1.\" 2.\" Copyright (c) 2001 Michael Smith 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 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 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 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 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD: src/share/man/man4/acpi.4,v 1.61.8.1 2009/04/15 03:14:26 kensmith Exp $ 27.\" 28.Dd August 31, 2015 29.Dt ACPI 4 30.Os 31.Sh NAME 32.Nm acpi 33.Nd Advanced Configuration and Power Management support 34.Sh SYNOPSIS 35.Cd "device acpi" 36.Pp 37.Cd "options ACPI_DEBUG" 38.Cd "options DDB" 39.Sh DESCRIPTION 40The 41.Nm 42driver provides support for the Intel/Microsoft/Compaq/Toshiba ACPI 43standard. 44This support includes platform hardware discovery (superseding the 45PnP and PCI BIOS), as well as power management (superseding APM) and 46other features. 47ACPI core support is provided by the ACPICA reference implementation 48from Intel. 49.Pp 50Note that the 51.Nm 52driver is automatically loaded by the 53.Xr loader 8 , 54and should only be 55compiled into the kernel on platforms where ACPI is mandatory. 56.Sh SYSCTL VARIABLES 57The 58.Nm 59driver is intended to provide power management without user intervention. 60If the default settings are not optimal, the following sysctls can be 61used to modify or monitor 62.Nm 63behavior. 64.Bl -tag -width indent 65.It Va debug.acpi.enable_debug_objects 66Enable dumping Debug objects without 67.Cd "options ACPI_DEBUG" . 68Default is 0, ignore Debug objects. 69.It Va hw.acpi.acline 70AC line state (1 means online, 0 means on battery power). 71.It Va hw.acpi.cpu.cx_usage 72Debugging information listing the percent of total usage for each sleep state. 73The values are reset when 74.Va hw.acpi.cpu.cx_lowest 75is modified. 76.It Va hw.acpi.cpu.cx_lowest 77Lowest Cx state to use for idling the CPU. 78A scheduling algorithm will select states between 79.Li C1 80and this setting 81as system load dictates. 82To enable ACPI CPU idling control, 83.Va machdep.cpu_idle_hlt 84must be set to 2 (the default value). 85.It Va hw.acpi.cpu.cx_supported 86List of supported CPU idle states and their transition latency 87in microseconds. 88Each state has a type (e.g., 89.Li C2 ) . 90.Li C1 91is equivalent to the ia32 92.Li HLT 93instruction, 94.Li C2 95provides a deeper 96sleep with the same semantics, and 97.Li C3 98provides the deepest sleep 99but additionally requires bus mastering to be disabled. 100States greater than 101.Li C3 102provide even more power savings with the same 103semantics as the 104.Li C3 105state. 106Deeper sleeps provide more power savings but increased transition 107latency when an interrupt occurs. 108.It Va hw.acpi.disable_on_reboot 109Disable ACPI during the reboot process. 110Most systems reboot fine with ACPI still enabled, but some require 111exiting to legacy mode first. 112Default is 0, leave ACPI enabled. 113.It Va hw.acpi.handle_reboot 114Use the ACPI Reset Register capability to reboot the system. 115Default is 0, use legacy reboot support. 116Some newer systems require use of this register, while some only work 117with legacy rebooting support. 118.It Va hw.acpi.lid_switch_state 119Suspend state 120.Pq Li S1 Ns \[en] Ns Li S5 121to enter when the lid switch (i.e., a notebook screen) is closed. 122Default is 123.Dq Li NONE 124(do nothing). 125.It Va hw.acpi.power_button_state 126Suspend state 127.Pq Li S1 Ns \[en] Ns Li S5 128to enter when the power button is pressed. 129Default is 130.Li S5 131(power-off nicely). 132.It Va hw.acpi.install_interface , hw.acpi.remove_interface 133Install or remove OS interface(s) to control the return value of the 134.Ql _OSI 135query method. 136When an OS interface is specified in 137.Va hw.acpi.install_interface , 138the 139.Li _OSI 140query for the interface returns it is 141.Em supported . 142Conversely, when an OS interface is specified in 143.Va hw.acpi.remove_interface , 144the 145.Li _OSI 146query returns it is 147.Em not supported . 148Multiple interfaces can be specified in a comma-separated list and 149any leading white spaces will be ignored. 150For example, 151.Qq Li FreeBSD, Linux 152is a valid list of two interfaces 153.Qq Li FreeBSD 154and 155.Qq Li Linux . 156.It Va hw.acpi.reset_video 157Reset the video adapter from real mode during the resume path. 158Some systems need this help, others have display problems if it is enabled. 159Default is 0 (disabled). 160.It Va hw.acpi.s4bios 161Indicate whether the system supports 162.Li S4BIOS . 163This means that the BIOS can handle all the functions of suspending the 164system to disk. 165Otherwise, the OS is responsible for suspending to disk 166.Pq Li S4OS . 167Most current systems do not support 168.Li S4BIOS . 169.It Va hw.acpi.sleep_button_state 170Suspend state 171.Pq Li S1 Ns \[en] Ns Li S5 172to enter when the sleep button is pressed. 173This is usually a special function button on the keyboard. 174Default is 175.Li S3 176(suspend-to-RAM). 177.It Va hw.acpi.sleep_delay 178Wait this number of seconds between preparing the system to suspend and 179actually entering the suspend state. 180Default is 1 second. 181.It Va hw.acpi.supported_sleep_state 182Suspend states 183.Pq Li S1 Ns \[en] Ns Li S5 184supported by the BIOS. 185.Bl -tag -width indent 186.It Li S1 187Quick suspend to RAM. 188The CPU enters a lower power state, but most peripherals are left running. 189.It Li S2 190Lower power state than 191.Li S1 , 192but with the same basic characteristics. 193Not supported by many systems. 194.It Li S3 195Suspend to RAM. 196Most devices are powered off, and the system stops running except for 197memory refresh. 198.It Li S4 199Suspend to disk. 200All devices are powered off, and the system stops running. 201When resuming, the system starts as if from a cold power on. 202Not yet supported by 203.Fx 204unless 205.Li S4BIOS 206is available. 207.It Li S5 208System shuts down cleanly and powers off. 209.El 210.It Va hw.acpi.verbose 211Enable verbose printing from the various ACPI subsystems. 212.El 213.Sh LOADER TUNABLES 214Tunables can be set at the 215.Xr loader 8 216prompt before booting the kernel or stored in 217.Pa /boot/loader.conf . 218Many of these tunables also have a matching 219.Xr sysctl 8 220entry for access after boot. 221.Bl -tag -width indent 222.It Va acpi_dsdt_load 223Enables loading of a custom ACPI DSDT. 224.It Va acpi_dsdt_name 225Name of the DSDT table to load, if loading is enabled. 226It is relative to 227.Pa /boot/kernel . 228.It Va debug.acpi.allow_method_calls 229If set, the 230.Xr acpicall 8 231utility can be used to directly call ACPI methods for debugging and 232tweaking purposes. 233.It Va debug.acpi.disabled 234Selectively disables portions of ACPI that are enabled by default, for 235debugging purposes. 236.It Va debug.acpi.enabled 237Selectively enables portions of ACPI that are disabled by default, for 238debugging purposes. 239.It Va debug.acpi.facs_addr32 240Favor 32-bit FACS table addresses over the 64-bit addresses. 241.It Va debug.acpi.fadt_addr32 242Favor 32-bit FADT register addresses over the 64-bit addresses. 243.It Va debug.acpi.ignore_xsdt 244Ignore the XSDT, forcing the use of the RSDT. 245.It Va debug.acpi.interpreter_slack 246Enable less strict ACPI implementations. 247Default is 1, ignore common BIOS mistakes. 248.It Va debug.acpi.max_threads 249Specify the number of task threads that are started on boot. 250Limiting this to 1 may help work around various BIOSes that cannot 251handle parallel requests. 252The default value is 3. 253.It Va debug.acpi.quirks 254Override any automatic quirks completely. 255.It Va debug.acpi.resume_beep 256Beep the PC speaker on resume. 257This can help diagnose suspend/resume problems. 258Default is 0 (disabled). 259.It Va hint.acpi.0.disabled 260Set this to 1 to disable all of ACPI. 261If ACPI has been disabled on your system due to a blacklist entry for your 262BIOS, you can set this to 0 to re-enable ACPI for testing. 263.It Va hw.acpi.ec.poll_timeout 264Delay in milliseconds to wait for the EC to respond. 265Try increasing this number if you get the error 266.Qq Li AE_NO_HARDWARE_RESPONSE . 267.It Va hw.acpi.host_mem_start 268Override the assumed memory starting address for PCI host bridges. 269.It Va hw.acpi.reset_video 270Enables calling the VESA reset BIOS vector on the resume path. 271This can fix some graphics cards that have problems such as LCD white-out 272after resume. 273Default is 0 (disabled). 274.It Va hw.acpi.auto_serialize_methods 275Auto-serialization of control methods to proactively prevent problems with 276ill-behaved reentrant control methods that create named ACPI objects. 277Default is 1 (enabled). 278.It Va hw.acpi.verbose 279Turn on verbose debugging information about what ACPI is doing. 280.It Va hw.pci.link.%s.%d.irq 281Override the interrupt to use for this link and index. 282This capability should be used carefully, and only if a device is not 283working with 284.Nm 285enabled. 286.Qq %s 287is the name of the link (e.g., LNKA). 288.Qq %d 289is the resource index when the link supports multiple IRQs. 290Most PCI links only have one IRQ resource, so the below form should be used. 291.It Va hw.pci.link.%s.irq 292Override the interrupt to use. 293This capability should be used carefully, and only if a device is not 294working with 295.Nm 296enabled. 297.Qq %s 298is the name of the link (e.g., LNKA). 299.El 300.Sh DISABLING ACPI 301Since ACPI support on different platforms varies greatly, there are many 302debugging and tuning options available. 303.Pp 304For machines known not to work with 305.Nm 306enabled, there is a BIOS blacklist. 307Currently, the blacklist only controls whether 308.Nm 309should be disabled or not. 310In the future, it will have more granularity to control features (the 311infrastructure for that is already there). 312.Pp 313To enable 314.Nm 315(for debugging purposes, etc.) on machines that are on the blacklist, set the 316kernel environment variable 317.Va hint.acpi.0.disabled 318to 0. 319Before trying this, consider updating your BIOS to a more recent version that 320may be compatible with ACPI. 321.Pp 322To disable the 323.Nm 324driver completely, set the kernel environment variable 325.Va hint.acpi.0.disabled 326to 1. 327.Pp 328Some i386 machines totally fail to operate with some or all of ACPI disabled. 329Other i386 machines fail with ACPI enabled. 330Disabling all or part of ACPI on non-i386 platforms (i.e., platforms where 331ACPI support is mandatory) may result in a non-functional system. 332.Pp 333The 334.Nm 335driver comprises a set of drivers, which may be selectively disabled 336in case of problems. 337To disable a sub-driver, list it in the kernel 338environment variable 339.Va debug.acpi.disabled . 340Multiple entries can be listed, separated by a space. 341.Pp 342ACPI sub-devices and features that can be disabled: 343.Bl -tag -width ".Li sysresource" 344.It Li all 345Disable all ACPI features and devices. 346.It Li acad 347.Pq Vt device 348Supports AC adapter. 349.It Li bus 350.Pq Vt feature 351Probes and attaches subdevices. 352Disabling will avoid scanning the ACPI namespace entirely. 353.It Li children 354.Pq Vt feature 355Attaches standard ACPI sub-drivers and devices enumerated in the 356ACPI namespace. 357Disabling this has a similar effect to disabling 358.Dq Li bus , 359except that the 360ACPI namespace will still be scanned. 361.It Li button 362.Pq Vt device 363Supports ACPI button devices (typically power and sleep buttons). 364.It Li cmbat 365.Pq Vt device 366Control-method batteries device. 367.It Li cpu 368.Pq Vt device 369Supports CPU power-saving and speed-setting functions. 370.It Li cpu_cst 371.Pq Vt device 372Supports CPU power-saving. 373Disabling 374.Dq Li cpu 375will also disable this device. 376.It Li cpu_pst 377.Pq Vt device 378Supports CPU speed-setting. 379Disabling 380.Dq Li cpu 381will also disable this device. 382.It Li dock 383.Pq Vt device 384Docking station device. 385.It Li ec 386.Pq Vt device 387Supports the ACPI Embedded Controller interface, used to communicate 388with embedded platform controllers. 389.It Li hpet 390.Pq Vt feature 391Supports the High Precision Event Timer. 392.It Li isa 393.Pq Vt device 394Supports an ISA bus bridge defined in the ACPI namespace, 395typically as a child of a PCI bus. 396.It Li lid 397.Pq Vt device 398Supports an ACPI laptop lid switch, which typically puts a 399system to sleep. 400.It Li quirks 401.Pq Vt feature 402Do not honor quirks. 403Quirks automatically disable ACPI functionality based on the XSDT table's 404OEM vendor name and revision date. 405.It Li pci 406.Pq Vt device 407Supports Host to PCI bridges. 408.It Li pci_link 409.Pq Vt feature 410Performs PCI interrupt routing. 411.It Li sysresource 412.Pq Vt device 413Pseudo-devices containing resources which ACPI claims. 414.It Li thermal 415.Pq Vt device 416Supports system cooling and heat management. 417.It Li timer 418.Pq Vt device 419Implements a timecounter using the ACPI fixed-frequency timer. 420.It Li video 421.Pq Vt device 422Supports 423.Xr acpi_video 4 424which may conflict with 425.Xr agp 4 426device. 427.El 428.Pp 429.\"The 430.\".Nm 431.\"driver comprises a set of drivers, 432.\"which may be selectively enabled in case of testing. 433.\"To enable a sub-driver, 434.\"list it in the kernel environment variable 435.\".Va debug.acpi.enabled . 436.\"Multiple entries can be listed, 437.\"separated by a space. 438.\".Pp 439.\"ACPI sub-devices and features that can be enabled: 440.\".Bl -tag -width ".Li sysresource" 441.\"[...] 442.\".El 443.\".Pp 444It is also possible to avoid portions of the ACPI namespace which 445may be causing problems, by listing the full path of the root of 446the region to be avoided in the kernel environment variable 447.Va debug.acpi.avoid . 448The object and all of its children will be ignored during the 449bus/children scan of the namespace. 450The ACPICA code will still know about the avoided region. 451.Sh DEBUGGING OUTPUT 452To enable debugging output, 453.Nm 454must be compiled with 455.Cd "options ACPI_DEBUG" . 456Debugging output is separated between layers and levels, where a layer is 457a component of the ACPI subsystem, and a level is a particular kind 458of debugging output. 459.Pp 460Both layers and levels are specified as a whitespace-separated list of 461tokens, with layers listed in 462.Va debug.acpi.layer 463and levels in 464.Va debug.acpi.level . 465.Pp 466The first set of layers is for ACPICA components, and the second is for 467.Dx 468drivers. 469The ACPICA layer descriptions include the prefix for the files they 470refer to. 471The supported layers are: 472.Pp 473.Bl -tag -compact -width ".Li ACPI_CA_DISASSEMBLER" 474.It Li ACPI_UTILITIES 475Utility ("ut") functions 476.It Li ACPI_HARDWARE 477Hardware access ("hw") 478.It Li ACPI_EVENTS 479Event and GPE ("ev") 480.It Li ACPI_TABLES 481Table access ("tb") 482.It Li ACPI_NAMESPACE 483Namespace evaluation ("ns") 484.It Li ACPI_PARSER 485AML parser ("ps") 486.It Li ACPI_DISPATCHER 487Internal representation of interpreter state ("ds") 488.It Li ACPI_EXECUTER 489Execute AML methods ("ex") 490.It Li ACPI_RESOURCES 491Resource parsing ("rs") 492.It Li ACPI_CA_DEBUGGER 493Debugger implementation ("db", "dm") 494.It Li ACPI_OS_SERVICES 495Usermode support routines ("os") 496.It Li ACPI_CA_DISASSEMBLER 497Disassembler implementation (unused) 498.It Li ACPI_ALL_COMPONENTS 499All the above ACPICA components 500.It Li ACPI_AC_ADAPTER 501AC adapter driver 502.It Li ACPI_BATTERY 503Control-method battery driver 504.It Li ACPI_BUS 505ACPI, ISA, and PCI bus drivers 506.It Li ACPI_BUTTON 507Power and sleep button driver 508.It Li ACPI_EC 509Embedded controller driver 510.It Li ACPI_FAN 511Fan driver 512.It Li ACPI_OEM 513Platform-specific driver for hotkeys, LED, etc. 514.It Li ACPI_POWER 515Power resource driver 516.It Li ACPI_PROCESSOR 517CPU driver 518.It Li ACPI_THERMAL 519Thermal zone driver 520.It Li ACPI_TIMER 521Timer driver 522.It Li ACPI_ALL_DRIVERS 523All the above 524.Dx 525ACPI drivers 526.El 527.Pp 528The supported levels are: 529.Pp 530.Bl -tag -compact -width ".Li ACPI_LV_AML_DISASSEMBLE" 531.It Li ACPI_LV_INIT 532Initialization progress 533.It Li ACPI_LV_DEBUG_OBJECT 534Stores to objects 535.It Li ACPI_LV_INFO 536General information and progress 537.It Li ACPI_LV_REPAIR 538Repair a common problem with predefined methods 539.It Li ACPI_LV_ALL_EXCEPTIONS 540All the previous levels 541.It Li ACPI_LV_PARSE 542.It Li ACPI_LV_DISPATCH 543.It Li ACPI_LV_EXEC 544.It Li ACPI_LV_NAMES 545.It Li ACPI_LV_OPREGION 546.It Li ACPI_LV_BFIELD 547.It Li ACPI_LV_TABLES 548.It Li ACPI_LV_VALUES 549.It Li ACPI_LV_OBJECTS 550.It Li ACPI_LV_RESOURCES 551.It Li ACPI_LV_USER_REQUESTS 552.It Li ACPI_LV_PACKAGE 553.It Li ACPI_LV_VERBOSITY1 554All the previous levels 555.It Li ACPI_LV_ALLOCATIONS 556.It Li ACPI_LV_FUNCTIONS 557.It Li ACPI_LV_OPTIMIZATIONS 558.It Li ACPI_LV_VERBOSITY2 559All the previous levels 560.It Li ACPI_LV_ALL 561Alias for 562.Qq Li ACPI_LV_VERBOSITY2 563.It Li ACPI_LV_MUTEX 564.It Li ACPI_LV_THREADS 565.It Li ACPI_LV_IO 566.It Li ACPI_LV_INTERRUPTS 567.It Li ACPI_LV_VERBOSITY3 568All the previous levels 569.It Li ACPI_LV_AML_DISASSEMBLE 570.It Li ACPI_LV_VERBOSE_INFO 571.It Li ACPI_LV_FULL_TABLES 572.It Li ACPI_LV_EVENTS 573.It Li ACPI_LV_VERBOSE 574All levels after 575.Qq Li ACPI_LV_VERBOSITY3 576.It Li ACPI_LV_INIT_NAMES 577Needs to be specified separately 578.It Li ACPI_LV_LOAD 579Needs to be specified separately 580.El 581.Pp 582Selection of the appropriate layer and level values is important 583to avoid massive amounts of debugging output. 584For example, the following configuration is a good way to gather initial 585information. 586It enables debug output for both ACPICA and the 587.Nm 588driver, printing basic information about errors, warnings, and progress. 589.Bd -literal -offset indent 590debug.acpi.layer="ACPI_ALL_COMPONENTS ACPI_ALL_DRIVERS" 591debug.acpi.level="ACPI_LV_ALL_EXCEPTIONS" 592.Ed 593.Pp 594Debugging output by the ACPICA subsystem is prefixed with the 595module name in lowercase, followed by a source line number. 596Output from the 597.Dx Ns -local 598code follows the same format, but 599the module name is uppercased. 600.Sh OVERRIDING YOUR BIOS BYTECODE 601ACPI interprets bytecode named AML 602(ACPI Machine Language) 603provided by the BIOS vendor as a memory image at boot time. 604Sometimes, the AML code contains a bug that does not appear when parsed 605by the Microsoft implementation. 606.Dx 607provides a way to override it with your own AML code to work around 608or debug such problems. 609Note that all AML in your DSDT and any SSDT tables is overridden. 610.Pp 611In order to load your AML code, copy it to 612.Pa /boot/kernel/acpi_dsdt.aml 613and add the following line to 614.Pa /boot/loader.conf . 615.Bd -literal -offset indent 616acpi_dsdt_load="YES" 617.Ed 618.Pp 619In order to prepare your AML code, you will need the 620.Xr acpidump 8 621and 622.Xr iasl 8 623utilities and some ACPI knowledge. 624.\".Sh COMPATIBILITY 625.\"ACPI is only found and supported on i386 and x86_64. 626.Sh SEE ALSO 627.Xr kenv 1 , 628.Xr acpi_asus 4 , 629.Xr acpi_dock 4 , 630.Xr acpi_fujitsu 4 , 631.Xr acpi_hp 4 , 632.Xr acpi_panasonic 4 , 633.Xr acpi_sony 4 , 634.Xr acpi_thermal 4 , 635.Xr acpi_thinkpad 4 , 636.Xr acpi_toshiba 4 , 637.Xr acpi_video 4 , 638.Xr aibs 4 , 639.Xr loader.conf 5 , 640.Xr acpibin 8 , 641.Xr acpicall 8 , 642.Xr acpiconf 8 , 643.Xr acpidump 8 , 644.Xr acpiexec 8 , 645.Xr acpinames 8 , 646.Xr acpixtract 8 , 647.Xr config 8 , 648.Xr iasl 8 649.Rs 650.%A "Hewlett-Packard Corporation" 651.%A "Intel Corporation" 652.%A "Microsoft Corporation" 653.%A "Phoenix Technologies Ltd." 654.%A "Toshiba Corporation" 655.%D November 13, 2013 656.%T "Advanced Configuration and Power Interface Specification" 657.%O http://acpi.info/spec.htm 658.Re 659.Sh AUTHORS 660.An -nosplit 661The ACPICA subsystem is developed and maintained by 662Intel Architecture Labs. 663.Pp 664The following people made notable contributions to the ACPI subsystem 665in 666.Dx : 667.An Michael Smith , 668.An Takanori Watanabe Aq Mt takawata@jp.FreeBSD.org , 669.An Mitsuru IWASAKI Aq Mt iwasaki@jp.FreeBSD.org , 670.An Munehiro Matsuda , 671.An Nate Lawson , 672the ACPI-jp mailing list at 673.Aq Mt acpi-jp@jp.FreeBSD.org , 674and many other contributors. 675.Pp 676This manual page was written by 677.An Michael Smith Aq Mt msmith@FreeBSD.org . 678.Sh BUGS 679Many BIOS versions have serious bugs that may cause system instability, 680break suspend/resume, or prevent devices from operating properly due to 681IRQ routing problems. 682Upgrade your BIOS to the latest version available from the vendor before 683deciding it is a problem with 684.Nm . 685.\".Pp 686.\"The 687.\".Nm 688.\"CPU idle power management drive conflicts with the local APIC (LAPIC) 689.\"timer. 690.\"Disable APIC mode with 691.\".Va hint.apic.0.disabled 692.\"or do not use the 693.\".Li C2 694.\"and 695.\".Li C3 696.\"states if APIC mode is enabled. 697