acpi(4) manual page

The acpi driver is intended to provide power management without user intervention. If the default settings are not optimal, the following sysctls can be used to modify or monitor acpi behavior. Note that some variables will be available only if the given hardware supports them (such as hw.acpi.acline).

debug.acpi.enable_debug_objects
	Enable dumping Debug objects without options ACPI_DEBUG . Default is 0, ignore Debug objects.
dev.cpu.N.cx_usage
	Debugging information listing the percent of total usage for each sleep state. The values are reset when dev.cpu.N.cx_lowest is modified.
dev.cpu.N.cx_lowest
	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.idle should be set to `acpi` if it is listed in machdep.idle_available.
hw.acpi.cpu.cx_supported
	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.
dev.cpu.N.cx_method
	List of supported CPU idle states and their transition methods, as directed by the firmware.
hw.acpi.acline
	AC line state (1 means online, 0 means on battery power).
hw.acpi.disable_on_reboot
	Disable ACPI during the reboot process. Most systems reboot fine with ACPI still enabled, but some require exiting to legacy mode first. Default is 0, leave ACPI enabled.
hw.acpi.handle_reboot
	Use the ACPI Reset Register capability to reboot the system. Some newer systems require use of this register, while some only work with legacy rebooting support.
hw.acpi.lid_switch_state
	Suspend state (`S1[en]S5`) to enter when the lid switch (i.e., a notebook screen) is closed. Default is "`NONE`" (do nothing).
hw.acpi.power_button_state
	Suspend state (`S1[en]S5`) to enter when the power button is pressed. Default is `S5` (power-off nicely).
hw.acpi.reset_video
	Reset the video adapter from real mode during the resume path. Some systems need this help, others have display problems if it is enabled. Default is 0 (disabled).
hw.acpi.s4bios
	Indicate whether the system supports `S4BIOS`. This means that the BIOS can handle all the functions of suspending the system to disk. Otherwise, the OS is responsible for suspending to disk (`S4OS`). Most current systems do not support `S4BIOS`.
hw.acpi.sleep_button_state
	Suspend state (`S1[en]S5`) to enter when the sleep button is pressed. This is usually a special function button on the keyboard. Default is `S3` (suspend-to-RAM).
hw.acpi.sleep_delay
	Wait this number of seconds between preparing the system to suspend and actually entering the suspend state. Default is 1 second.
hw.acpi.supported_sleep_state
	Suspend states (`S1[en]S5`) supported by the BIOS.
`S1`	Quick suspend to RAM. The CPU enters a lower power state, but most peripherals are left running.
`S2`	Lower power state than `S1`, but with the same basic characteristics. Not supported by many systems.
`S3`	Suspend to RAM. Most devices are powered off, and the system stops running except for memory refresh.
`S4`	Suspend to disk. All devices are powered off, and the system stops running. When resuming, the system starts as if from a cold power on. Not yet supported by FreeBSD unless `S4BIOS` is available.
`S5`	System shuts down cleanly and powers off.

hw.acpi.verbose
	Enable verbose printing from the various ACPI subsystems.

acpi_dsdt_load
	Enables loading of a custom ACPI DSDT.
acpi_dsdt_name
	Name of the DSDT table to load, if loading is enabled.
debug.acpi.cpu_unordered
	Do not use the MADT to match ACPI Processor objects to CPUs. This is needed on a few systems with a buggy BIOS that does not use consistent processor IDs. Default is 0 (disabled).
debug.acpi.disabled
	Selectively disables portions of ACPI for debugging purposes.
debug.acpi.interpreter_slack
	Enable less strict ACPI implementations. Default is 1, ignore common BIOS mistakes.
debug.acpi.max_threads
	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.
debug.acpi.quirks
	Override any automatic quirks completely.
debug.acpi.resume_beep
	Beep the PC speaker on resume. This can help diagnose suspend/resume problems. Default is 0 (disabled).
hint.acpi.0.disabled
	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.
hw.acpi.ec.poll_timeout
	Delay in milliseconds to wait for the EC to respond. Try increasing this number if you get the error "`AE_NO_HARDWARE_RESPONSE`".
hw.acpi.host_mem_start
	Override the assumed memory starting address for PCI host bridges.
hw.acpi.install_interface, hw.acpi.remove_interface
	Install or remove OS interface(s) to control return value of ‘`_OSI`’ query method. When an OS interface is specified in hw.acpi.install_interface, `_OSI` query for the interface returns it is supported. Conversely, when an OS interface is specified in hw.acpi.remove_interface, `_OSI` query returns it is not supported. Multiple interfaces can be specified in a comma-separated list and any leading white spaces will be ignored. For example, "`FreeBSD, Linux`" is a valid list of two interfaces "`FreeBSD`" and "`Linux`".
hw.acpi.reset_video
	Enables calling the VESA reset BIOS vector on the resume path. This can fix some graphics cards that have problems such as LCD white-out after resume. Default is 0 (disabled).
hw.acpi.serialize_methods
	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.
hw.acpi.verbose
	Turn on verbose debugging information about what ACPI is doing.
hw.pci.link.%s.%d.irq
	Override the interrupt to use for this link and index. This capability should be used carefully, and only if a device is not working with acpi enabled. "%s" is the name of the link (e.g., LNKA). "%d" is the resource index when the link supports multiple IRQs. Most PCI links only have one IRQ resource, so the below form should be used.
hw.pci.link.%s.irq
	Override the interrupt to use. This capability should be used carefully, and only if a device is not working with acpi enabled. "%s" is the name of the link (e.g., LNKA).

`all`	Disable all ACPI features and devices.
`acad`	(device) Supports AC adapter.
`bus`	(feature) Probes and attaches subdevices. Disabling will avoid scanning the ACPI namespace entirely.
`children`	(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.
`button`	(device) Supports ACPI button devices (typically power and sleep buttons).
`cmbat`	(device) Control-method batteries device.
`cpu`	(device) Supports CPU power-saving and speed-setting functions.
`ec`	(device) Supports the ACPI Embedded Controller interface, used to communicate with embedded platform controllers.
`isa`	(device) Supports an ISA bus bridge defined in the ACPI namespace, typically as a child of a PCI bus.
`lid`	(device) Supports an ACPI laptop lid switch, which typically puts a system to sleep.
`mwait`	(feature) Do not ask firmware for available x86-vendor specific methods to enter `Cx` sleep states. Only query and use the generic I/O-based entrance method. The knob is provided to work around inconsistencies in the tables filled by firmware.
`quirks`	(feature) Do not honor quirks. Quirks automatically disable ACPI functionality based on the XSDT table's OEM vendor name and revision date.
`pci`	(device) Supports Host to PCI bridges.
`pci_link`	(feature) Performs PCI interrupt routing.
`sysresource`	(device) Pseudo-devices containing resources which ACPI claims.
`thermal`	(device) Supports system cooling and heat management.
`timer`	(device) Implements a timecounter using the ACPI fixed-frequency timer.
`video`	(device) Supports acpi_video(4) which may conflict with agp(4) device.

`ACPI_UTILITIES`	Utility ("ut") functions
`ACPI_HARDWARE`	Hardware access ("hw")
`ACPI_EVENTS`	Event and GPE ("ev")
`ACPI_TABLES`	Table access ("tb")
`ACPI_NAMESPACE`	Namespace evaluation ("ns")
`ACPI_PARSER`	AML parser ("ps")
`ACPI_DISPATCHER`	Internal representation of interpreter state ("ds")
`ACPI_EXECUTER`	Execute AML methods ("ex")
`ACPI_RESOURCES`	Resource parsing ("rs")
`ACPI_CA_DEBUGGER`	Debugger implementation ("db", "dm")
`ACPI_OS_SERVICES`	Usermode support routines ("os")
`ACPI_CA_DISASSEMBLER`	Disassembler implementation (unused)
`ACPI_ALL_COMPONENTS`	All the above ACPI-CA components
`ACPI_AC_ADAPTER`	AC adapter driver
`ACPI_BATTERY`	Control-method battery driver
`ACPI_BUS`	ACPI, ISA, and PCI bus drivers
`ACPI_BUTTON`	Power and sleep button driver
`ACPI_EC`	Embedded controller driver
`ACPI_FAN`	Fan driver
`ACPI_OEM`	Platform-specific driver for hotkeys, LED, etc.
`ACPI_POWER`	Power resource driver
`ACPI_PROCESSOR`	CPU driver
`ACPI_THERMAL`	Thermal zone driver
`ACPI_TIMER`	Timer driver
`ACPI_ALL_DRIVERS`	All the above FreeBSD ACPI drivers

`ACPI_LV_INIT`	Initialization progress
`ACPI_LV_DEBUG_OBJECT`	Stores to objects
`ACPI_LV_INFO`	General information and progress
`ACPI_LV_REPAIR`	Repair a common problem with predefined methods
`ACPI_LV_ALL_EXCEPTIONS`	All the previous levels
`ACPI_LV_PARSE` `ACPI_LV_DISPATCH` `ACPI_LV_EXEC` `ACPI_LV_NAMES` `ACPI_LV_OPREGION` `ACPI_LV_BFIELD` `ACPI_LV_TABLES` `ACPI_LV_VALUES` `ACPI_LV_OBJECTS` `ACPI_LV_RESOURCES` `ACPI_LV_USER_REQUESTS` `ACPI_LV_PACKAGE` `ACPI_LV_VERBOSITY1`
	All the previous levels
`ACPI_LV_ALLOCATIONS` `ACPI_LV_FUNCTIONS` `ACPI_LV_OPTIMIZATIONS` `ACPI_LV_VERBOSITY2`
	All the previous levels
`ACPI_LV_ALL`	Synonym for "`ACPI_LV_VERBOSITY2`"
`ACPI_LV_MUTEX` `ACPI_LV_THREADS` `ACPI_LV_IO` `ACPI_LV_INTERRUPTS` `ACPI_LV_VERBOSITY3`
	All the previous levels
`ACPI_LV_AML_DISASSEMBLE` `ACPI_LV_VERBOSE_INFO` `ACPI_LV_FULL_TABLES` `ACPI_LV_EVENTS` `ACPI_LV_VERBOSE`
	All levels after "`ACPI_LV_VERBOSITY3`"
`ACPI_LV_INIT_NAMES` `ACPI_LV_LOAD`

Manual Pages — ACPI

NAME

CONTENTS

SYNOPSIS

DESCRIPTION

SYSCTL VARIABLES

LOADER TUNABLES

DISABLING ACPI

DEBUGGING OUTPUT

OVERRIDING YOUR BIOS BYTECODE

COMPATIBILITY

SEE ALSO

AUTHORS

BUGS