2 .\" Copyright (c) 2001 Michael Smith
3 .\" All rights reserved.
5 .\" Redistribution and use in source and binary forms, with or without
6 .\" modification, are permitted provided that the following conditions
8 .\" 1. Redistributions of source code must retain the above copyright
9 .\" notice, this list of conditions and the following disclaimer.
10 .\" 2. Redistributions in binary form must reproduce the above copyright
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14 .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 .\" $FreeBSD: src/share/man/man4/acpi.4,v 1.61.8.1 2009/04/15 03:14:26 kensmith Exp $
33 .Nd Advanced Configuration and Power Management support
37 .Cd "options ACPI_DEBUG"
42 driver provides support for the Intel/Microsoft/Compaq/Toshiba ACPI
44 This support includes platform hardware discovery (superseding the
45 PnP and PCI BIOS), as well as power management (superseding APM) and
47 ACPI core support is provided by the ACPICA reference implementation
52 driver is automatically loaded by the
55 compiled into the kernel on platforms where ACPI is mandatory.
59 driver is intended to provide power management without user intervention.
60 If the default settings are not optimal, the following sysctls can be
61 used to modify or monitor
64 .Bl -tag -width indent
65 .It Va debug.acpi.enable_debug_objects
66 Enable dumping Debug objects without
67 .Cd "options ACPI_DEBUG" .
68 Default is 0, ignore Debug objects.
70 AC line state (1 means online, 0 means on battery power).
71 .It Va hw.acpi.cpu.cx_usage
72 Debugging information listing the percent of total usage for each sleep state.
73 The values are reset when
74 .Va hw.acpi.cpu.cx_lowest
76 .It Va hw.acpi.cpu.cx_lowest
77 Lowest Cx state to use for idling the CPU.
78 A scheduling algorithm will select states between
81 as system load dictates.
82 To enable ACPI CPU idling control,
83 .Va machdep.cpu_idle_hlt
84 must be set to 2 (the default value).
85 .It Va hw.acpi.cpu.cx_supported
86 List of supported CPU idle states and their transition latency
88 Each state has a type (e.g.,
91 is equivalent to the ia32
96 sleep with the same semantics, and
98 provides the deepest sleep
99 but additionally requires bus mastering to be disabled.
102 provide even more power savings with the same
106 Deeper sleeps provide more power savings but increased transition
107 latency when an interrupt occurs.
108 .It Va hw.acpi.disable_on_reboot
109 Disable ACPI during the reboot process.
110 Most systems reboot fine with ACPI still enabled, but some require
111 exiting to legacy mode first.
112 Default is 0, leave ACPI enabled.
113 .It Va hw.acpi.handle_reboot
114 Use the ACPI Reset Register capability to reboot the system.
115 Default is 0, use legacy reboot support.
116 Some newer systems require use of this register, while some only work
117 with legacy rebooting support.
118 .It Va hw.acpi.lid_switch_state
120 .Pq Li S1 Ns \[en] Ns Li S5
121 to enter when the lid switch (i.e., a notebook screen) is closed.
125 .It Va hw.acpi.power_button_state
127 .Pq Li S1 Ns \[en] Ns Li S5
128 to enter when the power button is pressed.
132 .It Va hw.acpi.reset_video
133 Reset the video adapter from real mode during the resume path.
134 Some systems need this help, others have display problems if it is enabled.
135 Default is 0 (disabled).
136 .It Va hw.acpi.s4bios
137 Indicate whether the system supports
139 This means that the BIOS can handle all the functions of suspending the
141 Otherwise, the OS is responsible for suspending to disk
143 Most current systems do not support
145 .It Va hw.acpi.sleep_button_state
147 .Pq Li S1 Ns \[en] Ns Li S5
148 to enter when the sleep button is pressed.
149 This is usually a special function button on the keyboard.
153 .It Va hw.acpi.sleep_delay
154 Wait this number of seconds between preparing the system to suspend and
155 actually entering the suspend state.
157 .It Va hw.acpi.supported_sleep_state
159 .Pq Li S1 Ns \[en] Ns Li S5
160 supported by the BIOS.
161 .Bl -tag -width indent
163 Quick suspend to RAM.
164 The CPU enters a lower power state, but most peripherals are left running.
166 Lower power state than
168 but with the same basic characteristics.
169 Not supported by many systems.
172 Most devices are powered off, and the system stops running except for
176 All devices are powered off, and the system stops running.
177 When resuming, the system starts as if from a cold power on.
184 System shuts down cleanly and powers off.
186 .It Va hw.acpi.verbose
187 Enable verbose printing from the various ACPI subsystems.
190 Tunables can be set at the
192 prompt before booting the kernel or stored in
193 .Pa /boot/loader.conf .
194 Many of these tunables also have a matching
196 entry for access after boot.
197 .Bl -tag -width indent
198 .It Va acpi_dsdt_load
199 Enables loading of a custom ACPI DSDT.
200 .It Va acpi_dsdt_name
201 Name of the DSDT table to load, if loading is enabled.
204 .It Va debug.acpi.allow_method_calls
207 utility can be used to directly call ACPI methods for debugging and
209 .It Va debug.acpi.disabled
210 Selectively disables portions of ACPI that are enabled by default, for
212 .It Va debug.acpi.enabled
213 Selectively enables portions of ACPI that are disabled by default, for
215 .It Va debug.acpi.facs_addr32
216 Favor 32-bit FACS table addresses over the 64-bit addresses.
217 .It Va debug.acpi.fadt_addr32
218 Favor 32-bit FADT register addresses over the 64-bit addresses.
219 .It Va debug.acpi.ignore_xsdt
220 Ignore the XSDT, forcing the use of the RSDT.
221 .It Va debug.acpi.interpreter_slack
222 Enable less strict ACPI implementations.
223 Default is 1, ignore common BIOS mistakes.
224 .It Va debug.acpi.max_threads
225 Specify the number of task threads that are started on boot.
226 Limiting this to 1 may help work around various BIOSes that cannot
227 handle parallel requests.
228 The default value is 3.
229 .It Va debug.acpi.quirks
230 Override any automatic quirks completely.
231 .It Va debug.acpi.resume_beep
232 Beep the PC speaker on resume.
233 This can help diagnose suspend/resume problems.
234 Default is 0 (disabled).
235 .It Va hint.acpi.0.disabled
236 Set this to 1 to disable all of ACPI.
237 If ACPI has been disabled on your system due to a blacklist entry for your
238 BIOS, you can set this to 0 to re-enable ACPI for testing.
239 .It Va hw.acpi.ec.poll_timeout
240 Delay in milliseconds to wait for the EC to respond.
241 Try increasing this number if you get the error
242 .Qq Li AE_NO_HARDWARE_RESPONSE .
243 .It Va hw.acpi.host_mem_start
244 Override the assumed memory starting address for PCI host bridges.
245 .It Va hw.acpi.install_interface , hw.acpi.remove_interface
246 Install or remove OS interface(s) to control the return value of the
249 When an OS interface is specified in
250 .Va hw.acpi.install_interface ,
253 query for the interface returns it is
255 Conversely, when an OS interface is specified in
256 .Va hw.acpi.remove_interface ,
261 Multiple interfaces can be specified in a comma-separated list and
262 any leading white spaces will be ignored.
264 .Qq Li FreeBSD, Linux
265 is a valid list of two interfaces
269 .It Va hw.acpi.reset_video
270 Enables calling the VESA reset BIOS vector on the resume path.
271 This can fix some graphics cards that have problems such as LCD white-out
273 Default is 0 (disabled).
274 .It Va hw.acpi.auto_serialize_methods
275 Auto-serialization of control methods to proactively prevent problems with
276 ill-behaved reentrant control methods that create named ACPI objects.
277 Default is 1 (enabled).
278 .It Va hw.acpi.verbose
279 Turn on verbose debugging information about what ACPI is doing.
280 .It Va hw.pci.link.%s.%d.irq
281 Override the interrupt to use for this link and index.
282 This capability should be used carefully, and only if a device is not
287 is the name of the link (e.g., LNKA).
289 is the resource index when the link supports multiple IRQs.
290 Most PCI links only have one IRQ resource, so the below form should be used.
291 .It Va hw.pci.link.%s.irq
292 Override the interrupt to use.
293 This capability should be used carefully, and only if a device is not
298 is the name of the link (e.g., LNKA).
301 Since ACPI support on different platforms varies greatly, there are many
302 debugging and tuning options available.
304 For machines known not to work with
306 enabled, there is a BIOS blacklist.
307 Currently, the blacklist only controls whether
309 should be disabled or not.
310 In the future, it will have more granularity to control features (the
311 infrastructure for that is already there).
315 (for debugging purposes, etc.) on machines that are on the blacklist, set the
316 kernel environment variable
317 .Va hint.acpi.0.disabled
319 Before trying this, consider updating your BIOS to a more recent version that
320 may be compatible with ACPI.
324 driver completely, set the kernel environment variable
325 .Va hint.acpi.0.disabled
328 Disabling all or part of ACPI may result in a non-functional system.
332 driver comprises a set of drivers, which may be selectively disabled
334 To disable a sub-driver, list it in the kernel
336 .Va debug.acpi.disabled .
337 Multiple entries can be listed, separated by a space.
339 ACPI sub-devices and features that can be disabled:
340 .Bl -tag -width ".Li sysresource"
342 Disable all ACPI features and devices.
348 Probes and attaches subdevices.
349 Disabling will avoid scanning the ACPI namespace entirely.
352 Attaches standard ACPI sub-drivers and devices enumerated in the
354 Disabling this has a similar effect to disabling
357 ACPI namespace will still be scanned.
360 Supports ACPI button devices (typically power and sleep buttons).
363 Control-method batteries device.
366 Supports CPU power-saving and speed-setting functions.
369 Supports CPU power-saving.
372 will also disable this device.
375 Supports CPU speed-setting.
378 will also disable this device.
381 Docking station device.
384 Supports the ACPI Embedded Controller interface, used to communicate
385 with embedded platform controllers.
388 Supports the High Precision Event Timer.
391 Supports an ISA bus bridge defined in the ACPI namespace,
392 typically as a child of a PCI bus.
395 Supports an ACPI laptop lid switch, which typically puts a
400 Quirks automatically disable ACPI functionality based on the XSDT table's
401 OEM vendor name and revision date.
404 Supports Host to PCI bridges.
407 Performs PCI interrupt routing.
410 Pseudo-devices containing resources which ACPI claims.
413 Supports system cooling and heat management.
416 Implements a timecounter using the ACPI fixed-frequency timer.
421 which may conflict with
428 .\"driver comprises a set of drivers,
429 .\"which may be selectively enabled in case of testing.
430 .\"To enable a sub-driver,
431 .\"list it in the kernel environment variable
432 .\".Va debug.acpi.enabled .
433 .\"Multiple entries can be listed,
434 .\"separated by a space.
436 .\"ACPI sub-devices and features that can be enabled:
437 .\".Bl -tag -width ".Li sysresource"
441 It is also possible to avoid portions of the ACPI namespace which
442 may be causing problems, by listing the full path of the root of
443 the region to be avoided in the kernel environment variable
444 .Va debug.acpi.avoid .
445 The object and all of its children will be ignored during the
446 bus/children scan of the namespace.
447 The ACPICA code will still know about the avoided region.
449 To enable debugging output,
451 must be compiled with
452 .Cd "options ACPI_DEBUG" .
453 Debugging output is separated between layers and levels, where a layer is
454 a component of the ACPI subsystem, and a level is a particular kind
457 Both layers and levels are specified as a whitespace-separated list of
458 tokens, with layers listed in
461 .Va debug.acpi.level .
463 The first set of layers is for ACPICA components, and the second is for
466 The ACPICA layer descriptions include the prefix for the files they
468 The supported layers are:
470 .Bl -tag -compact -width ".Li ACPI_CA_DISASSEMBLER"
471 .It Li ACPI_UTILITIES
472 Utility ("ut") functions
474 Hardware access ("hw")
479 .It Li ACPI_NAMESPACE
480 Namespace evaluation ("ns")
483 .It Li ACPI_DISPATCHER
484 Internal representation of interpreter state ("ds")
486 Execute AML methods ("ex")
487 .It Li ACPI_RESOURCES
488 Resource parsing ("rs")
489 .It Li ACPI_CA_DEBUGGER
490 Debugger implementation ("db", "dm")
491 .It Li ACPI_OS_SERVICES
492 Usermode support routines ("os")
493 .It Li ACPI_CA_DISASSEMBLER
494 Disassembler implementation (unused)
495 .It Li ACPI_ALL_COMPONENTS
496 All the above ACPICA components
497 .It Li ACPI_AC_ADAPTER
500 Control-method battery driver
502 ACPI, ISA, and PCI bus drivers
504 Power and sleep button driver
506 Embedded controller driver
510 Platform-specific driver for hotkeys, LED, etc.
512 Power resource driver
513 .It Li ACPI_PROCESSOR
519 .It Li ACPI_ALL_DRIVERS
525 The supported levels are:
527 .Bl -tag -compact -width ".Li ACPI_LV_AML_DISASSEMBLE"
529 Initialization progress
530 .It Li ACPI_LV_DEBUG_OBJECT
533 General information and progress
534 .It Li ACPI_LV_REPAIR
535 Repair a common problem with predefined methods
536 .It Li ACPI_LV_ALL_EXCEPTIONS
537 All the previous levels
539 .It Li ACPI_LV_DISPATCH
542 .It Li ACPI_LV_OPREGION
543 .It Li ACPI_LV_BFIELD
544 .It Li ACPI_LV_TABLES
545 .It Li ACPI_LV_VALUES
546 .It Li ACPI_LV_OBJECTS
547 .It Li ACPI_LV_RESOURCES
548 .It Li ACPI_LV_USER_REQUESTS
549 .It Li ACPI_LV_PACKAGE
550 .It Li ACPI_LV_VERBOSITY1
551 All the previous levels
552 .It Li ACPI_LV_ALLOCATIONS
553 .It Li ACPI_LV_FUNCTIONS
554 .It Li ACPI_LV_OPTIMIZATIONS
555 .It Li ACPI_LV_VERBOSITY2
556 All the previous levels
559 .Qq Li ACPI_LV_VERBOSITY2
561 .It Li ACPI_LV_THREADS
563 .It Li ACPI_LV_INTERRUPTS
564 .It Li ACPI_LV_VERBOSITY3
565 All the previous levels
566 .It Li ACPI_LV_AML_DISASSEMBLE
567 .It Li ACPI_LV_VERBOSE_INFO
568 .It Li ACPI_LV_FULL_TABLES
569 .It Li ACPI_LV_EVENTS
570 .It Li ACPI_LV_VERBOSE
572 .Qq Li ACPI_LV_VERBOSITY3
573 .It Li ACPI_LV_INIT_NAMES
574 Needs to be specified separately
576 Needs to be specified separately
579 Selection of the appropriate layer and level values is important
580 to avoid massive amounts of debugging output.
581 For example, the following configuration is a good way to gather initial
583 It enables debug output for both ACPICA and the
585 driver, printing basic information about errors, warnings, and progress.
586 .Bd -literal -offset indent
587 debug.acpi.layer="ACPI_ALL_COMPONENTS ACPI_ALL_DRIVERS"
588 debug.acpi.level="ACPI_LV_ALL_EXCEPTIONS"
591 Debugging output by the ACPICA subsystem is prefixed with the
592 module name in lowercase, followed by a source line number.
595 code follows the same format, but
596 the module name is uppercased.
597 .Sh OVERRIDING YOUR BIOS BYTECODE
598 ACPI interprets bytecode named AML
599 (ACPI Machine Language)
600 provided by the BIOS vendor as a memory image at boot time.
601 Sometimes, the AML code contains a bug that does not appear when parsed
602 by the Microsoft implementation.
604 provides a way to override it with your own AML code to work around
605 or debug such problems.
606 Note that all AML in your DSDT and any SSDT tables is overridden.
608 In order to load your AML code, copy it to
609 .Pa /boot/kernel/acpi_dsdt.aml
610 and add the following line to
611 .Pa /boot/loader.conf .
612 .Bd -literal -offset indent
616 In order to prepare your AML code, you will need the
620 utilities and some ACPI knowledge.
627 .Xr acpi_panasonic 4 ,
630 .Xr acpi_thinkpad 4 ,
645 .%A "Hewlett-Packard Corporation"
646 .%A "Intel Corporation"
647 .%A "Microsoft Corporation"
648 .%A "Phoenix Technologies Ltd."
649 .%A "Toshiba Corporation"
650 .%D November 13, 2013
651 .%T "Advanced Configuration and Power Interface Specification"
652 .%O http://acpi.info/spec.htm
656 The ACPICA subsystem is developed and maintained by
657 Intel Architecture Labs.
659 The following people made notable contributions to the ACPI subsystem
663 .An Takanori Watanabe Aq Mt takawata@jp.FreeBSD.org ,
664 .An Mitsuru IWASAKI Aq Mt iwasaki@jp.FreeBSD.org ,
665 .An Munehiro Matsuda ,
667 the ACPI-jp mailing list at
668 .Aq Mt acpi-jp@jp.FreeBSD.org ,
669 and many other contributors.
671 This manual page was written by
672 .An Michael Smith Aq Mt msmith@FreeBSD.org .
674 Many BIOS versions have serious bugs that may cause system instability,
675 break suspend/resume, or prevent devices from operating properly due to
676 IRQ routing problems.
677 Upgrade your BIOS to the latest version available from the vendor before
678 deciding it is a problem with
683 .\"CPU idle power management drive conflicts with the local APIC (LAPIC)
685 .\"Disable APIC mode with
686 .\".Va hint.apic.0.disabled
691 .\"states if APIC mode is enabled.