ia32 HLT instruction, C2 provides a deeper sleep with the same semantics, and C3 provides the deepest sleep but additionally requires bus mastering to be disabled. States greater than C3 provide even more power savings with the same semantics as the C3 state. Deeper sleeps provide more power savings but increased transition latency when an interrupt occurs.
Name of the DSDT table to load, if loading is enabled.
Selectively disables portions of ACPI for debugging purposes.
Specify the number of task threads that are started on boot. Limiting this to 1 may help work around various BIOSes that cannot handle parallel requests. The default value is 3.
Override any automatic quirks completely.
Set this to 1 to disable all of ACPI. If ACPI has been disabled on your system due to a blacklist entry for your BIOS, you can set this to 0 to re-enable ACPI for testing.
Delay in milliseconds to wait for the EC to respond. Try increasing this number if you get the error "AE_NO_HARDWARE_RESPONSE".
Override the assumed memory starting address for PCI host bridges.
Override the interrupt to use.
Enables calling the VESA reset BIOS vector on the resume path. Some graphic chips have problems such as LCD white-out after resume. Try setting this to 0 if this causes problems for you.
Allow override of whether methods execute in parallel or not. Enable this for serial behavior, which fixes "AE_ALREADY_EXISTS" errors for AML that really cannot handle parallel method execution. It is off by default since this breaks recursive methods and some IBMs use such code.
Turn on verbose debugging information about what ACPI is doing.
(Vt feature) Probes and attaches subdevices. Disabling will avoid scanning the ACPI namespace entirely.
(Vt feature) Attaches standard ACPI sub-drivers and devices enumerated in the ACPI namespace. Disabling this has a similar effect to disabling "bus", except that the ACPI namespace will still be scanned.
(Vt device) Supports ACPI button devices (typically power and sleep buttons).
(Vt device) Control-method batteries device.
(Vt device) Supports CPU power-saving and speed-setting functions.
(Vt device) Supports the ACPI Embedded Controller interface, used to communicate with embedded platform controllers.
(Vt device) Supports an ISA bus bridge defined in the ACPI namespace, typically as a child of a PCI bus.
(Vt device) Supports an ACPI laptop lid switch, which typically puts a system to sleep.
(Vt feature) Do not honor quirks. Quirks automatically disable ACPI functionality based on the XSDT tables OEM vendor name and revision date.
(Vt device) Supports Host to PCI bridges.
(Vt feature) Performs PCI interrupt routing.
(Vt device) Pseudo-devices containing resources which ACPI claims.
(Vt device) Supports system cooling and heat management.
(Vt device) Implements a timecounter using the ACPI fixed-frequency timer.
(Vt device) Supports acpi_video(4) which may conflict with agp(4) device.
It is also possible to avoid portions of the ACPI namespace which may be causing problems, by listing the full path of the root of the region to be avoided in the kernel environment variable debug.acpi.avoid. The object and all of its children will be ignored during the bus/children scan of the namespace. The ACPI CA code will still know about the avoided region.
Selection of the appropriate layer and level values is important to avoid massive amounts of debugging output. For example, the following configuration is a good way to gather initial information. It enables debug output for both ACPI-CA and the acpi driver, printing basic information about errors, warnings, and progress.
Debugging output by the ACPI CA subsystem is prefixed with the module name in lowercase, followed by a source line number. Output from the .Fx Ns -local code follows the same format, but the module name is uppercased.