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
53 select HAVE_USER_RETURN_NOTIFIER
57 default "elf32-i386" if X86_32
58 default "elf64-x86-64" if X86_64
62 default "arch/x86/configs/i386_defconfig" if X86_32
63 default "arch/x86/configs/x86_64_defconfig" if X86_64
68 config GENERIC_CMOS_UPDATE
71 config CLOCKSOURCE_WATCHDOG
74 config GENERIC_CLOCKEVENTS
77 config GENERIC_CLOCKEVENTS_BROADCAST
79 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
81 config LOCKDEP_SUPPORT
84 config STACKTRACE_SUPPORT
87 config HAVE_LATENCYTOP_SUPPORT
90 config FAST_CMPXCHG_LOCAL
103 config GENERIC_ISA_DMA
112 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
114 config GENERIC_BUG_RELATIVE_POINTERS
117 config GENERIC_HWEIGHT
123 config ARCH_MAY_HAVE_PC_FDC
126 config RWSEM_GENERIC_SPINLOCK
129 config RWSEM_XCHGADD_ALGORITHM
132 config ARCH_HAS_CPU_IDLE_WAIT
135 config GENERIC_CALIBRATE_DELAY
138 config GENERIC_TIME_VSYSCALL
142 config ARCH_HAS_CPU_RELAX
145 config ARCH_HAS_DEFAULT_IDLE
148 config ARCH_HAS_CACHE_LINE_SIZE
151 config HAVE_SETUP_PER_CPU_AREA
154 config NEED_PER_CPU_EMBED_FIRST_CHUNK
157 config NEED_PER_CPU_PAGE_FIRST_CHUNK
160 config HAVE_CPUMASK_OF_CPU_MAP
163 config ARCH_HIBERNATION_POSSIBLE
166 config ARCH_SUSPEND_POSSIBLE
173 config ARCH_POPULATES_NODE_MAP
180 config ARCH_SUPPORTS_OPTIMIZED_INLINING
183 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
186 config HAVE_INTEL_TXT
188 depends on EXPERIMENTAL && DMAR && ACPI
190 # Use the generic interrupt handling code in kernel/irq/:
191 config GENERIC_HARDIRQS
195 config GENERIC_HARDIRQS_NO__DO_IRQ
198 config GENERIC_IRQ_PROBE
202 config GENERIC_PENDING_IRQ
204 depends on GENERIC_HARDIRQS && SMP
207 config USE_GENERIC_SMP_HELPERS
213 depends on X86_32 && SMP
217 depends on X86_64 && SMP
224 config X86_TRAMPOLINE
226 depends on SMP || (64BIT && ACPI_SLEEP)
229 config X86_32_LAZY_GS
231 depends on X86_32 && !CC_STACKPROTECTOR
235 source "init/Kconfig"
236 source "kernel/Kconfig.freezer"
238 menu "Processor type and features"
240 source "kernel/time/Kconfig"
243 bool "Symmetric multi-processing support"
245 This enables support for systems with more than one CPU. If you have
246 a system with only one CPU, like most personal computers, say N. If
247 you have a system with more than one CPU, say Y.
249 If you say N here, the kernel will run on single and multiprocessor
250 machines, but will use only one CPU of a multiprocessor machine. If
251 you say Y here, the kernel will run on many, but not all,
252 singleprocessor machines. On a singleprocessor machine, the kernel
253 will run faster if you say N here.
255 Note that if you say Y here and choose architecture "586" or
256 "Pentium" under "Processor family", the kernel will not work on 486
257 architectures. Similarly, multiprocessor kernels for the "PPro"
258 architecture may not work on all Pentium based boards.
260 People using multiprocessor machines who say Y here should also say
261 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
262 Management" code will be disabled if you say Y here.
264 See also <file:Documentation/i386/IO-APIC.txt>,
265 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
266 <http://www.tldp.org/docs.html#howto>.
268 If you don't know what to do here, say N.
271 bool "Support x2apic"
272 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
274 This enables x2apic support on CPUs that have this feature.
276 This allows 32-bit apic IDs (so it can support very large systems),
277 and accesses the local apic via MSRs not via mmio.
279 If you don't know what to do here, say N.
282 bool "Support sparse irq numbering"
283 depends on PCI_MSI || HT_IRQ
285 This enables support for sparse irqs. This is useful for distro
286 kernels that want to define a high CONFIG_NR_CPUS value but still
287 want to have low kernel memory footprint on smaller machines.
289 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
290 out the irq_desc[] array in a more NUMA-friendly way. )
292 If you don't know what to do here, say N.
296 depends on SPARSE_IRQ && NUMA
299 bool "Enable MPS table" if ACPI
301 depends on X86_LOCAL_APIC
303 For old smp systems that do not have proper acpi support. Newer systems
304 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
307 bool "Support for big SMP systems with more than 8 CPUs"
308 depends on X86_32 && SMP
310 This option is needed for the systems that have more than 8 CPUs
313 config X86_EXTENDED_PLATFORM
314 bool "Support for extended (non-PC) x86 platforms"
317 If you disable this option then the kernel will only support
318 standard PC platforms. (which covers the vast majority of
321 If you enable this option then you'll be able to select support
322 for the following (non-PC) 32 bit x86 platforms:
326 SGI 320/540 (Visual Workstation)
327 Summit/EXA (IBM x440)
328 Unisys ES7000 IA32 series
329 Moorestown MID devices
331 If you have one of these systems, or if you want to build a
332 generic distribution kernel, say Y here - otherwise say N.
336 config X86_EXTENDED_PLATFORM
337 bool "Support for extended (non-PC) x86 platforms"
340 If you disable this option then the kernel will only support
341 standard PC platforms. (which covers the vast majority of
344 If you enable this option then you'll be able to select support
345 for the following (non-PC) 64 bit x86 platforms:
349 If you have one of these systems, or if you want to build a
350 generic distribution kernel, say Y here - otherwise say N.
352 # This is an alphabetically sorted list of 64 bit extended platforms
353 # Please maintain the alphabetic order if and when there are additions
358 depends on X86_64 && PCI
359 depends on X86_EXTENDED_PLATFORM
361 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
362 supposed to run on these EM64T-based machines. Only choose this option
363 if you have one of these machines.
366 bool "SGI Ultraviolet"
368 depends on X86_EXTENDED_PLATFORM
370 depends on X86_X2APIC
372 This option is needed in order to support SGI Ultraviolet systems.
373 If you don't have one of these, you should say N here.
375 # Following is an alphabetically sorted list of 32 bit extended platforms
376 # Please maintain the alphabetic order if and when there are additions
381 depends on X86_EXTENDED_PLATFORM
383 Select this for an AMD Elan processor.
385 Do not use this option for K6/Athlon/Opteron processors!
387 If unsure, choose "PC-compatible" instead.
390 bool "Moorestown MID platform"
392 depends on X86_EXTENDED_PLATFORM
394 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
395 Internet Device(MID) platform. Moorestown consists of two chips:
396 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
397 Unlike standard x86 PCs, Moorestown does not have many legacy devices
398 nor standard legacy replacement devices/features. e.g. Moorestown does
399 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
402 bool "RDC R-321x SoC"
404 depends on X86_EXTENDED_PLATFORM
406 select X86_REBOOTFIXUPS
408 This option is needed for RDC R-321x system-on-chip, also known
410 If you don't have one of these chips, you should say N here.
412 config X86_32_NON_STANDARD
413 bool "Support non-standard 32-bit SMP architectures"
414 depends on X86_32 && SMP
415 depends on X86_EXTENDED_PLATFORM
417 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
418 subarchitectures. It is intended for a generic binary kernel.
419 if you select them all, kernel will probe it one by one. and will
422 # Alphabetically sorted list of Non standard 32 bit platforms
425 bool "NUMAQ (IBM/Sequent)"
426 depends on X86_32_NON_STANDARD
430 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
431 NUMA multiquad box. This changes the way that processors are
432 bootstrapped, and uses Clustered Logical APIC addressing mode instead
433 of Flat Logical. You will need a new lynxer.elf file to flash your
434 firmware with - send email to <Martin.Bligh@us.ibm.com>.
436 config X86_SUPPORTS_MEMORY_FAILURE
438 # MCE code calls memory_failure():
440 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
441 depends on !X86_NUMAQ
442 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
443 depends on X86_64 || !SPARSEMEM
444 select ARCH_SUPPORTS_MEMORY_FAILURE
448 bool "SGI 320/540 (Visual Workstation)"
449 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
450 depends on X86_32_NON_STANDARD
452 The SGI Visual Workstation series is an IA32-based workstation
453 based on SGI systems chips with some legacy PC hardware attached.
455 Say Y here to create a kernel to run on the SGI 320 or 540.
457 A kernel compiled for the Visual Workstation will run on general
458 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
461 bool "Summit/EXA (IBM x440)"
462 depends on X86_32_NON_STANDARD
464 This option is needed for IBM systems that use the Summit/EXA chipset.
465 In particular, it is needed for the x440.
468 bool "Unisys ES7000 IA32 series"
469 depends on X86_32_NON_STANDARD && X86_BIGSMP
471 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
472 supposed to run on an IA32-based Unisys ES7000 system.
474 config SCHED_OMIT_FRAME_POINTER
476 prompt "Single-depth WCHAN output"
479 Calculate simpler /proc/<PID>/wchan values. If this option
480 is disabled then wchan values will recurse back to the
481 caller function. This provides more accurate wchan values,
482 at the expense of slightly more scheduling overhead.
484 If in doubt, say "Y".
486 menuconfig PARAVIRT_GUEST
487 bool "Paravirtualized guest support"
489 Say Y here to get to see options related to running Linux under
490 various hypervisors. This option alone does not add any kernel code.
492 If you say N, all options in this submenu will be skipped and disabled.
496 source "arch/x86/xen/Kconfig"
499 bool "VMI Guest support"
503 VMI provides a paravirtualized interface to the VMware ESX server
504 (it could be used by other hypervisors in theory too, but is not
505 at the moment), by linking the kernel to a GPL-ed ROM module
506 provided by the hypervisor.
509 bool "KVM paravirtualized clock"
511 select PARAVIRT_CLOCK
513 Turning on this option will allow you to run a paravirtualized clock
514 when running over the KVM hypervisor. Instead of relying on a PIT
515 (or probably other) emulation by the underlying device model, the host
516 provides the guest with timing infrastructure such as time of day, and
520 bool "KVM Guest support"
523 This option enables various optimizations for running under the KVM
526 source "arch/x86/lguest/Kconfig"
529 bool "Enable paravirtualization code"
531 This changes the kernel so it can modify itself when it is run
532 under a hypervisor, potentially improving performance significantly
533 over full virtualization. However, when run without a hypervisor
534 the kernel is theoretically slower and slightly larger.
536 config PARAVIRT_SPINLOCKS
537 bool "Paravirtualization layer for spinlocks"
538 depends on PARAVIRT && SMP && EXPERIMENTAL
540 Paravirtualized spinlocks allow a pvops backend to replace the
541 spinlock implementation with something virtualization-friendly
542 (for example, block the virtual CPU rather than spinning).
544 Unfortunately the downside is an up to 5% performance hit on
545 native kernels, with various workloads.
547 If you are unsure how to answer this question, answer N.
549 config PARAVIRT_CLOCK
555 config PARAVIRT_DEBUG
556 bool "paravirt-ops debugging"
557 depends on PARAVIRT && DEBUG_KERNEL
559 Enable to debug paravirt_ops internals. Specifically, BUG if
560 a paravirt_op is missing when it is called.
565 This option adds a kernel parameter 'memtest', which allows memtest
567 memtest=0, mean disabled; -- default
568 memtest=1, mean do 1 test pattern;
570 memtest=4, mean do 4 test patterns.
571 If you are unsure how to answer this question, answer N.
573 config X86_SUMMIT_NUMA
575 depends on X86_32 && NUMA && X86_32_NON_STANDARD
577 config X86_CYCLONE_TIMER
579 depends on X86_32_NON_STANDARD
581 source "arch/x86/Kconfig.cpu"
585 prompt "HPET Timer Support" if X86_32
587 Use the IA-PC HPET (High Precision Event Timer) to manage
588 time in preference to the PIT and RTC, if a HPET is
590 HPET is the next generation timer replacing legacy 8254s.
591 The HPET provides a stable time base on SMP
592 systems, unlike the TSC, but it is more expensive to access,
593 as it is off-chip. You can find the HPET spec at
594 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
596 You can safely choose Y here. However, HPET will only be
597 activated if the platform and the BIOS support this feature.
598 Otherwise the 8254 will be used for timing services.
600 Choose N to continue using the legacy 8254 timer.
602 config HPET_EMULATE_RTC
604 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
606 # Mark as embedded because too many people got it wrong.
607 # The code disables itself when not needed.
610 bool "Enable DMI scanning" if EMBEDDED
612 Enabled scanning of DMI to identify machine quirks. Say Y
613 here unless you have verified that your setup is not
614 affected by entries in the DMI blacklist. Required by PNP
618 bool "GART IOMMU support" if EMBEDDED
621 depends on X86_64 && PCI
623 Support for full DMA access of devices with 32bit memory access only
624 on systems with more than 3GB. This is usually needed for USB,
625 sound, many IDE/SATA chipsets and some other devices.
626 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
627 based hardware IOMMU and a software bounce buffer based IOMMU used
628 on Intel systems and as fallback.
629 The code is only active when needed (enough memory and limited
630 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
634 bool "IBM Calgary IOMMU support"
636 depends on X86_64 && PCI && EXPERIMENTAL
638 Support for hardware IOMMUs in IBM's xSeries x366 and x460
639 systems. Needed to run systems with more than 3GB of memory
640 properly with 32-bit PCI devices that do not support DAC
641 (Double Address Cycle). Calgary also supports bus level
642 isolation, where all DMAs pass through the IOMMU. This
643 prevents them from going anywhere except their intended
644 destination. This catches hard-to-find kernel bugs and
645 mis-behaving drivers and devices that do not use the DMA-API
646 properly to set up their DMA buffers. The IOMMU can be
647 turned off at boot time with the iommu=off parameter.
648 Normally the kernel will make the right choice by itself.
651 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
653 prompt "Should Calgary be enabled by default?"
654 depends on CALGARY_IOMMU
656 Should Calgary be enabled by default? if you choose 'y', Calgary
657 will be used (if it exists). If you choose 'n', Calgary will not be
658 used even if it exists. If you choose 'n' and would like to use
659 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
663 bool "AMD IOMMU support"
666 depends on X86_64 && PCI && ACPI
668 With this option you can enable support for AMD IOMMU hardware in
669 your system. An IOMMU is a hardware component which provides
670 remapping of DMA memory accesses from devices. With an AMD IOMMU you
671 can isolate the the DMA memory of different devices and protect the
672 system from misbehaving device drivers or hardware.
674 You can find out if your system has an AMD IOMMU if you look into
675 your BIOS for an option to enable it or if you have an IVRS ACPI
678 config AMD_IOMMU_STATS
679 bool "Export AMD IOMMU statistics to debugfs"
683 This option enables code in the AMD IOMMU driver to collect various
684 statistics about whats happening in the driver and exports that
685 information to userspace via debugfs.
688 # need this always selected by IOMMU for the VIA workaround
692 Support for software bounce buffers used on x86-64 systems
693 which don't have a hardware IOMMU (e.g. the current generation
694 of Intel's x86-64 CPUs). Using this PCI devices which can only
695 access 32-bits of memory can be used on systems with more than
696 3 GB of memory. If unsure, say Y.
699 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
702 def_bool (AMD_IOMMU || DMAR)
705 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
706 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
707 select CPUMASK_OFFSTACK
710 Configure maximum number of CPUS and NUMA Nodes for this architecture.
714 int "Maximum number of CPUs" if SMP && !MAXSMP
715 range 2 8 if SMP && X86_32 && !X86_BIGSMP
716 range 2 512 if SMP && !MAXSMP
718 default "4096" if MAXSMP
719 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
722 This allows you to specify the maximum number of CPUs which this
723 kernel will support. The maximum supported value is 512 and the
724 minimum value which makes sense is 2.
726 This is purely to save memory - each supported CPU adds
727 approximately eight kilobytes to the kernel image.
730 bool "SMT (Hyperthreading) scheduler support"
733 SMT scheduler support improves the CPU scheduler's decision making
734 when dealing with Intel Pentium 4 chips with HyperThreading at a
735 cost of slightly increased overhead in some places. If unsure say
740 prompt "Multi-core scheduler support"
743 Multi-core scheduler support improves the CPU scheduler's decision
744 making when dealing with multi-core CPU chips at a cost of slightly
745 increased overhead in some places. If unsure say N here.
747 source "kernel/Kconfig.preempt"
750 bool "Local APIC support on uniprocessors"
751 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
753 A local APIC (Advanced Programmable Interrupt Controller) is an
754 integrated interrupt controller in the CPU. If you have a single-CPU
755 system which has a processor with a local APIC, you can say Y here to
756 enable and use it. If you say Y here even though your machine doesn't
757 have a local APIC, then the kernel will still run with no slowdown at
758 all. The local APIC supports CPU-generated self-interrupts (timer,
759 performance counters), and the NMI watchdog which detects hard
763 bool "IO-APIC support on uniprocessors"
764 depends on X86_UP_APIC
766 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
767 SMP-capable replacement for PC-style interrupt controllers. Most
768 SMP systems and many recent uniprocessor systems have one.
770 If you have a single-CPU system with an IO-APIC, you can say Y here
771 to use it. If you say Y here even though your machine doesn't have
772 an IO-APIC, then the kernel will still run with no slowdown at all.
774 config X86_LOCAL_APIC
776 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
780 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
782 config X86_VISWS_APIC
784 depends on X86_32 && X86_VISWS
786 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
787 bool "Reroute for broken boot IRQs"
789 depends on X86_IO_APIC
791 This option enables a workaround that fixes a source of
792 spurious interrupts. This is recommended when threaded
793 interrupt handling is used on systems where the generation of
794 superfluous "boot interrupts" cannot be disabled.
796 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
797 entry in the chipset's IO-APIC is masked (as, e.g. the RT
798 kernel does during interrupt handling). On chipsets where this
799 boot IRQ generation cannot be disabled, this workaround keeps
800 the original IRQ line masked so that only the equivalent "boot
801 IRQ" is delivered to the CPUs. The workaround also tells the
802 kernel to set up the IRQ handler on the boot IRQ line. In this
803 way only one interrupt is delivered to the kernel. Otherwise
804 the spurious second interrupt may cause the kernel to bring
805 down (vital) interrupt lines.
807 Only affects "broken" chipsets. Interrupt sharing may be
808 increased on these systems.
811 bool "Machine Check / overheating reporting"
813 Machine Check support allows the processor to notify the
814 kernel if it detects a problem (e.g. overheating, data corruption).
815 The action the kernel takes depends on the severity of the problem,
816 ranging from warning messages to halting the machine.
820 prompt "Intel MCE features"
821 depends on X86_MCE && X86_LOCAL_APIC
823 Additional support for intel specific MCE features such as
828 prompt "AMD MCE features"
829 depends on X86_MCE && X86_LOCAL_APIC
831 Additional support for AMD specific MCE features such as
832 the DRAM Error Threshold.
834 config X86_ANCIENT_MCE
836 depends on X86_32 && X86_MCE
837 prompt "Support for old Pentium 5 / WinChip machine checks"
839 Include support for machine check handling on old Pentium 5 or WinChip
840 systems. These typically need to be enabled explicitely on the command
843 config X86_MCE_THRESHOLD
844 depends on X86_MCE_AMD || X86_MCE_INTEL
848 config X86_MCE_INJECT
850 tristate "Machine check injector support"
852 Provide support for injecting machine checks for testing purposes.
853 If you don't know what a machine check is and you don't do kernel
854 QA it is safe to say n.
856 config X86_THERMAL_VECTOR
858 depends on X86_MCE_INTEL
861 bool "Enable VM86 support" if EMBEDDED
865 This option is required by programs like DOSEMU to run 16-bit legacy
866 code on X86 processors. It also may be needed by software like
867 XFree86 to initialize some video cards via BIOS. Disabling this
868 option saves about 6k.
871 tristate "Toshiba Laptop support"
874 This adds a driver to safely access the System Management Mode of
875 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
876 not work on models with a Phoenix BIOS. The System Management Mode
877 is used to set the BIOS and power saving options on Toshiba portables.
879 For information on utilities to make use of this driver see the
880 Toshiba Linux utilities web site at:
881 <http://www.buzzard.org.uk/toshiba/>.
883 Say Y if you intend to run this kernel on a Toshiba portable.
887 tristate "Dell laptop support"
889 This adds a driver to safely access the System Management Mode
890 of the CPU on the Dell Inspiron 8000. The System Management Mode
891 is used to read cpu temperature and cooling fan status and to
892 control the fans on the I8K portables.
894 This driver has been tested only on the Inspiron 8000 but it may
895 also work with other Dell laptops. You can force loading on other
896 models by passing the parameter `force=1' to the module. Use at
899 For information on utilities to make use of this driver see the
900 I8K Linux utilities web site at:
901 <http://people.debian.org/~dz/i8k/>
903 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
906 config X86_REBOOTFIXUPS
907 bool "Enable X86 board specific fixups for reboot"
910 This enables chipset and/or board specific fixups to be done
911 in order to get reboot to work correctly. This is only needed on
912 some combinations of hardware and BIOS. The symptom, for which
913 this config is intended, is when reboot ends with a stalled/hung
916 Currently, the only fixup is for the Geode machines using
917 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
919 Say Y if you want to enable the fixup. Currently, it's safe to
920 enable this option even if you don't need it.
924 tristate "/dev/cpu/microcode - microcode support"
927 If you say Y here, you will be able to update the microcode on
928 certain Intel and AMD processors. The Intel support is for the
929 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
930 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
931 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
932 You will obviously need the actual microcode binary data itself
933 which is not shipped with the Linux kernel.
935 This option selects the general module only, you need to select
936 at least one vendor specific module as well.
938 To compile this driver as a module, choose M here: the
939 module will be called microcode.
941 config MICROCODE_INTEL
942 bool "Intel microcode patch loading support"
947 This options enables microcode patch loading support for Intel
950 For latest news and information on obtaining all the required
951 Intel ingredients for this driver, check:
952 <http://www.urbanmyth.org/microcode/>.
955 bool "AMD microcode patch loading support"
959 If you select this option, microcode patch loading support for AMD
960 processors will be enabled.
962 config MICROCODE_OLD_INTERFACE
967 tristate "/dev/cpu/*/msr - Model-specific register support"
969 This device gives privileged processes access to the x86
970 Model-Specific Registers (MSRs). It is a character device with
971 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
972 MSR accesses are directed to a specific CPU on multi-processor
976 tristate "/dev/cpu/*/cpuid - CPU information support"
978 This device gives processes access to the x86 CPUID instruction to
979 be executed on a specific processor. It is a character device
980 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
984 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
986 If you select this option, this will provide various x86 CPUs
987 information through debugfs.
990 prompt "High Memory Support"
991 default HIGHMEM4G if !X86_NUMAQ
992 default HIGHMEM64G if X86_NUMAQ
997 depends on !X86_NUMAQ
999 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1000 However, the address space of 32-bit x86 processors is only 4
1001 Gigabytes large. That means that, if you have a large amount of
1002 physical memory, not all of it can be "permanently mapped" by the
1003 kernel. The physical memory that's not permanently mapped is called
1006 If you are compiling a kernel which will never run on a machine with
1007 more than 1 Gigabyte total physical RAM, answer "off" here (default
1008 choice and suitable for most users). This will result in a "3GB/1GB"
1009 split: 3GB are mapped so that each process sees a 3GB virtual memory
1010 space and the remaining part of the 4GB virtual memory space is used
1011 by the kernel to permanently map as much physical memory as
1014 If the machine has between 1 and 4 Gigabytes physical RAM, then
1017 If more than 4 Gigabytes is used then answer "64GB" here. This
1018 selection turns Intel PAE (Physical Address Extension) mode on.
1019 PAE implements 3-level paging on IA32 processors. PAE is fully
1020 supported by Linux, PAE mode is implemented on all recent Intel
1021 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1022 then the kernel will not boot on CPUs that don't support PAE!
1024 The actual amount of total physical memory will either be
1025 auto detected or can be forced by using a kernel command line option
1026 such as "mem=256M". (Try "man bootparam" or see the documentation of
1027 your boot loader (lilo or loadlin) about how to pass options to the
1028 kernel at boot time.)
1030 If unsure, say "off".
1034 depends on !X86_NUMAQ
1036 Select this if you have a 32-bit processor and between 1 and 4
1037 gigabytes of physical RAM.
1041 depends on !M386 && !M486
1044 Select this if you have a 32-bit processor and more than 4
1045 gigabytes of physical RAM.
1050 depends on EXPERIMENTAL
1051 prompt "Memory split" if EMBEDDED
1055 Select the desired split between kernel and user memory.
1057 If the address range available to the kernel is less than the
1058 physical memory installed, the remaining memory will be available
1059 as "high memory". Accessing high memory is a little more costly
1060 than low memory, as it needs to be mapped into the kernel first.
1061 Note that increasing the kernel address space limits the range
1062 available to user programs, making the address space there
1063 tighter. Selecting anything other than the default 3G/1G split
1064 will also likely make your kernel incompatible with binary-only
1067 If you are not absolutely sure what you are doing, leave this
1071 bool "3G/1G user/kernel split"
1072 config VMSPLIT_3G_OPT
1074 bool "3G/1G user/kernel split (for full 1G low memory)"
1076 bool "2G/2G user/kernel split"
1077 config VMSPLIT_2G_OPT
1079 bool "2G/2G user/kernel split (for full 2G low memory)"
1081 bool "1G/3G user/kernel split"
1086 default 0xB0000000 if VMSPLIT_3G_OPT
1087 default 0x80000000 if VMSPLIT_2G
1088 default 0x78000000 if VMSPLIT_2G_OPT
1089 default 0x40000000 if VMSPLIT_1G
1095 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1098 bool "PAE (Physical Address Extension) Support"
1099 depends on X86_32 && !HIGHMEM4G
1101 PAE is required for NX support, and furthermore enables
1102 larger swapspace support for non-overcommit purposes. It
1103 has the cost of more pagetable lookup overhead, and also
1104 consumes more pagetable space per process.
1106 config ARCH_PHYS_ADDR_T_64BIT
1107 def_bool X86_64 || X86_PAE
1109 config DIRECT_GBPAGES
1110 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1114 Allow the kernel linear mapping to use 1GB pages on CPUs that
1115 support it. This can improve the kernel's performance a tiny bit by
1116 reducing TLB pressure. If in doubt, say "Y".
1118 # Common NUMA Features
1120 bool "Numa Memory Allocation and Scheduler Support"
1122 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1123 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1125 Enable NUMA (Non Uniform Memory Access) support.
1127 The kernel will try to allocate memory used by a CPU on the
1128 local memory controller of the CPU and add some more
1129 NUMA awareness to the kernel.
1131 For 64-bit this is recommended if the system is Intel Core i7
1132 (or later), AMD Opteron, or EM64T NUMA.
1134 For 32-bit this is only needed on (rare) 32-bit-only platforms
1135 that support NUMA topologies, such as NUMAQ / Summit, or if you
1136 boot a 32-bit kernel on a 64-bit NUMA platform.
1138 Otherwise, you should say N.
1140 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1141 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1145 prompt "Old style AMD Opteron NUMA detection"
1146 depends on X86_64 && NUMA && PCI
1148 Enable K8 NUMA node topology detection. You should say Y here if
1149 you have a multi processor AMD K8 system. This uses an old
1150 method to read the NUMA configuration directly from the builtin
1151 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1152 instead, which also takes priority if both are compiled in.
1154 config X86_64_ACPI_NUMA
1156 prompt "ACPI NUMA detection"
1157 depends on X86_64 && NUMA && ACPI && PCI
1160 Enable ACPI SRAT based node topology detection.
1162 # Some NUMA nodes have memory ranges that span
1163 # other nodes. Even though a pfn is valid and
1164 # between a node's start and end pfns, it may not
1165 # reside on that node. See memmap_init_zone()
1167 config NODES_SPAN_OTHER_NODES
1169 depends on X86_64_ACPI_NUMA
1172 bool "NUMA emulation"
1173 depends on X86_64 && NUMA
1175 Enable NUMA emulation. A flat machine will be split
1176 into virtual nodes when booted with "numa=fake=N", where N is the
1177 number of nodes. This is only useful for debugging.
1180 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1182 default "9" if MAXSMP
1183 default "6" if X86_64
1184 default "4" if X86_NUMAQ
1186 depends on NEED_MULTIPLE_NODES
1188 Specify the maximum number of NUMA Nodes available on the target
1189 system. Increases memory reserved to accommodate various tables.
1191 config HAVE_ARCH_BOOTMEM
1193 depends on X86_32 && NUMA
1195 config ARCH_HAVE_MEMORY_PRESENT
1197 depends on X86_32 && DISCONTIGMEM
1199 config NEED_NODE_MEMMAP_SIZE
1201 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1203 config HAVE_ARCH_ALLOC_REMAP
1205 depends on X86_32 && NUMA
1207 config ARCH_FLATMEM_ENABLE
1209 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1211 config ARCH_DISCONTIGMEM_ENABLE
1213 depends on NUMA && X86_32
1215 config ARCH_DISCONTIGMEM_DEFAULT
1217 depends on NUMA && X86_32
1219 config ARCH_PROC_KCORE_TEXT
1221 depends on X86_64 && PROC_KCORE
1223 config ARCH_SPARSEMEM_DEFAULT
1227 config ARCH_SPARSEMEM_ENABLE
1229 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1230 select SPARSEMEM_STATIC if X86_32
1231 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1233 config ARCH_SELECT_MEMORY_MODEL
1235 depends on ARCH_SPARSEMEM_ENABLE
1237 config ARCH_MEMORY_PROBE
1239 depends on MEMORY_HOTPLUG
1244 bool "Allocate 3rd-level pagetables from highmem"
1245 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1247 The VM uses one page table entry for each page of physical memory.
1248 For systems with a lot of RAM, this can be wasteful of precious
1249 low memory. Setting this option will put user-space page table
1250 entries in high memory.
1252 config X86_CHECK_BIOS_CORRUPTION
1253 bool "Check for low memory corruption"
1255 Periodically check for memory corruption in low memory, which
1256 is suspected to be caused by BIOS. Even when enabled in the
1257 configuration, it is disabled at runtime. Enable it by
1258 setting "memory_corruption_check=1" on the kernel command
1259 line. By default it scans the low 64k of memory every 60
1260 seconds; see the memory_corruption_check_size and
1261 memory_corruption_check_period parameters in
1262 Documentation/kernel-parameters.txt to adjust this.
1264 When enabled with the default parameters, this option has
1265 almost no overhead, as it reserves a relatively small amount
1266 of memory and scans it infrequently. It both detects corruption
1267 and prevents it from affecting the running system.
1269 It is, however, intended as a diagnostic tool; if repeatable
1270 BIOS-originated corruption always affects the same memory,
1271 you can use memmap= to prevent the kernel from using that
1274 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1275 bool "Set the default setting of memory_corruption_check"
1276 depends on X86_CHECK_BIOS_CORRUPTION
1279 Set whether the default state of memory_corruption_check is
1282 config X86_RESERVE_LOW_64K
1283 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1286 Reserve the first 64K of physical RAM on BIOSes that are known
1287 to potentially corrupt that memory range. A numbers of BIOSes are
1288 known to utilize this area during suspend/resume, so it must not
1289 be used by the kernel.
1291 Set this to N if you are absolutely sure that you trust the BIOS
1292 to get all its memory reservations and usages right.
1294 If you have doubts about the BIOS (e.g. suspend/resume does not
1295 work or there's kernel crashes after certain hardware hotplug
1296 events) and it's not AMI or Phoenix, then you might want to enable
1297 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1298 corruption patterns.
1302 config MATH_EMULATION
1304 prompt "Math emulation" if X86_32
1306 Linux can emulate a math coprocessor (used for floating point
1307 operations) if you don't have one. 486DX and Pentium processors have
1308 a math coprocessor built in, 486SX and 386 do not, unless you added
1309 a 487DX or 387, respectively. (The messages during boot time can
1310 give you some hints here ["man dmesg"].) Everyone needs either a
1311 coprocessor or this emulation.
1313 If you don't have a math coprocessor, you need to say Y here; if you
1314 say Y here even though you have a coprocessor, the coprocessor will
1315 be used nevertheless. (This behavior can be changed with the kernel
1316 command line option "no387", which comes handy if your coprocessor
1317 is broken. Try "man bootparam" or see the documentation of your boot
1318 loader (lilo or loadlin) about how to pass options to the kernel at
1319 boot time.) This means that it is a good idea to say Y here if you
1320 intend to use this kernel on different machines.
1322 More information about the internals of the Linux math coprocessor
1323 emulation can be found in <file:arch/x86/math-emu/README>.
1325 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1326 kernel, it won't hurt.
1329 bool "MTRR (Memory Type Range Register) support"
1331 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1332 the Memory Type Range Registers (MTRRs) may be used to control
1333 processor access to memory ranges. This is most useful if you have
1334 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1335 allows bus write transfers to be combined into a larger transfer
1336 before bursting over the PCI/AGP bus. This can increase performance
1337 of image write operations 2.5 times or more. Saying Y here creates a
1338 /proc/mtrr file which may be used to manipulate your processor's
1339 MTRRs. Typically the X server should use this.
1341 This code has a reasonably generic interface so that similar
1342 control registers on other processors can be easily supported
1345 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1346 Registers (ARRs) which provide a similar functionality to MTRRs. For
1347 these, the ARRs are used to emulate the MTRRs.
1348 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1349 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1350 write-combining. All of these processors are supported by this code
1351 and it makes sense to say Y here if you have one of them.
1353 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1354 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1355 can lead to all sorts of problems, so it's good to say Y here.
1357 You can safely say Y even if your machine doesn't have MTRRs, you'll
1358 just add about 9 KB to your kernel.
1360 See <file:Documentation/x86/mtrr.txt> for more information.
1362 config MTRR_SANITIZER
1364 prompt "MTRR cleanup support"
1367 Convert MTRR layout from continuous to discrete, so X drivers can
1368 add writeback entries.
1370 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1371 The largest mtrr entry size for a continuous block can be set with
1376 config MTRR_SANITIZER_ENABLE_DEFAULT
1377 int "MTRR cleanup enable value (0-1)"
1380 depends on MTRR_SANITIZER
1382 Enable mtrr cleanup default value
1384 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1385 int "MTRR cleanup spare reg num (0-7)"
1388 depends on MTRR_SANITIZER
1390 mtrr cleanup spare entries default, it can be changed via
1391 mtrr_spare_reg_nr=N on the kernel command line.
1395 prompt "x86 PAT support"
1398 Use PAT attributes to setup page level cache control.
1400 PATs are the modern equivalents of MTRRs and are much more
1401 flexible than MTRRs.
1403 Say N here if you see bootup problems (boot crash, boot hang,
1404 spontaneous reboots) or a non-working video driver.
1408 config ARCH_USES_PG_UNCACHED
1413 bool "EFI runtime service support"
1416 This enables the kernel to use EFI runtime services that are
1417 available (such as the EFI variable services).
1419 This option is only useful on systems that have EFI firmware.
1420 In addition, you should use the latest ELILO loader available
1421 at <http://elilo.sourceforge.net> in order to take advantage
1422 of EFI runtime services. However, even with this option, the
1423 resultant kernel should continue to boot on existing non-EFI
1428 prompt "Enable seccomp to safely compute untrusted bytecode"
1430 This kernel feature is useful for number crunching applications
1431 that may need to compute untrusted bytecode during their
1432 execution. By using pipes or other transports made available to
1433 the process as file descriptors supporting the read/write
1434 syscalls, it's possible to isolate those applications in
1435 their own address space using seccomp. Once seccomp is
1436 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1437 and the task is only allowed to execute a few safe syscalls
1438 defined by each seccomp mode.
1440 If unsure, say Y. Only embedded should say N here.
1442 config CC_STACKPROTECTOR_ALL
1445 config CC_STACKPROTECTOR
1446 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1447 select CC_STACKPROTECTOR_ALL
1449 This option turns on the -fstack-protector GCC feature. This
1450 feature puts, at the beginning of functions, a canary value on
1451 the stack just before the return address, and validates
1452 the value just before actually returning. Stack based buffer
1453 overflows (that need to overwrite this return address) now also
1454 overwrite the canary, which gets detected and the attack is then
1455 neutralized via a kernel panic.
1457 This feature requires gcc version 4.2 or above, or a distribution
1458 gcc with the feature backported. Older versions are automatically
1459 detected and for those versions, this configuration option is
1460 ignored. (and a warning is printed during bootup)
1462 source kernel/Kconfig.hz
1465 bool "kexec system call"
1467 kexec is a system call that implements the ability to shutdown your
1468 current kernel, and to start another kernel. It is like a reboot
1469 but it is independent of the system firmware. And like a reboot
1470 you can start any kernel with it, not just Linux.
1472 The name comes from the similarity to the exec system call.
1474 It is an ongoing process to be certain the hardware in a machine
1475 is properly shutdown, so do not be surprised if this code does not
1476 initially work for you. It may help to enable device hotplugging
1477 support. As of this writing the exact hardware interface is
1478 strongly in flux, so no good recommendation can be made.
1481 bool "kernel crash dumps"
1482 depends on X86_64 || (X86_32 && HIGHMEM)
1484 Generate crash dump after being started by kexec.
1485 This should be normally only set in special crash dump kernels
1486 which are loaded in the main kernel with kexec-tools into
1487 a specially reserved region and then later executed after
1488 a crash by kdump/kexec. The crash dump kernel must be compiled
1489 to a memory address not used by the main kernel or BIOS using
1490 PHYSICAL_START, or it must be built as a relocatable image
1491 (CONFIG_RELOCATABLE=y).
1492 For more details see Documentation/kdump/kdump.txt
1495 bool "kexec jump (EXPERIMENTAL)"
1496 depends on EXPERIMENTAL
1497 depends on KEXEC && HIBERNATION
1499 Jump between original kernel and kexeced kernel and invoke
1500 code in physical address mode via KEXEC
1502 config PHYSICAL_START
1503 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1506 This gives the physical address where the kernel is loaded.
1508 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1509 bzImage will decompress itself to above physical address and
1510 run from there. Otherwise, bzImage will run from the address where
1511 it has been loaded by the boot loader and will ignore above physical
1514 In normal kdump cases one does not have to set/change this option
1515 as now bzImage can be compiled as a completely relocatable image
1516 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1517 address. This option is mainly useful for the folks who don't want
1518 to use a bzImage for capturing the crash dump and want to use a
1519 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1520 to be specifically compiled to run from a specific memory area
1521 (normally a reserved region) and this option comes handy.
1523 So if you are using bzImage for capturing the crash dump,
1524 leave the value here unchanged to 0x1000000 and set
1525 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1526 for capturing the crash dump change this value to start of
1527 the reserved region. In other words, it can be set based on
1528 the "X" value as specified in the "crashkernel=YM@XM"
1529 command line boot parameter passed to the panic-ed
1530 kernel. Please take a look at Documentation/kdump/kdump.txt
1531 for more details about crash dumps.
1533 Usage of bzImage for capturing the crash dump is recommended as
1534 one does not have to build two kernels. Same kernel can be used
1535 as production kernel and capture kernel. Above option should have
1536 gone away after relocatable bzImage support is introduced. But it
1537 is present because there are users out there who continue to use
1538 vmlinux for dump capture. This option should go away down the
1541 Don't change this unless you know what you are doing.
1544 bool "Build a relocatable kernel"
1547 This builds a kernel image that retains relocation information
1548 so it can be loaded someplace besides the default 1MB.
1549 The relocations tend to make the kernel binary about 10% larger,
1550 but are discarded at runtime.
1552 One use is for the kexec on panic case where the recovery kernel
1553 must live at a different physical address than the primary
1556 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1557 it has been loaded at and the compile time physical address
1558 (CONFIG_PHYSICAL_START) is ignored.
1560 # Relocation on x86-32 needs some additional build support
1561 config X86_NEED_RELOCS
1563 depends on X86_32 && RELOCATABLE
1565 config PHYSICAL_ALIGN
1567 prompt "Alignment value to which kernel should be aligned" if X86_32
1569 range 0x2000 0x1000000
1571 This value puts the alignment restrictions on physical address
1572 where kernel is loaded and run from. Kernel is compiled for an
1573 address which meets above alignment restriction.
1575 If bootloader loads the kernel at a non-aligned address and
1576 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1577 address aligned to above value and run from there.
1579 If bootloader loads the kernel at a non-aligned address and
1580 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1581 load address and decompress itself to the address it has been
1582 compiled for and run from there. The address for which kernel is
1583 compiled already meets above alignment restrictions. Hence the
1584 end result is that kernel runs from a physical address meeting
1585 above alignment restrictions.
1587 Don't change this unless you know what you are doing.
1590 bool "Support for hot-pluggable CPUs"
1591 depends on SMP && HOTPLUG
1593 Say Y here to allow turning CPUs off and on. CPUs can be
1594 controlled through /sys/devices/system/cpu.
1595 ( Note: power management support will enable this option
1596 automatically on SMP systems. )
1597 Say N if you want to disable CPU hotplug.
1601 prompt "Compat VDSO support"
1602 depends on X86_32 || IA32_EMULATION
1604 Map the 32-bit VDSO to the predictable old-style address too.
1606 Say N here if you are running a sufficiently recent glibc
1607 version (2.3.3 or later), to remove the high-mapped
1608 VDSO mapping and to exclusively use the randomized VDSO.
1613 bool "Built-in kernel command line"
1616 Allow for specifying boot arguments to the kernel at
1617 build time. On some systems (e.g. embedded ones), it is
1618 necessary or convenient to provide some or all of the
1619 kernel boot arguments with the kernel itself (that is,
1620 to not rely on the boot loader to provide them.)
1622 To compile command line arguments into the kernel,
1623 set this option to 'Y', then fill in the
1624 the boot arguments in CONFIG_CMDLINE.
1626 Systems with fully functional boot loaders (i.e. non-embedded)
1627 should leave this option set to 'N'.
1630 string "Built-in kernel command string"
1631 depends on CMDLINE_BOOL
1634 Enter arguments here that should be compiled into the kernel
1635 image and used at boot time. If the boot loader provides a
1636 command line at boot time, it is appended to this string to
1637 form the full kernel command line, when the system boots.
1639 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1640 change this behavior.
1642 In most cases, the command line (whether built-in or provided
1643 by the boot loader) should specify the device for the root
1646 config CMDLINE_OVERRIDE
1647 bool "Built-in command line overrides boot loader arguments"
1649 depends on CMDLINE_BOOL
1651 Set this option to 'Y' to have the kernel ignore the boot loader
1652 command line, and use ONLY the built-in command line.
1654 This is used to work around broken boot loaders. This should
1655 be set to 'N' under normal conditions.
1659 config ARCH_ENABLE_MEMORY_HOTPLUG
1661 depends on X86_64 || (X86_32 && HIGHMEM)
1663 config ARCH_ENABLE_MEMORY_HOTREMOVE
1665 depends on MEMORY_HOTPLUG
1667 config HAVE_ARCH_EARLY_PFN_TO_NID
1671 menu "Power management and ACPI options"
1673 config ARCH_HIBERNATION_HEADER
1675 depends on X86_64 && HIBERNATION
1677 source "kernel/power/Kconfig"
1679 source "drivers/acpi/Kconfig"
1681 source "drivers/sfi/Kconfig"
1686 depends on APM || APM_MODULE
1689 tristate "APM (Advanced Power Management) BIOS support"
1690 depends on X86_32 && PM_SLEEP
1692 APM is a BIOS specification for saving power using several different
1693 techniques. This is mostly useful for battery powered laptops with
1694 APM compliant BIOSes. If you say Y here, the system time will be
1695 reset after a RESUME operation, the /proc/apm device will provide
1696 battery status information, and user-space programs will receive
1697 notification of APM "events" (e.g. battery status change).
1699 If you select "Y" here, you can disable actual use of the APM
1700 BIOS by passing the "apm=off" option to the kernel at boot time.
1702 Note that the APM support is almost completely disabled for
1703 machines with more than one CPU.
1705 In order to use APM, you will need supporting software. For location
1706 and more information, read <file:Documentation/power/pm.txt> and the
1707 Battery Powered Linux mini-HOWTO, available from
1708 <http://www.tldp.org/docs.html#howto>.
1710 This driver does not spin down disk drives (see the hdparm(8)
1711 manpage ("man 8 hdparm") for that), and it doesn't turn off
1712 VESA-compliant "green" monitors.
1714 This driver does not support the TI 4000M TravelMate and the ACER
1715 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1716 desktop machines also don't have compliant BIOSes, and this driver
1717 may cause those machines to panic during the boot phase.
1719 Generally, if you don't have a battery in your machine, there isn't
1720 much point in using this driver and you should say N. If you get
1721 random kernel OOPSes or reboots that don't seem to be related to
1722 anything, try disabling/enabling this option (or disabling/enabling
1725 Some other things you should try when experiencing seemingly random,
1728 1) make sure that you have enough swap space and that it is
1730 2) pass the "no-hlt" option to the kernel
1731 3) switch on floating point emulation in the kernel and pass
1732 the "no387" option to the kernel
1733 4) pass the "floppy=nodma" option to the kernel
1734 5) pass the "mem=4M" option to the kernel (thereby disabling
1735 all but the first 4 MB of RAM)
1736 6) make sure that the CPU is not over clocked.
1737 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1738 8) disable the cache from your BIOS settings
1739 9) install a fan for the video card or exchange video RAM
1740 10) install a better fan for the CPU
1741 11) exchange RAM chips
1742 12) exchange the motherboard.
1744 To compile this driver as a module, choose M here: the
1745 module will be called apm.
1749 config APM_IGNORE_USER_SUSPEND
1750 bool "Ignore USER SUSPEND"
1752 This option will ignore USER SUSPEND requests. On machines with a
1753 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1754 series notebooks, it is necessary to say Y because of a BIOS bug.
1756 config APM_DO_ENABLE
1757 bool "Enable PM at boot time"
1759 Enable APM features at boot time. From page 36 of the APM BIOS
1760 specification: "When disabled, the APM BIOS does not automatically
1761 power manage devices, enter the Standby State, enter the Suspend
1762 State, or take power saving steps in response to CPU Idle calls."
1763 This driver will make CPU Idle calls when Linux is idle (unless this
1764 feature is turned off -- see "Do CPU IDLE calls", below). This
1765 should always save battery power, but more complicated APM features
1766 will be dependent on your BIOS implementation. You may need to turn
1767 this option off if your computer hangs at boot time when using APM
1768 support, or if it beeps continuously instead of suspending. Turn
1769 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1770 T400CDT. This is off by default since most machines do fine without
1774 bool "Make CPU Idle calls when idle"
1776 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1777 On some machines, this can activate improved power savings, such as
1778 a slowed CPU clock rate, when the machine is idle. These idle calls
1779 are made after the idle loop has run for some length of time (e.g.,
1780 333 mS). On some machines, this will cause a hang at boot time or
1781 whenever the CPU becomes idle. (On machines with more than one CPU,
1782 this option does nothing.)
1784 config APM_DISPLAY_BLANK
1785 bool "Enable console blanking using APM"
1787 Enable console blanking using the APM. Some laptops can use this to
1788 turn off the LCD backlight when the screen blanker of the Linux
1789 virtual console blanks the screen. Note that this is only used by
1790 the virtual console screen blanker, and won't turn off the backlight
1791 when using the X Window system. This also doesn't have anything to
1792 do with your VESA-compliant power-saving monitor. Further, this
1793 option doesn't work for all laptops -- it might not turn off your
1794 backlight at all, or it might print a lot of errors to the console,
1795 especially if you are using gpm.
1797 config APM_ALLOW_INTS
1798 bool "Allow interrupts during APM BIOS calls"
1800 Normally we disable external interrupts while we are making calls to
1801 the APM BIOS as a measure to lessen the effects of a badly behaving
1802 BIOS implementation. The BIOS should reenable interrupts if it
1803 needs to. Unfortunately, some BIOSes do not -- especially those in
1804 many of the newer IBM Thinkpads. If you experience hangs when you
1805 suspend, try setting this to Y. Otherwise, say N.
1809 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1811 source "drivers/cpuidle/Kconfig"
1813 source "drivers/idle/Kconfig"
1818 menu "Bus options (PCI etc.)"
1823 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1825 Find out whether you have a PCI motherboard. PCI is the name of a
1826 bus system, i.e. the way the CPU talks to the other stuff inside
1827 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1828 VESA. If you have PCI, say Y, otherwise N.
1831 prompt "PCI access mode"
1832 depends on X86_32 && PCI
1835 On PCI systems, the BIOS can be used to detect the PCI devices and
1836 determine their configuration. However, some old PCI motherboards
1837 have BIOS bugs and may crash if this is done. Also, some embedded
1838 PCI-based systems don't have any BIOS at all. Linux can also try to
1839 detect the PCI hardware directly without using the BIOS.
1841 With this option, you can specify how Linux should detect the
1842 PCI devices. If you choose "BIOS", the BIOS will be used,
1843 if you choose "Direct", the BIOS won't be used, and if you
1844 choose "MMConfig", then PCI Express MMCONFIG will be used.
1845 If you choose "Any", the kernel will try MMCONFIG, then the
1846 direct access method and falls back to the BIOS if that doesn't
1847 work. If unsure, go with the default, which is "Any".
1852 config PCI_GOMMCONFIG
1869 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1871 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1874 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1878 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1882 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1889 bool "Support mmconfig PCI config space access"
1890 depends on X86_64 && PCI && ACPI
1893 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1894 depends on PCI_MSI && ACPI && EXPERIMENTAL
1896 DMA remapping (DMAR) devices support enables independent address
1897 translations for Direct Memory Access (DMA) from devices.
1898 These DMA remapping devices are reported via ACPI tables
1899 and include PCI device scope covered by these DMA
1902 config DMAR_DEFAULT_ON
1904 prompt "Enable DMA Remapping Devices by default"
1907 Selecting this option will enable a DMAR device at boot time if
1908 one is found. If this option is not selected, DMAR support can
1909 be enabled by passing intel_iommu=on to the kernel. It is
1910 recommended you say N here while the DMAR code remains
1913 config DMAR_BROKEN_GFX_WA
1915 prompt "Workaround broken graphics drivers (going away soon)"
1916 depends on DMAR && BROKEN
1918 Current Graphics drivers tend to use physical address
1919 for DMA and avoid using DMA APIs. Setting this config
1920 option permits the IOMMU driver to set a unity map for
1921 all the OS-visible memory. Hence the driver can continue
1922 to use physical addresses for DMA, at least until this
1923 option is removed in the 2.6.32 kernel.
1925 config DMAR_FLOPPY_WA
1929 Floppy disk drivers are known to bypass DMA API calls
1930 thereby failing to work when IOMMU is enabled. This
1931 workaround will setup a 1:1 mapping for the first
1932 16MiB to make floppy (an ISA device) work.
1935 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1936 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1938 Supports Interrupt remapping for IO-APIC and MSI devices.
1939 To use x2apic mode in the CPU's which support x2APIC enhancements or
1940 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1942 source "drivers/pci/pcie/Kconfig"
1944 source "drivers/pci/Kconfig"
1946 # x86_64 have no ISA slots, but do have ISA-style DMA.
1955 Find out whether you have ISA slots on your motherboard. ISA is the
1956 name of a bus system, i.e. the way the CPU talks to the other stuff
1957 inside your box. Other bus systems are PCI, EISA, MicroChannel
1958 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1959 newer boards don't support it. If you have ISA, say Y, otherwise N.
1965 The Extended Industry Standard Architecture (EISA) bus was
1966 developed as an open alternative to the IBM MicroChannel bus.
1968 The EISA bus provided some of the features of the IBM MicroChannel
1969 bus while maintaining backward compatibility with cards made for
1970 the older ISA bus. The EISA bus saw limited use between 1988 and
1971 1995 when it was made obsolete by the PCI bus.
1973 Say Y here if you are building a kernel for an EISA-based machine.
1977 source "drivers/eisa/Kconfig"
1982 MicroChannel Architecture is found in some IBM PS/2 machines and
1983 laptops. It is a bus system similar to PCI or ISA. See
1984 <file:Documentation/mca.txt> (and especially the web page given
1985 there) before attempting to build an MCA bus kernel.
1987 source "drivers/mca/Kconfig"
1990 tristate "NatSemi SCx200 support"
1992 This provides basic support for National Semiconductor's
1993 (now AMD's) Geode processors. The driver probes for the
1994 PCI-IDs of several on-chip devices, so its a good dependency
1995 for other scx200_* drivers.
1997 If compiled as a module, the driver is named scx200.
1999 config SCx200HR_TIMER
2000 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2001 depends on SCx200 && GENERIC_TIME
2004 This driver provides a clocksource built upon the on-chip
2005 27MHz high-resolution timer. Its also a workaround for
2006 NSC Geode SC-1100's buggy TSC, which loses time when the
2007 processor goes idle (as is done by the scheduler). The
2008 other workaround is idle=poll boot option.
2010 config GEODE_MFGPT_TIMER
2012 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2013 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2015 This driver provides a clock event source based on the MFGPT
2016 timer(s) in the CS5535 and CS5536 companion chip for the geode.
2017 MFGPTs have a better resolution and max interval than the
2018 generic PIT, and are suitable for use as high-res timers.
2021 bool "One Laptop Per Child support"
2024 Add support for detecting the unique features of the OLPC
2031 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2033 source "drivers/pcmcia/Kconfig"
2035 source "drivers/pci/hotplug/Kconfig"
2040 menu "Executable file formats / Emulations"
2042 source "fs/Kconfig.binfmt"
2044 config IA32_EMULATION
2045 bool "IA32 Emulation"
2047 select COMPAT_BINFMT_ELF
2049 Include code to run 32-bit programs under a 64-bit kernel. You should
2050 likely turn this on, unless you're 100% sure that you don't have any
2051 32-bit programs left.
2054 tristate "IA32 a.out support"
2055 depends on IA32_EMULATION
2057 Support old a.out binaries in the 32bit emulation.
2061 depends on IA32_EMULATION
2063 config COMPAT_FOR_U64_ALIGNMENT
2067 config SYSVIPC_COMPAT
2069 depends on COMPAT && SYSVIPC
2074 config HAVE_ATOMIC_IOMAP
2078 source "net/Kconfig"
2080 source "drivers/Kconfig"
2082 source "drivers/firmware/Kconfig"
2086 source "arch/x86/Kconfig.debug"
2088 source "security/Kconfig"
2090 source "crypto/Kconfig"
2092 source "arch/x86/kvm/Kconfig"
2094 source "lib/Kconfig"