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 ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
26 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
27 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
28 select ARCH_HAS_FAST_MULTIPLIER
29 select ARCH_HAS_GCOV_PROFILE_ALL
30 select ARCH_MIGHT_HAVE_PC_PARPORT
31 select ARCH_MIGHT_HAVE_PC_SERIO
32 select HAVE_AOUT if X86_32
33 select HAVE_UNSTABLE_SCHED_CLOCK
34 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
35 select ARCH_SUPPORTS_INT128 if X86_64
38 select HAVE_PCSPKR_PLATFORM
39 select HAVE_PERF_EVENTS
40 select HAVE_IOREMAP_PROT
43 select HAVE_MEMBLOCK_NODE_MAP
44 select ARCH_DISCARD_MEMBLOCK
45 select ARCH_WANT_OPTIONAL_GPIOLIB
46 select ARCH_WANT_FRAME_POINTERS
48 select HAVE_DMA_CONTIGUOUS
49 select HAVE_KRETPROBES
50 select GENERIC_EARLY_IOREMAP
52 select HAVE_KPROBES_ON_FTRACE
53 select HAVE_FTRACE_MCOUNT_RECORD
54 select HAVE_FENTRY if X86_64
55 select HAVE_C_RECORDMCOUNT
56 select HAVE_DYNAMIC_FTRACE
57 select HAVE_DYNAMIC_FTRACE_WITH_REGS
58 select HAVE_FUNCTION_TRACER
59 select HAVE_FUNCTION_GRAPH_TRACER
60 select HAVE_FUNCTION_GRAPH_FP_TEST
61 select HAVE_SYSCALL_TRACEPOINTS
62 select SYSCTL_EXCEPTION_TRACE
65 select HAVE_ARCH_TRACEHOOK
66 select HAVE_GENERIC_DMA_COHERENT if X86_32
67 select HAVE_EFFICIENT_UNALIGNED_ACCESS
68 select USER_STACKTRACE_SUPPORT
69 select HAVE_REGS_AND_STACK_ACCESS_API
70 select HAVE_DMA_API_DEBUG
71 select HAVE_KERNEL_GZIP
72 select HAVE_KERNEL_BZIP2
73 select HAVE_KERNEL_LZMA
75 select HAVE_KERNEL_LZO
76 select HAVE_KERNEL_LZ4
77 select HAVE_HW_BREAKPOINT
78 select HAVE_MIXED_BREAKPOINTS_REGS
80 select HAVE_PERF_EVENTS_NMI
82 select HAVE_PERF_USER_STACK_DUMP
83 select HAVE_DEBUG_KMEMLEAK
85 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
86 select HAVE_CMPXCHG_LOCAL
87 select HAVE_CMPXCHG_DOUBLE
88 select HAVE_ARCH_KMEMCHECK
89 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
90 select HAVE_USER_RETURN_NOTIFIER
91 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
92 select HAVE_ARCH_JUMP_LABEL
93 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
95 select GENERIC_FIND_FIRST_BIT
96 select GENERIC_IRQ_PROBE
97 select GENERIC_PENDING_IRQ if SMP
98 select GENERIC_IRQ_SHOW
99 select GENERIC_CLOCKEVENTS_MIN_ADJUST
100 select IRQ_FORCED_THREADING
101 select HAVE_BPF_JIT if X86_64
102 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
103 select ARCH_HAS_SG_CHAIN
105 select ARCH_HAVE_NMI_SAFE_CMPXCHG
107 select DCACHE_WORD_ACCESS
108 select GENERIC_SMP_IDLE_THREAD
109 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
110 select HAVE_ARCH_SECCOMP_FILTER
111 select BUILDTIME_EXTABLE_SORT
112 select GENERIC_CMOS_UPDATE
113 select HAVE_ARCH_SOFT_DIRTY if X86_64
114 select CLOCKSOURCE_WATCHDOG
115 select GENERIC_CLOCKEVENTS
116 select ARCH_CLOCKSOURCE_DATA
117 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
118 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
119 select GENERIC_TIME_VSYSCALL
120 select GENERIC_STRNCPY_FROM_USER
121 select GENERIC_STRNLEN_USER
122 select HAVE_CONTEXT_TRACKING if X86_64
123 select HAVE_IRQ_TIME_ACCOUNTING
125 select MODULES_USE_ELF_REL if X86_32
126 select MODULES_USE_ELF_RELA if X86_64
127 select CLONE_BACKWARDS if X86_32
128 select ARCH_USE_BUILTIN_BSWAP
129 select ARCH_USE_QUEUE_RWLOCK
130 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
131 select OLD_SIGACTION if X86_32
132 select COMPAT_OLD_SIGACTION if IA32_EMULATION
134 select HAVE_DEBUG_STACKOVERFLOW
135 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
136 select HAVE_CC_STACKPROTECTOR
137 select GENERIC_CPU_AUTOPROBE
138 select HAVE_ARCH_AUDITSYSCALL
139 select ARCH_SUPPORTS_ATOMIC_RMW
140 select HAVE_ACPI_APEI if ACPI
141 select HAVE_ACPI_APEI_NMI if ACPI
142 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
143 select X86_FEATURE_NAMES if PROC_FS
146 config INSTRUCTION_DECODER
148 depends on KPROBES || PERF_EVENTS || UPROBES
150 config PERF_EVENTS_INTEL_UNCORE
152 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
156 default "elf32-i386" if X86_32
157 default "elf64-x86-64" if X86_64
159 config ARCH_DEFCONFIG
161 default "arch/x86/configs/i386_defconfig" if X86_32
162 default "arch/x86/configs/x86_64_defconfig" if X86_64
164 config LOCKDEP_SUPPORT
167 config STACKTRACE_SUPPORT
170 config HAVE_LATENCYTOP_SUPPORT
179 config NEED_DMA_MAP_STATE
181 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
183 config NEED_SG_DMA_LENGTH
186 config GENERIC_ISA_DMA
188 depends on ISA_DMA_API
193 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
195 config GENERIC_BUG_RELATIVE_POINTERS
198 config GENERIC_HWEIGHT
201 config ARCH_MAY_HAVE_PC_FDC
203 depends on ISA_DMA_API
205 config RWSEM_XCHGADD_ALGORITHM
208 config GENERIC_CALIBRATE_DELAY
211 config ARCH_HAS_CPU_RELAX
214 config ARCH_HAS_CACHE_LINE_SIZE
217 config HAVE_SETUP_PER_CPU_AREA
220 config NEED_PER_CPU_EMBED_FIRST_CHUNK
223 config NEED_PER_CPU_PAGE_FIRST_CHUNK
226 config ARCH_HIBERNATION_POSSIBLE
229 config ARCH_SUSPEND_POSSIBLE
232 config ARCH_WANT_HUGE_PMD_SHARE
235 config ARCH_WANT_GENERAL_HUGETLB
244 config ARCH_SUPPORTS_OPTIMIZED_INLINING
247 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
250 config HAVE_INTEL_TXT
252 depends on INTEL_IOMMU && ACPI
256 depends on X86_32 && SMP
260 depends on X86_64 && SMP
266 config X86_32_LAZY_GS
268 depends on X86_32 && !CC_STACKPROTECTOR
270 config ARCH_HWEIGHT_CFLAGS
272 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
273 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
275 config ARCH_SUPPORTS_UPROBES
278 config FIX_EARLYCON_MEM
281 source "init/Kconfig"
282 source "kernel/Kconfig.freezer"
284 menu "Processor type and features"
287 bool "DMA memory allocation support" if EXPERT
290 DMA memory allocation support allows devices with less than 32-bit
291 addressing to allocate within the first 16MB of address space.
292 Disable if no such devices will be used.
297 bool "Symmetric multi-processing support"
299 This enables support for systems with more than one CPU. If you have
300 a system with only one CPU, say N. If you have a system with more
303 If you say N here, the kernel will run on uni- and multiprocessor
304 machines, but will use only one CPU of a multiprocessor machine. If
305 you say Y here, the kernel will run on many, but not all,
306 uniprocessor machines. On a uniprocessor machine, the kernel
307 will run faster if you say N here.
309 Note that if you say Y here and choose architecture "586" or
310 "Pentium" under "Processor family", the kernel will not work on 486
311 architectures. Similarly, multiprocessor kernels for the "PPro"
312 architecture may not work on all Pentium based boards.
314 People using multiprocessor machines who say Y here should also say
315 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
316 Management" code will be disabled if you say Y here.
318 See also <file:Documentation/x86/i386/IO-APIC.txt>,
319 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
320 <http://www.tldp.org/docs.html#howto>.
322 If you don't know what to do here, say N.
324 config X86_FEATURE_NAMES
325 bool "Processor feature human-readable names" if EMBEDDED
328 This option compiles in a table of x86 feature bits and corresponding
329 names. This is required to support /proc/cpuinfo and a few kernel
330 messages. You can disable this to save space, at the expense of
331 making those few kernel messages show numeric feature bits instead.
336 bool "Support x2apic"
337 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
339 This enables x2apic support on CPUs that have this feature.
341 This allows 32-bit apic IDs (so it can support very large systems),
342 and accesses the local apic via MSRs not via mmio.
344 If you don't know what to do here, say N.
347 bool "Enable MPS table" if ACPI || SFI
349 depends on X86_LOCAL_APIC
351 For old smp systems that do not have proper acpi support. Newer systems
352 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
355 bool "Support for big SMP systems with more than 8 CPUs"
356 depends on X86_32 && SMP
358 This option is needed for the systems that have more than 8 CPUs
362 depends on X86_GOLDFISH
365 config X86_EXTENDED_PLATFORM
366 bool "Support for extended (non-PC) x86 platforms"
369 If you disable this option then the kernel will only support
370 standard PC platforms. (which covers the vast majority of
373 If you enable this option then you'll be able to select support
374 for the following (non-PC) 32 bit x86 platforms:
375 Goldfish (Android emulator)
378 SGI 320/540 (Visual Workstation)
379 STA2X11-based (e.g. Northville)
380 Moorestown MID devices
382 If you have one of these systems, or if you want to build a
383 generic distribution kernel, say Y here - otherwise say N.
387 config X86_EXTENDED_PLATFORM
388 bool "Support for extended (non-PC) x86 platforms"
391 If you disable this option then the kernel will only support
392 standard PC platforms. (which covers the vast majority of
395 If you enable this option then you'll be able to select support
396 for the following (non-PC) 64 bit x86 platforms:
401 If you have one of these systems, or if you want to build a
402 generic distribution kernel, say Y here - otherwise say N.
404 # This is an alphabetically sorted list of 64 bit extended platforms
405 # Please maintain the alphabetic order if and when there are additions
407 bool "Numascale NumaChip"
409 depends on X86_EXTENDED_PLATFORM
412 depends on X86_X2APIC
413 depends on PCI_MMCONFIG
415 Adds support for Numascale NumaChip large-SMP systems. Needed to
416 enable more than ~168 cores.
417 If you don't have one of these, you should say N here.
421 select HYPERVISOR_GUEST
423 depends on X86_64 && PCI
424 depends on X86_EXTENDED_PLATFORM
427 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
428 supposed to run on these EM64T-based machines. Only choose this option
429 if you have one of these machines.
432 bool "SGI Ultraviolet"
434 depends on X86_EXTENDED_PLATFORM
436 depends on X86_X2APIC
438 This option is needed in order to support SGI Ultraviolet systems.
439 If you don't have one of these, you should say N here.
441 # Following is an alphabetically sorted list of 32 bit extended platforms
442 # Please maintain the alphabetic order if and when there are additions
445 bool "Goldfish (Virtual Platform)"
446 depends on X86_EXTENDED_PLATFORM
448 Enable support for the Goldfish virtual platform used primarily
449 for Android development. Unless you are building for the Android
450 Goldfish emulator say N here.
453 bool "CE4100 TV platform"
455 depends on PCI_GODIRECT
456 depends on X86_IO_APIC
458 depends on X86_EXTENDED_PLATFORM
459 select X86_REBOOTFIXUPS
461 select OF_EARLY_FLATTREE
464 Select for the Intel CE media processor (CE4100) SOC.
465 This option compiles in support for the CE4100 SOC for settop
466 boxes and media devices.
469 bool "Intel MID platform support"
471 depends on X86_EXTENDED_PLATFORM
472 depends on X86_PLATFORM_DEVICES
475 depends on X86_IO_APIC
481 select MFD_INTEL_MSIC
483 Select to build a kernel capable of supporting Intel MID (Mobile
484 Internet Device) platform systems which do not have the PCI legacy
485 interfaces. If you are building for a PC class system say N here.
487 Intel MID platforms are based on an Intel processor and chipset which
488 consume less power than most of the x86 derivatives.
490 config X86_INTEL_QUARK
491 bool "Intel Quark platform support"
493 depends on X86_EXTENDED_PLATFORM
494 depends on X86_PLATFORM_DEVICES
498 depends on X86_IO_APIC
503 Select to include support for Quark X1000 SoC.
504 Say Y here if you have a Quark based system such as the Arduino
505 compatible Intel Galileo.
507 config X86_INTEL_LPSS
508 bool "Intel Low Power Subsystem Support"
513 Select to build support for Intel Low Power Subsystem such as
514 found on Intel Lynxpoint PCH. Selecting this option enables
515 things like clock tree (common clock framework) and pincontrol
516 which are needed by the LPSS peripheral drivers.
518 config X86_AMD_PLATFORM_DEVICE
519 bool "AMD ACPI2Platform devices support"
524 Select to interpret AMD specific ACPI device to platform device
525 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
526 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
527 implemented under PINCTRL subsystem.
530 tristate "Intel SoC IOSF Sideband support for SoC platforms"
533 This option enables sideband register access support for Intel SoC
534 platforms. On these platforms the IOSF sideband is used in lieu of
535 MSR's for some register accesses, mostly but not limited to thermal
536 and power. Drivers may query the availability of this device to
537 determine if they need the sideband in order to work on these
538 platforms. The sideband is available on the following SoC products.
539 This list is not meant to be exclusive.
544 You should say Y if you are running a kernel on one of these SoC's.
546 config IOSF_MBI_DEBUG
547 bool "Enable IOSF sideband access through debugfs"
548 depends on IOSF_MBI && DEBUG_FS
550 Select this option to expose the IOSF sideband access registers (MCR,
551 MDR, MCRX) through debugfs to write and read register information from
552 different units on the SoC. This is most useful for obtaining device
553 state information for debug and analysis. As this is a general access
554 mechanism, users of this option would have specific knowledge of the
555 device they want to access.
557 If you don't require the option or are in doubt, say N.
560 bool "RDC R-321x SoC"
562 depends on X86_EXTENDED_PLATFORM
564 select X86_REBOOTFIXUPS
566 This option is needed for RDC R-321x system-on-chip, also known
568 If you don't have one of these chips, you should say N here.
570 config X86_32_NON_STANDARD
571 bool "Support non-standard 32-bit SMP architectures"
572 depends on X86_32 && SMP
573 depends on X86_EXTENDED_PLATFORM
575 This option compiles in the bigsmp and STA2X11 default
576 subarchitectures. It is intended for a generic binary
577 kernel. If you select them all, kernel will probe it one by
578 one and will fallback to default.
580 # Alphabetically sorted list of Non standard 32 bit platforms
582 config X86_SUPPORTS_MEMORY_FAILURE
584 # MCE code calls memory_failure():
586 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
587 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
588 depends on X86_64 || !SPARSEMEM
589 select ARCH_SUPPORTS_MEMORY_FAILURE
592 bool "STA2X11 Companion Chip Support"
593 depends on X86_32_NON_STANDARD && PCI
594 select X86_DEV_DMA_OPS
598 select ARCH_REQUIRE_GPIOLIB
601 This adds support for boards based on the STA2X11 IO-Hub,
602 a.k.a. "ConneXt". The chip is used in place of the standard
603 PC chipset, so all "standard" peripherals are missing. If this
604 option is selected the kernel will still be able to boot on
605 standard PC machines.
608 tristate "Eurobraille/Iris poweroff module"
611 The Iris machines from EuroBraille do not have APM or ACPI support
612 to shut themselves down properly. A special I/O sequence is
613 needed to do so, which is what this module does at
616 This is only for Iris machines from EuroBraille.
620 config SCHED_OMIT_FRAME_POINTER
622 prompt "Single-depth WCHAN output" if !LTO && !FRAME_POINTER
625 Calculate simpler /proc/<PID>/wchan values. If this option
626 is disabled then wchan values will recurse back to the
627 caller function. This provides more accurate wchan values,
628 at the expense of slightly more scheduling overhead.
630 If in doubt, say "Y".
632 menuconfig HYPERVISOR_GUEST
633 bool "Linux guest support"
635 Say Y here to enable options for running Linux under various hyper-
636 visors. This option enables basic hypervisor detection and platform
639 If you say N, all options in this submenu will be skipped and
640 disabled, and Linux guest support won't be built in.
645 bool "Enable paravirtualization code"
647 This changes the kernel so it can modify itself when it is run
648 under a hypervisor, potentially improving performance significantly
649 over full virtualization. However, when run without a hypervisor
650 the kernel is theoretically slower and slightly larger.
652 config PARAVIRT_DEBUG
653 bool "paravirt-ops debugging"
654 depends on PARAVIRT && DEBUG_KERNEL
656 Enable to debug paravirt_ops internals. Specifically, BUG if
657 a paravirt_op is missing when it is called.
659 config PARAVIRT_SPINLOCKS
660 bool "Paravirtualization layer for spinlocks"
661 depends on PARAVIRT && SMP
662 select UNINLINE_SPIN_UNLOCK
664 Paravirtualized spinlocks allow a pvops backend to replace the
665 spinlock implementation with something virtualization-friendly
666 (for example, block the virtual CPU rather than spinning).
668 It has a minimal impact on native kernels and gives a nice performance
669 benefit on paravirtualized KVM / Xen kernels.
671 If you are unsure how to answer this question, answer Y.
673 source "arch/x86/xen/Kconfig"
676 bool "KVM Guest support (including kvmclock)"
678 select PARAVIRT_CLOCK
681 This option enables various optimizations for running under the KVM
682 hypervisor. It includes a paravirtualized clock, so that instead
683 of relying on a PIT (or probably other) emulation by the
684 underlying device model, the host provides the guest with
685 timing infrastructure such as time of day, and system time
688 bool "Enable debug information for KVM Guests in debugfs"
689 depends on KVM_GUEST && DEBUG_FS
692 This option enables collection of various statistics for KVM guest.
693 Statistics are displayed in debugfs filesystem. Enabling this option
694 may incur significant overhead.
696 source "arch/x86/lguest/Kconfig"
698 config PARAVIRT_TIME_ACCOUNTING
699 bool "Paravirtual steal time accounting"
703 Select this option to enable fine granularity task steal time
704 accounting. Time spent executing other tasks in parallel with
705 the current vCPU is discounted from the vCPU power. To account for
706 that, there can be a small performance impact.
708 If in doubt, say N here.
710 config PARAVIRT_CLOCK
713 endif #HYPERVISOR_GUEST
721 This option adds a kernel parameter 'memtest', which allows memtest
723 memtest=0, mean disabled; -- default
724 memtest=1, mean do 1 test pattern;
726 memtest=4, mean do 4 test patterns.
727 If you are unsure how to answer this question, answer N.
729 source "arch/x86/Kconfig.cpu"
733 prompt "HPET Timer Support" if X86_32
735 Use the IA-PC HPET (High Precision Event Timer) to manage
736 time in preference to the PIT and RTC, if a HPET is
738 HPET is the next generation timer replacing legacy 8254s.
739 The HPET provides a stable time base on SMP
740 systems, unlike the TSC, but it is more expensive to access,
741 as it is off-chip. You can find the HPET spec at
742 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
744 You can safely choose Y here. However, HPET will only be
745 activated if the platform and the BIOS support this feature.
746 Otherwise the 8254 will be used for timing services.
748 Choose N to continue using the legacy 8254 timer.
750 config HPET_EMULATE_RTC
752 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
755 def_bool y if X86_INTEL_MID
756 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
758 depends on X86_INTEL_MID && SFI
760 APB timer is the replacement for 8254, HPET on X86 MID platforms.
761 The APBT provides a stable time base on SMP
762 systems, unlike the TSC, but it is more expensive to access,
763 as it is off-chip. APB timers are always running regardless of CPU
764 C states, they are used as per CPU clockevent device when possible.
766 # Mark as expert because too many people got it wrong.
767 # The code disables itself when not needed.
770 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
771 bool "Enable DMI scanning" if EXPERT
773 Enabled scanning of DMI to identify machine quirks. Say Y
774 here unless you have verified that your setup is not
775 affected by entries in the DMI blacklist. Required by PNP
779 bool "Old AMD GART IOMMU support"
781 depends on X86_64 && PCI && AMD_NB
783 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
784 GART based hardware IOMMUs.
786 The GART supports full DMA access for devices with 32-bit access
787 limitations, on systems with more than 3 GB. This is usually needed
788 for USB, sound, many IDE/SATA chipsets and some other devices.
790 Newer systems typically have a modern AMD IOMMU, supported via
791 the CONFIG_AMD_IOMMU=y config option.
793 In normal configurations this driver is only active when needed:
794 there's more than 3 GB of memory and the system contains a
795 32-bit limited device.
800 bool "IBM Calgary IOMMU support"
802 depends on X86_64 && PCI
804 Support for hardware IOMMUs in IBM's xSeries x366 and x460
805 systems. Needed to run systems with more than 3GB of memory
806 properly with 32-bit PCI devices that do not support DAC
807 (Double Address Cycle). Calgary also supports bus level
808 isolation, where all DMAs pass through the IOMMU. This
809 prevents them from going anywhere except their intended
810 destination. This catches hard-to-find kernel bugs and
811 mis-behaving drivers and devices that do not use the DMA-API
812 properly to set up their DMA buffers. The IOMMU can be
813 turned off at boot time with the iommu=off parameter.
814 Normally the kernel will make the right choice by itself.
817 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
819 prompt "Should Calgary be enabled by default?"
820 depends on CALGARY_IOMMU
822 Should Calgary be enabled by default? if you choose 'y', Calgary
823 will be used (if it exists). If you choose 'n', Calgary will not be
824 used even if it exists. If you choose 'n' and would like to use
825 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
828 # need this always selected by IOMMU for the VIA workaround
832 Support for software bounce buffers used on x86-64 systems
833 which don't have a hardware IOMMU. Using this PCI devices
834 which can only access 32-bits of memory can be used on systems
835 with more than 3 GB of memory.
840 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
843 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
844 depends on X86_64 && SMP && DEBUG_KERNEL
845 select CPUMASK_OFFSTACK
847 Enable maximum number of CPUS and NUMA Nodes for this architecture.
851 int "Maximum number of CPUs" if SMP && !MAXSMP
852 range 2 8 if SMP && X86_32 && !X86_BIGSMP
853 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
854 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
856 default "8192" if MAXSMP
857 default "32" if SMP && X86_BIGSMP
860 This allows you to specify the maximum number of CPUs which this
861 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
862 supported value is 4096, otherwise the maximum value is 512. The
863 minimum value which makes sense is 2.
865 This is purely to save memory - each supported CPU adds
866 approximately eight kilobytes to the kernel image.
869 bool "SMT (Hyperthreading) scheduler support"
872 SMT scheduler support improves the CPU scheduler's decision making
873 when dealing with Intel Pentium 4 chips with HyperThreading at a
874 cost of slightly increased overhead in some places. If unsure say
879 prompt "Multi-core scheduler support"
882 Multi-core scheduler support improves the CPU scheduler's decision
883 making when dealing with multi-core CPU chips at a cost of slightly
884 increased overhead in some places. If unsure say N here.
886 source "kernel/Kconfig.preempt"
890 depends on !SMP && X86_LOCAL_APIC
893 bool "Local APIC support on uniprocessors" if !PCI_MSI
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
907 bool "IO-APIC support on uniprocessors"
908 depends on X86_UP_APIC
910 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
911 SMP-capable replacement for PC-style interrupt controllers. Most
912 SMP systems and many recent uniprocessor systems have one.
914 If you have a single-CPU system with an IO-APIC, you can say Y here
915 to use it. If you say Y here even though your machine doesn't have
916 an IO-APIC, then the kernel will still run with no slowdown at all.
918 config X86_LOCAL_APIC
920 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
921 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
925 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
928 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
929 bool "Reroute for broken boot IRQs"
930 depends on X86_IO_APIC
932 This option enables a workaround that fixes a source of
933 spurious interrupts. This is recommended when threaded
934 interrupt handling is used on systems where the generation of
935 superfluous "boot interrupts" cannot be disabled.
937 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
938 entry in the chipset's IO-APIC is masked (as, e.g. the RT
939 kernel does during interrupt handling). On chipsets where this
940 boot IRQ generation cannot be disabled, this workaround keeps
941 the original IRQ line masked so that only the equivalent "boot
942 IRQ" is delivered to the CPUs. The workaround also tells the
943 kernel to set up the IRQ handler on the boot IRQ line. In this
944 way only one interrupt is delivered to the kernel. Otherwise
945 the spurious second interrupt may cause the kernel to bring
946 down (vital) interrupt lines.
948 Only affects "broken" chipsets. Interrupt sharing may be
949 increased on these systems.
952 bool "Machine Check / overheating reporting"
955 Machine Check support allows the processor to notify the
956 kernel if it detects a problem (e.g. overheating, data corruption).
957 The action the kernel takes depends on the severity of the problem,
958 ranging from warning messages to halting the machine.
962 prompt "Intel MCE features"
963 depends on X86_MCE && X86_LOCAL_APIC
965 Additional support for intel specific MCE features such as
970 prompt "AMD MCE features"
971 depends on X86_MCE && X86_LOCAL_APIC
973 Additional support for AMD specific MCE features such as
974 the DRAM Error Threshold.
976 config X86_ANCIENT_MCE
977 bool "Support for old Pentium 5 / WinChip machine checks"
978 depends on X86_32 && X86_MCE
980 Include support for machine check handling on old Pentium 5 or WinChip
981 systems. These typically need to be enabled explicitly on the command
984 config X86_MCE_THRESHOLD
985 depends on X86_MCE_AMD || X86_MCE_INTEL
988 config X86_MCE_INJECT
990 tristate "Machine check injector support"
992 Provide support for injecting machine checks for testing purposes.
993 If you don't know what a machine check is and you don't do kernel
994 QA it is safe to say n.
996 config X86_THERMAL_VECTOR
998 depends on X86_MCE_INTEL
1001 bool "Enable VM86 support" if EXPERT
1005 This option is required by programs like DOSEMU to run
1006 16-bit real mode legacy code on x86 processors. It also may
1007 be needed by software like XFree86 to initialize some video
1008 cards via BIOS. Disabling this option saves about 6K.
1011 bool "Enable support for 16-bit segments" if EXPERT
1014 This option is required by programs like Wine to run 16-bit
1015 protected mode legacy code on x86 processors. Disabling
1016 this option saves about 300 bytes on i386, or around 6K text
1017 plus 16K runtime memory on x86-64,
1021 depends on X86_16BIT && X86_32
1025 depends on X86_16BIT && X86_64
1027 config X86_VSYSCALL_EMULATION
1028 bool "Enable vsyscall emulation" if EXPERT
1032 This enables emulation of the legacy vsyscall page. Disabling
1033 it is roughly equivalent to booting with vsyscall=none, except
1034 that it will also disable the helpful warning if a program
1035 tries to use a vsyscall. With this option set to N, offending
1036 programs will just segfault, citing addresses of the form
1039 This option is required by many programs built before 2013, and
1040 care should be used even with newer programs if set to N.
1042 Disabling this option saves about 7K of kernel size and
1043 possibly 4K of additional runtime pagetable memory.
1046 tristate "Toshiba Laptop support"
1049 This adds a driver to safely access the System Management Mode of
1050 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1051 not work on models with a Phoenix BIOS. The System Management Mode
1052 is used to set the BIOS and power saving options on Toshiba portables.
1054 For information on utilities to make use of this driver see the
1055 Toshiba Linux utilities web site at:
1056 <http://www.buzzard.org.uk/toshiba/>.
1058 Say Y if you intend to run this kernel on a Toshiba portable.
1062 tristate "Dell laptop support"
1065 This adds a driver to safely access the System Management Mode
1066 of the CPU on the Dell Inspiron 8000. The System Management Mode
1067 is used to read cpu temperature and cooling fan status and to
1068 control the fans on the I8K portables.
1070 This driver has been tested only on the Inspiron 8000 but it may
1071 also work with other Dell laptops. You can force loading on other
1072 models by passing the parameter `force=1' to the module. Use at
1075 For information on utilities to make use of this driver see the
1076 I8K Linux utilities web site at:
1077 <http://people.debian.org/~dz/i8k/>
1079 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1082 config X86_REBOOTFIXUPS
1083 bool "Enable X86 board specific fixups for reboot"
1086 This enables chipset and/or board specific fixups to be done
1087 in order to get reboot to work correctly. This is only needed on
1088 some combinations of hardware and BIOS. The symptom, for which
1089 this config is intended, is when reboot ends with a stalled/hung
1092 Currently, the only fixup is for the Geode machines using
1093 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1095 Say Y if you want to enable the fixup. Currently, it's safe to
1096 enable this option even if you don't need it.
1100 tristate "CPU microcode loading support"
1101 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1105 If you say Y here, you will be able to update the microcode on
1106 certain Intel and AMD processors. The Intel support is for the
1107 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1108 Xeon etc. The AMD support is for families 0x10 and later. You will
1109 obviously need the actual microcode binary data itself which is not
1110 shipped with the Linux kernel.
1112 This option selects the general module only, you need to select
1113 at least one vendor specific module as well.
1115 To compile this driver as a module, choose M here: the module
1116 will be called microcode.
1118 config MICROCODE_INTEL
1119 bool "Intel microcode loading support"
1120 depends on MICROCODE
1124 This options enables microcode patch loading support for Intel
1127 For the current Intel microcode data package go to
1128 <https://downloadcenter.intel.com> and search for
1129 'Linux Processor Microcode Data File'.
1131 config MICROCODE_AMD
1132 bool "AMD microcode loading support"
1133 depends on MICROCODE
1136 If you select this option, microcode patch loading support for AMD
1137 processors will be enabled.
1139 config MICROCODE_OLD_INTERFACE
1141 depends on MICROCODE
1143 config MICROCODE_INTEL_EARLY
1146 config MICROCODE_AMD_EARLY
1149 config MICROCODE_EARLY
1150 bool "Early load microcode"
1151 depends on MICROCODE=y && BLK_DEV_INITRD
1152 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1153 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1156 This option provides functionality to read additional microcode data
1157 at the beginning of initrd image. The data tells kernel to load
1158 microcode to CPU's as early as possible. No functional change if no
1159 microcode data is glued to the initrd, therefore it's safe to say Y.
1162 tristate "/dev/cpu/*/msr - Model-specific register support"
1164 This device gives privileged processes access to the x86
1165 Model-Specific Registers (MSRs). It is a character device with
1166 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1167 MSR accesses are directed to a specific CPU on multi-processor
1171 tristate "/dev/cpu/*/cpuid - CPU information support"
1173 This device gives processes access to the x86 CPUID instruction to
1174 be executed on a specific processor. It is a character device
1175 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1179 prompt "High Memory Support"
1186 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1187 However, the address space of 32-bit x86 processors is only 4
1188 Gigabytes large. That means that, if you have a large amount of
1189 physical memory, not all of it can be "permanently mapped" by the
1190 kernel. The physical memory that's not permanently mapped is called
1193 If you are compiling a kernel which will never run on a machine with
1194 more than 1 Gigabyte total physical RAM, answer "off" here (default
1195 choice and suitable for most users). This will result in a "3GB/1GB"
1196 split: 3GB are mapped so that each process sees a 3GB virtual memory
1197 space and the remaining part of the 4GB virtual memory space is used
1198 by the kernel to permanently map as much physical memory as
1201 If the machine has between 1 and 4 Gigabytes physical RAM, then
1204 If more than 4 Gigabytes is used then answer "64GB" here. This
1205 selection turns Intel PAE (Physical Address Extension) mode on.
1206 PAE implements 3-level paging on IA32 processors. PAE is fully
1207 supported by Linux, PAE mode is implemented on all recent Intel
1208 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1209 then the kernel will not boot on CPUs that don't support PAE!
1211 The actual amount of total physical memory will either be
1212 auto detected or can be forced by using a kernel command line option
1213 such as "mem=256M". (Try "man bootparam" or see the documentation of
1214 your boot loader (lilo or loadlin) about how to pass options to the
1215 kernel at boot time.)
1217 If unsure, say "off".
1222 Select this if you have a 32-bit processor and between 1 and 4
1223 gigabytes of physical RAM.
1230 Select this if you have a 32-bit processor and more than 4
1231 gigabytes of physical RAM.
1236 prompt "Memory split" if EXPERT
1240 Select the desired split between kernel and user memory.
1242 If the address range available to the kernel is less than the
1243 physical memory installed, the remaining memory will be available
1244 as "high memory". Accessing high memory is a little more costly
1245 than low memory, as it needs to be mapped into the kernel first.
1246 Note that increasing the kernel address space limits the range
1247 available to user programs, making the address space there
1248 tighter. Selecting anything other than the default 3G/1G split
1249 will also likely make your kernel incompatible with binary-only
1252 If you are not absolutely sure what you are doing, leave this
1256 bool "3G/1G user/kernel split"
1257 config VMSPLIT_3G_OPT
1259 bool "3G/1G user/kernel split (for full 1G low memory)"
1261 bool "2G/2G user/kernel split"
1262 config VMSPLIT_2G_OPT
1264 bool "2G/2G user/kernel split (for full 2G low memory)"
1266 bool "1G/3G user/kernel split"
1271 default 0xB0000000 if VMSPLIT_3G_OPT
1272 default 0x80000000 if VMSPLIT_2G
1273 default 0x78000000 if VMSPLIT_2G_OPT
1274 default 0x40000000 if VMSPLIT_1G
1280 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1283 bool "PAE (Physical Address Extension) Support"
1284 depends on X86_32 && !HIGHMEM4G
1286 PAE is required for NX support, and furthermore enables
1287 larger swapspace support for non-overcommit purposes. It
1288 has the cost of more pagetable lookup overhead, and also
1289 consumes more pagetable space per process.
1291 config ARCH_PHYS_ADDR_T_64BIT
1293 depends on X86_64 || X86_PAE
1295 config ARCH_DMA_ADDR_T_64BIT
1297 depends on X86_64 || HIGHMEM64G
1299 config X86_DIRECT_GBPAGES
1301 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1303 Certain kernel features effectively disable kernel
1304 linear 1 GB mappings (even if the CPU otherwise
1305 supports them), so don't confuse the user by printing
1306 that we have them enabled.
1308 # Common NUMA Features
1310 bool "Numa Memory Allocation and Scheduler Support"
1312 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1313 default y if X86_BIGSMP
1315 Enable NUMA (Non Uniform Memory Access) support.
1317 The kernel will try to allocate memory used by a CPU on the
1318 local memory controller of the CPU and add some more
1319 NUMA awareness to the kernel.
1321 For 64-bit this is recommended if the system is Intel Core i7
1322 (or later), AMD Opteron, or EM64T NUMA.
1324 For 32-bit this is only needed if you boot a 32-bit
1325 kernel on a 64-bit NUMA platform.
1327 Otherwise, you should say N.
1331 prompt "Old style AMD Opteron NUMA detection"
1332 depends on X86_64 && NUMA && PCI
1334 Enable AMD NUMA node topology detection. You should say Y here if
1335 you have a multi processor AMD system. This uses an old method to
1336 read the NUMA configuration directly from the builtin Northbridge
1337 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1338 which also takes priority if both are compiled in.
1340 config X86_64_ACPI_NUMA
1342 prompt "ACPI NUMA detection"
1343 depends on X86_64 && NUMA && ACPI && PCI
1346 Enable ACPI SRAT based node topology detection.
1348 # Some NUMA nodes have memory ranges that span
1349 # other nodes. Even though a pfn is valid and
1350 # between a node's start and end pfns, it may not
1351 # reside on that node. See memmap_init_zone()
1353 config NODES_SPAN_OTHER_NODES
1355 depends on X86_64_ACPI_NUMA
1358 bool "NUMA emulation"
1361 Enable NUMA emulation. A flat machine will be split
1362 into virtual nodes when booted with "numa=fake=N", where N is the
1363 number of nodes. This is only useful for debugging.
1366 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1368 default "10" if MAXSMP
1369 default "6" if X86_64
1371 depends on NEED_MULTIPLE_NODES
1373 Specify the maximum number of NUMA Nodes available on the target
1374 system. Increases memory reserved to accommodate various tables.
1376 config ARCH_HAVE_MEMORY_PRESENT
1378 depends on X86_32 && DISCONTIGMEM
1380 config NEED_NODE_MEMMAP_SIZE
1382 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1384 config ARCH_FLATMEM_ENABLE
1386 depends on X86_32 && !NUMA
1388 config ARCH_DISCONTIGMEM_ENABLE
1390 depends on NUMA && X86_32
1392 config ARCH_DISCONTIGMEM_DEFAULT
1394 depends on NUMA && X86_32
1396 config ARCH_SPARSEMEM_ENABLE
1398 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1399 select SPARSEMEM_STATIC if X86_32
1400 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1402 config ARCH_SPARSEMEM_DEFAULT
1406 config ARCH_SELECT_MEMORY_MODEL
1408 depends on ARCH_SPARSEMEM_ENABLE
1410 config ARCH_MEMORY_PROBE
1411 bool "Enable sysfs memory/probe interface"
1412 depends on X86_64 && MEMORY_HOTPLUG
1414 This option enables a sysfs memory/probe interface for testing.
1415 See Documentation/memory-hotplug.txt for more information.
1416 If you are unsure how to answer this question, answer N.
1418 config ARCH_PROC_KCORE_TEXT
1420 depends on X86_64 && PROC_KCORE
1422 config ILLEGAL_POINTER_VALUE
1425 default 0xdead000000000000 if X86_64
1429 config X86_PMEM_LEGACY
1430 bool "Support non-standard NVDIMMs and ADR protected memory"
1432 Treat memory marked using the non-standard e820 type of 12 as used
1433 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1434 The kernel will offer these regions to the 'pmem' driver so
1435 they can be used for persistent storage.
1440 bool "Allocate 3rd-level pagetables from highmem"
1443 The VM uses one page table entry for each page of physical memory.
1444 For systems with a lot of RAM, this can be wasteful of precious
1445 low memory. Setting this option will put user-space page table
1446 entries in high memory.
1448 config X86_CHECK_BIOS_CORRUPTION
1449 bool "Check for low memory corruption"
1451 Periodically check for memory corruption in low memory, which
1452 is suspected to be caused by BIOS. Even when enabled in the
1453 configuration, it is disabled at runtime. Enable it by
1454 setting "memory_corruption_check=1" on the kernel command
1455 line. By default it scans the low 64k of memory every 60
1456 seconds; see the memory_corruption_check_size and
1457 memory_corruption_check_period parameters in
1458 Documentation/kernel-parameters.txt to adjust this.
1460 When enabled with the default parameters, this option has
1461 almost no overhead, as it reserves a relatively small amount
1462 of memory and scans it infrequently. It both detects corruption
1463 and prevents it from affecting the running system.
1465 It is, however, intended as a diagnostic tool; if repeatable
1466 BIOS-originated corruption always affects the same memory,
1467 you can use memmap= to prevent the kernel from using that
1470 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1471 bool "Set the default setting of memory_corruption_check"
1472 depends on X86_CHECK_BIOS_CORRUPTION
1475 Set whether the default state of memory_corruption_check is
1478 config X86_RESERVE_LOW
1479 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1483 Specify the amount of low memory to reserve for the BIOS.
1485 The first page contains BIOS data structures that the kernel
1486 must not use, so that page must always be reserved.
1488 By default we reserve the first 64K of physical RAM, as a
1489 number of BIOSes are known to corrupt that memory range
1490 during events such as suspend/resume or monitor cable
1491 insertion, so it must not be used by the kernel.
1493 You can set this to 4 if you are absolutely sure that you
1494 trust the BIOS to get all its memory reservations and usages
1495 right. If you know your BIOS have problems beyond the
1496 default 64K area, you can set this to 640 to avoid using the
1497 entire low memory range.
1499 If you have doubts about the BIOS (e.g. suspend/resume does
1500 not work or there's kernel crashes after certain hardware
1501 hotplug events) then you might want to enable
1502 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1503 typical corruption patterns.
1505 Leave this to the default value of 64 if you are unsure.
1507 config MATH_EMULATION
1509 prompt "Math emulation" if X86_32
1511 Linux can emulate a math coprocessor (used for floating point
1512 operations) if you don't have one. 486DX and Pentium processors have
1513 a math coprocessor built in, 486SX and 386 do not, unless you added
1514 a 487DX or 387, respectively. (The messages during boot time can
1515 give you some hints here ["man dmesg"].) Everyone needs either a
1516 coprocessor or this emulation.
1518 If you don't have a math coprocessor, you need to say Y here; if you
1519 say Y here even though you have a coprocessor, the coprocessor will
1520 be used nevertheless. (This behavior can be changed with the kernel
1521 command line option "no387", which comes handy if your coprocessor
1522 is broken. Try "man bootparam" or see the documentation of your boot
1523 loader (lilo or loadlin) about how to pass options to the kernel at
1524 boot time.) This means that it is a good idea to say Y here if you
1525 intend to use this kernel on different machines.
1527 More information about the internals of the Linux math coprocessor
1528 emulation can be found in <file:arch/x86/math-emu/README>.
1530 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1531 kernel, it won't hurt.
1535 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1537 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1538 the Memory Type Range Registers (MTRRs) may be used to control
1539 processor access to memory ranges. This is most useful if you have
1540 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1541 allows bus write transfers to be combined into a larger transfer
1542 before bursting over the PCI/AGP bus. This can increase performance
1543 of image write operations 2.5 times or more. Saying Y here creates a
1544 /proc/mtrr file which may be used to manipulate your processor's
1545 MTRRs. Typically the X server should use this.
1547 This code has a reasonably generic interface so that similar
1548 control registers on other processors can be easily supported
1551 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1552 Registers (ARRs) which provide a similar functionality to MTRRs. For
1553 these, the ARRs are used to emulate the MTRRs.
1554 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1555 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1556 write-combining. All of these processors are supported by this code
1557 and it makes sense to say Y here if you have one of them.
1559 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1560 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1561 can lead to all sorts of problems, so it's good to say Y here.
1563 You can safely say Y even if your machine doesn't have MTRRs, you'll
1564 just add about 9 KB to your kernel.
1566 See <file:Documentation/x86/mtrr.txt> for more information.
1568 config MTRR_SANITIZER
1570 prompt "MTRR cleanup support"
1573 Convert MTRR layout from continuous to discrete, so X drivers can
1574 add writeback entries.
1576 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1577 The largest mtrr entry size for a continuous block can be set with
1582 config MTRR_SANITIZER_ENABLE_DEFAULT
1583 int "MTRR cleanup enable value (0-1)"
1586 depends on MTRR_SANITIZER
1588 Enable mtrr cleanup default value
1590 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1591 int "MTRR cleanup spare reg num (0-7)"
1594 depends on MTRR_SANITIZER
1596 mtrr cleanup spare entries default, it can be changed via
1597 mtrr_spare_reg_nr=N on the kernel command line.
1601 prompt "x86 PAT support" if EXPERT
1604 Use PAT attributes to setup page level cache control.
1606 PATs are the modern equivalents of MTRRs and are much more
1607 flexible than MTRRs.
1609 Say N here if you see bootup problems (boot crash, boot hang,
1610 spontaneous reboots) or a non-working video driver.
1614 config ARCH_USES_PG_UNCACHED
1620 prompt "x86 architectural random number generator" if EXPERT
1622 Enable the x86 architectural RDRAND instruction
1623 (Intel Bull Mountain technology) to generate random numbers.
1624 If supported, this is a high bandwidth, cryptographically
1625 secure hardware random number generator.
1629 prompt "Supervisor Mode Access Prevention" if EXPERT
1631 Supervisor Mode Access Prevention (SMAP) is a security
1632 feature in newer Intel processors. There is a small
1633 performance cost if this enabled and turned on; there is
1634 also a small increase in the kernel size if this is enabled.
1638 config X86_INTEL_MPX
1639 prompt "Intel MPX (Memory Protection Extensions)"
1641 depends on CPU_SUP_INTEL
1643 MPX provides hardware features that can be used in
1644 conjunction with compiler-instrumented code to check
1645 memory references. It is designed to detect buffer
1646 overflow or underflow bugs.
1648 This option enables running applications which are
1649 instrumented or otherwise use MPX. It does not use MPX
1650 itself inside the kernel or to protect the kernel
1651 against bad memory references.
1653 Enabling this option will make the kernel larger:
1654 ~8k of kernel text and 36 bytes of data on a 64-bit
1655 defconfig. It adds a long to the 'mm_struct' which
1656 will increase the kernel memory overhead of each
1657 process and adds some branches to paths used during
1658 exec() and munmap().
1660 For details, see Documentation/x86/intel_mpx.txt
1665 bool "EFI runtime service support"
1668 select EFI_RUNTIME_WRAPPERS
1670 This enables the kernel to use EFI runtime services that are
1671 available (such as the EFI variable services).
1673 This option is only useful on systems that have EFI firmware.
1674 In addition, you should use the latest ELILO loader available
1675 at <http://elilo.sourceforge.net> in order to take advantage
1676 of EFI runtime services. However, even with this option, the
1677 resultant kernel should continue to boot on existing non-EFI
1681 bool "EFI stub support"
1682 depends on EFI && !X86_USE_3DNOW
1685 This kernel feature allows a bzImage to be loaded directly
1686 by EFI firmware without the use of a bootloader.
1688 See Documentation/efi-stub.txt for more information.
1691 bool "EFI mixed-mode support"
1692 depends on EFI_STUB && X86_64
1694 Enabling this feature allows a 64-bit kernel to be booted
1695 on a 32-bit firmware, provided that your CPU supports 64-bit
1698 Note that it is not possible to boot a mixed-mode enabled
1699 kernel via the EFI boot stub - a bootloader that supports
1700 the EFI handover protocol must be used.
1706 prompt "Enable seccomp to safely compute untrusted bytecode"
1708 This kernel feature is useful for number crunching applications
1709 that may need to compute untrusted bytecode during their
1710 execution. By using pipes or other transports made available to
1711 the process as file descriptors supporting the read/write
1712 syscalls, it's possible to isolate those applications in
1713 their own address space using seccomp. Once seccomp is
1714 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1715 and the task is only allowed to execute a few safe syscalls
1716 defined by each seccomp mode.
1718 If unsure, say Y. Only embedded should say N here.
1720 source kernel/Kconfig.hz
1723 bool "kexec system call"
1725 kexec is a system call that implements the ability to shutdown your
1726 current kernel, and to start another kernel. It is like a reboot
1727 but it is independent of the system firmware. And like a reboot
1728 you can start any kernel with it, not just Linux.
1730 The name comes from the similarity to the exec system call.
1732 It is an ongoing process to be certain the hardware in a machine
1733 is properly shutdown, so do not be surprised if this code does not
1734 initially work for you. As of this writing the exact hardware
1735 interface is strongly in flux, so no good recommendation can be
1739 bool "kexec file based system call"
1744 depends on CRYPTO_SHA256=y
1746 This is new version of kexec system call. This system call is
1747 file based and takes file descriptors as system call argument
1748 for kernel and initramfs as opposed to list of segments as
1749 accepted by previous system call.
1751 config KEXEC_VERIFY_SIG
1752 bool "Verify kernel signature during kexec_file_load() syscall"
1753 depends on KEXEC_FILE
1755 This option makes kernel signature verification mandatory for
1756 the kexec_file_load() syscall.
1758 In addition to that option, you need to enable signature
1759 verification for the corresponding kernel image type being
1760 loaded in order for this to work.
1762 config KEXEC_BZIMAGE_VERIFY_SIG
1763 bool "Enable bzImage signature verification support"
1764 depends on KEXEC_VERIFY_SIG
1765 depends on SIGNED_PE_FILE_VERIFICATION
1766 select SYSTEM_TRUSTED_KEYRING
1768 Enable bzImage signature verification support.
1771 bool "kernel crash dumps"
1772 depends on X86_64 || (X86_32 && HIGHMEM)
1774 Generate crash dump after being started by kexec.
1775 This should be normally only set in special crash dump kernels
1776 which are loaded in the main kernel with kexec-tools into
1777 a specially reserved region and then later executed after
1778 a crash by kdump/kexec. The crash dump kernel must be compiled
1779 to a memory address not used by the main kernel or BIOS using
1780 PHYSICAL_START, or it must be built as a relocatable image
1781 (CONFIG_RELOCATABLE=y).
1782 For more details see Documentation/kdump/kdump.txt
1786 depends on KEXEC && HIBERNATION
1788 Jump between original kernel and kexeced kernel and invoke
1789 code in physical address mode via KEXEC
1791 config PHYSICAL_START
1792 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1795 This gives the physical address where the kernel is loaded.
1797 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1798 bzImage will decompress itself to above physical address and
1799 run from there. Otherwise, bzImage will run from the address where
1800 it has been loaded by the boot loader and will ignore above physical
1803 In normal kdump cases one does not have to set/change this option
1804 as now bzImage can be compiled as a completely relocatable image
1805 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1806 address. This option is mainly useful for the folks who don't want
1807 to use a bzImage for capturing the crash dump and want to use a
1808 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1809 to be specifically compiled to run from a specific memory area
1810 (normally a reserved region) and this option comes handy.
1812 So if you are using bzImage for capturing the crash dump,
1813 leave the value here unchanged to 0x1000000 and set
1814 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1815 for capturing the crash dump change this value to start of
1816 the reserved region. In other words, it can be set based on
1817 the "X" value as specified in the "crashkernel=YM@XM"
1818 command line boot parameter passed to the panic-ed
1819 kernel. Please take a look at Documentation/kdump/kdump.txt
1820 for more details about crash dumps.
1822 Usage of bzImage for capturing the crash dump is recommended as
1823 one does not have to build two kernels. Same kernel can be used
1824 as production kernel and capture kernel. Above option should have
1825 gone away after relocatable bzImage support is introduced. But it
1826 is present because there are users out there who continue to use
1827 vmlinux for dump capture. This option should go away down the
1830 Don't change this unless you know what you are doing.
1833 bool "Build a relocatable kernel"
1836 This builds a kernel image that retains relocation information
1837 so it can be loaded someplace besides the default 1MB.
1838 The relocations tend to make the kernel binary about 10% larger,
1839 but are discarded at runtime.
1841 One use is for the kexec on panic case where the recovery kernel
1842 must live at a different physical address than the primary
1845 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1846 it has been loaded at and the compile time physical address
1847 (CONFIG_PHYSICAL_START) is used as the minimum location.
1849 config RANDOMIZE_BASE
1850 bool "Randomize the address of the kernel image"
1851 depends on RELOCATABLE
1854 Randomizes the physical and virtual address at which the
1855 kernel image is decompressed, as a security feature that
1856 deters exploit attempts relying on knowledge of the location
1857 of kernel internals.
1859 Entropy is generated using the RDRAND instruction if it is
1860 supported. If RDTSC is supported, it is used as well. If
1861 neither RDRAND nor RDTSC are supported, then randomness is
1862 read from the i8254 timer.
1864 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1865 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1866 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1867 minimum of 2MiB, only 10 bits of entropy is theoretically
1868 possible. At best, due to page table layouts, 64-bit can use
1869 9 bits of entropy and 32-bit uses 8 bits.
1873 config RANDOMIZE_BASE_MAX_OFFSET
1874 hex "Maximum kASLR offset allowed" if EXPERT
1875 depends on RANDOMIZE_BASE
1876 range 0x0 0x20000000 if X86_32
1877 default "0x20000000" if X86_32
1878 range 0x0 0x40000000 if X86_64
1879 default "0x40000000" if X86_64
1881 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1882 memory is used to determine the maximal offset in bytes that will
1883 be applied to the kernel when kernel Address Space Layout
1884 Randomization (kASLR) is active. This must be a multiple of
1887 On 32-bit this is limited to 512MiB by page table layouts. The
1890 On 64-bit this is limited by how the kernel fixmap page table is
1891 positioned, so this cannot be larger than 1GiB currently. Without
1892 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1893 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1894 modules area will shrink to compensate, up to the current maximum
1895 1GiB to 1GiB split. The default is 1GiB.
1897 If unsure, leave at the default value.
1899 # Relocation on x86 needs some additional build support
1900 config X86_NEED_RELOCS
1902 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1904 config PHYSICAL_ALIGN
1905 hex "Alignment value to which kernel should be aligned"
1907 range 0x2000 0x1000000 if X86_32
1908 range 0x200000 0x1000000 if X86_64
1910 This value puts the alignment restrictions on physical address
1911 where kernel is loaded and run from. Kernel is compiled for an
1912 address which meets above alignment restriction.
1914 If bootloader loads the kernel at a non-aligned address and
1915 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1916 address aligned to above value and run from there.
1918 If bootloader loads the kernel at a non-aligned address and
1919 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1920 load address and decompress itself to the address it has been
1921 compiled for and run from there. The address for which kernel is
1922 compiled already meets above alignment restrictions. Hence the
1923 end result is that kernel runs from a physical address meeting
1924 above alignment restrictions.
1926 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1927 this value must be a multiple of 0x200000.
1929 Don't change this unless you know what you are doing.
1932 bool "Support for hot-pluggable CPUs"
1935 Say Y here to allow turning CPUs off and on. CPUs can be
1936 controlled through /sys/devices/system/cpu.
1937 ( Note: power management support will enable this option
1938 automatically on SMP systems. )
1939 Say N if you want to disable CPU hotplug.
1941 config BOOTPARAM_HOTPLUG_CPU0
1942 bool "Set default setting of cpu0_hotpluggable"
1944 depends on HOTPLUG_CPU
1946 Set whether default state of cpu0_hotpluggable is on or off.
1948 Say Y here to enable CPU0 hotplug by default. If this switch
1949 is turned on, there is no need to give cpu0_hotplug kernel
1950 parameter and the CPU0 hotplug feature is enabled by default.
1952 Please note: there are two known CPU0 dependencies if you want
1953 to enable the CPU0 hotplug feature either by this switch or by
1954 cpu0_hotplug kernel parameter.
1956 First, resume from hibernate or suspend always starts from CPU0.
1957 So hibernate and suspend are prevented if CPU0 is offline.
1959 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1960 offline if any interrupt can not migrate out of CPU0. There may
1961 be other CPU0 dependencies.
1963 Please make sure the dependencies are under your control before
1964 you enable this feature.
1966 Say N if you don't want to enable CPU0 hotplug feature by default.
1967 You still can enable the CPU0 hotplug feature at boot by kernel
1968 parameter cpu0_hotplug.
1970 config DEBUG_HOTPLUG_CPU0
1972 prompt "Debug CPU0 hotplug"
1973 depends on HOTPLUG_CPU
1975 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1976 soon as possible and boots up userspace with CPU0 offlined. User
1977 can online CPU0 back after boot time.
1979 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1980 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1981 compilation or giving cpu0_hotplug kernel parameter at boot.
1987 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1988 depends on X86_32 || IA32_EMULATION
1990 Certain buggy versions of glibc will crash if they are
1991 presented with a 32-bit vDSO that is not mapped at the address
1992 indicated in its segment table.
1994 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1995 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1996 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1997 the only released version with the bug, but OpenSUSE 9
1998 contains a buggy "glibc 2.3.2".
2000 The symptom of the bug is that everything crashes on startup, saying:
2001 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2003 Saying Y here changes the default value of the vdso32 boot
2004 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2005 This works around the glibc bug but hurts performance.
2007 If unsure, say N: if you are compiling your own kernel, you
2008 are unlikely to be using a buggy version of glibc.
2011 bool "Built-in kernel command line"
2013 Allow for specifying boot arguments to the kernel at
2014 build time. On some systems (e.g. embedded ones), it is
2015 necessary or convenient to provide some or all of the
2016 kernel boot arguments with the kernel itself (that is,
2017 to not rely on the boot loader to provide them.)
2019 To compile command line arguments into the kernel,
2020 set this option to 'Y', then fill in the
2021 the boot arguments in CONFIG_CMDLINE.
2023 Systems with fully functional boot loaders (i.e. non-embedded)
2024 should leave this option set to 'N'.
2027 string "Built-in kernel command string"
2028 depends on CMDLINE_BOOL
2031 Enter arguments here that should be compiled into the kernel
2032 image and used at boot time. If the boot loader provides a
2033 command line at boot time, it is appended to this string to
2034 form the full kernel command line, when the system boots.
2036 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2037 change this behavior.
2039 In most cases, the command line (whether built-in or provided
2040 by the boot loader) should specify the device for the root
2043 config CMDLINE_OVERRIDE
2044 bool "Built-in command line overrides boot loader arguments"
2045 depends on CMDLINE_BOOL
2047 Set this option to 'Y' to have the kernel ignore the boot loader
2048 command line, and use ONLY the built-in command line.
2050 This is used to work around broken boot loaders. This should
2051 be set to 'N' under normal conditions.
2053 source "kernel/livepatch/Kconfig"
2057 config ARCH_ENABLE_MEMORY_HOTPLUG
2059 depends on X86_64 || (X86_32 && HIGHMEM)
2061 config ARCH_ENABLE_MEMORY_HOTREMOVE
2063 depends on MEMORY_HOTPLUG
2065 config USE_PERCPU_NUMA_NODE_ID
2069 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2071 depends on X86_64 || X86_PAE
2073 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2075 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2077 menu "Power management and ACPI options"
2079 config ARCH_HIBERNATION_HEADER
2081 depends on X86_64 && HIBERNATION
2083 source "kernel/power/Kconfig"
2085 source "drivers/acpi/Kconfig"
2087 source "drivers/sfi/Kconfig"
2094 tristate "APM (Advanced Power Management) BIOS support"
2095 depends on X86_32 && PM_SLEEP
2097 APM is a BIOS specification for saving power using several different
2098 techniques. This is mostly useful for battery powered laptops with
2099 APM compliant BIOSes. If you say Y here, the system time will be
2100 reset after a RESUME operation, the /proc/apm device will provide
2101 battery status information, and user-space programs will receive
2102 notification of APM "events" (e.g. battery status change).
2104 If you select "Y" here, you can disable actual use of the APM
2105 BIOS by passing the "apm=off" option to the kernel at boot time.
2107 Note that the APM support is almost completely disabled for
2108 machines with more than one CPU.
2110 In order to use APM, you will need supporting software. For location
2111 and more information, read <file:Documentation/power/apm-acpi.txt>
2112 and the Battery Powered Linux mini-HOWTO, available from
2113 <http://www.tldp.org/docs.html#howto>.
2115 This driver does not spin down disk drives (see the hdparm(8)
2116 manpage ("man 8 hdparm") for that), and it doesn't turn off
2117 VESA-compliant "green" monitors.
2119 This driver does not support the TI 4000M TravelMate and the ACER
2120 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2121 desktop machines also don't have compliant BIOSes, and this driver
2122 may cause those machines to panic during the boot phase.
2124 Generally, if you don't have a battery in your machine, there isn't
2125 much point in using this driver and you should say N. If you get
2126 random kernel OOPSes or reboots that don't seem to be related to
2127 anything, try disabling/enabling this option (or disabling/enabling
2130 Some other things you should try when experiencing seemingly random,
2133 1) make sure that you have enough swap space and that it is
2135 2) pass the "no-hlt" option to the kernel
2136 3) switch on floating point emulation in the kernel and pass
2137 the "no387" option to the kernel
2138 4) pass the "floppy=nodma" option to the kernel
2139 5) pass the "mem=4M" option to the kernel (thereby disabling
2140 all but the first 4 MB of RAM)
2141 6) make sure that the CPU is not over clocked.
2142 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2143 8) disable the cache from your BIOS settings
2144 9) install a fan for the video card or exchange video RAM
2145 10) install a better fan for the CPU
2146 11) exchange RAM chips
2147 12) exchange the motherboard.
2149 To compile this driver as a module, choose M here: the
2150 module will be called apm.
2154 config APM_IGNORE_USER_SUSPEND
2155 bool "Ignore USER SUSPEND"
2157 This option will ignore USER SUSPEND requests. On machines with a
2158 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2159 series notebooks, it is necessary to say Y because of a BIOS bug.
2161 config APM_DO_ENABLE
2162 bool "Enable PM at boot time"
2164 Enable APM features at boot time. From page 36 of the APM BIOS
2165 specification: "When disabled, the APM BIOS does not automatically
2166 power manage devices, enter the Standby State, enter the Suspend
2167 State, or take power saving steps in response to CPU Idle calls."
2168 This driver will make CPU Idle calls when Linux is idle (unless this
2169 feature is turned off -- see "Do CPU IDLE calls", below). This
2170 should always save battery power, but more complicated APM features
2171 will be dependent on your BIOS implementation. You may need to turn
2172 this option off if your computer hangs at boot time when using APM
2173 support, or if it beeps continuously instead of suspending. Turn
2174 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2175 T400CDT. This is off by default since most machines do fine without
2180 bool "Make CPU Idle calls when idle"
2182 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2183 On some machines, this can activate improved power savings, such as
2184 a slowed CPU clock rate, when the machine is idle. These idle calls
2185 are made after the idle loop has run for some length of time (e.g.,
2186 333 mS). On some machines, this will cause a hang at boot time or
2187 whenever the CPU becomes idle. (On machines with more than one CPU,
2188 this option does nothing.)
2190 config APM_DISPLAY_BLANK
2191 bool "Enable console blanking using APM"
2193 Enable console blanking using the APM. Some laptops can use this to
2194 turn off the LCD backlight when the screen blanker of the Linux
2195 virtual console blanks the screen. Note that this is only used by
2196 the virtual console screen blanker, and won't turn off the backlight
2197 when using the X Window system. This also doesn't have anything to
2198 do with your VESA-compliant power-saving monitor. Further, this
2199 option doesn't work for all laptops -- it might not turn off your
2200 backlight at all, or it might print a lot of errors to the console,
2201 especially if you are using gpm.
2203 config APM_ALLOW_INTS
2204 bool "Allow interrupts during APM BIOS calls"
2206 Normally we disable external interrupts while we are making calls to
2207 the APM BIOS as a measure to lessen the effects of a badly behaving
2208 BIOS implementation. The BIOS should reenable interrupts if it
2209 needs to. Unfortunately, some BIOSes do not -- especially those in
2210 many of the newer IBM Thinkpads. If you experience hangs when you
2211 suspend, try setting this to Y. Otherwise, say N.
2215 source "drivers/cpufreq/Kconfig"
2217 source "drivers/cpuidle/Kconfig"
2219 source "drivers/idle/Kconfig"
2224 menu "Bus options (PCI etc.)"
2230 Find out whether you have a PCI motherboard. PCI is the name of a
2231 bus system, i.e. the way the CPU talks to the other stuff inside
2232 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2233 VESA. If you have PCI, say Y, otherwise N.
2236 prompt "PCI access mode"
2237 depends on X86_32 && PCI
2240 On PCI systems, the BIOS can be used to detect the PCI devices and
2241 determine their configuration. However, some old PCI motherboards
2242 have BIOS bugs and may crash if this is done. Also, some embedded
2243 PCI-based systems don't have any BIOS at all. Linux can also try to
2244 detect the PCI hardware directly without using the BIOS.
2246 With this option, you can specify how Linux should detect the
2247 PCI devices. If you choose "BIOS", the BIOS will be used,
2248 if you choose "Direct", the BIOS won't be used, and if you
2249 choose "MMConfig", then PCI Express MMCONFIG will be used.
2250 If you choose "Any", the kernel will try MMCONFIG, then the
2251 direct access method and falls back to the BIOS if that doesn't
2252 work. If unsure, go with the default, which is "Any".
2257 config PCI_GOMMCONFIG
2274 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2276 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2279 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2283 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2287 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2291 depends on PCI && XEN
2299 bool "Support mmconfig PCI config space access"
2300 depends on X86_64 && PCI && ACPI
2302 config PCI_CNB20LE_QUIRK
2303 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2306 Read the PCI windows out of the CNB20LE host bridge. This allows
2307 PCI hotplug to work on systems with the CNB20LE chipset which do
2310 There's no public spec for this chipset, and this functionality
2311 is known to be incomplete.
2313 You should say N unless you know you need this.
2315 source "drivers/pci/pcie/Kconfig"
2317 source "drivers/pci/Kconfig"
2319 # x86_64 have no ISA slots, but can have ISA-style DMA.
2321 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2324 Enables ISA-style DMA support for devices requiring such controllers.
2332 Find out whether you have ISA slots on your motherboard. ISA is the
2333 name of a bus system, i.e. the way the CPU talks to the other stuff
2334 inside your box. Other bus systems are PCI, EISA, MicroChannel
2335 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2336 newer boards don't support it. If you have ISA, say Y, otherwise N.
2342 The Extended Industry Standard Architecture (EISA) bus was
2343 developed as an open alternative to the IBM MicroChannel bus.
2345 The EISA bus provided some of the features of the IBM MicroChannel
2346 bus while maintaining backward compatibility with cards made for
2347 the older ISA bus. The EISA bus saw limited use between 1988 and
2348 1995 when it was made obsolete by the PCI bus.
2350 Say Y here if you are building a kernel for an EISA-based machine.
2354 source "drivers/eisa/Kconfig"
2357 tristate "NatSemi SCx200 support"
2359 This provides basic support for National Semiconductor's
2360 (now AMD's) Geode processors. The driver probes for the
2361 PCI-IDs of several on-chip devices, so its a good dependency
2362 for other scx200_* drivers.
2364 If compiled as a module, the driver is named scx200.
2366 config SCx200HR_TIMER
2367 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2371 This driver provides a clocksource built upon the on-chip
2372 27MHz high-resolution timer. Its also a workaround for
2373 NSC Geode SC-1100's buggy TSC, which loses time when the
2374 processor goes idle (as is done by the scheduler). The
2375 other workaround is idle=poll boot option.
2378 bool "One Laptop Per Child support"
2385 Add support for detecting the unique features of the OLPC
2389 bool "OLPC XO-1 Power Management"
2390 depends on OLPC && MFD_CS5535 && PM_SLEEP
2393 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2396 bool "OLPC XO-1 Real Time Clock"
2397 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2399 Add support for the XO-1 real time clock, which can be used as a
2400 programmable wakeup source.
2403 bool "OLPC XO-1 SCI extras"
2404 depends on OLPC && OLPC_XO1_PM
2410 Add support for SCI-based features of the OLPC XO-1 laptop:
2411 - EC-driven system wakeups
2415 - AC adapter status updates
2416 - Battery status updates
2418 config OLPC_XO15_SCI
2419 bool "OLPC XO-1.5 SCI extras"
2420 depends on OLPC && ACPI
2423 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2424 - EC-driven system wakeups
2425 - AC adapter status updates
2426 - Battery status updates
2429 bool "PCEngines ALIX System Support (LED setup)"
2432 This option enables system support for the PCEngines ALIX.
2433 At present this just sets up LEDs for GPIO control on
2434 ALIX2/3/6 boards. However, other system specific setup should
2437 Note: You must still enable the drivers for GPIO and LED support
2438 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2440 Note: You have to set alix.force=1 for boards with Award BIOS.
2443 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2446 This option enables system support for the Soekris Engineering net5501.
2449 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2453 This option enables system support for the Traverse Technologies GEOS.
2456 bool "Technologic Systems TS-5500 platform support"
2458 select CHECK_SIGNATURE
2462 This option enables system support for the Technologic Systems TS-5500.
2468 depends on CPU_SUP_AMD && PCI
2470 source "drivers/pcmcia/Kconfig"
2472 source "drivers/pci/hotplug/Kconfig"
2475 tristate "RapidIO support"
2479 If enabled this option will include drivers and the core
2480 infrastructure code to support RapidIO interconnect devices.
2482 source "drivers/rapidio/Kconfig"
2485 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2487 Firmwares often provide initial graphics framebuffers so the BIOS,
2488 bootloader or kernel can show basic video-output during boot for
2489 user-guidance and debugging. Historically, x86 used the VESA BIOS
2490 Extensions and EFI-framebuffers for this, which are mostly limited
2492 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2493 framebuffers so the new generic system-framebuffer drivers can be
2494 used on x86. If the framebuffer is not compatible with the generic
2495 modes, it is adverticed as fallback platform framebuffer so legacy
2496 drivers like efifb, vesafb and uvesafb can pick it up.
2497 If this option is not selected, all system framebuffers are always
2498 marked as fallback platform framebuffers as usual.
2500 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2501 not be able to pick up generic system framebuffers if this option
2502 is selected. You are highly encouraged to enable simplefb as
2503 replacement if you select this option. simplefb can correctly deal
2504 with generic system framebuffers. But you should still keep vesafb
2505 and others enabled as fallback if a system framebuffer is
2506 incompatible with simplefb.
2513 menu "Executable file formats / Emulations"
2515 source "fs/Kconfig.binfmt"
2517 config IA32_EMULATION
2518 bool "IA32 Emulation"
2521 select COMPAT_BINFMT_ELF
2524 Include code to run legacy 32-bit programs under a
2525 64-bit kernel. You should likely turn this on, unless you're
2526 100% sure that you don't have any 32-bit programs left.
2529 tristate "IA32 a.out support"
2530 depends on IA32_EMULATION
2532 Support old a.out binaries in the 32bit emulation.
2535 bool "x32 ABI for 64-bit mode"
2536 depends on X86_64 && IA32_EMULATION
2538 Include code to run binaries for the x32 native 32-bit ABI
2539 for 64-bit processors. An x32 process gets access to the
2540 full 64-bit register file and wide data path while leaving
2541 pointers at 32 bits for smaller memory footprint.
2543 You will need a recent binutils (2.22 or later) with
2544 elf32_x86_64 support enabled to compile a kernel with this
2549 depends on IA32_EMULATION || X86_X32
2550 select ARCH_WANT_OLD_COMPAT_IPC
2553 config COMPAT_FOR_U64_ALIGNMENT
2556 config SYSVIPC_COMPAT
2568 config HAVE_ATOMIC_IOMAP
2572 config X86_DEV_DMA_OPS
2574 depends on X86_64 || STA2X11
2576 config X86_DMA_REMAP
2584 source "net/Kconfig"
2586 source "drivers/Kconfig"
2588 source "drivers/firmware/Kconfig"
2592 source "arch/x86/Kconfig.debug"
2594 source "security/Kconfig"
2596 source "crypto/Kconfig"
2598 source "arch/x86/kvm/Kconfig"
2600 source "lib/Kconfig"