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
20 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
27 select ARCH_HAS_ELF_RANDOMIZE
28 select ARCH_HAS_FAST_MULTIPLIER
29 select ARCH_HAS_GCOV_PROFILE_ALL
30 select ARCH_HAS_SG_CHAIN
31 select ARCH_HAVE_NMI_SAFE_CMPXCHG
32 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
33 select ARCH_MIGHT_HAVE_PC_PARPORT
34 select ARCH_MIGHT_HAVE_PC_SERIO
35 select ARCH_SUPPORTS_ATOMIC_RMW
36 select ARCH_SUPPORTS_INT128 if X86_64
37 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
38 select ARCH_USE_BUILTIN_BSWAP
39 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
40 select ARCH_USE_QUEUED_RWLOCKS
41 select ARCH_USE_QUEUED_SPINLOCKS
42 select ARCH_WANT_FRAME_POINTERS
43 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
44 select ARCH_WANT_OPTIONAL_GPIOLIB
45 select BUILDTIME_EXTABLE_SORT
47 select CLKSRC_I8253 if X86_32
48 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
49 select CLOCKSOURCE_WATCHDOG
50 select CLONE_BACKWARDS if X86_32
51 select COMPAT_OLD_SIGACTION if IA32_EMULATION
52 select DCACHE_WORD_ACCESS
53 select GENERIC_CLOCKEVENTS
54 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
55 select GENERIC_CLOCKEVENTS_MIN_ADJUST
56 select GENERIC_CMOS_UPDATE
57 select GENERIC_CPU_AUTOPROBE
58 select GENERIC_EARLY_IOREMAP
59 select GENERIC_FIND_FIRST_BIT
61 select GENERIC_IRQ_PROBE
62 select GENERIC_IRQ_SHOW
63 select GENERIC_PENDING_IRQ if SMP
64 select GENERIC_SMP_IDLE_THREAD
65 select GENERIC_STRNCPY_FROM_USER
66 select GENERIC_STRNLEN_USER
67 select GENERIC_TIME_VSYSCALL
68 select HAVE_ACPI_APEI if ACPI
69 select HAVE_ACPI_APEI_NMI if ACPI
70 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
71 select HAVE_AOUT if X86_32
72 select HAVE_ARCH_AUDITSYSCALL
73 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
74 select HAVE_ARCH_JUMP_LABEL
75 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
77 select HAVE_ARCH_KMEMCHECK
78 select HAVE_ARCH_SECCOMP_FILTER
79 select HAVE_ARCH_SOFT_DIRTY if X86_64
80 select HAVE_ARCH_TRACEHOOK
81 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
82 select HAVE_BPF_JIT if X86_64
83 select HAVE_CC_STACKPROTECTOR
84 select HAVE_CMPXCHG_DOUBLE
85 select HAVE_CMPXCHG_LOCAL
86 select HAVE_CONTEXT_TRACKING if X86_64
87 select HAVE_C_RECORDMCOUNT
88 select HAVE_DEBUG_KMEMLEAK
89 select HAVE_DEBUG_STACKOVERFLOW
90 select HAVE_DMA_API_DEBUG
92 select HAVE_DMA_CONTIGUOUS
93 select HAVE_DYNAMIC_FTRACE
94 select HAVE_DYNAMIC_FTRACE_WITH_REGS
95 select HAVE_EFFICIENT_UNALIGNED_ACCESS
96 select HAVE_FENTRY if X86_64
97 select HAVE_FTRACE_MCOUNT_RECORD
98 select HAVE_FUNCTION_GRAPH_FP_TEST
99 select HAVE_FUNCTION_GRAPH_TRACER
100 select HAVE_FUNCTION_TRACER
101 select HAVE_GENERIC_DMA_COHERENT if X86_32
102 select HAVE_HW_BREAKPOINT
104 select HAVE_IOREMAP_PROT
105 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
106 select HAVE_IRQ_TIME_ACCOUNTING
107 select HAVE_KERNEL_BZIP2
108 select HAVE_KERNEL_GZIP
109 select HAVE_KERNEL_LZ4
110 select HAVE_KERNEL_LZMA
111 select HAVE_KERNEL_LZO
112 select HAVE_KERNEL_XZ
114 select HAVE_KPROBES_ON_FTRACE
115 select HAVE_KRETPROBES
117 select HAVE_LIVEPATCH if X86_64
119 select HAVE_MEMBLOCK_NODE_MAP
120 select HAVE_MIXED_BREAKPOINTS_REGS
122 select HAVE_OPTPROBES
123 select HAVE_PCSPKR_PLATFORM
124 select HAVE_PERF_EVENTS
125 select HAVE_PERF_EVENTS_NMI
126 select HAVE_PERF_REGS
127 select HAVE_PERF_USER_STACK_DUMP
128 select HAVE_REGS_AND_STACK_ACCESS_API
129 select HAVE_SYSCALL_TRACEPOINTS
130 select HAVE_UID16 if X86_32
131 select HAVE_UNSTABLE_SCHED_CLOCK
132 select HAVE_USER_RETURN_NOTIFIER
133 select IRQ_FORCED_THREADING
134 select MODULES_USE_ELF_RELA if X86_64
135 select MODULES_USE_ELF_REL if X86_32
136 select OLD_SIGACTION if X86_32
137 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
142 select SYSCTL_EXCEPTION_TRACE
143 select USER_STACKTRACE_SUPPORT
145 select X86_DEV_DMA_OPS if X86_64
146 select X86_FEATURE_NAMES if PROC_FS
148 config INSTRUCTION_DECODER
150 depends on KPROBES || PERF_EVENTS || UPROBES
152 config PERF_EVENTS_INTEL_UNCORE
154 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
158 default "elf32-i386" if X86_32
159 default "elf64-x86-64" if X86_64
161 config ARCH_DEFCONFIG
163 default "arch/x86/configs/i386_defconfig" if X86_32
164 default "arch/x86/configs/x86_64_defconfig" if X86_64
166 config LOCKDEP_SUPPORT
169 config STACKTRACE_SUPPORT
172 config HAVE_LATENCYTOP_SUPPORT
181 config NEED_DMA_MAP_STATE
183 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
185 config NEED_SG_DMA_LENGTH
188 config GENERIC_ISA_DMA
190 depends on ISA_DMA_API
195 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
197 config GENERIC_BUG_RELATIVE_POINTERS
200 config GENERIC_HWEIGHT
203 config ARCH_MAY_HAVE_PC_FDC
205 depends on ISA_DMA_API
207 config RWSEM_XCHGADD_ALGORITHM
210 config GENERIC_CALIBRATE_DELAY
213 config ARCH_HAS_CPU_RELAX
216 config ARCH_HAS_CACHE_LINE_SIZE
219 config HAVE_SETUP_PER_CPU_AREA
222 config NEED_PER_CPU_EMBED_FIRST_CHUNK
225 config NEED_PER_CPU_PAGE_FIRST_CHUNK
228 config ARCH_HIBERNATION_POSSIBLE
231 config ARCH_SUSPEND_POSSIBLE
234 config ARCH_WANT_HUGE_PMD_SHARE
237 config ARCH_WANT_GENERAL_HUGETLB
246 config ARCH_SUPPORTS_OPTIMIZED_INLINING
249 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
252 config HAVE_INTEL_TXT
254 depends on INTEL_IOMMU && ACPI
258 depends on X86_32 && SMP
262 depends on X86_64 && SMP
264 config X86_32_LAZY_GS
266 depends on X86_32 && !CC_STACKPROTECTOR
268 config ARCH_HWEIGHT_CFLAGS
270 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
271 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
273 config ARCH_SUPPORTS_UPROBES
276 config FIX_EARLYCON_MEM
279 config PGTABLE_LEVELS
285 source "init/Kconfig"
286 source "kernel/Kconfig.freezer"
288 menu "Processor type and features"
291 bool "DMA memory allocation support" if EXPERT
294 DMA memory allocation support allows devices with less than 32-bit
295 addressing to allocate within the first 16MB of address space.
296 Disable if no such devices will be used.
301 bool "Symmetric multi-processing support"
303 This enables support for systems with more than one CPU. If you have
304 a system with only one CPU, say N. If you have a system with more
307 If you say N here, the kernel will run on uni- and multiprocessor
308 machines, but will use only one CPU of a multiprocessor machine. If
309 you say Y here, the kernel will run on many, but not all,
310 uniprocessor machines. On a uniprocessor machine, the kernel
311 will run faster if you say N here.
313 Note that if you say Y here and choose architecture "586" or
314 "Pentium" under "Processor family", the kernel will not work on 486
315 architectures. Similarly, multiprocessor kernels for the "PPro"
316 architecture may not work on all Pentium based boards.
318 People using multiprocessor machines who say Y here should also say
319 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
320 Management" code will be disabled if you say Y here.
322 See also <file:Documentation/x86/i386/IO-APIC.txt>,
323 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
324 <http://www.tldp.org/docs.html#howto>.
326 If you don't know what to do here, say N.
328 config X86_FEATURE_NAMES
329 bool "Processor feature human-readable names" if EMBEDDED
332 This option compiles in a table of x86 feature bits and corresponding
333 names. This is required to support /proc/cpuinfo and a few kernel
334 messages. You can disable this to save space, at the expense of
335 making those few kernel messages show numeric feature bits instead.
340 bool "Support x2apic"
341 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
343 This enables x2apic support on CPUs that have this feature.
345 This allows 32-bit apic IDs (so it can support very large systems),
346 and accesses the local apic via MSRs not via mmio.
348 If you don't know what to do here, say N.
351 bool "Enable MPS table" if ACPI || SFI
353 depends on X86_LOCAL_APIC
355 For old smp systems that do not have proper acpi support. Newer systems
356 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
359 bool "Support for big SMP systems with more than 8 CPUs"
360 depends on X86_32 && SMP
362 This option is needed for the systems that have more than 8 CPUs
366 depends on X86_GOLDFISH
369 config X86_EXTENDED_PLATFORM
370 bool "Support for extended (non-PC) x86 platforms"
373 If you disable this option then the kernel will only support
374 standard PC platforms. (which covers the vast majority of
377 If you enable this option then you'll be able to select support
378 for the following (non-PC) 32 bit x86 platforms:
379 Goldfish (Android emulator)
382 SGI 320/540 (Visual Workstation)
383 STA2X11-based (e.g. Northville)
384 Moorestown MID devices
386 If you have one of these systems, or if you want to build a
387 generic distribution kernel, say Y here - otherwise say N.
391 config X86_EXTENDED_PLATFORM
392 bool "Support for extended (non-PC) x86 platforms"
395 If you disable this option then the kernel will only support
396 standard PC platforms. (which covers the vast majority of
399 If you enable this option then you'll be able to select support
400 for the following (non-PC) 64 bit x86 platforms:
405 If you have one of these systems, or if you want to build a
406 generic distribution kernel, say Y here - otherwise say N.
408 # This is an alphabetically sorted list of 64 bit extended platforms
409 # Please maintain the alphabetic order if and when there are additions
411 bool "Numascale NumaChip"
413 depends on X86_EXTENDED_PLATFORM
416 depends on X86_X2APIC
417 depends on PCI_MMCONFIG
419 Adds support for Numascale NumaChip large-SMP systems. Needed to
420 enable more than ~168 cores.
421 If you don't have one of these, you should say N here.
425 select HYPERVISOR_GUEST
427 depends on X86_64 && PCI
428 depends on X86_EXTENDED_PLATFORM
431 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
432 supposed to run on these EM64T-based machines. Only choose this option
433 if you have one of these machines.
436 bool "SGI Ultraviolet"
438 depends on X86_EXTENDED_PLATFORM
440 depends on X86_X2APIC
443 This option is needed in order to support SGI Ultraviolet systems.
444 If you don't have one of these, you should say N here.
446 # Following is an alphabetically sorted list of 32 bit extended platforms
447 # Please maintain the alphabetic order if and when there are additions
450 bool "Goldfish (Virtual Platform)"
451 depends on X86_EXTENDED_PLATFORM
453 Enable support for the Goldfish virtual platform used primarily
454 for Android development. Unless you are building for the Android
455 Goldfish emulator say N here.
458 bool "CE4100 TV platform"
460 depends on PCI_GODIRECT
461 depends on X86_IO_APIC
463 depends on X86_EXTENDED_PLATFORM
464 select X86_REBOOTFIXUPS
466 select OF_EARLY_FLATTREE
468 Select for the Intel CE media processor (CE4100) SOC.
469 This option compiles in support for the CE4100 SOC for settop
470 boxes and media devices.
473 bool "Intel MID platform support"
475 depends on X86_EXTENDED_PLATFORM
476 depends on X86_PLATFORM_DEVICES
479 depends on X86_IO_APIC
485 select MFD_INTEL_MSIC
487 Select to build a kernel capable of supporting Intel MID (Mobile
488 Internet Device) platform systems which do not have the PCI legacy
489 interfaces. If you are building for a PC class system say N here.
491 Intel MID platforms are based on an Intel processor and chipset which
492 consume less power than most of the x86 derivatives.
494 config X86_INTEL_QUARK
495 bool "Intel Quark platform support"
497 depends on X86_EXTENDED_PLATFORM
498 depends on X86_PLATFORM_DEVICES
502 depends on X86_IO_APIC
507 Select to include support for Quark X1000 SoC.
508 Say Y here if you have a Quark based system such as the Arduino
509 compatible Intel Galileo.
511 config X86_INTEL_LPSS
512 bool "Intel Low Power Subsystem Support"
517 Select to build support for Intel Low Power Subsystem such as
518 found on Intel Lynxpoint PCH. Selecting this option enables
519 things like clock tree (common clock framework) and pincontrol
520 which are needed by the LPSS peripheral drivers.
522 config X86_AMD_PLATFORM_DEVICE
523 bool "AMD ACPI2Platform devices support"
528 Select to interpret AMD specific ACPI device to platform device
529 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
530 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
531 implemented under PINCTRL subsystem.
534 tristate "Intel SoC IOSF Sideband support for SoC platforms"
537 This option enables sideband register access support for Intel SoC
538 platforms. On these platforms the IOSF sideband is used in lieu of
539 MSR's for some register accesses, mostly but not limited to thermal
540 and power. Drivers may query the availability of this device to
541 determine if they need the sideband in order to work on these
542 platforms. The sideband is available on the following SoC products.
543 This list is not meant to be exclusive.
548 You should say Y if you are running a kernel on one of these SoC's.
550 config IOSF_MBI_DEBUG
551 bool "Enable IOSF sideband access through debugfs"
552 depends on IOSF_MBI && DEBUG_FS
554 Select this option to expose the IOSF sideband access registers (MCR,
555 MDR, MCRX) through debugfs to write and read register information from
556 different units on the SoC. This is most useful for obtaining device
557 state information for debug and analysis. As this is a general access
558 mechanism, users of this option would have specific knowledge of the
559 device they want to access.
561 If you don't require the option or are in doubt, say N.
564 bool "RDC R-321x SoC"
566 depends on X86_EXTENDED_PLATFORM
568 select X86_REBOOTFIXUPS
570 This option is needed for RDC R-321x system-on-chip, also known
572 If you don't have one of these chips, you should say N here.
574 config X86_32_NON_STANDARD
575 bool "Support non-standard 32-bit SMP architectures"
576 depends on X86_32 && SMP
577 depends on X86_EXTENDED_PLATFORM
579 This option compiles in the bigsmp and STA2X11 default
580 subarchitectures. It is intended for a generic binary
581 kernel. If you select them all, kernel will probe it one by
582 one and will fallback to default.
584 # Alphabetically sorted list of Non standard 32 bit platforms
586 config X86_SUPPORTS_MEMORY_FAILURE
588 # MCE code calls memory_failure():
590 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
591 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
592 depends on X86_64 || !SPARSEMEM
593 select ARCH_SUPPORTS_MEMORY_FAILURE
596 bool "STA2X11 Companion Chip Support"
597 depends on X86_32_NON_STANDARD && PCI
598 select X86_DEV_DMA_OPS
602 select ARCH_REQUIRE_GPIOLIB
605 This adds support for boards based on the STA2X11 IO-Hub,
606 a.k.a. "ConneXt". The chip is used in place of the standard
607 PC chipset, so all "standard" peripherals are missing. If this
608 option is selected the kernel will still be able to boot on
609 standard PC machines.
612 tristate "Eurobraille/Iris poweroff module"
615 The Iris machines from EuroBraille do not have APM or ACPI support
616 to shut themselves down properly. A special I/O sequence is
617 needed to do so, which is what this module does at
620 This is only for Iris machines from EuroBraille.
624 config SCHED_OMIT_FRAME_POINTER
626 prompt "Single-depth WCHAN output"
629 Calculate simpler /proc/<PID>/wchan values. If this option
630 is disabled then wchan values will recurse back to the
631 caller function. This provides more accurate wchan values,
632 at the expense of slightly more scheduling overhead.
634 If in doubt, say "Y".
636 menuconfig HYPERVISOR_GUEST
637 bool "Linux guest support"
639 Say Y here to enable options for running Linux under various hyper-
640 visors. This option enables basic hypervisor detection and platform
643 If you say N, all options in this submenu will be skipped and
644 disabled, and Linux guest support won't be built in.
649 bool "Enable paravirtualization code"
651 This changes the kernel so it can modify itself when it is run
652 under a hypervisor, potentially improving performance significantly
653 over full virtualization. However, when run without a hypervisor
654 the kernel is theoretically slower and slightly larger.
656 config PARAVIRT_DEBUG
657 bool "paravirt-ops debugging"
658 depends on PARAVIRT && DEBUG_KERNEL
660 Enable to debug paravirt_ops internals. Specifically, BUG if
661 a paravirt_op is missing when it is called.
663 config PARAVIRT_SPINLOCKS
664 bool "Paravirtualization layer for spinlocks"
665 depends on PARAVIRT && SMP
666 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
668 Paravirtualized spinlocks allow a pvops backend to replace the
669 spinlock implementation with something virtualization-friendly
670 (for example, block the virtual CPU rather than spinning).
672 It has a minimal impact on native kernels and gives a nice performance
673 benefit on paravirtualized KVM / Xen kernels.
675 If you are unsure how to answer this question, answer Y.
677 source "arch/x86/xen/Kconfig"
680 bool "KVM Guest support (including kvmclock)"
682 select PARAVIRT_CLOCK
685 This option enables various optimizations for running under the KVM
686 hypervisor. It includes a paravirtualized clock, so that instead
687 of relying on a PIT (or probably other) emulation by the
688 underlying device model, the host provides the guest with
689 timing infrastructure such as time of day, and system time
692 bool "Enable debug information for KVM Guests in debugfs"
693 depends on KVM_GUEST && DEBUG_FS
696 This option enables collection of various statistics for KVM guest.
697 Statistics are displayed in debugfs filesystem. Enabling this option
698 may incur significant overhead.
700 source "arch/x86/lguest/Kconfig"
702 config PARAVIRT_TIME_ACCOUNTING
703 bool "Paravirtual steal time accounting"
707 Select this option to enable fine granularity task steal time
708 accounting. Time spent executing other tasks in parallel with
709 the current vCPU is discounted from the vCPU power. To account for
710 that, there can be a small performance impact.
712 If in doubt, say N here.
714 config PARAVIRT_CLOCK
717 endif #HYPERVISOR_GUEST
722 source "arch/x86/Kconfig.cpu"
726 prompt "HPET Timer Support" if X86_32
728 Use the IA-PC HPET (High Precision Event Timer) to manage
729 time in preference to the PIT and RTC, if a HPET is
731 HPET is the next generation timer replacing legacy 8254s.
732 The HPET provides a stable time base on SMP
733 systems, unlike the TSC, but it is more expensive to access,
734 as it is off-chip. You can find the HPET spec at
735 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
737 You can safely choose Y here. However, HPET will only be
738 activated if the platform and the BIOS support this feature.
739 Otherwise the 8254 will be used for timing services.
741 Choose N to continue using the legacy 8254 timer.
743 config HPET_EMULATE_RTC
745 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
748 def_bool y if X86_INTEL_MID
749 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
751 depends on X86_INTEL_MID && SFI
753 APB timer is the replacement for 8254, HPET on X86 MID platforms.
754 The APBT provides a stable time base on SMP
755 systems, unlike the TSC, but it is more expensive to access,
756 as it is off-chip. APB timers are always running regardless of CPU
757 C states, they are used as per CPU clockevent device when possible.
759 # Mark as expert because too many people got it wrong.
760 # The code disables itself when not needed.
763 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
764 bool "Enable DMI scanning" if EXPERT
766 Enabled scanning of DMI to identify machine quirks. Say Y
767 here unless you have verified that your setup is not
768 affected by entries in the DMI blacklist. Required by PNP
772 bool "Old AMD GART IOMMU support"
774 depends on X86_64 && PCI && AMD_NB
776 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
777 GART based hardware IOMMUs.
779 The GART supports full DMA access for devices with 32-bit access
780 limitations, on systems with more than 3 GB. This is usually needed
781 for USB, sound, many IDE/SATA chipsets and some other devices.
783 Newer systems typically have a modern AMD IOMMU, supported via
784 the CONFIG_AMD_IOMMU=y config option.
786 In normal configurations this driver is only active when needed:
787 there's more than 3 GB of memory and the system contains a
788 32-bit limited device.
793 bool "IBM Calgary IOMMU support"
795 depends on X86_64 && PCI
797 Support for hardware IOMMUs in IBM's xSeries x366 and x460
798 systems. Needed to run systems with more than 3GB of memory
799 properly with 32-bit PCI devices that do not support DAC
800 (Double Address Cycle). Calgary also supports bus level
801 isolation, where all DMAs pass through the IOMMU. This
802 prevents them from going anywhere except their intended
803 destination. This catches hard-to-find kernel bugs and
804 mis-behaving drivers and devices that do not use the DMA-API
805 properly to set up their DMA buffers. The IOMMU can be
806 turned off at boot time with the iommu=off parameter.
807 Normally the kernel will make the right choice by itself.
810 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
812 prompt "Should Calgary be enabled by default?"
813 depends on CALGARY_IOMMU
815 Should Calgary be enabled by default? if you choose 'y', Calgary
816 will be used (if it exists). If you choose 'n', Calgary will not be
817 used even if it exists. If you choose 'n' and would like to use
818 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
821 # need this always selected by IOMMU for the VIA workaround
825 Support for software bounce buffers used on x86-64 systems
826 which don't have a hardware IOMMU. Using this PCI devices
827 which can only access 32-bits of memory can be used on systems
828 with more than 3 GB of memory.
833 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
836 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
837 depends on X86_64 && SMP && DEBUG_KERNEL
838 select CPUMASK_OFFSTACK
840 Enable maximum number of CPUS and NUMA Nodes for this architecture.
844 int "Maximum number of CPUs" if SMP && !MAXSMP
845 range 2 8 if SMP && X86_32 && !X86_BIGSMP
846 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
847 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
849 default "8192" if MAXSMP
850 default "32" if SMP && X86_BIGSMP
851 default "8" if SMP && X86_32
854 This allows you to specify the maximum number of CPUs which this
855 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
856 supported value is 8192, otherwise the maximum value is 512. The
857 minimum value which makes sense is 2.
859 This is purely to save memory - each supported CPU adds
860 approximately eight kilobytes to the kernel image.
863 bool "SMT (Hyperthreading) scheduler support"
866 SMT scheduler support improves the CPU scheduler's decision making
867 when dealing with Intel Pentium 4 chips with HyperThreading at a
868 cost of slightly increased overhead in some places. If unsure say
873 prompt "Multi-core scheduler support"
876 Multi-core scheduler support improves the CPU scheduler's decision
877 making when dealing with multi-core CPU chips at a cost of slightly
878 increased overhead in some places. If unsure say N here.
880 source "kernel/Kconfig.preempt"
884 depends on !SMP && X86_LOCAL_APIC
887 bool "Local APIC support on uniprocessors" if !PCI_MSI
889 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
891 A local APIC (Advanced Programmable Interrupt Controller) is an
892 integrated interrupt controller in the CPU. If you have a single-CPU
893 system which has a processor with a local APIC, you can say Y here to
894 enable and use it. If you say Y here even though your machine doesn't
895 have a local APIC, then the kernel will still run with no slowdown at
896 all. The local APIC supports CPU-generated self-interrupts (timer,
897 performance counters), and the NMI watchdog which detects hard
901 bool "IO-APIC support on uniprocessors"
902 depends on X86_UP_APIC
904 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
905 SMP-capable replacement for PC-style interrupt controllers. Most
906 SMP systems and many recent uniprocessor systems have one.
908 If you have a single-CPU system with an IO-APIC, you can say Y here
909 to use it. If you say Y here even though your machine doesn't have
910 an IO-APIC, then the kernel will still run with no slowdown at all.
912 config X86_LOCAL_APIC
914 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
915 select IRQ_DOMAIN_HIERARCHY
916 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
920 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
922 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
923 bool "Reroute for broken boot IRQs"
924 depends on X86_IO_APIC
926 This option enables a workaround that fixes a source of
927 spurious interrupts. This is recommended when threaded
928 interrupt handling is used on systems where the generation of
929 superfluous "boot interrupts" cannot be disabled.
931 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
932 entry in the chipset's IO-APIC is masked (as, e.g. the RT
933 kernel does during interrupt handling). On chipsets where this
934 boot IRQ generation cannot be disabled, this workaround keeps
935 the original IRQ line masked so that only the equivalent "boot
936 IRQ" is delivered to the CPUs. The workaround also tells the
937 kernel to set up the IRQ handler on the boot IRQ line. In this
938 way only one interrupt is delivered to the kernel. Otherwise
939 the spurious second interrupt may cause the kernel to bring
940 down (vital) interrupt lines.
942 Only affects "broken" chipsets. Interrupt sharing may be
943 increased on these systems.
946 bool "Machine Check / overheating reporting"
949 Machine Check support allows the processor to notify the
950 kernel if it detects a problem (e.g. overheating, data corruption).
951 The action the kernel takes depends on the severity of the problem,
952 ranging from warning messages to halting the machine.
956 prompt "Intel MCE features"
957 depends on X86_MCE && X86_LOCAL_APIC
959 Additional support for intel specific MCE features such as
964 prompt "AMD MCE features"
965 depends on X86_MCE && X86_LOCAL_APIC
967 Additional support for AMD specific MCE features such as
968 the DRAM Error Threshold.
970 config X86_ANCIENT_MCE
971 bool "Support for old Pentium 5 / WinChip machine checks"
972 depends on X86_32 && X86_MCE
974 Include support for machine check handling on old Pentium 5 or WinChip
975 systems. These typically need to be enabled explicitly on the command
978 config X86_MCE_THRESHOLD
979 depends on X86_MCE_AMD || X86_MCE_INTEL
982 config X86_MCE_INJECT
984 tristate "Machine check injector support"
986 Provide support for injecting machine checks for testing purposes.
987 If you don't know what a machine check is and you don't do kernel
988 QA it is safe to say n.
990 config X86_THERMAL_VECTOR
992 depends on X86_MCE_INTEL
995 bool "Enable VM86 support" if EXPERT
999 This option is required by programs like DOSEMU to run
1000 16-bit real mode legacy code on x86 processors. It also may
1001 be needed by software like XFree86 to initialize some video
1002 cards via BIOS. Disabling this option saves about 6K.
1005 bool "Enable support for 16-bit segments" if EXPERT
1008 This option is required by programs like Wine to run 16-bit
1009 protected mode legacy code on x86 processors. Disabling
1010 this option saves about 300 bytes on i386, or around 6K text
1011 plus 16K runtime memory on x86-64,
1015 depends on X86_16BIT && X86_32
1019 depends on X86_16BIT && X86_64
1021 config X86_VSYSCALL_EMULATION
1022 bool "Enable vsyscall emulation" if EXPERT
1026 This enables emulation of the legacy vsyscall page. Disabling
1027 it is roughly equivalent to booting with vsyscall=none, except
1028 that it will also disable the helpful warning if a program
1029 tries to use a vsyscall. With this option set to N, offending
1030 programs will just segfault, citing addresses of the form
1033 This option is required by many programs built before 2013, and
1034 care should be used even with newer programs if set to N.
1036 Disabling this option saves about 7K of kernel size and
1037 possibly 4K of additional runtime pagetable memory.
1040 tristate "Toshiba Laptop support"
1043 This adds a driver to safely access the System Management Mode of
1044 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1045 not work on models with a Phoenix BIOS. The System Management Mode
1046 is used to set the BIOS and power saving options on Toshiba portables.
1048 For information on utilities to make use of this driver see the
1049 Toshiba Linux utilities web site at:
1050 <http://www.buzzard.org.uk/toshiba/>.
1052 Say Y if you intend to run this kernel on a Toshiba portable.
1056 tristate "Dell laptop support"
1059 This adds a driver to safely access the System Management Mode
1060 of the CPU on the Dell Inspiron 8000. The System Management Mode
1061 is used to read cpu temperature and cooling fan status and to
1062 control the fans on the I8K portables.
1064 This driver has been tested only on the Inspiron 8000 but it may
1065 also work with other Dell laptops. You can force loading on other
1066 models by passing the parameter `force=1' to the module. Use at
1069 For information on utilities to make use of this driver see the
1070 I8K Linux utilities web site at:
1071 <http://people.debian.org/~dz/i8k/>
1073 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1076 config X86_REBOOTFIXUPS
1077 bool "Enable X86 board specific fixups for reboot"
1080 This enables chipset and/or board specific fixups to be done
1081 in order to get reboot to work correctly. This is only needed on
1082 some combinations of hardware and BIOS. The symptom, for which
1083 this config is intended, is when reboot ends with a stalled/hung
1086 Currently, the only fixup is for the Geode machines using
1087 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1089 Say Y if you want to enable the fixup. Currently, it's safe to
1090 enable this option even if you don't need it.
1094 tristate "CPU microcode loading support"
1095 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1099 If you say Y here, you will be able to update the microcode on
1100 certain Intel and AMD processors. The Intel support is for the
1101 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1102 Xeon etc. The AMD support is for families 0x10 and later. You will
1103 obviously need the actual microcode binary data itself which is not
1104 shipped with the Linux kernel.
1106 This option selects the general module only, you need to select
1107 at least one vendor specific module as well.
1109 To compile this driver as a module, choose M here: the module
1110 will be called microcode.
1112 config MICROCODE_INTEL
1113 bool "Intel microcode loading support"
1114 depends on MICROCODE
1118 This options enables microcode patch loading support for Intel
1121 For the current Intel microcode data package go to
1122 <https://downloadcenter.intel.com> and search for
1123 'Linux Processor Microcode Data File'.
1125 config MICROCODE_AMD
1126 bool "AMD microcode loading support"
1127 depends on MICROCODE
1130 If you select this option, microcode patch loading support for AMD
1131 processors will be enabled.
1133 config MICROCODE_OLD_INTERFACE
1135 depends on MICROCODE
1137 config MICROCODE_INTEL_EARLY
1140 config MICROCODE_AMD_EARLY
1143 config MICROCODE_EARLY
1144 bool "Early load microcode"
1145 depends on MICROCODE=y && BLK_DEV_INITRD
1146 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1147 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1150 This option provides functionality to read additional microcode data
1151 at the beginning of initrd image. The data tells kernel to load
1152 microcode to CPU's as early as possible. No functional change if no
1153 microcode data is glued to the initrd, therefore it's safe to say Y.
1156 tristate "/dev/cpu/*/msr - Model-specific register support"
1158 This device gives privileged processes access to the x86
1159 Model-Specific Registers (MSRs). It is a character device with
1160 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1161 MSR accesses are directed to a specific CPU on multi-processor
1165 tristate "/dev/cpu/*/cpuid - CPU information support"
1167 This device gives processes access to the x86 CPUID instruction to
1168 be executed on a specific processor. It is a character device
1169 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1173 prompt "High Memory Support"
1180 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1181 However, the address space of 32-bit x86 processors is only 4
1182 Gigabytes large. That means that, if you have a large amount of
1183 physical memory, not all of it can be "permanently mapped" by the
1184 kernel. The physical memory that's not permanently mapped is called
1187 If you are compiling a kernel which will never run on a machine with
1188 more than 1 Gigabyte total physical RAM, answer "off" here (default
1189 choice and suitable for most users). This will result in a "3GB/1GB"
1190 split: 3GB are mapped so that each process sees a 3GB virtual memory
1191 space and the remaining part of the 4GB virtual memory space is used
1192 by the kernel to permanently map as much physical memory as
1195 If the machine has between 1 and 4 Gigabytes physical RAM, then
1198 If more than 4 Gigabytes is used then answer "64GB" here. This
1199 selection turns Intel PAE (Physical Address Extension) mode on.
1200 PAE implements 3-level paging on IA32 processors. PAE is fully
1201 supported by Linux, PAE mode is implemented on all recent Intel
1202 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1203 then the kernel will not boot on CPUs that don't support PAE!
1205 The actual amount of total physical memory will either be
1206 auto detected or can be forced by using a kernel command line option
1207 such as "mem=256M". (Try "man bootparam" or see the documentation of
1208 your boot loader (lilo or loadlin) about how to pass options to the
1209 kernel at boot time.)
1211 If unsure, say "off".
1216 Select this if you have a 32-bit processor and between 1 and 4
1217 gigabytes of physical RAM.
1224 Select this if you have a 32-bit processor and more than 4
1225 gigabytes of physical RAM.
1230 prompt "Memory split" if EXPERT
1234 Select the desired split between kernel and user memory.
1236 If the address range available to the kernel is less than the
1237 physical memory installed, the remaining memory will be available
1238 as "high memory". Accessing high memory is a little more costly
1239 than low memory, as it needs to be mapped into the kernel first.
1240 Note that increasing the kernel address space limits the range
1241 available to user programs, making the address space there
1242 tighter. Selecting anything other than the default 3G/1G split
1243 will also likely make your kernel incompatible with binary-only
1246 If you are not absolutely sure what you are doing, leave this
1250 bool "3G/1G user/kernel split"
1251 config VMSPLIT_3G_OPT
1253 bool "3G/1G user/kernel split (for full 1G low memory)"
1255 bool "2G/2G user/kernel split"
1256 config VMSPLIT_2G_OPT
1258 bool "2G/2G user/kernel split (for full 2G low memory)"
1260 bool "1G/3G user/kernel split"
1265 default 0xB0000000 if VMSPLIT_3G_OPT
1266 default 0x80000000 if VMSPLIT_2G
1267 default 0x78000000 if VMSPLIT_2G_OPT
1268 default 0x40000000 if VMSPLIT_1G
1274 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1277 bool "PAE (Physical Address Extension) Support"
1278 depends on X86_32 && !HIGHMEM4G
1280 PAE is required for NX support, and furthermore enables
1281 larger swapspace support for non-overcommit purposes. It
1282 has the cost of more pagetable lookup overhead, and also
1283 consumes more pagetable space per process.
1285 config ARCH_PHYS_ADDR_T_64BIT
1287 depends on X86_64 || X86_PAE
1289 config ARCH_DMA_ADDR_T_64BIT
1291 depends on X86_64 || HIGHMEM64G
1293 config X86_DIRECT_GBPAGES
1295 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1297 Certain kernel features effectively disable kernel
1298 linear 1 GB mappings (even if the CPU otherwise
1299 supports them), so don't confuse the user by printing
1300 that we have them enabled.
1302 # Common NUMA Features
1304 bool "Numa Memory Allocation and Scheduler Support"
1306 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1307 default y if X86_BIGSMP
1309 Enable NUMA (Non Uniform Memory Access) support.
1311 The kernel will try to allocate memory used by a CPU on the
1312 local memory controller of the CPU and add some more
1313 NUMA awareness to the kernel.
1315 For 64-bit this is recommended if the system is Intel Core i7
1316 (or later), AMD Opteron, or EM64T NUMA.
1318 For 32-bit this is only needed if you boot a 32-bit
1319 kernel on a 64-bit NUMA platform.
1321 Otherwise, you should say N.
1325 prompt "Old style AMD Opteron NUMA detection"
1326 depends on X86_64 && NUMA && PCI
1328 Enable AMD NUMA node topology detection. You should say Y here if
1329 you have a multi processor AMD system. This uses an old method to
1330 read the NUMA configuration directly from the builtin Northbridge
1331 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1332 which also takes priority if both are compiled in.
1334 config X86_64_ACPI_NUMA
1336 prompt "ACPI NUMA detection"
1337 depends on X86_64 && NUMA && ACPI && PCI
1340 Enable ACPI SRAT based node topology detection.
1342 # Some NUMA nodes have memory ranges that span
1343 # other nodes. Even though a pfn is valid and
1344 # between a node's start and end pfns, it may not
1345 # reside on that node. See memmap_init_zone()
1347 config NODES_SPAN_OTHER_NODES
1349 depends on X86_64_ACPI_NUMA
1352 bool "NUMA emulation"
1355 Enable NUMA emulation. A flat machine will be split
1356 into virtual nodes when booted with "numa=fake=N", where N is the
1357 number of nodes. This is only useful for debugging.
1360 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1362 default "10" if MAXSMP
1363 default "6" if X86_64
1365 depends on NEED_MULTIPLE_NODES
1367 Specify the maximum number of NUMA Nodes available on the target
1368 system. Increases memory reserved to accommodate various tables.
1370 config ARCH_HAVE_MEMORY_PRESENT
1372 depends on X86_32 && DISCONTIGMEM
1374 config NEED_NODE_MEMMAP_SIZE
1376 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1378 config ARCH_FLATMEM_ENABLE
1380 depends on X86_32 && !NUMA
1382 config ARCH_DISCONTIGMEM_ENABLE
1384 depends on NUMA && X86_32
1386 config ARCH_DISCONTIGMEM_DEFAULT
1388 depends on NUMA && X86_32
1390 config ARCH_SPARSEMEM_ENABLE
1392 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1393 select SPARSEMEM_STATIC if X86_32
1394 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1396 config ARCH_SPARSEMEM_DEFAULT
1400 config ARCH_SELECT_MEMORY_MODEL
1402 depends on ARCH_SPARSEMEM_ENABLE
1404 config ARCH_MEMORY_PROBE
1405 bool "Enable sysfs memory/probe interface"
1406 depends on X86_64 && MEMORY_HOTPLUG
1408 This option enables a sysfs memory/probe interface for testing.
1409 See Documentation/memory-hotplug.txt for more information.
1410 If you are unsure how to answer this question, answer N.
1412 config ARCH_PROC_KCORE_TEXT
1414 depends on X86_64 && PROC_KCORE
1416 config ILLEGAL_POINTER_VALUE
1419 default 0xdead000000000000 if X86_64
1423 config X86_PMEM_LEGACY
1424 bool "Support non-standard NVDIMMs and ADR protected memory"
1426 Treat memory marked using the non-standard e820 type of 12 as used
1427 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1428 The kernel will offer these regions to the 'pmem' driver so
1429 they can be used for persistent storage.
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 the kexec_file_load() syscall.
1752 In addition to that option, you need to enable signature
1753 verification for the corresponding kernel image type being
1754 loaded in order for this to work.
1756 config KEXEC_BZIMAGE_VERIFY_SIG
1757 bool "Enable bzImage signature verification support"
1758 depends on KEXEC_VERIFY_SIG
1759 depends on SIGNED_PE_FILE_VERIFICATION
1760 select SYSTEM_TRUSTED_KEYRING
1762 Enable bzImage signature verification support.
1765 bool "kernel crash dumps"
1766 depends on X86_64 || (X86_32 && HIGHMEM)
1768 Generate crash dump after being started by kexec.
1769 This should be normally only set in special crash dump kernels
1770 which are loaded in the main kernel with kexec-tools into
1771 a specially reserved region and then later executed after
1772 a crash by kdump/kexec. The crash dump kernel must be compiled
1773 to a memory address not used by the main kernel or BIOS using
1774 PHYSICAL_START, or it must be built as a relocatable image
1775 (CONFIG_RELOCATABLE=y).
1776 For more details see Documentation/kdump/kdump.txt
1780 depends on KEXEC && HIBERNATION
1782 Jump between original kernel and kexeced kernel and invoke
1783 code in physical address mode via KEXEC
1785 config PHYSICAL_START
1786 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1789 This gives the physical address where the kernel is loaded.
1791 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1792 bzImage will decompress itself to above physical address and
1793 run from there. Otherwise, bzImage will run from the address where
1794 it has been loaded by the boot loader and will ignore above physical
1797 In normal kdump cases one does not have to set/change this option
1798 as now bzImage can be compiled as a completely relocatable image
1799 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1800 address. This option is mainly useful for the folks who don't want
1801 to use a bzImage for capturing the crash dump and want to use a
1802 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1803 to be specifically compiled to run from a specific memory area
1804 (normally a reserved region) and this option comes handy.
1806 So if you are using bzImage for capturing the crash dump,
1807 leave the value here unchanged to 0x1000000 and set
1808 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1809 for capturing the crash dump change this value to start of
1810 the reserved region. In other words, it can be set based on
1811 the "X" value as specified in the "crashkernel=YM@XM"
1812 command line boot parameter passed to the panic-ed
1813 kernel. Please take a look at Documentation/kdump/kdump.txt
1814 for more details about crash dumps.
1816 Usage of bzImage for capturing the crash dump is recommended as
1817 one does not have to build two kernels. Same kernel can be used
1818 as production kernel and capture kernel. Above option should have
1819 gone away after relocatable bzImage support is introduced. But it
1820 is present because there are users out there who continue to use
1821 vmlinux for dump capture. This option should go away down the
1824 Don't change this unless you know what you are doing.
1827 bool "Build a relocatable kernel"
1830 This builds a kernel image that retains relocation information
1831 so it can be loaded someplace besides the default 1MB.
1832 The relocations tend to make the kernel binary about 10% larger,
1833 but are discarded at runtime.
1835 One use is for the kexec on panic case where the recovery kernel
1836 must live at a different physical address than the primary
1839 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1840 it has been loaded at and the compile time physical address
1841 (CONFIG_PHYSICAL_START) is used as the minimum location.
1843 config RANDOMIZE_BASE
1844 bool "Randomize the address of the kernel image"
1845 depends on RELOCATABLE
1848 Randomizes the physical and virtual address at which the
1849 kernel image is decompressed, as a security feature that
1850 deters exploit attempts relying on knowledge of the location
1851 of kernel internals.
1853 Entropy is generated using the RDRAND instruction if it is
1854 supported. If RDTSC is supported, it is used as well. If
1855 neither RDRAND nor RDTSC are supported, then randomness is
1856 read from the i8254 timer.
1858 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1859 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1860 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1861 minimum of 2MiB, only 10 bits of entropy is theoretically
1862 possible. At best, due to page table layouts, 64-bit can use
1863 9 bits of entropy and 32-bit uses 8 bits.
1867 config RANDOMIZE_BASE_MAX_OFFSET
1868 hex "Maximum kASLR offset allowed" if EXPERT
1869 depends on RANDOMIZE_BASE
1870 range 0x0 0x20000000 if X86_32
1871 default "0x20000000" if X86_32
1872 range 0x0 0x40000000 if X86_64
1873 default "0x40000000" if X86_64
1875 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1876 memory is used to determine the maximal offset in bytes that will
1877 be applied to the kernel when kernel Address Space Layout
1878 Randomization (kASLR) is active. This must be a multiple of
1881 On 32-bit this is limited to 512MiB by page table layouts. The
1884 On 64-bit this is limited by how the kernel fixmap page table is
1885 positioned, so this cannot be larger than 1GiB currently. Without
1886 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1887 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1888 modules area will shrink to compensate, up to the current maximum
1889 1GiB to 1GiB split. The default is 1GiB.
1891 If unsure, leave at the default value.
1893 # Relocation on x86 needs some additional build support
1894 config X86_NEED_RELOCS
1896 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1898 config PHYSICAL_ALIGN
1899 hex "Alignment value to which kernel should be aligned"
1901 range 0x2000 0x1000000 if X86_32
1902 range 0x200000 0x1000000 if X86_64
1904 This value puts the alignment restrictions on physical address
1905 where kernel is loaded and run from. Kernel is compiled for an
1906 address which meets above alignment restriction.
1908 If bootloader loads the kernel at a non-aligned address and
1909 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1910 address aligned to above value and run from there.
1912 If bootloader loads the kernel at a non-aligned address and
1913 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1914 load address and decompress itself to the address it has been
1915 compiled for and run from there. The address for which kernel is
1916 compiled already meets above alignment restrictions. Hence the
1917 end result is that kernel runs from a physical address meeting
1918 above alignment restrictions.
1920 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1921 this value must be a multiple of 0x200000.
1923 Don't change this unless you know what you are doing.
1926 bool "Support for hot-pluggable CPUs"
1929 Say Y here to allow turning CPUs off and on. CPUs can be
1930 controlled through /sys/devices/system/cpu.
1931 ( Note: power management support will enable this option
1932 automatically on SMP systems. )
1933 Say N if you want to disable CPU hotplug.
1935 config BOOTPARAM_HOTPLUG_CPU0
1936 bool "Set default setting of cpu0_hotpluggable"
1938 depends on HOTPLUG_CPU
1940 Set whether default state of cpu0_hotpluggable is on or off.
1942 Say Y here to enable CPU0 hotplug by default. If this switch
1943 is turned on, there is no need to give cpu0_hotplug kernel
1944 parameter and the CPU0 hotplug feature is enabled by default.
1946 Please note: there are two known CPU0 dependencies if you want
1947 to enable the CPU0 hotplug feature either by this switch or by
1948 cpu0_hotplug kernel parameter.
1950 First, resume from hibernate or suspend always starts from CPU0.
1951 So hibernate and suspend are prevented if CPU0 is offline.
1953 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1954 offline if any interrupt can not migrate out of CPU0. There may
1955 be other CPU0 dependencies.
1957 Please make sure the dependencies are under your control before
1958 you enable this feature.
1960 Say N if you don't want to enable CPU0 hotplug feature by default.
1961 You still can enable the CPU0 hotplug feature at boot by kernel
1962 parameter cpu0_hotplug.
1964 config DEBUG_HOTPLUG_CPU0
1966 prompt "Debug CPU0 hotplug"
1967 depends on HOTPLUG_CPU
1969 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1970 soon as possible and boots up userspace with CPU0 offlined. User
1971 can online CPU0 back after boot time.
1973 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1974 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1975 compilation or giving cpu0_hotplug kernel parameter at boot.
1981 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1982 depends on X86_32 || IA32_EMULATION
1984 Certain buggy versions of glibc will crash if they are
1985 presented with a 32-bit vDSO that is not mapped at the address
1986 indicated in its segment table.
1988 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1989 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1990 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1991 the only released version with the bug, but OpenSUSE 9
1992 contains a buggy "glibc 2.3.2".
1994 The symptom of the bug is that everything crashes on startup, saying:
1995 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1997 Saying Y here changes the default value of the vdso32 boot
1998 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1999 This works around the glibc bug but hurts performance.
2001 If unsure, say N: if you are compiling your own kernel, you
2002 are unlikely to be using a buggy version of glibc.
2005 bool "Built-in kernel command line"
2007 Allow for specifying boot arguments to the kernel at
2008 build time. On some systems (e.g. embedded ones), it is
2009 necessary or convenient to provide some or all of the
2010 kernel boot arguments with the kernel itself (that is,
2011 to not rely on the boot loader to provide them.)
2013 To compile command line arguments into the kernel,
2014 set this option to 'Y', then fill in the
2015 the boot arguments in CONFIG_CMDLINE.
2017 Systems with fully functional boot loaders (i.e. non-embedded)
2018 should leave this option set to 'N'.
2021 string "Built-in kernel command string"
2022 depends on CMDLINE_BOOL
2025 Enter arguments here that should be compiled into the kernel
2026 image and used at boot time. If the boot loader provides a
2027 command line at boot time, it is appended to this string to
2028 form the full kernel command line, when the system boots.
2030 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2031 change this behavior.
2033 In most cases, the command line (whether built-in or provided
2034 by the boot loader) should specify the device for the root
2037 config CMDLINE_OVERRIDE
2038 bool "Built-in command line overrides boot loader arguments"
2039 depends on CMDLINE_BOOL
2041 Set this option to 'Y' to have the kernel ignore the boot loader
2042 command line, and use ONLY the built-in command line.
2044 This is used to work around broken boot loaders. This should
2045 be set to 'N' under normal conditions.
2047 source "kernel/livepatch/Kconfig"
2051 config ARCH_ENABLE_MEMORY_HOTPLUG
2053 depends on X86_64 || (X86_32 && HIGHMEM)
2055 config ARCH_ENABLE_MEMORY_HOTREMOVE
2057 depends on MEMORY_HOTPLUG
2059 config USE_PERCPU_NUMA_NODE_ID
2063 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2065 depends on X86_64 || X86_PAE
2067 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2069 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2071 menu "Power management and ACPI options"
2073 config ARCH_HIBERNATION_HEADER
2075 depends on X86_64 && HIBERNATION
2077 source "kernel/power/Kconfig"
2079 source "drivers/acpi/Kconfig"
2081 source "drivers/sfi/Kconfig"
2088 tristate "APM (Advanced Power Management) BIOS support"
2089 depends on X86_32 && PM_SLEEP
2091 APM is a BIOS specification for saving power using several different
2092 techniques. This is mostly useful for battery powered laptops with
2093 APM compliant BIOSes. If you say Y here, the system time will be
2094 reset after a RESUME operation, the /proc/apm device will provide
2095 battery status information, and user-space programs will receive
2096 notification of APM "events" (e.g. battery status change).
2098 If you select "Y" here, you can disable actual use of the APM
2099 BIOS by passing the "apm=off" option to the kernel at boot time.
2101 Note that the APM support is almost completely disabled for
2102 machines with more than one CPU.
2104 In order to use APM, you will need supporting software. For location
2105 and more information, read <file:Documentation/power/apm-acpi.txt>
2106 and the Battery Powered Linux mini-HOWTO, available from
2107 <http://www.tldp.org/docs.html#howto>.
2109 This driver does not spin down disk drives (see the hdparm(8)
2110 manpage ("man 8 hdparm") for that), and it doesn't turn off
2111 VESA-compliant "green" monitors.
2113 This driver does not support the TI 4000M TravelMate and the ACER
2114 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2115 desktop machines also don't have compliant BIOSes, and this driver
2116 may cause those machines to panic during the boot phase.
2118 Generally, if you don't have a battery in your machine, there isn't
2119 much point in using this driver and you should say N. If you get
2120 random kernel OOPSes or reboots that don't seem to be related to
2121 anything, try disabling/enabling this option (or disabling/enabling
2124 Some other things you should try when experiencing seemingly random,
2127 1) make sure that you have enough swap space and that it is
2129 2) pass the "no-hlt" option to the kernel
2130 3) switch on floating point emulation in the kernel and pass
2131 the "no387" option to the kernel
2132 4) pass the "floppy=nodma" option to the kernel
2133 5) pass the "mem=4M" option to the kernel (thereby disabling
2134 all but the first 4 MB of RAM)
2135 6) make sure that the CPU is not over clocked.
2136 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2137 8) disable the cache from your BIOS settings
2138 9) install a fan for the video card or exchange video RAM
2139 10) install a better fan for the CPU
2140 11) exchange RAM chips
2141 12) exchange the motherboard.
2143 To compile this driver as a module, choose M here: the
2144 module will be called apm.
2148 config APM_IGNORE_USER_SUSPEND
2149 bool "Ignore USER SUSPEND"
2151 This option will ignore USER SUSPEND requests. On machines with a
2152 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2153 series notebooks, it is necessary to say Y because of a BIOS bug.
2155 config APM_DO_ENABLE
2156 bool "Enable PM at boot time"
2158 Enable APM features at boot time. From page 36 of the APM BIOS
2159 specification: "When disabled, the APM BIOS does not automatically
2160 power manage devices, enter the Standby State, enter the Suspend
2161 State, or take power saving steps in response to CPU Idle calls."
2162 This driver will make CPU Idle calls when Linux is idle (unless this
2163 feature is turned off -- see "Do CPU IDLE calls", below). This
2164 should always save battery power, but more complicated APM features
2165 will be dependent on your BIOS implementation. You may need to turn
2166 this option off if your computer hangs at boot time when using APM
2167 support, or if it beeps continuously instead of suspending. Turn
2168 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2169 T400CDT. This is off by default since most machines do fine without
2174 bool "Make CPU Idle calls when idle"
2176 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2177 On some machines, this can activate improved power savings, such as
2178 a slowed CPU clock rate, when the machine is idle. These idle calls
2179 are made after the idle loop has run for some length of time (e.g.,
2180 333 mS). On some machines, this will cause a hang at boot time or
2181 whenever the CPU becomes idle. (On machines with more than one CPU,
2182 this option does nothing.)
2184 config APM_DISPLAY_BLANK
2185 bool "Enable console blanking using APM"
2187 Enable console blanking using the APM. Some laptops can use this to
2188 turn off the LCD backlight when the screen blanker of the Linux
2189 virtual console blanks the screen. Note that this is only used by
2190 the virtual console screen blanker, and won't turn off the backlight
2191 when using the X Window system. This also doesn't have anything to
2192 do with your VESA-compliant power-saving monitor. Further, this
2193 option doesn't work for all laptops -- it might not turn off your
2194 backlight at all, or it might print a lot of errors to the console,
2195 especially if you are using gpm.
2197 config APM_ALLOW_INTS
2198 bool "Allow interrupts during APM BIOS calls"
2200 Normally we disable external interrupts while we are making calls to
2201 the APM BIOS as a measure to lessen the effects of a badly behaving
2202 BIOS implementation. The BIOS should reenable interrupts if it
2203 needs to. Unfortunately, some BIOSes do not -- especially those in
2204 many of the newer IBM Thinkpads. If you experience hangs when you
2205 suspend, try setting this to Y. Otherwise, say N.
2209 source "drivers/cpufreq/Kconfig"
2211 source "drivers/cpuidle/Kconfig"
2213 source "drivers/idle/Kconfig"
2218 menu "Bus options (PCI etc.)"
2224 Find out whether you have a PCI motherboard. PCI is the name of a
2225 bus system, i.e. the way the CPU talks to the other stuff inside
2226 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2227 VESA. If you have PCI, say Y, otherwise N.
2230 prompt "PCI access mode"
2231 depends on X86_32 && PCI
2234 On PCI systems, the BIOS can be used to detect the PCI devices and
2235 determine their configuration. However, some old PCI motherboards
2236 have BIOS bugs and may crash if this is done. Also, some embedded
2237 PCI-based systems don't have any BIOS at all. Linux can also try to
2238 detect the PCI hardware directly without using the BIOS.
2240 With this option, you can specify how Linux should detect the
2241 PCI devices. If you choose "BIOS", the BIOS will be used,
2242 if you choose "Direct", the BIOS won't be used, and if you
2243 choose "MMConfig", then PCI Express MMCONFIG will be used.
2244 If you choose "Any", the kernel will try MMCONFIG, then the
2245 direct access method and falls back to the BIOS if that doesn't
2246 work. If unsure, go with the default, which is "Any".
2251 config PCI_GOMMCONFIG
2268 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2270 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2273 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2277 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2281 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2285 depends on PCI && XEN
2293 bool "Support mmconfig PCI config space access"
2294 depends on X86_64 && PCI && ACPI
2296 config PCI_CNB20LE_QUIRK
2297 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2300 Read the PCI windows out of the CNB20LE host bridge. This allows
2301 PCI hotplug to work on systems with the CNB20LE chipset which do
2304 There's no public spec for this chipset, and this functionality
2305 is known to be incomplete.
2307 You should say N unless you know you need this.
2309 source "drivers/pci/pcie/Kconfig"
2311 source "drivers/pci/Kconfig"
2313 # x86_64 have no ISA slots, but can have ISA-style DMA.
2315 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2318 Enables ISA-style DMA support for devices requiring such controllers.
2326 Find out whether you have ISA slots on your motherboard. ISA is the
2327 name of a bus system, i.e. the way the CPU talks to the other stuff
2328 inside your box. Other bus systems are PCI, EISA, MicroChannel
2329 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2330 newer boards don't support it. If you have ISA, say Y, otherwise N.
2336 The Extended Industry Standard Architecture (EISA) bus was
2337 developed as an open alternative to the IBM MicroChannel bus.
2339 The EISA bus provided some of the features of the IBM MicroChannel
2340 bus while maintaining backward compatibility with cards made for
2341 the older ISA bus. The EISA bus saw limited use between 1988 and
2342 1995 when it was made obsolete by the PCI bus.
2344 Say Y here if you are building a kernel for an EISA-based machine.
2348 source "drivers/eisa/Kconfig"
2351 tristate "NatSemi SCx200 support"
2353 This provides basic support for National Semiconductor's
2354 (now AMD's) Geode processors. The driver probes for the
2355 PCI-IDs of several on-chip devices, so its a good dependency
2356 for other scx200_* drivers.
2358 If compiled as a module, the driver is named scx200.
2360 config SCx200HR_TIMER
2361 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2365 This driver provides a clocksource built upon the on-chip
2366 27MHz high-resolution timer. Its also a workaround for
2367 NSC Geode SC-1100's buggy TSC, which loses time when the
2368 processor goes idle (as is done by the scheduler). The
2369 other workaround is idle=poll boot option.
2372 bool "One Laptop Per Child support"
2379 Add support for detecting the unique features of the OLPC
2383 bool "OLPC XO-1 Power Management"
2384 depends on OLPC && MFD_CS5535 && PM_SLEEP
2387 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2390 bool "OLPC XO-1 Real Time Clock"
2391 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2393 Add support for the XO-1 real time clock, which can be used as a
2394 programmable wakeup source.
2397 bool "OLPC XO-1 SCI extras"
2398 depends on OLPC && OLPC_XO1_PM
2404 Add support for SCI-based features of the OLPC XO-1 laptop:
2405 - EC-driven system wakeups
2409 - AC adapter status updates
2410 - Battery status updates
2412 config OLPC_XO15_SCI
2413 bool "OLPC XO-1.5 SCI extras"
2414 depends on OLPC && ACPI
2417 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2418 - EC-driven system wakeups
2419 - AC adapter status updates
2420 - Battery status updates
2423 bool "PCEngines ALIX System Support (LED setup)"
2426 This option enables system support for the PCEngines ALIX.
2427 At present this just sets up LEDs for GPIO control on
2428 ALIX2/3/6 boards. However, other system specific setup should
2431 Note: You must still enable the drivers for GPIO and LED support
2432 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2434 Note: You have to set alix.force=1 for boards with Award BIOS.
2437 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2440 This option enables system support for the Soekris Engineering net5501.
2443 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2447 This option enables system support for the Traverse Technologies GEOS.
2450 bool "Technologic Systems TS-5500 platform support"
2452 select CHECK_SIGNATURE
2456 This option enables system support for the Technologic Systems TS-5500.
2462 depends on CPU_SUP_AMD && PCI
2464 source "drivers/pcmcia/Kconfig"
2466 source "drivers/pci/hotplug/Kconfig"
2469 tristate "RapidIO support"
2473 If enabled this option will include drivers and the core
2474 infrastructure code to support RapidIO interconnect devices.
2476 source "drivers/rapidio/Kconfig"
2479 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2481 Firmwares often provide initial graphics framebuffers so the BIOS,
2482 bootloader or kernel can show basic video-output during boot for
2483 user-guidance and debugging. Historically, x86 used the VESA BIOS
2484 Extensions and EFI-framebuffers for this, which are mostly limited
2486 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2487 framebuffers so the new generic system-framebuffer drivers can be
2488 used on x86. If the framebuffer is not compatible with the generic
2489 modes, it is adverticed as fallback platform framebuffer so legacy
2490 drivers like efifb, vesafb and uvesafb can pick it up.
2491 If this option is not selected, all system framebuffers are always
2492 marked as fallback platform framebuffers as usual.
2494 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2495 not be able to pick up generic system framebuffers if this option
2496 is selected. You are highly encouraged to enable simplefb as
2497 replacement if you select this option. simplefb can correctly deal
2498 with generic system framebuffers. But you should still keep vesafb
2499 and others enabled as fallback if a system framebuffer is
2500 incompatible with simplefb.
2507 menu "Executable file formats / Emulations"
2509 source "fs/Kconfig.binfmt"
2511 config IA32_EMULATION
2512 bool "IA32 Emulation"
2515 select COMPAT_BINFMT_ELF
2518 Include code to run legacy 32-bit programs under a
2519 64-bit kernel. You should likely turn this on, unless you're
2520 100% sure that you don't have any 32-bit programs left.
2523 tristate "IA32 a.out support"
2524 depends on IA32_EMULATION
2526 Support old a.out binaries in the 32bit emulation.
2529 bool "x32 ABI for 64-bit mode"
2530 depends on X86_64 && IA32_EMULATION
2532 Include code to run binaries for the x32 native 32-bit ABI
2533 for 64-bit processors. An x32 process gets access to the
2534 full 64-bit register file and wide data path while leaving
2535 pointers at 32 bits for smaller memory footprint.
2537 You will need a recent binutils (2.22 or later) with
2538 elf32_x86_64 support enabled to compile a kernel with this
2543 depends on IA32_EMULATION || X86_X32
2544 select ARCH_WANT_OLD_COMPAT_IPC
2547 config COMPAT_FOR_U64_ALIGNMENT
2550 config SYSVIPC_COMPAT
2562 config HAVE_ATOMIC_IOMAP
2566 config X86_DEV_DMA_OPS
2568 depends on X86_64 || STA2X11
2570 config X86_DMA_REMAP
2578 source "net/Kconfig"
2580 source "drivers/Kconfig"
2582 source "drivers/firmware/Kconfig"
2586 source "arch/x86/Kconfig.debug"
2588 source "security/Kconfig"
2590 source "crypto/Kconfig"
2592 source "arch/x86/kvm/Kconfig"
2594 source "lib/Kconfig"