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
24 select HAVE_UNSTABLE_SCHED_CLOCK
27 select HAVE_PERF_EVENTS if (!M386 && !M486)
28 select HAVE_IOREMAP_PROT
30 select ARCH_WANT_OPTIONAL_GPIOLIB
31 select ARCH_WANT_FRAME_POINTERS
33 select HAVE_KRETPROBES
34 select HAVE_FTRACE_MCOUNT_RECORD
35 select HAVE_DYNAMIC_FTRACE
36 select HAVE_FUNCTION_TRACER
37 select HAVE_FUNCTION_GRAPH_TRACER
38 select HAVE_FUNCTION_GRAPH_FP_TEST
39 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
40 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
41 select HAVE_SYSCALL_TRACEPOINTS
44 select HAVE_ARCH_TRACEHOOK
45 select HAVE_GENERIC_DMA_COHERENT if X86_32
46 select HAVE_EFFICIENT_UNALIGNED_ACCESS
47 select USER_STACKTRACE_SUPPORT
48 select HAVE_DMA_API_DEBUG
49 select HAVE_KERNEL_GZIP
50 select HAVE_KERNEL_BZIP2
51 select HAVE_KERNEL_LZMA
52 select HAVE_ARCH_KMEMCHECK
56 default "elf32-i386" if X86_32
57 default "elf64-x86-64" if X86_64
61 default "arch/x86/configs/i386_defconfig" if X86_32
62 default "arch/x86/configs/x86_64_defconfig" if X86_64
67 config GENERIC_CMOS_UPDATE
70 config CLOCKSOURCE_WATCHDOG
73 config GENERIC_CLOCKEVENTS
76 config GENERIC_CLOCKEVENTS_BROADCAST
78 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
80 config LOCKDEP_SUPPORT
83 config STACKTRACE_SUPPORT
86 config HAVE_LATENCYTOP_SUPPORT
98 config GENERIC_ISA_DMA
107 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
109 config GENERIC_BUG_RELATIVE_POINTERS
112 config GENERIC_HWEIGHT
118 config ARCH_MAY_HAVE_PC_FDC
121 config RWSEM_GENERIC_SPINLOCK
124 config RWSEM_XCHGADD_ALGORITHM
127 config ARCH_HAS_CPU_IDLE_WAIT
130 config GENERIC_CALIBRATE_DELAY
133 config GENERIC_TIME_VSYSCALL
137 config ARCH_HAS_CPU_RELAX
140 config ARCH_HAS_DEFAULT_IDLE
143 config ARCH_HAS_CACHE_LINE_SIZE
146 config HAVE_SETUP_PER_CPU_AREA
149 config NEED_PER_CPU_EMBED_FIRST_CHUNK
152 config NEED_PER_CPU_PAGE_FIRST_CHUNK
155 config HAVE_CPUMASK_OF_CPU_MAP
158 config ARCH_HIBERNATION_POSSIBLE
161 config ARCH_SUSPEND_POSSIBLE
168 config ARCH_POPULATES_NODE_MAP
175 config ARCH_SUPPORTS_OPTIMIZED_INLINING
178 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
181 config HAVE_INTEL_TXT
183 depends on EXPERIMENTAL && DMAR && ACPI
185 # Use the generic interrupt handling code in kernel/irq/:
186 config GENERIC_HARDIRQS
190 config GENERIC_HARDIRQS_NO__DO_IRQ
193 config GENERIC_IRQ_PROBE
197 config GENERIC_PENDING_IRQ
199 depends on GENERIC_HARDIRQS && SMP
202 config USE_GENERIC_SMP_HELPERS
208 depends on X86_32 && SMP
212 depends on X86_64 && SMP
219 config X86_TRAMPOLINE
221 depends on SMP || (64BIT && ACPI_SLEEP)
224 config X86_32_LAZY_GS
226 depends on X86_32 && !CC_STACKPROTECTOR
230 source "init/Kconfig"
231 source "kernel/Kconfig.freezer"
233 menu "Processor type and features"
235 source "kernel/time/Kconfig"
238 bool "Symmetric multi-processing support"
240 This enables support for systems with more than one CPU. If you have
241 a system with only one CPU, like most personal computers, say N. If
242 you have a system with more than one CPU, say Y.
244 If you say N here, the kernel will run on single and multiprocessor
245 machines, but will use only one CPU of a multiprocessor machine. If
246 you say Y here, the kernel will run on many, but not all,
247 singleprocessor machines. On a singleprocessor machine, the kernel
248 will run faster if you say N here.
250 Note that if you say Y here and choose architecture "586" or
251 "Pentium" under "Processor family", the kernel will not work on 486
252 architectures. Similarly, multiprocessor kernels for the "PPro"
253 architecture may not work on all Pentium based boards.
255 People using multiprocessor machines who say Y here should also say
256 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
257 Management" code will be disabled if you say Y here.
259 See also <file:Documentation/i386/IO-APIC.txt>,
260 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
261 <http://www.tldp.org/docs.html#howto>.
263 If you don't know what to do here, say N.
266 bool "Support x2apic"
267 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
269 This enables x2apic support on CPUs that have this feature.
271 This allows 32-bit apic IDs (so it can support very large systems),
272 and accesses the local apic via MSRs not via mmio.
274 If you don't know what to do here, say N.
277 bool "Support sparse irq numbering"
278 depends on PCI_MSI || HT_IRQ
280 This enables support for sparse irqs. This is useful for distro
281 kernels that want to define a high CONFIG_NR_CPUS value but still
282 want to have low kernel memory footprint on smaller machines.
284 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
285 out the irq_desc[] array in a more NUMA-friendly way. )
287 If you don't know what to do here, say N.
291 depends on SPARSE_IRQ && NUMA
294 bool "Enable MPS table" if ACPI
296 depends on X86_LOCAL_APIC
298 For old smp systems that do not have proper acpi support. Newer systems
299 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
302 bool "Support for big SMP systems with more than 8 CPUs"
303 depends on X86_32 && SMP
305 This option is needed for the systems that have more than 8 CPUs
308 config X86_EXTENDED_PLATFORM
309 bool "Support for extended (non-PC) x86 platforms"
312 If you disable this option then the kernel will only support
313 standard PC platforms. (which covers the vast majority of
316 If you enable this option then you'll be able to select support
317 for the following (non-PC) 32 bit x86 platforms:
321 SGI 320/540 (Visual Workstation)
322 Summit/EXA (IBM x440)
323 Unisys ES7000 IA32 series
324 Moorestown MID devices
326 If you have one of these systems, or if you want to build a
327 generic distribution kernel, say Y here - otherwise say N.
331 config X86_EXTENDED_PLATFORM
332 bool "Support for extended (non-PC) x86 platforms"
335 If you disable this option then the kernel will only support
336 standard PC platforms. (which covers the vast majority of
339 If you enable this option then you'll be able to select support
340 for the following (non-PC) 64 bit x86 platforms:
344 If you have one of these systems, or if you want to build a
345 generic distribution kernel, say Y here - otherwise say N.
347 # This is an alphabetically sorted list of 64 bit extended platforms
348 # Please maintain the alphabetic order if and when there are additions
353 depends on X86_64 && PCI
354 depends on X86_EXTENDED_PLATFORM
356 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
357 supposed to run on these EM64T-based machines. Only choose this option
358 if you have one of these machines.
361 bool "SGI Ultraviolet"
363 depends on X86_EXTENDED_PLATFORM
365 depends on X86_X2APIC
367 This option is needed in order to support SGI Ultraviolet systems.
368 If you don't have one of these, you should say N here.
370 # Following is an alphabetically sorted list of 32 bit extended platforms
371 # Please maintain the alphabetic order if and when there are additions
376 depends on X86_EXTENDED_PLATFORM
378 Select this for an AMD Elan processor.
380 Do not use this option for K6/Athlon/Opteron processors!
382 If unsure, choose "PC-compatible" instead.
385 bool "Moorestown MID platform"
387 depends on X86_EXTENDED_PLATFORM
389 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
390 Internet Device(MID) platform. Moorestown consists of two chips:
391 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
392 Unlike standard x86 PCs, Moorestown does not have many legacy devices
393 nor standard legacy replacement devices/features. e.g. Moorestown does
394 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
397 bool "RDC R-321x SoC"
399 depends on X86_EXTENDED_PLATFORM
401 select X86_REBOOTFIXUPS
403 This option is needed for RDC R-321x system-on-chip, also known
405 If you don't have one of these chips, you should say N here.
407 config X86_32_NON_STANDARD
408 bool "Support non-standard 32-bit SMP architectures"
409 depends on X86_32 && SMP
410 depends on X86_EXTENDED_PLATFORM
412 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
413 subarchitectures. It is intended for a generic binary kernel.
414 if you select them all, kernel will probe it one by one. and will
417 # Alphabetically sorted list of Non standard 32 bit platforms
420 bool "NUMAQ (IBM/Sequent)"
421 depends on X86_32_NON_STANDARD
425 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
426 NUMA multiquad box. This changes the way that processors are
427 bootstrapped, and uses Clustered Logical APIC addressing mode instead
428 of Flat Logical. You will need a new lynxer.elf file to flash your
429 firmware with - send email to <Martin.Bligh@us.ibm.com>.
431 config X86_SUPPORTS_MEMORY_FAILURE
433 # MCE code calls memory_failure():
435 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
436 depends on !X86_NUMAQ
437 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
438 depends on X86_64 || !SPARSEMEM
439 select ARCH_SUPPORTS_MEMORY_FAILURE
443 bool "SGI 320/540 (Visual Workstation)"
444 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
445 depends on X86_32_NON_STANDARD
447 The SGI Visual Workstation series is an IA32-based workstation
448 based on SGI systems chips with some legacy PC hardware attached.
450 Say Y here to create a kernel to run on the SGI 320 or 540.
452 A kernel compiled for the Visual Workstation will run on general
453 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
456 bool "Summit/EXA (IBM x440)"
457 depends on X86_32_NON_STANDARD
459 This option is needed for IBM systems that use the Summit/EXA chipset.
460 In particular, it is needed for the x440.
463 bool "Unisys ES7000 IA32 series"
464 depends on X86_32_NON_STANDARD && X86_BIGSMP
466 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
467 supposed to run on an IA32-based Unisys ES7000 system.
469 config SCHED_OMIT_FRAME_POINTER
471 prompt "Single-depth WCHAN output"
474 Calculate simpler /proc/<PID>/wchan values. If this option
475 is disabled then wchan values will recurse back to the
476 caller function. This provides more accurate wchan values,
477 at the expense of slightly more scheduling overhead.
479 If in doubt, say "Y".
481 menuconfig PARAVIRT_GUEST
482 bool "Paravirtualized guest support"
484 Say Y here to get to see options related to running Linux under
485 various hypervisors. This option alone does not add any kernel code.
487 If you say N, all options in this submenu will be skipped and disabled.
491 source "arch/x86/xen/Kconfig"
494 bool "VMI Guest support"
498 VMI provides a paravirtualized interface to the VMware ESX server
499 (it could be used by other hypervisors in theory too, but is not
500 at the moment), by linking the kernel to a GPL-ed ROM module
501 provided by the hypervisor.
504 bool "KVM paravirtualized clock"
506 select PARAVIRT_CLOCK
508 Turning on this option will allow you to run a paravirtualized clock
509 when running over the KVM hypervisor. Instead of relying on a PIT
510 (or probably other) emulation by the underlying device model, the host
511 provides the guest with timing infrastructure such as time of day, and
515 bool "KVM Guest support"
518 This option enables various optimizations for running under the KVM
521 source "arch/x86/lguest/Kconfig"
524 bool "Enable paravirtualization code"
526 This changes the kernel so it can modify itself when it is run
527 under a hypervisor, potentially improving performance significantly
528 over full virtualization. However, when run without a hypervisor
529 the kernel is theoretically slower and slightly larger.
531 config PARAVIRT_SPINLOCKS
532 bool "Paravirtualization layer for spinlocks"
533 depends on PARAVIRT && SMP && EXPERIMENTAL
535 Paravirtualized spinlocks allow a pvops backend to replace the
536 spinlock implementation with something virtualization-friendly
537 (for example, block the virtual CPU rather than spinning).
539 Unfortunately the downside is an up to 5% performance hit on
540 native kernels, with various workloads.
542 If you are unsure how to answer this question, answer N.
544 config PARAVIRT_CLOCK
550 config PARAVIRT_DEBUG
551 bool "paravirt-ops debugging"
552 depends on PARAVIRT && DEBUG_KERNEL
554 Enable to debug paravirt_ops internals. Specifically, BUG if
555 a paravirt_op is missing when it is called.
560 This option adds a kernel parameter 'memtest', which allows memtest
562 memtest=0, mean disabled; -- default
563 memtest=1, mean do 1 test pattern;
565 memtest=4, mean do 4 test patterns.
566 If you are unsure how to answer this question, answer N.
568 config X86_SUMMIT_NUMA
570 depends on X86_32 && NUMA && X86_32_NON_STANDARD
572 config X86_CYCLONE_TIMER
574 depends on X86_32_NON_STANDARD
576 source "arch/x86/Kconfig.cpu"
580 prompt "HPET Timer Support" if X86_32
582 Use the IA-PC HPET (High Precision Event Timer) to manage
583 time in preference to the PIT and RTC, if a HPET is
585 HPET is the next generation timer replacing legacy 8254s.
586 The HPET provides a stable time base on SMP
587 systems, unlike the TSC, but it is more expensive to access,
588 as it is off-chip. You can find the HPET spec at
589 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
591 You can safely choose Y here. However, HPET will only be
592 activated if the platform and the BIOS support this feature.
593 Otherwise the 8254 will be used for timing services.
595 Choose N to continue using the legacy 8254 timer.
597 config HPET_EMULATE_RTC
599 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
601 # Mark as embedded because too many people got it wrong.
602 # The code disables itself when not needed.
605 bool "Enable DMI scanning" if EMBEDDED
607 Enabled scanning of DMI to identify machine quirks. Say Y
608 here unless you have verified that your setup is not
609 affected by entries in the DMI blacklist. Required by PNP
613 bool "GART IOMMU support" if EMBEDDED
616 depends on X86_64 && PCI
618 Support for full DMA access of devices with 32bit memory access only
619 on systems with more than 3GB. This is usually needed for USB,
620 sound, many IDE/SATA chipsets and some other devices.
621 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
622 based hardware IOMMU and a software bounce buffer based IOMMU used
623 on Intel systems and as fallback.
624 The code is only active when needed (enough memory and limited
625 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
629 bool "IBM Calgary IOMMU support"
631 depends on X86_64 && PCI && EXPERIMENTAL
633 Support for hardware IOMMUs in IBM's xSeries x366 and x460
634 systems. Needed to run systems with more than 3GB of memory
635 properly with 32-bit PCI devices that do not support DAC
636 (Double Address Cycle). Calgary also supports bus level
637 isolation, where all DMAs pass through the IOMMU. This
638 prevents them from going anywhere except their intended
639 destination. This catches hard-to-find kernel bugs and
640 mis-behaving drivers and devices that do not use the DMA-API
641 properly to set up their DMA buffers. The IOMMU can be
642 turned off at boot time with the iommu=off parameter.
643 Normally the kernel will make the right choice by itself.
646 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
648 prompt "Should Calgary be enabled by default?"
649 depends on CALGARY_IOMMU
651 Should Calgary be enabled by default? if you choose 'y', Calgary
652 will be used (if it exists). If you choose 'n', Calgary will not be
653 used even if it exists. If you choose 'n' and would like to use
654 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
658 bool "AMD IOMMU support"
661 depends on X86_64 && PCI && ACPI
663 With this option you can enable support for AMD IOMMU hardware in
664 your system. An IOMMU is a hardware component which provides
665 remapping of DMA memory accesses from devices. With an AMD IOMMU you
666 can isolate the the DMA memory of different devices and protect the
667 system from misbehaving device drivers or hardware.
669 You can find out if your system has an AMD IOMMU if you look into
670 your BIOS for an option to enable it or if you have an IVRS ACPI
673 config AMD_IOMMU_STATS
674 bool "Export AMD IOMMU statistics to debugfs"
678 This option enables code in the AMD IOMMU driver to collect various
679 statistics about whats happening in the driver and exports that
680 information to userspace via debugfs.
683 # need this always selected by IOMMU for the VIA workaround
687 Support for software bounce buffers used on x86-64 systems
688 which don't have a hardware IOMMU (e.g. the current generation
689 of Intel's x86-64 CPUs). Using this PCI devices which can only
690 access 32-bits of memory can be used on systems with more than
691 3 GB of memory. If unsure, say Y.
694 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
697 def_bool (AMD_IOMMU || DMAR)
700 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
701 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
702 select CPUMASK_OFFSTACK
705 Configure maximum number of CPUS and NUMA Nodes for this architecture.
709 int "Maximum number of CPUs" if SMP && !MAXSMP
710 range 2 8 if SMP && X86_32 && !X86_BIGSMP
711 range 2 512 if SMP && !MAXSMP
713 default "4096" if MAXSMP
714 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
717 This allows you to specify the maximum number of CPUs which this
718 kernel will support. The maximum supported value is 512 and the
719 minimum value which makes sense is 2.
721 This is purely to save memory - each supported CPU adds
722 approximately eight kilobytes to the kernel image.
725 bool "SMT (Hyperthreading) scheduler support"
728 SMT scheduler support improves the CPU scheduler's decision making
729 when dealing with Intel Pentium 4 chips with HyperThreading at a
730 cost of slightly increased overhead in some places. If unsure say
735 prompt "Multi-core scheduler support"
738 Multi-core scheduler support improves the CPU scheduler's decision
739 making when dealing with multi-core CPU chips at a cost of slightly
740 increased overhead in some places. If unsure say N here.
742 source "kernel/Kconfig.preempt"
745 bool "Local APIC support on uniprocessors"
746 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
748 A local APIC (Advanced Programmable Interrupt Controller) is an
749 integrated interrupt controller in the CPU. If you have a single-CPU
750 system which has a processor with a local APIC, you can say Y here to
751 enable and use it. If you say Y here even though your machine doesn't
752 have a local APIC, then the kernel will still run with no slowdown at
753 all. The local APIC supports CPU-generated self-interrupts (timer,
754 performance counters), and the NMI watchdog which detects hard
758 bool "IO-APIC support on uniprocessors"
759 depends on X86_UP_APIC
761 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
762 SMP-capable replacement for PC-style interrupt controllers. Most
763 SMP systems and many recent uniprocessor systems have one.
765 If you have a single-CPU system with an IO-APIC, you can say Y here
766 to use it. If you say Y here even though your machine doesn't have
767 an IO-APIC, then the kernel will still run with no slowdown at all.
769 config X86_LOCAL_APIC
771 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
775 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
777 config X86_VISWS_APIC
779 depends on X86_32 && X86_VISWS
781 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
782 bool "Reroute for broken boot IRQs"
784 depends on X86_IO_APIC
786 This option enables a workaround that fixes a source of
787 spurious interrupts. This is recommended when threaded
788 interrupt handling is used on systems where the generation of
789 superfluous "boot interrupts" cannot be disabled.
791 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
792 entry in the chipset's IO-APIC is masked (as, e.g. the RT
793 kernel does during interrupt handling). On chipsets where this
794 boot IRQ generation cannot be disabled, this workaround keeps
795 the original IRQ line masked so that only the equivalent "boot
796 IRQ" is delivered to the CPUs. The workaround also tells the
797 kernel to set up the IRQ handler on the boot IRQ line. In this
798 way only one interrupt is delivered to the kernel. Otherwise
799 the spurious second interrupt may cause the kernel to bring
800 down (vital) interrupt lines.
802 Only affects "broken" chipsets. Interrupt sharing may be
803 increased on these systems.
806 bool "Machine Check / overheating reporting"
808 Machine Check support allows the processor to notify the
809 kernel if it detects a problem (e.g. overheating, data corruption).
810 The action the kernel takes depends on the severity of the problem,
811 ranging from warning messages to halting the machine.
815 prompt "Intel MCE features"
816 depends on X86_MCE && X86_LOCAL_APIC
818 Additional support for intel specific MCE features such as
823 prompt "AMD MCE features"
824 depends on X86_MCE && X86_LOCAL_APIC
826 Additional support for AMD specific MCE features such as
827 the DRAM Error Threshold.
829 config X86_ANCIENT_MCE
831 depends on X86_32 && X86_MCE
832 prompt "Support for old Pentium 5 / WinChip machine checks"
834 Include support for machine check handling on old Pentium 5 or WinChip
835 systems. These typically need to be enabled explicitely on the command
838 config X86_MCE_THRESHOLD
839 depends on X86_MCE_AMD || X86_MCE_INTEL
843 config X86_MCE_INJECT
845 tristate "Machine check injector support"
847 Provide support for injecting machine checks for testing purposes.
848 If you don't know what a machine check is and you don't do kernel
849 QA it is safe to say n.
851 config X86_THERMAL_VECTOR
853 depends on X86_MCE_INTEL
856 bool "Enable VM86 support" if EMBEDDED
860 This option is required by programs like DOSEMU to run 16-bit legacy
861 code on X86 processors. It also may be needed by software like
862 XFree86 to initialize some video cards via BIOS. Disabling this
863 option saves about 6k.
866 tristate "Toshiba Laptop support"
869 This adds a driver to safely access the System Management Mode of
870 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
871 not work on models with a Phoenix BIOS. The System Management Mode
872 is used to set the BIOS and power saving options on Toshiba portables.
874 For information on utilities to make use of this driver see the
875 Toshiba Linux utilities web site at:
876 <http://www.buzzard.org.uk/toshiba/>.
878 Say Y if you intend to run this kernel on a Toshiba portable.
882 tristate "Dell laptop support"
884 This adds a driver to safely access the System Management Mode
885 of the CPU on the Dell Inspiron 8000. The System Management Mode
886 is used to read cpu temperature and cooling fan status and to
887 control the fans on the I8K portables.
889 This driver has been tested only on the Inspiron 8000 but it may
890 also work with other Dell laptops. You can force loading on other
891 models by passing the parameter `force=1' to the module. Use at
894 For information on utilities to make use of this driver see the
895 I8K Linux utilities web site at:
896 <http://people.debian.org/~dz/i8k/>
898 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
901 config X86_REBOOTFIXUPS
902 bool "Enable X86 board specific fixups for reboot"
905 This enables chipset and/or board specific fixups to be done
906 in order to get reboot to work correctly. This is only needed on
907 some combinations of hardware and BIOS. The symptom, for which
908 this config is intended, is when reboot ends with a stalled/hung
911 Currently, the only fixup is for the Geode machines using
912 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
914 Say Y if you want to enable the fixup. Currently, it's safe to
915 enable this option even if you don't need it.
919 tristate "/dev/cpu/microcode - microcode support"
922 If you say Y here, you will be able to update the microcode on
923 certain Intel and AMD processors. The Intel support is for the
924 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
925 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
926 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
927 You will obviously need the actual microcode binary data itself
928 which is not shipped with the Linux kernel.
930 This option selects the general module only, you need to select
931 at least one vendor specific module as well.
933 To compile this driver as a module, choose M here: the
934 module will be called microcode.
936 config MICROCODE_INTEL
937 bool "Intel microcode patch loading support"
942 This options enables microcode patch loading support for Intel
945 For latest news and information on obtaining all the required
946 Intel ingredients for this driver, check:
947 <http://www.urbanmyth.org/microcode/>.
950 bool "AMD microcode patch loading support"
954 If you select this option, microcode patch loading support for AMD
955 processors will be enabled.
957 config MICROCODE_OLD_INTERFACE
962 tristate "/dev/cpu/*/msr - Model-specific register support"
964 This device gives privileged processes access to the x86
965 Model-Specific Registers (MSRs). It is a character device with
966 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
967 MSR accesses are directed to a specific CPU on multi-processor
971 tristate "/dev/cpu/*/cpuid - CPU information support"
973 This device gives processes access to the x86 CPUID instruction to
974 be executed on a specific processor. It is a character device
975 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
979 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
981 If you select this option, this will provide various x86 CPUs
982 information through debugfs.
985 prompt "High Memory Support"
986 default HIGHMEM4G if !X86_NUMAQ
987 default HIGHMEM64G if X86_NUMAQ
992 depends on !X86_NUMAQ
994 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
995 However, the address space of 32-bit x86 processors is only 4
996 Gigabytes large. That means that, if you have a large amount of
997 physical memory, not all of it can be "permanently mapped" by the
998 kernel. The physical memory that's not permanently mapped is called
1001 If you are compiling a kernel which will never run on a machine with
1002 more than 1 Gigabyte total physical RAM, answer "off" here (default
1003 choice and suitable for most users). This will result in a "3GB/1GB"
1004 split: 3GB are mapped so that each process sees a 3GB virtual memory
1005 space and the remaining part of the 4GB virtual memory space is used
1006 by the kernel to permanently map as much physical memory as
1009 If the machine has between 1 and 4 Gigabytes physical RAM, then
1012 If more than 4 Gigabytes is used then answer "64GB" here. This
1013 selection turns Intel PAE (Physical Address Extension) mode on.
1014 PAE implements 3-level paging on IA32 processors. PAE is fully
1015 supported by Linux, PAE mode is implemented on all recent Intel
1016 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1017 then the kernel will not boot on CPUs that don't support PAE!
1019 The actual amount of total physical memory will either be
1020 auto detected or can be forced by using a kernel command line option
1021 such as "mem=256M". (Try "man bootparam" or see the documentation of
1022 your boot loader (lilo or loadlin) about how to pass options to the
1023 kernel at boot time.)
1025 If unsure, say "off".
1029 depends on !X86_NUMAQ
1031 Select this if you have a 32-bit processor and between 1 and 4
1032 gigabytes of physical RAM.
1036 depends on !M386 && !M486
1039 Select this if you have a 32-bit processor and more than 4
1040 gigabytes of physical RAM.
1045 depends on EXPERIMENTAL
1046 prompt "Memory split" if EMBEDDED
1050 Select the desired split between kernel and user memory.
1052 If the address range available to the kernel is less than the
1053 physical memory installed, the remaining memory will be available
1054 as "high memory". Accessing high memory is a little more costly
1055 than low memory, as it needs to be mapped into the kernel first.
1056 Note that increasing the kernel address space limits the range
1057 available to user programs, making the address space there
1058 tighter. Selecting anything other than the default 3G/1G split
1059 will also likely make your kernel incompatible with binary-only
1062 If you are not absolutely sure what you are doing, leave this
1066 bool "3G/1G user/kernel split"
1067 config VMSPLIT_3G_OPT
1069 bool "3G/1G user/kernel split (for full 1G low memory)"
1071 bool "2G/2G user/kernel split"
1072 config VMSPLIT_2G_OPT
1074 bool "2G/2G user/kernel split (for full 2G low memory)"
1076 bool "1G/3G user/kernel split"
1081 default 0xB0000000 if VMSPLIT_3G_OPT
1082 default 0x80000000 if VMSPLIT_2G
1083 default 0x78000000 if VMSPLIT_2G_OPT
1084 default 0x40000000 if VMSPLIT_1G
1090 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1093 bool "PAE (Physical Address Extension) Support"
1094 depends on X86_32 && !HIGHMEM4G
1096 PAE is required for NX support, and furthermore enables
1097 larger swapspace support for non-overcommit purposes. It
1098 has the cost of more pagetable lookup overhead, and also
1099 consumes more pagetable space per process.
1101 config ARCH_PHYS_ADDR_T_64BIT
1102 def_bool X86_64 || X86_PAE
1104 config DIRECT_GBPAGES
1105 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1109 Allow the kernel linear mapping to use 1GB pages on CPUs that
1110 support it. This can improve the kernel's performance a tiny bit by
1111 reducing TLB pressure. If in doubt, say "Y".
1113 # Common NUMA Features
1115 bool "Numa Memory Allocation and Scheduler Support"
1117 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1118 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1120 Enable NUMA (Non Uniform Memory Access) support.
1122 The kernel will try to allocate memory used by a CPU on the
1123 local memory controller of the CPU and add some more
1124 NUMA awareness to the kernel.
1126 For 64-bit this is recommended if the system is Intel Core i7
1127 (or later), AMD Opteron, or EM64T NUMA.
1129 For 32-bit this is only needed on (rare) 32-bit-only platforms
1130 that support NUMA topologies, such as NUMAQ / Summit, or if you
1131 boot a 32-bit kernel on a 64-bit NUMA platform.
1133 Otherwise, you should say N.
1135 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1136 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1140 prompt "Old style AMD Opteron NUMA detection"
1141 depends on X86_64 && NUMA && PCI
1143 Enable K8 NUMA node topology detection. You should say Y here if
1144 you have a multi processor AMD K8 system. This uses an old
1145 method to read the NUMA configuration directly from the builtin
1146 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1147 instead, which also takes priority if both are compiled in.
1149 config X86_64_ACPI_NUMA
1151 prompt "ACPI NUMA detection"
1152 depends on X86_64 && NUMA && ACPI && PCI
1155 Enable ACPI SRAT based node topology detection.
1157 # Some NUMA nodes have memory ranges that span
1158 # other nodes. Even though a pfn is valid and
1159 # between a node's start and end pfns, it may not
1160 # reside on that node. See memmap_init_zone()
1162 config NODES_SPAN_OTHER_NODES
1164 depends on X86_64_ACPI_NUMA
1167 bool "NUMA emulation"
1168 depends on X86_64 && NUMA
1170 Enable NUMA emulation. A flat machine will be split
1171 into virtual nodes when booted with "numa=fake=N", where N is the
1172 number of nodes. This is only useful for debugging.
1175 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1177 default "9" if MAXSMP
1178 default "6" if X86_64
1179 default "4" if X86_NUMAQ
1181 depends on NEED_MULTIPLE_NODES
1183 Specify the maximum number of NUMA Nodes available on the target
1184 system. Increases memory reserved to accommodate various tables.
1186 config HAVE_ARCH_BOOTMEM
1188 depends on X86_32 && NUMA
1190 config ARCH_HAVE_MEMORY_PRESENT
1192 depends on X86_32 && DISCONTIGMEM
1194 config NEED_NODE_MEMMAP_SIZE
1196 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1198 config HAVE_ARCH_ALLOC_REMAP
1200 depends on X86_32 && NUMA
1202 config ARCH_FLATMEM_ENABLE
1204 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1206 config ARCH_DISCONTIGMEM_ENABLE
1208 depends on NUMA && X86_32
1210 config ARCH_DISCONTIGMEM_DEFAULT
1212 depends on NUMA && X86_32
1214 config ARCH_PROC_KCORE_TEXT
1216 depends on X86_64 && PROC_KCORE
1218 config ARCH_SPARSEMEM_DEFAULT
1222 config ARCH_SPARSEMEM_ENABLE
1224 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1225 select SPARSEMEM_STATIC if X86_32
1226 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1228 config ARCH_SELECT_MEMORY_MODEL
1230 depends on ARCH_SPARSEMEM_ENABLE
1232 config ARCH_MEMORY_PROBE
1234 depends on MEMORY_HOTPLUG
1239 bool "Allocate 3rd-level pagetables from highmem"
1240 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1242 The VM uses one page table entry for each page of physical memory.
1243 For systems with a lot of RAM, this can be wasteful of precious
1244 low memory. Setting this option will put user-space page table
1245 entries in high memory.
1247 config X86_CHECK_BIOS_CORRUPTION
1248 bool "Check for low memory corruption"
1250 Periodically check for memory corruption in low memory, which
1251 is suspected to be caused by BIOS. Even when enabled in the
1252 configuration, it is disabled at runtime. Enable it by
1253 setting "memory_corruption_check=1" on the kernel command
1254 line. By default it scans the low 64k of memory every 60
1255 seconds; see the memory_corruption_check_size and
1256 memory_corruption_check_period parameters in
1257 Documentation/kernel-parameters.txt to adjust this.
1259 When enabled with the default parameters, this option has
1260 almost no overhead, as it reserves a relatively small amount
1261 of memory and scans it infrequently. It both detects corruption
1262 and prevents it from affecting the running system.
1264 It is, however, intended as a diagnostic tool; if repeatable
1265 BIOS-originated corruption always affects the same memory,
1266 you can use memmap= to prevent the kernel from using that
1269 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1270 bool "Set the default setting of memory_corruption_check"
1271 depends on X86_CHECK_BIOS_CORRUPTION
1274 Set whether the default state of memory_corruption_check is
1277 config X86_RESERVE_LOW_64K
1278 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1281 Reserve the first 64K of physical RAM on BIOSes that are known
1282 to potentially corrupt that memory range. A numbers of BIOSes are
1283 known to utilize this area during suspend/resume, so it must not
1284 be used by the kernel.
1286 Set this to N if you are absolutely sure that you trust the BIOS
1287 to get all its memory reservations and usages right.
1289 If you have doubts about the BIOS (e.g. suspend/resume does not
1290 work or there's kernel crashes after certain hardware hotplug
1291 events) and it's not AMI or Phoenix, then you might want to enable
1292 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1293 corruption patterns.
1297 config MATH_EMULATION
1299 prompt "Math emulation" if X86_32
1301 Linux can emulate a math coprocessor (used for floating point
1302 operations) if you don't have one. 486DX and Pentium processors have
1303 a math coprocessor built in, 486SX and 386 do not, unless you added
1304 a 487DX or 387, respectively. (The messages during boot time can
1305 give you some hints here ["man dmesg"].) Everyone needs either a
1306 coprocessor or this emulation.
1308 If you don't have a math coprocessor, you need to say Y here; if you
1309 say Y here even though you have a coprocessor, the coprocessor will
1310 be used nevertheless. (This behavior can be changed with the kernel
1311 command line option "no387", which comes handy if your coprocessor
1312 is broken. Try "man bootparam" or see the documentation of your boot
1313 loader (lilo or loadlin) about how to pass options to the kernel at
1314 boot time.) This means that it is a good idea to say Y here if you
1315 intend to use this kernel on different machines.
1317 More information about the internals of the Linux math coprocessor
1318 emulation can be found in <file:arch/x86/math-emu/README>.
1320 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1321 kernel, it won't hurt.
1324 bool "MTRR (Memory Type Range Register) support"
1326 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1327 the Memory Type Range Registers (MTRRs) may be used to control
1328 processor access to memory ranges. This is most useful if you have
1329 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1330 allows bus write transfers to be combined into a larger transfer
1331 before bursting over the PCI/AGP bus. This can increase performance
1332 of image write operations 2.5 times or more. Saying Y here creates a
1333 /proc/mtrr file which may be used to manipulate your processor's
1334 MTRRs. Typically the X server should use this.
1336 This code has a reasonably generic interface so that similar
1337 control registers on other processors can be easily supported
1340 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1341 Registers (ARRs) which provide a similar functionality to MTRRs. For
1342 these, the ARRs are used to emulate the MTRRs.
1343 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1344 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1345 write-combining. All of these processors are supported by this code
1346 and it makes sense to say Y here if you have one of them.
1348 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1349 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1350 can lead to all sorts of problems, so it's good to say Y here.
1352 You can safely say Y even if your machine doesn't have MTRRs, you'll
1353 just add about 9 KB to your kernel.
1355 See <file:Documentation/x86/mtrr.txt> for more information.
1357 config MTRR_SANITIZER
1359 prompt "MTRR cleanup support"
1362 Convert MTRR layout from continuous to discrete, so X drivers can
1363 add writeback entries.
1365 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1366 The largest mtrr entry size for a continuous block can be set with
1371 config MTRR_SANITIZER_ENABLE_DEFAULT
1372 int "MTRR cleanup enable value (0-1)"
1375 depends on MTRR_SANITIZER
1377 Enable mtrr cleanup default value
1379 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1380 int "MTRR cleanup spare reg num (0-7)"
1383 depends on MTRR_SANITIZER
1385 mtrr cleanup spare entries default, it can be changed via
1386 mtrr_spare_reg_nr=N on the kernel command line.
1390 prompt "x86 PAT support"
1393 Use PAT attributes to setup page level cache control.
1395 PATs are the modern equivalents of MTRRs and are much more
1396 flexible than MTRRs.
1398 Say N here if you see bootup problems (boot crash, boot hang,
1399 spontaneous reboots) or a non-working video driver.
1403 config ARCH_USES_PG_UNCACHED
1408 bool "EFI runtime service support"
1411 This enables the kernel to use EFI runtime services that are
1412 available (such as the EFI variable services).
1414 This option is only useful on systems that have EFI firmware.
1415 In addition, you should use the latest ELILO loader available
1416 at <http://elilo.sourceforge.net> in order to take advantage
1417 of EFI runtime services. However, even with this option, the
1418 resultant kernel should continue to boot on existing non-EFI
1423 prompt "Enable seccomp to safely compute untrusted bytecode"
1425 This kernel feature is useful for number crunching applications
1426 that may need to compute untrusted bytecode during their
1427 execution. By using pipes or other transports made available to
1428 the process as file descriptors supporting the read/write
1429 syscalls, it's possible to isolate those applications in
1430 their own address space using seccomp. Once seccomp is
1431 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1432 and the task is only allowed to execute a few safe syscalls
1433 defined by each seccomp mode.
1435 If unsure, say Y. Only embedded should say N here.
1437 config CC_STACKPROTECTOR_ALL
1440 config CC_STACKPROTECTOR
1441 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1442 select CC_STACKPROTECTOR_ALL
1444 This option turns on the -fstack-protector GCC feature. This
1445 feature puts, at the beginning of functions, a canary value on
1446 the stack just before the return address, and validates
1447 the value just before actually returning. Stack based buffer
1448 overflows (that need to overwrite this return address) now also
1449 overwrite the canary, which gets detected and the attack is then
1450 neutralized via a kernel panic.
1452 This feature requires gcc version 4.2 or above, or a distribution
1453 gcc with the feature backported. Older versions are automatically
1454 detected and for those versions, this configuration option is
1455 ignored. (and a warning is printed during bootup)
1457 source kernel/Kconfig.hz
1460 bool "kexec system call"
1462 kexec is a system call that implements the ability to shutdown your
1463 current kernel, and to start another kernel. It is like a reboot
1464 but it is independent of the system firmware. And like a reboot
1465 you can start any kernel with it, not just Linux.
1467 The name comes from the similarity to the exec system call.
1469 It is an ongoing process to be certain the hardware in a machine
1470 is properly shutdown, so do not be surprised if this code does not
1471 initially work for you. It may help to enable device hotplugging
1472 support. As of this writing the exact hardware interface is
1473 strongly in flux, so no good recommendation can be made.
1476 bool "kernel crash dumps"
1477 depends on X86_64 || (X86_32 && HIGHMEM)
1479 Generate crash dump after being started by kexec.
1480 This should be normally only set in special crash dump kernels
1481 which are loaded in the main kernel with kexec-tools into
1482 a specially reserved region and then later executed after
1483 a crash by kdump/kexec. The crash dump kernel must be compiled
1484 to a memory address not used by the main kernel or BIOS using
1485 PHYSICAL_START, or it must be built as a relocatable image
1486 (CONFIG_RELOCATABLE=y).
1487 For more details see Documentation/kdump/kdump.txt
1490 bool "kexec jump (EXPERIMENTAL)"
1491 depends on EXPERIMENTAL
1492 depends on KEXEC && HIBERNATION
1494 Jump between original kernel and kexeced kernel and invoke
1495 code in physical address mode via KEXEC
1497 config PHYSICAL_START
1498 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1501 This gives the physical address where the kernel is loaded.
1503 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1504 bzImage will decompress itself to above physical address and
1505 run from there. Otherwise, bzImage will run from the address where
1506 it has been loaded by the boot loader and will ignore above physical
1509 In normal kdump cases one does not have to set/change this option
1510 as now bzImage can be compiled as a completely relocatable image
1511 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1512 address. This option is mainly useful for the folks who don't want
1513 to use a bzImage for capturing the crash dump and want to use a
1514 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1515 to be specifically compiled to run from a specific memory area
1516 (normally a reserved region) and this option comes handy.
1518 So if you are using bzImage for capturing the crash dump,
1519 leave the value here unchanged to 0x1000000 and set
1520 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1521 for capturing the crash dump change this value to start of
1522 the reserved region. In other words, it can be set based on
1523 the "X" value as specified in the "crashkernel=YM@XM"
1524 command line boot parameter passed to the panic-ed
1525 kernel. Please take a look at Documentation/kdump/kdump.txt
1526 for more details about crash dumps.
1528 Usage of bzImage for capturing the crash dump is recommended as
1529 one does not have to build two kernels. Same kernel can be used
1530 as production kernel and capture kernel. Above option should have
1531 gone away after relocatable bzImage support is introduced. But it
1532 is present because there are users out there who continue to use
1533 vmlinux for dump capture. This option should go away down the
1536 Don't change this unless you know what you are doing.
1539 bool "Build a relocatable kernel"
1542 This builds a kernel image that retains relocation information
1543 so it can be loaded someplace besides the default 1MB.
1544 The relocations tend to make the kernel binary about 10% larger,
1545 but are discarded at runtime.
1547 One use is for the kexec on panic case where the recovery kernel
1548 must live at a different physical address than the primary
1551 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1552 it has been loaded at and the compile time physical address
1553 (CONFIG_PHYSICAL_START) is ignored.
1555 # Relocation on x86-32 needs some additional build support
1556 config X86_NEED_RELOCS
1558 depends on X86_32 && RELOCATABLE
1560 config PHYSICAL_ALIGN
1562 prompt "Alignment value to which kernel should be aligned" if X86_32
1564 range 0x2000 0x1000000
1566 This value puts the alignment restrictions on physical address
1567 where kernel is loaded and run from. Kernel is compiled for an
1568 address which meets above alignment restriction.
1570 If bootloader loads the kernel at a non-aligned address and
1571 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1572 address aligned to above value and run from there.
1574 If bootloader loads the kernel at a non-aligned address and
1575 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1576 load address and decompress itself to the address it has been
1577 compiled for and run from there. The address for which kernel is
1578 compiled already meets above alignment restrictions. Hence the
1579 end result is that kernel runs from a physical address meeting
1580 above alignment restrictions.
1582 Don't change this unless you know what you are doing.
1585 bool "Support for hot-pluggable CPUs"
1586 depends on SMP && HOTPLUG
1588 Say Y here to allow turning CPUs off and on. CPUs can be
1589 controlled through /sys/devices/system/cpu.
1590 ( Note: power management support will enable this option
1591 automatically on SMP systems. )
1592 Say N if you want to disable CPU hotplug.
1596 prompt "Compat VDSO support"
1597 depends on X86_32 || IA32_EMULATION
1599 Map the 32-bit VDSO to the predictable old-style address too.
1601 Say N here if you are running a sufficiently recent glibc
1602 version (2.3.3 or later), to remove the high-mapped
1603 VDSO mapping and to exclusively use the randomized VDSO.
1608 bool "Built-in kernel command line"
1611 Allow for specifying boot arguments to the kernel at
1612 build time. On some systems (e.g. embedded ones), it is
1613 necessary or convenient to provide some or all of the
1614 kernel boot arguments with the kernel itself (that is,
1615 to not rely on the boot loader to provide them.)
1617 To compile command line arguments into the kernel,
1618 set this option to 'Y', then fill in the
1619 the boot arguments in CONFIG_CMDLINE.
1621 Systems with fully functional boot loaders (i.e. non-embedded)
1622 should leave this option set to 'N'.
1625 string "Built-in kernel command string"
1626 depends on CMDLINE_BOOL
1629 Enter arguments here that should be compiled into the kernel
1630 image and used at boot time. If the boot loader provides a
1631 command line at boot time, it is appended to this string to
1632 form the full kernel command line, when the system boots.
1634 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1635 change this behavior.
1637 In most cases, the command line (whether built-in or provided
1638 by the boot loader) should specify the device for the root
1641 config CMDLINE_OVERRIDE
1642 bool "Built-in command line overrides boot loader arguments"
1644 depends on CMDLINE_BOOL
1646 Set this option to 'Y' to have the kernel ignore the boot loader
1647 command line, and use ONLY the built-in command line.
1649 This is used to work around broken boot loaders. This should
1650 be set to 'N' under normal conditions.
1654 config ARCH_ENABLE_MEMORY_HOTPLUG
1656 depends on X86_64 || (X86_32 && HIGHMEM)
1658 config ARCH_ENABLE_MEMORY_HOTREMOVE
1660 depends on MEMORY_HOTPLUG
1662 config HAVE_ARCH_EARLY_PFN_TO_NID
1666 menu "Power management and ACPI options"
1668 config ARCH_HIBERNATION_HEADER
1670 depends on X86_64 && HIBERNATION
1672 source "kernel/power/Kconfig"
1674 source "drivers/acpi/Kconfig"
1676 source "drivers/sfi/Kconfig"
1681 depends on APM || APM_MODULE
1684 tristate "APM (Advanced Power Management) BIOS support"
1685 depends on X86_32 && PM_SLEEP
1687 APM is a BIOS specification for saving power using several different
1688 techniques. This is mostly useful for battery powered laptops with
1689 APM compliant BIOSes. If you say Y here, the system time will be
1690 reset after a RESUME operation, the /proc/apm device will provide
1691 battery status information, and user-space programs will receive
1692 notification of APM "events" (e.g. battery status change).
1694 If you select "Y" here, you can disable actual use of the APM
1695 BIOS by passing the "apm=off" option to the kernel at boot time.
1697 Note that the APM support is almost completely disabled for
1698 machines with more than one CPU.
1700 In order to use APM, you will need supporting software. For location
1701 and more information, read <file:Documentation/power/pm.txt> and the
1702 Battery Powered Linux mini-HOWTO, available from
1703 <http://www.tldp.org/docs.html#howto>.
1705 This driver does not spin down disk drives (see the hdparm(8)
1706 manpage ("man 8 hdparm") for that), and it doesn't turn off
1707 VESA-compliant "green" monitors.
1709 This driver does not support the TI 4000M TravelMate and the ACER
1710 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1711 desktop machines also don't have compliant BIOSes, and this driver
1712 may cause those machines to panic during the boot phase.
1714 Generally, if you don't have a battery in your machine, there isn't
1715 much point in using this driver and you should say N. If you get
1716 random kernel OOPSes or reboots that don't seem to be related to
1717 anything, try disabling/enabling this option (or disabling/enabling
1720 Some other things you should try when experiencing seemingly random,
1723 1) make sure that you have enough swap space and that it is
1725 2) pass the "no-hlt" option to the kernel
1726 3) switch on floating point emulation in the kernel and pass
1727 the "no387" option to the kernel
1728 4) pass the "floppy=nodma" option to the kernel
1729 5) pass the "mem=4M" option to the kernel (thereby disabling
1730 all but the first 4 MB of RAM)
1731 6) make sure that the CPU is not over clocked.
1732 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1733 8) disable the cache from your BIOS settings
1734 9) install a fan for the video card or exchange video RAM
1735 10) install a better fan for the CPU
1736 11) exchange RAM chips
1737 12) exchange the motherboard.
1739 To compile this driver as a module, choose M here: the
1740 module will be called apm.
1744 config APM_IGNORE_USER_SUSPEND
1745 bool "Ignore USER SUSPEND"
1747 This option will ignore USER SUSPEND requests. On machines with a
1748 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1749 series notebooks, it is necessary to say Y because of a BIOS bug.
1751 config APM_DO_ENABLE
1752 bool "Enable PM at boot time"
1754 Enable APM features at boot time. From page 36 of the APM BIOS
1755 specification: "When disabled, the APM BIOS does not automatically
1756 power manage devices, enter the Standby State, enter the Suspend
1757 State, or take power saving steps in response to CPU Idle calls."
1758 This driver will make CPU Idle calls when Linux is idle (unless this
1759 feature is turned off -- see "Do CPU IDLE calls", below). This
1760 should always save battery power, but more complicated APM features
1761 will be dependent on your BIOS implementation. You may need to turn
1762 this option off if your computer hangs at boot time when using APM
1763 support, or if it beeps continuously instead of suspending. Turn
1764 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1765 T400CDT. This is off by default since most machines do fine without
1769 bool "Make CPU Idle calls when idle"
1771 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1772 On some machines, this can activate improved power savings, such as
1773 a slowed CPU clock rate, when the machine is idle. These idle calls
1774 are made after the idle loop has run for some length of time (e.g.,
1775 333 mS). On some machines, this will cause a hang at boot time or
1776 whenever the CPU becomes idle. (On machines with more than one CPU,
1777 this option does nothing.)
1779 config APM_DISPLAY_BLANK
1780 bool "Enable console blanking using APM"
1782 Enable console blanking using the APM. Some laptops can use this to
1783 turn off the LCD backlight when the screen blanker of the Linux
1784 virtual console blanks the screen. Note that this is only used by
1785 the virtual console screen blanker, and won't turn off the backlight
1786 when using the X Window system. This also doesn't have anything to
1787 do with your VESA-compliant power-saving monitor. Further, this
1788 option doesn't work for all laptops -- it might not turn off your
1789 backlight at all, or it might print a lot of errors to the console,
1790 especially if you are using gpm.
1792 config APM_ALLOW_INTS
1793 bool "Allow interrupts during APM BIOS calls"
1795 Normally we disable external interrupts while we are making calls to
1796 the APM BIOS as a measure to lessen the effects of a badly behaving
1797 BIOS implementation. The BIOS should reenable interrupts if it
1798 needs to. Unfortunately, some BIOSes do not -- especially those in
1799 many of the newer IBM Thinkpads. If you experience hangs when you
1800 suspend, try setting this to Y. Otherwise, say N.
1804 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1806 source "drivers/cpuidle/Kconfig"
1808 source "drivers/idle/Kconfig"
1813 menu "Bus options (PCI etc.)"
1818 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1820 Find out whether you have a PCI motherboard. PCI is the name of a
1821 bus system, i.e. the way the CPU talks to the other stuff inside
1822 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1823 VESA. If you have PCI, say Y, otherwise N.
1826 prompt "PCI access mode"
1827 depends on X86_32 && PCI
1830 On PCI systems, the BIOS can be used to detect the PCI devices and
1831 determine their configuration. However, some old PCI motherboards
1832 have BIOS bugs and may crash if this is done. Also, some embedded
1833 PCI-based systems don't have any BIOS at all. Linux can also try to
1834 detect the PCI hardware directly without using the BIOS.
1836 With this option, you can specify how Linux should detect the
1837 PCI devices. If you choose "BIOS", the BIOS will be used,
1838 if you choose "Direct", the BIOS won't be used, and if you
1839 choose "MMConfig", then PCI Express MMCONFIG will be used.
1840 If you choose "Any", the kernel will try MMCONFIG, then the
1841 direct access method and falls back to the BIOS if that doesn't
1842 work. If unsure, go with the default, which is "Any".
1847 config PCI_GOMMCONFIG
1864 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1866 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1869 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1873 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1877 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1884 bool "Support mmconfig PCI config space access"
1885 depends on X86_64 && PCI && ACPI
1888 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1889 depends on PCI_MSI && ACPI && EXPERIMENTAL
1891 DMA remapping (DMAR) devices support enables independent address
1892 translations for Direct Memory Access (DMA) from devices.
1893 These DMA remapping devices are reported via ACPI tables
1894 and include PCI device scope covered by these DMA
1897 config DMAR_DEFAULT_ON
1899 prompt "Enable DMA Remapping Devices by default"
1902 Selecting this option will enable a DMAR device at boot time if
1903 one is found. If this option is not selected, DMAR support can
1904 be enabled by passing intel_iommu=on to the kernel. It is
1905 recommended you say N here while the DMAR code remains
1908 config DMAR_BROKEN_GFX_WA
1910 prompt "Workaround broken graphics drivers (going away soon)"
1911 depends on DMAR && BROKEN
1913 Current Graphics drivers tend to use physical address
1914 for DMA and avoid using DMA APIs. Setting this config
1915 option permits the IOMMU driver to set a unity map for
1916 all the OS-visible memory. Hence the driver can continue
1917 to use physical addresses for DMA, at least until this
1918 option is removed in the 2.6.32 kernel.
1920 config DMAR_FLOPPY_WA
1924 Floppy disk drivers are known to bypass DMA API calls
1925 thereby failing to work when IOMMU is enabled. This
1926 workaround will setup a 1:1 mapping for the first
1927 16MiB to make floppy (an ISA device) work.
1930 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1931 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1933 Supports Interrupt remapping for IO-APIC and MSI devices.
1934 To use x2apic mode in the CPU's which support x2APIC enhancements or
1935 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1937 source "drivers/pci/pcie/Kconfig"
1939 source "drivers/pci/Kconfig"
1941 # x86_64 have no ISA slots, but do have ISA-style DMA.
1950 Find out whether you have ISA slots on your motherboard. ISA is the
1951 name of a bus system, i.e. the way the CPU talks to the other stuff
1952 inside your box. Other bus systems are PCI, EISA, MicroChannel
1953 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1954 newer boards don't support it. If you have ISA, say Y, otherwise N.
1960 The Extended Industry Standard Architecture (EISA) bus was
1961 developed as an open alternative to the IBM MicroChannel bus.
1963 The EISA bus provided some of the features of the IBM MicroChannel
1964 bus while maintaining backward compatibility with cards made for
1965 the older ISA bus. The EISA bus saw limited use between 1988 and
1966 1995 when it was made obsolete by the PCI bus.
1968 Say Y here if you are building a kernel for an EISA-based machine.
1972 source "drivers/eisa/Kconfig"
1977 MicroChannel Architecture is found in some IBM PS/2 machines and
1978 laptops. It is a bus system similar to PCI or ISA. See
1979 <file:Documentation/mca.txt> (and especially the web page given
1980 there) before attempting to build an MCA bus kernel.
1982 source "drivers/mca/Kconfig"
1985 tristate "NatSemi SCx200 support"
1987 This provides basic support for National Semiconductor's
1988 (now AMD's) Geode processors. The driver probes for the
1989 PCI-IDs of several on-chip devices, so its a good dependency
1990 for other scx200_* drivers.
1992 If compiled as a module, the driver is named scx200.
1994 config SCx200HR_TIMER
1995 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1996 depends on SCx200 && GENERIC_TIME
1999 This driver provides a clocksource built upon the on-chip
2000 27MHz high-resolution timer. Its also a workaround for
2001 NSC Geode SC-1100's buggy TSC, which loses time when the
2002 processor goes idle (as is done by the scheduler). The
2003 other workaround is idle=poll boot option.
2005 config GEODE_MFGPT_TIMER
2007 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2008 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2010 This driver provides a clock event source based on the MFGPT
2011 timer(s) in the CS5535 and CS5536 companion chip for the geode.
2012 MFGPTs have a better resolution and max interval than the
2013 generic PIT, and are suitable for use as high-res timers.
2016 bool "One Laptop Per Child support"
2019 Add support for detecting the unique features of the OLPC
2026 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2028 source "drivers/pcmcia/Kconfig"
2030 source "drivers/pci/hotplug/Kconfig"
2035 menu "Executable file formats / Emulations"
2037 source "fs/Kconfig.binfmt"
2039 config IA32_EMULATION
2040 bool "IA32 Emulation"
2042 select COMPAT_BINFMT_ELF
2044 Include code to run 32-bit programs under a 64-bit kernel. You should
2045 likely turn this on, unless you're 100% sure that you don't have any
2046 32-bit programs left.
2049 tristate "IA32 a.out support"
2050 depends on IA32_EMULATION
2052 Support old a.out binaries in the 32bit emulation.
2056 depends on IA32_EMULATION
2058 config COMPAT_FOR_U64_ALIGNMENT
2062 config SYSVIPC_COMPAT
2064 depends on COMPAT && SYSVIPC
2069 config HAVE_ATOMIC_IOMAP
2073 source "net/Kconfig"
2075 source "drivers/Kconfig"
2077 source "drivers/firmware/Kconfig"
2081 source "arch/x86/Kconfig.debug"
2083 source "security/Kconfig"
2085 source "crypto/Kconfig"
2087 source "arch/x86/kvm/Kconfig"
2089 source "lib/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob