2 mainmenu "Linux Kernel Configuration for x86"
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
9 Say yes to build a 64-bit kernel - formerly known as x86_64
10 Say no to build a 32-bit kernel - formerly known as i386
21 select HAVE_AOUT if X86_32
22 select HAVE_UNSTABLE_SCHED_CLOCK
25 select HAVE_IOREMAP_PROT
27 select ARCH_WANT_OPTIONAL_GPIOLIB
28 select HAVE_KRETPROBES
29 select HAVE_FTRACE_MCOUNT_RECORD
30 select HAVE_DYNAMIC_FTRACE
31 select HAVE_FUNCTION_TRACER
32 select HAVE_FUNCTION_GRAPH_TRACER
33 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
34 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
35 select HAVE_ARCH_KGDB if !X86_VOYAGER
36 select HAVE_ARCH_TRACEHOOK
37 select HAVE_GENERIC_DMA_COHERENT if X86_32
38 select HAVE_EFFICIENT_UNALIGNED_ACCESS
39 select USER_STACKTRACE_SUPPORT
43 default "arch/x86/configs/i386_defconfig" if X86_32
44 default "arch/x86/configs/x86_64_defconfig" if X86_64
49 config GENERIC_CMOS_UPDATE
52 config CLOCKSOURCE_WATCHDOG
55 config GENERIC_CLOCKEVENTS
58 config GENERIC_CLOCKEVENTS_BROADCAST
60 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
62 config LOCKDEP_SUPPORT
65 config STACKTRACE_SUPPORT
68 config HAVE_LATENCYTOP_SUPPORT
71 config FAST_CMPXCHG_LOCAL
84 config GENERIC_ISA_DMA
94 config GENERIC_HWEIGHT
100 config ARCH_MAY_HAVE_PC_FDC
103 config RWSEM_GENERIC_SPINLOCK
106 config RWSEM_XCHGADD_ALGORITHM
109 config ARCH_HAS_CPU_IDLE_WAIT
112 config GENERIC_CALIBRATE_DELAY
115 config GENERIC_TIME_VSYSCALL
119 config ARCH_HAS_CPU_RELAX
122 config ARCH_HAS_DEFAULT_IDLE
125 config ARCH_HAS_CACHE_LINE_SIZE
128 config HAVE_SETUP_PER_CPU_AREA
129 def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER)
131 config HAVE_CPUMASK_OF_CPU_MAP
134 config ARCH_HIBERNATION_POSSIBLE
136 depends on !SMP || !X86_VOYAGER
138 config ARCH_SUSPEND_POSSIBLE
140 depends on !X86_VOYAGER
146 config ARCH_POPULATES_NODE_MAP
153 config ARCH_SUPPORTS_OPTIMIZED_INLINING
156 # Use the generic interrupt handling code in kernel/irq/:
157 config GENERIC_HARDIRQS
161 config GENERIC_IRQ_PROBE
165 config GENERIC_PENDING_IRQ
167 depends on GENERIC_HARDIRQS && SMP
172 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
175 config USE_GENERIC_SMP_HELPERS
181 depends on X86_32 && SMP
185 depends on X86_64 && SMP
190 depends on (X86_32 && !X86_VOYAGER) || X86_64
193 config X86_BIOS_REBOOT
195 depends on !X86_VOYAGER
198 config X86_TRAMPOLINE
200 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
205 source "init/Kconfig"
206 source "kernel/Kconfig.freezer"
208 menu "Processor type and features"
210 source "kernel/time/Kconfig"
213 bool "Symmetric multi-processing support"
215 This enables support for systems with more than one CPU. If you have
216 a system with only one CPU, like most personal computers, say N. If
217 you have a system with more than one CPU, say Y.
219 If you say N here, the kernel will run on single and multiprocessor
220 machines, but will use only one CPU of a multiprocessor machine. If
221 you say Y here, the kernel will run on many, but not all,
222 singleprocessor machines. On a singleprocessor machine, the kernel
223 will run faster if you say N here.
225 Note that if you say Y here and choose architecture "586" or
226 "Pentium" under "Processor family", the kernel will not work on 486
227 architectures. Similarly, multiprocessor kernels for the "PPro"
228 architecture may not work on all Pentium based boards.
230 People using multiprocessor machines who say Y here should also say
231 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
232 Management" code will be disabled if you say Y here.
234 See also <file:Documentation/i386/IO-APIC.txt>,
235 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
236 <http://www.tldp.org/docs.html#howto>.
238 If you don't know what to do here, say N.
240 config X86_HAS_BOOT_CPU_ID
242 depends on X86_VOYAGER
245 bool "Support sparse irq numbering"
246 depends on (PCI_MSI || HT_IRQ) && SMP
249 This enables support for sparse irq, esp for msi/msi-x. You may need
250 if you have lots of cards supports msi-x installed.
252 If you don't know what to do here, say Y.
254 config X86_FIND_SMP_CONFIG
256 depends on X86_MPPARSE || X86_VOYAGER
261 bool "Enable MPS table"
262 depends on X86_LOCAL_APIC
264 For old smp systems that do not have proper acpi support. Newer systems
265 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
271 depends on X86_LOCAL_APIC
275 prompt "Subarchitecture Type"
281 Choose this option if your computer is a standard PC or compatible.
287 Select this for an AMD Elan processor.
289 Do not use this option for K6/Athlon/Opteron processors!
291 If unsure, choose "PC-compatible" instead.
295 depends on X86_32 && (SMP || BROKEN) && !PCI
297 Voyager is an MCA-based 32-way capable SMP architecture proprietary
298 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
302 If you do not specifically know you have a Voyager based machine,
303 say N here, otherwise the kernel you build will not be bootable.
305 config X86_GENERICARCH
306 bool "Generic architecture"
309 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
310 subarchitectures. It is intended for a generic binary kernel.
311 if you select them all, kernel will probe it one by one. and will
317 bool "NUMAQ (IBM/Sequent)"
318 depends on SMP && X86_32 && PCI && X86_MPPARSE
321 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
322 NUMA multiquad box. This changes the way that processors are
323 bootstrapped, and uses Clustered Logical APIC addressing mode instead
324 of Flat Logical. You will need a new lynxer.elf file to flash your
325 firmware with - send email to <Martin.Bligh@us.ibm.com>.
328 bool "Summit/EXA (IBM x440)"
329 depends on X86_32 && SMP
331 This option is needed for IBM systems that use the Summit/EXA chipset.
332 In particular, it is needed for the x440.
335 bool "Support for Unisys ES7000 IA32 series"
336 depends on X86_32 && SMP
338 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
339 supposed to run on an IA32-based Unisys ES7000 system.
342 bool "Support for big SMP systems with more than 8 CPUs"
343 depends on X86_32 && SMP
345 This option is needed for the systems that have more than 8 CPUs
346 and if the system is not of any sub-arch type above.
351 bool "Support for ScaleMP vSMP"
353 depends on X86_64 && PCI
355 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
356 supposed to run on these EM64T-based machines. Only choose this option
357 if you have one of these machines.
362 bool "SGI 320/540 (Visual Workstation)"
363 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
365 The SGI Visual Workstation series is an IA32-based workstation
366 based on SGI systems chips with some legacy PC hardware attached.
368 Say Y here to create a kernel to run on the SGI 320 or 540.
370 A kernel compiled for the Visual Workstation will run on general
371 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
374 bool "RDC R-321x SoC"
377 select X86_REBOOTFIXUPS
379 This option is needed for RDC R-321x system-on-chip, also known
381 If you don't have one of these chips, you should say N here.
383 config SCHED_OMIT_FRAME_POINTER
385 prompt "Single-depth WCHAN output"
388 Calculate simpler /proc/<PID>/wchan values. If this option
389 is disabled then wchan values will recurse back to the
390 caller function. This provides more accurate wchan values,
391 at the expense of slightly more scheduling overhead.
393 If in doubt, say "Y".
395 menuconfig PARAVIRT_GUEST
396 bool "Paravirtualized guest support"
398 Say Y here to get to see options related to running Linux under
399 various hypervisors. This option alone does not add any kernel code.
401 If you say N, all options in this submenu will be skipped and disabled.
405 source "arch/x86/xen/Kconfig"
408 bool "VMI Guest support"
411 depends on !X86_VOYAGER
413 VMI provides a paravirtualized interface to the VMware ESX server
414 (it could be used by other hypervisors in theory too, but is not
415 at the moment), by linking the kernel to a GPL-ed ROM module
416 provided by the hypervisor.
419 bool "KVM paravirtualized clock"
421 select PARAVIRT_CLOCK
422 depends on !X86_VOYAGER
424 Turning on this option will allow you to run a paravirtualized clock
425 when running over the KVM hypervisor. Instead of relying on a PIT
426 (or probably other) emulation by the underlying device model, the host
427 provides the guest with timing infrastructure such as time of day, and
431 bool "KVM Guest support"
433 depends on !X86_VOYAGER
435 This option enables various optimizations for running under the KVM
438 source "arch/x86/lguest/Kconfig"
441 bool "Enable paravirtualization code"
442 depends on !X86_VOYAGER
444 This changes the kernel so it can modify itself when it is run
445 under a hypervisor, potentially improving performance significantly
446 over full virtualization. However, when run without a hypervisor
447 the kernel is theoretically slower and slightly larger.
449 config PARAVIRT_CLOCK
455 config PARAVIRT_DEBUG
456 bool "paravirt-ops debugging"
457 depends on PARAVIRT && DEBUG_KERNEL
459 Enable to debug paravirt_ops internals. Specifically, BUG if
460 a paravirt_op is missing when it is called.
465 This option adds a kernel parameter 'memtest', which allows memtest
467 memtest=0, mean disabled; -- default
468 memtest=1, mean do 1 test pattern;
470 memtest=4, mean do 4 test patterns.
471 If you are unsure how to answer this question, answer N.
473 config X86_SUMMIT_NUMA
475 depends on X86_32 && NUMA && X86_GENERICARCH
477 config X86_CYCLONE_TIMER
479 depends on X86_GENERICARCH
481 source "arch/x86/Kconfig.cpu"
485 prompt "HPET Timer Support" if X86_32
487 Use the IA-PC HPET (High Precision Event Timer) to manage
488 time in preference to the PIT and RTC, if a HPET is
490 HPET is the next generation timer replacing legacy 8254s.
491 The HPET provides a stable time base on SMP
492 systems, unlike the TSC, but it is more expensive to access,
493 as it is off-chip. You can find the HPET spec at
494 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
496 You can safely choose Y here. However, HPET will only be
497 activated if the platform and the BIOS support this feature.
498 Otherwise the 8254 will be used for timing services.
500 Choose N to continue using the legacy 8254 timer.
502 config HPET_EMULATE_RTC
504 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506 # Mark as embedded because too many people got it wrong.
507 # The code disables itself when not needed.
510 bool "Enable DMI scanning" if EMBEDDED
512 Enabled scanning of DMI to identify machine quirks. Say Y
513 here unless you have verified that your setup is not
514 affected by entries in the DMI blacklist. Required by PNP
518 bool "GART IOMMU support" if EMBEDDED
522 depends on X86_64 && PCI
524 Support for full DMA access of devices with 32bit memory access only
525 on systems with more than 3GB. This is usually needed for USB,
526 sound, many IDE/SATA chipsets and some other devices.
527 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
528 based hardware IOMMU and a software bounce buffer based IOMMU used
529 on Intel systems and as fallback.
530 The code is only active when needed (enough memory and limited
531 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
535 bool "IBM Calgary IOMMU support"
537 depends on X86_64 && PCI && EXPERIMENTAL
539 Support for hardware IOMMUs in IBM's xSeries x366 and x460
540 systems. Needed to run systems with more than 3GB of memory
541 properly with 32-bit PCI devices that do not support DAC
542 (Double Address Cycle). Calgary also supports bus level
543 isolation, where all DMAs pass through the IOMMU. This
544 prevents them from going anywhere except their intended
545 destination. This catches hard-to-find kernel bugs and
546 mis-behaving drivers and devices that do not use the DMA-API
547 properly to set up their DMA buffers. The IOMMU can be
548 turned off at boot time with the iommu=off parameter.
549 Normally the kernel will make the right choice by itself.
552 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
554 prompt "Should Calgary be enabled by default?"
555 depends on CALGARY_IOMMU
557 Should Calgary be enabled by default? if you choose 'y', Calgary
558 will be used (if it exists). If you choose 'n', Calgary will not be
559 used even if it exists. If you choose 'n' and would like to use
560 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
564 bool "AMD IOMMU support"
567 depends on X86_64 && PCI && ACPI
569 With this option you can enable support for AMD IOMMU hardware in
570 your system. An IOMMU is a hardware component which provides
571 remapping of DMA memory accesses from devices. With an AMD IOMMU you
572 can isolate the the DMA memory of different devices and protect the
573 system from misbehaving device drivers or hardware.
575 You can find out if your system has an AMD IOMMU if you look into
576 your BIOS for an option to enable it or if you have an IVRS ACPI
579 # need this always selected by IOMMU for the VIA workaround
583 Support for software bounce buffers used on x86-64 systems
584 which don't have a hardware IOMMU (e.g. the current generation
585 of Intel's x86-64 CPUs). Using this PCI devices which can only
586 access 32-bits of memory can be used on systems with more than
587 3 GB of memory. If unsure, say Y.
590 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
593 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
594 depends on X86_64 && SMP && BROKEN
597 Configure maximum number of CPUS and NUMA Nodes for this architecture.
601 int "Maximum number of CPUs (2-512)" if !MAXSMP
604 default "4096" if MAXSMP
605 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
608 This allows you to specify the maximum number of CPUs which this
609 kernel will support. The maximum supported value is 512 and the
610 minimum value which makes sense is 2.
612 This is purely to save memory - each supported CPU adds
613 approximately eight kilobytes to the kernel image.
616 bool "SMT (Hyperthreading) scheduler support"
619 SMT scheduler support improves the CPU scheduler's decision making
620 when dealing with Intel Pentium 4 chips with HyperThreading at a
621 cost of slightly increased overhead in some places. If unsure say
626 prompt "Multi-core scheduler support"
629 Multi-core scheduler support improves the CPU scheduler's decision
630 making when dealing with multi-core CPU chips at a cost of slightly
631 increased overhead in some places. If unsure say N here.
633 source "kernel/Kconfig.preempt"
636 bool "Local APIC support on uniprocessors"
637 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
639 A local APIC (Advanced Programmable Interrupt Controller) is an
640 integrated interrupt controller in the CPU. If you have a single-CPU
641 system which has a processor with a local APIC, you can say Y here to
642 enable and use it. If you say Y here even though your machine doesn't
643 have a local APIC, then the kernel will still run with no slowdown at
644 all. The local APIC supports CPU-generated self-interrupts (timer,
645 performance counters), and the NMI watchdog which detects hard
649 bool "IO-APIC support on uniprocessors"
650 depends on X86_UP_APIC
652 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
653 SMP-capable replacement for PC-style interrupt controllers. Most
654 SMP systems and many recent uniprocessor systems have one.
656 If you have a single-CPU system with an IO-APIC, you can say Y here
657 to use it. If you say Y here even though your machine doesn't have
658 an IO-APIC, then the kernel will still run with no slowdown at all.
660 config X86_LOCAL_APIC
662 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
666 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
668 config X86_VISWS_APIC
670 depends on X86_32 && X86_VISWS
673 bool "Machine Check Exception"
674 depends on !X86_VOYAGER
676 Machine Check Exception support allows the processor to notify the
677 kernel if it detects a problem (e.g. overheating, component failure).
678 The action the kernel takes depends on the severity of the problem,
679 ranging from a warning message on the console, to halting the machine.
680 Your processor must be a Pentium or newer to support this - check the
681 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
682 have a design flaw which leads to false MCE events - hence MCE is
683 disabled on all P5 processors, unless explicitly enabled with "mce"
684 as a boot argument. Similarly, if MCE is built in and creates a
685 problem on some new non-standard machine, you can boot with "nomce"
686 to disable it. MCE support simply ignores non-MCE processors like
687 the 386 and 486, so nearly everyone can say Y here.
691 prompt "Intel MCE features"
692 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
694 Additional support for intel specific MCE features such as
699 prompt "AMD MCE features"
700 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
702 Additional support for AMD specific MCE features such as
703 the DRAM Error Threshold.
705 config X86_MCE_NONFATAL
706 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
707 depends on X86_32 && X86_MCE
709 Enabling this feature starts a timer that triggers every 5 seconds which
710 will look at the machine check registers to see if anything happened.
711 Non-fatal problems automatically get corrected (but still logged).
712 Disable this if you don't want to see these messages.
713 Seeing the messages this option prints out may be indicative of dying
714 or out-of-spec (ie, overclocked) hardware.
715 This option only does something on certain CPUs.
716 (AMD Athlon/Duron and Intel Pentium 4)
718 config X86_MCE_P4THERMAL
719 bool "check for P4 thermal throttling interrupt."
720 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
722 Enabling this feature will cause a message to be printed when the P4
723 enters thermal throttling.
726 bool "Enable VM86 support" if EMBEDDED
730 This option is required by programs like DOSEMU to run 16-bit legacy
731 code on X86 processors. It also may be needed by software like
732 XFree86 to initialize some video cards via BIOS. Disabling this
733 option saves about 6k.
736 tristate "Toshiba Laptop support"
739 This adds a driver to safely access the System Management Mode of
740 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
741 not work on models with a Phoenix BIOS. The System Management Mode
742 is used to set the BIOS and power saving options on Toshiba portables.
744 For information on utilities to make use of this driver see the
745 Toshiba Linux utilities web site at:
746 <http://www.buzzard.org.uk/toshiba/>.
748 Say Y if you intend to run this kernel on a Toshiba portable.
752 tristate "Dell laptop support"
754 This adds a driver to safely access the System Management Mode
755 of the CPU on the Dell Inspiron 8000. The System Management Mode
756 is used to read cpu temperature and cooling fan status and to
757 control the fans on the I8K portables.
759 This driver has been tested only on the Inspiron 8000 but it may
760 also work with other Dell laptops. You can force loading on other
761 models by passing the parameter `force=1' to the module. Use at
764 For information on utilities to make use of this driver see the
765 I8K Linux utilities web site at:
766 <http://people.debian.org/~dz/i8k/>
768 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
771 config X86_REBOOTFIXUPS
772 bool "Enable X86 board specific fixups for reboot"
775 This enables chipset and/or board specific fixups to be done
776 in order to get reboot to work correctly. This is only needed on
777 some combinations of hardware and BIOS. The symptom, for which
778 this config is intended, is when reboot ends with a stalled/hung
781 Currently, the only fixup is for the Geode machines using
782 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
784 Say Y if you want to enable the fixup. Currently, it's safe to
785 enable this option even if you don't need it.
789 tristate "/dev/cpu/microcode - microcode support"
792 If you say Y here, you will be able to update the microcode on
793 certain Intel and AMD processors. The Intel support is for the
794 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
795 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
796 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
797 You will obviously need the actual microcode binary data itself
798 which is not shipped with the Linux kernel.
800 This option selects the general module only, you need to select
801 at least one vendor specific module as well.
803 To compile this driver as a module, choose M here: the
804 module will be called microcode.
806 config MICROCODE_INTEL
807 bool "Intel microcode patch loading support"
812 This options enables microcode patch loading support for Intel
815 For latest news and information on obtaining all the required
816 Intel ingredients for this driver, check:
817 <http://www.urbanmyth.org/microcode/>.
820 bool "AMD microcode patch loading support"
824 If you select this option, microcode patch loading support for AMD
825 processors will be enabled.
827 config MICROCODE_OLD_INTERFACE
832 tristate "/dev/cpu/*/msr - Model-specific register support"
834 This device gives privileged processes access to the x86
835 Model-Specific Registers (MSRs). It is a character device with
836 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
837 MSR accesses are directed to a specific CPU on multi-processor
841 tristate "/dev/cpu/*/cpuid - CPU information support"
843 This device gives processes access to the x86 CPUID instruction to
844 be executed on a specific processor. It is a character device
845 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
849 prompt "High Memory Support"
850 default HIGHMEM4G if !X86_NUMAQ
851 default HIGHMEM64G if X86_NUMAQ
856 depends on !X86_NUMAQ
858 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
859 However, the address space of 32-bit x86 processors is only 4
860 Gigabytes large. That means that, if you have a large amount of
861 physical memory, not all of it can be "permanently mapped" by the
862 kernel. The physical memory that's not permanently mapped is called
865 If you are compiling a kernel which will never run on a machine with
866 more than 1 Gigabyte total physical RAM, answer "off" here (default
867 choice and suitable for most users). This will result in a "3GB/1GB"
868 split: 3GB are mapped so that each process sees a 3GB virtual memory
869 space and the remaining part of the 4GB virtual memory space is used
870 by the kernel to permanently map as much physical memory as
873 If the machine has between 1 and 4 Gigabytes physical RAM, then
876 If more than 4 Gigabytes is used then answer "64GB" here. This
877 selection turns Intel PAE (Physical Address Extension) mode on.
878 PAE implements 3-level paging on IA32 processors. PAE is fully
879 supported by Linux, PAE mode is implemented on all recent Intel
880 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
881 then the kernel will not boot on CPUs that don't support PAE!
883 The actual amount of total physical memory will either be
884 auto detected or can be forced by using a kernel command line option
885 such as "mem=256M". (Try "man bootparam" or see the documentation of
886 your boot loader (lilo or loadlin) about how to pass options to the
887 kernel at boot time.)
889 If unsure, say "off".
893 depends on !X86_NUMAQ
895 Select this if you have a 32-bit processor and between 1 and 4
896 gigabytes of physical RAM.
900 depends on !M386 && !M486
903 Select this if you have a 32-bit processor and more than 4
904 gigabytes of physical RAM.
909 depends on EXPERIMENTAL
910 prompt "Memory split" if EMBEDDED
914 Select the desired split between kernel and user memory.
916 If the address range available to the kernel is less than the
917 physical memory installed, the remaining memory will be available
918 as "high memory". Accessing high memory is a little more costly
919 than low memory, as it needs to be mapped into the kernel first.
920 Note that increasing the kernel address space limits the range
921 available to user programs, making the address space there
922 tighter. Selecting anything other than the default 3G/1G split
923 will also likely make your kernel incompatible with binary-only
926 If you are not absolutely sure what you are doing, leave this
930 bool "3G/1G user/kernel split"
931 config VMSPLIT_3G_OPT
933 bool "3G/1G user/kernel split (for full 1G low memory)"
935 bool "2G/2G user/kernel split"
936 config VMSPLIT_2G_OPT
938 bool "2G/2G user/kernel split (for full 2G low memory)"
940 bool "1G/3G user/kernel split"
945 default 0xB0000000 if VMSPLIT_3G_OPT
946 default 0x80000000 if VMSPLIT_2G
947 default 0x78000000 if VMSPLIT_2G_OPT
948 default 0x40000000 if VMSPLIT_1G
954 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
957 bool "PAE (Physical Address Extension) Support"
958 depends on X86_32 && !HIGHMEM4G
960 PAE is required for NX support, and furthermore enables
961 larger swapspace support for non-overcommit purposes. It
962 has the cost of more pagetable lookup overhead, and also
963 consumes more pagetable space per process.
965 config ARCH_PHYS_ADDR_T_64BIT
966 def_bool X86_64 || X86_PAE
968 # Common NUMA Features
970 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
972 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
974 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
976 Enable NUMA (Non Uniform Memory Access) support.
977 The kernel will try to allocate memory used by a CPU on the
978 local memory controller of the CPU and add some more
979 NUMA awareness to the kernel.
981 For 32-bit this is currently highly experimental and should be only
982 used for kernel development. It might also cause boot failures.
983 For 64-bit this is recommended on all multiprocessor Opteron systems.
984 If the system is EM64T, you should say N unless your system is
987 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
988 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
992 prompt "Old style AMD Opteron NUMA detection"
993 depends on X86_64 && NUMA && PCI
995 Enable K8 NUMA node topology detection. You should say Y here if
996 you have a multi processor AMD K8 system. This uses an old
997 method to read the NUMA configuration directly from the builtin
998 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
999 instead, which also takes priority if both are compiled in.
1001 config X86_64_ACPI_NUMA
1003 prompt "ACPI NUMA detection"
1004 depends on X86_64 && NUMA && ACPI && PCI
1007 Enable ACPI SRAT based node topology detection.
1009 # Some NUMA nodes have memory ranges that span
1010 # other nodes. Even though a pfn is valid and
1011 # between a node's start and end pfns, it may not
1012 # reside on that node. See memmap_init_zone()
1014 config NODES_SPAN_OTHER_NODES
1016 depends on X86_64_ACPI_NUMA
1019 bool "NUMA emulation"
1020 depends on X86_64 && NUMA
1022 Enable NUMA emulation. A flat machine will be split
1023 into virtual nodes when booted with "numa=fake=N", where N is the
1024 number of nodes. This is only useful for debugging.
1027 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1029 default "9" if MAXSMP
1030 default "6" if X86_64
1031 default "4" if X86_NUMAQ
1033 depends on NEED_MULTIPLE_NODES
1035 Specify the maximum number of NUMA Nodes available on the target
1036 system. Increases memory reserved to accomodate various tables.
1038 config HAVE_ARCH_BOOTMEM_NODE
1040 depends on X86_32 && NUMA
1042 config ARCH_HAVE_MEMORY_PRESENT
1044 depends on X86_32 && DISCONTIGMEM
1046 config NEED_NODE_MEMMAP_SIZE
1048 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1050 config HAVE_ARCH_ALLOC_REMAP
1052 depends on X86_32 && NUMA
1054 config ARCH_FLATMEM_ENABLE
1056 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1058 config ARCH_DISCONTIGMEM_ENABLE
1060 depends on NUMA && X86_32
1062 config ARCH_DISCONTIGMEM_DEFAULT
1064 depends on NUMA && X86_32
1066 config ARCH_SPARSEMEM_DEFAULT
1070 config ARCH_SPARSEMEM_ENABLE
1072 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1073 select SPARSEMEM_STATIC if X86_32
1074 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1076 config ARCH_SELECT_MEMORY_MODEL
1078 depends on ARCH_SPARSEMEM_ENABLE
1080 config ARCH_MEMORY_PROBE
1082 depends on MEMORY_HOTPLUG
1087 bool "Allocate 3rd-level pagetables from highmem"
1088 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1090 The VM uses one page table entry for each page of physical memory.
1091 For systems with a lot of RAM, this can be wasteful of precious
1092 low memory. Setting this option will put user-space page table
1093 entries in high memory.
1095 config X86_CHECK_BIOS_CORRUPTION
1096 bool "Check for low memory corruption"
1098 Periodically check for memory corruption in low memory, which
1099 is suspected to be caused by BIOS. Even when enabled in the
1100 configuration, it is disabled at runtime. Enable it by
1101 setting "memory_corruption_check=1" on the kernel command
1102 line. By default it scans the low 64k of memory every 60
1103 seconds; see the memory_corruption_check_size and
1104 memory_corruption_check_period parameters in
1105 Documentation/kernel-parameters.txt to adjust this.
1107 When enabled with the default parameters, this option has
1108 almost no overhead, as it reserves a relatively small amount
1109 of memory and scans it infrequently. It both detects corruption
1110 and prevents it from affecting the running system.
1112 It is, however, intended as a diagnostic tool; if repeatable
1113 BIOS-originated corruption always affects the same memory,
1114 you can use memmap= to prevent the kernel from using that
1117 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1118 bool "Set the default setting of memory_corruption_check"
1119 depends on X86_CHECK_BIOS_CORRUPTION
1122 Set whether the default state of memory_corruption_check is
1125 config X86_RESERVE_LOW_64K
1126 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1129 Reserve the first 64K of physical RAM on BIOSes that are known
1130 to potentially corrupt that memory range. A numbers of BIOSes are
1131 known to utilize this area during suspend/resume, so it must not
1132 be used by the kernel.
1134 Set this to N if you are absolutely sure that you trust the BIOS
1135 to get all its memory reservations and usages right.
1137 If you have doubts about the BIOS (e.g. suspend/resume does not
1138 work or there's kernel crashes after certain hardware hotplug
1139 events) and it's not AMI or Phoenix, then you might want to enable
1140 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1141 corruption patterns.
1145 config MATH_EMULATION
1147 prompt "Math emulation" if X86_32
1149 Linux can emulate a math coprocessor (used for floating point
1150 operations) if you don't have one. 486DX and Pentium processors have
1151 a math coprocessor built in, 486SX and 386 do not, unless you added
1152 a 487DX or 387, respectively. (The messages during boot time can
1153 give you some hints here ["man dmesg"].) Everyone needs either a
1154 coprocessor or this emulation.
1156 If you don't have a math coprocessor, you need to say Y here; if you
1157 say Y here even though you have a coprocessor, the coprocessor will
1158 be used nevertheless. (This behavior can be changed with the kernel
1159 command line option "no387", which comes handy if your coprocessor
1160 is broken. Try "man bootparam" or see the documentation of your boot
1161 loader (lilo or loadlin) about how to pass options to the kernel at
1162 boot time.) This means that it is a good idea to say Y here if you
1163 intend to use this kernel on different machines.
1165 More information about the internals of the Linux math coprocessor
1166 emulation can be found in <file:arch/x86/math-emu/README>.
1168 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1169 kernel, it won't hurt.
1172 bool "MTRR (Memory Type Range Register) support"
1174 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1175 the Memory Type Range Registers (MTRRs) may be used to control
1176 processor access to memory ranges. This is most useful if you have
1177 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1178 allows bus write transfers to be combined into a larger transfer
1179 before bursting over the PCI/AGP bus. This can increase performance
1180 of image write operations 2.5 times or more. Saying Y here creates a
1181 /proc/mtrr file which may be used to manipulate your processor's
1182 MTRRs. Typically the X server should use this.
1184 This code has a reasonably generic interface so that similar
1185 control registers on other processors can be easily supported
1188 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1189 Registers (ARRs) which provide a similar functionality to MTRRs. For
1190 these, the ARRs are used to emulate the MTRRs.
1191 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1192 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1193 write-combining. All of these processors are supported by this code
1194 and it makes sense to say Y here if you have one of them.
1196 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1197 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1198 can lead to all sorts of problems, so it's good to say Y here.
1200 You can safely say Y even if your machine doesn't have MTRRs, you'll
1201 just add about 9 KB to your kernel.
1203 See <file:Documentation/x86/mtrr.txt> for more information.
1205 config MTRR_SANITIZER
1207 prompt "MTRR cleanup support"
1210 Convert MTRR layout from continuous to discrete, so X drivers can
1211 add writeback entries.
1213 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1214 The largest mtrr entry size for a continous block can be set with
1219 config MTRR_SANITIZER_ENABLE_DEFAULT
1220 int "MTRR cleanup enable value (0-1)"
1223 depends on MTRR_SANITIZER
1225 Enable mtrr cleanup default value
1227 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1228 int "MTRR cleanup spare reg num (0-7)"
1231 depends on MTRR_SANITIZER
1233 mtrr cleanup spare entries default, it can be changed via
1234 mtrr_spare_reg_nr=N on the kernel command line.
1238 prompt "x86 PAT support"
1241 Use PAT attributes to setup page level cache control.
1243 PATs are the modern equivalents of MTRRs and are much more
1244 flexible than MTRRs.
1246 Say N here if you see bootup problems (boot crash, boot hang,
1247 spontaneous reboots) or a non-working video driver.
1252 bool "EFI runtime service support"
1255 This enables the kernel to use EFI runtime services that are
1256 available (such as the EFI variable services).
1258 This option is only useful on systems that have EFI firmware.
1259 In addition, you should use the latest ELILO loader available
1260 at <http://elilo.sourceforge.net> in order to take advantage
1261 of EFI runtime services. However, even with this option, the
1262 resultant kernel should continue to boot on existing non-EFI
1267 prompt "Enable seccomp to safely compute untrusted bytecode"
1269 This kernel feature is useful for number crunching applications
1270 that may need to compute untrusted bytecode during their
1271 execution. By using pipes or other transports made available to
1272 the process as file descriptors supporting the read/write
1273 syscalls, it's possible to isolate those applications in
1274 their own address space using seccomp. Once seccomp is
1275 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1276 and the task is only allowed to execute a few safe syscalls
1277 defined by each seccomp mode.
1279 If unsure, say Y. Only embedded should say N here.
1281 config CC_STACKPROTECTOR
1282 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1283 depends on X86_64 && EXPERIMENTAL && BROKEN
1285 This option turns on the -fstack-protector GCC feature. This
1286 feature puts, at the beginning of critical functions, a canary
1287 value on the stack just before the return address, and validates
1288 the value just before actually returning. Stack based buffer
1289 overflows (that need to overwrite this return address) now also
1290 overwrite the canary, which gets detected and the attack is then
1291 neutralized via a kernel panic.
1293 This feature requires gcc version 4.2 or above, or a distribution
1294 gcc with the feature backported. Older versions are automatically
1295 detected and for those versions, this configuration option is ignored.
1297 config CC_STACKPROTECTOR_ALL
1298 bool "Use stack-protector for all functions"
1299 depends on CC_STACKPROTECTOR
1301 Normally, GCC only inserts the canary value protection for
1302 functions that use large-ish on-stack buffers. By enabling
1303 this option, GCC will be asked to do this for ALL functions.
1305 source kernel/Kconfig.hz
1308 bool "kexec system call"
1309 depends on X86_BIOS_REBOOT
1311 kexec is a system call that implements the ability to shutdown your
1312 current kernel, and to start another kernel. It is like a reboot
1313 but it is independent of the system firmware. And like a reboot
1314 you can start any kernel with it, not just Linux.
1316 The name comes from the similarity to the exec system call.
1318 It is an ongoing process to be certain the hardware in a machine
1319 is properly shutdown, so do not be surprised if this code does not
1320 initially work for you. It may help to enable device hotplugging
1321 support. As of this writing the exact hardware interface is
1322 strongly in flux, so no good recommendation can be made.
1325 bool "kernel crash dumps"
1326 depends on X86_64 || (X86_32 && HIGHMEM)
1328 Generate crash dump after being started by kexec.
1329 This should be normally only set in special crash dump kernels
1330 which are loaded in the main kernel with kexec-tools into
1331 a specially reserved region and then later executed after
1332 a crash by kdump/kexec. The crash dump kernel must be compiled
1333 to a memory address not used by the main kernel or BIOS using
1334 PHYSICAL_START, or it must be built as a relocatable image
1335 (CONFIG_RELOCATABLE=y).
1336 For more details see Documentation/kdump/kdump.txt
1339 bool "kexec jump (EXPERIMENTAL)"
1340 depends on EXPERIMENTAL
1341 depends on KEXEC && HIBERNATION && X86_32
1343 Jump between original kernel and kexeced kernel and invoke
1344 code in physical address mode via KEXEC
1346 config PHYSICAL_START
1347 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1348 default "0x1000000" if X86_NUMAQ
1349 default "0x200000" if X86_64
1352 This gives the physical address where the kernel is loaded.
1354 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1355 bzImage will decompress itself to above physical address and
1356 run from there. Otherwise, bzImage will run from the address where
1357 it has been loaded by the boot loader and will ignore above physical
1360 In normal kdump cases one does not have to set/change this option
1361 as now bzImage can be compiled as a completely relocatable image
1362 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1363 address. This option is mainly useful for the folks who don't want
1364 to use a bzImage for capturing the crash dump and want to use a
1365 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1366 to be specifically compiled to run from a specific memory area
1367 (normally a reserved region) and this option comes handy.
1369 So if you are using bzImage for capturing the crash dump, leave
1370 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1371 Otherwise if you plan to use vmlinux for capturing the crash dump
1372 change this value to start of the reserved region (Typically 16MB
1373 0x1000000). In other words, it can be set based on the "X" value as
1374 specified in the "crashkernel=YM@XM" command line boot parameter
1375 passed to the panic-ed kernel. Typically this parameter is set as
1376 crashkernel=64M@16M. Please take a look at
1377 Documentation/kdump/kdump.txt for more details about crash dumps.
1379 Usage of bzImage for capturing the crash dump is recommended as
1380 one does not have to build two kernels. Same kernel can be used
1381 as production kernel and capture kernel. Above option should have
1382 gone away after relocatable bzImage support is introduced. But it
1383 is present because there are users out there who continue to use
1384 vmlinux for dump capture. This option should go away down the
1387 Don't change this unless you know what you are doing.
1390 bool "Build a relocatable kernel (EXPERIMENTAL)"
1391 depends on EXPERIMENTAL
1393 This builds a kernel image that retains relocation information
1394 so it can be loaded someplace besides the default 1MB.
1395 The relocations tend to make the kernel binary about 10% larger,
1396 but are discarded at runtime.
1398 One use is for the kexec on panic case where the recovery kernel
1399 must live at a different physical address than the primary
1402 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1403 it has been loaded at and the compile time physical address
1404 (CONFIG_PHYSICAL_START) is ignored.
1406 config PHYSICAL_ALIGN
1408 prompt "Alignment value to which kernel should be aligned" if X86_32
1409 default "0x100000" if X86_32
1410 default "0x200000" if X86_64
1411 range 0x2000 0x400000
1413 This value puts the alignment restrictions on physical address
1414 where kernel is loaded and run from. Kernel is compiled for an
1415 address which meets above alignment restriction.
1417 If bootloader loads the kernel at a non-aligned address and
1418 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1419 address aligned to above value and run from there.
1421 If bootloader loads the kernel at a non-aligned address and
1422 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1423 load address and decompress itself to the address it has been
1424 compiled for and run from there. The address for which kernel is
1425 compiled already meets above alignment restrictions. Hence the
1426 end result is that kernel runs from a physical address meeting
1427 above alignment restrictions.
1429 Don't change this unless you know what you are doing.
1432 bool "Support for hot-pluggable CPUs"
1433 depends on SMP && HOTPLUG && !X86_VOYAGER
1435 Say Y here to allow turning CPUs off and on. CPUs can be
1436 controlled through /sys/devices/system/cpu.
1437 ( Note: power management support will enable this option
1438 automatically on SMP systems. )
1439 Say N if you want to disable CPU hotplug.
1443 prompt "Compat VDSO support"
1444 depends on X86_32 || IA32_EMULATION
1446 Map the 32-bit VDSO to the predictable old-style address too.
1448 Say N here if you are running a sufficiently recent glibc
1449 version (2.3.3 or later), to remove the high-mapped
1450 VDSO mapping and to exclusively use the randomized VDSO.
1455 bool "Built-in kernel command line"
1458 Allow for specifying boot arguments to the kernel at
1459 build time. On some systems (e.g. embedded ones), it is
1460 necessary or convenient to provide some or all of the
1461 kernel boot arguments with the kernel itself (that is,
1462 to not rely on the boot loader to provide them.)
1464 To compile command line arguments into the kernel,
1465 set this option to 'Y', then fill in the
1466 the boot arguments in CONFIG_CMDLINE.
1468 Systems with fully functional boot loaders (i.e. non-embedded)
1469 should leave this option set to 'N'.
1472 string "Built-in kernel command string"
1473 depends on CMDLINE_BOOL
1476 Enter arguments here that should be compiled into the kernel
1477 image and used at boot time. If the boot loader provides a
1478 command line at boot time, it is appended to this string to
1479 form the full kernel command line, when the system boots.
1481 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1482 change this behavior.
1484 In most cases, the command line (whether built-in or provided
1485 by the boot loader) should specify the device for the root
1488 config CMDLINE_OVERRIDE
1489 bool "Built-in command line overrides boot loader arguments"
1491 depends on CMDLINE_BOOL
1493 Set this option to 'Y' to have the kernel ignore the boot loader
1494 command line, and use ONLY the built-in command line.
1496 This is used to work around broken boot loaders. This should
1497 be set to 'N' under normal conditions.
1501 config ARCH_ENABLE_MEMORY_HOTPLUG
1503 depends on X86_64 || (X86_32 && HIGHMEM)
1505 config HAVE_ARCH_EARLY_PFN_TO_NID
1509 menu "Power management and ACPI options"
1510 depends on !X86_VOYAGER
1512 config ARCH_HIBERNATION_HEADER
1514 depends on X86_64 && HIBERNATION
1516 source "kernel/power/Kconfig"
1518 source "drivers/acpi/Kconfig"
1523 depends on APM || APM_MODULE
1526 tristate "APM (Advanced Power Management) BIOS support"
1527 depends on X86_32 && PM_SLEEP
1529 APM is a BIOS specification for saving power using several different
1530 techniques. This is mostly useful for battery powered laptops with
1531 APM compliant BIOSes. If you say Y here, the system time will be
1532 reset after a RESUME operation, the /proc/apm device will provide
1533 battery status information, and user-space programs will receive
1534 notification of APM "events" (e.g. battery status change).
1536 If you select "Y" here, you can disable actual use of the APM
1537 BIOS by passing the "apm=off" option to the kernel at boot time.
1539 Note that the APM support is almost completely disabled for
1540 machines with more than one CPU.
1542 In order to use APM, you will need supporting software. For location
1543 and more information, read <file:Documentation/power/pm.txt> and the
1544 Battery Powered Linux mini-HOWTO, available from
1545 <http://www.tldp.org/docs.html#howto>.
1547 This driver does not spin down disk drives (see the hdparm(8)
1548 manpage ("man 8 hdparm") for that), and it doesn't turn off
1549 VESA-compliant "green" monitors.
1551 This driver does not support the TI 4000M TravelMate and the ACER
1552 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1553 desktop machines also don't have compliant BIOSes, and this driver
1554 may cause those machines to panic during the boot phase.
1556 Generally, if you don't have a battery in your machine, there isn't
1557 much point in using this driver and you should say N. If you get
1558 random kernel OOPSes or reboots that don't seem to be related to
1559 anything, try disabling/enabling this option (or disabling/enabling
1562 Some other things you should try when experiencing seemingly random,
1565 1) make sure that you have enough swap space and that it is
1567 2) pass the "no-hlt" option to the kernel
1568 3) switch on floating point emulation in the kernel and pass
1569 the "no387" option to the kernel
1570 4) pass the "floppy=nodma" option to the kernel
1571 5) pass the "mem=4M" option to the kernel (thereby disabling
1572 all but the first 4 MB of RAM)
1573 6) make sure that the CPU is not over clocked.
1574 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1575 8) disable the cache from your BIOS settings
1576 9) install a fan for the video card or exchange video RAM
1577 10) install a better fan for the CPU
1578 11) exchange RAM chips
1579 12) exchange the motherboard.
1581 To compile this driver as a module, choose M here: the
1582 module will be called apm.
1586 config APM_IGNORE_USER_SUSPEND
1587 bool "Ignore USER SUSPEND"
1589 This option will ignore USER SUSPEND requests. On machines with a
1590 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1591 series notebooks, it is necessary to say Y because of a BIOS bug.
1593 config APM_DO_ENABLE
1594 bool "Enable PM at boot time"
1596 Enable APM features at boot time. From page 36 of the APM BIOS
1597 specification: "When disabled, the APM BIOS does not automatically
1598 power manage devices, enter the Standby State, enter the Suspend
1599 State, or take power saving steps in response to CPU Idle calls."
1600 This driver will make CPU Idle calls when Linux is idle (unless this
1601 feature is turned off -- see "Do CPU IDLE calls", below). This
1602 should always save battery power, but more complicated APM features
1603 will be dependent on your BIOS implementation. You may need to turn
1604 this option off if your computer hangs at boot time when using APM
1605 support, or if it beeps continuously instead of suspending. Turn
1606 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1607 T400CDT. This is off by default since most machines do fine without
1611 bool "Make CPU Idle calls when idle"
1613 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1614 On some machines, this can activate improved power savings, such as
1615 a slowed CPU clock rate, when the machine is idle. These idle calls
1616 are made after the idle loop has run for some length of time (e.g.,
1617 333 mS). On some machines, this will cause a hang at boot time or
1618 whenever the CPU becomes idle. (On machines with more than one CPU,
1619 this option does nothing.)
1621 config APM_DISPLAY_BLANK
1622 bool "Enable console blanking using APM"
1624 Enable console blanking using the APM. Some laptops can use this to
1625 turn off the LCD backlight when the screen blanker of the Linux
1626 virtual console blanks the screen. Note that this is only used by
1627 the virtual console screen blanker, and won't turn off the backlight
1628 when using the X Window system. This also doesn't have anything to
1629 do with your VESA-compliant power-saving monitor. Further, this
1630 option doesn't work for all laptops -- it might not turn off your
1631 backlight at all, or it might print a lot of errors to the console,
1632 especially if you are using gpm.
1634 config APM_ALLOW_INTS
1635 bool "Allow interrupts during APM BIOS calls"
1637 Normally we disable external interrupts while we are making calls to
1638 the APM BIOS as a measure to lessen the effects of a badly behaving
1639 BIOS implementation. The BIOS should reenable interrupts if it
1640 needs to. Unfortunately, some BIOSes do not -- especially those in
1641 many of the newer IBM Thinkpads. If you experience hangs when you
1642 suspend, try setting this to Y. Otherwise, say N.
1646 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1648 source "drivers/cpuidle/Kconfig"
1650 source "drivers/idle/Kconfig"
1655 menu "Bus options (PCI etc.)"
1660 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1662 Find out whether you have a PCI motherboard. PCI is the name of a
1663 bus system, i.e. the way the CPU talks to the other stuff inside
1664 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1665 VESA. If you have PCI, say Y, otherwise N.
1668 prompt "PCI access mode"
1669 depends on X86_32 && PCI
1672 On PCI systems, the BIOS can be used to detect the PCI devices and
1673 determine their configuration. However, some old PCI motherboards
1674 have BIOS bugs and may crash if this is done. Also, some embedded
1675 PCI-based systems don't have any BIOS at all. Linux can also try to
1676 detect the PCI hardware directly without using the BIOS.
1678 With this option, you can specify how Linux should detect the
1679 PCI devices. If you choose "BIOS", the BIOS will be used,
1680 if you choose "Direct", the BIOS won't be used, and if you
1681 choose "MMConfig", then PCI Express MMCONFIG will be used.
1682 If you choose "Any", the kernel will try MMCONFIG, then the
1683 direct access method and falls back to the BIOS if that doesn't
1684 work. If unsure, go with the default, which is "Any".
1689 config PCI_GOMMCONFIG
1706 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1708 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1711 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1715 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1719 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1726 bool "Support mmconfig PCI config space access"
1727 depends on X86_64 && PCI && ACPI
1730 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1731 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1733 DMA remapping (DMAR) devices support enables independent address
1734 translations for Direct Memory Access (DMA) from devices.
1735 These DMA remapping devices are reported via ACPI tables
1736 and include PCI device scope covered by these DMA
1741 prompt "Support for Graphics workaround"
1744 Current Graphics drivers tend to use physical address
1745 for DMA and avoid using DMA APIs. Setting this config
1746 option permits the IOMMU driver to set a unity map for
1747 all the OS-visible memory. Hence the driver can continue
1748 to use physical addresses for DMA.
1750 config DMAR_FLOPPY_WA
1754 Floppy disk drivers are know to bypass DMA API calls
1755 thereby failing to work when IOMMU is enabled. This
1756 workaround will setup a 1:1 mapping for the first
1757 16M to make floppy (an ISA device) work.
1760 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1761 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1763 Supports Interrupt remapping for IO-APIC and MSI devices.
1764 To use x2apic mode in the CPU's which support x2APIC enhancements or
1765 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1767 source "drivers/pci/pcie/Kconfig"
1769 source "drivers/pci/Kconfig"
1771 # x86_64 have no ISA slots, but do have ISA-style DMA.
1779 depends on !X86_VOYAGER
1781 Find out whether you have ISA slots on your motherboard. ISA is the
1782 name of a bus system, i.e. the way the CPU talks to the other stuff
1783 inside your box. Other bus systems are PCI, EISA, MicroChannel
1784 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1785 newer boards don't support it. If you have ISA, say Y, otherwise N.
1791 The Extended Industry Standard Architecture (EISA) bus was
1792 developed as an open alternative to the IBM MicroChannel bus.
1794 The EISA bus provided some of the features of the IBM MicroChannel
1795 bus while maintaining backward compatibility with cards made for
1796 the older ISA bus. The EISA bus saw limited use between 1988 and
1797 1995 when it was made obsolete by the PCI bus.
1799 Say Y here if you are building a kernel for an EISA-based machine.
1803 source "drivers/eisa/Kconfig"
1806 bool "MCA support" if !X86_VOYAGER
1807 default y if X86_VOYAGER
1809 MicroChannel Architecture is found in some IBM PS/2 machines and
1810 laptops. It is a bus system similar to PCI or ISA. See
1811 <file:Documentation/mca.txt> (and especially the web page given
1812 there) before attempting to build an MCA bus kernel.
1814 source "drivers/mca/Kconfig"
1817 tristate "NatSemi SCx200 support"
1818 depends on !X86_VOYAGER
1820 This provides basic support for National Semiconductor's
1821 (now AMD's) Geode processors. The driver probes for the
1822 PCI-IDs of several on-chip devices, so its a good dependency
1823 for other scx200_* drivers.
1825 If compiled as a module, the driver is named scx200.
1827 config SCx200HR_TIMER
1828 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1829 depends on SCx200 && GENERIC_TIME
1832 This driver provides a clocksource built upon the on-chip
1833 27MHz high-resolution timer. Its also a workaround for
1834 NSC Geode SC-1100's buggy TSC, which loses time when the
1835 processor goes idle (as is done by the scheduler). The
1836 other workaround is idle=poll boot option.
1838 config GEODE_MFGPT_TIMER
1840 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1841 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1843 This driver provides a clock event source based on the MFGPT
1844 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1845 MFGPTs have a better resolution and max interval than the
1846 generic PIT, and are suitable for use as high-res timers.
1849 bool "One Laptop Per Child support"
1852 Add support for detecting the unique features of the OLPC
1859 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1861 source "drivers/pcmcia/Kconfig"
1863 source "drivers/pci/hotplug/Kconfig"
1868 menu "Executable file formats / Emulations"
1870 source "fs/Kconfig.binfmt"
1872 config IA32_EMULATION
1873 bool "IA32 Emulation"
1875 select COMPAT_BINFMT_ELF
1877 Include code to run 32-bit programs under a 64-bit kernel. You should
1878 likely turn this on, unless you're 100% sure that you don't have any
1879 32-bit programs left.
1882 tristate "IA32 a.out support"
1883 depends on IA32_EMULATION
1885 Support old a.out binaries in the 32bit emulation.
1889 depends on IA32_EMULATION
1891 config COMPAT_FOR_U64_ALIGNMENT
1895 config SYSVIPC_COMPAT
1897 depends on COMPAT && SYSVIPC
1902 config HAVE_ATOMIC_IOMAP
1906 source "net/Kconfig"
1908 source "drivers/Kconfig"
1910 source "drivers/firmware/Kconfig"
1914 source "arch/x86/Kconfig.debug"
1916 source "security/Kconfig"
1918 source "crypto/Kconfig"
1920 source "arch/x86/kvm/Kconfig"
1922 source "lib/Kconfig"
projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blob