3 bool "64-bit kernel" if ARCH = "x86"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
24 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
25 select ARCH_MIGHT_HAVE_PC_PARPORT
26 select HAVE_AOUT if X86_32
27 select HAVE_UNSTABLE_SCHED_CLOCK
28 select ARCH_SUPPORTS_NUMA_BALANCING
29 select ARCH_SUPPORTS_INT128 if X86_64
30 select ARCH_WANTS_PROT_NUMA_PROT_NONE
33 select HAVE_PCSPKR_PLATFORM
34 select HAVE_PERF_EVENTS
35 select HAVE_IOREMAP_PROT
38 select HAVE_MEMBLOCK_NODE_MAP
39 select ARCH_DISCARD_MEMBLOCK
40 select ARCH_WANT_OPTIONAL_GPIOLIB
41 select ARCH_WANT_FRAME_POINTERS
43 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
44 select HAVE_KRETPROBES
46 select HAVE_KPROBES_ON_FTRACE
47 select HAVE_FTRACE_MCOUNT_RECORD
48 select HAVE_FENTRY if X86_64
49 select HAVE_C_RECORDMCOUNT
50 select HAVE_DYNAMIC_FTRACE
51 select HAVE_DYNAMIC_FTRACE_WITH_REGS
52 select HAVE_FUNCTION_TRACER
53 select HAVE_FUNCTION_GRAPH_TRACER
54 select HAVE_FUNCTION_GRAPH_FP_TEST
55 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
56 select HAVE_SYSCALL_TRACEPOINTS
57 select SYSCTL_EXCEPTION_TRACE
60 select HAVE_ARCH_TRACEHOOK
61 select HAVE_GENERIC_DMA_COHERENT if X86_32
62 select HAVE_EFFICIENT_UNALIGNED_ACCESS
63 select USER_STACKTRACE_SUPPORT
64 select HAVE_REGS_AND_STACK_ACCESS_API
65 select HAVE_DMA_API_DEBUG
66 select HAVE_KERNEL_GZIP
67 select HAVE_KERNEL_BZIP2
68 select HAVE_KERNEL_LZMA
70 select HAVE_KERNEL_LZO
71 select HAVE_KERNEL_LZ4
72 select HAVE_HW_BREAKPOINT
73 select HAVE_MIXED_BREAKPOINTS_REGS
75 select HAVE_PERF_EVENTS_NMI
77 select HAVE_PERF_USER_STACK_DUMP
78 select HAVE_DEBUG_KMEMLEAK
80 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
81 select HAVE_CMPXCHG_LOCAL
82 select HAVE_CMPXCHG_DOUBLE
83 select HAVE_ARCH_KMEMCHECK
84 select HAVE_USER_RETURN_NOTIFIER
85 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
86 select HAVE_ARCH_JUMP_LABEL
87 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
89 select GENERIC_FIND_FIRST_BIT
90 select GENERIC_IRQ_PROBE
91 select GENERIC_PENDING_IRQ if SMP
92 select GENERIC_IRQ_SHOW
93 select GENERIC_CLOCKEVENTS_MIN_ADJUST
94 select IRQ_FORCED_THREADING
95 select HAVE_BPF_JIT if X86_64
96 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
98 select ARCH_HAVE_NMI_SAFE_CMPXCHG
100 select DCACHE_WORD_ACCESS
101 select GENERIC_SMP_IDLE_THREAD
102 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
103 select HAVE_ARCH_SECCOMP_FILTER
104 select BUILDTIME_EXTABLE_SORT
105 select GENERIC_CMOS_UPDATE
106 select HAVE_ARCH_SOFT_DIRTY
107 select CLOCKSOURCE_WATCHDOG
108 select GENERIC_CLOCKEVENTS
109 select ARCH_CLOCKSOURCE_DATA if X86_64
110 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
111 select GENERIC_TIME_VSYSCALL if X86_64
112 select KTIME_SCALAR if X86_32
113 select GENERIC_STRNCPY_FROM_USER
114 select GENERIC_STRNLEN_USER
115 select HAVE_CONTEXT_TRACKING if X86_64
116 select HAVE_IRQ_TIME_ACCOUNTING
118 select MODULES_USE_ELF_REL if X86_32
119 select MODULES_USE_ELF_RELA if X86_64
120 select CLONE_BACKWARDS if X86_32
121 select ARCH_USE_BUILTIN_BSWAP
122 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
123 select OLD_SIGACTION if X86_32
124 select COMPAT_OLD_SIGACTION if IA32_EMULATION
126 select HAVE_DEBUG_STACKOVERFLOW
127 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
128 select HAVE_ARCH_AUDITSYSCALL
130 config INSTRUCTION_DECODER
132 depends on KPROBES || PERF_EVENTS || UPROBES
136 default "elf32-i386" if X86_32
137 default "elf64-x86-64" if X86_64
139 config ARCH_DEFCONFIG
141 default "arch/x86/configs/i386_defconfig" if X86_32
142 default "arch/x86/configs/x86_64_defconfig" if X86_64
144 config LOCKDEP_SUPPORT
147 config STACKTRACE_SUPPORT
150 config HAVE_LATENCYTOP_SUPPORT
159 config NEED_DMA_MAP_STATE
161 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
163 config NEED_SG_DMA_LENGTH
166 config GENERIC_ISA_DMA
168 depends on ISA_DMA_API
173 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
175 config GENERIC_BUG_RELATIVE_POINTERS
178 config GENERIC_HWEIGHT
181 config ARCH_MAY_HAVE_PC_FDC
183 depends on ISA_DMA_API
185 config RWSEM_XCHGADD_ALGORITHM
188 config GENERIC_CALIBRATE_DELAY
191 config ARCH_HAS_CPU_RELAX
194 config ARCH_HAS_CACHE_LINE_SIZE
197 config ARCH_HAS_CPU_AUTOPROBE
200 config HAVE_SETUP_PER_CPU_AREA
203 config NEED_PER_CPU_EMBED_FIRST_CHUNK
206 config NEED_PER_CPU_PAGE_FIRST_CHUNK
209 config ARCH_HIBERNATION_POSSIBLE
212 config ARCH_SUSPEND_POSSIBLE
215 config ARCH_WANT_HUGE_PMD_SHARE
218 config ARCH_WANT_GENERAL_HUGETLB
229 config ARCH_SUPPORTS_OPTIMIZED_INLINING
232 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
235 config HAVE_INTEL_TXT
237 depends on INTEL_IOMMU && ACPI
241 depends on X86_32 && SMP
245 depends on X86_64 && SMP
251 config X86_32_LAZY_GS
253 depends on X86_32 && !CC_STACKPROTECTOR
255 config ARCH_HWEIGHT_CFLAGS
257 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
258 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
260 config ARCH_SUPPORTS_UPROBES
263 source "init/Kconfig"
264 source "kernel/Kconfig.freezer"
266 menu "Processor type and features"
269 bool "DMA memory allocation support" if EXPERT
272 DMA memory allocation support allows devices with less than 32-bit
273 addressing to allocate within the first 16MB of address space.
274 Disable if no such devices will be used.
279 bool "Symmetric multi-processing support"
281 This enables support for systems with more than one CPU. If you have
282 a system with only one CPU, like most personal computers, say N. If
283 you have a system with more than one CPU, say Y.
285 If you say N here, the kernel will run on single and multiprocessor
286 machines, but will use only one CPU of a multiprocessor machine. If
287 you say Y here, the kernel will run on many, but not all,
288 singleprocessor machines. On a singleprocessor machine, the kernel
289 will run faster if you say N here.
291 Note that if you say Y here and choose architecture "586" or
292 "Pentium" under "Processor family", the kernel will not work on 486
293 architectures. Similarly, multiprocessor kernels for the "PPro"
294 architecture may not work on all Pentium based boards.
296 People using multiprocessor machines who say Y here should also say
297 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
298 Management" code will be disabled if you say Y here.
300 See also <file:Documentation/x86/i386/IO-APIC.txt>,
301 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
302 <http://www.tldp.org/docs.html#howto>.
304 If you don't know what to do here, say N.
307 bool "Support x2apic"
308 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
310 This enables x2apic support on CPUs that have this feature.
312 This allows 32-bit apic IDs (so it can support very large systems),
313 and accesses the local apic via MSRs not via mmio.
315 If you don't know what to do here, say N.
318 bool "Enable MPS table" if ACPI || SFI
320 depends on X86_LOCAL_APIC
322 For old smp systems that do not have proper acpi support. Newer systems
323 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
326 bool "Support for big SMP systems with more than 8 CPUs"
327 depends on X86_32 && SMP
329 This option is needed for the systems that have more than 8 CPUs
333 depends on X86_GOLDFISH
336 config X86_EXTENDED_PLATFORM
337 bool "Support for extended (non-PC) x86 platforms"
340 If you disable this option then the kernel will only support
341 standard PC platforms. (which covers the vast majority of
344 If you enable this option then you'll be able to select support
345 for the following (non-PC) 32 bit x86 platforms:
346 Goldfish (Android emulator)
350 SGI 320/540 (Visual Workstation)
351 STA2X11-based (e.g. Northville)
352 Summit/EXA (IBM x440)
353 Unisys ES7000 IA32 series
354 Moorestown MID devices
356 If you have one of these systems, or if you want to build a
357 generic distribution kernel, say Y here - otherwise say N.
361 config X86_EXTENDED_PLATFORM
362 bool "Support for extended (non-PC) x86 platforms"
365 If you disable this option then the kernel will only support
366 standard PC platforms. (which covers the vast majority of
369 If you enable this option then you'll be able to select support
370 for the following (non-PC) 64 bit x86 platforms:
375 If you have one of these systems, or if you want to build a
376 generic distribution kernel, say Y here - otherwise say N.
378 # This is an alphabetically sorted list of 64 bit extended platforms
379 # Please maintain the alphabetic order if and when there are additions
381 bool "Numascale NumaChip"
383 depends on X86_EXTENDED_PLATFORM
386 depends on X86_X2APIC
387 depends on PCI_MMCONFIG
389 Adds support for Numascale NumaChip large-SMP systems. Needed to
390 enable more than ~168 cores.
391 If you don't have one of these, you should say N here.
395 select HYPERVISOR_GUEST
397 depends on X86_64 && PCI
398 depends on X86_EXTENDED_PLATFORM
401 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
402 supposed to run on these EM64T-based machines. Only choose this option
403 if you have one of these machines.
406 bool "SGI Ultraviolet"
408 depends on X86_EXTENDED_PLATFORM
410 depends on X86_X2APIC
412 This option is needed in order to support SGI Ultraviolet systems.
413 If you don't have one of these, you should say N here.
415 # Following is an alphabetically sorted list of 32 bit extended platforms
416 # Please maintain the alphabetic order if and when there are additions
419 bool "Goldfish (Virtual Platform)"
421 depends on X86_EXTENDED_PLATFORM
423 Enable support for the Goldfish virtual platform used primarily
424 for Android development. Unless you are building for the Android
425 Goldfish emulator say N here.
428 bool "CE4100 TV platform"
430 depends on PCI_GODIRECT
432 depends on X86_EXTENDED_PLATFORM
433 select X86_REBOOTFIXUPS
435 select OF_EARLY_FLATTREE
438 Select for the Intel CE media processor (CE4100) SOC.
439 This option compiles in support for the CE4100 SOC for settop
440 boxes and media devices.
442 config X86_WANT_INTEL_MID
443 bool "Intel MID platform support"
445 depends on X86_EXTENDED_PLATFORM
447 Select to build a kernel capable of supporting Intel MID platform
448 systems which do not have the PCI legacy interfaces (Moorestown,
449 Medfield). If you are building for a PC class system say N here.
451 if X86_WANT_INTEL_MID
457 bool "Medfield MID platform"
460 depends on X86_IO_APIC
468 select X86_PLATFORM_DEVICES
469 select MFD_INTEL_MSIC
471 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
472 Internet Device(MID) platform.
473 Unlike standard x86 PCs, Medfield does not have many legacy devices
474 nor standard legacy replacement devices/features. e.g. Medfield does
475 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
479 config X86_INTEL_LPSS
480 bool "Intel Low Power Subsystem Support"
485 Select to build support for Intel Low Power Subsystem such as
486 found on Intel Lynxpoint PCH. Selecting this option enables
487 things like clock tree (common clock framework) and pincontrol
488 which are needed by the LPSS peripheral drivers.
491 bool "RDC R-321x SoC"
493 depends on X86_EXTENDED_PLATFORM
495 select X86_REBOOTFIXUPS
497 This option is needed for RDC R-321x system-on-chip, also known
499 If you don't have one of these chips, you should say N here.
501 config X86_32_NON_STANDARD
502 bool "Support non-standard 32-bit SMP architectures"
503 depends on X86_32 && SMP
504 depends on X86_EXTENDED_PLATFORM
506 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
507 STA2X11, default subarchitectures. It is intended for a generic
508 binary kernel. If you select them all, kernel will probe it
509 one by one and will fallback to default.
511 # Alphabetically sorted list of Non standard 32 bit platforms
514 bool "NUMAQ (IBM/Sequent)"
515 depends on X86_32_NON_STANDARD
520 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
521 NUMA multiquad box. This changes the way that processors are
522 bootstrapped, and uses Clustered Logical APIC addressing mode instead
523 of Flat Logical. You will need a new lynxer.elf file to flash your
524 firmware with - send email to <Martin.Bligh@us.ibm.com>.
526 config X86_SUPPORTS_MEMORY_FAILURE
528 # MCE code calls memory_failure():
530 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
531 depends on !X86_NUMAQ
532 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
533 depends on X86_64 || !SPARSEMEM
534 select ARCH_SUPPORTS_MEMORY_FAILURE
537 bool "SGI 320/540 (Visual Workstation)"
538 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
539 depends on X86_32_NON_STANDARD
541 The SGI Visual Workstation series is an IA32-based workstation
542 based on SGI systems chips with some legacy PC hardware attached.
544 Say Y here to create a kernel to run on the SGI 320 or 540.
546 A kernel compiled for the Visual Workstation will run on general
547 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
550 bool "STA2X11 Companion Chip Support"
551 depends on X86_32_NON_STANDARD && PCI
552 select X86_DEV_DMA_OPS
556 select ARCH_REQUIRE_GPIOLIB
559 This adds support for boards based on the STA2X11 IO-Hub,
560 a.k.a. "ConneXt". The chip is used in place of the standard
561 PC chipset, so all "standard" peripherals are missing. If this
562 option is selected the kernel will still be able to boot on
563 standard PC machines.
566 bool "Summit/EXA (IBM x440)"
567 depends on X86_32_NON_STANDARD
569 This option is needed for IBM systems that use the Summit/EXA chipset.
570 In particular, it is needed for the x440.
573 bool "Unisys ES7000 IA32 series"
574 depends on X86_32_NON_STANDARD && X86_BIGSMP
576 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
577 supposed to run on an IA32-based Unisys ES7000 system.
580 tristate "Eurobraille/Iris poweroff module"
583 The Iris machines from EuroBraille do not have APM or ACPI support
584 to shut themselves down properly. A special I/O sequence is
585 needed to do so, which is what this module does at
588 This is only for Iris machines from EuroBraille.
592 config SCHED_OMIT_FRAME_POINTER
594 prompt "Single-depth WCHAN output"
597 Calculate simpler /proc/<PID>/wchan values. If this option
598 is disabled then wchan values will recurse back to the
599 caller function. This provides more accurate wchan values,
600 at the expense of slightly more scheduling overhead.
602 If in doubt, say "Y".
604 menuconfig HYPERVISOR_GUEST
605 bool "Linux guest support"
607 Say Y here to enable options for running Linux under various hyper-
608 visors. This option enables basic hypervisor detection and platform
611 If you say N, all options in this submenu will be skipped and
612 disabled, and Linux guest support won't be built in.
617 bool "Enable paravirtualization code"
619 This changes the kernel so it can modify itself when it is run
620 under a hypervisor, potentially improving performance significantly
621 over full virtualization. However, when run without a hypervisor
622 the kernel is theoretically slower and slightly larger.
624 config PARAVIRT_DEBUG
625 bool "paravirt-ops debugging"
626 depends on PARAVIRT && DEBUG_KERNEL
628 Enable to debug paravirt_ops internals. Specifically, BUG if
629 a paravirt_op is missing when it is called.
631 config PARAVIRT_SPINLOCKS
632 bool "Paravirtualization layer for spinlocks"
633 depends on PARAVIRT && SMP
634 select UNINLINE_SPIN_UNLOCK
636 Paravirtualized spinlocks allow a pvops backend to replace the
637 spinlock implementation with something virtualization-friendly
638 (for example, block the virtual CPU rather than spinning).
640 It has a minimal impact on native kernels and gives a nice performance
641 benefit on paravirtualized KVM / Xen kernels.
643 If you are unsure how to answer this question, answer Y.
645 source "arch/x86/xen/Kconfig"
648 bool "KVM Guest support (including kvmclock)"
650 select PARAVIRT_CLOCK
653 This option enables various optimizations for running under the KVM
654 hypervisor. It includes a paravirtualized clock, so that instead
655 of relying on a PIT (or probably other) emulation by the
656 underlying device model, the host provides the guest with
657 timing infrastructure such as time of day, and system time
660 bool "Enable debug information for KVM Guests in debugfs"
661 depends on KVM_GUEST && DEBUG_FS
664 This option enables collection of various statistics for KVM guest.
665 Statistics are displayed in debugfs filesystem. Enabling this option
666 may incur significant overhead.
668 source "arch/x86/lguest/Kconfig"
670 config PARAVIRT_TIME_ACCOUNTING
671 bool "Paravirtual steal time accounting"
675 Select this option to enable fine granularity task steal time
676 accounting. Time spent executing other tasks in parallel with
677 the current vCPU is discounted from the vCPU power. To account for
678 that, there can be a small performance impact.
680 If in doubt, say N here.
682 config PARAVIRT_CLOCK
685 endif #HYPERVISOR_GUEST
693 This option adds a kernel parameter 'memtest', which allows memtest
695 memtest=0, mean disabled; -- default
696 memtest=1, mean do 1 test pattern;
698 memtest=4, mean do 4 test patterns.
699 If you are unsure how to answer this question, answer N.
701 config X86_SUMMIT_NUMA
703 depends on X86_32 && NUMA && X86_32_NON_STANDARD
705 config X86_CYCLONE_TIMER
707 depends on X86_SUMMIT
709 source "arch/x86/Kconfig.cpu"
713 prompt "HPET Timer Support" if X86_32
715 Use the IA-PC HPET (High Precision Event Timer) to manage
716 time in preference to the PIT and RTC, if a HPET is
718 HPET is the next generation timer replacing legacy 8254s.
719 The HPET provides a stable time base on SMP
720 systems, unlike the TSC, but it is more expensive to access,
721 as it is off-chip. You can find the HPET spec at
722 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
724 You can safely choose Y here. However, HPET will only be
725 activated if the platform and the BIOS support this feature.
726 Otherwise the 8254 will be used for timing services.
728 Choose N to continue using the legacy 8254 timer.
730 config HPET_EMULATE_RTC
732 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
735 def_bool y if X86_INTEL_MID
736 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
738 depends on X86_INTEL_MID && SFI
740 APB timer is the replacement for 8254, HPET on X86 MID platforms.
741 The APBT provides a stable time base on SMP
742 systems, unlike the TSC, but it is more expensive to access,
743 as it is off-chip. APB timers are always running regardless of CPU
744 C states, they are used as per CPU clockevent device when possible.
746 # Mark as expert because too many people got it wrong.
747 # The code disables itself when not needed.
750 bool "Enable DMI scanning" if EXPERT
752 Enabled scanning of DMI to identify machine quirks. Say Y
753 here unless you have verified that your setup is not
754 affected by entries in the DMI blacklist. Required by PNP
758 bool "Old AMD GART IOMMU support"
760 depends on X86_64 && PCI && AMD_NB
762 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
763 GART based hardware IOMMUs.
765 The GART supports full DMA access for devices with 32-bit access
766 limitations, on systems with more than 3 GB. This is usually needed
767 for USB, sound, many IDE/SATA chipsets and some other devices.
769 Newer systems typically have a modern AMD IOMMU, supported via
770 the CONFIG_AMD_IOMMU=y config option.
772 In normal configurations this driver is only active when needed:
773 there's more than 3 GB of memory and the system contains a
774 32-bit limited device.
779 bool "IBM Calgary IOMMU support"
781 depends on X86_64 && PCI
783 Support for hardware IOMMUs in IBM's xSeries x366 and x460
784 systems. Needed to run systems with more than 3GB of memory
785 properly with 32-bit PCI devices that do not support DAC
786 (Double Address Cycle). Calgary also supports bus level
787 isolation, where all DMAs pass through the IOMMU. This
788 prevents them from going anywhere except their intended
789 destination. This catches hard-to-find kernel bugs and
790 mis-behaving drivers and devices that do not use the DMA-API
791 properly to set up their DMA buffers. The IOMMU can be
792 turned off at boot time with the iommu=off parameter.
793 Normally the kernel will make the right choice by itself.
796 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
798 prompt "Should Calgary be enabled by default?"
799 depends on CALGARY_IOMMU
801 Should Calgary be enabled by default? if you choose 'y', Calgary
802 will be used (if it exists). If you choose 'n', Calgary will not be
803 used even if it exists. If you choose 'n' and would like to use
804 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
807 # need this always selected by IOMMU for the VIA workaround
811 Support for software bounce buffers used on x86-64 systems
812 which don't have a hardware IOMMU. Using this PCI devices
813 which can only access 32-bits of memory can be used on systems
814 with more than 3 GB of memory.
819 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
822 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
823 depends on X86_64 && SMP && DEBUG_KERNEL
824 select CPUMASK_OFFSTACK
826 Enable maximum number of CPUS and NUMA Nodes for this architecture.
830 int "Maximum number of CPUs" if SMP && !MAXSMP
831 range 2 8 if SMP && X86_32 && !X86_BIGSMP
832 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
833 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
835 default "8192" if MAXSMP
836 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
839 This allows you to specify the maximum number of CPUs which this
840 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
841 supported value is 4096, otherwise the maximum value is 512. The
842 minimum value which makes sense is 2.
844 This is purely to save memory - each supported CPU adds
845 approximately eight kilobytes to the kernel image.
848 bool "SMT (Hyperthreading) scheduler support"
851 SMT scheduler support improves the CPU scheduler's decision making
852 when dealing with Intel Pentium 4 chips with HyperThreading at a
853 cost of slightly increased overhead in some places. If unsure say
858 prompt "Multi-core scheduler support"
861 Multi-core scheduler support improves the CPU scheduler's decision
862 making when dealing with multi-core CPU chips at a cost of slightly
863 increased overhead in some places. If unsure say N here.
865 source "kernel/Kconfig.preempt"
868 bool "Local APIC support on uniprocessors"
869 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
871 A local APIC (Advanced Programmable Interrupt Controller) is an
872 integrated interrupt controller in the CPU. If you have a single-CPU
873 system which has a processor with a local APIC, you can say Y here to
874 enable and use it. If you say Y here even though your machine doesn't
875 have a local APIC, then the kernel will still run with no slowdown at
876 all. The local APIC supports CPU-generated self-interrupts (timer,
877 performance counters), and the NMI watchdog which detects hard
881 bool "IO-APIC support on uniprocessors"
882 depends on X86_UP_APIC
884 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
885 SMP-capable replacement for PC-style interrupt controllers. Most
886 SMP systems and many recent uniprocessor systems have one.
888 If you have a single-CPU system with an IO-APIC, you can say Y here
889 to use it. If you say Y here even though your machine doesn't have
890 an IO-APIC, then the kernel will still run with no slowdown at all.
892 config X86_LOCAL_APIC
894 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
898 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
900 config X86_VISWS_APIC
902 depends on X86_32 && X86_VISWS
904 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
905 bool "Reroute for broken boot IRQs"
906 depends on X86_IO_APIC
908 This option enables a workaround that fixes a source of
909 spurious interrupts. This is recommended when threaded
910 interrupt handling is used on systems where the generation of
911 superfluous "boot interrupts" cannot be disabled.
913 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
914 entry in the chipset's IO-APIC is masked (as, e.g. the RT
915 kernel does during interrupt handling). On chipsets where this
916 boot IRQ generation cannot be disabled, this workaround keeps
917 the original IRQ line masked so that only the equivalent "boot
918 IRQ" is delivered to the CPUs. The workaround also tells the
919 kernel to set up the IRQ handler on the boot IRQ line. In this
920 way only one interrupt is delivered to the kernel. Otherwise
921 the spurious second interrupt may cause the kernel to bring
922 down (vital) interrupt lines.
924 Only affects "broken" chipsets. Interrupt sharing may be
925 increased on these systems.
928 bool "Machine Check / overheating reporting"
931 Machine Check support allows the processor to notify the
932 kernel if it detects a problem (e.g. overheating, data corruption).
933 The action the kernel takes depends on the severity of the problem,
934 ranging from warning messages to halting the machine.
938 prompt "Intel MCE features"
939 depends on X86_MCE && X86_LOCAL_APIC
941 Additional support for intel specific MCE features such as
946 prompt "AMD MCE features"
947 depends on X86_MCE && X86_LOCAL_APIC
949 Additional support for AMD specific MCE features such as
950 the DRAM Error Threshold.
952 config X86_ANCIENT_MCE
953 bool "Support for old Pentium 5 / WinChip machine checks"
954 depends on X86_32 && X86_MCE
956 Include support for machine check handling on old Pentium 5 or WinChip
957 systems. These typically need to be enabled explicitely on the command
960 config X86_MCE_THRESHOLD
961 depends on X86_MCE_AMD || X86_MCE_INTEL
964 config X86_MCE_INJECT
966 tristate "Machine check injector support"
968 Provide support for injecting machine checks for testing purposes.
969 If you don't know what a machine check is and you don't do kernel
970 QA it is safe to say n.
972 config X86_THERMAL_VECTOR
974 depends on X86_MCE_INTEL
977 bool "Enable VM86 support" if EXPERT
981 This option is required by programs like DOSEMU to run 16-bit legacy
982 code on X86 processors. It also may be needed by software like
983 XFree86 to initialize some video cards via BIOS. Disabling this
984 option saves about 6k.
987 tristate "Toshiba Laptop support"
990 This adds a driver to safely access the System Management Mode of
991 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
992 not work on models with a Phoenix BIOS. The System Management Mode
993 is used to set the BIOS and power saving options on Toshiba portables.
995 For information on utilities to make use of this driver see the
996 Toshiba Linux utilities web site at:
997 <http://www.buzzard.org.uk/toshiba/>.
999 Say Y if you intend to run this kernel on a Toshiba portable.
1003 tristate "Dell laptop support"
1006 This adds a driver to safely access the System Management Mode
1007 of the CPU on the Dell Inspiron 8000. The System Management Mode
1008 is used to read cpu temperature and cooling fan status and to
1009 control the fans on the I8K portables.
1011 This driver has been tested only on the Inspiron 8000 but it may
1012 also work with other Dell laptops. You can force loading on other
1013 models by passing the parameter `force=1' to the module. Use at
1016 For information on utilities to make use of this driver see the
1017 I8K Linux utilities web site at:
1018 <http://people.debian.org/~dz/i8k/>
1020 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1023 config X86_REBOOTFIXUPS
1024 bool "Enable X86 board specific fixups for reboot"
1027 This enables chipset and/or board specific fixups to be done
1028 in order to get reboot to work correctly. This is only needed on
1029 some combinations of hardware and BIOS. The symptom, for which
1030 this config is intended, is when reboot ends with a stalled/hung
1033 Currently, the only fixup is for the Geode machines using
1034 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1036 Say Y if you want to enable the fixup. Currently, it's safe to
1037 enable this option even if you don't need it.
1041 tristate "CPU microcode loading support"
1042 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1046 If you say Y here, you will be able to update the microcode on
1047 certain Intel and AMD processors. The Intel support is for the
1048 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1049 Xeon etc. The AMD support is for families 0x10 and later. You will
1050 obviously need the actual microcode binary data itself which is not
1051 shipped with the Linux kernel.
1053 This option selects the general module only, you need to select
1054 at least one vendor specific module as well.
1056 To compile this driver as a module, choose M here: the module
1057 will be called microcode.
1059 config MICROCODE_INTEL
1060 bool "Intel microcode loading support"
1061 depends on MICROCODE
1065 This options enables microcode patch loading support for Intel
1068 For latest news and information on obtaining all the required
1069 Intel ingredients for this driver, check:
1070 <http://www.urbanmyth.org/microcode/>.
1072 config MICROCODE_AMD
1073 bool "AMD microcode loading support"
1074 depends on MICROCODE
1077 If you select this option, microcode patch loading support for AMD
1078 processors will be enabled.
1080 config MICROCODE_OLD_INTERFACE
1082 depends on MICROCODE
1084 config MICROCODE_INTEL_LIB
1086 depends on MICROCODE_INTEL
1088 config MICROCODE_INTEL_EARLY
1091 config MICROCODE_AMD_EARLY
1094 config MICROCODE_EARLY
1095 bool "Early load microcode"
1096 depends on MICROCODE=y && BLK_DEV_INITRD
1097 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1098 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1101 This option provides functionality to read additional microcode data
1102 at the beginning of initrd image. The data tells kernel to load
1103 microcode to CPU's as early as possible. No functional change if no
1104 microcode data is glued to the initrd, therefore it's safe to say Y.
1107 tristate "/dev/cpu/*/msr - Model-specific register support"
1109 This device gives privileged processes access to the x86
1110 Model-Specific Registers (MSRs). It is a character device with
1111 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1112 MSR accesses are directed to a specific CPU on multi-processor
1116 tristate "/dev/cpu/*/cpuid - CPU information support"
1118 This device gives processes access to the x86 CPUID instruction to
1119 be executed on a specific processor. It is a character device
1120 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1124 prompt "High Memory Support"
1125 default HIGHMEM64G if X86_NUMAQ
1131 depends on !X86_NUMAQ
1133 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1134 However, the address space of 32-bit x86 processors is only 4
1135 Gigabytes large. That means that, if you have a large amount of
1136 physical memory, not all of it can be "permanently mapped" by the
1137 kernel. The physical memory that's not permanently mapped is called
1140 If you are compiling a kernel which will never run on a machine with
1141 more than 1 Gigabyte total physical RAM, answer "off" here (default
1142 choice and suitable for most users). This will result in a "3GB/1GB"
1143 split: 3GB are mapped so that each process sees a 3GB virtual memory
1144 space and the remaining part of the 4GB virtual memory space is used
1145 by the kernel to permanently map as much physical memory as
1148 If the machine has between 1 and 4 Gigabytes physical RAM, then
1151 If more than 4 Gigabytes is used then answer "64GB" here. This
1152 selection turns Intel PAE (Physical Address Extension) mode on.
1153 PAE implements 3-level paging on IA32 processors. PAE is fully
1154 supported by Linux, PAE mode is implemented on all recent Intel
1155 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1156 then the kernel will not boot on CPUs that don't support PAE!
1158 The actual amount of total physical memory will either be
1159 auto detected or can be forced by using a kernel command line option
1160 such as "mem=256M". (Try "man bootparam" or see the documentation of
1161 your boot loader (lilo or loadlin) about how to pass options to the
1162 kernel at boot time.)
1164 If unsure, say "off".
1168 depends on !X86_NUMAQ
1170 Select this if you have a 32-bit processor and between 1 and 4
1171 gigabytes of physical RAM.
1178 Select this if you have a 32-bit processor and more than 4
1179 gigabytes of physical RAM.
1184 prompt "Memory split" if EXPERT
1188 Select the desired split between kernel and user memory.
1190 If the address range available to the kernel is less than the
1191 physical memory installed, the remaining memory will be available
1192 as "high memory". Accessing high memory is a little more costly
1193 than low memory, as it needs to be mapped into the kernel first.
1194 Note that increasing the kernel address space limits the range
1195 available to user programs, making the address space there
1196 tighter. Selecting anything other than the default 3G/1G split
1197 will also likely make your kernel incompatible with binary-only
1200 If you are not absolutely sure what you are doing, leave this
1204 bool "3G/1G user/kernel split"
1205 config VMSPLIT_3G_OPT
1207 bool "3G/1G user/kernel split (for full 1G low memory)"
1209 bool "2G/2G user/kernel split"
1210 config VMSPLIT_2G_OPT
1212 bool "2G/2G user/kernel split (for full 2G low memory)"
1214 bool "1G/3G user/kernel split"
1219 default 0xB0000000 if VMSPLIT_3G_OPT
1220 default 0x80000000 if VMSPLIT_2G
1221 default 0x78000000 if VMSPLIT_2G_OPT
1222 default 0x40000000 if VMSPLIT_1G
1228 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1231 bool "PAE (Physical Address Extension) Support"
1232 depends on X86_32 && !HIGHMEM4G
1234 PAE is required for NX support, and furthermore enables
1235 larger swapspace support for non-overcommit purposes. It
1236 has the cost of more pagetable lookup overhead, and also
1237 consumes more pagetable space per process.
1239 config ARCH_PHYS_ADDR_T_64BIT
1241 depends on X86_64 || X86_PAE
1243 config ARCH_DMA_ADDR_T_64BIT
1245 depends on X86_64 || HIGHMEM64G
1247 config DIRECT_GBPAGES
1248 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1252 Allow the kernel linear mapping to use 1GB pages on CPUs that
1253 support it. This can improve the kernel's performance a tiny bit by
1254 reducing TLB pressure. If in doubt, say "Y".
1256 # Common NUMA Features
1258 bool "Numa Memory Allocation and Scheduler Support"
1260 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1261 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1263 Enable NUMA (Non Uniform Memory Access) support.
1265 The kernel will try to allocate memory used by a CPU on the
1266 local memory controller of the CPU and add some more
1267 NUMA awareness to the kernel.
1269 For 64-bit this is recommended if the system is Intel Core i7
1270 (or later), AMD Opteron, or EM64T NUMA.
1272 For 32-bit this is only needed on (rare) 32-bit-only platforms
1273 that support NUMA topologies, such as NUMAQ / Summit, or if you
1274 boot a 32-bit kernel on a 64-bit NUMA platform.
1276 Otherwise, you should say N.
1278 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1279 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1283 prompt "Old style AMD Opteron NUMA detection"
1284 depends on X86_64 && NUMA && PCI
1286 Enable AMD NUMA node topology detection. You should say Y here if
1287 you have a multi processor AMD system. This uses an old method to
1288 read the NUMA configuration directly from the builtin Northbridge
1289 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1290 which also takes priority if both are compiled in.
1292 config X86_64_ACPI_NUMA
1294 prompt "ACPI NUMA detection"
1295 depends on X86_64 && NUMA && ACPI && PCI
1298 Enable ACPI SRAT based node topology detection.
1300 # Some NUMA nodes have memory ranges that span
1301 # other nodes. Even though a pfn is valid and
1302 # between a node's start and end pfns, it may not
1303 # reside on that node. See memmap_init_zone()
1305 config NODES_SPAN_OTHER_NODES
1307 depends on X86_64_ACPI_NUMA
1310 bool "NUMA emulation"
1313 Enable NUMA emulation. A flat machine will be split
1314 into virtual nodes when booted with "numa=fake=N", where N is the
1315 number of nodes. This is only useful for debugging.
1318 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1320 default "10" if MAXSMP
1321 default "6" if X86_64
1322 default "4" if X86_NUMAQ
1324 depends on NEED_MULTIPLE_NODES
1326 Specify the maximum number of NUMA Nodes available on the target
1327 system. Increases memory reserved to accommodate various tables.
1329 config ARCH_HAVE_MEMORY_PRESENT
1331 depends on X86_32 && DISCONTIGMEM
1333 config NEED_NODE_MEMMAP_SIZE
1335 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1337 config ARCH_FLATMEM_ENABLE
1339 depends on X86_32 && !NUMA
1341 config ARCH_DISCONTIGMEM_ENABLE
1343 depends on NUMA && X86_32
1345 config ARCH_DISCONTIGMEM_DEFAULT
1347 depends on NUMA && X86_32
1349 config ARCH_SPARSEMEM_ENABLE
1351 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1352 select SPARSEMEM_STATIC if X86_32
1353 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1355 config ARCH_SPARSEMEM_DEFAULT
1359 config ARCH_SELECT_MEMORY_MODEL
1361 depends on ARCH_SPARSEMEM_ENABLE
1363 config ARCH_MEMORY_PROBE
1364 bool "Enable sysfs memory/probe interface"
1365 depends on X86_64 && MEMORY_HOTPLUG
1367 This option enables a sysfs memory/probe interface for testing.
1368 See Documentation/memory-hotplug.txt for more information.
1369 If you are unsure how to answer this question, answer N.
1371 config ARCH_PROC_KCORE_TEXT
1373 depends on X86_64 && PROC_KCORE
1375 config ILLEGAL_POINTER_VALUE
1378 default 0xdead000000000000 if X86_64
1383 bool "Allocate 3rd-level pagetables from highmem"
1386 The VM uses one page table entry for each page of physical memory.
1387 For systems with a lot of RAM, this can be wasteful of precious
1388 low memory. Setting this option will put user-space page table
1389 entries in high memory.
1391 config X86_CHECK_BIOS_CORRUPTION
1392 bool "Check for low memory corruption"
1394 Periodically check for memory corruption in low memory, which
1395 is suspected to be caused by BIOS. Even when enabled in the
1396 configuration, it is disabled at runtime. Enable it by
1397 setting "memory_corruption_check=1" on the kernel command
1398 line. By default it scans the low 64k of memory every 60
1399 seconds; see the memory_corruption_check_size and
1400 memory_corruption_check_period parameters in
1401 Documentation/kernel-parameters.txt to adjust this.
1403 When enabled with the default parameters, this option has
1404 almost no overhead, as it reserves a relatively small amount
1405 of memory and scans it infrequently. It both detects corruption
1406 and prevents it from affecting the running system.
1408 It is, however, intended as a diagnostic tool; if repeatable
1409 BIOS-originated corruption always affects the same memory,
1410 you can use memmap= to prevent the kernel from using that
1413 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1414 bool "Set the default setting of memory_corruption_check"
1415 depends on X86_CHECK_BIOS_CORRUPTION
1418 Set whether the default state of memory_corruption_check is
1421 config X86_RESERVE_LOW
1422 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1426 Specify the amount of low memory to reserve for the BIOS.
1428 The first page contains BIOS data structures that the kernel
1429 must not use, so that page must always be reserved.
1431 By default we reserve the first 64K of physical RAM, as a
1432 number of BIOSes are known to corrupt that memory range
1433 during events such as suspend/resume or monitor cable
1434 insertion, so it must not be used by the kernel.
1436 You can set this to 4 if you are absolutely sure that you
1437 trust the BIOS to get all its memory reservations and usages
1438 right. If you know your BIOS have problems beyond the
1439 default 64K area, you can set this to 640 to avoid using the
1440 entire low memory range.
1442 If you have doubts about the BIOS (e.g. suspend/resume does
1443 not work or there's kernel crashes after certain hardware
1444 hotplug events) then you might want to enable
1445 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1446 typical corruption patterns.
1448 Leave this to the default value of 64 if you are unsure.
1450 config MATH_EMULATION
1452 prompt "Math emulation" if X86_32
1454 Linux can emulate a math coprocessor (used for floating point
1455 operations) if you don't have one. 486DX and Pentium processors have
1456 a math coprocessor built in, 486SX and 386 do not, unless you added
1457 a 487DX or 387, respectively. (The messages during boot time can
1458 give you some hints here ["man dmesg"].) Everyone needs either a
1459 coprocessor or this emulation.
1461 If you don't have a math coprocessor, you need to say Y here; if you
1462 say Y here even though you have a coprocessor, the coprocessor will
1463 be used nevertheless. (This behavior can be changed with the kernel
1464 command line option "no387", which comes handy if your coprocessor
1465 is broken. Try "man bootparam" or see the documentation of your boot
1466 loader (lilo or loadlin) about how to pass options to the kernel at
1467 boot time.) This means that it is a good idea to say Y here if you
1468 intend to use this kernel on different machines.
1470 More information about the internals of the Linux math coprocessor
1471 emulation can be found in <file:arch/x86/math-emu/README>.
1473 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1474 kernel, it won't hurt.
1478 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1480 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1481 the Memory Type Range Registers (MTRRs) may be used to control
1482 processor access to memory ranges. This is most useful if you have
1483 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1484 allows bus write transfers to be combined into a larger transfer
1485 before bursting over the PCI/AGP bus. This can increase performance
1486 of image write operations 2.5 times or more. Saying Y here creates a
1487 /proc/mtrr file which may be used to manipulate your processor's
1488 MTRRs. Typically the X server should use this.
1490 This code has a reasonably generic interface so that similar
1491 control registers on other processors can be easily supported
1494 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1495 Registers (ARRs) which provide a similar functionality to MTRRs. For
1496 these, the ARRs are used to emulate the MTRRs.
1497 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1498 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1499 write-combining. All of these processors are supported by this code
1500 and it makes sense to say Y here if you have one of them.
1502 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1503 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1504 can lead to all sorts of problems, so it's good to say Y here.
1506 You can safely say Y even if your machine doesn't have MTRRs, you'll
1507 just add about 9 KB to your kernel.
1509 See <file:Documentation/x86/mtrr.txt> for more information.
1511 config MTRR_SANITIZER
1513 prompt "MTRR cleanup support"
1516 Convert MTRR layout from continuous to discrete, so X drivers can
1517 add writeback entries.
1519 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1520 The largest mtrr entry size for a continuous block can be set with
1525 config MTRR_SANITIZER_ENABLE_DEFAULT
1526 int "MTRR cleanup enable value (0-1)"
1529 depends on MTRR_SANITIZER
1531 Enable mtrr cleanup default value
1533 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1534 int "MTRR cleanup spare reg num (0-7)"
1537 depends on MTRR_SANITIZER
1539 mtrr cleanup spare entries default, it can be changed via
1540 mtrr_spare_reg_nr=N on the kernel command line.
1544 prompt "x86 PAT support" if EXPERT
1547 Use PAT attributes to setup page level cache control.
1549 PATs are the modern equivalents of MTRRs and are much more
1550 flexible than MTRRs.
1552 Say N here if you see bootup problems (boot crash, boot hang,
1553 spontaneous reboots) or a non-working video driver.
1557 config ARCH_USES_PG_UNCACHED
1563 prompt "x86 architectural random number generator" if EXPERT
1565 Enable the x86 architectural RDRAND instruction
1566 (Intel Bull Mountain technology) to generate random numbers.
1567 If supported, this is a high bandwidth, cryptographically
1568 secure hardware random number generator.
1572 prompt "Supervisor Mode Access Prevention" if EXPERT
1574 Supervisor Mode Access Prevention (SMAP) is a security
1575 feature in newer Intel processors. There is a small
1576 performance cost if this enabled and turned on; there is
1577 also a small increase in the kernel size if this is enabled.
1582 bool "EFI runtime service support"
1586 This enables the kernel to use EFI runtime services that are
1587 available (such as the EFI variable services).
1589 This option is only useful on systems that have EFI firmware.
1590 In addition, you should use the latest ELILO loader available
1591 at <http://elilo.sourceforge.net> in order to take advantage
1592 of EFI runtime services. However, even with this option, the
1593 resultant kernel should continue to boot on existing non-EFI
1597 bool "EFI stub support"
1600 This kernel feature allows a bzImage to be loaded directly
1601 by EFI firmware without the use of a bootloader.
1603 See Documentation/efi-stub.txt for more information.
1607 prompt "Enable seccomp to safely compute untrusted bytecode"
1609 This kernel feature is useful for number crunching applications
1610 that may need to compute untrusted bytecode during their
1611 execution. By using pipes or other transports made available to
1612 the process as file descriptors supporting the read/write
1613 syscalls, it's possible to isolate those applications in
1614 their own address space using seccomp. Once seccomp is
1615 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1616 and the task is only allowed to execute a few safe syscalls
1617 defined by each seccomp mode.
1619 If unsure, say Y. Only embedded should say N here.
1621 config CC_STACKPROTECTOR
1622 bool "Enable -fstack-protector buffer overflow detection"
1624 This option turns on the -fstack-protector GCC feature. This
1625 feature puts, at the beginning of functions, a canary value on
1626 the stack just before the return address, and validates
1627 the value just before actually returning. Stack based buffer
1628 overflows (that need to overwrite this return address) now also
1629 overwrite the canary, which gets detected and the attack is then
1630 neutralized via a kernel panic.
1632 This feature requires gcc version 4.2 or above, or a distribution
1633 gcc with the feature backported. Older versions are automatically
1634 detected and for those versions, this configuration option is
1635 ignored. (and a warning is printed during bootup)
1637 source kernel/Kconfig.hz
1640 bool "kexec system call"
1642 kexec is a system call that implements the ability to shutdown your
1643 current kernel, and to start another kernel. It is like a reboot
1644 but it is independent of the system firmware. And like a reboot
1645 you can start any kernel with it, not just Linux.
1647 The name comes from the similarity to the exec system call.
1649 It is an ongoing process to be certain the hardware in a machine
1650 is properly shutdown, so do not be surprised if this code does not
1651 initially work for you. As of this writing the exact hardware
1652 interface is strongly in flux, so no good recommendation can be
1656 bool "kernel crash dumps"
1657 depends on X86_64 || (X86_32 && HIGHMEM)
1659 Generate crash dump after being started by kexec.
1660 This should be normally only set in special crash dump kernels
1661 which are loaded in the main kernel with kexec-tools into
1662 a specially reserved region and then later executed after
1663 a crash by kdump/kexec. The crash dump kernel must be compiled
1664 to a memory address not used by the main kernel or BIOS using
1665 PHYSICAL_START, or it must be built as a relocatable image
1666 (CONFIG_RELOCATABLE=y).
1667 For more details see Documentation/kdump/kdump.txt
1671 depends on KEXEC && HIBERNATION
1673 Jump between original kernel and kexeced kernel and invoke
1674 code in physical address mode via KEXEC
1676 config PHYSICAL_START
1677 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1680 This gives the physical address where the kernel is loaded.
1682 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1683 bzImage will decompress itself to above physical address and
1684 run from there. Otherwise, bzImage will run from the address where
1685 it has been loaded by the boot loader and will ignore above physical
1688 In normal kdump cases one does not have to set/change this option
1689 as now bzImage can be compiled as a completely relocatable image
1690 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1691 address. This option is mainly useful for the folks who don't want
1692 to use a bzImage for capturing the crash dump and want to use a
1693 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1694 to be specifically compiled to run from a specific memory area
1695 (normally a reserved region) and this option comes handy.
1697 So if you are using bzImage for capturing the crash dump,
1698 leave the value here unchanged to 0x1000000 and set
1699 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1700 for capturing the crash dump change this value to start of
1701 the reserved region. In other words, it can be set based on
1702 the "X" value as specified in the "crashkernel=YM@XM"
1703 command line boot parameter passed to the panic-ed
1704 kernel. Please take a look at Documentation/kdump/kdump.txt
1705 for more details about crash dumps.
1707 Usage of bzImage for capturing the crash dump is recommended as
1708 one does not have to build two kernels. Same kernel can be used
1709 as production kernel and capture kernel. Above option should have
1710 gone away after relocatable bzImage support is introduced. But it
1711 is present because there are users out there who continue to use
1712 vmlinux for dump capture. This option should go away down the
1715 Don't change this unless you know what you are doing.
1718 bool "Build a relocatable kernel"
1721 This builds a kernel image that retains relocation information
1722 so it can be loaded someplace besides the default 1MB.
1723 The relocations tend to make the kernel binary about 10% larger,
1724 but are discarded at runtime.
1726 One use is for the kexec on panic case where the recovery kernel
1727 must live at a different physical address than the primary
1730 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1731 it has been loaded at and the compile time physical address
1732 (CONFIG_PHYSICAL_START) is ignored.
1734 # Relocation on x86-32 needs some additional build support
1735 config X86_NEED_RELOCS
1737 depends on X86_32 && RELOCATABLE
1739 config PHYSICAL_ALIGN
1740 hex "Alignment value to which kernel should be aligned"
1742 range 0x2000 0x1000000 if X86_32
1743 range 0x200000 0x1000000 if X86_64
1745 This value puts the alignment restrictions on physical address
1746 where kernel is loaded and run from. Kernel is compiled for an
1747 address which meets above alignment restriction.
1749 If bootloader loads the kernel at a non-aligned address and
1750 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1751 address aligned to above value and run from there.
1753 If bootloader loads the kernel at a non-aligned address and
1754 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1755 load address and decompress itself to the address it has been
1756 compiled for and run from there. The address for which kernel is
1757 compiled already meets above alignment restrictions. Hence the
1758 end result is that kernel runs from a physical address meeting
1759 above alignment restrictions.
1761 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1762 this value must be a multiple of 0x200000.
1764 Don't change this unless you know what you are doing.
1767 bool "Support for hot-pluggable CPUs"
1770 Say Y here to allow turning CPUs off and on. CPUs can be
1771 controlled through /sys/devices/system/cpu.
1772 ( Note: power management support will enable this option
1773 automatically on SMP systems. )
1774 Say N if you want to disable CPU hotplug.
1776 config BOOTPARAM_HOTPLUG_CPU0
1777 bool "Set default setting of cpu0_hotpluggable"
1779 depends on HOTPLUG_CPU
1781 Set whether default state of cpu0_hotpluggable is on or off.
1783 Say Y here to enable CPU0 hotplug by default. If this switch
1784 is turned on, there is no need to give cpu0_hotplug kernel
1785 parameter and the CPU0 hotplug feature is enabled by default.
1787 Please note: there are two known CPU0 dependencies if you want
1788 to enable the CPU0 hotplug feature either by this switch or by
1789 cpu0_hotplug kernel parameter.
1791 First, resume from hibernate or suspend always starts from CPU0.
1792 So hibernate and suspend are prevented if CPU0 is offline.
1794 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1795 offline if any interrupt can not migrate out of CPU0. There may
1796 be other CPU0 dependencies.
1798 Please make sure the dependencies are under your control before
1799 you enable this feature.
1801 Say N if you don't want to enable CPU0 hotplug feature by default.
1802 You still can enable the CPU0 hotplug feature at boot by kernel
1803 parameter cpu0_hotplug.
1805 config DEBUG_HOTPLUG_CPU0
1807 prompt "Debug CPU0 hotplug"
1808 depends on HOTPLUG_CPU
1810 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1811 soon as possible and boots up userspace with CPU0 offlined. User
1812 can online CPU0 back after boot time.
1814 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1815 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1816 compilation or giving cpu0_hotplug kernel parameter at boot.
1822 prompt "Compat VDSO support"
1823 depends on X86_32 || IA32_EMULATION
1825 Map the 32-bit VDSO to the predictable old-style address too.
1827 Say N here if you are running a sufficiently recent glibc
1828 version (2.3.3 or later), to remove the high-mapped
1829 VDSO mapping and to exclusively use the randomized VDSO.
1834 bool "Built-in kernel command line"
1836 Allow for specifying boot arguments to the kernel at
1837 build time. On some systems (e.g. embedded ones), it is
1838 necessary or convenient to provide some or all of the
1839 kernel boot arguments with the kernel itself (that is,
1840 to not rely on the boot loader to provide them.)
1842 To compile command line arguments into the kernel,
1843 set this option to 'Y', then fill in the
1844 the boot arguments in CONFIG_CMDLINE.
1846 Systems with fully functional boot loaders (i.e. non-embedded)
1847 should leave this option set to 'N'.
1850 string "Built-in kernel command string"
1851 depends on CMDLINE_BOOL
1854 Enter arguments here that should be compiled into the kernel
1855 image and used at boot time. If the boot loader provides a
1856 command line at boot time, it is appended to this string to
1857 form the full kernel command line, when the system boots.
1859 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1860 change this behavior.
1862 In most cases, the command line (whether built-in or provided
1863 by the boot loader) should specify the device for the root
1866 config CMDLINE_OVERRIDE
1867 bool "Built-in command line overrides boot loader arguments"
1868 depends on CMDLINE_BOOL
1870 Set this option to 'Y' to have the kernel ignore the boot loader
1871 command line, and use ONLY the built-in command line.
1873 This is used to work around broken boot loaders. This should
1874 be set to 'N' under normal conditions.
1878 config ARCH_ENABLE_MEMORY_HOTPLUG
1880 depends on X86_64 || (X86_32 && HIGHMEM)
1882 config ARCH_ENABLE_MEMORY_HOTREMOVE
1884 depends on MEMORY_HOTPLUG
1886 config USE_PERCPU_NUMA_NODE_ID
1890 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1892 depends on X86_64 || X86_PAE
1894 menu "Power management and ACPI options"
1896 config ARCH_HIBERNATION_HEADER
1898 depends on X86_64 && HIBERNATION
1900 source "kernel/power/Kconfig"
1902 source "drivers/acpi/Kconfig"
1904 source "drivers/sfi/Kconfig"
1911 tristate "APM (Advanced Power Management) BIOS support"
1912 depends on X86_32 && PM_SLEEP
1914 APM is a BIOS specification for saving power using several different
1915 techniques. This is mostly useful for battery powered laptops with
1916 APM compliant BIOSes. If you say Y here, the system time will be
1917 reset after a RESUME operation, the /proc/apm device will provide
1918 battery status information, and user-space programs will receive
1919 notification of APM "events" (e.g. battery status change).
1921 If you select "Y" here, you can disable actual use of the APM
1922 BIOS by passing the "apm=off" option to the kernel at boot time.
1924 Note that the APM support is almost completely disabled for
1925 machines with more than one CPU.
1927 In order to use APM, you will need supporting software. For location
1928 and more information, read <file:Documentation/power/apm-acpi.txt>
1929 and the Battery Powered Linux mini-HOWTO, available from
1930 <http://www.tldp.org/docs.html#howto>.
1932 This driver does not spin down disk drives (see the hdparm(8)
1933 manpage ("man 8 hdparm") for that), and it doesn't turn off
1934 VESA-compliant "green" monitors.
1936 This driver does not support the TI 4000M TravelMate and the ACER
1937 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1938 desktop machines also don't have compliant BIOSes, and this driver
1939 may cause those machines to panic during the boot phase.
1941 Generally, if you don't have a battery in your machine, there isn't
1942 much point in using this driver and you should say N. If you get
1943 random kernel OOPSes or reboots that don't seem to be related to
1944 anything, try disabling/enabling this option (or disabling/enabling
1947 Some other things you should try when experiencing seemingly random,
1950 1) make sure that you have enough swap space and that it is
1952 2) pass the "no-hlt" option to the kernel
1953 3) switch on floating point emulation in the kernel and pass
1954 the "no387" option to the kernel
1955 4) pass the "floppy=nodma" option to the kernel
1956 5) pass the "mem=4M" option to the kernel (thereby disabling
1957 all but the first 4 MB of RAM)
1958 6) make sure that the CPU is not over clocked.
1959 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1960 8) disable the cache from your BIOS settings
1961 9) install a fan for the video card or exchange video RAM
1962 10) install a better fan for the CPU
1963 11) exchange RAM chips
1964 12) exchange the motherboard.
1966 To compile this driver as a module, choose M here: the
1967 module will be called apm.
1971 config APM_IGNORE_USER_SUSPEND
1972 bool "Ignore USER SUSPEND"
1974 This option will ignore USER SUSPEND requests. On machines with a
1975 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1976 series notebooks, it is necessary to say Y because of a BIOS bug.
1978 config APM_DO_ENABLE
1979 bool "Enable PM at boot time"
1981 Enable APM features at boot time. From page 36 of the APM BIOS
1982 specification: "When disabled, the APM BIOS does not automatically
1983 power manage devices, enter the Standby State, enter the Suspend
1984 State, or take power saving steps in response to CPU Idle calls."
1985 This driver will make CPU Idle calls when Linux is idle (unless this
1986 feature is turned off -- see "Do CPU IDLE calls", below). This
1987 should always save battery power, but more complicated APM features
1988 will be dependent on your BIOS implementation. You may need to turn
1989 this option off if your computer hangs at boot time when using APM
1990 support, or if it beeps continuously instead of suspending. Turn
1991 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1992 T400CDT. This is off by default since most machines do fine without
1997 bool "Make CPU Idle calls when idle"
1999 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2000 On some machines, this can activate improved power savings, such as
2001 a slowed CPU clock rate, when the machine is idle. These idle calls
2002 are made after the idle loop has run for some length of time (e.g.,
2003 333 mS). On some machines, this will cause a hang at boot time or
2004 whenever the CPU becomes idle. (On machines with more than one CPU,
2005 this option does nothing.)
2007 config APM_DISPLAY_BLANK
2008 bool "Enable console blanking using APM"
2010 Enable console blanking using the APM. Some laptops can use this to
2011 turn off the LCD backlight when the screen blanker of the Linux
2012 virtual console blanks the screen. Note that this is only used by
2013 the virtual console screen blanker, and won't turn off the backlight
2014 when using the X Window system. This also doesn't have anything to
2015 do with your VESA-compliant power-saving monitor. Further, this
2016 option doesn't work for all laptops -- it might not turn off your
2017 backlight at all, or it might print a lot of errors to the console,
2018 especially if you are using gpm.
2020 config APM_ALLOW_INTS
2021 bool "Allow interrupts during APM BIOS calls"
2023 Normally we disable external interrupts while we are making calls to
2024 the APM BIOS as a measure to lessen the effects of a badly behaving
2025 BIOS implementation. The BIOS should reenable interrupts if it
2026 needs to. Unfortunately, some BIOSes do not -- especially those in
2027 many of the newer IBM Thinkpads. If you experience hangs when you
2028 suspend, try setting this to Y. Otherwise, say N.
2032 source "drivers/cpufreq/Kconfig"
2034 source "drivers/cpuidle/Kconfig"
2036 source "drivers/idle/Kconfig"
2041 menu "Bus options (PCI etc.)"
2047 Find out whether you have a PCI motherboard. PCI is the name of a
2048 bus system, i.e. the way the CPU talks to the other stuff inside
2049 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2050 VESA. If you have PCI, say Y, otherwise N.
2053 prompt "PCI access mode"
2054 depends on X86_32 && PCI
2057 On PCI systems, the BIOS can be used to detect the PCI devices and
2058 determine their configuration. However, some old PCI motherboards
2059 have BIOS bugs and may crash if this is done. Also, some embedded
2060 PCI-based systems don't have any BIOS at all. Linux can also try to
2061 detect the PCI hardware directly without using the BIOS.
2063 With this option, you can specify how Linux should detect the
2064 PCI devices. If you choose "BIOS", the BIOS will be used,
2065 if you choose "Direct", the BIOS won't be used, and if you
2066 choose "MMConfig", then PCI Express MMCONFIG will be used.
2067 If you choose "Any", the kernel will try MMCONFIG, then the
2068 direct access method and falls back to the BIOS if that doesn't
2069 work. If unsure, go with the default, which is "Any".
2074 config PCI_GOMMCONFIG
2091 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2093 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2096 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2100 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2104 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2108 depends on PCI && XEN
2116 bool "Support mmconfig PCI config space access"
2117 depends on X86_64 && PCI && ACPI
2119 config PCI_CNB20LE_QUIRK
2120 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2123 Read the PCI windows out of the CNB20LE host bridge. This allows
2124 PCI hotplug to work on systems with the CNB20LE chipset which do
2127 There's no public spec for this chipset, and this functionality
2128 is known to be incomplete.
2130 You should say N unless you know you need this.
2132 source "drivers/pci/pcie/Kconfig"
2134 source "drivers/pci/Kconfig"
2136 # x86_64 have no ISA slots, but can have ISA-style DMA.
2138 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2141 Enables ISA-style DMA support for devices requiring such controllers.
2149 Find out whether you have ISA slots on your motherboard. ISA is the
2150 name of a bus system, i.e. the way the CPU talks to the other stuff
2151 inside your box. Other bus systems are PCI, EISA, MicroChannel
2152 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2153 newer boards don't support it. If you have ISA, say Y, otherwise N.
2159 The Extended Industry Standard Architecture (EISA) bus was
2160 developed as an open alternative to the IBM MicroChannel bus.
2162 The EISA bus provided some of the features of the IBM MicroChannel
2163 bus while maintaining backward compatibility with cards made for
2164 the older ISA bus. The EISA bus saw limited use between 1988 and
2165 1995 when it was made obsolete by the PCI bus.
2167 Say Y here if you are building a kernel for an EISA-based machine.
2171 source "drivers/eisa/Kconfig"
2174 tristate "NatSemi SCx200 support"
2176 This provides basic support for National Semiconductor's
2177 (now AMD's) Geode processors. The driver probes for the
2178 PCI-IDs of several on-chip devices, so its a good dependency
2179 for other scx200_* drivers.
2181 If compiled as a module, the driver is named scx200.
2183 config SCx200HR_TIMER
2184 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2188 This driver provides a clocksource built upon the on-chip
2189 27MHz high-resolution timer. Its also a workaround for
2190 NSC Geode SC-1100's buggy TSC, which loses time when the
2191 processor goes idle (as is done by the scheduler). The
2192 other workaround is idle=poll boot option.
2195 bool "One Laptop Per Child support"
2202 Add support for detecting the unique features of the OLPC
2206 bool "OLPC XO-1 Power Management"
2207 depends on OLPC && MFD_CS5535 && PM_SLEEP
2210 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2213 bool "OLPC XO-1 Real Time Clock"
2214 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2216 Add support for the XO-1 real time clock, which can be used as a
2217 programmable wakeup source.
2220 bool "OLPC XO-1 SCI extras"
2221 depends on OLPC && OLPC_XO1_PM
2227 Add support for SCI-based features of the OLPC XO-1 laptop:
2228 - EC-driven system wakeups
2232 - AC adapter status updates
2233 - Battery status updates
2235 config OLPC_XO15_SCI
2236 bool "OLPC XO-1.5 SCI extras"
2237 depends on OLPC && ACPI
2240 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2241 - EC-driven system wakeups
2242 - AC adapter status updates
2243 - Battery status updates
2246 bool "PCEngines ALIX System Support (LED setup)"
2249 This option enables system support for the PCEngines ALIX.
2250 At present this just sets up LEDs for GPIO control on
2251 ALIX2/3/6 boards. However, other system specific setup should
2254 Note: You must still enable the drivers for GPIO and LED support
2255 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2257 Note: You have to set alix.force=1 for boards with Award BIOS.
2260 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2263 This option enables system support for the Soekris Engineering net5501.
2266 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2270 This option enables system support for the Traverse Technologies GEOS.
2273 bool "Technologic Systems TS-5500 platform support"
2275 select CHECK_SIGNATURE
2279 This option enables system support for the Technologic Systems TS-5500.
2285 depends on CPU_SUP_AMD && PCI
2287 source "drivers/pcmcia/Kconfig"
2289 source "drivers/pci/hotplug/Kconfig"
2292 tristate "RapidIO support"
2296 If enabled this option will include drivers and the core
2297 infrastructure code to support RapidIO interconnect devices.
2299 source "drivers/rapidio/Kconfig"
2302 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2304 Firmwares often provide initial graphics framebuffers so the BIOS,
2305 bootloader or kernel can show basic video-output during boot for
2306 user-guidance and debugging. Historically, x86 used the VESA BIOS
2307 Extensions and EFI-framebuffers for this, which are mostly limited
2309 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2310 framebuffers so the new generic system-framebuffer drivers can be
2311 used on x86. If the framebuffer is not compatible with the generic
2312 modes, it is adverticed as fallback platform framebuffer so legacy
2313 drivers like efifb, vesafb and uvesafb can pick it up.
2314 If this option is not selected, all system framebuffers are always
2315 marked as fallback platform framebuffers as usual.
2317 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2318 not be able to pick up generic system framebuffers if this option
2319 is selected. You are highly encouraged to enable simplefb as
2320 replacement if you select this option. simplefb can correctly deal
2321 with generic system framebuffers. But you should still keep vesafb
2322 and others enabled as fallback if a system framebuffer is
2323 incompatible with simplefb.
2330 menu "Executable file formats / Emulations"
2332 source "fs/Kconfig.binfmt"
2334 config IA32_EMULATION
2335 bool "IA32 Emulation"
2338 select COMPAT_BINFMT_ELF
2341 Include code to run legacy 32-bit programs under a
2342 64-bit kernel. You should likely turn this on, unless you're
2343 100% sure that you don't have any 32-bit programs left.
2346 tristate "IA32 a.out support"
2347 depends on IA32_EMULATION
2349 Support old a.out binaries in the 32bit emulation.
2352 bool "x32 ABI for 64-bit mode"
2353 depends on X86_64 && IA32_EMULATION
2355 Include code to run binaries for the x32 native 32-bit ABI
2356 for 64-bit processors. An x32 process gets access to the
2357 full 64-bit register file and wide data path while leaving
2358 pointers at 32 bits for smaller memory footprint.
2360 You will need a recent binutils (2.22 or later) with
2361 elf32_x86_64 support enabled to compile a kernel with this
2366 depends on IA32_EMULATION || X86_X32
2367 select ARCH_WANT_OLD_COMPAT_IPC
2370 config COMPAT_FOR_U64_ALIGNMENT
2373 config SYSVIPC_COMPAT
2385 config HAVE_ATOMIC_IOMAP
2389 config X86_DEV_DMA_OPS
2391 depends on X86_64 || STA2X11
2393 config X86_DMA_REMAP
2397 source "net/Kconfig"
2399 source "drivers/Kconfig"
2401 source "drivers/firmware/Kconfig"
2405 source "arch/x86/Kconfig.debug"
2407 source "security/Kconfig"
2409 source "crypto/Kconfig"
2411 source "arch/x86/kvm/Kconfig"
2413 source "lib/Kconfig"