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_ALIGNED_STRUCT_PAGE if SLUB && !M386
64 select HAVE_CMPXCHG_LOCAL if !M386
65 select HAVE_CMPXCHG_DOUBLE
66 select HAVE_ARCH_KMEMCHECK
67 select HAVE_USER_RETURN_NOTIFIER
68 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
69 select HAVE_ARCH_JUMP_LABEL
70 select HAVE_TEXT_POKE_SMP
71 select HAVE_GENERIC_HARDIRQS
72 select HAVE_SPARSE_IRQ
74 select GENERIC_FIND_FIRST_BIT
75 select GENERIC_IRQ_PROBE
76 select GENERIC_PENDING_IRQ if SMP
77 select GENERIC_IRQ_SHOW
78 select GENERIC_CLOCKEVENTS_MIN_ADJUST
79 select IRQ_FORCED_THREADING
80 select USE_GENERIC_SMP_HELPERS if SMP
81 select HAVE_BPF_JIT if (X86_64 && NET)
83 select ARCH_HAVE_NMI_SAFE_CMPXCHG
85 select DCACHE_WORD_ACCESS if !DEBUG_PAGEALLOC
87 config INSTRUCTION_DECODER
88 def_bool (KPROBES || PERF_EVENTS)
92 default "elf32-i386" if X86_32
93 default "elf64-x86-64" if X86_64
97 default "arch/x86/configs/i386_defconfig" if X86_32
98 default "arch/x86/configs/x86_64_defconfig" if X86_64
100 config GENERIC_CMOS_UPDATE
103 config CLOCKSOURCE_WATCHDOG
106 config GENERIC_CLOCKEVENTS
109 config ARCH_CLOCKSOURCE_DATA
113 config GENERIC_CLOCKEVENTS_BROADCAST
115 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
117 config LOCKDEP_SUPPORT
120 config STACKTRACE_SUPPORT
123 config HAVE_LATENCYTOP_SUPPORT
132 config NEED_DMA_MAP_STATE
133 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG)
135 config NEED_SG_DMA_LENGTH
138 config GENERIC_ISA_DMA
144 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
146 config GENERIC_BUG_RELATIVE_POINTERS
149 config GENERIC_HWEIGHT
155 config ARCH_MAY_HAVE_PC_FDC
158 config RWSEM_GENERIC_SPINLOCK
161 config RWSEM_XCHGADD_ALGORITHM
164 config ARCH_HAS_CPU_IDLE_WAIT
167 config GENERIC_CALIBRATE_DELAY
170 config GENERIC_TIME_VSYSCALL
174 config ARCH_HAS_CPU_RELAX
177 config ARCH_HAS_DEFAULT_IDLE
180 config ARCH_HAS_CACHE_LINE_SIZE
183 config HAVE_SETUP_PER_CPU_AREA
186 config NEED_PER_CPU_EMBED_FIRST_CHUNK
189 config NEED_PER_CPU_PAGE_FIRST_CHUNK
192 config ARCH_HIBERNATION_POSSIBLE
195 config ARCH_SUSPEND_POSSIBLE
206 config ARCH_SUPPORTS_OPTIMIZED_INLINING
209 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
212 config HAVE_INTEL_TXT
214 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
218 depends on X86_32 && SMP
222 depends on X86_64 && SMP
228 config X86_32_LAZY_GS
230 depends on X86_32 && !CC_STACKPROTECTOR
232 config ARCH_HWEIGHT_CFLAGS
234 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
235 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
240 config ARCH_CPU_PROBE_RELEASE
242 depends on HOTPLUG_CPU
244 source "init/Kconfig"
245 source "kernel/Kconfig.freezer"
247 menu "Processor type and features"
250 bool "DMA memory allocation support" if EXPERT
253 DMA memory allocation support allows devices with less than 32-bit
254 addressing to allocate within the first 16MB of address space.
255 Disable if no such devices will be used.
259 source "kernel/time/Kconfig"
262 bool "Symmetric multi-processing support"
264 This enables support for systems with more than one CPU. If you have
265 a system with only one CPU, like most personal computers, say N. If
266 you have a system with more than one CPU, say Y.
268 If you say N here, the kernel will run on single and multiprocessor
269 machines, but will use only one CPU of a multiprocessor machine. If
270 you say Y here, the kernel will run on many, but not all,
271 singleprocessor machines. On a singleprocessor machine, the kernel
272 will run faster if you say N here.
274 Note that if you say Y here and choose architecture "586" or
275 "Pentium" under "Processor family", the kernel will not work on 486
276 architectures. Similarly, multiprocessor kernels for the "PPro"
277 architecture may not work on all Pentium based boards.
279 People using multiprocessor machines who say Y here should also say
280 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
281 Management" code will be disabled if you say Y here.
283 See also <file:Documentation/x86/i386/IO-APIC.txt>,
284 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
285 <http://www.tldp.org/docs.html#howto>.
287 If you don't know what to do here, say N.
290 bool "Support x2apic"
291 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
293 This enables x2apic support on CPUs that have this feature.
295 This allows 32-bit apic IDs (so it can support very large systems),
296 and accesses the local apic via MSRs not via mmio.
298 If you don't know what to do here, say N.
301 bool "Enable MPS table" if ACPI
303 depends on X86_LOCAL_APIC
305 For old smp systems that do not have proper acpi support. Newer systems
306 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
309 bool "Support for big SMP systems with more than 8 CPUs"
310 depends on X86_32 && SMP
312 This option is needed for the systems that have more than 8 CPUs
315 config X86_EXTENDED_PLATFORM
316 bool "Support for extended (non-PC) x86 platforms"
319 If you disable this option then the kernel will only support
320 standard PC platforms. (which covers the vast majority of
323 If you enable this option then you'll be able to select support
324 for the following (non-PC) 32 bit x86 platforms:
328 SGI 320/540 (Visual Workstation)
329 Summit/EXA (IBM x440)
330 Unisys ES7000 IA32 series
331 Moorestown MID devices
333 If you have one of these systems, or if you want to build a
334 generic distribution kernel, say Y here - otherwise say N.
338 config X86_EXTENDED_PLATFORM
339 bool "Support for extended (non-PC) x86 platforms"
342 If you disable this option then the kernel will only support
343 standard PC platforms. (which covers the vast majority of
346 If you enable this option then you'll be able to select support
347 for the following (non-PC) 64 bit x86 platforms:
352 If you have one of these systems, or if you want to build a
353 generic distribution kernel, say Y here - otherwise say N.
355 # This is an alphabetically sorted list of 64 bit extended platforms
356 # Please maintain the alphabetic order if and when there are additions
358 bool "Numascale NumaChip"
360 depends on X86_EXTENDED_PLATFORM
363 depends on X86_X2APIC
365 Adds support for Numascale NumaChip large-SMP systems. Needed to
366 enable more than ~168 cores.
367 If you don't have one of these, you should say N here.
371 select PARAVIRT_GUEST
373 depends on X86_64 && PCI
374 depends on X86_EXTENDED_PLATFORM
376 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
377 supposed to run on these EM64T-based machines. Only choose this option
378 if you have one of these machines.
381 bool "SGI Ultraviolet"
383 depends on X86_EXTENDED_PLATFORM
385 depends on X86_X2APIC
387 This option is needed in order to support SGI Ultraviolet systems.
388 If you don't have one of these, you should say N here.
390 # Following is an alphabetically sorted list of 32 bit extended platforms
391 # Please maintain the alphabetic order if and when there are additions
394 bool "CE4100 TV platform"
396 depends on PCI_GODIRECT
398 depends on X86_EXTENDED_PLATFORM
399 select X86_REBOOTFIXUPS
401 select OF_EARLY_FLATTREE
403 Select for the Intel CE media processor (CE4100) SOC.
404 This option compiles in support for the CE4100 SOC for settop
405 boxes and media devices.
407 config X86_WANT_INTEL_MID
408 bool "Intel MID platform support"
410 depends on X86_EXTENDED_PLATFORM
412 Select to build a kernel capable of supporting Intel MID platform
413 systems which do not have the PCI legacy interfaces (Moorestown,
414 Medfield). If you are building for a PC class system say N here.
416 if X86_WANT_INTEL_MID
422 bool "Moorestown MID platform"
425 depends on X86_IO_APIC
433 select X86_PLATFORM_DEVICES
435 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
436 Internet Device(MID) platform. Moorestown consists of two chips:
437 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
438 Unlike standard x86 PCs, Moorestown does not have many legacy devices
439 nor standard legacy replacement devices/features. e.g. Moorestown does
440 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
443 bool "Medfield MID platform"
446 depends on X86_IO_APIC
454 select X86_PLATFORM_DEVICES
456 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
457 Internet Device(MID) platform.
458 Unlike standard x86 PCs, Medfield does not have many legacy devices
459 nor standard legacy replacement devices/features. e.g. Medfield does
460 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
465 bool "RDC R-321x SoC"
467 depends on X86_EXTENDED_PLATFORM
469 select X86_REBOOTFIXUPS
471 This option is needed for RDC R-321x system-on-chip, also known
473 If you don't have one of these chips, you should say N here.
475 config X86_32_NON_STANDARD
476 bool "Support non-standard 32-bit SMP architectures"
477 depends on X86_32 && SMP
478 depends on X86_EXTENDED_PLATFORM
480 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
481 subarchitectures. It is intended for a generic binary kernel.
482 if you select them all, kernel will probe it one by one. and will
485 # Alphabetically sorted list of Non standard 32 bit platforms
488 bool "NUMAQ (IBM/Sequent)"
489 depends on X86_32_NON_STANDARD
494 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
495 NUMA multiquad box. This changes the way that processors are
496 bootstrapped, and uses Clustered Logical APIC addressing mode instead
497 of Flat Logical. You will need a new lynxer.elf file to flash your
498 firmware with - send email to <Martin.Bligh@us.ibm.com>.
500 config X86_SUPPORTS_MEMORY_FAILURE
502 # MCE code calls memory_failure():
504 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
505 depends on !X86_NUMAQ
506 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
507 depends on X86_64 || !SPARSEMEM
508 select ARCH_SUPPORTS_MEMORY_FAILURE
511 bool "SGI 320/540 (Visual Workstation)"
512 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
513 depends on X86_32_NON_STANDARD
515 The SGI Visual Workstation series is an IA32-based workstation
516 based on SGI systems chips with some legacy PC hardware attached.
518 Say Y here to create a kernel to run on the SGI 320 or 540.
520 A kernel compiled for the Visual Workstation will run on general
521 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
524 bool "Summit/EXA (IBM x440)"
525 depends on X86_32_NON_STANDARD
527 This option is needed for IBM systems that use the Summit/EXA chipset.
528 In particular, it is needed for the x440.
531 bool "Unisys ES7000 IA32 series"
532 depends on X86_32_NON_STANDARD && X86_BIGSMP
534 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
535 supposed to run on an IA32-based Unisys ES7000 system.
538 tristate "Eurobraille/Iris poweroff module"
541 The Iris machines from EuroBraille do not have APM or ACPI support
542 to shut themselves down properly. A special I/O sequence is
543 needed to do so, which is what this module does at
546 This is only for Iris machines from EuroBraille.
550 config SCHED_OMIT_FRAME_POINTER
552 prompt "Single-depth WCHAN output"
555 Calculate simpler /proc/<PID>/wchan values. If this option
556 is disabled then wchan values will recurse back to the
557 caller function. This provides more accurate wchan values,
558 at the expense of slightly more scheduling overhead.
560 If in doubt, say "Y".
562 menuconfig PARAVIRT_GUEST
563 bool "Paravirtualized guest support"
565 Say Y here to get to see options related to running Linux under
566 various hypervisors. This option alone does not add any kernel code.
568 If you say N, all options in this submenu will be skipped and disabled.
572 config PARAVIRT_TIME_ACCOUNTING
573 bool "Paravirtual steal time accounting"
577 Select this option to enable fine granularity task steal time
578 accounting. Time spent executing other tasks in parallel with
579 the current vCPU is discounted from the vCPU power. To account for
580 that, there can be a small performance impact.
582 If in doubt, say N here.
584 source "arch/x86/xen/Kconfig"
587 bool "KVM paravirtualized clock"
589 select PARAVIRT_CLOCK
591 Turning on this option will allow you to run a paravirtualized clock
592 when running over the KVM hypervisor. Instead of relying on a PIT
593 (or probably other) emulation by the underlying device model, the host
594 provides the guest with timing infrastructure such as time of day, and
598 bool "KVM Guest support"
601 This option enables various optimizations for running under the KVM
604 source "arch/x86/lguest/Kconfig"
607 bool "Enable paravirtualization code"
609 This changes the kernel so it can modify itself when it is run
610 under a hypervisor, potentially improving performance significantly
611 over full virtualization. However, when run without a hypervisor
612 the kernel is theoretically slower and slightly larger.
614 config PARAVIRT_SPINLOCKS
615 bool "Paravirtualization layer for spinlocks"
616 depends on PARAVIRT && SMP && EXPERIMENTAL
618 Paravirtualized spinlocks allow a pvops backend to replace the
619 spinlock implementation with something virtualization-friendly
620 (for example, block the virtual CPU rather than spinning).
622 Unfortunately the downside is an up to 5% performance hit on
623 native kernels, with various workloads.
625 If you are unsure how to answer this question, answer N.
627 config PARAVIRT_CLOCK
632 config PARAVIRT_DEBUG
633 bool "paravirt-ops debugging"
634 depends on PARAVIRT && DEBUG_KERNEL
636 Enable to debug paravirt_ops internals. Specifically, BUG if
637 a paravirt_op is missing when it is called.
645 This option adds a kernel parameter 'memtest', which allows memtest
647 memtest=0, mean disabled; -- default
648 memtest=1, mean do 1 test pattern;
650 memtest=4, mean do 4 test patterns.
651 If you are unsure how to answer this question, answer N.
653 config X86_SUMMIT_NUMA
655 depends on X86_32 && NUMA && X86_32_NON_STANDARD
657 config X86_CYCLONE_TIMER
659 depends on X86_SUMMIT
661 source "arch/x86/Kconfig.cpu"
665 prompt "HPET Timer Support" if X86_32
667 Use the IA-PC HPET (High Precision Event Timer) to manage
668 time in preference to the PIT and RTC, if a HPET is
670 HPET is the next generation timer replacing legacy 8254s.
671 The HPET provides a stable time base on SMP
672 systems, unlike the TSC, but it is more expensive to access,
673 as it is off-chip. You can find the HPET spec at
674 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
676 You can safely choose Y here. However, HPET will only be
677 activated if the platform and the BIOS support this feature.
678 Otherwise the 8254 will be used for timing services.
680 Choose N to continue using the legacy 8254 timer.
682 config HPET_EMULATE_RTC
684 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
687 def_bool y if X86_INTEL_MID
688 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
690 depends on X86_INTEL_MID && SFI
692 APB timer is the replacement for 8254, HPET on X86 MID platforms.
693 The APBT provides a stable time base on SMP
694 systems, unlike the TSC, but it is more expensive to access,
695 as it is off-chip. APB timers are always running regardless of CPU
696 C states, they are used as per CPU clockevent device when possible.
698 # Mark as expert because too many people got it wrong.
699 # The code disables itself when not needed.
702 bool "Enable DMI scanning" if EXPERT
704 Enabled scanning of DMI to identify machine quirks. Say Y
705 here unless you have verified that your setup is not
706 affected by entries in the DMI blacklist. Required by PNP
710 bool "GART IOMMU support" if EXPERT
713 depends on X86_64 && PCI && AMD_NB
715 Support for full DMA access of devices with 32bit memory access only
716 on systems with more than 3GB. This is usually needed for USB,
717 sound, many IDE/SATA chipsets and some other devices.
718 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
719 based hardware IOMMU and a software bounce buffer based IOMMU used
720 on Intel systems and as fallback.
721 The code is only active when needed (enough memory and limited
722 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
726 bool "IBM Calgary IOMMU support"
728 depends on X86_64 && PCI && EXPERIMENTAL
730 Support for hardware IOMMUs in IBM's xSeries x366 and x460
731 systems. Needed to run systems with more than 3GB of memory
732 properly with 32-bit PCI devices that do not support DAC
733 (Double Address Cycle). Calgary also supports bus level
734 isolation, where all DMAs pass through the IOMMU. This
735 prevents them from going anywhere except their intended
736 destination. This catches hard-to-find kernel bugs and
737 mis-behaving drivers and devices that do not use the DMA-API
738 properly to set up their DMA buffers. The IOMMU can be
739 turned off at boot time with the iommu=off parameter.
740 Normally the kernel will make the right choice by itself.
743 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
745 prompt "Should Calgary be enabled by default?"
746 depends on CALGARY_IOMMU
748 Should Calgary be enabled by default? if you choose 'y', Calgary
749 will be used (if it exists). If you choose 'n', Calgary will not be
750 used even if it exists. If you choose 'n' and would like to use
751 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
754 # need this always selected by IOMMU for the VIA workaround
758 Support for software bounce buffers used on x86-64 systems
759 which don't have a hardware IOMMU (e.g. the current generation
760 of Intel's x86-64 CPUs). Using this PCI devices which can only
761 access 32-bits of memory can be used on systems with more than
762 3 GB of memory. If unsure, say Y.
765 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
768 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
769 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
770 select CPUMASK_OFFSTACK
772 Enable maximum number of CPUS and NUMA Nodes for this architecture.
776 int "Maximum number of CPUs" if SMP && !MAXSMP
777 range 2 8 if SMP && X86_32 && !X86_BIGSMP
778 range 2 512 if SMP && !MAXSMP
780 default "4096" if MAXSMP
781 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
784 This allows you to specify the maximum number of CPUs which this
785 kernel will support. The maximum supported value is 512 and the
786 minimum value which makes sense is 2.
788 This is purely to save memory - each supported CPU adds
789 approximately eight kilobytes to the kernel image.
792 bool "SMT (Hyperthreading) scheduler support"
795 SMT scheduler support improves the CPU scheduler's decision making
796 when dealing with Intel Pentium 4 chips with HyperThreading at a
797 cost of slightly increased overhead in some places. If unsure say
802 prompt "Multi-core scheduler support"
805 Multi-core scheduler support improves the CPU scheduler's decision
806 making when dealing with multi-core CPU chips at a cost of slightly
807 increased overhead in some places. If unsure say N here.
809 config IRQ_TIME_ACCOUNTING
810 bool "Fine granularity task level IRQ time accounting"
813 Select this option to enable fine granularity task irq time
814 accounting. This is done by reading a timestamp on each
815 transitions between softirq and hardirq state, so there can be a
816 small performance impact.
818 If in doubt, say N here.
820 source "kernel/Kconfig.preempt"
823 bool "Local APIC support on uniprocessors"
824 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
826 A local APIC (Advanced Programmable Interrupt Controller) is an
827 integrated interrupt controller in the CPU. If you have a single-CPU
828 system which has a processor with a local APIC, you can say Y here to
829 enable and use it. If you say Y here even though your machine doesn't
830 have a local APIC, then the kernel will still run with no slowdown at
831 all. The local APIC supports CPU-generated self-interrupts (timer,
832 performance counters), and the NMI watchdog which detects hard
836 bool "IO-APIC support on uniprocessors"
837 depends on X86_UP_APIC
839 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
840 SMP-capable replacement for PC-style interrupt controllers. Most
841 SMP systems and many recent uniprocessor systems have one.
843 If you have a single-CPU system with an IO-APIC, you can say Y here
844 to use it. If you say Y here even though your machine doesn't have
845 an IO-APIC, then the kernel will still run with no slowdown at all.
847 config X86_LOCAL_APIC
849 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
853 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
855 config X86_VISWS_APIC
857 depends on X86_32 && X86_VISWS
859 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
860 bool "Reroute for broken boot IRQs"
861 depends on X86_IO_APIC
863 This option enables a workaround that fixes a source of
864 spurious interrupts. This is recommended when threaded
865 interrupt handling is used on systems where the generation of
866 superfluous "boot interrupts" cannot be disabled.
868 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
869 entry in the chipset's IO-APIC is masked (as, e.g. the RT
870 kernel does during interrupt handling). On chipsets where this
871 boot IRQ generation cannot be disabled, this workaround keeps
872 the original IRQ line masked so that only the equivalent "boot
873 IRQ" is delivered to the CPUs. The workaround also tells the
874 kernel to set up the IRQ handler on the boot IRQ line. In this
875 way only one interrupt is delivered to the kernel. Otherwise
876 the spurious second interrupt may cause the kernel to bring
877 down (vital) interrupt lines.
879 Only affects "broken" chipsets. Interrupt sharing may be
880 increased on these systems.
883 bool "Machine Check / overheating reporting"
885 Machine Check support allows the processor to notify the
886 kernel if it detects a problem (e.g. overheating, data corruption).
887 The action the kernel takes depends on the severity of the problem,
888 ranging from warning messages to halting the machine.
892 prompt "Intel MCE features"
893 depends on X86_MCE && X86_LOCAL_APIC
895 Additional support for intel specific MCE features such as
900 prompt "AMD MCE features"
901 depends on X86_MCE && X86_LOCAL_APIC
903 Additional support for AMD specific MCE features such as
904 the DRAM Error Threshold.
906 config X86_ANCIENT_MCE
907 bool "Support for old Pentium 5 / WinChip machine checks"
908 depends on X86_32 && X86_MCE
910 Include support for machine check handling on old Pentium 5 or WinChip
911 systems. These typically need to be enabled explicitely on the command
914 config X86_MCE_THRESHOLD
915 depends on X86_MCE_AMD || X86_MCE_INTEL
918 config X86_MCE_INJECT
920 tristate "Machine check injector support"
922 Provide support for injecting machine checks for testing purposes.
923 If you don't know what a machine check is and you don't do kernel
924 QA it is safe to say n.
926 config X86_THERMAL_VECTOR
928 depends on X86_MCE_INTEL
931 bool "Enable VM86 support" if EXPERT
935 This option is required by programs like DOSEMU to run 16-bit legacy
936 code on X86 processors. It also may be needed by software like
937 XFree86 to initialize some video cards via BIOS. Disabling this
938 option saves about 6k.
941 tristate "Toshiba Laptop support"
944 This adds a driver to safely access the System Management Mode of
945 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
946 not work on models with a Phoenix BIOS. The System Management Mode
947 is used to set the BIOS and power saving options on Toshiba portables.
949 For information on utilities to make use of this driver see the
950 Toshiba Linux utilities web site at:
951 <http://www.buzzard.org.uk/toshiba/>.
953 Say Y if you intend to run this kernel on a Toshiba portable.
957 tristate "Dell laptop support"
960 This adds a driver to safely access the System Management Mode
961 of the CPU on the Dell Inspiron 8000. The System Management Mode
962 is used to read cpu temperature and cooling fan status and to
963 control the fans on the I8K portables.
965 This driver has been tested only on the Inspiron 8000 but it may
966 also work with other Dell laptops. You can force loading on other
967 models by passing the parameter `force=1' to the module. Use at
970 For information on utilities to make use of this driver see the
971 I8K Linux utilities web site at:
972 <http://people.debian.org/~dz/i8k/>
974 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
977 config X86_REBOOTFIXUPS
978 bool "Enable X86 board specific fixups for reboot"
981 This enables chipset and/or board specific fixups to be done
982 in order to get reboot to work correctly. This is only needed on
983 some combinations of hardware and BIOS. The symptom, for which
984 this config is intended, is when reboot ends with a stalled/hung
987 Currently, the only fixup is for the Geode machines using
988 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
990 Say Y if you want to enable the fixup. Currently, it's safe to
991 enable this option even if you don't need it.
995 tristate "/dev/cpu/microcode - microcode support"
998 If you say Y here, you will be able to update the microcode on
999 certain Intel and AMD processors. The Intel support is for the
1000 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
1001 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
1002 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
1003 You will obviously need the actual microcode binary data itself
1004 which is not shipped with the Linux kernel.
1006 This option selects the general module only, you need to select
1007 at least one vendor specific module as well.
1009 To compile this driver as a module, choose M here: the
1010 module will be called microcode.
1012 config MICROCODE_INTEL
1013 bool "Intel microcode patch loading support"
1014 depends on MICROCODE
1018 This options enables microcode patch loading support for Intel
1021 For latest news and information on obtaining all the required
1022 Intel ingredients for this driver, check:
1023 <http://www.urbanmyth.org/microcode/>.
1025 config MICROCODE_AMD
1026 bool "AMD microcode patch loading support"
1027 depends on MICROCODE
1030 If you select this option, microcode patch loading support for AMD
1031 processors will be enabled.
1033 config MICROCODE_OLD_INTERFACE
1035 depends on MICROCODE
1038 tristate "/dev/cpu/*/msr - Model-specific register support"
1040 This device gives privileged processes access to the x86
1041 Model-Specific Registers (MSRs). It is a character device with
1042 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1043 MSR accesses are directed to a specific CPU on multi-processor
1047 tristate "/dev/cpu/*/cpuid - CPU information support"
1049 This device gives processes access to the x86 CPUID instruction to
1050 be executed on a specific processor. It is a character device
1051 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1055 prompt "High Memory Support"
1056 default HIGHMEM64G if X86_NUMAQ
1062 depends on !X86_NUMAQ
1064 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1065 However, the address space of 32-bit x86 processors is only 4
1066 Gigabytes large. That means that, if you have a large amount of
1067 physical memory, not all of it can be "permanently mapped" by the
1068 kernel. The physical memory that's not permanently mapped is called
1071 If you are compiling a kernel which will never run on a machine with
1072 more than 1 Gigabyte total physical RAM, answer "off" here (default
1073 choice and suitable for most users). This will result in a "3GB/1GB"
1074 split: 3GB are mapped so that each process sees a 3GB virtual memory
1075 space and the remaining part of the 4GB virtual memory space is used
1076 by the kernel to permanently map as much physical memory as
1079 If the machine has between 1 and 4 Gigabytes physical RAM, then
1082 If more than 4 Gigabytes is used then answer "64GB" here. This
1083 selection turns Intel PAE (Physical Address Extension) mode on.
1084 PAE implements 3-level paging on IA32 processors. PAE is fully
1085 supported by Linux, PAE mode is implemented on all recent Intel
1086 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1087 then the kernel will not boot on CPUs that don't support PAE!
1089 The actual amount of total physical memory will either be
1090 auto detected or can be forced by using a kernel command line option
1091 such as "mem=256M". (Try "man bootparam" or see the documentation of
1092 your boot loader (lilo or loadlin) about how to pass options to the
1093 kernel at boot time.)
1095 If unsure, say "off".
1099 depends on !X86_NUMAQ
1101 Select this if you have a 32-bit processor and between 1 and 4
1102 gigabytes of physical RAM.
1106 depends on !M386 && !M486
1109 Select this if you have a 32-bit processor and more than 4
1110 gigabytes of physical RAM.
1115 depends on EXPERIMENTAL
1116 prompt "Memory split" if EXPERT
1120 Select the desired split between kernel and user memory.
1122 If the address range available to the kernel is less than the
1123 physical memory installed, the remaining memory will be available
1124 as "high memory". Accessing high memory is a little more costly
1125 than low memory, as it needs to be mapped into the kernel first.
1126 Note that increasing the kernel address space limits the range
1127 available to user programs, making the address space there
1128 tighter. Selecting anything other than the default 3G/1G split
1129 will also likely make your kernel incompatible with binary-only
1132 If you are not absolutely sure what you are doing, leave this
1136 bool "3G/1G user/kernel split"
1137 config VMSPLIT_3G_OPT
1139 bool "3G/1G user/kernel split (for full 1G low memory)"
1141 bool "2G/2G user/kernel split"
1142 config VMSPLIT_2G_OPT
1144 bool "2G/2G user/kernel split (for full 2G low memory)"
1146 bool "1G/3G user/kernel split"
1151 default 0xB0000000 if VMSPLIT_3G_OPT
1152 default 0x80000000 if VMSPLIT_2G
1153 default 0x78000000 if VMSPLIT_2G_OPT
1154 default 0x40000000 if VMSPLIT_1G
1160 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1163 bool "PAE (Physical Address Extension) Support"
1164 depends on X86_32 && !HIGHMEM4G
1166 PAE is required for NX support, and furthermore enables
1167 larger swapspace support for non-overcommit purposes. It
1168 has the cost of more pagetable lookup overhead, and also
1169 consumes more pagetable space per process.
1171 config ARCH_PHYS_ADDR_T_64BIT
1172 def_bool X86_64 || X86_PAE
1174 config ARCH_DMA_ADDR_T_64BIT
1175 def_bool X86_64 || HIGHMEM64G
1177 config DIRECT_GBPAGES
1178 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1182 Allow the kernel linear mapping to use 1GB pages on CPUs that
1183 support it. This can improve the kernel's performance a tiny bit by
1184 reducing TLB pressure. If in doubt, say "Y".
1186 # Common NUMA Features
1188 bool "Numa Memory Allocation and Scheduler Support"
1190 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1191 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1193 Enable NUMA (Non Uniform Memory Access) support.
1195 The kernel will try to allocate memory used by a CPU on the
1196 local memory controller of the CPU and add some more
1197 NUMA awareness to the kernel.
1199 For 64-bit this is recommended if the system is Intel Core i7
1200 (or later), AMD Opteron, or EM64T NUMA.
1202 For 32-bit this is only needed on (rare) 32-bit-only platforms
1203 that support NUMA topologies, such as NUMAQ / Summit, or if you
1204 boot a 32-bit kernel on a 64-bit NUMA platform.
1206 Otherwise, you should say N.
1208 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1209 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1213 prompt "Old style AMD Opteron NUMA detection"
1214 depends on X86_64 && NUMA && PCI
1216 Enable AMD NUMA node topology detection. You should say Y here if
1217 you have a multi processor AMD system. This uses an old method to
1218 read the NUMA configuration directly from the builtin Northbridge
1219 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1220 which also takes priority if both are compiled in.
1222 config X86_64_ACPI_NUMA
1224 prompt "ACPI NUMA detection"
1225 depends on X86_64 && NUMA && ACPI && PCI
1228 Enable ACPI SRAT based node topology detection.
1230 # Some NUMA nodes have memory ranges that span
1231 # other nodes. Even though a pfn is valid and
1232 # between a node's start and end pfns, it may not
1233 # reside on that node. See memmap_init_zone()
1235 config NODES_SPAN_OTHER_NODES
1237 depends on X86_64_ACPI_NUMA
1240 bool "NUMA emulation"
1243 Enable NUMA emulation. A flat machine will be split
1244 into virtual nodes when booted with "numa=fake=N", where N is the
1245 number of nodes. This is only useful for debugging.
1248 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1250 default "10" if MAXSMP
1251 default "6" if X86_64
1252 default "4" if X86_NUMAQ
1254 depends on NEED_MULTIPLE_NODES
1256 Specify the maximum number of NUMA Nodes available on the target
1257 system. Increases memory reserved to accommodate various tables.
1259 config HAVE_ARCH_BOOTMEM
1261 depends on X86_32 && NUMA
1263 config HAVE_ARCH_ALLOC_REMAP
1265 depends on X86_32 && NUMA
1267 config ARCH_HAVE_MEMORY_PRESENT
1269 depends on X86_32 && DISCONTIGMEM
1271 config NEED_NODE_MEMMAP_SIZE
1273 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1275 config ARCH_FLATMEM_ENABLE
1277 depends on X86_32 && !NUMA
1279 config ARCH_DISCONTIGMEM_ENABLE
1281 depends on NUMA && X86_32
1283 config ARCH_DISCONTIGMEM_DEFAULT
1285 depends on NUMA && X86_32
1287 config ARCH_SPARSEMEM_ENABLE
1289 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1290 select SPARSEMEM_STATIC if X86_32
1291 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1293 config ARCH_SPARSEMEM_DEFAULT
1297 config ARCH_SELECT_MEMORY_MODEL
1299 depends on ARCH_SPARSEMEM_ENABLE
1301 config ARCH_MEMORY_PROBE
1303 depends on MEMORY_HOTPLUG
1305 config ARCH_PROC_KCORE_TEXT
1307 depends on X86_64 && PROC_KCORE
1309 config ILLEGAL_POINTER_VALUE
1312 default 0xdead000000000000 if X86_64
1317 bool "Allocate 3rd-level pagetables from highmem"
1320 The VM uses one page table entry for each page of physical memory.
1321 For systems with a lot of RAM, this can be wasteful of precious
1322 low memory. Setting this option will put user-space page table
1323 entries in high memory.
1325 config X86_CHECK_BIOS_CORRUPTION
1326 bool "Check for low memory corruption"
1328 Periodically check for memory corruption in low memory, which
1329 is suspected to be caused by BIOS. Even when enabled in the
1330 configuration, it is disabled at runtime. Enable it by
1331 setting "memory_corruption_check=1" on the kernel command
1332 line. By default it scans the low 64k of memory every 60
1333 seconds; see the memory_corruption_check_size and
1334 memory_corruption_check_period parameters in
1335 Documentation/kernel-parameters.txt to adjust this.
1337 When enabled with the default parameters, this option has
1338 almost no overhead, as it reserves a relatively small amount
1339 of memory and scans it infrequently. It both detects corruption
1340 and prevents it from affecting the running system.
1342 It is, however, intended as a diagnostic tool; if repeatable
1343 BIOS-originated corruption always affects the same memory,
1344 you can use memmap= to prevent the kernel from using that
1347 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1348 bool "Set the default setting of memory_corruption_check"
1349 depends on X86_CHECK_BIOS_CORRUPTION
1352 Set whether the default state of memory_corruption_check is
1355 config X86_RESERVE_LOW
1356 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1360 Specify the amount of low memory to reserve for the BIOS.
1362 The first page contains BIOS data structures that the kernel
1363 must not use, so that page must always be reserved.
1365 By default we reserve the first 64K of physical RAM, as a
1366 number of BIOSes are known to corrupt that memory range
1367 during events such as suspend/resume or monitor cable
1368 insertion, so it must not be used by the kernel.
1370 You can set this to 4 if you are absolutely sure that you
1371 trust the BIOS to get all its memory reservations and usages
1372 right. If you know your BIOS have problems beyond the
1373 default 64K area, you can set this to 640 to avoid using the
1374 entire low memory range.
1376 If you have doubts about the BIOS (e.g. suspend/resume does
1377 not work or there's kernel crashes after certain hardware
1378 hotplug events) then you might want to enable
1379 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1380 typical corruption patterns.
1382 Leave this to the default value of 64 if you are unsure.
1384 config MATH_EMULATION
1386 prompt "Math emulation" if X86_32
1388 Linux can emulate a math coprocessor (used for floating point
1389 operations) if you don't have one. 486DX and Pentium processors have
1390 a math coprocessor built in, 486SX and 386 do not, unless you added
1391 a 487DX or 387, respectively. (The messages during boot time can
1392 give you some hints here ["man dmesg"].) Everyone needs either a
1393 coprocessor or this emulation.
1395 If you don't have a math coprocessor, you need to say Y here; if you
1396 say Y here even though you have a coprocessor, the coprocessor will
1397 be used nevertheless. (This behavior can be changed with the kernel
1398 command line option "no387", which comes handy if your coprocessor
1399 is broken. Try "man bootparam" or see the documentation of your boot
1400 loader (lilo or loadlin) about how to pass options to the kernel at
1401 boot time.) This means that it is a good idea to say Y here if you
1402 intend to use this kernel on different machines.
1404 More information about the internals of the Linux math coprocessor
1405 emulation can be found in <file:arch/x86/math-emu/README>.
1407 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1408 kernel, it won't hurt.
1412 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1414 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1415 the Memory Type Range Registers (MTRRs) may be used to control
1416 processor access to memory ranges. This is most useful if you have
1417 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1418 allows bus write transfers to be combined into a larger transfer
1419 before bursting over the PCI/AGP bus. This can increase performance
1420 of image write operations 2.5 times or more. Saying Y here creates a
1421 /proc/mtrr file which may be used to manipulate your processor's
1422 MTRRs. Typically the X server should use this.
1424 This code has a reasonably generic interface so that similar
1425 control registers on other processors can be easily supported
1428 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1429 Registers (ARRs) which provide a similar functionality to MTRRs. For
1430 these, the ARRs are used to emulate the MTRRs.
1431 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1432 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1433 write-combining. All of these processors are supported by this code
1434 and it makes sense to say Y here if you have one of them.
1436 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1437 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1438 can lead to all sorts of problems, so it's good to say Y here.
1440 You can safely say Y even if your machine doesn't have MTRRs, you'll
1441 just add about 9 KB to your kernel.
1443 See <file:Documentation/x86/mtrr.txt> for more information.
1445 config MTRR_SANITIZER
1447 prompt "MTRR cleanup support"
1450 Convert MTRR layout from continuous to discrete, so X drivers can
1451 add writeback entries.
1453 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1454 The largest mtrr entry size for a continuous block can be set with
1459 config MTRR_SANITIZER_ENABLE_DEFAULT
1460 int "MTRR cleanup enable value (0-1)"
1463 depends on MTRR_SANITIZER
1465 Enable mtrr cleanup default value
1467 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1468 int "MTRR cleanup spare reg num (0-7)"
1471 depends on MTRR_SANITIZER
1473 mtrr cleanup spare entries default, it can be changed via
1474 mtrr_spare_reg_nr=N on the kernel command line.
1478 prompt "x86 PAT support" if EXPERT
1481 Use PAT attributes to setup page level cache control.
1483 PATs are the modern equivalents of MTRRs and are much more
1484 flexible than MTRRs.
1486 Say N here if you see bootup problems (boot crash, boot hang,
1487 spontaneous reboots) or a non-working video driver.
1491 config ARCH_USES_PG_UNCACHED
1497 prompt "x86 architectural random number generator" if EXPERT
1499 Enable the x86 architectural RDRAND instruction
1500 (Intel Bull Mountain technology) to generate random numbers.
1501 If supported, this is a high bandwidth, cryptographically
1502 secure hardware random number generator.
1505 bool "EFI runtime service support"
1508 This enables the kernel to use EFI runtime services that are
1509 available (such as the EFI variable services).
1511 This option is only useful on systems that have EFI firmware.
1512 In addition, you should use the latest ELILO loader available
1513 at <http://elilo.sourceforge.net> in order to take advantage
1514 of EFI runtime services. However, even with this option, the
1515 resultant kernel should continue to boot on existing non-EFI
1519 bool "EFI stub support"
1522 This kernel feature allows a bzImage to be loaded directly
1523 by EFI firmware without the use of a bootloader.
1527 prompt "Enable seccomp to safely compute untrusted bytecode"
1529 This kernel feature is useful for number crunching applications
1530 that may need to compute untrusted bytecode during their
1531 execution. By using pipes or other transports made available to
1532 the process as file descriptors supporting the read/write
1533 syscalls, it's possible to isolate those applications in
1534 their own address space using seccomp. Once seccomp is
1535 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1536 and the task is only allowed to execute a few safe syscalls
1537 defined by each seccomp mode.
1539 If unsure, say Y. Only embedded should say N here.
1541 config CC_STACKPROTECTOR
1542 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1544 This option turns on the -fstack-protector GCC feature. This
1545 feature puts, at the beginning of functions, a canary value on
1546 the stack just before the return address, and validates
1547 the value just before actually returning. Stack based buffer
1548 overflows (that need to overwrite this return address) now also
1549 overwrite the canary, which gets detected and the attack is then
1550 neutralized via a kernel panic.
1552 This feature requires gcc version 4.2 or above, or a distribution
1553 gcc with the feature backported. Older versions are automatically
1554 detected and for those versions, this configuration option is
1555 ignored. (and a warning is printed during bootup)
1557 source kernel/Kconfig.hz
1560 bool "kexec system call"
1562 kexec is a system call that implements the ability to shutdown your
1563 current kernel, and to start another kernel. It is like a reboot
1564 but it is independent of the system firmware. And like a reboot
1565 you can start any kernel with it, not just Linux.
1567 The name comes from the similarity to the exec system call.
1569 It is an ongoing process to be certain the hardware in a machine
1570 is properly shutdown, so do not be surprised if this code does not
1571 initially work for you. It may help to enable device hotplugging
1572 support. As of this writing the exact hardware interface is
1573 strongly in flux, so no good recommendation can be made.
1576 bool "kernel crash dumps"
1577 depends on X86_64 || (X86_32 && HIGHMEM)
1579 Generate crash dump after being started by kexec.
1580 This should be normally only set in special crash dump kernels
1581 which are loaded in the main kernel with kexec-tools into
1582 a specially reserved region and then later executed after
1583 a crash by kdump/kexec. The crash dump kernel must be compiled
1584 to a memory address not used by the main kernel or BIOS using
1585 PHYSICAL_START, or it must be built as a relocatable image
1586 (CONFIG_RELOCATABLE=y).
1587 For more details see Documentation/kdump/kdump.txt
1590 bool "kexec jump (EXPERIMENTAL)"
1591 depends on EXPERIMENTAL
1592 depends on KEXEC && HIBERNATION
1594 Jump between original kernel and kexeced kernel and invoke
1595 code in physical address mode via KEXEC
1597 config PHYSICAL_START
1598 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1601 This gives the physical address where the kernel is loaded.
1603 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1604 bzImage will decompress itself to above physical address and
1605 run from there. Otherwise, bzImage will run from the address where
1606 it has been loaded by the boot loader and will ignore above physical
1609 In normal kdump cases one does not have to set/change this option
1610 as now bzImage can be compiled as a completely relocatable image
1611 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1612 address. This option is mainly useful for the folks who don't want
1613 to use a bzImage for capturing the crash dump and want to use a
1614 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1615 to be specifically compiled to run from a specific memory area
1616 (normally a reserved region) and this option comes handy.
1618 So if you are using bzImage for capturing the crash dump,
1619 leave the value here unchanged to 0x1000000 and set
1620 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1621 for capturing the crash dump change this value to start of
1622 the reserved region. In other words, it can be set based on
1623 the "X" value as specified in the "crashkernel=YM@XM"
1624 command line boot parameter passed to the panic-ed
1625 kernel. Please take a look at Documentation/kdump/kdump.txt
1626 for more details about crash dumps.
1628 Usage of bzImage for capturing the crash dump is recommended as
1629 one does not have to build two kernels. Same kernel can be used
1630 as production kernel and capture kernel. Above option should have
1631 gone away after relocatable bzImage support is introduced. But it
1632 is present because there are users out there who continue to use
1633 vmlinux for dump capture. This option should go away down the
1636 Don't change this unless you know what you are doing.
1639 bool "Build a relocatable kernel"
1642 This builds a kernel image that retains relocation information
1643 so it can be loaded someplace besides the default 1MB.
1644 The relocations tend to make the kernel binary about 10% larger,
1645 but are discarded at runtime.
1647 One use is for the kexec on panic case where the recovery kernel
1648 must live at a different physical address than the primary
1651 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1652 it has been loaded at and the compile time physical address
1653 (CONFIG_PHYSICAL_START) is ignored.
1655 # Relocation on x86-32 needs some additional build support
1656 config X86_NEED_RELOCS
1658 depends on X86_32 && RELOCATABLE
1660 config PHYSICAL_ALIGN
1661 hex "Alignment value to which kernel should be aligned" if X86_32
1663 range 0x2000 0x1000000
1665 This value puts the alignment restrictions on physical address
1666 where kernel is loaded and run from. Kernel is compiled for an
1667 address which meets above alignment restriction.
1669 If bootloader loads the kernel at a non-aligned address and
1670 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1671 address aligned to above value and run from there.
1673 If bootloader loads the kernel at a non-aligned address and
1674 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1675 load address and decompress itself to the address it has been
1676 compiled for and run from there. The address for which kernel is
1677 compiled already meets above alignment restrictions. Hence the
1678 end result is that kernel runs from a physical address meeting
1679 above alignment restrictions.
1681 Don't change this unless you know what you are doing.
1684 bool "Support for hot-pluggable CPUs"
1685 depends on SMP && HOTPLUG
1687 Say Y here to allow turning CPUs off and on. CPUs can be
1688 controlled through /sys/devices/system/cpu.
1689 ( Note: power management support will enable this option
1690 automatically on SMP systems. )
1691 Say N if you want to disable CPU hotplug.
1695 prompt "Compat VDSO support"
1696 depends on X86_32 || IA32_EMULATION
1698 Map the 32-bit VDSO to the predictable old-style address too.
1700 Say N here if you are running a sufficiently recent glibc
1701 version (2.3.3 or later), to remove the high-mapped
1702 VDSO mapping and to exclusively use the randomized VDSO.
1707 bool "Built-in kernel command line"
1709 Allow for specifying boot arguments to the kernel at
1710 build time. On some systems (e.g. embedded ones), it is
1711 necessary or convenient to provide some or all of the
1712 kernel boot arguments with the kernel itself (that is,
1713 to not rely on the boot loader to provide them.)
1715 To compile command line arguments into the kernel,
1716 set this option to 'Y', then fill in the
1717 the boot arguments in CONFIG_CMDLINE.
1719 Systems with fully functional boot loaders (i.e. non-embedded)
1720 should leave this option set to 'N'.
1723 string "Built-in kernel command string"
1724 depends on CMDLINE_BOOL
1727 Enter arguments here that should be compiled into the kernel
1728 image and used at boot time. If the boot loader provides a
1729 command line at boot time, it is appended to this string to
1730 form the full kernel command line, when the system boots.
1732 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1733 change this behavior.
1735 In most cases, the command line (whether built-in or provided
1736 by the boot loader) should specify the device for the root
1739 config CMDLINE_OVERRIDE
1740 bool "Built-in command line overrides boot loader arguments"
1741 depends on CMDLINE_BOOL
1743 Set this option to 'Y' to have the kernel ignore the boot loader
1744 command line, and use ONLY the built-in command line.
1746 This is used to work around broken boot loaders. This should
1747 be set to 'N' under normal conditions.
1751 config ARCH_ENABLE_MEMORY_HOTPLUG
1753 depends on X86_64 || (X86_32 && HIGHMEM)
1755 config ARCH_ENABLE_MEMORY_HOTREMOVE
1757 depends on MEMORY_HOTPLUG
1759 config USE_PERCPU_NUMA_NODE_ID
1763 menu "Power management and ACPI options"
1765 config ARCH_HIBERNATION_HEADER
1767 depends on X86_64 && HIBERNATION
1769 source "kernel/power/Kconfig"
1771 source "drivers/acpi/Kconfig"
1773 source "drivers/sfi/Kconfig"
1780 tristate "APM (Advanced Power Management) BIOS support"
1781 depends on X86_32 && PM_SLEEP
1783 APM is a BIOS specification for saving power using several different
1784 techniques. This is mostly useful for battery powered laptops with
1785 APM compliant BIOSes. If you say Y here, the system time will be
1786 reset after a RESUME operation, the /proc/apm device will provide
1787 battery status information, and user-space programs will receive
1788 notification of APM "events" (e.g. battery status change).
1790 If you select "Y" here, you can disable actual use of the APM
1791 BIOS by passing the "apm=off" option to the kernel at boot time.
1793 Note that the APM support is almost completely disabled for
1794 machines with more than one CPU.
1796 In order to use APM, you will need supporting software. For location
1797 and more information, read <file:Documentation/power/apm-acpi.txt>
1798 and the Battery Powered Linux mini-HOWTO, available from
1799 <http://www.tldp.org/docs.html#howto>.
1801 This driver does not spin down disk drives (see the hdparm(8)
1802 manpage ("man 8 hdparm") for that), and it doesn't turn off
1803 VESA-compliant "green" monitors.
1805 This driver does not support the TI 4000M TravelMate and the ACER
1806 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1807 desktop machines also don't have compliant BIOSes, and this driver
1808 may cause those machines to panic during the boot phase.
1810 Generally, if you don't have a battery in your machine, there isn't
1811 much point in using this driver and you should say N. If you get
1812 random kernel OOPSes or reboots that don't seem to be related to
1813 anything, try disabling/enabling this option (or disabling/enabling
1816 Some other things you should try when experiencing seemingly random,
1819 1) make sure that you have enough swap space and that it is
1821 2) pass the "no-hlt" option to the kernel
1822 3) switch on floating point emulation in the kernel and pass
1823 the "no387" option to the kernel
1824 4) pass the "floppy=nodma" option to the kernel
1825 5) pass the "mem=4M" option to the kernel (thereby disabling
1826 all but the first 4 MB of RAM)
1827 6) make sure that the CPU is not over clocked.
1828 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1829 8) disable the cache from your BIOS settings
1830 9) install a fan for the video card or exchange video RAM
1831 10) install a better fan for the CPU
1832 11) exchange RAM chips
1833 12) exchange the motherboard.
1835 To compile this driver as a module, choose M here: the
1836 module will be called apm.
1840 config APM_IGNORE_USER_SUSPEND
1841 bool "Ignore USER SUSPEND"
1843 This option will ignore USER SUSPEND requests. On machines with a
1844 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1845 series notebooks, it is necessary to say Y because of a BIOS bug.
1847 config APM_DO_ENABLE
1848 bool "Enable PM at boot time"
1850 Enable APM features at boot time. From page 36 of the APM BIOS
1851 specification: "When disabled, the APM BIOS does not automatically
1852 power manage devices, enter the Standby State, enter the Suspend
1853 State, or take power saving steps in response to CPU Idle calls."
1854 This driver will make CPU Idle calls when Linux is idle (unless this
1855 feature is turned off -- see "Do CPU IDLE calls", below). This
1856 should always save battery power, but more complicated APM features
1857 will be dependent on your BIOS implementation. You may need to turn
1858 this option off if your computer hangs at boot time when using APM
1859 support, or if it beeps continuously instead of suspending. Turn
1860 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1861 T400CDT. This is off by default since most machines do fine without
1865 bool "Make CPU Idle calls when idle"
1867 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1868 On some machines, this can activate improved power savings, such as
1869 a slowed CPU clock rate, when the machine is idle. These idle calls
1870 are made after the idle loop has run for some length of time (e.g.,
1871 333 mS). On some machines, this will cause a hang at boot time or
1872 whenever the CPU becomes idle. (On machines with more than one CPU,
1873 this option does nothing.)
1875 config APM_DISPLAY_BLANK
1876 bool "Enable console blanking using APM"
1878 Enable console blanking using the APM. Some laptops can use this to
1879 turn off the LCD backlight when the screen blanker of the Linux
1880 virtual console blanks the screen. Note that this is only used by
1881 the virtual console screen blanker, and won't turn off the backlight
1882 when using the X Window system. This also doesn't have anything to
1883 do with your VESA-compliant power-saving monitor. Further, this
1884 option doesn't work for all laptops -- it might not turn off your
1885 backlight at all, or it might print a lot of errors to the console,
1886 especially if you are using gpm.
1888 config APM_ALLOW_INTS
1889 bool "Allow interrupts during APM BIOS calls"
1891 Normally we disable external interrupts while we are making calls to
1892 the APM BIOS as a measure to lessen the effects of a badly behaving
1893 BIOS implementation. The BIOS should reenable interrupts if it
1894 needs to. Unfortunately, some BIOSes do not -- especially those in
1895 many of the newer IBM Thinkpads. If you experience hangs when you
1896 suspend, try setting this to Y. Otherwise, say N.
1900 source "drivers/cpufreq/Kconfig"
1902 source "drivers/cpuidle/Kconfig"
1904 source "drivers/idle/Kconfig"
1909 menu "Bus options (PCI etc.)"
1914 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1916 Find out whether you have a PCI motherboard. PCI is the name of a
1917 bus system, i.e. the way the CPU talks to the other stuff inside
1918 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1919 VESA. If you have PCI, say Y, otherwise N.
1922 prompt "PCI access mode"
1923 depends on X86_32 && PCI
1926 On PCI systems, the BIOS can be used to detect the PCI devices and
1927 determine their configuration. However, some old PCI motherboards
1928 have BIOS bugs and may crash if this is done. Also, some embedded
1929 PCI-based systems don't have any BIOS at all. Linux can also try to
1930 detect the PCI hardware directly without using the BIOS.
1932 With this option, you can specify how Linux should detect the
1933 PCI devices. If you choose "BIOS", the BIOS will be used,
1934 if you choose "Direct", the BIOS won't be used, and if you
1935 choose "MMConfig", then PCI Express MMCONFIG will be used.
1936 If you choose "Any", the kernel will try MMCONFIG, then the
1937 direct access method and falls back to the BIOS if that doesn't
1938 work. If unsure, go with the default, which is "Any".
1943 config PCI_GOMMCONFIG
1960 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1962 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1965 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1969 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1973 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1977 depends on PCI && XEN
1985 bool "Support mmconfig PCI config space access"
1986 depends on X86_64 && PCI && ACPI
1988 config PCI_CNB20LE_QUIRK
1989 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1991 depends on PCI && EXPERIMENTAL
1993 Read the PCI windows out of the CNB20LE host bridge. This allows
1994 PCI hotplug to work on systems with the CNB20LE chipset which do
1997 There's no public spec for this chipset, and this functionality
1998 is known to be incomplete.
2000 You should say N unless you know you need this.
2002 source "drivers/pci/pcie/Kconfig"
2004 source "drivers/pci/Kconfig"
2006 # x86_64 have no ISA slots, but can have ISA-style DMA.
2008 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2011 Enables ISA-style DMA support for devices requiring such controllers.
2019 Find out whether you have ISA slots on your motherboard. ISA is the
2020 name of a bus system, i.e. the way the CPU talks to the other stuff
2021 inside your box. Other bus systems are PCI, EISA, MicroChannel
2022 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2023 newer boards don't support it. If you have ISA, say Y, otherwise N.
2029 The Extended Industry Standard Architecture (EISA) bus was
2030 developed as an open alternative to the IBM MicroChannel bus.
2032 The EISA bus provided some of the features of the IBM MicroChannel
2033 bus while maintaining backward compatibility with cards made for
2034 the older ISA bus. The EISA bus saw limited use between 1988 and
2035 1995 when it was made obsolete by the PCI bus.
2037 Say Y here if you are building a kernel for an EISA-based machine.
2041 source "drivers/eisa/Kconfig"
2046 MicroChannel Architecture is found in some IBM PS/2 machines and
2047 laptops. It is a bus system similar to PCI or ISA. See
2048 <file:Documentation/mca.txt> (and especially the web page given
2049 there) before attempting to build an MCA bus kernel.
2051 source "drivers/mca/Kconfig"
2054 tristate "NatSemi SCx200 support"
2056 This provides basic support for National Semiconductor's
2057 (now AMD's) Geode processors. The driver probes for the
2058 PCI-IDs of several on-chip devices, so its a good dependency
2059 for other scx200_* drivers.
2061 If compiled as a module, the driver is named scx200.
2063 config SCx200HR_TIMER
2064 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2068 This driver provides a clocksource built upon the on-chip
2069 27MHz high-resolution timer. Its also a workaround for
2070 NSC Geode SC-1100's buggy TSC, which loses time when the
2071 processor goes idle (as is done by the scheduler). The
2072 other workaround is idle=poll boot option.
2075 bool "One Laptop Per Child support"
2081 Add support for detecting the unique features of the OLPC
2085 bool "OLPC XO-1 Power Management"
2086 depends on OLPC && MFD_CS5535 && PM_SLEEP
2089 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2092 bool "OLPC XO-1 Real Time Clock"
2093 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2095 Add support for the XO-1 real time clock, which can be used as a
2096 programmable wakeup source.
2099 bool "OLPC XO-1 SCI extras"
2100 depends on OLPC && OLPC_XO1_PM
2105 Add support for SCI-based features of the OLPC XO-1 laptop:
2106 - EC-driven system wakeups
2110 - AC adapter status updates
2111 - Battery status updates
2113 config OLPC_XO15_SCI
2114 bool "OLPC XO-1.5 SCI extras"
2115 depends on OLPC && ACPI
2118 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2119 - EC-driven system wakeups
2120 - AC adapter status updates
2121 - Battery status updates
2124 bool "PCEngines ALIX System Support (LED setup)"
2127 This option enables system support for the PCEngines ALIX.
2128 At present this just sets up LEDs for GPIO control on
2129 ALIX2/3/6 boards. However, other system specific setup should
2132 Note: You must still enable the drivers for GPIO and LED support
2133 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2135 Note: You have to set alix.force=1 for boards with Award BIOS.
2141 depends on CPU_SUP_AMD && PCI
2143 source "drivers/pcmcia/Kconfig"
2145 source "drivers/pci/hotplug/Kconfig"
2148 bool "RapidIO support"
2152 If you say Y here, the kernel will include drivers and
2153 infrastructure code to support RapidIO interconnect devices.
2155 source "drivers/rapidio/Kconfig"
2160 menu "Executable file formats / Emulations"
2162 source "fs/Kconfig.binfmt"
2164 config IA32_EMULATION
2165 bool "IA32 Emulation"
2167 select COMPAT_BINFMT_ELF
2169 Include code to run 32-bit programs under a 64-bit kernel. You should
2170 likely turn this on, unless you're 100% sure that you don't have any
2171 32-bit programs left.
2174 tristate "IA32 a.out support"
2175 depends on IA32_EMULATION
2177 Support old a.out binaries in the 32bit emulation.
2181 depends on IA32_EMULATION
2183 config COMPAT_FOR_U64_ALIGNMENT
2187 config SYSVIPC_COMPAT
2189 depends on COMPAT && SYSVIPC
2193 depends on COMPAT && KEYS
2199 config HAVE_ATOMIC_IOMAP
2203 config HAVE_TEXT_POKE_SMP
2205 select STOP_MACHINE if SMP
2207 source "net/Kconfig"
2209 source "drivers/Kconfig"
2211 source "drivers/firmware/Kconfig"
2215 source "arch/x86/Kconfig.debug"
2217 source "security/Kconfig"
2219 source "crypto/Kconfig"
2221 source "arch/x86/kvm/Kconfig"
2223 source "lib/Kconfig"