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
25 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
27 select ARCH_HAS_FAST_MULTIPLIER
28 select ARCH_HAS_GCOV_PROFILE_ALL
29 select ARCH_MIGHT_HAVE_PC_PARPORT
30 select ARCH_MIGHT_HAVE_PC_SERIO
31 select HAVE_AOUT if X86_32
32 select HAVE_UNSTABLE_SCHED_CLOCK
33 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
34 select ARCH_SUPPORTS_INT128 if X86_64
37 select HAVE_PCSPKR_PLATFORM
38 select HAVE_PERF_EVENTS
39 select HAVE_IOREMAP_PROT
42 select HAVE_MEMBLOCK_NODE_MAP
43 select ARCH_DISCARD_MEMBLOCK
44 select ARCH_WANT_OPTIONAL_GPIOLIB
45 select ARCH_WANT_FRAME_POINTERS
47 select HAVE_DMA_CONTIGUOUS
48 select HAVE_KRETPROBES
49 select GENERIC_EARLY_IOREMAP
51 select HAVE_KPROBES_ON_FTRACE
52 select HAVE_FTRACE_MCOUNT_RECORD
53 select HAVE_FENTRY if X86_64
54 select HAVE_C_RECORDMCOUNT
55 select HAVE_DYNAMIC_FTRACE
56 select HAVE_DYNAMIC_FTRACE_WITH_REGS
57 select HAVE_FUNCTION_TRACER
58 select HAVE_FUNCTION_GRAPH_TRACER
59 select HAVE_FUNCTION_GRAPH_FP_TEST
60 select HAVE_SYSCALL_TRACEPOINTS
61 select SYSCTL_EXCEPTION_TRACE
64 select HAVE_ARCH_TRACEHOOK
65 select HAVE_GENERIC_DMA_COHERENT if X86_32
66 select HAVE_EFFICIENT_UNALIGNED_ACCESS
67 select USER_STACKTRACE_SUPPORT
68 select HAVE_REGS_AND_STACK_ACCESS_API
69 select HAVE_DMA_API_DEBUG
70 select HAVE_KERNEL_GZIP
71 select HAVE_KERNEL_BZIP2
72 select HAVE_KERNEL_LZMA
74 select HAVE_KERNEL_LZO
75 select HAVE_KERNEL_LZ4
76 select HAVE_HW_BREAKPOINT
77 select HAVE_MIXED_BREAKPOINTS_REGS
79 select HAVE_PERF_EVENTS_NMI
81 select HAVE_PERF_USER_STACK_DUMP
82 select HAVE_DEBUG_KMEMLEAK
84 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
85 select HAVE_CMPXCHG_LOCAL
86 select HAVE_CMPXCHG_DOUBLE
87 select HAVE_ARCH_KMEMCHECK
88 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
89 select HAVE_USER_RETURN_NOTIFIER
90 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
91 select HAVE_ARCH_JUMP_LABEL
92 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
94 select GENERIC_FIND_FIRST_BIT
95 select GENERIC_IRQ_PROBE
96 select GENERIC_PENDING_IRQ if SMP
97 select GENERIC_IRQ_SHOW
98 select GENERIC_CLOCKEVENTS_MIN_ADJUST
99 select IRQ_FORCED_THREADING
100 select HAVE_BPF_JIT if X86_64
101 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
102 select ARCH_HAS_SG_CHAIN
104 select ARCH_HAVE_NMI_SAFE_CMPXCHG
106 select DCACHE_WORD_ACCESS
107 select GENERIC_SMP_IDLE_THREAD
108 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
109 select HAVE_ARCH_SECCOMP_FILTER
110 select BUILDTIME_EXTABLE_SORT
111 select GENERIC_CMOS_UPDATE
112 select HAVE_ARCH_SOFT_DIRTY if X86_64
113 select CLOCKSOURCE_WATCHDOG
114 select GENERIC_CLOCKEVENTS
115 select ARCH_CLOCKSOURCE_DATA
116 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
117 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
118 select GENERIC_TIME_VSYSCALL
119 select GENERIC_STRNCPY_FROM_USER
120 select GENERIC_STRNLEN_USER
121 select HAVE_CONTEXT_TRACKING if X86_64
122 select HAVE_IRQ_TIME_ACCOUNTING
124 select MODULES_USE_ELF_REL if X86_32
125 select MODULES_USE_ELF_RELA if X86_64
126 select CLONE_BACKWARDS if X86_32
127 select ARCH_USE_BUILTIN_BSWAP
128 select ARCH_USE_QUEUE_RWLOCK
129 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
130 select OLD_SIGACTION if X86_32
131 select COMPAT_OLD_SIGACTION if IA32_EMULATION
133 select HAVE_DEBUG_STACKOVERFLOW
134 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
135 select HAVE_CC_STACKPROTECTOR
136 select GENERIC_CPU_AUTOPROBE
137 select HAVE_ARCH_AUDITSYSCALL
138 select ARCH_SUPPORTS_ATOMIC_RMW
139 select HAVE_ACPI_APEI if ACPI
140 select HAVE_ACPI_APEI_NMI if ACPI
141 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
142 select X86_FEATURE_NAMES if PROC_FS
145 config INSTRUCTION_DECODER
147 depends on KPROBES || PERF_EVENTS || UPROBES
149 config PERF_EVENTS_INTEL_UNCORE
151 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
155 default "elf32-i386" if X86_32
156 default "elf64-x86-64" if X86_64
158 config ARCH_DEFCONFIG
160 default "arch/x86/configs/i386_defconfig" if X86_32
161 default "arch/x86/configs/x86_64_defconfig" if X86_64
163 config LOCKDEP_SUPPORT
166 config STACKTRACE_SUPPORT
169 config HAVE_LATENCYTOP_SUPPORT
178 config NEED_DMA_MAP_STATE
180 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
182 config NEED_SG_DMA_LENGTH
185 config GENERIC_ISA_DMA
187 depends on ISA_DMA_API
192 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
194 config GENERIC_BUG_RELATIVE_POINTERS
197 config GENERIC_HWEIGHT
200 config ARCH_MAY_HAVE_PC_FDC
202 depends on ISA_DMA_API
204 config RWSEM_XCHGADD_ALGORITHM
207 config GENERIC_CALIBRATE_DELAY
210 config ARCH_HAS_CPU_RELAX
213 config ARCH_HAS_CACHE_LINE_SIZE
216 config HAVE_SETUP_PER_CPU_AREA
219 config NEED_PER_CPU_EMBED_FIRST_CHUNK
222 config NEED_PER_CPU_PAGE_FIRST_CHUNK
225 config ARCH_HIBERNATION_POSSIBLE
228 config ARCH_SUSPEND_POSSIBLE
231 config ARCH_WANT_HUGE_PMD_SHARE
234 config ARCH_WANT_GENERAL_HUGETLB
245 config ARCH_SUPPORTS_OPTIMIZED_INLINING
248 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
251 config HAVE_INTEL_TXT
253 depends on INTEL_IOMMU && ACPI
257 depends on X86_32 && SMP
261 depends on X86_64 && SMP
267 config X86_32_LAZY_GS
269 depends on X86_32 && !CC_STACKPROTECTOR
271 config ARCH_HWEIGHT_CFLAGS
273 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
274 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
276 config ARCH_SUPPORTS_UPROBES
279 config FIX_EARLYCON_MEM
282 source "init/Kconfig"
283 source "kernel/Kconfig.freezer"
285 menu "Processor type and features"
288 bool "DMA memory allocation support" if EXPERT
291 DMA memory allocation support allows devices with less than 32-bit
292 addressing to allocate within the first 16MB of address space.
293 Disable if no such devices will be used.
298 bool "Symmetric multi-processing support"
300 This enables support for systems with more than one CPU. If you have
301 a system with only one CPU, say N. If you have a system with more
304 If you say N here, the kernel will run on uni- and multiprocessor
305 machines, but will use only one CPU of a multiprocessor machine. If
306 you say Y here, the kernel will run on many, but not all,
307 uniprocessor machines. On a uniprocessor machine, the kernel
308 will run faster if you say N here.
310 Note that if you say Y here and choose architecture "586" or
311 "Pentium" under "Processor family", the kernel will not work on 486
312 architectures. Similarly, multiprocessor kernels for the "PPro"
313 architecture may not work on all Pentium based boards.
315 People using multiprocessor machines who say Y here should also say
316 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
317 Management" code will be disabled if you say Y here.
319 See also <file:Documentation/x86/i386/IO-APIC.txt>,
320 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
321 <http://www.tldp.org/docs.html#howto>.
323 If you don't know what to do here, say N.
325 config X86_FEATURE_NAMES
326 bool "Processor feature human-readable names" if EMBEDDED
329 This option compiles in a table of x86 feature bits and corresponding
330 names. This is required to support /proc/cpuinfo and a few kernel
331 messages. You can disable this to save space, at the expense of
332 making those few kernel messages show numeric feature bits instead.
337 bool "Support x2apic"
338 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
340 This enables x2apic support on CPUs that have this feature.
342 This allows 32-bit apic IDs (so it can support very large systems),
343 and accesses the local apic via MSRs not via mmio.
345 If you don't know what to do here, say N.
348 bool "Enable MPS table" if ACPI || SFI
350 depends on X86_LOCAL_APIC
352 For old smp systems that do not have proper acpi support. Newer systems
353 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
356 bool "Support for big SMP systems with more than 8 CPUs"
357 depends on X86_32 && SMP
359 This option is needed for the systems that have more than 8 CPUs
363 depends on X86_GOLDFISH
366 config X86_EXTENDED_PLATFORM
367 bool "Support for extended (non-PC) x86 platforms"
370 If you disable this option then the kernel will only support
371 standard PC platforms. (which covers the vast majority of
374 If you enable this option then you'll be able to select support
375 for the following (non-PC) 32 bit x86 platforms:
376 Goldfish (Android emulator)
379 SGI 320/540 (Visual Workstation)
380 STA2X11-based (e.g. Northville)
381 Moorestown MID devices
383 If you have one of these systems, or if you want to build a
384 generic distribution kernel, say Y here - otherwise say N.
388 config X86_EXTENDED_PLATFORM
389 bool "Support for extended (non-PC) x86 platforms"
392 If you disable this option then the kernel will only support
393 standard PC platforms. (which covers the vast majority of
396 If you enable this option then you'll be able to select support
397 for the following (non-PC) 64 bit x86 platforms:
402 If you have one of these systems, or if you want to build a
403 generic distribution kernel, say Y here - otherwise say N.
405 # This is an alphabetically sorted list of 64 bit extended platforms
406 # Please maintain the alphabetic order if and when there are additions
408 bool "Numascale NumaChip"
410 depends on X86_EXTENDED_PLATFORM
413 depends on X86_X2APIC
414 depends on PCI_MMCONFIG
416 Adds support for Numascale NumaChip large-SMP systems. Needed to
417 enable more than ~168 cores.
418 If you don't have one of these, you should say N here.
422 select HYPERVISOR_GUEST
424 depends on X86_64 && PCI
425 depends on X86_EXTENDED_PLATFORM
428 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
429 supposed to run on these EM64T-based machines. Only choose this option
430 if you have one of these machines.
433 bool "SGI Ultraviolet"
435 depends on X86_EXTENDED_PLATFORM
437 depends on X86_X2APIC
439 This option is needed in order to support SGI Ultraviolet systems.
440 If you don't have one of these, you should say N here.
442 # Following is an alphabetically sorted list of 32 bit extended platforms
443 # Please maintain the alphabetic order if and when there are additions
446 bool "Goldfish (Virtual Platform)"
447 depends on X86_EXTENDED_PLATFORM
449 Enable support for the Goldfish virtual platform used primarily
450 for Android development. Unless you are building for the Android
451 Goldfish emulator say N here.
454 bool "CE4100 TV platform"
456 depends on PCI_GODIRECT
457 depends on X86_IO_APIC
459 depends on X86_EXTENDED_PLATFORM
460 select X86_REBOOTFIXUPS
462 select OF_EARLY_FLATTREE
465 Select for the Intel CE media processor (CE4100) SOC.
466 This option compiles in support for the CE4100 SOC for settop
467 boxes and media devices.
470 bool "Intel MID platform support"
472 depends on X86_EXTENDED_PLATFORM
473 depends on X86_PLATFORM_DEVICES
476 depends on X86_IO_APIC
482 select MFD_INTEL_MSIC
484 Select to build a kernel capable of supporting Intel MID (Mobile
485 Internet Device) platform systems which do not have the PCI legacy
486 interfaces. If you are building for a PC class system say N here.
488 Intel MID platforms are based on an Intel processor and chipset which
489 consume less power than most of the x86 derivatives.
491 config X86_INTEL_QUARK
492 bool "Intel Quark platform support"
494 depends on X86_EXTENDED_PLATFORM
495 depends on X86_PLATFORM_DEVICES
499 depends on X86_IO_APIC
504 Select to include support for Quark X1000 SoC.
505 Say Y here if you have a Quark based system such as the Arduino
506 compatible Intel Galileo.
508 config X86_INTEL_LPSS
509 bool "Intel Low Power Subsystem Support"
514 Select to build support for Intel Low Power Subsystem such as
515 found on Intel Lynxpoint PCH. Selecting this option enables
516 things like clock tree (common clock framework) and pincontrol
517 which are needed by the LPSS peripheral drivers.
519 config X86_AMD_PLATFORM_DEVICE
520 bool "AMD ACPI2Platform devices support"
525 Select to interpret AMD specific ACPI device to platform device
526 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
527 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
528 implemented under PINCTRL subsystem.
531 tristate "Intel SoC IOSF Sideband support for SoC platforms"
534 This option enables sideband register access support for Intel SoC
535 platforms. On these platforms the IOSF sideband is used in lieu of
536 MSR's for some register accesses, mostly but not limited to thermal
537 and power. Drivers may query the availability of this device to
538 determine if they need the sideband in order to work on these
539 platforms. The sideband is available on the following SoC products.
540 This list is not meant to be exclusive.
545 You should say Y if you are running a kernel on one of these SoC's.
547 config IOSF_MBI_DEBUG
548 bool "Enable IOSF sideband access through debugfs"
549 depends on IOSF_MBI && DEBUG_FS
551 Select this option to expose the IOSF sideband access registers (MCR,
552 MDR, MCRX) through debugfs to write and read register information from
553 different units on the SoC. This is most useful for obtaining device
554 state information for debug and analysis. As this is a general access
555 mechanism, users of this option would have specific knowledge of the
556 device they want to access.
558 If you don't require the option or are in doubt, say N.
561 bool "RDC R-321x SoC"
563 depends on X86_EXTENDED_PLATFORM
565 select X86_REBOOTFIXUPS
567 This option is needed for RDC R-321x system-on-chip, also known
569 If you don't have one of these chips, you should say N here.
571 config X86_32_NON_STANDARD
572 bool "Support non-standard 32-bit SMP architectures"
573 depends on X86_32 && SMP
574 depends on X86_EXTENDED_PLATFORM
576 This option compiles in the bigsmp and STA2X11 default
577 subarchitectures. It is intended for a generic binary
578 kernel. If you select them all, kernel will probe it one by
579 one and will fallback to default.
581 # Alphabetically sorted list of Non standard 32 bit platforms
583 config X86_SUPPORTS_MEMORY_FAILURE
585 # MCE code calls memory_failure():
587 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
588 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
589 depends on X86_64 || !SPARSEMEM
590 select ARCH_SUPPORTS_MEMORY_FAILURE
593 bool "STA2X11 Companion Chip Support"
594 depends on X86_32_NON_STANDARD && PCI
595 select X86_DEV_DMA_OPS
599 select ARCH_REQUIRE_GPIOLIB
602 This adds support for boards based on the STA2X11 IO-Hub,
603 a.k.a. "ConneXt". The chip is used in place of the standard
604 PC chipset, so all "standard" peripherals are missing. If this
605 option is selected the kernel will still be able to boot on
606 standard PC machines.
609 tristate "Eurobraille/Iris poweroff module"
612 The Iris machines from EuroBraille do not have APM or ACPI support
613 to shut themselves down properly. A special I/O sequence is
614 needed to do so, which is what this module does at
617 This is only for Iris machines from EuroBraille.
621 config SCHED_OMIT_FRAME_POINTER
623 prompt "Single-depth WCHAN output"
626 Calculate simpler /proc/<PID>/wchan values. If this option
627 is disabled then wchan values will recurse back to the
628 caller function. This provides more accurate wchan values,
629 at the expense of slightly more scheduling overhead.
631 If in doubt, say "Y".
633 menuconfig HYPERVISOR_GUEST
634 bool "Linux guest support"
636 Say Y here to enable options for running Linux under various hyper-
637 visors. This option enables basic hypervisor detection and platform
640 If you say N, all options in this submenu will be skipped and
641 disabled, and Linux guest support won't be built in.
646 bool "Enable paravirtualization code"
648 This changes the kernel so it can modify itself when it is run
649 under a hypervisor, potentially improving performance significantly
650 over full virtualization. However, when run without a hypervisor
651 the kernel is theoretically slower and slightly larger.
653 config PARAVIRT_DEBUG
654 bool "paravirt-ops debugging"
655 depends on PARAVIRT && DEBUG_KERNEL
657 Enable to debug paravirt_ops internals. Specifically, BUG if
658 a paravirt_op is missing when it is called.
660 config PARAVIRT_SPINLOCKS
661 bool "Paravirtualization layer for spinlocks"
662 depends on PARAVIRT && SMP
663 select UNINLINE_SPIN_UNLOCK
665 Paravirtualized spinlocks allow a pvops backend to replace the
666 spinlock implementation with something virtualization-friendly
667 (for example, block the virtual CPU rather than spinning).
669 It has a minimal impact on native kernels and gives a nice performance
670 benefit on paravirtualized KVM / Xen kernels.
672 If you are unsure how to answer this question, answer Y.
674 source "arch/x86/xen/Kconfig"
677 bool "KVM Guest support (including kvmclock)"
679 select PARAVIRT_CLOCK
682 This option enables various optimizations for running under the KVM
683 hypervisor. It includes a paravirtualized clock, so that instead
684 of relying on a PIT (or probably other) emulation by the
685 underlying device model, the host provides the guest with
686 timing infrastructure such as time of day, and system time
689 bool "Enable debug information for KVM Guests in debugfs"
690 depends on KVM_GUEST && DEBUG_FS
693 This option enables collection of various statistics for KVM guest.
694 Statistics are displayed in debugfs filesystem. Enabling this option
695 may incur significant overhead.
697 source "arch/x86/lguest/Kconfig"
699 config PARAVIRT_TIME_ACCOUNTING
700 bool "Paravirtual steal time accounting"
704 Select this option to enable fine granularity task steal time
705 accounting. Time spent executing other tasks in parallel with
706 the current vCPU is discounted from the vCPU power. To account for
707 that, there can be a small performance impact.
709 If in doubt, say N here.
711 config PARAVIRT_CLOCK
714 endif #HYPERVISOR_GUEST
722 This option adds a kernel parameter 'memtest', which allows memtest
724 memtest=0, mean disabled; -- default
725 memtest=1, mean do 1 test pattern;
727 memtest=4, mean do 4 test patterns.
728 If you are unsure how to answer this question, answer N.
730 source "arch/x86/Kconfig.cpu"
734 prompt "HPET Timer Support" if X86_32
736 Use the IA-PC HPET (High Precision Event Timer) to manage
737 time in preference to the PIT and RTC, if a HPET is
739 HPET is the next generation timer replacing legacy 8254s.
740 The HPET provides a stable time base on SMP
741 systems, unlike the TSC, but it is more expensive to access,
742 as it is off-chip. You can find the HPET spec at
743 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
745 You can safely choose Y here. However, HPET will only be
746 activated if the platform and the BIOS support this feature.
747 Otherwise the 8254 will be used for timing services.
749 Choose N to continue using the legacy 8254 timer.
751 config HPET_EMULATE_RTC
753 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
756 def_bool y if X86_INTEL_MID
757 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
759 depends on X86_INTEL_MID && SFI
761 APB timer is the replacement for 8254, HPET on X86 MID platforms.
762 The APBT provides a stable time base on SMP
763 systems, unlike the TSC, but it is more expensive to access,
764 as it is off-chip. APB timers are always running regardless of CPU
765 C states, they are used as per CPU clockevent device when possible.
767 # Mark as expert because too many people got it wrong.
768 # The code disables itself when not needed.
771 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
772 bool "Enable DMI scanning" if EXPERT
774 Enabled scanning of DMI to identify machine quirks. Say Y
775 here unless you have verified that your setup is not
776 affected by entries in the DMI blacklist. Required by PNP
780 bool "Old AMD GART IOMMU support"
782 depends on X86_64 && PCI && AMD_NB
784 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
785 GART based hardware IOMMUs.
787 The GART supports full DMA access for devices with 32-bit access
788 limitations, on systems with more than 3 GB. This is usually needed
789 for USB, sound, many IDE/SATA chipsets and some other devices.
791 Newer systems typically have a modern AMD IOMMU, supported via
792 the CONFIG_AMD_IOMMU=y config option.
794 In normal configurations this driver is only active when needed:
795 there's more than 3 GB of memory and the system contains a
796 32-bit limited device.
801 bool "IBM Calgary IOMMU support"
803 depends on X86_64 && PCI
805 Support for hardware IOMMUs in IBM's xSeries x366 and x460
806 systems. Needed to run systems with more than 3GB of memory
807 properly with 32-bit PCI devices that do not support DAC
808 (Double Address Cycle). Calgary also supports bus level
809 isolation, where all DMAs pass through the IOMMU. This
810 prevents them from going anywhere except their intended
811 destination. This catches hard-to-find kernel bugs and
812 mis-behaving drivers and devices that do not use the DMA-API
813 properly to set up their DMA buffers. The IOMMU can be
814 turned off at boot time with the iommu=off parameter.
815 Normally the kernel will make the right choice by itself.
818 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
820 prompt "Should Calgary be enabled by default?"
821 depends on CALGARY_IOMMU
823 Should Calgary be enabled by default? if you choose 'y', Calgary
824 will be used (if it exists). If you choose 'n', Calgary will not be
825 used even if it exists. If you choose 'n' and would like to use
826 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
829 # need this always selected by IOMMU for the VIA workaround
833 Support for software bounce buffers used on x86-64 systems
834 which don't have a hardware IOMMU. Using this PCI devices
835 which can only access 32-bits of memory can be used on systems
836 with more than 3 GB of memory.
841 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
844 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
845 depends on X86_64 && SMP && DEBUG_KERNEL
846 select CPUMASK_OFFSTACK
848 Enable maximum number of CPUS and NUMA Nodes for this architecture.
852 int "Maximum number of CPUs" if SMP && !MAXSMP
853 range 2 8 if SMP && X86_32 && !X86_BIGSMP
854 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
855 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
857 default "8192" if MAXSMP
858 default "32" if SMP && X86_BIGSMP
861 This allows you to specify the maximum number of CPUs which this
862 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
863 supported value is 4096, otherwise the maximum value is 512. The
864 minimum value which makes sense is 2.
866 This is purely to save memory - each supported CPU adds
867 approximately eight kilobytes to the kernel image.
870 bool "SMT (Hyperthreading) scheduler support"
873 SMT scheduler support improves the CPU scheduler's decision making
874 when dealing with Intel Pentium 4 chips with HyperThreading at a
875 cost of slightly increased overhead in some places. If unsure say
880 prompt "Multi-core scheduler support"
883 Multi-core scheduler support improves the CPU scheduler's decision
884 making when dealing with multi-core CPU chips at a cost of slightly
885 increased overhead in some places. If unsure say N here.
887 source "kernel/Kconfig.preempt"
891 depends on !SMP && X86_LOCAL_APIC
894 bool "Local APIC support on uniprocessors"
895 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
897 A local APIC (Advanced Programmable Interrupt Controller) is an
898 integrated interrupt controller in the CPU. If you have a single-CPU
899 system which has a processor with a local APIC, you can say Y here to
900 enable and use it. If you say Y here even though your machine doesn't
901 have a local APIC, then the kernel will still run with no slowdown at
902 all. The local APIC supports CPU-generated self-interrupts (timer,
903 performance counters), and the NMI watchdog which detects hard
906 config X86_UP_APIC_MSI
908 select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
911 bool "IO-APIC support on uniprocessors"
912 depends on X86_UP_APIC
914 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
915 SMP-capable replacement for PC-style interrupt controllers. Most
916 SMP systems and many recent uniprocessor systems have one.
918 If you have a single-CPU system with an IO-APIC, you can say Y here
919 to use it. If you say Y here even though your machine doesn't have
920 an IO-APIC, then the kernel will still run with no slowdown at all.
922 config X86_LOCAL_APIC
924 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
925 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
928 def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
929 depends on X86_LOCAL_APIC
932 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
933 bool "Reroute for broken boot IRQs"
934 depends on X86_IO_APIC
936 This option enables a workaround that fixes a source of
937 spurious interrupts. This is recommended when threaded
938 interrupt handling is used on systems where the generation of
939 superfluous "boot interrupts" cannot be disabled.
941 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
942 entry in the chipset's IO-APIC is masked (as, e.g. the RT
943 kernel does during interrupt handling). On chipsets where this
944 boot IRQ generation cannot be disabled, this workaround keeps
945 the original IRQ line masked so that only the equivalent "boot
946 IRQ" is delivered to the CPUs. The workaround also tells the
947 kernel to set up the IRQ handler on the boot IRQ line. In this
948 way only one interrupt is delivered to the kernel. Otherwise
949 the spurious second interrupt may cause the kernel to bring
950 down (vital) interrupt lines.
952 Only affects "broken" chipsets. Interrupt sharing may be
953 increased on these systems.
956 bool "Machine Check / overheating reporting"
959 Machine Check support allows the processor to notify the
960 kernel if it detects a problem (e.g. overheating, data corruption).
961 The action the kernel takes depends on the severity of the problem,
962 ranging from warning messages to halting the machine.
966 prompt "Intel MCE features"
967 depends on X86_MCE && X86_LOCAL_APIC
969 Additional support for intel specific MCE features such as
974 prompt "AMD MCE features"
975 depends on X86_MCE && X86_LOCAL_APIC
977 Additional support for AMD specific MCE features such as
978 the DRAM Error Threshold.
980 config X86_ANCIENT_MCE
981 bool "Support for old Pentium 5 / WinChip machine checks"
982 depends on X86_32 && X86_MCE
984 Include support for machine check handling on old Pentium 5 or WinChip
985 systems. These typically need to be enabled explicitly on the command
988 config X86_MCE_THRESHOLD
989 depends on X86_MCE_AMD || X86_MCE_INTEL
992 config X86_MCE_INJECT
994 tristate "Machine check injector support"
996 Provide support for injecting machine checks for testing purposes.
997 If you don't know what a machine check is and you don't do kernel
998 QA it is safe to say n.
1000 config X86_THERMAL_VECTOR
1002 depends on X86_MCE_INTEL
1005 bool "Enable VM86 support" if EXPERT
1009 This option is required by programs like DOSEMU to run
1010 16-bit real mode legacy code on x86 processors. It also may
1011 be needed by software like XFree86 to initialize some video
1012 cards via BIOS. Disabling this option saves about 6K.
1015 bool "Enable support for 16-bit segments" if EXPERT
1018 This option is required by programs like Wine to run 16-bit
1019 protected mode legacy code on x86 processors. Disabling
1020 this option saves about 300 bytes on i386, or around 6K text
1021 plus 16K runtime memory on x86-64,
1025 depends on X86_16BIT && X86_32
1029 depends on X86_16BIT && X86_64
1031 config X86_VSYSCALL_EMULATION
1032 bool "Enable vsyscall emulation" if EXPERT
1036 This enables emulation of the legacy vsyscall page. Disabling
1037 it is roughly equivalent to booting with vsyscall=none, except
1038 that it will also disable the helpful warning if a program
1039 tries to use a vsyscall. With this option set to N, offending
1040 programs will just segfault, citing addresses of the form
1043 This option is required by many programs built before 2013, and
1044 care should be used even with newer programs if set to N.
1046 Disabling this option saves about 7K of kernel size and
1047 possibly 4K of additional runtime pagetable memory.
1050 tristate "Toshiba Laptop support"
1053 This adds a driver to safely access the System Management Mode of
1054 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1055 not work on models with a Phoenix BIOS. The System Management Mode
1056 is used to set the BIOS and power saving options on Toshiba portables.
1058 For information on utilities to make use of this driver see the
1059 Toshiba Linux utilities web site at:
1060 <http://www.buzzard.org.uk/toshiba/>.
1062 Say Y if you intend to run this kernel on a Toshiba portable.
1066 tristate "Dell laptop support"
1069 This adds a driver to safely access the System Management Mode
1070 of the CPU on the Dell Inspiron 8000. The System Management Mode
1071 is used to read cpu temperature and cooling fan status and to
1072 control the fans on the I8K portables.
1074 This driver has been tested only on the Inspiron 8000 but it may
1075 also work with other Dell laptops. You can force loading on other
1076 models by passing the parameter `force=1' to the module. Use at
1079 For information on utilities to make use of this driver see the
1080 I8K Linux utilities web site at:
1081 <http://people.debian.org/~dz/i8k/>
1083 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1086 config X86_REBOOTFIXUPS
1087 bool "Enable X86 board specific fixups for reboot"
1090 This enables chipset and/or board specific fixups to be done
1091 in order to get reboot to work correctly. This is only needed on
1092 some combinations of hardware and BIOS. The symptom, for which
1093 this config is intended, is when reboot ends with a stalled/hung
1096 Currently, the only fixup is for the Geode machines using
1097 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1099 Say Y if you want to enable the fixup. Currently, it's safe to
1100 enable this option even if you don't need it.
1104 tristate "CPU microcode loading support"
1105 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1109 If you say Y here, you will be able to update the microcode on
1110 certain Intel and AMD processors. The Intel support is for the
1111 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1112 Xeon etc. The AMD support is for families 0x10 and later. You will
1113 obviously need the actual microcode binary data itself which is not
1114 shipped with the Linux kernel.
1116 This option selects the general module only, you need to select
1117 at least one vendor specific module as well.
1119 To compile this driver as a module, choose M here: the module
1120 will be called microcode.
1122 config MICROCODE_INTEL
1123 bool "Intel microcode loading support"
1124 depends on MICROCODE
1128 This options enables microcode patch loading support for Intel
1131 For the current Intel microcode data package go to
1132 <https://downloadcenter.intel.com> and search for
1133 'Linux Processor Microcode Data File'.
1135 config MICROCODE_AMD
1136 bool "AMD microcode loading support"
1137 depends on MICROCODE
1140 If you select this option, microcode patch loading support for AMD
1141 processors will be enabled.
1143 config MICROCODE_OLD_INTERFACE
1145 depends on MICROCODE
1147 config MICROCODE_INTEL_EARLY
1150 config MICROCODE_AMD_EARLY
1153 config MICROCODE_EARLY
1154 bool "Early load microcode"
1155 depends on MICROCODE=y && BLK_DEV_INITRD
1156 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1157 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1160 This option provides functionality to read additional microcode data
1161 at the beginning of initrd image. The data tells kernel to load
1162 microcode to CPU's as early as possible. No functional change if no
1163 microcode data is glued to the initrd, therefore it's safe to say Y.
1166 tristate "/dev/cpu/*/msr - Model-specific register support"
1168 This device gives privileged processes access to the x86
1169 Model-Specific Registers (MSRs). It is a character device with
1170 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1171 MSR accesses are directed to a specific CPU on multi-processor
1175 tristate "/dev/cpu/*/cpuid - CPU information support"
1177 This device gives processes access to the x86 CPUID instruction to
1178 be executed on a specific processor. It is a character device
1179 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1183 prompt "High Memory Support"
1190 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1191 However, the address space of 32-bit x86 processors is only 4
1192 Gigabytes large. That means that, if you have a large amount of
1193 physical memory, not all of it can be "permanently mapped" by the
1194 kernel. The physical memory that's not permanently mapped is called
1197 If you are compiling a kernel which will never run on a machine with
1198 more than 1 Gigabyte total physical RAM, answer "off" here (default
1199 choice and suitable for most users). This will result in a "3GB/1GB"
1200 split: 3GB are mapped so that each process sees a 3GB virtual memory
1201 space and the remaining part of the 4GB virtual memory space is used
1202 by the kernel to permanently map as much physical memory as
1205 If the machine has between 1 and 4 Gigabytes physical RAM, then
1208 If more than 4 Gigabytes is used then answer "64GB" here. This
1209 selection turns Intel PAE (Physical Address Extension) mode on.
1210 PAE implements 3-level paging on IA32 processors. PAE is fully
1211 supported by Linux, PAE mode is implemented on all recent Intel
1212 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1213 then the kernel will not boot on CPUs that don't support PAE!
1215 The actual amount of total physical memory will either be
1216 auto detected or can be forced by using a kernel command line option
1217 such as "mem=256M". (Try "man bootparam" or see the documentation of
1218 your boot loader (lilo or loadlin) about how to pass options to the
1219 kernel at boot time.)
1221 If unsure, say "off".
1226 Select this if you have a 32-bit processor and between 1 and 4
1227 gigabytes of physical RAM.
1234 Select this if you have a 32-bit processor and more than 4
1235 gigabytes of physical RAM.
1240 prompt "Memory split" if EXPERT
1244 Select the desired split between kernel and user memory.
1246 If the address range available to the kernel is less than the
1247 physical memory installed, the remaining memory will be available
1248 as "high memory". Accessing high memory is a little more costly
1249 than low memory, as it needs to be mapped into the kernel first.
1250 Note that increasing the kernel address space limits the range
1251 available to user programs, making the address space there
1252 tighter. Selecting anything other than the default 3G/1G split
1253 will also likely make your kernel incompatible with binary-only
1256 If you are not absolutely sure what you are doing, leave this
1260 bool "3G/1G user/kernel split"
1261 config VMSPLIT_3G_OPT
1263 bool "3G/1G user/kernel split (for full 1G low memory)"
1265 bool "2G/2G user/kernel split"
1266 config VMSPLIT_2G_OPT
1268 bool "2G/2G user/kernel split (for full 2G low memory)"
1270 bool "1G/3G user/kernel split"
1275 default 0xB0000000 if VMSPLIT_3G_OPT
1276 default 0x80000000 if VMSPLIT_2G
1277 default 0x78000000 if VMSPLIT_2G_OPT
1278 default 0x40000000 if VMSPLIT_1G
1284 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1287 bool "PAE (Physical Address Extension) Support"
1288 depends on X86_32 && !HIGHMEM4G
1290 PAE is required for NX support, and furthermore enables
1291 larger swapspace support for non-overcommit purposes. It
1292 has the cost of more pagetable lookup overhead, and also
1293 consumes more pagetable space per process.
1295 config ARCH_PHYS_ADDR_T_64BIT
1297 depends on X86_64 || X86_PAE
1299 config ARCH_DMA_ADDR_T_64BIT
1301 depends on X86_64 || HIGHMEM64G
1303 config DIRECT_GBPAGES
1304 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1308 Allow the kernel linear mapping to use 1GB pages on CPUs that
1309 support it. This can improve the kernel's performance a tiny bit by
1310 reducing TLB pressure. If in doubt, say "Y".
1312 # Common NUMA Features
1314 bool "Numa Memory Allocation and Scheduler Support"
1316 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1317 default y if X86_BIGSMP
1319 Enable NUMA (Non Uniform Memory Access) support.
1321 The kernel will try to allocate memory used by a CPU on the
1322 local memory controller of the CPU and add some more
1323 NUMA awareness to the kernel.
1325 For 64-bit this is recommended if the system is Intel Core i7
1326 (or later), AMD Opteron, or EM64T NUMA.
1328 For 32-bit this is only needed if you boot a 32-bit
1329 kernel on a 64-bit NUMA platform.
1331 Otherwise, you should say N.
1335 prompt "Old style AMD Opteron NUMA detection"
1336 depends on X86_64 && NUMA && PCI
1338 Enable AMD NUMA node topology detection. You should say Y here if
1339 you have a multi processor AMD system. This uses an old method to
1340 read the NUMA configuration directly from the builtin Northbridge
1341 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1342 which also takes priority if both are compiled in.
1344 config X86_64_ACPI_NUMA
1346 prompt "ACPI NUMA detection"
1347 depends on X86_64 && NUMA && ACPI && PCI
1350 Enable ACPI SRAT based node topology detection.
1352 # Some NUMA nodes have memory ranges that span
1353 # other nodes. Even though a pfn is valid and
1354 # between a node's start and end pfns, it may not
1355 # reside on that node. See memmap_init_zone()
1357 config NODES_SPAN_OTHER_NODES
1359 depends on X86_64_ACPI_NUMA
1362 bool "NUMA emulation"
1365 Enable NUMA emulation. A flat machine will be split
1366 into virtual nodes when booted with "numa=fake=N", where N is the
1367 number of nodes. This is only useful for debugging.
1370 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1372 default "10" if MAXSMP
1373 default "6" if X86_64
1375 depends on NEED_MULTIPLE_NODES
1377 Specify the maximum number of NUMA Nodes available on the target
1378 system. Increases memory reserved to accommodate various tables.
1380 config ARCH_HAVE_MEMORY_PRESENT
1382 depends on X86_32 && DISCONTIGMEM
1384 config NEED_NODE_MEMMAP_SIZE
1386 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1388 config ARCH_FLATMEM_ENABLE
1390 depends on X86_32 && !NUMA
1392 config ARCH_DISCONTIGMEM_ENABLE
1394 depends on NUMA && X86_32
1396 config ARCH_DISCONTIGMEM_DEFAULT
1398 depends on NUMA && X86_32
1400 config ARCH_SPARSEMEM_ENABLE
1402 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1403 select SPARSEMEM_STATIC if X86_32
1404 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1406 config ARCH_SPARSEMEM_DEFAULT
1410 config ARCH_SELECT_MEMORY_MODEL
1412 depends on ARCH_SPARSEMEM_ENABLE
1414 config ARCH_MEMORY_PROBE
1415 bool "Enable sysfs memory/probe interface"
1416 depends on X86_64 && MEMORY_HOTPLUG
1418 This option enables a sysfs memory/probe interface for testing.
1419 See Documentation/memory-hotplug.txt for more information.
1420 If you are unsure how to answer this question, answer N.
1422 config ARCH_PROC_KCORE_TEXT
1424 depends on X86_64 && PROC_KCORE
1426 config ILLEGAL_POINTER_VALUE
1429 default 0xdead000000000000 if X86_64
1434 bool "Allocate 3rd-level pagetables from highmem"
1437 The VM uses one page table entry for each page of physical memory.
1438 For systems with a lot of RAM, this can be wasteful of precious
1439 low memory. Setting this option will put user-space page table
1440 entries in high memory.
1442 config X86_CHECK_BIOS_CORRUPTION
1443 bool "Check for low memory corruption"
1445 Periodically check for memory corruption in low memory, which
1446 is suspected to be caused by BIOS. Even when enabled in the
1447 configuration, it is disabled at runtime. Enable it by
1448 setting "memory_corruption_check=1" on the kernel command
1449 line. By default it scans the low 64k of memory every 60
1450 seconds; see the memory_corruption_check_size and
1451 memory_corruption_check_period parameters in
1452 Documentation/kernel-parameters.txt to adjust this.
1454 When enabled with the default parameters, this option has
1455 almost no overhead, as it reserves a relatively small amount
1456 of memory and scans it infrequently. It both detects corruption
1457 and prevents it from affecting the running system.
1459 It is, however, intended as a diagnostic tool; if repeatable
1460 BIOS-originated corruption always affects the same memory,
1461 you can use memmap= to prevent the kernel from using that
1464 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1465 bool "Set the default setting of memory_corruption_check"
1466 depends on X86_CHECK_BIOS_CORRUPTION
1469 Set whether the default state of memory_corruption_check is
1472 config X86_RESERVE_LOW
1473 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1477 Specify the amount of low memory to reserve for the BIOS.
1479 The first page contains BIOS data structures that the kernel
1480 must not use, so that page must always be reserved.
1482 By default we reserve the first 64K of physical RAM, as a
1483 number of BIOSes are known to corrupt that memory range
1484 during events such as suspend/resume or monitor cable
1485 insertion, so it must not be used by the kernel.
1487 You can set this to 4 if you are absolutely sure that you
1488 trust the BIOS to get all its memory reservations and usages
1489 right. If you know your BIOS have problems beyond the
1490 default 64K area, you can set this to 640 to avoid using the
1491 entire low memory range.
1493 If you have doubts about the BIOS (e.g. suspend/resume does
1494 not work or there's kernel crashes after certain hardware
1495 hotplug events) then you might want to enable
1496 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1497 typical corruption patterns.
1499 Leave this to the default value of 64 if you are unsure.
1501 config MATH_EMULATION
1503 prompt "Math emulation" if X86_32
1505 Linux can emulate a math coprocessor (used for floating point
1506 operations) if you don't have one. 486DX and Pentium processors have
1507 a math coprocessor built in, 486SX and 386 do not, unless you added
1508 a 487DX or 387, respectively. (The messages during boot time can
1509 give you some hints here ["man dmesg"].) Everyone needs either a
1510 coprocessor or this emulation.
1512 If you don't have a math coprocessor, you need to say Y here; if you
1513 say Y here even though you have a coprocessor, the coprocessor will
1514 be used nevertheless. (This behavior can be changed with the kernel
1515 command line option "no387", which comes handy if your coprocessor
1516 is broken. Try "man bootparam" or see the documentation of your boot
1517 loader (lilo or loadlin) about how to pass options to the kernel at
1518 boot time.) This means that it is a good idea to say Y here if you
1519 intend to use this kernel on different machines.
1521 More information about the internals of the Linux math coprocessor
1522 emulation can be found in <file:arch/x86/math-emu/README>.
1524 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1525 kernel, it won't hurt.
1529 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1531 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1532 the Memory Type Range Registers (MTRRs) may be used to control
1533 processor access to memory ranges. This is most useful if you have
1534 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1535 allows bus write transfers to be combined into a larger transfer
1536 before bursting over the PCI/AGP bus. This can increase performance
1537 of image write operations 2.5 times or more. Saying Y here creates a
1538 /proc/mtrr file which may be used to manipulate your processor's
1539 MTRRs. Typically the X server should use this.
1541 This code has a reasonably generic interface so that similar
1542 control registers on other processors can be easily supported
1545 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1546 Registers (ARRs) which provide a similar functionality to MTRRs. For
1547 these, the ARRs are used to emulate the MTRRs.
1548 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1549 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1550 write-combining. All of these processors are supported by this code
1551 and it makes sense to say Y here if you have one of them.
1553 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1554 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1555 can lead to all sorts of problems, so it's good to say Y here.
1557 You can safely say Y even if your machine doesn't have MTRRs, you'll
1558 just add about 9 KB to your kernel.
1560 See <file:Documentation/x86/mtrr.txt> for more information.
1562 config MTRR_SANITIZER
1564 prompt "MTRR cleanup support"
1567 Convert MTRR layout from continuous to discrete, so X drivers can
1568 add writeback entries.
1570 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1571 The largest mtrr entry size for a continuous block can be set with
1576 config MTRR_SANITIZER_ENABLE_DEFAULT
1577 int "MTRR cleanup enable value (0-1)"
1580 depends on MTRR_SANITIZER
1582 Enable mtrr cleanup default value
1584 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1585 int "MTRR cleanup spare reg num (0-7)"
1588 depends on MTRR_SANITIZER
1590 mtrr cleanup spare entries default, it can be changed via
1591 mtrr_spare_reg_nr=N on the kernel command line.
1595 prompt "x86 PAT support" if EXPERT
1598 Use PAT attributes to setup page level cache control.
1600 PATs are the modern equivalents of MTRRs and are much more
1601 flexible than MTRRs.
1603 Say N here if you see bootup problems (boot crash, boot hang,
1604 spontaneous reboots) or a non-working video driver.
1608 config ARCH_USES_PG_UNCACHED
1614 prompt "x86 architectural random number generator" if EXPERT
1616 Enable the x86 architectural RDRAND instruction
1617 (Intel Bull Mountain technology) to generate random numbers.
1618 If supported, this is a high bandwidth, cryptographically
1619 secure hardware random number generator.
1623 prompt "Supervisor Mode Access Prevention" if EXPERT
1625 Supervisor Mode Access Prevention (SMAP) is a security
1626 feature in newer Intel processors. There is a small
1627 performance cost if this enabled and turned on; there is
1628 also a small increase in the kernel size if this is enabled.
1632 config X86_INTEL_MPX
1633 prompt "Intel MPX (Memory Protection Extensions)"
1635 depends on CPU_SUP_INTEL
1637 MPX provides hardware features that can be used in
1638 conjunction with compiler-instrumented code to check
1639 memory references. It is designed to detect buffer
1640 overflow or underflow bugs.
1642 This option enables running applications which are
1643 instrumented or otherwise use MPX. It does not use MPX
1644 itself inside the kernel or to protect the kernel
1645 against bad memory references.
1647 Enabling this option will make the kernel larger:
1648 ~8k of kernel text and 36 bytes of data on a 64-bit
1649 defconfig. It adds a long to the 'mm_struct' which
1650 will increase the kernel memory overhead of each
1651 process and adds some branches to paths used during
1652 exec() and munmap().
1654 For details, see Documentation/x86/intel_mpx.txt
1659 bool "EFI runtime service support"
1662 select EFI_RUNTIME_WRAPPERS
1664 This enables the kernel to use EFI runtime services that are
1665 available (such as the EFI variable services).
1667 This option is only useful on systems that have EFI firmware.
1668 In addition, you should use the latest ELILO loader available
1669 at <http://elilo.sourceforge.net> in order to take advantage
1670 of EFI runtime services. However, even with this option, the
1671 resultant kernel should continue to boot on existing non-EFI
1675 bool "EFI stub support"
1676 depends on EFI && !X86_USE_3DNOW
1679 This kernel feature allows a bzImage to be loaded directly
1680 by EFI firmware without the use of a bootloader.
1682 See Documentation/efi-stub.txt for more information.
1685 bool "EFI mixed-mode support"
1686 depends on EFI_STUB && X86_64
1688 Enabling this feature allows a 64-bit kernel to be booted
1689 on a 32-bit firmware, provided that your CPU supports 64-bit
1692 Note that it is not possible to boot a mixed-mode enabled
1693 kernel via the EFI boot stub - a bootloader that supports
1694 the EFI handover protocol must be used.
1700 prompt "Enable seccomp to safely compute untrusted bytecode"
1702 This kernel feature is useful for number crunching applications
1703 that may need to compute untrusted bytecode during their
1704 execution. By using pipes or other transports made available to
1705 the process as file descriptors supporting the read/write
1706 syscalls, it's possible to isolate those applications in
1707 their own address space using seccomp. Once seccomp is
1708 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1709 and the task is only allowed to execute a few safe syscalls
1710 defined by each seccomp mode.
1712 If unsure, say Y. Only embedded should say N here.
1714 source kernel/Kconfig.hz
1717 bool "kexec system call"
1719 kexec is a system call that implements the ability to shutdown your
1720 current kernel, and to start another kernel. It is like a reboot
1721 but it is independent of the system firmware. And like a reboot
1722 you can start any kernel with it, not just Linux.
1724 The name comes from the similarity to the exec system call.
1726 It is an ongoing process to be certain the hardware in a machine
1727 is properly shutdown, so do not be surprised if this code does not
1728 initially work for you. As of this writing the exact hardware
1729 interface is strongly in flux, so no good recommendation can be
1733 bool "kexec file based system call"
1738 depends on CRYPTO_SHA256=y
1740 This is new version of kexec system call. This system call is
1741 file based and takes file descriptors as system call argument
1742 for kernel and initramfs as opposed to list of segments as
1743 accepted by previous system call.
1745 config KEXEC_VERIFY_SIG
1746 bool "Verify kernel signature during kexec_file_load() syscall"
1747 depends on KEXEC_FILE
1749 This option makes kernel signature verification mandatory for
1750 kexec_file_load() syscall. If kernel is signature can not be
1751 verified, kexec_file_load() will fail.
1753 This option enforces signature verification at generic level.
1754 One needs to enable signature verification for type of kernel
1755 image being loaded to make sure it works. For example, enable
1756 bzImage signature verification option to be able to load and
1757 verify signatures of bzImage. Otherwise kernel loading will fail.
1759 config KEXEC_BZIMAGE_VERIFY_SIG
1760 bool "Enable bzImage signature verification support"
1761 depends on KEXEC_VERIFY_SIG
1762 depends on SIGNED_PE_FILE_VERIFICATION
1763 select SYSTEM_TRUSTED_KEYRING
1765 Enable bzImage signature verification support.
1768 bool "kernel crash dumps"
1769 depends on X86_64 || (X86_32 && HIGHMEM)
1771 Generate crash dump after being started by kexec.
1772 This should be normally only set in special crash dump kernels
1773 which are loaded in the main kernel with kexec-tools into
1774 a specially reserved region and then later executed after
1775 a crash by kdump/kexec. The crash dump kernel must be compiled
1776 to a memory address not used by the main kernel or BIOS using
1777 PHYSICAL_START, or it must be built as a relocatable image
1778 (CONFIG_RELOCATABLE=y).
1779 For more details see Documentation/kdump/kdump.txt
1783 depends on KEXEC && HIBERNATION
1785 Jump between original kernel and kexeced kernel and invoke
1786 code in physical address mode via KEXEC
1788 config PHYSICAL_START
1789 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1792 This gives the physical address where the kernel is loaded.
1794 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1795 bzImage will decompress itself to above physical address and
1796 run from there. Otherwise, bzImage will run from the address where
1797 it has been loaded by the boot loader and will ignore above physical
1800 In normal kdump cases one does not have to set/change this option
1801 as now bzImage can be compiled as a completely relocatable image
1802 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1803 address. This option is mainly useful for the folks who don't want
1804 to use a bzImage for capturing the crash dump and want to use a
1805 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1806 to be specifically compiled to run from a specific memory area
1807 (normally a reserved region) and this option comes handy.
1809 So if you are using bzImage for capturing the crash dump,
1810 leave the value here unchanged to 0x1000000 and set
1811 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1812 for capturing the crash dump change this value to start of
1813 the reserved region. In other words, it can be set based on
1814 the "X" value as specified in the "crashkernel=YM@XM"
1815 command line boot parameter passed to the panic-ed
1816 kernel. Please take a look at Documentation/kdump/kdump.txt
1817 for more details about crash dumps.
1819 Usage of bzImage for capturing the crash dump is recommended as
1820 one does not have to build two kernels. Same kernel can be used
1821 as production kernel and capture kernel. Above option should have
1822 gone away after relocatable bzImage support is introduced. But it
1823 is present because there are users out there who continue to use
1824 vmlinux for dump capture. This option should go away down the
1827 Don't change this unless you know what you are doing.
1830 bool "Build a relocatable kernel"
1833 This builds a kernel image that retains relocation information
1834 so it can be loaded someplace besides the default 1MB.
1835 The relocations tend to make the kernel binary about 10% larger,
1836 but are discarded at runtime.
1838 One use is for the kexec on panic case where the recovery kernel
1839 must live at a different physical address than the primary
1842 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1843 it has been loaded at and the compile time physical address
1844 (CONFIG_PHYSICAL_START) is used as the minimum location.
1846 config RANDOMIZE_BASE
1847 bool "Randomize the address of the kernel image"
1848 depends on RELOCATABLE
1851 Randomizes the physical and virtual address at which the
1852 kernel image is decompressed, as a security feature that
1853 deters exploit attempts relying on knowledge of the location
1854 of kernel internals.
1856 Entropy is generated using the RDRAND instruction if it is
1857 supported. If RDTSC is supported, it is used as well. If
1858 neither RDRAND nor RDTSC are supported, then randomness is
1859 read from the i8254 timer.
1861 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1862 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1863 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1864 minimum of 2MiB, only 10 bits of entropy is theoretically
1865 possible. At best, due to page table layouts, 64-bit can use
1866 9 bits of entropy and 32-bit uses 8 bits.
1870 config RANDOMIZE_BASE_MAX_OFFSET
1871 hex "Maximum kASLR offset allowed" if EXPERT
1872 depends on RANDOMIZE_BASE
1873 range 0x0 0x20000000 if X86_32
1874 default "0x20000000" if X86_32
1875 range 0x0 0x40000000 if X86_64
1876 default "0x40000000" if X86_64
1878 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1879 memory is used to determine the maximal offset in bytes that will
1880 be applied to the kernel when kernel Address Space Layout
1881 Randomization (kASLR) is active. This must be a multiple of
1884 On 32-bit this is limited to 512MiB by page table layouts. The
1887 On 64-bit this is limited by how the kernel fixmap page table is
1888 positioned, so this cannot be larger than 1GiB currently. Without
1889 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1890 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1891 modules area will shrink to compensate, up to the current maximum
1892 1GiB to 1GiB split. The default is 1GiB.
1894 If unsure, leave at the default value.
1896 # Relocation on x86 needs some additional build support
1897 config X86_NEED_RELOCS
1899 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1901 config PHYSICAL_ALIGN
1902 hex "Alignment value to which kernel should be aligned"
1904 range 0x2000 0x1000000 if X86_32
1905 range 0x200000 0x1000000 if X86_64
1907 This value puts the alignment restrictions on physical address
1908 where kernel is loaded and run from. Kernel is compiled for an
1909 address which meets above alignment restriction.
1911 If bootloader loads the kernel at a non-aligned address and
1912 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1913 address aligned to above value and run from there.
1915 If bootloader loads the kernel at a non-aligned address and
1916 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1917 load address and decompress itself to the address it has been
1918 compiled for and run from there. The address for which kernel is
1919 compiled already meets above alignment restrictions. Hence the
1920 end result is that kernel runs from a physical address meeting
1921 above alignment restrictions.
1923 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1924 this value must be a multiple of 0x200000.
1926 Don't change this unless you know what you are doing.
1929 bool "Support for hot-pluggable CPUs"
1932 Say Y here to allow turning CPUs off and on. CPUs can be
1933 controlled through /sys/devices/system/cpu.
1934 ( Note: power management support will enable this option
1935 automatically on SMP systems. )
1936 Say N if you want to disable CPU hotplug.
1938 config BOOTPARAM_HOTPLUG_CPU0
1939 bool "Set default setting of cpu0_hotpluggable"
1941 depends on HOTPLUG_CPU
1943 Set whether default state of cpu0_hotpluggable is on or off.
1945 Say Y here to enable CPU0 hotplug by default. If this switch
1946 is turned on, there is no need to give cpu0_hotplug kernel
1947 parameter and the CPU0 hotplug feature is enabled by default.
1949 Please note: there are two known CPU0 dependencies if you want
1950 to enable the CPU0 hotplug feature either by this switch or by
1951 cpu0_hotplug kernel parameter.
1953 First, resume from hibernate or suspend always starts from CPU0.
1954 So hibernate and suspend are prevented if CPU0 is offline.
1956 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1957 offline if any interrupt can not migrate out of CPU0. There may
1958 be other CPU0 dependencies.
1960 Please make sure the dependencies are under your control before
1961 you enable this feature.
1963 Say N if you don't want to enable CPU0 hotplug feature by default.
1964 You still can enable the CPU0 hotplug feature at boot by kernel
1965 parameter cpu0_hotplug.
1967 config DEBUG_HOTPLUG_CPU0
1969 prompt "Debug CPU0 hotplug"
1970 depends on HOTPLUG_CPU
1972 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1973 soon as possible and boots up userspace with CPU0 offlined. User
1974 can online CPU0 back after boot time.
1976 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1977 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1978 compilation or giving cpu0_hotplug kernel parameter at boot.
1984 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1985 depends on X86_32 || IA32_EMULATION
1987 Certain buggy versions of glibc will crash if they are
1988 presented with a 32-bit vDSO that is not mapped at the address
1989 indicated in its segment table.
1991 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1992 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1993 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1994 the only released version with the bug, but OpenSUSE 9
1995 contains a buggy "glibc 2.3.2".
1997 The symptom of the bug is that everything crashes on startup, saying:
1998 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2000 Saying Y here changes the default value of the vdso32 boot
2001 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2002 This works around the glibc bug but hurts performance.
2004 If unsure, say N: if you are compiling your own kernel, you
2005 are unlikely to be using a buggy version of glibc.
2008 bool "Built-in kernel command line"
2010 Allow for specifying boot arguments to the kernel at
2011 build time. On some systems (e.g. embedded ones), it is
2012 necessary or convenient to provide some or all of the
2013 kernel boot arguments with the kernel itself (that is,
2014 to not rely on the boot loader to provide them.)
2016 To compile command line arguments into the kernel,
2017 set this option to 'Y', then fill in the
2018 the boot arguments in CONFIG_CMDLINE.
2020 Systems with fully functional boot loaders (i.e. non-embedded)
2021 should leave this option set to 'N'.
2024 string "Built-in kernel command string"
2025 depends on CMDLINE_BOOL
2028 Enter arguments here that should be compiled into the kernel
2029 image and used at boot time. If the boot loader provides a
2030 command line at boot time, it is appended to this string to
2031 form the full kernel command line, when the system boots.
2033 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2034 change this behavior.
2036 In most cases, the command line (whether built-in or provided
2037 by the boot loader) should specify the device for the root
2040 config CMDLINE_OVERRIDE
2041 bool "Built-in command line overrides boot loader arguments"
2042 depends on CMDLINE_BOOL
2044 Set this option to 'Y' to have the kernel ignore the boot loader
2045 command line, and use ONLY the built-in command line.
2047 This is used to work around broken boot loaders. This should
2048 be set to 'N' under normal conditions.
2050 source "kernel/livepatch/Kconfig"
2054 config ARCH_ENABLE_MEMORY_HOTPLUG
2056 depends on X86_64 || (X86_32 && HIGHMEM)
2058 config ARCH_ENABLE_MEMORY_HOTREMOVE
2060 depends on MEMORY_HOTPLUG
2062 config USE_PERCPU_NUMA_NODE_ID
2066 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2068 depends on X86_64 || X86_PAE
2070 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2072 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2074 menu "Power management and ACPI options"
2076 config ARCH_HIBERNATION_HEADER
2078 depends on X86_64 && HIBERNATION
2080 source "kernel/power/Kconfig"
2082 source "drivers/acpi/Kconfig"
2084 source "drivers/sfi/Kconfig"
2091 tristate "APM (Advanced Power Management) BIOS support"
2092 depends on X86_32 && PM_SLEEP
2094 APM is a BIOS specification for saving power using several different
2095 techniques. This is mostly useful for battery powered laptops with
2096 APM compliant BIOSes. If you say Y here, the system time will be
2097 reset after a RESUME operation, the /proc/apm device will provide
2098 battery status information, and user-space programs will receive
2099 notification of APM "events" (e.g. battery status change).
2101 If you select "Y" here, you can disable actual use of the APM
2102 BIOS by passing the "apm=off" option to the kernel at boot time.
2104 Note that the APM support is almost completely disabled for
2105 machines with more than one CPU.
2107 In order to use APM, you will need supporting software. For location
2108 and more information, read <file:Documentation/power/apm-acpi.txt>
2109 and the Battery Powered Linux mini-HOWTO, available from
2110 <http://www.tldp.org/docs.html#howto>.
2112 This driver does not spin down disk drives (see the hdparm(8)
2113 manpage ("man 8 hdparm") for that), and it doesn't turn off
2114 VESA-compliant "green" monitors.
2116 This driver does not support the TI 4000M TravelMate and the ACER
2117 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2118 desktop machines also don't have compliant BIOSes, and this driver
2119 may cause those machines to panic during the boot phase.
2121 Generally, if you don't have a battery in your machine, there isn't
2122 much point in using this driver and you should say N. If you get
2123 random kernel OOPSes or reboots that don't seem to be related to
2124 anything, try disabling/enabling this option (or disabling/enabling
2127 Some other things you should try when experiencing seemingly random,
2130 1) make sure that you have enough swap space and that it is
2132 2) pass the "no-hlt" option to the kernel
2133 3) switch on floating point emulation in the kernel and pass
2134 the "no387" option to the kernel
2135 4) pass the "floppy=nodma" option to the kernel
2136 5) pass the "mem=4M" option to the kernel (thereby disabling
2137 all but the first 4 MB of RAM)
2138 6) make sure that the CPU is not over clocked.
2139 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2140 8) disable the cache from your BIOS settings
2141 9) install a fan for the video card or exchange video RAM
2142 10) install a better fan for the CPU
2143 11) exchange RAM chips
2144 12) exchange the motherboard.
2146 To compile this driver as a module, choose M here: the
2147 module will be called apm.
2151 config APM_IGNORE_USER_SUSPEND
2152 bool "Ignore USER SUSPEND"
2154 This option will ignore USER SUSPEND requests. On machines with a
2155 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2156 series notebooks, it is necessary to say Y because of a BIOS bug.
2158 config APM_DO_ENABLE
2159 bool "Enable PM at boot time"
2161 Enable APM features at boot time. From page 36 of the APM BIOS
2162 specification: "When disabled, the APM BIOS does not automatically
2163 power manage devices, enter the Standby State, enter the Suspend
2164 State, or take power saving steps in response to CPU Idle calls."
2165 This driver will make CPU Idle calls when Linux is idle (unless this
2166 feature is turned off -- see "Do CPU IDLE calls", below). This
2167 should always save battery power, but more complicated APM features
2168 will be dependent on your BIOS implementation. You may need to turn
2169 this option off if your computer hangs at boot time when using APM
2170 support, or if it beeps continuously instead of suspending. Turn
2171 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2172 T400CDT. This is off by default since most machines do fine without
2177 bool "Make CPU Idle calls when idle"
2179 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2180 On some machines, this can activate improved power savings, such as
2181 a slowed CPU clock rate, when the machine is idle. These idle calls
2182 are made after the idle loop has run for some length of time (e.g.,
2183 333 mS). On some machines, this will cause a hang at boot time or
2184 whenever the CPU becomes idle. (On machines with more than one CPU,
2185 this option does nothing.)
2187 config APM_DISPLAY_BLANK
2188 bool "Enable console blanking using APM"
2190 Enable console blanking using the APM. Some laptops can use this to
2191 turn off the LCD backlight when the screen blanker of the Linux
2192 virtual console blanks the screen. Note that this is only used by
2193 the virtual console screen blanker, and won't turn off the backlight
2194 when using the X Window system. This also doesn't have anything to
2195 do with your VESA-compliant power-saving monitor. Further, this
2196 option doesn't work for all laptops -- it might not turn off your
2197 backlight at all, or it might print a lot of errors to the console,
2198 especially if you are using gpm.
2200 config APM_ALLOW_INTS
2201 bool "Allow interrupts during APM BIOS calls"
2203 Normally we disable external interrupts while we are making calls to
2204 the APM BIOS as a measure to lessen the effects of a badly behaving
2205 BIOS implementation. The BIOS should reenable interrupts if it
2206 needs to. Unfortunately, some BIOSes do not -- especially those in
2207 many of the newer IBM Thinkpads. If you experience hangs when you
2208 suspend, try setting this to Y. Otherwise, say N.
2212 source "drivers/cpufreq/Kconfig"
2214 source "drivers/cpuidle/Kconfig"
2216 source "drivers/idle/Kconfig"
2221 menu "Bus options (PCI etc.)"
2227 Find out whether you have a PCI motherboard. PCI is the name of a
2228 bus system, i.e. the way the CPU talks to the other stuff inside
2229 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2230 VESA. If you have PCI, say Y, otherwise N.
2233 prompt "PCI access mode"
2234 depends on X86_32 && PCI
2237 On PCI systems, the BIOS can be used to detect the PCI devices and
2238 determine their configuration. However, some old PCI motherboards
2239 have BIOS bugs and may crash if this is done. Also, some embedded
2240 PCI-based systems don't have any BIOS at all. Linux can also try to
2241 detect the PCI hardware directly without using the BIOS.
2243 With this option, you can specify how Linux should detect the
2244 PCI devices. If you choose "BIOS", the BIOS will be used,
2245 if you choose "Direct", the BIOS won't be used, and if you
2246 choose "MMConfig", then PCI Express MMCONFIG will be used.
2247 If you choose "Any", the kernel will try MMCONFIG, then the
2248 direct access method and falls back to the BIOS if that doesn't
2249 work. If unsure, go with the default, which is "Any".
2254 config PCI_GOMMCONFIG
2271 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2273 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2276 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2280 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2284 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2288 depends on PCI && XEN
2296 bool "Support mmconfig PCI config space access"
2297 depends on X86_64 && PCI && ACPI
2299 config PCI_CNB20LE_QUIRK
2300 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2303 Read the PCI windows out of the CNB20LE host bridge. This allows
2304 PCI hotplug to work on systems with the CNB20LE chipset which do
2307 There's no public spec for this chipset, and this functionality
2308 is known to be incomplete.
2310 You should say N unless you know you need this.
2312 source "drivers/pci/pcie/Kconfig"
2314 source "drivers/pci/Kconfig"
2316 # x86_64 have no ISA slots, but can have ISA-style DMA.
2318 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2321 Enables ISA-style DMA support for devices requiring such controllers.
2329 Find out whether you have ISA slots on your motherboard. ISA is the
2330 name of a bus system, i.e. the way the CPU talks to the other stuff
2331 inside your box. Other bus systems are PCI, EISA, MicroChannel
2332 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2333 newer boards don't support it. If you have ISA, say Y, otherwise N.
2339 The Extended Industry Standard Architecture (EISA) bus was
2340 developed as an open alternative to the IBM MicroChannel bus.
2342 The EISA bus provided some of the features of the IBM MicroChannel
2343 bus while maintaining backward compatibility with cards made for
2344 the older ISA bus. The EISA bus saw limited use between 1988 and
2345 1995 when it was made obsolete by the PCI bus.
2347 Say Y here if you are building a kernel for an EISA-based machine.
2351 source "drivers/eisa/Kconfig"
2354 tristate "NatSemi SCx200 support"
2356 This provides basic support for National Semiconductor's
2357 (now AMD's) Geode processors. The driver probes for the
2358 PCI-IDs of several on-chip devices, so its a good dependency
2359 for other scx200_* drivers.
2361 If compiled as a module, the driver is named scx200.
2363 config SCx200HR_TIMER
2364 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2368 This driver provides a clocksource built upon the on-chip
2369 27MHz high-resolution timer. Its also a workaround for
2370 NSC Geode SC-1100's buggy TSC, which loses time when the
2371 processor goes idle (as is done by the scheduler). The
2372 other workaround is idle=poll boot option.
2375 bool "One Laptop Per Child support"
2382 Add support for detecting the unique features of the OLPC
2386 bool "OLPC XO-1 Power Management"
2387 depends on OLPC && MFD_CS5535 && PM_SLEEP
2390 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2393 bool "OLPC XO-1 Real Time Clock"
2394 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2396 Add support for the XO-1 real time clock, which can be used as a
2397 programmable wakeup source.
2400 bool "OLPC XO-1 SCI extras"
2401 depends on OLPC && OLPC_XO1_PM
2407 Add support for SCI-based features of the OLPC XO-1 laptop:
2408 - EC-driven system wakeups
2412 - AC adapter status updates
2413 - Battery status updates
2415 config OLPC_XO15_SCI
2416 bool "OLPC XO-1.5 SCI extras"
2417 depends on OLPC && ACPI
2420 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2421 - EC-driven system wakeups
2422 - AC adapter status updates
2423 - Battery status updates
2426 bool "PCEngines ALIX System Support (LED setup)"
2429 This option enables system support for the PCEngines ALIX.
2430 At present this just sets up LEDs for GPIO control on
2431 ALIX2/3/6 boards. However, other system specific setup should
2434 Note: You must still enable the drivers for GPIO and LED support
2435 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2437 Note: You have to set alix.force=1 for boards with Award BIOS.
2440 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2443 This option enables system support for the Soekris Engineering net5501.
2446 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2450 This option enables system support for the Traverse Technologies GEOS.
2453 bool "Technologic Systems TS-5500 platform support"
2455 select CHECK_SIGNATURE
2459 This option enables system support for the Technologic Systems TS-5500.
2465 depends on CPU_SUP_AMD && PCI
2467 source "drivers/pcmcia/Kconfig"
2469 source "drivers/pci/hotplug/Kconfig"
2472 tristate "RapidIO support"
2476 If enabled this option will include drivers and the core
2477 infrastructure code to support RapidIO interconnect devices.
2479 source "drivers/rapidio/Kconfig"
2482 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2484 Firmwares often provide initial graphics framebuffers so the BIOS,
2485 bootloader or kernel can show basic video-output during boot for
2486 user-guidance and debugging. Historically, x86 used the VESA BIOS
2487 Extensions and EFI-framebuffers for this, which are mostly limited
2489 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2490 framebuffers so the new generic system-framebuffer drivers can be
2491 used on x86. If the framebuffer is not compatible with the generic
2492 modes, it is adverticed as fallback platform framebuffer so legacy
2493 drivers like efifb, vesafb and uvesafb can pick it up.
2494 If this option is not selected, all system framebuffers are always
2495 marked as fallback platform framebuffers as usual.
2497 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2498 not be able to pick up generic system framebuffers if this option
2499 is selected. You are highly encouraged to enable simplefb as
2500 replacement if you select this option. simplefb can correctly deal
2501 with generic system framebuffers. But you should still keep vesafb
2502 and others enabled as fallback if a system framebuffer is
2503 incompatible with simplefb.
2510 menu "Executable file formats / Emulations"
2512 source "fs/Kconfig.binfmt"
2514 config IA32_EMULATION
2515 bool "IA32 Emulation"
2518 select COMPAT_BINFMT_ELF
2521 Include code to run legacy 32-bit programs under a
2522 64-bit kernel. You should likely turn this on, unless you're
2523 100% sure that you don't have any 32-bit programs left.
2526 tristate "IA32 a.out support"
2527 depends on IA32_EMULATION
2529 Support old a.out binaries in the 32bit emulation.
2532 bool "x32 ABI for 64-bit mode"
2533 depends on X86_64 && IA32_EMULATION
2535 Include code to run binaries for the x32 native 32-bit ABI
2536 for 64-bit processors. An x32 process gets access to the
2537 full 64-bit register file and wide data path while leaving
2538 pointers at 32 bits for smaller memory footprint.
2540 You will need a recent binutils (2.22 or later) with
2541 elf32_x86_64 support enabled to compile a kernel with this
2546 depends on IA32_EMULATION || X86_X32
2547 select ARCH_WANT_OLD_COMPAT_IPC
2550 config COMPAT_FOR_U64_ALIGNMENT
2553 config SYSVIPC_COMPAT
2565 config HAVE_ATOMIC_IOMAP
2569 config X86_DEV_DMA_OPS
2571 depends on X86_64 || STA2X11
2573 config X86_DMA_REMAP
2581 source "net/Kconfig"
2583 source "drivers/Kconfig"
2585 source "drivers/firmware/Kconfig"
2589 source "arch/x86/Kconfig.debug"
2591 source "security/Kconfig"
2593 source "crypto/Kconfig"
2595 source "arch/x86/kvm/Kconfig"
2597 source "lib/Kconfig"
projects / linux-2.6-block.git / blob