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.\" $FreeBSD$ 27.\" 28.Dd February 13, 2005 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.Sh DESCRIPTION 39The 40.Nm 41driver provides support for the Intel/Microsoft/Compaq/Toshiba ACPI 42standard. 43This support includes platform hardware discovery (superseding the 44PnP and PCI BIOS), as well as power management (superseding APM) and 45other features. 46ACPI core support is provided by the ACPI CA reference implementation 47from Intel. 48.Pp 49Note that the 50.Nm 51driver is automatically loaded by the 52.Xr loader 8 , 53and should only be 54compiled into the kernel on platforms where ACPI is mandatory. 55.Sh SYSCTLS 56The 57.Nm 58driver is intended to provide power management without user intervention. 59Thus, some of these sysctls are controlled automatically by the 60.Pa power_profile 61.Xr rc 8 62script, which can be configured via 63.Xr rc.conf 5 . 64If values are specified manually, they may be overridden. 65.Bl -tag -width indent 66.It Va hw.acpi.cpu.cx_usage 67Debugging information listing the percent of total usage for each sleep state. 68The values are reset when 69.Va hw.acpi.cpu.cx_lowest 70is modified. 71.It Va hw.acpi.cpu.cx_lowest 72Lowest Cx state to use for idling the CPU. 73A scheduling algorithm will select states between C1 and this setting 74as system load dictates. 75To enable ACPI CPU idling control, 76.Va machdep.cpu_idle_hlt 77must be set to 1. 78.It Va hw.acpi.cpu.cx_supported 79List of supported CPU idle states and their transition latency 80in microseconds. 81Each state has a type (e.g., C2). 82C1 is equivalent to the ia32 HLT instruction, C2 provides a deeper 83sleep with the same semantics, and C3 provides the deepest sleep 84but additionally requires bus mastering to be disabled. 85States greater than C3 provide even more power savings with the same 86semantics as the C3 state. 87Deeper sleeps provide more power savings but increased transition 88latency when an interrupt occurs. 89.El 90.Sh TUNABLES 91Tunables can be set at the 92.Xr loader 8 93prompt before booting the kernel or stored in 94.Pa /boot/loader.conf . 95.Bl -tag -width indent 96.It Va acpi_dsdt_load 97Enables loading of a custom ACPI DSDT. 98.It Va acpi_dsdt_name 99Name of the DSDT table to load, if loading is enabled. 100.It Va debug.acpi.disabled 101Selectively disables portions of ACPI for debugging purposes. 102.It Va debug.acpi.max_threads 103Specify the number of task threads that are started on boot. 104Limiting this to 1 may help work around various BIOSes that cannot 105handle parallel requests. 106The default value is 3. 107.It Va debug.acpi.quirks 108Override any automatic quirks completely. 109.It Va hint.acpi.0.disabled 110Set this to 1 to disable all of ACPI. 111If ACPI has been disabled on your system due to a blacklist entry for your 112BIOS, you can set this to 0 to re-enable ACPI for testing. 113.It Va hw.acpi.ec.poll_timeout 114Delay in milliseconds to wait for the EC to respond. 115Try increasing this number if you get the error 116.Qq Li AE_NO_HARDWARE_RESPONSE . 117.It Va hw.acpi.host_mem_start 118Override the assumed memory starting address for PCI host bridges. 119.It Va hw.acpi.pci.link.%d.%d.%d.irq 120Override the interrupt to use. 121.It Va hw.acpi.reset_video 122Enables calling the VESA reset BIOS vector on the resume path. 123Some graphic chips have problems such as LCD white-out after resume. 124Try setting this to 0 if this causes problems for you. 125.It Va hw.acpi.serialize_methods 126Allow override of whether methods execute in parallel or not. 127Enable this for serial behavior, which fixes 128.Qq Li AE_ALREADY_EXISTS 129errors for 130AML that really cannot handle parallel method execution. 131It is off by default since this breaks recursive methods and some IBMs use 132such code. 133.It Va hw.acpi.verbose 134Turn on verbose debugging information about what ACPI is doing. 135.El 136.Sh DISABLING ACPI 137Since ACPI support on different platforms varies greatly, there are many 138debugging and tuning options available. 139.Pp 140For machines known not to work with 141.Nm 142enabled, there is a BIOS blacklist. 143Currently, the blacklist only controls whether 144.Nm 145should be disabled or not. 146In the future, it will have more granularity to control features (the 147infrastructure for that is already there). 148.Pp 149To enable 150.Nm 151(for debugging purposes, etc.) on machines that are on the blacklist, set the 152kernel environment variable 153.Va hint.acpi.0.disabled 154to 0. 155Before trying this, consider updating your BIOS to a more recent version that 156may be compatible with ACPI. 157.Pp 158To disable the 159.Nm 160driver completely, set the kernel environment variable 161.Va hint.acpi.0.disabled 162to 1. 163.Pp 164Some i386 machines totally fail to operate with some or all of ACPI disabled. 165Other i386 machines fail with ACPI enabled. 166Disabling all or part of ACPI on non-i386 platforms (i.e., platforms where 167ACPI support is mandatory) may result in a non-functional system. 168.Pp 169The 170.Nm 171driver comprises a set of drivers, which may be selectively disabled 172in case of problems. 173To disable a sub-driver, list it in the kernel 174environment variable 175.Va debug.acpi.disabled . 176Multiple entries can be listed, separated by a space. 177.Pp 178ACPI sub-devices and features that can be disabled: 179.Bl -tag -width ".Li sysresource" 180.It Li all 181Disable all ACPI features and devices. 182.It Li acad 183.Pq Vt device 184Supports AC adapter. 185.It Li bus 186.Pq Vt feature 187Probes and attaches subdevices. 188Disabling will avoid scanning the ACPI namespace entirely. 189.It Li children 190.Pq Vt feature 191Attaches standard ACPI sub-drivers and devices enumerated in the 192ACPI namespace. 193Disabling this has a similar effect to disabling 194.Dq Li bus , 195except that the 196ACPI namespace will still be scanned. 197.It Li button 198.Pq Vt device 199Supports ACPI button devices (typically power and sleep buttons). 200.It Li cmbat 201.Pq Vt device 202Control-method batteries device. 203.It Li cpu 204.Pq Vt device 205Supports CPU power-saving and speed-setting functions. 206.It Li ec 207.Pq Vt device 208Supports the ACPI Embedded Controller interface, used to communicate 209with embedded platform controllers. 210.It Li isa 211.Pq Vt device 212Supports an ISA bus bridge defined in the ACPI namespace, 213typically as a child of a PCI bus. 214.It Li lid 215.Pq Vt device 216Supports an ACPI laptop lid switch, which typically puts a 217system to sleep. 218.It Li quirks 219.Pq Vt feature 220Do not honor quirks. 221Quirks automatically disable ACPI functionality based on the XSDT table's 222OEM vendor name and revision date. 223.It Li pci 224.Pq Vt device 225Supports Host to PCI bridges. 226.It Li pci_link 227.Pq Vt feature 228Performs PCI interrupt routing. 229.It Li sysresource 230.Pq Vt device 231Pseudo-devices containing resources which ACPI claims. 232.It Li thermal 233.Pq Vt device 234Supports system cooling and heat management. 235.It Li timer 236.Pq Vt device 237Implements a timecounter using the ACPI fixed-frequency timer. 238.It Li video 239.Pq Vt device 240Supports acpi_video which may conflict with agp device. 241.El 242.Pp 243It is also possible to avoid portions of the ACPI namespace which 244may be causing problems, by listing the full path of the root of 245the region to be avoided in the kernel environment variable 246.Va debug.acpi.avoid . 247The object and all of its children will be ignored during the 248bus/children scan of the namespace. 249The ACPI CA code will still know about the avoided region. 250.Sh DEBUGGING OUTPUT 251To enable debugging output, 252.Nm 253must be compiled with 254.Cd "options ACPI_DEBUG" . 255Debugging output is separated between layers and levels, where a layer is 256a component of the ACPI subsystem, and a level is a particular kind 257of debugging output. 258.Pp 259Both layers and levels are specified as a whitespace-separated list of 260tokens, with layers listed in 261.Va debug.acpi.layer 262and levels in 263.Va debug.acpi.level . 264.Pp 265The first set of layers is for ACPI-CA components, and the second is for 266.Fx 267drivers. 268The ACPI-CA layer descriptions include the prefix for the files they 269refer to. 270The supported layers are: 271.Pp 272.Bl -tag -compact -width ".Li ACPI_CA_DISASSEMBLER" 273.It Li ACPI_UTILITIES 274Utility ("ut") functions 275.It Li ACPI_HARDWARE 276Hardware access ("hw") 277.It Li ACPI_EVENTS 278Event and GPE ("ev") 279.It Li ACPI_TABLES 280Table access ("tb") 281.It Li ACPI_NAMESPACE 282Namespace evaluation ("ns") 283.It Li ACPI_PARSER 284AML parser ("ps") 285.It Li ACPI_DISPATCHER 286Internal representation of interpreter state ("ds") 287.It Li ACPI_EXECUTER 288Execute AML methods ("ex") 289.It Li ACPI_RESOURCES 290Resource parsing ("rs") 291.It Li ACPI_CA_DEBUGGER 292Debugger implementation ("db", "dm") 293.It Li ACPI_OS_SERVICES 294Usermode support routines ("os") 295.It Li ACPI_CA_DISASSEMBLER 296Disassembler implementation (unused) 297.It Li ACPI_ALL_COMPONENTS 298All the above ACPI-CA components 299.It Li ACPI_AC_ADAPTER 300AC adapter driver 301.It Li ACPI_BATTERY 302Control-method battery driver 303.It Li ACPI_BUS 304ACPI, ISA, and PCI bus drivers 305.It Li ACPI_BUTTON 306Power and sleep button driver 307.It Li ACPI_EC 308Embedded controller driver 309.It Li ACPI_FAN 310Fan driver 311.It Li ACPI_OEM 312Platform-specific driver for hotkeys, LED, etc. 313.It Li ACPI_POWER 314Power resource driver 315.It Li ACPI_PROCESSOR 316CPU driver 317.It Li ACPI_THERMAL 318Thermal zone driver 319.It Li ACPI_TIMER 320Timer driver 321.It Li ACPI_ALL_DRIVERS 322All the above 323.Fx 324ACPI drivers 325.El 326.Pp 327The supported levels are: 328.Pp 329.Bl -tag -compact -width ".Li ACPI_LV_AML_DISASSEMBLE" 330.It Li ACPI_LV_ERROR 331Fatal error conditions 332.It Li ACPI_LV_WARN 333Warnings and potential problems 334.It Li ACPI_LV_INIT 335Initialization progress 336.It Li ACPI_LV_DEBUG_OBJECT 337Stores to objects 338.It Li ACPI_LV_INFO 339General information and progress 340.It Li ACPI_LV_ALL_EXCEPTIONS 341All the previous levels 342.It Li ACPI_LV_INIT_NAMES 343.It Li ACPI_LV_PARSE 344.It Li ACPI_LV_LOAD 345.It Li ACPI_LV_DISPATCH 346.It Li ACPI_LV_EXEC 347.It Li ACPI_LV_NAMES 348.It Li ACPI_LV_OPREGION 349.It Li ACPI_LV_BFIELD 350.It Li ACPI_LV_TABLES 351.It Li ACPI_LV_VALUES 352.It Li ACPI_LV_OBJECTS 353.It Li ACPI_LV_RESOURCES 354.It Li ACPI_LV_USER_REQUESTS 355.It Li ACPI_LV_PACKAGE 356.It Li ACPI_LV_VERBOSITY1 357All the previous levels 358.It Li ACPI_LV_ALLOCATIONS 359.It Li ACPI_LV_FUNCTIONS 360.It Li ACPI_LV_OPTIMIZATIONS 361.It Li ACPI_LV_VERBOSITY2 362.It Li ACPI_LV_ALL 363.It Li ACPI_LV_MUTEX 364.It Li ACPI_LV_THREADS 365.It Li ACPI_LV_IO 366.It Li ACPI_LV_INTERRUPTS 367.It Li ACPI_LV_VERBOSITY3 368All the previous levels 369.It Li ACPI_LV_AML_DISASSEMBLE 370.It Li ACPI_LV_VERBOSE_INFO 371.It Li ACPI_LV_FULL_TABLES 372.It Li ACPI_LV_EVENTS 373.It Li ACPI_LV_VERBOSE 374All levels after 375.Qq Li ACPI_LV_VERBOSITY3 376.El 377.Pp 378Selection of the appropriate layer and level values is important 379to avoid massive amounts of debugging output. 380For example, the following configuration is a good way to gather initial 381information. 382It enables debug output for both ACPI-CA and the 383.Nm 384driver, printing basic information about errors, warnings, and progress. 385.Bd -literal -offset indent 386debug.acpi.layer="ACPI_ALL_COMPONENTS ACPI_ALL_DRIVERS" 387debug.acpi.level="ACPI_LV_ALL_EXCEPTIONS" 388.Ed 389.Pp 390Debugging output by the ACPI CA subsystem is prefixed with the 391module name in lowercase, followed by a source line number. 392Output from the 393.Fx Ns -local 394code follows the same format, but 395the module name is uppercased. 396.Sh OVERRIDING YOUR BIOS BYTECODE 397ACPI interprets bytecode named AML 398(ACPI Machine Language) 399provided by the BIOS vendor as a memory image at boot time. 400Sometimes, the AML code contains a bug that does not appear when parsed 401by the Microsoft implementation. 402.Fx 403provides a way to override it with your own AML code to work around 404or debug such problems. 405Note that all AML in your DSDT and any SSDT tables is overridden. 406.Pp 407In order to load your AML code, you must edit 408.Pa /boot/loader.conf 409and include the following lines. 410.Bd -literal -offset indent 411acpi_dsdt_load="YES" 412acpi_dsdt_name="/boot/acpi_dsdt.aml" # You may change this name. 413.Ed 414.Pp 415In order to prepare your AML code, you will need the 416.Xr acpidump 8 417and 418.Xr iasl 8 419utilities and some ACPI knowledge. 420.Sh COMPATIBILITY 421ACPI is only found and supported on i386/ia32, ia64, and amd64. 422.Sh SEE ALSO 423.Xr kenv 1 , 424.Xr acpi_thermal 4 , 425.Xr device.hints 5 , 426.Xr loader.conf 5 , 427.Xr acpiconf 8 , 428.Xr acpidump 8 , 429.Xr config 8 , 430.Xr iasl 8 431.Rs 432.%A "Compaq Computer Corporation" 433.%A "Intel Corporation" 434.%A "Microsoft Corporation" 435.%A "Phoenix Technologies Ltd." 436.%A "Toshiba Corporation" 437.%D August 25, 2003 438.%T "Advanced Configuration and Power Interface Specification" 439.%O http://acpi.info/spec.htm 440.Re 441.Sh AUTHORS 442.An -nosplit 443The ACPI CA subsystem is developed and maintained by 444Intel Architecture Labs. 445.Pp 446The following people made notable contributions to the ACPI subsystem 447in 448.Fx : 449.An Michael Smith , 450.An Takanori Watanabe Aq takawata@jp.FreeBSD.org , 451.An Mitsuru IWASAKI Aq iwasaki@jp.FreeBSD.org , 452.An Munehiro Matsuda , 453.An Nate Lawson , 454the ACPI-jp mailing list at 455.Aq acpi-jp@jp.FreeBSD.org , 456and many other contributors. 457.Pp 458This manual page was written by 459.An Michael Smith Aq msmith@FreeBSD.org . 460.Sh BUGS 461If the 462.Nm 463driver is loaded as a module when it is already linked as part of the 464kernel, odd things may happen. 465