3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select HAVE_AOUT if X86_32
21 select HAVE_UNSTABLE_SCHED_CLOCK
24 select HAVE_PERF_EVENTS if (!M386 && !M486)
26 select HAVE_IOREMAP_PROT
29 select ARCH_WANT_OPTIONAL_GPIOLIB
30 select ARCH_WANT_FRAME_POINTERS
32 select HAVE_KRETPROBES
34 select HAVE_FTRACE_MCOUNT_RECORD
35 select HAVE_C_RECORDMCOUNT
36 select HAVE_DYNAMIC_FTRACE
37 select HAVE_FUNCTION_TRACER
38 select HAVE_FUNCTION_GRAPH_TRACER
39 select HAVE_FUNCTION_GRAPH_FP_TEST
40 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
41 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
42 select HAVE_SYSCALL_TRACEPOINTS
45 select HAVE_ARCH_TRACEHOOK
46 select HAVE_GENERIC_DMA_COHERENT if X86_32
47 select HAVE_EFFICIENT_UNALIGNED_ACCESS
48 select USER_STACKTRACE_SUPPORT
49 select HAVE_REGS_AND_STACK_ACCESS_API
50 select HAVE_DMA_API_DEBUG
51 select HAVE_KERNEL_GZIP
52 select HAVE_KERNEL_BZIP2
53 select HAVE_KERNEL_LZMA
54 select HAVE_KERNEL_LZO
55 select HAVE_HW_BREAKPOINT
56 select HAVE_MIXED_BREAKPOINTS_REGS
58 select HAVE_PERF_EVENTS_NMI
60 select HAVE_ARCH_KMEMCHECK
61 select HAVE_USER_RETURN_NOTIFIER
62 select HAVE_ARCH_JUMP_LABEL
63 select HAVE_TEXT_POKE_SMP
64 select HAVE_GENERIC_HARDIRQS
65 select HAVE_SPARSE_IRQ
66 select GENERIC_IRQ_PROBE
67 select GENERIC_PENDING_IRQ if SMP
69 config INSTRUCTION_DECODER
70 def_bool (KPROBES || PERF_EVENTS)
74 default "elf32-i386" if X86_32
75 default "elf64-x86-64" if X86_64
79 default "arch/x86/configs/i386_defconfig" if X86_32
80 default "arch/x86/configs/x86_64_defconfig" if X86_64
82 config GENERIC_CMOS_UPDATE
85 config CLOCKSOURCE_WATCHDOG
88 config GENERIC_CLOCKEVENTS
91 config GENERIC_CLOCKEVENTS_BROADCAST
93 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
95 config LOCKDEP_SUPPORT
98 config STACKTRACE_SUPPORT
101 config HAVE_LATENCYTOP_SUPPORT
113 config NEED_DMA_MAP_STATE
114 def_bool (X86_64 || DMAR || DMA_API_DEBUG)
116 config NEED_SG_DMA_LENGTH
119 config GENERIC_ISA_DMA
128 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
130 config GENERIC_BUG_RELATIVE_POINTERS
133 config GENERIC_HWEIGHT
139 config ARCH_MAY_HAVE_PC_FDC
142 config RWSEM_GENERIC_SPINLOCK
145 config RWSEM_XCHGADD_ALGORITHM
148 config ARCH_HAS_CPU_IDLE_WAIT
151 config GENERIC_CALIBRATE_DELAY
154 config GENERIC_TIME_VSYSCALL
158 config ARCH_HAS_CPU_RELAX
161 config ARCH_HAS_DEFAULT_IDLE
164 config ARCH_HAS_CACHE_LINE_SIZE
167 config HAVE_SETUP_PER_CPU_AREA
170 config NEED_PER_CPU_EMBED_FIRST_CHUNK
173 config NEED_PER_CPU_PAGE_FIRST_CHUNK
176 config HAVE_CPUMASK_OF_CPU_MAP
179 config ARCH_HIBERNATION_POSSIBLE
182 config ARCH_SUSPEND_POSSIBLE
189 config ARCH_POPULATES_NODE_MAP
196 config ARCH_SUPPORTS_OPTIMIZED_INLINING
199 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
202 config HAVE_INTEL_TXT
204 depends on EXPERIMENTAL && DMAR && ACPI
206 config USE_GENERIC_SMP_HELPERS
212 depends on X86_32 && SMP
216 depends on X86_64 && SMP
222 config X86_TRAMPOLINE
224 depends on SMP || (64BIT && ACPI_SLEEP)
226 config X86_32_LAZY_GS
228 depends on X86_32 && !CC_STACKPROTECTOR
230 config ARCH_HWEIGHT_CFLAGS
232 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
233 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
238 config ARCH_CPU_PROBE_RELEASE
240 depends on HOTPLUG_CPU
242 source "init/Kconfig"
243 source "kernel/Kconfig.freezer"
245 menu "Processor type and features"
247 source "kernel/time/Kconfig"
250 bool "Symmetric multi-processing support"
252 This enables support for systems with more than one CPU. If you have
253 a system with only one CPU, like most personal computers, say N. If
254 you have a system with more than one CPU, say Y.
256 If you say N here, the kernel will run on single and multiprocessor
257 machines, but will use only one CPU of a multiprocessor machine. If
258 you say Y here, the kernel will run on many, but not all,
259 singleprocessor machines. On a singleprocessor machine, the kernel
260 will run faster if you say N here.
262 Note that if you say Y here and choose architecture "586" or
263 "Pentium" under "Processor family", the kernel will not work on 486
264 architectures. Similarly, multiprocessor kernels for the "PPro"
265 architecture may not work on all Pentium based boards.
267 People using multiprocessor machines who say Y here should also say
268 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
269 Management" code will be disabled if you say Y here.
271 See also <file:Documentation/i386/IO-APIC.txt>,
272 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
273 <http://www.tldp.org/docs.html#howto>.
275 If you don't know what to do here, say N.
278 bool "Support x2apic"
279 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
281 This enables x2apic support on CPUs that have this feature.
283 This allows 32-bit apic IDs (so it can support very large systems),
284 and accesses the local apic via MSRs not via mmio.
286 If you don't know what to do here, say N.
289 bool "Enable MPS table" if ACPI
291 depends on X86_LOCAL_APIC
293 For old smp systems that do not have proper acpi support. Newer systems
294 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
297 bool "Support for big SMP systems with more than 8 CPUs"
298 depends on X86_32 && SMP
300 This option is needed for the systems that have more than 8 CPUs
303 config X86_EXTENDED_PLATFORM
304 bool "Support for extended (non-PC) x86 platforms"
307 If you disable this option then the kernel will only support
308 standard PC platforms. (which covers the vast majority of
311 If you enable this option then you'll be able to select support
312 for the following (non-PC) 32 bit x86 platforms:
316 SGI 320/540 (Visual Workstation)
317 Summit/EXA (IBM x440)
318 Unisys ES7000 IA32 series
319 Moorestown MID devices
321 If you have one of these systems, or if you want to build a
322 generic distribution kernel, say Y here - otherwise say N.
326 config X86_EXTENDED_PLATFORM
327 bool "Support for extended (non-PC) x86 platforms"
330 If you disable this option then the kernel will only support
331 standard PC platforms. (which covers the vast majority of
334 If you enable this option then you'll be able to select support
335 for the following (non-PC) 64 bit x86 platforms:
339 If you have one of these systems, or if you want to build a
340 generic distribution kernel, say Y here - otherwise say N.
342 # This is an alphabetically sorted list of 64 bit extended platforms
343 # Please maintain the alphabetic order if and when there are additions
347 select PARAVIRT_GUEST
349 depends on X86_64 && PCI
350 depends on X86_EXTENDED_PLATFORM
352 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
353 supposed to run on these EM64T-based machines. Only choose this option
354 if you have one of these machines.
357 bool "SGI Ultraviolet"
359 depends on X86_EXTENDED_PLATFORM
361 depends on X86_X2APIC
363 This option is needed in order to support SGI Ultraviolet systems.
364 If you don't have one of these, you should say N here.
366 # Following is an alphabetically sorted list of 32 bit extended platforms
367 # Please maintain the alphabetic order if and when there are additions
372 depends on X86_EXTENDED_PLATFORM
374 Select this for an AMD Elan processor.
376 Do not use this option for K6/Athlon/Opteron processors!
378 If unsure, choose "PC-compatible" instead.
381 bool "CE4100 TV platform"
383 depends on PCI_GODIRECT
385 depends on X86_EXTENDED_PLATFORM
386 select X86_REBOOTFIXUPS
388 Select for the Intel CE media processor (CE4100) SOC.
389 This option compiles in support for the CE4100 SOC for settop
390 boxes and media devices.
393 bool "Moorestown MID platform"
397 depends on X86_EXTENDED_PLATFORM
398 depends on X86_IO_APIC
403 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
404 Internet Device(MID) platform. Moorestown consists of two chips:
405 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
406 Unlike standard x86 PCs, Moorestown does not have many legacy devices
407 nor standard legacy replacement devices/features. e.g. Moorestown does
408 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
411 bool "RDC R-321x SoC"
413 depends on X86_EXTENDED_PLATFORM
415 select X86_REBOOTFIXUPS
417 This option is needed for RDC R-321x system-on-chip, also known
419 If you don't have one of these chips, you should say N here.
421 config X86_32_NON_STANDARD
422 bool "Support non-standard 32-bit SMP architectures"
423 depends on X86_32 && SMP
424 depends on X86_EXTENDED_PLATFORM
426 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
427 subarchitectures. It is intended for a generic binary kernel.
428 if you select them all, kernel will probe it one by one. and will
431 # Alphabetically sorted list of Non standard 32 bit platforms
434 bool "NUMAQ (IBM/Sequent)"
435 depends on X86_32_NON_STANDARD
440 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
441 NUMA multiquad box. This changes the way that processors are
442 bootstrapped, and uses Clustered Logical APIC addressing mode instead
443 of Flat Logical. You will need a new lynxer.elf file to flash your
444 firmware with - send email to <Martin.Bligh@us.ibm.com>.
446 config X86_SUPPORTS_MEMORY_FAILURE
448 # MCE code calls memory_failure():
450 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
451 depends on !X86_NUMAQ
452 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
453 depends on X86_64 || !SPARSEMEM
454 select ARCH_SUPPORTS_MEMORY_FAILURE
457 bool "SGI 320/540 (Visual Workstation)"
458 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
459 depends on X86_32_NON_STANDARD
461 The SGI Visual Workstation series is an IA32-based workstation
462 based on SGI systems chips with some legacy PC hardware attached.
464 Say Y here to create a kernel to run on the SGI 320 or 540.
466 A kernel compiled for the Visual Workstation will run on general
467 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
470 bool "Summit/EXA (IBM x440)"
471 depends on X86_32_NON_STANDARD
473 This option is needed for IBM systems that use the Summit/EXA chipset.
474 In particular, it is needed for the x440.
477 bool "Unisys ES7000 IA32 series"
478 depends on X86_32_NON_STANDARD && X86_BIGSMP
480 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
481 supposed to run on an IA32-based Unisys ES7000 system.
483 config SCHED_OMIT_FRAME_POINTER
485 prompt "Single-depth WCHAN output"
488 Calculate simpler /proc/<PID>/wchan values. If this option
489 is disabled then wchan values will recurse back to the
490 caller function. This provides more accurate wchan values,
491 at the expense of slightly more scheduling overhead.
493 If in doubt, say "Y".
495 menuconfig PARAVIRT_GUEST
496 bool "Paravirtualized guest support"
498 Say Y here to get to see options related to running Linux under
499 various hypervisors. This option alone does not add any kernel code.
501 If you say N, all options in this submenu will be skipped and disabled.
505 source "arch/x86/xen/Kconfig"
508 bool "KVM paravirtualized clock"
510 select PARAVIRT_CLOCK
512 Turning on this option will allow you to run a paravirtualized clock
513 when running over the KVM hypervisor. Instead of relying on a PIT
514 (or probably other) emulation by the underlying device model, the host
515 provides the guest with timing infrastructure such as time of day, and
519 bool "KVM Guest support"
522 This option enables various optimizations for running under the KVM
525 source "arch/x86/lguest/Kconfig"
528 bool "Enable paravirtualization code"
530 This changes the kernel so it can modify itself when it is run
531 under a hypervisor, potentially improving performance significantly
532 over full virtualization. However, when run without a hypervisor
533 the kernel is theoretically slower and slightly larger.
535 config PARAVIRT_SPINLOCKS
536 bool "Paravirtualization layer for spinlocks"
537 depends on PARAVIRT && SMP && EXPERIMENTAL
539 Paravirtualized spinlocks allow a pvops backend to replace the
540 spinlock implementation with something virtualization-friendly
541 (for example, block the virtual CPU rather than spinning).
543 Unfortunately the downside is an up to 5% performance hit on
544 native kernels, with various workloads.
546 If you are unsure how to answer this question, answer N.
548 config PARAVIRT_CLOCK
553 config PARAVIRT_DEBUG
554 bool "paravirt-ops debugging"
555 depends on PARAVIRT && DEBUG_KERNEL
557 Enable to debug paravirt_ops internals. Specifically, BUG if
558 a paravirt_op is missing when it is called.
566 This option adds a kernel parameter 'memtest', which allows memtest
568 memtest=0, mean disabled; -- default
569 memtest=1, mean do 1 test pattern;
571 memtest=4, mean do 4 test patterns.
572 If you are unsure how to answer this question, answer N.
574 config X86_SUMMIT_NUMA
576 depends on X86_32 && NUMA && X86_32_NON_STANDARD
578 config X86_CYCLONE_TIMER
580 depends on X86_32_NON_STANDARD
582 source "arch/x86/Kconfig.cpu"
586 prompt "HPET Timer Support" if X86_32
588 Use the IA-PC HPET (High Precision Event Timer) to manage
589 time in preference to the PIT and RTC, if a HPET is
591 HPET is the next generation timer replacing legacy 8254s.
592 The HPET provides a stable time base on SMP
593 systems, unlike the TSC, but it is more expensive to access,
594 as it is off-chip. You can find the HPET spec at
595 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
597 You can safely choose Y here. However, HPET will only be
598 activated if the platform and the BIOS support this feature.
599 Otherwise the 8254 will be used for timing services.
601 Choose N to continue using the legacy 8254 timer.
603 config HPET_EMULATE_RTC
605 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
609 prompt "Langwell APB Timer Support" if X86_MRST
611 APB timer is the replacement for 8254, HPET on X86 MID platforms.
612 The APBT provides a stable time base on SMP
613 systems, unlike the TSC, but it is more expensive to access,
614 as it is off-chip. APB timers are always running regardless of CPU
615 C states, they are used as per CPU clockevent device when possible.
617 # Mark as embedded because too many people got it wrong.
618 # The code disables itself when not needed.
621 bool "Enable DMI scanning" if EMBEDDED
623 Enabled scanning of DMI to identify machine quirks. Say Y
624 here unless you have verified that your setup is not
625 affected by entries in the DMI blacklist. Required by PNP
629 bool "GART IOMMU support" if EMBEDDED
632 depends on X86_64 && PCI && AMD_NB
634 Support for full DMA access of devices with 32bit memory access only
635 on systems with more than 3GB. This is usually needed for USB,
636 sound, many IDE/SATA chipsets and some other devices.
637 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
638 based hardware IOMMU and a software bounce buffer based IOMMU used
639 on Intel systems and as fallback.
640 The code is only active when needed (enough memory and limited
641 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
645 bool "IBM Calgary IOMMU support"
647 depends on X86_64 && PCI && EXPERIMENTAL
649 Support for hardware IOMMUs in IBM's xSeries x366 and x460
650 systems. Needed to run systems with more than 3GB of memory
651 properly with 32-bit PCI devices that do not support DAC
652 (Double Address Cycle). Calgary also supports bus level
653 isolation, where all DMAs pass through the IOMMU. This
654 prevents them from going anywhere except their intended
655 destination. This catches hard-to-find kernel bugs and
656 mis-behaving drivers and devices that do not use the DMA-API
657 properly to set up their DMA buffers. The IOMMU can be
658 turned off at boot time with the iommu=off parameter.
659 Normally the kernel will make the right choice by itself.
662 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
664 prompt "Should Calgary be enabled by default?"
665 depends on CALGARY_IOMMU
667 Should Calgary be enabled by default? if you choose 'y', Calgary
668 will be used (if it exists). If you choose 'n', Calgary will not be
669 used even if it exists. If you choose 'n' and would like to use
670 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
674 bool "AMD IOMMU support"
677 depends on X86_64 && PCI && ACPI
679 With this option you can enable support for AMD IOMMU hardware in
680 your system. An IOMMU is a hardware component which provides
681 remapping of DMA memory accesses from devices. With an AMD IOMMU you
682 can isolate the the DMA memory of different devices and protect the
683 system from misbehaving device drivers or hardware.
685 You can find out if your system has an AMD IOMMU if you look into
686 your BIOS for an option to enable it or if you have an IVRS ACPI
689 config AMD_IOMMU_STATS
690 bool "Export AMD IOMMU statistics to debugfs"
694 This option enables code in the AMD IOMMU driver to collect various
695 statistics about whats happening in the driver and exports that
696 information to userspace via debugfs.
699 # need this always selected by IOMMU for the VIA workaround
703 Support for software bounce buffers used on x86-64 systems
704 which don't have a hardware IOMMU (e.g. the current generation
705 of Intel's x86-64 CPUs). Using this PCI devices which can only
706 access 32-bits of memory can be used on systems with more than
707 3 GB of memory. If unsure, say Y.
710 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
713 def_bool (AMD_IOMMU || DMAR)
716 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
717 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
718 select CPUMASK_OFFSTACK
720 Enable maximum number of CPUS and NUMA Nodes for this architecture.
724 int "Maximum number of CPUs" if SMP && !MAXSMP
725 range 2 8 if SMP && X86_32 && !X86_BIGSMP
726 range 2 512 if SMP && !MAXSMP
728 default "4096" if MAXSMP
729 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
732 This allows you to specify the maximum number of CPUs which this
733 kernel will support. The maximum supported value is 512 and the
734 minimum value which makes sense is 2.
736 This is purely to save memory - each supported CPU adds
737 approximately eight kilobytes to the kernel image.
740 bool "SMT (Hyperthreading) scheduler support"
743 SMT scheduler support improves the CPU scheduler's decision making
744 when dealing with Intel Pentium 4 chips with HyperThreading at a
745 cost of slightly increased overhead in some places. If unsure say
750 prompt "Multi-core scheduler support"
753 Multi-core scheduler support improves the CPU scheduler's decision
754 making when dealing with multi-core CPU chips at a cost of slightly
755 increased overhead in some places. If unsure say N here.
757 config IRQ_TIME_ACCOUNTING
758 bool "Fine granularity task level IRQ time accounting"
761 Select this option to enable fine granularity task irq time
762 accounting. This is done by reading a timestamp on each
763 transitions between softirq and hardirq state, so there can be a
764 small performance impact.
766 If in doubt, say N here.
768 source "kernel/Kconfig.preempt"
771 bool "Local APIC support on uniprocessors"
772 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
774 A local APIC (Advanced Programmable Interrupt Controller) is an
775 integrated interrupt controller in the CPU. If you have a single-CPU
776 system which has a processor with a local APIC, you can say Y here to
777 enable and use it. If you say Y here even though your machine doesn't
778 have a local APIC, then the kernel will still run with no slowdown at
779 all. The local APIC supports CPU-generated self-interrupts (timer,
780 performance counters), and the NMI watchdog which detects hard
784 bool "IO-APIC support on uniprocessors"
785 depends on X86_UP_APIC
787 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
788 SMP-capable replacement for PC-style interrupt controllers. Most
789 SMP systems and many recent uniprocessor systems have one.
791 If you have a single-CPU system with an IO-APIC, you can say Y here
792 to use it. If you say Y here even though your machine doesn't have
793 an IO-APIC, then the kernel will still run with no slowdown at all.
795 config X86_LOCAL_APIC
797 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
801 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
803 config X86_VISWS_APIC
805 depends on X86_32 && X86_VISWS
807 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
808 bool "Reroute for broken boot IRQs"
809 depends on X86_IO_APIC
811 This option enables a workaround that fixes a source of
812 spurious interrupts. This is recommended when threaded
813 interrupt handling is used on systems where the generation of
814 superfluous "boot interrupts" cannot be disabled.
816 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
817 entry in the chipset's IO-APIC is masked (as, e.g. the RT
818 kernel does during interrupt handling). On chipsets where this
819 boot IRQ generation cannot be disabled, this workaround keeps
820 the original IRQ line masked so that only the equivalent "boot
821 IRQ" is delivered to the CPUs. The workaround also tells the
822 kernel to set up the IRQ handler on the boot IRQ line. In this
823 way only one interrupt is delivered to the kernel. Otherwise
824 the spurious second interrupt may cause the kernel to bring
825 down (vital) interrupt lines.
827 Only affects "broken" chipsets. Interrupt sharing may be
828 increased on these systems.
831 bool "Machine Check / overheating reporting"
833 Machine Check support allows the processor to notify the
834 kernel if it detects a problem (e.g. overheating, data corruption).
835 The action the kernel takes depends on the severity of the problem,
836 ranging from warning messages to halting the machine.
840 prompt "Intel MCE features"
841 depends on X86_MCE && X86_LOCAL_APIC
843 Additional support for intel specific MCE features such as
848 prompt "AMD MCE features"
849 depends on X86_MCE && X86_LOCAL_APIC
851 Additional support for AMD specific MCE features such as
852 the DRAM Error Threshold.
854 config X86_ANCIENT_MCE
855 bool "Support for old Pentium 5 / WinChip machine checks"
856 depends on X86_32 && X86_MCE
858 Include support for machine check handling on old Pentium 5 or WinChip
859 systems. These typically need to be enabled explicitely on the command
862 config X86_MCE_THRESHOLD
863 depends on X86_MCE_AMD || X86_MCE_INTEL
866 config X86_MCE_INJECT
868 tristate "Machine check injector support"
870 Provide support for injecting machine checks for testing purposes.
871 If you don't know what a machine check is and you don't do kernel
872 QA it is safe to say n.
874 config X86_THERMAL_VECTOR
876 depends on X86_MCE_INTEL
879 bool "Enable VM86 support" if EMBEDDED
883 This option is required by programs like DOSEMU to run 16-bit legacy
884 code on X86 processors. It also may be needed by software like
885 XFree86 to initialize some video cards via BIOS. Disabling this
886 option saves about 6k.
889 tristate "Toshiba Laptop support"
892 This adds a driver to safely access the System Management Mode of
893 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
894 not work on models with a Phoenix BIOS. The System Management Mode
895 is used to set the BIOS and power saving options on Toshiba portables.
897 For information on utilities to make use of this driver see the
898 Toshiba Linux utilities web site at:
899 <http://www.buzzard.org.uk/toshiba/>.
901 Say Y if you intend to run this kernel on a Toshiba portable.
905 tristate "Dell laptop support"
907 This adds a driver to safely access the System Management Mode
908 of the CPU on the Dell Inspiron 8000. The System Management Mode
909 is used to read cpu temperature and cooling fan status and to
910 control the fans on the I8K portables.
912 This driver has been tested only on the Inspiron 8000 but it may
913 also work with other Dell laptops. You can force loading on other
914 models by passing the parameter `force=1' to the module. Use at
917 For information on utilities to make use of this driver see the
918 I8K Linux utilities web site at:
919 <http://people.debian.org/~dz/i8k/>
921 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
924 config X86_REBOOTFIXUPS
925 bool "Enable X86 board specific fixups for reboot"
928 This enables chipset and/or board specific fixups to be done
929 in order to get reboot to work correctly. This is only needed on
930 some combinations of hardware and BIOS. The symptom, for which
931 this config is intended, is when reboot ends with a stalled/hung
934 Currently, the only fixup is for the Geode machines using
935 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
937 Say Y if you want to enable the fixup. Currently, it's safe to
938 enable this option even if you don't need it.
942 tristate "/dev/cpu/microcode - microcode support"
945 If you say Y here, you will be able to update the microcode on
946 certain Intel and AMD processors. The Intel support is for the
947 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
948 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
949 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
950 You will obviously need the actual microcode binary data itself
951 which is not shipped with the Linux kernel.
953 This option selects the general module only, you need to select
954 at least one vendor specific module as well.
956 To compile this driver as a module, choose M here: the
957 module will be called microcode.
959 config MICROCODE_INTEL
960 bool "Intel microcode patch loading support"
965 This options enables microcode patch loading support for Intel
968 For latest news and information on obtaining all the required
969 Intel ingredients for this driver, check:
970 <http://www.urbanmyth.org/microcode/>.
973 bool "AMD microcode patch loading support"
977 If you select this option, microcode patch loading support for AMD
978 processors will be enabled.
980 config MICROCODE_OLD_INTERFACE
985 tristate "/dev/cpu/*/msr - Model-specific register support"
987 This device gives privileged processes access to the x86
988 Model-Specific Registers (MSRs). It is a character device with
989 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
990 MSR accesses are directed to a specific CPU on multi-processor
994 tristate "/dev/cpu/*/cpuid - CPU information support"
996 This device gives processes access to the x86 CPUID instruction to
997 be executed on a specific processor. It is a character device
998 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1002 prompt "High Memory Support"
1003 default HIGHMEM64G if X86_NUMAQ
1009 depends on !X86_NUMAQ
1011 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1012 However, the address space of 32-bit x86 processors is only 4
1013 Gigabytes large. That means that, if you have a large amount of
1014 physical memory, not all of it can be "permanently mapped" by the
1015 kernel. The physical memory that's not permanently mapped is called
1018 If you are compiling a kernel which will never run on a machine with
1019 more than 1 Gigabyte total physical RAM, answer "off" here (default
1020 choice and suitable for most users). This will result in a "3GB/1GB"
1021 split: 3GB are mapped so that each process sees a 3GB virtual memory
1022 space and the remaining part of the 4GB virtual memory space is used
1023 by the kernel to permanently map as much physical memory as
1026 If the machine has between 1 and 4 Gigabytes physical RAM, then
1029 If more than 4 Gigabytes is used then answer "64GB" here. This
1030 selection turns Intel PAE (Physical Address Extension) mode on.
1031 PAE implements 3-level paging on IA32 processors. PAE is fully
1032 supported by Linux, PAE mode is implemented on all recent Intel
1033 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1034 then the kernel will not boot on CPUs that don't support PAE!
1036 The actual amount of total physical memory will either be
1037 auto detected or can be forced by using a kernel command line option
1038 such as "mem=256M". (Try "man bootparam" or see the documentation of
1039 your boot loader (lilo or loadlin) about how to pass options to the
1040 kernel at boot time.)
1042 If unsure, say "off".
1046 depends on !X86_NUMAQ
1048 Select this if you have a 32-bit processor and between 1 and 4
1049 gigabytes of physical RAM.
1053 depends on !M386 && !M486
1056 Select this if you have a 32-bit processor and more than 4
1057 gigabytes of physical RAM.
1062 depends on EXPERIMENTAL
1063 prompt "Memory split" if EMBEDDED
1067 Select the desired split between kernel and user memory.
1069 If the address range available to the kernel is less than the
1070 physical memory installed, the remaining memory will be available
1071 as "high memory". Accessing high memory is a little more costly
1072 than low memory, as it needs to be mapped into the kernel first.
1073 Note that increasing the kernel address space limits the range
1074 available to user programs, making the address space there
1075 tighter. Selecting anything other than the default 3G/1G split
1076 will also likely make your kernel incompatible with binary-only
1079 If you are not absolutely sure what you are doing, leave this
1083 bool "3G/1G user/kernel split"
1084 config VMSPLIT_3G_OPT
1086 bool "3G/1G user/kernel split (for full 1G low memory)"
1088 bool "2G/2G user/kernel split"
1089 config VMSPLIT_2G_OPT
1091 bool "2G/2G user/kernel split (for full 2G low memory)"
1093 bool "1G/3G user/kernel split"
1098 default 0xB0000000 if VMSPLIT_3G_OPT
1099 default 0x80000000 if VMSPLIT_2G
1100 default 0x78000000 if VMSPLIT_2G_OPT
1101 default 0x40000000 if VMSPLIT_1G
1107 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1110 bool "PAE (Physical Address Extension) Support"
1111 depends on X86_32 && !HIGHMEM4G
1113 PAE is required for NX support, and furthermore enables
1114 larger swapspace support for non-overcommit purposes. It
1115 has the cost of more pagetable lookup overhead, and also
1116 consumes more pagetable space per process.
1118 config ARCH_PHYS_ADDR_T_64BIT
1119 def_bool X86_64 || X86_PAE
1121 config ARCH_DMA_ADDR_T_64BIT
1122 def_bool X86_64 || HIGHMEM64G
1124 config DIRECT_GBPAGES
1125 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1129 Allow the kernel linear mapping to use 1GB pages on CPUs that
1130 support it. This can improve the kernel's performance a tiny bit by
1131 reducing TLB pressure. If in doubt, say "Y".
1133 # Common NUMA Features
1135 bool "Numa Memory Allocation and Scheduler Support"
1137 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1138 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1140 Enable NUMA (Non Uniform Memory Access) support.
1142 The kernel will try to allocate memory used by a CPU on the
1143 local memory controller of the CPU and add some more
1144 NUMA awareness to the kernel.
1146 For 64-bit this is recommended if the system is Intel Core i7
1147 (or later), AMD Opteron, or EM64T NUMA.
1149 For 32-bit this is only needed on (rare) 32-bit-only platforms
1150 that support NUMA topologies, such as NUMAQ / Summit, or if you
1151 boot a 32-bit kernel on a 64-bit NUMA platform.
1153 Otherwise, you should say N.
1155 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1156 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1160 prompt "Old style AMD Opteron NUMA detection"
1161 depends on X86_64 && NUMA && PCI
1163 Enable K8 NUMA node topology detection. You should say Y here if
1164 you have a multi processor AMD K8 system. This uses an old
1165 method to read the NUMA configuration directly from the builtin
1166 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1167 instead, which also takes priority if both are compiled in.
1169 config X86_64_ACPI_NUMA
1171 prompt "ACPI NUMA detection"
1172 depends on X86_64 && NUMA && ACPI && PCI
1175 Enable ACPI SRAT based node topology detection.
1177 # Some NUMA nodes have memory ranges that span
1178 # other nodes. Even though a pfn is valid and
1179 # between a node's start and end pfns, it may not
1180 # reside on that node. See memmap_init_zone()
1182 config NODES_SPAN_OTHER_NODES
1184 depends on X86_64_ACPI_NUMA
1187 bool "NUMA emulation"
1188 depends on X86_64 && NUMA
1190 Enable NUMA emulation. A flat machine will be split
1191 into virtual nodes when booted with "numa=fake=N", where N is the
1192 number of nodes. This is only useful for debugging.
1195 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1197 default "10" if MAXSMP
1198 default "6" if X86_64
1199 default "4" if X86_NUMAQ
1201 depends on NEED_MULTIPLE_NODES
1203 Specify the maximum number of NUMA Nodes available on the target
1204 system. Increases memory reserved to accommodate various tables.
1206 config HAVE_ARCH_BOOTMEM
1208 depends on X86_32 && NUMA
1210 config ARCH_HAVE_MEMORY_PRESENT
1212 depends on X86_32 && DISCONTIGMEM
1214 config NEED_NODE_MEMMAP_SIZE
1216 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1218 config HAVE_ARCH_ALLOC_REMAP
1220 depends on X86_32 && NUMA
1222 config ARCH_FLATMEM_ENABLE
1224 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1226 config ARCH_DISCONTIGMEM_ENABLE
1228 depends on NUMA && X86_32
1230 config ARCH_DISCONTIGMEM_DEFAULT
1232 depends on NUMA && X86_32
1234 config ARCH_PROC_KCORE_TEXT
1236 depends on X86_64 && PROC_KCORE
1238 config ARCH_SPARSEMEM_DEFAULT
1242 config ARCH_SPARSEMEM_ENABLE
1244 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1245 select SPARSEMEM_STATIC if X86_32
1246 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1248 config ARCH_SELECT_MEMORY_MODEL
1250 depends on ARCH_SPARSEMEM_ENABLE
1252 config ARCH_MEMORY_PROBE
1254 depends on MEMORY_HOTPLUG
1256 config ILLEGAL_POINTER_VALUE
1259 default 0xdead000000000000 if X86_64
1264 bool "Allocate 3rd-level pagetables from highmem"
1267 The VM uses one page table entry for each page of physical memory.
1268 For systems with a lot of RAM, this can be wasteful of precious
1269 low memory. Setting this option will put user-space page table
1270 entries in high memory.
1272 config X86_CHECK_BIOS_CORRUPTION
1273 bool "Check for low memory corruption"
1275 Periodically check for memory corruption in low memory, which
1276 is suspected to be caused by BIOS. Even when enabled in the
1277 configuration, it is disabled at runtime. Enable it by
1278 setting "memory_corruption_check=1" on the kernel command
1279 line. By default it scans the low 64k of memory every 60
1280 seconds; see the memory_corruption_check_size and
1281 memory_corruption_check_period parameters in
1282 Documentation/kernel-parameters.txt to adjust this.
1284 When enabled with the default parameters, this option has
1285 almost no overhead, as it reserves a relatively small amount
1286 of memory and scans it infrequently. It both detects corruption
1287 and prevents it from affecting the running system.
1289 It is, however, intended as a diagnostic tool; if repeatable
1290 BIOS-originated corruption always affects the same memory,
1291 you can use memmap= to prevent the kernel from using that
1294 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1295 bool "Set the default setting of memory_corruption_check"
1296 depends on X86_CHECK_BIOS_CORRUPTION
1299 Set whether the default state of memory_corruption_check is
1302 config X86_RESERVE_LOW
1303 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1307 Specify the amount of low memory to reserve for the BIOS.
1309 The first page contains BIOS data structures that the kernel
1310 must not use, so that page must always be reserved.
1312 By default we reserve the first 64K of physical RAM, as a
1313 number of BIOSes are known to corrupt that memory range
1314 during events such as suspend/resume or monitor cable
1315 insertion, so it must not be used by the kernel.
1317 You can set this to 4 if you are absolutely sure that you
1318 trust the BIOS to get all its memory reservations and usages
1319 right. If you know your BIOS have problems beyond the
1320 default 64K area, you can set this to 640 to avoid using the
1321 entire low memory range.
1323 If you have doubts about the BIOS (e.g. suspend/resume does
1324 not work or there's kernel crashes after certain hardware
1325 hotplug events) then you might want to enable
1326 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1327 typical corruption patterns.
1329 Leave this to the default value of 64 if you are unsure.
1331 config MATH_EMULATION
1333 prompt "Math emulation" if X86_32
1335 Linux can emulate a math coprocessor (used for floating point
1336 operations) if you don't have one. 486DX and Pentium processors have
1337 a math coprocessor built in, 486SX and 386 do not, unless you added
1338 a 487DX or 387, respectively. (The messages during boot time can
1339 give you some hints here ["man dmesg"].) Everyone needs either a
1340 coprocessor or this emulation.
1342 If you don't have a math coprocessor, you need to say Y here; if you
1343 say Y here even though you have a coprocessor, the coprocessor will
1344 be used nevertheless. (This behavior can be changed with the kernel
1345 command line option "no387", which comes handy if your coprocessor
1346 is broken. Try "man bootparam" or see the documentation of your boot
1347 loader (lilo or loadlin) about how to pass options to the kernel at
1348 boot time.) This means that it is a good idea to say Y here if you
1349 intend to use this kernel on different machines.
1351 More information about the internals of the Linux math coprocessor
1352 emulation can be found in <file:arch/x86/math-emu/README>.
1354 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1355 kernel, it won't hurt.
1359 prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1361 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1362 the Memory Type Range Registers (MTRRs) may be used to control
1363 processor access to memory ranges. This is most useful if you have
1364 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1365 allows bus write transfers to be combined into a larger transfer
1366 before bursting over the PCI/AGP bus. This can increase performance
1367 of image write operations 2.5 times or more. Saying Y here creates a
1368 /proc/mtrr file which may be used to manipulate your processor's
1369 MTRRs. Typically the X server should use this.
1371 This code has a reasonably generic interface so that similar
1372 control registers on other processors can be easily supported
1375 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1376 Registers (ARRs) which provide a similar functionality to MTRRs. For
1377 these, the ARRs are used to emulate the MTRRs.
1378 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1379 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1380 write-combining. All of these processors are supported by this code
1381 and it makes sense to say Y here if you have one of them.
1383 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1384 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1385 can lead to all sorts of problems, so it's good to say Y here.
1387 You can safely say Y even if your machine doesn't have MTRRs, you'll
1388 just add about 9 KB to your kernel.
1390 See <file:Documentation/x86/mtrr.txt> for more information.
1392 config MTRR_SANITIZER
1394 prompt "MTRR cleanup support"
1397 Convert MTRR layout from continuous to discrete, so X drivers can
1398 add writeback entries.
1400 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1401 The largest mtrr entry size for a continuous block can be set with
1406 config MTRR_SANITIZER_ENABLE_DEFAULT
1407 int "MTRR cleanup enable value (0-1)"
1410 depends on MTRR_SANITIZER
1412 Enable mtrr cleanup default value
1414 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1415 int "MTRR cleanup spare reg num (0-7)"
1418 depends on MTRR_SANITIZER
1420 mtrr cleanup spare entries default, it can be changed via
1421 mtrr_spare_reg_nr=N on the kernel command line.
1425 prompt "x86 PAT support" if EMBEDDED
1428 Use PAT attributes to setup page level cache control.
1430 PATs are the modern equivalents of MTRRs and are much more
1431 flexible than MTRRs.
1433 Say N here if you see bootup problems (boot crash, boot hang,
1434 spontaneous reboots) or a non-working video driver.
1438 config ARCH_USES_PG_UNCACHED
1443 bool "EFI runtime service support"
1446 This enables the kernel to use EFI runtime services that are
1447 available (such as the EFI variable services).
1449 This option is only useful on systems that have EFI firmware.
1450 In addition, you should use the latest ELILO loader available
1451 at <http://elilo.sourceforge.net> in order to take advantage
1452 of EFI runtime services. However, even with this option, the
1453 resultant kernel should continue to boot on existing non-EFI
1458 prompt "Enable seccomp to safely compute untrusted bytecode"
1460 This kernel feature is useful for number crunching applications
1461 that may need to compute untrusted bytecode during their
1462 execution. By using pipes or other transports made available to
1463 the process as file descriptors supporting the read/write
1464 syscalls, it's possible to isolate those applications in
1465 their own address space using seccomp. Once seccomp is
1466 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1467 and the task is only allowed to execute a few safe syscalls
1468 defined by each seccomp mode.
1470 If unsure, say Y. Only embedded should say N here.
1472 config CC_STACKPROTECTOR
1473 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1475 This option turns on the -fstack-protector GCC feature. This
1476 feature puts, at the beginning of functions, a canary value on
1477 the stack just before the return address, and validates
1478 the value just before actually returning. Stack based buffer
1479 overflows (that need to overwrite this return address) now also
1480 overwrite the canary, which gets detected and the attack is then
1481 neutralized via a kernel panic.
1483 This feature requires gcc version 4.2 or above, or a distribution
1484 gcc with the feature backported. Older versions are automatically
1485 detected and for those versions, this configuration option is
1486 ignored. (and a warning is printed during bootup)
1488 source kernel/Kconfig.hz
1491 bool "kexec system call"
1493 kexec is a system call that implements the ability to shutdown your
1494 current kernel, and to start another kernel. It is like a reboot
1495 but it is independent of the system firmware. And like a reboot
1496 you can start any kernel with it, not just Linux.
1498 The name comes from the similarity to the exec system call.
1500 It is an ongoing process to be certain the hardware in a machine
1501 is properly shutdown, so do not be surprised if this code does not
1502 initially work for you. It may help to enable device hotplugging
1503 support. As of this writing the exact hardware interface is
1504 strongly in flux, so no good recommendation can be made.
1507 bool "kernel crash dumps"
1508 depends on X86_64 || (X86_32 && HIGHMEM)
1510 Generate crash dump after being started by kexec.
1511 This should be normally only set in special crash dump kernels
1512 which are loaded in the main kernel with kexec-tools into
1513 a specially reserved region and then later executed after
1514 a crash by kdump/kexec. The crash dump kernel must be compiled
1515 to a memory address not used by the main kernel or BIOS using
1516 PHYSICAL_START, or it must be built as a relocatable image
1517 (CONFIG_RELOCATABLE=y).
1518 For more details see Documentation/kdump/kdump.txt
1521 bool "kexec jump (EXPERIMENTAL)"
1522 depends on EXPERIMENTAL
1523 depends on KEXEC && HIBERNATION
1525 Jump between original kernel and kexeced kernel and invoke
1526 code in physical address mode via KEXEC
1528 config PHYSICAL_START
1529 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1532 This gives the physical address where the kernel is loaded.
1534 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1535 bzImage will decompress itself to above physical address and
1536 run from there. Otherwise, bzImage will run from the address where
1537 it has been loaded by the boot loader and will ignore above physical
1540 In normal kdump cases one does not have to set/change this option
1541 as now bzImage can be compiled as a completely relocatable image
1542 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1543 address. This option is mainly useful for the folks who don't want
1544 to use a bzImage for capturing the crash dump and want to use a
1545 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1546 to be specifically compiled to run from a specific memory area
1547 (normally a reserved region) and this option comes handy.
1549 So if you are using bzImage for capturing the crash dump,
1550 leave the value here unchanged to 0x1000000 and set
1551 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1552 for capturing the crash dump change this value to start of
1553 the reserved region. In other words, it can be set based on
1554 the "X" value as specified in the "crashkernel=YM@XM"
1555 command line boot parameter passed to the panic-ed
1556 kernel. Please take a look at Documentation/kdump/kdump.txt
1557 for more details about crash dumps.
1559 Usage of bzImage for capturing the crash dump is recommended as
1560 one does not have to build two kernels. Same kernel can be used
1561 as production kernel and capture kernel. Above option should have
1562 gone away after relocatable bzImage support is introduced. But it
1563 is present because there are users out there who continue to use
1564 vmlinux for dump capture. This option should go away down the
1567 Don't change this unless you know what you are doing.
1570 bool "Build a relocatable kernel"
1573 This builds a kernel image that retains relocation information
1574 so it can be loaded someplace besides the default 1MB.
1575 The relocations tend to make the kernel binary about 10% larger,
1576 but are discarded at runtime.
1578 One use is for the kexec on panic case where the recovery kernel
1579 must live at a different physical address than the primary
1582 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1583 it has been loaded at and the compile time physical address
1584 (CONFIG_PHYSICAL_START) is ignored.
1586 # Relocation on x86-32 needs some additional build support
1587 config X86_NEED_RELOCS
1589 depends on X86_32 && RELOCATABLE
1591 config PHYSICAL_ALIGN
1592 hex "Alignment value to which kernel should be aligned" if X86_32
1594 range 0x2000 0x1000000
1596 This value puts the alignment restrictions on physical address
1597 where kernel is loaded and run from. Kernel is compiled for an
1598 address which meets above alignment restriction.
1600 If bootloader loads the kernel at a non-aligned address and
1601 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1602 address aligned to above value and run from there.
1604 If bootloader loads the kernel at a non-aligned address and
1605 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1606 load address and decompress itself to the address it has been
1607 compiled for and run from there. The address for which kernel is
1608 compiled already meets above alignment restrictions. Hence the
1609 end result is that kernel runs from a physical address meeting
1610 above alignment restrictions.
1612 Don't change this unless you know what you are doing.
1615 bool "Support for hot-pluggable CPUs"
1616 depends on SMP && HOTPLUG
1618 Say Y here to allow turning CPUs off and on. CPUs can be
1619 controlled through /sys/devices/system/cpu.
1620 ( Note: power management support will enable this option
1621 automatically on SMP systems. )
1622 Say N if you want to disable CPU hotplug.
1626 prompt "Compat VDSO support"
1627 depends on X86_32 || IA32_EMULATION
1629 Map the 32-bit VDSO to the predictable old-style address too.
1631 Say N here if you are running a sufficiently recent glibc
1632 version (2.3.3 or later), to remove the high-mapped
1633 VDSO mapping and to exclusively use the randomized VDSO.
1638 bool "Built-in kernel command line"
1640 Allow for specifying boot arguments to the kernel at
1641 build time. On some systems (e.g. embedded ones), it is
1642 necessary or convenient to provide some or all of the
1643 kernel boot arguments with the kernel itself (that is,
1644 to not rely on the boot loader to provide them.)
1646 To compile command line arguments into the kernel,
1647 set this option to 'Y', then fill in the
1648 the boot arguments in CONFIG_CMDLINE.
1650 Systems with fully functional boot loaders (i.e. non-embedded)
1651 should leave this option set to 'N'.
1654 string "Built-in kernel command string"
1655 depends on CMDLINE_BOOL
1658 Enter arguments here that should be compiled into the kernel
1659 image and used at boot time. If the boot loader provides a
1660 command line at boot time, it is appended to this string to
1661 form the full kernel command line, when the system boots.
1663 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1664 change this behavior.
1666 In most cases, the command line (whether built-in or provided
1667 by the boot loader) should specify the device for the root
1670 config CMDLINE_OVERRIDE
1671 bool "Built-in command line overrides boot loader arguments"
1672 depends on CMDLINE_BOOL
1674 Set this option to 'Y' to have the kernel ignore the boot loader
1675 command line, and use ONLY the built-in command line.
1677 This is used to work around broken boot loaders. This should
1678 be set to 'N' under normal conditions.
1682 config ARCH_ENABLE_MEMORY_HOTPLUG
1684 depends on X86_64 || (X86_32 && HIGHMEM)
1686 config ARCH_ENABLE_MEMORY_HOTREMOVE
1688 depends on MEMORY_HOTPLUG
1690 config HAVE_ARCH_EARLY_PFN_TO_NID
1694 config USE_PERCPU_NUMA_NODE_ID
1698 menu "Power management and ACPI options"
1700 config ARCH_HIBERNATION_HEADER
1702 depends on X86_64 && HIBERNATION
1704 source "kernel/power/Kconfig"
1706 source "drivers/acpi/Kconfig"
1708 source "drivers/sfi/Kconfig"
1712 depends on APM || APM_MODULE
1715 tristate "APM (Advanced Power Management) BIOS support"
1716 depends on X86_32 && PM_SLEEP
1718 APM is a BIOS specification for saving power using several different
1719 techniques. This is mostly useful for battery powered laptops with
1720 APM compliant BIOSes. If you say Y here, the system time will be
1721 reset after a RESUME operation, the /proc/apm device will provide
1722 battery status information, and user-space programs will receive
1723 notification of APM "events" (e.g. battery status change).
1725 If you select "Y" here, you can disable actual use of the APM
1726 BIOS by passing the "apm=off" option to the kernel at boot time.
1728 Note that the APM support is almost completely disabled for
1729 machines with more than one CPU.
1731 In order to use APM, you will need supporting software. For location
1732 and more information, read <file:Documentation/power/pm.txt> and the
1733 Battery Powered Linux mini-HOWTO, available from
1734 <http://www.tldp.org/docs.html#howto>.
1736 This driver does not spin down disk drives (see the hdparm(8)
1737 manpage ("man 8 hdparm") for that), and it doesn't turn off
1738 VESA-compliant "green" monitors.
1740 This driver does not support the TI 4000M TravelMate and the ACER
1741 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1742 desktop machines also don't have compliant BIOSes, and this driver
1743 may cause those machines to panic during the boot phase.
1745 Generally, if you don't have a battery in your machine, there isn't
1746 much point in using this driver and you should say N. If you get
1747 random kernel OOPSes or reboots that don't seem to be related to
1748 anything, try disabling/enabling this option (or disabling/enabling
1751 Some other things you should try when experiencing seemingly random,
1754 1) make sure that you have enough swap space and that it is
1756 2) pass the "no-hlt" option to the kernel
1757 3) switch on floating point emulation in the kernel and pass
1758 the "no387" option to the kernel
1759 4) pass the "floppy=nodma" option to the kernel
1760 5) pass the "mem=4M" option to the kernel (thereby disabling
1761 all but the first 4 MB of RAM)
1762 6) make sure that the CPU is not over clocked.
1763 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1764 8) disable the cache from your BIOS settings
1765 9) install a fan for the video card or exchange video RAM
1766 10) install a better fan for the CPU
1767 11) exchange RAM chips
1768 12) exchange the motherboard.
1770 To compile this driver as a module, choose M here: the
1771 module will be called apm.
1775 config APM_IGNORE_USER_SUSPEND
1776 bool "Ignore USER SUSPEND"
1778 This option will ignore USER SUSPEND requests. On machines with a
1779 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1780 series notebooks, it is necessary to say Y because of a BIOS bug.
1782 config APM_DO_ENABLE
1783 bool "Enable PM at boot time"
1785 Enable APM features at boot time. From page 36 of the APM BIOS
1786 specification: "When disabled, the APM BIOS does not automatically
1787 power manage devices, enter the Standby State, enter the Suspend
1788 State, or take power saving steps in response to CPU Idle calls."
1789 This driver will make CPU Idle calls when Linux is idle (unless this
1790 feature is turned off -- see "Do CPU IDLE calls", below). This
1791 should always save battery power, but more complicated APM features
1792 will be dependent on your BIOS implementation. You may need to turn
1793 this option off if your computer hangs at boot time when using APM
1794 support, or if it beeps continuously instead of suspending. Turn
1795 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1796 T400CDT. This is off by default since most machines do fine without
1800 bool "Make CPU Idle calls when idle"
1802 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1803 On some machines, this can activate improved power savings, such as
1804 a slowed CPU clock rate, when the machine is idle. These idle calls
1805 are made after the idle loop has run for some length of time (e.g.,
1806 333 mS). On some machines, this will cause a hang at boot time or
1807 whenever the CPU becomes idle. (On machines with more than one CPU,
1808 this option does nothing.)
1810 config APM_DISPLAY_BLANK
1811 bool "Enable console blanking using APM"
1813 Enable console blanking using the APM. Some laptops can use this to
1814 turn off the LCD backlight when the screen blanker of the Linux
1815 virtual console blanks the screen. Note that this is only used by
1816 the virtual console screen blanker, and won't turn off the backlight
1817 when using the X Window system. This also doesn't have anything to
1818 do with your VESA-compliant power-saving monitor. Further, this
1819 option doesn't work for all laptops -- it might not turn off your
1820 backlight at all, or it might print a lot of errors to the console,
1821 especially if you are using gpm.
1823 config APM_ALLOW_INTS
1824 bool "Allow interrupts during APM BIOS calls"
1826 Normally we disable external interrupts while we are making calls to
1827 the APM BIOS as a measure to lessen the effects of a badly behaving
1828 BIOS implementation. The BIOS should reenable interrupts if it
1829 needs to. Unfortunately, some BIOSes do not -- especially those in
1830 many of the newer IBM Thinkpads. If you experience hangs when you
1831 suspend, try setting this to Y. Otherwise, say N.
1835 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1837 source "drivers/cpuidle/Kconfig"
1839 source "drivers/idle/Kconfig"
1844 menu "Bus options (PCI etc.)"
1849 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1851 Find out whether you have a PCI motherboard. PCI is the name of a
1852 bus system, i.e. the way the CPU talks to the other stuff inside
1853 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1854 VESA. If you have PCI, say Y, otherwise N.
1857 prompt "PCI access mode"
1858 depends on X86_32 && PCI
1861 On PCI systems, the BIOS can be used to detect the PCI devices and
1862 determine their configuration. However, some old PCI motherboards
1863 have BIOS bugs and may crash if this is done. Also, some embedded
1864 PCI-based systems don't have any BIOS at all. Linux can also try to
1865 detect the PCI hardware directly without using the BIOS.
1867 With this option, you can specify how Linux should detect the
1868 PCI devices. If you choose "BIOS", the BIOS will be used,
1869 if you choose "Direct", the BIOS won't be used, and if you
1870 choose "MMConfig", then PCI Express MMCONFIG will be used.
1871 If you choose "Any", the kernel will try MMCONFIG, then the
1872 direct access method and falls back to the BIOS if that doesn't
1873 work. If unsure, go with the default, which is "Any".
1878 config PCI_GOMMCONFIG
1895 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1897 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1900 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1904 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1908 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1912 depends on PCI && XEN
1920 bool "Support mmconfig PCI config space access"
1921 depends on X86_64 && PCI && ACPI
1923 config PCI_CNB20LE_QUIRK
1924 bool "Read CNB20LE Host Bridge Windows"
1927 Read the PCI windows out of the CNB20LE host bridge. This allows
1928 PCI hotplug to work on systems with the CNB20LE chipset which do
1932 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1933 depends on PCI_MSI && ACPI && EXPERIMENTAL
1935 DMA remapping (DMAR) devices support enables independent address
1936 translations for Direct Memory Access (DMA) from devices.
1937 These DMA remapping devices are reported via ACPI tables
1938 and include PCI device scope covered by these DMA
1941 config DMAR_DEFAULT_ON
1943 prompt "Enable DMA Remapping Devices by default"
1946 Selecting this option will enable a DMAR device at boot time if
1947 one is found. If this option is not selected, DMAR support can
1948 be enabled by passing intel_iommu=on to the kernel. It is
1949 recommended you say N here while the DMAR code remains
1952 config DMAR_BROKEN_GFX_WA
1953 bool "Workaround broken graphics drivers (going away soon)"
1954 depends on DMAR && BROKEN
1956 Current Graphics drivers tend to use physical address
1957 for DMA and avoid using DMA APIs. Setting this config
1958 option permits the IOMMU driver to set a unity map for
1959 all the OS-visible memory. Hence the driver can continue
1960 to use physical addresses for DMA, at least until this
1961 option is removed in the 2.6.32 kernel.
1963 config DMAR_FLOPPY_WA
1967 Floppy disk drivers are known to bypass DMA API calls
1968 thereby failing to work when IOMMU is enabled. This
1969 workaround will setup a 1:1 mapping for the first
1970 16MiB to make floppy (an ISA device) work.
1973 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1974 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1976 Supports Interrupt remapping for IO-APIC and MSI devices.
1977 To use x2apic mode in the CPU's which support x2APIC enhancements or
1978 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1980 source "drivers/pci/pcie/Kconfig"
1982 source "drivers/pci/Kconfig"
1984 # x86_64 have no ISA slots, but do have ISA-style DMA.
1993 Find out whether you have ISA slots on your motherboard. ISA is the
1994 name of a bus system, i.e. the way the CPU talks to the other stuff
1995 inside your box. Other bus systems are PCI, EISA, MicroChannel
1996 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1997 newer boards don't support it. If you have ISA, say Y, otherwise N.
2003 The Extended Industry Standard Architecture (EISA) bus was
2004 developed as an open alternative to the IBM MicroChannel bus.
2006 The EISA bus provided some of the features of the IBM MicroChannel
2007 bus while maintaining backward compatibility with cards made for
2008 the older ISA bus. The EISA bus saw limited use between 1988 and
2009 1995 when it was made obsolete by the PCI bus.
2011 Say Y here if you are building a kernel for an EISA-based machine.
2015 source "drivers/eisa/Kconfig"
2020 MicroChannel Architecture is found in some IBM PS/2 machines and
2021 laptops. It is a bus system similar to PCI or ISA. See
2022 <file:Documentation/mca.txt> (and especially the web page given
2023 there) before attempting to build an MCA bus kernel.
2025 source "drivers/mca/Kconfig"
2028 tristate "NatSemi SCx200 support"
2030 This provides basic support for National Semiconductor's
2031 (now AMD's) Geode processors. The driver probes for the
2032 PCI-IDs of several on-chip devices, so its a good dependency
2033 for other scx200_* drivers.
2035 If compiled as a module, the driver is named scx200.
2037 config SCx200HR_TIMER
2038 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2042 This driver provides a clocksource built upon the on-chip
2043 27MHz high-resolution timer. Its also a workaround for
2044 NSC Geode SC-1100's buggy TSC, which loses time when the
2045 processor goes idle (as is done by the scheduler). The
2046 other workaround is idle=poll boot option.
2049 bool "One Laptop Per Child support"
2051 select OLPC_OPENFIRMWARE
2053 Add support for detecting the unique features of the OLPC
2057 tristate "OLPC XO-1 support"
2058 depends on OLPC && PCI
2060 Add support for non-essential features of the OLPC XO-1 laptop.
2062 config OLPC_OPENFIRMWARE
2063 bool "Support for OLPC's Open Firmware"
2064 depends on !X86_64 && !X86_PAE
2067 This option adds support for the implementation of Open Firmware
2068 that is used on the OLPC XO-1 Children's Machine.
2069 If unsure, say N here.
2075 depends on CPU_SUP_AMD && PCI
2077 source "drivers/pcmcia/Kconfig"
2079 source "drivers/pci/hotplug/Kconfig"
2084 menu "Executable file formats / Emulations"
2086 source "fs/Kconfig.binfmt"
2088 config IA32_EMULATION
2089 bool "IA32 Emulation"
2091 select COMPAT_BINFMT_ELF
2093 Include code to run 32-bit programs under a 64-bit kernel. You should
2094 likely turn this on, unless you're 100% sure that you don't have any
2095 32-bit programs left.
2098 tristate "IA32 a.out support"
2099 depends on IA32_EMULATION
2101 Support old a.out binaries in the 32bit emulation.
2105 depends on IA32_EMULATION
2107 config COMPAT_FOR_U64_ALIGNMENT
2111 config SYSVIPC_COMPAT
2113 depends on COMPAT && SYSVIPC
2118 config HAVE_ATOMIC_IOMAP
2122 config HAVE_TEXT_POKE_SMP
2124 select STOP_MACHINE if SMP
2126 source "net/Kconfig"
2128 source "drivers/Kconfig"
2130 source "drivers/firmware/Kconfig"
2134 source "arch/x86/Kconfig.debug"
2136 source "security/Kconfig"
2138 source "crypto/Kconfig"
2140 source "arch/x86/kvm/Kconfig"
2142 source "lib/Kconfig"
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