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_FUNCTION_TRACE_MCOUNT_TEST
58 select HAVE_SYSCALL_TRACEPOINTS
59 select SYSCTL_EXCEPTION_TRACE
62 select HAVE_ARCH_TRACEHOOK
63 select HAVE_GENERIC_DMA_COHERENT if X86_32
64 select HAVE_EFFICIENT_UNALIGNED_ACCESS
65 select USER_STACKTRACE_SUPPORT
66 select HAVE_REGS_AND_STACK_ACCESS_API
67 select HAVE_DMA_API_DEBUG
68 select HAVE_KERNEL_GZIP
69 select HAVE_KERNEL_BZIP2
70 select HAVE_KERNEL_LZMA
72 select HAVE_KERNEL_LZO
73 select HAVE_KERNEL_LZ4
74 select HAVE_HW_BREAKPOINT
75 select HAVE_MIXED_BREAKPOINTS_REGS
77 select HAVE_PERF_EVENTS_NMI
79 select HAVE_PERF_USER_STACK_DUMP
80 select HAVE_DEBUG_KMEMLEAK
82 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
83 select HAVE_CMPXCHG_LOCAL
84 select HAVE_CMPXCHG_DOUBLE
85 select HAVE_ARCH_KMEMCHECK
86 select HAVE_USER_RETURN_NOTIFIER
87 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
88 select HAVE_ARCH_JUMP_LABEL
89 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
91 select GENERIC_FIND_FIRST_BIT
92 select GENERIC_IRQ_PROBE
93 select GENERIC_PENDING_IRQ if SMP
94 select GENERIC_IRQ_SHOW
95 select GENERIC_CLOCKEVENTS_MIN_ADJUST
96 select IRQ_FORCED_THREADING
97 select HAVE_BPF_JIT if X86_64
98 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
100 select ARCH_HAVE_NMI_SAFE_CMPXCHG
102 select DCACHE_WORD_ACCESS
103 select GENERIC_SMP_IDLE_THREAD
104 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
105 select HAVE_ARCH_SECCOMP_FILTER
106 select BUILDTIME_EXTABLE_SORT
107 select GENERIC_CMOS_UPDATE
108 select HAVE_ARCH_SOFT_DIRTY if X86_64
109 select CLOCKSOURCE_WATCHDOG
110 select GENERIC_CLOCKEVENTS
111 select ARCH_CLOCKSOURCE_DATA
112 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
113 select GENERIC_TIME_VSYSCALL
114 select KTIME_SCALAR if X86_32
115 select GENERIC_STRNCPY_FROM_USER
116 select GENERIC_STRNLEN_USER
117 select HAVE_CONTEXT_TRACKING if X86_64
118 select HAVE_IRQ_TIME_ACCOUNTING
120 select MODULES_USE_ELF_REL if X86_32
121 select MODULES_USE_ELF_RELA if X86_64
122 select CLONE_BACKWARDS if X86_32
123 select ARCH_USE_BUILTIN_BSWAP
124 select ARCH_USE_QUEUE_RWLOCK
125 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
126 select OLD_SIGACTION if X86_32
127 select COMPAT_OLD_SIGACTION if IA32_EMULATION
129 select HAVE_DEBUG_STACKOVERFLOW
130 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
131 select HAVE_CC_STACKPROTECTOR
132 select GENERIC_CPU_AUTOPROBE
133 select HAVE_ARCH_AUDITSYSCALL
134 select ARCH_SUPPORTS_ATOMIC_RMW
136 config INSTRUCTION_DECODER
138 depends on KPROBES || PERF_EVENTS || UPROBES
142 default "elf32-i386" if X86_32
143 default "elf64-x86-64" if X86_64
145 config ARCH_DEFCONFIG
147 default "arch/x86/configs/i386_defconfig" if X86_32
148 default "arch/x86/configs/x86_64_defconfig" if X86_64
150 config LOCKDEP_SUPPORT
153 config STACKTRACE_SUPPORT
156 config HAVE_LATENCYTOP_SUPPORT
165 config NEED_DMA_MAP_STATE
167 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
169 config NEED_SG_DMA_LENGTH
172 config GENERIC_ISA_DMA
174 depends on ISA_DMA_API
179 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
181 config GENERIC_BUG_RELATIVE_POINTERS
184 config GENERIC_HWEIGHT
187 config ARCH_MAY_HAVE_PC_FDC
189 depends on ISA_DMA_API
191 config RWSEM_XCHGADD_ALGORITHM
194 config GENERIC_CALIBRATE_DELAY
197 config ARCH_HAS_CPU_RELAX
200 config ARCH_HAS_CACHE_LINE_SIZE
203 config HAVE_SETUP_PER_CPU_AREA
206 config NEED_PER_CPU_EMBED_FIRST_CHUNK
209 config NEED_PER_CPU_PAGE_FIRST_CHUNK
212 config ARCH_HIBERNATION_POSSIBLE
215 config ARCH_SUSPEND_POSSIBLE
218 config ARCH_WANT_HUGE_PMD_SHARE
221 config ARCH_WANT_GENERAL_HUGETLB
232 config ARCH_SUPPORTS_OPTIMIZED_INLINING
235 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
238 config HAVE_INTEL_TXT
240 depends on INTEL_IOMMU && ACPI
244 depends on X86_32 && SMP
248 depends on X86_64 && SMP
254 config X86_32_LAZY_GS
256 depends on X86_32 && !CC_STACKPROTECTOR
258 config ARCH_HWEIGHT_CFLAGS
260 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
261 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
263 config ARCH_SUPPORTS_UPROBES
266 config FIX_EARLYCON_MEM
269 source "init/Kconfig"
270 source "kernel/Kconfig.freezer"
272 menu "Processor type and features"
275 bool "DMA memory allocation support" if EXPERT
278 DMA memory allocation support allows devices with less than 32-bit
279 addressing to allocate within the first 16MB of address space.
280 Disable if no such devices will be used.
285 bool "Symmetric multi-processing support"
287 This enables support for systems with more than one CPU. If you have
288 a system with only one CPU, say N. If you have a system with more
291 If you say N here, the kernel will run on uni- and multiprocessor
292 machines, but will use only one CPU of a multiprocessor machine. If
293 you say Y here, the kernel will run on many, but not all,
294 uniprocessor machines. On a uniprocessor machine, the kernel
295 will run faster if you say N here.
297 Note that if you say Y here and choose architecture "586" or
298 "Pentium" under "Processor family", the kernel will not work on 486
299 architectures. Similarly, multiprocessor kernels for the "PPro"
300 architecture may not work on all Pentium based boards.
302 People using multiprocessor machines who say Y here should also say
303 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
304 Management" code will be disabled if you say Y here.
306 See also <file:Documentation/x86/i386/IO-APIC.txt>,
307 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
308 <http://www.tldp.org/docs.html#howto>.
310 If you don't know what to do here, say N.
313 bool "Support x2apic"
314 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
316 This enables x2apic support on CPUs that have this feature.
318 This allows 32-bit apic IDs (so it can support very large systems),
319 and accesses the local apic via MSRs not via mmio.
321 If you don't know what to do here, say N.
324 bool "Enable MPS table" if ACPI || SFI
326 depends on X86_LOCAL_APIC
328 For old smp systems that do not have proper acpi support. Newer systems
329 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
332 bool "Support for big SMP systems with more than 8 CPUs"
333 depends on X86_32 && SMP
335 This option is needed for the systems that have more than 8 CPUs
339 depends on X86_GOLDFISH
342 config X86_EXTENDED_PLATFORM
343 bool "Support for extended (non-PC) x86 platforms"
346 If you disable this option then the kernel will only support
347 standard PC platforms. (which covers the vast majority of
350 If you enable this option then you'll be able to select support
351 for the following (non-PC) 32 bit x86 platforms:
352 Goldfish (Android emulator)
355 SGI 320/540 (Visual Workstation)
356 STA2X11-based (e.g. Northville)
357 Moorestown MID devices
359 If you have one of these systems, or if you want to build a
360 generic distribution kernel, say Y here - otherwise say N.
364 config X86_EXTENDED_PLATFORM
365 bool "Support for extended (non-PC) x86 platforms"
368 If you disable this option then the kernel will only support
369 standard PC platforms. (which covers the vast majority of
372 If you enable this option then you'll be able to select support
373 for the following (non-PC) 64 bit x86 platforms:
378 If you have one of these systems, or if you want to build a
379 generic distribution kernel, say Y here - otherwise say N.
381 # This is an alphabetically sorted list of 64 bit extended platforms
382 # Please maintain the alphabetic order if and when there are additions
384 bool "Numascale NumaChip"
386 depends on X86_EXTENDED_PLATFORM
389 depends on X86_X2APIC
390 depends on PCI_MMCONFIG
392 Adds support for Numascale NumaChip large-SMP systems. Needed to
393 enable more than ~168 cores.
394 If you don't have one of these, you should say N here.
398 select HYPERVISOR_GUEST
400 depends on X86_64 && PCI
401 depends on X86_EXTENDED_PLATFORM
404 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
405 supposed to run on these EM64T-based machines. Only choose this option
406 if you have one of these machines.
409 bool "SGI Ultraviolet"
411 depends on X86_EXTENDED_PLATFORM
413 depends on X86_X2APIC
415 This option is needed in order to support SGI Ultraviolet systems.
416 If you don't have one of these, you should say N here.
418 # Following is an alphabetically sorted list of 32 bit extended platforms
419 # Please maintain the alphabetic order if and when there are additions
422 bool "Goldfish (Virtual Platform)"
423 depends on X86_EXTENDED_PLATFORM
425 Enable support for the Goldfish virtual platform used primarily
426 for Android development. Unless you are building for the Android
427 Goldfish emulator say N here.
430 bool "CE4100 TV platform"
432 depends on PCI_GODIRECT
434 depends on X86_EXTENDED_PLATFORM
435 select X86_REBOOTFIXUPS
437 select OF_EARLY_FLATTREE
440 Select for the Intel CE media processor (CE4100) SOC.
441 This option compiles in support for the CE4100 SOC for settop
442 boxes and media devices.
445 bool "Intel MID platform support"
447 depends on X86_EXTENDED_PLATFORM
448 depends on X86_PLATFORM_DEVICES
451 depends on X86_IO_APIC
457 select MFD_INTEL_MSIC
459 Select to build a kernel capable of supporting Intel MID (Mobile
460 Internet Device) platform systems which do not have the PCI legacy
461 interfaces. If you are building for a PC class system say N here.
463 Intel MID platforms are based on an Intel processor and chipset which
464 consume less power than most of the x86 derivatives.
466 config X86_INTEL_LPSS
467 bool "Intel Low Power Subsystem Support"
472 Select to build support for Intel Low Power Subsystem such as
473 found on Intel Lynxpoint PCH. Selecting this option enables
474 things like clock tree (common clock framework) and pincontrol
475 which are needed by the LPSS peripheral drivers.
478 bool "RDC R-321x SoC"
480 depends on X86_EXTENDED_PLATFORM
482 select X86_REBOOTFIXUPS
484 This option is needed for RDC R-321x system-on-chip, also known
486 If you don't have one of these chips, you should say N here.
488 config X86_32_NON_STANDARD
489 bool "Support non-standard 32-bit SMP architectures"
490 depends on X86_32 && SMP
491 depends on X86_EXTENDED_PLATFORM
493 This option compiles in the bigsmp and STA2X11 default
494 subarchitectures. It is intended for a generic binary
495 kernel. If you select them all, kernel will probe it one by
496 one and will fallback to default.
498 # Alphabetically sorted list of Non standard 32 bit platforms
500 config X86_SUPPORTS_MEMORY_FAILURE
502 # MCE code calls memory_failure():
504 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
505 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
506 depends on X86_64 || !SPARSEMEM
507 select ARCH_SUPPORTS_MEMORY_FAILURE
510 bool "STA2X11 Companion Chip Support"
511 depends on X86_32_NON_STANDARD && PCI
512 select X86_DEV_DMA_OPS
516 select ARCH_REQUIRE_GPIOLIB
519 This adds support for boards based on the STA2X11 IO-Hub,
520 a.k.a. "ConneXt". The chip is used in place of the standard
521 PC chipset, so all "standard" peripherals are missing. If this
522 option is selected the kernel will still be able to boot on
523 standard PC machines.
526 tristate "Eurobraille/Iris poweroff module"
529 The Iris machines from EuroBraille do not have APM or ACPI support
530 to shut themselves down properly. A special I/O sequence is
531 needed to do so, which is what this module does at
534 This is only for Iris machines from EuroBraille.
538 config SCHED_OMIT_FRAME_POINTER
540 prompt "Single-depth WCHAN output"
543 Calculate simpler /proc/<PID>/wchan values. If this option
544 is disabled then wchan values will recurse back to the
545 caller function. This provides more accurate wchan values,
546 at the expense of slightly more scheduling overhead.
548 If in doubt, say "Y".
550 menuconfig HYPERVISOR_GUEST
551 bool "Linux guest support"
553 Say Y here to enable options for running Linux under various hyper-
554 visors. This option enables basic hypervisor detection and platform
557 If you say N, all options in this submenu will be skipped and
558 disabled, and Linux guest support won't be built in.
563 bool "Enable paravirtualization code"
565 This changes the kernel so it can modify itself when it is run
566 under a hypervisor, potentially improving performance significantly
567 over full virtualization. However, when run without a hypervisor
568 the kernel is theoretically slower and slightly larger.
570 config PARAVIRT_DEBUG
571 bool "paravirt-ops debugging"
572 depends on PARAVIRT && DEBUG_KERNEL
574 Enable to debug paravirt_ops internals. Specifically, BUG if
575 a paravirt_op is missing when it is called.
577 config PARAVIRT_SPINLOCKS
578 bool "Paravirtualization layer for spinlocks"
579 depends on PARAVIRT && SMP
580 select UNINLINE_SPIN_UNLOCK
582 Paravirtualized spinlocks allow a pvops backend to replace the
583 spinlock implementation with something virtualization-friendly
584 (for example, block the virtual CPU rather than spinning).
586 It has a minimal impact on native kernels and gives a nice performance
587 benefit on paravirtualized KVM / Xen kernels.
589 If you are unsure how to answer this question, answer Y.
591 source "arch/x86/xen/Kconfig"
594 bool "KVM Guest support (including kvmclock)"
596 select PARAVIRT_CLOCK
599 This option enables various optimizations for running under the KVM
600 hypervisor. It includes a paravirtualized clock, so that instead
601 of relying on a PIT (or probably other) emulation by the
602 underlying device model, the host provides the guest with
603 timing infrastructure such as time of day, and system time
606 bool "Enable debug information for KVM Guests in debugfs"
607 depends on KVM_GUEST && DEBUG_FS
610 This option enables collection of various statistics for KVM guest.
611 Statistics are displayed in debugfs filesystem. Enabling this option
612 may incur significant overhead.
614 source "arch/x86/lguest/Kconfig"
616 config PARAVIRT_TIME_ACCOUNTING
617 bool "Paravirtual steal time accounting"
621 Select this option to enable fine granularity task steal time
622 accounting. Time spent executing other tasks in parallel with
623 the current vCPU is discounted from the vCPU power. To account for
624 that, there can be a small performance impact.
626 If in doubt, say N here.
628 config PARAVIRT_CLOCK
631 endif #HYPERVISOR_GUEST
639 This option adds a kernel parameter 'memtest', which allows memtest
641 memtest=0, mean disabled; -- default
642 memtest=1, mean do 1 test pattern;
644 memtest=4, mean do 4 test patterns.
645 If you are unsure how to answer this question, answer N.
647 source "arch/x86/Kconfig.cpu"
651 prompt "HPET Timer Support" if X86_32
653 Use the IA-PC HPET (High Precision Event Timer) to manage
654 time in preference to the PIT and RTC, if a HPET is
656 HPET is the next generation timer replacing legacy 8254s.
657 The HPET provides a stable time base on SMP
658 systems, unlike the TSC, but it is more expensive to access,
659 as it is off-chip. You can find the HPET spec at
660 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
662 You can safely choose Y here. However, HPET will only be
663 activated if the platform and the BIOS support this feature.
664 Otherwise the 8254 will be used for timing services.
666 Choose N to continue using the legacy 8254 timer.
668 config HPET_EMULATE_RTC
670 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
673 def_bool y if X86_INTEL_MID
674 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
676 depends on X86_INTEL_MID && SFI
678 APB timer is the replacement for 8254, HPET on X86 MID platforms.
679 The APBT provides a stable time base on SMP
680 systems, unlike the TSC, but it is more expensive to access,
681 as it is off-chip. APB timers are always running regardless of CPU
682 C states, they are used as per CPU clockevent device when possible.
684 # Mark as expert because too many people got it wrong.
685 # The code disables itself when not needed.
688 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
689 bool "Enable DMI scanning" if EXPERT
691 Enabled scanning of DMI to identify machine quirks. Say Y
692 here unless you have verified that your setup is not
693 affected by entries in the DMI blacklist. Required by PNP
697 bool "Old AMD GART IOMMU support"
699 depends on X86_64 && PCI && AMD_NB
701 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
702 GART based hardware IOMMUs.
704 The GART supports full DMA access for devices with 32-bit access
705 limitations, on systems with more than 3 GB. This is usually needed
706 for USB, sound, many IDE/SATA chipsets and some other devices.
708 Newer systems typically have a modern AMD IOMMU, supported via
709 the CONFIG_AMD_IOMMU=y config option.
711 In normal configurations this driver is only active when needed:
712 there's more than 3 GB of memory and the system contains a
713 32-bit limited device.
718 bool "IBM Calgary IOMMU support"
720 depends on X86_64 && PCI
722 Support for hardware IOMMUs in IBM's xSeries x366 and x460
723 systems. Needed to run systems with more than 3GB of memory
724 properly with 32-bit PCI devices that do not support DAC
725 (Double Address Cycle). Calgary also supports bus level
726 isolation, where all DMAs pass through the IOMMU. This
727 prevents them from going anywhere except their intended
728 destination. This catches hard-to-find kernel bugs and
729 mis-behaving drivers and devices that do not use the DMA-API
730 properly to set up their DMA buffers. The IOMMU can be
731 turned off at boot time with the iommu=off parameter.
732 Normally the kernel will make the right choice by itself.
735 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
737 prompt "Should Calgary be enabled by default?"
738 depends on CALGARY_IOMMU
740 Should Calgary be enabled by default? if you choose 'y', Calgary
741 will be used (if it exists). If you choose 'n', Calgary will not be
742 used even if it exists. If you choose 'n' and would like to use
743 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
746 # need this always selected by IOMMU for the VIA workaround
750 Support for software bounce buffers used on x86-64 systems
751 which don't have a hardware IOMMU. Using this PCI devices
752 which can only access 32-bits of memory can be used on systems
753 with more than 3 GB of memory.
758 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
761 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
762 depends on X86_64 && SMP && DEBUG_KERNEL
763 select CPUMASK_OFFSTACK
765 Enable maximum number of CPUS and NUMA Nodes for this architecture.
769 int "Maximum number of CPUs" if SMP && !MAXSMP
770 range 2 8 if SMP && X86_32 && !X86_BIGSMP
771 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
772 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
774 default "8192" if MAXSMP
775 default "32" if SMP && X86_BIGSMP
778 This allows you to specify the maximum number of CPUs which this
779 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
780 supported value is 4096, otherwise the maximum value is 512. The
781 minimum value which makes sense is 2.
783 This is purely to save memory - each supported CPU adds
784 approximately eight kilobytes to the kernel image.
787 bool "SMT (Hyperthreading) scheduler support"
790 SMT scheduler support improves the CPU scheduler's decision making
791 when dealing with Intel Pentium 4 chips with HyperThreading at a
792 cost of slightly increased overhead in some places. If unsure say
797 prompt "Multi-core scheduler support"
800 Multi-core scheduler support improves the CPU scheduler's decision
801 making when dealing with multi-core CPU chips at a cost of slightly
802 increased overhead in some places. If unsure say N here.
804 source "kernel/Kconfig.preempt"
807 bool "Local APIC support on uniprocessors"
808 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
810 A local APIC (Advanced Programmable Interrupt Controller) is an
811 integrated interrupt controller in the CPU. If you have a single-CPU
812 system which has a processor with a local APIC, you can say Y here to
813 enable and use it. If you say Y here even though your machine doesn't
814 have a local APIC, then the kernel will still run with no slowdown at
815 all. The local APIC supports CPU-generated self-interrupts (timer,
816 performance counters), and the NMI watchdog which detects hard
820 bool "IO-APIC support on uniprocessors"
821 depends on X86_UP_APIC
823 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
824 SMP-capable replacement for PC-style interrupt controllers. Most
825 SMP systems and many recent uniprocessor systems have one.
827 If you have a single-CPU system with an IO-APIC, you can say Y here
828 to use it. If you say Y here even though your machine doesn't have
829 an IO-APIC, then the kernel will still run with no slowdown at all.
831 config X86_LOCAL_APIC
833 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
837 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
838 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
840 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
841 bool "Reroute for broken boot IRQs"
842 depends on X86_IO_APIC
844 This option enables a workaround that fixes a source of
845 spurious interrupts. This is recommended when threaded
846 interrupt handling is used on systems where the generation of
847 superfluous "boot interrupts" cannot be disabled.
849 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
850 entry in the chipset's IO-APIC is masked (as, e.g. the RT
851 kernel does during interrupt handling). On chipsets where this
852 boot IRQ generation cannot be disabled, this workaround keeps
853 the original IRQ line masked so that only the equivalent "boot
854 IRQ" is delivered to the CPUs. The workaround also tells the
855 kernel to set up the IRQ handler on the boot IRQ line. In this
856 way only one interrupt is delivered to the kernel. Otherwise
857 the spurious second interrupt may cause the kernel to bring
858 down (vital) interrupt lines.
860 Only affects "broken" chipsets. Interrupt sharing may be
861 increased on these systems.
864 bool "Machine Check / overheating reporting"
867 Machine Check support allows the processor to notify the
868 kernel if it detects a problem (e.g. overheating, data corruption).
869 The action the kernel takes depends on the severity of the problem,
870 ranging from warning messages to halting the machine.
874 prompt "Intel MCE features"
875 depends on X86_MCE && X86_LOCAL_APIC
877 Additional support for intel specific MCE features such as
882 prompt "AMD MCE features"
883 depends on X86_MCE && X86_LOCAL_APIC
885 Additional support for AMD specific MCE features such as
886 the DRAM Error Threshold.
888 config X86_ANCIENT_MCE
889 bool "Support for old Pentium 5 / WinChip machine checks"
890 depends on X86_32 && X86_MCE
892 Include support for machine check handling on old Pentium 5 or WinChip
893 systems. These typically need to be enabled explicitly on the command
896 config X86_MCE_THRESHOLD
897 depends on X86_MCE_AMD || X86_MCE_INTEL
900 config X86_MCE_INJECT
902 tristate "Machine check injector support"
904 Provide support for injecting machine checks for testing purposes.
905 If you don't know what a machine check is and you don't do kernel
906 QA it is safe to say n.
908 config X86_THERMAL_VECTOR
910 depends on X86_MCE_INTEL
913 bool "Enable VM86 support" if EXPERT
917 This option is required by programs like DOSEMU to run
918 16-bit real mode legacy code on x86 processors. It also may
919 be needed by software like XFree86 to initialize some video
920 cards via BIOS. Disabling this option saves about 6K.
923 bool "Enable support for 16-bit segments" if EXPERT
926 This option is required by programs like Wine to run 16-bit
927 protected mode legacy code on x86 processors. Disabling
928 this option saves about 300 bytes on i386, or around 6K text
929 plus 16K runtime memory on x86-64,
933 depends on X86_16BIT && X86_32
937 depends on X86_16BIT && X86_64
940 tristate "Toshiba Laptop support"
943 This adds a driver to safely access the System Management Mode of
944 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
945 not work on models with a Phoenix BIOS. The System Management Mode
946 is used to set the BIOS and power saving options on Toshiba portables.
948 For information on utilities to make use of this driver see the
949 Toshiba Linux utilities web site at:
950 <http://www.buzzard.org.uk/toshiba/>.
952 Say Y if you intend to run this kernel on a Toshiba portable.
956 tristate "Dell laptop support"
959 This adds a driver to safely access the System Management Mode
960 of the CPU on the Dell Inspiron 8000. The System Management Mode
961 is used to read cpu temperature and cooling fan status and to
962 control the fans on the I8K portables.
964 This driver has been tested only on the Inspiron 8000 but it may
965 also work with other Dell laptops. You can force loading on other
966 models by passing the parameter `force=1' to the module. Use at
969 For information on utilities to make use of this driver see the
970 I8K Linux utilities web site at:
971 <http://people.debian.org/~dz/i8k/>
973 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
976 config X86_REBOOTFIXUPS
977 bool "Enable X86 board specific fixups for reboot"
980 This enables chipset and/or board specific fixups to be done
981 in order to get reboot to work correctly. This is only needed on
982 some combinations of hardware and BIOS. The symptom, for which
983 this config is intended, is when reboot ends with a stalled/hung
986 Currently, the only fixup is for the Geode machines using
987 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
989 Say Y if you want to enable the fixup. Currently, it's safe to
990 enable this option even if you don't need it.
994 tristate "CPU microcode loading support"
995 depends on CPU_SUP_AMD || CPU_SUP_INTEL
999 If you say Y here, you will be able to update the microcode on
1000 certain Intel and AMD processors. The Intel support is for the
1001 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1002 Xeon etc. The AMD support is for families 0x10 and later. You will
1003 obviously need the actual microcode binary data itself which is not
1004 shipped with the Linux kernel.
1006 This option selects the general module only, you need to select
1007 at least one vendor specific module as well.
1009 To compile this driver as a module, choose M here: the module
1010 will be called microcode.
1012 config MICROCODE_INTEL
1013 bool "Intel microcode loading support"
1014 depends on MICROCODE
1018 This options enables microcode patch loading support for Intel
1021 For the current Intel microcode data package go to
1022 <https://downloadcenter.intel.com> and search for
1023 'Linux Processor Microcode Data File'.
1025 config MICROCODE_AMD
1026 bool "AMD microcode loading support"
1027 depends on MICROCODE
1030 If you select this option, microcode patch loading support for AMD
1031 processors will be enabled.
1033 config MICROCODE_OLD_INTERFACE
1035 depends on MICROCODE
1037 config MICROCODE_INTEL_EARLY
1040 config MICROCODE_AMD_EARLY
1043 config MICROCODE_EARLY
1044 bool "Early load microcode"
1045 depends on MICROCODE=y && BLK_DEV_INITRD
1046 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1047 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1050 This option provides functionality to read additional microcode data
1051 at the beginning of initrd image. The data tells kernel to load
1052 microcode to CPU's as early as possible. No functional change if no
1053 microcode data is glued to the initrd, therefore it's safe to say Y.
1056 tristate "/dev/cpu/*/msr - Model-specific register support"
1058 This device gives privileged processes access to the x86
1059 Model-Specific Registers (MSRs). It is a character device with
1060 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1061 MSR accesses are directed to a specific CPU on multi-processor
1065 tristate "/dev/cpu/*/cpuid - CPU information support"
1067 This device gives processes access to the x86 CPUID instruction to
1068 be executed on a specific processor. It is a character device
1069 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1073 prompt "High Memory Support"
1080 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1081 However, the address space of 32-bit x86 processors is only 4
1082 Gigabytes large. That means that, if you have a large amount of
1083 physical memory, not all of it can be "permanently mapped" by the
1084 kernel. The physical memory that's not permanently mapped is called
1087 If you are compiling a kernel which will never run on a machine with
1088 more than 1 Gigabyte total physical RAM, answer "off" here (default
1089 choice and suitable for most users). This will result in a "3GB/1GB"
1090 split: 3GB are mapped so that each process sees a 3GB virtual memory
1091 space and the remaining part of the 4GB virtual memory space is used
1092 by the kernel to permanently map as much physical memory as
1095 If the machine has between 1 and 4 Gigabytes physical RAM, then
1098 If more than 4 Gigabytes is used then answer "64GB" here. This
1099 selection turns Intel PAE (Physical Address Extension) mode on.
1100 PAE implements 3-level paging on IA32 processors. PAE is fully
1101 supported by Linux, PAE mode is implemented on all recent Intel
1102 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1103 then the kernel will not boot on CPUs that don't support PAE!
1105 The actual amount of total physical memory will either be
1106 auto detected or can be forced by using a kernel command line option
1107 such as "mem=256M". (Try "man bootparam" or see the documentation of
1108 your boot loader (lilo or loadlin) about how to pass options to the
1109 kernel at boot time.)
1111 If unsure, say "off".
1116 Select this if you have a 32-bit processor and between 1 and 4
1117 gigabytes of physical RAM.
1124 Select this if you have a 32-bit processor and more than 4
1125 gigabytes of physical RAM.
1130 prompt "Memory split" if EXPERT
1134 Select the desired split between kernel and user memory.
1136 If the address range available to the kernel is less than the
1137 physical memory installed, the remaining memory will be available
1138 as "high memory". Accessing high memory is a little more costly
1139 than low memory, as it needs to be mapped into the kernel first.
1140 Note that increasing the kernel address space limits the range
1141 available to user programs, making the address space there
1142 tighter. Selecting anything other than the default 3G/1G split
1143 will also likely make your kernel incompatible with binary-only
1146 If you are not absolutely sure what you are doing, leave this
1150 bool "3G/1G user/kernel split"
1151 config VMSPLIT_3G_OPT
1153 bool "3G/1G user/kernel split (for full 1G low memory)"
1155 bool "2G/2G user/kernel split"
1156 config VMSPLIT_2G_OPT
1158 bool "2G/2G user/kernel split (for full 2G low memory)"
1160 bool "1G/3G user/kernel split"
1165 default 0xB0000000 if VMSPLIT_3G_OPT
1166 default 0x80000000 if VMSPLIT_2G
1167 default 0x78000000 if VMSPLIT_2G_OPT
1168 default 0x40000000 if VMSPLIT_1G
1174 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1177 bool "PAE (Physical Address Extension) Support"
1178 depends on X86_32 && !HIGHMEM4G
1180 PAE is required for NX support, and furthermore enables
1181 larger swapspace support for non-overcommit purposes. It
1182 has the cost of more pagetable lookup overhead, and also
1183 consumes more pagetable space per process.
1185 config ARCH_PHYS_ADDR_T_64BIT
1187 depends on X86_64 || X86_PAE
1189 config ARCH_DMA_ADDR_T_64BIT
1191 depends on X86_64 || HIGHMEM64G
1193 config DIRECT_GBPAGES
1194 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1198 Allow the kernel linear mapping to use 1GB pages on CPUs that
1199 support it. This can improve the kernel's performance a tiny bit by
1200 reducing TLB pressure. If in doubt, say "Y".
1202 # Common NUMA Features
1204 bool "Numa Memory Allocation and Scheduler Support"
1206 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1207 default y if X86_BIGSMP
1209 Enable NUMA (Non Uniform Memory Access) support.
1211 The kernel will try to allocate memory used by a CPU on the
1212 local memory controller of the CPU and add some more
1213 NUMA awareness to the kernel.
1215 For 64-bit this is recommended if the system is Intel Core i7
1216 (or later), AMD Opteron, or EM64T NUMA.
1218 For 32-bit this is only needed if you boot a 32-bit
1219 kernel on a 64-bit NUMA platform.
1221 Otherwise, you should say N.
1225 prompt "Old style AMD Opteron NUMA detection"
1226 depends on X86_64 && NUMA && PCI
1228 Enable AMD NUMA node topology detection. You should say Y here if
1229 you have a multi processor AMD system. This uses an old method to
1230 read the NUMA configuration directly from the builtin Northbridge
1231 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1232 which also takes priority if both are compiled in.
1234 config X86_64_ACPI_NUMA
1236 prompt "ACPI NUMA detection"
1237 depends on X86_64 && NUMA && ACPI && PCI
1240 Enable ACPI SRAT based node topology detection.
1242 # Some NUMA nodes have memory ranges that span
1243 # other nodes. Even though a pfn is valid and
1244 # between a node's start and end pfns, it may not
1245 # reside on that node. See memmap_init_zone()
1247 config NODES_SPAN_OTHER_NODES
1249 depends on X86_64_ACPI_NUMA
1252 bool "NUMA emulation"
1255 Enable NUMA emulation. A flat machine will be split
1256 into virtual nodes when booted with "numa=fake=N", where N is the
1257 number of nodes. This is only useful for debugging.
1260 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1262 default "10" if MAXSMP
1263 default "6" if X86_64
1265 depends on NEED_MULTIPLE_NODES
1267 Specify the maximum number of NUMA Nodes available on the target
1268 system. Increases memory reserved to accommodate various tables.
1270 config ARCH_HAVE_MEMORY_PRESENT
1272 depends on X86_32 && DISCONTIGMEM
1274 config NEED_NODE_MEMMAP_SIZE
1276 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1278 config ARCH_FLATMEM_ENABLE
1280 depends on X86_32 && !NUMA
1282 config ARCH_DISCONTIGMEM_ENABLE
1284 depends on NUMA && X86_32
1286 config ARCH_DISCONTIGMEM_DEFAULT
1288 depends on NUMA && X86_32
1290 config ARCH_SPARSEMEM_ENABLE
1292 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1293 select SPARSEMEM_STATIC if X86_32
1294 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1296 config ARCH_SPARSEMEM_DEFAULT
1300 config ARCH_SELECT_MEMORY_MODEL
1302 depends on ARCH_SPARSEMEM_ENABLE
1304 config ARCH_MEMORY_PROBE
1305 bool "Enable sysfs memory/probe interface"
1306 depends on X86_64 && MEMORY_HOTPLUG
1308 This option enables a sysfs memory/probe interface for testing.
1309 See Documentation/memory-hotplug.txt for more information.
1310 If you are unsure how to answer this question, answer N.
1312 config ARCH_PROC_KCORE_TEXT
1314 depends on X86_64 && PROC_KCORE
1316 config ILLEGAL_POINTER_VALUE
1319 default 0xdead000000000000 if X86_64
1324 bool "Allocate 3rd-level pagetables from highmem"
1327 The VM uses one page table entry for each page of physical memory.
1328 For systems with a lot of RAM, this can be wasteful of precious
1329 low memory. Setting this option will put user-space page table
1330 entries in high memory.
1332 config X86_CHECK_BIOS_CORRUPTION
1333 bool "Check for low memory corruption"
1335 Periodically check for memory corruption in low memory, which
1336 is suspected to be caused by BIOS. Even when enabled in the
1337 configuration, it is disabled at runtime. Enable it by
1338 setting "memory_corruption_check=1" on the kernel command
1339 line. By default it scans the low 64k of memory every 60
1340 seconds; see the memory_corruption_check_size and
1341 memory_corruption_check_period parameters in
1342 Documentation/kernel-parameters.txt to adjust this.
1344 When enabled with the default parameters, this option has
1345 almost no overhead, as it reserves a relatively small amount
1346 of memory and scans it infrequently. It both detects corruption
1347 and prevents it from affecting the running system.
1349 It is, however, intended as a diagnostic tool; if repeatable
1350 BIOS-originated corruption always affects the same memory,
1351 you can use memmap= to prevent the kernel from using that
1354 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1355 bool "Set the default setting of memory_corruption_check"
1356 depends on X86_CHECK_BIOS_CORRUPTION
1359 Set whether the default state of memory_corruption_check is
1362 config X86_RESERVE_LOW
1363 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1367 Specify the amount of low memory to reserve for the BIOS.
1369 The first page contains BIOS data structures that the kernel
1370 must not use, so that page must always be reserved.
1372 By default we reserve the first 64K of physical RAM, as a
1373 number of BIOSes are known to corrupt that memory range
1374 during events such as suspend/resume or monitor cable
1375 insertion, so it must not be used by the kernel.
1377 You can set this to 4 if you are absolutely sure that you
1378 trust the BIOS to get all its memory reservations and usages
1379 right. If you know your BIOS have problems beyond the
1380 default 64K area, you can set this to 640 to avoid using the
1381 entire low memory range.
1383 If you have doubts about the BIOS (e.g. suspend/resume does
1384 not work or there's kernel crashes after certain hardware
1385 hotplug events) then you might want to enable
1386 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1387 typical corruption patterns.
1389 Leave this to the default value of 64 if you are unsure.
1391 config MATH_EMULATION
1393 prompt "Math emulation" if X86_32
1395 Linux can emulate a math coprocessor (used for floating point
1396 operations) if you don't have one. 486DX and Pentium processors have
1397 a math coprocessor built in, 486SX and 386 do not, unless you added
1398 a 487DX or 387, respectively. (The messages during boot time can
1399 give you some hints here ["man dmesg"].) Everyone needs either a
1400 coprocessor or this emulation.
1402 If you don't have a math coprocessor, you need to say Y here; if you
1403 say Y here even though you have a coprocessor, the coprocessor will
1404 be used nevertheless. (This behavior can be changed with the kernel
1405 command line option "no387", which comes handy if your coprocessor
1406 is broken. Try "man bootparam" or see the documentation of your boot
1407 loader (lilo or loadlin) about how to pass options to the kernel at
1408 boot time.) This means that it is a good idea to say Y here if you
1409 intend to use this kernel on different machines.
1411 More information about the internals of the Linux math coprocessor
1412 emulation can be found in <file:arch/x86/math-emu/README>.
1414 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1415 kernel, it won't hurt.
1419 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1421 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1422 the Memory Type Range Registers (MTRRs) may be used to control
1423 processor access to memory ranges. This is most useful if you have
1424 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1425 allows bus write transfers to be combined into a larger transfer
1426 before bursting over the PCI/AGP bus. This can increase performance
1427 of image write operations 2.5 times or more. Saying Y here creates a
1428 /proc/mtrr file which may be used to manipulate your processor's
1429 MTRRs. Typically the X server should use this.
1431 This code has a reasonably generic interface so that similar
1432 control registers on other processors can be easily supported
1435 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1436 Registers (ARRs) which provide a similar functionality to MTRRs. For
1437 these, the ARRs are used to emulate the MTRRs.
1438 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1439 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1440 write-combining. All of these processors are supported by this code
1441 and it makes sense to say Y here if you have one of them.
1443 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1444 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1445 can lead to all sorts of problems, so it's good to say Y here.
1447 You can safely say Y even if your machine doesn't have MTRRs, you'll
1448 just add about 9 KB to your kernel.
1450 See <file:Documentation/x86/mtrr.txt> for more information.
1452 config MTRR_SANITIZER
1454 prompt "MTRR cleanup support"
1457 Convert MTRR layout from continuous to discrete, so X drivers can
1458 add writeback entries.
1460 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1461 The largest mtrr entry size for a continuous block can be set with
1466 config MTRR_SANITIZER_ENABLE_DEFAULT
1467 int "MTRR cleanup enable value (0-1)"
1470 depends on MTRR_SANITIZER
1472 Enable mtrr cleanup default value
1474 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1475 int "MTRR cleanup spare reg num (0-7)"
1478 depends on MTRR_SANITIZER
1480 mtrr cleanup spare entries default, it can be changed via
1481 mtrr_spare_reg_nr=N on the kernel command line.
1485 prompt "x86 PAT support" if EXPERT
1488 Use PAT attributes to setup page level cache control.
1490 PATs are the modern equivalents of MTRRs and are much more
1491 flexible than MTRRs.
1493 Say N here if you see bootup problems (boot crash, boot hang,
1494 spontaneous reboots) or a non-working video driver.
1498 config ARCH_USES_PG_UNCACHED
1504 prompt "x86 architectural random number generator" if EXPERT
1506 Enable the x86 architectural RDRAND instruction
1507 (Intel Bull Mountain technology) to generate random numbers.
1508 If supported, this is a high bandwidth, cryptographically
1509 secure hardware random number generator.
1513 prompt "Supervisor Mode Access Prevention" if EXPERT
1515 Supervisor Mode Access Prevention (SMAP) is a security
1516 feature in newer Intel processors. There is a small
1517 performance cost if this enabled and turned on; there is
1518 also a small increase in the kernel size if this is enabled.
1523 bool "EFI runtime service support"
1527 This enables the kernel to use EFI runtime services that are
1528 available (such as the EFI variable services).
1530 This option is only useful on systems that have EFI firmware.
1531 In addition, you should use the latest ELILO loader available
1532 at <http://elilo.sourceforge.net> in order to take advantage
1533 of EFI runtime services. However, even with this option, the
1534 resultant kernel should continue to boot on existing non-EFI
1538 bool "EFI stub support"
1541 This kernel feature allows a bzImage to be loaded directly
1542 by EFI firmware without the use of a bootloader.
1544 See Documentation/efi-stub.txt for more information.
1547 bool "EFI mixed-mode support"
1548 depends on EFI_STUB && X86_64
1550 Enabling this feature allows a 64-bit kernel to be booted
1551 on a 32-bit firmware, provided that your CPU supports 64-bit
1554 Note that it is not possible to boot a mixed-mode enabled
1555 kernel via the EFI boot stub - a bootloader that supports
1556 the EFI handover protocol must be used.
1562 prompt "Enable seccomp to safely compute untrusted bytecode"
1564 This kernel feature is useful for number crunching applications
1565 that may need to compute untrusted bytecode during their
1566 execution. By using pipes or other transports made available to
1567 the process as file descriptors supporting the read/write
1568 syscalls, it's possible to isolate those applications in
1569 their own address space using seccomp. Once seccomp is
1570 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1571 and the task is only allowed to execute a few safe syscalls
1572 defined by each seccomp mode.
1574 If unsure, say Y. Only embedded should say N here.
1576 source kernel/Kconfig.hz
1579 bool "kexec system call"
1581 kexec is a system call that implements the ability to shutdown your
1582 current kernel, and to start another kernel. It is like a reboot
1583 but it is independent of the system firmware. And like a reboot
1584 you can start any kernel with it, not just Linux.
1586 The name comes from the similarity to the exec system call.
1588 It is an ongoing process to be certain the hardware in a machine
1589 is properly shutdown, so do not be surprised if this code does not
1590 initially work for you. As of this writing the exact hardware
1591 interface is strongly in flux, so no good recommendation can be
1595 bool "kernel crash dumps"
1596 depends on X86_64 || (X86_32 && HIGHMEM)
1598 Generate crash dump after being started by kexec.
1599 This should be normally only set in special crash dump kernels
1600 which are loaded in the main kernel with kexec-tools into
1601 a specially reserved region and then later executed after
1602 a crash by kdump/kexec. The crash dump kernel must be compiled
1603 to a memory address not used by the main kernel or BIOS using
1604 PHYSICAL_START, or it must be built as a relocatable image
1605 (CONFIG_RELOCATABLE=y).
1606 For more details see Documentation/kdump/kdump.txt
1610 depends on KEXEC && HIBERNATION
1612 Jump between original kernel and kexeced kernel and invoke
1613 code in physical address mode via KEXEC
1615 config PHYSICAL_START
1616 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1619 This gives the physical address where the kernel is loaded.
1621 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1622 bzImage will decompress itself to above physical address and
1623 run from there. Otherwise, bzImage will run from the address where
1624 it has been loaded by the boot loader and will ignore above physical
1627 In normal kdump cases one does not have to set/change this option
1628 as now bzImage can be compiled as a completely relocatable image
1629 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1630 address. This option is mainly useful for the folks who don't want
1631 to use a bzImage for capturing the crash dump and want to use a
1632 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1633 to be specifically compiled to run from a specific memory area
1634 (normally a reserved region) and this option comes handy.
1636 So if you are using bzImage for capturing the crash dump,
1637 leave the value here unchanged to 0x1000000 and set
1638 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1639 for capturing the crash dump change this value to start of
1640 the reserved region. In other words, it can be set based on
1641 the "X" value as specified in the "crashkernel=YM@XM"
1642 command line boot parameter passed to the panic-ed
1643 kernel. Please take a look at Documentation/kdump/kdump.txt
1644 for more details about crash dumps.
1646 Usage of bzImage for capturing the crash dump is recommended as
1647 one does not have to build two kernels. Same kernel can be used
1648 as production kernel and capture kernel. Above option should have
1649 gone away after relocatable bzImage support is introduced. But it
1650 is present because there are users out there who continue to use
1651 vmlinux for dump capture. This option should go away down the
1654 Don't change this unless you know what you are doing.
1657 bool "Build a relocatable kernel"
1660 This builds a kernel image that retains relocation information
1661 so it can be loaded someplace besides the default 1MB.
1662 The relocations tend to make the kernel binary about 10% larger,
1663 but are discarded at runtime.
1665 One use is for the kexec on panic case where the recovery kernel
1666 must live at a different physical address than the primary
1669 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1670 it has been loaded at and the compile time physical address
1671 (CONFIG_PHYSICAL_START) is used as the minimum location.
1673 config RANDOMIZE_BASE
1674 bool "Randomize the address of the kernel image"
1675 depends on RELOCATABLE
1678 Randomizes the physical and virtual address at which the
1679 kernel image is decompressed, as a security feature that
1680 deters exploit attempts relying on knowledge of the location
1681 of kernel internals.
1683 Entropy is generated using the RDRAND instruction if it is
1684 supported. If RDTSC is supported, it is used as well. If
1685 neither RDRAND nor RDTSC are supported, then randomness is
1686 read from the i8254 timer.
1688 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1689 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1690 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1691 minimum of 2MiB, only 10 bits of entropy is theoretically
1692 possible. At best, due to page table layouts, 64-bit can use
1693 9 bits of entropy and 32-bit uses 8 bits.
1697 config RANDOMIZE_BASE_MAX_OFFSET
1698 hex "Maximum kASLR offset allowed" if EXPERT
1699 depends on RANDOMIZE_BASE
1700 range 0x0 0x20000000 if X86_32
1701 default "0x20000000" if X86_32
1702 range 0x0 0x40000000 if X86_64
1703 default "0x40000000" if X86_64
1705 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1706 memory is used to determine the maximal offset in bytes that will
1707 be applied to the kernel when kernel Address Space Layout
1708 Randomization (kASLR) is active. This must be a multiple of
1711 On 32-bit this is limited to 512MiB by page table layouts. The
1714 On 64-bit this is limited by how the kernel fixmap page table is
1715 positioned, so this cannot be larger than 1GiB currently. Without
1716 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1717 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1718 modules area will shrink to compensate, up to the current maximum
1719 1GiB to 1GiB split. The default is 1GiB.
1721 If unsure, leave at the default value.
1723 # Relocation on x86 needs some additional build support
1724 config X86_NEED_RELOCS
1726 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1728 config PHYSICAL_ALIGN
1729 hex "Alignment value to which kernel should be aligned"
1731 range 0x2000 0x1000000 if X86_32
1732 range 0x200000 0x1000000 if X86_64
1734 This value puts the alignment restrictions on physical address
1735 where kernel is loaded and run from. Kernel is compiled for an
1736 address which meets above alignment restriction.
1738 If bootloader loads the kernel at a non-aligned address and
1739 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1740 address aligned to above value and run from there.
1742 If bootloader loads the kernel at a non-aligned address and
1743 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1744 load address and decompress itself to the address it has been
1745 compiled for and run from there. The address for which kernel is
1746 compiled already meets above alignment restrictions. Hence the
1747 end result is that kernel runs from a physical address meeting
1748 above alignment restrictions.
1750 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1751 this value must be a multiple of 0x200000.
1753 Don't change this unless you know what you are doing.
1756 bool "Support for hot-pluggable CPUs"
1759 Say Y here to allow turning CPUs off and on. CPUs can be
1760 controlled through /sys/devices/system/cpu.
1761 ( Note: power management support will enable this option
1762 automatically on SMP systems. )
1763 Say N if you want to disable CPU hotplug.
1765 config BOOTPARAM_HOTPLUG_CPU0
1766 bool "Set default setting of cpu0_hotpluggable"
1768 depends on HOTPLUG_CPU
1770 Set whether default state of cpu0_hotpluggable is on or off.
1772 Say Y here to enable CPU0 hotplug by default. If this switch
1773 is turned on, there is no need to give cpu0_hotplug kernel
1774 parameter and the CPU0 hotplug feature is enabled by default.
1776 Please note: there are two known CPU0 dependencies if you want
1777 to enable the CPU0 hotplug feature either by this switch or by
1778 cpu0_hotplug kernel parameter.
1780 First, resume from hibernate or suspend always starts from CPU0.
1781 So hibernate and suspend are prevented if CPU0 is offline.
1783 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1784 offline if any interrupt can not migrate out of CPU0. There may
1785 be other CPU0 dependencies.
1787 Please make sure the dependencies are under your control before
1788 you enable this feature.
1790 Say N if you don't want to enable CPU0 hotplug feature by default.
1791 You still can enable the CPU0 hotplug feature at boot by kernel
1792 parameter cpu0_hotplug.
1794 config DEBUG_HOTPLUG_CPU0
1796 prompt "Debug CPU0 hotplug"
1797 depends on HOTPLUG_CPU
1799 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1800 soon as possible and boots up userspace with CPU0 offlined. User
1801 can online CPU0 back after boot time.
1803 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1804 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1805 compilation or giving cpu0_hotplug kernel parameter at boot.
1811 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1812 depends on X86_32 || IA32_EMULATION
1814 Certain buggy versions of glibc will crash if they are
1815 presented with a 32-bit vDSO that is not mapped at the address
1816 indicated in its segment table.
1818 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1819 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1820 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1821 the only released version with the bug, but OpenSUSE 9
1822 contains a buggy "glibc 2.3.2".
1824 The symptom of the bug is that everything crashes on startup, saying:
1825 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1827 Saying Y here changes the default value of the vdso32 boot
1828 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1829 This works around the glibc bug but hurts performance.
1831 If unsure, say N: if you are compiling your own kernel, you
1832 are unlikely to be using a buggy version of glibc.
1835 bool "Built-in kernel command line"
1837 Allow for specifying boot arguments to the kernel at
1838 build time. On some systems (e.g. embedded ones), it is
1839 necessary or convenient to provide some or all of the
1840 kernel boot arguments with the kernel itself (that is,
1841 to not rely on the boot loader to provide them.)
1843 To compile command line arguments into the kernel,
1844 set this option to 'Y', then fill in the
1845 the boot arguments in CONFIG_CMDLINE.
1847 Systems with fully functional boot loaders (i.e. non-embedded)
1848 should leave this option set to 'N'.
1851 string "Built-in kernel command string"
1852 depends on CMDLINE_BOOL
1855 Enter arguments here that should be compiled into the kernel
1856 image and used at boot time. If the boot loader provides a
1857 command line at boot time, it is appended to this string to
1858 form the full kernel command line, when the system boots.
1860 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1861 change this behavior.
1863 In most cases, the command line (whether built-in or provided
1864 by the boot loader) should specify the device for the root
1867 config CMDLINE_OVERRIDE
1868 bool "Built-in command line overrides boot loader arguments"
1869 depends on CMDLINE_BOOL
1871 Set this option to 'Y' to have the kernel ignore the boot loader
1872 command line, and use ONLY the built-in command line.
1874 This is used to work around broken boot loaders. This should
1875 be set to 'N' under normal conditions.
1879 config ARCH_ENABLE_MEMORY_HOTPLUG
1881 depends on X86_64 || (X86_32 && HIGHMEM)
1883 config ARCH_ENABLE_MEMORY_HOTREMOVE
1885 depends on MEMORY_HOTPLUG
1887 config USE_PERCPU_NUMA_NODE_ID
1891 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1893 depends on X86_64 || X86_PAE
1895 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1897 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1899 menu "Power management and ACPI options"
1901 config ARCH_HIBERNATION_HEADER
1903 depends on X86_64 && HIBERNATION
1905 source "kernel/power/Kconfig"
1907 source "drivers/acpi/Kconfig"
1909 source "drivers/sfi/Kconfig"
1916 tristate "APM (Advanced Power Management) BIOS support"
1917 depends on X86_32 && PM_SLEEP
1919 APM is a BIOS specification for saving power using several different
1920 techniques. This is mostly useful for battery powered laptops with
1921 APM compliant BIOSes. If you say Y here, the system time will be
1922 reset after a RESUME operation, the /proc/apm device will provide
1923 battery status information, and user-space programs will receive
1924 notification of APM "events" (e.g. battery status change).
1926 If you select "Y" here, you can disable actual use of the APM
1927 BIOS by passing the "apm=off" option to the kernel at boot time.
1929 Note that the APM support is almost completely disabled for
1930 machines with more than one CPU.
1932 In order to use APM, you will need supporting software. For location
1933 and more information, read <file:Documentation/power/apm-acpi.txt>
1934 and the Battery Powered Linux mini-HOWTO, available from
1935 <http://www.tldp.org/docs.html#howto>.
1937 This driver does not spin down disk drives (see the hdparm(8)
1938 manpage ("man 8 hdparm") for that), and it doesn't turn off
1939 VESA-compliant "green" monitors.
1941 This driver does not support the TI 4000M TravelMate and the ACER
1942 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1943 desktop machines also don't have compliant BIOSes, and this driver
1944 may cause those machines to panic during the boot phase.
1946 Generally, if you don't have a battery in your machine, there isn't
1947 much point in using this driver and you should say N. If you get
1948 random kernel OOPSes or reboots that don't seem to be related to
1949 anything, try disabling/enabling this option (or disabling/enabling
1952 Some other things you should try when experiencing seemingly random,
1955 1) make sure that you have enough swap space and that it is
1957 2) pass the "no-hlt" option to the kernel
1958 3) switch on floating point emulation in the kernel and pass
1959 the "no387" option to the kernel
1960 4) pass the "floppy=nodma" option to the kernel
1961 5) pass the "mem=4M" option to the kernel (thereby disabling
1962 all but the first 4 MB of RAM)
1963 6) make sure that the CPU is not over clocked.
1964 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1965 8) disable the cache from your BIOS settings
1966 9) install a fan for the video card or exchange video RAM
1967 10) install a better fan for the CPU
1968 11) exchange RAM chips
1969 12) exchange the motherboard.
1971 To compile this driver as a module, choose M here: the
1972 module will be called apm.
1976 config APM_IGNORE_USER_SUSPEND
1977 bool "Ignore USER SUSPEND"
1979 This option will ignore USER SUSPEND requests. On machines with a
1980 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1981 series notebooks, it is necessary to say Y because of a BIOS bug.
1983 config APM_DO_ENABLE
1984 bool "Enable PM at boot time"
1986 Enable APM features at boot time. From page 36 of the APM BIOS
1987 specification: "When disabled, the APM BIOS does not automatically
1988 power manage devices, enter the Standby State, enter the Suspend
1989 State, or take power saving steps in response to CPU Idle calls."
1990 This driver will make CPU Idle calls when Linux is idle (unless this
1991 feature is turned off -- see "Do CPU IDLE calls", below). This
1992 should always save battery power, but more complicated APM features
1993 will be dependent on your BIOS implementation. You may need to turn
1994 this option off if your computer hangs at boot time when using APM
1995 support, or if it beeps continuously instead of suspending. Turn
1996 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1997 T400CDT. This is off by default since most machines do fine without
2002 bool "Make CPU Idle calls when idle"
2004 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2005 On some machines, this can activate improved power savings, such as
2006 a slowed CPU clock rate, when the machine is idle. These idle calls
2007 are made after the idle loop has run for some length of time (e.g.,
2008 333 mS). On some machines, this will cause a hang at boot time or
2009 whenever the CPU becomes idle. (On machines with more than one CPU,
2010 this option does nothing.)
2012 config APM_DISPLAY_BLANK
2013 bool "Enable console blanking using APM"
2015 Enable console blanking using the APM. Some laptops can use this to
2016 turn off the LCD backlight when the screen blanker of the Linux
2017 virtual console blanks the screen. Note that this is only used by
2018 the virtual console screen blanker, and won't turn off the backlight
2019 when using the X Window system. This also doesn't have anything to
2020 do with your VESA-compliant power-saving monitor. Further, this
2021 option doesn't work for all laptops -- it might not turn off your
2022 backlight at all, or it might print a lot of errors to the console,
2023 especially if you are using gpm.
2025 config APM_ALLOW_INTS
2026 bool "Allow interrupts during APM BIOS calls"
2028 Normally we disable external interrupts while we are making calls to
2029 the APM BIOS as a measure to lessen the effects of a badly behaving
2030 BIOS implementation. The BIOS should reenable interrupts if it
2031 needs to. Unfortunately, some BIOSes do not -- especially those in
2032 many of the newer IBM Thinkpads. If you experience hangs when you
2033 suspend, try setting this to Y. Otherwise, say N.
2037 source "drivers/cpufreq/Kconfig"
2039 source "drivers/cpuidle/Kconfig"
2041 source "drivers/idle/Kconfig"
2046 menu "Bus options (PCI etc.)"
2052 Find out whether you have a PCI motherboard. PCI is the name of a
2053 bus system, i.e. the way the CPU talks to the other stuff inside
2054 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2055 VESA. If you have PCI, say Y, otherwise N.
2058 prompt "PCI access mode"
2059 depends on X86_32 && PCI
2062 On PCI systems, the BIOS can be used to detect the PCI devices and
2063 determine their configuration. However, some old PCI motherboards
2064 have BIOS bugs and may crash if this is done. Also, some embedded
2065 PCI-based systems don't have any BIOS at all. Linux can also try to
2066 detect the PCI hardware directly without using the BIOS.
2068 With this option, you can specify how Linux should detect the
2069 PCI devices. If you choose "BIOS", the BIOS will be used,
2070 if you choose "Direct", the BIOS won't be used, and if you
2071 choose "MMConfig", then PCI Express MMCONFIG will be used.
2072 If you choose "Any", the kernel will try MMCONFIG, then the
2073 direct access method and falls back to the BIOS if that doesn't
2074 work. If unsure, go with the default, which is "Any".
2079 config PCI_GOMMCONFIG
2096 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2098 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2101 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2105 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2109 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2113 depends on PCI && XEN
2121 bool "Support mmconfig PCI config space access"
2122 depends on X86_64 && PCI && ACPI
2124 config PCI_CNB20LE_QUIRK
2125 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2128 Read the PCI windows out of the CNB20LE host bridge. This allows
2129 PCI hotplug to work on systems with the CNB20LE chipset which do
2132 There's no public spec for this chipset, and this functionality
2133 is known to be incomplete.
2135 You should say N unless you know you need this.
2137 source "drivers/pci/pcie/Kconfig"
2139 source "drivers/pci/Kconfig"
2141 # x86_64 have no ISA slots, but can have ISA-style DMA.
2143 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2146 Enables ISA-style DMA support for devices requiring such controllers.
2154 Find out whether you have ISA slots on your motherboard. ISA is the
2155 name of a bus system, i.e. the way the CPU talks to the other stuff
2156 inside your box. Other bus systems are PCI, EISA, MicroChannel
2157 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2158 newer boards don't support it. If you have ISA, say Y, otherwise N.
2164 The Extended Industry Standard Architecture (EISA) bus was
2165 developed as an open alternative to the IBM MicroChannel bus.
2167 The EISA bus provided some of the features of the IBM MicroChannel
2168 bus while maintaining backward compatibility with cards made for
2169 the older ISA bus. The EISA bus saw limited use between 1988 and
2170 1995 when it was made obsolete by the PCI bus.
2172 Say Y here if you are building a kernel for an EISA-based machine.
2176 source "drivers/eisa/Kconfig"
2179 tristate "NatSemi SCx200 support"
2181 This provides basic support for National Semiconductor's
2182 (now AMD's) Geode processors. The driver probes for the
2183 PCI-IDs of several on-chip devices, so its a good dependency
2184 for other scx200_* drivers.
2186 If compiled as a module, the driver is named scx200.
2188 config SCx200HR_TIMER
2189 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2193 This driver provides a clocksource built upon the on-chip
2194 27MHz high-resolution timer. Its also a workaround for
2195 NSC Geode SC-1100's buggy TSC, which loses time when the
2196 processor goes idle (as is done by the scheduler). The
2197 other workaround is idle=poll boot option.
2200 bool "One Laptop Per Child support"
2207 Add support for detecting the unique features of the OLPC
2211 bool "OLPC XO-1 Power Management"
2212 depends on OLPC && MFD_CS5535 && PM_SLEEP
2215 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2218 bool "OLPC XO-1 Real Time Clock"
2219 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2221 Add support for the XO-1 real time clock, which can be used as a
2222 programmable wakeup source.
2225 bool "OLPC XO-1 SCI extras"
2226 depends on OLPC && OLPC_XO1_PM
2232 Add support for SCI-based features of the OLPC XO-1 laptop:
2233 - EC-driven system wakeups
2237 - AC adapter status updates
2238 - Battery status updates
2240 config OLPC_XO15_SCI
2241 bool "OLPC XO-1.5 SCI extras"
2242 depends on OLPC && ACPI
2245 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2246 - EC-driven system wakeups
2247 - AC adapter status updates
2248 - Battery status updates
2251 bool "PCEngines ALIX System Support (LED setup)"
2254 This option enables system support for the PCEngines ALIX.
2255 At present this just sets up LEDs for GPIO control on
2256 ALIX2/3/6 boards. However, other system specific setup should
2259 Note: You must still enable the drivers for GPIO and LED support
2260 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2262 Note: You have to set alix.force=1 for boards with Award BIOS.
2265 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2268 This option enables system support for the Soekris Engineering net5501.
2271 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2275 This option enables system support for the Traverse Technologies GEOS.
2278 bool "Technologic Systems TS-5500 platform support"
2280 select CHECK_SIGNATURE
2284 This option enables system support for the Technologic Systems TS-5500.
2290 depends on CPU_SUP_AMD && PCI
2292 source "drivers/pcmcia/Kconfig"
2294 source "drivers/pci/hotplug/Kconfig"
2297 tristate "RapidIO support"
2301 If enabled this option will include drivers and the core
2302 infrastructure code to support RapidIO interconnect devices.
2304 source "drivers/rapidio/Kconfig"
2307 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2309 Firmwares often provide initial graphics framebuffers so the BIOS,
2310 bootloader or kernel can show basic video-output during boot for
2311 user-guidance and debugging. Historically, x86 used the VESA BIOS
2312 Extensions and EFI-framebuffers for this, which are mostly limited
2314 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2315 framebuffers so the new generic system-framebuffer drivers can be
2316 used on x86. If the framebuffer is not compatible with the generic
2317 modes, it is adverticed as fallback platform framebuffer so legacy
2318 drivers like efifb, vesafb and uvesafb can pick it up.
2319 If this option is not selected, all system framebuffers are always
2320 marked as fallback platform framebuffers as usual.
2322 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2323 not be able to pick up generic system framebuffers if this option
2324 is selected. You are highly encouraged to enable simplefb as
2325 replacement if you select this option. simplefb can correctly deal
2326 with generic system framebuffers. But you should still keep vesafb
2327 and others enabled as fallback if a system framebuffer is
2328 incompatible with simplefb.
2335 menu "Executable file formats / Emulations"
2337 source "fs/Kconfig.binfmt"
2339 config IA32_EMULATION
2340 bool "IA32 Emulation"
2343 select COMPAT_BINFMT_ELF
2346 Include code to run legacy 32-bit programs under a
2347 64-bit kernel. You should likely turn this on, unless you're
2348 100% sure that you don't have any 32-bit programs left.
2351 tristate "IA32 a.out support"
2352 depends on IA32_EMULATION
2354 Support old a.out binaries in the 32bit emulation.
2357 bool "x32 ABI for 64-bit mode"
2358 depends on X86_64 && IA32_EMULATION
2360 Include code to run binaries for the x32 native 32-bit ABI
2361 for 64-bit processors. An x32 process gets access to the
2362 full 64-bit register file and wide data path while leaving
2363 pointers at 32 bits for smaller memory footprint.
2365 You will need a recent binutils (2.22 or later) with
2366 elf32_x86_64 support enabled to compile a kernel with this
2371 depends on IA32_EMULATION || X86_X32
2372 select ARCH_WANT_OLD_COMPAT_IPC
2375 config COMPAT_FOR_U64_ALIGNMENT
2378 config SYSVIPC_COMPAT
2390 config HAVE_ATOMIC_IOMAP
2394 config X86_DEV_DMA_OPS
2396 depends on X86_64 || STA2X11
2398 config X86_DMA_REMAP
2407 source "net/Kconfig"
2409 source "drivers/Kconfig"
2411 source "drivers/firmware/Kconfig"
2415 source "arch/x86/Kconfig.debug"
2417 source "security/Kconfig"
2419 source "crypto/Kconfig"
2421 source "arch/x86/kvm/Kconfig"
2423 source "lib/Kconfig"