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_MIGHT_HAVE_ACPI_PDC if ACPI
25 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
26 select ARCH_HAS_FAST_MULTIPLIER
27 select ARCH_HAS_GCOV_PROFILE_ALL
28 select ARCH_MIGHT_HAVE_PC_PARPORT
29 select ARCH_MIGHT_HAVE_PC_SERIO
30 select HAVE_AOUT if X86_32
31 select HAVE_UNSTABLE_SCHED_CLOCK
32 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
33 select ARCH_SUPPORTS_INT128 if X86_64
36 select HAVE_PCSPKR_PLATFORM
37 select HAVE_PERF_EVENTS
38 select HAVE_IOREMAP_PROT
41 select HAVE_MEMBLOCK_NODE_MAP
42 select ARCH_DISCARD_MEMBLOCK
43 select ARCH_WANT_OPTIONAL_GPIOLIB
44 select ARCH_WANT_FRAME_POINTERS
46 select HAVE_DMA_CONTIGUOUS
47 select HAVE_KRETPROBES
48 select GENERIC_EARLY_IOREMAP
50 select HAVE_KPROBES_ON_FTRACE
51 select HAVE_FTRACE_MCOUNT_RECORD
52 select HAVE_FENTRY if X86_64
53 select HAVE_C_RECORDMCOUNT
54 select HAVE_DYNAMIC_FTRACE
55 select HAVE_DYNAMIC_FTRACE_WITH_REGS
56 select HAVE_FUNCTION_TRACER
57 select HAVE_FUNCTION_GRAPH_TRACER
58 select HAVE_FUNCTION_GRAPH_FP_TEST
59 select HAVE_SYSCALL_TRACEPOINTS
60 select SYSCTL_EXCEPTION_TRACE
63 select HAVE_ARCH_TRACEHOOK
64 select HAVE_GENERIC_DMA_COHERENT if X86_32
65 select HAVE_EFFICIENT_UNALIGNED_ACCESS
66 select USER_STACKTRACE_SUPPORT
67 select HAVE_REGS_AND_STACK_ACCESS_API
68 select HAVE_DMA_API_DEBUG
69 select HAVE_KERNEL_GZIP
70 select HAVE_KERNEL_BZIP2
71 select HAVE_KERNEL_LZMA
73 select HAVE_KERNEL_LZO
74 select HAVE_KERNEL_LZ4
75 select HAVE_HW_BREAKPOINT
76 select HAVE_MIXED_BREAKPOINTS_REGS
78 select HAVE_PERF_EVENTS_NMI
80 select HAVE_PERF_USER_STACK_DUMP
81 select HAVE_DEBUG_KMEMLEAK
83 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
84 select HAVE_CMPXCHG_LOCAL
85 select HAVE_CMPXCHG_DOUBLE
86 select HAVE_ARCH_KMEMCHECK
87 select HAVE_USER_RETURN_NOTIFIER
88 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
89 select HAVE_ARCH_JUMP_LABEL
90 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
92 select GENERIC_FIND_FIRST_BIT
93 select GENERIC_IRQ_PROBE
94 select GENERIC_PENDING_IRQ if SMP
95 select GENERIC_IRQ_SHOW
96 select GENERIC_CLOCKEVENTS_MIN_ADJUST
97 select IRQ_FORCED_THREADING
98 select HAVE_BPF_JIT if X86_64
99 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
100 select ARCH_HAS_SG_CHAIN
102 select ARCH_HAVE_NMI_SAFE_CMPXCHG
104 select DCACHE_WORD_ACCESS
105 select GENERIC_SMP_IDLE_THREAD
106 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
107 select HAVE_ARCH_SECCOMP_FILTER
108 select BUILDTIME_EXTABLE_SORT
109 select GENERIC_CMOS_UPDATE
110 select HAVE_ARCH_SOFT_DIRTY if X86_64
111 select CLOCKSOURCE_WATCHDOG
112 select GENERIC_CLOCKEVENTS
113 select ARCH_CLOCKSOURCE_DATA
114 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
115 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
116 select GENERIC_TIME_VSYSCALL
117 select GENERIC_STRNCPY_FROM_USER
118 select GENERIC_STRNLEN_USER
119 select HAVE_CONTEXT_TRACKING if X86_64
120 select HAVE_IRQ_TIME_ACCOUNTING
122 select MODULES_USE_ELF_REL if X86_32
123 select MODULES_USE_ELF_RELA if X86_64
124 select CLONE_BACKWARDS if X86_32
125 select ARCH_USE_BUILTIN_BSWAP
126 select ARCH_USE_QUEUE_RWLOCK
127 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
128 select OLD_SIGACTION if X86_32
129 select COMPAT_OLD_SIGACTION if IA32_EMULATION
131 select HAVE_DEBUG_STACKOVERFLOW
132 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
133 select HAVE_CC_STACKPROTECTOR
134 select GENERIC_CPU_AUTOPROBE
135 select HAVE_ARCH_AUDITSYSCALL
136 select ARCH_SUPPORTS_ATOMIC_RMW
137 select HAVE_ACPI_APEI if ACPI
138 select HAVE_ACPI_APEI_NMI if ACPI
139 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
140 select X86_FEATURE_NAMES if PROC_FS
142 config INSTRUCTION_DECODER
144 depends on KPROBES || PERF_EVENTS || UPROBES
146 config PERF_EVENTS_INTEL_UNCORE
148 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
152 default "elf32-i386" if X86_32
153 default "elf64-x86-64" if X86_64
155 config ARCH_DEFCONFIG
157 default "arch/x86/configs/i386_defconfig" if X86_32
158 default "arch/x86/configs/x86_64_defconfig" if X86_64
160 config LOCKDEP_SUPPORT
163 config STACKTRACE_SUPPORT
166 config HAVE_LATENCYTOP_SUPPORT
175 config NEED_DMA_MAP_STATE
177 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
179 config NEED_SG_DMA_LENGTH
182 config GENERIC_ISA_DMA
184 depends on ISA_DMA_API
189 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
191 config GENERIC_BUG_RELATIVE_POINTERS
194 config GENERIC_HWEIGHT
197 config ARCH_MAY_HAVE_PC_FDC
199 depends on ISA_DMA_API
201 config RWSEM_XCHGADD_ALGORITHM
204 config GENERIC_CALIBRATE_DELAY
207 config ARCH_HAS_CPU_RELAX
210 config ARCH_HAS_CACHE_LINE_SIZE
213 config HAVE_SETUP_PER_CPU_AREA
216 config NEED_PER_CPU_EMBED_FIRST_CHUNK
219 config NEED_PER_CPU_PAGE_FIRST_CHUNK
222 config ARCH_HIBERNATION_POSSIBLE
225 config ARCH_SUSPEND_POSSIBLE
228 config ARCH_WANT_HUGE_PMD_SHARE
231 config ARCH_WANT_GENERAL_HUGETLB
242 config ARCH_SUPPORTS_OPTIMIZED_INLINING
245 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
248 config HAVE_INTEL_TXT
250 depends on INTEL_IOMMU && ACPI
254 depends on X86_32 && SMP
258 depends on X86_64 && SMP
264 config X86_32_LAZY_GS
266 depends on X86_32 && !CC_STACKPROTECTOR
268 config ARCH_HWEIGHT_CFLAGS
270 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
271 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
273 config ARCH_SUPPORTS_UPROBES
276 config FIX_EARLYCON_MEM
279 source "init/Kconfig"
280 source "kernel/Kconfig.freezer"
282 menu "Processor type and features"
285 bool "DMA memory allocation support" if EXPERT
288 DMA memory allocation support allows devices with less than 32-bit
289 addressing to allocate within the first 16MB of address space.
290 Disable if no such devices will be used.
295 bool "Symmetric multi-processing support"
297 This enables support for systems with more than one CPU. If you have
298 a system with only one CPU, say N. If you have a system with more
301 If you say N here, the kernel will run on uni- and multiprocessor
302 machines, but will use only one CPU of a multiprocessor machine. If
303 you say Y here, the kernel will run on many, but not all,
304 uniprocessor machines. On a uniprocessor machine, the kernel
305 will run faster if you say N here.
307 Note that if you say Y here and choose architecture "586" or
308 "Pentium" under "Processor family", the kernel will not work on 486
309 architectures. Similarly, multiprocessor kernels for the "PPro"
310 architecture may not work on all Pentium based boards.
312 People using multiprocessor machines who say Y here should also say
313 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
314 Management" code will be disabled if you say Y here.
316 See also <file:Documentation/x86/i386/IO-APIC.txt>,
317 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
318 <http://www.tldp.org/docs.html#howto>.
320 If you don't know what to do here, say N.
322 config X86_FEATURE_NAMES
323 bool "Processor feature human-readable names" if EMBEDDED
326 This option compiles in a table of x86 feature bits and corresponding
327 names. This is required to support /proc/cpuinfo and a few kernel
328 messages. You can disable this to save space, at the expense of
329 making those few kernel messages show numeric feature bits instead.
334 bool "Support x2apic"
335 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
337 This enables x2apic support on CPUs that have this feature.
339 This allows 32-bit apic IDs (so it can support very large systems),
340 and accesses the local apic via MSRs not via mmio.
342 If you don't know what to do here, say N.
345 bool "Enable MPS table" if ACPI || SFI
347 depends on X86_LOCAL_APIC
349 For old smp systems that do not have proper acpi support. Newer systems
350 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
353 bool "Support for big SMP systems with more than 8 CPUs"
354 depends on X86_32 && SMP
356 This option is needed for the systems that have more than 8 CPUs
360 depends on X86_GOLDFISH
363 config X86_EXTENDED_PLATFORM
364 bool "Support for extended (non-PC) x86 platforms"
367 If you disable this option then the kernel will only support
368 standard PC platforms. (which covers the vast majority of
371 If you enable this option then you'll be able to select support
372 for the following (non-PC) 32 bit x86 platforms:
373 Goldfish (Android emulator)
376 SGI 320/540 (Visual Workstation)
377 STA2X11-based (e.g. Northville)
378 Moorestown MID devices
380 If you have one of these systems, or if you want to build a
381 generic distribution kernel, say Y here - otherwise say N.
385 config X86_EXTENDED_PLATFORM
386 bool "Support for extended (non-PC) x86 platforms"
389 If you disable this option then the kernel will only support
390 standard PC platforms. (which covers the vast majority of
393 If you enable this option then you'll be able to select support
394 for the following (non-PC) 64 bit x86 platforms:
399 If you have one of these systems, or if you want to build a
400 generic distribution kernel, say Y here - otherwise say N.
402 # This is an alphabetically sorted list of 64 bit extended platforms
403 # Please maintain the alphabetic order if and when there are additions
405 bool "Numascale NumaChip"
407 depends on X86_EXTENDED_PLATFORM
410 depends on X86_X2APIC
411 depends on PCI_MMCONFIG
413 Adds support for Numascale NumaChip large-SMP systems. Needed to
414 enable more than ~168 cores.
415 If you don't have one of these, you should say N here.
419 select HYPERVISOR_GUEST
421 depends on X86_64 && PCI
422 depends on X86_EXTENDED_PLATFORM
425 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
426 supposed to run on these EM64T-based machines. Only choose this option
427 if you have one of these machines.
430 bool "SGI Ultraviolet"
432 depends on X86_EXTENDED_PLATFORM
434 depends on X86_X2APIC
436 This option is needed in order to support SGI Ultraviolet systems.
437 If you don't have one of these, you should say N here.
439 # Following is an alphabetically sorted list of 32 bit extended platforms
440 # Please maintain the alphabetic order if and when there are additions
443 bool "Goldfish (Virtual Platform)"
444 depends on X86_EXTENDED_PLATFORM
446 Enable support for the Goldfish virtual platform used primarily
447 for Android development. Unless you are building for the Android
448 Goldfish emulator say N here.
451 bool "CE4100 TV platform"
453 depends on PCI_GODIRECT
454 depends on X86_IO_APIC
456 depends on X86_EXTENDED_PLATFORM
457 select X86_REBOOTFIXUPS
459 select OF_EARLY_FLATTREE
462 Select for the Intel CE media processor (CE4100) SOC.
463 This option compiles in support for the CE4100 SOC for settop
464 boxes and media devices.
467 bool "Intel MID platform support"
469 depends on X86_EXTENDED_PLATFORM
470 depends on X86_PLATFORM_DEVICES
473 depends on X86_IO_APIC
479 select MFD_INTEL_MSIC
481 Select to build a kernel capable of supporting Intel MID (Mobile
482 Internet Device) platform systems which do not have the PCI legacy
483 interfaces. If you are building for a PC class system say N here.
485 Intel MID platforms are based on an Intel processor and chipset which
486 consume less power than most of the x86 derivatives.
488 config X86_INTEL_LPSS
489 bool "Intel Low Power Subsystem Support"
494 Select to build support for Intel Low Power Subsystem such as
495 found on Intel Lynxpoint PCH. Selecting this option enables
496 things like clock tree (common clock framework) and pincontrol
497 which are needed by the LPSS peripheral drivers.
500 tristate "Intel SoC IOSF Sideband support for SoC platforms"
503 This option enables sideband register access support for Intel SoC
504 platforms. On these platforms the IOSF sideband is used in lieu of
505 MSR's for some register accesses, mostly but not limited to thermal
506 and power. Drivers may query the availability of this device to
507 determine if they need the sideband in order to work on these
508 platforms. The sideband is available on the following SoC products.
509 This list is not meant to be exclusive.
514 You should say Y if you are running a kernel on one of these SoC's.
516 config IOSF_MBI_DEBUG
517 bool "Enable IOSF sideband access through debugfs"
518 depends on IOSF_MBI && DEBUG_FS
520 Select this option to expose the IOSF sideband access registers (MCR,
521 MDR, MCRX) through debugfs to write and read register information from
522 different units on the SoC. This is most useful for obtaining device
523 state information for debug and analysis. As this is a general access
524 mechanism, users of this option would have specific knowledge of the
525 device they want to access.
527 If you don't require the option or are in doubt, say N.
530 bool "RDC R-321x SoC"
532 depends on X86_EXTENDED_PLATFORM
534 select X86_REBOOTFIXUPS
536 This option is needed for RDC R-321x system-on-chip, also known
538 If you don't have one of these chips, you should say N here.
540 config X86_32_NON_STANDARD
541 bool "Support non-standard 32-bit SMP architectures"
542 depends on X86_32 && SMP
543 depends on X86_EXTENDED_PLATFORM
545 This option compiles in the bigsmp and STA2X11 default
546 subarchitectures. It is intended for a generic binary
547 kernel. If you select them all, kernel will probe it one by
548 one and will fallback to default.
550 # Alphabetically sorted list of Non standard 32 bit platforms
552 config X86_SUPPORTS_MEMORY_FAILURE
554 # MCE code calls memory_failure():
556 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
557 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
558 depends on X86_64 || !SPARSEMEM
559 select ARCH_SUPPORTS_MEMORY_FAILURE
562 bool "STA2X11 Companion Chip Support"
563 depends on X86_32_NON_STANDARD && PCI
564 select X86_DEV_DMA_OPS
568 select ARCH_REQUIRE_GPIOLIB
571 This adds support for boards based on the STA2X11 IO-Hub,
572 a.k.a. "ConneXt". The chip is used in place of the standard
573 PC chipset, so all "standard" peripherals are missing. If this
574 option is selected the kernel will still be able to boot on
575 standard PC machines.
578 tristate "Eurobraille/Iris poweroff module"
581 The Iris machines from EuroBraille do not have APM or ACPI support
582 to shut themselves down properly. A special I/O sequence is
583 needed to do so, which is what this module does at
586 This is only for Iris machines from EuroBraille.
590 config SCHED_OMIT_FRAME_POINTER
592 prompt "Single-depth WCHAN output"
595 Calculate simpler /proc/<PID>/wchan values. If this option
596 is disabled then wchan values will recurse back to the
597 caller function. This provides more accurate wchan values,
598 at the expense of slightly more scheduling overhead.
600 If in doubt, say "Y".
602 menuconfig HYPERVISOR_GUEST
603 bool "Linux guest support"
605 Say Y here to enable options for running Linux under various hyper-
606 visors. This option enables basic hypervisor detection and platform
609 If you say N, all options in this submenu will be skipped and
610 disabled, and Linux guest support won't be built in.
615 bool "Enable paravirtualization code"
617 This changes the kernel so it can modify itself when it is run
618 under a hypervisor, potentially improving performance significantly
619 over full virtualization. However, when run without a hypervisor
620 the kernel is theoretically slower and slightly larger.
622 config PARAVIRT_DEBUG
623 bool "paravirt-ops debugging"
624 depends on PARAVIRT && DEBUG_KERNEL
626 Enable to debug paravirt_ops internals. Specifically, BUG if
627 a paravirt_op is missing when it is called.
629 config PARAVIRT_SPINLOCKS
630 bool "Paravirtualization layer for spinlocks"
631 depends on PARAVIRT && SMP
632 select UNINLINE_SPIN_UNLOCK
634 Paravirtualized spinlocks allow a pvops backend to replace the
635 spinlock implementation with something virtualization-friendly
636 (for example, block the virtual CPU rather than spinning).
638 It has a minimal impact on native kernels and gives a nice performance
639 benefit on paravirtualized KVM / Xen kernels.
641 If you are unsure how to answer this question, answer Y.
643 source "arch/x86/xen/Kconfig"
646 bool "KVM Guest support (including kvmclock)"
648 select PARAVIRT_CLOCK
651 This option enables various optimizations for running under the KVM
652 hypervisor. It includes a paravirtualized clock, so that instead
653 of relying on a PIT (or probably other) emulation by the
654 underlying device model, the host provides the guest with
655 timing infrastructure such as time of day, and system time
658 bool "Enable debug information for KVM Guests in debugfs"
659 depends on KVM_GUEST && DEBUG_FS
662 This option enables collection of various statistics for KVM guest.
663 Statistics are displayed in debugfs filesystem. Enabling this option
664 may incur significant overhead.
666 source "arch/x86/lguest/Kconfig"
668 config PARAVIRT_TIME_ACCOUNTING
669 bool "Paravirtual steal time accounting"
673 Select this option to enable fine granularity task steal time
674 accounting. Time spent executing other tasks in parallel with
675 the current vCPU is discounted from the vCPU power. To account for
676 that, there can be a small performance impact.
678 If in doubt, say N here.
680 config PARAVIRT_CLOCK
683 endif #HYPERVISOR_GUEST
691 This option adds a kernel parameter 'memtest', which allows memtest
693 memtest=0, mean disabled; -- default
694 memtest=1, mean do 1 test pattern;
696 memtest=4, mean do 4 test patterns.
697 If you are unsure how to answer this question, answer N.
699 source "arch/x86/Kconfig.cpu"
703 prompt "HPET Timer Support" if X86_32
705 Use the IA-PC HPET (High Precision Event Timer) to manage
706 time in preference to the PIT and RTC, if a HPET is
708 HPET is the next generation timer replacing legacy 8254s.
709 The HPET provides a stable time base on SMP
710 systems, unlike the TSC, but it is more expensive to access,
711 as it is off-chip. You can find the HPET spec at
712 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
714 You can safely choose Y here. However, HPET will only be
715 activated if the platform and the BIOS support this feature.
716 Otherwise the 8254 will be used for timing services.
718 Choose N to continue using the legacy 8254 timer.
720 config HPET_EMULATE_RTC
722 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
725 def_bool y if X86_INTEL_MID
726 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
728 depends on X86_INTEL_MID && SFI
730 APB timer is the replacement for 8254, HPET on X86 MID platforms.
731 The APBT provides a stable time base on SMP
732 systems, unlike the TSC, but it is more expensive to access,
733 as it is off-chip. APB timers are always running regardless of CPU
734 C states, they are used as per CPU clockevent device when possible.
736 # Mark as expert because too many people got it wrong.
737 # The code disables itself when not needed.
740 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
741 bool "Enable DMI scanning" if EXPERT
743 Enabled scanning of DMI to identify machine quirks. Say Y
744 here unless you have verified that your setup is not
745 affected by entries in the DMI blacklist. Required by PNP
749 bool "Old AMD GART IOMMU support"
751 depends on X86_64 && PCI && AMD_NB
753 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
754 GART based hardware IOMMUs.
756 The GART supports full DMA access for devices with 32-bit access
757 limitations, on systems with more than 3 GB. This is usually needed
758 for USB, sound, many IDE/SATA chipsets and some other devices.
760 Newer systems typically have a modern AMD IOMMU, supported via
761 the CONFIG_AMD_IOMMU=y config option.
763 In normal configurations this driver is only active when needed:
764 there's more than 3 GB of memory and the system contains a
765 32-bit limited device.
770 bool "IBM Calgary IOMMU support"
772 depends on X86_64 && PCI
774 Support for hardware IOMMUs in IBM's xSeries x366 and x460
775 systems. Needed to run systems with more than 3GB of memory
776 properly with 32-bit PCI devices that do not support DAC
777 (Double Address Cycle). Calgary also supports bus level
778 isolation, where all DMAs pass through the IOMMU. This
779 prevents them from going anywhere except their intended
780 destination. This catches hard-to-find kernel bugs and
781 mis-behaving drivers and devices that do not use the DMA-API
782 properly to set up their DMA buffers. The IOMMU can be
783 turned off at boot time with the iommu=off parameter.
784 Normally the kernel will make the right choice by itself.
787 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
789 prompt "Should Calgary be enabled by default?"
790 depends on CALGARY_IOMMU
792 Should Calgary be enabled by default? if you choose 'y', Calgary
793 will be used (if it exists). If you choose 'n', Calgary will not be
794 used even if it exists. If you choose 'n' and would like to use
795 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
798 # need this always selected by IOMMU for the VIA workaround
802 Support for software bounce buffers used on x86-64 systems
803 which don't have a hardware IOMMU. Using this PCI devices
804 which can only access 32-bits of memory can be used on systems
805 with more than 3 GB of memory.
810 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
813 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
814 depends on X86_64 && SMP && DEBUG_KERNEL
815 select CPUMASK_OFFSTACK
817 Enable maximum number of CPUS and NUMA Nodes for this architecture.
821 int "Maximum number of CPUs" if SMP && !MAXSMP
822 range 2 8 if SMP && X86_32 && !X86_BIGSMP
823 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
824 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
826 default "8192" if MAXSMP
827 default "32" if SMP && X86_BIGSMP
830 This allows you to specify the maximum number of CPUs which this
831 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
832 supported value is 4096, otherwise the maximum value is 512. The
833 minimum value which makes sense is 2.
835 This is purely to save memory - each supported CPU adds
836 approximately eight kilobytes to the kernel image.
839 bool "SMT (Hyperthreading) scheduler support"
842 SMT scheduler support improves the CPU scheduler's decision making
843 when dealing with Intel Pentium 4 chips with HyperThreading at a
844 cost of slightly increased overhead in some places. If unsure say
849 prompt "Multi-core scheduler support"
852 Multi-core scheduler support improves the CPU scheduler's decision
853 making when dealing with multi-core CPU chips at a cost of slightly
854 increased overhead in some places. If unsure say N here.
856 source "kernel/Kconfig.preempt"
859 bool "Local APIC support on uniprocessors"
860 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
862 A local APIC (Advanced Programmable Interrupt Controller) is an
863 integrated interrupt controller in the CPU. If you have a single-CPU
864 system which has a processor with a local APIC, you can say Y here to
865 enable and use it. If you say Y here even though your machine doesn't
866 have a local APIC, then the kernel will still run with no slowdown at
867 all. The local APIC supports CPU-generated self-interrupts (timer,
868 performance counters), and the NMI watchdog which detects hard
872 bool "IO-APIC support on uniprocessors"
873 depends on X86_UP_APIC
875 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
876 SMP-capable replacement for PC-style interrupt controllers. Most
877 SMP systems and many recent uniprocessor systems have one.
879 If you have a single-CPU system with an IO-APIC, you can say Y here
880 to use it. If you say Y here even though your machine doesn't have
881 an IO-APIC, then the kernel will still run with no slowdown at all.
883 config X86_LOCAL_APIC
885 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
886 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
889 def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
890 depends on X86_LOCAL_APIC
893 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
894 bool "Reroute for broken boot IRQs"
895 depends on X86_IO_APIC
897 This option enables a workaround that fixes a source of
898 spurious interrupts. This is recommended when threaded
899 interrupt handling is used on systems where the generation of
900 superfluous "boot interrupts" cannot be disabled.
902 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
903 entry in the chipset's IO-APIC is masked (as, e.g. the RT
904 kernel does during interrupt handling). On chipsets where this
905 boot IRQ generation cannot be disabled, this workaround keeps
906 the original IRQ line masked so that only the equivalent "boot
907 IRQ" is delivered to the CPUs. The workaround also tells the
908 kernel to set up the IRQ handler on the boot IRQ line. In this
909 way only one interrupt is delivered to the kernel. Otherwise
910 the spurious second interrupt may cause the kernel to bring
911 down (vital) interrupt lines.
913 Only affects "broken" chipsets. Interrupt sharing may be
914 increased on these systems.
917 bool "Machine Check / overheating reporting"
920 Machine Check support allows the processor to notify the
921 kernel if it detects a problem (e.g. overheating, data corruption).
922 The action the kernel takes depends on the severity of the problem,
923 ranging from warning messages to halting the machine.
927 prompt "Intel MCE features"
928 depends on X86_MCE && X86_LOCAL_APIC
930 Additional support for intel specific MCE features such as
935 prompt "AMD MCE features"
936 depends on X86_MCE && X86_LOCAL_APIC
938 Additional support for AMD specific MCE features such as
939 the DRAM Error Threshold.
941 config X86_ANCIENT_MCE
942 bool "Support for old Pentium 5 / WinChip machine checks"
943 depends on X86_32 && X86_MCE
945 Include support for machine check handling on old Pentium 5 or WinChip
946 systems. These typically need to be enabled explicitly on the command
949 config X86_MCE_THRESHOLD
950 depends on X86_MCE_AMD || X86_MCE_INTEL
953 config X86_MCE_INJECT
955 tristate "Machine check injector support"
957 Provide support for injecting machine checks for testing purposes.
958 If you don't know what a machine check is and you don't do kernel
959 QA it is safe to say n.
961 config X86_THERMAL_VECTOR
963 depends on X86_MCE_INTEL
966 bool "Enable VM86 support" if EXPERT
970 This option is required by programs like DOSEMU to run
971 16-bit real mode legacy code on x86 processors. It also may
972 be needed by software like XFree86 to initialize some video
973 cards via BIOS. Disabling this option saves about 6K.
976 bool "Enable support for 16-bit segments" if EXPERT
979 This option is required by programs like Wine to run 16-bit
980 protected mode legacy code on x86 processors. Disabling
981 this option saves about 300 bytes on i386, or around 6K text
982 plus 16K runtime memory on x86-64,
986 depends on X86_16BIT && X86_32
990 depends on X86_16BIT && X86_64
992 config X86_VSYSCALL_EMULATION
993 bool "Enable vsyscall emulation" if EXPERT
997 This enables emulation of the legacy vsyscall page. Disabling
998 it is roughly equivalent to booting with vsyscall=none, except
999 that it will also disable the helpful warning if a program
1000 tries to use a vsyscall. With this option set to N, offending
1001 programs will just segfault, citing addresses of the form
1004 This option is required by many programs built before 2013, and
1005 care should be used even with newer programs if set to N.
1007 Disabling this option saves about 7K of kernel size and
1008 possibly 4K of additional runtime pagetable memory.
1011 tristate "Toshiba Laptop support"
1014 This adds a driver to safely access the System Management Mode of
1015 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1016 not work on models with a Phoenix BIOS. The System Management Mode
1017 is used to set the BIOS and power saving options on Toshiba portables.
1019 For information on utilities to make use of this driver see the
1020 Toshiba Linux utilities web site at:
1021 <http://www.buzzard.org.uk/toshiba/>.
1023 Say Y if you intend to run this kernel on a Toshiba portable.
1027 tristate "Dell laptop support"
1030 This adds a driver to safely access the System Management Mode
1031 of the CPU on the Dell Inspiron 8000. The System Management Mode
1032 is used to read cpu temperature and cooling fan status and to
1033 control the fans on the I8K portables.
1035 This driver has been tested only on the Inspiron 8000 but it may
1036 also work with other Dell laptops. You can force loading on other
1037 models by passing the parameter `force=1' to the module. Use at
1040 For information on utilities to make use of this driver see the
1041 I8K Linux utilities web site at:
1042 <http://people.debian.org/~dz/i8k/>
1044 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1047 config X86_REBOOTFIXUPS
1048 bool "Enable X86 board specific fixups for reboot"
1051 This enables chipset and/or board specific fixups to be done
1052 in order to get reboot to work correctly. This is only needed on
1053 some combinations of hardware and BIOS. The symptom, for which
1054 this config is intended, is when reboot ends with a stalled/hung
1057 Currently, the only fixup is for the Geode machines using
1058 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1060 Say Y if you want to enable the fixup. Currently, it's safe to
1061 enable this option even if you don't need it.
1065 tristate "CPU microcode loading support"
1066 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1070 If you say Y here, you will be able to update the microcode on
1071 certain Intel and AMD processors. The Intel support is for the
1072 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1073 Xeon etc. The AMD support is for families 0x10 and later. You will
1074 obviously need the actual microcode binary data itself which is not
1075 shipped with the Linux kernel.
1077 This option selects the general module only, you need to select
1078 at least one vendor specific module as well.
1080 To compile this driver as a module, choose M here: the module
1081 will be called microcode.
1083 config MICROCODE_INTEL
1084 bool "Intel microcode loading support"
1085 depends on MICROCODE
1089 This options enables microcode patch loading support for Intel
1092 For the current Intel microcode data package go to
1093 <https://downloadcenter.intel.com> and search for
1094 'Linux Processor Microcode Data File'.
1096 config MICROCODE_AMD
1097 bool "AMD microcode loading support"
1098 depends on MICROCODE
1101 If you select this option, microcode patch loading support for AMD
1102 processors will be enabled.
1104 config MICROCODE_OLD_INTERFACE
1106 depends on MICROCODE
1108 config MICROCODE_INTEL_EARLY
1111 config MICROCODE_AMD_EARLY
1114 config MICROCODE_EARLY
1115 bool "Early load microcode"
1116 depends on MICROCODE=y && BLK_DEV_INITRD
1117 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1118 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1121 This option provides functionality to read additional microcode data
1122 at the beginning of initrd image. The data tells kernel to load
1123 microcode to CPU's as early as possible. No functional change if no
1124 microcode data is glued to the initrd, therefore it's safe to say Y.
1127 tristate "/dev/cpu/*/msr - Model-specific register support"
1129 This device gives privileged processes access to the x86
1130 Model-Specific Registers (MSRs). It is a character device with
1131 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1132 MSR accesses are directed to a specific CPU on multi-processor
1136 tristate "/dev/cpu/*/cpuid - CPU information support"
1138 This device gives processes access to the x86 CPUID instruction to
1139 be executed on a specific processor. It is a character device
1140 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1144 prompt "High Memory Support"
1151 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1152 However, the address space of 32-bit x86 processors is only 4
1153 Gigabytes large. That means that, if you have a large amount of
1154 physical memory, not all of it can be "permanently mapped" by the
1155 kernel. The physical memory that's not permanently mapped is called
1158 If you are compiling a kernel which will never run on a machine with
1159 more than 1 Gigabyte total physical RAM, answer "off" here (default
1160 choice and suitable for most users). This will result in a "3GB/1GB"
1161 split: 3GB are mapped so that each process sees a 3GB virtual memory
1162 space and the remaining part of the 4GB virtual memory space is used
1163 by the kernel to permanently map as much physical memory as
1166 If the machine has between 1 and 4 Gigabytes physical RAM, then
1169 If more than 4 Gigabytes is used then answer "64GB" here. This
1170 selection turns Intel PAE (Physical Address Extension) mode on.
1171 PAE implements 3-level paging on IA32 processors. PAE is fully
1172 supported by Linux, PAE mode is implemented on all recent Intel
1173 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1174 then the kernel will not boot on CPUs that don't support PAE!
1176 The actual amount of total physical memory will either be
1177 auto detected or can be forced by using a kernel command line option
1178 such as "mem=256M". (Try "man bootparam" or see the documentation of
1179 your boot loader (lilo or loadlin) about how to pass options to the
1180 kernel at boot time.)
1182 If unsure, say "off".
1187 Select this if you have a 32-bit processor and between 1 and 4
1188 gigabytes of physical RAM.
1195 Select this if you have a 32-bit processor and more than 4
1196 gigabytes of physical RAM.
1201 prompt "Memory split" if EXPERT
1205 Select the desired split between kernel and user memory.
1207 If the address range available to the kernel is less than the
1208 physical memory installed, the remaining memory will be available
1209 as "high memory". Accessing high memory is a little more costly
1210 than low memory, as it needs to be mapped into the kernel first.
1211 Note that increasing the kernel address space limits the range
1212 available to user programs, making the address space there
1213 tighter. Selecting anything other than the default 3G/1G split
1214 will also likely make your kernel incompatible with binary-only
1217 If you are not absolutely sure what you are doing, leave this
1221 bool "3G/1G user/kernel split"
1222 config VMSPLIT_3G_OPT
1224 bool "3G/1G user/kernel split (for full 1G low memory)"
1226 bool "2G/2G user/kernel split"
1227 config VMSPLIT_2G_OPT
1229 bool "2G/2G user/kernel split (for full 2G low memory)"
1231 bool "1G/3G user/kernel split"
1236 default 0xB0000000 if VMSPLIT_3G_OPT
1237 default 0x80000000 if VMSPLIT_2G
1238 default 0x78000000 if VMSPLIT_2G_OPT
1239 default 0x40000000 if VMSPLIT_1G
1245 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1248 bool "PAE (Physical Address Extension) Support"
1249 depends on X86_32 && !HIGHMEM4G
1251 PAE is required for NX support, and furthermore enables
1252 larger swapspace support for non-overcommit purposes. It
1253 has the cost of more pagetable lookup overhead, and also
1254 consumes more pagetable space per process.
1256 config ARCH_PHYS_ADDR_T_64BIT
1258 depends on X86_64 || X86_PAE
1260 config ARCH_DMA_ADDR_T_64BIT
1262 depends on X86_64 || HIGHMEM64G
1264 config DIRECT_GBPAGES
1265 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1269 Allow the kernel linear mapping to use 1GB pages on CPUs that
1270 support it. This can improve the kernel's performance a tiny bit by
1271 reducing TLB pressure. If in doubt, say "Y".
1273 # Common NUMA Features
1275 bool "Numa Memory Allocation and Scheduler Support"
1277 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1278 default y if X86_BIGSMP
1280 Enable NUMA (Non Uniform Memory Access) support.
1282 The kernel will try to allocate memory used by a CPU on the
1283 local memory controller of the CPU and add some more
1284 NUMA awareness to the kernel.
1286 For 64-bit this is recommended if the system is Intel Core i7
1287 (or later), AMD Opteron, or EM64T NUMA.
1289 For 32-bit this is only needed if you boot a 32-bit
1290 kernel on a 64-bit NUMA platform.
1292 Otherwise, you should say N.
1296 prompt "Old style AMD Opteron NUMA detection"
1297 depends on X86_64 && NUMA && PCI
1299 Enable AMD NUMA node topology detection. You should say Y here if
1300 you have a multi processor AMD system. This uses an old method to
1301 read the NUMA configuration directly from the builtin Northbridge
1302 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1303 which also takes priority if both are compiled in.
1305 config X86_64_ACPI_NUMA
1307 prompt "ACPI NUMA detection"
1308 depends on X86_64 && NUMA && ACPI && PCI
1311 Enable ACPI SRAT based node topology detection.
1313 # Some NUMA nodes have memory ranges that span
1314 # other nodes. Even though a pfn is valid and
1315 # between a node's start and end pfns, it may not
1316 # reside on that node. See memmap_init_zone()
1318 config NODES_SPAN_OTHER_NODES
1320 depends on X86_64_ACPI_NUMA
1323 bool "NUMA emulation"
1326 Enable NUMA emulation. A flat machine will be split
1327 into virtual nodes when booted with "numa=fake=N", where N is the
1328 number of nodes. This is only useful for debugging.
1331 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1333 default "10" if MAXSMP
1334 default "6" if X86_64
1336 depends on NEED_MULTIPLE_NODES
1338 Specify the maximum number of NUMA Nodes available on the target
1339 system. Increases memory reserved to accommodate various tables.
1341 config ARCH_HAVE_MEMORY_PRESENT
1343 depends on X86_32 && DISCONTIGMEM
1345 config NEED_NODE_MEMMAP_SIZE
1347 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1349 config ARCH_FLATMEM_ENABLE
1351 depends on X86_32 && !NUMA
1353 config ARCH_DISCONTIGMEM_ENABLE
1355 depends on NUMA && X86_32
1357 config ARCH_DISCONTIGMEM_DEFAULT
1359 depends on NUMA && X86_32
1361 config ARCH_SPARSEMEM_ENABLE
1363 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1364 select SPARSEMEM_STATIC if X86_32
1365 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1367 config ARCH_SPARSEMEM_DEFAULT
1371 config ARCH_SELECT_MEMORY_MODEL
1373 depends on ARCH_SPARSEMEM_ENABLE
1375 config ARCH_MEMORY_PROBE
1376 bool "Enable sysfs memory/probe interface"
1377 depends on X86_64 && MEMORY_HOTPLUG
1379 This option enables a sysfs memory/probe interface for testing.
1380 See Documentation/memory-hotplug.txt for more information.
1381 If you are unsure how to answer this question, answer N.
1383 config ARCH_PROC_KCORE_TEXT
1385 depends on X86_64 && PROC_KCORE
1387 config ILLEGAL_POINTER_VALUE
1390 default 0xdead000000000000 if X86_64
1395 bool "Allocate 3rd-level pagetables from highmem"
1398 The VM uses one page table entry for each page of physical memory.
1399 For systems with a lot of RAM, this can be wasteful of precious
1400 low memory. Setting this option will put user-space page table
1401 entries in high memory.
1403 config X86_CHECK_BIOS_CORRUPTION
1404 bool "Check for low memory corruption"
1406 Periodically check for memory corruption in low memory, which
1407 is suspected to be caused by BIOS. Even when enabled in the
1408 configuration, it is disabled at runtime. Enable it by
1409 setting "memory_corruption_check=1" on the kernel command
1410 line. By default it scans the low 64k of memory every 60
1411 seconds; see the memory_corruption_check_size and
1412 memory_corruption_check_period parameters in
1413 Documentation/kernel-parameters.txt to adjust this.
1415 When enabled with the default parameters, this option has
1416 almost no overhead, as it reserves a relatively small amount
1417 of memory and scans it infrequently. It both detects corruption
1418 and prevents it from affecting the running system.
1420 It is, however, intended as a diagnostic tool; if repeatable
1421 BIOS-originated corruption always affects the same memory,
1422 you can use memmap= to prevent the kernel from using that
1425 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1426 bool "Set the default setting of memory_corruption_check"
1427 depends on X86_CHECK_BIOS_CORRUPTION
1430 Set whether the default state of memory_corruption_check is
1433 config X86_RESERVE_LOW
1434 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1438 Specify the amount of low memory to reserve for the BIOS.
1440 The first page contains BIOS data structures that the kernel
1441 must not use, so that page must always be reserved.
1443 By default we reserve the first 64K of physical RAM, as a
1444 number of BIOSes are known to corrupt that memory range
1445 during events such as suspend/resume or monitor cable
1446 insertion, so it must not be used by the kernel.
1448 You can set this to 4 if you are absolutely sure that you
1449 trust the BIOS to get all its memory reservations and usages
1450 right. If you know your BIOS have problems beyond the
1451 default 64K area, you can set this to 640 to avoid using the
1452 entire low memory range.
1454 If you have doubts about the BIOS (e.g. suspend/resume does
1455 not work or there's kernel crashes after certain hardware
1456 hotplug events) then you might want to enable
1457 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1458 typical corruption patterns.
1460 Leave this to the default value of 64 if you are unsure.
1462 config MATH_EMULATION
1464 prompt "Math emulation" if X86_32
1466 Linux can emulate a math coprocessor (used for floating point
1467 operations) if you don't have one. 486DX and Pentium processors have
1468 a math coprocessor built in, 486SX and 386 do not, unless you added
1469 a 487DX or 387, respectively. (The messages during boot time can
1470 give you some hints here ["man dmesg"].) Everyone needs either a
1471 coprocessor or this emulation.
1473 If you don't have a math coprocessor, you need to say Y here; if you
1474 say Y here even though you have a coprocessor, the coprocessor will
1475 be used nevertheless. (This behavior can be changed with the kernel
1476 command line option "no387", which comes handy if your coprocessor
1477 is broken. Try "man bootparam" or see the documentation of your boot
1478 loader (lilo or loadlin) about how to pass options to the kernel at
1479 boot time.) This means that it is a good idea to say Y here if you
1480 intend to use this kernel on different machines.
1482 More information about the internals of the Linux math coprocessor
1483 emulation can be found in <file:arch/x86/math-emu/README>.
1485 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1486 kernel, it won't hurt.
1490 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1492 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1493 the Memory Type Range Registers (MTRRs) may be used to control
1494 processor access to memory ranges. This is most useful if you have
1495 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1496 allows bus write transfers to be combined into a larger transfer
1497 before bursting over the PCI/AGP bus. This can increase performance
1498 of image write operations 2.5 times or more. Saying Y here creates a
1499 /proc/mtrr file which may be used to manipulate your processor's
1500 MTRRs. Typically the X server should use this.
1502 This code has a reasonably generic interface so that similar
1503 control registers on other processors can be easily supported
1506 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1507 Registers (ARRs) which provide a similar functionality to MTRRs. For
1508 these, the ARRs are used to emulate the MTRRs.
1509 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1510 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1511 write-combining. All of these processors are supported by this code
1512 and it makes sense to say Y here if you have one of them.
1514 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1515 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1516 can lead to all sorts of problems, so it's good to say Y here.
1518 You can safely say Y even if your machine doesn't have MTRRs, you'll
1519 just add about 9 KB to your kernel.
1521 See <file:Documentation/x86/mtrr.txt> for more information.
1523 config MTRR_SANITIZER
1525 prompt "MTRR cleanup support"
1528 Convert MTRR layout from continuous to discrete, so X drivers can
1529 add writeback entries.
1531 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1532 The largest mtrr entry size for a continuous block can be set with
1537 config MTRR_SANITIZER_ENABLE_DEFAULT
1538 int "MTRR cleanup enable value (0-1)"
1541 depends on MTRR_SANITIZER
1543 Enable mtrr cleanup default value
1545 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1546 int "MTRR cleanup spare reg num (0-7)"
1549 depends on MTRR_SANITIZER
1551 mtrr cleanup spare entries default, it can be changed via
1552 mtrr_spare_reg_nr=N on the kernel command line.
1556 prompt "x86 PAT support" if EXPERT
1559 Use PAT attributes to setup page level cache control.
1561 PATs are the modern equivalents of MTRRs and are much more
1562 flexible than MTRRs.
1564 Say N here if you see bootup problems (boot crash, boot hang,
1565 spontaneous reboots) or a non-working video driver.
1569 config ARCH_USES_PG_UNCACHED
1575 prompt "x86 architectural random number generator" if EXPERT
1577 Enable the x86 architectural RDRAND instruction
1578 (Intel Bull Mountain technology) to generate random numbers.
1579 If supported, this is a high bandwidth, cryptographically
1580 secure hardware random number generator.
1584 prompt "Supervisor Mode Access Prevention" if EXPERT
1586 Supervisor Mode Access Prevention (SMAP) is a security
1587 feature in newer Intel processors. There is a small
1588 performance cost if this enabled and turned on; there is
1589 also a small increase in the kernel size if this is enabled.
1593 config X86_INTEL_MPX
1594 prompt "Intel MPX (Memory Protection Extensions)"
1596 depends on CPU_SUP_INTEL
1598 MPX provides hardware features that can be used in
1599 conjunction with compiler-instrumented code to check
1600 memory references. It is designed to detect buffer
1601 overflow or underflow bugs.
1603 This option enables running applications which are
1604 instrumented or otherwise use MPX. It does not use MPX
1605 itself inside the kernel or to protect the kernel
1606 against bad memory references.
1608 Enabling this option will make the kernel larger:
1609 ~8k of kernel text and 36 bytes of data on a 64-bit
1610 defconfig. It adds a long to the 'mm_struct' which
1611 will increase the kernel memory overhead of each
1612 process and adds some branches to paths used during
1613 exec() and munmap().
1615 For details, see Documentation/x86/intel_mpx.txt
1620 bool "EFI runtime service support"
1623 select EFI_RUNTIME_WRAPPERS
1625 This enables the kernel to use EFI runtime services that are
1626 available (such as the EFI variable services).
1628 This option is only useful on systems that have EFI firmware.
1629 In addition, you should use the latest ELILO loader available
1630 at <http://elilo.sourceforge.net> in order to take advantage
1631 of EFI runtime services. However, even with this option, the
1632 resultant kernel should continue to boot on existing non-EFI
1636 bool "EFI stub support"
1637 depends on EFI && !X86_USE_3DNOW
1640 This kernel feature allows a bzImage to be loaded directly
1641 by EFI firmware without the use of a bootloader.
1643 See Documentation/efi-stub.txt for more information.
1646 bool "EFI mixed-mode support"
1647 depends on EFI_STUB && X86_64
1649 Enabling this feature allows a 64-bit kernel to be booted
1650 on a 32-bit firmware, provided that your CPU supports 64-bit
1653 Note that it is not possible to boot a mixed-mode enabled
1654 kernel via the EFI boot stub - a bootloader that supports
1655 the EFI handover protocol must be used.
1661 prompt "Enable seccomp to safely compute untrusted bytecode"
1663 This kernel feature is useful for number crunching applications
1664 that may need to compute untrusted bytecode during their
1665 execution. By using pipes or other transports made available to
1666 the process as file descriptors supporting the read/write
1667 syscalls, it's possible to isolate those applications in
1668 their own address space using seccomp. Once seccomp is
1669 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1670 and the task is only allowed to execute a few safe syscalls
1671 defined by each seccomp mode.
1673 If unsure, say Y. Only embedded should say N here.
1675 source kernel/Kconfig.hz
1678 bool "kexec system call"
1680 kexec is a system call that implements the ability to shutdown your
1681 current kernel, and to start another kernel. It is like a reboot
1682 but it is independent of the system firmware. And like a reboot
1683 you can start any kernel with it, not just Linux.
1685 The name comes from the similarity to the exec system call.
1687 It is an ongoing process to be certain the hardware in a machine
1688 is properly shutdown, so do not be surprised if this code does not
1689 initially work for you. As of this writing the exact hardware
1690 interface is strongly in flux, so no good recommendation can be
1694 bool "kexec file based system call"
1699 depends on CRYPTO_SHA256=y
1701 This is new version of kexec system call. This system call is
1702 file based and takes file descriptors as system call argument
1703 for kernel and initramfs as opposed to list of segments as
1704 accepted by previous system call.
1706 config KEXEC_VERIFY_SIG
1707 bool "Verify kernel signature during kexec_file_load() syscall"
1708 depends on KEXEC_FILE
1710 This option makes kernel signature verification mandatory for
1711 kexec_file_load() syscall. If kernel is signature can not be
1712 verified, kexec_file_load() will fail.
1714 This option enforces signature verification at generic level.
1715 One needs to enable signature verification for type of kernel
1716 image being loaded to make sure it works. For example, enable
1717 bzImage signature verification option to be able to load and
1718 verify signatures of bzImage. Otherwise kernel loading will fail.
1720 config KEXEC_BZIMAGE_VERIFY_SIG
1721 bool "Enable bzImage signature verification support"
1722 depends on KEXEC_VERIFY_SIG
1723 depends on SIGNED_PE_FILE_VERIFICATION
1724 select SYSTEM_TRUSTED_KEYRING
1726 Enable bzImage signature verification support.
1729 bool "kernel crash dumps"
1730 depends on X86_64 || (X86_32 && HIGHMEM)
1732 Generate crash dump after being started by kexec.
1733 This should be normally only set in special crash dump kernels
1734 which are loaded in the main kernel with kexec-tools into
1735 a specially reserved region and then later executed after
1736 a crash by kdump/kexec. The crash dump kernel must be compiled
1737 to a memory address not used by the main kernel or BIOS using
1738 PHYSICAL_START, or it must be built as a relocatable image
1739 (CONFIG_RELOCATABLE=y).
1740 For more details see Documentation/kdump/kdump.txt
1744 depends on KEXEC && HIBERNATION
1746 Jump between original kernel and kexeced kernel and invoke
1747 code in physical address mode via KEXEC
1749 config PHYSICAL_START
1750 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1753 This gives the physical address where the kernel is loaded.
1755 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1756 bzImage will decompress itself to above physical address and
1757 run from there. Otherwise, bzImage will run from the address where
1758 it has been loaded by the boot loader and will ignore above physical
1761 In normal kdump cases one does not have to set/change this option
1762 as now bzImage can be compiled as a completely relocatable image
1763 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1764 address. This option is mainly useful for the folks who don't want
1765 to use a bzImage for capturing the crash dump and want to use a
1766 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1767 to be specifically compiled to run from a specific memory area
1768 (normally a reserved region) and this option comes handy.
1770 So if you are using bzImage for capturing the crash dump,
1771 leave the value here unchanged to 0x1000000 and set
1772 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1773 for capturing the crash dump change this value to start of
1774 the reserved region. In other words, it can be set based on
1775 the "X" value as specified in the "crashkernel=YM@XM"
1776 command line boot parameter passed to the panic-ed
1777 kernel. Please take a look at Documentation/kdump/kdump.txt
1778 for more details about crash dumps.
1780 Usage of bzImage for capturing the crash dump is recommended as
1781 one does not have to build two kernels. Same kernel can be used
1782 as production kernel and capture kernel. Above option should have
1783 gone away after relocatable bzImage support is introduced. But it
1784 is present because there are users out there who continue to use
1785 vmlinux for dump capture. This option should go away down the
1788 Don't change this unless you know what you are doing.
1791 bool "Build a relocatable kernel"
1794 This builds a kernel image that retains relocation information
1795 so it can be loaded someplace besides the default 1MB.
1796 The relocations tend to make the kernel binary about 10% larger,
1797 but are discarded at runtime.
1799 One use is for the kexec on panic case where the recovery kernel
1800 must live at a different physical address than the primary
1803 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1804 it has been loaded at and the compile time physical address
1805 (CONFIG_PHYSICAL_START) is used as the minimum location.
1807 config RANDOMIZE_BASE
1808 bool "Randomize the address of the kernel image"
1809 depends on RELOCATABLE
1812 Randomizes the physical and virtual address at which the
1813 kernel image is decompressed, as a security feature that
1814 deters exploit attempts relying on knowledge of the location
1815 of kernel internals.
1817 Entropy is generated using the RDRAND instruction if it is
1818 supported. If RDTSC is supported, it is used as well. If
1819 neither RDRAND nor RDTSC are supported, then randomness is
1820 read from the i8254 timer.
1822 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1823 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1824 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1825 minimum of 2MiB, only 10 bits of entropy is theoretically
1826 possible. At best, due to page table layouts, 64-bit can use
1827 9 bits of entropy and 32-bit uses 8 bits.
1831 config RANDOMIZE_BASE_MAX_OFFSET
1832 hex "Maximum kASLR offset allowed" if EXPERT
1833 depends on RANDOMIZE_BASE
1834 range 0x0 0x20000000 if X86_32
1835 default "0x20000000" if X86_32
1836 range 0x0 0x40000000 if X86_64
1837 default "0x40000000" if X86_64
1839 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1840 memory is used to determine the maximal offset in bytes that will
1841 be applied to the kernel when kernel Address Space Layout
1842 Randomization (kASLR) is active. This must be a multiple of
1845 On 32-bit this is limited to 512MiB by page table layouts. The
1848 On 64-bit this is limited by how the kernel fixmap page table is
1849 positioned, so this cannot be larger than 1GiB currently. Without
1850 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1851 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1852 modules area will shrink to compensate, up to the current maximum
1853 1GiB to 1GiB split. The default is 1GiB.
1855 If unsure, leave at the default value.
1857 # Relocation on x86 needs some additional build support
1858 config X86_NEED_RELOCS
1860 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1862 config PHYSICAL_ALIGN
1863 hex "Alignment value to which kernel should be aligned"
1865 range 0x2000 0x1000000 if X86_32
1866 range 0x200000 0x1000000 if X86_64
1868 This value puts the alignment restrictions on physical address
1869 where kernel is loaded and run from. Kernel is compiled for an
1870 address which meets above alignment restriction.
1872 If bootloader loads the kernel at a non-aligned address and
1873 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1874 address aligned to above value and run from there.
1876 If bootloader loads the kernel at a non-aligned address and
1877 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1878 load address and decompress itself to the address it has been
1879 compiled for and run from there. The address for which kernel is
1880 compiled already meets above alignment restrictions. Hence the
1881 end result is that kernel runs from a physical address meeting
1882 above alignment restrictions.
1884 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1885 this value must be a multiple of 0x200000.
1887 Don't change this unless you know what you are doing.
1890 bool "Support for hot-pluggable CPUs"
1893 Say Y here to allow turning CPUs off and on. CPUs can be
1894 controlled through /sys/devices/system/cpu.
1895 ( Note: power management support will enable this option
1896 automatically on SMP systems. )
1897 Say N if you want to disable CPU hotplug.
1899 config BOOTPARAM_HOTPLUG_CPU0
1900 bool "Set default setting of cpu0_hotpluggable"
1902 depends on HOTPLUG_CPU
1904 Set whether default state of cpu0_hotpluggable is on or off.
1906 Say Y here to enable CPU0 hotplug by default. If this switch
1907 is turned on, there is no need to give cpu0_hotplug kernel
1908 parameter and the CPU0 hotplug feature is enabled by default.
1910 Please note: there are two known CPU0 dependencies if you want
1911 to enable the CPU0 hotplug feature either by this switch or by
1912 cpu0_hotplug kernel parameter.
1914 First, resume from hibernate or suspend always starts from CPU0.
1915 So hibernate and suspend are prevented if CPU0 is offline.
1917 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1918 offline if any interrupt can not migrate out of CPU0. There may
1919 be other CPU0 dependencies.
1921 Please make sure the dependencies are under your control before
1922 you enable this feature.
1924 Say N if you don't want to enable CPU0 hotplug feature by default.
1925 You still can enable the CPU0 hotplug feature at boot by kernel
1926 parameter cpu0_hotplug.
1928 config DEBUG_HOTPLUG_CPU0
1930 prompt "Debug CPU0 hotplug"
1931 depends on HOTPLUG_CPU
1933 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1934 soon as possible and boots up userspace with CPU0 offlined. User
1935 can online CPU0 back after boot time.
1937 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1938 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1939 compilation or giving cpu0_hotplug kernel parameter at boot.
1945 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1946 depends on X86_32 || IA32_EMULATION
1948 Certain buggy versions of glibc will crash if they are
1949 presented with a 32-bit vDSO that is not mapped at the address
1950 indicated in its segment table.
1952 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1953 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1954 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1955 the only released version with the bug, but OpenSUSE 9
1956 contains a buggy "glibc 2.3.2".
1958 The symptom of the bug is that everything crashes on startup, saying:
1959 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1961 Saying Y here changes the default value of the vdso32 boot
1962 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1963 This works around the glibc bug but hurts performance.
1965 If unsure, say N: if you are compiling your own kernel, you
1966 are unlikely to be using a buggy version of glibc.
1969 bool "Built-in kernel command line"
1971 Allow for specifying boot arguments to the kernel at
1972 build time. On some systems (e.g. embedded ones), it is
1973 necessary or convenient to provide some or all of the
1974 kernel boot arguments with the kernel itself (that is,
1975 to not rely on the boot loader to provide them.)
1977 To compile command line arguments into the kernel,
1978 set this option to 'Y', then fill in the
1979 the boot arguments in CONFIG_CMDLINE.
1981 Systems with fully functional boot loaders (i.e. non-embedded)
1982 should leave this option set to 'N'.
1985 string "Built-in kernel command string"
1986 depends on CMDLINE_BOOL
1989 Enter arguments here that should be compiled into the kernel
1990 image and used at boot time. If the boot loader provides a
1991 command line at boot time, it is appended to this string to
1992 form the full kernel command line, when the system boots.
1994 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1995 change this behavior.
1997 In most cases, the command line (whether built-in or provided
1998 by the boot loader) should specify the device for the root
2001 config CMDLINE_OVERRIDE
2002 bool "Built-in command line overrides boot loader arguments"
2003 depends on CMDLINE_BOOL
2005 Set this option to 'Y' to have the kernel ignore the boot loader
2006 command line, and use ONLY the built-in command line.
2008 This is used to work around broken boot loaders. This should
2009 be set to 'N' under normal conditions.
2013 config ARCH_ENABLE_MEMORY_HOTPLUG
2015 depends on X86_64 || (X86_32 && HIGHMEM)
2017 config ARCH_ENABLE_MEMORY_HOTREMOVE
2019 depends on MEMORY_HOTPLUG
2021 config USE_PERCPU_NUMA_NODE_ID
2025 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2027 depends on X86_64 || X86_PAE
2029 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2031 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2033 menu "Power management and ACPI options"
2035 config ARCH_HIBERNATION_HEADER
2037 depends on X86_64 && HIBERNATION
2039 source "kernel/power/Kconfig"
2041 source "drivers/acpi/Kconfig"
2043 source "drivers/sfi/Kconfig"
2050 tristate "APM (Advanced Power Management) BIOS support"
2051 depends on X86_32 && PM_SLEEP
2053 APM is a BIOS specification for saving power using several different
2054 techniques. This is mostly useful for battery powered laptops with
2055 APM compliant BIOSes. If you say Y here, the system time will be
2056 reset after a RESUME operation, the /proc/apm device will provide
2057 battery status information, and user-space programs will receive
2058 notification of APM "events" (e.g. battery status change).
2060 If you select "Y" here, you can disable actual use of the APM
2061 BIOS by passing the "apm=off" option to the kernel at boot time.
2063 Note that the APM support is almost completely disabled for
2064 machines with more than one CPU.
2066 In order to use APM, you will need supporting software. For location
2067 and more information, read <file:Documentation/power/apm-acpi.txt>
2068 and the Battery Powered Linux mini-HOWTO, available from
2069 <http://www.tldp.org/docs.html#howto>.
2071 This driver does not spin down disk drives (see the hdparm(8)
2072 manpage ("man 8 hdparm") for that), and it doesn't turn off
2073 VESA-compliant "green" monitors.
2075 This driver does not support the TI 4000M TravelMate and the ACER
2076 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2077 desktop machines also don't have compliant BIOSes, and this driver
2078 may cause those machines to panic during the boot phase.
2080 Generally, if you don't have a battery in your machine, there isn't
2081 much point in using this driver and you should say N. If you get
2082 random kernel OOPSes or reboots that don't seem to be related to
2083 anything, try disabling/enabling this option (or disabling/enabling
2086 Some other things you should try when experiencing seemingly random,
2089 1) make sure that you have enough swap space and that it is
2091 2) pass the "no-hlt" option to the kernel
2092 3) switch on floating point emulation in the kernel and pass
2093 the "no387" option to the kernel
2094 4) pass the "floppy=nodma" option to the kernel
2095 5) pass the "mem=4M" option to the kernel (thereby disabling
2096 all but the first 4 MB of RAM)
2097 6) make sure that the CPU is not over clocked.
2098 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2099 8) disable the cache from your BIOS settings
2100 9) install a fan for the video card or exchange video RAM
2101 10) install a better fan for the CPU
2102 11) exchange RAM chips
2103 12) exchange the motherboard.
2105 To compile this driver as a module, choose M here: the
2106 module will be called apm.
2110 config APM_IGNORE_USER_SUSPEND
2111 bool "Ignore USER SUSPEND"
2113 This option will ignore USER SUSPEND requests. On machines with a
2114 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2115 series notebooks, it is necessary to say Y because of a BIOS bug.
2117 config APM_DO_ENABLE
2118 bool "Enable PM at boot time"
2120 Enable APM features at boot time. From page 36 of the APM BIOS
2121 specification: "When disabled, the APM BIOS does not automatically
2122 power manage devices, enter the Standby State, enter the Suspend
2123 State, or take power saving steps in response to CPU Idle calls."
2124 This driver will make CPU Idle calls when Linux is idle (unless this
2125 feature is turned off -- see "Do CPU IDLE calls", below). This
2126 should always save battery power, but more complicated APM features
2127 will be dependent on your BIOS implementation. You may need to turn
2128 this option off if your computer hangs at boot time when using APM
2129 support, or if it beeps continuously instead of suspending. Turn
2130 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2131 T400CDT. This is off by default since most machines do fine without
2136 bool "Make CPU Idle calls when idle"
2138 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2139 On some machines, this can activate improved power savings, such as
2140 a slowed CPU clock rate, when the machine is idle. These idle calls
2141 are made after the idle loop has run for some length of time (e.g.,
2142 333 mS). On some machines, this will cause a hang at boot time or
2143 whenever the CPU becomes idle. (On machines with more than one CPU,
2144 this option does nothing.)
2146 config APM_DISPLAY_BLANK
2147 bool "Enable console blanking using APM"
2149 Enable console blanking using the APM. Some laptops can use this to
2150 turn off the LCD backlight when the screen blanker of the Linux
2151 virtual console blanks the screen. Note that this is only used by
2152 the virtual console screen blanker, and won't turn off the backlight
2153 when using the X Window system. This also doesn't have anything to
2154 do with your VESA-compliant power-saving monitor. Further, this
2155 option doesn't work for all laptops -- it might not turn off your
2156 backlight at all, or it might print a lot of errors to the console,
2157 especially if you are using gpm.
2159 config APM_ALLOW_INTS
2160 bool "Allow interrupts during APM BIOS calls"
2162 Normally we disable external interrupts while we are making calls to
2163 the APM BIOS as a measure to lessen the effects of a badly behaving
2164 BIOS implementation. The BIOS should reenable interrupts if it
2165 needs to. Unfortunately, some BIOSes do not -- especially those in
2166 many of the newer IBM Thinkpads. If you experience hangs when you
2167 suspend, try setting this to Y. Otherwise, say N.
2171 source "drivers/cpufreq/Kconfig"
2173 source "drivers/cpuidle/Kconfig"
2175 source "drivers/idle/Kconfig"
2180 menu "Bus options (PCI etc.)"
2186 Find out whether you have a PCI motherboard. PCI is the name of a
2187 bus system, i.e. the way the CPU talks to the other stuff inside
2188 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2189 VESA. If you have PCI, say Y, otherwise N.
2192 prompt "PCI access mode"
2193 depends on X86_32 && PCI
2196 On PCI systems, the BIOS can be used to detect the PCI devices and
2197 determine their configuration. However, some old PCI motherboards
2198 have BIOS bugs and may crash if this is done. Also, some embedded
2199 PCI-based systems don't have any BIOS at all. Linux can also try to
2200 detect the PCI hardware directly without using the BIOS.
2202 With this option, you can specify how Linux should detect the
2203 PCI devices. If you choose "BIOS", the BIOS will be used,
2204 if you choose "Direct", the BIOS won't be used, and if you
2205 choose "MMConfig", then PCI Express MMCONFIG will be used.
2206 If you choose "Any", the kernel will try MMCONFIG, then the
2207 direct access method and falls back to the BIOS if that doesn't
2208 work. If unsure, go with the default, which is "Any".
2213 config PCI_GOMMCONFIG
2230 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2232 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2235 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2239 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2243 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2247 depends on PCI && XEN
2255 bool "Support mmconfig PCI config space access"
2256 depends on X86_64 && PCI && ACPI
2258 config PCI_CNB20LE_QUIRK
2259 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2262 Read the PCI windows out of the CNB20LE host bridge. This allows
2263 PCI hotplug to work on systems with the CNB20LE chipset which do
2266 There's no public spec for this chipset, and this functionality
2267 is known to be incomplete.
2269 You should say N unless you know you need this.
2271 source "drivers/pci/pcie/Kconfig"
2273 source "drivers/pci/Kconfig"
2275 # x86_64 have no ISA slots, but can have ISA-style DMA.
2277 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2280 Enables ISA-style DMA support for devices requiring such controllers.
2288 Find out whether you have ISA slots on your motherboard. ISA is the
2289 name of a bus system, i.e. the way the CPU talks to the other stuff
2290 inside your box. Other bus systems are PCI, EISA, MicroChannel
2291 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2292 newer boards don't support it. If you have ISA, say Y, otherwise N.
2298 The Extended Industry Standard Architecture (EISA) bus was
2299 developed as an open alternative to the IBM MicroChannel bus.
2301 The EISA bus provided some of the features of the IBM MicroChannel
2302 bus while maintaining backward compatibility with cards made for
2303 the older ISA bus. The EISA bus saw limited use between 1988 and
2304 1995 when it was made obsolete by the PCI bus.
2306 Say Y here if you are building a kernel for an EISA-based machine.
2310 source "drivers/eisa/Kconfig"
2313 tristate "NatSemi SCx200 support"
2315 This provides basic support for National Semiconductor's
2316 (now AMD's) Geode processors. The driver probes for the
2317 PCI-IDs of several on-chip devices, so its a good dependency
2318 for other scx200_* drivers.
2320 If compiled as a module, the driver is named scx200.
2322 config SCx200HR_TIMER
2323 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2327 This driver provides a clocksource built upon the on-chip
2328 27MHz high-resolution timer. Its also a workaround for
2329 NSC Geode SC-1100's buggy TSC, which loses time when the
2330 processor goes idle (as is done by the scheduler). The
2331 other workaround is idle=poll boot option.
2334 bool "One Laptop Per Child support"
2341 Add support for detecting the unique features of the OLPC
2345 bool "OLPC XO-1 Power Management"
2346 depends on OLPC && MFD_CS5535 && PM_SLEEP
2349 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2352 bool "OLPC XO-1 Real Time Clock"
2353 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2355 Add support for the XO-1 real time clock, which can be used as a
2356 programmable wakeup source.
2359 bool "OLPC XO-1 SCI extras"
2360 depends on OLPC && OLPC_XO1_PM
2366 Add support for SCI-based features of the OLPC XO-1 laptop:
2367 - EC-driven system wakeups
2371 - AC adapter status updates
2372 - Battery status updates
2374 config OLPC_XO15_SCI
2375 bool "OLPC XO-1.5 SCI extras"
2376 depends on OLPC && ACPI
2379 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2380 - EC-driven system wakeups
2381 - AC adapter status updates
2382 - Battery status updates
2385 bool "PCEngines ALIX System Support (LED setup)"
2388 This option enables system support for the PCEngines ALIX.
2389 At present this just sets up LEDs for GPIO control on
2390 ALIX2/3/6 boards. However, other system specific setup should
2393 Note: You must still enable the drivers for GPIO and LED support
2394 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2396 Note: You have to set alix.force=1 for boards with Award BIOS.
2399 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2402 This option enables system support for the Soekris Engineering net5501.
2405 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2409 This option enables system support for the Traverse Technologies GEOS.
2412 bool "Technologic Systems TS-5500 platform support"
2414 select CHECK_SIGNATURE
2418 This option enables system support for the Technologic Systems TS-5500.
2424 depends on CPU_SUP_AMD && PCI
2426 source "drivers/pcmcia/Kconfig"
2428 source "drivers/pci/hotplug/Kconfig"
2431 tristate "RapidIO support"
2435 If enabled this option will include drivers and the core
2436 infrastructure code to support RapidIO interconnect devices.
2438 source "drivers/rapidio/Kconfig"
2441 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2443 Firmwares often provide initial graphics framebuffers so the BIOS,
2444 bootloader or kernel can show basic video-output during boot for
2445 user-guidance and debugging. Historically, x86 used the VESA BIOS
2446 Extensions and EFI-framebuffers for this, which are mostly limited
2448 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2449 framebuffers so the new generic system-framebuffer drivers can be
2450 used on x86. If the framebuffer is not compatible with the generic
2451 modes, it is adverticed as fallback platform framebuffer so legacy
2452 drivers like efifb, vesafb and uvesafb can pick it up.
2453 If this option is not selected, all system framebuffers are always
2454 marked as fallback platform framebuffers as usual.
2456 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2457 not be able to pick up generic system framebuffers if this option
2458 is selected. You are highly encouraged to enable simplefb as
2459 replacement if you select this option. simplefb can correctly deal
2460 with generic system framebuffers. But you should still keep vesafb
2461 and others enabled as fallback if a system framebuffer is
2462 incompatible with simplefb.
2469 menu "Executable file formats / Emulations"
2471 source "fs/Kconfig.binfmt"
2473 config IA32_EMULATION
2474 bool "IA32 Emulation"
2477 select COMPAT_BINFMT_ELF
2480 Include code to run legacy 32-bit programs under a
2481 64-bit kernel. You should likely turn this on, unless you're
2482 100% sure that you don't have any 32-bit programs left.
2485 tristate "IA32 a.out support"
2486 depends on IA32_EMULATION
2488 Support old a.out binaries in the 32bit emulation.
2491 bool "x32 ABI for 64-bit mode"
2492 depends on X86_64 && IA32_EMULATION
2494 Include code to run binaries for the x32 native 32-bit ABI
2495 for 64-bit processors. An x32 process gets access to the
2496 full 64-bit register file and wide data path while leaving
2497 pointers at 32 bits for smaller memory footprint.
2499 You will need a recent binutils (2.22 or later) with
2500 elf32_x86_64 support enabled to compile a kernel with this
2505 depends on IA32_EMULATION || X86_X32
2506 select ARCH_WANT_OLD_COMPAT_IPC
2509 config COMPAT_FOR_U64_ALIGNMENT
2512 config SYSVIPC_COMPAT
2524 config HAVE_ATOMIC_IOMAP
2528 config X86_DEV_DMA_OPS
2530 depends on X86_64 || STA2X11
2532 config X86_DMA_REMAP
2540 source "net/Kconfig"
2542 source "drivers/Kconfig"
2544 source "drivers/firmware/Kconfig"
2548 source "arch/x86/Kconfig.debug"
2550 source "security/Kconfig"
2552 source "crypto/Kconfig"
2554 source "arch/x86/kvm/Kconfig"
2556 source "lib/Kconfig"
projects / cascardo / linux.git / blob