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
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
871 config X86_UP_APIC_MSI
873 select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
876 bool "IO-APIC support on uniprocessors"
877 depends on X86_UP_APIC
879 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
880 SMP-capable replacement for PC-style interrupt controllers. Most
881 SMP systems and many recent uniprocessor systems have one.
883 If you have a single-CPU system with an IO-APIC, you can say Y here
884 to use it. If you say Y here even though your machine doesn't have
885 an IO-APIC, then the kernel will still run with no slowdown at all.
887 config X86_LOCAL_APIC
889 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
890 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
893 def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
894 depends on X86_LOCAL_APIC
897 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
898 bool "Reroute for broken boot IRQs"
899 depends on X86_IO_APIC
901 This option enables a workaround that fixes a source of
902 spurious interrupts. This is recommended when threaded
903 interrupt handling is used on systems where the generation of
904 superfluous "boot interrupts" cannot be disabled.
906 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
907 entry in the chipset's IO-APIC is masked (as, e.g. the RT
908 kernel does during interrupt handling). On chipsets where this
909 boot IRQ generation cannot be disabled, this workaround keeps
910 the original IRQ line masked so that only the equivalent "boot
911 IRQ" is delivered to the CPUs. The workaround also tells the
912 kernel to set up the IRQ handler on the boot IRQ line. In this
913 way only one interrupt is delivered to the kernel. Otherwise
914 the spurious second interrupt may cause the kernel to bring
915 down (vital) interrupt lines.
917 Only affects "broken" chipsets. Interrupt sharing may be
918 increased on these systems.
921 bool "Machine Check / overheating reporting"
924 Machine Check support allows the processor to notify the
925 kernel if it detects a problem (e.g. overheating, data corruption).
926 The action the kernel takes depends on the severity of the problem,
927 ranging from warning messages to halting the machine.
931 prompt "Intel MCE features"
932 depends on X86_MCE && X86_LOCAL_APIC
934 Additional support for intel specific MCE features such as
939 prompt "AMD MCE features"
940 depends on X86_MCE && X86_LOCAL_APIC
942 Additional support for AMD specific MCE features such as
943 the DRAM Error Threshold.
945 config X86_ANCIENT_MCE
946 bool "Support for old Pentium 5 / WinChip machine checks"
947 depends on X86_32 && X86_MCE
949 Include support for machine check handling on old Pentium 5 or WinChip
950 systems. These typically need to be enabled explicitly on the command
953 config X86_MCE_THRESHOLD
954 depends on X86_MCE_AMD || X86_MCE_INTEL
957 config X86_MCE_INJECT
959 tristate "Machine check injector support"
961 Provide support for injecting machine checks for testing purposes.
962 If you don't know what a machine check is and you don't do kernel
963 QA it is safe to say n.
965 config X86_THERMAL_VECTOR
967 depends on X86_MCE_INTEL
970 bool "Enable VM86 support" if EXPERT
974 This option is required by programs like DOSEMU to run
975 16-bit real mode legacy code on x86 processors. It also may
976 be needed by software like XFree86 to initialize some video
977 cards via BIOS. Disabling this option saves about 6K.
980 bool "Enable support for 16-bit segments" if EXPERT
983 This option is required by programs like Wine to run 16-bit
984 protected mode legacy code on x86 processors. Disabling
985 this option saves about 300 bytes on i386, or around 6K text
986 plus 16K runtime memory on x86-64,
990 depends on X86_16BIT && X86_32
994 depends on X86_16BIT && X86_64
996 config X86_VSYSCALL_EMULATION
997 bool "Enable vsyscall emulation" if EXPERT
1001 This enables emulation of the legacy vsyscall page. Disabling
1002 it is roughly equivalent to booting with vsyscall=none, except
1003 that it will also disable the helpful warning if a program
1004 tries to use a vsyscall. With this option set to N, offending
1005 programs will just segfault, citing addresses of the form
1008 This option is required by many programs built before 2013, and
1009 care should be used even with newer programs if set to N.
1011 Disabling this option saves about 7K of kernel size and
1012 possibly 4K of additional runtime pagetable memory.
1015 tristate "Toshiba Laptop support"
1018 This adds a driver to safely access the System Management Mode of
1019 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1020 not work on models with a Phoenix BIOS. The System Management Mode
1021 is used to set the BIOS and power saving options on Toshiba portables.
1023 For information on utilities to make use of this driver see the
1024 Toshiba Linux utilities web site at:
1025 <http://www.buzzard.org.uk/toshiba/>.
1027 Say Y if you intend to run this kernel on a Toshiba portable.
1031 tristate "Dell laptop support"
1034 This adds a driver to safely access the System Management Mode
1035 of the CPU on the Dell Inspiron 8000. The System Management Mode
1036 is used to read cpu temperature and cooling fan status and to
1037 control the fans on the I8K portables.
1039 This driver has been tested only on the Inspiron 8000 but it may
1040 also work with other Dell laptops. You can force loading on other
1041 models by passing the parameter `force=1' to the module. Use at
1044 For information on utilities to make use of this driver see the
1045 I8K Linux utilities web site at:
1046 <http://people.debian.org/~dz/i8k/>
1048 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1051 config X86_REBOOTFIXUPS
1052 bool "Enable X86 board specific fixups for reboot"
1055 This enables chipset and/or board specific fixups to be done
1056 in order to get reboot to work correctly. This is only needed on
1057 some combinations of hardware and BIOS. The symptom, for which
1058 this config is intended, is when reboot ends with a stalled/hung
1061 Currently, the only fixup is for the Geode machines using
1062 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1064 Say Y if you want to enable the fixup. Currently, it's safe to
1065 enable this option even if you don't need it.
1069 tristate "CPU microcode loading support"
1070 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1074 If you say Y here, you will be able to update the microcode on
1075 certain Intel and AMD processors. The Intel support is for the
1076 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1077 Xeon etc. The AMD support is for families 0x10 and later. You will
1078 obviously need the actual microcode binary data itself which is not
1079 shipped with the Linux kernel.
1081 This option selects the general module only, you need to select
1082 at least one vendor specific module as well.
1084 To compile this driver as a module, choose M here: the module
1085 will be called microcode.
1087 config MICROCODE_INTEL
1088 bool "Intel microcode loading support"
1089 depends on MICROCODE
1093 This options enables microcode patch loading support for Intel
1096 For the current Intel microcode data package go to
1097 <https://downloadcenter.intel.com> and search for
1098 'Linux Processor Microcode Data File'.
1100 config MICROCODE_AMD
1101 bool "AMD microcode loading support"
1102 depends on MICROCODE
1105 If you select this option, microcode patch loading support for AMD
1106 processors will be enabled.
1108 config MICROCODE_OLD_INTERFACE
1110 depends on MICROCODE
1112 config MICROCODE_INTEL_EARLY
1115 config MICROCODE_AMD_EARLY
1118 config MICROCODE_EARLY
1119 bool "Early load microcode"
1120 depends on MICROCODE=y && BLK_DEV_INITRD
1121 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1122 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1125 This option provides functionality to read additional microcode data
1126 at the beginning of initrd image. The data tells kernel to load
1127 microcode to CPU's as early as possible. No functional change if no
1128 microcode data is glued to the initrd, therefore it's safe to say Y.
1131 tristate "/dev/cpu/*/msr - Model-specific register support"
1133 This device gives privileged processes access to the x86
1134 Model-Specific Registers (MSRs). It is a character device with
1135 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1136 MSR accesses are directed to a specific CPU on multi-processor
1140 tristate "/dev/cpu/*/cpuid - CPU information support"
1142 This device gives processes access to the x86 CPUID instruction to
1143 be executed on a specific processor. It is a character device
1144 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1148 prompt "High Memory Support"
1155 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1156 However, the address space of 32-bit x86 processors is only 4
1157 Gigabytes large. That means that, if you have a large amount of
1158 physical memory, not all of it can be "permanently mapped" by the
1159 kernel. The physical memory that's not permanently mapped is called
1162 If you are compiling a kernel which will never run on a machine with
1163 more than 1 Gigabyte total physical RAM, answer "off" here (default
1164 choice and suitable for most users). This will result in a "3GB/1GB"
1165 split: 3GB are mapped so that each process sees a 3GB virtual memory
1166 space and the remaining part of the 4GB virtual memory space is used
1167 by the kernel to permanently map as much physical memory as
1170 If the machine has between 1 and 4 Gigabytes physical RAM, then
1173 If more than 4 Gigabytes is used then answer "64GB" here. This
1174 selection turns Intel PAE (Physical Address Extension) mode on.
1175 PAE implements 3-level paging on IA32 processors. PAE is fully
1176 supported by Linux, PAE mode is implemented on all recent Intel
1177 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1178 then the kernel will not boot on CPUs that don't support PAE!
1180 The actual amount of total physical memory will either be
1181 auto detected or can be forced by using a kernel command line option
1182 such as "mem=256M". (Try "man bootparam" or see the documentation of
1183 your boot loader (lilo or loadlin) about how to pass options to the
1184 kernel at boot time.)
1186 If unsure, say "off".
1191 Select this if you have a 32-bit processor and between 1 and 4
1192 gigabytes of physical RAM.
1199 Select this if you have a 32-bit processor and more than 4
1200 gigabytes of physical RAM.
1205 prompt "Memory split" if EXPERT
1209 Select the desired split between kernel and user memory.
1211 If the address range available to the kernel is less than the
1212 physical memory installed, the remaining memory will be available
1213 as "high memory". Accessing high memory is a little more costly
1214 than low memory, as it needs to be mapped into the kernel first.
1215 Note that increasing the kernel address space limits the range
1216 available to user programs, making the address space there
1217 tighter. Selecting anything other than the default 3G/1G split
1218 will also likely make your kernel incompatible with binary-only
1221 If you are not absolutely sure what you are doing, leave this
1225 bool "3G/1G user/kernel split"
1226 config VMSPLIT_3G_OPT
1228 bool "3G/1G user/kernel split (for full 1G low memory)"
1230 bool "2G/2G user/kernel split"
1231 config VMSPLIT_2G_OPT
1233 bool "2G/2G user/kernel split (for full 2G low memory)"
1235 bool "1G/3G user/kernel split"
1240 default 0xB0000000 if VMSPLIT_3G_OPT
1241 default 0x80000000 if VMSPLIT_2G
1242 default 0x78000000 if VMSPLIT_2G_OPT
1243 default 0x40000000 if VMSPLIT_1G
1249 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1252 bool "PAE (Physical Address Extension) Support"
1253 depends on X86_32 && !HIGHMEM4G
1255 PAE is required for NX support, and furthermore enables
1256 larger swapspace support for non-overcommit purposes. It
1257 has the cost of more pagetable lookup overhead, and also
1258 consumes more pagetable space per process.
1260 config ARCH_PHYS_ADDR_T_64BIT
1262 depends on X86_64 || X86_PAE
1264 config ARCH_DMA_ADDR_T_64BIT
1266 depends on X86_64 || HIGHMEM64G
1268 config DIRECT_GBPAGES
1269 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1273 Allow the kernel linear mapping to use 1GB pages on CPUs that
1274 support it. This can improve the kernel's performance a tiny bit by
1275 reducing TLB pressure. If in doubt, say "Y".
1277 # Common NUMA Features
1279 bool "Numa Memory Allocation and Scheduler Support"
1281 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1282 default y if X86_BIGSMP
1284 Enable NUMA (Non Uniform Memory Access) support.
1286 The kernel will try to allocate memory used by a CPU on the
1287 local memory controller of the CPU and add some more
1288 NUMA awareness to the kernel.
1290 For 64-bit this is recommended if the system is Intel Core i7
1291 (or later), AMD Opteron, or EM64T NUMA.
1293 For 32-bit this is only needed if you boot a 32-bit
1294 kernel on a 64-bit NUMA platform.
1296 Otherwise, you should say N.
1300 prompt "Old style AMD Opteron NUMA detection"
1301 depends on X86_64 && NUMA && PCI
1303 Enable AMD NUMA node topology detection. You should say Y here if
1304 you have a multi processor AMD system. This uses an old method to
1305 read the NUMA configuration directly from the builtin Northbridge
1306 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1307 which also takes priority if both are compiled in.
1309 config X86_64_ACPI_NUMA
1311 prompt "ACPI NUMA detection"
1312 depends on X86_64 && NUMA && ACPI && PCI
1315 Enable ACPI SRAT based node topology detection.
1317 # Some NUMA nodes have memory ranges that span
1318 # other nodes. Even though a pfn is valid and
1319 # between a node's start and end pfns, it may not
1320 # reside on that node. See memmap_init_zone()
1322 config NODES_SPAN_OTHER_NODES
1324 depends on X86_64_ACPI_NUMA
1327 bool "NUMA emulation"
1330 Enable NUMA emulation. A flat machine will be split
1331 into virtual nodes when booted with "numa=fake=N", where N is the
1332 number of nodes. This is only useful for debugging.
1335 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1337 default "10" if MAXSMP
1338 default "6" if X86_64
1340 depends on NEED_MULTIPLE_NODES
1342 Specify the maximum number of NUMA Nodes available on the target
1343 system. Increases memory reserved to accommodate various tables.
1345 config ARCH_HAVE_MEMORY_PRESENT
1347 depends on X86_32 && DISCONTIGMEM
1349 config NEED_NODE_MEMMAP_SIZE
1351 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1353 config ARCH_FLATMEM_ENABLE
1355 depends on X86_32 && !NUMA
1357 config ARCH_DISCONTIGMEM_ENABLE
1359 depends on NUMA && X86_32
1361 config ARCH_DISCONTIGMEM_DEFAULT
1363 depends on NUMA && X86_32
1365 config ARCH_SPARSEMEM_ENABLE
1367 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1368 select SPARSEMEM_STATIC if X86_32
1369 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1371 config ARCH_SPARSEMEM_DEFAULT
1375 config ARCH_SELECT_MEMORY_MODEL
1377 depends on ARCH_SPARSEMEM_ENABLE
1379 config ARCH_MEMORY_PROBE
1380 bool "Enable sysfs memory/probe interface"
1381 depends on X86_64 && MEMORY_HOTPLUG
1383 This option enables a sysfs memory/probe interface for testing.
1384 See Documentation/memory-hotplug.txt for more information.
1385 If you are unsure how to answer this question, answer N.
1387 config ARCH_PROC_KCORE_TEXT
1389 depends on X86_64 && PROC_KCORE
1391 config ILLEGAL_POINTER_VALUE
1394 default 0xdead000000000000 if X86_64
1399 bool "Allocate 3rd-level pagetables from highmem"
1402 The VM uses one page table entry for each page of physical memory.
1403 For systems with a lot of RAM, this can be wasteful of precious
1404 low memory. Setting this option will put user-space page table
1405 entries in high memory.
1407 config X86_CHECK_BIOS_CORRUPTION
1408 bool "Check for low memory corruption"
1410 Periodically check for memory corruption in low memory, which
1411 is suspected to be caused by BIOS. Even when enabled in the
1412 configuration, it is disabled at runtime. Enable it by
1413 setting "memory_corruption_check=1" on the kernel command
1414 line. By default it scans the low 64k of memory every 60
1415 seconds; see the memory_corruption_check_size and
1416 memory_corruption_check_period parameters in
1417 Documentation/kernel-parameters.txt to adjust this.
1419 When enabled with the default parameters, this option has
1420 almost no overhead, as it reserves a relatively small amount
1421 of memory and scans it infrequently. It both detects corruption
1422 and prevents it from affecting the running system.
1424 It is, however, intended as a diagnostic tool; if repeatable
1425 BIOS-originated corruption always affects the same memory,
1426 you can use memmap= to prevent the kernel from using that
1429 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1430 bool "Set the default setting of memory_corruption_check"
1431 depends on X86_CHECK_BIOS_CORRUPTION
1434 Set whether the default state of memory_corruption_check is
1437 config X86_RESERVE_LOW
1438 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1442 Specify the amount of low memory to reserve for the BIOS.
1444 The first page contains BIOS data structures that the kernel
1445 must not use, so that page must always be reserved.
1447 By default we reserve the first 64K of physical RAM, as a
1448 number of BIOSes are known to corrupt that memory range
1449 during events such as suspend/resume or monitor cable
1450 insertion, so it must not be used by the kernel.
1452 You can set this to 4 if you are absolutely sure that you
1453 trust the BIOS to get all its memory reservations and usages
1454 right. If you know your BIOS have problems beyond the
1455 default 64K area, you can set this to 640 to avoid using the
1456 entire low memory range.
1458 If you have doubts about the BIOS (e.g. suspend/resume does
1459 not work or there's kernel crashes after certain hardware
1460 hotplug events) then you might want to enable
1461 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1462 typical corruption patterns.
1464 Leave this to the default value of 64 if you are unsure.
1466 config MATH_EMULATION
1468 prompt "Math emulation" if X86_32
1470 Linux can emulate a math coprocessor (used for floating point
1471 operations) if you don't have one. 486DX and Pentium processors have
1472 a math coprocessor built in, 486SX and 386 do not, unless you added
1473 a 487DX or 387, respectively. (The messages during boot time can
1474 give you some hints here ["man dmesg"].) Everyone needs either a
1475 coprocessor or this emulation.
1477 If you don't have a math coprocessor, you need to say Y here; if you
1478 say Y here even though you have a coprocessor, the coprocessor will
1479 be used nevertheless. (This behavior can be changed with the kernel
1480 command line option "no387", which comes handy if your coprocessor
1481 is broken. Try "man bootparam" or see the documentation of your boot
1482 loader (lilo or loadlin) about how to pass options to the kernel at
1483 boot time.) This means that it is a good idea to say Y here if you
1484 intend to use this kernel on different machines.
1486 More information about the internals of the Linux math coprocessor
1487 emulation can be found in <file:arch/x86/math-emu/README>.
1489 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1490 kernel, it won't hurt.
1494 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1496 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1497 the Memory Type Range Registers (MTRRs) may be used to control
1498 processor access to memory ranges. This is most useful if you have
1499 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1500 allows bus write transfers to be combined into a larger transfer
1501 before bursting over the PCI/AGP bus. This can increase performance
1502 of image write operations 2.5 times or more. Saying Y here creates a
1503 /proc/mtrr file which may be used to manipulate your processor's
1504 MTRRs. Typically the X server should use this.
1506 This code has a reasonably generic interface so that similar
1507 control registers on other processors can be easily supported
1510 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1511 Registers (ARRs) which provide a similar functionality to MTRRs. For
1512 these, the ARRs are used to emulate the MTRRs.
1513 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1514 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1515 write-combining. All of these processors are supported by this code
1516 and it makes sense to say Y here if you have one of them.
1518 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1519 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1520 can lead to all sorts of problems, so it's good to say Y here.
1522 You can safely say Y even if your machine doesn't have MTRRs, you'll
1523 just add about 9 KB to your kernel.
1525 See <file:Documentation/x86/mtrr.txt> for more information.
1527 config MTRR_SANITIZER
1529 prompt "MTRR cleanup support"
1532 Convert MTRR layout from continuous to discrete, so X drivers can
1533 add writeback entries.
1535 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1536 The largest mtrr entry size for a continuous block can be set with
1541 config MTRR_SANITIZER_ENABLE_DEFAULT
1542 int "MTRR cleanup enable value (0-1)"
1545 depends on MTRR_SANITIZER
1547 Enable mtrr cleanup default value
1549 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1550 int "MTRR cleanup spare reg num (0-7)"
1553 depends on MTRR_SANITIZER
1555 mtrr cleanup spare entries default, it can be changed via
1556 mtrr_spare_reg_nr=N on the kernel command line.
1560 prompt "x86 PAT support" if EXPERT
1563 Use PAT attributes to setup page level cache control.
1565 PATs are the modern equivalents of MTRRs and are much more
1566 flexible than MTRRs.
1568 Say N here if you see bootup problems (boot crash, boot hang,
1569 spontaneous reboots) or a non-working video driver.
1573 config ARCH_USES_PG_UNCACHED
1579 prompt "x86 architectural random number generator" if EXPERT
1581 Enable the x86 architectural RDRAND instruction
1582 (Intel Bull Mountain technology) to generate random numbers.
1583 If supported, this is a high bandwidth, cryptographically
1584 secure hardware random number generator.
1588 prompt "Supervisor Mode Access Prevention" if EXPERT
1590 Supervisor Mode Access Prevention (SMAP) is a security
1591 feature in newer Intel processors. There is a small
1592 performance cost if this enabled and turned on; there is
1593 also a small increase in the kernel size if this is enabled.
1597 config X86_INTEL_MPX
1598 prompt "Intel MPX (Memory Protection Extensions)"
1600 depends on CPU_SUP_INTEL
1602 MPX provides hardware features that can be used in
1603 conjunction with compiler-instrumented code to check
1604 memory references. It is designed to detect buffer
1605 overflow or underflow bugs.
1607 This option enables running applications which are
1608 instrumented or otherwise use MPX. It does not use MPX
1609 itself inside the kernel or to protect the kernel
1610 against bad memory references.
1612 Enabling this option will make the kernel larger:
1613 ~8k of kernel text and 36 bytes of data on a 64-bit
1614 defconfig. It adds a long to the 'mm_struct' which
1615 will increase the kernel memory overhead of each
1616 process and adds some branches to paths used during
1617 exec() and munmap().
1619 For details, see Documentation/x86/intel_mpx.txt
1624 bool "EFI runtime service support"
1627 select EFI_RUNTIME_WRAPPERS
1629 This enables the kernel to use EFI runtime services that are
1630 available (such as the EFI variable services).
1632 This option is only useful on systems that have EFI firmware.
1633 In addition, you should use the latest ELILO loader available
1634 at <http://elilo.sourceforge.net> in order to take advantage
1635 of EFI runtime services. However, even with this option, the
1636 resultant kernel should continue to boot on existing non-EFI
1640 bool "EFI stub support"
1641 depends on EFI && !X86_USE_3DNOW
1644 This kernel feature allows a bzImage to be loaded directly
1645 by EFI firmware without the use of a bootloader.
1647 See Documentation/efi-stub.txt for more information.
1650 bool "EFI mixed-mode support"
1651 depends on EFI_STUB && X86_64
1653 Enabling this feature allows a 64-bit kernel to be booted
1654 on a 32-bit firmware, provided that your CPU supports 64-bit
1657 Note that it is not possible to boot a mixed-mode enabled
1658 kernel via the EFI boot stub - a bootloader that supports
1659 the EFI handover protocol must be used.
1665 prompt "Enable seccomp to safely compute untrusted bytecode"
1667 This kernel feature is useful for number crunching applications
1668 that may need to compute untrusted bytecode during their
1669 execution. By using pipes or other transports made available to
1670 the process as file descriptors supporting the read/write
1671 syscalls, it's possible to isolate those applications in
1672 their own address space using seccomp. Once seccomp is
1673 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1674 and the task is only allowed to execute a few safe syscalls
1675 defined by each seccomp mode.
1677 If unsure, say Y. Only embedded should say N here.
1679 source kernel/Kconfig.hz
1682 bool "kexec system call"
1684 kexec is a system call that implements the ability to shutdown your
1685 current kernel, and to start another kernel. It is like a reboot
1686 but it is independent of the system firmware. And like a reboot
1687 you can start any kernel with it, not just Linux.
1689 The name comes from the similarity to the exec system call.
1691 It is an ongoing process to be certain the hardware in a machine
1692 is properly shutdown, so do not be surprised if this code does not
1693 initially work for you. As of this writing the exact hardware
1694 interface is strongly in flux, so no good recommendation can be
1698 bool "kexec file based system call"
1703 depends on CRYPTO_SHA256=y
1705 This is new version of kexec system call. This system call is
1706 file based and takes file descriptors as system call argument
1707 for kernel and initramfs as opposed to list of segments as
1708 accepted by previous system call.
1710 config KEXEC_VERIFY_SIG
1711 bool "Verify kernel signature during kexec_file_load() syscall"
1712 depends on KEXEC_FILE
1714 This option makes kernel signature verification mandatory for
1715 kexec_file_load() syscall. If kernel is signature can not be
1716 verified, kexec_file_load() will fail.
1718 This option enforces signature verification at generic level.
1719 One needs to enable signature verification for type of kernel
1720 image being loaded to make sure it works. For example, enable
1721 bzImage signature verification option to be able to load and
1722 verify signatures of bzImage. Otherwise kernel loading will fail.
1724 config KEXEC_BZIMAGE_VERIFY_SIG
1725 bool "Enable bzImage signature verification support"
1726 depends on KEXEC_VERIFY_SIG
1727 depends on SIGNED_PE_FILE_VERIFICATION
1728 select SYSTEM_TRUSTED_KEYRING
1730 Enable bzImage signature verification support.
1733 bool "kernel crash dumps"
1734 depends on X86_64 || (X86_32 && HIGHMEM)
1736 Generate crash dump after being started by kexec.
1737 This should be normally only set in special crash dump kernels
1738 which are loaded in the main kernel with kexec-tools into
1739 a specially reserved region and then later executed after
1740 a crash by kdump/kexec. The crash dump kernel must be compiled
1741 to a memory address not used by the main kernel or BIOS using
1742 PHYSICAL_START, or it must be built as a relocatable image
1743 (CONFIG_RELOCATABLE=y).
1744 For more details see Documentation/kdump/kdump.txt
1748 depends on KEXEC && HIBERNATION
1750 Jump between original kernel and kexeced kernel and invoke
1751 code in physical address mode via KEXEC
1753 config PHYSICAL_START
1754 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1757 This gives the physical address where the kernel is loaded.
1759 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1760 bzImage will decompress itself to above physical address and
1761 run from there. Otherwise, bzImage will run from the address where
1762 it has been loaded by the boot loader and will ignore above physical
1765 In normal kdump cases one does not have to set/change this option
1766 as now bzImage can be compiled as a completely relocatable image
1767 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1768 address. This option is mainly useful for the folks who don't want
1769 to use a bzImage for capturing the crash dump and want to use a
1770 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1771 to be specifically compiled to run from a specific memory area
1772 (normally a reserved region) and this option comes handy.
1774 So if you are using bzImage for capturing the crash dump,
1775 leave the value here unchanged to 0x1000000 and set
1776 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1777 for capturing the crash dump change this value to start of
1778 the reserved region. In other words, it can be set based on
1779 the "X" value as specified in the "crashkernel=YM@XM"
1780 command line boot parameter passed to the panic-ed
1781 kernel. Please take a look at Documentation/kdump/kdump.txt
1782 for more details about crash dumps.
1784 Usage of bzImage for capturing the crash dump is recommended as
1785 one does not have to build two kernels. Same kernel can be used
1786 as production kernel and capture kernel. Above option should have
1787 gone away after relocatable bzImage support is introduced. But it
1788 is present because there are users out there who continue to use
1789 vmlinux for dump capture. This option should go away down the
1792 Don't change this unless you know what you are doing.
1795 bool "Build a relocatable kernel"
1798 This builds a kernel image that retains relocation information
1799 so it can be loaded someplace besides the default 1MB.
1800 The relocations tend to make the kernel binary about 10% larger,
1801 but are discarded at runtime.
1803 One use is for the kexec on panic case where the recovery kernel
1804 must live at a different physical address than the primary
1807 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1808 it has been loaded at and the compile time physical address
1809 (CONFIG_PHYSICAL_START) is used as the minimum location.
1811 config RANDOMIZE_BASE
1812 bool "Randomize the address of the kernel image"
1813 depends on RELOCATABLE
1816 Randomizes the physical and virtual address at which the
1817 kernel image is decompressed, as a security feature that
1818 deters exploit attempts relying on knowledge of the location
1819 of kernel internals.
1821 Entropy is generated using the RDRAND instruction if it is
1822 supported. If RDTSC is supported, it is used as well. If
1823 neither RDRAND nor RDTSC are supported, then randomness is
1824 read from the i8254 timer.
1826 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1827 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1828 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1829 minimum of 2MiB, only 10 bits of entropy is theoretically
1830 possible. At best, due to page table layouts, 64-bit can use
1831 9 bits of entropy and 32-bit uses 8 bits.
1835 config RANDOMIZE_BASE_MAX_OFFSET
1836 hex "Maximum kASLR offset allowed" if EXPERT
1837 depends on RANDOMIZE_BASE
1838 range 0x0 0x20000000 if X86_32
1839 default "0x20000000" if X86_32
1840 range 0x0 0x40000000 if X86_64
1841 default "0x40000000" if X86_64
1843 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1844 memory is used to determine the maximal offset in bytes that will
1845 be applied to the kernel when kernel Address Space Layout
1846 Randomization (kASLR) is active. This must be a multiple of
1849 On 32-bit this is limited to 512MiB by page table layouts. The
1852 On 64-bit this is limited by how the kernel fixmap page table is
1853 positioned, so this cannot be larger than 1GiB currently. Without
1854 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1855 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1856 modules area will shrink to compensate, up to the current maximum
1857 1GiB to 1GiB split. The default is 1GiB.
1859 If unsure, leave at the default value.
1861 # Relocation on x86 needs some additional build support
1862 config X86_NEED_RELOCS
1864 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1866 config PHYSICAL_ALIGN
1867 hex "Alignment value to which kernel should be aligned"
1869 range 0x2000 0x1000000 if X86_32
1870 range 0x200000 0x1000000 if X86_64
1872 This value puts the alignment restrictions on physical address
1873 where kernel is loaded and run from. Kernel is compiled for an
1874 address which meets above alignment restriction.
1876 If bootloader loads the kernel at a non-aligned address and
1877 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1878 address aligned to above value and run from there.
1880 If bootloader loads the kernel at a non-aligned address and
1881 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1882 load address and decompress itself to the address it has been
1883 compiled for and run from there. The address for which kernel is
1884 compiled already meets above alignment restrictions. Hence the
1885 end result is that kernel runs from a physical address meeting
1886 above alignment restrictions.
1888 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1889 this value must be a multiple of 0x200000.
1891 Don't change this unless you know what you are doing.
1894 bool "Support for hot-pluggable CPUs"
1897 Say Y here to allow turning CPUs off and on. CPUs can be
1898 controlled through /sys/devices/system/cpu.
1899 ( Note: power management support will enable this option
1900 automatically on SMP systems. )
1901 Say N if you want to disable CPU hotplug.
1903 config BOOTPARAM_HOTPLUG_CPU0
1904 bool "Set default setting of cpu0_hotpluggable"
1906 depends on HOTPLUG_CPU
1908 Set whether default state of cpu0_hotpluggable is on or off.
1910 Say Y here to enable CPU0 hotplug by default. If this switch
1911 is turned on, there is no need to give cpu0_hotplug kernel
1912 parameter and the CPU0 hotplug feature is enabled by default.
1914 Please note: there are two known CPU0 dependencies if you want
1915 to enable the CPU0 hotplug feature either by this switch or by
1916 cpu0_hotplug kernel parameter.
1918 First, resume from hibernate or suspend always starts from CPU0.
1919 So hibernate and suspend are prevented if CPU0 is offline.
1921 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1922 offline if any interrupt can not migrate out of CPU0. There may
1923 be other CPU0 dependencies.
1925 Please make sure the dependencies are under your control before
1926 you enable this feature.
1928 Say N if you don't want to enable CPU0 hotplug feature by default.
1929 You still can enable the CPU0 hotplug feature at boot by kernel
1930 parameter cpu0_hotplug.
1932 config DEBUG_HOTPLUG_CPU0
1934 prompt "Debug CPU0 hotplug"
1935 depends on HOTPLUG_CPU
1937 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1938 soon as possible and boots up userspace with CPU0 offlined. User
1939 can online CPU0 back after boot time.
1941 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1942 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1943 compilation or giving cpu0_hotplug kernel parameter at boot.
1949 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1950 depends on X86_32 || IA32_EMULATION
1952 Certain buggy versions of glibc will crash if they are
1953 presented with a 32-bit vDSO that is not mapped at the address
1954 indicated in its segment table.
1956 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1957 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1958 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1959 the only released version with the bug, but OpenSUSE 9
1960 contains a buggy "glibc 2.3.2".
1962 The symptom of the bug is that everything crashes on startup, saying:
1963 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1965 Saying Y here changes the default value of the vdso32 boot
1966 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1967 This works around the glibc bug but hurts performance.
1969 If unsure, say N: if you are compiling your own kernel, you
1970 are unlikely to be using a buggy version of glibc.
1973 bool "Built-in kernel command line"
1975 Allow for specifying boot arguments to the kernel at
1976 build time. On some systems (e.g. embedded ones), it is
1977 necessary or convenient to provide some or all of the
1978 kernel boot arguments with the kernel itself (that is,
1979 to not rely on the boot loader to provide them.)
1981 To compile command line arguments into the kernel,
1982 set this option to 'Y', then fill in the
1983 the boot arguments in CONFIG_CMDLINE.
1985 Systems with fully functional boot loaders (i.e. non-embedded)
1986 should leave this option set to 'N'.
1989 string "Built-in kernel command string"
1990 depends on CMDLINE_BOOL
1993 Enter arguments here that should be compiled into the kernel
1994 image and used at boot time. If the boot loader provides a
1995 command line at boot time, it is appended to this string to
1996 form the full kernel command line, when the system boots.
1998 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1999 change this behavior.
2001 In most cases, the command line (whether built-in or provided
2002 by the boot loader) should specify the device for the root
2005 config CMDLINE_OVERRIDE
2006 bool "Built-in command line overrides boot loader arguments"
2007 depends on CMDLINE_BOOL
2009 Set this option to 'Y' to have the kernel ignore the boot loader
2010 command line, and use ONLY the built-in command line.
2012 This is used to work around broken boot loaders. This should
2013 be set to 'N' under normal conditions.
2017 config ARCH_ENABLE_MEMORY_HOTPLUG
2019 depends on X86_64 || (X86_32 && HIGHMEM)
2021 config ARCH_ENABLE_MEMORY_HOTREMOVE
2023 depends on MEMORY_HOTPLUG
2025 config USE_PERCPU_NUMA_NODE_ID
2029 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2031 depends on X86_64 || X86_PAE
2033 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2035 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2037 menu "Power management and ACPI options"
2039 config ARCH_HIBERNATION_HEADER
2041 depends on X86_64 && HIBERNATION
2043 source "kernel/power/Kconfig"
2045 source "drivers/acpi/Kconfig"
2047 source "drivers/sfi/Kconfig"
2054 tristate "APM (Advanced Power Management) BIOS support"
2055 depends on X86_32 && PM_SLEEP
2057 APM is a BIOS specification for saving power using several different
2058 techniques. This is mostly useful for battery powered laptops with
2059 APM compliant BIOSes. If you say Y here, the system time will be
2060 reset after a RESUME operation, the /proc/apm device will provide
2061 battery status information, and user-space programs will receive
2062 notification of APM "events" (e.g. battery status change).
2064 If you select "Y" here, you can disable actual use of the APM
2065 BIOS by passing the "apm=off" option to the kernel at boot time.
2067 Note that the APM support is almost completely disabled for
2068 machines with more than one CPU.
2070 In order to use APM, you will need supporting software. For location
2071 and more information, read <file:Documentation/power/apm-acpi.txt>
2072 and the Battery Powered Linux mini-HOWTO, available from
2073 <http://www.tldp.org/docs.html#howto>.
2075 This driver does not spin down disk drives (see the hdparm(8)
2076 manpage ("man 8 hdparm") for that), and it doesn't turn off
2077 VESA-compliant "green" monitors.
2079 This driver does not support the TI 4000M TravelMate and the ACER
2080 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2081 desktop machines also don't have compliant BIOSes, and this driver
2082 may cause those machines to panic during the boot phase.
2084 Generally, if you don't have a battery in your machine, there isn't
2085 much point in using this driver and you should say N. If you get
2086 random kernel OOPSes or reboots that don't seem to be related to
2087 anything, try disabling/enabling this option (or disabling/enabling
2090 Some other things you should try when experiencing seemingly random,
2093 1) make sure that you have enough swap space and that it is
2095 2) pass the "no-hlt" option to the kernel
2096 3) switch on floating point emulation in the kernel and pass
2097 the "no387" option to the kernel
2098 4) pass the "floppy=nodma" option to the kernel
2099 5) pass the "mem=4M" option to the kernel (thereby disabling
2100 all but the first 4 MB of RAM)
2101 6) make sure that the CPU is not over clocked.
2102 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2103 8) disable the cache from your BIOS settings
2104 9) install a fan for the video card or exchange video RAM
2105 10) install a better fan for the CPU
2106 11) exchange RAM chips
2107 12) exchange the motherboard.
2109 To compile this driver as a module, choose M here: the
2110 module will be called apm.
2114 config APM_IGNORE_USER_SUSPEND
2115 bool "Ignore USER SUSPEND"
2117 This option will ignore USER SUSPEND requests. On machines with a
2118 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2119 series notebooks, it is necessary to say Y because of a BIOS bug.
2121 config APM_DO_ENABLE
2122 bool "Enable PM at boot time"
2124 Enable APM features at boot time. From page 36 of the APM BIOS
2125 specification: "When disabled, the APM BIOS does not automatically
2126 power manage devices, enter the Standby State, enter the Suspend
2127 State, or take power saving steps in response to CPU Idle calls."
2128 This driver will make CPU Idle calls when Linux is idle (unless this
2129 feature is turned off -- see "Do CPU IDLE calls", below). This
2130 should always save battery power, but more complicated APM features
2131 will be dependent on your BIOS implementation. You may need to turn
2132 this option off if your computer hangs at boot time when using APM
2133 support, or if it beeps continuously instead of suspending. Turn
2134 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2135 T400CDT. This is off by default since most machines do fine without
2140 bool "Make CPU Idle calls when idle"
2142 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2143 On some machines, this can activate improved power savings, such as
2144 a slowed CPU clock rate, when the machine is idle. These idle calls
2145 are made after the idle loop has run for some length of time (e.g.,
2146 333 mS). On some machines, this will cause a hang at boot time or
2147 whenever the CPU becomes idle. (On machines with more than one CPU,
2148 this option does nothing.)
2150 config APM_DISPLAY_BLANK
2151 bool "Enable console blanking using APM"
2153 Enable console blanking using the APM. Some laptops can use this to
2154 turn off the LCD backlight when the screen blanker of the Linux
2155 virtual console blanks the screen. Note that this is only used by
2156 the virtual console screen blanker, and won't turn off the backlight
2157 when using the X Window system. This also doesn't have anything to
2158 do with your VESA-compliant power-saving monitor. Further, this
2159 option doesn't work for all laptops -- it might not turn off your
2160 backlight at all, or it might print a lot of errors to the console,
2161 especially if you are using gpm.
2163 config APM_ALLOW_INTS
2164 bool "Allow interrupts during APM BIOS calls"
2166 Normally we disable external interrupts while we are making calls to
2167 the APM BIOS as a measure to lessen the effects of a badly behaving
2168 BIOS implementation. The BIOS should reenable interrupts if it
2169 needs to. Unfortunately, some BIOSes do not -- especially those in
2170 many of the newer IBM Thinkpads. If you experience hangs when you
2171 suspend, try setting this to Y. Otherwise, say N.
2175 source "drivers/cpufreq/Kconfig"
2177 source "drivers/cpuidle/Kconfig"
2179 source "drivers/idle/Kconfig"
2184 menu "Bus options (PCI etc.)"
2190 Find out whether you have a PCI motherboard. PCI is the name of a
2191 bus system, i.e. the way the CPU talks to the other stuff inside
2192 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2193 VESA. If you have PCI, say Y, otherwise N.
2196 prompt "PCI access mode"
2197 depends on X86_32 && PCI
2200 On PCI systems, the BIOS can be used to detect the PCI devices and
2201 determine their configuration. However, some old PCI motherboards
2202 have BIOS bugs and may crash if this is done. Also, some embedded
2203 PCI-based systems don't have any BIOS at all. Linux can also try to
2204 detect the PCI hardware directly without using the BIOS.
2206 With this option, you can specify how Linux should detect the
2207 PCI devices. If you choose "BIOS", the BIOS will be used,
2208 if you choose "Direct", the BIOS won't be used, and if you
2209 choose "MMConfig", then PCI Express MMCONFIG will be used.
2210 If you choose "Any", the kernel will try MMCONFIG, then the
2211 direct access method and falls back to the BIOS if that doesn't
2212 work. If unsure, go with the default, which is "Any".
2217 config PCI_GOMMCONFIG
2234 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2236 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2239 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2243 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2247 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2251 depends on PCI && XEN
2259 bool "Support mmconfig PCI config space access"
2260 depends on X86_64 && PCI && ACPI
2262 config PCI_CNB20LE_QUIRK
2263 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2266 Read the PCI windows out of the CNB20LE host bridge. This allows
2267 PCI hotplug to work on systems with the CNB20LE chipset which do
2270 There's no public spec for this chipset, and this functionality
2271 is known to be incomplete.
2273 You should say N unless you know you need this.
2275 source "drivers/pci/pcie/Kconfig"
2277 source "drivers/pci/Kconfig"
2279 # x86_64 have no ISA slots, but can have ISA-style DMA.
2281 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2284 Enables ISA-style DMA support for devices requiring such controllers.
2292 Find out whether you have ISA slots on your motherboard. ISA is the
2293 name of a bus system, i.e. the way the CPU talks to the other stuff
2294 inside your box. Other bus systems are PCI, EISA, MicroChannel
2295 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2296 newer boards don't support it. If you have ISA, say Y, otherwise N.
2302 The Extended Industry Standard Architecture (EISA) bus was
2303 developed as an open alternative to the IBM MicroChannel bus.
2305 The EISA bus provided some of the features of the IBM MicroChannel
2306 bus while maintaining backward compatibility with cards made for
2307 the older ISA bus. The EISA bus saw limited use between 1988 and
2308 1995 when it was made obsolete by the PCI bus.
2310 Say Y here if you are building a kernel for an EISA-based machine.
2314 source "drivers/eisa/Kconfig"
2317 tristate "NatSemi SCx200 support"
2319 This provides basic support for National Semiconductor's
2320 (now AMD's) Geode processors. The driver probes for the
2321 PCI-IDs of several on-chip devices, so its a good dependency
2322 for other scx200_* drivers.
2324 If compiled as a module, the driver is named scx200.
2326 config SCx200HR_TIMER
2327 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2331 This driver provides a clocksource built upon the on-chip
2332 27MHz high-resolution timer. Its also a workaround for
2333 NSC Geode SC-1100's buggy TSC, which loses time when the
2334 processor goes idle (as is done by the scheduler). The
2335 other workaround is idle=poll boot option.
2338 bool "One Laptop Per Child support"
2345 Add support for detecting the unique features of the OLPC
2349 bool "OLPC XO-1 Power Management"
2350 depends on OLPC && MFD_CS5535 && PM_SLEEP
2353 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2356 bool "OLPC XO-1 Real Time Clock"
2357 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2359 Add support for the XO-1 real time clock, which can be used as a
2360 programmable wakeup source.
2363 bool "OLPC XO-1 SCI extras"
2364 depends on OLPC && OLPC_XO1_PM
2370 Add support for SCI-based features of the OLPC XO-1 laptop:
2371 - EC-driven system wakeups
2375 - AC adapter status updates
2376 - Battery status updates
2378 config OLPC_XO15_SCI
2379 bool "OLPC XO-1.5 SCI extras"
2380 depends on OLPC && ACPI
2383 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2384 - EC-driven system wakeups
2385 - AC adapter status updates
2386 - Battery status updates
2389 bool "PCEngines ALIX System Support (LED setup)"
2392 This option enables system support for the PCEngines ALIX.
2393 At present this just sets up LEDs for GPIO control on
2394 ALIX2/3/6 boards. However, other system specific setup should
2397 Note: You must still enable the drivers for GPIO and LED support
2398 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2400 Note: You have to set alix.force=1 for boards with Award BIOS.
2403 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2406 This option enables system support for the Soekris Engineering net5501.
2409 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2413 This option enables system support for the Traverse Technologies GEOS.
2416 bool "Technologic Systems TS-5500 platform support"
2418 select CHECK_SIGNATURE
2422 This option enables system support for the Technologic Systems TS-5500.
2428 depends on CPU_SUP_AMD && PCI
2430 source "drivers/pcmcia/Kconfig"
2432 source "drivers/pci/hotplug/Kconfig"
2435 tristate "RapidIO support"
2439 If enabled this option will include drivers and the core
2440 infrastructure code to support RapidIO interconnect devices.
2442 source "drivers/rapidio/Kconfig"
2445 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2447 Firmwares often provide initial graphics framebuffers so the BIOS,
2448 bootloader or kernel can show basic video-output during boot for
2449 user-guidance and debugging. Historically, x86 used the VESA BIOS
2450 Extensions and EFI-framebuffers for this, which are mostly limited
2452 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2453 framebuffers so the new generic system-framebuffer drivers can be
2454 used on x86. If the framebuffer is not compatible with the generic
2455 modes, it is adverticed as fallback platform framebuffer so legacy
2456 drivers like efifb, vesafb and uvesafb can pick it up.
2457 If this option is not selected, all system framebuffers are always
2458 marked as fallback platform framebuffers as usual.
2460 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2461 not be able to pick up generic system framebuffers if this option
2462 is selected. You are highly encouraged to enable simplefb as
2463 replacement if you select this option. simplefb can correctly deal
2464 with generic system framebuffers. But you should still keep vesafb
2465 and others enabled as fallback if a system framebuffer is
2466 incompatible with simplefb.
2473 menu "Executable file formats / Emulations"
2475 source "fs/Kconfig.binfmt"
2477 config IA32_EMULATION
2478 bool "IA32 Emulation"
2481 select COMPAT_BINFMT_ELF
2484 Include code to run legacy 32-bit programs under a
2485 64-bit kernel. You should likely turn this on, unless you're
2486 100% sure that you don't have any 32-bit programs left.
2489 tristate "IA32 a.out support"
2490 depends on IA32_EMULATION
2492 Support old a.out binaries in the 32bit emulation.
2495 bool "x32 ABI for 64-bit mode"
2496 depends on X86_64 && IA32_EMULATION
2498 Include code to run binaries for the x32 native 32-bit ABI
2499 for 64-bit processors. An x32 process gets access to the
2500 full 64-bit register file and wide data path while leaving
2501 pointers at 32 bits for smaller memory footprint.
2503 You will need a recent binutils (2.22 or later) with
2504 elf32_x86_64 support enabled to compile a kernel with this
2509 depends on IA32_EMULATION || X86_X32
2510 select ARCH_WANT_OLD_COMPAT_IPC
2513 config COMPAT_FOR_U64_ALIGNMENT
2516 config SYSVIPC_COMPAT
2528 config HAVE_ATOMIC_IOMAP
2532 config X86_DEV_DMA_OPS
2534 depends on X86_64 || STA2X11
2536 config X86_DMA_REMAP
2544 source "net/Kconfig"
2546 source "drivers/Kconfig"
2548 source "drivers/firmware/Kconfig"
2552 source "arch/x86/Kconfig.debug"
2554 source "security/Kconfig"
2556 source "crypto/Kconfig"
2558 source "arch/x86/kvm/Kconfig"
2560 source "lib/Kconfig"
projects / cascardo / linux.git / blob