ACPI(4) 						   BSD Kernel Interfaces Manual 						   ACPI(4)

NAME

     acpi -- Advanced Configuration and Power Interface

SYNOPSIS

     acpi0     at mainbus0

     options   ACPI_DEBUG
     options   ACPIVERBOSE
     options   ACPI_ACTIVATE_DEV
     options   ACPI_DSDT_OVERRIDE
     options   ACPI_DSDT_FILE=""
     options   ACPI_BLACKLIST_YEAR=2000

DESCRIPTION

     NetBSD provides machine-independent bus support for Advanced Configuration and Power Interface (ACPI) devices and includes several ACPI
     device drivers.

     The NetBSD implementation of ACPI integrates Intel's ACPI Component Architecture (ACPI-CA) for the OS-independent part.  The ACPI-CA provides
     OS-neutral ACPI functionalities such as ACPI BIOS table support, an ACPI event framework and an ACPI Machine Language (AML) interpreter.

     Options:

	ACPI_DEBUG		     Enable various debug facilities.

	ACPIVERBOSE		     Enable verbose debug messages.

	ACPI_ACTIVATE_DEV	     Determine if the ACPI driver should attempt to activate inactive devices.	The default is off.

	ACPI_DSDT_OVERRIDE	     Force a given Differentiated System Description Table (DSDT) instead of the version supplied by the BIOS.
				     Use ACPI_DSDT_FILE to specify a DSDT.

	ACPI_DSDT_FILE="filename"    If ACPI_DSDT_FILE is not specified, default to ``dsdt.hex'' in the build directory.

	ACPI_BLACKLIST_YEAR=2000     Do not use ACPI with any BIOS made on or before the specified year.

SYSCTL SUPPORT

     Few sysctl(8) variables are directly relevant for ACPI.

	   hw.acpi.root
		   The address of the ACPI root pointer in system memory.

	   hw.acpi.sleep.state
		   The system sleep state.

	   hw.acpi.sleep.states
		   A list of system sleep states that the machine supports.  The possible values are:

			 S0    fully running
			 S1    power on suspend (CPU and hard disks are off)
			 S2    similar to S3, usually not implemented
			 S3    suspend-to-RAM
			 S4    suspend-to-disk (not supported on NetBSD)
			 S5    power off

	   hw.acpi.sleep.beep
		   A boolean variable that controls whether the PC speaker beeps upon resume.

	   hw.acpi.sleep.vbios
		   Defines the handling of the graphics card.  The supported values are:

		     0	  No attempt to reset the VGA controller will be made.

		     1	  Call the VGA BIOS when still in real mode.  This can result in direct reboots.  In that case, use '2' or vbetool post
			  from the pkgsrc/sysutils/vbetool package.

		     2	  Call the VGA BIOS using the in-kernel x86 emulator.

		   If the system has problems in resuming from the S3 state, experimenting with different values may provide a solution.

	   hw.acpi.stat.gpe
		   The number of dispatched General Purpose Events (GPEs).

	   hw.acpi.stat.sci
		   The number of System Control Interrupts (SCIs).  See acpiec(4) for a brief description of both GPEs and SCIs.

	   hw.acpi.stat.fixed
		   The number of ``fixed events''.

	   hw.acpi.stat.method
		   The number of ACPI methods executed by the interpreter.

	   hw.acpi.power
		   This read-only node describes the ACPI power state of devices.  The values range from D0 (``on'') to D3 (``off'').

	   hw.acpi.wake
		   This node represents devices that can wake the system from the S3 or S4 sleep state.  By default, acpibut(4), acpilid(4), and
		   pckbd(4) are allowed to wake the system, provided that the devices are present and the firmware supports wake-up capabilities
		   for the devices.

SUPPORTED DEVICES

     NetBSD ACPI supports several machine-dependent and machine-independent devices, some specific to ACPI and some configured via it.

   Machine-independent devices
	   acpiacad(4)	 ACPI AC adapters.
	   acpibat(4)	 ACPI batteries.
	   acpibut(4)	 ACPI power and sleep buttons.
	   acpicpu(4)	 ACPI processors.
	   acpidalb(4)	 ACPI direction application launch buttons.
	   acpiec(4)	 ACPI embedded controllers.
	   acpiecdt(4)	 ACPI Embedded Controller Boot Resource Table (ECDT).
	   acpifan(4)	 ACPI fans.
	   acpilid(4)	 ACPI lid switches.
	   acpipmtr(4)	 ACPI power meters.
	   acpismbus(4)  ACPI SMBus via control method interface (CMI).
	   acpitz(4)	 ACPI thermal zones.
	   acpivga(4)	 ACPI display adapter and output devices.
	   acpiwmi(4)	 ACPI support for Windows Management Instrumentation.
	   acpiwdrt(4)	 ACPI watchdogs.
	   aibs(4)	 ASUSTeK voltage, temperature and fan sensors.
	   asus 	 ASUS laptop hotkeys.
	   attimer(4)	 AT Timer.
	   com(4)	 NS8250-, NS16450-, and NS16550-based serial ports.
	   fdc(4)	 Floppy disk controllers.
	   fujbp(4)	 Fujitsu brightness and pointer.
	   fujhk(4)	 Fujitsu hotkeys.
	   hpacel(4)	 HP 3D DriveGuard accelerometer.
	   hpet(4)	 High Precision Event Timer (HPET).
	   hpqlb(4)	 HP Quick Launch Buttons.
	   joy(4)	 Joystick/Game port interface.
	   lpt(4)	 Standard ISA parallel port interface.
	   mpu(4)	 Roland MPU-401 (compatible) MIDI UART.
	   pcppi(4)	 AT-style speaker sound.
	   thinkpad(4)	 IBM/Lenovo ThinkPad laptop device driver.
	   ug(4)	 Abit uGuru Hardware monitor.
	   vald(4)	 Toshiba Libretto device.
	   wb(4)	 Winbond W83L518D Integrated Media Reader.
	   wss(4)	 Windows Sound System-compatible sound cards
	   ym(4)	 Yamaha OPL3-SA2 and OPL3-SA3 audio device driver.

   i386-dependent devices
	   npx(4)	 i386 numeric processing extension coprocessor.
	   pckbc(4)	 PC keyboard controllers.
	   sony(4)	 Sony Miscellaneous Controller
	   spic(4)	 Sony programmable I/O controller.

DEBUGGING

     Although the situation has become better over the years, ACPI is typically prone to various errors, ranging from blatant flaws in the
     firmware to bugs in the implementation.  Before anything else, it is a good practice to upgrade the BIOS to the latest version available from
     the vendor.

     To ease the task of diagnosing and fixing different problems, the ACPICA reference implementation provides a rich facility of different
     debugging methods.  In NetBSD these are generally only available if the kernel has been compiled with the ACPI_DEBUG option.

   Verbose messages
     The ACPIVERBOSE compile time option enables some verbose debug messages printed during the system startup.  In a MODULAR (see options(4))
     system, the information can be printed also at runtime, regardless of the presence of ACPIVERBOSE.  To print the messages, modload(8) the
     acpiverbose module using the option -b dump=true.

   Custom DSDT
     ACPI interprets bytecode known as ACPI Machine Language (AML), provided by the BIOS as a memory image during the system bootstrap.  Most of
     the AML relevant to acpi is implemented in the so-called Differentiated System Descriptor Table (DSDT).  NetBSD provides support for overrid-
     ing the default DSDT supplied by the BIOS.

     The following steps can be used to override the DSDT:

	   1.	Dump the raw DSDT with acpidump(8).

	   2.	Disassemble the table with iasl(8).

	   3.	Modify the disassembled table.

	   4.	Compile the table with iasl(8) using the option -tc.

	   5.	Either copy the (*.hex) file to

		      src/sys/dev/acpi/acpica/Osd/custom_dsdt.hex

		or use the option

		      ACPI_DSDT_FILE="/some/directory/custom_dsdt.hex"

		in the kernel configuration file.

	   6.	Define ACPI_DSDT_OVERRIDE in the kernel configuration file and rebuild.

   Debugger
     The ACPICA interpreter provides its own debugger for low-level debugging.	It can be used to display internal data structures and namespace
     objects, and to debug the execution of control methods.  Single step and breakpoint functionality are available.  In NetBSD this is inte-
     grated to the in-kernel ddb(4).  In order to enter the ACPICA debugger from ddb(4), use the command call with the argument acpi_osd_debugger.

   Debug Output
     NetBSD provides three sysctl(8) variables that control the debug output at runtime.  The hw.acpi.debug.layer variable limits the output to a
     specific ACPI layer and the hw.acpi.debug.level variable controls the debug level.  Both sysctl(8) variables are string literals.	The third
     variable is hw.acpi.debug.object.	This is a boolean that controls whether debug messages internal to the AML are enabled.

     For the first two variables, the possible values are:

	   LAYER			   LEVEL
	   ACPI_DEBUG_NONE		   ACPI_DEBUG_NONE

	   ACPI_UTILITIES		   ACPI_LV_INIT
	   ACPI_HARDWARE		   ACPI_LV_DEBUG_OBJECT
	   ACPI_EVENTS			   ACPI_LV_INFO
	   ACPI_TABLES			   ACPI_LV_ALL_EXCEPTIONS *
	   ACPI_NAMESPACE
	   ACPI_PARSER			   ACPI_LV_INIT_NAMES
	   ACPI_DISPATCHER		   ACPI_LV_PARSE
	   ACPI_EXECUTER		   ACPI_LV_LOAD
	   ACPI_RESOURCES		   ACPI_LV_DISPATCH
	   ACPI_CA_DEBUGGER		   ACPI_LV_EXEC
	   ACPI_OS_SERVICES		   ACPI_LV_NAMES
	   ACPI_CA_DISASSEMBLER 	   ACPI_LV_OPREGION
	   ACPI_COMPILER		   ACPI_LV_BFIELD
	   ACPI_TOOLS			   ACPI_LV_TABLES
	   ACPI_EXAMPLE 		   ACPI_LV_VALUES
	   ACPI_DRIVER			   ACPI_LV_OBJECTS
	   ACPI_ALL_COMPONENTS *	   ACPI_LV_RESOURCES
					   ACPI_LV_USER_REQUESTS
	   ACPI_BUS_COMPONENT		   ACPI_LV_PACKAGE
	   ACPI_ACAD_COMPONENT		   ACPI_LV_VERBOSITY1 *
	   ACPI_BAT_COMPONENT
	   ACPI_BUTTON_COMPONENT	   ACPI_LV_ALLOCATIONS
	   APCI_EC_COMPONENT		   ACPI_LV_FUNCTIONS
	   ACPI_LID_COMPONENT		   ACPI_LV_OPTIMIZATIONS
	   ACPI_RESOURCE_COMPONENT	   ACPI_LV_VERBOSITY2 *
	   ACPI_TZ_COMPONENT
	   ACPI_DISPLAY_COMPONENT
	   ACPI_ALL_DRIVERS *		   ACPI_LV_MUTEX
					   ACPI_LV_THREADS
					   ACPI_LV_IO
					   ACPI_LV_AML_INTERRUPTS
	   * This is a compound 	   ACPI_LV_VERBOSITY3 *
	     constant, including
	     all previous elements.	   ACPI_LV_AML_DISASSEMBLE
					   ACPI_LV_VERBOSE_INFO
					   ACPI_LV_FULL_TABLES
					   ACPI_LV_EVENTS
					   ACPI_LV_VERBOSE *

     In addition, there is ACPI_DEBUG_DEFAULT that is used by ACPICA as the default debug level.  It includes ACPI_LV_INIT and
     ACPI_LV_DEBUG_OBJECT.

     The debug layer can be divided into two groups: the first one is specific to the ACPICA interpreter and the second one contains the internal
     ACPI components of NetBSD.  The constant ACPI_ALL_DRIVERS includes all NetBSD specific parts.

     The ACPICA interpreter uses several debug levels internally, but the NetBSD specific parts are typically limited to ACPI_LV_DEBUG_OBJECT and
     ACPI_LV_INFO.  The debug output can be stopped by setting hw.acpi.debug.level to ACPI_DEBUG_NONE.

   Example
     As an example, a driver may have defined the component it belongs to and the name of the module:

	   #define _COMPONENT	   ACPI_BUS_COMPONENT
	   ACPI_MODULE_NAME	   ("acpi_example")

     The driver may also utilize the debug facility:

	   ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Failed to evaluate _STA
"));

     With these options the debug message from the ACPI_DEBUG_PRINT macro is only visible when hw.acpi.debug.layer is either ACPI_BUS_COMPONENT or
     a compound constant including it, and hw.acpi.debug.level is ACPI_LV_INFO or some constant that includes it.  Finally, it can be noted that
     the ACPI implementation uses the prefix ACPI_DB, whereas the debug level sysctl(8) variable is always specified with the prefix ACPI_LV.

     Another example can be mentioned for the use of hw.acpi.debug.object.  The following could appear in an ASL code:

	   Method(_Q19, 0, NotSerialized)
	   {
		   Store("_Q19 invoked", Debug)
		   Notify(ACAD, 0x80)
	   }

     When hw.acpi.debug.object is set to 1, the message stored to the debug object is printed every time the method is called by the interpreter.

SEE ALSO

     ioapic(4), acpidump(8), amldb(8), iasl(8)

     Hewlett-Packard Corporation, Intel Corporation, Microsoft Corporation, Phoenix Technologies Ltd., and Toshiba Corporation, Advanced
     Configuration and Power Interface Specification, Revision 4.0, http://www.acpi.info/spec.htm, June 16, 2009.

     Intel Corporation, ACPI Component Architecture, Programmer Reference, OS-Independent Subsystem, Debugger, and Utilities, Revision 1.27,
     http://www.acpica.org/download/acpica-reference.pdf, January 20, 2010.

     Len Brown, ACPI in Linux - Myths vs. Reality, http://www.linuxsymposium.org/archives/OLS/Reprints-2007/brown_1-Reprint.pdf, 65-74, June
     27-30, 2007, Proceedings of the Linux Symposium.

     Joerg Sonnenberger and Jared D. McNeill, Sleeping Beauty - NetBSD on Modern Laptops, http://2008.asiabsdcon.org/papers/P9A-paper.pdf,
     127-134, February 3, 2008, Proceedings of AsiaBSDCon 2008.

     Takanori Watanabe, "ACPI Implementation on FreeBSD", Proceedings of the FREENIX Track: 2002 USENIX Annual Technical Conference, USENIX
     Association, http://www.usenix.org/event/usenix02/tech/freenix/full_papers/watanabe/watanabe.pdf, 121-131, June 10-15, 2002.

HISTORY

     The acpi driver appeared in NetBSD 1.6.

AUTHORS

     Authors of the acpi subsystem include Charles M. Hannum, Frank van der Linden, Jared D. McNeill, Jason R. Thorpe, Joerg Sonnenberger, and
     Jukka Ruohonen, among others.

BUGS

     Most of the ACPI power management functionalities are not implemented.

BSD
								  October 5, 2011							       BSD