3 bool "64-bit kernel" if ARCH = "x86"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
24 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
25 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
26 select ARCH_HAS_FAST_MULTIPLIER
27 select ARCH_HAS_GCOV_PROFILE_ALL
28 select ARCH_MIGHT_HAVE_PC_PARPORT
29 select ARCH_MIGHT_HAVE_PC_SERIO
30 select HAVE_AOUT if X86_32
31 select HAVE_UNSTABLE_SCHED_CLOCK
32 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
33 select ARCH_SUPPORTS_INT128 if X86_64
36 select HAVE_PCSPKR_PLATFORM
37 select HAVE_PERF_EVENTS
38 select HAVE_IOREMAP_PROT
41 select HAVE_MEMBLOCK_NODE_MAP
42 select ARCH_DISCARD_MEMBLOCK
43 select ARCH_WANT_OPTIONAL_GPIOLIB
44 select ARCH_WANT_FRAME_POINTERS
46 select HAVE_DMA_CONTIGUOUS
47 select HAVE_KRETPROBES
48 select GENERIC_EARLY_IOREMAP
50 select HAVE_KPROBES_ON_FTRACE
51 select HAVE_FTRACE_MCOUNT_RECORD
52 select HAVE_FENTRY if X86_64
53 select HAVE_C_RECORDMCOUNT
54 select HAVE_DYNAMIC_FTRACE
55 select HAVE_DYNAMIC_FTRACE_WITH_REGS
56 select HAVE_FUNCTION_TRACER
57 select HAVE_FUNCTION_GRAPH_TRACER
58 select HAVE_FUNCTION_GRAPH_FP_TEST
59 select HAVE_SYSCALL_TRACEPOINTS
60 select SYSCTL_EXCEPTION_TRACE
63 select HAVE_ARCH_TRACEHOOK
64 select HAVE_GENERIC_DMA_COHERENT if X86_32
65 select HAVE_EFFICIENT_UNALIGNED_ACCESS
66 select USER_STACKTRACE_SUPPORT
67 select HAVE_REGS_AND_STACK_ACCESS_API
68 select HAVE_DMA_API_DEBUG
69 select HAVE_KERNEL_GZIP
70 select HAVE_KERNEL_BZIP2
71 select HAVE_KERNEL_LZMA
73 select HAVE_KERNEL_LZO
74 select HAVE_KERNEL_LZ4
75 select HAVE_HW_BREAKPOINT
76 select HAVE_MIXED_BREAKPOINTS_REGS
78 select HAVE_PERF_EVENTS_NMI
80 select HAVE_PERF_USER_STACK_DUMP
81 select HAVE_DEBUG_KMEMLEAK
83 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
84 select HAVE_CMPXCHG_LOCAL
85 select HAVE_CMPXCHG_DOUBLE
86 select HAVE_ARCH_KMEMCHECK
87 select HAVE_USER_RETURN_NOTIFIER
88 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
89 select HAVE_ARCH_JUMP_LABEL
90 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
92 select GENERIC_FIND_FIRST_BIT
93 select GENERIC_IRQ_PROBE
94 select GENERIC_PENDING_IRQ if SMP
95 select GENERIC_IRQ_SHOW
96 select GENERIC_CLOCKEVENTS_MIN_ADJUST
97 select IRQ_FORCED_THREADING
98 select HAVE_BPF_JIT if X86_64
99 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
100 select ARCH_HAS_SG_CHAIN
102 select ARCH_HAVE_NMI_SAFE_CMPXCHG
104 select DCACHE_WORD_ACCESS
105 select GENERIC_SMP_IDLE_THREAD
106 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
107 select HAVE_ARCH_SECCOMP_FILTER
108 select BUILDTIME_EXTABLE_SORT
109 select GENERIC_CMOS_UPDATE
110 select HAVE_ARCH_SOFT_DIRTY if X86_64
111 select CLOCKSOURCE_WATCHDOG
112 select GENERIC_CLOCKEVENTS
113 select ARCH_CLOCKSOURCE_DATA
114 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
115 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
116 select GENERIC_TIME_VSYSCALL
117 select GENERIC_STRNCPY_FROM_USER
118 select GENERIC_STRNLEN_USER
119 select HAVE_CONTEXT_TRACKING if X86_64
120 select HAVE_IRQ_TIME_ACCOUNTING
122 select MODULES_USE_ELF_REL if X86_32
123 select MODULES_USE_ELF_RELA if X86_64
124 select CLONE_BACKWARDS if X86_32
125 select ARCH_USE_BUILTIN_BSWAP
126 select ARCH_USE_QUEUE_RWLOCK
127 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
128 select OLD_SIGACTION if X86_32
129 select COMPAT_OLD_SIGACTION if IA32_EMULATION
131 select HAVE_DEBUG_STACKOVERFLOW
132 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
133 select HAVE_CC_STACKPROTECTOR
134 select GENERIC_CPU_AUTOPROBE
135 select HAVE_ARCH_AUDITSYSCALL
136 select ARCH_SUPPORTS_ATOMIC_RMW
137 select HAVE_ACPI_APEI if ACPI
138 select HAVE_ACPI_APEI_NMI if ACPI
139 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
140 select X86_FEATURE_NAMES if PROC_FS
142 config INSTRUCTION_DECODER
144 depends on KPROBES || PERF_EVENTS || UPROBES
146 config PERF_EVENTS_INTEL_UNCORE
148 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
152 default "elf32-i386" if X86_32
153 default "elf64-x86-64" if X86_64
155 config ARCH_DEFCONFIG
157 default "arch/x86/configs/i386_defconfig" if X86_32
158 default "arch/x86/configs/x86_64_defconfig" if X86_64
160 config LOCKDEP_SUPPORT
163 config STACKTRACE_SUPPORT
166 config HAVE_LATENCYTOP_SUPPORT
175 config NEED_DMA_MAP_STATE
177 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
179 config NEED_SG_DMA_LENGTH
182 config GENERIC_ISA_DMA
184 depends on ISA_DMA_API
189 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
191 config GENERIC_BUG_RELATIVE_POINTERS
194 config GENERIC_HWEIGHT
197 config ARCH_MAY_HAVE_PC_FDC
199 depends on ISA_DMA_API
201 config RWSEM_XCHGADD_ALGORITHM
204 config GENERIC_CALIBRATE_DELAY
207 config ARCH_HAS_CPU_RELAX
210 config ARCH_HAS_CACHE_LINE_SIZE
213 config HAVE_SETUP_PER_CPU_AREA
216 config NEED_PER_CPU_EMBED_FIRST_CHUNK
219 config NEED_PER_CPU_PAGE_FIRST_CHUNK
222 config ARCH_HIBERNATION_POSSIBLE
225 config ARCH_SUSPEND_POSSIBLE
228 config ARCH_WANT_HUGE_PMD_SHARE
231 config ARCH_WANT_GENERAL_HUGETLB
242 config ARCH_SUPPORTS_OPTIMIZED_INLINING
245 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
248 config HAVE_INTEL_TXT
250 depends on INTEL_IOMMU && ACPI
254 depends on X86_32 && SMP
258 depends on X86_64 && SMP
264 config X86_32_LAZY_GS
266 depends on X86_32 && !CC_STACKPROTECTOR
268 config ARCH_HWEIGHT_CFLAGS
270 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
271 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
273 config ARCH_SUPPORTS_UPROBES
276 config FIX_EARLYCON_MEM
279 source "init/Kconfig"
280 source "kernel/Kconfig.freezer"
282 menu "Processor type and features"
285 bool "DMA memory allocation support" if EXPERT
288 DMA memory allocation support allows devices with less than 32-bit
289 addressing to allocate within the first 16MB of address space.
290 Disable if no such devices will be used.
295 bool "Symmetric multi-processing support"
297 This enables support for systems with more than one CPU. If you have
298 a system with only one CPU, say N. If you have a system with more
301 If you say N here, the kernel will run on uni- and multiprocessor
302 machines, but will use only one CPU of a multiprocessor machine. If
303 you say Y here, the kernel will run on many, but not all,
304 uniprocessor machines. On a uniprocessor machine, the kernel
305 will run faster if you say N here.
307 Note that if you say Y here and choose architecture "586" or
308 "Pentium" under "Processor family", the kernel will not work on 486
309 architectures. Similarly, multiprocessor kernels for the "PPro"
310 architecture may not work on all Pentium based boards.
312 People using multiprocessor machines who say Y here should also say
313 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
314 Management" code will be disabled if you say Y here.
316 See also <file:Documentation/x86/i386/IO-APIC.txt>,
317 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
318 <http://www.tldp.org/docs.html#howto>.
320 If you don't know what to do here, say N.
322 config X86_FEATURE_NAMES
323 bool "Processor feature human-readable names" if EMBEDDED
326 This option compiles in a table of x86 feature bits and corresponding
327 names. This is required to support /proc/cpuinfo and a few kernel
328 messages. You can disable this to save space, at the expense of
329 making those few kernel messages show numeric feature bits instead.
334 bool "Support x2apic"
335 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
337 This enables x2apic support on CPUs that have this feature.
339 This allows 32-bit apic IDs (so it can support very large systems),
340 and accesses the local apic via MSRs not via mmio.
342 If you don't know what to do here, say N.
345 bool "Enable MPS table" if ACPI || SFI
347 depends on X86_LOCAL_APIC
349 For old smp systems that do not have proper acpi support. Newer systems
350 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
353 bool "Support for big SMP systems with more than 8 CPUs"
354 depends on X86_32 && SMP
356 This option is needed for the systems that have more than 8 CPUs
360 depends on X86_GOLDFISH
363 config X86_EXTENDED_PLATFORM
364 bool "Support for extended (non-PC) x86 platforms"
367 If you disable this option then the kernel will only support
368 standard PC platforms. (which covers the vast majority of
371 If you enable this option then you'll be able to select support
372 for the following (non-PC) 32 bit x86 platforms:
373 Goldfish (Android emulator)
376 SGI 320/540 (Visual Workstation)
377 STA2X11-based (e.g. Northville)
378 Moorestown MID devices
380 If you have one of these systems, or if you want to build a
381 generic distribution kernel, say Y here - otherwise say N.
385 config X86_EXTENDED_PLATFORM
386 bool "Support for extended (non-PC) x86 platforms"
389 If you disable this option then the kernel will only support
390 standard PC platforms. (which covers the vast majority of
393 If you enable this option then you'll be able to select support
394 for the following (non-PC) 64 bit x86 platforms:
399 If you have one of these systems, or if you want to build a
400 generic distribution kernel, say Y here - otherwise say N.
402 # This is an alphabetically sorted list of 64 bit extended platforms
403 # Please maintain the alphabetic order if and when there are additions
405 bool "Numascale NumaChip"
407 depends on X86_EXTENDED_PLATFORM
410 depends on X86_X2APIC
411 depends on PCI_MMCONFIG
413 Adds support for Numascale NumaChip large-SMP systems. Needed to
414 enable more than ~168 cores.
415 If you don't have one of these, you should say N here.
419 select HYPERVISOR_GUEST
421 depends on X86_64 && PCI
422 depends on X86_EXTENDED_PLATFORM
425 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
426 supposed to run on these EM64T-based machines. Only choose this option
427 if you have one of these machines.
430 bool "SGI Ultraviolet"
432 depends on X86_EXTENDED_PLATFORM
434 depends on X86_X2APIC
436 This option is needed in order to support SGI Ultraviolet systems.
437 If you don't have one of these, you should say N here.
439 # Following is an alphabetically sorted list of 32 bit extended platforms
440 # Please maintain the alphabetic order if and when there are additions
443 bool "Goldfish (Virtual Platform)"
444 depends on X86_EXTENDED_PLATFORM
446 Enable support for the Goldfish virtual platform used primarily
447 for Android development. Unless you are building for the Android
448 Goldfish emulator say N here.
451 bool "CE4100 TV platform"
453 depends on PCI_GODIRECT
454 depends on X86_IO_APIC
456 depends on X86_EXTENDED_PLATFORM
457 select X86_REBOOTFIXUPS
459 select OF_EARLY_FLATTREE
462 Select for the Intel CE media processor (CE4100) SOC.
463 This option compiles in support for the CE4100 SOC for settop
464 boxes and media devices.
467 bool "Intel MID platform support"
469 depends on X86_EXTENDED_PLATFORM
470 depends on X86_PLATFORM_DEVICES
473 depends on X86_IO_APIC
479 select MFD_INTEL_MSIC
481 Select to build a kernel capable of supporting Intel MID (Mobile
482 Internet Device) platform systems which do not have the PCI legacy
483 interfaces. If you are building for a PC class system say N here.
485 Intel MID platforms are based on an Intel processor and chipset which
486 consume less power than most of the x86 derivatives.
488 config X86_INTEL_LPSS
489 bool "Intel Low Power Subsystem Support"
494 Select to build support for Intel Low Power Subsystem such as
495 found on Intel Lynxpoint PCH. Selecting this option enables
496 things like clock tree (common clock framework) and pincontrol
497 which are needed by the LPSS peripheral drivers.
499 config X86_AMD_PLATFORM_DEVICE
500 bool "AMD ACPI2Platform devices support"
505 Select to interpret AMD specific ACPI device to platform device
506 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
507 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
508 implemented under PINCTRL subsystem.
511 tristate "Intel SoC IOSF Sideband support for SoC platforms"
514 This option enables sideband register access support for Intel SoC
515 platforms. On these platforms the IOSF sideband is used in lieu of
516 MSR's for some register accesses, mostly but not limited to thermal
517 and power. Drivers may query the availability of this device to
518 determine if they need the sideband in order to work on these
519 platforms. The sideband is available on the following SoC products.
520 This list is not meant to be exclusive.
525 You should say Y if you are running a kernel on one of these SoC's.
527 config IOSF_MBI_DEBUG
528 bool "Enable IOSF sideband access through debugfs"
529 depends on IOSF_MBI && DEBUG_FS
531 Select this option to expose the IOSF sideband access registers (MCR,
532 MDR, MCRX) through debugfs to write and read register information from
533 different units on the SoC. This is most useful for obtaining device
534 state information for debug and analysis. As this is a general access
535 mechanism, users of this option would have specific knowledge of the
536 device they want to access.
538 If you don't require the option or are in doubt, say N.
541 bool "RDC R-321x SoC"
543 depends on X86_EXTENDED_PLATFORM
545 select X86_REBOOTFIXUPS
547 This option is needed for RDC R-321x system-on-chip, also known
549 If you don't have one of these chips, you should say N here.
551 config X86_32_NON_STANDARD
552 bool "Support non-standard 32-bit SMP architectures"
553 depends on X86_32 && SMP
554 depends on X86_EXTENDED_PLATFORM
556 This option compiles in the bigsmp and STA2X11 default
557 subarchitectures. It is intended for a generic binary
558 kernel. If you select them all, kernel will probe it one by
559 one and will fallback to default.
561 # Alphabetically sorted list of Non standard 32 bit platforms
563 config X86_SUPPORTS_MEMORY_FAILURE
565 # MCE code calls memory_failure():
567 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
568 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
569 depends on X86_64 || !SPARSEMEM
570 select ARCH_SUPPORTS_MEMORY_FAILURE
573 bool "STA2X11 Companion Chip Support"
574 depends on X86_32_NON_STANDARD && PCI
575 select X86_DEV_DMA_OPS
579 select ARCH_REQUIRE_GPIOLIB
582 This adds support for boards based on the STA2X11 IO-Hub,
583 a.k.a. "ConneXt". The chip is used in place of the standard
584 PC chipset, so all "standard" peripherals are missing. If this
585 option is selected the kernel will still be able to boot on
586 standard PC machines.
589 tristate "Eurobraille/Iris poweroff module"
592 The Iris machines from EuroBraille do not have APM or ACPI support
593 to shut themselves down properly. A special I/O sequence is
594 needed to do so, which is what this module does at
597 This is only for Iris machines from EuroBraille.
601 config SCHED_OMIT_FRAME_POINTER
603 prompt "Single-depth WCHAN output"
606 Calculate simpler /proc/<PID>/wchan values. If this option
607 is disabled then wchan values will recurse back to the
608 caller function. This provides more accurate wchan values,
609 at the expense of slightly more scheduling overhead.
611 If in doubt, say "Y".
613 menuconfig HYPERVISOR_GUEST
614 bool "Linux guest support"
616 Say Y here to enable options for running Linux under various hyper-
617 visors. This option enables basic hypervisor detection and platform
620 If you say N, all options in this submenu will be skipped and
621 disabled, and Linux guest support won't be built in.
626 bool "Enable paravirtualization code"
628 This changes the kernel so it can modify itself when it is run
629 under a hypervisor, potentially improving performance significantly
630 over full virtualization. However, when run without a hypervisor
631 the kernel is theoretically slower and slightly larger.
633 config PARAVIRT_DEBUG
634 bool "paravirt-ops debugging"
635 depends on PARAVIRT && DEBUG_KERNEL
637 Enable to debug paravirt_ops internals. Specifically, BUG if
638 a paravirt_op is missing when it is called.
640 config PARAVIRT_SPINLOCKS
641 bool "Paravirtualization layer for spinlocks"
642 depends on PARAVIRT && SMP
643 select UNINLINE_SPIN_UNLOCK
645 Paravirtualized spinlocks allow a pvops backend to replace the
646 spinlock implementation with something virtualization-friendly
647 (for example, block the virtual CPU rather than spinning).
649 It has a minimal impact on native kernels and gives a nice performance
650 benefit on paravirtualized KVM / Xen kernels.
652 If you are unsure how to answer this question, answer Y.
654 source "arch/x86/xen/Kconfig"
657 bool "KVM Guest support (including kvmclock)"
659 select PARAVIRT_CLOCK
662 This option enables various optimizations for running under the KVM
663 hypervisor. It includes a paravirtualized clock, so that instead
664 of relying on a PIT (or probably other) emulation by the
665 underlying device model, the host provides the guest with
666 timing infrastructure such as time of day, and system time
669 bool "Enable debug information for KVM Guests in debugfs"
670 depends on KVM_GUEST && DEBUG_FS
673 This option enables collection of various statistics for KVM guest.
674 Statistics are displayed in debugfs filesystem. Enabling this option
675 may incur significant overhead.
677 source "arch/x86/lguest/Kconfig"
679 config PARAVIRT_TIME_ACCOUNTING
680 bool "Paravirtual steal time accounting"
684 Select this option to enable fine granularity task steal time
685 accounting. Time spent executing other tasks in parallel with
686 the current vCPU is discounted from the vCPU power. To account for
687 that, there can be a small performance impact.
689 If in doubt, say N here.
691 config PARAVIRT_CLOCK
694 endif #HYPERVISOR_GUEST
702 This option adds a kernel parameter 'memtest', which allows memtest
704 memtest=0, mean disabled; -- default
705 memtest=1, mean do 1 test pattern;
707 memtest=4, mean do 4 test patterns.
708 If you are unsure how to answer this question, answer N.
710 source "arch/x86/Kconfig.cpu"
714 prompt "HPET Timer Support" if X86_32
716 Use the IA-PC HPET (High Precision Event Timer) to manage
717 time in preference to the PIT and RTC, if a HPET is
719 HPET is the next generation timer replacing legacy 8254s.
720 The HPET provides a stable time base on SMP
721 systems, unlike the TSC, but it is more expensive to access,
722 as it is off-chip. You can find the HPET spec at
723 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
725 You can safely choose Y here. However, HPET will only be
726 activated if the platform and the BIOS support this feature.
727 Otherwise the 8254 will be used for timing services.
729 Choose N to continue using the legacy 8254 timer.
731 config HPET_EMULATE_RTC
733 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
736 def_bool y if X86_INTEL_MID
737 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
739 depends on X86_INTEL_MID && SFI
741 APB timer is the replacement for 8254, HPET on X86 MID platforms.
742 The APBT provides a stable time base on SMP
743 systems, unlike the TSC, but it is more expensive to access,
744 as it is off-chip. APB timers are always running regardless of CPU
745 C states, they are used as per CPU clockevent device when possible.
747 # Mark as expert because too many people got it wrong.
748 # The code disables itself when not needed.
751 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
752 bool "Enable DMI scanning" if EXPERT
754 Enabled scanning of DMI to identify machine quirks. Say Y
755 here unless you have verified that your setup is not
756 affected by entries in the DMI blacklist. Required by PNP
760 bool "Old AMD GART IOMMU support"
762 depends on X86_64 && PCI && AMD_NB
764 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
765 GART based hardware IOMMUs.
767 The GART supports full DMA access for devices with 32-bit access
768 limitations, on systems with more than 3 GB. This is usually needed
769 for USB, sound, many IDE/SATA chipsets and some other devices.
771 Newer systems typically have a modern AMD IOMMU, supported via
772 the CONFIG_AMD_IOMMU=y config option.
774 In normal configurations this driver is only active when needed:
775 there's more than 3 GB of memory and the system contains a
776 32-bit limited device.
781 bool "IBM Calgary IOMMU support"
783 depends on X86_64 && PCI
785 Support for hardware IOMMUs in IBM's xSeries x366 and x460
786 systems. Needed to run systems with more than 3GB of memory
787 properly with 32-bit PCI devices that do not support DAC
788 (Double Address Cycle). Calgary also supports bus level
789 isolation, where all DMAs pass through the IOMMU. This
790 prevents them from going anywhere except their intended
791 destination. This catches hard-to-find kernel bugs and
792 mis-behaving drivers and devices that do not use the DMA-API
793 properly to set up their DMA buffers. The IOMMU can be
794 turned off at boot time with the iommu=off parameter.
795 Normally the kernel will make the right choice by itself.
798 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
800 prompt "Should Calgary be enabled by default?"
801 depends on CALGARY_IOMMU
803 Should Calgary be enabled by default? if you choose 'y', Calgary
804 will be used (if it exists). If you choose 'n', Calgary will not be
805 used even if it exists. If you choose 'n' and would like to use
806 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
809 # need this always selected by IOMMU for the VIA workaround
813 Support for software bounce buffers used on x86-64 systems
814 which don't have a hardware IOMMU. Using this PCI devices
815 which can only access 32-bits of memory can be used on systems
816 with more than 3 GB of memory.
821 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
824 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
825 depends on X86_64 && SMP && DEBUG_KERNEL
826 select CPUMASK_OFFSTACK
828 Enable maximum number of CPUS and NUMA Nodes for this architecture.
832 int "Maximum number of CPUs" if SMP && !MAXSMP
833 range 2 8 if SMP && X86_32 && !X86_BIGSMP
834 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
835 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
837 default "8192" if MAXSMP
838 default "32" if SMP && X86_BIGSMP
841 This allows you to specify the maximum number of CPUs which this
842 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
843 supported value is 4096, otherwise the maximum value is 512. The
844 minimum value which makes sense is 2.
846 This is purely to save memory - each supported CPU adds
847 approximately eight kilobytes to the kernel image.
850 bool "SMT (Hyperthreading) scheduler support"
853 SMT scheduler support improves the CPU scheduler's decision making
854 when dealing with Intel Pentium 4 chips with HyperThreading at a
855 cost of slightly increased overhead in some places. If unsure say
860 prompt "Multi-core scheduler support"
863 Multi-core scheduler support improves the CPU scheduler's decision
864 making when dealing with multi-core CPU chips at a cost of slightly
865 increased overhead in some places. If unsure say N here.
867 source "kernel/Kconfig.preempt"
870 bool "Local APIC support on uniprocessors"
871 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
873 A local APIC (Advanced Programmable Interrupt Controller) is an
874 integrated interrupt controller in the CPU. If you have a single-CPU
875 system which has a processor with a local APIC, you can say Y here to
876 enable and use it. If you say Y here even though your machine doesn't
877 have a local APIC, then the kernel will still run with no slowdown at
878 all. The local APIC supports CPU-generated self-interrupts (timer,
879 performance counters), and the NMI watchdog which detects hard
882 config X86_UP_APIC_MSI
884 select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
887 bool "IO-APIC support on uniprocessors"
888 depends on X86_UP_APIC
890 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
891 SMP-capable replacement for PC-style interrupt controllers. Most
892 SMP systems and many recent uniprocessor systems have one.
894 If you have a single-CPU system with an IO-APIC, you can say Y here
895 to use it. If you say Y here even though your machine doesn't have
896 an IO-APIC, then the kernel will still run with no slowdown at all.
898 config X86_LOCAL_APIC
900 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
901 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
904 def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
905 depends on X86_LOCAL_APIC
908 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
909 bool "Reroute for broken boot IRQs"
910 depends on X86_IO_APIC
912 This option enables a workaround that fixes a source of
913 spurious interrupts. This is recommended when threaded
914 interrupt handling is used on systems where the generation of
915 superfluous "boot interrupts" cannot be disabled.
917 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
918 entry in the chipset's IO-APIC is masked (as, e.g. the RT
919 kernel does during interrupt handling). On chipsets where this
920 boot IRQ generation cannot be disabled, this workaround keeps
921 the original IRQ line masked so that only the equivalent "boot
922 IRQ" is delivered to the CPUs. The workaround also tells the
923 kernel to set up the IRQ handler on the boot IRQ line. In this
924 way only one interrupt is delivered to the kernel. Otherwise
925 the spurious second interrupt may cause the kernel to bring
926 down (vital) interrupt lines.
928 Only affects "broken" chipsets. Interrupt sharing may be
929 increased on these systems.
932 bool "Machine Check / overheating reporting"
935 Machine Check support allows the processor to notify the
936 kernel if it detects a problem (e.g. overheating, data corruption).
937 The action the kernel takes depends on the severity of the problem,
938 ranging from warning messages to halting the machine.
942 prompt "Intel MCE features"
943 depends on X86_MCE && X86_LOCAL_APIC
945 Additional support for intel specific MCE features such as
950 prompt "AMD MCE features"
951 depends on X86_MCE && X86_LOCAL_APIC
953 Additional support for AMD specific MCE features such as
954 the DRAM Error Threshold.
956 config X86_ANCIENT_MCE
957 bool "Support for old Pentium 5 / WinChip machine checks"
958 depends on X86_32 && X86_MCE
960 Include support for machine check handling on old Pentium 5 or WinChip
961 systems. These typically need to be enabled explicitly on the command
964 config X86_MCE_THRESHOLD
965 depends on X86_MCE_AMD || X86_MCE_INTEL
968 config X86_MCE_INJECT
970 tristate "Machine check injector support"
972 Provide support for injecting machine checks for testing purposes.
973 If you don't know what a machine check is and you don't do kernel
974 QA it is safe to say n.
976 config X86_THERMAL_VECTOR
978 depends on X86_MCE_INTEL
981 bool "Enable VM86 support" if EXPERT
985 This option is required by programs like DOSEMU to run
986 16-bit real mode legacy code on x86 processors. It also may
987 be needed by software like XFree86 to initialize some video
988 cards via BIOS. Disabling this option saves about 6K.
991 bool "Enable support for 16-bit segments" if EXPERT
994 This option is required by programs like Wine to run 16-bit
995 protected mode legacy code on x86 processors. Disabling
996 this option saves about 300 bytes on i386, or around 6K text
997 plus 16K runtime memory on x86-64,
1001 depends on X86_16BIT && X86_32
1005 depends on X86_16BIT && X86_64
1007 config X86_VSYSCALL_EMULATION
1008 bool "Enable vsyscall emulation" if EXPERT
1012 This enables emulation of the legacy vsyscall page. Disabling
1013 it is roughly equivalent to booting with vsyscall=none, except
1014 that it will also disable the helpful warning if a program
1015 tries to use a vsyscall. With this option set to N, offending
1016 programs will just segfault, citing addresses of the form
1019 This option is required by many programs built before 2013, and
1020 care should be used even with newer programs if set to N.
1022 Disabling this option saves about 7K of kernel size and
1023 possibly 4K of additional runtime pagetable memory.
1026 tristate "Toshiba Laptop support"
1029 This adds a driver to safely access the System Management Mode of
1030 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1031 not work on models with a Phoenix BIOS. The System Management Mode
1032 is used to set the BIOS and power saving options on Toshiba portables.
1034 For information on utilities to make use of this driver see the
1035 Toshiba Linux utilities web site at:
1036 <http://www.buzzard.org.uk/toshiba/>.
1038 Say Y if you intend to run this kernel on a Toshiba portable.
1042 tristate "Dell laptop support"
1045 This adds a driver to safely access the System Management Mode
1046 of the CPU on the Dell Inspiron 8000. The System Management Mode
1047 is used to read cpu temperature and cooling fan status and to
1048 control the fans on the I8K portables.
1050 This driver has been tested only on the Inspiron 8000 but it may
1051 also work with other Dell laptops. You can force loading on other
1052 models by passing the parameter `force=1' to the module. Use at
1055 For information on utilities to make use of this driver see the
1056 I8K Linux utilities web site at:
1057 <http://people.debian.org/~dz/i8k/>
1059 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1062 config X86_REBOOTFIXUPS
1063 bool "Enable X86 board specific fixups for reboot"
1066 This enables chipset and/or board specific fixups to be done
1067 in order to get reboot to work correctly. This is only needed on
1068 some combinations of hardware and BIOS. The symptom, for which
1069 this config is intended, is when reboot ends with a stalled/hung
1072 Currently, the only fixup is for the Geode machines using
1073 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1075 Say Y if you want to enable the fixup. Currently, it's safe to
1076 enable this option even if you don't need it.
1080 tristate "CPU microcode loading support"
1081 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1085 If you say Y here, you will be able to update the microcode on
1086 certain Intel and AMD processors. The Intel support is for the
1087 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1088 Xeon etc. The AMD support is for families 0x10 and later. You will
1089 obviously need the actual microcode binary data itself which is not
1090 shipped with the Linux kernel.
1092 This option selects the general module only, you need to select
1093 at least one vendor specific module as well.
1095 To compile this driver as a module, choose M here: the module
1096 will be called microcode.
1098 config MICROCODE_INTEL
1099 bool "Intel microcode loading support"
1100 depends on MICROCODE
1104 This options enables microcode patch loading support for Intel
1107 For the current Intel microcode data package go to
1108 <https://downloadcenter.intel.com> and search for
1109 'Linux Processor Microcode Data File'.
1111 config MICROCODE_AMD
1112 bool "AMD microcode loading support"
1113 depends on MICROCODE
1116 If you select this option, microcode patch loading support for AMD
1117 processors will be enabled.
1119 config MICROCODE_OLD_INTERFACE
1121 depends on MICROCODE
1123 config MICROCODE_INTEL_EARLY
1126 config MICROCODE_AMD_EARLY
1129 config MICROCODE_EARLY
1130 bool "Early load microcode"
1131 depends on MICROCODE=y && BLK_DEV_INITRD
1132 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1133 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1136 This option provides functionality to read additional microcode data
1137 at the beginning of initrd image. The data tells kernel to load
1138 microcode to CPU's as early as possible. No functional change if no
1139 microcode data is glued to the initrd, therefore it's safe to say Y.
1142 tristate "/dev/cpu/*/msr - Model-specific register support"
1144 This device gives privileged processes access to the x86
1145 Model-Specific Registers (MSRs). It is a character device with
1146 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1147 MSR accesses are directed to a specific CPU on multi-processor
1151 tristate "/dev/cpu/*/cpuid - CPU information support"
1153 This device gives processes access to the x86 CPUID instruction to
1154 be executed on a specific processor. It is a character device
1155 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1159 prompt "High Memory Support"
1166 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1167 However, the address space of 32-bit x86 processors is only 4
1168 Gigabytes large. That means that, if you have a large amount of
1169 physical memory, not all of it can be "permanently mapped" by the
1170 kernel. The physical memory that's not permanently mapped is called
1173 If you are compiling a kernel which will never run on a machine with
1174 more than 1 Gigabyte total physical RAM, answer "off" here (default
1175 choice and suitable for most users). This will result in a "3GB/1GB"
1176 split: 3GB are mapped so that each process sees a 3GB virtual memory
1177 space and the remaining part of the 4GB virtual memory space is used
1178 by the kernel to permanently map as much physical memory as
1181 If the machine has between 1 and 4 Gigabytes physical RAM, then
1184 If more than 4 Gigabytes is used then answer "64GB" here. This
1185 selection turns Intel PAE (Physical Address Extension) mode on.
1186 PAE implements 3-level paging on IA32 processors. PAE is fully
1187 supported by Linux, PAE mode is implemented on all recent Intel
1188 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1189 then the kernel will not boot on CPUs that don't support PAE!
1191 The actual amount of total physical memory will either be
1192 auto detected or can be forced by using a kernel command line option
1193 such as "mem=256M". (Try "man bootparam" or see the documentation of
1194 your boot loader (lilo or loadlin) about how to pass options to the
1195 kernel at boot time.)
1197 If unsure, say "off".
1202 Select this if you have a 32-bit processor and between 1 and 4
1203 gigabytes of physical RAM.
1210 Select this if you have a 32-bit processor and more than 4
1211 gigabytes of physical RAM.
1216 prompt "Memory split" if EXPERT
1220 Select the desired split between kernel and user memory.
1222 If the address range available to the kernel is less than the
1223 physical memory installed, the remaining memory will be available
1224 as "high memory". Accessing high memory is a little more costly
1225 than low memory, as it needs to be mapped into the kernel first.
1226 Note that increasing the kernel address space limits the range
1227 available to user programs, making the address space there
1228 tighter. Selecting anything other than the default 3G/1G split
1229 will also likely make your kernel incompatible with binary-only
1232 If you are not absolutely sure what you are doing, leave this
1236 bool "3G/1G user/kernel split"
1237 config VMSPLIT_3G_OPT
1239 bool "3G/1G user/kernel split (for full 1G low memory)"
1241 bool "2G/2G user/kernel split"
1242 config VMSPLIT_2G_OPT
1244 bool "2G/2G user/kernel split (for full 2G low memory)"
1246 bool "1G/3G user/kernel split"
1251 default 0xB0000000 if VMSPLIT_3G_OPT
1252 default 0x80000000 if VMSPLIT_2G
1253 default 0x78000000 if VMSPLIT_2G_OPT
1254 default 0x40000000 if VMSPLIT_1G
1260 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1263 bool "PAE (Physical Address Extension) Support"
1264 depends on X86_32 && !HIGHMEM4G
1266 PAE is required for NX support, and furthermore enables
1267 larger swapspace support for non-overcommit purposes. It
1268 has the cost of more pagetable lookup overhead, and also
1269 consumes more pagetable space per process.
1271 config ARCH_PHYS_ADDR_T_64BIT
1273 depends on X86_64 || X86_PAE
1275 config ARCH_DMA_ADDR_T_64BIT
1277 depends on X86_64 || HIGHMEM64G
1279 config DIRECT_GBPAGES
1280 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1284 Allow the kernel linear mapping to use 1GB pages on CPUs that
1285 support it. This can improve the kernel's performance a tiny bit by
1286 reducing TLB pressure. If in doubt, say "Y".
1288 # Common NUMA Features
1290 bool "Numa Memory Allocation and Scheduler Support"
1292 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1293 default y if X86_BIGSMP
1295 Enable NUMA (Non Uniform Memory Access) support.
1297 The kernel will try to allocate memory used by a CPU on the
1298 local memory controller of the CPU and add some more
1299 NUMA awareness to the kernel.
1301 For 64-bit this is recommended if the system is Intel Core i7
1302 (or later), AMD Opteron, or EM64T NUMA.
1304 For 32-bit this is only needed if you boot a 32-bit
1305 kernel on a 64-bit NUMA platform.
1307 Otherwise, you should say N.
1311 prompt "Old style AMD Opteron NUMA detection"
1312 depends on X86_64 && NUMA && PCI
1314 Enable AMD NUMA node topology detection. You should say Y here if
1315 you have a multi processor AMD system. This uses an old method to
1316 read the NUMA configuration directly from the builtin Northbridge
1317 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1318 which also takes priority if both are compiled in.
1320 config X86_64_ACPI_NUMA
1322 prompt "ACPI NUMA detection"
1323 depends on X86_64 && NUMA && ACPI && PCI
1326 Enable ACPI SRAT based node topology detection.
1328 # Some NUMA nodes have memory ranges that span
1329 # other nodes. Even though a pfn is valid and
1330 # between a node's start and end pfns, it may not
1331 # reside on that node. See memmap_init_zone()
1333 config NODES_SPAN_OTHER_NODES
1335 depends on X86_64_ACPI_NUMA
1338 bool "NUMA emulation"
1341 Enable NUMA emulation. A flat machine will be split
1342 into virtual nodes when booted with "numa=fake=N", where N is the
1343 number of nodes. This is only useful for debugging.
1346 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1348 default "10" if MAXSMP
1349 default "6" if X86_64
1351 depends on NEED_MULTIPLE_NODES
1353 Specify the maximum number of NUMA Nodes available on the target
1354 system. Increases memory reserved to accommodate various tables.
1356 config ARCH_HAVE_MEMORY_PRESENT
1358 depends on X86_32 && DISCONTIGMEM
1360 config NEED_NODE_MEMMAP_SIZE
1362 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1364 config ARCH_FLATMEM_ENABLE
1366 depends on X86_32 && !NUMA
1368 config ARCH_DISCONTIGMEM_ENABLE
1370 depends on NUMA && X86_32
1372 config ARCH_DISCONTIGMEM_DEFAULT
1374 depends on NUMA && X86_32
1376 config ARCH_SPARSEMEM_ENABLE
1378 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1379 select SPARSEMEM_STATIC if X86_32
1380 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1382 config ARCH_SPARSEMEM_DEFAULT
1386 config ARCH_SELECT_MEMORY_MODEL
1388 depends on ARCH_SPARSEMEM_ENABLE
1390 config ARCH_MEMORY_PROBE
1391 bool "Enable sysfs memory/probe interface"
1392 depends on X86_64 && MEMORY_HOTPLUG
1394 This option enables a sysfs memory/probe interface for testing.
1395 See Documentation/memory-hotplug.txt for more information.
1396 If you are unsure how to answer this question, answer N.
1398 config ARCH_PROC_KCORE_TEXT
1400 depends on X86_64 && PROC_KCORE
1402 config ILLEGAL_POINTER_VALUE
1405 default 0xdead000000000000 if X86_64
1410 bool "Allocate 3rd-level pagetables from highmem"
1413 The VM uses one page table entry for each page of physical memory.
1414 For systems with a lot of RAM, this can be wasteful of precious
1415 low memory. Setting this option will put user-space page table
1416 entries in high memory.
1418 config X86_CHECK_BIOS_CORRUPTION
1419 bool "Check for low memory corruption"
1421 Periodically check for memory corruption in low memory, which
1422 is suspected to be caused by BIOS. Even when enabled in the
1423 configuration, it is disabled at runtime. Enable it by
1424 setting "memory_corruption_check=1" on the kernel command
1425 line. By default it scans the low 64k of memory every 60
1426 seconds; see the memory_corruption_check_size and
1427 memory_corruption_check_period parameters in
1428 Documentation/kernel-parameters.txt to adjust this.
1430 When enabled with the default parameters, this option has
1431 almost no overhead, as it reserves a relatively small amount
1432 of memory and scans it infrequently. It both detects corruption
1433 and prevents it from affecting the running system.
1435 It is, however, intended as a diagnostic tool; if repeatable
1436 BIOS-originated corruption always affects the same memory,
1437 you can use memmap= to prevent the kernel from using that
1440 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1441 bool "Set the default setting of memory_corruption_check"
1442 depends on X86_CHECK_BIOS_CORRUPTION
1445 Set whether the default state of memory_corruption_check is
1448 config X86_RESERVE_LOW
1449 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1453 Specify the amount of low memory to reserve for the BIOS.
1455 The first page contains BIOS data structures that the kernel
1456 must not use, so that page must always be reserved.
1458 By default we reserve the first 64K of physical RAM, as a
1459 number of BIOSes are known to corrupt that memory range
1460 during events such as suspend/resume or monitor cable
1461 insertion, so it must not be used by the kernel.
1463 You can set this to 4 if you are absolutely sure that you
1464 trust the BIOS to get all its memory reservations and usages
1465 right. If you know your BIOS have problems beyond the
1466 default 64K area, you can set this to 640 to avoid using the
1467 entire low memory range.
1469 If you have doubts about the BIOS (e.g. suspend/resume does
1470 not work or there's kernel crashes after certain hardware
1471 hotplug events) then you might want to enable
1472 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1473 typical corruption patterns.
1475 Leave this to the default value of 64 if you are unsure.
1477 config MATH_EMULATION
1479 prompt "Math emulation" if X86_32
1481 Linux can emulate a math coprocessor (used for floating point
1482 operations) if you don't have one. 486DX and Pentium processors have
1483 a math coprocessor built in, 486SX and 386 do not, unless you added
1484 a 487DX or 387, respectively. (The messages during boot time can
1485 give you some hints here ["man dmesg"].) Everyone needs either a
1486 coprocessor or this emulation.
1488 If you don't have a math coprocessor, you need to say Y here; if you
1489 say Y here even though you have a coprocessor, the coprocessor will
1490 be used nevertheless. (This behavior can be changed with the kernel
1491 command line option "no387", which comes handy if your coprocessor
1492 is broken. Try "man bootparam" or see the documentation of your boot
1493 loader (lilo or loadlin) about how to pass options to the kernel at
1494 boot time.) This means that it is a good idea to say Y here if you
1495 intend to use this kernel on different machines.
1497 More information about the internals of the Linux math coprocessor
1498 emulation can be found in <file:arch/x86/math-emu/README>.
1500 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1501 kernel, it won't hurt.
1505 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1507 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1508 the Memory Type Range Registers (MTRRs) may be used to control
1509 processor access to memory ranges. This is most useful if you have
1510 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1511 allows bus write transfers to be combined into a larger transfer
1512 before bursting over the PCI/AGP bus. This can increase performance
1513 of image write operations 2.5 times or more. Saying Y here creates a
1514 /proc/mtrr file which may be used to manipulate your processor's
1515 MTRRs. Typically the X server should use this.
1517 This code has a reasonably generic interface so that similar
1518 control registers on other processors can be easily supported
1521 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1522 Registers (ARRs) which provide a similar functionality to MTRRs. For
1523 these, the ARRs are used to emulate the MTRRs.
1524 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1525 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1526 write-combining. All of these processors are supported by this code
1527 and it makes sense to say Y here if you have one of them.
1529 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1530 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1531 can lead to all sorts of problems, so it's good to say Y here.
1533 You can safely say Y even if your machine doesn't have MTRRs, you'll
1534 just add about 9 KB to your kernel.
1536 See <file:Documentation/x86/mtrr.txt> for more information.
1538 config MTRR_SANITIZER
1540 prompt "MTRR cleanup support"
1543 Convert MTRR layout from continuous to discrete, so X drivers can
1544 add writeback entries.
1546 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1547 The largest mtrr entry size for a continuous block can be set with
1552 config MTRR_SANITIZER_ENABLE_DEFAULT
1553 int "MTRR cleanup enable value (0-1)"
1556 depends on MTRR_SANITIZER
1558 Enable mtrr cleanup default value
1560 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1561 int "MTRR cleanup spare reg num (0-7)"
1564 depends on MTRR_SANITIZER
1566 mtrr cleanup spare entries default, it can be changed via
1567 mtrr_spare_reg_nr=N on the kernel command line.
1571 prompt "x86 PAT support" if EXPERT
1574 Use PAT attributes to setup page level cache control.
1576 PATs are the modern equivalents of MTRRs and are much more
1577 flexible than MTRRs.
1579 Say N here if you see bootup problems (boot crash, boot hang,
1580 spontaneous reboots) or a non-working video driver.
1584 config ARCH_USES_PG_UNCACHED
1590 prompt "x86 architectural random number generator" if EXPERT
1592 Enable the x86 architectural RDRAND instruction
1593 (Intel Bull Mountain technology) to generate random numbers.
1594 If supported, this is a high bandwidth, cryptographically
1595 secure hardware random number generator.
1599 prompt "Supervisor Mode Access Prevention" if EXPERT
1601 Supervisor Mode Access Prevention (SMAP) is a security
1602 feature in newer Intel processors. There is a small
1603 performance cost if this enabled and turned on; there is
1604 also a small increase in the kernel size if this is enabled.
1608 config X86_INTEL_MPX
1609 prompt "Intel MPX (Memory Protection Extensions)"
1611 depends on CPU_SUP_INTEL
1613 MPX provides hardware features that can be used in
1614 conjunction with compiler-instrumented code to check
1615 memory references. It is designed to detect buffer
1616 overflow or underflow bugs.
1618 This option enables running applications which are
1619 instrumented or otherwise use MPX. It does not use MPX
1620 itself inside the kernel or to protect the kernel
1621 against bad memory references.
1623 Enabling this option will make the kernel larger:
1624 ~8k of kernel text and 36 bytes of data on a 64-bit
1625 defconfig. It adds a long to the 'mm_struct' which
1626 will increase the kernel memory overhead of each
1627 process and adds some branches to paths used during
1628 exec() and munmap().
1630 For details, see Documentation/x86/intel_mpx.txt
1635 bool "EFI runtime service support"
1638 select EFI_RUNTIME_WRAPPERS
1640 This enables the kernel to use EFI runtime services that are
1641 available (such as the EFI variable services).
1643 This option is only useful on systems that have EFI firmware.
1644 In addition, you should use the latest ELILO loader available
1645 at <http://elilo.sourceforge.net> in order to take advantage
1646 of EFI runtime services. However, even with this option, the
1647 resultant kernel should continue to boot on existing non-EFI
1651 bool "EFI stub support"
1652 depends on EFI && !X86_USE_3DNOW
1655 This kernel feature allows a bzImage to be loaded directly
1656 by EFI firmware without the use of a bootloader.
1658 See Documentation/efi-stub.txt for more information.
1661 bool "EFI mixed-mode support"
1662 depends on EFI_STUB && X86_64
1664 Enabling this feature allows a 64-bit kernel to be booted
1665 on a 32-bit firmware, provided that your CPU supports 64-bit
1668 Note that it is not possible to boot a mixed-mode enabled
1669 kernel via the EFI boot stub - a bootloader that supports
1670 the EFI handover protocol must be used.
1676 prompt "Enable seccomp to safely compute untrusted bytecode"
1678 This kernel feature is useful for number crunching applications
1679 that may need to compute untrusted bytecode during their
1680 execution. By using pipes or other transports made available to
1681 the process as file descriptors supporting the read/write
1682 syscalls, it's possible to isolate those applications in
1683 their own address space using seccomp. Once seccomp is
1684 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1685 and the task is only allowed to execute a few safe syscalls
1686 defined by each seccomp mode.
1688 If unsure, say Y. Only embedded should say N here.
1690 source kernel/Kconfig.hz
1693 bool "kexec system call"
1695 kexec is a system call that implements the ability to shutdown your
1696 current kernel, and to start another kernel. It is like a reboot
1697 but it is independent of the system firmware. And like a reboot
1698 you can start any kernel with it, not just Linux.
1700 The name comes from the similarity to the exec system call.
1702 It is an ongoing process to be certain the hardware in a machine
1703 is properly shutdown, so do not be surprised if this code does not
1704 initially work for you. As of this writing the exact hardware
1705 interface is strongly in flux, so no good recommendation can be
1709 bool "kexec file based system call"
1714 depends on CRYPTO_SHA256=y
1716 This is new version of kexec system call. This system call is
1717 file based and takes file descriptors as system call argument
1718 for kernel and initramfs as opposed to list of segments as
1719 accepted by previous system call.
1721 config KEXEC_VERIFY_SIG
1722 bool "Verify kernel signature during kexec_file_load() syscall"
1723 depends on KEXEC_FILE
1725 This option makes kernel signature verification mandatory for
1726 kexec_file_load() syscall. If kernel is signature can not be
1727 verified, kexec_file_load() will fail.
1729 This option enforces signature verification at generic level.
1730 One needs to enable signature verification for type of kernel
1731 image being loaded to make sure it works. For example, enable
1732 bzImage signature verification option to be able to load and
1733 verify signatures of bzImage. Otherwise kernel loading will fail.
1735 config KEXEC_BZIMAGE_VERIFY_SIG
1736 bool "Enable bzImage signature verification support"
1737 depends on KEXEC_VERIFY_SIG
1738 depends on SIGNED_PE_FILE_VERIFICATION
1739 select SYSTEM_TRUSTED_KEYRING
1741 Enable bzImage signature verification support.
1744 bool "kernel crash dumps"
1745 depends on X86_64 || (X86_32 && HIGHMEM)
1747 Generate crash dump after being started by kexec.
1748 This should be normally only set in special crash dump kernels
1749 which are loaded in the main kernel with kexec-tools into
1750 a specially reserved region and then later executed after
1751 a crash by kdump/kexec. The crash dump kernel must be compiled
1752 to a memory address not used by the main kernel or BIOS using
1753 PHYSICAL_START, or it must be built as a relocatable image
1754 (CONFIG_RELOCATABLE=y).
1755 For more details see Documentation/kdump/kdump.txt
1759 depends on KEXEC && HIBERNATION
1761 Jump between original kernel and kexeced kernel and invoke
1762 code in physical address mode via KEXEC
1764 config PHYSICAL_START
1765 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1768 This gives the physical address where the kernel is loaded.
1770 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1771 bzImage will decompress itself to above physical address and
1772 run from there. Otherwise, bzImage will run from the address where
1773 it has been loaded by the boot loader and will ignore above physical
1776 In normal kdump cases one does not have to set/change this option
1777 as now bzImage can be compiled as a completely relocatable image
1778 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1779 address. This option is mainly useful for the folks who don't want
1780 to use a bzImage for capturing the crash dump and want to use a
1781 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1782 to be specifically compiled to run from a specific memory area
1783 (normally a reserved region) and this option comes handy.
1785 So if you are using bzImage for capturing the crash dump,
1786 leave the value here unchanged to 0x1000000 and set
1787 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1788 for capturing the crash dump change this value to start of
1789 the reserved region. In other words, it can be set based on
1790 the "X" value as specified in the "crashkernel=YM@XM"
1791 command line boot parameter passed to the panic-ed
1792 kernel. Please take a look at Documentation/kdump/kdump.txt
1793 for more details about crash dumps.
1795 Usage of bzImage for capturing the crash dump is recommended as
1796 one does not have to build two kernels. Same kernel can be used
1797 as production kernel and capture kernel. Above option should have
1798 gone away after relocatable bzImage support is introduced. But it
1799 is present because there are users out there who continue to use
1800 vmlinux for dump capture. This option should go away down the
1803 Don't change this unless you know what you are doing.
1806 bool "Build a relocatable kernel"
1809 This builds a kernel image that retains relocation information
1810 so it can be loaded someplace besides the default 1MB.
1811 The relocations tend to make the kernel binary about 10% larger,
1812 but are discarded at runtime.
1814 One use is for the kexec on panic case where the recovery kernel
1815 must live at a different physical address than the primary
1818 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1819 it has been loaded at and the compile time physical address
1820 (CONFIG_PHYSICAL_START) is used as the minimum location.
1822 config RANDOMIZE_BASE
1823 bool "Randomize the address of the kernel image"
1824 depends on RELOCATABLE
1827 Randomizes the physical and virtual address at which the
1828 kernel image is decompressed, as a security feature that
1829 deters exploit attempts relying on knowledge of the location
1830 of kernel internals.
1832 Entropy is generated using the RDRAND instruction if it is
1833 supported. If RDTSC is supported, it is used as well. If
1834 neither RDRAND nor RDTSC are supported, then randomness is
1835 read from the i8254 timer.
1837 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1838 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1839 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1840 minimum of 2MiB, only 10 bits of entropy is theoretically
1841 possible. At best, due to page table layouts, 64-bit can use
1842 9 bits of entropy and 32-bit uses 8 bits.
1846 config RANDOMIZE_BASE_MAX_OFFSET
1847 hex "Maximum kASLR offset allowed" if EXPERT
1848 depends on RANDOMIZE_BASE
1849 range 0x0 0x20000000 if X86_32
1850 default "0x20000000" if X86_32
1851 range 0x0 0x40000000 if X86_64
1852 default "0x40000000" if X86_64
1854 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1855 memory is used to determine the maximal offset in bytes that will
1856 be applied to the kernel when kernel Address Space Layout
1857 Randomization (kASLR) is active. This must be a multiple of
1860 On 32-bit this is limited to 512MiB by page table layouts. The
1863 On 64-bit this is limited by how the kernel fixmap page table is
1864 positioned, so this cannot be larger than 1GiB currently. Without
1865 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1866 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1867 modules area will shrink to compensate, up to the current maximum
1868 1GiB to 1GiB split. The default is 1GiB.
1870 If unsure, leave at the default value.
1872 # Relocation on x86 needs some additional build support
1873 config X86_NEED_RELOCS
1875 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1877 config PHYSICAL_ALIGN
1878 hex "Alignment value to which kernel should be aligned"
1880 range 0x2000 0x1000000 if X86_32
1881 range 0x200000 0x1000000 if X86_64
1883 This value puts the alignment restrictions on physical address
1884 where kernel is loaded and run from. Kernel is compiled for an
1885 address which meets above alignment restriction.
1887 If bootloader loads the kernel at a non-aligned address and
1888 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1889 address aligned to above value and run from there.
1891 If bootloader loads the kernel at a non-aligned address and
1892 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1893 load address and decompress itself to the address it has been
1894 compiled for and run from there. The address for which kernel is
1895 compiled already meets above alignment restrictions. Hence the
1896 end result is that kernel runs from a physical address meeting
1897 above alignment restrictions.
1899 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1900 this value must be a multiple of 0x200000.
1902 Don't change this unless you know what you are doing.
1905 bool "Support for hot-pluggable CPUs"
1908 Say Y here to allow turning CPUs off and on. CPUs can be
1909 controlled through /sys/devices/system/cpu.
1910 ( Note: power management support will enable this option
1911 automatically on SMP systems. )
1912 Say N if you want to disable CPU hotplug.
1914 config BOOTPARAM_HOTPLUG_CPU0
1915 bool "Set default setting of cpu0_hotpluggable"
1917 depends on HOTPLUG_CPU
1919 Set whether default state of cpu0_hotpluggable is on or off.
1921 Say Y here to enable CPU0 hotplug by default. If this switch
1922 is turned on, there is no need to give cpu0_hotplug kernel
1923 parameter and the CPU0 hotplug feature is enabled by default.
1925 Please note: there are two known CPU0 dependencies if you want
1926 to enable the CPU0 hotplug feature either by this switch or by
1927 cpu0_hotplug kernel parameter.
1929 First, resume from hibernate or suspend always starts from CPU0.
1930 So hibernate and suspend are prevented if CPU0 is offline.
1932 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1933 offline if any interrupt can not migrate out of CPU0. There may
1934 be other CPU0 dependencies.
1936 Please make sure the dependencies are under your control before
1937 you enable this feature.
1939 Say N if you don't want to enable CPU0 hotplug feature by default.
1940 You still can enable the CPU0 hotplug feature at boot by kernel
1941 parameter cpu0_hotplug.
1943 config DEBUG_HOTPLUG_CPU0
1945 prompt "Debug CPU0 hotplug"
1946 depends on HOTPLUG_CPU
1948 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1949 soon as possible and boots up userspace with CPU0 offlined. User
1950 can online CPU0 back after boot time.
1952 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1953 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1954 compilation or giving cpu0_hotplug kernel parameter at boot.
1960 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1961 depends on X86_32 || IA32_EMULATION
1963 Certain buggy versions of glibc will crash if they are
1964 presented with a 32-bit vDSO that is not mapped at the address
1965 indicated in its segment table.
1967 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1968 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1969 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1970 the only released version with the bug, but OpenSUSE 9
1971 contains a buggy "glibc 2.3.2".
1973 The symptom of the bug is that everything crashes on startup, saying:
1974 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1976 Saying Y here changes the default value of the vdso32 boot
1977 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1978 This works around the glibc bug but hurts performance.
1980 If unsure, say N: if you are compiling your own kernel, you
1981 are unlikely to be using a buggy version of glibc.
1984 bool "Built-in kernel command line"
1986 Allow for specifying boot arguments to the kernel at
1987 build time. On some systems (e.g. embedded ones), it is
1988 necessary or convenient to provide some or all of the
1989 kernel boot arguments with the kernel itself (that is,
1990 to not rely on the boot loader to provide them.)
1992 To compile command line arguments into the kernel,
1993 set this option to 'Y', then fill in the
1994 the boot arguments in CONFIG_CMDLINE.
1996 Systems with fully functional boot loaders (i.e. non-embedded)
1997 should leave this option set to 'N'.
2000 string "Built-in kernel command string"
2001 depends on CMDLINE_BOOL
2004 Enter arguments here that should be compiled into the kernel
2005 image and used at boot time. If the boot loader provides a
2006 command line at boot time, it is appended to this string to
2007 form the full kernel command line, when the system boots.
2009 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2010 change this behavior.
2012 In most cases, the command line (whether built-in or provided
2013 by the boot loader) should specify the device for the root
2016 config CMDLINE_OVERRIDE
2017 bool "Built-in command line overrides boot loader arguments"
2018 depends on CMDLINE_BOOL
2020 Set this option to 'Y' to have the kernel ignore the boot loader
2021 command line, and use ONLY the built-in command line.
2023 This is used to work around broken boot loaders. This should
2024 be set to 'N' under normal conditions.
2028 config ARCH_ENABLE_MEMORY_HOTPLUG
2030 depends on X86_64 || (X86_32 && HIGHMEM)
2032 config ARCH_ENABLE_MEMORY_HOTREMOVE
2034 depends on MEMORY_HOTPLUG
2036 config USE_PERCPU_NUMA_NODE_ID
2040 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2042 depends on X86_64 || X86_PAE
2044 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2046 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2048 menu "Power management and ACPI options"
2050 config ARCH_HIBERNATION_HEADER
2052 depends on X86_64 && HIBERNATION
2054 source "kernel/power/Kconfig"
2056 source "drivers/acpi/Kconfig"
2058 source "drivers/sfi/Kconfig"
2065 tristate "APM (Advanced Power Management) BIOS support"
2066 depends on X86_32 && PM_SLEEP
2068 APM is a BIOS specification for saving power using several different
2069 techniques. This is mostly useful for battery powered laptops with
2070 APM compliant BIOSes. If you say Y here, the system time will be
2071 reset after a RESUME operation, the /proc/apm device will provide
2072 battery status information, and user-space programs will receive
2073 notification of APM "events" (e.g. battery status change).
2075 If you select "Y" here, you can disable actual use of the APM
2076 BIOS by passing the "apm=off" option to the kernel at boot time.
2078 Note that the APM support is almost completely disabled for
2079 machines with more than one CPU.
2081 In order to use APM, you will need supporting software. For location
2082 and more information, read <file:Documentation/power/apm-acpi.txt>
2083 and the Battery Powered Linux mini-HOWTO, available from
2084 <http://www.tldp.org/docs.html#howto>.
2086 This driver does not spin down disk drives (see the hdparm(8)
2087 manpage ("man 8 hdparm") for that), and it doesn't turn off
2088 VESA-compliant "green" monitors.
2090 This driver does not support the TI 4000M TravelMate and the ACER
2091 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2092 desktop machines also don't have compliant BIOSes, and this driver
2093 may cause those machines to panic during the boot phase.
2095 Generally, if you don't have a battery in your machine, there isn't
2096 much point in using this driver and you should say N. If you get
2097 random kernel OOPSes or reboots that don't seem to be related to
2098 anything, try disabling/enabling this option (or disabling/enabling
2101 Some other things you should try when experiencing seemingly random,
2104 1) make sure that you have enough swap space and that it is
2106 2) pass the "no-hlt" option to the kernel
2107 3) switch on floating point emulation in the kernel and pass
2108 the "no387" option to the kernel
2109 4) pass the "floppy=nodma" option to the kernel
2110 5) pass the "mem=4M" option to the kernel (thereby disabling
2111 all but the first 4 MB of RAM)
2112 6) make sure that the CPU is not over clocked.
2113 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2114 8) disable the cache from your BIOS settings
2115 9) install a fan for the video card or exchange video RAM
2116 10) install a better fan for the CPU
2117 11) exchange RAM chips
2118 12) exchange the motherboard.
2120 To compile this driver as a module, choose M here: the
2121 module will be called apm.
2125 config APM_IGNORE_USER_SUSPEND
2126 bool "Ignore USER SUSPEND"
2128 This option will ignore USER SUSPEND requests. On machines with a
2129 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2130 series notebooks, it is necessary to say Y because of a BIOS bug.
2132 config APM_DO_ENABLE
2133 bool "Enable PM at boot time"
2135 Enable APM features at boot time. From page 36 of the APM BIOS
2136 specification: "When disabled, the APM BIOS does not automatically
2137 power manage devices, enter the Standby State, enter the Suspend
2138 State, or take power saving steps in response to CPU Idle calls."
2139 This driver will make CPU Idle calls when Linux is idle (unless this
2140 feature is turned off -- see "Do CPU IDLE calls", below). This
2141 should always save battery power, but more complicated APM features
2142 will be dependent on your BIOS implementation. You may need to turn
2143 this option off if your computer hangs at boot time when using APM
2144 support, or if it beeps continuously instead of suspending. Turn
2145 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2146 T400CDT. This is off by default since most machines do fine without
2151 bool "Make CPU Idle calls when idle"
2153 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2154 On some machines, this can activate improved power savings, such as
2155 a slowed CPU clock rate, when the machine is idle. These idle calls
2156 are made after the idle loop has run for some length of time (e.g.,
2157 333 mS). On some machines, this will cause a hang at boot time or
2158 whenever the CPU becomes idle. (On machines with more than one CPU,
2159 this option does nothing.)
2161 config APM_DISPLAY_BLANK
2162 bool "Enable console blanking using APM"
2164 Enable console blanking using the APM. Some laptops can use this to
2165 turn off the LCD backlight when the screen blanker of the Linux
2166 virtual console blanks the screen. Note that this is only used by
2167 the virtual console screen blanker, and won't turn off the backlight
2168 when using the X Window system. This also doesn't have anything to
2169 do with your VESA-compliant power-saving monitor. Further, this
2170 option doesn't work for all laptops -- it might not turn off your
2171 backlight at all, or it might print a lot of errors to the console,
2172 especially if you are using gpm.
2174 config APM_ALLOW_INTS
2175 bool "Allow interrupts during APM BIOS calls"
2177 Normally we disable external interrupts while we are making calls to
2178 the APM BIOS as a measure to lessen the effects of a badly behaving
2179 BIOS implementation. The BIOS should reenable interrupts if it
2180 needs to. Unfortunately, some BIOSes do not -- especially those in
2181 many of the newer IBM Thinkpads. If you experience hangs when you
2182 suspend, try setting this to Y. Otherwise, say N.
2186 source "drivers/cpufreq/Kconfig"
2188 source "drivers/cpuidle/Kconfig"
2190 source "drivers/idle/Kconfig"
2195 menu "Bus options (PCI etc.)"
2201 Find out whether you have a PCI motherboard. PCI is the name of a
2202 bus system, i.e. the way the CPU talks to the other stuff inside
2203 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2204 VESA. If you have PCI, say Y, otherwise N.
2207 prompt "PCI access mode"
2208 depends on X86_32 && PCI
2211 On PCI systems, the BIOS can be used to detect the PCI devices and
2212 determine their configuration. However, some old PCI motherboards
2213 have BIOS bugs and may crash if this is done. Also, some embedded
2214 PCI-based systems don't have any BIOS at all. Linux can also try to
2215 detect the PCI hardware directly without using the BIOS.
2217 With this option, you can specify how Linux should detect the
2218 PCI devices. If you choose "BIOS", the BIOS will be used,
2219 if you choose "Direct", the BIOS won't be used, and if you
2220 choose "MMConfig", then PCI Express MMCONFIG will be used.
2221 If you choose "Any", the kernel will try MMCONFIG, then the
2222 direct access method and falls back to the BIOS if that doesn't
2223 work. If unsure, go with the default, which is "Any".
2228 config PCI_GOMMCONFIG
2245 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2247 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2250 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2254 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2258 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2262 depends on PCI && XEN
2270 bool "Support mmconfig PCI config space access"
2271 depends on X86_64 && PCI && ACPI
2273 config PCI_CNB20LE_QUIRK
2274 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2277 Read the PCI windows out of the CNB20LE host bridge. This allows
2278 PCI hotplug to work on systems with the CNB20LE chipset which do
2281 There's no public spec for this chipset, and this functionality
2282 is known to be incomplete.
2284 You should say N unless you know you need this.
2286 source "drivers/pci/pcie/Kconfig"
2288 source "drivers/pci/Kconfig"
2290 # x86_64 have no ISA slots, but can have ISA-style DMA.
2292 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2295 Enables ISA-style DMA support for devices requiring such controllers.
2303 Find out whether you have ISA slots on your motherboard. ISA is the
2304 name of a bus system, i.e. the way the CPU talks to the other stuff
2305 inside your box. Other bus systems are PCI, EISA, MicroChannel
2306 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2307 newer boards don't support it. If you have ISA, say Y, otherwise N.
2313 The Extended Industry Standard Architecture (EISA) bus was
2314 developed as an open alternative to the IBM MicroChannel bus.
2316 The EISA bus provided some of the features of the IBM MicroChannel
2317 bus while maintaining backward compatibility with cards made for
2318 the older ISA bus. The EISA bus saw limited use between 1988 and
2319 1995 when it was made obsolete by the PCI bus.
2321 Say Y here if you are building a kernel for an EISA-based machine.
2325 source "drivers/eisa/Kconfig"
2328 tristate "NatSemi SCx200 support"
2330 This provides basic support for National Semiconductor's
2331 (now AMD's) Geode processors. The driver probes for the
2332 PCI-IDs of several on-chip devices, so its a good dependency
2333 for other scx200_* drivers.
2335 If compiled as a module, the driver is named scx200.
2337 config SCx200HR_TIMER
2338 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2342 This driver provides a clocksource built upon the on-chip
2343 27MHz high-resolution timer. Its also a workaround for
2344 NSC Geode SC-1100's buggy TSC, which loses time when the
2345 processor goes idle (as is done by the scheduler). The
2346 other workaround is idle=poll boot option.
2349 bool "One Laptop Per Child support"
2356 Add support for detecting the unique features of the OLPC
2360 bool "OLPC XO-1 Power Management"
2361 depends on OLPC && MFD_CS5535 && PM_SLEEP
2364 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2367 bool "OLPC XO-1 Real Time Clock"
2368 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2370 Add support for the XO-1 real time clock, which can be used as a
2371 programmable wakeup source.
2374 bool "OLPC XO-1 SCI extras"
2375 depends on OLPC && OLPC_XO1_PM
2381 Add support for SCI-based features of the OLPC XO-1 laptop:
2382 - EC-driven system wakeups
2386 - AC adapter status updates
2387 - Battery status updates
2389 config OLPC_XO15_SCI
2390 bool "OLPC XO-1.5 SCI extras"
2391 depends on OLPC && ACPI
2394 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2395 - EC-driven system wakeups
2396 - AC adapter status updates
2397 - Battery status updates
2400 bool "PCEngines ALIX System Support (LED setup)"
2403 This option enables system support for the PCEngines ALIX.
2404 At present this just sets up LEDs for GPIO control on
2405 ALIX2/3/6 boards. However, other system specific setup should
2408 Note: You must still enable the drivers for GPIO and LED support
2409 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2411 Note: You have to set alix.force=1 for boards with Award BIOS.
2414 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2417 This option enables system support for the Soekris Engineering net5501.
2420 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2424 This option enables system support for the Traverse Technologies GEOS.
2427 bool "Technologic Systems TS-5500 platform support"
2429 select CHECK_SIGNATURE
2433 This option enables system support for the Technologic Systems TS-5500.
2439 depends on CPU_SUP_AMD && PCI
2441 source "drivers/pcmcia/Kconfig"
2443 source "drivers/pci/hotplug/Kconfig"
2446 tristate "RapidIO support"
2450 If enabled this option will include drivers and the core
2451 infrastructure code to support RapidIO interconnect devices.
2453 source "drivers/rapidio/Kconfig"
2456 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2458 Firmwares often provide initial graphics framebuffers so the BIOS,
2459 bootloader or kernel can show basic video-output during boot for
2460 user-guidance and debugging. Historically, x86 used the VESA BIOS
2461 Extensions and EFI-framebuffers for this, which are mostly limited
2463 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2464 framebuffers so the new generic system-framebuffer drivers can be
2465 used on x86. If the framebuffer is not compatible with the generic
2466 modes, it is adverticed as fallback platform framebuffer so legacy
2467 drivers like efifb, vesafb and uvesafb can pick it up.
2468 If this option is not selected, all system framebuffers are always
2469 marked as fallback platform framebuffers as usual.
2471 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2472 not be able to pick up generic system framebuffers if this option
2473 is selected. You are highly encouraged to enable simplefb as
2474 replacement if you select this option. simplefb can correctly deal
2475 with generic system framebuffers. But you should still keep vesafb
2476 and others enabled as fallback if a system framebuffer is
2477 incompatible with simplefb.
2484 menu "Executable file formats / Emulations"
2486 source "fs/Kconfig.binfmt"
2488 config IA32_EMULATION
2489 bool "IA32 Emulation"
2492 select COMPAT_BINFMT_ELF
2495 Include code to run legacy 32-bit programs under a
2496 64-bit kernel. You should likely turn this on, unless you're
2497 100% sure that you don't have any 32-bit programs left.
2500 tristate "IA32 a.out support"
2501 depends on IA32_EMULATION
2503 Support old a.out binaries in the 32bit emulation.
2506 bool "x32 ABI for 64-bit mode"
2507 depends on X86_64 && IA32_EMULATION
2509 Include code to run binaries for the x32 native 32-bit ABI
2510 for 64-bit processors. An x32 process gets access to the
2511 full 64-bit register file and wide data path while leaving
2512 pointers at 32 bits for smaller memory footprint.
2514 You will need a recent binutils (2.22 or later) with
2515 elf32_x86_64 support enabled to compile a kernel with this
2520 depends on IA32_EMULATION || X86_X32
2521 select ARCH_WANT_OLD_COMPAT_IPC
2524 config COMPAT_FOR_U64_ALIGNMENT
2527 config SYSVIPC_COMPAT
2539 config HAVE_ATOMIC_IOMAP
2543 config X86_DEV_DMA_OPS
2545 depends on X86_64 || STA2X11
2547 config X86_DMA_REMAP
2555 source "net/Kconfig"
2557 source "drivers/Kconfig"
2559 source "drivers/firmware/Kconfig"
2563 source "arch/x86/Kconfig.debug"
2565 source "security/Kconfig"
2567 source "crypto/Kconfig"
2569 source "arch/x86/kvm/Kconfig"
2571 source "lib/Kconfig"
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