Copyright (c) 2001 Michael Smith
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$FreeBSD: head/share/man/man4/acpi.4 79129 2001-07-03 07:45:04Z msmith $

.Dd July 2, 2001 .Dt ACPI 4 .Os .Sh NAME .Nm acpi .Nd Advanced Configuration and Power Management support .Sh SYNOPSIS .Cd device acpica

p .Cd options ACPI_DEBUG .Sh DESCRIPTION The .Nm driver provides support for the Intel/Microsoft/Compaq/Toshiba ACPI standard. This support includes platform hardware discovery (superseding the PnP and PCI BIOS), as well as power management (superseding APM) and other features. ACPI core support is provided by the ACPI CA reference implementation from Intel. .Sh ENVIRONMENT This support is still experimental, and thus there are many debugging and tuning options which are managed via the kernel environment space, and set in the loader before booting the kernel.

p Debugging is separated between layers and levels, where a layer is a portion of the ACPI subsystem, and a level is a particular kind of debugging output.

p Both layers and levels are specified as a whitespace-separated list of tokens, with layers listed in .Va debug.acpi.layer and levels in .Va debug.acpi.level . The supported layers are: l -bullet -offset indent -compact t ACPI_UTILITIES t ACPI_HARDWARE t ACPI_EVENTS t ACPI_TABLES t ACPI_NAMESPACE t ACPI_PARSER t ACPI_DISPATCHER t ACPI_EXECUTER t ACPI_RESOURCES t ACPI_POWER t ACPI_BUS t ACPI_POWER t ACPI_EC t ACPI_PROCESSOR t ACPI_AC_ADAPTER t ACPI_BATTERY t ACPI_BUTTON t ACPI_SYSTEM t ACPI_THERMAL t ACPI_DEBUGGER t ACPI_OS_SERVICES t ACPI_ALL_COMPONENTS .El The supported levels are: l -bullet -offset indent -compact t ACPI_OK t ACPI_INFO t ACPI_WARN t ACPI_ERROR t ACPI_FATAL t ACPI_DEBUG_OBJECT t ACPI_ALL t TRACE_THREADS t TRACE_PARSE t TRACE_DISPATCH t TRACE_LOAD t TRACE_EXEC t TRACE_NAMES t TRACE_OPREGION t TRACE_BFIELD t TRACE_TRASH t TRACE_TABLES t TRACE_FUNCTIONS t TRACE_VALUES t TRACE_OBJECTS t TRACE_ALLOCATIONS t TRACE_RESOURCES t TRACE_IO t TRACE_INTERRUPTS t TRACE_USER_REQUESTS t TRACE_PACKAGE t TRACE_MUTEX t TRACE_INIT t TRACE_ALL t VERBOSE_AML_DISASSEMBLE t VERBOSE_INFO t VERBOSE_TABLES t VERBOSE_EVENTS t VERBOSE_ALL .El

p Selection of the appropriate layer and level values is important to avoid massive amounts of debugging output. Check the code to see which you need.

p Debugging output by the ACPI CA subsystem is prefixed with the module name in lowercase, followed by a source line number. Output from the FreeBSD-local code follows the same format, but the module name is uppercased.

p The .Nm driver comprises a set of drivers, which may be selectively disabled in case of problems. To disable a sub-driver, list it in the kernel environment variable .Va debug.acpi.disable .

p ACPI sub-devices and features that can be disabled: l -tag -width processor t bus

q Vt feature Probes and attaches subdevices. Disabling will avoid scanning the ACPI namespace entirely. t children

q Vt feature Attaches standard ACPI sub-drivers and devices enumerated in the ACPI namespace. Disabling this has a similar effect to disabling .Dq bus , except that the ACPI namespace will still be scanned. t button

q Vt device Supports ACPI button devices (typically power and sleep buttons). t ec

q Vt device Supports the ACPI Embedded Controller interface, used to communicate with embedded platform controllers. t isa

q Vt device Supports an ISA bus bridge defined in the ACPI namespace, typically as a child of a PCI bus. t lid

q Vt device Supports an ACPI laptop lid switch, which typically puts a system to sleep. t pci

q Vt device Supports Host to PCI bridges. t processor

q Vt device Supports CPU power-saving and speed-setting functions. t thermal

q Vt device Supports system cooling and heat management. t timer

q Vt device Implements a timecounter using the ACPI fixed-frequency timer. .El

p 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 .Va 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. .Sh COMPATIBILITY ACPI is only found/supported on Intel platforms (i386/IA32 and IA64). .Sh SEE ALSO .Xr config 8 , .Xr acpi 9 .Sh AUTHOR The ACPI CA subsystem is developed and maintained by Intel Architecture Labs.

p The following people made notable contributions to the ACPI subsystem in .Fx : l -bullet -offset indent -compact t .An Michael Smith Aq msmith@freebsd.org , t .An Takanori Watanabe Aq takawata@jp.freebsd.org , t .An Mitsuru IWASAKI Aq iwasaki@jp.freebsd.org , t .An Munehiro Matsuda , t the ACPI-jp mailing list at .Aq acpi-jp@jp.freebsd.org , t and many other contributors. .El

p This manual page was written by .An Michael Smith Aq msmith@freebsd.org . .Sh BUGS The kernel device is .Cd device acpica for historical reasons. It will change to .Cd device acpi at some time in the future.