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
19 select HAVE_AOUT if X86_32
20 select HAVE_UNSTABLE_SCHED_CLOCK
23 select HAVE_PCSPKR_PLATFORM
24 select HAVE_PERF_EVENTS
26 select HAVE_IOREMAP_PROT
29 select HAVE_MEMBLOCK_NODE_MAP
30 select ARCH_DISCARD_MEMBLOCK
31 select ARCH_WANT_OPTIONAL_GPIOLIB
32 select ARCH_WANT_FRAME_POINTERS
34 select HAVE_KRETPROBES
36 select HAVE_FTRACE_MCOUNT_RECORD
37 select HAVE_C_RECORDMCOUNT
38 select HAVE_DYNAMIC_FTRACE
39 select HAVE_FUNCTION_TRACER
40 select HAVE_FUNCTION_GRAPH_TRACER
41 select HAVE_FUNCTION_GRAPH_FP_TEST
42 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
43 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
44 select HAVE_SYSCALL_TRACEPOINTS
47 select HAVE_ARCH_TRACEHOOK
48 select HAVE_GENERIC_DMA_COHERENT if X86_32
49 select HAVE_EFFICIENT_UNALIGNED_ACCESS
50 select USER_STACKTRACE_SUPPORT
51 select HAVE_REGS_AND_STACK_ACCESS_API
52 select HAVE_DMA_API_DEBUG
53 select HAVE_KERNEL_GZIP
54 select HAVE_KERNEL_BZIP2
55 select HAVE_KERNEL_LZMA
57 select HAVE_KERNEL_LZO
58 select HAVE_HW_BREAKPOINT
59 select HAVE_MIXED_BREAKPOINTS_REGS
61 select HAVE_PERF_EVENTS_NMI
63 select HAVE_ARCH_KMEMCHECK
64 select HAVE_USER_RETURN_NOTIFIER
65 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
66 select HAVE_ARCH_JUMP_LABEL
67 select HAVE_TEXT_POKE_SMP
68 select HAVE_GENERIC_HARDIRQS
69 select HAVE_SPARSE_IRQ
71 select GENERIC_FIND_FIRST_BIT
72 select GENERIC_IRQ_PROBE
73 select GENERIC_PENDING_IRQ if SMP
74 select GENERIC_IRQ_SHOW
75 select GENERIC_CLOCKEVENTS_MIN_ADJUST
76 select IRQ_FORCED_THREADING
77 select USE_GENERIC_SMP_HELPERS if SMP
78 select HAVE_BPF_JIT if (X86_64 && NET)
80 select ARCH_HAVE_NMI_SAFE_CMPXCHG
83 config INSTRUCTION_DECODER
84 def_bool (KPROBES || PERF_EVENTS)
88 default "elf32-i386" if X86_32
89 default "elf64-x86-64" if X86_64
93 default "arch/x86/configs/i386_defconfig" if X86_32
94 default "arch/x86/configs/x86_64_defconfig" if X86_64
96 config GENERIC_CMOS_UPDATE
99 config CLOCKSOURCE_WATCHDOG
102 config GENERIC_CLOCKEVENTS
105 config ARCH_CLOCKSOURCE_DATA
109 config GENERIC_CLOCKEVENTS_BROADCAST
111 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
113 config LOCKDEP_SUPPORT
116 config STACKTRACE_SUPPORT
119 config HAVE_LATENCYTOP_SUPPORT
126 bool "DMA memory allocation support" if EXPERT
129 DMA memory allocation support allows devices with less than 32-bit
130 addressing to allocate within the first 16MB of address space.
131 Disable if no such devices will be used.
138 config NEED_DMA_MAP_STATE
139 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG)
141 config NEED_SG_DMA_LENGTH
144 config GENERIC_ISA_DMA
150 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
152 config GENERIC_BUG_RELATIVE_POINTERS
155 config GENERIC_HWEIGHT
161 config ARCH_MAY_HAVE_PC_FDC
164 config RWSEM_GENERIC_SPINLOCK
167 config RWSEM_XCHGADD_ALGORITHM
170 config ARCH_HAS_CPU_IDLE_WAIT
173 config GENERIC_CALIBRATE_DELAY
176 config GENERIC_TIME_VSYSCALL
180 config ARCH_HAS_CPU_RELAX
183 config ARCH_HAS_DEFAULT_IDLE
186 config ARCH_HAS_CACHE_LINE_SIZE
189 config HAVE_SETUP_PER_CPU_AREA
192 config NEED_PER_CPU_EMBED_FIRST_CHUNK
195 config NEED_PER_CPU_PAGE_FIRST_CHUNK
198 config ARCH_HIBERNATION_POSSIBLE
201 config ARCH_SUSPEND_POSSIBLE
212 config ARCH_SUPPORTS_OPTIMIZED_INLINING
215 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
218 config HAVE_INTEL_TXT
220 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
224 depends on X86_32 && SMP
228 depends on X86_64 && SMP
234 config X86_32_LAZY_GS
236 depends on X86_32 && !CC_STACKPROTECTOR
238 config ARCH_HWEIGHT_CFLAGS
240 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
241 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
246 config ARCH_CPU_PROBE_RELEASE
248 depends on HOTPLUG_CPU
250 source "init/Kconfig"
251 source "kernel/Kconfig.freezer"
253 menu "Processor type and features"
255 source "kernel/time/Kconfig"
258 bool "Symmetric multi-processing support"
260 This enables support for systems with more than one CPU. If you have
261 a system with only one CPU, like most personal computers, say N. If
262 you have a system with more than one CPU, say Y.
264 If you say N here, the kernel will run on single and multiprocessor
265 machines, but will use only one CPU of a multiprocessor machine. If
266 you say Y here, the kernel will run on many, but not all,
267 singleprocessor machines. On a singleprocessor machine, the kernel
268 will run faster if you say N here.
270 Note that if you say Y here and choose architecture "586" or
271 "Pentium" under "Processor family", the kernel will not work on 486
272 architectures. Similarly, multiprocessor kernels for the "PPro"
273 architecture may not work on all Pentium based boards.
275 People using multiprocessor machines who say Y here should also say
276 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
277 Management" code will be disabled if you say Y here.
279 See also <file:Documentation/x86/i386/IO-APIC.txt>,
280 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
281 <http://www.tldp.org/docs.html#howto>.
283 If you don't know what to do here, say N.
286 bool "Support x2apic"
287 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
289 This enables x2apic support on CPUs that have this feature.
291 This allows 32-bit apic IDs (so it can support very large systems),
292 and accesses the local apic via MSRs not via mmio.
294 If you don't know what to do here, say N.
297 bool "Enable MPS table" if ACPI
299 depends on X86_LOCAL_APIC
301 For old smp systems that do not have proper acpi support. Newer systems
302 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
305 bool "Support for big SMP systems with more than 8 CPUs"
306 depends on X86_32 && SMP
308 This option is needed for the systems that have more than 8 CPUs
311 config X86_EXTENDED_PLATFORM
312 bool "Support for extended (non-PC) x86 platforms"
315 If you disable this option then the kernel will only support
316 standard PC platforms. (which covers the vast majority of
319 If you enable this option then you'll be able to select support
320 for the following (non-PC) 32 bit x86 platforms:
324 SGI 320/540 (Visual Workstation)
325 Summit/EXA (IBM x440)
326 Unisys ES7000 IA32 series
327 Moorestown MID devices
329 If you have one of these systems, or if you want to build a
330 generic distribution kernel, say Y here - otherwise say N.
334 config X86_EXTENDED_PLATFORM
335 bool "Support for extended (non-PC) x86 platforms"
338 If you disable this option then the kernel will only support
339 standard PC platforms. (which covers the vast majority of
342 If you enable this option then you'll be able to select support
343 for the following (non-PC) 64 bit x86 platforms:
348 If you have one of these systems, or if you want to build a
349 generic distribution kernel, say Y here - otherwise say N.
351 # This is an alphabetically sorted list of 64 bit extended platforms
352 # Please maintain the alphabetic order if and when there are additions
354 bool "Numascale NumaChip"
356 depends on X86_EXTENDED_PLATFORM
359 depends on X86_X2APIC
360 depends on !EDAC_AMD64
362 Adds support for Numascale NumaChip large-SMP systems. Needed to
363 enable more than ~168 cores.
364 If you don't have one of these, you should say N here.
368 select PARAVIRT_GUEST
370 depends on X86_64 && PCI
371 depends on X86_EXTENDED_PLATFORM
373 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
374 supposed to run on these EM64T-based machines. Only choose this option
375 if you have one of these machines.
378 bool "SGI Ultraviolet"
380 depends on X86_EXTENDED_PLATFORM
382 depends on X86_X2APIC
384 This option is needed in order to support SGI Ultraviolet systems.
385 If you don't have one of these, you should say N here.
387 # Following is an alphabetically sorted list of 32 bit extended platforms
388 # Please maintain the alphabetic order if and when there are additions
391 bool "CE4100 TV platform"
393 depends on PCI_GODIRECT
395 depends on X86_EXTENDED_PLATFORM
396 select X86_REBOOTFIXUPS
398 select OF_EARLY_FLATTREE
400 Select for the Intel CE media processor (CE4100) SOC.
401 This option compiles in support for the CE4100 SOC for settop
402 boxes and media devices.
404 config X86_WANT_INTEL_MID
405 bool "Intel MID platform support"
407 depends on X86_EXTENDED_PLATFORM
409 Select to build a kernel capable of supporting Intel MID platform
410 systems which do not have the PCI legacy interfaces (Moorestown,
411 Medfield). If you are building for a PC class system say N here.
413 if X86_WANT_INTEL_MID
419 bool "Moorestown MID platform"
422 depends on X86_IO_APIC
427 select X86_PLATFORM_DEVICES
430 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
431 Internet Device(MID) platform. Moorestown consists of two chips:
432 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
433 Unlike standard x86 PCs, Moorestown does not have many legacy devices
434 nor standard legacy replacement devices/features. e.g. Moorestown does
435 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
440 bool "RDC R-321x SoC"
442 depends on X86_EXTENDED_PLATFORM
444 select X86_REBOOTFIXUPS
446 This option is needed for RDC R-321x system-on-chip, also known
448 If you don't have one of these chips, you should say N here.
450 config X86_32_NON_STANDARD
451 bool "Support non-standard 32-bit SMP architectures"
452 depends on X86_32 && SMP
453 depends on X86_EXTENDED_PLATFORM
455 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
456 subarchitectures. It is intended for a generic binary kernel.
457 if you select them all, kernel will probe it one by one. and will
460 # Alphabetically sorted list of Non standard 32 bit platforms
463 bool "NUMAQ (IBM/Sequent)"
464 depends on X86_32_NON_STANDARD
469 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
470 NUMA multiquad box. This changes the way that processors are
471 bootstrapped, and uses Clustered Logical APIC addressing mode instead
472 of Flat Logical. You will need a new lynxer.elf file to flash your
473 firmware with - send email to <Martin.Bligh@us.ibm.com>.
475 config X86_SUPPORTS_MEMORY_FAILURE
477 # MCE code calls memory_failure():
479 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
480 depends on !X86_NUMAQ
481 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
482 depends on X86_64 || !SPARSEMEM
483 select ARCH_SUPPORTS_MEMORY_FAILURE
486 bool "SGI 320/540 (Visual Workstation)"
487 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
488 depends on X86_32_NON_STANDARD
490 The SGI Visual Workstation series is an IA32-based workstation
491 based on SGI systems chips with some legacy PC hardware attached.
493 Say Y here to create a kernel to run on the SGI 320 or 540.
495 A kernel compiled for the Visual Workstation will run on general
496 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
499 bool "Summit/EXA (IBM x440)"
500 depends on X86_32_NON_STANDARD
502 This option is needed for IBM systems that use the Summit/EXA chipset.
503 In particular, it is needed for the x440.
506 bool "Unisys ES7000 IA32 series"
507 depends on X86_32_NON_STANDARD && X86_BIGSMP
509 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
510 supposed to run on an IA32-based Unisys ES7000 system.
513 tristate "Eurobraille/Iris poweroff module"
516 The Iris machines from EuroBraille do not have APM or ACPI support
517 to shut themselves down properly. A special I/O sequence is
518 needed to do so, which is what this module does at
521 This is only for Iris machines from EuroBraille.
525 config SCHED_OMIT_FRAME_POINTER
527 prompt "Single-depth WCHAN output"
530 Calculate simpler /proc/<PID>/wchan values. If this option
531 is disabled then wchan values will recurse back to the
532 caller function. This provides more accurate wchan values,
533 at the expense of slightly more scheduling overhead.
535 If in doubt, say "Y".
537 menuconfig PARAVIRT_GUEST
538 bool "Paravirtualized guest support"
540 Say Y here to get to see options related to running Linux under
541 various hypervisors. This option alone does not add any kernel code.
543 If you say N, all options in this submenu will be skipped and disabled.
547 config PARAVIRT_TIME_ACCOUNTING
548 bool "Paravirtual steal time accounting"
552 Select this option to enable fine granularity task steal time
553 accounting. Time spent executing other tasks in parallel with
554 the current vCPU is discounted from the vCPU power. To account for
555 that, there can be a small performance impact.
557 If in doubt, say N here.
559 source "arch/x86/xen/Kconfig"
562 bool "KVM paravirtualized clock"
564 select PARAVIRT_CLOCK
566 Turning on this option will allow you to run a paravirtualized clock
567 when running over the KVM hypervisor. Instead of relying on a PIT
568 (or probably other) emulation by the underlying device model, the host
569 provides the guest with timing infrastructure such as time of day, and
573 bool "KVM Guest support"
576 This option enables various optimizations for running under the KVM
579 source "arch/x86/lguest/Kconfig"
582 bool "Enable paravirtualization code"
584 This changes the kernel so it can modify itself when it is run
585 under a hypervisor, potentially improving performance significantly
586 over full virtualization. However, when run without a hypervisor
587 the kernel is theoretically slower and slightly larger.
589 config PARAVIRT_SPINLOCKS
590 bool "Paravirtualization layer for spinlocks"
591 depends on PARAVIRT && SMP && EXPERIMENTAL
593 Paravirtualized spinlocks allow a pvops backend to replace the
594 spinlock implementation with something virtualization-friendly
595 (for example, block the virtual CPU rather than spinning).
597 Unfortunately the downside is an up to 5% performance hit on
598 native kernels, with various workloads.
600 If you are unsure how to answer this question, answer N.
602 config PARAVIRT_CLOCK
607 config PARAVIRT_DEBUG
608 bool "paravirt-ops debugging"
609 depends on PARAVIRT && DEBUG_KERNEL
611 Enable to debug paravirt_ops internals. Specifically, BUG if
612 a paravirt_op is missing when it is called.
620 This option adds a kernel parameter 'memtest', which allows memtest
622 memtest=0, mean disabled; -- default
623 memtest=1, mean do 1 test pattern;
625 memtest=4, mean do 4 test patterns.
626 If you are unsure how to answer this question, answer N.
628 config X86_SUMMIT_NUMA
630 depends on X86_32 && NUMA && X86_32_NON_STANDARD
632 config X86_CYCLONE_TIMER
634 depends on X86_32_NON_STANDARD
636 source "arch/x86/Kconfig.cpu"
640 prompt "HPET Timer Support" if X86_32
642 Use the IA-PC HPET (High Precision Event Timer) to manage
643 time in preference to the PIT and RTC, if a HPET is
645 HPET is the next generation timer replacing legacy 8254s.
646 The HPET provides a stable time base on SMP
647 systems, unlike the TSC, but it is more expensive to access,
648 as it is off-chip. You can find the HPET spec at
649 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
651 You can safely choose Y here. However, HPET will only be
652 activated if the platform and the BIOS support this feature.
653 Otherwise the 8254 will be used for timing services.
655 Choose N to continue using the legacy 8254 timer.
657 config HPET_EMULATE_RTC
659 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
663 prompt "Langwell APB Timer Support" if X86_MRST
666 APB timer is the replacement for 8254, HPET on X86 MID platforms.
667 The APBT provides a stable time base on SMP
668 systems, unlike the TSC, but it is more expensive to access,
669 as it is off-chip. APB timers are always running regardless of CPU
670 C states, they are used as per CPU clockevent device when possible.
672 # Mark as expert because too many people got it wrong.
673 # The code disables itself when not needed.
676 bool "Enable DMI scanning" if EXPERT
678 Enabled scanning of DMI to identify machine quirks. Say Y
679 here unless you have verified that your setup is not
680 affected by entries in the DMI blacklist. Required by PNP
684 bool "GART IOMMU support" if EXPERT
687 depends on X86_64 && PCI && AMD_NB
689 Support for full DMA access of devices with 32bit memory access only
690 on systems with more than 3GB. This is usually needed for USB,
691 sound, many IDE/SATA chipsets and some other devices.
692 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
693 based hardware IOMMU and a software bounce buffer based IOMMU used
694 on Intel systems and as fallback.
695 The code is only active when needed (enough memory and limited
696 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
700 bool "IBM Calgary IOMMU support"
702 depends on X86_64 && PCI && EXPERIMENTAL
704 Support for hardware IOMMUs in IBM's xSeries x366 and x460
705 systems. Needed to run systems with more than 3GB of memory
706 properly with 32-bit PCI devices that do not support DAC
707 (Double Address Cycle). Calgary also supports bus level
708 isolation, where all DMAs pass through the IOMMU. This
709 prevents them from going anywhere except their intended
710 destination. This catches hard-to-find kernel bugs and
711 mis-behaving drivers and devices that do not use the DMA-API
712 properly to set up their DMA buffers. The IOMMU can be
713 turned off at boot time with the iommu=off parameter.
714 Normally the kernel will make the right choice by itself.
717 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
719 prompt "Should Calgary be enabled by default?"
720 depends on CALGARY_IOMMU
722 Should Calgary be enabled by default? if you choose 'y', Calgary
723 will be used (if it exists). If you choose 'n', Calgary will not be
724 used even if it exists. If you choose 'n' and would like to use
725 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
728 # need this always selected by IOMMU for the VIA workaround
732 Support for software bounce buffers used on x86-64 systems
733 which don't have a hardware IOMMU (e.g. the current generation
734 of Intel's x86-64 CPUs). Using this PCI devices which can only
735 access 32-bits of memory can be used on systems with more than
736 3 GB of memory. If unsure, say Y.
739 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
742 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
743 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
744 select CPUMASK_OFFSTACK
746 Enable maximum number of CPUS and NUMA Nodes for this architecture.
750 int "Maximum number of CPUs" if SMP && !MAXSMP
751 range 2 8 if SMP && X86_32 && !X86_BIGSMP
752 range 2 512 if SMP && !MAXSMP
754 default "4096" if MAXSMP
755 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
758 This allows you to specify the maximum number of CPUs which this
759 kernel will support. The maximum supported value is 512 and the
760 minimum value which makes sense is 2.
762 This is purely to save memory - each supported CPU adds
763 approximately eight kilobytes to the kernel image.
766 bool "SMT (Hyperthreading) scheduler support"
769 SMT scheduler support improves the CPU scheduler's decision making
770 when dealing with Intel Pentium 4 chips with HyperThreading at a
771 cost of slightly increased overhead in some places. If unsure say
776 prompt "Multi-core scheduler support"
779 Multi-core scheduler support improves the CPU scheduler's decision
780 making when dealing with multi-core CPU chips at a cost of slightly
781 increased overhead in some places. If unsure say N here.
783 config IRQ_TIME_ACCOUNTING
784 bool "Fine granularity task level IRQ time accounting"
787 Select this option to enable fine granularity task irq time
788 accounting. This is done by reading a timestamp on each
789 transitions between softirq and hardirq state, so there can be a
790 small performance impact.
792 If in doubt, say N here.
794 source "kernel/Kconfig.preempt"
797 bool "Local APIC support on uniprocessors"
798 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
800 A local APIC (Advanced Programmable Interrupt Controller) is an
801 integrated interrupt controller in the CPU. If you have a single-CPU
802 system which has a processor with a local APIC, you can say Y here to
803 enable and use it. If you say Y here even though your machine doesn't
804 have a local APIC, then the kernel will still run with no slowdown at
805 all. The local APIC supports CPU-generated self-interrupts (timer,
806 performance counters), and the NMI watchdog which detects hard
810 bool "IO-APIC support on uniprocessors"
811 depends on X86_UP_APIC
813 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
814 SMP-capable replacement for PC-style interrupt controllers. Most
815 SMP systems and many recent uniprocessor systems have one.
817 If you have a single-CPU system with an IO-APIC, you can say Y here
818 to use it. If you say Y here even though your machine doesn't have
819 an IO-APIC, then the kernel will still run with no slowdown at all.
821 config X86_LOCAL_APIC
823 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
827 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
829 config X86_VISWS_APIC
831 depends on X86_32 && X86_VISWS
833 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
834 bool "Reroute for broken boot IRQs"
835 depends on X86_IO_APIC
837 This option enables a workaround that fixes a source of
838 spurious interrupts. This is recommended when threaded
839 interrupt handling is used on systems where the generation of
840 superfluous "boot interrupts" cannot be disabled.
842 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
843 entry in the chipset's IO-APIC is masked (as, e.g. the RT
844 kernel does during interrupt handling). On chipsets where this
845 boot IRQ generation cannot be disabled, this workaround keeps
846 the original IRQ line masked so that only the equivalent "boot
847 IRQ" is delivered to the CPUs. The workaround also tells the
848 kernel to set up the IRQ handler on the boot IRQ line. In this
849 way only one interrupt is delivered to the kernel. Otherwise
850 the spurious second interrupt may cause the kernel to bring
851 down (vital) interrupt lines.
853 Only affects "broken" chipsets. Interrupt sharing may be
854 increased on these systems.
857 bool "Machine Check / overheating reporting"
859 Machine Check support allows the processor to notify the
860 kernel if it detects a problem (e.g. overheating, data corruption).
861 The action the kernel takes depends on the severity of the problem,
862 ranging from warning messages to halting the machine.
866 prompt "Intel MCE features"
867 depends on X86_MCE && X86_LOCAL_APIC
869 Additional support for intel specific MCE features such as
874 prompt "AMD MCE features"
875 depends on X86_MCE && X86_LOCAL_APIC
877 Additional support for AMD specific MCE features such as
878 the DRAM Error Threshold.
880 config X86_ANCIENT_MCE
881 bool "Support for old Pentium 5 / WinChip machine checks"
882 depends on X86_32 && X86_MCE
884 Include support for machine check handling on old Pentium 5 or WinChip
885 systems. These typically need to be enabled explicitely on the command
888 config X86_MCE_THRESHOLD
889 depends on X86_MCE_AMD || X86_MCE_INTEL
892 config X86_MCE_INJECT
894 tristate "Machine check injector support"
896 Provide support for injecting machine checks for testing purposes.
897 If you don't know what a machine check is and you don't do kernel
898 QA it is safe to say n.
900 config X86_THERMAL_VECTOR
902 depends on X86_MCE_INTEL
905 bool "Enable VM86 support" if EXPERT
909 This option is required by programs like DOSEMU to run 16-bit legacy
910 code on X86 processors. It also may be needed by software like
911 XFree86 to initialize some video cards via BIOS. Disabling this
912 option saves about 6k.
915 tristate "Toshiba Laptop support"
918 This adds a driver to safely access the System Management Mode of
919 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
920 not work on models with a Phoenix BIOS. The System Management Mode
921 is used to set the BIOS and power saving options on Toshiba portables.
923 For information on utilities to make use of this driver see the
924 Toshiba Linux utilities web site at:
925 <http://www.buzzard.org.uk/toshiba/>.
927 Say Y if you intend to run this kernel on a Toshiba portable.
931 tristate "Dell laptop support"
934 This adds a driver to safely access the System Management Mode
935 of the CPU on the Dell Inspiron 8000. The System Management Mode
936 is used to read cpu temperature and cooling fan status and to
937 control the fans on the I8K portables.
939 This driver has been tested only on the Inspiron 8000 but it may
940 also work with other Dell laptops. You can force loading on other
941 models by passing the parameter `force=1' to the module. Use at
944 For information on utilities to make use of this driver see the
945 I8K Linux utilities web site at:
946 <http://people.debian.org/~dz/i8k/>
948 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
951 config X86_REBOOTFIXUPS
952 bool "Enable X86 board specific fixups for reboot"
955 This enables chipset and/or board specific fixups to be done
956 in order to get reboot to work correctly. This is only needed on
957 some combinations of hardware and BIOS. The symptom, for which
958 this config is intended, is when reboot ends with a stalled/hung
961 Currently, the only fixup is for the Geode machines using
962 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
964 Say Y if you want to enable the fixup. Currently, it's safe to
965 enable this option even if you don't need it.
969 tristate "/dev/cpu/microcode - microcode support"
972 If you say Y here, you will be able to update the microcode on
973 certain Intel and AMD processors. The Intel support is for the
974 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
975 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
976 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
977 You will obviously need the actual microcode binary data itself
978 which is not shipped with the Linux kernel.
980 This option selects the general module only, you need to select
981 at least one vendor specific module as well.
983 To compile this driver as a module, choose M here: the
984 module will be called microcode.
986 config MICROCODE_INTEL
987 bool "Intel microcode patch loading support"
992 This options enables microcode patch loading support for Intel
995 For latest news and information on obtaining all the required
996 Intel ingredients for this driver, check:
997 <http://www.urbanmyth.org/microcode/>.
1000 bool "AMD microcode patch loading support"
1001 depends on MICROCODE
1004 If you select this option, microcode patch loading support for AMD
1005 processors will be enabled.
1007 config MICROCODE_OLD_INTERFACE
1009 depends on MICROCODE
1012 tristate "/dev/cpu/*/msr - Model-specific register support"
1014 This device gives privileged processes access to the x86
1015 Model-Specific Registers (MSRs). It is a character device with
1016 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1017 MSR accesses are directed to a specific CPU on multi-processor
1021 tristate "/dev/cpu/*/cpuid - CPU information support"
1023 This device gives processes access to the x86 CPUID instruction to
1024 be executed on a specific processor. It is a character device
1025 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1029 prompt "High Memory Support"
1030 default HIGHMEM64G if X86_NUMAQ
1036 depends on !X86_NUMAQ
1038 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1039 However, the address space of 32-bit x86 processors is only 4
1040 Gigabytes large. That means that, if you have a large amount of
1041 physical memory, not all of it can be "permanently mapped" by the
1042 kernel. The physical memory that's not permanently mapped is called
1045 If you are compiling a kernel which will never run on a machine with
1046 more than 1 Gigabyte total physical RAM, answer "off" here (default
1047 choice and suitable for most users). This will result in a "3GB/1GB"
1048 split: 3GB are mapped so that each process sees a 3GB virtual memory
1049 space and the remaining part of the 4GB virtual memory space is used
1050 by the kernel to permanently map as much physical memory as
1053 If the machine has between 1 and 4 Gigabytes physical RAM, then
1056 If more than 4 Gigabytes is used then answer "64GB" here. This
1057 selection turns Intel PAE (Physical Address Extension) mode on.
1058 PAE implements 3-level paging on IA32 processors. PAE is fully
1059 supported by Linux, PAE mode is implemented on all recent Intel
1060 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1061 then the kernel will not boot on CPUs that don't support PAE!
1063 The actual amount of total physical memory will either be
1064 auto detected or can be forced by using a kernel command line option
1065 such as "mem=256M". (Try "man bootparam" or see the documentation of
1066 your boot loader (lilo or loadlin) about how to pass options to the
1067 kernel at boot time.)
1069 If unsure, say "off".
1073 depends on !X86_NUMAQ
1075 Select this if you have a 32-bit processor and between 1 and 4
1076 gigabytes of physical RAM.
1080 depends on !M386 && !M486
1083 Select this if you have a 32-bit processor and more than 4
1084 gigabytes of physical RAM.
1089 depends on EXPERIMENTAL
1090 prompt "Memory split" if EXPERT
1094 Select the desired split between kernel and user memory.
1096 If the address range available to the kernel is less than the
1097 physical memory installed, the remaining memory will be available
1098 as "high memory". Accessing high memory is a little more costly
1099 than low memory, as it needs to be mapped into the kernel first.
1100 Note that increasing the kernel address space limits the range
1101 available to user programs, making the address space there
1102 tighter. Selecting anything other than the default 3G/1G split
1103 will also likely make your kernel incompatible with binary-only
1106 If you are not absolutely sure what you are doing, leave this
1110 bool "3G/1G user/kernel split"
1111 config VMSPLIT_3G_OPT
1113 bool "3G/1G user/kernel split (for full 1G low memory)"
1115 bool "2G/2G user/kernel split"
1116 config VMSPLIT_2G_OPT
1118 bool "2G/2G user/kernel split (for full 2G low memory)"
1120 bool "1G/3G user/kernel split"
1125 default 0xB0000000 if VMSPLIT_3G_OPT
1126 default 0x80000000 if VMSPLIT_2G
1127 default 0x78000000 if VMSPLIT_2G_OPT
1128 default 0x40000000 if VMSPLIT_1G
1134 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1137 bool "PAE (Physical Address Extension) Support"
1138 depends on X86_32 && !HIGHMEM4G
1140 PAE is required for NX support, and furthermore enables
1141 larger swapspace support for non-overcommit purposes. It
1142 has the cost of more pagetable lookup overhead, and also
1143 consumes more pagetable space per process.
1145 config ARCH_PHYS_ADDR_T_64BIT
1146 def_bool X86_64 || X86_PAE
1148 config ARCH_DMA_ADDR_T_64BIT
1149 def_bool X86_64 || HIGHMEM64G
1151 config DIRECT_GBPAGES
1152 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1156 Allow the kernel linear mapping to use 1GB pages on CPUs that
1157 support it. This can improve the kernel's performance a tiny bit by
1158 reducing TLB pressure. If in doubt, say "Y".
1160 # Common NUMA Features
1162 bool "Numa Memory Allocation and Scheduler Support"
1164 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1165 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1167 Enable NUMA (Non Uniform Memory Access) support.
1169 The kernel will try to allocate memory used by a CPU on the
1170 local memory controller of the CPU and add some more
1171 NUMA awareness to the kernel.
1173 For 64-bit this is recommended if the system is Intel Core i7
1174 (or later), AMD Opteron, or EM64T NUMA.
1176 For 32-bit this is only needed on (rare) 32-bit-only platforms
1177 that support NUMA topologies, such as NUMAQ / Summit, or if you
1178 boot a 32-bit kernel on a 64-bit NUMA platform.
1180 Otherwise, you should say N.
1182 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1183 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1187 prompt "Old style AMD Opteron NUMA detection"
1188 depends on X86_64 && NUMA && PCI
1190 Enable AMD NUMA node topology detection. You should say Y here if
1191 you have a multi processor AMD system. This uses an old method to
1192 read the NUMA configuration directly from the builtin Northbridge
1193 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1194 which also takes priority if both are compiled in.
1196 config X86_64_ACPI_NUMA
1198 prompt "ACPI NUMA detection"
1199 depends on X86_64 && NUMA && ACPI && PCI
1202 Enable ACPI SRAT based node topology detection.
1204 # Some NUMA nodes have memory ranges that span
1205 # other nodes. Even though a pfn is valid and
1206 # between a node's start and end pfns, it may not
1207 # reside on that node. See memmap_init_zone()
1209 config NODES_SPAN_OTHER_NODES
1211 depends on X86_64_ACPI_NUMA
1214 bool "NUMA emulation"
1217 Enable NUMA emulation. A flat machine will be split
1218 into virtual nodes when booted with "numa=fake=N", where N is the
1219 number of nodes. This is only useful for debugging.
1222 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1224 default "10" if MAXSMP
1225 default "6" if X86_64
1226 default "4" if X86_NUMAQ
1228 depends on NEED_MULTIPLE_NODES
1230 Specify the maximum number of NUMA Nodes available on the target
1231 system. Increases memory reserved to accommodate various tables.
1233 config HAVE_ARCH_BOOTMEM
1235 depends on X86_32 && NUMA
1237 config HAVE_ARCH_ALLOC_REMAP
1239 depends on X86_32 && NUMA
1241 config ARCH_HAVE_MEMORY_PRESENT
1243 depends on X86_32 && DISCONTIGMEM
1245 config NEED_NODE_MEMMAP_SIZE
1247 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1249 config ARCH_FLATMEM_ENABLE
1251 depends on X86_32 && !NUMA
1253 config ARCH_DISCONTIGMEM_ENABLE
1255 depends on NUMA && X86_32
1257 config ARCH_DISCONTIGMEM_DEFAULT
1259 depends on NUMA && X86_32
1261 config ARCH_SPARSEMEM_ENABLE
1263 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1264 select SPARSEMEM_STATIC if X86_32
1265 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1267 config ARCH_SPARSEMEM_DEFAULT
1271 config ARCH_SELECT_MEMORY_MODEL
1273 depends on ARCH_SPARSEMEM_ENABLE
1275 config ARCH_MEMORY_PROBE
1277 depends on MEMORY_HOTPLUG
1279 config ARCH_PROC_KCORE_TEXT
1281 depends on X86_64 && PROC_KCORE
1283 config ILLEGAL_POINTER_VALUE
1286 default 0xdead000000000000 if X86_64
1291 bool "Allocate 3rd-level pagetables from highmem"
1294 The VM uses one page table entry for each page of physical memory.
1295 For systems with a lot of RAM, this can be wasteful of precious
1296 low memory. Setting this option will put user-space page table
1297 entries in high memory.
1299 config X86_CHECK_BIOS_CORRUPTION
1300 bool "Check for low memory corruption"
1302 Periodically check for memory corruption in low memory, which
1303 is suspected to be caused by BIOS. Even when enabled in the
1304 configuration, it is disabled at runtime. Enable it by
1305 setting "memory_corruption_check=1" on the kernel command
1306 line. By default it scans the low 64k of memory every 60
1307 seconds; see the memory_corruption_check_size and
1308 memory_corruption_check_period parameters in
1309 Documentation/kernel-parameters.txt to adjust this.
1311 When enabled with the default parameters, this option has
1312 almost no overhead, as it reserves a relatively small amount
1313 of memory and scans it infrequently. It both detects corruption
1314 and prevents it from affecting the running system.
1316 It is, however, intended as a diagnostic tool; if repeatable
1317 BIOS-originated corruption always affects the same memory,
1318 you can use memmap= to prevent the kernel from using that
1321 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1322 bool "Set the default setting of memory_corruption_check"
1323 depends on X86_CHECK_BIOS_CORRUPTION
1326 Set whether the default state of memory_corruption_check is
1329 config X86_RESERVE_LOW
1330 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1334 Specify the amount of low memory to reserve for the BIOS.
1336 The first page contains BIOS data structures that the kernel
1337 must not use, so that page must always be reserved.
1339 By default we reserve the first 64K of physical RAM, as a
1340 number of BIOSes are known to corrupt that memory range
1341 during events such as suspend/resume or monitor cable
1342 insertion, so it must not be used by the kernel.
1344 You can set this to 4 if you are absolutely sure that you
1345 trust the BIOS to get all its memory reservations and usages
1346 right. If you know your BIOS have problems beyond the
1347 default 64K area, you can set this to 640 to avoid using the
1348 entire low memory range.
1350 If you have doubts about the BIOS (e.g. suspend/resume does
1351 not work or there's kernel crashes after certain hardware
1352 hotplug events) then you might want to enable
1353 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1354 typical corruption patterns.
1356 Leave this to the default value of 64 if you are unsure.
1358 config MATH_EMULATION
1360 prompt "Math emulation" if X86_32
1362 Linux can emulate a math coprocessor (used for floating point
1363 operations) if you don't have one. 486DX and Pentium processors have
1364 a math coprocessor built in, 486SX and 386 do not, unless you added
1365 a 487DX or 387, respectively. (The messages during boot time can
1366 give you some hints here ["man dmesg"].) Everyone needs either a
1367 coprocessor or this emulation.
1369 If you don't have a math coprocessor, you need to say Y here; if you
1370 say Y here even though you have a coprocessor, the coprocessor will
1371 be used nevertheless. (This behavior can be changed with the kernel
1372 command line option "no387", which comes handy if your coprocessor
1373 is broken. Try "man bootparam" or see the documentation of your boot
1374 loader (lilo or loadlin) about how to pass options to the kernel at
1375 boot time.) This means that it is a good idea to say Y here if you
1376 intend to use this kernel on different machines.
1378 More information about the internals of the Linux math coprocessor
1379 emulation can be found in <file:arch/x86/math-emu/README>.
1381 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1382 kernel, it won't hurt.
1386 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1388 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1389 the Memory Type Range Registers (MTRRs) may be used to control
1390 processor access to memory ranges. This is most useful if you have
1391 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1392 allows bus write transfers to be combined into a larger transfer
1393 before bursting over the PCI/AGP bus. This can increase performance
1394 of image write operations 2.5 times or more. Saying Y here creates a
1395 /proc/mtrr file which may be used to manipulate your processor's
1396 MTRRs. Typically the X server should use this.
1398 This code has a reasonably generic interface so that similar
1399 control registers on other processors can be easily supported
1402 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1403 Registers (ARRs) which provide a similar functionality to MTRRs. For
1404 these, the ARRs are used to emulate the MTRRs.
1405 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1406 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1407 write-combining. All of these processors are supported by this code
1408 and it makes sense to say Y here if you have one of them.
1410 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1411 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1412 can lead to all sorts of problems, so it's good to say Y here.
1414 You can safely say Y even if your machine doesn't have MTRRs, you'll
1415 just add about 9 KB to your kernel.
1417 See <file:Documentation/x86/mtrr.txt> for more information.
1419 config MTRR_SANITIZER
1421 prompt "MTRR cleanup support"
1424 Convert MTRR layout from continuous to discrete, so X drivers can
1425 add writeback entries.
1427 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1428 The largest mtrr entry size for a continuous block can be set with
1433 config MTRR_SANITIZER_ENABLE_DEFAULT
1434 int "MTRR cleanup enable value (0-1)"
1437 depends on MTRR_SANITIZER
1439 Enable mtrr cleanup default value
1441 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1442 int "MTRR cleanup spare reg num (0-7)"
1445 depends on MTRR_SANITIZER
1447 mtrr cleanup spare entries default, it can be changed via
1448 mtrr_spare_reg_nr=N on the kernel command line.
1452 prompt "x86 PAT support" if EXPERT
1455 Use PAT attributes to setup page level cache control.
1457 PATs are the modern equivalents of MTRRs and are much more
1458 flexible than MTRRs.
1460 Say N here if you see bootup problems (boot crash, boot hang,
1461 spontaneous reboots) or a non-working video driver.
1465 config ARCH_USES_PG_UNCACHED
1471 prompt "x86 architectural random number generator" if EXPERT
1473 Enable the x86 architectural RDRAND instruction
1474 (Intel Bull Mountain technology) to generate random numbers.
1475 If supported, this is a high bandwidth, cryptographically
1476 secure hardware random number generator.
1479 bool "EFI runtime service support"
1482 This enables the kernel to use EFI runtime services that are
1483 available (such as the EFI variable services).
1485 This option is only useful on systems that have EFI firmware.
1486 In addition, you should use the latest ELILO loader available
1487 at <http://elilo.sourceforge.net> in order to take advantage
1488 of EFI runtime services. However, even with this option, the
1489 resultant kernel should continue to boot on existing non-EFI
1493 bool "EFI stub support"
1496 This kernel feature allows a bzImage to be loaded directly
1497 by EFI firmware without the use of a bootloader.
1501 prompt "Enable seccomp to safely compute untrusted bytecode"
1503 This kernel feature is useful for number crunching applications
1504 that may need to compute untrusted bytecode during their
1505 execution. By using pipes or other transports made available to
1506 the process as file descriptors supporting the read/write
1507 syscalls, it's possible to isolate those applications in
1508 their own address space using seccomp. Once seccomp is
1509 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1510 and the task is only allowed to execute a few safe syscalls
1511 defined by each seccomp mode.
1513 If unsure, say Y. Only embedded should say N here.
1515 config CC_STACKPROTECTOR
1516 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1518 This option turns on the -fstack-protector GCC feature. This
1519 feature puts, at the beginning of functions, a canary value on
1520 the stack just before the return address, and validates
1521 the value just before actually returning. Stack based buffer
1522 overflows (that need to overwrite this return address) now also
1523 overwrite the canary, which gets detected and the attack is then
1524 neutralized via a kernel panic.
1526 This feature requires gcc version 4.2 or above, or a distribution
1527 gcc with the feature backported. Older versions are automatically
1528 detected and for those versions, this configuration option is
1529 ignored. (and a warning is printed during bootup)
1531 source kernel/Kconfig.hz
1534 bool "kexec system call"
1536 kexec is a system call that implements the ability to shutdown your
1537 current kernel, and to start another kernel. It is like a reboot
1538 but it is independent of the system firmware. And like a reboot
1539 you can start any kernel with it, not just Linux.
1541 The name comes from the similarity to the exec system call.
1543 It is an ongoing process to be certain the hardware in a machine
1544 is properly shutdown, so do not be surprised if this code does not
1545 initially work for you. It may help to enable device hotplugging
1546 support. As of this writing the exact hardware interface is
1547 strongly in flux, so no good recommendation can be made.
1550 bool "kernel crash dumps"
1551 depends on X86_64 || (X86_32 && HIGHMEM)
1553 Generate crash dump after being started by kexec.
1554 This should be normally only set in special crash dump kernels
1555 which are loaded in the main kernel with kexec-tools into
1556 a specially reserved region and then later executed after
1557 a crash by kdump/kexec. The crash dump kernel must be compiled
1558 to a memory address not used by the main kernel or BIOS using
1559 PHYSICAL_START, or it must be built as a relocatable image
1560 (CONFIG_RELOCATABLE=y).
1561 For more details see Documentation/kdump/kdump.txt
1564 bool "kexec jump (EXPERIMENTAL)"
1565 depends on EXPERIMENTAL
1566 depends on KEXEC && HIBERNATION
1568 Jump between original kernel and kexeced kernel and invoke
1569 code in physical address mode via KEXEC
1571 config PHYSICAL_START
1572 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1575 This gives the physical address where the kernel is loaded.
1577 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1578 bzImage will decompress itself to above physical address and
1579 run from there. Otherwise, bzImage will run from the address where
1580 it has been loaded by the boot loader and will ignore above physical
1583 In normal kdump cases one does not have to set/change this option
1584 as now bzImage can be compiled as a completely relocatable image
1585 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1586 address. This option is mainly useful for the folks who don't want
1587 to use a bzImage for capturing the crash dump and want to use a
1588 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1589 to be specifically compiled to run from a specific memory area
1590 (normally a reserved region) and this option comes handy.
1592 So if you are using bzImage for capturing the crash dump,
1593 leave the value here unchanged to 0x1000000 and set
1594 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1595 for capturing the crash dump change this value to start of
1596 the reserved region. In other words, it can be set based on
1597 the "X" value as specified in the "crashkernel=YM@XM"
1598 command line boot parameter passed to the panic-ed
1599 kernel. Please take a look at Documentation/kdump/kdump.txt
1600 for more details about crash dumps.
1602 Usage of bzImage for capturing the crash dump is recommended as
1603 one does not have to build two kernels. Same kernel can be used
1604 as production kernel and capture kernel. Above option should have
1605 gone away after relocatable bzImage support is introduced. But it
1606 is present because there are users out there who continue to use
1607 vmlinux for dump capture. This option should go away down the
1610 Don't change this unless you know what you are doing.
1613 bool "Build a relocatable kernel"
1616 This builds a kernel image that retains relocation information
1617 so it can be loaded someplace besides the default 1MB.
1618 The relocations tend to make the kernel binary about 10% larger,
1619 but are discarded at runtime.
1621 One use is for the kexec on panic case where the recovery kernel
1622 must live at a different physical address than the primary
1625 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1626 it has been loaded at and the compile time physical address
1627 (CONFIG_PHYSICAL_START) is ignored.
1629 # Relocation on x86-32 needs some additional build support
1630 config X86_NEED_RELOCS
1632 depends on X86_32 && RELOCATABLE
1634 config PHYSICAL_ALIGN
1635 hex "Alignment value to which kernel should be aligned" if X86_32
1637 range 0x2000 0x1000000
1639 This value puts the alignment restrictions on physical address
1640 where kernel is loaded and run from. Kernel is compiled for an
1641 address which meets above alignment restriction.
1643 If bootloader loads the kernel at a non-aligned address and
1644 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1645 address aligned to above value and run from there.
1647 If bootloader loads the kernel at a non-aligned address and
1648 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1649 load address and decompress itself to the address it has been
1650 compiled for and run from there. The address for which kernel is
1651 compiled already meets above alignment restrictions. Hence the
1652 end result is that kernel runs from a physical address meeting
1653 above alignment restrictions.
1655 Don't change this unless you know what you are doing.
1658 bool "Support for hot-pluggable CPUs"
1659 depends on SMP && HOTPLUG
1661 Say Y here to allow turning CPUs off and on. CPUs can be
1662 controlled through /sys/devices/system/cpu.
1663 ( Note: power management support will enable this option
1664 automatically on SMP systems. )
1665 Say N if you want to disable CPU hotplug.
1669 prompt "Compat VDSO support"
1670 depends on X86_32 || IA32_EMULATION
1672 Map the 32-bit VDSO to the predictable old-style address too.
1674 Say N here if you are running a sufficiently recent glibc
1675 version (2.3.3 or later), to remove the high-mapped
1676 VDSO mapping and to exclusively use the randomized VDSO.
1681 bool "Built-in kernel command line"
1683 Allow for specifying boot arguments to the kernel at
1684 build time. On some systems (e.g. embedded ones), it is
1685 necessary or convenient to provide some or all of the
1686 kernel boot arguments with the kernel itself (that is,
1687 to not rely on the boot loader to provide them.)
1689 To compile command line arguments into the kernel,
1690 set this option to 'Y', then fill in the
1691 the boot arguments in CONFIG_CMDLINE.
1693 Systems with fully functional boot loaders (i.e. non-embedded)
1694 should leave this option set to 'N'.
1697 string "Built-in kernel command string"
1698 depends on CMDLINE_BOOL
1701 Enter arguments here that should be compiled into the kernel
1702 image and used at boot time. If the boot loader provides a
1703 command line at boot time, it is appended to this string to
1704 form the full kernel command line, when the system boots.
1706 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1707 change this behavior.
1709 In most cases, the command line (whether built-in or provided
1710 by the boot loader) should specify the device for the root
1713 config CMDLINE_OVERRIDE
1714 bool "Built-in command line overrides boot loader arguments"
1715 depends on CMDLINE_BOOL
1717 Set this option to 'Y' to have the kernel ignore the boot loader
1718 command line, and use ONLY the built-in command line.
1720 This is used to work around broken boot loaders. This should
1721 be set to 'N' under normal conditions.
1725 config ARCH_ENABLE_MEMORY_HOTPLUG
1727 depends on X86_64 || (X86_32 && HIGHMEM)
1729 config ARCH_ENABLE_MEMORY_HOTREMOVE
1731 depends on MEMORY_HOTPLUG
1733 config USE_PERCPU_NUMA_NODE_ID
1737 menu "Power management and ACPI options"
1739 config ARCH_HIBERNATION_HEADER
1741 depends on X86_64 && HIBERNATION
1743 source "kernel/power/Kconfig"
1745 source "drivers/acpi/Kconfig"
1747 source "drivers/sfi/Kconfig"
1754 tristate "APM (Advanced Power Management) BIOS support"
1755 depends on X86_32 && PM_SLEEP
1757 APM is a BIOS specification for saving power using several different
1758 techniques. This is mostly useful for battery powered laptops with
1759 APM compliant BIOSes. If you say Y here, the system time will be
1760 reset after a RESUME operation, the /proc/apm device will provide
1761 battery status information, and user-space programs will receive
1762 notification of APM "events" (e.g. battery status change).
1764 If you select "Y" here, you can disable actual use of the APM
1765 BIOS by passing the "apm=off" option to the kernel at boot time.
1767 Note that the APM support is almost completely disabled for
1768 machines with more than one CPU.
1770 In order to use APM, you will need supporting software. For location
1771 and more information, read <file:Documentation/power/apm-acpi.txt>
1772 and the Battery Powered Linux mini-HOWTO, available from
1773 <http://www.tldp.org/docs.html#howto>.
1775 This driver does not spin down disk drives (see the hdparm(8)
1776 manpage ("man 8 hdparm") for that), and it doesn't turn off
1777 VESA-compliant "green" monitors.
1779 This driver does not support the TI 4000M TravelMate and the ACER
1780 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1781 desktop machines also don't have compliant BIOSes, and this driver
1782 may cause those machines to panic during the boot phase.
1784 Generally, if you don't have a battery in your machine, there isn't
1785 much point in using this driver and you should say N. If you get
1786 random kernel OOPSes or reboots that don't seem to be related to
1787 anything, try disabling/enabling this option (or disabling/enabling
1790 Some other things you should try when experiencing seemingly random,
1793 1) make sure that you have enough swap space and that it is
1795 2) pass the "no-hlt" option to the kernel
1796 3) switch on floating point emulation in the kernel and pass
1797 the "no387" option to the kernel
1798 4) pass the "floppy=nodma" option to the kernel
1799 5) pass the "mem=4M" option to the kernel (thereby disabling
1800 all but the first 4 MB of RAM)
1801 6) make sure that the CPU is not over clocked.
1802 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1803 8) disable the cache from your BIOS settings
1804 9) install a fan for the video card or exchange video RAM
1805 10) install a better fan for the CPU
1806 11) exchange RAM chips
1807 12) exchange the motherboard.
1809 To compile this driver as a module, choose M here: the
1810 module will be called apm.
1814 config APM_IGNORE_USER_SUSPEND
1815 bool "Ignore USER SUSPEND"
1817 This option will ignore USER SUSPEND requests. On machines with a
1818 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1819 series notebooks, it is necessary to say Y because of a BIOS bug.
1821 config APM_DO_ENABLE
1822 bool "Enable PM at boot time"
1824 Enable APM features at boot time. From page 36 of the APM BIOS
1825 specification: "When disabled, the APM BIOS does not automatically
1826 power manage devices, enter the Standby State, enter the Suspend
1827 State, or take power saving steps in response to CPU Idle calls."
1828 This driver will make CPU Idle calls when Linux is idle (unless this
1829 feature is turned off -- see "Do CPU IDLE calls", below). This
1830 should always save battery power, but more complicated APM features
1831 will be dependent on your BIOS implementation. You may need to turn
1832 this option off if your computer hangs at boot time when using APM
1833 support, or if it beeps continuously instead of suspending. Turn
1834 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1835 T400CDT. This is off by default since most machines do fine without
1839 bool "Make CPU Idle calls when idle"
1841 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1842 On some machines, this can activate improved power savings, such as
1843 a slowed CPU clock rate, when the machine is idle. These idle calls
1844 are made after the idle loop has run for some length of time (e.g.,
1845 333 mS). On some machines, this will cause a hang at boot time or
1846 whenever the CPU becomes idle. (On machines with more than one CPU,
1847 this option does nothing.)
1849 config APM_DISPLAY_BLANK
1850 bool "Enable console blanking using APM"
1852 Enable console blanking using the APM. Some laptops can use this to
1853 turn off the LCD backlight when the screen blanker of the Linux
1854 virtual console blanks the screen. Note that this is only used by
1855 the virtual console screen blanker, and won't turn off the backlight
1856 when using the X Window system. This also doesn't have anything to
1857 do with your VESA-compliant power-saving monitor. Further, this
1858 option doesn't work for all laptops -- it might not turn off your
1859 backlight at all, or it might print a lot of errors to the console,
1860 especially if you are using gpm.
1862 config APM_ALLOW_INTS
1863 bool "Allow interrupts during APM BIOS calls"
1865 Normally we disable external interrupts while we are making calls to
1866 the APM BIOS as a measure to lessen the effects of a badly behaving
1867 BIOS implementation. The BIOS should reenable interrupts if it
1868 needs to. Unfortunately, some BIOSes do not -- especially those in
1869 many of the newer IBM Thinkpads. If you experience hangs when you
1870 suspend, try setting this to Y. Otherwise, say N.
1874 source "drivers/cpufreq/Kconfig"
1876 source "drivers/cpuidle/Kconfig"
1878 source "drivers/idle/Kconfig"
1883 menu "Bus options (PCI etc.)"
1888 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1890 Find out whether you have a PCI motherboard. PCI is the name of a
1891 bus system, i.e. the way the CPU talks to the other stuff inside
1892 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1893 VESA. If you have PCI, say Y, otherwise N.
1896 prompt "PCI access mode"
1897 depends on X86_32 && PCI
1900 On PCI systems, the BIOS can be used to detect the PCI devices and
1901 determine their configuration. However, some old PCI motherboards
1902 have BIOS bugs and may crash if this is done. Also, some embedded
1903 PCI-based systems don't have any BIOS at all. Linux can also try to
1904 detect the PCI hardware directly without using the BIOS.
1906 With this option, you can specify how Linux should detect the
1907 PCI devices. If you choose "BIOS", the BIOS will be used,
1908 if you choose "Direct", the BIOS won't be used, and if you
1909 choose "MMConfig", then PCI Express MMCONFIG will be used.
1910 If you choose "Any", the kernel will try MMCONFIG, then the
1911 direct access method and falls back to the BIOS if that doesn't
1912 work. If unsure, go with the default, which is "Any".
1917 config PCI_GOMMCONFIG
1934 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1936 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1939 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1943 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1947 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1951 depends on PCI && XEN
1959 bool "Support mmconfig PCI config space access"
1960 depends on X86_64 && PCI && ACPI
1962 config PCI_CNB20LE_QUIRK
1963 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1965 depends on PCI && EXPERIMENTAL
1967 Read the PCI windows out of the CNB20LE host bridge. This allows
1968 PCI hotplug to work on systems with the CNB20LE chipset which do
1971 There's no public spec for this chipset, and this functionality
1972 is known to be incomplete.
1974 You should say N unless you know you need this.
1976 source "drivers/pci/pcie/Kconfig"
1978 source "drivers/pci/Kconfig"
1980 # x86_64 have no ISA slots, but can have ISA-style DMA.
1982 bool "ISA-style DMA support" if (X86_64 && EXPERT)
1985 Enables ISA-style DMA support for devices requiring such controllers.
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"
2055 Add support for detecting the unique features of the OLPC
2059 bool "OLPC XO-1 Power Management"
2060 depends on OLPC && MFD_CS5535 && PM_SLEEP
2063 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2066 bool "OLPC XO-1 Real Time Clock"
2067 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2069 Add support for the XO-1 real time clock, which can be used as a
2070 programmable wakeup source.
2073 bool "OLPC XO-1 SCI extras"
2074 depends on OLPC && OLPC_XO1_PM
2079 Add support for SCI-based features of the OLPC XO-1 laptop:
2080 - EC-driven system wakeups
2084 - AC adapter status updates
2085 - Battery status updates
2087 config OLPC_XO15_SCI
2088 bool "OLPC XO-1.5 SCI extras"
2089 depends on OLPC && ACPI
2092 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2093 - EC-driven system wakeups
2094 - AC adapter status updates
2095 - Battery status updates
2098 bool "PCEngines ALIX System Support (LED setup)"
2101 This option enables system support for the PCEngines ALIX.
2102 At present this just sets up LEDs for GPIO control on
2103 ALIX2/3/6 boards. However, other system specific setup should
2106 Note: You must still enable the drivers for GPIO and LED support
2107 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2109 Note: You have to set alix.force=1 for boards with Award BIOS.
2115 depends on CPU_SUP_AMD && PCI
2117 source "drivers/pcmcia/Kconfig"
2119 source "drivers/pci/hotplug/Kconfig"
2122 bool "RapidIO support"
2126 If you say Y here, the kernel will include drivers and
2127 infrastructure code to support RapidIO interconnect devices.
2129 source "drivers/rapidio/Kconfig"
2134 menu "Executable file formats / Emulations"
2136 source "fs/Kconfig.binfmt"
2138 config IA32_EMULATION
2139 bool "IA32 Emulation"
2141 select COMPAT_BINFMT_ELF
2143 Include code to run 32-bit programs under a 64-bit kernel. You should
2144 likely turn this on, unless you're 100% sure that you don't have any
2145 32-bit programs left.
2148 tristate "IA32 a.out support"
2149 depends on IA32_EMULATION
2151 Support old a.out binaries in the 32bit emulation.
2155 depends on IA32_EMULATION
2157 config COMPAT_FOR_U64_ALIGNMENT
2161 config SYSVIPC_COMPAT
2163 depends on COMPAT && SYSVIPC
2167 depends on COMPAT && KEYS
2173 config HAVE_ATOMIC_IOMAP
2177 config HAVE_TEXT_POKE_SMP
2179 select STOP_MACHINE if SMP
2181 source "net/Kconfig"
2183 source "drivers/Kconfig"
2185 source "drivers/firmware/Kconfig"
2189 source "arch/x86/Kconfig.debug"
2191 source "security/Kconfig"
2193 source "crypto/Kconfig"
2195 source "arch/x86/kvm/Kconfig"
2197 source "lib/Kconfig"
projects / linux-drm-fsl-dcu.git / blob