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
20 select HAVE_LIVE_PATCHING
25 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
27 select ARCH_HAS_FAST_MULTIPLIER
28 select ARCH_HAS_GCOV_PROFILE_ALL
29 select ARCH_MIGHT_HAVE_PC_PARPORT
30 select ARCH_MIGHT_HAVE_PC_SERIO
31 select HAVE_AOUT if X86_32
32 select HAVE_UNSTABLE_SCHED_CLOCK
33 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
34 select ARCH_SUPPORTS_INT128 if X86_64
37 select HAVE_PCSPKR_PLATFORM
38 select HAVE_PERF_EVENTS
39 select HAVE_IOREMAP_PROT
42 select HAVE_MEMBLOCK_NODE_MAP
43 select ARCH_DISCARD_MEMBLOCK
44 select ARCH_WANT_OPTIONAL_GPIOLIB
45 select ARCH_WANT_FRAME_POINTERS
47 select HAVE_DMA_CONTIGUOUS
48 select HAVE_KRETPROBES
49 select GENERIC_EARLY_IOREMAP
51 select HAVE_KPROBES_ON_FTRACE
52 select HAVE_FTRACE_MCOUNT_RECORD
53 select HAVE_FENTRY if X86_64
54 select HAVE_C_RECORDMCOUNT
55 select HAVE_DYNAMIC_FTRACE
56 select HAVE_DYNAMIC_FTRACE_WITH_REGS
57 select HAVE_FUNCTION_TRACER
58 select HAVE_FUNCTION_GRAPH_TRACER
59 select HAVE_FUNCTION_GRAPH_FP_TEST
60 select HAVE_SYSCALL_TRACEPOINTS
61 select SYSCTL_EXCEPTION_TRACE
64 select HAVE_ARCH_TRACEHOOK
65 select HAVE_GENERIC_DMA_COHERENT if X86_32
66 select HAVE_EFFICIENT_UNALIGNED_ACCESS
67 select USER_STACKTRACE_SUPPORT
68 select HAVE_REGS_AND_STACK_ACCESS_API
69 select HAVE_DMA_API_DEBUG
70 select HAVE_KERNEL_GZIP
71 select HAVE_KERNEL_BZIP2
72 select HAVE_KERNEL_LZMA
74 select HAVE_KERNEL_LZO
75 select HAVE_KERNEL_LZ4
76 select HAVE_HW_BREAKPOINT
77 select HAVE_MIXED_BREAKPOINTS_REGS
79 select HAVE_PERF_EVENTS_NMI
81 select HAVE_PERF_USER_STACK_DUMP
82 select HAVE_DEBUG_KMEMLEAK
84 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
85 select HAVE_CMPXCHG_LOCAL
86 select HAVE_CMPXCHG_DOUBLE
87 select HAVE_ARCH_KMEMCHECK
88 select HAVE_USER_RETURN_NOTIFIER
89 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
90 select HAVE_ARCH_JUMP_LABEL
91 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
93 select GENERIC_FIND_FIRST_BIT
94 select GENERIC_IRQ_PROBE
95 select GENERIC_PENDING_IRQ if SMP
96 select GENERIC_IRQ_SHOW
97 select GENERIC_CLOCKEVENTS_MIN_ADJUST
98 select IRQ_FORCED_THREADING
99 select HAVE_BPF_JIT if X86_64
100 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
101 select ARCH_HAS_SG_CHAIN
103 select ARCH_HAVE_NMI_SAFE_CMPXCHG
105 select DCACHE_WORD_ACCESS
106 select GENERIC_SMP_IDLE_THREAD
107 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
108 select HAVE_ARCH_SECCOMP_FILTER
109 select BUILDTIME_EXTABLE_SORT
110 select GENERIC_CMOS_UPDATE
111 select HAVE_ARCH_SOFT_DIRTY if X86_64
112 select CLOCKSOURCE_WATCHDOG
113 select GENERIC_CLOCKEVENTS
114 select ARCH_CLOCKSOURCE_DATA
115 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
116 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
117 select GENERIC_TIME_VSYSCALL
118 select GENERIC_STRNCPY_FROM_USER
119 select GENERIC_STRNLEN_USER
120 select HAVE_CONTEXT_TRACKING if X86_64
121 select HAVE_IRQ_TIME_ACCOUNTING
123 select MODULES_USE_ELF_REL if X86_32
124 select MODULES_USE_ELF_RELA if X86_64
125 select CLONE_BACKWARDS if X86_32
126 select ARCH_USE_BUILTIN_BSWAP
127 select ARCH_USE_QUEUE_RWLOCK
128 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
129 select OLD_SIGACTION if X86_32
130 select COMPAT_OLD_SIGACTION if IA32_EMULATION
132 select HAVE_DEBUG_STACKOVERFLOW
133 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
134 select HAVE_CC_STACKPROTECTOR
135 select GENERIC_CPU_AUTOPROBE
136 select HAVE_ARCH_AUDITSYSCALL
137 select ARCH_SUPPORTS_ATOMIC_RMW
138 select HAVE_ACPI_APEI if ACPI
139 select HAVE_ACPI_APEI_NMI if ACPI
140 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
141 select X86_FEATURE_NAMES if PROC_FS
143 config INSTRUCTION_DECODER
145 depends on KPROBES || PERF_EVENTS || UPROBES
147 config PERF_EVENTS_INTEL_UNCORE
149 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
153 default "elf32-i386" if X86_32
154 default "elf64-x86-64" if X86_64
156 config ARCH_DEFCONFIG
158 default "arch/x86/configs/i386_defconfig" if X86_32
159 default "arch/x86/configs/x86_64_defconfig" if X86_64
161 config LOCKDEP_SUPPORT
164 config STACKTRACE_SUPPORT
167 config HAVE_LATENCYTOP_SUPPORT
176 config NEED_DMA_MAP_STATE
178 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
180 config NEED_SG_DMA_LENGTH
183 config GENERIC_ISA_DMA
185 depends on ISA_DMA_API
190 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
192 config GENERIC_BUG_RELATIVE_POINTERS
195 config GENERIC_HWEIGHT
198 config ARCH_MAY_HAVE_PC_FDC
200 depends on ISA_DMA_API
202 config RWSEM_XCHGADD_ALGORITHM
205 config GENERIC_CALIBRATE_DELAY
208 config ARCH_HAS_CPU_RELAX
211 config ARCH_HAS_CACHE_LINE_SIZE
214 config HAVE_SETUP_PER_CPU_AREA
217 config NEED_PER_CPU_EMBED_FIRST_CHUNK
220 config NEED_PER_CPU_PAGE_FIRST_CHUNK
223 config ARCH_HIBERNATION_POSSIBLE
226 config ARCH_SUSPEND_POSSIBLE
229 config ARCH_WANT_HUGE_PMD_SHARE
232 config ARCH_WANT_GENERAL_HUGETLB
243 config ARCH_SUPPORTS_OPTIMIZED_INLINING
246 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
249 config HAVE_INTEL_TXT
251 depends on INTEL_IOMMU && ACPI
255 depends on X86_32 && SMP
259 depends on X86_64 && SMP
265 config X86_32_LAZY_GS
267 depends on X86_32 && !CC_STACKPROTECTOR
269 config ARCH_HWEIGHT_CFLAGS
271 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
272 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
274 config ARCH_SUPPORTS_UPROBES
277 config FIX_EARLYCON_MEM
280 source "init/Kconfig"
281 source "kernel/Kconfig.freezer"
283 menu "Processor type and features"
286 bool "DMA memory allocation support" if EXPERT
289 DMA memory allocation support allows devices with less than 32-bit
290 addressing to allocate within the first 16MB of address space.
291 Disable if no such devices will be used.
296 bool "Symmetric multi-processing support"
298 This enables support for systems with more than one CPU. If you have
299 a system with only one CPU, say N. If you have a system with more
302 If you say N here, the kernel will run on uni- and multiprocessor
303 machines, but will use only one CPU of a multiprocessor machine. If
304 you say Y here, the kernel will run on many, but not all,
305 uniprocessor machines. On a uniprocessor machine, the kernel
306 will run faster if you say N here.
308 Note that if you say Y here and choose architecture "586" or
309 "Pentium" under "Processor family", the kernel will not work on 486
310 architectures. Similarly, multiprocessor kernels for the "PPro"
311 architecture may not work on all Pentium based boards.
313 People using multiprocessor machines who say Y here should also say
314 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
315 Management" code will be disabled if you say Y here.
317 See also <file:Documentation/x86/i386/IO-APIC.txt>,
318 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
319 <http://www.tldp.org/docs.html#howto>.
321 If you don't know what to do here, say N.
323 config X86_FEATURE_NAMES
324 bool "Processor feature human-readable names" if EMBEDDED
327 This option compiles in a table of x86 feature bits and corresponding
328 names. This is required to support /proc/cpuinfo and a few kernel
329 messages. You can disable this to save space, at the expense of
330 making those few kernel messages show numeric feature bits instead.
335 bool "Support x2apic"
336 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
338 This enables x2apic support on CPUs that have this feature.
340 This allows 32-bit apic IDs (so it can support very large systems),
341 and accesses the local apic via MSRs not via mmio.
343 If you don't know what to do here, say N.
346 bool "Enable MPS table" if ACPI || SFI
348 depends on X86_LOCAL_APIC
350 For old smp systems that do not have proper acpi support. Newer systems
351 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
354 bool "Support for big SMP systems with more than 8 CPUs"
355 depends on X86_32 && SMP
357 This option is needed for the systems that have more than 8 CPUs
361 depends on X86_GOLDFISH
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) 32 bit x86 platforms:
374 Goldfish (Android emulator)
377 SGI 320/540 (Visual Workstation)
378 STA2X11-based (e.g. Northville)
379 Moorestown MID devices
381 If you have one of these systems, or if you want to build a
382 generic distribution kernel, say Y here - otherwise say N.
386 config X86_EXTENDED_PLATFORM
387 bool "Support for extended (non-PC) x86 platforms"
390 If you disable this option then the kernel will only support
391 standard PC platforms. (which covers the vast majority of
394 If you enable this option then you'll be able to select support
395 for the following (non-PC) 64 bit x86 platforms:
400 If you have one of these systems, or if you want to build a
401 generic distribution kernel, say Y here - otherwise say N.
403 # This is an alphabetically sorted list of 64 bit extended platforms
404 # Please maintain the alphabetic order if and when there are additions
406 bool "Numascale NumaChip"
408 depends on X86_EXTENDED_PLATFORM
411 depends on X86_X2APIC
412 depends on PCI_MMCONFIG
414 Adds support for Numascale NumaChip large-SMP systems. Needed to
415 enable more than ~168 cores.
416 If you don't have one of these, you should say N here.
420 select HYPERVISOR_GUEST
422 depends on X86_64 && PCI
423 depends on X86_EXTENDED_PLATFORM
426 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
427 supposed to run on these EM64T-based machines. Only choose this option
428 if you have one of these machines.
431 bool "SGI Ultraviolet"
433 depends on X86_EXTENDED_PLATFORM
435 depends on X86_X2APIC
437 This option is needed in order to support SGI Ultraviolet systems.
438 If you don't have one of these, you should say N here.
440 # Following is an alphabetically sorted list of 32 bit extended platforms
441 # Please maintain the alphabetic order if and when there are additions
444 bool "Goldfish (Virtual Platform)"
445 depends on X86_EXTENDED_PLATFORM
447 Enable support for the Goldfish virtual platform used primarily
448 for Android development. Unless you are building for the Android
449 Goldfish emulator say N here.
452 bool "CE4100 TV platform"
454 depends on PCI_GODIRECT
455 depends on X86_IO_APIC
457 depends on X86_EXTENDED_PLATFORM
458 select X86_REBOOTFIXUPS
460 select OF_EARLY_FLATTREE
463 Select for the Intel CE media processor (CE4100) SOC.
464 This option compiles in support for the CE4100 SOC for settop
465 boxes and media devices.
468 bool "Intel MID platform support"
470 depends on X86_EXTENDED_PLATFORM
471 depends on X86_PLATFORM_DEVICES
474 depends on X86_IO_APIC
480 select MFD_INTEL_MSIC
482 Select to build a kernel capable of supporting Intel MID (Mobile
483 Internet Device) platform systems which do not have the PCI legacy
484 interfaces. If you are building for a PC class system say N here.
486 Intel MID platforms are based on an Intel processor and chipset which
487 consume less power than most of the x86 derivatives.
489 config X86_INTEL_LPSS
490 bool "Intel Low Power Subsystem Support"
495 Select to build support for Intel Low Power Subsystem such as
496 found on Intel Lynxpoint PCH. Selecting this option enables
497 things like clock tree (common clock framework) and pincontrol
498 which are needed by the LPSS peripheral drivers.
501 tristate "Intel SoC IOSF Sideband support for SoC platforms"
504 This option enables sideband register access support for Intel SoC
505 platforms. On these platforms the IOSF sideband is used in lieu of
506 MSR's for some register accesses, mostly but not limited to thermal
507 and power. Drivers may query the availability of this device to
508 determine if they need the sideband in order to work on these
509 platforms. The sideband is available on the following SoC products.
510 This list is not meant to be exclusive.
515 You should say Y if you are running a kernel on one of these SoC's.
517 config IOSF_MBI_DEBUG
518 bool "Enable IOSF sideband access through debugfs"
519 depends on IOSF_MBI && DEBUG_FS
521 Select this option to expose the IOSF sideband access registers (MCR,
522 MDR, MCRX) through debugfs to write and read register information from
523 different units on the SoC. This is most useful for obtaining device
524 state information for debug and analysis. As this is a general access
525 mechanism, users of this option would have specific knowledge of the
526 device they want to access.
528 If you don't require the option or are in doubt, say N.
531 bool "RDC R-321x SoC"
533 depends on X86_EXTENDED_PLATFORM
535 select X86_REBOOTFIXUPS
537 This option is needed for RDC R-321x system-on-chip, also known
539 If you don't have one of these chips, you should say N here.
541 config X86_32_NON_STANDARD
542 bool "Support non-standard 32-bit SMP architectures"
543 depends on X86_32 && SMP
544 depends on X86_EXTENDED_PLATFORM
546 This option compiles in the bigsmp and STA2X11 default
547 subarchitectures. It is intended for a generic binary
548 kernel. If you select them all, kernel will probe it one by
549 one and will fallback to default.
551 # Alphabetically sorted list of Non standard 32 bit platforms
553 config X86_SUPPORTS_MEMORY_FAILURE
555 # MCE code calls memory_failure():
557 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
558 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
559 depends on X86_64 || !SPARSEMEM
560 select ARCH_SUPPORTS_MEMORY_FAILURE
563 bool "STA2X11 Companion Chip Support"
564 depends on X86_32_NON_STANDARD && PCI
565 select X86_DEV_DMA_OPS
569 select ARCH_REQUIRE_GPIOLIB
572 This adds support for boards based on the STA2X11 IO-Hub,
573 a.k.a. "ConneXt". The chip is used in place of the standard
574 PC chipset, so all "standard" peripherals are missing. If this
575 option is selected the kernel will still be able to boot on
576 standard PC machines.
579 tristate "Eurobraille/Iris poweroff module"
582 The Iris machines from EuroBraille do not have APM or ACPI support
583 to shut themselves down properly. A special I/O sequence is
584 needed to do so, which is what this module does at
587 This is only for Iris machines from EuroBraille.
591 config SCHED_OMIT_FRAME_POINTER
593 prompt "Single-depth WCHAN output"
596 Calculate simpler /proc/<PID>/wchan values. If this option
597 is disabled then wchan values will recurse back to the
598 caller function. This provides more accurate wchan values,
599 at the expense of slightly more scheduling overhead.
601 If in doubt, say "Y".
603 menuconfig HYPERVISOR_GUEST
604 bool "Linux guest support"
606 Say Y here to enable options for running Linux under various hyper-
607 visors. This option enables basic hypervisor detection and platform
610 If you say N, all options in this submenu will be skipped and
611 disabled, and Linux guest support won't be built in.
616 bool "Enable paravirtualization code"
618 This changes the kernel so it can modify itself when it is run
619 under a hypervisor, potentially improving performance significantly
620 over full virtualization. However, when run without a hypervisor
621 the kernel is theoretically slower and slightly larger.
623 config PARAVIRT_DEBUG
624 bool "paravirt-ops debugging"
625 depends on PARAVIRT && DEBUG_KERNEL
627 Enable to debug paravirt_ops internals. Specifically, BUG if
628 a paravirt_op is missing when it is called.
630 config PARAVIRT_SPINLOCKS
631 bool "Paravirtualization layer for spinlocks"
632 depends on PARAVIRT && SMP
633 select UNINLINE_SPIN_UNLOCK
635 Paravirtualized spinlocks allow a pvops backend to replace the
636 spinlock implementation with something virtualization-friendly
637 (for example, block the virtual CPU rather than spinning).
639 It has a minimal impact on native kernels and gives a nice performance
640 benefit on paravirtualized KVM / Xen kernels.
642 If you are unsure how to answer this question, answer Y.
644 source "arch/x86/xen/Kconfig"
647 bool "KVM Guest support (including kvmclock)"
649 select PARAVIRT_CLOCK
652 This option enables various optimizations for running under the KVM
653 hypervisor. It includes a paravirtualized clock, so that instead
654 of relying on a PIT (or probably other) emulation by the
655 underlying device model, the host provides the guest with
656 timing infrastructure such as time of day, and system time
659 bool "Enable debug information for KVM Guests in debugfs"
660 depends on KVM_GUEST && DEBUG_FS
663 This option enables collection of various statistics for KVM guest.
664 Statistics are displayed in debugfs filesystem. Enabling this option
665 may incur significant overhead.
667 source "arch/x86/lguest/Kconfig"
669 config PARAVIRT_TIME_ACCOUNTING
670 bool "Paravirtual steal time accounting"
674 Select this option to enable fine granularity task steal time
675 accounting. Time spent executing other tasks in parallel with
676 the current vCPU is discounted from the vCPU power. To account for
677 that, there can be a small performance impact.
679 If in doubt, say N here.
681 config PARAVIRT_CLOCK
684 endif #HYPERVISOR_GUEST
692 This option adds a kernel parameter 'memtest', which allows memtest
694 memtest=0, mean disabled; -- default
695 memtest=1, mean do 1 test pattern;
697 memtest=4, mean do 4 test patterns.
698 If you are unsure how to answer this question, answer N.
700 source "arch/x86/Kconfig.cpu"
704 prompt "HPET Timer Support" if X86_32
706 Use the IA-PC HPET (High Precision Event Timer) to manage
707 time in preference to the PIT and RTC, if a HPET is
709 HPET is the next generation timer replacing legacy 8254s.
710 The HPET provides a stable time base on SMP
711 systems, unlike the TSC, but it is more expensive to access,
712 as it is off-chip. You can find the HPET spec at
713 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
715 You can safely choose Y here. However, HPET will only be
716 activated if the platform and the BIOS support this feature.
717 Otherwise the 8254 will be used for timing services.
719 Choose N to continue using the legacy 8254 timer.
721 config HPET_EMULATE_RTC
723 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
726 def_bool y if X86_INTEL_MID
727 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
729 depends on X86_INTEL_MID && SFI
731 APB timer is the replacement for 8254, HPET on X86 MID platforms.
732 The APBT provides a stable time base on SMP
733 systems, unlike the TSC, but it is more expensive to access,
734 as it is off-chip. APB timers are always running regardless of CPU
735 C states, they are used as per CPU clockevent device when possible.
737 # Mark as expert because too many people got it wrong.
738 # The code disables itself when not needed.
741 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
742 bool "Enable DMI scanning" if EXPERT
744 Enabled scanning of DMI to identify machine quirks. Say Y
745 here unless you have verified that your setup is not
746 affected by entries in the DMI blacklist. Required by PNP
750 bool "Old AMD GART IOMMU support"
752 depends on X86_64 && PCI && AMD_NB
754 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
755 GART based hardware IOMMUs.
757 The GART supports full DMA access for devices with 32-bit access
758 limitations, on systems with more than 3 GB. This is usually needed
759 for USB, sound, many IDE/SATA chipsets and some other devices.
761 Newer systems typically have a modern AMD IOMMU, supported via
762 the CONFIG_AMD_IOMMU=y config option.
764 In normal configurations this driver is only active when needed:
765 there's more than 3 GB of memory and the system contains a
766 32-bit limited device.
771 bool "IBM Calgary IOMMU support"
773 depends on X86_64 && PCI
775 Support for hardware IOMMUs in IBM's xSeries x366 and x460
776 systems. Needed to run systems with more than 3GB of memory
777 properly with 32-bit PCI devices that do not support DAC
778 (Double Address Cycle). Calgary also supports bus level
779 isolation, where all DMAs pass through the IOMMU. This
780 prevents them from going anywhere except their intended
781 destination. This catches hard-to-find kernel bugs and
782 mis-behaving drivers and devices that do not use the DMA-API
783 properly to set up their DMA buffers. The IOMMU can be
784 turned off at boot time with the iommu=off parameter.
785 Normally the kernel will make the right choice by itself.
788 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
790 prompt "Should Calgary be enabled by default?"
791 depends on CALGARY_IOMMU
793 Should Calgary be enabled by default? if you choose 'y', Calgary
794 will be used (if it exists). If you choose 'n', Calgary will not be
795 used even if it exists. If you choose 'n' and would like to use
796 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
799 # need this always selected by IOMMU for the VIA workaround
803 Support for software bounce buffers used on x86-64 systems
804 which don't have a hardware IOMMU. Using this PCI devices
805 which can only access 32-bits of memory can be used on systems
806 with more than 3 GB of memory.
811 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
814 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
815 depends on X86_64 && SMP && DEBUG_KERNEL
816 select CPUMASK_OFFSTACK
818 Enable maximum number of CPUS and NUMA Nodes for this architecture.
822 int "Maximum number of CPUs" if SMP && !MAXSMP
823 range 2 8 if SMP && X86_32 && !X86_BIGSMP
824 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
825 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
827 default "8192" if MAXSMP
828 default "32" if SMP && X86_BIGSMP
831 This allows you to specify the maximum number of CPUs which this
832 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
833 supported value is 4096, otherwise the maximum value is 512. The
834 minimum value which makes sense is 2.
836 This is purely to save memory - each supported CPU adds
837 approximately eight kilobytes to the kernel image.
840 bool "SMT (Hyperthreading) scheduler support"
843 SMT scheduler support improves the CPU scheduler's decision making
844 when dealing with Intel Pentium 4 chips with HyperThreading at a
845 cost of slightly increased overhead in some places. If unsure say
850 prompt "Multi-core scheduler support"
853 Multi-core scheduler support improves the CPU scheduler's decision
854 making when dealing with multi-core CPU chips at a cost of slightly
855 increased overhead in some places. If unsure say N here.
857 source "kernel/Kconfig.preempt"
860 bool "Local APIC support on uniprocessors"
861 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
863 A local APIC (Advanced Programmable Interrupt Controller) is an
864 integrated interrupt controller in the CPU. If you have a single-CPU
865 system which has a processor with a local APIC, you can say Y here to
866 enable and use it. If you say Y here even though your machine doesn't
867 have a local APIC, then the kernel will still run with no slowdown at
868 all. The local APIC supports CPU-generated self-interrupts (timer,
869 performance counters), and the NMI watchdog which detects hard
873 bool "IO-APIC support on uniprocessors"
874 depends on X86_UP_APIC
876 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
877 SMP-capable replacement for PC-style interrupt controllers. Most
878 SMP systems and many recent uniprocessor systems have one.
880 If you have a single-CPU system with an IO-APIC, you can say Y here
881 to use it. If you say Y here even though your machine doesn't have
882 an IO-APIC, then the kernel will still run with no slowdown at all.
884 config X86_LOCAL_APIC
886 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
887 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
890 def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
891 depends on X86_LOCAL_APIC
894 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
895 bool "Reroute for broken boot IRQs"
896 depends on X86_IO_APIC
898 This option enables a workaround that fixes a source of
899 spurious interrupts. This is recommended when threaded
900 interrupt handling is used on systems where the generation of
901 superfluous "boot interrupts" cannot be disabled.
903 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
904 entry in the chipset's IO-APIC is masked (as, e.g. the RT
905 kernel does during interrupt handling). On chipsets where this
906 boot IRQ generation cannot be disabled, this workaround keeps
907 the original IRQ line masked so that only the equivalent "boot
908 IRQ" is delivered to the CPUs. The workaround also tells the
909 kernel to set up the IRQ handler on the boot IRQ line. In this
910 way only one interrupt is delivered to the kernel. Otherwise
911 the spurious second interrupt may cause the kernel to bring
912 down (vital) interrupt lines.
914 Only affects "broken" chipsets. Interrupt sharing may be
915 increased on these systems.
918 bool "Machine Check / overheating reporting"
921 Machine Check support allows the processor to notify the
922 kernel if it detects a problem (e.g. overheating, data corruption).
923 The action the kernel takes depends on the severity of the problem,
924 ranging from warning messages to halting the machine.
928 prompt "Intel MCE features"
929 depends on X86_MCE && X86_LOCAL_APIC
931 Additional support for intel specific MCE features such as
936 prompt "AMD MCE features"
937 depends on X86_MCE && X86_LOCAL_APIC
939 Additional support for AMD specific MCE features such as
940 the DRAM Error Threshold.
942 config X86_ANCIENT_MCE
943 bool "Support for old Pentium 5 / WinChip machine checks"
944 depends on X86_32 && X86_MCE
946 Include support for machine check handling on old Pentium 5 or WinChip
947 systems. These typically need to be enabled explicitly on the command
950 config X86_MCE_THRESHOLD
951 depends on X86_MCE_AMD || X86_MCE_INTEL
954 config X86_MCE_INJECT
956 tristate "Machine check injector support"
958 Provide support for injecting machine checks for testing purposes.
959 If you don't know what a machine check is and you don't do kernel
960 QA it is safe to say n.
962 config X86_THERMAL_VECTOR
964 depends on X86_MCE_INTEL
967 bool "Enable VM86 support" if EXPERT
971 This option is required by programs like DOSEMU to run
972 16-bit real mode legacy code on x86 processors. It also may
973 be needed by software like XFree86 to initialize some video
974 cards via BIOS. Disabling this option saves about 6K.
977 bool "Enable support for 16-bit segments" if EXPERT
980 This option is required by programs like Wine to run 16-bit
981 protected mode legacy code on x86 processors. Disabling
982 this option saves about 300 bytes on i386, or around 6K text
983 plus 16K runtime memory on x86-64,
987 depends on X86_16BIT && X86_32
991 depends on X86_16BIT && X86_64
993 config X86_VSYSCALL_EMULATION
994 bool "Enable vsyscall emulation" if EXPERT
998 This enables emulation of the legacy vsyscall page. Disabling
999 it is roughly equivalent to booting with vsyscall=none, except
1000 that it will also disable the helpful warning if a program
1001 tries to use a vsyscall. With this option set to N, offending
1002 programs will just segfault, citing addresses of the form
1005 This option is required by many programs built before 2013, and
1006 care should be used even with newer programs if set to N.
1008 Disabling this option saves about 7K of kernel size and
1009 possibly 4K of additional runtime pagetable memory.
1012 tristate "Toshiba Laptop support"
1015 This adds a driver to safely access the System Management Mode of
1016 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1017 not work on models with a Phoenix BIOS. The System Management Mode
1018 is used to set the BIOS and power saving options on Toshiba portables.
1020 For information on utilities to make use of this driver see the
1021 Toshiba Linux utilities web site at:
1022 <http://www.buzzard.org.uk/toshiba/>.
1024 Say Y if you intend to run this kernel on a Toshiba portable.
1028 tristate "Dell laptop support"
1031 This adds a driver to safely access the System Management Mode
1032 of the CPU on the Dell Inspiron 8000. The System Management Mode
1033 is used to read cpu temperature and cooling fan status and to
1034 control the fans on the I8K portables.
1036 This driver has been tested only on the Inspiron 8000 but it may
1037 also work with other Dell laptops. You can force loading on other
1038 models by passing the parameter `force=1' to the module. Use at
1041 For information on utilities to make use of this driver see the
1042 I8K Linux utilities web site at:
1043 <http://people.debian.org/~dz/i8k/>
1045 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1048 config X86_REBOOTFIXUPS
1049 bool "Enable X86 board specific fixups for reboot"
1052 This enables chipset and/or board specific fixups to be done
1053 in order to get reboot to work correctly. This is only needed on
1054 some combinations of hardware and BIOS. The symptom, for which
1055 this config is intended, is when reboot ends with a stalled/hung
1058 Currently, the only fixup is for the Geode machines using
1059 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1061 Say Y if you want to enable the fixup. Currently, it's safe to
1062 enable this option even if you don't need it.
1066 tristate "CPU microcode loading support"
1067 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1071 If you say Y here, you will be able to update the microcode on
1072 certain Intel and AMD processors. The Intel support is for the
1073 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1074 Xeon etc. The AMD support is for families 0x10 and later. You will
1075 obviously need the actual microcode binary data itself which is not
1076 shipped with the Linux kernel.
1078 This option selects the general module only, you need to select
1079 at least one vendor specific module as well.
1081 To compile this driver as a module, choose M here: the module
1082 will be called microcode.
1084 config MICROCODE_INTEL
1085 bool "Intel microcode loading support"
1086 depends on MICROCODE
1090 This options enables microcode patch loading support for Intel
1093 For the current Intel microcode data package go to
1094 <https://downloadcenter.intel.com> and search for
1095 'Linux Processor Microcode Data File'.
1097 config MICROCODE_AMD
1098 bool "AMD microcode loading support"
1099 depends on MICROCODE
1102 If you select this option, microcode patch loading support for AMD
1103 processors will be enabled.
1105 config MICROCODE_OLD_INTERFACE
1107 depends on MICROCODE
1109 config MICROCODE_INTEL_EARLY
1112 config MICROCODE_AMD_EARLY
1115 config MICROCODE_EARLY
1116 bool "Early load microcode"
1117 depends on MICROCODE=y && BLK_DEV_INITRD
1118 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1119 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1122 This option provides functionality to read additional microcode data
1123 at the beginning of initrd image. The data tells kernel to load
1124 microcode to CPU's as early as possible. No functional change if no
1125 microcode data is glued to the initrd, therefore it's safe to say Y.
1128 tristate "/dev/cpu/*/msr - Model-specific register support"
1130 This device gives privileged processes access to the x86
1131 Model-Specific Registers (MSRs). It is a character device with
1132 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1133 MSR accesses are directed to a specific CPU on multi-processor
1137 tristate "/dev/cpu/*/cpuid - CPU information support"
1139 This device gives processes access to the x86 CPUID instruction to
1140 be executed on a specific processor. It is a character device
1141 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1145 prompt "High Memory Support"
1152 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1153 However, the address space of 32-bit x86 processors is only 4
1154 Gigabytes large. That means that, if you have a large amount of
1155 physical memory, not all of it can be "permanently mapped" by the
1156 kernel. The physical memory that's not permanently mapped is called
1159 If you are compiling a kernel which will never run on a machine with
1160 more than 1 Gigabyte total physical RAM, answer "off" here (default
1161 choice and suitable for most users). This will result in a "3GB/1GB"
1162 split: 3GB are mapped so that each process sees a 3GB virtual memory
1163 space and the remaining part of the 4GB virtual memory space is used
1164 by the kernel to permanently map as much physical memory as
1167 If the machine has between 1 and 4 Gigabytes physical RAM, then
1170 If more than 4 Gigabytes is used then answer "64GB" here. This
1171 selection turns Intel PAE (Physical Address Extension) mode on.
1172 PAE implements 3-level paging on IA32 processors. PAE is fully
1173 supported by Linux, PAE mode is implemented on all recent Intel
1174 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1175 then the kernel will not boot on CPUs that don't support PAE!
1177 The actual amount of total physical memory will either be
1178 auto detected or can be forced by using a kernel command line option
1179 such as "mem=256M". (Try "man bootparam" or see the documentation of
1180 your boot loader (lilo or loadlin) about how to pass options to the
1181 kernel at boot time.)
1183 If unsure, say "off".
1188 Select this if you have a 32-bit processor and between 1 and 4
1189 gigabytes of physical RAM.
1196 Select this if you have a 32-bit processor and more than 4
1197 gigabytes of physical RAM.
1202 prompt "Memory split" if EXPERT
1206 Select the desired split between kernel and user memory.
1208 If the address range available to the kernel is less than the
1209 physical memory installed, the remaining memory will be available
1210 as "high memory". Accessing high memory is a little more costly
1211 than low memory, as it needs to be mapped into the kernel first.
1212 Note that increasing the kernel address space limits the range
1213 available to user programs, making the address space there
1214 tighter. Selecting anything other than the default 3G/1G split
1215 will also likely make your kernel incompatible with binary-only
1218 If you are not absolutely sure what you are doing, leave this
1222 bool "3G/1G user/kernel split"
1223 config VMSPLIT_3G_OPT
1225 bool "3G/1G user/kernel split (for full 1G low memory)"
1227 bool "2G/2G user/kernel split"
1228 config VMSPLIT_2G_OPT
1230 bool "2G/2G user/kernel split (for full 2G low memory)"
1232 bool "1G/3G user/kernel split"
1237 default 0xB0000000 if VMSPLIT_3G_OPT
1238 default 0x80000000 if VMSPLIT_2G
1239 default 0x78000000 if VMSPLIT_2G_OPT
1240 default 0x40000000 if VMSPLIT_1G
1246 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1249 bool "PAE (Physical Address Extension) Support"
1250 depends on X86_32 && !HIGHMEM4G
1252 PAE is required for NX support, and furthermore enables
1253 larger swapspace support for non-overcommit purposes. It
1254 has the cost of more pagetable lookup overhead, and also
1255 consumes more pagetable space per process.
1257 config ARCH_PHYS_ADDR_T_64BIT
1259 depends on X86_64 || X86_PAE
1261 config ARCH_DMA_ADDR_T_64BIT
1263 depends on X86_64 || HIGHMEM64G
1265 config DIRECT_GBPAGES
1266 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1270 Allow the kernel linear mapping to use 1GB pages on CPUs that
1271 support it. This can improve the kernel's performance a tiny bit by
1272 reducing TLB pressure. If in doubt, say "Y".
1274 # Common NUMA Features
1276 bool "Numa Memory Allocation and Scheduler Support"
1278 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1279 default y if X86_BIGSMP
1281 Enable NUMA (Non Uniform Memory Access) support.
1283 The kernel will try to allocate memory used by a CPU on the
1284 local memory controller of the CPU and add some more
1285 NUMA awareness to the kernel.
1287 For 64-bit this is recommended if the system is Intel Core i7
1288 (or later), AMD Opteron, or EM64T NUMA.
1290 For 32-bit this is only needed if you boot a 32-bit
1291 kernel on a 64-bit NUMA platform.
1293 Otherwise, you should say N.
1297 prompt "Old style AMD Opteron NUMA detection"
1298 depends on X86_64 && NUMA && PCI
1300 Enable AMD NUMA node topology detection. You should say Y here if
1301 you have a multi processor AMD system. This uses an old method to
1302 read the NUMA configuration directly from the builtin Northbridge
1303 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1304 which also takes priority if both are compiled in.
1306 config X86_64_ACPI_NUMA
1308 prompt "ACPI NUMA detection"
1309 depends on X86_64 && NUMA && ACPI && PCI
1312 Enable ACPI SRAT based node topology detection.
1314 # Some NUMA nodes have memory ranges that span
1315 # other nodes. Even though a pfn is valid and
1316 # between a node's start and end pfns, it may not
1317 # reside on that node. See memmap_init_zone()
1319 config NODES_SPAN_OTHER_NODES
1321 depends on X86_64_ACPI_NUMA
1324 bool "NUMA emulation"
1327 Enable NUMA emulation. A flat machine will be split
1328 into virtual nodes when booted with "numa=fake=N", where N is the
1329 number of nodes. This is only useful for debugging.
1332 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1334 default "10" if MAXSMP
1335 default "6" if X86_64
1337 depends on NEED_MULTIPLE_NODES
1339 Specify the maximum number of NUMA Nodes available on the target
1340 system. Increases memory reserved to accommodate various tables.
1342 config ARCH_HAVE_MEMORY_PRESENT
1344 depends on X86_32 && DISCONTIGMEM
1346 config NEED_NODE_MEMMAP_SIZE
1348 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1350 config ARCH_FLATMEM_ENABLE
1352 depends on X86_32 && !NUMA
1354 config ARCH_DISCONTIGMEM_ENABLE
1356 depends on NUMA && X86_32
1358 config ARCH_DISCONTIGMEM_DEFAULT
1360 depends on NUMA && X86_32
1362 config ARCH_SPARSEMEM_ENABLE
1364 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1365 select SPARSEMEM_STATIC if X86_32
1366 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1368 config ARCH_SPARSEMEM_DEFAULT
1372 config ARCH_SELECT_MEMORY_MODEL
1374 depends on ARCH_SPARSEMEM_ENABLE
1376 config ARCH_MEMORY_PROBE
1377 bool "Enable sysfs memory/probe interface"
1378 depends on X86_64 && MEMORY_HOTPLUG
1380 This option enables a sysfs memory/probe interface for testing.
1381 See Documentation/memory-hotplug.txt for more information.
1382 If you are unsure how to answer this question, answer N.
1384 config ARCH_PROC_KCORE_TEXT
1386 depends on X86_64 && PROC_KCORE
1388 config ILLEGAL_POINTER_VALUE
1391 default 0xdead000000000000 if X86_64
1396 bool "Allocate 3rd-level pagetables from highmem"
1399 The VM uses one page table entry for each page of physical memory.
1400 For systems with a lot of RAM, this can be wasteful of precious
1401 low memory. Setting this option will put user-space page table
1402 entries in high memory.
1404 config X86_CHECK_BIOS_CORRUPTION
1405 bool "Check for low memory corruption"
1407 Periodically check for memory corruption in low memory, which
1408 is suspected to be caused by BIOS. Even when enabled in the
1409 configuration, it is disabled at runtime. Enable it by
1410 setting "memory_corruption_check=1" on the kernel command
1411 line. By default it scans the low 64k of memory every 60
1412 seconds; see the memory_corruption_check_size and
1413 memory_corruption_check_period parameters in
1414 Documentation/kernel-parameters.txt to adjust this.
1416 When enabled with the default parameters, this option has
1417 almost no overhead, as it reserves a relatively small amount
1418 of memory and scans it infrequently. It both detects corruption
1419 and prevents it from affecting the running system.
1421 It is, however, intended as a diagnostic tool; if repeatable
1422 BIOS-originated corruption always affects the same memory,
1423 you can use memmap= to prevent the kernel from using that
1426 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1427 bool "Set the default setting of memory_corruption_check"
1428 depends on X86_CHECK_BIOS_CORRUPTION
1431 Set whether the default state of memory_corruption_check is
1434 config X86_RESERVE_LOW
1435 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1439 Specify the amount of low memory to reserve for the BIOS.
1441 The first page contains BIOS data structures that the kernel
1442 must not use, so that page must always be reserved.
1444 By default we reserve the first 64K of physical RAM, as a
1445 number of BIOSes are known to corrupt that memory range
1446 during events such as suspend/resume or monitor cable
1447 insertion, so it must not be used by the kernel.
1449 You can set this to 4 if you are absolutely sure that you
1450 trust the BIOS to get all its memory reservations and usages
1451 right. If you know your BIOS have problems beyond the
1452 default 64K area, you can set this to 640 to avoid using the
1453 entire low memory range.
1455 If you have doubts about the BIOS (e.g. suspend/resume does
1456 not work or there's kernel crashes after certain hardware
1457 hotplug events) then you might want to enable
1458 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1459 typical corruption patterns.
1461 Leave this to the default value of 64 if you are unsure.
1463 config MATH_EMULATION
1465 prompt "Math emulation" if X86_32
1467 Linux can emulate a math coprocessor (used for floating point
1468 operations) if you don't have one. 486DX and Pentium processors have
1469 a math coprocessor built in, 486SX and 386 do not, unless you added
1470 a 487DX or 387, respectively. (The messages during boot time can
1471 give you some hints here ["man dmesg"].) Everyone needs either a
1472 coprocessor or this emulation.
1474 If you don't have a math coprocessor, you need to say Y here; if you
1475 say Y here even though you have a coprocessor, the coprocessor will
1476 be used nevertheless. (This behavior can be changed with the kernel
1477 command line option "no387", which comes handy if your coprocessor
1478 is broken. Try "man bootparam" or see the documentation of your boot
1479 loader (lilo or loadlin) about how to pass options to the kernel at
1480 boot time.) This means that it is a good idea to say Y here if you
1481 intend to use this kernel on different machines.
1483 More information about the internals of the Linux math coprocessor
1484 emulation can be found in <file:arch/x86/math-emu/README>.
1486 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1487 kernel, it won't hurt.
1491 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1493 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1494 the Memory Type Range Registers (MTRRs) may be used to control
1495 processor access to memory ranges. This is most useful if you have
1496 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1497 allows bus write transfers to be combined into a larger transfer
1498 before bursting over the PCI/AGP bus. This can increase performance
1499 of image write operations 2.5 times or more. Saying Y here creates a
1500 /proc/mtrr file which may be used to manipulate your processor's
1501 MTRRs. Typically the X server should use this.
1503 This code has a reasonably generic interface so that similar
1504 control registers on other processors can be easily supported
1507 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1508 Registers (ARRs) which provide a similar functionality to MTRRs. For
1509 these, the ARRs are used to emulate the MTRRs.
1510 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1511 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1512 write-combining. All of these processors are supported by this code
1513 and it makes sense to say Y here if you have one of them.
1515 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1516 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1517 can lead to all sorts of problems, so it's good to say Y here.
1519 You can safely say Y even if your machine doesn't have MTRRs, you'll
1520 just add about 9 KB to your kernel.
1522 See <file:Documentation/x86/mtrr.txt> for more information.
1524 config MTRR_SANITIZER
1526 prompt "MTRR cleanup support"
1529 Convert MTRR layout from continuous to discrete, so X drivers can
1530 add writeback entries.
1532 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1533 The largest mtrr entry size for a continuous block can be set with
1538 config MTRR_SANITIZER_ENABLE_DEFAULT
1539 int "MTRR cleanup enable value (0-1)"
1542 depends on MTRR_SANITIZER
1544 Enable mtrr cleanup default value
1546 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1547 int "MTRR cleanup spare reg num (0-7)"
1550 depends on MTRR_SANITIZER
1552 mtrr cleanup spare entries default, it can be changed via
1553 mtrr_spare_reg_nr=N on the kernel command line.
1557 prompt "x86 PAT support" if EXPERT
1560 Use PAT attributes to setup page level cache control.
1562 PATs are the modern equivalents of MTRRs and are much more
1563 flexible than MTRRs.
1565 Say N here if you see bootup problems (boot crash, boot hang,
1566 spontaneous reboots) or a non-working video driver.
1570 config ARCH_USES_PG_UNCACHED
1576 prompt "x86 architectural random number generator" if EXPERT
1578 Enable the x86 architectural RDRAND instruction
1579 (Intel Bull Mountain technology) to generate random numbers.
1580 If supported, this is a high bandwidth, cryptographically
1581 secure hardware random number generator.
1585 prompt "Supervisor Mode Access Prevention" if EXPERT
1587 Supervisor Mode Access Prevention (SMAP) is a security
1588 feature in newer Intel processors. There is a small
1589 performance cost if this enabled and turned on; there is
1590 also a small increase in the kernel size if this is enabled.
1594 config X86_INTEL_MPX
1595 prompt "Intel MPX (Memory Protection Extensions)"
1597 depends on CPU_SUP_INTEL
1599 MPX provides hardware features that can be used in
1600 conjunction with compiler-instrumented code to check
1601 memory references. It is designed to detect buffer
1602 overflow or underflow bugs.
1604 This option enables running applications which are
1605 instrumented or otherwise use MPX. It does not use MPX
1606 itself inside the kernel or to protect the kernel
1607 against bad memory references.
1609 Enabling this option will make the kernel larger:
1610 ~8k of kernel text and 36 bytes of data on a 64-bit
1611 defconfig. It adds a long to the 'mm_struct' which
1612 will increase the kernel memory overhead of each
1613 process and adds some branches to paths used during
1614 exec() and munmap().
1616 For details, see Documentation/x86/intel_mpx.txt
1621 bool "EFI runtime service support"
1624 select EFI_RUNTIME_WRAPPERS
1626 This enables the kernel to use EFI runtime services that are
1627 available (such as the EFI variable services).
1629 This option is only useful on systems that have EFI firmware.
1630 In addition, you should use the latest ELILO loader available
1631 at <http://elilo.sourceforge.net> in order to take advantage
1632 of EFI runtime services. However, even with this option, the
1633 resultant kernel should continue to boot on existing non-EFI
1637 bool "EFI stub support"
1638 depends on EFI && !X86_USE_3DNOW
1641 This kernel feature allows a bzImage to be loaded directly
1642 by EFI firmware without the use of a bootloader.
1644 See Documentation/efi-stub.txt for more information.
1647 bool "EFI mixed-mode support"
1648 depends on EFI_STUB && X86_64
1650 Enabling this feature allows a 64-bit kernel to be booted
1651 on a 32-bit firmware, provided that your CPU supports 64-bit
1654 Note that it is not possible to boot a mixed-mode enabled
1655 kernel via the EFI boot stub - a bootloader that supports
1656 the EFI handover protocol must be used.
1662 prompt "Enable seccomp to safely compute untrusted bytecode"
1664 This kernel feature is useful for number crunching applications
1665 that may need to compute untrusted bytecode during their
1666 execution. By using pipes or other transports made available to
1667 the process as file descriptors supporting the read/write
1668 syscalls, it's possible to isolate those applications in
1669 their own address space using seccomp. Once seccomp is
1670 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1671 and the task is only allowed to execute a few safe syscalls
1672 defined by each seccomp mode.
1674 If unsure, say Y. Only embedded should say N here.
1676 source kernel/Kconfig.hz
1679 bool "kexec system call"
1681 kexec is a system call that implements the ability to shutdown your
1682 current kernel, and to start another kernel. It is like a reboot
1683 but it is independent of the system firmware. And like a reboot
1684 you can start any kernel with it, not just Linux.
1686 The name comes from the similarity to the exec system call.
1688 It is an ongoing process to be certain the hardware in a machine
1689 is properly shutdown, so do not be surprised if this code does not
1690 initially work for you. As of this writing the exact hardware
1691 interface is strongly in flux, so no good recommendation can be
1695 bool "kexec file based system call"
1700 depends on CRYPTO_SHA256=y
1702 This is new version of kexec system call. This system call is
1703 file based and takes file descriptors as system call argument
1704 for kernel and initramfs as opposed to list of segments as
1705 accepted by previous system call.
1707 config KEXEC_VERIFY_SIG
1708 bool "Verify kernel signature during kexec_file_load() syscall"
1709 depends on KEXEC_FILE
1711 This option makes kernel signature verification mandatory for
1712 kexec_file_load() syscall. If kernel is signature can not be
1713 verified, kexec_file_load() will fail.
1715 This option enforces signature verification at generic level.
1716 One needs to enable signature verification for type of kernel
1717 image being loaded to make sure it works. For example, enable
1718 bzImage signature verification option to be able to load and
1719 verify signatures of bzImage. Otherwise kernel loading will fail.
1721 config KEXEC_BZIMAGE_VERIFY_SIG
1722 bool "Enable bzImage signature verification support"
1723 depends on KEXEC_VERIFY_SIG
1724 depends on SIGNED_PE_FILE_VERIFICATION
1725 select SYSTEM_TRUSTED_KEYRING
1727 Enable bzImage signature verification support.
1730 bool "kernel crash dumps"
1731 depends on X86_64 || (X86_32 && HIGHMEM)
1733 Generate crash dump after being started by kexec.
1734 This should be normally only set in special crash dump kernels
1735 which are loaded in the main kernel with kexec-tools into
1736 a specially reserved region and then later executed after
1737 a crash by kdump/kexec. The crash dump kernel must be compiled
1738 to a memory address not used by the main kernel or BIOS using
1739 PHYSICAL_START, or it must be built as a relocatable image
1740 (CONFIG_RELOCATABLE=y).
1741 For more details see Documentation/kdump/kdump.txt
1745 depends on KEXEC && HIBERNATION
1747 Jump between original kernel and kexeced kernel and invoke
1748 code in physical address mode via KEXEC
1750 config PHYSICAL_START
1751 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1754 This gives the physical address where the kernel is loaded.
1756 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1757 bzImage will decompress itself to above physical address and
1758 run from there. Otherwise, bzImage will run from the address where
1759 it has been loaded by the boot loader and will ignore above physical
1762 In normal kdump cases one does not have to set/change this option
1763 as now bzImage can be compiled as a completely relocatable image
1764 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1765 address. This option is mainly useful for the folks who don't want
1766 to use a bzImage for capturing the crash dump and want to use a
1767 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1768 to be specifically compiled to run from a specific memory area
1769 (normally a reserved region) and this option comes handy.
1771 So if you are using bzImage for capturing the crash dump,
1772 leave the value here unchanged to 0x1000000 and set
1773 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1774 for capturing the crash dump change this value to start of
1775 the reserved region. In other words, it can be set based on
1776 the "X" value as specified in the "crashkernel=YM@XM"
1777 command line boot parameter passed to the panic-ed
1778 kernel. Please take a look at Documentation/kdump/kdump.txt
1779 for more details about crash dumps.
1781 Usage of bzImage for capturing the crash dump is recommended as
1782 one does not have to build two kernels. Same kernel can be used
1783 as production kernel and capture kernel. Above option should have
1784 gone away after relocatable bzImage support is introduced. But it
1785 is present because there are users out there who continue to use
1786 vmlinux for dump capture. This option should go away down the
1789 Don't change this unless you know what you are doing.
1792 bool "Build a relocatable kernel"
1795 This builds a kernel image that retains relocation information
1796 so it can be loaded someplace besides the default 1MB.
1797 The relocations tend to make the kernel binary about 10% larger,
1798 but are discarded at runtime.
1800 One use is for the kexec on panic case where the recovery kernel
1801 must live at a different physical address than the primary
1804 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1805 it has been loaded at and the compile time physical address
1806 (CONFIG_PHYSICAL_START) is used as the minimum location.
1808 config RANDOMIZE_BASE
1809 bool "Randomize the address of the kernel image"
1810 depends on RELOCATABLE
1813 Randomizes the physical and virtual address at which the
1814 kernel image is decompressed, as a security feature that
1815 deters exploit attempts relying on knowledge of the location
1816 of kernel internals.
1818 Entropy is generated using the RDRAND instruction if it is
1819 supported. If RDTSC is supported, it is used as well. If
1820 neither RDRAND nor RDTSC are supported, then randomness is
1821 read from the i8254 timer.
1823 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1824 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1825 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1826 minimum of 2MiB, only 10 bits of entropy is theoretically
1827 possible. At best, due to page table layouts, 64-bit can use
1828 9 bits of entropy and 32-bit uses 8 bits.
1832 config RANDOMIZE_BASE_MAX_OFFSET
1833 hex "Maximum kASLR offset allowed" if EXPERT
1834 depends on RANDOMIZE_BASE
1835 range 0x0 0x20000000 if X86_32
1836 default "0x20000000" if X86_32
1837 range 0x0 0x40000000 if X86_64
1838 default "0x40000000" if X86_64
1840 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1841 memory is used to determine the maximal offset in bytes that will
1842 be applied to the kernel when kernel Address Space Layout
1843 Randomization (kASLR) is active. This must be a multiple of
1846 On 32-bit this is limited to 512MiB by page table layouts. The
1849 On 64-bit this is limited by how the kernel fixmap page table is
1850 positioned, so this cannot be larger than 1GiB currently. Without
1851 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1852 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1853 modules area will shrink to compensate, up to the current maximum
1854 1GiB to 1GiB split. The default is 1GiB.
1856 If unsure, leave at the default value.
1858 # Relocation on x86 needs some additional build support
1859 config X86_NEED_RELOCS
1861 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1863 config PHYSICAL_ALIGN
1864 hex "Alignment value to which kernel should be aligned"
1866 range 0x2000 0x1000000 if X86_32
1867 range 0x200000 0x1000000 if X86_64
1869 This value puts the alignment restrictions on physical address
1870 where kernel is loaded and run from. Kernel is compiled for an
1871 address which meets above alignment restriction.
1873 If bootloader loads the kernel at a non-aligned address and
1874 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1875 address aligned to above value and run from there.
1877 If bootloader loads the kernel at a non-aligned address and
1878 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1879 load address and decompress itself to the address it has been
1880 compiled for and run from there. The address for which kernel is
1881 compiled already meets above alignment restrictions. Hence the
1882 end result is that kernel runs from a physical address meeting
1883 above alignment restrictions.
1885 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1886 this value must be a multiple of 0x200000.
1888 Don't change this unless you know what you are doing.
1891 bool "Support for hot-pluggable CPUs"
1894 Say Y here to allow turning CPUs off and on. CPUs can be
1895 controlled through /sys/devices/system/cpu.
1896 ( Note: power management support will enable this option
1897 automatically on SMP systems. )
1898 Say N if you want to disable CPU hotplug.
1900 config BOOTPARAM_HOTPLUG_CPU0
1901 bool "Set default setting of cpu0_hotpluggable"
1903 depends on HOTPLUG_CPU
1905 Set whether default state of cpu0_hotpluggable is on or off.
1907 Say Y here to enable CPU0 hotplug by default. If this switch
1908 is turned on, there is no need to give cpu0_hotplug kernel
1909 parameter and the CPU0 hotplug feature is enabled by default.
1911 Please note: there are two known CPU0 dependencies if you want
1912 to enable the CPU0 hotplug feature either by this switch or by
1913 cpu0_hotplug kernel parameter.
1915 First, resume from hibernate or suspend always starts from CPU0.
1916 So hibernate and suspend are prevented if CPU0 is offline.
1918 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1919 offline if any interrupt can not migrate out of CPU0. There may
1920 be other CPU0 dependencies.
1922 Please make sure the dependencies are under your control before
1923 you enable this feature.
1925 Say N if you don't want to enable CPU0 hotplug feature by default.
1926 You still can enable the CPU0 hotplug feature at boot by kernel
1927 parameter cpu0_hotplug.
1929 config DEBUG_HOTPLUG_CPU0
1931 prompt "Debug CPU0 hotplug"
1932 depends on HOTPLUG_CPU
1934 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1935 soon as possible and boots up userspace with CPU0 offlined. User
1936 can online CPU0 back after boot time.
1938 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1939 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1940 compilation or giving cpu0_hotplug kernel parameter at boot.
1946 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1947 depends on X86_32 || IA32_EMULATION
1949 Certain buggy versions of glibc will crash if they are
1950 presented with a 32-bit vDSO that is not mapped at the address
1951 indicated in its segment table.
1953 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1954 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1955 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1956 the only released version with the bug, but OpenSUSE 9
1957 contains a buggy "glibc 2.3.2".
1959 The symptom of the bug is that everything crashes on startup, saying:
1960 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1962 Saying Y here changes the default value of the vdso32 boot
1963 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1964 This works around the glibc bug but hurts performance.
1966 If unsure, say N: if you are compiling your own kernel, you
1967 are unlikely to be using a buggy version of glibc.
1970 bool "Built-in kernel command line"
1972 Allow for specifying boot arguments to the kernel at
1973 build time. On some systems (e.g. embedded ones), it is
1974 necessary or convenient to provide some or all of the
1975 kernel boot arguments with the kernel itself (that is,
1976 to not rely on the boot loader to provide them.)
1978 To compile command line arguments into the kernel,
1979 set this option to 'Y', then fill in the
1980 the boot arguments in CONFIG_CMDLINE.
1982 Systems with fully functional boot loaders (i.e. non-embedded)
1983 should leave this option set to 'N'.
1986 string "Built-in kernel command string"
1987 depends on CMDLINE_BOOL
1990 Enter arguments here that should be compiled into the kernel
1991 image and used at boot time. If the boot loader provides a
1992 command line at boot time, it is appended to this string to
1993 form the full kernel command line, when the system boots.
1995 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1996 change this behavior.
1998 In most cases, the command line (whether built-in or provided
1999 by the boot loader) should specify the device for the root
2002 config CMDLINE_OVERRIDE
2003 bool "Built-in command line overrides boot loader arguments"
2004 depends on CMDLINE_BOOL
2006 Set this option to 'Y' to have the kernel ignore the boot loader
2007 command line, and use ONLY the built-in command line.
2009 This is used to work around broken boot loaders. This should
2010 be set to 'N' under normal conditions.
2012 source "kernel/livepatch/Kconfig"
2016 config ARCH_ENABLE_MEMORY_HOTPLUG
2018 depends on X86_64 || (X86_32 && HIGHMEM)
2020 config ARCH_ENABLE_MEMORY_HOTREMOVE
2022 depends on MEMORY_HOTPLUG
2024 config USE_PERCPU_NUMA_NODE_ID
2028 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2030 depends on X86_64 || X86_PAE
2032 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2034 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2036 menu "Power management and ACPI options"
2038 config ARCH_HIBERNATION_HEADER
2040 depends on X86_64 && HIBERNATION
2042 source "kernel/power/Kconfig"
2044 source "drivers/acpi/Kconfig"
2046 source "drivers/sfi/Kconfig"
2053 tristate "APM (Advanced Power Management) BIOS support"
2054 depends on X86_32 && PM_SLEEP
2056 APM is a BIOS specification for saving power using several different
2057 techniques. This is mostly useful for battery powered laptops with
2058 APM compliant BIOSes. If you say Y here, the system time will be
2059 reset after a RESUME operation, the /proc/apm device will provide
2060 battery status information, and user-space programs will receive
2061 notification of APM "events" (e.g. battery status change).
2063 If you select "Y" here, you can disable actual use of the APM
2064 BIOS by passing the "apm=off" option to the kernel at boot time.
2066 Note that the APM support is almost completely disabled for
2067 machines with more than one CPU.
2069 In order to use APM, you will need supporting software. For location
2070 and more information, read <file:Documentation/power/apm-acpi.txt>
2071 and the Battery Powered Linux mini-HOWTO, available from
2072 <http://www.tldp.org/docs.html#howto>.
2074 This driver does not spin down disk drives (see the hdparm(8)
2075 manpage ("man 8 hdparm") for that), and it doesn't turn off
2076 VESA-compliant "green" monitors.
2078 This driver does not support the TI 4000M TravelMate and the ACER
2079 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2080 desktop machines also don't have compliant BIOSes, and this driver
2081 may cause those machines to panic during the boot phase.
2083 Generally, if you don't have a battery in your machine, there isn't
2084 much point in using this driver and you should say N. If you get
2085 random kernel OOPSes or reboots that don't seem to be related to
2086 anything, try disabling/enabling this option (or disabling/enabling
2089 Some other things you should try when experiencing seemingly random,
2092 1) make sure that you have enough swap space and that it is
2094 2) pass the "no-hlt" option to the kernel
2095 3) switch on floating point emulation in the kernel and pass
2096 the "no387" option to the kernel
2097 4) pass the "floppy=nodma" option to the kernel
2098 5) pass the "mem=4M" option to the kernel (thereby disabling
2099 all but the first 4 MB of RAM)
2100 6) make sure that the CPU is not over clocked.
2101 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2102 8) disable the cache from your BIOS settings
2103 9) install a fan for the video card or exchange video RAM
2104 10) install a better fan for the CPU
2105 11) exchange RAM chips
2106 12) exchange the motherboard.
2108 To compile this driver as a module, choose M here: the
2109 module will be called apm.
2113 config APM_IGNORE_USER_SUSPEND
2114 bool "Ignore USER SUSPEND"
2116 This option will ignore USER SUSPEND requests. On machines with a
2117 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2118 series notebooks, it is necessary to say Y because of a BIOS bug.
2120 config APM_DO_ENABLE
2121 bool "Enable PM at boot time"
2123 Enable APM features at boot time. From page 36 of the APM BIOS
2124 specification: "When disabled, the APM BIOS does not automatically
2125 power manage devices, enter the Standby State, enter the Suspend
2126 State, or take power saving steps in response to CPU Idle calls."
2127 This driver will make CPU Idle calls when Linux is idle (unless this
2128 feature is turned off -- see "Do CPU IDLE calls", below). This
2129 should always save battery power, but more complicated APM features
2130 will be dependent on your BIOS implementation. You may need to turn
2131 this option off if your computer hangs at boot time when using APM
2132 support, or if it beeps continuously instead of suspending. Turn
2133 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2134 T400CDT. This is off by default since most machines do fine without
2139 bool "Make CPU Idle calls when idle"
2141 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2142 On some machines, this can activate improved power savings, such as
2143 a slowed CPU clock rate, when the machine is idle. These idle calls
2144 are made after the idle loop has run for some length of time (e.g.,
2145 333 mS). On some machines, this will cause a hang at boot time or
2146 whenever the CPU becomes idle. (On machines with more than one CPU,
2147 this option does nothing.)
2149 config APM_DISPLAY_BLANK
2150 bool "Enable console blanking using APM"
2152 Enable console blanking using the APM. Some laptops can use this to
2153 turn off the LCD backlight when the screen blanker of the Linux
2154 virtual console blanks the screen. Note that this is only used by
2155 the virtual console screen blanker, and won't turn off the backlight
2156 when using the X Window system. This also doesn't have anything to
2157 do with your VESA-compliant power-saving monitor. Further, this
2158 option doesn't work for all laptops -- it might not turn off your
2159 backlight at all, or it might print a lot of errors to the console,
2160 especially if you are using gpm.
2162 config APM_ALLOW_INTS
2163 bool "Allow interrupts during APM BIOS calls"
2165 Normally we disable external interrupts while we are making calls to
2166 the APM BIOS as a measure to lessen the effects of a badly behaving
2167 BIOS implementation. The BIOS should reenable interrupts if it
2168 needs to. Unfortunately, some BIOSes do not -- especially those in
2169 many of the newer IBM Thinkpads. If you experience hangs when you
2170 suspend, try setting this to Y. Otherwise, say N.
2174 source "drivers/cpufreq/Kconfig"
2176 source "drivers/cpuidle/Kconfig"
2178 source "drivers/idle/Kconfig"
2183 menu "Bus options (PCI etc.)"
2189 Find out whether you have a PCI motherboard. PCI is the name of a
2190 bus system, i.e. the way the CPU talks to the other stuff inside
2191 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2192 VESA. If you have PCI, say Y, otherwise N.
2195 prompt "PCI access mode"
2196 depends on X86_32 && PCI
2199 On PCI systems, the BIOS can be used to detect the PCI devices and
2200 determine their configuration. However, some old PCI motherboards
2201 have BIOS bugs and may crash if this is done. Also, some embedded
2202 PCI-based systems don't have any BIOS at all. Linux can also try to
2203 detect the PCI hardware directly without using the BIOS.
2205 With this option, you can specify how Linux should detect the
2206 PCI devices. If you choose "BIOS", the BIOS will be used,
2207 if you choose "Direct", the BIOS won't be used, and if you
2208 choose "MMConfig", then PCI Express MMCONFIG will be used.
2209 If you choose "Any", the kernel will try MMCONFIG, then the
2210 direct access method and falls back to the BIOS if that doesn't
2211 work. If unsure, go with the default, which is "Any".
2216 config PCI_GOMMCONFIG
2233 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2235 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2238 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2242 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2246 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2250 depends on PCI && XEN
2258 bool "Support mmconfig PCI config space access"
2259 depends on X86_64 && PCI && ACPI
2261 config PCI_CNB20LE_QUIRK
2262 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2265 Read the PCI windows out of the CNB20LE host bridge. This allows
2266 PCI hotplug to work on systems with the CNB20LE chipset which do
2269 There's no public spec for this chipset, and this functionality
2270 is known to be incomplete.
2272 You should say N unless you know you need this.
2274 source "drivers/pci/pcie/Kconfig"
2276 source "drivers/pci/Kconfig"
2278 # x86_64 have no ISA slots, but can have ISA-style DMA.
2280 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2283 Enables ISA-style DMA support for devices requiring such controllers.
2291 Find out whether you have ISA slots on your motherboard. ISA is the
2292 name of a bus system, i.e. the way the CPU talks to the other stuff
2293 inside your box. Other bus systems are PCI, EISA, MicroChannel
2294 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2295 newer boards don't support it. If you have ISA, say Y, otherwise N.
2301 The Extended Industry Standard Architecture (EISA) bus was
2302 developed as an open alternative to the IBM MicroChannel bus.
2304 The EISA bus provided some of the features of the IBM MicroChannel
2305 bus while maintaining backward compatibility with cards made for
2306 the older ISA bus. The EISA bus saw limited use between 1988 and
2307 1995 when it was made obsolete by the PCI bus.
2309 Say Y here if you are building a kernel for an EISA-based machine.
2313 source "drivers/eisa/Kconfig"
2316 tristate "NatSemi SCx200 support"
2318 This provides basic support for National Semiconductor's
2319 (now AMD's) Geode processors. The driver probes for the
2320 PCI-IDs of several on-chip devices, so its a good dependency
2321 for other scx200_* drivers.
2323 If compiled as a module, the driver is named scx200.
2325 config SCx200HR_TIMER
2326 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2330 This driver provides a clocksource built upon the on-chip
2331 27MHz high-resolution timer. Its also a workaround for
2332 NSC Geode SC-1100's buggy TSC, which loses time when the
2333 processor goes idle (as is done by the scheduler). The
2334 other workaround is idle=poll boot option.
2337 bool "One Laptop Per Child support"
2344 Add support for detecting the unique features of the OLPC
2348 bool "OLPC XO-1 Power Management"
2349 depends on OLPC && MFD_CS5535 && PM_SLEEP
2352 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2355 bool "OLPC XO-1 Real Time Clock"
2356 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2358 Add support for the XO-1 real time clock, which can be used as a
2359 programmable wakeup source.
2362 bool "OLPC XO-1 SCI extras"
2363 depends on OLPC && OLPC_XO1_PM
2369 Add support for SCI-based features of the OLPC XO-1 laptop:
2370 - EC-driven system wakeups
2374 - AC adapter status updates
2375 - Battery status updates
2377 config OLPC_XO15_SCI
2378 bool "OLPC XO-1.5 SCI extras"
2379 depends on OLPC && ACPI
2382 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2383 - EC-driven system wakeups
2384 - AC adapter status updates
2385 - Battery status updates
2388 bool "PCEngines ALIX System Support (LED setup)"
2391 This option enables system support for the PCEngines ALIX.
2392 At present this just sets up LEDs for GPIO control on
2393 ALIX2/3/6 boards. However, other system specific setup should
2396 Note: You must still enable the drivers for GPIO and LED support
2397 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2399 Note: You have to set alix.force=1 for boards with Award BIOS.
2402 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2405 This option enables system support for the Soekris Engineering net5501.
2408 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2412 This option enables system support for the Traverse Technologies GEOS.
2415 bool "Technologic Systems TS-5500 platform support"
2417 select CHECK_SIGNATURE
2421 This option enables system support for the Technologic Systems TS-5500.
2427 depends on CPU_SUP_AMD && PCI
2429 source "drivers/pcmcia/Kconfig"
2431 source "drivers/pci/hotplug/Kconfig"
2434 tristate "RapidIO support"
2438 If enabled this option will include drivers and the core
2439 infrastructure code to support RapidIO interconnect devices.
2441 source "drivers/rapidio/Kconfig"
2444 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2446 Firmwares often provide initial graphics framebuffers so the BIOS,
2447 bootloader or kernel can show basic video-output during boot for
2448 user-guidance and debugging. Historically, x86 used the VESA BIOS
2449 Extensions and EFI-framebuffers for this, which are mostly limited
2451 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2452 framebuffers so the new generic system-framebuffer drivers can be
2453 used on x86. If the framebuffer is not compatible with the generic
2454 modes, it is adverticed as fallback platform framebuffer so legacy
2455 drivers like efifb, vesafb and uvesafb can pick it up.
2456 If this option is not selected, all system framebuffers are always
2457 marked as fallback platform framebuffers as usual.
2459 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2460 not be able to pick up generic system framebuffers if this option
2461 is selected. You are highly encouraged to enable simplefb as
2462 replacement if you select this option. simplefb can correctly deal
2463 with generic system framebuffers. But you should still keep vesafb
2464 and others enabled as fallback if a system framebuffer is
2465 incompatible with simplefb.
2472 menu "Executable file formats / Emulations"
2474 source "fs/Kconfig.binfmt"
2476 config IA32_EMULATION
2477 bool "IA32 Emulation"
2480 select COMPAT_BINFMT_ELF
2483 Include code to run legacy 32-bit programs under a
2484 64-bit kernel. You should likely turn this on, unless you're
2485 100% sure that you don't have any 32-bit programs left.
2488 tristate "IA32 a.out support"
2489 depends on IA32_EMULATION
2491 Support old a.out binaries in the 32bit emulation.
2494 bool "x32 ABI for 64-bit mode"
2495 depends on X86_64 && IA32_EMULATION
2497 Include code to run binaries for the x32 native 32-bit ABI
2498 for 64-bit processors. An x32 process gets access to the
2499 full 64-bit register file and wide data path while leaving
2500 pointers at 32 bits for smaller memory footprint.
2502 You will need a recent binutils (2.22 or later) with
2503 elf32_x86_64 support enabled to compile a kernel with this
2508 depends on IA32_EMULATION || X86_X32
2509 select ARCH_WANT_OLD_COMPAT_IPC
2512 config COMPAT_FOR_U64_ALIGNMENT
2515 config SYSVIPC_COMPAT
2527 config HAVE_ATOMIC_IOMAP
2531 config X86_DEV_DMA_OPS
2533 depends on X86_64 || STA2X11
2535 config X86_DMA_REMAP
2543 source "net/Kconfig"
2545 source "drivers/Kconfig"
2547 source "drivers/firmware/Kconfig"
2551 source "arch/x86/Kconfig.debug"
2553 source "security/Kconfig"
2555 source "crypto/Kconfig"
2557 source "arch/x86/kvm/Kconfig"
2559 source "lib/Kconfig"
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