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
143 config INSTRUCTION_DECODER
145 depends on KPROBES || PERF_EVENTS || UPROBES
147 config PERF_EVENTS_INTEL_UNCORE
149 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
153 default "elf32-i386" if X86_32
154 default "elf64-x86-64" if X86_64
156 config ARCH_DEFCONFIG
158 default "arch/x86/configs/i386_defconfig" if X86_32
159 default "arch/x86/configs/x86_64_defconfig" if X86_64
161 config LOCKDEP_SUPPORT
164 config STACKTRACE_SUPPORT
167 config HAVE_LATENCYTOP_SUPPORT
176 config NEED_DMA_MAP_STATE
178 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
180 config NEED_SG_DMA_LENGTH
183 config GENERIC_ISA_DMA
185 depends on ISA_DMA_API
190 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
192 config GENERIC_BUG_RELATIVE_POINTERS
195 config GENERIC_HWEIGHT
198 config ARCH_MAY_HAVE_PC_FDC
200 depends on ISA_DMA_API
202 config RWSEM_XCHGADD_ALGORITHM
205 config GENERIC_CALIBRATE_DELAY
208 config ARCH_HAS_CPU_RELAX
211 config ARCH_HAS_CACHE_LINE_SIZE
214 config HAVE_SETUP_PER_CPU_AREA
217 config NEED_PER_CPU_EMBED_FIRST_CHUNK
220 config NEED_PER_CPU_PAGE_FIRST_CHUNK
223 config ARCH_HIBERNATION_POSSIBLE
226 config ARCH_SUSPEND_POSSIBLE
229 config ARCH_WANT_HUGE_PMD_SHARE
232 config ARCH_WANT_GENERAL_HUGETLB
243 config ARCH_SUPPORTS_OPTIMIZED_INLINING
246 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
249 config HAVE_INTEL_TXT
251 depends on INTEL_IOMMU && ACPI
255 depends on X86_32 && SMP
259 depends on X86_64 && SMP
265 config X86_32_LAZY_GS
267 depends on X86_32 && !CC_STACKPROTECTOR
269 config ARCH_HWEIGHT_CFLAGS
271 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
272 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
274 config ARCH_SUPPORTS_UPROBES
277 config FIX_EARLYCON_MEM
280 source "init/Kconfig"
281 source "kernel/Kconfig.freezer"
283 menu "Processor type and features"
286 bool "DMA memory allocation support" if EXPERT
289 DMA memory allocation support allows devices with less than 32-bit
290 addressing to allocate within the first 16MB of address space.
291 Disable if no such devices will be used.
296 bool "Symmetric multi-processing support"
298 This enables support for systems with more than one CPU. If you have
299 a system with only one CPU, say N. If you have a system with more
302 If you say N here, the kernel will run on uni- and multiprocessor
303 machines, but will use only one CPU of a multiprocessor machine. If
304 you say Y here, the kernel will run on many, but not all,
305 uniprocessor machines. On a uniprocessor machine, the kernel
306 will run faster if you say N here.
308 Note that if you say Y here and choose architecture "586" or
309 "Pentium" under "Processor family", the kernel will not work on 486
310 architectures. Similarly, multiprocessor kernels for the "PPro"
311 architecture may not work on all Pentium based boards.
313 People using multiprocessor machines who say Y here should also say
314 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
315 Management" code will be disabled if you say Y here.
317 See also <file:Documentation/x86/i386/IO-APIC.txt>,
318 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
319 <http://www.tldp.org/docs.html#howto>.
321 If you don't know what to do here, say N.
323 config X86_FEATURE_NAMES
324 bool "Processor feature human-readable names" if EMBEDDED
327 This option compiles in a table of x86 feature bits and corresponding
328 names. This is required to support /proc/cpuinfo and a few kernel
329 messages. You can disable this to save space, at the expense of
330 making those few kernel messages show numeric feature bits instead.
335 bool "Support x2apic"
336 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
338 This enables x2apic support on CPUs that have this feature.
340 This allows 32-bit apic IDs (so it can support very large systems),
341 and accesses the local apic via MSRs not via mmio.
343 If you don't know what to do here, say N.
346 bool "Enable MPS table" if ACPI || SFI
348 depends on X86_LOCAL_APIC
350 For old smp systems that do not have proper acpi support. Newer systems
351 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
354 bool "Support for big SMP systems with more than 8 CPUs"
355 depends on X86_32 && SMP
357 This option is needed for the systems that have more than 8 CPUs
361 depends on X86_GOLDFISH
364 config X86_EXTENDED_PLATFORM
365 bool "Support for extended (non-PC) x86 platforms"
368 If you disable this option then the kernel will only support
369 standard PC platforms. (which covers the vast majority of
372 If you enable this option then you'll be able to select support
373 for the following (non-PC) 32 bit x86 platforms:
374 Goldfish (Android emulator)
377 SGI 320/540 (Visual Workstation)
378 STA2X11-based (e.g. Northville)
379 Moorestown MID devices
381 If you have one of these systems, or if you want to build a
382 generic distribution kernel, say Y here - otherwise say N.
386 config X86_EXTENDED_PLATFORM
387 bool "Support for extended (non-PC) x86 platforms"
390 If you disable this option then the kernel will only support
391 standard PC platforms. (which covers the vast majority of
394 If you enable this option then you'll be able to select support
395 for the following (non-PC) 64 bit x86 platforms:
400 If you have one of these systems, or if you want to build a
401 generic distribution kernel, say Y here - otherwise say N.
403 # This is an alphabetically sorted list of 64 bit extended platforms
404 # Please maintain the alphabetic order if and when there are additions
406 bool "Numascale NumaChip"
408 depends on X86_EXTENDED_PLATFORM
411 depends on X86_X2APIC
412 depends on PCI_MMCONFIG
414 Adds support for Numascale NumaChip large-SMP systems. Needed to
415 enable more than ~168 cores.
416 If you don't have one of these, you should say N here.
420 select HYPERVISOR_GUEST
422 depends on X86_64 && PCI
423 depends on X86_EXTENDED_PLATFORM
426 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
427 supposed to run on these EM64T-based machines. Only choose this option
428 if you have one of these machines.
431 bool "SGI Ultraviolet"
433 depends on X86_EXTENDED_PLATFORM
435 depends on X86_X2APIC
437 This option is needed in order to support SGI Ultraviolet systems.
438 If you don't have one of these, you should say N here.
440 # Following is an alphabetically sorted list of 32 bit extended platforms
441 # Please maintain the alphabetic order if and when there are additions
444 bool "Goldfish (Virtual Platform)"
445 depends on X86_EXTENDED_PLATFORM
447 Enable support for the Goldfish virtual platform used primarily
448 for Android development. Unless you are building for the Android
449 Goldfish emulator say N here.
452 bool "CE4100 TV platform"
454 depends on PCI_GODIRECT
455 depends on X86_IO_APIC
457 depends on X86_EXTENDED_PLATFORM
458 select X86_REBOOTFIXUPS
460 select OF_EARLY_FLATTREE
463 Select for the Intel CE media processor (CE4100) SOC.
464 This option compiles in support for the CE4100 SOC for settop
465 boxes and media devices.
468 bool "Intel MID platform support"
470 depends on X86_EXTENDED_PLATFORM
471 depends on X86_PLATFORM_DEVICES
474 depends on X86_IO_APIC
480 select MFD_INTEL_MSIC
482 Select to build a kernel capable of supporting Intel MID (Mobile
483 Internet Device) platform systems which do not have the PCI legacy
484 interfaces. If you are building for a PC class system say N here.
486 Intel MID platforms are based on an Intel processor and chipset which
487 consume less power than most of the x86 derivatives.
489 config X86_INTEL_LPSS
490 bool "Intel Low Power Subsystem Support"
495 Select to build support for Intel Low Power Subsystem such as
496 found on Intel Lynxpoint PCH. Selecting this option enables
497 things like clock tree (common clock framework) and pincontrol
498 which are needed by the LPSS peripheral drivers.
500 config X86_AMD_PLATFORM_DEVICE
501 bool "AMD ACPI2Platform devices support"
506 Select to interpret AMD specific ACPI device to platform device
507 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
508 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
509 implemented under PINCTRL subsystem.
512 tristate "Intel SoC IOSF Sideband support for SoC platforms"
515 This option enables sideband register access support for Intel SoC
516 platforms. On these platforms the IOSF sideband is used in lieu of
517 MSR's for some register accesses, mostly but not limited to thermal
518 and power. Drivers may query the availability of this device to
519 determine if they need the sideband in order to work on these
520 platforms. The sideband is available on the following SoC products.
521 This list is not meant to be exclusive.
526 You should say Y if you are running a kernel on one of these SoC's.
528 config IOSF_MBI_DEBUG
529 bool "Enable IOSF sideband access through debugfs"
530 depends on IOSF_MBI && DEBUG_FS
532 Select this option to expose the IOSF sideband access registers (MCR,
533 MDR, MCRX) through debugfs to write and read register information from
534 different units on the SoC. This is most useful for obtaining device
535 state information for debug and analysis. As this is a general access
536 mechanism, users of this option would have specific knowledge of the
537 device they want to access.
539 If you don't require the option or are in doubt, say N.
542 bool "RDC R-321x SoC"
544 depends on X86_EXTENDED_PLATFORM
546 select X86_REBOOTFIXUPS
548 This option is needed for RDC R-321x system-on-chip, also known
550 If you don't have one of these chips, you should say N here.
552 config X86_32_NON_STANDARD
553 bool "Support non-standard 32-bit SMP architectures"
554 depends on X86_32 && SMP
555 depends on X86_EXTENDED_PLATFORM
557 This option compiles in the bigsmp and STA2X11 default
558 subarchitectures. It is intended for a generic binary
559 kernel. If you select them all, kernel will probe it one by
560 one and will fallback to default.
562 # Alphabetically sorted list of Non standard 32 bit platforms
564 config X86_SUPPORTS_MEMORY_FAILURE
566 # MCE code calls memory_failure():
568 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
569 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
570 depends on X86_64 || !SPARSEMEM
571 select ARCH_SUPPORTS_MEMORY_FAILURE
574 bool "STA2X11 Companion Chip Support"
575 depends on X86_32_NON_STANDARD && PCI
576 select X86_DEV_DMA_OPS
580 select ARCH_REQUIRE_GPIOLIB
583 This adds support for boards based on the STA2X11 IO-Hub,
584 a.k.a. "ConneXt". The chip is used in place of the standard
585 PC chipset, so all "standard" peripherals are missing. If this
586 option is selected the kernel will still be able to boot on
587 standard PC machines.
590 tristate "Eurobraille/Iris poweroff module"
593 The Iris machines from EuroBraille do not have APM or ACPI support
594 to shut themselves down properly. A special I/O sequence is
595 needed to do so, which is what this module does at
598 This is only for Iris machines from EuroBraille.
602 config SCHED_OMIT_FRAME_POINTER
604 prompt "Single-depth WCHAN output"
607 Calculate simpler /proc/<PID>/wchan values. If this option
608 is disabled then wchan values will recurse back to the
609 caller function. This provides more accurate wchan values,
610 at the expense of slightly more scheduling overhead.
612 If in doubt, say "Y".
614 menuconfig HYPERVISOR_GUEST
615 bool "Linux guest support"
617 Say Y here to enable options for running Linux under various hyper-
618 visors. This option enables basic hypervisor detection and platform
621 If you say N, all options in this submenu will be skipped and
622 disabled, and Linux guest support won't be built in.
627 bool "Enable paravirtualization code"
629 This changes the kernel so it can modify itself when it is run
630 under a hypervisor, potentially improving performance significantly
631 over full virtualization. However, when run without a hypervisor
632 the kernel is theoretically slower and slightly larger.
634 config PARAVIRT_DEBUG
635 bool "paravirt-ops debugging"
636 depends on PARAVIRT && DEBUG_KERNEL
638 Enable to debug paravirt_ops internals. Specifically, BUG if
639 a paravirt_op is missing when it is called.
641 config PARAVIRT_SPINLOCKS
642 bool "Paravirtualization layer for spinlocks"
643 depends on PARAVIRT && SMP
644 select UNINLINE_SPIN_UNLOCK
646 Paravirtualized spinlocks allow a pvops backend to replace the
647 spinlock implementation with something virtualization-friendly
648 (for example, block the virtual CPU rather than spinning).
650 It has a minimal impact on native kernels and gives a nice performance
651 benefit on paravirtualized KVM / Xen kernels.
653 If you are unsure how to answer this question, answer Y.
655 source "arch/x86/xen/Kconfig"
658 bool "KVM Guest support (including kvmclock)"
660 select PARAVIRT_CLOCK
663 This option enables various optimizations for running under the KVM
664 hypervisor. It includes a paravirtualized clock, so that instead
665 of relying on a PIT (or probably other) emulation by the
666 underlying device model, the host provides the guest with
667 timing infrastructure such as time of day, and system time
670 bool "Enable debug information for KVM Guests in debugfs"
671 depends on KVM_GUEST && DEBUG_FS
674 This option enables collection of various statistics for KVM guest.
675 Statistics are displayed in debugfs filesystem. Enabling this option
676 may incur significant overhead.
678 source "arch/x86/lguest/Kconfig"
680 config PARAVIRT_TIME_ACCOUNTING
681 bool "Paravirtual steal time accounting"
685 Select this option to enable fine granularity task steal time
686 accounting. Time spent executing other tasks in parallel with
687 the current vCPU is discounted from the vCPU power. To account for
688 that, there can be a small performance impact.
690 If in doubt, say N here.
692 config PARAVIRT_CLOCK
695 endif #HYPERVISOR_GUEST
703 This option adds a kernel parameter 'memtest', which allows memtest
705 memtest=0, mean disabled; -- default
706 memtest=1, mean do 1 test pattern;
708 memtest=4, mean do 4 test patterns.
709 If you are unsure how to answer this question, answer N.
711 source "arch/x86/Kconfig.cpu"
715 prompt "HPET Timer Support" if X86_32
717 Use the IA-PC HPET (High Precision Event Timer) to manage
718 time in preference to the PIT and RTC, if a HPET is
720 HPET is the next generation timer replacing legacy 8254s.
721 The HPET provides a stable time base on SMP
722 systems, unlike the TSC, but it is more expensive to access,
723 as it is off-chip. You can find the HPET spec at
724 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
726 You can safely choose Y here. However, HPET will only be
727 activated if the platform and the BIOS support this feature.
728 Otherwise the 8254 will be used for timing services.
730 Choose N to continue using the legacy 8254 timer.
732 config HPET_EMULATE_RTC
734 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
737 def_bool y if X86_INTEL_MID
738 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
740 depends on X86_INTEL_MID && SFI
742 APB timer is the replacement for 8254, HPET on X86 MID platforms.
743 The APBT provides a stable time base on SMP
744 systems, unlike the TSC, but it is more expensive to access,
745 as it is off-chip. APB timers are always running regardless of CPU
746 C states, they are used as per CPU clockevent device when possible.
748 # Mark as expert because too many people got it wrong.
749 # The code disables itself when not needed.
752 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
753 bool "Enable DMI scanning" if EXPERT
755 Enabled scanning of DMI to identify machine quirks. Say Y
756 here unless you have verified that your setup is not
757 affected by entries in the DMI blacklist. Required by PNP
761 bool "Old AMD GART IOMMU support"
763 depends on X86_64 && PCI && AMD_NB
765 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
766 GART based hardware IOMMUs.
768 The GART supports full DMA access for devices with 32-bit access
769 limitations, on systems with more than 3 GB. This is usually needed
770 for USB, sound, many IDE/SATA chipsets and some other devices.
772 Newer systems typically have a modern AMD IOMMU, supported via
773 the CONFIG_AMD_IOMMU=y config option.
775 In normal configurations this driver is only active when needed:
776 there's more than 3 GB of memory and the system contains a
777 32-bit limited device.
782 bool "IBM Calgary IOMMU support"
784 depends on X86_64 && PCI
786 Support for hardware IOMMUs in IBM's xSeries x366 and x460
787 systems. Needed to run systems with more than 3GB of memory
788 properly with 32-bit PCI devices that do not support DAC
789 (Double Address Cycle). Calgary also supports bus level
790 isolation, where all DMAs pass through the IOMMU. This
791 prevents them from going anywhere except their intended
792 destination. This catches hard-to-find kernel bugs and
793 mis-behaving drivers and devices that do not use the DMA-API
794 properly to set up their DMA buffers. The IOMMU can be
795 turned off at boot time with the iommu=off parameter.
796 Normally the kernel will make the right choice by itself.
799 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
801 prompt "Should Calgary be enabled by default?"
802 depends on CALGARY_IOMMU
804 Should Calgary be enabled by default? if you choose 'y', Calgary
805 will be used (if it exists). If you choose 'n', Calgary will not be
806 used even if it exists. If you choose 'n' and would like to use
807 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
810 # need this always selected by IOMMU for the VIA workaround
814 Support for software bounce buffers used on x86-64 systems
815 which don't have a hardware IOMMU. Using this PCI devices
816 which can only access 32-bits of memory can be used on systems
817 with more than 3 GB of memory.
822 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
825 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
826 depends on X86_64 && SMP && DEBUG_KERNEL
827 select CPUMASK_OFFSTACK
829 Enable maximum number of CPUS and NUMA Nodes for this architecture.
833 int "Maximum number of CPUs" if SMP && !MAXSMP
834 range 2 8 if SMP && X86_32 && !X86_BIGSMP
835 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
836 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
838 default "8192" if MAXSMP
839 default "32" if SMP && X86_BIGSMP
842 This allows you to specify the maximum number of CPUs which this
843 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
844 supported value is 4096, otherwise the maximum value is 512. The
845 minimum value which makes sense is 2.
847 This is purely to save memory - each supported CPU adds
848 approximately eight kilobytes to the kernel image.
851 bool "SMT (Hyperthreading) scheduler support"
854 SMT scheduler support improves the CPU scheduler's decision making
855 when dealing with Intel Pentium 4 chips with HyperThreading at a
856 cost of slightly increased overhead in some places. If unsure say
861 prompt "Multi-core scheduler support"
864 Multi-core scheduler support improves the CPU scheduler's decision
865 making when dealing with multi-core CPU chips at a cost of slightly
866 increased overhead in some places. If unsure say N here.
868 source "kernel/Kconfig.preempt"
872 depends on !SMP && X86_LOCAL_APIC
875 bool "Local APIC support on uniprocessors"
876 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
878 A local APIC (Advanced Programmable Interrupt Controller) is an
879 integrated interrupt controller in the CPU. If you have a single-CPU
880 system which has a processor with a local APIC, you can say Y here to
881 enable and use it. If you say Y here even though your machine doesn't
882 have a local APIC, then the kernel will still run with no slowdown at
883 all. The local APIC supports CPU-generated self-interrupts (timer,
884 performance counters), and the NMI watchdog which detects hard
887 config X86_UP_APIC_MSI
889 select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
892 bool "IO-APIC support on uniprocessors"
893 depends on X86_UP_APIC
895 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
896 SMP-capable replacement for PC-style interrupt controllers. Most
897 SMP systems and many recent uniprocessor systems have one.
899 If you have a single-CPU system with an IO-APIC, you can say Y here
900 to use it. If you say Y here even though your machine doesn't have
901 an IO-APIC, then the kernel will still run with no slowdown at all.
903 config X86_LOCAL_APIC
905 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
906 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
909 def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
910 depends on X86_LOCAL_APIC
913 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
914 bool "Reroute for broken boot IRQs"
915 depends on X86_IO_APIC
917 This option enables a workaround that fixes a source of
918 spurious interrupts. This is recommended when threaded
919 interrupt handling is used on systems where the generation of
920 superfluous "boot interrupts" cannot be disabled.
922 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
923 entry in the chipset's IO-APIC is masked (as, e.g. the RT
924 kernel does during interrupt handling). On chipsets where this
925 boot IRQ generation cannot be disabled, this workaround keeps
926 the original IRQ line masked so that only the equivalent "boot
927 IRQ" is delivered to the CPUs. The workaround also tells the
928 kernel to set up the IRQ handler on the boot IRQ line. In this
929 way only one interrupt is delivered to the kernel. Otherwise
930 the spurious second interrupt may cause the kernel to bring
931 down (vital) interrupt lines.
933 Only affects "broken" chipsets. Interrupt sharing may be
934 increased on these systems.
937 bool "Machine Check / overheating reporting"
940 Machine Check support allows the processor to notify the
941 kernel if it detects a problem (e.g. overheating, data corruption).
942 The action the kernel takes depends on the severity of the problem,
943 ranging from warning messages to halting the machine.
947 prompt "Intel MCE features"
948 depends on X86_MCE && X86_LOCAL_APIC
950 Additional support for intel specific MCE features such as
955 prompt "AMD MCE features"
956 depends on X86_MCE && X86_LOCAL_APIC
958 Additional support for AMD specific MCE features such as
959 the DRAM Error Threshold.
961 config X86_ANCIENT_MCE
962 bool "Support for old Pentium 5 / WinChip machine checks"
963 depends on X86_32 && X86_MCE
965 Include support for machine check handling on old Pentium 5 or WinChip
966 systems. These typically need to be enabled explicitly on the command
969 config X86_MCE_THRESHOLD
970 depends on X86_MCE_AMD || X86_MCE_INTEL
973 config X86_MCE_INJECT
975 tristate "Machine check injector support"
977 Provide support for injecting machine checks for testing purposes.
978 If you don't know what a machine check is and you don't do kernel
979 QA it is safe to say n.
981 config X86_THERMAL_VECTOR
983 depends on X86_MCE_INTEL
986 bool "Enable VM86 support" if EXPERT
990 This option is required by programs like DOSEMU to run
991 16-bit real mode legacy code on x86 processors. It also may
992 be needed by software like XFree86 to initialize some video
993 cards via BIOS. Disabling this option saves about 6K.
996 bool "Enable support for 16-bit segments" if EXPERT
999 This option is required by programs like Wine to run 16-bit
1000 protected mode legacy code on x86 processors. Disabling
1001 this option saves about 300 bytes on i386, or around 6K text
1002 plus 16K runtime memory on x86-64,
1006 depends on X86_16BIT && X86_32
1010 depends on X86_16BIT && X86_64
1012 config X86_VSYSCALL_EMULATION
1013 bool "Enable vsyscall emulation" if EXPERT
1017 This enables emulation of the legacy vsyscall page. Disabling
1018 it is roughly equivalent to booting with vsyscall=none, except
1019 that it will also disable the helpful warning if a program
1020 tries to use a vsyscall. With this option set to N, offending
1021 programs will just segfault, citing addresses of the form
1024 This option is required by many programs built before 2013, and
1025 care should be used even with newer programs if set to N.
1027 Disabling this option saves about 7K of kernel size and
1028 possibly 4K of additional runtime pagetable memory.
1031 tristate "Toshiba Laptop support"
1034 This adds a driver to safely access the System Management Mode of
1035 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1036 not work on models with a Phoenix BIOS. The System Management Mode
1037 is used to set the BIOS and power saving options on Toshiba portables.
1039 For information on utilities to make use of this driver see the
1040 Toshiba Linux utilities web site at:
1041 <http://www.buzzard.org.uk/toshiba/>.
1043 Say Y if you intend to run this kernel on a Toshiba portable.
1047 tristate "Dell laptop support"
1050 This adds a driver to safely access the System Management Mode
1051 of the CPU on the Dell Inspiron 8000. The System Management Mode
1052 is used to read cpu temperature and cooling fan status and to
1053 control the fans on the I8K portables.
1055 This driver has been tested only on the Inspiron 8000 but it may
1056 also work with other Dell laptops. You can force loading on other
1057 models by passing the parameter `force=1' to the module. Use at
1060 For information on utilities to make use of this driver see the
1061 I8K Linux utilities web site at:
1062 <http://people.debian.org/~dz/i8k/>
1064 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1067 config X86_REBOOTFIXUPS
1068 bool "Enable X86 board specific fixups for reboot"
1071 This enables chipset and/or board specific fixups to be done
1072 in order to get reboot to work correctly. This is only needed on
1073 some combinations of hardware and BIOS. The symptom, for which
1074 this config is intended, is when reboot ends with a stalled/hung
1077 Currently, the only fixup is for the Geode machines using
1078 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1080 Say Y if you want to enable the fixup. Currently, it's safe to
1081 enable this option even if you don't need it.
1085 tristate "CPU microcode loading support"
1086 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1090 If you say Y here, you will be able to update the microcode on
1091 certain Intel and AMD processors. The Intel support is for the
1092 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1093 Xeon etc. The AMD support is for families 0x10 and later. You will
1094 obviously need the actual microcode binary data itself which is not
1095 shipped with the Linux kernel.
1097 This option selects the general module only, you need to select
1098 at least one vendor specific module as well.
1100 To compile this driver as a module, choose M here: the module
1101 will be called microcode.
1103 config MICROCODE_INTEL
1104 bool "Intel microcode loading support"
1105 depends on MICROCODE
1109 This options enables microcode patch loading support for Intel
1112 For the current Intel microcode data package go to
1113 <https://downloadcenter.intel.com> and search for
1114 'Linux Processor Microcode Data File'.
1116 config MICROCODE_AMD
1117 bool "AMD microcode loading support"
1118 depends on MICROCODE
1121 If you select this option, microcode patch loading support for AMD
1122 processors will be enabled.
1124 config MICROCODE_OLD_INTERFACE
1126 depends on MICROCODE
1128 config MICROCODE_INTEL_EARLY
1131 config MICROCODE_AMD_EARLY
1134 config MICROCODE_EARLY
1135 bool "Early load microcode"
1136 depends on MICROCODE=y && BLK_DEV_INITRD
1137 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1138 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1141 This option provides functionality to read additional microcode data
1142 at the beginning of initrd image. The data tells kernel to load
1143 microcode to CPU's as early as possible. No functional change if no
1144 microcode data is glued to the initrd, therefore it's safe to say Y.
1147 tristate "/dev/cpu/*/msr - Model-specific register support"
1149 This device gives privileged processes access to the x86
1150 Model-Specific Registers (MSRs). It is a character device with
1151 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1152 MSR accesses are directed to a specific CPU on multi-processor
1156 tristate "/dev/cpu/*/cpuid - CPU information support"
1158 This device gives processes access to the x86 CPUID instruction to
1159 be executed on a specific processor. It is a character device
1160 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1164 prompt "High Memory Support"
1171 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1172 However, the address space of 32-bit x86 processors is only 4
1173 Gigabytes large. That means that, if you have a large amount of
1174 physical memory, not all of it can be "permanently mapped" by the
1175 kernel. The physical memory that's not permanently mapped is called
1178 If you are compiling a kernel which will never run on a machine with
1179 more than 1 Gigabyte total physical RAM, answer "off" here (default
1180 choice and suitable for most users). This will result in a "3GB/1GB"
1181 split: 3GB are mapped so that each process sees a 3GB virtual memory
1182 space and the remaining part of the 4GB virtual memory space is used
1183 by the kernel to permanently map as much physical memory as
1186 If the machine has between 1 and 4 Gigabytes physical RAM, then
1189 If more than 4 Gigabytes is used then answer "64GB" here. This
1190 selection turns Intel PAE (Physical Address Extension) mode on.
1191 PAE implements 3-level paging on IA32 processors. PAE is fully
1192 supported by Linux, PAE mode is implemented on all recent Intel
1193 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1194 then the kernel will not boot on CPUs that don't support PAE!
1196 The actual amount of total physical memory will either be
1197 auto detected or can be forced by using a kernel command line option
1198 such as "mem=256M". (Try "man bootparam" or see the documentation of
1199 your boot loader (lilo or loadlin) about how to pass options to the
1200 kernel at boot time.)
1202 If unsure, say "off".
1207 Select this if you have a 32-bit processor and between 1 and 4
1208 gigabytes of physical RAM.
1215 Select this if you have a 32-bit processor and more than 4
1216 gigabytes of physical RAM.
1221 prompt "Memory split" if EXPERT
1225 Select the desired split between kernel and user memory.
1227 If the address range available to the kernel is less than the
1228 physical memory installed, the remaining memory will be available
1229 as "high memory". Accessing high memory is a little more costly
1230 than low memory, as it needs to be mapped into the kernel first.
1231 Note that increasing the kernel address space limits the range
1232 available to user programs, making the address space there
1233 tighter. Selecting anything other than the default 3G/1G split
1234 will also likely make your kernel incompatible with binary-only
1237 If you are not absolutely sure what you are doing, leave this
1241 bool "3G/1G user/kernel split"
1242 config VMSPLIT_3G_OPT
1244 bool "3G/1G user/kernel split (for full 1G low memory)"
1246 bool "2G/2G user/kernel split"
1247 config VMSPLIT_2G_OPT
1249 bool "2G/2G user/kernel split (for full 2G low memory)"
1251 bool "1G/3G user/kernel split"
1256 default 0xB0000000 if VMSPLIT_3G_OPT
1257 default 0x80000000 if VMSPLIT_2G
1258 default 0x78000000 if VMSPLIT_2G_OPT
1259 default 0x40000000 if VMSPLIT_1G
1265 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1268 bool "PAE (Physical Address Extension) Support"
1269 depends on X86_32 && !HIGHMEM4G
1271 PAE is required for NX support, and furthermore enables
1272 larger swapspace support for non-overcommit purposes. It
1273 has the cost of more pagetable lookup overhead, and also
1274 consumes more pagetable space per process.
1276 config ARCH_PHYS_ADDR_T_64BIT
1278 depends on X86_64 || X86_PAE
1280 config ARCH_DMA_ADDR_T_64BIT
1282 depends on X86_64 || HIGHMEM64G
1284 config DIRECT_GBPAGES
1285 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1289 Allow the kernel linear mapping to use 1GB pages on CPUs that
1290 support it. This can improve the kernel's performance a tiny bit by
1291 reducing TLB pressure. If in doubt, say "Y".
1293 # Common NUMA Features
1295 bool "Numa Memory Allocation and Scheduler Support"
1297 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1298 default y if X86_BIGSMP
1300 Enable NUMA (Non Uniform Memory Access) support.
1302 The kernel will try to allocate memory used by a CPU on the
1303 local memory controller of the CPU and add some more
1304 NUMA awareness to the kernel.
1306 For 64-bit this is recommended if the system is Intel Core i7
1307 (or later), AMD Opteron, or EM64T NUMA.
1309 For 32-bit this is only needed if you boot a 32-bit
1310 kernel on a 64-bit NUMA platform.
1312 Otherwise, you should say N.
1316 prompt "Old style AMD Opteron NUMA detection"
1317 depends on X86_64 && NUMA && PCI
1319 Enable AMD NUMA node topology detection. You should say Y here if
1320 you have a multi processor AMD system. This uses an old method to
1321 read the NUMA configuration directly from the builtin Northbridge
1322 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1323 which also takes priority if both are compiled in.
1325 config X86_64_ACPI_NUMA
1327 prompt "ACPI NUMA detection"
1328 depends on X86_64 && NUMA && ACPI && PCI
1331 Enable ACPI SRAT based node topology detection.
1333 # Some NUMA nodes have memory ranges that span
1334 # other nodes. Even though a pfn is valid and
1335 # between a node's start and end pfns, it may not
1336 # reside on that node. See memmap_init_zone()
1338 config NODES_SPAN_OTHER_NODES
1340 depends on X86_64_ACPI_NUMA
1343 bool "NUMA emulation"
1346 Enable NUMA emulation. A flat machine will be split
1347 into virtual nodes when booted with "numa=fake=N", where N is the
1348 number of nodes. This is only useful for debugging.
1351 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1353 default "10" if MAXSMP
1354 default "6" if X86_64
1356 depends on NEED_MULTIPLE_NODES
1358 Specify the maximum number of NUMA Nodes available on the target
1359 system. Increases memory reserved to accommodate various tables.
1361 config ARCH_HAVE_MEMORY_PRESENT
1363 depends on X86_32 && DISCONTIGMEM
1365 config NEED_NODE_MEMMAP_SIZE
1367 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1369 config ARCH_FLATMEM_ENABLE
1371 depends on X86_32 && !NUMA
1373 config ARCH_DISCONTIGMEM_ENABLE
1375 depends on NUMA && X86_32
1377 config ARCH_DISCONTIGMEM_DEFAULT
1379 depends on NUMA && X86_32
1381 config ARCH_SPARSEMEM_ENABLE
1383 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1384 select SPARSEMEM_STATIC if X86_32
1385 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1387 config ARCH_SPARSEMEM_DEFAULT
1391 config ARCH_SELECT_MEMORY_MODEL
1393 depends on ARCH_SPARSEMEM_ENABLE
1395 config ARCH_MEMORY_PROBE
1396 bool "Enable sysfs memory/probe interface"
1397 depends on X86_64 && MEMORY_HOTPLUG
1399 This option enables a sysfs memory/probe interface for testing.
1400 See Documentation/memory-hotplug.txt for more information.
1401 If you are unsure how to answer this question, answer N.
1403 config ARCH_PROC_KCORE_TEXT
1405 depends on X86_64 && PROC_KCORE
1407 config ILLEGAL_POINTER_VALUE
1410 default 0xdead000000000000 if X86_64
1415 bool "Allocate 3rd-level pagetables from highmem"
1418 The VM uses one page table entry for each page of physical memory.
1419 For systems with a lot of RAM, this can be wasteful of precious
1420 low memory. Setting this option will put user-space page table
1421 entries in high memory.
1423 config X86_CHECK_BIOS_CORRUPTION
1424 bool "Check for low memory corruption"
1426 Periodically check for memory corruption in low memory, which
1427 is suspected to be caused by BIOS. Even when enabled in the
1428 configuration, it is disabled at runtime. Enable it by
1429 setting "memory_corruption_check=1" on the kernel command
1430 line. By default it scans the low 64k of memory every 60
1431 seconds; see the memory_corruption_check_size and
1432 memory_corruption_check_period parameters in
1433 Documentation/kernel-parameters.txt to adjust this.
1435 When enabled with the default parameters, this option has
1436 almost no overhead, as it reserves a relatively small amount
1437 of memory and scans it infrequently. It both detects corruption
1438 and prevents it from affecting the running system.
1440 It is, however, intended as a diagnostic tool; if repeatable
1441 BIOS-originated corruption always affects the same memory,
1442 you can use memmap= to prevent the kernel from using that
1445 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1446 bool "Set the default setting of memory_corruption_check"
1447 depends on X86_CHECK_BIOS_CORRUPTION
1450 Set whether the default state of memory_corruption_check is
1453 config X86_RESERVE_LOW
1454 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1458 Specify the amount of low memory to reserve for the BIOS.
1460 The first page contains BIOS data structures that the kernel
1461 must not use, so that page must always be reserved.
1463 By default we reserve the first 64K of physical RAM, as a
1464 number of BIOSes are known to corrupt that memory range
1465 during events such as suspend/resume or monitor cable
1466 insertion, so it must not be used by the kernel.
1468 You can set this to 4 if you are absolutely sure that you
1469 trust the BIOS to get all its memory reservations and usages
1470 right. If you know your BIOS have problems beyond the
1471 default 64K area, you can set this to 640 to avoid using the
1472 entire low memory range.
1474 If you have doubts about the BIOS (e.g. suspend/resume does
1475 not work or there's kernel crashes after certain hardware
1476 hotplug events) then you might want to enable
1477 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1478 typical corruption patterns.
1480 Leave this to the default value of 64 if you are unsure.
1482 config MATH_EMULATION
1484 prompt "Math emulation" if X86_32
1486 Linux can emulate a math coprocessor (used for floating point
1487 operations) if you don't have one. 486DX and Pentium processors have
1488 a math coprocessor built in, 486SX and 386 do not, unless you added
1489 a 487DX or 387, respectively. (The messages during boot time can
1490 give you some hints here ["man dmesg"].) Everyone needs either a
1491 coprocessor or this emulation.
1493 If you don't have a math coprocessor, you need to say Y here; if you
1494 say Y here even though you have a coprocessor, the coprocessor will
1495 be used nevertheless. (This behavior can be changed with the kernel
1496 command line option "no387", which comes handy if your coprocessor
1497 is broken. Try "man bootparam" or see the documentation of your boot
1498 loader (lilo or loadlin) about how to pass options to the kernel at
1499 boot time.) This means that it is a good idea to say Y here if you
1500 intend to use this kernel on different machines.
1502 More information about the internals of the Linux math coprocessor
1503 emulation can be found in <file:arch/x86/math-emu/README>.
1505 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1506 kernel, it won't hurt.
1510 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1512 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1513 the Memory Type Range Registers (MTRRs) may be used to control
1514 processor access to memory ranges. This is most useful if you have
1515 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1516 allows bus write transfers to be combined into a larger transfer
1517 before bursting over the PCI/AGP bus. This can increase performance
1518 of image write operations 2.5 times or more. Saying Y here creates a
1519 /proc/mtrr file which may be used to manipulate your processor's
1520 MTRRs. Typically the X server should use this.
1522 This code has a reasonably generic interface so that similar
1523 control registers on other processors can be easily supported
1526 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1527 Registers (ARRs) which provide a similar functionality to MTRRs. For
1528 these, the ARRs are used to emulate the MTRRs.
1529 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1530 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1531 write-combining. All of these processors are supported by this code
1532 and it makes sense to say Y here if you have one of them.
1534 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1535 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1536 can lead to all sorts of problems, so it's good to say Y here.
1538 You can safely say Y even if your machine doesn't have MTRRs, you'll
1539 just add about 9 KB to your kernel.
1541 See <file:Documentation/x86/mtrr.txt> for more information.
1543 config MTRR_SANITIZER
1545 prompt "MTRR cleanup support"
1548 Convert MTRR layout from continuous to discrete, so X drivers can
1549 add writeback entries.
1551 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1552 The largest mtrr entry size for a continuous block can be set with
1557 config MTRR_SANITIZER_ENABLE_DEFAULT
1558 int "MTRR cleanup enable value (0-1)"
1561 depends on MTRR_SANITIZER
1563 Enable mtrr cleanup default value
1565 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1566 int "MTRR cleanup spare reg num (0-7)"
1569 depends on MTRR_SANITIZER
1571 mtrr cleanup spare entries default, it can be changed via
1572 mtrr_spare_reg_nr=N on the kernel command line.
1576 prompt "x86 PAT support" if EXPERT
1579 Use PAT attributes to setup page level cache control.
1581 PATs are the modern equivalents of MTRRs and are much more
1582 flexible than MTRRs.
1584 Say N here if you see bootup problems (boot crash, boot hang,
1585 spontaneous reboots) or a non-working video driver.
1589 config ARCH_USES_PG_UNCACHED
1595 prompt "x86 architectural random number generator" if EXPERT
1597 Enable the x86 architectural RDRAND instruction
1598 (Intel Bull Mountain technology) to generate random numbers.
1599 If supported, this is a high bandwidth, cryptographically
1600 secure hardware random number generator.
1604 prompt "Supervisor Mode Access Prevention" if EXPERT
1606 Supervisor Mode Access Prevention (SMAP) is a security
1607 feature in newer Intel processors. There is a small
1608 performance cost if this enabled and turned on; there is
1609 also a small increase in the kernel size if this is enabled.
1613 config X86_INTEL_MPX
1614 prompt "Intel MPX (Memory Protection Extensions)"
1616 depends on CPU_SUP_INTEL
1618 MPX provides hardware features that can be used in
1619 conjunction with compiler-instrumented code to check
1620 memory references. It is designed to detect buffer
1621 overflow or underflow bugs.
1623 This option enables running applications which are
1624 instrumented or otherwise use MPX. It does not use MPX
1625 itself inside the kernel or to protect the kernel
1626 against bad memory references.
1628 Enabling this option will make the kernel larger:
1629 ~8k of kernel text and 36 bytes of data on a 64-bit
1630 defconfig. It adds a long to the 'mm_struct' which
1631 will increase the kernel memory overhead of each
1632 process and adds some branches to paths used during
1633 exec() and munmap().
1635 For details, see Documentation/x86/intel_mpx.txt
1640 bool "EFI runtime service support"
1643 select EFI_RUNTIME_WRAPPERS
1645 This enables the kernel to use EFI runtime services that are
1646 available (such as the EFI variable services).
1648 This option is only useful on systems that have EFI firmware.
1649 In addition, you should use the latest ELILO loader available
1650 at <http://elilo.sourceforge.net> in order to take advantage
1651 of EFI runtime services. However, even with this option, the
1652 resultant kernel should continue to boot on existing non-EFI
1656 bool "EFI stub support"
1657 depends on EFI && !X86_USE_3DNOW
1660 This kernel feature allows a bzImage to be loaded directly
1661 by EFI firmware without the use of a bootloader.
1663 See Documentation/efi-stub.txt for more information.
1666 bool "EFI mixed-mode support"
1667 depends on EFI_STUB && X86_64
1669 Enabling this feature allows a 64-bit kernel to be booted
1670 on a 32-bit firmware, provided that your CPU supports 64-bit
1673 Note that it is not possible to boot a mixed-mode enabled
1674 kernel via the EFI boot stub - a bootloader that supports
1675 the EFI handover protocol must be used.
1681 prompt "Enable seccomp to safely compute untrusted bytecode"
1683 This kernel feature is useful for number crunching applications
1684 that may need to compute untrusted bytecode during their
1685 execution. By using pipes or other transports made available to
1686 the process as file descriptors supporting the read/write
1687 syscalls, it's possible to isolate those applications in
1688 their own address space using seccomp. Once seccomp is
1689 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1690 and the task is only allowed to execute a few safe syscalls
1691 defined by each seccomp mode.
1693 If unsure, say Y. Only embedded should say N here.
1695 source kernel/Kconfig.hz
1698 bool "kexec system call"
1700 kexec is a system call that implements the ability to shutdown your
1701 current kernel, and to start another kernel. It is like a reboot
1702 but it is independent of the system firmware. And like a reboot
1703 you can start any kernel with it, not just Linux.
1705 The name comes from the similarity to the exec system call.
1707 It is an ongoing process to be certain the hardware in a machine
1708 is properly shutdown, so do not be surprised if this code does not
1709 initially work for you. As of this writing the exact hardware
1710 interface is strongly in flux, so no good recommendation can be
1714 bool "kexec file based system call"
1719 depends on CRYPTO_SHA256=y
1721 This is new version of kexec system call. This system call is
1722 file based and takes file descriptors as system call argument
1723 for kernel and initramfs as opposed to list of segments as
1724 accepted by previous system call.
1726 config KEXEC_VERIFY_SIG
1727 bool "Verify kernel signature during kexec_file_load() syscall"
1728 depends on KEXEC_FILE
1730 This option makes kernel signature verification mandatory for
1731 kexec_file_load() syscall. If kernel is signature can not be
1732 verified, kexec_file_load() will fail.
1734 This option enforces signature verification at generic level.
1735 One needs to enable signature verification for type of kernel
1736 image being loaded to make sure it works. For example, enable
1737 bzImage signature verification option to be able to load and
1738 verify signatures of bzImage. Otherwise kernel loading will fail.
1740 config KEXEC_BZIMAGE_VERIFY_SIG
1741 bool "Enable bzImage signature verification support"
1742 depends on KEXEC_VERIFY_SIG
1743 depends on SIGNED_PE_FILE_VERIFICATION
1744 select SYSTEM_TRUSTED_KEYRING
1746 Enable bzImage signature verification support.
1749 bool "kernel crash dumps"
1750 depends on X86_64 || (X86_32 && HIGHMEM)
1752 Generate crash dump after being started by kexec.
1753 This should be normally only set in special crash dump kernels
1754 which are loaded in the main kernel with kexec-tools into
1755 a specially reserved region and then later executed after
1756 a crash by kdump/kexec. The crash dump kernel must be compiled
1757 to a memory address not used by the main kernel or BIOS using
1758 PHYSICAL_START, or it must be built as a relocatable image
1759 (CONFIG_RELOCATABLE=y).
1760 For more details see Documentation/kdump/kdump.txt
1764 depends on KEXEC && HIBERNATION
1766 Jump between original kernel and kexeced kernel and invoke
1767 code in physical address mode via KEXEC
1769 config PHYSICAL_START
1770 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1773 This gives the physical address where the kernel is loaded.
1775 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1776 bzImage will decompress itself to above physical address and
1777 run from there. Otherwise, bzImage will run from the address where
1778 it has been loaded by the boot loader and will ignore above physical
1781 In normal kdump cases one does not have to set/change this option
1782 as now bzImage can be compiled as a completely relocatable image
1783 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1784 address. This option is mainly useful for the folks who don't want
1785 to use a bzImage for capturing the crash dump and want to use a
1786 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1787 to be specifically compiled to run from a specific memory area
1788 (normally a reserved region) and this option comes handy.
1790 So if you are using bzImage for capturing the crash dump,
1791 leave the value here unchanged to 0x1000000 and set
1792 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1793 for capturing the crash dump change this value to start of
1794 the reserved region. In other words, it can be set based on
1795 the "X" value as specified in the "crashkernel=YM@XM"
1796 command line boot parameter passed to the panic-ed
1797 kernel. Please take a look at Documentation/kdump/kdump.txt
1798 for more details about crash dumps.
1800 Usage of bzImage for capturing the crash dump is recommended as
1801 one does not have to build two kernels. Same kernel can be used
1802 as production kernel and capture kernel. Above option should have
1803 gone away after relocatable bzImage support is introduced. But it
1804 is present because there are users out there who continue to use
1805 vmlinux for dump capture. This option should go away down the
1808 Don't change this unless you know what you are doing.
1811 bool "Build a relocatable kernel"
1814 This builds a kernel image that retains relocation information
1815 so it can be loaded someplace besides the default 1MB.
1816 The relocations tend to make the kernel binary about 10% larger,
1817 but are discarded at runtime.
1819 One use is for the kexec on panic case where the recovery kernel
1820 must live at a different physical address than the primary
1823 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1824 it has been loaded at and the compile time physical address
1825 (CONFIG_PHYSICAL_START) is used as the minimum location.
1827 config RANDOMIZE_BASE
1828 bool "Randomize the address of the kernel image"
1829 depends on RELOCATABLE
1832 Randomizes the physical and virtual address at which the
1833 kernel image is decompressed, as a security feature that
1834 deters exploit attempts relying on knowledge of the location
1835 of kernel internals.
1837 Entropy is generated using the RDRAND instruction if it is
1838 supported. If RDTSC is supported, it is used as well. If
1839 neither RDRAND nor RDTSC are supported, then randomness is
1840 read from the i8254 timer.
1842 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1843 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1844 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1845 minimum of 2MiB, only 10 bits of entropy is theoretically
1846 possible. At best, due to page table layouts, 64-bit can use
1847 9 bits of entropy and 32-bit uses 8 bits.
1851 config RANDOMIZE_BASE_MAX_OFFSET
1852 hex "Maximum kASLR offset allowed" if EXPERT
1853 depends on RANDOMIZE_BASE
1854 range 0x0 0x20000000 if X86_32
1855 default "0x20000000" if X86_32
1856 range 0x0 0x40000000 if X86_64
1857 default "0x40000000" if X86_64
1859 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1860 memory is used to determine the maximal offset in bytes that will
1861 be applied to the kernel when kernel Address Space Layout
1862 Randomization (kASLR) is active. This must be a multiple of
1865 On 32-bit this is limited to 512MiB by page table layouts. The
1868 On 64-bit this is limited by how the kernel fixmap page table is
1869 positioned, so this cannot be larger than 1GiB currently. Without
1870 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1871 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1872 modules area will shrink to compensate, up to the current maximum
1873 1GiB to 1GiB split. The default is 1GiB.
1875 If unsure, leave at the default value.
1877 # Relocation on x86 needs some additional build support
1878 config X86_NEED_RELOCS
1880 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1882 config PHYSICAL_ALIGN
1883 hex "Alignment value to which kernel should be aligned"
1885 range 0x2000 0x1000000 if X86_32
1886 range 0x200000 0x1000000 if X86_64
1888 This value puts the alignment restrictions on physical address
1889 where kernel is loaded and run from. Kernel is compiled for an
1890 address which meets above alignment restriction.
1892 If bootloader loads the kernel at a non-aligned address and
1893 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1894 address aligned to above value and run from there.
1896 If bootloader loads the kernel at a non-aligned address and
1897 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1898 load address and decompress itself to the address it has been
1899 compiled for and run from there. The address for which kernel is
1900 compiled already meets above alignment restrictions. Hence the
1901 end result is that kernel runs from a physical address meeting
1902 above alignment restrictions.
1904 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1905 this value must be a multiple of 0x200000.
1907 Don't change this unless you know what you are doing.
1910 bool "Support for hot-pluggable CPUs"
1913 Say Y here to allow turning CPUs off and on. CPUs can be
1914 controlled through /sys/devices/system/cpu.
1915 ( Note: power management support will enable this option
1916 automatically on SMP systems. )
1917 Say N if you want to disable CPU hotplug.
1919 config BOOTPARAM_HOTPLUG_CPU0
1920 bool "Set default setting of cpu0_hotpluggable"
1922 depends on HOTPLUG_CPU
1924 Set whether default state of cpu0_hotpluggable is on or off.
1926 Say Y here to enable CPU0 hotplug by default. If this switch
1927 is turned on, there is no need to give cpu0_hotplug kernel
1928 parameter and the CPU0 hotplug feature is enabled by default.
1930 Please note: there are two known CPU0 dependencies if you want
1931 to enable the CPU0 hotplug feature either by this switch or by
1932 cpu0_hotplug kernel parameter.
1934 First, resume from hibernate or suspend always starts from CPU0.
1935 So hibernate and suspend are prevented if CPU0 is offline.
1937 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1938 offline if any interrupt can not migrate out of CPU0. There may
1939 be other CPU0 dependencies.
1941 Please make sure the dependencies are under your control before
1942 you enable this feature.
1944 Say N if you don't want to enable CPU0 hotplug feature by default.
1945 You still can enable the CPU0 hotplug feature at boot by kernel
1946 parameter cpu0_hotplug.
1948 config DEBUG_HOTPLUG_CPU0
1950 prompt "Debug CPU0 hotplug"
1951 depends on HOTPLUG_CPU
1953 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1954 soon as possible and boots up userspace with CPU0 offlined. User
1955 can online CPU0 back after boot time.
1957 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1958 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1959 compilation or giving cpu0_hotplug kernel parameter at boot.
1965 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1966 depends on X86_32 || IA32_EMULATION
1968 Certain buggy versions of glibc will crash if they are
1969 presented with a 32-bit vDSO that is not mapped at the address
1970 indicated in its segment table.
1972 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1973 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1974 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1975 the only released version with the bug, but OpenSUSE 9
1976 contains a buggy "glibc 2.3.2".
1978 The symptom of the bug is that everything crashes on startup, saying:
1979 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1981 Saying Y here changes the default value of the vdso32 boot
1982 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1983 This works around the glibc bug but hurts performance.
1985 If unsure, say N: if you are compiling your own kernel, you
1986 are unlikely to be using a buggy version of glibc.
1989 bool "Built-in kernel command line"
1991 Allow for specifying boot arguments to the kernel at
1992 build time. On some systems (e.g. embedded ones), it is
1993 necessary or convenient to provide some or all of the
1994 kernel boot arguments with the kernel itself (that is,
1995 to not rely on the boot loader to provide them.)
1997 To compile command line arguments into the kernel,
1998 set this option to 'Y', then fill in the
1999 the boot arguments in CONFIG_CMDLINE.
2001 Systems with fully functional boot loaders (i.e. non-embedded)
2002 should leave this option set to 'N'.
2005 string "Built-in kernel command string"
2006 depends on CMDLINE_BOOL
2009 Enter arguments here that should be compiled into the kernel
2010 image and used at boot time. If the boot loader provides a
2011 command line at boot time, it is appended to this string to
2012 form the full kernel command line, when the system boots.
2014 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2015 change this behavior.
2017 In most cases, the command line (whether built-in or provided
2018 by the boot loader) should specify the device for the root
2021 config CMDLINE_OVERRIDE
2022 bool "Built-in command line overrides boot loader arguments"
2023 depends on CMDLINE_BOOL
2025 Set this option to 'Y' to have the kernel ignore the boot loader
2026 command line, and use ONLY the built-in command line.
2028 This is used to work around broken boot loaders. This should
2029 be set to 'N' under normal conditions.
2033 config ARCH_ENABLE_MEMORY_HOTPLUG
2035 depends on X86_64 || (X86_32 && HIGHMEM)
2037 config ARCH_ENABLE_MEMORY_HOTREMOVE
2039 depends on MEMORY_HOTPLUG
2041 config USE_PERCPU_NUMA_NODE_ID
2045 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2047 depends on X86_64 || X86_PAE
2049 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2051 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2053 menu "Power management and ACPI options"
2055 config ARCH_HIBERNATION_HEADER
2057 depends on X86_64 && HIBERNATION
2059 source "kernel/power/Kconfig"
2061 source "drivers/acpi/Kconfig"
2063 source "drivers/sfi/Kconfig"
2070 tristate "APM (Advanced Power Management) BIOS support"
2071 depends on X86_32 && PM_SLEEP
2073 APM is a BIOS specification for saving power using several different
2074 techniques. This is mostly useful for battery powered laptops with
2075 APM compliant BIOSes. If you say Y here, the system time will be
2076 reset after a RESUME operation, the /proc/apm device will provide
2077 battery status information, and user-space programs will receive
2078 notification of APM "events" (e.g. battery status change).
2080 If you select "Y" here, you can disable actual use of the APM
2081 BIOS by passing the "apm=off" option to the kernel at boot time.
2083 Note that the APM support is almost completely disabled for
2084 machines with more than one CPU.
2086 In order to use APM, you will need supporting software. For location
2087 and more information, read <file:Documentation/power/apm-acpi.txt>
2088 and the Battery Powered Linux mini-HOWTO, available from
2089 <http://www.tldp.org/docs.html#howto>.
2091 This driver does not spin down disk drives (see the hdparm(8)
2092 manpage ("man 8 hdparm") for that), and it doesn't turn off
2093 VESA-compliant "green" monitors.
2095 This driver does not support the TI 4000M TravelMate and the ACER
2096 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2097 desktop machines also don't have compliant BIOSes, and this driver
2098 may cause those machines to panic during the boot phase.
2100 Generally, if you don't have a battery in your machine, there isn't
2101 much point in using this driver and you should say N. If you get
2102 random kernel OOPSes or reboots that don't seem to be related to
2103 anything, try disabling/enabling this option (or disabling/enabling
2106 Some other things you should try when experiencing seemingly random,
2109 1) make sure that you have enough swap space and that it is
2111 2) pass the "no-hlt" option to the kernel
2112 3) switch on floating point emulation in the kernel and pass
2113 the "no387" option to the kernel
2114 4) pass the "floppy=nodma" option to the kernel
2115 5) pass the "mem=4M" option to the kernel (thereby disabling
2116 all but the first 4 MB of RAM)
2117 6) make sure that the CPU is not over clocked.
2118 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2119 8) disable the cache from your BIOS settings
2120 9) install a fan for the video card or exchange video RAM
2121 10) install a better fan for the CPU
2122 11) exchange RAM chips
2123 12) exchange the motherboard.
2125 To compile this driver as a module, choose M here: the
2126 module will be called apm.
2130 config APM_IGNORE_USER_SUSPEND
2131 bool "Ignore USER SUSPEND"
2133 This option will ignore USER SUSPEND requests. On machines with a
2134 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2135 series notebooks, it is necessary to say Y because of a BIOS bug.
2137 config APM_DO_ENABLE
2138 bool "Enable PM at boot time"
2140 Enable APM features at boot time. From page 36 of the APM BIOS
2141 specification: "When disabled, the APM BIOS does not automatically
2142 power manage devices, enter the Standby State, enter the Suspend
2143 State, or take power saving steps in response to CPU Idle calls."
2144 This driver will make CPU Idle calls when Linux is idle (unless this
2145 feature is turned off -- see "Do CPU IDLE calls", below). This
2146 should always save battery power, but more complicated APM features
2147 will be dependent on your BIOS implementation. You may need to turn
2148 this option off if your computer hangs at boot time when using APM
2149 support, or if it beeps continuously instead of suspending. Turn
2150 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2151 T400CDT. This is off by default since most machines do fine without
2156 bool "Make CPU Idle calls when idle"
2158 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2159 On some machines, this can activate improved power savings, such as
2160 a slowed CPU clock rate, when the machine is idle. These idle calls
2161 are made after the idle loop has run for some length of time (e.g.,
2162 333 mS). On some machines, this will cause a hang at boot time or
2163 whenever the CPU becomes idle. (On machines with more than one CPU,
2164 this option does nothing.)
2166 config APM_DISPLAY_BLANK
2167 bool "Enable console blanking using APM"
2169 Enable console blanking using the APM. Some laptops can use this to
2170 turn off the LCD backlight when the screen blanker of the Linux
2171 virtual console blanks the screen. Note that this is only used by
2172 the virtual console screen blanker, and won't turn off the backlight
2173 when using the X Window system. This also doesn't have anything to
2174 do with your VESA-compliant power-saving monitor. Further, this
2175 option doesn't work for all laptops -- it might not turn off your
2176 backlight at all, or it might print a lot of errors to the console,
2177 especially if you are using gpm.
2179 config APM_ALLOW_INTS
2180 bool "Allow interrupts during APM BIOS calls"
2182 Normally we disable external interrupts while we are making calls to
2183 the APM BIOS as a measure to lessen the effects of a badly behaving
2184 BIOS implementation. The BIOS should reenable interrupts if it
2185 needs to. Unfortunately, some BIOSes do not -- especially those in
2186 many of the newer IBM Thinkpads. If you experience hangs when you
2187 suspend, try setting this to Y. Otherwise, say N.
2191 source "drivers/cpufreq/Kconfig"
2193 source "drivers/cpuidle/Kconfig"
2195 source "drivers/idle/Kconfig"
2200 menu "Bus options (PCI etc.)"
2206 Find out whether you have a PCI motherboard. PCI is the name of a
2207 bus system, i.e. the way the CPU talks to the other stuff inside
2208 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2209 VESA. If you have PCI, say Y, otherwise N.
2212 prompt "PCI access mode"
2213 depends on X86_32 && PCI
2216 On PCI systems, the BIOS can be used to detect the PCI devices and
2217 determine their configuration. However, some old PCI motherboards
2218 have BIOS bugs and may crash if this is done. Also, some embedded
2219 PCI-based systems don't have any BIOS at all. Linux can also try to
2220 detect the PCI hardware directly without using the BIOS.
2222 With this option, you can specify how Linux should detect the
2223 PCI devices. If you choose "BIOS", the BIOS will be used,
2224 if you choose "Direct", the BIOS won't be used, and if you
2225 choose "MMConfig", then PCI Express MMCONFIG will be used.
2226 If you choose "Any", the kernel will try MMCONFIG, then the
2227 direct access method and falls back to the BIOS if that doesn't
2228 work. If unsure, go with the default, which is "Any".
2233 config PCI_GOMMCONFIG
2250 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2252 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2255 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2259 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2263 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2267 depends on PCI && XEN
2275 bool "Support mmconfig PCI config space access"
2276 depends on X86_64 && PCI && ACPI
2278 config PCI_CNB20LE_QUIRK
2279 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2282 Read the PCI windows out of the CNB20LE host bridge. This allows
2283 PCI hotplug to work on systems with the CNB20LE chipset which do
2286 There's no public spec for this chipset, and this functionality
2287 is known to be incomplete.
2289 You should say N unless you know you need this.
2291 source "drivers/pci/pcie/Kconfig"
2293 source "drivers/pci/Kconfig"
2295 # x86_64 have no ISA slots, but can have ISA-style DMA.
2297 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2300 Enables ISA-style DMA support for devices requiring such controllers.
2308 Find out whether you have ISA slots on your motherboard. ISA is the
2309 name of a bus system, i.e. the way the CPU talks to the other stuff
2310 inside your box. Other bus systems are PCI, EISA, MicroChannel
2311 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2312 newer boards don't support it. If you have ISA, say Y, otherwise N.
2318 The Extended Industry Standard Architecture (EISA) bus was
2319 developed as an open alternative to the IBM MicroChannel bus.
2321 The EISA bus provided some of the features of the IBM MicroChannel
2322 bus while maintaining backward compatibility with cards made for
2323 the older ISA bus. The EISA bus saw limited use between 1988 and
2324 1995 when it was made obsolete by the PCI bus.
2326 Say Y here if you are building a kernel for an EISA-based machine.
2330 source "drivers/eisa/Kconfig"
2333 tristate "NatSemi SCx200 support"
2335 This provides basic support for National Semiconductor's
2336 (now AMD's) Geode processors. The driver probes for the
2337 PCI-IDs of several on-chip devices, so its a good dependency
2338 for other scx200_* drivers.
2340 If compiled as a module, the driver is named scx200.
2342 config SCx200HR_TIMER
2343 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2347 This driver provides a clocksource built upon the on-chip
2348 27MHz high-resolution timer. Its also a workaround for
2349 NSC Geode SC-1100's buggy TSC, which loses time when the
2350 processor goes idle (as is done by the scheduler). The
2351 other workaround is idle=poll boot option.
2354 bool "One Laptop Per Child support"
2361 Add support for detecting the unique features of the OLPC
2365 bool "OLPC XO-1 Power Management"
2366 depends on OLPC && MFD_CS5535 && PM_SLEEP
2369 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2372 bool "OLPC XO-1 Real Time Clock"
2373 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2375 Add support for the XO-1 real time clock, which can be used as a
2376 programmable wakeup source.
2379 bool "OLPC XO-1 SCI extras"
2380 depends on OLPC && OLPC_XO1_PM
2386 Add support for SCI-based features of the OLPC XO-1 laptop:
2387 - EC-driven system wakeups
2391 - AC adapter status updates
2392 - Battery status updates
2394 config OLPC_XO15_SCI
2395 bool "OLPC XO-1.5 SCI extras"
2396 depends on OLPC && ACPI
2399 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2400 - EC-driven system wakeups
2401 - AC adapter status updates
2402 - Battery status updates
2405 bool "PCEngines ALIX System Support (LED setup)"
2408 This option enables system support for the PCEngines ALIX.
2409 At present this just sets up LEDs for GPIO control on
2410 ALIX2/3/6 boards. However, other system specific setup should
2413 Note: You must still enable the drivers for GPIO and LED support
2414 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2416 Note: You have to set alix.force=1 for boards with Award BIOS.
2419 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2422 This option enables system support for the Soekris Engineering net5501.
2425 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2429 This option enables system support for the Traverse Technologies GEOS.
2432 bool "Technologic Systems TS-5500 platform support"
2434 select CHECK_SIGNATURE
2438 This option enables system support for the Technologic Systems TS-5500.
2444 depends on CPU_SUP_AMD && PCI
2446 source "drivers/pcmcia/Kconfig"
2448 source "drivers/pci/hotplug/Kconfig"
2451 tristate "RapidIO support"
2455 If enabled this option will include drivers and the core
2456 infrastructure code to support RapidIO interconnect devices.
2458 source "drivers/rapidio/Kconfig"
2461 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2463 Firmwares often provide initial graphics framebuffers so the BIOS,
2464 bootloader or kernel can show basic video-output during boot for
2465 user-guidance and debugging. Historically, x86 used the VESA BIOS
2466 Extensions and EFI-framebuffers for this, which are mostly limited
2468 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2469 framebuffers so the new generic system-framebuffer drivers can be
2470 used on x86. If the framebuffer is not compatible with the generic
2471 modes, it is adverticed as fallback platform framebuffer so legacy
2472 drivers like efifb, vesafb and uvesafb can pick it up.
2473 If this option is not selected, all system framebuffers are always
2474 marked as fallback platform framebuffers as usual.
2476 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2477 not be able to pick up generic system framebuffers if this option
2478 is selected. You are highly encouraged to enable simplefb as
2479 replacement if you select this option. simplefb can correctly deal
2480 with generic system framebuffers. But you should still keep vesafb
2481 and others enabled as fallback if a system framebuffer is
2482 incompatible with simplefb.
2489 menu "Executable file formats / Emulations"
2491 source "fs/Kconfig.binfmt"
2493 config IA32_EMULATION
2494 bool "IA32 Emulation"
2497 select COMPAT_BINFMT_ELF
2500 Include code to run legacy 32-bit programs under a
2501 64-bit kernel. You should likely turn this on, unless you're
2502 100% sure that you don't have any 32-bit programs left.
2505 tristate "IA32 a.out support"
2506 depends on IA32_EMULATION
2508 Support old a.out binaries in the 32bit emulation.
2511 bool "x32 ABI for 64-bit mode"
2512 depends on X86_64 && IA32_EMULATION
2514 Include code to run binaries for the x32 native 32-bit ABI
2515 for 64-bit processors. An x32 process gets access to the
2516 full 64-bit register file and wide data path while leaving
2517 pointers at 32 bits for smaller memory footprint.
2519 You will need a recent binutils (2.22 or later) with
2520 elf32_x86_64 support enabled to compile a kernel with this
2525 depends on IA32_EMULATION || X86_X32
2526 select ARCH_WANT_OLD_COMPAT_IPC
2529 config COMPAT_FOR_U64_ALIGNMENT
2532 config SYSVIPC_COMPAT
2544 config HAVE_ATOMIC_IOMAP
2548 config X86_DEV_DMA_OPS
2550 depends on X86_64 || STA2X11
2552 config X86_DMA_REMAP
2560 source "net/Kconfig"
2562 source "drivers/Kconfig"
2564 source "drivers/firmware/Kconfig"
2568 source "arch/x86/Kconfig.debug"
2570 source "security/Kconfig"
2572 source "crypto/Kconfig"
2574 source "arch/x86/kvm/Kconfig"
2576 source "lib/Kconfig"
projects / linux-drm-fsl-dcu.git / blob