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
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 if !SWIOTLB
45 select HAVE_KRETPROBES
47 select HAVE_KPROBES_ON_FTRACE
48 select HAVE_FTRACE_MCOUNT_RECORD
49 select HAVE_FENTRY if X86_64
50 select HAVE_C_RECORDMCOUNT
51 select HAVE_DYNAMIC_FTRACE
52 select HAVE_DYNAMIC_FTRACE_WITH_REGS
53 select HAVE_FUNCTION_TRACER
54 select HAVE_FUNCTION_GRAPH_TRACER
55 select HAVE_FUNCTION_GRAPH_FP_TEST
56 select HAVE_FUNCTION_TRACE_MCOUNT_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
108 select CLOCKSOURCE_WATCHDOG
109 select GENERIC_CLOCKEVENTS
110 select ARCH_CLOCKSOURCE_DATA if X86_64
111 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
112 select GENERIC_TIME_VSYSCALL if X86_64
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 OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
124 select OLD_SIGACTION if X86_32
125 select COMPAT_OLD_SIGACTION if IA32_EMULATION
127 select HAVE_DEBUG_STACKOVERFLOW
128 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
129 select HAVE_CC_STACKPROTECTOR
131 config INSTRUCTION_DECODER
133 depends on KPROBES || PERF_EVENTS || UPROBES
137 default "elf32-i386" if X86_32
138 default "elf64-x86-64" if X86_64
140 config ARCH_DEFCONFIG
142 default "arch/x86/configs/i386_defconfig" if X86_32
143 default "arch/x86/configs/x86_64_defconfig" if X86_64
145 config LOCKDEP_SUPPORT
148 config STACKTRACE_SUPPORT
151 config HAVE_LATENCYTOP_SUPPORT
160 config NEED_DMA_MAP_STATE
162 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
164 config NEED_SG_DMA_LENGTH
167 config GENERIC_ISA_DMA
169 depends on ISA_DMA_API
174 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
176 config GENERIC_BUG_RELATIVE_POINTERS
179 config GENERIC_HWEIGHT
182 config ARCH_MAY_HAVE_PC_FDC
184 depends on ISA_DMA_API
186 config RWSEM_XCHGADD_ALGORITHM
189 config GENERIC_CALIBRATE_DELAY
192 config ARCH_HAS_CPU_RELAX
195 config ARCH_HAS_CACHE_LINE_SIZE
198 config ARCH_HAS_CPU_AUTOPROBE
201 config HAVE_SETUP_PER_CPU_AREA
204 config NEED_PER_CPU_EMBED_FIRST_CHUNK
207 config NEED_PER_CPU_PAGE_FIRST_CHUNK
210 config ARCH_HIBERNATION_POSSIBLE
213 config ARCH_SUSPEND_POSSIBLE
216 config ARCH_WANT_HUGE_PMD_SHARE
219 config ARCH_WANT_GENERAL_HUGETLB
230 config ARCH_SUPPORTS_OPTIMIZED_INLINING
233 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
236 config HAVE_INTEL_TXT
238 depends on INTEL_IOMMU && ACPI
242 depends on X86_32 && SMP
246 depends on X86_64 && SMP
252 config X86_32_LAZY_GS
254 depends on X86_32 && !CC_STACKPROTECTOR
256 config ARCH_HWEIGHT_CFLAGS
258 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
259 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
261 config ARCH_SUPPORTS_UPROBES
264 source "init/Kconfig"
265 source "kernel/Kconfig.freezer"
267 menu "Processor type and features"
270 bool "DMA memory allocation support" if EXPERT
273 DMA memory allocation support allows devices with less than 32-bit
274 addressing to allocate within the first 16MB of address space.
275 Disable if no such devices will be used.
280 bool "Symmetric multi-processing support"
282 This enables support for systems with more than one CPU. If you have
283 a system with only one CPU, say N. If you have a system with more
286 If you say N here, the kernel will run on uni- and multiprocessor
287 machines, but will use only one CPU of a multiprocessor machine. If
288 you say Y here, the kernel will run on many, but not all,
289 uniprocessor machines. On a uniprocessor machine, the kernel
290 will run faster if you say N here.
292 Note that if you say Y here and choose architecture "586" or
293 "Pentium" under "Processor family", the kernel will not work on 486
294 architectures. Similarly, multiprocessor kernels for the "PPro"
295 architecture may not work on all Pentium based boards.
297 People using multiprocessor machines who say Y here should also say
298 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
299 Management" code will be disabled if you say Y here.
301 See also <file:Documentation/x86/i386/IO-APIC.txt>,
302 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
303 <http://www.tldp.org/docs.html#howto>.
305 If you don't know what to do here, say N.
308 bool "Support x2apic"
309 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
311 This enables x2apic support on CPUs that have this feature.
313 This allows 32-bit apic IDs (so it can support very large systems),
314 and accesses the local apic via MSRs not via mmio.
316 If you don't know what to do here, say N.
319 bool "Enable MPS table" if ACPI || SFI
321 depends on X86_LOCAL_APIC
323 For old smp systems that do not have proper acpi support. Newer systems
324 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
327 bool "Support for big SMP systems with more than 8 CPUs"
328 depends on X86_32 && SMP
330 This option is needed for the systems that have more than 8 CPUs
334 depends on X86_GOLDFISH
337 config X86_EXTENDED_PLATFORM
338 bool "Support for extended (non-PC) x86 platforms"
341 If you disable this option then the kernel will only support
342 standard PC platforms. (which covers the vast majority of
345 If you enable this option then you'll be able to select support
346 for the following (non-PC) 32 bit x86 platforms:
347 Goldfish (Android emulator)
351 SGI 320/540 (Visual Workstation)
352 STA2X11-based (e.g. Northville)
353 Summit/EXA (IBM x440)
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.
443 bool "Intel MID platform support"
445 depends on X86_EXTENDED_PLATFORM
446 depends on X86_PLATFORM_DEVICES
449 depends on X86_IO_APIC
455 select MFD_INTEL_MSIC
457 Select to build a kernel capable of supporting Intel MID (Mobile
458 Internet Device) platform systems which do not have the PCI legacy
459 interfaces. If you are building for a PC class system say N here.
461 Intel MID platforms are based on an Intel processor and chipset which
462 consume less power than most of the x86 derivatives.
464 config X86_INTEL_LPSS
465 bool "Intel Low Power Subsystem Support"
470 Select to build support for Intel Low Power Subsystem such as
471 found on Intel Lynxpoint PCH. Selecting this option enables
472 things like clock tree (common clock framework) and pincontrol
473 which are needed by the LPSS peripheral drivers.
476 bool "RDC R-321x SoC"
478 depends on X86_EXTENDED_PLATFORM
480 select X86_REBOOTFIXUPS
482 This option is needed for RDC R-321x system-on-chip, also known
484 If you don't have one of these chips, you should say N here.
486 config X86_32_NON_STANDARD
487 bool "Support non-standard 32-bit SMP architectures"
488 depends on X86_32 && SMP
489 depends on X86_EXTENDED_PLATFORM
491 This option compiles in the NUMAQ, Summit, bigsmp,
492 STA2X11, default subarchitectures. It is intended for a generic
493 binary kernel. If you select them all, kernel will probe it
494 one by one and will fallback to default.
496 # Alphabetically sorted list of Non standard 32 bit platforms
499 bool "NUMAQ (IBM/Sequent)"
500 depends on X86_32_NON_STANDARD
505 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
506 NUMA multiquad box. This changes the way that processors are
507 bootstrapped, and uses Clustered Logical APIC addressing mode instead
508 of Flat Logical. You will need a new lynxer.elf file to flash your
509 firmware with - send email to <Martin.Bligh@us.ibm.com>.
511 config X86_SUPPORTS_MEMORY_FAILURE
513 # MCE code calls memory_failure():
515 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
516 depends on !X86_NUMAQ
517 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
518 depends on X86_64 || !SPARSEMEM
519 select ARCH_SUPPORTS_MEMORY_FAILURE
522 bool "SGI 320/540 (Visual Workstation)"
523 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
524 depends on X86_32_NON_STANDARD
526 The SGI Visual Workstation series is an IA32-based workstation
527 based on SGI systems chips with some legacy PC hardware attached.
529 Say Y here to create a kernel to run on the SGI 320 or 540.
531 A kernel compiled for the Visual Workstation will run on general
532 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
535 bool "STA2X11 Companion Chip Support"
536 depends on X86_32_NON_STANDARD && PCI
537 select X86_DEV_DMA_OPS
541 select ARCH_REQUIRE_GPIOLIB
544 This adds support for boards based on the STA2X11 IO-Hub,
545 a.k.a. "ConneXt". The chip is used in place of the standard
546 PC chipset, so all "standard" peripherals are missing. If this
547 option is selected the kernel will still be able to boot on
548 standard PC machines.
551 bool "Summit/EXA (IBM x440)"
552 depends on X86_32_NON_STANDARD
554 This option is needed for IBM systems that use the Summit/EXA chipset.
555 In particular, it is needed for the x440.
558 tristate "Eurobraille/Iris poweroff module"
561 The Iris machines from EuroBraille do not have APM or ACPI support
562 to shut themselves down properly. A special I/O sequence is
563 needed to do so, which is what this module does at
566 This is only for Iris machines from EuroBraille.
570 config SCHED_OMIT_FRAME_POINTER
572 prompt "Single-depth WCHAN output"
575 Calculate simpler /proc/<PID>/wchan values. If this option
576 is disabled then wchan values will recurse back to the
577 caller function. This provides more accurate wchan values,
578 at the expense of slightly more scheduling overhead.
580 If in doubt, say "Y".
582 menuconfig HYPERVISOR_GUEST
583 bool "Linux guest support"
585 Say Y here to enable options for running Linux under various hyper-
586 visors. This option enables basic hypervisor detection and platform
589 If you say N, all options in this submenu will be skipped and
590 disabled, and Linux guest support won't be built in.
595 bool "Enable paravirtualization code"
597 This changes the kernel so it can modify itself when it is run
598 under a hypervisor, potentially improving performance significantly
599 over full virtualization. However, when run without a hypervisor
600 the kernel is theoretically slower and slightly larger.
602 config PARAVIRT_DEBUG
603 bool "paravirt-ops debugging"
604 depends on PARAVIRT && DEBUG_KERNEL
606 Enable to debug paravirt_ops internals. Specifically, BUG if
607 a paravirt_op is missing when it is called.
609 config PARAVIRT_SPINLOCKS
610 bool "Paravirtualization layer for spinlocks"
611 depends on PARAVIRT && SMP
612 select UNINLINE_SPIN_UNLOCK
614 Paravirtualized spinlocks allow a pvops backend to replace the
615 spinlock implementation with something virtualization-friendly
616 (for example, block the virtual CPU rather than spinning).
618 It has a minimal impact on native kernels and gives a nice performance
619 benefit on paravirtualized KVM / Xen kernels.
621 If you are unsure how to answer this question, answer Y.
623 source "arch/x86/xen/Kconfig"
626 bool "KVM Guest support (including kvmclock)"
628 select PARAVIRT_CLOCK
631 This option enables various optimizations for running under the KVM
632 hypervisor. It includes a paravirtualized clock, so that instead
633 of relying on a PIT (or probably other) emulation by the
634 underlying device model, the host provides the guest with
635 timing infrastructure such as time of day, and system time
638 bool "Enable debug information for KVM Guests in debugfs"
639 depends on KVM_GUEST && DEBUG_FS
642 This option enables collection of various statistics for KVM guest.
643 Statistics are displayed in debugfs filesystem. Enabling this option
644 may incur significant overhead.
646 source "arch/x86/lguest/Kconfig"
648 config PARAVIRT_TIME_ACCOUNTING
649 bool "Paravirtual steal time accounting"
653 Select this option to enable fine granularity task steal time
654 accounting. Time spent executing other tasks in parallel with
655 the current vCPU is discounted from the vCPU power. To account for
656 that, there can be a small performance impact.
658 If in doubt, say N here.
660 config PARAVIRT_CLOCK
663 endif #HYPERVISOR_GUEST
671 This option adds a kernel parameter 'memtest', which allows memtest
673 memtest=0, mean disabled; -- default
674 memtest=1, mean do 1 test pattern;
676 memtest=4, mean do 4 test patterns.
677 If you are unsure how to answer this question, answer N.
679 config X86_SUMMIT_NUMA
681 depends on X86_32 && NUMA && X86_32_NON_STANDARD
683 config X86_CYCLONE_TIMER
685 depends on X86_SUMMIT
687 source "arch/x86/Kconfig.cpu"
691 prompt "HPET Timer Support" if X86_32
693 Use the IA-PC HPET (High Precision Event Timer) to manage
694 time in preference to the PIT and RTC, if a HPET is
696 HPET is the next generation timer replacing legacy 8254s.
697 The HPET provides a stable time base on SMP
698 systems, unlike the TSC, but it is more expensive to access,
699 as it is off-chip. You can find the HPET spec at
700 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
702 You can safely choose Y here. However, HPET will only be
703 activated if the platform and the BIOS support this feature.
704 Otherwise the 8254 will be used for timing services.
706 Choose N to continue using the legacy 8254 timer.
708 config HPET_EMULATE_RTC
710 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
713 def_bool y if X86_INTEL_MID
714 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
716 depends on X86_INTEL_MID && SFI
718 APB timer is the replacement for 8254, HPET on X86 MID platforms.
719 The APBT 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. APB timers are always running regardless of CPU
722 C states, they are used as per CPU clockevent device when possible.
724 # Mark as expert because too many people got it wrong.
725 # The code disables itself when not needed.
728 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
729 bool "Enable DMI scanning" if EXPERT
731 Enabled scanning of DMI to identify machine quirks. Say Y
732 here unless you have verified that your setup is not
733 affected by entries in the DMI blacklist. Required by PNP
737 bool "Old AMD GART IOMMU support"
739 depends on X86_64 && PCI && AMD_NB
741 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
742 GART based hardware IOMMUs.
744 The GART supports full DMA access for devices with 32-bit access
745 limitations, on systems with more than 3 GB. This is usually needed
746 for USB, sound, many IDE/SATA chipsets and some other devices.
748 Newer systems typically have a modern AMD IOMMU, supported via
749 the CONFIG_AMD_IOMMU=y config option.
751 In normal configurations this driver is only active when needed:
752 there's more than 3 GB of memory and the system contains a
753 32-bit limited device.
758 bool "IBM Calgary IOMMU support"
760 depends on X86_64 && PCI
762 Support for hardware IOMMUs in IBM's xSeries x366 and x460
763 systems. Needed to run systems with more than 3GB of memory
764 properly with 32-bit PCI devices that do not support DAC
765 (Double Address Cycle). Calgary also supports bus level
766 isolation, where all DMAs pass through the IOMMU. This
767 prevents them from going anywhere except their intended
768 destination. This catches hard-to-find kernel bugs and
769 mis-behaving drivers and devices that do not use the DMA-API
770 properly to set up their DMA buffers. The IOMMU can be
771 turned off at boot time with the iommu=off parameter.
772 Normally the kernel will make the right choice by itself.
775 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
777 prompt "Should Calgary be enabled by default?"
778 depends on CALGARY_IOMMU
780 Should Calgary be enabled by default? if you choose 'y', Calgary
781 will be used (if it exists). If you choose 'n', Calgary will not be
782 used even if it exists. If you choose 'n' and would like to use
783 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
786 # need this always selected by IOMMU for the VIA workaround
790 Support for software bounce buffers used on x86-64 systems
791 which don't have a hardware IOMMU. Using this PCI devices
792 which can only access 32-bits of memory can be used on systems
793 with more than 3 GB of memory.
798 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
801 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
802 depends on X86_64 && SMP && DEBUG_KERNEL
803 select CPUMASK_OFFSTACK
805 Enable maximum number of CPUS and NUMA Nodes for this architecture.
809 int "Maximum number of CPUs" if SMP && !MAXSMP
810 range 2 8 if SMP && X86_32 && !X86_BIGSMP
811 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
812 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
814 default "8192" if MAXSMP
815 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
818 This allows you to specify the maximum number of CPUs which this
819 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
820 supported value is 4096, otherwise the maximum value is 512. The
821 minimum value which makes sense is 2.
823 This is purely to save memory - each supported CPU adds
824 approximately eight kilobytes to the kernel image.
827 bool "SMT (Hyperthreading) scheduler support"
830 SMT scheduler support improves the CPU scheduler's decision making
831 when dealing with Intel Pentium 4 chips with HyperThreading at a
832 cost of slightly increased overhead in some places. If unsure say
837 prompt "Multi-core scheduler support"
840 Multi-core scheduler support improves the CPU scheduler's decision
841 making when dealing with multi-core CPU chips at a cost of slightly
842 increased overhead in some places. If unsure say N here.
844 source "kernel/Kconfig.preempt"
847 bool "Local APIC support on uniprocessors"
848 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
850 A local APIC (Advanced Programmable Interrupt Controller) is an
851 integrated interrupt controller in the CPU. If you have a single-CPU
852 system which has a processor with a local APIC, you can say Y here to
853 enable and use it. If you say Y here even though your machine doesn't
854 have a local APIC, then the kernel will still run with no slowdown at
855 all. The local APIC supports CPU-generated self-interrupts (timer,
856 performance counters), and the NMI watchdog which detects hard
860 bool "IO-APIC support on uniprocessors"
861 depends on X86_UP_APIC
863 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
864 SMP-capable replacement for PC-style interrupt controllers. Most
865 SMP systems and many recent uniprocessor systems have one.
867 If you have a single-CPU system with an IO-APIC, you can say Y here
868 to use it. If you say Y here even though your machine doesn't have
869 an IO-APIC, then the kernel will still run with no slowdown at all.
871 config X86_LOCAL_APIC
873 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
877 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
879 config X86_VISWS_APIC
881 depends on X86_32 && X86_VISWS
883 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
884 bool "Reroute for broken boot IRQs"
885 depends on X86_IO_APIC
887 This option enables a workaround that fixes a source of
888 spurious interrupts. This is recommended when threaded
889 interrupt handling is used on systems where the generation of
890 superfluous "boot interrupts" cannot be disabled.
892 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
893 entry in the chipset's IO-APIC is masked (as, e.g. the RT
894 kernel does during interrupt handling). On chipsets where this
895 boot IRQ generation cannot be disabled, this workaround keeps
896 the original IRQ line masked so that only the equivalent "boot
897 IRQ" is delivered to the CPUs. The workaround also tells the
898 kernel to set up the IRQ handler on the boot IRQ line. In this
899 way only one interrupt is delivered to the kernel. Otherwise
900 the spurious second interrupt may cause the kernel to bring
901 down (vital) interrupt lines.
903 Only affects "broken" chipsets. Interrupt sharing may be
904 increased on these systems.
907 bool "Machine Check / overheating reporting"
910 Machine Check support allows the processor to notify the
911 kernel if it detects a problem (e.g. overheating, data corruption).
912 The action the kernel takes depends on the severity of the problem,
913 ranging from warning messages to halting the machine.
917 prompt "Intel MCE features"
918 depends on X86_MCE && X86_LOCAL_APIC
920 Additional support for intel specific MCE features such as
925 prompt "AMD MCE features"
926 depends on X86_MCE && X86_LOCAL_APIC
928 Additional support for AMD specific MCE features such as
929 the DRAM Error Threshold.
931 config X86_ANCIENT_MCE
932 bool "Support for old Pentium 5 / WinChip machine checks"
933 depends on X86_32 && X86_MCE
935 Include support for machine check handling on old Pentium 5 or WinChip
936 systems. These typically need to be enabled explicitly on the command
939 config X86_MCE_THRESHOLD
940 depends on X86_MCE_AMD || X86_MCE_INTEL
943 config X86_MCE_INJECT
945 tristate "Machine check injector support"
947 Provide support for injecting machine checks for testing purposes.
948 If you don't know what a machine check is and you don't do kernel
949 QA it is safe to say n.
951 config X86_THERMAL_VECTOR
953 depends on X86_MCE_INTEL
956 bool "Enable VM86 support" if EXPERT
960 This option is required by programs like DOSEMU to run 16-bit legacy
961 code on X86 processors. It also may be needed by software like
962 XFree86 to initialize some video cards via BIOS. Disabling this
963 option saves about 6k.
966 tristate "Toshiba Laptop support"
969 This adds a driver to safely access the System Management Mode of
970 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
971 not work on models with a Phoenix BIOS. The System Management Mode
972 is used to set the BIOS and power saving options on Toshiba portables.
974 For information on utilities to make use of this driver see the
975 Toshiba Linux utilities web site at:
976 <http://www.buzzard.org.uk/toshiba/>.
978 Say Y if you intend to run this kernel on a Toshiba portable.
982 tristate "Dell laptop support"
985 This adds a driver to safely access the System Management Mode
986 of the CPU on the Dell Inspiron 8000. The System Management Mode
987 is used to read cpu temperature and cooling fan status and to
988 control the fans on the I8K portables.
990 This driver has been tested only on the Inspiron 8000 but it may
991 also work with other Dell laptops. You can force loading on other
992 models by passing the parameter `force=1' to the module. Use at
995 For information on utilities to make use of this driver see the
996 I8K Linux utilities web site at:
997 <http://people.debian.org/~dz/i8k/>
999 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1002 config X86_REBOOTFIXUPS
1003 bool "Enable X86 board specific fixups for reboot"
1006 This enables chipset and/or board specific fixups to be done
1007 in order to get reboot to work correctly. This is only needed on
1008 some combinations of hardware and BIOS. The symptom, for which
1009 this config is intended, is when reboot ends with a stalled/hung
1012 Currently, the only fixup is for the Geode machines using
1013 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1015 Say Y if you want to enable the fixup. Currently, it's safe to
1016 enable this option even if you don't need it.
1020 tristate "CPU microcode loading support"
1021 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1025 If you say Y here, you will be able to update the microcode on
1026 certain Intel and AMD processors. The Intel support is for the
1027 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1028 Xeon etc. The AMD support is for families 0x10 and later. You will
1029 obviously need the actual microcode binary data itself which is not
1030 shipped with the Linux kernel.
1032 This option selects the general module only, you need to select
1033 at least one vendor specific module as well.
1035 To compile this driver as a module, choose M here: the module
1036 will be called microcode.
1038 config MICROCODE_INTEL
1039 bool "Intel microcode loading support"
1040 depends on MICROCODE
1044 This options enables microcode patch loading support for Intel
1047 For the current Intel microcode data package go to
1048 <https://downloadcenter.intel.com> and search for
1049 'Linux Processor Microcode Data File'.
1051 config MICROCODE_AMD
1052 bool "AMD microcode loading support"
1053 depends on MICROCODE
1056 If you select this option, microcode patch loading support for AMD
1057 processors will be enabled.
1059 config MICROCODE_OLD_INTERFACE
1061 depends on MICROCODE
1063 config MICROCODE_INTEL_EARLY
1066 config MICROCODE_AMD_EARLY
1069 config MICROCODE_EARLY
1070 bool "Early load microcode"
1071 depends on MICROCODE=y && BLK_DEV_INITRD
1072 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1073 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1076 This option provides functionality to read additional microcode data
1077 at the beginning of initrd image. The data tells kernel to load
1078 microcode to CPU's as early as possible. No functional change if no
1079 microcode data is glued to the initrd, therefore it's safe to say Y.
1082 tristate "/dev/cpu/*/msr - Model-specific register support"
1084 This device gives privileged processes access to the x86
1085 Model-Specific Registers (MSRs). It is a character device with
1086 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1087 MSR accesses are directed to a specific CPU on multi-processor
1091 tristate "/dev/cpu/*/cpuid - CPU information support"
1093 This device gives processes access to the x86 CPUID instruction to
1094 be executed on a specific processor. It is a character device
1095 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1099 prompt "High Memory Support"
1100 default HIGHMEM64G if X86_NUMAQ
1106 depends on !X86_NUMAQ
1108 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1109 However, the address space of 32-bit x86 processors is only 4
1110 Gigabytes large. That means that, if you have a large amount of
1111 physical memory, not all of it can be "permanently mapped" by the
1112 kernel. The physical memory that's not permanently mapped is called
1115 If you are compiling a kernel which will never run on a machine with
1116 more than 1 Gigabyte total physical RAM, answer "off" here (default
1117 choice and suitable for most users). This will result in a "3GB/1GB"
1118 split: 3GB are mapped so that each process sees a 3GB virtual memory
1119 space and the remaining part of the 4GB virtual memory space is used
1120 by the kernel to permanently map as much physical memory as
1123 If the machine has between 1 and 4 Gigabytes physical RAM, then
1126 If more than 4 Gigabytes is used then answer "64GB" here. This
1127 selection turns Intel PAE (Physical Address Extension) mode on.
1128 PAE implements 3-level paging on IA32 processors. PAE is fully
1129 supported by Linux, PAE mode is implemented on all recent Intel
1130 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1131 then the kernel will not boot on CPUs that don't support PAE!
1133 The actual amount of total physical memory will either be
1134 auto detected or can be forced by using a kernel command line option
1135 such as "mem=256M". (Try "man bootparam" or see the documentation of
1136 your boot loader (lilo or loadlin) about how to pass options to the
1137 kernel at boot time.)
1139 If unsure, say "off".
1143 depends on !X86_NUMAQ
1145 Select this if you have a 32-bit processor and between 1 and 4
1146 gigabytes of physical RAM.
1153 Select this if you have a 32-bit processor and more than 4
1154 gigabytes of physical RAM.
1159 prompt "Memory split" if EXPERT
1163 Select the desired split between kernel and user memory.
1165 If the address range available to the kernel is less than the
1166 physical memory installed, the remaining memory will be available
1167 as "high memory". Accessing high memory is a little more costly
1168 than low memory, as it needs to be mapped into the kernel first.
1169 Note that increasing the kernel address space limits the range
1170 available to user programs, making the address space there
1171 tighter. Selecting anything other than the default 3G/1G split
1172 will also likely make your kernel incompatible with binary-only
1175 If you are not absolutely sure what you are doing, leave this
1179 bool "3G/1G user/kernel split"
1180 config VMSPLIT_3G_OPT
1182 bool "3G/1G user/kernel split (for full 1G low memory)"
1184 bool "2G/2G user/kernel split"
1185 config VMSPLIT_2G_OPT
1187 bool "2G/2G user/kernel split (for full 2G low memory)"
1189 bool "1G/3G user/kernel split"
1194 default 0xB0000000 if VMSPLIT_3G_OPT
1195 default 0x80000000 if VMSPLIT_2G
1196 default 0x78000000 if VMSPLIT_2G_OPT
1197 default 0x40000000 if VMSPLIT_1G
1203 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1206 bool "PAE (Physical Address Extension) Support"
1207 depends on X86_32 && !HIGHMEM4G
1209 PAE is required for NX support, and furthermore enables
1210 larger swapspace support for non-overcommit purposes. It
1211 has the cost of more pagetable lookup overhead, and also
1212 consumes more pagetable space per process.
1214 config ARCH_PHYS_ADDR_T_64BIT
1216 depends on X86_64 || X86_PAE
1218 config ARCH_DMA_ADDR_T_64BIT
1220 depends on X86_64 || HIGHMEM64G
1222 config DIRECT_GBPAGES
1223 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1227 Allow the kernel linear mapping to use 1GB pages on CPUs that
1228 support it. This can improve the kernel's performance a tiny bit by
1229 reducing TLB pressure. If in doubt, say "Y".
1231 # Common NUMA Features
1233 bool "Numa Memory Allocation and Scheduler Support"
1235 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1236 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1238 Enable NUMA (Non Uniform Memory Access) support.
1240 The kernel will try to allocate memory used by a CPU on the
1241 local memory controller of the CPU and add some more
1242 NUMA awareness to the kernel.
1244 For 64-bit this is recommended if the system is Intel Core i7
1245 (or later), AMD Opteron, or EM64T NUMA.
1247 For 32-bit this is only needed on (rare) 32-bit-only platforms
1248 that support NUMA topologies, such as NUMAQ / Summit, or if you
1249 boot a 32-bit kernel on a 64-bit NUMA platform.
1251 Otherwise, you should say N.
1253 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1254 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1258 prompt "Old style AMD Opteron NUMA detection"
1259 depends on X86_64 && NUMA && PCI
1261 Enable AMD NUMA node topology detection. You should say Y here if
1262 you have a multi processor AMD system. This uses an old method to
1263 read the NUMA configuration directly from the builtin Northbridge
1264 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1265 which also takes priority if both are compiled in.
1267 config X86_64_ACPI_NUMA
1269 prompt "ACPI NUMA detection"
1270 depends on X86_64 && NUMA && ACPI && PCI
1273 Enable ACPI SRAT based node topology detection.
1275 # Some NUMA nodes have memory ranges that span
1276 # other nodes. Even though a pfn is valid and
1277 # between a node's start and end pfns, it may not
1278 # reside on that node. See memmap_init_zone()
1280 config NODES_SPAN_OTHER_NODES
1282 depends on X86_64_ACPI_NUMA
1285 bool "NUMA emulation"
1288 Enable NUMA emulation. A flat machine will be split
1289 into virtual nodes when booted with "numa=fake=N", where N is the
1290 number of nodes. This is only useful for debugging.
1293 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1295 default "10" if MAXSMP
1296 default "6" if X86_64
1297 default "4" if X86_NUMAQ
1299 depends on NEED_MULTIPLE_NODES
1301 Specify the maximum number of NUMA Nodes available on the target
1302 system. Increases memory reserved to accommodate various tables.
1304 config ARCH_HAVE_MEMORY_PRESENT
1306 depends on X86_32 && DISCONTIGMEM
1308 config NEED_NODE_MEMMAP_SIZE
1310 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1312 config ARCH_FLATMEM_ENABLE
1314 depends on X86_32 && !NUMA
1316 config ARCH_DISCONTIGMEM_ENABLE
1318 depends on NUMA && X86_32
1320 config ARCH_DISCONTIGMEM_DEFAULT
1322 depends on NUMA && X86_32
1324 config ARCH_SPARSEMEM_ENABLE
1326 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1327 select SPARSEMEM_STATIC if X86_32
1328 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1330 config ARCH_SPARSEMEM_DEFAULT
1334 config ARCH_SELECT_MEMORY_MODEL
1336 depends on ARCH_SPARSEMEM_ENABLE
1338 config ARCH_MEMORY_PROBE
1339 bool "Enable sysfs memory/probe interface"
1340 depends on X86_64 && MEMORY_HOTPLUG
1342 This option enables a sysfs memory/probe interface for testing.
1343 See Documentation/memory-hotplug.txt for more information.
1344 If you are unsure how to answer this question, answer N.
1346 config ARCH_PROC_KCORE_TEXT
1348 depends on X86_64 && PROC_KCORE
1350 config ILLEGAL_POINTER_VALUE
1353 default 0xdead000000000000 if X86_64
1358 bool "Allocate 3rd-level pagetables from highmem"
1361 The VM uses one page table entry for each page of physical memory.
1362 For systems with a lot of RAM, this can be wasteful of precious
1363 low memory. Setting this option will put user-space page table
1364 entries in high memory.
1366 config X86_CHECK_BIOS_CORRUPTION
1367 bool "Check for low memory corruption"
1369 Periodically check for memory corruption in low memory, which
1370 is suspected to be caused by BIOS. Even when enabled in the
1371 configuration, it is disabled at runtime. Enable it by
1372 setting "memory_corruption_check=1" on the kernel command
1373 line. By default it scans the low 64k of memory every 60
1374 seconds; see the memory_corruption_check_size and
1375 memory_corruption_check_period parameters in
1376 Documentation/kernel-parameters.txt to adjust this.
1378 When enabled with the default parameters, this option has
1379 almost no overhead, as it reserves a relatively small amount
1380 of memory and scans it infrequently. It both detects corruption
1381 and prevents it from affecting the running system.
1383 It is, however, intended as a diagnostic tool; if repeatable
1384 BIOS-originated corruption always affects the same memory,
1385 you can use memmap= to prevent the kernel from using that
1388 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1389 bool "Set the default setting of memory_corruption_check"
1390 depends on X86_CHECK_BIOS_CORRUPTION
1393 Set whether the default state of memory_corruption_check is
1396 config X86_RESERVE_LOW
1397 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1401 Specify the amount of low memory to reserve for the BIOS.
1403 The first page contains BIOS data structures that the kernel
1404 must not use, so that page must always be reserved.
1406 By default we reserve the first 64K of physical RAM, as a
1407 number of BIOSes are known to corrupt that memory range
1408 during events such as suspend/resume or monitor cable
1409 insertion, so it must not be used by the kernel.
1411 You can set this to 4 if you are absolutely sure that you
1412 trust the BIOS to get all its memory reservations and usages
1413 right. If you know your BIOS have problems beyond the
1414 default 64K area, you can set this to 640 to avoid using the
1415 entire low memory range.
1417 If you have doubts about the BIOS (e.g. suspend/resume does
1418 not work or there's kernel crashes after certain hardware
1419 hotplug events) then you might want to enable
1420 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1421 typical corruption patterns.
1423 Leave this to the default value of 64 if you are unsure.
1425 config MATH_EMULATION
1427 prompt "Math emulation" if X86_32
1429 Linux can emulate a math coprocessor (used for floating point
1430 operations) if you don't have one. 486DX and Pentium processors have
1431 a math coprocessor built in, 486SX and 386 do not, unless you added
1432 a 487DX or 387, respectively. (The messages during boot time can
1433 give you some hints here ["man dmesg"].) Everyone needs either a
1434 coprocessor or this emulation.
1436 If you don't have a math coprocessor, you need to say Y here; if you
1437 say Y here even though you have a coprocessor, the coprocessor will
1438 be used nevertheless. (This behavior can be changed with the kernel
1439 command line option "no387", which comes handy if your coprocessor
1440 is broken. Try "man bootparam" or see the documentation of your boot
1441 loader (lilo or loadlin) about how to pass options to the kernel at
1442 boot time.) This means that it is a good idea to say Y here if you
1443 intend to use this kernel on different machines.
1445 More information about the internals of the Linux math coprocessor
1446 emulation can be found in <file:arch/x86/math-emu/README>.
1448 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1449 kernel, it won't hurt.
1453 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1455 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1456 the Memory Type Range Registers (MTRRs) may be used to control
1457 processor access to memory ranges. This is most useful if you have
1458 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1459 allows bus write transfers to be combined into a larger transfer
1460 before bursting over the PCI/AGP bus. This can increase performance
1461 of image write operations 2.5 times or more. Saying Y here creates a
1462 /proc/mtrr file which may be used to manipulate your processor's
1463 MTRRs. Typically the X server should use this.
1465 This code has a reasonably generic interface so that similar
1466 control registers on other processors can be easily supported
1469 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1470 Registers (ARRs) which provide a similar functionality to MTRRs. For
1471 these, the ARRs are used to emulate the MTRRs.
1472 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1473 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1474 write-combining. All of these processors are supported by this code
1475 and it makes sense to say Y here if you have one of them.
1477 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1478 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1479 can lead to all sorts of problems, so it's good to say Y here.
1481 You can safely say Y even if your machine doesn't have MTRRs, you'll
1482 just add about 9 KB to your kernel.
1484 See <file:Documentation/x86/mtrr.txt> for more information.
1486 config MTRR_SANITIZER
1488 prompt "MTRR cleanup support"
1491 Convert MTRR layout from continuous to discrete, so X drivers can
1492 add writeback entries.
1494 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1495 The largest mtrr entry size for a continuous block can be set with
1500 config MTRR_SANITIZER_ENABLE_DEFAULT
1501 int "MTRR cleanup enable value (0-1)"
1504 depends on MTRR_SANITIZER
1506 Enable mtrr cleanup default value
1508 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1509 int "MTRR cleanup spare reg num (0-7)"
1512 depends on MTRR_SANITIZER
1514 mtrr cleanup spare entries default, it can be changed via
1515 mtrr_spare_reg_nr=N on the kernel command line.
1519 prompt "x86 PAT support" if EXPERT
1522 Use PAT attributes to setup page level cache control.
1524 PATs are the modern equivalents of MTRRs and are much more
1525 flexible than MTRRs.
1527 Say N here if you see bootup problems (boot crash, boot hang,
1528 spontaneous reboots) or a non-working video driver.
1532 config ARCH_USES_PG_UNCACHED
1538 prompt "x86 architectural random number generator" if EXPERT
1540 Enable the x86 architectural RDRAND instruction
1541 (Intel Bull Mountain technology) to generate random numbers.
1542 If supported, this is a high bandwidth, cryptographically
1543 secure hardware random number generator.
1547 prompt "Supervisor Mode Access Prevention" if EXPERT
1549 Supervisor Mode Access Prevention (SMAP) is a security
1550 feature in newer Intel processors. There is a small
1551 performance cost if this enabled and turned on; there is
1552 also a small increase in the kernel size if this is enabled.
1557 bool "EFI runtime service support"
1561 This enables the kernel to use EFI runtime services that are
1562 available (such as the EFI variable services).
1564 This option is only useful on systems that have EFI firmware.
1565 In addition, you should use the latest ELILO loader available
1566 at <http://elilo.sourceforge.net> in order to take advantage
1567 of EFI runtime services. However, even with this option, the
1568 resultant kernel should continue to boot on existing non-EFI
1572 bool "EFI stub support"
1575 This kernel feature allows a bzImage to be loaded directly
1576 by EFI firmware without the use of a bootloader.
1578 See Documentation/efi-stub.txt for more information.
1582 prompt "Enable seccomp to safely compute untrusted bytecode"
1584 This kernel feature is useful for number crunching applications
1585 that may need to compute untrusted bytecode during their
1586 execution. By using pipes or other transports made available to
1587 the process as file descriptors supporting the read/write
1588 syscalls, it's possible to isolate those applications in
1589 their own address space using seccomp. Once seccomp is
1590 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1591 and the task is only allowed to execute a few safe syscalls
1592 defined by each seccomp mode.
1594 If unsure, say Y. Only embedded should say N here.
1596 source kernel/Kconfig.hz
1599 bool "kexec system call"
1601 kexec is a system call that implements the ability to shutdown your
1602 current kernel, and to start another kernel. It is like a reboot
1603 but it is independent of the system firmware. And like a reboot
1604 you can start any kernel with it, not just Linux.
1606 The name comes from the similarity to the exec system call.
1608 It is an ongoing process to be certain the hardware in a machine
1609 is properly shutdown, so do not be surprised if this code does not
1610 initially work for you. As of this writing the exact hardware
1611 interface is strongly in flux, so no good recommendation can be
1615 bool "kernel crash dumps"
1616 depends on X86_64 || (X86_32 && HIGHMEM)
1618 Generate crash dump after being started by kexec.
1619 This should be normally only set in special crash dump kernels
1620 which are loaded in the main kernel with kexec-tools into
1621 a specially reserved region and then later executed after
1622 a crash by kdump/kexec. The crash dump kernel must be compiled
1623 to a memory address not used by the main kernel or BIOS using
1624 PHYSICAL_START, or it must be built as a relocatable image
1625 (CONFIG_RELOCATABLE=y).
1626 For more details see Documentation/kdump/kdump.txt
1630 depends on KEXEC && HIBERNATION
1632 Jump between original kernel and kexeced kernel and invoke
1633 code in physical address mode via KEXEC
1635 config PHYSICAL_START
1636 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1639 This gives the physical address where the kernel is loaded.
1641 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1642 bzImage will decompress itself to above physical address and
1643 run from there. Otherwise, bzImage will run from the address where
1644 it has been loaded by the boot loader and will ignore above physical
1647 In normal kdump cases one does not have to set/change this option
1648 as now bzImage can be compiled as a completely relocatable image
1649 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1650 address. This option is mainly useful for the folks who don't want
1651 to use a bzImage for capturing the crash dump and want to use a
1652 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1653 to be specifically compiled to run from a specific memory area
1654 (normally a reserved region) and this option comes handy.
1656 So if you are using bzImage for capturing the crash dump,
1657 leave the value here unchanged to 0x1000000 and set
1658 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1659 for capturing the crash dump change this value to start of
1660 the reserved region. In other words, it can be set based on
1661 the "X" value as specified in the "crashkernel=YM@XM"
1662 command line boot parameter passed to the panic-ed
1663 kernel. Please take a look at Documentation/kdump/kdump.txt
1664 for more details about crash dumps.
1666 Usage of bzImage for capturing the crash dump is recommended as
1667 one does not have to build two kernels. Same kernel can be used
1668 as production kernel and capture kernel. Above option should have
1669 gone away after relocatable bzImage support is introduced. But it
1670 is present because there are users out there who continue to use
1671 vmlinux for dump capture. This option should go away down the
1674 Don't change this unless you know what you are doing.
1677 bool "Build a relocatable kernel"
1680 This builds a kernel image that retains relocation information
1681 so it can be loaded someplace besides the default 1MB.
1682 The relocations tend to make the kernel binary about 10% larger,
1683 but are discarded at runtime.
1685 One use is for the kexec on panic case where the recovery kernel
1686 must live at a different physical address than the primary
1689 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1690 it has been loaded at and the compile time physical address
1691 (CONFIG_PHYSICAL_START) is used as the minimum location.
1693 config RANDOMIZE_BASE
1694 bool "Randomize the address of the kernel image"
1695 depends on RELOCATABLE
1696 depends on !HIBERNATION
1699 Randomizes the physical and virtual address at which the
1700 kernel image is decompressed, as a security feature that
1701 deters exploit attempts relying on knowledge of the location
1702 of kernel internals.
1704 Entropy is generated using the RDRAND instruction if it is
1705 supported. If RDTSC is supported, it is used as well. If
1706 neither RDRAND nor RDTSC are supported, then randomness is
1707 read from the i8254 timer.
1709 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1710 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1711 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1712 minimum of 2MiB, only 10 bits of entropy is theoretically
1713 possible. At best, due to page table layouts, 64-bit can use
1714 9 bits of entropy and 32-bit uses 8 bits.
1718 config RANDOMIZE_BASE_MAX_OFFSET
1719 hex "Maximum kASLR offset allowed" if EXPERT
1720 depends on RANDOMIZE_BASE
1721 range 0x0 0x20000000 if X86_32
1722 default "0x20000000" if X86_32
1723 range 0x0 0x40000000 if X86_64
1724 default "0x40000000" if X86_64
1726 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1727 memory is used to determine the maximal offset in bytes that will
1728 be applied to the kernel when kernel Address Space Layout
1729 Randomization (kASLR) is active. This must be a multiple of
1732 On 32-bit this is limited to 512MiB by page table layouts. The
1735 On 64-bit this is limited by how the kernel fixmap page table is
1736 positioned, so this cannot be larger than 1GiB currently. Without
1737 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1738 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1739 modules area will shrink to compensate, up to the current maximum
1740 1GiB to 1GiB split. The default is 1GiB.
1742 If unsure, leave at the default value.
1744 # Relocation on x86 needs some additional build support
1745 config X86_NEED_RELOCS
1747 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1749 config PHYSICAL_ALIGN
1750 hex "Alignment value to which kernel should be aligned"
1752 range 0x2000 0x1000000 if X86_32
1753 range 0x200000 0x1000000 if X86_64
1755 This value puts the alignment restrictions on physical address
1756 where kernel is loaded and run from. Kernel is compiled for an
1757 address which meets above alignment restriction.
1759 If bootloader loads the kernel at a non-aligned address and
1760 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1761 address aligned to above value and run from there.
1763 If bootloader loads the kernel at a non-aligned address and
1764 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1765 load address and decompress itself to the address it has been
1766 compiled for and run from there. The address for which kernel is
1767 compiled already meets above alignment restrictions. Hence the
1768 end result is that kernel runs from a physical address meeting
1769 above alignment restrictions.
1771 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1772 this value must be a multiple of 0x200000.
1774 Don't change this unless you know what you are doing.
1777 bool "Support for hot-pluggable CPUs"
1780 Say Y here to allow turning CPUs off and on. CPUs can be
1781 controlled through /sys/devices/system/cpu.
1782 ( Note: power management support will enable this option
1783 automatically on SMP systems. )
1784 Say N if you want to disable CPU hotplug.
1786 config BOOTPARAM_HOTPLUG_CPU0
1787 bool "Set default setting of cpu0_hotpluggable"
1789 depends on HOTPLUG_CPU
1791 Set whether default state of cpu0_hotpluggable is on or off.
1793 Say Y here to enable CPU0 hotplug by default. If this switch
1794 is turned on, there is no need to give cpu0_hotplug kernel
1795 parameter and the CPU0 hotplug feature is enabled by default.
1797 Please note: there are two known CPU0 dependencies if you want
1798 to enable the CPU0 hotplug feature either by this switch or by
1799 cpu0_hotplug kernel parameter.
1801 First, resume from hibernate or suspend always starts from CPU0.
1802 So hibernate and suspend are prevented if CPU0 is offline.
1804 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1805 offline if any interrupt can not migrate out of CPU0. There may
1806 be other CPU0 dependencies.
1808 Please make sure the dependencies are under your control before
1809 you enable this feature.
1811 Say N if you don't want to enable CPU0 hotplug feature by default.
1812 You still can enable the CPU0 hotplug feature at boot by kernel
1813 parameter cpu0_hotplug.
1815 config DEBUG_HOTPLUG_CPU0
1817 prompt "Debug CPU0 hotplug"
1818 depends on HOTPLUG_CPU
1820 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1821 soon as possible and boots up userspace with CPU0 offlined. User
1822 can online CPU0 back after boot time.
1824 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1825 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1826 compilation or giving cpu0_hotplug kernel parameter at boot.
1832 prompt "Compat VDSO support"
1833 depends on X86_32 || IA32_EMULATION
1835 Map the 32-bit VDSO to the predictable old-style address too.
1837 Say N here if you are running a sufficiently recent glibc
1838 version (2.3.3 or later), to remove the high-mapped
1839 VDSO mapping and to exclusively use the randomized VDSO.
1844 bool "Built-in kernel command line"
1846 Allow for specifying boot arguments to the kernel at
1847 build time. On some systems (e.g. embedded ones), it is
1848 necessary or convenient to provide some or all of the
1849 kernel boot arguments with the kernel itself (that is,
1850 to not rely on the boot loader to provide them.)
1852 To compile command line arguments into the kernel,
1853 set this option to 'Y', then fill in the
1854 the boot arguments in CONFIG_CMDLINE.
1856 Systems with fully functional boot loaders (i.e. non-embedded)
1857 should leave this option set to 'N'.
1860 string "Built-in kernel command string"
1861 depends on CMDLINE_BOOL
1864 Enter arguments here that should be compiled into the kernel
1865 image and used at boot time. If the boot loader provides a
1866 command line at boot time, it is appended to this string to
1867 form the full kernel command line, when the system boots.
1869 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1870 change this behavior.
1872 In most cases, the command line (whether built-in or provided
1873 by the boot loader) should specify the device for the root
1876 config CMDLINE_OVERRIDE
1877 bool "Built-in command line overrides boot loader arguments"
1878 depends on CMDLINE_BOOL
1880 Set this option to 'Y' to have the kernel ignore the boot loader
1881 command line, and use ONLY the built-in command line.
1883 This is used to work around broken boot loaders. This should
1884 be set to 'N' under normal conditions.
1888 config ARCH_ENABLE_MEMORY_HOTPLUG
1890 depends on X86_64 || (X86_32 && HIGHMEM)
1892 config ARCH_ENABLE_MEMORY_HOTREMOVE
1894 depends on MEMORY_HOTPLUG
1896 config USE_PERCPU_NUMA_NODE_ID
1900 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1902 depends on X86_64 || X86_PAE
1904 menu "Power management and ACPI options"
1906 config ARCH_HIBERNATION_HEADER
1908 depends on X86_64 && HIBERNATION
1910 source "kernel/power/Kconfig"
1912 source "drivers/acpi/Kconfig"
1914 source "drivers/sfi/Kconfig"
1921 tristate "APM (Advanced Power Management) BIOS support"
1922 depends on X86_32 && PM_SLEEP
1924 APM is a BIOS specification for saving power using several different
1925 techniques. This is mostly useful for battery powered laptops with
1926 APM compliant BIOSes. If you say Y here, the system time will be
1927 reset after a RESUME operation, the /proc/apm device will provide
1928 battery status information, and user-space programs will receive
1929 notification of APM "events" (e.g. battery status change).
1931 If you select "Y" here, you can disable actual use of the APM
1932 BIOS by passing the "apm=off" option to the kernel at boot time.
1934 Note that the APM support is almost completely disabled for
1935 machines with more than one CPU.
1937 In order to use APM, you will need supporting software. For location
1938 and more information, read <file:Documentation/power/apm-acpi.txt>
1939 and the Battery Powered Linux mini-HOWTO, available from
1940 <http://www.tldp.org/docs.html#howto>.
1942 This driver does not spin down disk drives (see the hdparm(8)
1943 manpage ("man 8 hdparm") for that), and it doesn't turn off
1944 VESA-compliant "green" monitors.
1946 This driver does not support the TI 4000M TravelMate and the ACER
1947 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1948 desktop machines also don't have compliant BIOSes, and this driver
1949 may cause those machines to panic during the boot phase.
1951 Generally, if you don't have a battery in your machine, there isn't
1952 much point in using this driver and you should say N. If you get
1953 random kernel OOPSes or reboots that don't seem to be related to
1954 anything, try disabling/enabling this option (or disabling/enabling
1957 Some other things you should try when experiencing seemingly random,
1960 1) make sure that you have enough swap space and that it is
1962 2) pass the "no-hlt" option to the kernel
1963 3) switch on floating point emulation in the kernel and pass
1964 the "no387" option to the kernel
1965 4) pass the "floppy=nodma" option to the kernel
1966 5) pass the "mem=4M" option to the kernel (thereby disabling
1967 all but the first 4 MB of RAM)
1968 6) make sure that the CPU is not over clocked.
1969 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1970 8) disable the cache from your BIOS settings
1971 9) install a fan for the video card or exchange video RAM
1972 10) install a better fan for the CPU
1973 11) exchange RAM chips
1974 12) exchange the motherboard.
1976 To compile this driver as a module, choose M here: the
1977 module will be called apm.
1981 config APM_IGNORE_USER_SUSPEND
1982 bool "Ignore USER SUSPEND"
1984 This option will ignore USER SUSPEND requests. On machines with a
1985 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1986 series notebooks, it is necessary to say Y because of a BIOS bug.
1988 config APM_DO_ENABLE
1989 bool "Enable PM at boot time"
1991 Enable APM features at boot time. From page 36 of the APM BIOS
1992 specification: "When disabled, the APM BIOS does not automatically
1993 power manage devices, enter the Standby State, enter the Suspend
1994 State, or take power saving steps in response to CPU Idle calls."
1995 This driver will make CPU Idle calls when Linux is idle (unless this
1996 feature is turned off -- see "Do CPU IDLE calls", below). This
1997 should always save battery power, but more complicated APM features
1998 will be dependent on your BIOS implementation. You may need to turn
1999 this option off if your computer hangs at boot time when using APM
2000 support, or if it beeps continuously instead of suspending. Turn
2001 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2002 T400CDT. This is off by default since most machines do fine without
2007 bool "Make CPU Idle calls when idle"
2009 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2010 On some machines, this can activate improved power savings, such as
2011 a slowed CPU clock rate, when the machine is idle. These idle calls
2012 are made after the idle loop has run for some length of time (e.g.,
2013 333 mS). On some machines, this will cause a hang at boot time or
2014 whenever the CPU becomes idle. (On machines with more than one CPU,
2015 this option does nothing.)
2017 config APM_DISPLAY_BLANK
2018 bool "Enable console blanking using APM"
2020 Enable console blanking using the APM. Some laptops can use this to
2021 turn off the LCD backlight when the screen blanker of the Linux
2022 virtual console blanks the screen. Note that this is only used by
2023 the virtual console screen blanker, and won't turn off the backlight
2024 when using the X Window system. This also doesn't have anything to
2025 do with your VESA-compliant power-saving monitor. Further, this
2026 option doesn't work for all laptops -- it might not turn off your
2027 backlight at all, or it might print a lot of errors to the console,
2028 especially if you are using gpm.
2030 config APM_ALLOW_INTS
2031 bool "Allow interrupts during APM BIOS calls"
2033 Normally we disable external interrupts while we are making calls to
2034 the APM BIOS as a measure to lessen the effects of a badly behaving
2035 BIOS implementation. The BIOS should reenable interrupts if it
2036 needs to. Unfortunately, some BIOSes do not -- especially those in
2037 many of the newer IBM Thinkpads. If you experience hangs when you
2038 suspend, try setting this to Y. Otherwise, say N.
2042 source "drivers/cpufreq/Kconfig"
2044 source "drivers/cpuidle/Kconfig"
2046 source "drivers/idle/Kconfig"
2051 menu "Bus options (PCI etc.)"
2057 Find out whether you have a PCI motherboard. PCI is the name of a
2058 bus system, i.e. the way the CPU talks to the other stuff inside
2059 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2060 VESA. If you have PCI, say Y, otherwise N.
2063 prompt "PCI access mode"
2064 depends on X86_32 && PCI
2067 On PCI systems, the BIOS can be used to detect the PCI devices and
2068 determine their configuration. However, some old PCI motherboards
2069 have BIOS bugs and may crash if this is done. Also, some embedded
2070 PCI-based systems don't have any BIOS at all. Linux can also try to
2071 detect the PCI hardware directly without using the BIOS.
2073 With this option, you can specify how Linux should detect the
2074 PCI devices. If you choose "BIOS", the BIOS will be used,
2075 if you choose "Direct", the BIOS won't be used, and if you
2076 choose "MMConfig", then PCI Express MMCONFIG will be used.
2077 If you choose "Any", the kernel will try MMCONFIG, then the
2078 direct access method and falls back to the BIOS if that doesn't
2079 work. If unsure, go with the default, which is "Any".
2084 config PCI_GOMMCONFIG
2101 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2103 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2106 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2110 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2114 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2118 depends on PCI && XEN
2126 bool "Support mmconfig PCI config space access"
2127 depends on X86_64 && PCI && ACPI
2129 config PCI_CNB20LE_QUIRK
2130 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2133 Read the PCI windows out of the CNB20LE host bridge. This allows
2134 PCI hotplug to work on systems with the CNB20LE chipset which do
2137 There's no public spec for this chipset, and this functionality
2138 is known to be incomplete.
2140 You should say N unless you know you need this.
2142 source "drivers/pci/pcie/Kconfig"
2144 source "drivers/pci/Kconfig"
2146 # x86_64 have no ISA slots, but can have ISA-style DMA.
2148 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2151 Enables ISA-style DMA support for devices requiring such controllers.
2159 Find out whether you have ISA slots on your motherboard. ISA is the
2160 name of a bus system, i.e. the way the CPU talks to the other stuff
2161 inside your box. Other bus systems are PCI, EISA, MicroChannel
2162 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2163 newer boards don't support it. If you have ISA, say Y, otherwise N.
2169 The Extended Industry Standard Architecture (EISA) bus was
2170 developed as an open alternative to the IBM MicroChannel bus.
2172 The EISA bus provided some of the features of the IBM MicroChannel
2173 bus while maintaining backward compatibility with cards made for
2174 the older ISA bus. The EISA bus saw limited use between 1988 and
2175 1995 when it was made obsolete by the PCI bus.
2177 Say Y here if you are building a kernel for an EISA-based machine.
2181 source "drivers/eisa/Kconfig"
2184 tristate "NatSemi SCx200 support"
2186 This provides basic support for National Semiconductor's
2187 (now AMD's) Geode processors. The driver probes for the
2188 PCI-IDs of several on-chip devices, so its a good dependency
2189 for other scx200_* drivers.
2191 If compiled as a module, the driver is named scx200.
2193 config SCx200HR_TIMER
2194 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2198 This driver provides a clocksource built upon the on-chip
2199 27MHz high-resolution timer. Its also a workaround for
2200 NSC Geode SC-1100's buggy TSC, which loses time when the
2201 processor goes idle (as is done by the scheduler). The
2202 other workaround is idle=poll boot option.
2205 bool "One Laptop Per Child support"
2212 Add support for detecting the unique features of the OLPC
2216 bool "OLPC XO-1 Power Management"
2217 depends on OLPC && MFD_CS5535 && PM_SLEEP
2220 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2223 bool "OLPC XO-1 Real Time Clock"
2224 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2226 Add support for the XO-1 real time clock, which can be used as a
2227 programmable wakeup source.
2230 bool "OLPC XO-1 SCI extras"
2231 depends on OLPC && OLPC_XO1_PM
2237 Add support for SCI-based features of the OLPC XO-1 laptop:
2238 - EC-driven system wakeups
2242 - AC adapter status updates
2243 - Battery status updates
2245 config OLPC_XO15_SCI
2246 bool "OLPC XO-1.5 SCI extras"
2247 depends on OLPC && ACPI
2250 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2251 - EC-driven system wakeups
2252 - AC adapter status updates
2253 - Battery status updates
2256 bool "PCEngines ALIX System Support (LED setup)"
2259 This option enables system support for the PCEngines ALIX.
2260 At present this just sets up LEDs for GPIO control on
2261 ALIX2/3/6 boards. However, other system specific setup should
2264 Note: You must still enable the drivers for GPIO and LED support
2265 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2267 Note: You have to set alix.force=1 for boards with Award BIOS.
2270 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2273 This option enables system support for the Soekris Engineering net5501.
2276 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2280 This option enables system support for the Traverse Technologies GEOS.
2283 bool "Technologic Systems TS-5500 platform support"
2285 select CHECK_SIGNATURE
2289 This option enables system support for the Technologic Systems TS-5500.
2295 depends on CPU_SUP_AMD && PCI
2297 source "drivers/pcmcia/Kconfig"
2299 source "drivers/pci/hotplug/Kconfig"
2302 tristate "RapidIO support"
2306 If enabled this option will include drivers and the core
2307 infrastructure code to support RapidIO interconnect devices.
2309 source "drivers/rapidio/Kconfig"
2312 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2314 Firmwares often provide initial graphics framebuffers so the BIOS,
2315 bootloader or kernel can show basic video-output during boot for
2316 user-guidance and debugging. Historically, x86 used the VESA BIOS
2317 Extensions and EFI-framebuffers for this, which are mostly limited
2319 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2320 framebuffers so the new generic system-framebuffer drivers can be
2321 used on x86. If the framebuffer is not compatible with the generic
2322 modes, it is adverticed as fallback platform framebuffer so legacy
2323 drivers like efifb, vesafb and uvesafb can pick it up.
2324 If this option is not selected, all system framebuffers are always
2325 marked as fallback platform framebuffers as usual.
2327 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2328 not be able to pick up generic system framebuffers if this option
2329 is selected. You are highly encouraged to enable simplefb as
2330 replacement if you select this option. simplefb can correctly deal
2331 with generic system framebuffers. But you should still keep vesafb
2332 and others enabled as fallback if a system framebuffer is
2333 incompatible with simplefb.
2340 menu "Executable file formats / Emulations"
2342 source "fs/Kconfig.binfmt"
2344 config IA32_EMULATION
2345 bool "IA32 Emulation"
2348 select COMPAT_BINFMT_ELF
2351 Include code to run legacy 32-bit programs under a
2352 64-bit kernel. You should likely turn this on, unless you're
2353 100% sure that you don't have any 32-bit programs left.
2356 tristate "IA32 a.out support"
2357 depends on IA32_EMULATION
2359 Support old a.out binaries in the 32bit emulation.
2362 bool "x32 ABI for 64-bit mode"
2363 depends on X86_64 && IA32_EMULATION
2365 Include code to run binaries for the x32 native 32-bit ABI
2366 for 64-bit processors. An x32 process gets access to the
2367 full 64-bit register file and wide data path while leaving
2368 pointers at 32 bits for smaller memory footprint.
2370 You will need a recent binutils (2.22 or later) with
2371 elf32_x86_64 support enabled to compile a kernel with this
2376 depends on IA32_EMULATION || X86_X32
2377 select ARCH_WANT_OLD_COMPAT_IPC
2380 config COMPAT_FOR_U64_ALIGNMENT
2383 config SYSVIPC_COMPAT
2395 config HAVE_ATOMIC_IOMAP
2399 config X86_DEV_DMA_OPS
2401 depends on X86_64 || STA2X11
2403 config X86_DMA_REMAP
2411 To be selected by modules requiring access to the Intel OnChip System
2412 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms
2415 source "net/Kconfig"
2417 source "drivers/Kconfig"
2419 source "drivers/firmware/Kconfig"
2423 source "arch/x86/Kconfig.debug"
2425 source "security/Kconfig"
2427 source "crypto/Kconfig"
2429 source "arch/x86/kvm/Kconfig"
2431 source "lib/Kconfig"