2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
6 mainmenu "Linux Kernel Configuration"
12 This is Linux's home port. Linux was originally native to the Intel
13 386, and runs on all the later x86 processors including the Intel
14 486, 586, Pentiums, and various instruction-set-compatible chips by
15 AMD, Cyrix, and others.
17 config SEMAPHORE_SLEEPERS
32 config GENERIC_ISA_DMA
40 config ARCH_MAY_HAVE_PC_FDC
46 menu "Processor type and features"
49 prompt "Subarchitecture Type"
55 Choose this option if your computer is a standard PC or compatible.
60 Select this for an AMD Elan processor.
62 Do not use this option for K6/Athlon/Opteron processors!
64 If unsure, choose "PC-compatible" instead.
69 Voyager is an MCA-based 32-way capable SMP architecture proprietary
70 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
74 If you do not specifically know you have a Voyager based machine,
75 say N here, otherwise the kernel you build will not be bootable.
78 bool "NUMAQ (IBM/Sequent)"
81 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
82 multiquad box. This changes the way that processors are bootstrapped,
83 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
84 You will need a new lynxer.elf file to flash your firmware with - send
85 email to <Martin.Bligh@us.ibm.com>.
88 bool "Summit/EXA (IBM x440)"
91 This option is needed for IBM systems that use the Summit/EXA chipset.
92 In particular, it is needed for the x440.
94 If you don't have one of these computers, you should say N here.
97 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
100 This option is needed for the systems that have more than 8 CPUs
101 and if the system is not of any sub-arch type above.
103 If you don't have such a system, you should say N here.
106 bool "SGI 320/540 (Visual Workstation)"
108 The SGI Visual Workstation series is an IA32-based workstation
109 based on SGI systems chips with some legacy PC hardware attached.
111 Say Y here to create a kernel to run on the SGI 320 or 540.
113 A kernel compiled for the Visual Workstation will not run on PCs
114 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
116 config X86_GENERICARCH
117 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
120 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
121 It is intended for a generic binary kernel.
124 bool "Support for Unisys ES7000 IA32 series"
127 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
128 supposed to run on an IA32-based Unisys ES7000 system.
129 Only choose this option if you have such a system, otherwise you
137 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
139 config X86_SUMMIT_NUMA
142 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
144 config X86_CYCLONE_TIMER
147 depends on X86_SUMMIT || X86_GENERICARCH
149 config ES7000_CLUSTERED_APIC
152 depends on SMP && X86_ES7000 && MPENTIUMIII
154 source "arch/i386/Kconfig.cpu"
157 bool "HPET Timer Support"
159 This enables the use of the HPET for the kernel's internal timer.
160 HPET is the next generation timer replacing legacy 8254s.
161 You can safely choose Y here. However, HPET will only be
162 activated if the platform and the BIOS support this feature.
163 Otherwise the 8254 will be used for timing services.
165 Choose N to continue using the legacy 8254 timer.
167 config HPET_EMULATE_RTC
169 depends on HPET_TIMER && RTC=y
173 bool "Symmetric multi-processing support"
175 This enables support for systems with more than one CPU. If you have
176 a system with only one CPU, like most personal computers, say N. If
177 you have a system with more than one CPU, say Y.
179 If you say N here, the kernel will run on single and multiprocessor
180 machines, but will use only one CPU of a multiprocessor machine. If
181 you say Y here, the kernel will run on many, but not all,
182 singleprocessor machines. On a singleprocessor machine, the kernel
183 will run faster if you say N here.
185 Note that if you say Y here and choose architecture "586" or
186 "Pentium" under "Processor family", the kernel will not work on 486
187 architectures. Similarly, multiprocessor kernels for the "PPro"
188 architecture may not work on all Pentium based boards.
190 People using multiprocessor machines who say Y here should also say
191 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
192 Management" code will be disabled if you say Y here.
194 See also the <file:Documentation/smp.txt>,
195 <file:Documentation/i386/IO-APIC.txt>,
196 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
197 <http://www.tldp.org/docs.html#howto>.
199 If you don't know what to do here, say N.
202 int "Maximum number of CPUs (2-255)"
205 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
208 This allows you to specify the maximum number of CPUs which this
209 kernel will support. The maximum supported value is 255 and the
210 minimum value which makes sense is 2.
212 This is purely to save memory - each supported CPU adds
213 approximately eight kilobytes to the kernel image.
216 bool "SMT (Hyperthreading) scheduler support"
220 SMT scheduler support improves the CPU scheduler's decision making
221 when dealing with Intel Pentium 4 chips with HyperThreading at a
222 cost of slightly increased overhead in some places. If unsure say
225 source "kernel/Kconfig.preempt"
228 bool "Local APIC support on uniprocessors"
229 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
231 A local APIC (Advanced Programmable Interrupt Controller) is an
232 integrated interrupt controller in the CPU. If you have a single-CPU
233 system which has a processor with a local APIC, you can say Y here to
234 enable and use it. If you say Y here even though your machine doesn't
235 have a local APIC, then the kernel will still run with no slowdown at
236 all. The local APIC supports CPU-generated self-interrupts (timer,
237 performance counters), and the NMI watchdog which detects hard
241 bool "IO-APIC support on uniprocessors"
242 depends on X86_UP_APIC
244 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
245 SMP-capable replacement for PC-style interrupt controllers. Most
246 SMP systems and many recent uniprocessor systems have one.
248 If you have a single-CPU system with an IO-APIC, you can say Y here
249 to use it. If you say Y here even though your machine doesn't have
250 an IO-APIC, then the kernel will still run with no slowdown at all.
252 config X86_LOCAL_APIC
254 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
259 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
262 config X86_VISWS_APIC
268 bool "Machine Check Exception"
269 depends on !X86_VOYAGER
271 Machine Check Exception support allows the processor to notify the
272 kernel if it detects a problem (e.g. overheating, component failure).
273 The action the kernel takes depends on the severity of the problem,
274 ranging from a warning message on the console, to halting the machine.
275 Your processor must be a Pentium or newer to support this - check the
276 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
277 have a design flaw which leads to false MCE events - hence MCE is
278 disabled on all P5 processors, unless explicitly enabled with "mce"
279 as a boot argument. Similarly, if MCE is built in and creates a
280 problem on some new non-standard machine, you can boot with "nomce"
281 to disable it. MCE support simply ignores non-MCE processors like
282 the 386 and 486, so nearly everyone can say Y here.
284 config X86_MCE_NONFATAL
285 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
288 Enabling this feature starts a timer that triggers every 5 seconds which
289 will look at the machine check registers to see if anything happened.
290 Non-fatal problems automatically get corrected (but still logged).
291 Disable this if you don't want to see these messages.
292 Seeing the messages this option prints out may be indicative of dying hardware,
293 or out-of-spec (ie, overclocked) hardware.
294 This option only does something on certain CPUs.
295 (AMD Athlon/Duron and Intel Pentium 4)
297 config X86_MCE_P4THERMAL
298 bool "check for P4 thermal throttling interrupt."
299 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
301 Enabling this feature will cause a message to be printed when the P4
302 enters thermal throttling.
305 tristate "Toshiba Laptop support"
307 This adds a driver to safely access the System Management Mode of
308 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
309 not work on models with a Phoenix BIOS. The System Management Mode
310 is used to set the BIOS and power saving options on Toshiba portables.
312 For information on utilities to make use of this driver see the
313 Toshiba Linux utilities web site at:
314 <http://www.buzzard.org.uk/toshiba/>.
316 Say Y if you intend to run this kernel on a Toshiba portable.
320 tristate "Dell laptop support"
322 This adds a driver to safely access the System Management Mode
323 of the CPU on the Dell Inspiron 8000. The System Management Mode
324 is used to read cpu temperature and cooling fan status and to
325 control the fans on the I8K portables.
327 This driver has been tested only on the Inspiron 8000 but it may
328 also work with other Dell laptops. You can force loading on other
329 models by passing the parameter `force=1' to the module. Use at
332 For information on utilities to make use of this driver see the
333 I8K Linux utilities web site at:
334 <http://people.debian.org/~dz/i8k/>
336 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
339 config X86_REBOOTFIXUPS
340 bool "Enable X86 board specific fixups for reboot"
344 This enables chipset and/or board specific fixups to be done
345 in order to get reboot to work correctly. This is only needed on
346 some combinations of hardware and BIOS. The symptom, for which
347 this config is intended, is when reboot ends with a stalled/hung
350 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
353 Say Y if you want to enable the fixup. Currently, it's safe to
354 enable this option even if you don't need it.
358 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
360 If you say Y here and also to "/dev file system support" in the
361 'File systems' section, you will be able to update the microcode on
362 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
363 Pentium III, Pentium 4, Xeon etc. You will obviously need the
364 actual microcode binary data itself which is not shipped with the
367 For latest news and information on obtaining all the required
368 ingredients for this driver, check:
369 <http://www.urbanmyth.org/microcode/>.
371 To compile this driver as a module, choose M here: the
372 module will be called microcode.
375 tristate "/dev/cpu/*/msr - Model-specific register support"
377 This device gives privileged processes access to the x86
378 Model-Specific Registers (MSRs). It is a character device with
379 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
380 MSR accesses are directed to a specific CPU on multi-processor
384 tristate "/dev/cpu/*/cpuid - CPU information support"
386 This device gives processes access to the x86 CPUID instruction to
387 be executed on a specific processor. It is a character device
388 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
391 source "drivers/firmware/Kconfig"
394 prompt "High Memory Support"
400 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
401 However, the address space of 32-bit x86 processors is only 4
402 Gigabytes large. That means that, if you have a large amount of
403 physical memory, not all of it can be "permanently mapped" by the
404 kernel. The physical memory that's not permanently mapped is called
407 If you are compiling a kernel which will never run on a machine with
408 more than 1 Gigabyte total physical RAM, answer "off" here (default
409 choice and suitable for most users). This will result in a "3GB/1GB"
410 split: 3GB are mapped so that each process sees a 3GB virtual memory
411 space and the remaining part of the 4GB virtual memory space is used
412 by the kernel to permanently map as much physical memory as
415 If the machine has between 1 and 4 Gigabytes physical RAM, then
418 If more than 4 Gigabytes is used then answer "64GB" here. This
419 selection turns Intel PAE (Physical Address Extension) mode on.
420 PAE implements 3-level paging on IA32 processors. PAE is fully
421 supported by Linux, PAE mode is implemented on all recent Intel
422 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
423 then the kernel will not boot on CPUs that don't support PAE!
425 The actual amount of total physical memory will either be
426 auto detected or can be forced by using a kernel command line option
427 such as "mem=256M". (Try "man bootparam" or see the documentation of
428 your boot loader (lilo or loadlin) about how to pass options to the
429 kernel at boot time.)
431 If unsure, say "off".
436 Select this if you have a 32-bit processor and between 1 and 4
437 gigabytes of physical RAM.
442 Select this if you have a 32-bit processor and more than 4
443 gigabytes of physical RAM.
449 depends on HIGHMEM64G || HIGHMEM4G
454 depends on HIGHMEM64G
457 # Common NUMA Features
459 bool "Numa Memory Allocation and Scheduler Support"
460 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
462 default y if (X86_NUMAQ || X86_SUMMIT)
464 # Need comments to help the hapless user trying to turn on NUMA support
465 comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support"
466 depends on X86_NUMAQ && (!HIGHMEM64G || !SMP)
468 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
469 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
471 config HAVE_ARCH_BOOTMEM_NODE
476 config ARCH_HAVE_MEMORY_PRESENT
478 depends on DISCONTIGMEM
481 config NEED_NODE_MEMMAP_SIZE
483 depends on DISCONTIGMEM || SPARSEMEM
486 config HAVE_ARCH_ALLOC_REMAP
491 config ARCH_FLATMEM_ENABLE
493 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
495 config ARCH_DISCONTIGMEM_ENABLE
499 config ARCH_DISCONTIGMEM_DEFAULT
503 config ARCH_SPARSEMEM_ENABLE
505 depends on (NUMA || (X86_PC && EXPERIMENTAL))
506 select SPARSEMEM_STATIC
508 config ARCH_SELECT_MEMORY_MODEL
510 depends on ARCH_SPARSEMEM_ENABLE
514 config HAVE_ARCH_EARLY_PFN_TO_NID
520 bool "Allocate 3rd-level pagetables from highmem"
521 depends on HIGHMEM4G || HIGHMEM64G
523 The VM uses one page table entry for each page of physical memory.
524 For systems with a lot of RAM, this can be wasteful of precious
525 low memory. Setting this option will put user-space page table
526 entries in high memory.
528 config MATH_EMULATION
529 bool "Math emulation"
531 Linux can emulate a math coprocessor (used for floating point
532 operations) if you don't have one. 486DX and Pentium processors have
533 a math coprocessor built in, 486SX and 386 do not, unless you added
534 a 487DX or 387, respectively. (The messages during boot time can
535 give you some hints here ["man dmesg"].) Everyone needs either a
536 coprocessor or this emulation.
538 If you don't have a math coprocessor, you need to say Y here; if you
539 say Y here even though you have a coprocessor, the coprocessor will
540 be used nevertheless. (This behavior can be changed with the kernel
541 command line option "no387", which comes handy if your coprocessor
542 is broken. Try "man bootparam" or see the documentation of your boot
543 loader (lilo or loadlin) about how to pass options to the kernel at
544 boot time.) This means that it is a good idea to say Y here if you
545 intend to use this kernel on different machines.
547 More information about the internals of the Linux math coprocessor
548 emulation can be found in <file:arch/i386/math-emu/README>.
550 If you are not sure, say Y; apart from resulting in a 66 KB bigger
551 kernel, it won't hurt.
554 bool "MTRR (Memory Type Range Register) support"
556 On Intel P6 family processors (Pentium Pro, Pentium II and later)
557 the Memory Type Range Registers (MTRRs) may be used to control
558 processor access to memory ranges. This is most useful if you have
559 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
560 allows bus write transfers to be combined into a larger transfer
561 before bursting over the PCI/AGP bus. This can increase performance
562 of image write operations 2.5 times or more. Saying Y here creates a
563 /proc/mtrr file which may be used to manipulate your processor's
564 MTRRs. Typically the X server should use this.
566 This code has a reasonably generic interface so that similar
567 control registers on other processors can be easily supported
570 The Cyrix 6x86, 6x86MX and M II processors have Address Range
571 Registers (ARRs) which provide a similar functionality to MTRRs. For
572 these, the ARRs are used to emulate the MTRRs.
573 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
574 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
575 write-combining. All of these processors are supported by this code
576 and it makes sense to say Y here if you have one of them.
578 Saying Y here also fixes a problem with buggy SMP BIOSes which only
579 set the MTRRs for the boot CPU and not for the secondary CPUs. This
580 can lead to all sorts of problems, so it's good to say Y here.
582 You can safely say Y even if your machine doesn't have MTRRs, you'll
583 just add about 9 KB to your kernel.
585 See <file:Documentation/mtrr.txt> for more information.
588 bool "Boot from EFI support (EXPERIMENTAL)"
592 This enables the the kernel to boot on EFI platforms using
593 system configuration information passed to it from the firmware.
594 This also enables the kernel to use any EFI runtime services that are
595 available (such as the EFI variable services).
597 This option is only useful on systems that have EFI firmware
598 and will result in a kernel image that is ~8k larger. In addition,
599 you must use the latest ELILO loader available at
600 <http://elilo.sourceforge.net> in order to take advantage of
601 kernel initialization using EFI information (neither GRUB nor LILO know
602 anything about EFI). However, even with this option, the resultant
603 kernel should continue to boot on existing non-EFI platforms.
606 bool "Enable kernel irq balancing"
607 depends on SMP && X86_IO_APIC
610 The default yes will allow the kernel to do irq load balancing.
611 Saying no will keep the kernel from doing irq load balancing.
613 # turning this on wastes a bunch of space.
614 # Summit needs it only when NUMA is on
617 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
621 bool "Use register arguments (EXPERIMENTAL)"
622 depends on EXPERIMENTAL
625 Compile the kernel with -mregparm=3. This uses a different ABI
626 and passes the first three arguments of a function call in registers.
627 This will probably break binary only modules.
630 bool "Enable seccomp to safely compute untrusted bytecode"
634 This kernel feature is useful for number crunching applications
635 that may need to compute untrusted bytecode during their
636 execution. By using pipes or other transports made available to
637 the process as file descriptors supporting the read/write
638 syscalls, it's possible to isolate those applications in
639 their own address space using seccomp. Once seccomp is
640 enabled via /proc/<pid>/seccomp, it cannot be disabled
641 and the task is only allowed to execute a few safe syscalls
642 defined by each seccomp mode.
644 If unsure, say Y. Only embedded should say N here.
646 source kernel/Kconfig.hz
649 bool "kexec system call (EXPERIMENTAL)"
650 depends on EXPERIMENTAL
652 kexec is a system call that implements the ability to shutdown your
653 current kernel, and to start another kernel. It is like a reboot
654 but it is indepedent of the system firmware. And like a reboot
655 you can start any kernel with it, not just Linux.
657 The name comes from the similiarity to the exec system call.
659 It is an ongoing process to be certain the hardware in a machine
660 is properly shutdown, so do not be surprised if this code does not
661 initially work for you. It may help to enable device hotplugging
662 support. As of this writing the exact hardware interface is
663 strongly in flux, so no good recommendation can be made.
666 bool "kernel crash dumps (EXPERIMENTAL)"
667 depends on EXPERIMENTAL
670 Generate crash dump after being started by kexec.
672 config PHYSICAL_START
673 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
675 default "0x1000000" if CRASH_DUMP
678 This gives the physical address where the kernel is loaded. Normally
679 for regular kernels this value is 0x100000 (1MB). But in the case
680 of kexec on panic the fail safe kernel needs to run at a different
681 address than the panic-ed kernel. This option is used to set the load
682 address for kernels used to capture crash dump on being kexec'ed
683 after panic. The default value for crash dump kernels is
684 0x1000000 (16MB). This can also be set based on the "X" value as
685 specified in the "crashkernel=YM@XM" command line boot parameter
686 passed to the panic-ed kernel. Typically this parameter is set as
687 crashkernel=64M@16M. Please take a look at
688 Documentation/kdump/kdump.txt for more details about crash dumps.
690 Don't change this unless you know what you are doing.
695 menu "Power management options (ACPI, APM)"
696 depends on !X86_VOYAGER
698 source kernel/power/Kconfig
700 source "drivers/acpi/Kconfig"
702 menu "APM (Advanced Power Management) BIOS Support"
703 depends on PM && !X86_VISWS
706 tristate "APM (Advanced Power Management) BIOS support"
709 APM is a BIOS specification for saving power using several different
710 techniques. This is mostly useful for battery powered laptops with
711 APM compliant BIOSes. If you say Y here, the system time will be
712 reset after a RESUME operation, the /proc/apm device will provide
713 battery status information, and user-space programs will receive
714 notification of APM "events" (e.g. battery status change).
716 If you select "Y" here, you can disable actual use of the APM
717 BIOS by passing the "apm=off" option to the kernel at boot time.
719 Note that the APM support is almost completely disabled for
720 machines with more than one CPU.
722 In order to use APM, you will need supporting software. For location
723 and more information, read <file:Documentation/pm.txt> and the
724 Battery Powered Linux mini-HOWTO, available from
725 <http://www.tldp.org/docs.html#howto>.
727 This driver does not spin down disk drives (see the hdparm(8)
728 manpage ("man 8 hdparm") for that), and it doesn't turn off
729 VESA-compliant "green" monitors.
731 This driver does not support the TI 4000M TravelMate and the ACER
732 486/DX4/75 because they don't have compliant BIOSes. Many "green"
733 desktop machines also don't have compliant BIOSes, and this driver
734 may cause those machines to panic during the boot phase.
736 Generally, if you don't have a battery in your machine, there isn't
737 much point in using this driver and you should say N. If you get
738 random kernel OOPSes or reboots that don't seem to be related to
739 anything, try disabling/enabling this option (or disabling/enabling
742 Some other things you should try when experiencing seemingly random,
745 1) make sure that you have enough swap space and that it is
747 2) pass the "no-hlt" option to the kernel
748 3) switch on floating point emulation in the kernel and pass
749 the "no387" option to the kernel
750 4) pass the "floppy=nodma" option to the kernel
751 5) pass the "mem=4M" option to the kernel (thereby disabling
752 all but the first 4 MB of RAM)
753 6) make sure that the CPU is not over clocked.
754 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
755 8) disable the cache from your BIOS settings
756 9) install a fan for the video card or exchange video RAM
757 10) install a better fan for the CPU
758 11) exchange RAM chips
759 12) exchange the motherboard.
761 To compile this driver as a module, choose M here: the
762 module will be called apm.
764 config APM_IGNORE_USER_SUSPEND
765 bool "Ignore USER SUSPEND"
768 This option will ignore USER SUSPEND requests. On machines with a
769 compliant APM BIOS, you want to say N. However, on the NEC Versa M
770 series notebooks, it is necessary to say Y because of a BIOS bug.
773 bool "Enable PM at boot time"
776 Enable APM features at boot time. From page 36 of the APM BIOS
777 specification: "When disabled, the APM BIOS does not automatically
778 power manage devices, enter the Standby State, enter the Suspend
779 State, or take power saving steps in response to CPU Idle calls."
780 This driver will make CPU Idle calls when Linux is idle (unless this
781 feature is turned off -- see "Do CPU IDLE calls", below). This
782 should always save battery power, but more complicated APM features
783 will be dependent on your BIOS implementation. You may need to turn
784 this option off if your computer hangs at boot time when using APM
785 support, or if it beeps continuously instead of suspending. Turn
786 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
787 T400CDT. This is off by default since most machines do fine without
791 bool "Make CPU Idle calls when idle"
794 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
795 On some machines, this can activate improved power savings, such as
796 a slowed CPU clock rate, when the machine is idle. These idle calls
797 are made after the idle loop has run for some length of time (e.g.,
798 333 mS). On some machines, this will cause a hang at boot time or
799 whenever the CPU becomes idle. (On machines with more than one CPU,
800 this option does nothing.)
802 config APM_DISPLAY_BLANK
803 bool "Enable console blanking using APM"
806 Enable console blanking using the APM. Some laptops can use this to
807 turn off the LCD backlight when the screen blanker of the Linux
808 virtual console blanks the screen. Note that this is only used by
809 the virtual console screen blanker, and won't turn off the backlight
810 when using the X Window system. This also doesn't have anything to
811 do with your VESA-compliant power-saving monitor. Further, this
812 option doesn't work for all laptops -- it might not turn off your
813 backlight at all, or it might print a lot of errors to the console,
814 especially if you are using gpm.
816 config APM_RTC_IS_GMT
817 bool "RTC stores time in GMT"
820 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
821 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
824 It is in fact recommended to store GMT in your RTC, because then you
825 don't have to worry about daylight savings time changes. The only
826 reason not to use GMT in your RTC is if you also run a broken OS
827 that doesn't understand GMT.
829 config APM_ALLOW_INTS
830 bool "Allow interrupts during APM BIOS calls"
833 Normally we disable external interrupts while we are making calls to
834 the APM BIOS as a measure to lessen the effects of a badly behaving
835 BIOS implementation. The BIOS should reenable interrupts if it
836 needs to. Unfortunately, some BIOSes do not -- especially those in
837 many of the newer IBM Thinkpads. If you experience hangs when you
838 suspend, try setting this to Y. Otherwise, say N.
840 config APM_REAL_MODE_POWER_OFF
841 bool "Use real mode APM BIOS call to power off"
844 Use real mode APM BIOS calls to switch off the computer. This is
845 a work-around for a number of buggy BIOSes. Switch this option on if
846 your computer crashes instead of powering off properly.
850 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
854 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
857 bool "PCI support" if !X86_VISWS
858 depends on !X86_VOYAGER
859 default y if X86_VISWS
861 Find out whether you have a PCI motherboard. PCI is the name of a
862 bus system, i.e. the way the CPU talks to the other stuff inside
863 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
864 VESA. If you have PCI, say Y, otherwise N.
866 The PCI-HOWTO, available from
867 <http://www.tldp.org/docs.html#howto>, contains valuable
868 information about which PCI hardware does work under Linux and which
872 prompt "PCI access mode"
873 depends on PCI && !X86_VISWS
876 On PCI systems, the BIOS can be used to detect the PCI devices and
877 determine their configuration. However, some old PCI motherboards
878 have BIOS bugs and may crash if this is done. Also, some embedded
879 PCI-based systems don't have any BIOS at all. Linux can also try to
880 detect the PCI hardware directly without using the BIOS.
882 With this option, you can specify how Linux should detect the
883 PCI devices. If you choose "BIOS", the BIOS will be used,
884 if you choose "Direct", the BIOS won't be used, and if you
885 choose "MMConfig", then PCI Express MMCONFIG will be used.
886 If you choose "Any", the kernel will try MMCONFIG, then the
887 direct access method and falls back to the BIOS if that doesn't
888 work. If unsure, go with the default, which is "Any".
893 config PCI_GOMMCONFIG
906 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
911 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
916 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
919 source "drivers/pci/pcie/Kconfig"
921 source "drivers/pci/Kconfig"
929 depends on !(X86_VOYAGER || X86_VISWS)
931 Find out whether you have ISA slots on your motherboard. ISA is the
932 name of a bus system, i.e. the way the CPU talks to the other stuff
933 inside your box. Other bus systems are PCI, EISA, MicroChannel
934 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
935 newer boards don't support it. If you have ISA, say Y, otherwise N.
941 The Extended Industry Standard Architecture (EISA) bus was
942 developed as an open alternative to the IBM MicroChannel bus.
944 The EISA bus provided some of the features of the IBM MicroChannel
945 bus while maintaining backward compatibility with cards made for
946 the older ISA bus. The EISA bus saw limited use between 1988 and
947 1995 when it was made obsolete by the PCI bus.
949 Say Y here if you are building a kernel for an EISA-based machine.
953 source "drivers/eisa/Kconfig"
956 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
957 default y if X86_VOYAGER
959 MicroChannel Architecture is found in some IBM PS/2 machines and
960 laptops. It is a bus system similar to PCI or ISA. See
961 <file:Documentation/mca.txt> (and especially the web page given
962 there) before attempting to build an MCA bus kernel.
964 source "drivers/mca/Kconfig"
967 tristate "NatSemi SCx200 support"
968 depends on !X86_VOYAGER
970 This provides basic support for the National Semiconductor SCx200
971 processor. Right now this is just a driver for the GPIO pins.
973 If you don't know what to do here, say N.
975 This support is also available as a module. If compiled as a
976 module, it will be called scx200.
979 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
980 depends on SMP && HOTPLUG && EXPERIMENTAL
982 Say Y here to experiment with turning CPUs off and on. CPUs
983 can be controlled through /sys/devices/system/cpu.
987 source "drivers/pcmcia/Kconfig"
989 source "drivers/pci/hotplug/Kconfig"
993 menu "Executable file formats"
995 source "fs/Kconfig.binfmt"
1001 source "drivers/Kconfig"
1005 menu "Instrumentation Support"
1006 depends on EXPERIMENTAL
1008 source "arch/i386/oprofile/Kconfig"
1011 bool "Kprobes (EXPERIMENTAL)"
1013 Kprobes allows you to trap at almost any kernel address and
1014 execute a callback function. register_kprobe() establishes
1015 a probepoint and specifies the callback. Kprobes is useful
1016 for kernel debugging, non-intrusive instrumentation and testing.
1017 If in doubt, say "N".
1020 source "arch/i386/Kconfig.debug"
1022 source "security/Kconfig"
1024 source "crypto/Kconfig"
1026 source "lib/Kconfig"
1029 # Use the generic interrupt handling code in kernel/irq/:
1031 config GENERIC_HARDIRQS
1035 config GENERIC_IRQ_PROBE
1039 config GENERIC_PENDING_IRQ
1041 depends on GENERIC_HARDIRQS && SMP
1046 depends on SMP && !X86_VOYAGER
1051 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1054 config X86_BIOS_REBOOT
1056 depends on !(X86_VISWS || X86_VOYAGER)
1059 config X86_TRAMPOLINE
1061 depends on X86_SMP || (X86_VOYAGER && SMP)
git.openpandora.org / pandora-kernel.git / blob