Advanced Configuration and Power Interface (ACPI) support for Linux requires an ACPI-compliant platform (hardware/firmware), and assumes the presence of OS-directed configuration and power management (OSPM) software. This option will enlarge your kernel by about 70K. Linux ACPI provides a robust functional replacement for several legacy configuration and power management interfaces, including the Plug-and-Play BIOS specification (PnP BIOS), the MultiProcessor Specification (MPS), and the Advanced Power Management (APM) specification. If both ACPI and APM support are configured, ACPI is used. The project home page for the Linux ACPI subsystem is here: <http://www.lesswatts.org/projects/acpi/> Linux support for ACPI is based on Intel Corporation's ACPI Component Architecture (ACPI CA). For more information on the ACPI CA, see: <http://acpica.org/> ACPI is an open industry specification co-developed by Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba. The specification is available at: <http://www.acpi.info>
For backwards compatibility, this option allows deprecated /proc/acpi/ files to exist, even when they have been replaced by functions in /sys. This option has no effect on /proc/acpi/ files and functions which do not yet exist in /sys. Say N to delete /proc/acpi/ files that have moved to /sys/
For backwards compatibility, this option allows deprecated power /proc/acpi/ directories to exist, even when they have been replaced by functions in /sys. The deprecated directories (and their replacements) include: /proc/acpi/battery/* (/sys/class/power_supply/*) /proc/acpi/ac_adapter/* (sys/class/power_supply/*) This option has no effect on /proc/acpi/ directories and functions, which do not yet exist in /sys This option, together with the proc directories, will be deleted in 2.6.39. Say N to delete power /proc/acpi/ directories that have moved to /sys/
Say N to disable Embedded Controller /sys/kernel/debug interface Be aware that using this interface can confuse your Embedded Controller in a way that a normal reboot is not enough. You then have to power off your system, and remove the laptop battery for some seconds. An Embedded Controller typically is available on laptops and reads sensor values like battery state and temperature. The kernel accesses the EC through ACPI parsed code provided by BIOS tables. This option allows to access the EC directly without ACPI code being involved. Thus this option is a debug option that helps to write ACPI drivers and can be used to identify ACPI code or EC firmware bugs.
A user-space daemon, acpid, typically reads /proc/acpi/event and handles all ACPI-generated events. These events are now delivered to user-space either via the input layer or as netlink events. This build option enables the old code for legacy user-space implementation. After some time, this will be moved under CONFIG_ACPI_PROCFS, and then deleted. Say Y here to retain the old behaviour. Say N if your user-space is newer than kernel 2.6.23 (September 2007).
This driver supports the AC Adapter object, which indicates whether a system is on AC or not. If you have a system that can switch between A/C and battery, say Y. To compile this driver as a module, choose M here: the module will be called ac.
This driver adds support for battery information through /proc/acpi/battery. If you have a mobile system with a battery, say Y. To compile this driver as a module, choose M here: the module will be called battery.
This driver handles events on the power, sleep, and lid buttons. A daemon reads /proc/acpi/event and perform user-defined actions such as shutting down the system. This is necessary for software-controlled poweroff. To compile this driver as a module, choose M here: the module will be called button.
This driver implements the ACPI Extensions For Display Adapters for integrated graphics devices on motherboard, as specified in ACPI 2.0 Specification, Appendix B. This supports basic operations such as defining the video POST device, retrieving EDID information, and setting up a video output. To compile this driver as a module, choose M here: the module will be called video.
This driver supports ACPI fan devices, allowing user-mode applications to perform basic fan control (on, off, status). To compile this driver as a module, choose M here: the module will be called fan.
This driver supports ACPI-controlled docking stations and removable drive bays such as the IBM Ultrabay and the Dell Module Bay.
This driver installs ACPI as the idle handler for Linux and uses ACPI C2 and C3 processor states to save power on systems that support it. It is required by several flavors of cpufreq performance-state drivers. To compile this driver as a module, choose M here: the module will be called processor.
This driver enables the ACPI to access the BMC controller. And it uses the IPMI request/response message to communicate with BMC controller, which can be found on on the server. To compile this driver as a module, choose M here: the module will be called as acpi_ipmi.
ACPI 4.0 defines processor Aggregator, which enables OS to perform specific processor configuration and control that applies to all processors in the platform. Currently only logical processor idling is defined, which is to reduce power consumption. This driver supports the new device.
This driver supports ACPI thermal zones. Most mobile and some desktop systems support ACPI thermal zones. It is HIGHLY recommended that this option be enabled, as your processor(s) may be damaged without it. To compile this driver as a module, choose M here: the module will be called thermal.
This option supports a custom DSDT by linking it into the kernel. See Documentation/acpi/dsdt-override.txt Enter the full path name to the file which includes the AmlCode declaration. If unsure, don't enter a file name.
Enter a 4-digit year, e.g., 2001, to disable ACPI by default on platforms with DMI BIOS date before January 1st that year. "acpi=force" can be used to override this mechanism. Enter 0 to disable this mechanism and allow ACPI to run by default no matter what the year. (default)
The ACPI subsystem can produce debug output. Saying Y enables this output and increases the kernel size by around 50K. Use the acpi.debug_layer and acpi.debug_level kernel command-line parameters documented in Documentation/acpi/debug.txt and Documentation/kernel-parameters.txt to control the type and amount of debug output.
ACPI Debug Statements slow down ACPI processing. Function trace is about half of the penalty and is rarely useful.
This driver creates entries in /sys/bus/pci/slots/ for all PCI slots in the system. This can help correlate PCI bus addresses, i.e., segment/bus/device/function tuples, with physical slots in the system. If you are unsure, say N. To compile this driver as a module, choose M here: the module will be called pci_slot.
The Power Management Timer is available on all ACPI-capable, in most cases even if ACPI is unusable or blacklisted. This timing source is not affected by power management features like aggressive processor idling, throttling, frequency and/or voltage scaling, unlike the commonly used Time Stamp Counter (TSC) timing source. You should nearly always say Y here because many modern systems require this timer.
This driver supports ACPI Container and Module devices (IDs ACPI0004, PNP0A05, and PNP0A06). This helps support hotplug of nodes, CPUs, and memory. To compile this driver as a module, choose M here: the module will be called container.
This driver supports ACPI memory hotplug. The driver fields notifications on ACPI memory devices (PNP0C80), which represent memory ranges that may be onlined or offlined during runtime. If your hardware and firmware do not support adding or removing memory devices at runtime, you need not enable this driver. To compile this driver as a module, choose M here: the module will be called acpi_memhotplug.
This driver supports the Smart Battery System, another type of access to battery information, found on some laptops. To compile this driver as a module, choose M here: the modules will be called sbs and sbshc.
This driver supports the Hardware Error Device (PNP0C33), which is used to report some hardware errors notified via SCI, mainly the corrected errors.
This debug facility allows ACPI AML methods to me inserted and/or replaced without rebooting the system. For details refer to: Documentation/acpi/method-customizing.txt. NOTE: This option is security sensitive, because it allows arbitrary kernel memory to be written to by root (uid=0) users, allowing them to bypass certain security measures (e.g. if root is not allowed to load additional kernel modules after boot, this feature may be used to override that restriction).