3 bool "64-bit kernel" if ARCH = "x86"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
20 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
27 select ARCH_HAS_ELF_RANDOMIZE
28 select ARCH_HAS_FAST_MULTIPLIER
29 select ARCH_HAS_GCOV_PROFILE_ALL
30 select ARCH_HAS_PMEM_API
31 select ARCH_HAS_SG_CHAIN
32 select ARCH_HAVE_NMI_SAFE_CMPXCHG
33 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
34 select ARCH_MIGHT_HAVE_PC_PARPORT
35 select ARCH_MIGHT_HAVE_PC_SERIO
36 select ARCH_SUPPORTS_ATOMIC_RMW
37 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
38 select ARCH_SUPPORTS_INT128 if X86_64
39 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
40 select ARCH_USE_BUILTIN_BSWAP
41 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
42 select ARCH_USE_QUEUED_RWLOCKS
43 select ARCH_USE_QUEUED_SPINLOCKS
44 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
45 select ARCH_WANT_FRAME_POINTERS
46 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
47 select ARCH_WANT_OPTIONAL_GPIOLIB
48 select BUILDTIME_EXTABLE_SORT
50 select CLKSRC_I8253 if X86_32
51 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
52 select CLOCKSOURCE_WATCHDOG
53 select CLONE_BACKWARDS if X86_32
54 select COMPAT_OLD_SIGACTION if IA32_EMULATION
55 select DCACHE_WORD_ACCESS
56 select EDAC_ATOMIC_SCRUB
58 select GENERIC_CLOCKEVENTS
59 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
60 select GENERIC_CLOCKEVENTS_MIN_ADJUST
61 select GENERIC_CMOS_UPDATE
62 select GENERIC_CPU_AUTOPROBE
63 select GENERIC_EARLY_IOREMAP
64 select GENERIC_FIND_FIRST_BIT
66 select GENERIC_IRQ_PROBE
67 select GENERIC_IRQ_SHOW
68 select GENERIC_PENDING_IRQ if SMP
69 select GENERIC_SMP_IDLE_THREAD
70 select GENERIC_STRNCPY_FROM_USER
71 select GENERIC_STRNLEN_USER
72 select GENERIC_TIME_VSYSCALL
73 select HAVE_ACPI_APEI if ACPI
74 select HAVE_ACPI_APEI_NMI if ACPI
75 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
76 select HAVE_AOUT if X86_32
77 select HAVE_ARCH_AUDITSYSCALL
78 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
79 select HAVE_ARCH_JUMP_LABEL
80 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
82 select HAVE_ARCH_KMEMCHECK
83 select HAVE_ARCH_SECCOMP_FILTER
84 select HAVE_ARCH_SOFT_DIRTY if X86_64
85 select HAVE_ARCH_TRACEHOOK
86 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
87 select HAVE_BPF_JIT if X86_64
88 select HAVE_CC_STACKPROTECTOR
89 select HAVE_CMPXCHG_DOUBLE
90 select HAVE_CMPXCHG_LOCAL
91 select HAVE_CONTEXT_TRACKING if X86_64
92 select HAVE_COPY_THREAD_TLS
93 select HAVE_C_RECORDMCOUNT
94 select HAVE_DEBUG_KMEMLEAK
95 select HAVE_DEBUG_STACKOVERFLOW
96 select HAVE_DMA_API_DEBUG
98 select HAVE_DMA_CONTIGUOUS
99 select HAVE_DYNAMIC_FTRACE
100 select HAVE_DYNAMIC_FTRACE_WITH_REGS
101 select HAVE_EFFICIENT_UNALIGNED_ACCESS
102 select HAVE_FENTRY if X86_64
103 select HAVE_FTRACE_MCOUNT_RECORD
104 select HAVE_FUNCTION_GRAPH_FP_TEST
105 select HAVE_FUNCTION_GRAPH_TRACER
106 select HAVE_FUNCTION_TRACER
107 select HAVE_GENERIC_DMA_COHERENT if X86_32
108 select HAVE_HW_BREAKPOINT
110 select HAVE_IOREMAP_PROT
111 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
112 select HAVE_IRQ_TIME_ACCOUNTING
113 select HAVE_KERNEL_BZIP2
114 select HAVE_KERNEL_GZIP
115 select HAVE_KERNEL_LZ4
116 select HAVE_KERNEL_LZMA
117 select HAVE_KERNEL_LZO
118 select HAVE_KERNEL_XZ
120 select HAVE_KPROBES_ON_FTRACE
121 select HAVE_KRETPROBES
123 select HAVE_LIVEPATCH if X86_64
125 select HAVE_MEMBLOCK_NODE_MAP
126 select HAVE_MIXED_BREAKPOINTS_REGS
128 select HAVE_OPTPROBES
129 select HAVE_PCSPKR_PLATFORM
130 select HAVE_PERF_EVENTS
131 select HAVE_PERF_EVENTS_NMI
132 select HAVE_PERF_REGS
133 select HAVE_PERF_USER_STACK_DUMP
134 select HAVE_REGS_AND_STACK_ACCESS_API
135 select HAVE_SYSCALL_TRACEPOINTS
136 select HAVE_UID16 if X86_32
137 select HAVE_UNSTABLE_SCHED_CLOCK
138 select HAVE_USER_RETURN_NOTIFIER
139 select IRQ_FORCED_THREADING
140 select MODULES_USE_ELF_RELA if X86_64
141 select MODULES_USE_ELF_REL if X86_32
142 select OLD_SIGACTION if X86_32
143 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
148 select SYSCTL_EXCEPTION_TRACE
149 select USER_STACKTRACE_SUPPORT
151 select X86_DEV_DMA_OPS if X86_64
152 select X86_FEATURE_NAMES if PROC_FS
154 config INSTRUCTION_DECODER
156 depends on KPROBES || PERF_EVENTS || UPROBES
158 config PERF_EVENTS_INTEL_UNCORE
160 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
164 default "elf32-i386" if X86_32
165 default "elf64-x86-64" if X86_64
167 config ARCH_DEFCONFIG
169 default "arch/x86/configs/i386_defconfig" if X86_32
170 default "arch/x86/configs/x86_64_defconfig" if X86_64
172 config LOCKDEP_SUPPORT
175 config STACKTRACE_SUPPORT
178 config HAVE_LATENCYTOP_SUPPORT
187 config NEED_DMA_MAP_STATE
189 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
191 config NEED_SG_DMA_LENGTH
194 config GENERIC_ISA_DMA
196 depends on ISA_DMA_API
201 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
203 config GENERIC_BUG_RELATIVE_POINTERS
206 config GENERIC_HWEIGHT
209 config ARCH_MAY_HAVE_PC_FDC
211 depends on ISA_DMA_API
213 config RWSEM_XCHGADD_ALGORITHM
216 config GENERIC_CALIBRATE_DELAY
219 config ARCH_HAS_CPU_RELAX
222 config ARCH_HAS_CACHE_LINE_SIZE
225 config HAVE_SETUP_PER_CPU_AREA
228 config NEED_PER_CPU_EMBED_FIRST_CHUNK
231 config NEED_PER_CPU_PAGE_FIRST_CHUNK
234 config ARCH_HIBERNATION_POSSIBLE
237 config ARCH_SUSPEND_POSSIBLE
240 config ARCH_WANT_HUGE_PMD_SHARE
243 config ARCH_WANT_GENERAL_HUGETLB
252 config ARCH_SUPPORTS_OPTIMIZED_INLINING
255 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
258 config KASAN_SHADOW_OFFSET
261 default 0xdffffc0000000000
263 config HAVE_INTEL_TXT
265 depends on INTEL_IOMMU && ACPI
269 depends on X86_32 && SMP
273 depends on X86_64 && SMP
275 config X86_32_LAZY_GS
277 depends on X86_32 && !CC_STACKPROTECTOR
279 config ARCH_HWEIGHT_CFLAGS
281 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
282 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
284 config ARCH_SUPPORTS_UPROBES
287 config FIX_EARLYCON_MEM
290 config PGTABLE_LEVELS
296 source "init/Kconfig"
297 source "kernel/Kconfig.freezer"
299 menu "Processor type and features"
302 bool "DMA memory allocation support" if EXPERT
305 DMA memory allocation support allows devices with less than 32-bit
306 addressing to allocate within the first 16MB of address space.
307 Disable if no such devices will be used.
312 bool "Symmetric multi-processing support"
314 This enables support for systems with more than one CPU. If you have
315 a system with only one CPU, say N. If you have a system with more
318 If you say N here, the kernel will run on uni- and multiprocessor
319 machines, but will use only one CPU of a multiprocessor machine. If
320 you say Y here, the kernel will run on many, but not all,
321 uniprocessor machines. On a uniprocessor machine, the kernel
322 will run faster if you say N here.
324 Note that if you say Y here and choose architecture "586" or
325 "Pentium" under "Processor family", the kernel will not work on 486
326 architectures. Similarly, multiprocessor kernels for the "PPro"
327 architecture may not work on all Pentium based boards.
329 People using multiprocessor machines who say Y here should also say
330 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
331 Management" code will be disabled if you say Y here.
333 See also <file:Documentation/x86/i386/IO-APIC.txt>,
334 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
335 <http://www.tldp.org/docs.html#howto>.
337 If you don't know what to do here, say N.
339 config X86_FEATURE_NAMES
340 bool "Processor feature human-readable names" if EMBEDDED
343 This option compiles in a table of x86 feature bits and corresponding
344 names. This is required to support /proc/cpuinfo and a few kernel
345 messages. You can disable this to save space, at the expense of
346 making those few kernel messages show numeric feature bits instead.
351 bool "Support x2apic"
352 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
354 This enables x2apic support on CPUs that have this feature.
356 This allows 32-bit apic IDs (so it can support very large systems),
357 and accesses the local apic via MSRs not via mmio.
359 If you don't know what to do here, say N.
362 bool "Enable MPS table" if ACPI || SFI
364 depends on X86_LOCAL_APIC
366 For old smp systems that do not have proper acpi support. Newer systems
367 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
370 bool "Support for big SMP systems with more than 8 CPUs"
371 depends on X86_32 && SMP
373 This option is needed for the systems that have more than 8 CPUs
377 depends on X86_GOLDFISH
380 config X86_EXTENDED_PLATFORM
381 bool "Support for extended (non-PC) x86 platforms"
384 If you disable this option then the kernel will only support
385 standard PC platforms. (which covers the vast majority of
388 If you enable this option then you'll be able to select support
389 for the following (non-PC) 32 bit x86 platforms:
390 Goldfish (Android emulator)
393 SGI 320/540 (Visual Workstation)
394 STA2X11-based (e.g. Northville)
395 Moorestown MID devices
397 If you have one of these systems, or if you want to build a
398 generic distribution kernel, say Y here - otherwise say N.
402 config X86_EXTENDED_PLATFORM
403 bool "Support for extended (non-PC) x86 platforms"
406 If you disable this option then the kernel will only support
407 standard PC platforms. (which covers the vast majority of
410 If you enable this option then you'll be able to select support
411 for the following (non-PC) 64 bit x86 platforms:
416 If you have one of these systems, or if you want to build a
417 generic distribution kernel, say Y here - otherwise say N.
419 # This is an alphabetically sorted list of 64 bit extended platforms
420 # Please maintain the alphabetic order if and when there are additions
422 bool "Numascale NumaChip"
424 depends on X86_EXTENDED_PLATFORM
427 depends on X86_X2APIC
428 depends on PCI_MMCONFIG
430 Adds support for Numascale NumaChip large-SMP systems. Needed to
431 enable more than ~168 cores.
432 If you don't have one of these, you should say N here.
436 select HYPERVISOR_GUEST
438 depends on X86_64 && PCI
439 depends on X86_EXTENDED_PLATFORM
442 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
443 supposed to run on these EM64T-based machines. Only choose this option
444 if you have one of these machines.
447 bool "SGI Ultraviolet"
449 depends on X86_EXTENDED_PLATFORM
451 depends on X86_X2APIC
454 This option is needed in order to support SGI Ultraviolet systems.
455 If you don't have one of these, you should say N here.
457 # Following is an alphabetically sorted list of 32 bit extended platforms
458 # Please maintain the alphabetic order if and when there are additions
461 bool "Goldfish (Virtual Platform)"
462 depends on X86_EXTENDED_PLATFORM
464 Enable support for the Goldfish virtual platform used primarily
465 for Android development. Unless you are building for the Android
466 Goldfish emulator say N here.
469 bool "CE4100 TV platform"
471 depends on PCI_GODIRECT
472 depends on X86_IO_APIC
474 depends on X86_EXTENDED_PLATFORM
475 select X86_REBOOTFIXUPS
477 select OF_EARLY_FLATTREE
479 Select for the Intel CE media processor (CE4100) SOC.
480 This option compiles in support for the CE4100 SOC for settop
481 boxes and media devices.
484 bool "Intel MID platform support"
486 depends on X86_EXTENDED_PLATFORM
487 depends on X86_PLATFORM_DEVICES
490 depends on X86_IO_APIC
496 select MFD_INTEL_MSIC
498 Select to build a kernel capable of supporting Intel MID (Mobile
499 Internet Device) platform systems which do not have the PCI legacy
500 interfaces. If you are building for a PC class system say N here.
502 Intel MID platforms are based on an Intel processor and chipset which
503 consume less power than most of the x86 derivatives.
505 config X86_INTEL_QUARK
506 bool "Intel Quark platform support"
508 depends on X86_EXTENDED_PLATFORM
509 depends on X86_PLATFORM_DEVICES
513 depends on X86_IO_APIC
518 Select to include support for Quark X1000 SoC.
519 Say Y here if you have a Quark based system such as the Arduino
520 compatible Intel Galileo.
522 config X86_INTEL_LPSS
523 bool "Intel Low Power Subsystem Support"
528 Select to build support for Intel Low Power Subsystem such as
529 found on Intel Lynxpoint PCH. Selecting this option enables
530 things like clock tree (common clock framework) and pincontrol
531 which are needed by the LPSS peripheral drivers.
533 config X86_AMD_PLATFORM_DEVICE
534 bool "AMD ACPI2Platform devices support"
539 Select to interpret AMD specific ACPI device to platform device
540 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
541 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
542 implemented under PINCTRL subsystem.
545 tristate "Intel SoC IOSF Sideband support for SoC platforms"
548 This option enables sideband register access support for Intel SoC
549 platforms. On these platforms the IOSF sideband is used in lieu of
550 MSR's for some register accesses, mostly but not limited to thermal
551 and power. Drivers may query the availability of this device to
552 determine if they need the sideband in order to work on these
553 platforms. The sideband is available on the following SoC products.
554 This list is not meant to be exclusive.
559 You should say Y if you are running a kernel on one of these SoC's.
561 config IOSF_MBI_DEBUG
562 bool "Enable IOSF sideband access through debugfs"
563 depends on IOSF_MBI && DEBUG_FS
565 Select this option to expose the IOSF sideband access registers (MCR,
566 MDR, MCRX) through debugfs to write and read register information from
567 different units on the SoC. This is most useful for obtaining device
568 state information for debug and analysis. As this is a general access
569 mechanism, users of this option would have specific knowledge of the
570 device they want to access.
572 If you don't require the option or are in doubt, say N.
575 bool "RDC R-321x SoC"
577 depends on X86_EXTENDED_PLATFORM
579 select X86_REBOOTFIXUPS
581 This option is needed for RDC R-321x system-on-chip, also known
583 If you don't have one of these chips, you should say N here.
585 config X86_32_NON_STANDARD
586 bool "Support non-standard 32-bit SMP architectures"
587 depends on X86_32 && SMP
588 depends on X86_EXTENDED_PLATFORM
590 This option compiles in the bigsmp and STA2X11 default
591 subarchitectures. It is intended for a generic binary
592 kernel. If you select them all, kernel will probe it one by
593 one and will fallback to default.
595 # Alphabetically sorted list of Non standard 32 bit platforms
597 config X86_SUPPORTS_MEMORY_FAILURE
599 # MCE code calls memory_failure():
601 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
602 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
603 depends on X86_64 || !SPARSEMEM
604 select ARCH_SUPPORTS_MEMORY_FAILURE
607 bool "STA2X11 Companion Chip Support"
608 depends on X86_32_NON_STANDARD && PCI
609 select X86_DEV_DMA_OPS
613 select ARCH_REQUIRE_GPIOLIB
616 This adds support for boards based on the STA2X11 IO-Hub,
617 a.k.a. "ConneXt". The chip is used in place of the standard
618 PC chipset, so all "standard" peripherals are missing. If this
619 option is selected the kernel will still be able to boot on
620 standard PC machines.
623 tristate "Eurobraille/Iris poweroff module"
626 The Iris machines from EuroBraille do not have APM or ACPI support
627 to shut themselves down properly. A special I/O sequence is
628 needed to do so, which is what this module does at
631 This is only for Iris machines from EuroBraille.
635 config SCHED_OMIT_FRAME_POINTER
637 prompt "Single-depth WCHAN output"
640 Calculate simpler /proc/<PID>/wchan values. If this option
641 is disabled then wchan values will recurse back to the
642 caller function. This provides more accurate wchan values,
643 at the expense of slightly more scheduling overhead.
645 If in doubt, say "Y".
647 menuconfig HYPERVISOR_GUEST
648 bool "Linux guest support"
650 Say Y here to enable options for running Linux under various hyper-
651 visors. This option enables basic hypervisor detection and platform
654 If you say N, all options in this submenu will be skipped and
655 disabled, and Linux guest support won't be built in.
660 bool "Enable paravirtualization code"
662 This changes the kernel so it can modify itself when it is run
663 under a hypervisor, potentially improving performance significantly
664 over full virtualization. However, when run without a hypervisor
665 the kernel is theoretically slower and slightly larger.
667 config PARAVIRT_DEBUG
668 bool "paravirt-ops debugging"
669 depends on PARAVIRT && DEBUG_KERNEL
671 Enable to debug paravirt_ops internals. Specifically, BUG if
672 a paravirt_op is missing when it is called.
674 config PARAVIRT_SPINLOCKS
675 bool "Paravirtualization layer for spinlocks"
676 depends on PARAVIRT && SMP
677 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
679 Paravirtualized spinlocks allow a pvops backend to replace the
680 spinlock implementation with something virtualization-friendly
681 (for example, block the virtual CPU rather than spinning).
683 It has a minimal impact on native kernels and gives a nice performance
684 benefit on paravirtualized KVM / Xen kernels.
686 If you are unsure how to answer this question, answer Y.
688 source "arch/x86/xen/Kconfig"
691 bool "KVM Guest support (including kvmclock)"
693 select PARAVIRT_CLOCK
696 This option enables various optimizations for running under the KVM
697 hypervisor. It includes a paravirtualized clock, so that instead
698 of relying on a PIT (or probably other) emulation by the
699 underlying device model, the host provides the guest with
700 timing infrastructure such as time of day, and system time
703 bool "Enable debug information for KVM Guests in debugfs"
704 depends on KVM_GUEST && DEBUG_FS
707 This option enables collection of various statistics for KVM guest.
708 Statistics are displayed in debugfs filesystem. Enabling this option
709 may incur significant overhead.
711 source "arch/x86/lguest/Kconfig"
713 config PARAVIRT_TIME_ACCOUNTING
714 bool "Paravirtual steal time accounting"
718 Select this option to enable fine granularity task steal time
719 accounting. Time spent executing other tasks in parallel with
720 the current vCPU is discounted from the vCPU power. To account for
721 that, there can be a small performance impact.
723 If in doubt, say N here.
725 config PARAVIRT_CLOCK
728 endif #HYPERVISOR_GUEST
733 source "arch/x86/Kconfig.cpu"
737 prompt "HPET Timer Support" if X86_32
739 Use the IA-PC HPET (High Precision Event Timer) to manage
740 time in preference to the PIT and RTC, if a HPET is
742 HPET is the next generation timer replacing legacy 8254s.
743 The HPET 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. You can find the HPET spec at
746 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
748 You can safely choose Y here. However, HPET will only be
749 activated if the platform and the BIOS support this feature.
750 Otherwise the 8254 will be used for timing services.
752 Choose N to continue using the legacy 8254 timer.
754 config HPET_EMULATE_RTC
756 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
759 def_bool y if X86_INTEL_MID
760 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
762 depends on X86_INTEL_MID && SFI
764 APB timer is the replacement for 8254, HPET on X86 MID platforms.
765 The APBT provides a stable time base on SMP
766 systems, unlike the TSC, but it is more expensive to access,
767 as it is off-chip. APB timers are always running regardless of CPU
768 C states, they are used as per CPU clockevent device when possible.
770 # Mark as expert because too many people got it wrong.
771 # The code disables itself when not needed.
774 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
775 bool "Enable DMI scanning" if EXPERT
777 Enabled scanning of DMI to identify machine quirks. Say Y
778 here unless you have verified that your setup is not
779 affected by entries in the DMI blacklist. Required by PNP
783 bool "Old AMD GART IOMMU support"
785 depends on X86_64 && PCI && AMD_NB
787 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
788 GART based hardware IOMMUs.
790 The GART supports full DMA access for devices with 32-bit access
791 limitations, on systems with more than 3 GB. This is usually needed
792 for USB, sound, many IDE/SATA chipsets and some other devices.
794 Newer systems typically have a modern AMD IOMMU, supported via
795 the CONFIG_AMD_IOMMU=y config option.
797 In normal configurations this driver is only active when needed:
798 there's more than 3 GB of memory and the system contains a
799 32-bit limited device.
804 bool "IBM Calgary IOMMU support"
806 depends on X86_64 && PCI
808 Support for hardware IOMMUs in IBM's xSeries x366 and x460
809 systems. Needed to run systems with more than 3GB of memory
810 properly with 32-bit PCI devices that do not support DAC
811 (Double Address Cycle). Calgary also supports bus level
812 isolation, where all DMAs pass through the IOMMU. This
813 prevents them from going anywhere except their intended
814 destination. This catches hard-to-find kernel bugs and
815 mis-behaving drivers and devices that do not use the DMA-API
816 properly to set up their DMA buffers. The IOMMU can be
817 turned off at boot time with the iommu=off parameter.
818 Normally the kernel will make the right choice by itself.
821 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
823 prompt "Should Calgary be enabled by default?"
824 depends on CALGARY_IOMMU
826 Should Calgary be enabled by default? if you choose 'y', Calgary
827 will be used (if it exists). If you choose 'n', Calgary will not be
828 used even if it exists. If you choose 'n' and would like to use
829 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
832 # need this always selected by IOMMU for the VIA workaround
836 Support for software bounce buffers used on x86-64 systems
837 which don't have a hardware IOMMU. Using this PCI devices
838 which can only access 32-bits of memory can be used on systems
839 with more than 3 GB of memory.
844 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
847 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
848 depends on X86_64 && SMP && DEBUG_KERNEL
849 select CPUMASK_OFFSTACK
851 Enable maximum number of CPUS and NUMA Nodes for this architecture.
855 int "Maximum number of CPUs" if SMP && !MAXSMP
856 range 2 8 if SMP && X86_32 && !X86_BIGSMP
857 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
858 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
860 default "8192" if MAXSMP
861 default "32" if SMP && X86_BIGSMP
862 default "8" if SMP && X86_32
865 This allows you to specify the maximum number of CPUs which this
866 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
867 supported value is 8192, otherwise the maximum value is 512. The
868 minimum value which makes sense is 2.
870 This is purely to save memory - each supported CPU adds
871 approximately eight kilobytes to the kernel image.
874 bool "SMT (Hyperthreading) scheduler support"
877 SMT scheduler support improves the CPU scheduler's decision making
878 when dealing with Intel Pentium 4 chips with HyperThreading at a
879 cost of slightly increased overhead in some places. If unsure say
884 prompt "Multi-core scheduler support"
887 Multi-core scheduler support improves the CPU scheduler's decision
888 making when dealing with multi-core CPU chips at a cost of slightly
889 increased overhead in some places. If unsure say N here.
891 source "kernel/Kconfig.preempt"
895 depends on !SMP && X86_LOCAL_APIC
898 bool "Local APIC support on uniprocessors" if !PCI_MSI
900 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
902 A local APIC (Advanced Programmable Interrupt Controller) is an
903 integrated interrupt controller in the CPU. If you have a single-CPU
904 system which has a processor with a local APIC, you can say Y here to
905 enable and use it. If you say Y here even though your machine doesn't
906 have a local APIC, then the kernel will still run with no slowdown at
907 all. The local APIC supports CPU-generated self-interrupts (timer,
908 performance counters), and the NMI watchdog which detects hard
912 bool "IO-APIC support on uniprocessors"
913 depends on X86_UP_APIC
915 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
916 SMP-capable replacement for PC-style interrupt controllers. Most
917 SMP systems and many recent uniprocessor systems have one.
919 If you have a single-CPU system with an IO-APIC, you can say Y here
920 to use it. If you say Y here even though your machine doesn't have
921 an IO-APIC, then the kernel will still run with no slowdown at all.
923 config X86_LOCAL_APIC
925 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
926 select IRQ_DOMAIN_HIERARCHY
927 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
931 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
933 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
934 bool "Reroute for broken boot IRQs"
935 depends on X86_IO_APIC
937 This option enables a workaround that fixes a source of
938 spurious interrupts. This is recommended when threaded
939 interrupt handling is used on systems where the generation of
940 superfluous "boot interrupts" cannot be disabled.
942 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
943 entry in the chipset's IO-APIC is masked (as, e.g. the RT
944 kernel does during interrupt handling). On chipsets where this
945 boot IRQ generation cannot be disabled, this workaround keeps
946 the original IRQ line masked so that only the equivalent "boot
947 IRQ" is delivered to the CPUs. The workaround also tells the
948 kernel to set up the IRQ handler on the boot IRQ line. In this
949 way only one interrupt is delivered to the kernel. Otherwise
950 the spurious second interrupt may cause the kernel to bring
951 down (vital) interrupt lines.
953 Only affects "broken" chipsets. Interrupt sharing may be
954 increased on these systems.
957 bool "Machine Check / overheating reporting"
960 Machine Check support allows the processor to notify the
961 kernel if it detects a problem (e.g. overheating, data corruption).
962 The action the kernel takes depends on the severity of the problem,
963 ranging from warning messages to halting the machine.
967 prompt "Intel MCE features"
968 depends on X86_MCE && X86_LOCAL_APIC
970 Additional support for intel specific MCE features such as
975 prompt "AMD MCE features"
976 depends on X86_MCE && X86_LOCAL_APIC
978 Additional support for AMD specific MCE features such as
979 the DRAM Error Threshold.
981 config X86_ANCIENT_MCE
982 bool "Support for old Pentium 5 / WinChip machine checks"
983 depends on X86_32 && X86_MCE
985 Include support for machine check handling on old Pentium 5 or WinChip
986 systems. These typically need to be enabled explicitly on the command
989 config X86_MCE_THRESHOLD
990 depends on X86_MCE_AMD || X86_MCE_INTEL
993 config X86_MCE_INJECT
995 tristate "Machine check injector support"
997 Provide support for injecting machine checks for testing purposes.
998 If you don't know what a machine check is and you don't do kernel
999 QA it is safe to say n.
1001 config X86_THERMAL_VECTOR
1003 depends on X86_MCE_INTEL
1006 bool "Enable VM86 support" if EXPERT
1010 This option is required by programs like DOSEMU to run
1011 16-bit real mode legacy code on x86 processors. It also may
1012 be needed by software like XFree86 to initialize some video
1013 cards via BIOS. Disabling this option saves about 6K.
1016 bool "Enable support for 16-bit segments" if EXPERT
1019 This option is required by programs like Wine to run 16-bit
1020 protected mode legacy code on x86 processors. Disabling
1021 this option saves about 300 bytes on i386, or around 6K text
1022 plus 16K runtime memory on x86-64,
1026 depends on X86_16BIT && X86_32
1030 depends on X86_16BIT && X86_64
1032 config X86_VSYSCALL_EMULATION
1033 bool "Enable vsyscall emulation" if EXPERT
1037 This enables emulation of the legacy vsyscall page. Disabling
1038 it is roughly equivalent to booting with vsyscall=none, except
1039 that it will also disable the helpful warning if a program
1040 tries to use a vsyscall. With this option set to N, offending
1041 programs will just segfault, citing addresses of the form
1044 This option is required by many programs built before 2013, and
1045 care should be used even with newer programs if set to N.
1047 Disabling this option saves about 7K of kernel size and
1048 possibly 4K of additional runtime pagetable memory.
1051 tristate "Toshiba Laptop support"
1054 This adds a driver to safely access the System Management Mode of
1055 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1056 not work on models with a Phoenix BIOS. The System Management Mode
1057 is used to set the BIOS and power saving options on Toshiba portables.
1059 For information on utilities to make use of this driver see the
1060 Toshiba Linux utilities web site at:
1061 <http://www.buzzard.org.uk/toshiba/>.
1063 Say Y if you intend to run this kernel on a Toshiba portable.
1067 tristate "Dell i8k legacy laptop support"
1069 select SENSORS_DELL_SMM
1071 This option enables legacy /proc/i8k userspace interface in hwmon
1072 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1073 temperature and allows controlling fan speeds of Dell laptops via
1074 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1075 it reports also power and hotkey status. For fan speed control is
1076 needed userspace package i8kutils.
1078 Say Y if you intend to run this kernel on old Dell laptops or want to
1079 use userspace package i8kutils.
1082 config X86_REBOOTFIXUPS
1083 bool "Enable X86 board specific fixups for reboot"
1086 This enables chipset and/or board specific fixups to be done
1087 in order to get reboot to work correctly. This is only needed on
1088 some combinations of hardware and BIOS. The symptom, for which
1089 this config is intended, is when reboot ends with a stalled/hung
1092 Currently, the only fixup is for the Geode machines using
1093 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1095 Say Y if you want to enable the fixup. Currently, it's safe to
1096 enable this option even if you don't need it.
1100 tristate "CPU microcode loading support"
1101 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1105 If you say Y here, you will be able to update the microcode on
1106 certain Intel and AMD processors. The Intel support is for the
1107 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1108 Xeon etc. The AMD support is for families 0x10 and later. You will
1109 obviously need the actual microcode binary data itself which is not
1110 shipped with the Linux kernel.
1112 This option selects the general module only, you need to select
1113 at least one vendor specific module as well.
1115 To compile this driver as a module, choose M here: the module
1116 will be called microcode.
1118 config MICROCODE_INTEL
1119 bool "Intel microcode loading support"
1120 depends on MICROCODE
1124 This options enables microcode patch loading support for Intel
1127 For the current Intel microcode data package go to
1128 <https://downloadcenter.intel.com> and search for
1129 'Linux Processor Microcode Data File'.
1131 config MICROCODE_AMD
1132 bool "AMD microcode loading support"
1133 depends on MICROCODE
1136 If you select this option, microcode patch loading support for AMD
1137 processors will be enabled.
1139 config MICROCODE_OLD_INTERFACE
1141 depends on MICROCODE
1143 config MICROCODE_INTEL_EARLY
1146 config MICROCODE_AMD_EARLY
1149 config MICROCODE_EARLY
1150 bool "Early load microcode"
1151 depends on MICROCODE=y && BLK_DEV_INITRD
1152 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1153 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1156 This option provides functionality to read additional microcode data
1157 at the beginning of initrd image. The data tells kernel to load
1158 microcode to CPU's as early as possible. No functional change if no
1159 microcode data is glued to the initrd, therefore it's safe to say Y.
1162 tristate "/dev/cpu/*/msr - Model-specific register support"
1164 This device gives privileged processes access to the x86
1165 Model-Specific Registers (MSRs). It is a character device with
1166 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1167 MSR accesses are directed to a specific CPU on multi-processor
1171 tristate "/dev/cpu/*/cpuid - CPU information support"
1173 This device gives processes access to the x86 CPUID instruction to
1174 be executed on a specific processor. It is a character device
1175 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1179 prompt "High Memory Support"
1186 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1187 However, the address space of 32-bit x86 processors is only 4
1188 Gigabytes large. That means that, if you have a large amount of
1189 physical memory, not all of it can be "permanently mapped" by the
1190 kernel. The physical memory that's not permanently mapped is called
1193 If you are compiling a kernel which will never run on a machine with
1194 more than 1 Gigabyte total physical RAM, answer "off" here (default
1195 choice and suitable for most users). This will result in a "3GB/1GB"
1196 split: 3GB are mapped so that each process sees a 3GB virtual memory
1197 space and the remaining part of the 4GB virtual memory space is used
1198 by the kernel to permanently map as much physical memory as
1201 If the machine has between 1 and 4 Gigabytes physical RAM, then
1204 If more than 4 Gigabytes is used then answer "64GB" here. This
1205 selection turns Intel PAE (Physical Address Extension) mode on.
1206 PAE implements 3-level paging on IA32 processors. PAE is fully
1207 supported by Linux, PAE mode is implemented on all recent Intel
1208 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1209 then the kernel will not boot on CPUs that don't support PAE!
1211 The actual amount of total physical memory will either be
1212 auto detected or can be forced by using a kernel command line option
1213 such as "mem=256M". (Try "man bootparam" or see the documentation of
1214 your boot loader (lilo or loadlin) about how to pass options to the
1215 kernel at boot time.)
1217 If unsure, say "off".
1222 Select this if you have a 32-bit processor and between 1 and 4
1223 gigabytes of physical RAM.
1230 Select this if you have a 32-bit processor and more than 4
1231 gigabytes of physical RAM.
1236 prompt "Memory split" if EXPERT
1240 Select the desired split between kernel and user memory.
1242 If the address range available to the kernel is less than the
1243 physical memory installed, the remaining memory will be available
1244 as "high memory". Accessing high memory is a little more costly
1245 than low memory, as it needs to be mapped into the kernel first.
1246 Note that increasing the kernel address space limits the range
1247 available to user programs, making the address space there
1248 tighter. Selecting anything other than the default 3G/1G split
1249 will also likely make your kernel incompatible with binary-only
1252 If you are not absolutely sure what you are doing, leave this
1256 bool "3G/1G user/kernel split"
1257 config VMSPLIT_3G_OPT
1259 bool "3G/1G user/kernel split (for full 1G low memory)"
1261 bool "2G/2G user/kernel split"
1262 config VMSPLIT_2G_OPT
1264 bool "2G/2G user/kernel split (for full 2G low memory)"
1266 bool "1G/3G user/kernel split"
1271 default 0xB0000000 if VMSPLIT_3G_OPT
1272 default 0x80000000 if VMSPLIT_2G
1273 default 0x78000000 if VMSPLIT_2G_OPT
1274 default 0x40000000 if VMSPLIT_1G
1280 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1283 bool "PAE (Physical Address Extension) Support"
1284 depends on X86_32 && !HIGHMEM4G
1286 PAE is required for NX support, and furthermore enables
1287 larger swapspace support for non-overcommit purposes. It
1288 has the cost of more pagetable lookup overhead, and also
1289 consumes more pagetable space per process.
1291 config ARCH_PHYS_ADDR_T_64BIT
1293 depends on X86_64 || X86_PAE
1295 config ARCH_DMA_ADDR_T_64BIT
1297 depends on X86_64 || HIGHMEM64G
1299 config X86_DIRECT_GBPAGES
1301 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1303 Certain kernel features effectively disable kernel
1304 linear 1 GB mappings (even if the CPU otherwise
1305 supports them), so don't confuse the user by printing
1306 that we have them enabled.
1308 # Common NUMA Features
1310 bool "Numa Memory Allocation and Scheduler Support"
1312 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1313 default y if X86_BIGSMP
1315 Enable NUMA (Non Uniform Memory Access) support.
1317 The kernel will try to allocate memory used by a CPU on the
1318 local memory controller of the CPU and add some more
1319 NUMA awareness to the kernel.
1321 For 64-bit this is recommended if the system is Intel Core i7
1322 (or later), AMD Opteron, or EM64T NUMA.
1324 For 32-bit this is only needed if you boot a 32-bit
1325 kernel on a 64-bit NUMA platform.
1327 Otherwise, you should say N.
1331 prompt "Old style AMD Opteron NUMA detection"
1332 depends on X86_64 && NUMA && PCI
1334 Enable AMD NUMA node topology detection. You should say Y here if
1335 you have a multi processor AMD system. This uses an old method to
1336 read the NUMA configuration directly from the builtin Northbridge
1337 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1338 which also takes priority if both are compiled in.
1340 config X86_64_ACPI_NUMA
1342 prompt "ACPI NUMA detection"
1343 depends on X86_64 && NUMA && ACPI && PCI
1346 Enable ACPI SRAT based node topology detection.
1348 # Some NUMA nodes have memory ranges that span
1349 # other nodes. Even though a pfn is valid and
1350 # between a node's start and end pfns, it may not
1351 # reside on that node. See memmap_init_zone()
1353 config NODES_SPAN_OTHER_NODES
1355 depends on X86_64_ACPI_NUMA
1358 bool "NUMA emulation"
1361 Enable NUMA emulation. A flat machine will be split
1362 into virtual nodes when booted with "numa=fake=N", where N is the
1363 number of nodes. This is only useful for debugging.
1366 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1368 default "10" if MAXSMP
1369 default "6" if X86_64
1371 depends on NEED_MULTIPLE_NODES
1373 Specify the maximum number of NUMA Nodes available on the target
1374 system. Increases memory reserved to accommodate various tables.
1376 config ARCH_HAVE_MEMORY_PRESENT
1378 depends on X86_32 && DISCONTIGMEM
1380 config NEED_NODE_MEMMAP_SIZE
1382 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1384 config ARCH_FLATMEM_ENABLE
1386 depends on X86_32 && !NUMA
1388 config ARCH_DISCONTIGMEM_ENABLE
1390 depends on NUMA && X86_32
1392 config ARCH_DISCONTIGMEM_DEFAULT
1394 depends on NUMA && X86_32
1396 config ARCH_SPARSEMEM_ENABLE
1398 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1399 select SPARSEMEM_STATIC if X86_32
1400 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1402 config ARCH_SPARSEMEM_DEFAULT
1406 config ARCH_SELECT_MEMORY_MODEL
1408 depends on ARCH_SPARSEMEM_ENABLE
1410 config ARCH_MEMORY_PROBE
1411 bool "Enable sysfs memory/probe interface"
1412 depends on X86_64 && MEMORY_HOTPLUG
1414 This option enables a sysfs memory/probe interface for testing.
1415 See Documentation/memory-hotplug.txt for more information.
1416 If you are unsure how to answer this question, answer N.
1418 config ARCH_PROC_KCORE_TEXT
1420 depends on X86_64 && PROC_KCORE
1422 config ILLEGAL_POINTER_VALUE
1425 default 0xdead000000000000 if X86_64
1429 config X86_PMEM_LEGACY
1430 bool "Support non-standard NVDIMMs and ADR protected memory"
1431 depends on PHYS_ADDR_T_64BIT
1435 Treat memory marked using the non-standard e820 type of 12 as used
1436 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1437 The kernel will offer these regions to the 'pmem' driver so
1438 they can be used for persistent storage.
1443 bool "Allocate 3rd-level pagetables from highmem"
1446 The VM uses one page table entry for each page of physical memory.
1447 For systems with a lot of RAM, this can be wasteful of precious
1448 low memory. Setting this option will put user-space page table
1449 entries in high memory.
1451 config X86_CHECK_BIOS_CORRUPTION
1452 bool "Check for low memory corruption"
1454 Periodically check for memory corruption in low memory, which
1455 is suspected to be caused by BIOS. Even when enabled in the
1456 configuration, it is disabled at runtime. Enable it by
1457 setting "memory_corruption_check=1" on the kernel command
1458 line. By default it scans the low 64k of memory every 60
1459 seconds; see the memory_corruption_check_size and
1460 memory_corruption_check_period parameters in
1461 Documentation/kernel-parameters.txt to adjust this.
1463 When enabled with the default parameters, this option has
1464 almost no overhead, as it reserves a relatively small amount
1465 of memory and scans it infrequently. It both detects corruption
1466 and prevents it from affecting the running system.
1468 It is, however, intended as a diagnostic tool; if repeatable
1469 BIOS-originated corruption always affects the same memory,
1470 you can use memmap= to prevent the kernel from using that
1473 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1474 bool "Set the default setting of memory_corruption_check"
1475 depends on X86_CHECK_BIOS_CORRUPTION
1478 Set whether the default state of memory_corruption_check is
1481 config X86_RESERVE_LOW
1482 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1486 Specify the amount of low memory to reserve for the BIOS.
1488 The first page contains BIOS data structures that the kernel
1489 must not use, so that page must always be reserved.
1491 By default we reserve the first 64K of physical RAM, as a
1492 number of BIOSes are known to corrupt that memory range
1493 during events such as suspend/resume or monitor cable
1494 insertion, so it must not be used by the kernel.
1496 You can set this to 4 if you are absolutely sure that you
1497 trust the BIOS to get all its memory reservations and usages
1498 right. If you know your BIOS have problems beyond the
1499 default 64K area, you can set this to 640 to avoid using the
1500 entire low memory range.
1502 If you have doubts about the BIOS (e.g. suspend/resume does
1503 not work or there's kernel crashes after certain hardware
1504 hotplug events) then you might want to enable
1505 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1506 typical corruption patterns.
1508 Leave this to the default value of 64 if you are unsure.
1510 config MATH_EMULATION
1512 prompt "Math emulation" if X86_32
1514 Linux can emulate a math coprocessor (used for floating point
1515 operations) if you don't have one. 486DX and Pentium processors have
1516 a math coprocessor built in, 486SX and 386 do not, unless you added
1517 a 487DX or 387, respectively. (The messages during boot time can
1518 give you some hints here ["man dmesg"].) Everyone needs either a
1519 coprocessor or this emulation.
1521 If you don't have a math coprocessor, you need to say Y here; if you
1522 say Y here even though you have a coprocessor, the coprocessor will
1523 be used nevertheless. (This behavior can be changed with the kernel
1524 command line option "no387", which comes handy if your coprocessor
1525 is broken. Try "man bootparam" or see the documentation of your boot
1526 loader (lilo or loadlin) about how to pass options to the kernel at
1527 boot time.) This means that it is a good idea to say Y here if you
1528 intend to use this kernel on different machines.
1530 More information about the internals of the Linux math coprocessor
1531 emulation can be found in <file:arch/x86/math-emu/README>.
1533 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1534 kernel, it won't hurt.
1538 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1540 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1541 the Memory Type Range Registers (MTRRs) may be used to control
1542 processor access to memory ranges. This is most useful if you have
1543 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1544 allows bus write transfers to be combined into a larger transfer
1545 before bursting over the PCI/AGP bus. This can increase performance
1546 of image write operations 2.5 times or more. Saying Y here creates a
1547 /proc/mtrr file which may be used to manipulate your processor's
1548 MTRRs. Typically the X server should use this.
1550 This code has a reasonably generic interface so that similar
1551 control registers on other processors can be easily supported
1554 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1555 Registers (ARRs) which provide a similar functionality to MTRRs. For
1556 these, the ARRs are used to emulate the MTRRs.
1557 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1558 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1559 write-combining. All of these processors are supported by this code
1560 and it makes sense to say Y here if you have one of them.
1562 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1563 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1564 can lead to all sorts of problems, so it's good to say Y here.
1566 You can safely say Y even if your machine doesn't have MTRRs, you'll
1567 just add about 9 KB to your kernel.
1569 See <file:Documentation/x86/mtrr.txt> for more information.
1571 config MTRR_SANITIZER
1573 prompt "MTRR cleanup support"
1576 Convert MTRR layout from continuous to discrete, so X drivers can
1577 add writeback entries.
1579 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1580 The largest mtrr entry size for a continuous block can be set with
1585 config MTRR_SANITIZER_ENABLE_DEFAULT
1586 int "MTRR cleanup enable value (0-1)"
1589 depends on MTRR_SANITIZER
1591 Enable mtrr cleanup default value
1593 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1594 int "MTRR cleanup spare reg num (0-7)"
1597 depends on MTRR_SANITIZER
1599 mtrr cleanup spare entries default, it can be changed via
1600 mtrr_spare_reg_nr=N on the kernel command line.
1604 prompt "x86 PAT support" if EXPERT
1607 Use PAT attributes to setup page level cache control.
1609 PATs are the modern equivalents of MTRRs and are much more
1610 flexible than MTRRs.
1612 Say N here if you see bootup problems (boot crash, boot hang,
1613 spontaneous reboots) or a non-working video driver.
1617 config ARCH_USES_PG_UNCACHED
1623 prompt "x86 architectural random number generator" if EXPERT
1625 Enable the x86 architectural RDRAND instruction
1626 (Intel Bull Mountain technology) to generate random numbers.
1627 If supported, this is a high bandwidth, cryptographically
1628 secure hardware random number generator.
1632 prompt "Supervisor Mode Access Prevention" if EXPERT
1634 Supervisor Mode Access Prevention (SMAP) is a security
1635 feature in newer Intel processors. There is a small
1636 performance cost if this enabled and turned on; there is
1637 also a small increase in the kernel size if this is enabled.
1641 config X86_INTEL_MPX
1642 prompt "Intel MPX (Memory Protection Extensions)"
1644 depends on CPU_SUP_INTEL
1646 MPX provides hardware features that can be used in
1647 conjunction with compiler-instrumented code to check
1648 memory references. It is designed to detect buffer
1649 overflow or underflow bugs.
1651 This option enables running applications which are
1652 instrumented or otherwise use MPX. It does not use MPX
1653 itself inside the kernel or to protect the kernel
1654 against bad memory references.
1656 Enabling this option will make the kernel larger:
1657 ~8k of kernel text and 36 bytes of data on a 64-bit
1658 defconfig. It adds a long to the 'mm_struct' which
1659 will increase the kernel memory overhead of each
1660 process and adds some branches to paths used during
1661 exec() and munmap().
1663 For details, see Documentation/x86/intel_mpx.txt
1668 bool "EFI runtime service support"
1671 select EFI_RUNTIME_WRAPPERS
1673 This enables the kernel to use EFI runtime services that are
1674 available (such as the EFI variable services).
1676 This option is only useful on systems that have EFI firmware.
1677 In addition, you should use the latest ELILO loader available
1678 at <http://elilo.sourceforge.net> in order to take advantage
1679 of EFI runtime services. However, even with this option, the
1680 resultant kernel should continue to boot on existing non-EFI
1684 bool "EFI stub support"
1685 depends on EFI && !X86_USE_3DNOW
1688 This kernel feature allows a bzImage to be loaded directly
1689 by EFI firmware without the use of a bootloader.
1691 See Documentation/efi-stub.txt for more information.
1694 bool "EFI mixed-mode support"
1695 depends on EFI_STUB && X86_64
1697 Enabling this feature allows a 64-bit kernel to be booted
1698 on a 32-bit firmware, provided that your CPU supports 64-bit
1701 Note that it is not possible to boot a mixed-mode enabled
1702 kernel via the EFI boot stub - a bootloader that supports
1703 the EFI handover protocol must be used.
1709 prompt "Enable seccomp to safely compute untrusted bytecode"
1711 This kernel feature is useful for number crunching applications
1712 that may need to compute untrusted bytecode during their
1713 execution. By using pipes or other transports made available to
1714 the process as file descriptors supporting the read/write
1715 syscalls, it's possible to isolate those applications in
1716 their own address space using seccomp. Once seccomp is
1717 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1718 and the task is only allowed to execute a few safe syscalls
1719 defined by each seccomp mode.
1721 If unsure, say Y. Only embedded should say N here.
1723 source kernel/Kconfig.hz
1726 bool "kexec system call"
1728 kexec is a system call that implements the ability to shutdown your
1729 current kernel, and to start another kernel. It is like a reboot
1730 but it is independent of the system firmware. And like a reboot
1731 you can start any kernel with it, not just Linux.
1733 The name comes from the similarity to the exec system call.
1735 It is an ongoing process to be certain the hardware in a machine
1736 is properly shutdown, so do not be surprised if this code does not
1737 initially work for you. As of this writing the exact hardware
1738 interface is strongly in flux, so no good recommendation can be
1742 bool "kexec file based system call"
1747 depends on CRYPTO_SHA256=y
1749 This is new version of kexec system call. This system call is
1750 file based and takes file descriptors as system call argument
1751 for kernel and initramfs as opposed to list of segments as
1752 accepted by previous system call.
1754 config KEXEC_VERIFY_SIG
1755 bool "Verify kernel signature during kexec_file_load() syscall"
1756 depends on KEXEC_FILE
1758 This option makes kernel signature verification mandatory for
1759 the kexec_file_load() syscall.
1761 In addition to that option, you need to enable signature
1762 verification for the corresponding kernel image type being
1763 loaded in order for this to work.
1765 config KEXEC_BZIMAGE_VERIFY_SIG
1766 bool "Enable bzImage signature verification support"
1767 depends on KEXEC_VERIFY_SIG
1768 depends on SIGNED_PE_FILE_VERIFICATION
1769 select SYSTEM_TRUSTED_KEYRING
1771 Enable bzImage signature verification support.
1774 bool "kernel crash dumps"
1775 depends on X86_64 || (X86_32 && HIGHMEM)
1777 Generate crash dump after being started by kexec.
1778 This should be normally only set in special crash dump kernels
1779 which are loaded in the main kernel with kexec-tools into
1780 a specially reserved region and then later executed after
1781 a crash by kdump/kexec. The crash dump kernel must be compiled
1782 to a memory address not used by the main kernel or BIOS using
1783 PHYSICAL_START, or it must be built as a relocatable image
1784 (CONFIG_RELOCATABLE=y).
1785 For more details see Documentation/kdump/kdump.txt
1789 depends on KEXEC && HIBERNATION
1791 Jump between original kernel and kexeced kernel and invoke
1792 code in physical address mode via KEXEC
1794 config PHYSICAL_START
1795 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1798 This gives the physical address where the kernel is loaded.
1800 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1801 bzImage will decompress itself to above physical address and
1802 run from there. Otherwise, bzImage will run from the address where
1803 it has been loaded by the boot loader and will ignore above physical
1806 In normal kdump cases one does not have to set/change this option
1807 as now bzImage can be compiled as a completely relocatable image
1808 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1809 address. This option is mainly useful for the folks who don't want
1810 to use a bzImage for capturing the crash dump and want to use a
1811 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1812 to be specifically compiled to run from a specific memory area
1813 (normally a reserved region) and this option comes handy.
1815 So if you are using bzImage for capturing the crash dump,
1816 leave the value here unchanged to 0x1000000 and set
1817 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1818 for capturing the crash dump change this value to start of
1819 the reserved region. In other words, it can be set based on
1820 the "X" value as specified in the "crashkernel=YM@XM"
1821 command line boot parameter passed to the panic-ed
1822 kernel. Please take a look at Documentation/kdump/kdump.txt
1823 for more details about crash dumps.
1825 Usage of bzImage for capturing the crash dump is recommended as
1826 one does not have to build two kernels. Same kernel can be used
1827 as production kernel and capture kernel. Above option should have
1828 gone away after relocatable bzImage support is introduced. But it
1829 is present because there are users out there who continue to use
1830 vmlinux for dump capture. This option should go away down the
1833 Don't change this unless you know what you are doing.
1836 bool "Build a relocatable kernel"
1839 This builds a kernel image that retains relocation information
1840 so it can be loaded someplace besides the default 1MB.
1841 The relocations tend to make the kernel binary about 10% larger,
1842 but are discarded at runtime.
1844 One use is for the kexec on panic case where the recovery kernel
1845 must live at a different physical address than the primary
1848 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1849 it has been loaded at and the compile time physical address
1850 (CONFIG_PHYSICAL_START) is used as the minimum location.
1852 config RANDOMIZE_BASE
1853 bool "Randomize the address of the kernel image"
1854 depends on RELOCATABLE
1857 Randomizes the physical and virtual address at which the
1858 kernel image is decompressed, as a security feature that
1859 deters exploit attempts relying on knowledge of the location
1860 of kernel internals.
1862 Entropy is generated using the RDRAND instruction if it is
1863 supported. If RDTSC is supported, it is used as well. If
1864 neither RDRAND nor RDTSC are supported, then randomness is
1865 read from the i8254 timer.
1867 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1868 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1869 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1870 minimum of 2MiB, only 10 bits of entropy is theoretically
1871 possible. At best, due to page table layouts, 64-bit can use
1872 9 bits of entropy and 32-bit uses 8 bits.
1876 config RANDOMIZE_BASE_MAX_OFFSET
1877 hex "Maximum kASLR offset allowed" if EXPERT
1878 depends on RANDOMIZE_BASE
1879 range 0x0 0x20000000 if X86_32
1880 default "0x20000000" if X86_32
1881 range 0x0 0x40000000 if X86_64
1882 default "0x40000000" if X86_64
1884 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1885 memory is used to determine the maximal offset in bytes that will
1886 be applied to the kernel when kernel Address Space Layout
1887 Randomization (kASLR) is active. This must be a multiple of
1890 On 32-bit this is limited to 512MiB by page table layouts. The
1893 On 64-bit this is limited by how the kernel fixmap page table is
1894 positioned, so this cannot be larger than 1GiB currently. Without
1895 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1896 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1897 modules area will shrink to compensate, up to the current maximum
1898 1GiB to 1GiB split. The default is 1GiB.
1900 If unsure, leave at the default value.
1902 # Relocation on x86 needs some additional build support
1903 config X86_NEED_RELOCS
1905 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1907 config PHYSICAL_ALIGN
1908 hex "Alignment value to which kernel should be aligned"
1910 range 0x2000 0x1000000 if X86_32
1911 range 0x200000 0x1000000 if X86_64
1913 This value puts the alignment restrictions on physical address
1914 where kernel is loaded and run from. Kernel is compiled for an
1915 address which meets above alignment restriction.
1917 If bootloader loads the kernel at a non-aligned address and
1918 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1919 address aligned to above value and run from there.
1921 If bootloader loads the kernel at a non-aligned address and
1922 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1923 load address and decompress itself to the address it has been
1924 compiled for and run from there. The address for which kernel is
1925 compiled already meets above alignment restrictions. Hence the
1926 end result is that kernel runs from a physical address meeting
1927 above alignment restrictions.
1929 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1930 this value must be a multiple of 0x200000.
1932 Don't change this unless you know what you are doing.
1935 bool "Support for hot-pluggable CPUs"
1938 Say Y here to allow turning CPUs off and on. CPUs can be
1939 controlled through /sys/devices/system/cpu.
1940 ( Note: power management support will enable this option
1941 automatically on SMP systems. )
1942 Say N if you want to disable CPU hotplug.
1944 config BOOTPARAM_HOTPLUG_CPU0
1945 bool "Set default setting of cpu0_hotpluggable"
1947 depends on HOTPLUG_CPU
1949 Set whether default state of cpu0_hotpluggable is on or off.
1951 Say Y here to enable CPU0 hotplug by default. If this switch
1952 is turned on, there is no need to give cpu0_hotplug kernel
1953 parameter and the CPU0 hotplug feature is enabled by default.
1955 Please note: there are two known CPU0 dependencies if you want
1956 to enable the CPU0 hotplug feature either by this switch or by
1957 cpu0_hotplug kernel parameter.
1959 First, resume from hibernate or suspend always starts from CPU0.
1960 So hibernate and suspend are prevented if CPU0 is offline.
1962 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1963 offline if any interrupt can not migrate out of CPU0. There may
1964 be other CPU0 dependencies.
1966 Please make sure the dependencies are under your control before
1967 you enable this feature.
1969 Say N if you don't want to enable CPU0 hotplug feature by default.
1970 You still can enable the CPU0 hotplug feature at boot by kernel
1971 parameter cpu0_hotplug.
1973 config DEBUG_HOTPLUG_CPU0
1975 prompt "Debug CPU0 hotplug"
1976 depends on HOTPLUG_CPU
1978 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1979 soon as possible and boots up userspace with CPU0 offlined. User
1980 can online CPU0 back after boot time.
1982 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1983 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1984 compilation or giving cpu0_hotplug kernel parameter at boot.
1990 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1991 depends on X86_32 || IA32_EMULATION
1993 Certain buggy versions of glibc will crash if they are
1994 presented with a 32-bit vDSO that is not mapped at the address
1995 indicated in its segment table.
1997 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1998 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1999 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2000 the only released version with the bug, but OpenSUSE 9
2001 contains a buggy "glibc 2.3.2".
2003 The symptom of the bug is that everything crashes on startup, saying:
2004 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2006 Saying Y here changes the default value of the vdso32 boot
2007 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2008 This works around the glibc bug but hurts performance.
2010 If unsure, say N: if you are compiling your own kernel, you
2011 are unlikely to be using a buggy version of glibc.
2014 bool "Built-in kernel command line"
2016 Allow for specifying boot arguments to the kernel at
2017 build time. On some systems (e.g. embedded ones), it is
2018 necessary or convenient to provide some or all of the
2019 kernel boot arguments with the kernel itself (that is,
2020 to not rely on the boot loader to provide them.)
2022 To compile command line arguments into the kernel,
2023 set this option to 'Y', then fill in the
2024 boot arguments in CONFIG_CMDLINE.
2026 Systems with fully functional boot loaders (i.e. non-embedded)
2027 should leave this option set to 'N'.
2030 string "Built-in kernel command string"
2031 depends on CMDLINE_BOOL
2034 Enter arguments here that should be compiled into the kernel
2035 image and used at boot time. If the boot loader provides a
2036 command line at boot time, it is appended to this string to
2037 form the full kernel command line, when the system boots.
2039 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2040 change this behavior.
2042 In most cases, the command line (whether built-in or provided
2043 by the boot loader) should specify the device for the root
2046 config CMDLINE_OVERRIDE
2047 bool "Built-in command line overrides boot loader arguments"
2048 depends on CMDLINE_BOOL
2050 Set this option to 'Y' to have the kernel ignore the boot loader
2051 command line, and use ONLY the built-in command line.
2053 This is used to work around broken boot loaders. This should
2054 be set to 'N' under normal conditions.
2056 source "kernel/livepatch/Kconfig"
2060 config ARCH_ENABLE_MEMORY_HOTPLUG
2062 depends on X86_64 || (X86_32 && HIGHMEM)
2064 config ARCH_ENABLE_MEMORY_HOTREMOVE
2066 depends on MEMORY_HOTPLUG
2068 config USE_PERCPU_NUMA_NODE_ID
2072 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2074 depends on X86_64 || X86_PAE
2076 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2078 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2080 menu "Power management and ACPI options"
2082 config ARCH_HIBERNATION_HEADER
2084 depends on X86_64 && HIBERNATION
2086 source "kernel/power/Kconfig"
2088 source "drivers/acpi/Kconfig"
2090 source "drivers/sfi/Kconfig"
2097 tristate "APM (Advanced Power Management) BIOS support"
2098 depends on X86_32 && PM_SLEEP
2100 APM is a BIOS specification for saving power using several different
2101 techniques. This is mostly useful for battery powered laptops with
2102 APM compliant BIOSes. If you say Y here, the system time will be
2103 reset after a RESUME operation, the /proc/apm device will provide
2104 battery status information, and user-space programs will receive
2105 notification of APM "events" (e.g. battery status change).
2107 If you select "Y" here, you can disable actual use of the APM
2108 BIOS by passing the "apm=off" option to the kernel at boot time.
2110 Note that the APM support is almost completely disabled for
2111 machines with more than one CPU.
2113 In order to use APM, you will need supporting software. For location
2114 and more information, read <file:Documentation/power/apm-acpi.txt>
2115 and the Battery Powered Linux mini-HOWTO, available from
2116 <http://www.tldp.org/docs.html#howto>.
2118 This driver does not spin down disk drives (see the hdparm(8)
2119 manpage ("man 8 hdparm") for that), and it doesn't turn off
2120 VESA-compliant "green" monitors.
2122 This driver does not support the TI 4000M TravelMate and the ACER
2123 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2124 desktop machines also don't have compliant BIOSes, and this driver
2125 may cause those machines to panic during the boot phase.
2127 Generally, if you don't have a battery in your machine, there isn't
2128 much point in using this driver and you should say N. If you get
2129 random kernel OOPSes or reboots that don't seem to be related to
2130 anything, try disabling/enabling this option (or disabling/enabling
2133 Some other things you should try when experiencing seemingly random,
2136 1) make sure that you have enough swap space and that it is
2138 2) pass the "no-hlt" option to the kernel
2139 3) switch on floating point emulation in the kernel and pass
2140 the "no387" option to the kernel
2141 4) pass the "floppy=nodma" option to the kernel
2142 5) pass the "mem=4M" option to the kernel (thereby disabling
2143 all but the first 4 MB of RAM)
2144 6) make sure that the CPU is not over clocked.
2145 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2146 8) disable the cache from your BIOS settings
2147 9) install a fan for the video card or exchange video RAM
2148 10) install a better fan for the CPU
2149 11) exchange RAM chips
2150 12) exchange the motherboard.
2152 To compile this driver as a module, choose M here: the
2153 module will be called apm.
2157 config APM_IGNORE_USER_SUSPEND
2158 bool "Ignore USER SUSPEND"
2160 This option will ignore USER SUSPEND requests. On machines with a
2161 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2162 series notebooks, it is necessary to say Y because of a BIOS bug.
2164 config APM_DO_ENABLE
2165 bool "Enable PM at boot time"
2167 Enable APM features at boot time. From page 36 of the APM BIOS
2168 specification: "When disabled, the APM BIOS does not automatically
2169 power manage devices, enter the Standby State, enter the Suspend
2170 State, or take power saving steps in response to CPU Idle calls."
2171 This driver will make CPU Idle calls when Linux is idle (unless this
2172 feature is turned off -- see "Do CPU IDLE calls", below). This
2173 should always save battery power, but more complicated APM features
2174 will be dependent on your BIOS implementation. You may need to turn
2175 this option off if your computer hangs at boot time when using APM
2176 support, or if it beeps continuously instead of suspending. Turn
2177 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2178 T400CDT. This is off by default since most machines do fine without
2183 bool "Make CPU Idle calls when idle"
2185 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2186 On some machines, this can activate improved power savings, such as
2187 a slowed CPU clock rate, when the machine is idle. These idle calls
2188 are made after the idle loop has run for some length of time (e.g.,
2189 333 mS). On some machines, this will cause a hang at boot time or
2190 whenever the CPU becomes idle. (On machines with more than one CPU,
2191 this option does nothing.)
2193 config APM_DISPLAY_BLANK
2194 bool "Enable console blanking using APM"
2196 Enable console blanking using the APM. Some laptops can use this to
2197 turn off the LCD backlight when the screen blanker of the Linux
2198 virtual console blanks the screen. Note that this is only used by
2199 the virtual console screen blanker, and won't turn off the backlight
2200 when using the X Window system. This also doesn't have anything to
2201 do with your VESA-compliant power-saving monitor. Further, this
2202 option doesn't work for all laptops -- it might not turn off your
2203 backlight at all, or it might print a lot of errors to the console,
2204 especially if you are using gpm.
2206 config APM_ALLOW_INTS
2207 bool "Allow interrupts during APM BIOS calls"
2209 Normally we disable external interrupts while we are making calls to
2210 the APM BIOS as a measure to lessen the effects of a badly behaving
2211 BIOS implementation. The BIOS should reenable interrupts if it
2212 needs to. Unfortunately, some BIOSes do not -- especially those in
2213 many of the newer IBM Thinkpads. If you experience hangs when you
2214 suspend, try setting this to Y. Otherwise, say N.
2218 source "drivers/cpufreq/Kconfig"
2220 source "drivers/cpuidle/Kconfig"
2222 source "drivers/idle/Kconfig"
2227 menu "Bus options (PCI etc.)"
2233 Find out whether you have a PCI motherboard. PCI is the name of a
2234 bus system, i.e. the way the CPU talks to the other stuff inside
2235 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2236 VESA. If you have PCI, say Y, otherwise N.
2239 prompt "PCI access mode"
2240 depends on X86_32 && PCI
2243 On PCI systems, the BIOS can be used to detect the PCI devices and
2244 determine their configuration. However, some old PCI motherboards
2245 have BIOS bugs and may crash if this is done. Also, some embedded
2246 PCI-based systems don't have any BIOS at all. Linux can also try to
2247 detect the PCI hardware directly without using the BIOS.
2249 With this option, you can specify how Linux should detect the
2250 PCI devices. If you choose "BIOS", the BIOS will be used,
2251 if you choose "Direct", the BIOS won't be used, and if you
2252 choose "MMConfig", then PCI Express MMCONFIG will be used.
2253 If you choose "Any", the kernel will try MMCONFIG, then the
2254 direct access method and falls back to the BIOS if that doesn't
2255 work. If unsure, go with the default, which is "Any".
2260 config PCI_GOMMCONFIG
2277 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2279 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2282 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2286 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2290 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2294 depends on PCI && XEN
2302 bool "Support mmconfig PCI config space access"
2303 depends on X86_64 && PCI && ACPI
2305 config PCI_CNB20LE_QUIRK
2306 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2309 Read the PCI windows out of the CNB20LE host bridge. This allows
2310 PCI hotplug to work on systems with the CNB20LE chipset which do
2313 There's no public spec for this chipset, and this functionality
2314 is known to be incomplete.
2316 You should say N unless you know you need this.
2318 source "drivers/pci/pcie/Kconfig"
2320 source "drivers/pci/Kconfig"
2322 # x86_64 have no ISA slots, but can have ISA-style DMA.
2324 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2327 Enables ISA-style DMA support for devices requiring such controllers.
2335 Find out whether you have ISA slots on your motherboard. ISA is the
2336 name of a bus system, i.e. the way the CPU talks to the other stuff
2337 inside your box. Other bus systems are PCI, EISA, MicroChannel
2338 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2339 newer boards don't support it. If you have ISA, say Y, otherwise N.
2345 The Extended Industry Standard Architecture (EISA) bus was
2346 developed as an open alternative to the IBM MicroChannel bus.
2348 The EISA bus provided some of the features of the IBM MicroChannel
2349 bus while maintaining backward compatibility with cards made for
2350 the older ISA bus. The EISA bus saw limited use between 1988 and
2351 1995 when it was made obsolete by the PCI bus.
2353 Say Y here if you are building a kernel for an EISA-based machine.
2357 source "drivers/eisa/Kconfig"
2360 tristate "NatSemi SCx200 support"
2362 This provides basic support for National Semiconductor's
2363 (now AMD's) Geode processors. The driver probes for the
2364 PCI-IDs of several on-chip devices, so its a good dependency
2365 for other scx200_* drivers.
2367 If compiled as a module, the driver is named scx200.
2369 config SCx200HR_TIMER
2370 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2374 This driver provides a clocksource built upon the on-chip
2375 27MHz high-resolution timer. Its also a workaround for
2376 NSC Geode SC-1100's buggy TSC, which loses time when the
2377 processor goes idle (as is done by the scheduler). The
2378 other workaround is idle=poll boot option.
2381 bool "One Laptop Per Child support"
2388 Add support for detecting the unique features of the OLPC
2392 bool "OLPC XO-1 Power Management"
2393 depends on OLPC && MFD_CS5535 && PM_SLEEP
2396 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2399 bool "OLPC XO-1 Real Time Clock"
2400 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2402 Add support for the XO-1 real time clock, which can be used as a
2403 programmable wakeup source.
2406 bool "OLPC XO-1 SCI extras"
2407 depends on OLPC && OLPC_XO1_PM
2413 Add support for SCI-based features of the OLPC XO-1 laptop:
2414 - EC-driven system wakeups
2418 - AC adapter status updates
2419 - Battery status updates
2421 config OLPC_XO15_SCI
2422 bool "OLPC XO-1.5 SCI extras"
2423 depends on OLPC && ACPI
2426 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2427 - EC-driven system wakeups
2428 - AC adapter status updates
2429 - Battery status updates
2432 bool "PCEngines ALIX System Support (LED setup)"
2435 This option enables system support for the PCEngines ALIX.
2436 At present this just sets up LEDs for GPIO control on
2437 ALIX2/3/6 boards. However, other system specific setup should
2440 Note: You must still enable the drivers for GPIO and LED support
2441 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2443 Note: You have to set alix.force=1 for boards with Award BIOS.
2446 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2449 This option enables system support for the Soekris Engineering net5501.
2452 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2456 This option enables system support for the Traverse Technologies GEOS.
2459 bool "Technologic Systems TS-5500 platform support"
2461 select CHECK_SIGNATURE
2465 This option enables system support for the Technologic Systems TS-5500.
2471 depends on CPU_SUP_AMD && PCI
2473 source "drivers/pcmcia/Kconfig"
2475 source "drivers/pci/hotplug/Kconfig"
2478 tristate "RapidIO support"
2482 If enabled this option will include drivers and the core
2483 infrastructure code to support RapidIO interconnect devices.
2485 source "drivers/rapidio/Kconfig"
2488 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2490 Firmwares often provide initial graphics framebuffers so the BIOS,
2491 bootloader or kernel can show basic video-output during boot for
2492 user-guidance and debugging. Historically, x86 used the VESA BIOS
2493 Extensions and EFI-framebuffers for this, which are mostly limited
2495 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2496 framebuffers so the new generic system-framebuffer drivers can be
2497 used on x86. If the framebuffer is not compatible with the generic
2498 modes, it is adverticed as fallback platform framebuffer so legacy
2499 drivers like efifb, vesafb and uvesafb can pick it up.
2500 If this option is not selected, all system framebuffers are always
2501 marked as fallback platform framebuffers as usual.
2503 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2504 not be able to pick up generic system framebuffers if this option
2505 is selected. You are highly encouraged to enable simplefb as
2506 replacement if you select this option. simplefb can correctly deal
2507 with generic system framebuffers. But you should still keep vesafb
2508 and others enabled as fallback if a system framebuffer is
2509 incompatible with simplefb.
2516 menu "Executable file formats / Emulations"
2518 source "fs/Kconfig.binfmt"
2520 config IA32_EMULATION
2521 bool "IA32 Emulation"
2524 select COMPAT_BINFMT_ELF
2527 Include code to run legacy 32-bit programs under a
2528 64-bit kernel. You should likely turn this on, unless you're
2529 100% sure that you don't have any 32-bit programs left.
2532 tristate "IA32 a.out support"
2533 depends on IA32_EMULATION
2535 Support old a.out binaries in the 32bit emulation.
2538 bool "x32 ABI for 64-bit mode"
2539 depends on X86_64 && IA32_EMULATION
2541 Include code to run binaries for the x32 native 32-bit ABI
2542 for 64-bit processors. An x32 process gets access to the
2543 full 64-bit register file and wide data path while leaving
2544 pointers at 32 bits for smaller memory footprint.
2546 You will need a recent binutils (2.22 or later) with
2547 elf32_x86_64 support enabled to compile a kernel with this
2552 depends on IA32_EMULATION || X86_X32
2553 select ARCH_WANT_OLD_COMPAT_IPC
2556 config COMPAT_FOR_U64_ALIGNMENT
2559 config SYSVIPC_COMPAT
2571 config HAVE_ATOMIC_IOMAP
2575 config X86_DEV_DMA_OPS
2577 depends on X86_64 || STA2X11
2579 config X86_DMA_REMAP
2587 source "net/Kconfig"
2589 source "drivers/Kconfig"
2591 source "drivers/firmware/Kconfig"
2595 source "arch/x86/Kconfig.debug"
2597 source "security/Kconfig"
2599 source "crypto/Kconfig"
2601 source "arch/x86/kvm/Kconfig"
2603 source "lib/Kconfig"
projects / linux-drm-fsl-dcu.git / blob