1 # SPDX-License-Identifier: GPL-2.0
6 config ARCH_SUPPORTS_ACPI
10 bool "ACPI (Advanced Configuration and Power Interface) Support"
11 depends on ARCH_SUPPORTS_ACPI
17 Advanced Configuration and Power Interface (ACPI) support for
18 Linux requires an ACPI-compliant platform (hardware/firmware),
19 and assumes the presence of OS-directed configuration and power
20 management (OSPM) software. This option will enlarge your
23 Linux ACPI provides a robust functional replacement for several
24 legacy configuration and power management interfaces, including
25 the Plug-and-Play BIOS specification (PnP BIOS), the
26 MultiProcessor Specification (MPS), and the Advanced Power
27 Management (APM) specification. If both ACPI and APM support
28 are configured, ACPI is used.
30 Linux support for ACPI is based on Intel Corporation's ACPI
31 Component Architecture (ACPI CA). For more information on the
35 ACPI is an open industry specification originally co-developed by
36 Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba. Currently,
37 it is developed by the ACPI Specification Working Group (ASWG) under
38 the UEFI Forum and any UEFI member can join the ASWG and contribute
39 to the ACPI specification.
40 The specification is available at:
41 <https://uefi.org/specifications>
45 config ACPI_LEGACY_TABLES_LOOKUP
48 config ARCH_MIGHT_HAVE_ACPI_PDC
51 config ACPI_GENERIC_GSI
54 config ACPI_SYSTEM_POWER_STATES_SUPPORT
57 config ACPI_CCA_REQUIRED
64 bool "AML debugger interface"
67 Enable in-kernel debugging of AML facilities: statistics,
68 internal object dump, single step control method execution.
69 This is still under development, currently enabling this only
70 results in the compilation of the ACPICA debugger files.
74 config ACPI_DEBUGGER_USER
75 tristate "Userspace debugger accessibility"
78 Export /sys/kernel/debug/acpi/acpidbg for userspace utilities
79 to access the debugger functionalities.
83 config ACPI_SPCR_TABLE
84 bool "ACPI Serial Port Console Redirection Support"
87 Enable support for Serial Port Console Redirection (SPCR) Table.
88 This table provides information about the configuration of the
92 bool "ACPI Firmware Performance Data Table (FPDT) support"
95 Enable support for the Firmware Performance Data Table (FPDT).
96 This table provides information on the timing of the system
97 boot, S3 suspend and S3 resume firmware code paths.
106 depends on SUSPEND || HIBERNATION
107 depends on ACPI_SYSTEM_POWER_STATES_SUPPORT
110 config ACPI_REV_OVERRIDE_POSSIBLE
111 bool "Allow supported ACPI revision to be overridden"
115 The platform firmware on some systems expects Linux to return "5" as
116 the supported ACPI revision which makes it expose system configuration
117 information in a special way.
119 For example, based on what ACPI exports as the supported revision,
120 Dell XPS 13 (2015) configures its audio device to either work in HDA
121 mode or in I2S mode, where the former is supposed to be used on Linux
122 until the latter is fully supported (in the kernel as well as in user
125 This option enables a DMI-based quirk for the above Dell machine (so
126 that HDA audio is exposed by the platform firmware to the kernel) and
127 makes it possible to force the kernel to return "5" as the supported
128 ACPI revision via the "acpi_rev_override" command line switch.
130 config ACPI_EC_DEBUGFS
131 tristate "EC read/write access through /sys/kernel/debug/ec"
133 Say N to disable Embedded Controller /sys/kernel/debug interface
135 Be aware that using this interface can confuse your Embedded
136 Controller in a way that a normal reboot is not enough. You then
137 have to power off your system, and remove the laptop battery for
139 An Embedded Controller typically is available on laptops and reads
140 sensor values like battery state and temperature.
141 The kernel accesses the EC through ACPI parsed code provided by BIOS
142 tables. This option allows to access the EC directly without ACPI
144 Thus this option is a debug option that helps to write ACPI drivers
145 and can be used to identify ACPI code or EC firmware bugs.
148 tristate "AC Adapter"
152 This driver supports the AC Adapter object, which indicates
153 whether a system is on AC or not. If you have a system that can
154 switch between A/C and battery, say Y.
156 To compile this driver as a module, choose M here:
157 the module will be called ac.
164 This driver adds support for battery information through
165 /proc/acpi/battery. If you have a mobile system with a battery,
168 To compile this driver as a module, choose M here:
169 the module will be called battery.
176 This driver handles events on the power, sleep, and lid buttons.
177 A daemon reads events from input devices or via netlink and
178 performs user-defined actions such as shutting down the system.
179 This is necessary for software-controlled poweroff.
181 To compile this driver as a module, choose M here:
182 the module will be called button.
184 config ACPI_TINY_POWER_BUTTON
185 tristate "Tiny Power Button Driver"
186 depends on !ACPI_BUTTON
188 This driver provides a tiny alternative to the ACPI Button driver.
189 The tiny power button driver only handles the power button. Rather
190 than notifying userspace via the input layer or a netlink event, this
191 driver directly signals the init process to shut down.
193 This driver is particularly suitable for cloud and VM environments,
194 which use a simulated power button to initiate a controlled poweroff,
195 but which may not want to run a separate userspace daemon to process
198 config ACPI_TINY_POWER_BUTTON_SIGNAL
199 int "Tiny Power Button Signal"
200 depends on ACPI_TINY_POWER_BUTTON
203 Default signal to send to init in response to the power button.
205 Likely values here include 38 (SIGRTMIN+4) to power off, or 2
206 (SIGINT) to simulate Ctrl+Alt+Del.
210 depends on BACKLIGHT_CLASS_DEVICE
214 This driver implements the ACPI Extensions For Display Adapters
215 for integrated graphics devices on motherboard, as specified in
216 ACPI 2.0 Specification, Appendix B. This supports basic operations
217 such as defining the video POST device, retrieving EDID information,
218 and setting up a video output.
220 To compile this driver as a module, choose M here:
221 the module will be called video.
228 This driver supports ACPI fan devices, allowing user-mode
229 applications to perform basic fan control (on, off, status).
231 To compile this driver as a module, choose M here:
232 the module will be called fan.
235 tristate "ACPI Time and Alarm (TAD) Device Support"
236 depends on SYSFS && PM_SLEEP
238 The ACPI Time and Alarm (TAD) device is an alternative to the Real
239 Time Clock (RTC). Its wake timers allow the system to transition from
240 the S3 (or optionally S4/S5) state to S0 state after a time period
241 elapses. In comparison with the RTC Alarm, the TAD provides a larger
242 scale of flexibility in the wake timers. The time capabilities of the
243 TAD maintain the time of day information across platform power
244 transitions, and keep track of time even when the platform is turned
250 This driver supports ACPI-controlled docking stations and removable
251 drive bays such as the IBM Ultrabay and the Dell Module Bay.
253 config ACPI_CPU_FREQ_PSS
256 config ACPI_PROCESSOR_CSTATE
258 depends on ACPI_PROCESSOR
259 depends on IA64 || X86
261 config ACPI_PROCESSOR_IDLE
270 depends on ACPI_PROCESSOR
274 If this option is enabled, this file implements common functionality
275 to parse CPPC tables as described in the ACPI 5.1+ spec. The
276 routines implemented are meant to be used by other
277 drivers to control CPU performance using CPPC semantics.
278 If your platform does not support CPPC in firmware,
279 leave this option disabled.
281 config ACPI_PROCESSOR
283 depends on X86 || IA64 || ARM64 || LOONGARCH
284 select ACPI_PROCESSOR_IDLE
285 select ACPI_CPU_FREQ_PSS if X86 || IA64 || LOONGARCH
289 This driver adds support for the ACPI Processor package. It is required
290 by several flavors of cpufreq performance-state, thermal, throttling and
293 To compile this driver as a module, choose M here:
294 the module will be called processor.
298 depends on IPMI_HANDLER
300 This driver enables the ACPI to access the BMC controller. And it
301 uses the IPMI request/response message to communicate with BMC
302 controller, which can be found on the server.
304 To compile this driver as a module, choose M here:
305 the module will be called as acpi_ipmi.
307 config ACPI_HOTPLUG_CPU
309 depends on ACPI_PROCESSOR && HOTPLUG_CPU
310 select ACPI_CONTAINER
313 config ACPI_PROCESSOR_AGGREGATOR
314 tristate "Processor Aggregator"
315 depends on ACPI_PROCESSOR
318 ACPI 4.0 defines processor Aggregator, which enables OS to perform
319 specific processor configuration and control that applies to all
320 processors in the platform. Currently only logical processor idling
321 is defined, which is to reduce power consumption. This driver
322 supports the new device.
325 tristate "Thermal Zone"
326 depends on ACPI_PROCESSOR
330 This driver supports ACPI thermal zones. Most mobile and
331 some desktop systems support ACPI thermal zones. It is HIGHLY
332 recommended that this option be enabled, as your processor(s)
333 may be damaged without it.
335 To compile this driver as a module, choose M here:
336 the module will be called thermal.
338 config ACPI_PLATFORM_PROFILE
341 config ACPI_CUSTOM_DSDT_FILE
342 string "Custom DSDT Table file to include"
344 depends on !STANDALONE
346 This option supports a custom DSDT by linking it into the kernel.
348 Enter the full path name to the file which includes the AmlCode
349 or dsdt_aml_code declaration.
351 If unsure, don't enter a file name.
353 config ACPI_CUSTOM_DSDT
355 default ACPI_CUSTOM_DSDT_FILE != ""
357 config ARCH_HAS_ACPI_TABLE_UPGRADE
360 config ACPI_TABLE_UPGRADE
361 bool "Allow upgrading ACPI tables via initrd"
362 depends on BLK_DEV_INITRD && ARCH_HAS_ACPI_TABLE_UPGRADE
365 This option provides functionality to upgrade arbitrary ACPI tables
366 via initrd. No functional change if no ACPI tables are passed via
367 initrd, therefore it's safe to say Y.
368 See Documentation/admin-guide/acpi/initrd_table_override.rst for details
370 config ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD
371 bool "Override ACPI tables from built-in initrd"
372 depends on ACPI_TABLE_UPGRADE
373 depends on INITRAMFS_SOURCE!="" && INITRAMFS_COMPRESSION_NONE
375 This option provides functionality to override arbitrary ACPI tables
376 from built-in uncompressed initrd.
378 See Documentation/admin-guide/acpi/initrd_table_override.rst for details
381 bool "Debug Statements"
383 The ACPI subsystem can produce debug output. Saying Y enables this
384 output and increases the kernel size by around 50K.
386 Use the acpi.debug_layer and acpi.debug_level kernel command-line
387 parameters documented in Documentation/firmware-guide/acpi/debug.rst and
388 Documentation/admin-guide/kernel-parameters.rst to control the type and
389 amount of debug output.
392 bool "PCI slot detection driver"
393 depends on SYSFS && PCI
395 This driver creates entries in /sys/bus/pci/slots/ for all PCI
396 slots in the system. This can help correlate PCI bus addresses,
397 i.e., segment/bus/device/function tuples, with physical slots in
398 the system. If you are unsure, say N.
400 config ACPI_CONTAINER
401 bool "Container and Module Devices"
402 default (ACPI_HOTPLUG_MEMORY || ACPI_HOTPLUG_CPU)
404 This driver supports ACPI Container and Module devices (IDs
405 ACPI0004, PNP0A05, and PNP0A06).
407 This helps support hotplug of nodes, CPUs, and memory.
409 config ACPI_HOTPLUG_MEMORY
410 bool "Memory Hotplug"
411 depends on MEMORY_HOTPLUG
413 This driver supports ACPI memory hotplug. The driver
414 fields notifications on ACPI memory devices (PNP0C80),
415 which represent memory ranges that may be onlined or
416 offlined during runtime.
418 If your hardware and firmware do not support adding or
419 removing memory devices at runtime, you need not enable
422 config ACPI_HOTPLUG_IOAPIC
425 depends on X86_IO_APIC
429 tristate "Smart Battery System"
433 This driver supports the Smart Battery System, another
434 type of access to battery information, found on some laptops.
436 To compile this driver as a module, choose M here:
437 the modules will be called sbs and sbshc.
440 tristate "Hardware Error Device"
442 This driver supports the Hardware Error Device (PNP0C33),
443 which is used to report some hardware errors notified via
444 SCI, mainly the corrected errors.
446 config ACPI_CUSTOM_METHOD
447 tristate "Allow ACPI methods to be inserted/replaced at run time"
450 This debug facility allows ACPI AML methods to be inserted and/or
451 replaced without rebooting the system. For details refer to:
452 Documentation/firmware-guide/acpi/method-customizing.rst.
454 NOTE: This option is security sensitive, because it allows arbitrary
455 kernel memory to be written to by root (uid=0) users, allowing them
456 to bypass certain security measures (e.g. if root is not allowed to
457 load additional kernel modules after boot, this feature may be used
458 to override that restriction).
461 bool "Boottime Graphics Resource Table support"
462 depends on EFI && (X86 || ARM64)
464 This driver adds support for exposing the ACPI Boottime Graphics
465 Resource Table, which allows the operating system to obtain
466 data from the firmware boot splash. It will appear under
467 /sys/firmware/acpi/bgrt/ .
469 config ACPI_REDUCED_HARDWARE_ONLY
470 bool "Hardware-reduced ACPI support only" if EXPERT
473 This config item changes the way the ACPI code is built. When this
474 option is selected, the kernel will use a specialized version of
475 ACPICA that ONLY supports the ACPI "reduced hardware" mode. The
476 resulting kernel will be smaller but it will also be restricted to
477 running in ACPI reduced hardware mode ONLY.
479 If you are unsure what to do, do not enable this option.
481 source "drivers/acpi/nfit/Kconfig"
482 source "drivers/acpi/numa/Kconfig"
483 source "drivers/acpi/apei/Kconfig"
484 source "drivers/acpi/dptf/Kconfig"
490 tristate "Extended Error Log support"
491 depends on X86_MCE && X86_LOCAL_APIC && EDAC
494 Certain usages such as Predictive Failure Analysis (PFA) require
495 more information about the error than what can be described in
496 processor machine check banks. Most server processors log
497 additional information about the error in processor uncore
498 registers. Since the addresses and layout of these registers vary
499 widely from one processor to another, system software cannot
500 readily make use of them. To complicate matters further, some of
501 the additional error information cannot be constructed without
502 detailed knowledge about platform topology.
504 Enhanced MCA Logging allows firmware to provide additional error
505 information to system software, synchronous with MCE or CMCI. This
506 driver adds support for that functionality with corresponding
507 tracepoint which carries that information to userspace.
513 tristate "ACPI configfs support"
516 Select this option to enable support for ACPI configuration from
517 userspace. The configurable ACPI groups will be visible under
518 /config/acpi, assuming configfs is mounted under /config.
521 tristate "ACPI Platform Firmware Runtime Update and Telemetry"
524 This mechanism allows certain pieces of the platform firmware
525 to be updated on the fly while the system is running (runtime)
526 without the need to restart it, which is key in the cases when
527 the system needs to be available 100% of the time and it cannot
528 afford the downtime related to restarting it, or when the work
529 carried out by the system is particularly important, so it cannot
530 be interrupted, and it is not practical to wait until it is complete.
532 The existing firmware code can be modified (driver update) or
533 extended by adding new code to the firmware (code injection).
535 Besides, the telemetry driver allows user space to fetch telemetry
536 data from the firmware with the help of the Platform Firmware Runtime
539 To compile the drivers as modules, choose M here:
540 the modules will be called pfr_update and pfr_telemetry.
543 source "drivers/acpi/arm64/Kconfig"
550 bool "ACPI PCC Address Space"
554 The PCC Address Space also referred as PCC Operation Region pertains
555 to the region of PCC subspace that succeeds the PCC signature.
557 The PCC Operation Region works in conjunction with the PCC Table
558 (Platform Communications Channel Table). PCC subspaces that are
559 marked for use as PCC Operation Regions must not be used as PCC
560 subspaces for the standard ACPI features such as CPPC, RASF, PDTT and
561 MPST. These standard features must always use the PCC Table instead.
563 Enable this feature if you want to set up and install the PCC Address
564 Space handler to handle PCC OpRegion in the firmware.
566 source "drivers/acpi/pmic/Kconfig"
572 bool "Platform Runtime Mechanism Support"
573 depends on EFI && (X86_64 || ARM64)
576 Platform Runtime Mechanism (PRM) is a firmware interface exposing a
577 set of binary executables that can be called from the AML interpreter
578 or directly from device drivers.
580 Say Y to enable the AML interpreter to execute the PRM code.
582 While this feature is optional in principle, leaving it out may
583 substantially increase computational overhead related to the
584 initialization of some server systems.
589 bool "Power Management Timer Support" if EXPERT
590 depends on X86 && (ACPI || JAILHOUSE_GUEST)
593 The Power Management Timer is available on all ACPI-capable,
594 in most cases even if ACPI is unusable or blacklisted.
596 This timing source is not affected by power management features
597 like aggressive processor idling, throttling, frequency and/or
598 voltage scaling, unlike the commonly used Time Stamp Counter
601 You should nearly always say Y here because many modern
602 systems require this timer.