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 ARCH_MIGHT_HAVE_PC_SERIO
27 select HAVE_AOUT if X86_32
28 select HAVE_UNSTABLE_SCHED_CLOCK
29 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
30 select ARCH_SUPPORTS_INT128 if X86_64
31 select ARCH_WANTS_PROT_NUMA_PROT_NONE
34 select HAVE_PCSPKR_PLATFORM
35 select HAVE_PERF_EVENTS
36 select HAVE_IOREMAP_PROT
39 select HAVE_MEMBLOCK_NODE_MAP
40 select ARCH_DISCARD_MEMBLOCK
41 select ARCH_WANT_OPTIONAL_GPIOLIB
42 select ARCH_WANT_FRAME_POINTERS
44 select HAVE_DMA_CONTIGUOUS
45 select HAVE_KRETPROBES
46 select GENERIC_EARLY_IOREMAP
48 select HAVE_KPROBES_ON_FTRACE
49 select HAVE_FTRACE_MCOUNT_RECORD
50 select HAVE_FENTRY if X86_64
51 select HAVE_C_RECORDMCOUNT
52 select HAVE_DYNAMIC_FTRACE
53 select HAVE_DYNAMIC_FTRACE_WITH_REGS
54 select HAVE_FUNCTION_TRACER
55 select HAVE_FUNCTION_GRAPH_TRACER
56 select HAVE_FUNCTION_GRAPH_FP_TEST
57 select HAVE_SYSCALL_TRACEPOINTS
58 select SYSCTL_EXCEPTION_TRACE
61 select HAVE_ARCH_TRACEHOOK
62 select HAVE_GENERIC_DMA_COHERENT if X86_32
63 select HAVE_EFFICIENT_UNALIGNED_ACCESS
64 select USER_STACKTRACE_SUPPORT
65 select HAVE_REGS_AND_STACK_ACCESS_API
66 select HAVE_DMA_API_DEBUG
67 select HAVE_KERNEL_GZIP
68 select HAVE_KERNEL_BZIP2
69 select HAVE_KERNEL_LZMA
71 select HAVE_KERNEL_LZO
72 select HAVE_KERNEL_LZ4
73 select HAVE_HW_BREAKPOINT
74 select HAVE_MIXED_BREAKPOINTS_REGS
76 select HAVE_PERF_EVENTS_NMI
78 select HAVE_PERF_USER_STACK_DUMP
79 select HAVE_DEBUG_KMEMLEAK
81 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
82 select HAVE_CMPXCHG_LOCAL
83 select HAVE_CMPXCHG_DOUBLE
84 select HAVE_ARCH_KMEMCHECK
85 select HAVE_USER_RETURN_NOTIFIER
86 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
87 select HAVE_ARCH_JUMP_LABEL
88 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
90 select GENERIC_FIND_FIRST_BIT
91 select GENERIC_IRQ_PROBE
92 select GENERIC_PENDING_IRQ if SMP
93 select GENERIC_IRQ_SHOW
94 select GENERIC_CLOCKEVENTS_MIN_ADJUST
95 select IRQ_FORCED_THREADING
96 select HAVE_BPF_JIT if X86_64
97 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
99 select ARCH_HAVE_NMI_SAFE_CMPXCHG
101 select DCACHE_WORD_ACCESS
102 select GENERIC_SMP_IDLE_THREAD
103 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
104 select HAVE_ARCH_SECCOMP_FILTER
105 select BUILDTIME_EXTABLE_SORT
106 select GENERIC_CMOS_UPDATE
107 select HAVE_ARCH_SOFT_DIRTY if X86_64
108 select CLOCKSOURCE_WATCHDOG
109 select GENERIC_CLOCKEVENTS
110 select ARCH_CLOCKSOURCE_DATA
111 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
112 select GENERIC_TIME_VSYSCALL
113 select KTIME_SCALAR if X86_32
114 select GENERIC_STRNCPY_FROM_USER
115 select GENERIC_STRNLEN_USER
116 select HAVE_CONTEXT_TRACKING if X86_64
117 select HAVE_IRQ_TIME_ACCOUNTING
119 select MODULES_USE_ELF_REL if X86_32
120 select MODULES_USE_ELF_RELA if X86_64
121 select CLONE_BACKWARDS if X86_32
122 select ARCH_USE_BUILTIN_BSWAP
123 select ARCH_USE_QUEUE_RWLOCK
124 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
125 select OLD_SIGACTION if X86_32
126 select COMPAT_OLD_SIGACTION if IA32_EMULATION
128 select HAVE_DEBUG_STACKOVERFLOW
129 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
130 select HAVE_CC_STACKPROTECTOR
131 select GENERIC_CPU_AUTOPROBE
132 select HAVE_ARCH_AUDITSYSCALL
133 select ARCH_SUPPORTS_ATOMIC_RMW
134 select HAVE_ACPI_APEI if ACPI
135 select HAVE_ACPI_APEI_NMI if ACPI
137 config INSTRUCTION_DECODER
139 depends on KPROBES || PERF_EVENTS || UPROBES
143 default "elf32-i386" if X86_32
144 default "elf64-x86-64" if X86_64
146 config ARCH_DEFCONFIG
148 default "arch/x86/configs/i386_defconfig" if X86_32
149 default "arch/x86/configs/x86_64_defconfig" if X86_64
151 config LOCKDEP_SUPPORT
154 config STACKTRACE_SUPPORT
157 config HAVE_LATENCYTOP_SUPPORT
166 config NEED_DMA_MAP_STATE
168 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
170 config NEED_SG_DMA_LENGTH
173 config GENERIC_ISA_DMA
175 depends on ISA_DMA_API
180 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
182 config GENERIC_BUG_RELATIVE_POINTERS
185 config GENERIC_HWEIGHT
188 config ARCH_MAY_HAVE_PC_FDC
190 depends on ISA_DMA_API
192 config RWSEM_XCHGADD_ALGORITHM
195 config GENERIC_CALIBRATE_DELAY
198 config ARCH_HAS_CPU_RELAX
201 config ARCH_HAS_CACHE_LINE_SIZE
204 config HAVE_SETUP_PER_CPU_AREA
207 config NEED_PER_CPU_EMBED_FIRST_CHUNK
210 config NEED_PER_CPU_PAGE_FIRST_CHUNK
213 config ARCH_HIBERNATION_POSSIBLE
216 config ARCH_SUSPEND_POSSIBLE
219 config ARCH_WANT_HUGE_PMD_SHARE
222 config ARCH_WANT_GENERAL_HUGETLB
233 config ARCH_SUPPORTS_OPTIMIZED_INLINING
236 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
239 config HAVE_INTEL_TXT
241 depends on INTEL_IOMMU && ACPI
245 depends on X86_32 && SMP
249 depends on X86_64 && SMP
255 config X86_32_LAZY_GS
257 depends on X86_32 && !CC_STACKPROTECTOR
259 config ARCH_HWEIGHT_CFLAGS
261 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
262 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
264 config ARCH_SUPPORTS_UPROBES
267 config FIX_EARLYCON_MEM
270 source "init/Kconfig"
271 source "kernel/Kconfig.freezer"
273 menu "Processor type and features"
276 bool "DMA memory allocation support" if EXPERT
279 DMA memory allocation support allows devices with less than 32-bit
280 addressing to allocate within the first 16MB of address space.
281 Disable if no such devices will be used.
286 bool "Symmetric multi-processing support"
288 This enables support for systems with more than one CPU. If you have
289 a system with only one CPU, say N. If you have a system with more
292 If you say N here, the kernel will run on uni- and multiprocessor
293 machines, but will use only one CPU of a multiprocessor machine. If
294 you say Y here, the kernel will run on many, but not all,
295 uniprocessor machines. On a uniprocessor machine, the kernel
296 will run faster if you say N here.
298 Note that if you say Y here and choose architecture "586" or
299 "Pentium" under "Processor family", the kernel will not work on 486
300 architectures. Similarly, multiprocessor kernels for the "PPro"
301 architecture may not work on all Pentium based boards.
303 People using multiprocessor machines who say Y here should also say
304 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
305 Management" code will be disabled if you say Y here.
307 See also <file:Documentation/x86/i386/IO-APIC.txt>,
308 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
309 <http://www.tldp.org/docs.html#howto>.
311 If you don't know what to do here, say N.
314 bool "Support x2apic"
315 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
317 This enables x2apic support on CPUs that have this feature.
319 This allows 32-bit apic IDs (so it can support very large systems),
320 and accesses the local apic via MSRs not via mmio.
322 If you don't know what to do here, say N.
325 bool "Enable MPS table" if ACPI || SFI
327 depends on X86_LOCAL_APIC
329 For old smp systems that do not have proper acpi support. Newer systems
330 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
333 bool "Support for big SMP systems with more than 8 CPUs"
334 depends on X86_32 && SMP
336 This option is needed for the systems that have more than 8 CPUs
340 depends on X86_GOLDFISH
343 config X86_EXTENDED_PLATFORM
344 bool "Support for extended (non-PC) x86 platforms"
347 If you disable this option then the kernel will only support
348 standard PC platforms. (which covers the vast majority of
351 If you enable this option then you'll be able to select support
352 for the following (non-PC) 32 bit x86 platforms:
353 Goldfish (Android emulator)
356 SGI 320/540 (Visual Workstation)
357 STA2X11-based (e.g. Northville)
358 Moorestown MID devices
360 If you have one of these systems, or if you want to build a
361 generic distribution kernel, say Y here - otherwise say N.
365 config X86_EXTENDED_PLATFORM
366 bool "Support for extended (non-PC) x86 platforms"
369 If you disable this option then the kernel will only support
370 standard PC platforms. (which covers the vast majority of
373 If you enable this option then you'll be able to select support
374 for the following (non-PC) 64 bit x86 platforms:
379 If you have one of these systems, or if you want to build a
380 generic distribution kernel, say Y here - otherwise say N.
382 # This is an alphabetically sorted list of 64 bit extended platforms
383 # Please maintain the alphabetic order if and when there are additions
385 bool "Numascale NumaChip"
387 depends on X86_EXTENDED_PLATFORM
390 depends on X86_X2APIC
391 depends on PCI_MMCONFIG
393 Adds support for Numascale NumaChip large-SMP systems. Needed to
394 enable more than ~168 cores.
395 If you don't have one of these, you should say N here.
399 select HYPERVISOR_GUEST
401 depends on X86_64 && PCI
402 depends on X86_EXTENDED_PLATFORM
405 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
406 supposed to run on these EM64T-based machines. Only choose this option
407 if you have one of these machines.
410 bool "SGI Ultraviolet"
412 depends on X86_EXTENDED_PLATFORM
414 depends on X86_X2APIC
416 This option is needed in order to support SGI Ultraviolet systems.
417 If you don't have one of these, you should say N here.
419 # Following is an alphabetically sorted list of 32 bit extended platforms
420 # Please maintain the alphabetic order if and when there are additions
423 bool "Goldfish (Virtual Platform)"
424 depends on X86_EXTENDED_PLATFORM
426 Enable support for the Goldfish virtual platform used primarily
427 for Android development. Unless you are building for the Android
428 Goldfish emulator say N here.
431 bool "CE4100 TV platform"
433 depends on PCI_GODIRECT
435 depends on X86_EXTENDED_PLATFORM
436 select X86_REBOOTFIXUPS
438 select OF_EARLY_FLATTREE
441 Select for the Intel CE media processor (CE4100) SOC.
442 This option compiles in support for the CE4100 SOC for settop
443 boxes and media devices.
446 bool "Intel MID platform support"
448 depends on X86_EXTENDED_PLATFORM
449 depends on X86_PLATFORM_DEVICES
452 depends on X86_IO_APIC
458 select MFD_INTEL_MSIC
460 Select to build a kernel capable of supporting Intel MID (Mobile
461 Internet Device) platform systems which do not have the PCI legacy
462 interfaces. If you are building for a PC class system say N here.
464 Intel MID platforms are based on an Intel processor and chipset which
465 consume less power than most of the x86 derivatives.
467 config X86_INTEL_LPSS
468 bool "Intel Low Power Subsystem Support"
473 Select to build support for Intel Low Power Subsystem such as
474 found on Intel Lynxpoint PCH. Selecting this option enables
475 things like clock tree (common clock framework) and pincontrol
476 which are needed by the LPSS peripheral drivers.
479 bool "RDC R-321x SoC"
481 depends on X86_EXTENDED_PLATFORM
483 select X86_REBOOTFIXUPS
485 This option is needed for RDC R-321x system-on-chip, also known
487 If you don't have one of these chips, you should say N here.
489 config X86_32_NON_STANDARD
490 bool "Support non-standard 32-bit SMP architectures"
491 depends on X86_32 && SMP
492 depends on X86_EXTENDED_PLATFORM
494 This option compiles in the bigsmp and STA2X11 default
495 subarchitectures. It is intended for a generic binary
496 kernel. If you select them all, kernel will probe it one by
497 one and will fallback to default.
499 # Alphabetically sorted list of Non standard 32 bit platforms
501 config X86_SUPPORTS_MEMORY_FAILURE
503 # MCE code calls memory_failure():
505 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
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 "STA2X11 Companion Chip Support"
512 depends on X86_32_NON_STANDARD && PCI
513 select X86_DEV_DMA_OPS
517 select ARCH_REQUIRE_GPIOLIB
520 This adds support for boards based on the STA2X11 IO-Hub,
521 a.k.a. "ConneXt". The chip is used in place of the standard
522 PC chipset, so all "standard" peripherals are missing. If this
523 option is selected the kernel will still be able to boot on
524 standard PC machines.
527 tristate "Eurobraille/Iris poweroff module"
530 The Iris machines from EuroBraille do not have APM or ACPI support
531 to shut themselves down properly. A special I/O sequence is
532 needed to do so, which is what this module does at
535 This is only for Iris machines from EuroBraille.
539 config SCHED_OMIT_FRAME_POINTER
541 prompt "Single-depth WCHAN output"
544 Calculate simpler /proc/<PID>/wchan values. If this option
545 is disabled then wchan values will recurse back to the
546 caller function. This provides more accurate wchan values,
547 at the expense of slightly more scheduling overhead.
549 If in doubt, say "Y".
551 menuconfig HYPERVISOR_GUEST
552 bool "Linux guest support"
554 Say Y here to enable options for running Linux under various hyper-
555 visors. This option enables basic hypervisor detection and platform
558 If you say N, all options in this submenu will be skipped and
559 disabled, and Linux guest support won't be built in.
564 bool "Enable paravirtualization code"
566 This changes the kernel so it can modify itself when it is run
567 under a hypervisor, potentially improving performance significantly
568 over full virtualization. However, when run without a hypervisor
569 the kernel is theoretically slower and slightly larger.
571 config PARAVIRT_DEBUG
572 bool "paravirt-ops debugging"
573 depends on PARAVIRT && DEBUG_KERNEL
575 Enable to debug paravirt_ops internals. Specifically, BUG if
576 a paravirt_op is missing when it is called.
578 config PARAVIRT_SPINLOCKS
579 bool "Paravirtualization layer for spinlocks"
580 depends on PARAVIRT && SMP
581 select UNINLINE_SPIN_UNLOCK
583 Paravirtualized spinlocks allow a pvops backend to replace the
584 spinlock implementation with something virtualization-friendly
585 (for example, block the virtual CPU rather than spinning).
587 It has a minimal impact on native kernels and gives a nice performance
588 benefit on paravirtualized KVM / Xen kernels.
590 If you are unsure how to answer this question, answer Y.
592 source "arch/x86/xen/Kconfig"
595 bool "KVM Guest support (including kvmclock)"
597 select PARAVIRT_CLOCK
600 This option enables various optimizations for running under the KVM
601 hypervisor. It includes a paravirtualized clock, so that instead
602 of relying on a PIT (or probably other) emulation by the
603 underlying device model, the host provides the guest with
604 timing infrastructure such as time of day, and system time
607 bool "Enable debug information for KVM Guests in debugfs"
608 depends on KVM_GUEST && DEBUG_FS
611 This option enables collection of various statistics for KVM guest.
612 Statistics are displayed in debugfs filesystem. Enabling this option
613 may incur significant overhead.
615 source "arch/x86/lguest/Kconfig"
617 config PARAVIRT_TIME_ACCOUNTING
618 bool "Paravirtual steal time accounting"
622 Select this option to enable fine granularity task steal time
623 accounting. Time spent executing other tasks in parallel with
624 the current vCPU is discounted from the vCPU power. To account for
625 that, there can be a small performance impact.
627 If in doubt, say N here.
629 config PARAVIRT_CLOCK
632 endif #HYPERVISOR_GUEST
640 This option adds a kernel parameter 'memtest', which allows memtest
642 memtest=0, mean disabled; -- default
643 memtest=1, mean do 1 test pattern;
645 memtest=4, mean do 4 test patterns.
646 If you are unsure how to answer this question, answer N.
648 source "arch/x86/Kconfig.cpu"
652 prompt "HPET Timer Support" if X86_32
654 Use the IA-PC HPET (High Precision Event Timer) to manage
655 time in preference to the PIT and RTC, if a HPET is
657 HPET is the next generation timer replacing legacy 8254s.
658 The HPET provides a stable time base on SMP
659 systems, unlike the TSC, but it is more expensive to access,
660 as it is off-chip. You can find the HPET spec at
661 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
663 You can safely choose Y here. However, HPET will only be
664 activated if the platform and the BIOS support this feature.
665 Otherwise the 8254 will be used for timing services.
667 Choose N to continue using the legacy 8254 timer.
669 config HPET_EMULATE_RTC
671 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
674 def_bool y if X86_INTEL_MID
675 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
677 depends on X86_INTEL_MID && SFI
679 APB timer is the replacement for 8254, HPET on X86 MID platforms.
680 The APBT provides a stable time base on SMP
681 systems, unlike the TSC, but it is more expensive to access,
682 as it is off-chip. APB timers are always running regardless of CPU
683 C states, they are used as per CPU clockevent device when possible.
685 # Mark as expert because too many people got it wrong.
686 # The code disables itself when not needed.
689 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
690 bool "Enable DMI scanning" if EXPERT
692 Enabled scanning of DMI to identify machine quirks. Say Y
693 here unless you have verified that your setup is not
694 affected by entries in the DMI blacklist. Required by PNP
698 bool "Old AMD GART IOMMU support"
700 depends on X86_64 && PCI && AMD_NB
702 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
703 GART based hardware IOMMUs.
705 The GART supports full DMA access for devices with 32-bit access
706 limitations, on systems with more than 3 GB. This is usually needed
707 for USB, sound, many IDE/SATA chipsets and some other devices.
709 Newer systems typically have a modern AMD IOMMU, supported via
710 the CONFIG_AMD_IOMMU=y config option.
712 In normal configurations this driver is only active when needed:
713 there's more than 3 GB of memory and the system contains a
714 32-bit limited device.
719 bool "IBM Calgary IOMMU support"
721 depends on X86_64 && PCI
723 Support for hardware IOMMUs in IBM's xSeries x366 and x460
724 systems. Needed to run systems with more than 3GB of memory
725 properly with 32-bit PCI devices that do not support DAC
726 (Double Address Cycle). Calgary also supports bus level
727 isolation, where all DMAs pass through the IOMMU. This
728 prevents them from going anywhere except their intended
729 destination. This catches hard-to-find kernel bugs and
730 mis-behaving drivers and devices that do not use the DMA-API
731 properly to set up their DMA buffers. The IOMMU can be
732 turned off at boot time with the iommu=off parameter.
733 Normally the kernel will make the right choice by itself.
736 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
738 prompt "Should Calgary be enabled by default?"
739 depends on CALGARY_IOMMU
741 Should Calgary be enabled by default? if you choose 'y', Calgary
742 will be used (if it exists). If you choose 'n', Calgary will not be
743 used even if it exists. If you choose 'n' and would like to use
744 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
747 # need this always selected by IOMMU for the VIA workaround
751 Support for software bounce buffers used on x86-64 systems
752 which don't have a hardware IOMMU. Using this PCI devices
753 which can only access 32-bits of memory can be used on systems
754 with more than 3 GB of memory.
759 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
762 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
763 depends on X86_64 && SMP && DEBUG_KERNEL
764 select CPUMASK_OFFSTACK
766 Enable maximum number of CPUS and NUMA Nodes for this architecture.
770 int "Maximum number of CPUs" if SMP && !MAXSMP
771 range 2 8 if SMP && X86_32 && !X86_BIGSMP
772 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
773 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
775 default "8192" if MAXSMP
776 default "32" if SMP && X86_BIGSMP
779 This allows you to specify the maximum number of CPUs which this
780 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
781 supported value is 4096, otherwise the maximum value is 512. The
782 minimum value which makes sense is 2.
784 This is purely to save memory - each supported CPU adds
785 approximately eight kilobytes to the kernel image.
788 bool "SMT (Hyperthreading) scheduler support"
791 SMT scheduler support improves the CPU scheduler's decision making
792 when dealing with Intel Pentium 4 chips with HyperThreading at a
793 cost of slightly increased overhead in some places. If unsure say
798 prompt "Multi-core scheduler support"
801 Multi-core scheduler support improves the CPU scheduler's decision
802 making when dealing with multi-core CPU chips at a cost of slightly
803 increased overhead in some places. If unsure say N here.
805 source "kernel/Kconfig.preempt"
808 bool "Local APIC support on uniprocessors"
809 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
811 A local APIC (Advanced Programmable Interrupt Controller) is an
812 integrated interrupt controller in the CPU. If you have a single-CPU
813 system which has a processor with a local APIC, you can say Y here to
814 enable and use it. If you say Y here even though your machine doesn't
815 have a local APIC, then the kernel will still run with no slowdown at
816 all. The local APIC supports CPU-generated self-interrupts (timer,
817 performance counters), and the NMI watchdog which detects hard
821 bool "IO-APIC support on uniprocessors"
822 depends on X86_UP_APIC
824 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
825 SMP-capable replacement for PC-style interrupt controllers. Most
826 SMP systems and many recent uniprocessor systems have one.
828 If you have a single-CPU system with an IO-APIC, you can say Y here
829 to use it. If you say Y here even though your machine doesn't have
830 an IO-APIC, then the kernel will still run with no slowdown at all.
832 config X86_LOCAL_APIC
834 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
838 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
839 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
841 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
842 bool "Reroute for broken boot IRQs"
843 depends on X86_IO_APIC
845 This option enables a workaround that fixes a source of
846 spurious interrupts. This is recommended when threaded
847 interrupt handling is used on systems where the generation of
848 superfluous "boot interrupts" cannot be disabled.
850 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
851 entry in the chipset's IO-APIC is masked (as, e.g. the RT
852 kernel does during interrupt handling). On chipsets where this
853 boot IRQ generation cannot be disabled, this workaround keeps
854 the original IRQ line masked so that only the equivalent "boot
855 IRQ" is delivered to the CPUs. The workaround also tells the
856 kernel to set up the IRQ handler on the boot IRQ line. In this
857 way only one interrupt is delivered to the kernel. Otherwise
858 the spurious second interrupt may cause the kernel to bring
859 down (vital) interrupt lines.
861 Only affects "broken" chipsets. Interrupt sharing may be
862 increased on these systems.
865 bool "Machine Check / overheating reporting"
868 Machine Check support allows the processor to notify the
869 kernel if it detects a problem (e.g. overheating, data corruption).
870 The action the kernel takes depends on the severity of the problem,
871 ranging from warning messages to halting the machine.
875 prompt "Intel MCE features"
876 depends on X86_MCE && X86_LOCAL_APIC
878 Additional support for intel specific MCE features such as
883 prompt "AMD MCE features"
884 depends on X86_MCE && X86_LOCAL_APIC
886 Additional support for AMD specific MCE features such as
887 the DRAM Error Threshold.
889 config X86_ANCIENT_MCE
890 bool "Support for old Pentium 5 / WinChip machine checks"
891 depends on X86_32 && X86_MCE
893 Include support for machine check handling on old Pentium 5 or WinChip
894 systems. These typically need to be enabled explicitly on the command
897 config X86_MCE_THRESHOLD
898 depends on X86_MCE_AMD || X86_MCE_INTEL
901 config X86_MCE_INJECT
903 tristate "Machine check injector support"
905 Provide support for injecting machine checks for testing purposes.
906 If you don't know what a machine check is and you don't do kernel
907 QA it is safe to say n.
909 config X86_THERMAL_VECTOR
911 depends on X86_MCE_INTEL
914 bool "Enable VM86 support" if EXPERT
918 This option is required by programs like DOSEMU to run
919 16-bit real mode legacy code on x86 processors. It also may
920 be needed by software like XFree86 to initialize some video
921 cards via BIOS. Disabling this option saves about 6K.
924 bool "Enable support for 16-bit segments" if EXPERT
927 This option is required by programs like Wine to run 16-bit
928 protected mode legacy code on x86 processors. Disabling
929 this option saves about 300 bytes on i386, or around 6K text
930 plus 16K runtime memory on x86-64,
934 depends on X86_16BIT && X86_32
938 depends on X86_16BIT && X86_64
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 "CPU microcode loading support"
996 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1000 If you say Y here, you will be able to update the microcode on
1001 certain Intel and AMD processors. The Intel support is for the
1002 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1003 Xeon etc. The AMD support is for families 0x10 and later. You will
1004 obviously need the actual microcode binary data itself which is not
1005 shipped with the Linux kernel.
1007 This option selects the general module only, you need to select
1008 at least one vendor specific module as well.
1010 To compile this driver as a module, choose M here: the module
1011 will be called microcode.
1013 config MICROCODE_INTEL
1014 bool "Intel microcode loading support"
1015 depends on MICROCODE
1019 This options enables microcode patch loading support for Intel
1022 For the current Intel microcode data package go to
1023 <https://downloadcenter.intel.com> and search for
1024 'Linux Processor Microcode Data File'.
1026 config MICROCODE_AMD
1027 bool "AMD microcode loading support"
1028 depends on MICROCODE
1031 If you select this option, microcode patch loading support for AMD
1032 processors will be enabled.
1034 config MICROCODE_OLD_INTERFACE
1036 depends on MICROCODE
1038 config MICROCODE_INTEL_EARLY
1041 config MICROCODE_AMD_EARLY
1044 config MICROCODE_EARLY
1045 bool "Early load microcode"
1046 depends on MICROCODE=y && BLK_DEV_INITRD
1047 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1048 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1051 This option provides functionality to read additional microcode data
1052 at the beginning of initrd image. The data tells kernel to load
1053 microcode to CPU's as early as possible. No functional change if no
1054 microcode data is glued to the initrd, therefore it's safe to say Y.
1057 tristate "/dev/cpu/*/msr - Model-specific register support"
1059 This device gives privileged processes access to the x86
1060 Model-Specific Registers (MSRs). It is a character device with
1061 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1062 MSR accesses are directed to a specific CPU on multi-processor
1066 tristate "/dev/cpu/*/cpuid - CPU information support"
1068 This device gives processes access to the x86 CPUID instruction to
1069 be executed on a specific processor. It is a character device
1070 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1074 prompt "High Memory Support"
1081 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1082 However, the address space of 32-bit x86 processors is only 4
1083 Gigabytes large. That means that, if you have a large amount of
1084 physical memory, not all of it can be "permanently mapped" by the
1085 kernel. The physical memory that's not permanently mapped is called
1088 If you are compiling a kernel which will never run on a machine with
1089 more than 1 Gigabyte total physical RAM, answer "off" here (default
1090 choice and suitable for most users). This will result in a "3GB/1GB"
1091 split: 3GB are mapped so that each process sees a 3GB virtual memory
1092 space and the remaining part of the 4GB virtual memory space is used
1093 by the kernel to permanently map as much physical memory as
1096 If the machine has between 1 and 4 Gigabytes physical RAM, then
1099 If more than 4 Gigabytes is used then answer "64GB" here. This
1100 selection turns Intel PAE (Physical Address Extension) mode on.
1101 PAE implements 3-level paging on IA32 processors. PAE is fully
1102 supported by Linux, PAE mode is implemented on all recent Intel
1103 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1104 then the kernel will not boot on CPUs that don't support PAE!
1106 The actual amount of total physical memory will either be
1107 auto detected or can be forced by using a kernel command line option
1108 such as "mem=256M". (Try "man bootparam" or see the documentation of
1109 your boot loader (lilo or loadlin) about how to pass options to the
1110 kernel at boot time.)
1112 If unsure, say "off".
1117 Select this if you have a 32-bit processor and between 1 and 4
1118 gigabytes of physical RAM.
1125 Select this if you have a 32-bit processor and more than 4
1126 gigabytes of physical RAM.
1131 prompt "Memory split" if EXPERT
1135 Select the desired split between kernel and user memory.
1137 If the address range available to the kernel is less than the
1138 physical memory installed, the remaining memory will be available
1139 as "high memory". Accessing high memory is a little more costly
1140 than low memory, as it needs to be mapped into the kernel first.
1141 Note that increasing the kernel address space limits the range
1142 available to user programs, making the address space there
1143 tighter. Selecting anything other than the default 3G/1G split
1144 will also likely make your kernel incompatible with binary-only
1147 If you are not absolutely sure what you are doing, leave this
1151 bool "3G/1G user/kernel split"
1152 config VMSPLIT_3G_OPT
1154 bool "3G/1G user/kernel split (for full 1G low memory)"
1156 bool "2G/2G user/kernel split"
1157 config VMSPLIT_2G_OPT
1159 bool "2G/2G user/kernel split (for full 2G low memory)"
1161 bool "1G/3G user/kernel split"
1166 default 0xB0000000 if VMSPLIT_3G_OPT
1167 default 0x80000000 if VMSPLIT_2G
1168 default 0x78000000 if VMSPLIT_2G_OPT
1169 default 0x40000000 if VMSPLIT_1G
1175 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1178 bool "PAE (Physical Address Extension) Support"
1179 depends on X86_32 && !HIGHMEM4G
1181 PAE is required for NX support, and furthermore enables
1182 larger swapspace support for non-overcommit purposes. It
1183 has the cost of more pagetable lookup overhead, and also
1184 consumes more pagetable space per process.
1186 config ARCH_PHYS_ADDR_T_64BIT
1188 depends on X86_64 || X86_PAE
1190 config ARCH_DMA_ADDR_T_64BIT
1192 depends on X86_64 || HIGHMEM64G
1194 config DIRECT_GBPAGES
1195 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1199 Allow the kernel linear mapping to use 1GB pages on CPUs that
1200 support it. This can improve the kernel's performance a tiny bit by
1201 reducing TLB pressure. If in doubt, say "Y".
1203 # Common NUMA Features
1205 bool "Numa Memory Allocation and Scheduler Support"
1207 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1208 default y if X86_BIGSMP
1210 Enable NUMA (Non Uniform Memory Access) support.
1212 The kernel will try to allocate memory used by a CPU on the
1213 local memory controller of the CPU and add some more
1214 NUMA awareness to the kernel.
1216 For 64-bit this is recommended if the system is Intel Core i7
1217 (or later), AMD Opteron, or EM64T NUMA.
1219 For 32-bit this is only needed if you boot a 32-bit
1220 kernel on a 64-bit NUMA platform.
1222 Otherwise, you should say N.
1226 prompt "Old style AMD Opteron NUMA detection"
1227 depends on X86_64 && NUMA && PCI
1229 Enable AMD NUMA node topology detection. You should say Y here if
1230 you have a multi processor AMD system. This uses an old method to
1231 read the NUMA configuration directly from the builtin Northbridge
1232 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1233 which also takes priority if both are compiled in.
1235 config X86_64_ACPI_NUMA
1237 prompt "ACPI NUMA detection"
1238 depends on X86_64 && NUMA && ACPI && PCI
1241 Enable ACPI SRAT based node topology detection.
1243 # Some NUMA nodes have memory ranges that span
1244 # other nodes. Even though a pfn is valid and
1245 # between a node's start and end pfns, it may not
1246 # reside on that node. See memmap_init_zone()
1248 config NODES_SPAN_OTHER_NODES
1250 depends on X86_64_ACPI_NUMA
1253 bool "NUMA emulation"
1256 Enable NUMA emulation. A flat machine will be split
1257 into virtual nodes when booted with "numa=fake=N", where N is the
1258 number of nodes. This is only useful for debugging.
1261 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1263 default "10" if MAXSMP
1264 default "6" if X86_64
1266 depends on NEED_MULTIPLE_NODES
1268 Specify the maximum number of NUMA Nodes available on the target
1269 system. Increases memory reserved to accommodate various tables.
1271 config ARCH_HAVE_MEMORY_PRESENT
1273 depends on X86_32 && DISCONTIGMEM
1275 config NEED_NODE_MEMMAP_SIZE
1277 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1279 config ARCH_FLATMEM_ENABLE
1281 depends on X86_32 && !NUMA
1283 config ARCH_DISCONTIGMEM_ENABLE
1285 depends on NUMA && X86_32
1287 config ARCH_DISCONTIGMEM_DEFAULT
1289 depends on NUMA && X86_32
1291 config ARCH_SPARSEMEM_ENABLE
1293 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1294 select SPARSEMEM_STATIC if X86_32
1295 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1297 config ARCH_SPARSEMEM_DEFAULT
1301 config ARCH_SELECT_MEMORY_MODEL
1303 depends on ARCH_SPARSEMEM_ENABLE
1305 config ARCH_MEMORY_PROBE
1306 bool "Enable sysfs memory/probe interface"
1307 depends on X86_64 && MEMORY_HOTPLUG
1309 This option enables a sysfs memory/probe interface for testing.
1310 See Documentation/memory-hotplug.txt for more information.
1311 If you are unsure how to answer this question, answer N.
1313 config ARCH_PROC_KCORE_TEXT
1315 depends on X86_64 && PROC_KCORE
1317 config ILLEGAL_POINTER_VALUE
1320 default 0xdead000000000000 if X86_64
1325 bool "Allocate 3rd-level pagetables from highmem"
1328 The VM uses one page table entry for each page of physical memory.
1329 For systems with a lot of RAM, this can be wasteful of precious
1330 low memory. Setting this option will put user-space page table
1331 entries in high memory.
1333 config X86_CHECK_BIOS_CORRUPTION
1334 bool "Check for low memory corruption"
1336 Periodically check for memory corruption in low memory, which
1337 is suspected to be caused by BIOS. Even when enabled in the
1338 configuration, it is disabled at runtime. Enable it by
1339 setting "memory_corruption_check=1" on the kernel command
1340 line. By default it scans the low 64k of memory every 60
1341 seconds; see the memory_corruption_check_size and
1342 memory_corruption_check_period parameters in
1343 Documentation/kernel-parameters.txt to adjust this.
1345 When enabled with the default parameters, this option has
1346 almost no overhead, as it reserves a relatively small amount
1347 of memory and scans it infrequently. It both detects corruption
1348 and prevents it from affecting the running system.
1350 It is, however, intended as a diagnostic tool; if repeatable
1351 BIOS-originated corruption always affects the same memory,
1352 you can use memmap= to prevent the kernel from using that
1355 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1356 bool "Set the default setting of memory_corruption_check"
1357 depends on X86_CHECK_BIOS_CORRUPTION
1360 Set whether the default state of memory_corruption_check is
1363 config X86_RESERVE_LOW
1364 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1368 Specify the amount of low memory to reserve for the BIOS.
1370 The first page contains BIOS data structures that the kernel
1371 must not use, so that page must always be reserved.
1373 By default we reserve the first 64K of physical RAM, as a
1374 number of BIOSes are known to corrupt that memory range
1375 during events such as suspend/resume or monitor cable
1376 insertion, so it must not be used by the kernel.
1378 You can set this to 4 if you are absolutely sure that you
1379 trust the BIOS to get all its memory reservations and usages
1380 right. If you know your BIOS have problems beyond the
1381 default 64K area, you can set this to 640 to avoid using the
1382 entire low memory range.
1384 If you have doubts about the BIOS (e.g. suspend/resume does
1385 not work or there's kernel crashes after certain hardware
1386 hotplug events) then you might want to enable
1387 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1388 typical corruption patterns.
1390 Leave this to the default value of 64 if you are unsure.
1392 config MATH_EMULATION
1394 prompt "Math emulation" if X86_32
1396 Linux can emulate a math coprocessor (used for floating point
1397 operations) if you don't have one. 486DX and Pentium processors have
1398 a math coprocessor built in, 486SX and 386 do not, unless you added
1399 a 487DX or 387, respectively. (The messages during boot time can
1400 give you some hints here ["man dmesg"].) Everyone needs either a
1401 coprocessor or this emulation.
1403 If you don't have a math coprocessor, you need to say Y here; if you
1404 say Y here even though you have a coprocessor, the coprocessor will
1405 be used nevertheless. (This behavior can be changed with the kernel
1406 command line option "no387", which comes handy if your coprocessor
1407 is broken. Try "man bootparam" or see the documentation of your boot
1408 loader (lilo or loadlin) about how to pass options to the kernel at
1409 boot time.) This means that it is a good idea to say Y here if you
1410 intend to use this kernel on different machines.
1412 More information about the internals of the Linux math coprocessor
1413 emulation can be found in <file:arch/x86/math-emu/README>.
1415 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1416 kernel, it won't hurt.
1420 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1422 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1423 the Memory Type Range Registers (MTRRs) may be used to control
1424 processor access to memory ranges. This is most useful if you have
1425 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1426 allows bus write transfers to be combined into a larger transfer
1427 before bursting over the PCI/AGP bus. This can increase performance
1428 of image write operations 2.5 times or more. Saying Y here creates a
1429 /proc/mtrr file which may be used to manipulate your processor's
1430 MTRRs. Typically the X server should use this.
1432 This code has a reasonably generic interface so that similar
1433 control registers on other processors can be easily supported
1436 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1437 Registers (ARRs) which provide a similar functionality to MTRRs. For
1438 these, the ARRs are used to emulate the MTRRs.
1439 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1440 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1441 write-combining. All of these processors are supported by this code
1442 and it makes sense to say Y here if you have one of them.
1444 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1445 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1446 can lead to all sorts of problems, so it's good to say Y here.
1448 You can safely say Y even if your machine doesn't have MTRRs, you'll
1449 just add about 9 KB to your kernel.
1451 See <file:Documentation/x86/mtrr.txt> for more information.
1453 config MTRR_SANITIZER
1455 prompt "MTRR cleanup support"
1458 Convert MTRR layout from continuous to discrete, so X drivers can
1459 add writeback entries.
1461 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1462 The largest mtrr entry size for a continuous block can be set with
1467 config MTRR_SANITIZER_ENABLE_DEFAULT
1468 int "MTRR cleanup enable value (0-1)"
1471 depends on MTRR_SANITIZER
1473 Enable mtrr cleanup default value
1475 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1476 int "MTRR cleanup spare reg num (0-7)"
1479 depends on MTRR_SANITIZER
1481 mtrr cleanup spare entries default, it can be changed via
1482 mtrr_spare_reg_nr=N on the kernel command line.
1486 prompt "x86 PAT support" if EXPERT
1489 Use PAT attributes to setup page level cache control.
1491 PATs are the modern equivalents of MTRRs and are much more
1492 flexible than MTRRs.
1494 Say N here if you see bootup problems (boot crash, boot hang,
1495 spontaneous reboots) or a non-working video driver.
1499 config ARCH_USES_PG_UNCACHED
1505 prompt "x86 architectural random number generator" if EXPERT
1507 Enable the x86 architectural RDRAND instruction
1508 (Intel Bull Mountain technology) to generate random numbers.
1509 If supported, this is a high bandwidth, cryptographically
1510 secure hardware random number generator.
1514 prompt "Supervisor Mode Access Prevention" if EXPERT
1516 Supervisor Mode Access Prevention (SMAP) is a security
1517 feature in newer Intel processors. There is a small
1518 performance cost if this enabled and turned on; there is
1519 also a small increase in the kernel size if this is enabled.
1524 bool "EFI runtime service support"
1527 select EFI_RUNTIME_WRAPPERS
1529 This enables the kernel to use EFI runtime services that are
1530 available (such as the EFI variable services).
1532 This option is only useful on systems that have EFI firmware.
1533 In addition, you should use the latest ELILO loader available
1534 at <http://elilo.sourceforge.net> in order to take advantage
1535 of EFI runtime services. However, even with this option, the
1536 resultant kernel should continue to boot on existing non-EFI
1540 bool "EFI stub support"
1543 This kernel feature allows a bzImage to be loaded directly
1544 by EFI firmware without the use of a bootloader.
1546 See Documentation/efi-stub.txt for more information.
1549 bool "EFI mixed-mode support"
1550 depends on EFI_STUB && X86_64
1552 Enabling this feature allows a 64-bit kernel to be booted
1553 on a 32-bit firmware, provided that your CPU supports 64-bit
1556 Note that it is not possible to boot a mixed-mode enabled
1557 kernel via the EFI boot stub - a bootloader that supports
1558 the EFI handover protocol must be used.
1564 prompt "Enable seccomp to safely compute untrusted bytecode"
1566 This kernel feature is useful for number crunching applications
1567 that may need to compute untrusted bytecode during their
1568 execution. By using pipes or other transports made available to
1569 the process as file descriptors supporting the read/write
1570 syscalls, it's possible to isolate those applications in
1571 their own address space using seccomp. Once seccomp is
1572 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1573 and the task is only allowed to execute a few safe syscalls
1574 defined by each seccomp mode.
1576 If unsure, say Y. Only embedded should say N here.
1578 source kernel/Kconfig.hz
1581 bool "kexec system call"
1583 kexec is a system call that implements the ability to shutdown your
1584 current kernel, and to start another kernel. It is like a reboot
1585 but it is independent of the system firmware. And like a reboot
1586 you can start any kernel with it, not just Linux.
1588 The name comes from the similarity to the exec system call.
1590 It is an ongoing process to be certain the hardware in a machine
1591 is properly shutdown, so do not be surprised if this code does not
1592 initially work for you. As of this writing the exact hardware
1593 interface is strongly in flux, so no good recommendation can be
1597 bool "kernel crash dumps"
1598 depends on X86_64 || (X86_32 && HIGHMEM)
1600 Generate crash dump after being started by kexec.
1601 This should be normally only set in special crash dump kernels
1602 which are loaded in the main kernel with kexec-tools into
1603 a specially reserved region and then later executed after
1604 a crash by kdump/kexec. The crash dump kernel must be compiled
1605 to a memory address not used by the main kernel or BIOS using
1606 PHYSICAL_START, or it must be built as a relocatable image
1607 (CONFIG_RELOCATABLE=y).
1608 For more details see Documentation/kdump/kdump.txt
1612 depends on KEXEC && HIBERNATION
1614 Jump between original kernel and kexeced kernel and invoke
1615 code in physical address mode via KEXEC
1617 config PHYSICAL_START
1618 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1621 This gives the physical address where the kernel is loaded.
1623 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1624 bzImage will decompress itself to above physical address and
1625 run from there. Otherwise, bzImage will run from the address where
1626 it has been loaded by the boot loader and will ignore above physical
1629 In normal kdump cases one does not have to set/change this option
1630 as now bzImage can be compiled as a completely relocatable image
1631 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1632 address. This option is mainly useful for the folks who don't want
1633 to use a bzImage for capturing the crash dump and want to use a
1634 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1635 to be specifically compiled to run from a specific memory area
1636 (normally a reserved region) and this option comes handy.
1638 So if you are using bzImage for capturing the crash dump,
1639 leave the value here unchanged to 0x1000000 and set
1640 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1641 for capturing the crash dump change this value to start of
1642 the reserved region. In other words, it can be set based on
1643 the "X" value as specified in the "crashkernel=YM@XM"
1644 command line boot parameter passed to the panic-ed
1645 kernel. Please take a look at Documentation/kdump/kdump.txt
1646 for more details about crash dumps.
1648 Usage of bzImage for capturing the crash dump is recommended as
1649 one does not have to build two kernels. Same kernel can be used
1650 as production kernel and capture kernel. Above option should have
1651 gone away after relocatable bzImage support is introduced. But it
1652 is present because there are users out there who continue to use
1653 vmlinux for dump capture. This option should go away down the
1656 Don't change this unless you know what you are doing.
1659 bool "Build a relocatable kernel"
1662 This builds a kernel image that retains relocation information
1663 so it can be loaded someplace besides the default 1MB.
1664 The relocations tend to make the kernel binary about 10% larger,
1665 but are discarded at runtime.
1667 One use is for the kexec on panic case where the recovery kernel
1668 must live at a different physical address than the primary
1671 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1672 it has been loaded at and the compile time physical address
1673 (CONFIG_PHYSICAL_START) is used as the minimum location.
1675 config RANDOMIZE_BASE
1676 bool "Randomize the address of the kernel image"
1677 depends on RELOCATABLE
1680 Randomizes the physical and virtual address at which the
1681 kernel image is decompressed, as a security feature that
1682 deters exploit attempts relying on knowledge of the location
1683 of kernel internals.
1685 Entropy is generated using the RDRAND instruction if it is
1686 supported. If RDTSC is supported, it is used as well. If
1687 neither RDRAND nor RDTSC are supported, then randomness is
1688 read from the i8254 timer.
1690 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1691 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1692 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1693 minimum of 2MiB, only 10 bits of entropy is theoretically
1694 possible. At best, due to page table layouts, 64-bit can use
1695 9 bits of entropy and 32-bit uses 8 bits.
1699 config RANDOMIZE_BASE_MAX_OFFSET
1700 hex "Maximum kASLR offset allowed" if EXPERT
1701 depends on RANDOMIZE_BASE
1702 range 0x0 0x20000000 if X86_32
1703 default "0x20000000" if X86_32
1704 range 0x0 0x40000000 if X86_64
1705 default "0x40000000" if X86_64
1707 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1708 memory is used to determine the maximal offset in bytes that will
1709 be applied to the kernel when kernel Address Space Layout
1710 Randomization (kASLR) is active. This must be a multiple of
1713 On 32-bit this is limited to 512MiB by page table layouts. The
1716 On 64-bit this is limited by how the kernel fixmap page table is
1717 positioned, so this cannot be larger than 1GiB currently. Without
1718 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1719 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1720 modules area will shrink to compensate, up to the current maximum
1721 1GiB to 1GiB split. The default is 1GiB.
1723 If unsure, leave at the default value.
1725 # Relocation on x86 needs some additional build support
1726 config X86_NEED_RELOCS
1728 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1730 config PHYSICAL_ALIGN
1731 hex "Alignment value to which kernel should be aligned"
1733 range 0x2000 0x1000000 if X86_32
1734 range 0x200000 0x1000000 if X86_64
1736 This value puts the alignment restrictions on physical address
1737 where kernel is loaded and run from. Kernel is compiled for an
1738 address which meets above alignment restriction.
1740 If bootloader loads the kernel at a non-aligned address and
1741 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1742 address aligned to above value and run from there.
1744 If bootloader loads the kernel at a non-aligned address and
1745 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1746 load address and decompress itself to the address it has been
1747 compiled for and run from there. The address for which kernel is
1748 compiled already meets above alignment restrictions. Hence the
1749 end result is that kernel runs from a physical address meeting
1750 above alignment restrictions.
1752 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1753 this value must be a multiple of 0x200000.
1755 Don't change this unless you know what you are doing.
1758 bool "Support for hot-pluggable CPUs"
1761 Say Y here to allow turning CPUs off and on. CPUs can be
1762 controlled through /sys/devices/system/cpu.
1763 ( Note: power management support will enable this option
1764 automatically on SMP systems. )
1765 Say N if you want to disable CPU hotplug.
1767 config BOOTPARAM_HOTPLUG_CPU0
1768 bool "Set default setting of cpu0_hotpluggable"
1770 depends on HOTPLUG_CPU
1772 Set whether default state of cpu0_hotpluggable is on or off.
1774 Say Y here to enable CPU0 hotplug by default. If this switch
1775 is turned on, there is no need to give cpu0_hotplug kernel
1776 parameter and the CPU0 hotplug feature is enabled by default.
1778 Please note: there are two known CPU0 dependencies if you want
1779 to enable the CPU0 hotplug feature either by this switch or by
1780 cpu0_hotplug kernel parameter.
1782 First, resume from hibernate or suspend always starts from CPU0.
1783 So hibernate and suspend are prevented if CPU0 is offline.
1785 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1786 offline if any interrupt can not migrate out of CPU0. There may
1787 be other CPU0 dependencies.
1789 Please make sure the dependencies are under your control before
1790 you enable this feature.
1792 Say N if you don't want to enable CPU0 hotplug feature by default.
1793 You still can enable the CPU0 hotplug feature at boot by kernel
1794 parameter cpu0_hotplug.
1796 config DEBUG_HOTPLUG_CPU0
1798 prompt "Debug CPU0 hotplug"
1799 depends on HOTPLUG_CPU
1801 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1802 soon as possible and boots up userspace with CPU0 offlined. User
1803 can online CPU0 back after boot time.
1805 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1806 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1807 compilation or giving cpu0_hotplug kernel parameter at boot.
1813 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1814 depends on X86_32 || IA32_EMULATION
1816 Certain buggy versions of glibc will crash if they are
1817 presented with a 32-bit vDSO that is not mapped at the address
1818 indicated in its segment table.
1820 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1821 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1822 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1823 the only released version with the bug, but OpenSUSE 9
1824 contains a buggy "glibc 2.3.2".
1826 The symptom of the bug is that everything crashes on startup, saying:
1827 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1829 Saying Y here changes the default value of the vdso32 boot
1830 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1831 This works around the glibc bug but hurts performance.
1833 If unsure, say N: if you are compiling your own kernel, you
1834 are unlikely to be using a buggy version of glibc.
1837 bool "Built-in kernel command line"
1839 Allow for specifying boot arguments to the kernel at
1840 build time. On some systems (e.g. embedded ones), it is
1841 necessary or convenient to provide some or all of the
1842 kernel boot arguments with the kernel itself (that is,
1843 to not rely on the boot loader to provide them.)
1845 To compile command line arguments into the kernel,
1846 set this option to 'Y', then fill in the
1847 the boot arguments in CONFIG_CMDLINE.
1849 Systems with fully functional boot loaders (i.e. non-embedded)
1850 should leave this option set to 'N'.
1853 string "Built-in kernel command string"
1854 depends on CMDLINE_BOOL
1857 Enter arguments here that should be compiled into the kernel
1858 image and used at boot time. If the boot loader provides a
1859 command line at boot time, it is appended to this string to
1860 form the full kernel command line, when the system boots.
1862 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1863 change this behavior.
1865 In most cases, the command line (whether built-in or provided
1866 by the boot loader) should specify the device for the root
1869 config CMDLINE_OVERRIDE
1870 bool "Built-in command line overrides boot loader arguments"
1871 depends on CMDLINE_BOOL
1873 Set this option to 'Y' to have the kernel ignore the boot loader
1874 command line, and use ONLY the built-in command line.
1876 This is used to work around broken boot loaders. This should
1877 be set to 'N' under normal conditions.
1881 config ARCH_ENABLE_MEMORY_HOTPLUG
1883 depends on X86_64 || (X86_32 && HIGHMEM)
1885 config ARCH_ENABLE_MEMORY_HOTREMOVE
1887 depends on MEMORY_HOTPLUG
1889 config USE_PERCPU_NUMA_NODE_ID
1893 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1895 depends on X86_64 || X86_PAE
1897 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1899 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1901 menu "Power management and ACPI options"
1903 config ARCH_HIBERNATION_HEADER
1905 depends on X86_64 && HIBERNATION
1907 source "kernel/power/Kconfig"
1909 source "drivers/acpi/Kconfig"
1911 source "drivers/sfi/Kconfig"
1918 tristate "APM (Advanced Power Management) BIOS support"
1919 depends on X86_32 && PM_SLEEP
1921 APM is a BIOS specification for saving power using several different
1922 techniques. This is mostly useful for battery powered laptops with
1923 APM compliant BIOSes. If you say Y here, the system time will be
1924 reset after a RESUME operation, the /proc/apm device will provide
1925 battery status information, and user-space programs will receive
1926 notification of APM "events" (e.g. battery status change).
1928 If you select "Y" here, you can disable actual use of the APM
1929 BIOS by passing the "apm=off" option to the kernel at boot time.
1931 Note that the APM support is almost completely disabled for
1932 machines with more than one CPU.
1934 In order to use APM, you will need supporting software. For location
1935 and more information, read <file:Documentation/power/apm-acpi.txt>
1936 and the Battery Powered Linux mini-HOWTO, available from
1937 <http://www.tldp.org/docs.html#howto>.
1939 This driver does not spin down disk drives (see the hdparm(8)
1940 manpage ("man 8 hdparm") for that), and it doesn't turn off
1941 VESA-compliant "green" monitors.
1943 This driver does not support the TI 4000M TravelMate and the ACER
1944 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1945 desktop machines also don't have compliant BIOSes, and this driver
1946 may cause those machines to panic during the boot phase.
1948 Generally, if you don't have a battery in your machine, there isn't
1949 much point in using this driver and you should say N. If you get
1950 random kernel OOPSes or reboots that don't seem to be related to
1951 anything, try disabling/enabling this option (or disabling/enabling
1954 Some other things you should try when experiencing seemingly random,
1957 1) make sure that you have enough swap space and that it is
1959 2) pass the "no-hlt" option to the kernel
1960 3) switch on floating point emulation in the kernel and pass
1961 the "no387" option to the kernel
1962 4) pass the "floppy=nodma" option to the kernel
1963 5) pass the "mem=4M" option to the kernel (thereby disabling
1964 all but the first 4 MB of RAM)
1965 6) make sure that the CPU is not over clocked.
1966 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1967 8) disable the cache from your BIOS settings
1968 9) install a fan for the video card or exchange video RAM
1969 10) install a better fan for the CPU
1970 11) exchange RAM chips
1971 12) exchange the motherboard.
1973 To compile this driver as a module, choose M here: the
1974 module will be called apm.
1978 config APM_IGNORE_USER_SUSPEND
1979 bool "Ignore USER SUSPEND"
1981 This option will ignore USER SUSPEND requests. On machines with a
1982 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1983 series notebooks, it is necessary to say Y because of a BIOS bug.
1985 config APM_DO_ENABLE
1986 bool "Enable PM at boot time"
1988 Enable APM features at boot time. From page 36 of the APM BIOS
1989 specification: "When disabled, the APM BIOS does not automatically
1990 power manage devices, enter the Standby State, enter the Suspend
1991 State, or take power saving steps in response to CPU Idle calls."
1992 This driver will make CPU Idle calls when Linux is idle (unless this
1993 feature is turned off -- see "Do CPU IDLE calls", below). This
1994 should always save battery power, but more complicated APM features
1995 will be dependent on your BIOS implementation. You may need to turn
1996 this option off if your computer hangs at boot time when using APM
1997 support, or if it beeps continuously instead of suspending. Turn
1998 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1999 T400CDT. This is off by default since most machines do fine without
2004 bool "Make CPU Idle calls when idle"
2006 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2007 On some machines, this can activate improved power savings, such as
2008 a slowed CPU clock rate, when the machine is idle. These idle calls
2009 are made after the idle loop has run for some length of time (e.g.,
2010 333 mS). On some machines, this will cause a hang at boot time or
2011 whenever the CPU becomes idle. (On machines with more than one CPU,
2012 this option does nothing.)
2014 config APM_DISPLAY_BLANK
2015 bool "Enable console blanking using APM"
2017 Enable console blanking using the APM. Some laptops can use this to
2018 turn off the LCD backlight when the screen blanker of the Linux
2019 virtual console blanks the screen. Note that this is only used by
2020 the virtual console screen blanker, and won't turn off the backlight
2021 when using the X Window system. This also doesn't have anything to
2022 do with your VESA-compliant power-saving monitor. Further, this
2023 option doesn't work for all laptops -- it might not turn off your
2024 backlight at all, or it might print a lot of errors to the console,
2025 especially if you are using gpm.
2027 config APM_ALLOW_INTS
2028 bool "Allow interrupts during APM BIOS calls"
2030 Normally we disable external interrupts while we are making calls to
2031 the APM BIOS as a measure to lessen the effects of a badly behaving
2032 BIOS implementation. The BIOS should reenable interrupts if it
2033 needs to. Unfortunately, some BIOSes do not -- especially those in
2034 many of the newer IBM Thinkpads. If you experience hangs when you
2035 suspend, try setting this to Y. Otherwise, say N.
2039 source "drivers/cpufreq/Kconfig"
2041 source "drivers/cpuidle/Kconfig"
2043 source "drivers/idle/Kconfig"
2048 menu "Bus options (PCI etc.)"
2054 Find out whether you have a PCI motherboard. PCI is the name of a
2055 bus system, i.e. the way the CPU talks to the other stuff inside
2056 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2057 VESA. If you have PCI, say Y, otherwise N.
2060 prompt "PCI access mode"
2061 depends on X86_32 && PCI
2064 On PCI systems, the BIOS can be used to detect the PCI devices and
2065 determine their configuration. However, some old PCI motherboards
2066 have BIOS bugs and may crash if this is done. Also, some embedded
2067 PCI-based systems don't have any BIOS at all. Linux can also try to
2068 detect the PCI hardware directly without using the BIOS.
2070 With this option, you can specify how Linux should detect the
2071 PCI devices. If you choose "BIOS", the BIOS will be used,
2072 if you choose "Direct", the BIOS won't be used, and if you
2073 choose "MMConfig", then PCI Express MMCONFIG will be used.
2074 If you choose "Any", the kernel will try MMCONFIG, then the
2075 direct access method and falls back to the BIOS if that doesn't
2076 work. If unsure, go with the default, which is "Any".
2081 config PCI_GOMMCONFIG
2098 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2100 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2103 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2107 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2111 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2115 depends on PCI && XEN
2123 bool "Support mmconfig PCI config space access"
2124 depends on X86_64 && PCI && ACPI
2126 config PCI_CNB20LE_QUIRK
2127 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2130 Read the PCI windows out of the CNB20LE host bridge. This allows
2131 PCI hotplug to work on systems with the CNB20LE chipset which do
2134 There's no public spec for this chipset, and this functionality
2135 is known to be incomplete.
2137 You should say N unless you know you need this.
2139 source "drivers/pci/pcie/Kconfig"
2141 source "drivers/pci/Kconfig"
2143 # x86_64 have no ISA slots, but can have ISA-style DMA.
2145 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2148 Enables ISA-style DMA support for devices requiring such controllers.
2156 Find out whether you have ISA slots on your motherboard. ISA is the
2157 name of a bus system, i.e. the way the CPU talks to the other stuff
2158 inside your box. Other bus systems are PCI, EISA, MicroChannel
2159 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2160 newer boards don't support it. If you have ISA, say Y, otherwise N.
2166 The Extended Industry Standard Architecture (EISA) bus was
2167 developed as an open alternative to the IBM MicroChannel bus.
2169 The EISA bus provided some of the features of the IBM MicroChannel
2170 bus while maintaining backward compatibility with cards made for
2171 the older ISA bus. The EISA bus saw limited use between 1988 and
2172 1995 when it was made obsolete by the PCI bus.
2174 Say Y here if you are building a kernel for an EISA-based machine.
2178 source "drivers/eisa/Kconfig"
2181 tristate "NatSemi SCx200 support"
2183 This provides basic support for National Semiconductor's
2184 (now AMD's) Geode processors. The driver probes for the
2185 PCI-IDs of several on-chip devices, so its a good dependency
2186 for other scx200_* drivers.
2188 If compiled as a module, the driver is named scx200.
2190 config SCx200HR_TIMER
2191 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2195 This driver provides a clocksource built upon the on-chip
2196 27MHz high-resolution timer. Its also a workaround for
2197 NSC Geode SC-1100's buggy TSC, which loses time when the
2198 processor goes idle (as is done by the scheduler). The
2199 other workaround is idle=poll boot option.
2202 bool "One Laptop Per Child support"
2209 Add support for detecting the unique features of the OLPC
2213 bool "OLPC XO-1 Power Management"
2214 depends on OLPC && MFD_CS5535 && PM_SLEEP
2217 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2220 bool "OLPC XO-1 Real Time Clock"
2221 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2223 Add support for the XO-1 real time clock, which can be used as a
2224 programmable wakeup source.
2227 bool "OLPC XO-1 SCI extras"
2228 depends on OLPC && OLPC_XO1_PM
2234 Add support for SCI-based features of the OLPC XO-1 laptop:
2235 - EC-driven system wakeups
2239 - AC adapter status updates
2240 - Battery status updates
2242 config OLPC_XO15_SCI
2243 bool "OLPC XO-1.5 SCI extras"
2244 depends on OLPC && ACPI
2247 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2248 - EC-driven system wakeups
2249 - AC adapter status updates
2250 - Battery status updates
2253 bool "PCEngines ALIX System Support (LED setup)"
2256 This option enables system support for the PCEngines ALIX.
2257 At present this just sets up LEDs for GPIO control on
2258 ALIX2/3/6 boards. However, other system specific setup should
2261 Note: You must still enable the drivers for GPIO and LED support
2262 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2264 Note: You have to set alix.force=1 for boards with Award BIOS.
2267 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2270 This option enables system support for the Soekris Engineering net5501.
2273 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2277 This option enables system support for the Traverse Technologies GEOS.
2280 bool "Technologic Systems TS-5500 platform support"
2282 select CHECK_SIGNATURE
2286 This option enables system support for the Technologic Systems TS-5500.
2292 depends on CPU_SUP_AMD && PCI
2294 source "drivers/pcmcia/Kconfig"
2296 source "drivers/pci/hotplug/Kconfig"
2299 tristate "RapidIO support"
2303 If enabled this option will include drivers and the core
2304 infrastructure code to support RapidIO interconnect devices.
2306 source "drivers/rapidio/Kconfig"
2309 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2311 Firmwares often provide initial graphics framebuffers so the BIOS,
2312 bootloader or kernel can show basic video-output during boot for
2313 user-guidance and debugging. Historically, x86 used the VESA BIOS
2314 Extensions and EFI-framebuffers for this, which are mostly limited
2316 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2317 framebuffers so the new generic system-framebuffer drivers can be
2318 used on x86. If the framebuffer is not compatible with the generic
2319 modes, it is adverticed as fallback platform framebuffer so legacy
2320 drivers like efifb, vesafb and uvesafb can pick it up.
2321 If this option is not selected, all system framebuffers are always
2322 marked as fallback platform framebuffers as usual.
2324 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2325 not be able to pick up generic system framebuffers if this option
2326 is selected. You are highly encouraged to enable simplefb as
2327 replacement if you select this option. simplefb can correctly deal
2328 with generic system framebuffers. But you should still keep vesafb
2329 and others enabled as fallback if a system framebuffer is
2330 incompatible with simplefb.
2337 menu "Executable file formats / Emulations"
2339 source "fs/Kconfig.binfmt"
2341 config IA32_EMULATION
2342 bool "IA32 Emulation"
2345 select COMPAT_BINFMT_ELF
2348 Include code to run legacy 32-bit programs under a
2349 64-bit kernel. You should likely turn this on, unless you're
2350 100% sure that you don't have any 32-bit programs left.
2353 tristate "IA32 a.out support"
2354 depends on IA32_EMULATION
2356 Support old a.out binaries in the 32bit emulation.
2359 bool "x32 ABI for 64-bit mode"
2360 depends on X86_64 && IA32_EMULATION
2362 Include code to run binaries for the x32 native 32-bit ABI
2363 for 64-bit processors. An x32 process gets access to the
2364 full 64-bit register file and wide data path while leaving
2365 pointers at 32 bits for smaller memory footprint.
2367 You will need a recent binutils (2.22 or later) with
2368 elf32_x86_64 support enabled to compile a kernel with this
2373 depends on IA32_EMULATION || X86_X32
2374 select ARCH_WANT_OLD_COMPAT_IPC
2377 config COMPAT_FOR_U64_ALIGNMENT
2380 config SYSVIPC_COMPAT
2392 config HAVE_ATOMIC_IOMAP
2396 config X86_DEV_DMA_OPS
2398 depends on X86_64 || STA2X11
2400 config X86_DMA_REMAP
2413 source "net/Kconfig"
2415 source "drivers/Kconfig"
2417 source "drivers/firmware/Kconfig"
2421 source "arch/x86/Kconfig.debug"
2423 source "security/Kconfig"
2425 source "crypto/Kconfig"
2427 source "arch/x86/kvm/Kconfig"
2429 source "lib/Kconfig"