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 June 30, 2004 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 bootloader, and should not normally 52be compiled into the kernel. 53.Sh ENVIRONMENT 54This support is still experimental, and thus there are many debugging 55and tuning options which are managed via the kernel environment. 56Tunables can be set at the 57.Xr loader 8 58prompt before booting the kernel or stored in 59.Pa /boot/loader.conf . 60.Pp 61Debugging is separated between layers and levels, where a layer is 62a portion of the ACPI subsystem, and a level is a particular kind 63of debugging output. 64.Pp 65Both layers and levels are specified as a whitespace-separated list of 66tokens, with layers listed in 67.Va debug.acpi.layer 68and levels in 69.Va debug.acpi.level . 70The supported layers are: 71.Pp 72.Bl -item -offset indent -compact 73.It 74.Li ACPI_UTILITIES 75.It 76.Li ACPI_HARDWARE 77.It 78.Li ACPI_EVENTS 79.It 80.Li ACPI_TABLES 81.It 82.Li ACPI_NAMESPACE 83.It 84.Li ACPI_PARSER 85.It 86.Li ACPI_DISPATCHER 87.It 88.Li ACPI_EXECUTER 89.It 90.Li ACPI_RESOURCES 91.It 92.Li ACPI_CA_DEBUGGER 93.It 94.Li ACPI_OS_SERVICES 95.It 96.Li ACPI_CA_DISASSEMBLER 97.It 98.Li ACPI_ALL_COMPONENTS 99.It 100.Li ACPI_AC_ADAPTER 101.It 102.Li ACPI_BATTERY 103.It 104.Li ACPI_BUS 105.It 106.Li ACPI_BUTTON 107.It 108.Li ACPI_EC 109.It 110.Li ACPI_FAN 111.It 112.Li ACPI_POWER 113.It 114.Li ACPI_PROCESSOR 115.It 116.Li ACPI_THERMAL 117.It 118.Li ACPI_TIMER 119.It 120.Li ACPI_ALL_DRIVERS 121.El 122.Pp 123The supported levels are: 124.Pp 125.Bl -item -offset indent -compact 126.It 127.Li ACPI_LV_ERROR 128.It 129.Li ACPI_LV_WARN 130.It 131.Li ACPI_LV_INIT 132.It 133.Li ACPI_LV_DEBUG_OBJECT 134.It 135.Li ACPI_LV_INFO 136.It 137.Li ACPI_LV_ALL_EXCEPTIONS 138.It 139.Li ACPI_LV_INIT_NAMES 140.It 141.Li ACPI_LV_PARSE 142.It 143.Li ACPI_LV_LOAD 144.It 145.Li ACPI_LV_DISPATCH 146.It 147.Li ACPI_LV_EXEC 148.It 149.Li ACPI_LV_NAMES 150.It 151.Li ACPI_LV_OPREGION 152.It 153.Li ACPI_LV_BFIELD 154.It 155.Li ACPI_LV_TABLES 156.It 157.Li ACPI_LV_VALUES 158.It 159.Li ACPI_LV_OBJECTS 160.It 161.Li ACPI_LV_RESOURCES 162.It 163.Li ACPI_LV_USER_REQUESTS 164.It 165.Li ACPI_LV_PACKAGE 166.It 167.Li ACPI_LV_VERBOSITY1 168.It 169.Li ACPI_LV_ALLOCATIONS 170.It 171.Li ACPI_LV_FUNCTIONS 172.It 173.Li ACPI_LV_OPTIMIZATIONS 174.It 175.Li ACPI_LV_VERBOSITY2 176.It 177.Li ACPI_LV_ALL 178.It 179.Li ACPI_LV_MUTEX 180.It 181.Li ACPI_LV_THREADS 182.It 183.Li ACPI_LV_IO 184.It 185.Li ACPI_LV_INTERRUPTS 186.It 187.Li ACPI_LV_VERBOSITY3 188.It 189.Li ACPI_LV_AML_DISASSEMBLE 190.It 191.Li ACPI_LV_VERBOSE_INFO 192.It 193.Li ACPI_LV_FULL_TABLES 194.It 195.Li ACPI_LV_EVENTS 196.It 197.Li ACPI_LV_VERBOSE 198.El 199.Pp 200Selection of the appropriate layer and level values is important 201to avoid massive amounts of debugging output. 202Check the code to see which you need. 203.Pp 204Debugging output by the ACPI CA subsystem is prefixed with the 205module name in lowercase, followed by a source line number. 206Output from the 207.Fx Ns -local 208code follows the same format, but 209the module name is uppercased. 210.Pp 211For machines known not to work with 212.Nm 213enabled, there is a BIOS blacklist. 214Currently, the blacklist only controls whether 215.Nm 216should be disabled or not. 217In the future, it will have more granularity to control features (the 218infrastructure for that is already there). 219.Pp 220To enable 221.Nm 222(for debugging purposes, etc.) on machines that are on the blacklist, set the 223kernel environment variable 224.Va hint.acpi.0.disabled 225to 0. 226Before trying this, consider updating your BIOS to a more recent version that 227may be compatible with ACPI. 228.Pp 229To disable the 230.Nm 231driver completely, set the kernel environment variable 232.Va hint.acpi.0.disabled 233to 1. 234.Pp 235Some i386 machines totally fail to operate with some or all of ACPI disabled. 236Other i386 machines fail with ACPI enabled. 237Non-i386 platforms do not support operating systems which do not use ACPI. 238Disabling all or part of ACPI on non-i386 platforms may result in a 239non-functional system. 240.Pp 241The 242.Nm 243driver comprises a set of drivers, which may be selectively disabled 244in case of problems. 245To disable a sub-driver, list it in the kernel 246environment variable 247.Va debug.acpi.disabled . 248Multiple entries can be listed, separated by a space. 249.Pp 250ACPI sub-devices and features that can be disabled: 251.Bl -tag -width sysresource 252.It Li all 253Disable all ACPI features and devices. 254.It Li acad 255.Pq Vt device 256Supports AC adapter. 257.It Li bus 258.Pq Vt feature 259Probes and attaches subdevices. 260Disabling will avoid scanning the ACPI namespace entirely. 261.It Li children 262.Pq Vt feature 263Attaches standard ACPI sub-drivers and devices enumerated in the 264ACPI namespace. 265Disabling this has a similar effect to disabling 266.Dq Li bus , 267except that the 268ACPI namespace will still be scanned. 269.It Li button 270.Pq Vt device 271Supports ACPI button devices (typically power and sleep buttons). 272.It Li cmbat 273.Pq Vt device 274Control-method batteries device. 275.It Li cpu 276.Pq Vt device 277Supports CPU power-saving and speed-setting functions. 278.It Li ec 279.Pq Vt device 280Supports the ACPI Embedded Controller interface, used to communicate 281with embedded platform controllers. 282.It Li isa 283.Pq Vt device 284Supports an ISA bus bridge defined in the ACPI namespace, 285typically as a child of a PCI bus. 286.It Li lid 287.Pq Vt device 288Supports an ACPI laptop lid switch, which typically puts a 289system to sleep. 290.It Li quirks 291.Pq Vt feature 292Do not honor quirks. 293Quirks automatically disable ACPI functionality based on the XSDT table's 294OEM vendor name and revision date. 295.It Li pci 296.Pq Vt device 297Supports Host to PCI bridges. 298.It Li pci_link 299.Pq Vt feature 300Performs PCI interrupt routing. 301.It Li sysresource 302.Pq Vt device 303Pseudo-devices containing resources which ACPI claims. 304.It Li thermal 305.Pq Vt device 306Supports system cooling and heat management. 307.It Li timer 308.Pq Vt device 309Implements a timecounter using the ACPI fixed-frequency timer. 310.El 311.Pp 312It is also possible to avoid portions of the ACPI namespace which 313may be causing problems, by listing the full path of the root of 314the region to be avoided in the kernel environment variable 315.Va debug.acpi.avoid . 316The object and all of its children will be ignored during the 317bus/children scan of the namespace. 318The ACPI CA code will still 319know about the avoided region. 320.Sh OVERRIDING YOUR BIOS BYTECODE 321ACPI interprets bytecode named AML, ACPI Machine Language, provided by the BIOS 322vendor as a memory image at boot time. 323Sometimes, the AML code contains 324a problem that does not appear in the Microsoft implementation. 325So we provide a way to override it with your own AML code. 326.Pp 327In order to load your AML code, 328you must edit 329.Pa /boot/loader.conf 330and 331include the following lines. 332.Bd -literal -offset indent 333acpi_dsdt_load="YES" 334acpi_dsdt_name="/boot/acpi_dsdt.aml" #You may change the name. 335.Ed 336.Pp 337In order to prepare your AML code, you will need the 338.Xr acpidump 8 339and 340.Xr iasl 1 341utilities and some ACPI knowledge. 342.Sh TUNABLES 343.Bl -tag -width indent 344.It Va acpi_dsdt_load 345Enables loading of a custom ACPI DSDT. 346.It Va acpi_dsdt_name 347Name of the DSDT table to load, if loading is enabled. 348.It Va debug.acpi.disabled 349Selectively disables portions of ACPI for debugging purposes. 350.It Va hint.acpi.0.disabled 351Set this to 1 to disable all of ACPI. 352If ACPI has been disabled on your system due to a blacklist entry for your 353BIOS, you can set this to 0 to re-enable ACPI for testing. 354.It Va hw.acpi.ec.poll_timeout 355Delay in milliseconds to wait for the EC to respond. 356Try increasing this number if you get the error 357.Er AE_NO_HARDWARE_RESPONSE . 358.It Va hw.acpi.reset_video 359Enables calling the VESA reset BIOS vector on the resume path. 360Some graphic chips have problems such as LCD white-out after resume. 361Try setting this to 0 if this causes problems for you. 362.It Va hw.acpi.osname 363Some systems' ASL may have problems because they look for names 364of Microsoft operating systems. 365This tunable overrides the value of the 366.Qq Li \e_OS 367object from its default of 368.Qq Li FreeBSD . 369.It Va hw.acpi.pci.link.%d.%d.%d.irq 370Override the interrupt to use. 371.It Va hw.acpi.verbose 372Turn on verbose debugging information about what ACPI is doing. 373.El 374.Sh SYSCTLS 375.Bl -tag -width indent 376.It Va hw.acpi.cpu.throttle_max 377Maximum value for CPU throttling, equal to 100% of the clock rate. 378.It Va hw.acpi.cpu.throttle_state 379Get or set the current throttling state, from 1 to 380.Va hw.acpi.cpu.throttle_max . 381This scales back the CPU clock rate and the corresponding power consumption. 382.It Va hw.acpi.cpu.cx_usage 383Debugging information listing the percent of total usage for each sleep state. 384The values are reset when 385.Va hw.acpi.cpu.cx_lowest 386is modified. 387.It Va hw.acpi.cpu.cx_lowest 388Lowest Cx state to use for idling the CPU. 389A scheduling algorithm will select states between C1 and this setting 390as system load dictates. 391To enable ACPI CPU idling control, 392.Va machdep.cpu_idle_hlt 393must be set to 1. 394.It Va hw.acpi.cpu.cx_supported 395List of supported CPU idle states and their transition latency 396in microseconds. 397Each state has a type (e.g., C2). 398C1 is equivalent to the ia32 HLT instruction, C2 provides a deeper 399sleep with the same semantics, and C3 provides the deepest sleep 400but additionally requires bus mastering to be disabled. 401States greater than C3 provide even more power savings with the same 402semantics as the C3 state. 403Deeper sleeps provide more power savings but increased transition 404latency when an interrupt occurs. 405.El 406.Sh COMPATIBILITY 407ACPI is only found and supported on i386/ia32, ia64, and amd64. 408.Sh SEE ALSO 409.Xr kenv 1 , 410.Xr acpi_thermal 4 , 411.Xr device.hints 5 , 412.Xr loader.conf 5 , 413.Xr acpiconf 8 , 414.Xr acpidump 8 , 415.Xr config 8 , 416.Xr iasl 8 417.Rs 418.%A "Compaq Computer Corporation" 419.%A "Intel Corporation" 420.%A "Microsoft Corporation" 421.%A "Phoenix Technologies Ltd." 422.%A "Toshiba Corporation" 423.%D August 25, 2003 424.%T "Advanced Configuration and Power Interface Specification" 425.%O http://acpi.info/spec.htm 426.Re 427.Sh AUTHORS 428.An -nosplit 429The ACPI CA subsystem is developed and maintained by 430Intel Architecture Labs. 431.Pp 432The following people made notable contributions to the ACPI subsystem 433in 434.Fx : 435.An Michael Smith , 436.An Takanori Watanabe Aq takawata@jp.FreeBSD.org , 437.An Mitsuru IWASAKI Aq iwasaki@jp.FreeBSD.org , 438.An Munehiro Matsuda , 439.An Nate Lawson , 440the ACPI-jp mailing list at 441.Aq acpi-jp@jp.FreeBSD.org , 442and many other contributors. 443.Pp 444This manual page was written by 445.An Michael Smith Aq msmith@FreeBSD.org . 446.Sh BUGS 447If the 448.Nm 449driver is loaded as a module when it is already linked as part of the 450kernel, odd things may happen. 451