Copyright (c) 2001 Michael Smith
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$FreeBSD: head/share/man/man4/acpi.4 115697 2003-06-02 15:02:06Z ru $
.Dd July 2, 2001 .Dt ACPI 4 .Os .Sh NAME .Nm acpi .Nd Advanced Configuration and Power Management support .Sh SYNOPSIS .Cd "device acpi"
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.
p Note that the .Nm driver is automatically loaded by the bootloader, and should not normally be compiled into the kernel. .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 .Xr loader 8 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:
p l -item -offset indent -compact t .Li ACPI_UTILITIES t .Li ACPI_HARDWARE t .Li ACPI_EVENTS t .Li ACPI_TABLES t .Li ACPI_NAMESPACE t .Li ACPI_PARSER t .Li ACPI_DISPATCHER t .Li ACPI_EXECUTER t .Li ACPI_RESOURCES t .Li ACPI_DEBUGGER t .Li ACPI_OS_SERVICES t .Li ACPI_BUS t .Li ACPI_SYSTEM t .Li ACPI_POWER t .Li ACPI_EC t .Li ACPI_AC_ADAPTER t .Li ACPI_BATTERY t .Li ACPI_BUTTON t .Li ACPI_PROCESSOR t .Li ACPI_THERMAL t .Li ACPI_FAN t .Li ACPI_ALL_COMPONENTS .El
p The supported levels are:
p l -item -offset indent -compact t .Li ACPI_LV_OK t .Li ACPI_LV_INFO t .Li ACPI_LV_WARN t .Li ACPI_LV_ERROR t .Li ACPI_LV_FATAL t .Li ACPI_LV_DEBUG_OBJECT t .Li ACPI_LV_ALL_EXCEPTIONS t .Li ACPI_LV_THREADS t .Li ACPI_LV_PARSE t .Li ACPI_LV_DISPATCH t .Li ACPI_LV_LOAD t .Li ACPI_LV_EXEC t .Li ACPI_LV_NAMES t .Li ACPI_LV_OPREGION t .Li ACPI_LV_BFIELD t .Li ACPI_LV_TRASH t .Li ACPI_LV_TABLES t .Li ACPI_LV_FUNCTIONS t .Li ACPI_LV_VALUES t .Li ACPI_LV_OBJECTS t .Li ACPI_LV_ALLOCATIONS t .Li ACPI_LV_RESOURCES t .Li ACPI_LV_IO t .Li ACPI_LV_INTERRUPTS t .Li ACPI_LV_USER_REQUESTS t .Li ACPI_LV_PACKAGE t .Li ACPI_LV_MUTEX t .Li ACPI_LV_INIT t .Li ACPI_LV_ALL t .Li ACPI_DB_AML_DISASSEMBLE t .Li ACPI_DB_VERBOSE_INFO t .Li ACPI_DB_FULL_TABLES t .Li ACPI_DB_EVENTS t .Li ACPI_DB_VERBOSE .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 .Fx Ns -local code follows the same format, but the module name is uppercased.
p To disable the .Nm driver completely, set the kernel environment variable .Va hint.acpi.0.disabled to 1. Some i386 machines totally fail to operate with some or all of ACPI disabled. Other i386 machines fail with ACPI enabled. Non-i386 platforms do not support operating systems which do not use ACPI. Disabling all or part of ACPI on non-i386 platforms may result in a non-functional system.
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 children t Li bus
q Vt feature Probes and attaches subdevices. Disabling will avoid scanning the ACPI namespace entirely. t Li 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 Li bus , except that the ACPI namespace will still be scanned. t Li button
q Vt device Supports ACPI button devices (typically power and sleep buttons). t Li ec
q Vt device Supports the ACPI Embedded Controller interface, used to communicate with embedded platform controllers. t Li isa
q Vt device Supports an ISA bus bridge defined in the ACPI namespace, typically as a child of a PCI bus. t Li lid
q Vt device Supports an ACPI laptop lid switch, which typically puts a system to sleep. t Li pci
q Vt device Supports Host to PCI bridges. t Li cpu
q Vt device Supports CPU power-saving and speed-setting functions. t Li thermal
q Vt device Supports system cooling and heat management. t Li 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 OVERRIDING YOUR BIOS BYTECODE ACPI interprets bytecode named AML, ACPI Machine Language, provided by the BIOS vendor as a memory image at boot time. Sometimes, the AML code contains a problem that does not appear in the Microsoft implementation. So we provide a way to override it with your own AML code.
p In order to load your AML code, you must edit
a /boot/loader.conf and include the following lines. d -literal -offset indent acpi_dsdt_load="YES" acpi_dsdt_name="/boot/acpi_dsdt.aml" #You may change the name. .Ed
p In order to prepare your AML code, you will need the .Xr acpidump 8 and .Xr iasl 1 utilities from the
a devel/acpicatools port, and some ACPI knowledge. .Sh TUNABLES l -tag -width indent t Va acpi_dsdt_load Enables loading of a custom ACPI DSDT. t Va acpi_dsdt_name Name of the DSDT table to load, if loading is enabled. t Va debug.acpi.disable Selectively disables portions of ACPI for debugging purposes. t Va hint.acpi.0.disabled Disables all of ACPI. t Va hw.acpi.cpu.performance_speed Sets the speed of the CPU, if it supports multiple speeds, while in the performance power profile. t Va hw.acpi.cpu.economy_speed Sets the speed of the CPU, if it supports multiple speeds, while in the economy power profile. t Va hw.acpi.ec.event_driven Enables or disables the event driven model for the embedded controller driver. t Va hw.acpi.pci.link.%d.%d.%d.irq Override the interrupt to use. t Va hw.acpi.verbose Turn on verbose debugging information about what ACPI is doing. .El .Sh COMPATIBILITY ACPI is only found/supported on i386/ia32, ia64 and amd64. .Sh SEE ALSO .Xr loader.conf 5 , .Xr acpiconf 8 , .Xr acpidump 8 , .Xr config 8 .Rs .%A "Compaq Computer Corporation" .%A "Intel Corporation" .%A "Microsoft Corporation" .%A "Phoenix Technologies Ltd." .%A "Toshiba Corporation" .%D July 27 2000 .%T "Advanced Configuration and Power Interface Specification" .%O http://acpi.info/spec.htm .Re .Sh AUTHORS .An -nosplit 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 : .An Michael Smith Aq msmith@FreeBSD.org , .An Takanori Watanabe Aq takawata@jp.FreeBSD.org , .An Mitsuru IWASAKI Aq iwasaki@jp.FreeBSD.org , .An Munehiro Matsuda , the ACPI-jp mailing list at .Aq acpi-jp@jp.FreeBSD.org , and many other contributors.
p This manual page was written by .An Michael Smith Aq msmith@FreeBSD.org . .Sh BUGS If the .Nm driver is loaded as a module when it is already linked as part of the kernel, odd things may happen.