3 bool "64-bit kernel" if ARCH = "x86"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
25 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
27 select ARCH_HAS_FAST_MULTIPLIER
28 select ARCH_HAS_GCOV_PROFILE_ALL
29 select ARCH_MIGHT_HAVE_PC_PARPORT
30 select ARCH_MIGHT_HAVE_PC_SERIO
31 select HAVE_AOUT if X86_32
32 select HAVE_UNSTABLE_SCHED_CLOCK
33 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
34 select ARCH_SUPPORTS_INT128 if X86_64
37 select HAVE_PCSPKR_PLATFORM
38 select HAVE_PERF_EVENTS
39 select HAVE_IOREMAP_PROT
42 select HAVE_MEMBLOCK_NODE_MAP
43 select ARCH_DISCARD_MEMBLOCK
44 select ARCH_WANT_OPTIONAL_GPIOLIB
45 select ARCH_WANT_FRAME_POINTERS
47 select HAVE_DMA_CONTIGUOUS
48 select HAVE_KRETPROBES
49 select GENERIC_EARLY_IOREMAP
51 select HAVE_KPROBES_ON_FTRACE
52 select HAVE_FTRACE_MCOUNT_RECORD
53 select HAVE_FENTRY if X86_64
54 select HAVE_C_RECORDMCOUNT
55 select HAVE_DYNAMIC_FTRACE
56 select HAVE_DYNAMIC_FTRACE_WITH_REGS
57 select HAVE_FUNCTION_TRACER
58 select HAVE_FUNCTION_GRAPH_TRACER
59 select HAVE_FUNCTION_GRAPH_FP_TEST
60 select HAVE_SYSCALL_TRACEPOINTS
61 select SYSCTL_EXCEPTION_TRACE
64 select HAVE_ARCH_TRACEHOOK
65 select HAVE_GENERIC_DMA_COHERENT if X86_32
66 select HAVE_EFFICIENT_UNALIGNED_ACCESS
67 select USER_STACKTRACE_SUPPORT
68 select HAVE_REGS_AND_STACK_ACCESS_API
69 select HAVE_DMA_API_DEBUG
70 select HAVE_KERNEL_GZIP
71 select HAVE_KERNEL_BZIP2
72 select HAVE_KERNEL_LZMA
74 select HAVE_KERNEL_LZO
75 select HAVE_KERNEL_LZ4
76 select HAVE_HW_BREAKPOINT
77 select HAVE_MIXED_BREAKPOINTS_REGS
79 select HAVE_PERF_EVENTS_NMI
81 select HAVE_PERF_USER_STACK_DUMP
82 select HAVE_DEBUG_KMEMLEAK
84 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
85 select HAVE_CMPXCHG_LOCAL
86 select HAVE_CMPXCHG_DOUBLE
87 select HAVE_ARCH_KMEMCHECK
88 select HAVE_USER_RETURN_NOTIFIER
89 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
90 select HAVE_ARCH_JUMP_LABEL
91 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
93 select GENERIC_FIND_FIRST_BIT
94 select GENERIC_IRQ_PROBE
95 select GENERIC_PENDING_IRQ if SMP
96 select GENERIC_IRQ_SHOW
97 select GENERIC_CLOCKEVENTS_MIN_ADJUST
98 select IRQ_FORCED_THREADING
99 select HAVE_BPF_JIT if X86_64
100 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
101 select ARCH_HAS_SG_CHAIN
103 select ARCH_HAVE_NMI_SAFE_CMPXCHG
105 select DCACHE_WORD_ACCESS
106 select GENERIC_SMP_IDLE_THREAD
107 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
108 select HAVE_ARCH_SECCOMP_FILTER
109 select BUILDTIME_EXTABLE_SORT
110 select GENERIC_CMOS_UPDATE
111 select HAVE_ARCH_SOFT_DIRTY if X86_64
112 select CLOCKSOURCE_WATCHDOG
113 select GENERIC_CLOCKEVENTS
114 select ARCH_CLOCKSOURCE_DATA
115 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
116 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
117 select GENERIC_TIME_VSYSCALL
118 select GENERIC_STRNCPY_FROM_USER
119 select GENERIC_STRNLEN_USER
120 select HAVE_CONTEXT_TRACKING if X86_64
121 select HAVE_IRQ_TIME_ACCOUNTING
123 select MODULES_USE_ELF_REL if X86_32
124 select MODULES_USE_ELF_RELA if X86_64
125 select CLONE_BACKWARDS if X86_32
126 select ARCH_USE_BUILTIN_BSWAP
127 select ARCH_USE_QUEUE_RWLOCK
128 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
129 select OLD_SIGACTION if X86_32
130 select COMPAT_OLD_SIGACTION if IA32_EMULATION
132 select HAVE_DEBUG_STACKOVERFLOW
133 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
134 select HAVE_CC_STACKPROTECTOR
135 select GENERIC_CPU_AUTOPROBE
136 select HAVE_ARCH_AUDITSYSCALL
137 select ARCH_SUPPORTS_ATOMIC_RMW
138 select HAVE_ACPI_APEI if ACPI
139 select HAVE_ACPI_APEI_NMI if ACPI
140 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
141 select X86_FEATURE_NAMES if PROC_FS
144 config INSTRUCTION_DECODER
146 depends on KPROBES || PERF_EVENTS || UPROBES
148 config PERF_EVENTS_INTEL_UNCORE
150 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
154 default "elf32-i386" if X86_32
155 default "elf64-x86-64" if X86_64
157 config ARCH_DEFCONFIG
159 default "arch/x86/configs/i386_defconfig" if X86_32
160 default "arch/x86/configs/x86_64_defconfig" if X86_64
162 config LOCKDEP_SUPPORT
165 config STACKTRACE_SUPPORT
168 config HAVE_LATENCYTOP_SUPPORT
177 config NEED_DMA_MAP_STATE
179 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
181 config NEED_SG_DMA_LENGTH
184 config GENERIC_ISA_DMA
186 depends on ISA_DMA_API
191 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
193 config GENERIC_BUG_RELATIVE_POINTERS
196 config GENERIC_HWEIGHT
199 config ARCH_MAY_HAVE_PC_FDC
201 depends on ISA_DMA_API
203 config RWSEM_XCHGADD_ALGORITHM
206 config GENERIC_CALIBRATE_DELAY
209 config ARCH_HAS_CPU_RELAX
212 config ARCH_HAS_CACHE_LINE_SIZE
215 config HAVE_SETUP_PER_CPU_AREA
218 config NEED_PER_CPU_EMBED_FIRST_CHUNK
221 config NEED_PER_CPU_PAGE_FIRST_CHUNK
224 config ARCH_HIBERNATION_POSSIBLE
227 config ARCH_SUSPEND_POSSIBLE
230 config ARCH_WANT_HUGE_PMD_SHARE
233 config ARCH_WANT_GENERAL_HUGETLB
244 config ARCH_SUPPORTS_OPTIMIZED_INLINING
247 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
250 config HAVE_INTEL_TXT
252 depends on INTEL_IOMMU && ACPI
256 depends on X86_32 && SMP
260 depends on X86_64 && SMP
266 config X86_32_LAZY_GS
268 depends on X86_32 && !CC_STACKPROTECTOR
270 config ARCH_HWEIGHT_CFLAGS
272 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
273 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
275 config ARCH_SUPPORTS_UPROBES
278 config FIX_EARLYCON_MEM
281 source "init/Kconfig"
282 source "kernel/Kconfig.freezer"
284 menu "Processor type and features"
287 bool "DMA memory allocation support" if EXPERT
290 DMA memory allocation support allows devices with less than 32-bit
291 addressing to allocate within the first 16MB of address space.
292 Disable if no such devices will be used.
297 bool "Symmetric multi-processing support"
299 This enables support for systems with more than one CPU. If you have
300 a system with only one CPU, say N. If you have a system with more
303 If you say N here, the kernel will run on uni- and multiprocessor
304 machines, but will use only one CPU of a multiprocessor machine. If
305 you say Y here, the kernel will run on many, but not all,
306 uniprocessor machines. On a uniprocessor machine, the kernel
307 will run faster if you say N here.
309 Note that if you say Y here and choose architecture "586" or
310 "Pentium" under "Processor family", the kernel will not work on 486
311 architectures. Similarly, multiprocessor kernels for the "PPro"
312 architecture may not work on all Pentium based boards.
314 People using multiprocessor machines who say Y here should also say
315 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
316 Management" code will be disabled if you say Y here.
318 See also <file:Documentation/x86/i386/IO-APIC.txt>,
319 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
320 <http://www.tldp.org/docs.html#howto>.
322 If you don't know what to do here, say N.
324 config X86_FEATURE_NAMES
325 bool "Processor feature human-readable names" if EMBEDDED
328 This option compiles in a table of x86 feature bits and corresponding
329 names. This is required to support /proc/cpuinfo and a few kernel
330 messages. You can disable this to save space, at the expense of
331 making those few kernel messages show numeric feature bits instead.
336 bool "Support x2apic"
337 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
339 This enables x2apic support on CPUs that have this feature.
341 This allows 32-bit apic IDs (so it can support very large systems),
342 and accesses the local apic via MSRs not via mmio.
344 If you don't know what to do here, say N.
347 bool "Enable MPS table" if ACPI || SFI
349 depends on X86_LOCAL_APIC
351 For old smp systems that do not have proper acpi support. Newer systems
352 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
355 bool "Support for big SMP systems with more than 8 CPUs"
356 depends on X86_32 && SMP
358 This option is needed for the systems that have more than 8 CPUs
362 depends on X86_GOLDFISH
365 config X86_EXTENDED_PLATFORM
366 bool "Support for extended (non-PC) x86 platforms"
369 If you disable this option then the kernel will only support
370 standard PC platforms. (which covers the vast majority of
373 If you enable this option then you'll be able to select support
374 for the following (non-PC) 32 bit x86 platforms:
375 Goldfish (Android emulator)
378 SGI 320/540 (Visual Workstation)
379 STA2X11-based (e.g. Northville)
380 Moorestown MID devices
382 If you have one of these systems, or if you want to build a
383 generic distribution kernel, say Y here - otherwise say N.
387 config X86_EXTENDED_PLATFORM
388 bool "Support for extended (non-PC) x86 platforms"
391 If you disable this option then the kernel will only support
392 standard PC platforms. (which covers the vast majority of
395 If you enable this option then you'll be able to select support
396 for the following (non-PC) 64 bit x86 platforms:
401 If you have one of these systems, or if you want to build a
402 generic distribution kernel, say Y here - otherwise say N.
404 # This is an alphabetically sorted list of 64 bit extended platforms
405 # Please maintain the alphabetic order if and when there are additions
407 bool "Numascale NumaChip"
409 depends on X86_EXTENDED_PLATFORM
412 depends on X86_X2APIC
413 depends on PCI_MMCONFIG
415 Adds support for Numascale NumaChip large-SMP systems. Needed to
416 enable more than ~168 cores.
417 If you don't have one of these, you should say N here.
421 select HYPERVISOR_GUEST
423 depends on X86_64 && PCI
424 depends on X86_EXTENDED_PLATFORM
427 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
428 supposed to run on these EM64T-based machines. Only choose this option
429 if you have one of these machines.
432 bool "SGI Ultraviolet"
434 depends on X86_EXTENDED_PLATFORM
436 depends on X86_X2APIC
438 This option is needed in order to support SGI Ultraviolet systems.
439 If you don't have one of these, you should say N here.
441 # Following is an alphabetically sorted list of 32 bit extended platforms
442 # Please maintain the alphabetic order if and when there are additions
445 bool "Goldfish (Virtual Platform)"
446 depends on X86_EXTENDED_PLATFORM
448 Enable support for the Goldfish virtual platform used primarily
449 for Android development. Unless you are building for the Android
450 Goldfish emulator say N here.
453 bool "CE4100 TV platform"
455 depends on PCI_GODIRECT
456 depends on X86_IO_APIC
458 depends on X86_EXTENDED_PLATFORM
459 select X86_REBOOTFIXUPS
461 select OF_EARLY_FLATTREE
464 Select for the Intel CE media processor (CE4100) SOC.
465 This option compiles in support for the CE4100 SOC for settop
466 boxes and media devices.
469 bool "Intel MID platform support"
471 depends on X86_EXTENDED_PLATFORM
472 depends on X86_PLATFORM_DEVICES
475 depends on X86_IO_APIC
481 select MFD_INTEL_MSIC
483 Select to build a kernel capable of supporting Intel MID (Mobile
484 Internet Device) platform systems which do not have the PCI legacy
485 interfaces. If you are building for a PC class system say N here.
487 Intel MID platforms are based on an Intel processor and chipset which
488 consume less power than most of the x86 derivatives.
490 config X86_INTEL_LPSS
491 bool "Intel Low Power Subsystem Support"
496 Select to build support for Intel Low Power Subsystem such as
497 found on Intel Lynxpoint PCH. Selecting this option enables
498 things like clock tree (common clock framework) and pincontrol
499 which are needed by the LPSS peripheral drivers.
501 config X86_AMD_PLATFORM_DEVICE
502 bool "AMD ACPI2Platform devices support"
507 Select to interpret AMD specific ACPI device to platform device
508 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
509 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
510 implemented under PINCTRL subsystem.
513 tristate "Intel SoC IOSF Sideband support for SoC platforms"
516 This option enables sideband register access support for Intel SoC
517 platforms. On these platforms the IOSF sideband is used in lieu of
518 MSR's for some register accesses, mostly but not limited to thermal
519 and power. Drivers may query the availability of this device to
520 determine if they need the sideband in order to work on these
521 platforms. The sideband is available on the following SoC products.
522 This list is not meant to be exclusive.
527 You should say Y if you are running a kernel on one of these SoC's.
529 config IOSF_MBI_DEBUG
530 bool "Enable IOSF sideband access through debugfs"
531 depends on IOSF_MBI && DEBUG_FS
533 Select this option to expose the IOSF sideband access registers (MCR,
534 MDR, MCRX) through debugfs to write and read register information from
535 different units on the SoC. This is most useful for obtaining device
536 state information for debug and analysis. As this is a general access
537 mechanism, users of this option would have specific knowledge of the
538 device they want to access.
540 If you don't require the option or are in doubt, say N.
543 bool "RDC R-321x SoC"
545 depends on X86_EXTENDED_PLATFORM
547 select X86_REBOOTFIXUPS
549 This option is needed for RDC R-321x system-on-chip, also known
551 If you don't have one of these chips, you should say N here.
553 config X86_32_NON_STANDARD
554 bool "Support non-standard 32-bit SMP architectures"
555 depends on X86_32 && SMP
556 depends on X86_EXTENDED_PLATFORM
558 This option compiles in the bigsmp and STA2X11 default
559 subarchitectures. It is intended for a generic binary
560 kernel. If you select them all, kernel will probe it one by
561 one and will fallback to default.
563 # Alphabetically sorted list of Non standard 32 bit platforms
565 config X86_SUPPORTS_MEMORY_FAILURE
567 # MCE code calls memory_failure():
569 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
570 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
571 depends on X86_64 || !SPARSEMEM
572 select ARCH_SUPPORTS_MEMORY_FAILURE
575 bool "STA2X11 Companion Chip Support"
576 depends on X86_32_NON_STANDARD && PCI
577 select X86_DEV_DMA_OPS
581 select ARCH_REQUIRE_GPIOLIB
584 This adds support for boards based on the STA2X11 IO-Hub,
585 a.k.a. "ConneXt". The chip is used in place of the standard
586 PC chipset, so all "standard" peripherals are missing. If this
587 option is selected the kernel will still be able to boot on
588 standard PC machines.
591 tristate "Eurobraille/Iris poweroff module"
594 The Iris machines from EuroBraille do not have APM or ACPI support
595 to shut themselves down properly. A special I/O sequence is
596 needed to do so, which is what this module does at
599 This is only for Iris machines from EuroBraille.
603 config SCHED_OMIT_FRAME_POINTER
605 prompt "Single-depth WCHAN output"
608 Calculate simpler /proc/<PID>/wchan values. If this option
609 is disabled then wchan values will recurse back to the
610 caller function. This provides more accurate wchan values,
611 at the expense of slightly more scheduling overhead.
613 If in doubt, say "Y".
615 menuconfig HYPERVISOR_GUEST
616 bool "Linux guest support"
618 Say Y here to enable options for running Linux under various hyper-
619 visors. This option enables basic hypervisor detection and platform
622 If you say N, all options in this submenu will be skipped and
623 disabled, and Linux guest support won't be built in.
628 bool "Enable paravirtualization code"
630 This changes the kernel so it can modify itself when it is run
631 under a hypervisor, potentially improving performance significantly
632 over full virtualization. However, when run without a hypervisor
633 the kernel is theoretically slower and slightly larger.
635 config PARAVIRT_DEBUG
636 bool "paravirt-ops debugging"
637 depends on PARAVIRT && DEBUG_KERNEL
639 Enable to debug paravirt_ops internals. Specifically, BUG if
640 a paravirt_op is missing when it is called.
642 config PARAVIRT_SPINLOCKS
643 bool "Paravirtualization layer for spinlocks"
644 depends on PARAVIRT && SMP
645 select UNINLINE_SPIN_UNLOCK
647 Paravirtualized spinlocks allow a pvops backend to replace the
648 spinlock implementation with something virtualization-friendly
649 (for example, block the virtual CPU rather than spinning).
651 It has a minimal impact on native kernels and gives a nice performance
652 benefit on paravirtualized KVM / Xen kernels.
654 If you are unsure how to answer this question, answer Y.
656 source "arch/x86/xen/Kconfig"
659 bool "KVM Guest support (including kvmclock)"
661 select PARAVIRT_CLOCK
664 This option enables various optimizations for running under the KVM
665 hypervisor. It includes a paravirtualized clock, so that instead
666 of relying on a PIT (or probably other) emulation by the
667 underlying device model, the host provides the guest with
668 timing infrastructure such as time of day, and system time
671 bool "Enable debug information for KVM Guests in debugfs"
672 depends on KVM_GUEST && DEBUG_FS
675 This option enables collection of various statistics for KVM guest.
676 Statistics are displayed in debugfs filesystem. Enabling this option
677 may incur significant overhead.
679 source "arch/x86/lguest/Kconfig"
681 config PARAVIRT_TIME_ACCOUNTING
682 bool "Paravirtual steal time accounting"
686 Select this option to enable fine granularity task steal time
687 accounting. Time spent executing other tasks in parallel with
688 the current vCPU is discounted from the vCPU power. To account for
689 that, there can be a small performance impact.
691 If in doubt, say N here.
693 config PARAVIRT_CLOCK
696 endif #HYPERVISOR_GUEST
704 This option adds a kernel parameter 'memtest', which allows memtest
706 memtest=0, mean disabled; -- default
707 memtest=1, mean do 1 test pattern;
709 memtest=4, mean do 4 test patterns.
710 If you are unsure how to answer this question, answer N.
712 source "arch/x86/Kconfig.cpu"
716 prompt "HPET Timer Support" if X86_32
718 Use the IA-PC HPET (High Precision Event Timer) to manage
719 time in preference to the PIT and RTC, if a HPET is
721 HPET is the next generation timer replacing legacy 8254s.
722 The HPET provides a stable time base on SMP
723 systems, unlike the TSC, but it is more expensive to access,
724 as it is off-chip. You can find the HPET spec at
725 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
727 You can safely choose Y here. However, HPET will only be
728 activated if the platform and the BIOS support this feature.
729 Otherwise the 8254 will be used for timing services.
731 Choose N to continue using the legacy 8254 timer.
733 config HPET_EMULATE_RTC
735 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
738 def_bool y if X86_INTEL_MID
739 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
741 depends on X86_INTEL_MID && SFI
743 APB timer is the replacement for 8254, HPET on X86 MID platforms.
744 The APBT provides a stable time base on SMP
745 systems, unlike the TSC, but it is more expensive to access,
746 as it is off-chip. APB timers are always running regardless of CPU
747 C states, they are used as per CPU clockevent device when possible.
749 # Mark as expert because too many people got it wrong.
750 # The code disables itself when not needed.
753 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
754 bool "Enable DMI scanning" if EXPERT
756 Enabled scanning of DMI to identify machine quirks. Say Y
757 here unless you have verified that your setup is not
758 affected by entries in the DMI blacklist. Required by PNP
762 bool "Old AMD GART IOMMU support"
764 depends on X86_64 && PCI && AMD_NB
766 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
767 GART based hardware IOMMUs.
769 The GART supports full DMA access for devices with 32-bit access
770 limitations, on systems with more than 3 GB. This is usually needed
771 for USB, sound, many IDE/SATA chipsets and some other devices.
773 Newer systems typically have a modern AMD IOMMU, supported via
774 the CONFIG_AMD_IOMMU=y config option.
776 In normal configurations this driver is only active when needed:
777 there's more than 3 GB of memory and the system contains a
778 32-bit limited device.
783 bool "IBM Calgary IOMMU support"
785 depends on X86_64 && PCI
787 Support for hardware IOMMUs in IBM's xSeries x366 and x460
788 systems. Needed to run systems with more than 3GB of memory
789 properly with 32-bit PCI devices that do not support DAC
790 (Double Address Cycle). Calgary also supports bus level
791 isolation, where all DMAs pass through the IOMMU. This
792 prevents them from going anywhere except their intended
793 destination. This catches hard-to-find kernel bugs and
794 mis-behaving drivers and devices that do not use the DMA-API
795 properly to set up their DMA buffers. The IOMMU can be
796 turned off at boot time with the iommu=off parameter.
797 Normally the kernel will make the right choice by itself.
800 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
802 prompt "Should Calgary be enabled by default?"
803 depends on CALGARY_IOMMU
805 Should Calgary be enabled by default? if you choose 'y', Calgary
806 will be used (if it exists). If you choose 'n', Calgary will not be
807 used even if it exists. If you choose 'n' and would like to use
808 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
811 # need this always selected by IOMMU for the VIA workaround
815 Support for software bounce buffers used on x86-64 systems
816 which don't have a hardware IOMMU. Using this PCI devices
817 which can only access 32-bits of memory can be used on systems
818 with more than 3 GB of memory.
823 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
826 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
827 depends on X86_64 && SMP && DEBUG_KERNEL
828 select CPUMASK_OFFSTACK
830 Enable maximum number of CPUS and NUMA Nodes for this architecture.
834 int "Maximum number of CPUs" if SMP && !MAXSMP
835 range 2 8 if SMP && X86_32 && !X86_BIGSMP
836 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
837 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
839 default "8192" if MAXSMP
840 default "32" if SMP && X86_BIGSMP
843 This allows you to specify the maximum number of CPUs which this
844 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
845 supported value is 4096, otherwise the maximum value is 512. The
846 minimum value which makes sense is 2.
848 This is purely to save memory - each supported CPU adds
849 approximately eight kilobytes to the kernel image.
852 bool "SMT (Hyperthreading) scheduler support"
855 SMT scheduler support improves the CPU scheduler's decision making
856 when dealing with Intel Pentium 4 chips with HyperThreading at a
857 cost of slightly increased overhead in some places. If unsure say
862 prompt "Multi-core scheduler support"
865 Multi-core scheduler support improves the CPU scheduler's decision
866 making when dealing with multi-core CPU chips at a cost of slightly
867 increased overhead in some places. If unsure say N here.
869 source "kernel/Kconfig.preempt"
873 depends on !SMP && X86_LOCAL_APIC
876 bool "Local APIC support on uniprocessors"
877 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
879 A local APIC (Advanced Programmable Interrupt Controller) is an
880 integrated interrupt controller in the CPU. If you have a single-CPU
881 system which has a processor with a local APIC, you can say Y here to
882 enable and use it. If you say Y here even though your machine doesn't
883 have a local APIC, then the kernel will still run with no slowdown at
884 all. The local APIC supports CPU-generated self-interrupts (timer,
885 performance counters), and the NMI watchdog which detects hard
888 config X86_UP_APIC_MSI
890 select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
893 bool "IO-APIC support on uniprocessors"
894 depends on X86_UP_APIC
896 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
897 SMP-capable replacement for PC-style interrupt controllers. Most
898 SMP systems and many recent uniprocessor systems have one.
900 If you have a single-CPU system with an IO-APIC, you can say Y here
901 to use it. If you say Y here even though your machine doesn't have
902 an IO-APIC, then the kernel will still run with no slowdown at all.
904 config X86_LOCAL_APIC
906 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
907 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
910 def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
911 depends on X86_LOCAL_APIC
914 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
915 bool "Reroute for broken boot IRQs"
916 depends on X86_IO_APIC
918 This option enables a workaround that fixes a source of
919 spurious interrupts. This is recommended when threaded
920 interrupt handling is used on systems where the generation of
921 superfluous "boot interrupts" cannot be disabled.
923 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
924 entry in the chipset's IO-APIC is masked (as, e.g. the RT
925 kernel does during interrupt handling). On chipsets where this
926 boot IRQ generation cannot be disabled, this workaround keeps
927 the original IRQ line masked so that only the equivalent "boot
928 IRQ" is delivered to the CPUs. The workaround also tells the
929 kernel to set up the IRQ handler on the boot IRQ line. In this
930 way only one interrupt is delivered to the kernel. Otherwise
931 the spurious second interrupt may cause the kernel to bring
932 down (vital) interrupt lines.
934 Only affects "broken" chipsets. Interrupt sharing may be
935 increased on these systems.
938 bool "Machine Check / overheating reporting"
941 Machine Check support allows the processor to notify the
942 kernel if it detects a problem (e.g. overheating, data corruption).
943 The action the kernel takes depends on the severity of the problem,
944 ranging from warning messages to halting the machine.
948 prompt "Intel MCE features"
949 depends on X86_MCE && X86_LOCAL_APIC
951 Additional support for intel specific MCE features such as
956 prompt "AMD MCE features"
957 depends on X86_MCE && X86_LOCAL_APIC
959 Additional support for AMD specific MCE features such as
960 the DRAM Error Threshold.
962 config X86_ANCIENT_MCE
963 bool "Support for old Pentium 5 / WinChip machine checks"
964 depends on X86_32 && X86_MCE
966 Include support for machine check handling on old Pentium 5 or WinChip
967 systems. These typically need to be enabled explicitly on the command
970 config X86_MCE_THRESHOLD
971 depends on X86_MCE_AMD || X86_MCE_INTEL
974 config X86_MCE_INJECT
976 tristate "Machine check injector support"
978 Provide support for injecting machine checks for testing purposes.
979 If you don't know what a machine check is and you don't do kernel
980 QA it is safe to say n.
982 config X86_THERMAL_VECTOR
984 depends on X86_MCE_INTEL
987 bool "Enable VM86 support" if EXPERT
991 This option is required by programs like DOSEMU to run
992 16-bit real mode legacy code on x86 processors. It also may
993 be needed by software like XFree86 to initialize some video
994 cards via BIOS. Disabling this option saves about 6K.
997 bool "Enable support for 16-bit segments" if EXPERT
1000 This option is required by programs like Wine to run 16-bit
1001 protected mode legacy code on x86 processors. Disabling
1002 this option saves about 300 bytes on i386, or around 6K text
1003 plus 16K runtime memory on x86-64,
1007 depends on X86_16BIT && X86_32
1011 depends on X86_16BIT && X86_64
1013 config X86_VSYSCALL_EMULATION
1014 bool "Enable vsyscall emulation" if EXPERT
1018 This enables emulation of the legacy vsyscall page. Disabling
1019 it is roughly equivalent to booting with vsyscall=none, except
1020 that it will also disable the helpful warning if a program
1021 tries to use a vsyscall. With this option set to N, offending
1022 programs will just segfault, citing addresses of the form
1025 This option is required by many programs built before 2013, and
1026 care should be used even with newer programs if set to N.
1028 Disabling this option saves about 7K of kernel size and
1029 possibly 4K of additional runtime pagetable memory.
1032 tristate "Toshiba Laptop support"
1035 This adds a driver to safely access the System Management Mode of
1036 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1037 not work on models with a Phoenix BIOS. The System Management Mode
1038 is used to set the BIOS and power saving options on Toshiba portables.
1040 For information on utilities to make use of this driver see the
1041 Toshiba Linux utilities web site at:
1042 <http://www.buzzard.org.uk/toshiba/>.
1044 Say Y if you intend to run this kernel on a Toshiba portable.
1048 tristate "Dell laptop support"
1051 This adds a driver to safely access the System Management Mode
1052 of the CPU on the Dell Inspiron 8000. The System Management Mode
1053 is used to read cpu temperature and cooling fan status and to
1054 control the fans on the I8K portables.
1056 This driver has been tested only on the Inspiron 8000 but it may
1057 also work with other Dell laptops. You can force loading on other
1058 models by passing the parameter `force=1' to the module. Use at
1061 For information on utilities to make use of this driver see the
1062 I8K Linux utilities web site at:
1063 <http://people.debian.org/~dz/i8k/>
1065 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1068 config X86_REBOOTFIXUPS
1069 bool "Enable X86 board specific fixups for reboot"
1072 This enables chipset and/or board specific fixups to be done
1073 in order to get reboot to work correctly. This is only needed on
1074 some combinations of hardware and BIOS. The symptom, for which
1075 this config is intended, is when reboot ends with a stalled/hung
1078 Currently, the only fixup is for the Geode machines using
1079 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1081 Say Y if you want to enable the fixup. Currently, it's safe to
1082 enable this option even if you don't need it.
1086 tristate "CPU microcode loading support"
1087 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1091 If you say Y here, you will be able to update the microcode on
1092 certain Intel and AMD processors. The Intel support is for the
1093 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1094 Xeon etc. The AMD support is for families 0x10 and later. You will
1095 obviously need the actual microcode binary data itself which is not
1096 shipped with the Linux kernel.
1098 This option selects the general module only, you need to select
1099 at least one vendor specific module as well.
1101 To compile this driver as a module, choose M here: the module
1102 will be called microcode.
1104 config MICROCODE_INTEL
1105 bool "Intel microcode loading support"
1106 depends on MICROCODE
1110 This options enables microcode patch loading support for Intel
1113 For the current Intel microcode data package go to
1114 <https://downloadcenter.intel.com> and search for
1115 'Linux Processor Microcode Data File'.
1117 config MICROCODE_AMD
1118 bool "AMD microcode loading support"
1119 depends on MICROCODE
1122 If you select this option, microcode patch loading support for AMD
1123 processors will be enabled.
1125 config MICROCODE_OLD_INTERFACE
1127 depends on MICROCODE
1129 config MICROCODE_INTEL_EARLY
1132 config MICROCODE_AMD_EARLY
1135 config MICROCODE_EARLY
1136 bool "Early load microcode"
1137 depends on MICROCODE=y && BLK_DEV_INITRD
1138 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1139 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1142 This option provides functionality to read additional microcode data
1143 at the beginning of initrd image. The data tells kernel to load
1144 microcode to CPU's as early as possible. No functional change if no
1145 microcode data is glued to the initrd, therefore it's safe to say Y.
1148 tristate "/dev/cpu/*/msr - Model-specific register support"
1150 This device gives privileged processes access to the x86
1151 Model-Specific Registers (MSRs). It is a character device with
1152 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1153 MSR accesses are directed to a specific CPU on multi-processor
1157 tristate "/dev/cpu/*/cpuid - CPU information support"
1159 This device gives processes access to the x86 CPUID instruction to
1160 be executed on a specific processor. It is a character device
1161 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1165 prompt "High Memory Support"
1172 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1173 However, the address space of 32-bit x86 processors is only 4
1174 Gigabytes large. That means that, if you have a large amount of
1175 physical memory, not all of it can be "permanently mapped" by the
1176 kernel. The physical memory that's not permanently mapped is called
1179 If you are compiling a kernel which will never run on a machine with
1180 more than 1 Gigabyte total physical RAM, answer "off" here (default
1181 choice and suitable for most users). This will result in a "3GB/1GB"
1182 split: 3GB are mapped so that each process sees a 3GB virtual memory
1183 space and the remaining part of the 4GB virtual memory space is used
1184 by the kernel to permanently map as much physical memory as
1187 If the machine has between 1 and 4 Gigabytes physical RAM, then
1190 If more than 4 Gigabytes is used then answer "64GB" here. This
1191 selection turns Intel PAE (Physical Address Extension) mode on.
1192 PAE implements 3-level paging on IA32 processors. PAE is fully
1193 supported by Linux, PAE mode is implemented on all recent Intel
1194 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1195 then the kernel will not boot on CPUs that don't support PAE!
1197 The actual amount of total physical memory will either be
1198 auto detected or can be forced by using a kernel command line option
1199 such as "mem=256M". (Try "man bootparam" or see the documentation of
1200 your boot loader (lilo or loadlin) about how to pass options to the
1201 kernel at boot time.)
1203 If unsure, say "off".
1208 Select this if you have a 32-bit processor and between 1 and 4
1209 gigabytes of physical RAM.
1216 Select this if you have a 32-bit processor and more than 4
1217 gigabytes of physical RAM.
1222 prompt "Memory split" if EXPERT
1226 Select the desired split between kernel and user memory.
1228 If the address range available to the kernel is less than the
1229 physical memory installed, the remaining memory will be available
1230 as "high memory". Accessing high memory is a little more costly
1231 than low memory, as it needs to be mapped into the kernel first.
1232 Note that increasing the kernel address space limits the range
1233 available to user programs, making the address space there
1234 tighter. Selecting anything other than the default 3G/1G split
1235 will also likely make your kernel incompatible with binary-only
1238 If you are not absolutely sure what you are doing, leave this
1242 bool "3G/1G user/kernel split"
1243 config VMSPLIT_3G_OPT
1245 bool "3G/1G user/kernel split (for full 1G low memory)"
1247 bool "2G/2G user/kernel split"
1248 config VMSPLIT_2G_OPT
1250 bool "2G/2G user/kernel split (for full 2G low memory)"
1252 bool "1G/3G user/kernel split"
1257 default 0xB0000000 if VMSPLIT_3G_OPT
1258 default 0x80000000 if VMSPLIT_2G
1259 default 0x78000000 if VMSPLIT_2G_OPT
1260 default 0x40000000 if VMSPLIT_1G
1266 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1269 bool "PAE (Physical Address Extension) Support"
1270 depends on X86_32 && !HIGHMEM4G
1272 PAE is required for NX support, and furthermore enables
1273 larger swapspace support for non-overcommit purposes. It
1274 has the cost of more pagetable lookup overhead, and also
1275 consumes more pagetable space per process.
1277 config ARCH_PHYS_ADDR_T_64BIT
1279 depends on X86_64 || X86_PAE
1281 config ARCH_DMA_ADDR_T_64BIT
1283 depends on X86_64 || HIGHMEM64G
1285 config DIRECT_GBPAGES
1286 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1290 Allow the kernel linear mapping to use 1GB pages on CPUs that
1291 support it. This can improve the kernel's performance a tiny bit by
1292 reducing TLB pressure. If in doubt, say "Y".
1294 # Common NUMA Features
1296 bool "Numa Memory Allocation and Scheduler Support"
1298 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1299 default y if X86_BIGSMP
1301 Enable NUMA (Non Uniform Memory Access) support.
1303 The kernel will try to allocate memory used by a CPU on the
1304 local memory controller of the CPU and add some more
1305 NUMA awareness to the kernel.
1307 For 64-bit this is recommended if the system is Intel Core i7
1308 (or later), AMD Opteron, or EM64T NUMA.
1310 For 32-bit this is only needed if you boot a 32-bit
1311 kernel on a 64-bit NUMA platform.
1313 Otherwise, you should say N.
1317 prompt "Old style AMD Opteron NUMA detection"
1318 depends on X86_64 && NUMA && PCI
1320 Enable AMD NUMA node topology detection. You should say Y here if
1321 you have a multi processor AMD system. This uses an old method to
1322 read the NUMA configuration directly from the builtin Northbridge
1323 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1324 which also takes priority if both are compiled in.
1326 config X86_64_ACPI_NUMA
1328 prompt "ACPI NUMA detection"
1329 depends on X86_64 && NUMA && ACPI && PCI
1332 Enable ACPI SRAT based node topology detection.
1334 # Some NUMA nodes have memory ranges that span
1335 # other nodes. Even though a pfn is valid and
1336 # between a node's start and end pfns, it may not
1337 # reside on that node. See memmap_init_zone()
1339 config NODES_SPAN_OTHER_NODES
1341 depends on X86_64_ACPI_NUMA
1344 bool "NUMA emulation"
1347 Enable NUMA emulation. A flat machine will be split
1348 into virtual nodes when booted with "numa=fake=N", where N is the
1349 number of nodes. This is only useful for debugging.
1352 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1354 default "10" if MAXSMP
1355 default "6" if X86_64
1357 depends on NEED_MULTIPLE_NODES
1359 Specify the maximum number of NUMA Nodes available on the target
1360 system. Increases memory reserved to accommodate various tables.
1362 config ARCH_HAVE_MEMORY_PRESENT
1364 depends on X86_32 && DISCONTIGMEM
1366 config NEED_NODE_MEMMAP_SIZE
1368 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1370 config ARCH_FLATMEM_ENABLE
1372 depends on X86_32 && !NUMA
1374 config ARCH_DISCONTIGMEM_ENABLE
1376 depends on NUMA && X86_32
1378 config ARCH_DISCONTIGMEM_DEFAULT
1380 depends on NUMA && X86_32
1382 config ARCH_SPARSEMEM_ENABLE
1384 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1385 select SPARSEMEM_STATIC if X86_32
1386 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1388 config ARCH_SPARSEMEM_DEFAULT
1392 config ARCH_SELECT_MEMORY_MODEL
1394 depends on ARCH_SPARSEMEM_ENABLE
1396 config ARCH_MEMORY_PROBE
1397 bool "Enable sysfs memory/probe interface"
1398 depends on X86_64 && MEMORY_HOTPLUG
1400 This option enables a sysfs memory/probe interface for testing.
1401 See Documentation/memory-hotplug.txt for more information.
1402 If you are unsure how to answer this question, answer N.
1404 config ARCH_PROC_KCORE_TEXT
1406 depends on X86_64 && PROC_KCORE
1408 config ILLEGAL_POINTER_VALUE
1411 default 0xdead000000000000 if X86_64
1416 bool "Allocate 3rd-level pagetables from highmem"
1419 The VM uses one page table entry for each page of physical memory.
1420 For systems with a lot of RAM, this can be wasteful of precious
1421 low memory. Setting this option will put user-space page table
1422 entries in high memory.
1424 config X86_CHECK_BIOS_CORRUPTION
1425 bool "Check for low memory corruption"
1427 Periodically check for memory corruption in low memory, which
1428 is suspected to be caused by BIOS. Even when enabled in the
1429 configuration, it is disabled at runtime. Enable it by
1430 setting "memory_corruption_check=1" on the kernel command
1431 line. By default it scans the low 64k of memory every 60
1432 seconds; see the memory_corruption_check_size and
1433 memory_corruption_check_period parameters in
1434 Documentation/kernel-parameters.txt to adjust this.
1436 When enabled with the default parameters, this option has
1437 almost no overhead, as it reserves a relatively small amount
1438 of memory and scans it infrequently. It both detects corruption
1439 and prevents it from affecting the running system.
1441 It is, however, intended as a diagnostic tool; if repeatable
1442 BIOS-originated corruption always affects the same memory,
1443 you can use memmap= to prevent the kernel from using that
1446 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1447 bool "Set the default setting of memory_corruption_check"
1448 depends on X86_CHECK_BIOS_CORRUPTION
1451 Set whether the default state of memory_corruption_check is
1454 config X86_RESERVE_LOW
1455 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1459 Specify the amount of low memory to reserve for the BIOS.
1461 The first page contains BIOS data structures that the kernel
1462 must not use, so that page must always be reserved.
1464 By default we reserve the first 64K of physical RAM, as a
1465 number of BIOSes are known to corrupt that memory range
1466 during events such as suspend/resume or monitor cable
1467 insertion, so it must not be used by the kernel.
1469 You can set this to 4 if you are absolutely sure that you
1470 trust the BIOS to get all its memory reservations and usages
1471 right. If you know your BIOS have problems beyond the
1472 default 64K area, you can set this to 640 to avoid using the
1473 entire low memory range.
1475 If you have doubts about the BIOS (e.g. suspend/resume does
1476 not work or there's kernel crashes after certain hardware
1477 hotplug events) then you might want to enable
1478 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1479 typical corruption patterns.
1481 Leave this to the default value of 64 if you are unsure.
1483 config MATH_EMULATION
1485 prompt "Math emulation" if X86_32
1487 Linux can emulate a math coprocessor (used for floating point
1488 operations) if you don't have one. 486DX and Pentium processors have
1489 a math coprocessor built in, 486SX and 386 do not, unless you added
1490 a 487DX or 387, respectively. (The messages during boot time can
1491 give you some hints here ["man dmesg"].) Everyone needs either a
1492 coprocessor or this emulation.
1494 If you don't have a math coprocessor, you need to say Y here; if you
1495 say Y here even though you have a coprocessor, the coprocessor will
1496 be used nevertheless. (This behavior can be changed with the kernel
1497 command line option "no387", which comes handy if your coprocessor
1498 is broken. Try "man bootparam" or see the documentation of your boot
1499 loader (lilo or loadlin) about how to pass options to the kernel at
1500 boot time.) This means that it is a good idea to say Y here if you
1501 intend to use this kernel on different machines.
1503 More information about the internals of the Linux math coprocessor
1504 emulation can be found in <file:arch/x86/math-emu/README>.
1506 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1507 kernel, it won't hurt.
1511 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1513 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1514 the Memory Type Range Registers (MTRRs) may be used to control
1515 processor access to memory ranges. This is most useful if you have
1516 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1517 allows bus write transfers to be combined into a larger transfer
1518 before bursting over the PCI/AGP bus. This can increase performance
1519 of image write operations 2.5 times or more. Saying Y here creates a
1520 /proc/mtrr file which may be used to manipulate your processor's
1521 MTRRs. Typically the X server should use this.
1523 This code has a reasonably generic interface so that similar
1524 control registers on other processors can be easily supported
1527 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1528 Registers (ARRs) which provide a similar functionality to MTRRs. For
1529 these, the ARRs are used to emulate the MTRRs.
1530 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1531 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1532 write-combining. All of these processors are supported by this code
1533 and it makes sense to say Y here if you have one of them.
1535 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1536 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1537 can lead to all sorts of problems, so it's good to say Y here.
1539 You can safely say Y even if your machine doesn't have MTRRs, you'll
1540 just add about 9 KB to your kernel.
1542 See <file:Documentation/x86/mtrr.txt> for more information.
1544 config MTRR_SANITIZER
1546 prompt "MTRR cleanup support"
1549 Convert MTRR layout from continuous to discrete, so X drivers can
1550 add writeback entries.
1552 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1553 The largest mtrr entry size for a continuous block can be set with
1558 config MTRR_SANITIZER_ENABLE_DEFAULT
1559 int "MTRR cleanup enable value (0-1)"
1562 depends on MTRR_SANITIZER
1564 Enable mtrr cleanup default value
1566 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1567 int "MTRR cleanup spare reg num (0-7)"
1570 depends on MTRR_SANITIZER
1572 mtrr cleanup spare entries default, it can be changed via
1573 mtrr_spare_reg_nr=N on the kernel command line.
1577 prompt "x86 PAT support" if EXPERT
1580 Use PAT attributes to setup page level cache control.
1582 PATs are the modern equivalents of MTRRs and are much more
1583 flexible than MTRRs.
1585 Say N here if you see bootup problems (boot crash, boot hang,
1586 spontaneous reboots) or a non-working video driver.
1590 config ARCH_USES_PG_UNCACHED
1596 prompt "x86 architectural random number generator" if EXPERT
1598 Enable the x86 architectural RDRAND instruction
1599 (Intel Bull Mountain technology) to generate random numbers.
1600 If supported, this is a high bandwidth, cryptographically
1601 secure hardware random number generator.
1605 prompt "Supervisor Mode Access Prevention" if EXPERT
1607 Supervisor Mode Access Prevention (SMAP) is a security
1608 feature in newer Intel processors. There is a small
1609 performance cost if this enabled and turned on; there is
1610 also a small increase in the kernel size if this is enabled.
1614 config X86_INTEL_MPX
1615 prompt "Intel MPX (Memory Protection Extensions)"
1617 depends on CPU_SUP_INTEL
1619 MPX provides hardware features that can be used in
1620 conjunction with compiler-instrumented code to check
1621 memory references. It is designed to detect buffer
1622 overflow or underflow bugs.
1624 This option enables running applications which are
1625 instrumented or otherwise use MPX. It does not use MPX
1626 itself inside the kernel or to protect the kernel
1627 against bad memory references.
1629 Enabling this option will make the kernel larger:
1630 ~8k of kernel text and 36 bytes of data on a 64-bit
1631 defconfig. It adds a long to the 'mm_struct' which
1632 will increase the kernel memory overhead of each
1633 process and adds some branches to paths used during
1634 exec() and munmap().
1636 For details, see Documentation/x86/intel_mpx.txt
1641 bool "EFI runtime service support"
1644 select EFI_RUNTIME_WRAPPERS
1646 This enables the kernel to use EFI runtime services that are
1647 available (such as the EFI variable services).
1649 This option is only useful on systems that have EFI firmware.
1650 In addition, you should use the latest ELILO loader available
1651 at <http://elilo.sourceforge.net> in order to take advantage
1652 of EFI runtime services. However, even with this option, the
1653 resultant kernel should continue to boot on existing non-EFI
1657 bool "EFI stub support"
1658 depends on EFI && !X86_USE_3DNOW
1661 This kernel feature allows a bzImage to be loaded directly
1662 by EFI firmware without the use of a bootloader.
1664 See Documentation/efi-stub.txt for more information.
1667 bool "EFI mixed-mode support"
1668 depends on EFI_STUB && X86_64
1670 Enabling this feature allows a 64-bit kernel to be booted
1671 on a 32-bit firmware, provided that your CPU supports 64-bit
1674 Note that it is not possible to boot a mixed-mode enabled
1675 kernel via the EFI boot stub - a bootloader that supports
1676 the EFI handover protocol must be used.
1682 prompt "Enable seccomp to safely compute untrusted bytecode"
1684 This kernel feature is useful for number crunching applications
1685 that may need to compute untrusted bytecode during their
1686 execution. By using pipes or other transports made available to
1687 the process as file descriptors supporting the read/write
1688 syscalls, it's possible to isolate those applications in
1689 their own address space using seccomp. Once seccomp is
1690 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1691 and the task is only allowed to execute a few safe syscalls
1692 defined by each seccomp mode.
1694 If unsure, say Y. Only embedded should say N here.
1696 source kernel/Kconfig.hz
1699 bool "kexec system call"
1701 kexec is a system call that implements the ability to shutdown your
1702 current kernel, and to start another kernel. It is like a reboot
1703 but it is independent of the system firmware. And like a reboot
1704 you can start any kernel with it, not just Linux.
1706 The name comes from the similarity to the exec system call.
1708 It is an ongoing process to be certain the hardware in a machine
1709 is properly shutdown, so do not be surprised if this code does not
1710 initially work for you. As of this writing the exact hardware
1711 interface is strongly in flux, so no good recommendation can be
1715 bool "kexec file based system call"
1720 depends on CRYPTO_SHA256=y
1722 This is new version of kexec system call. This system call is
1723 file based and takes file descriptors as system call argument
1724 for kernel and initramfs as opposed to list of segments as
1725 accepted by previous system call.
1727 config KEXEC_VERIFY_SIG
1728 bool "Verify kernel signature during kexec_file_load() syscall"
1729 depends on KEXEC_FILE
1731 This option makes kernel signature verification mandatory for
1732 kexec_file_load() syscall. If kernel is signature can not be
1733 verified, kexec_file_load() will fail.
1735 This option enforces signature verification at generic level.
1736 One needs to enable signature verification for type of kernel
1737 image being loaded to make sure it works. For example, enable
1738 bzImage signature verification option to be able to load and
1739 verify signatures of bzImage. Otherwise kernel loading will fail.
1741 config KEXEC_BZIMAGE_VERIFY_SIG
1742 bool "Enable bzImage signature verification support"
1743 depends on KEXEC_VERIFY_SIG
1744 depends on SIGNED_PE_FILE_VERIFICATION
1745 select SYSTEM_TRUSTED_KEYRING
1747 Enable bzImage signature verification support.
1750 bool "kernel crash dumps"
1751 depends on X86_64 || (X86_32 && HIGHMEM)
1753 Generate crash dump after being started by kexec.
1754 This should be normally only set in special crash dump kernels
1755 which are loaded in the main kernel with kexec-tools into
1756 a specially reserved region and then later executed after
1757 a crash by kdump/kexec. The crash dump kernel must be compiled
1758 to a memory address not used by the main kernel or BIOS using
1759 PHYSICAL_START, or it must be built as a relocatable image
1760 (CONFIG_RELOCATABLE=y).
1761 For more details see Documentation/kdump/kdump.txt
1765 depends on KEXEC && HIBERNATION
1767 Jump between original kernel and kexeced kernel and invoke
1768 code in physical address mode via KEXEC
1770 config PHYSICAL_START
1771 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1774 This gives the physical address where the kernel is loaded.
1776 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1777 bzImage will decompress itself to above physical address and
1778 run from there. Otherwise, bzImage will run from the address where
1779 it has been loaded by the boot loader and will ignore above physical
1782 In normal kdump cases one does not have to set/change this option
1783 as now bzImage can be compiled as a completely relocatable image
1784 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1785 address. This option is mainly useful for the folks who don't want
1786 to use a bzImage for capturing the crash dump and want to use a
1787 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1788 to be specifically compiled to run from a specific memory area
1789 (normally a reserved region) and this option comes handy.
1791 So if you are using bzImage for capturing the crash dump,
1792 leave the value here unchanged to 0x1000000 and set
1793 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1794 for capturing the crash dump change this value to start of
1795 the reserved region. In other words, it can be set based on
1796 the "X" value as specified in the "crashkernel=YM@XM"
1797 command line boot parameter passed to the panic-ed
1798 kernel. Please take a look at Documentation/kdump/kdump.txt
1799 for more details about crash dumps.
1801 Usage of bzImage for capturing the crash dump is recommended as
1802 one does not have to build two kernels. Same kernel can be used
1803 as production kernel and capture kernel. Above option should have
1804 gone away after relocatable bzImage support is introduced. But it
1805 is present because there are users out there who continue to use
1806 vmlinux for dump capture. This option should go away down the
1809 Don't change this unless you know what you are doing.
1812 bool "Build a relocatable kernel"
1815 This builds a kernel image that retains relocation information
1816 so it can be loaded someplace besides the default 1MB.
1817 The relocations tend to make the kernel binary about 10% larger,
1818 but are discarded at runtime.
1820 One use is for the kexec on panic case where the recovery kernel
1821 must live at a different physical address than the primary
1824 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1825 it has been loaded at and the compile time physical address
1826 (CONFIG_PHYSICAL_START) is used as the minimum location.
1828 config RANDOMIZE_BASE
1829 bool "Randomize the address of the kernel image"
1830 depends on RELOCATABLE
1833 Randomizes the physical and virtual address at which the
1834 kernel image is decompressed, as a security feature that
1835 deters exploit attempts relying on knowledge of the location
1836 of kernel internals.
1838 Entropy is generated using the RDRAND instruction if it is
1839 supported. If RDTSC is supported, it is used as well. If
1840 neither RDRAND nor RDTSC are supported, then randomness is
1841 read from the i8254 timer.
1843 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1844 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1845 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1846 minimum of 2MiB, only 10 bits of entropy is theoretically
1847 possible. At best, due to page table layouts, 64-bit can use
1848 9 bits of entropy and 32-bit uses 8 bits.
1852 config RANDOMIZE_BASE_MAX_OFFSET
1853 hex "Maximum kASLR offset allowed" if EXPERT
1854 depends on RANDOMIZE_BASE
1855 range 0x0 0x20000000 if X86_32
1856 default "0x20000000" if X86_32
1857 range 0x0 0x40000000 if X86_64
1858 default "0x40000000" if X86_64
1860 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1861 memory is used to determine the maximal offset in bytes that will
1862 be applied to the kernel when kernel Address Space Layout
1863 Randomization (kASLR) is active. This must be a multiple of
1866 On 32-bit this is limited to 512MiB by page table layouts. The
1869 On 64-bit this is limited by how the kernel fixmap page table is
1870 positioned, so this cannot be larger than 1GiB currently. Without
1871 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1872 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1873 modules area will shrink to compensate, up to the current maximum
1874 1GiB to 1GiB split. The default is 1GiB.
1876 If unsure, leave at the default value.
1878 # Relocation on x86 needs some additional build support
1879 config X86_NEED_RELOCS
1881 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1883 config PHYSICAL_ALIGN
1884 hex "Alignment value to which kernel should be aligned"
1886 range 0x2000 0x1000000 if X86_32
1887 range 0x200000 0x1000000 if X86_64
1889 This value puts the alignment restrictions on physical address
1890 where kernel is loaded and run from. Kernel is compiled for an
1891 address which meets above alignment restriction.
1893 If bootloader loads the kernel at a non-aligned address and
1894 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1895 address aligned to above value and run from there.
1897 If bootloader loads the kernel at a non-aligned address and
1898 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1899 load address and decompress itself to the address it has been
1900 compiled for and run from there. The address for which kernel is
1901 compiled already meets above alignment restrictions. Hence the
1902 end result is that kernel runs from a physical address meeting
1903 above alignment restrictions.
1905 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1906 this value must be a multiple of 0x200000.
1908 Don't change this unless you know what you are doing.
1911 bool "Support for hot-pluggable CPUs"
1914 Say Y here to allow turning CPUs off and on. CPUs can be
1915 controlled through /sys/devices/system/cpu.
1916 ( Note: power management support will enable this option
1917 automatically on SMP systems. )
1918 Say N if you want to disable CPU hotplug.
1920 config BOOTPARAM_HOTPLUG_CPU0
1921 bool "Set default setting of cpu0_hotpluggable"
1923 depends on HOTPLUG_CPU
1925 Set whether default state of cpu0_hotpluggable is on or off.
1927 Say Y here to enable CPU0 hotplug by default. If this switch
1928 is turned on, there is no need to give cpu0_hotplug kernel
1929 parameter and the CPU0 hotplug feature is enabled by default.
1931 Please note: there are two known CPU0 dependencies if you want
1932 to enable the CPU0 hotplug feature either by this switch or by
1933 cpu0_hotplug kernel parameter.
1935 First, resume from hibernate or suspend always starts from CPU0.
1936 So hibernate and suspend are prevented if CPU0 is offline.
1938 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1939 offline if any interrupt can not migrate out of CPU0. There may
1940 be other CPU0 dependencies.
1942 Please make sure the dependencies are under your control before
1943 you enable this feature.
1945 Say N if you don't want to enable CPU0 hotplug feature by default.
1946 You still can enable the CPU0 hotplug feature at boot by kernel
1947 parameter cpu0_hotplug.
1949 config DEBUG_HOTPLUG_CPU0
1951 prompt "Debug CPU0 hotplug"
1952 depends on HOTPLUG_CPU
1954 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1955 soon as possible and boots up userspace with CPU0 offlined. User
1956 can online CPU0 back after boot time.
1958 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1959 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1960 compilation or giving cpu0_hotplug kernel parameter at boot.
1966 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1967 depends on X86_32 || IA32_EMULATION
1969 Certain buggy versions of glibc will crash if they are
1970 presented with a 32-bit vDSO that is not mapped at the address
1971 indicated in its segment table.
1973 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1974 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1975 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1976 the only released version with the bug, but OpenSUSE 9
1977 contains a buggy "glibc 2.3.2".
1979 The symptom of the bug is that everything crashes on startup, saying:
1980 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1982 Saying Y here changes the default value of the vdso32 boot
1983 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1984 This works around the glibc bug but hurts performance.
1986 If unsure, say N: if you are compiling your own kernel, you
1987 are unlikely to be using a buggy version of glibc.
1990 bool "Built-in kernel command line"
1992 Allow for specifying boot arguments to the kernel at
1993 build time. On some systems (e.g. embedded ones), it is
1994 necessary or convenient to provide some or all of the
1995 kernel boot arguments with the kernel itself (that is,
1996 to not rely on the boot loader to provide them.)
1998 To compile command line arguments into the kernel,
1999 set this option to 'Y', then fill in the
2000 the boot arguments in CONFIG_CMDLINE.
2002 Systems with fully functional boot loaders (i.e. non-embedded)
2003 should leave this option set to 'N'.
2006 string "Built-in kernel command string"
2007 depends on CMDLINE_BOOL
2010 Enter arguments here that should be compiled into the kernel
2011 image and used at boot time. If the boot loader provides a
2012 command line at boot time, it is appended to this string to
2013 form the full kernel command line, when the system boots.
2015 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2016 change this behavior.
2018 In most cases, the command line (whether built-in or provided
2019 by the boot loader) should specify the device for the root
2022 config CMDLINE_OVERRIDE
2023 bool "Built-in command line overrides boot loader arguments"
2024 depends on CMDLINE_BOOL
2026 Set this option to 'Y' to have the kernel ignore the boot loader
2027 command line, and use ONLY the built-in command line.
2029 This is used to work around broken boot loaders. This should
2030 be set to 'N' under normal conditions.
2032 source "kernel/livepatch/Kconfig"
2036 config ARCH_ENABLE_MEMORY_HOTPLUG
2038 depends on X86_64 || (X86_32 && HIGHMEM)
2040 config ARCH_ENABLE_MEMORY_HOTREMOVE
2042 depends on MEMORY_HOTPLUG
2044 config USE_PERCPU_NUMA_NODE_ID
2048 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2050 depends on X86_64 || X86_PAE
2052 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2054 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2056 menu "Power management and ACPI options"
2058 config ARCH_HIBERNATION_HEADER
2060 depends on X86_64 && HIBERNATION
2062 source "kernel/power/Kconfig"
2064 source "drivers/acpi/Kconfig"
2066 source "drivers/sfi/Kconfig"
2073 tristate "APM (Advanced Power Management) BIOS support"
2074 depends on X86_32 && PM_SLEEP
2076 APM is a BIOS specification for saving power using several different
2077 techniques. This is mostly useful for battery powered laptops with
2078 APM compliant BIOSes. If you say Y here, the system time will be
2079 reset after a RESUME operation, the /proc/apm device will provide
2080 battery status information, and user-space programs will receive
2081 notification of APM "events" (e.g. battery status change).
2083 If you select "Y" here, you can disable actual use of the APM
2084 BIOS by passing the "apm=off" option to the kernel at boot time.
2086 Note that the APM support is almost completely disabled for
2087 machines with more than one CPU.
2089 In order to use APM, you will need supporting software. For location
2090 and more information, read <file:Documentation/power/apm-acpi.txt>
2091 and the Battery Powered Linux mini-HOWTO, available from
2092 <http://www.tldp.org/docs.html#howto>.
2094 This driver does not spin down disk drives (see the hdparm(8)
2095 manpage ("man 8 hdparm") for that), and it doesn't turn off
2096 VESA-compliant "green" monitors.
2098 This driver does not support the TI 4000M TravelMate and the ACER
2099 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2100 desktop machines also don't have compliant BIOSes, and this driver
2101 may cause those machines to panic during the boot phase.
2103 Generally, if you don't have a battery in your machine, there isn't
2104 much point in using this driver and you should say N. If you get
2105 random kernel OOPSes or reboots that don't seem to be related to
2106 anything, try disabling/enabling this option (or disabling/enabling
2109 Some other things you should try when experiencing seemingly random,
2112 1) make sure that you have enough swap space and that it is
2114 2) pass the "no-hlt" option to the kernel
2115 3) switch on floating point emulation in the kernel and pass
2116 the "no387" option to the kernel
2117 4) pass the "floppy=nodma" option to the kernel
2118 5) pass the "mem=4M" option to the kernel (thereby disabling
2119 all but the first 4 MB of RAM)
2120 6) make sure that the CPU is not over clocked.
2121 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2122 8) disable the cache from your BIOS settings
2123 9) install a fan for the video card or exchange video RAM
2124 10) install a better fan for the CPU
2125 11) exchange RAM chips
2126 12) exchange the motherboard.
2128 To compile this driver as a module, choose M here: the
2129 module will be called apm.
2133 config APM_IGNORE_USER_SUSPEND
2134 bool "Ignore USER SUSPEND"
2136 This option will ignore USER SUSPEND requests. On machines with a
2137 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2138 series notebooks, it is necessary to say Y because of a BIOS bug.
2140 config APM_DO_ENABLE
2141 bool "Enable PM at boot time"
2143 Enable APM features at boot time. From page 36 of the APM BIOS
2144 specification: "When disabled, the APM BIOS does not automatically
2145 power manage devices, enter the Standby State, enter the Suspend
2146 State, or take power saving steps in response to CPU Idle calls."
2147 This driver will make CPU Idle calls when Linux is idle (unless this
2148 feature is turned off -- see "Do CPU IDLE calls", below). This
2149 should always save battery power, but more complicated APM features
2150 will be dependent on your BIOS implementation. You may need to turn
2151 this option off if your computer hangs at boot time when using APM
2152 support, or if it beeps continuously instead of suspending. Turn
2153 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2154 T400CDT. This is off by default since most machines do fine without
2159 bool "Make CPU Idle calls when idle"
2161 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2162 On some machines, this can activate improved power savings, such as
2163 a slowed CPU clock rate, when the machine is idle. These idle calls
2164 are made after the idle loop has run for some length of time (e.g.,
2165 333 mS). On some machines, this will cause a hang at boot time or
2166 whenever the CPU becomes idle. (On machines with more than one CPU,
2167 this option does nothing.)
2169 config APM_DISPLAY_BLANK
2170 bool "Enable console blanking using APM"
2172 Enable console blanking using the APM. Some laptops can use this to
2173 turn off the LCD backlight when the screen blanker of the Linux
2174 virtual console blanks the screen. Note that this is only used by
2175 the virtual console screen blanker, and won't turn off the backlight
2176 when using the X Window system. This also doesn't have anything to
2177 do with your VESA-compliant power-saving monitor. Further, this
2178 option doesn't work for all laptops -- it might not turn off your
2179 backlight at all, or it might print a lot of errors to the console,
2180 especially if you are using gpm.
2182 config APM_ALLOW_INTS
2183 bool "Allow interrupts during APM BIOS calls"
2185 Normally we disable external interrupts while we are making calls to
2186 the APM BIOS as a measure to lessen the effects of a badly behaving
2187 BIOS implementation. The BIOS should reenable interrupts if it
2188 needs to. Unfortunately, some BIOSes do not -- especially those in
2189 many of the newer IBM Thinkpads. If you experience hangs when you
2190 suspend, try setting this to Y. Otherwise, say N.
2194 source "drivers/cpufreq/Kconfig"
2196 source "drivers/cpuidle/Kconfig"
2198 source "drivers/idle/Kconfig"
2203 menu "Bus options (PCI etc.)"
2209 Find out whether you have a PCI motherboard. PCI is the name of a
2210 bus system, i.e. the way the CPU talks to the other stuff inside
2211 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2212 VESA. If you have PCI, say Y, otherwise N.
2215 prompt "PCI access mode"
2216 depends on X86_32 && PCI
2219 On PCI systems, the BIOS can be used to detect the PCI devices and
2220 determine their configuration. However, some old PCI motherboards
2221 have BIOS bugs and may crash if this is done. Also, some embedded
2222 PCI-based systems don't have any BIOS at all. Linux can also try to
2223 detect the PCI hardware directly without using the BIOS.
2225 With this option, you can specify how Linux should detect the
2226 PCI devices. If you choose "BIOS", the BIOS will be used,
2227 if you choose "Direct", the BIOS won't be used, and if you
2228 choose "MMConfig", then PCI Express MMCONFIG will be used.
2229 If you choose "Any", the kernel will try MMCONFIG, then the
2230 direct access method and falls back to the BIOS if that doesn't
2231 work. If unsure, go with the default, which is "Any".
2236 config PCI_GOMMCONFIG
2253 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2255 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2258 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2262 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2266 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2270 depends on PCI && XEN
2278 bool "Support mmconfig PCI config space access"
2279 depends on X86_64 && PCI && ACPI
2281 config PCI_CNB20LE_QUIRK
2282 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2285 Read the PCI windows out of the CNB20LE host bridge. This allows
2286 PCI hotplug to work on systems with the CNB20LE chipset which do
2289 There's no public spec for this chipset, and this functionality
2290 is known to be incomplete.
2292 You should say N unless you know you need this.
2294 source "drivers/pci/pcie/Kconfig"
2296 source "drivers/pci/Kconfig"
2298 # x86_64 have no ISA slots, but can have ISA-style DMA.
2300 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2303 Enables ISA-style DMA support for devices requiring such controllers.
2311 Find out whether you have ISA slots on your motherboard. ISA is the
2312 name of a bus system, i.e. the way the CPU talks to the other stuff
2313 inside your box. Other bus systems are PCI, EISA, MicroChannel
2314 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2315 newer boards don't support it. If you have ISA, say Y, otherwise N.
2321 The Extended Industry Standard Architecture (EISA) bus was
2322 developed as an open alternative to the IBM MicroChannel bus.
2324 The EISA bus provided some of the features of the IBM MicroChannel
2325 bus while maintaining backward compatibility with cards made for
2326 the older ISA bus. The EISA bus saw limited use between 1988 and
2327 1995 when it was made obsolete by the PCI bus.
2329 Say Y here if you are building a kernel for an EISA-based machine.
2333 source "drivers/eisa/Kconfig"
2336 tristate "NatSemi SCx200 support"
2338 This provides basic support for National Semiconductor's
2339 (now AMD's) Geode processors. The driver probes for the
2340 PCI-IDs of several on-chip devices, so its a good dependency
2341 for other scx200_* drivers.
2343 If compiled as a module, the driver is named scx200.
2345 config SCx200HR_TIMER
2346 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2350 This driver provides a clocksource built upon the on-chip
2351 27MHz high-resolution timer. Its also a workaround for
2352 NSC Geode SC-1100's buggy TSC, which loses time when the
2353 processor goes idle (as is done by the scheduler). The
2354 other workaround is idle=poll boot option.
2357 bool "One Laptop Per Child support"
2364 Add support for detecting the unique features of the OLPC
2368 bool "OLPC XO-1 Power Management"
2369 depends on OLPC && MFD_CS5535 && PM_SLEEP
2372 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2375 bool "OLPC XO-1 Real Time Clock"
2376 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2378 Add support for the XO-1 real time clock, which can be used as a
2379 programmable wakeup source.
2382 bool "OLPC XO-1 SCI extras"
2383 depends on OLPC && OLPC_XO1_PM
2389 Add support for SCI-based features of the OLPC XO-1 laptop:
2390 - EC-driven system wakeups
2394 - AC adapter status updates
2395 - Battery status updates
2397 config OLPC_XO15_SCI
2398 bool "OLPC XO-1.5 SCI extras"
2399 depends on OLPC && ACPI
2402 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2403 - EC-driven system wakeups
2404 - AC adapter status updates
2405 - Battery status updates
2408 bool "PCEngines ALIX System Support (LED setup)"
2411 This option enables system support for the PCEngines ALIX.
2412 At present this just sets up LEDs for GPIO control on
2413 ALIX2/3/6 boards. However, other system specific setup should
2416 Note: You must still enable the drivers for GPIO and LED support
2417 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2419 Note: You have to set alix.force=1 for boards with Award BIOS.
2422 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2425 This option enables system support for the Soekris Engineering net5501.
2428 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2432 This option enables system support for the Traverse Technologies GEOS.
2435 bool "Technologic Systems TS-5500 platform support"
2437 select CHECK_SIGNATURE
2441 This option enables system support for the Technologic Systems TS-5500.
2447 depends on CPU_SUP_AMD && PCI
2449 source "drivers/pcmcia/Kconfig"
2451 source "drivers/pci/hotplug/Kconfig"
2454 tristate "RapidIO support"
2458 If enabled this option will include drivers and the core
2459 infrastructure code to support RapidIO interconnect devices.
2461 source "drivers/rapidio/Kconfig"
2464 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2466 Firmwares often provide initial graphics framebuffers so the BIOS,
2467 bootloader or kernel can show basic video-output during boot for
2468 user-guidance and debugging. Historically, x86 used the VESA BIOS
2469 Extensions and EFI-framebuffers for this, which are mostly limited
2471 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2472 framebuffers so the new generic system-framebuffer drivers can be
2473 used on x86. If the framebuffer is not compatible with the generic
2474 modes, it is adverticed as fallback platform framebuffer so legacy
2475 drivers like efifb, vesafb and uvesafb can pick it up.
2476 If this option is not selected, all system framebuffers are always
2477 marked as fallback platform framebuffers as usual.
2479 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2480 not be able to pick up generic system framebuffers if this option
2481 is selected. You are highly encouraged to enable simplefb as
2482 replacement if you select this option. simplefb can correctly deal
2483 with generic system framebuffers. But you should still keep vesafb
2484 and others enabled as fallback if a system framebuffer is
2485 incompatible with simplefb.
2492 menu "Executable file formats / Emulations"
2494 source "fs/Kconfig.binfmt"
2496 config IA32_EMULATION
2497 bool "IA32 Emulation"
2500 select COMPAT_BINFMT_ELF
2503 Include code to run legacy 32-bit programs under a
2504 64-bit kernel. You should likely turn this on, unless you're
2505 100% sure that you don't have any 32-bit programs left.
2508 tristate "IA32 a.out support"
2509 depends on IA32_EMULATION
2511 Support old a.out binaries in the 32bit emulation.
2514 bool "x32 ABI for 64-bit mode"
2515 depends on X86_64 && IA32_EMULATION
2517 Include code to run binaries for the x32 native 32-bit ABI
2518 for 64-bit processors. An x32 process gets access to the
2519 full 64-bit register file and wide data path while leaving
2520 pointers at 32 bits for smaller memory footprint.
2522 You will need a recent binutils (2.22 or later) with
2523 elf32_x86_64 support enabled to compile a kernel with this
2528 depends on IA32_EMULATION || X86_X32
2529 select ARCH_WANT_OLD_COMPAT_IPC
2532 config COMPAT_FOR_U64_ALIGNMENT
2535 config SYSVIPC_COMPAT
2547 config HAVE_ATOMIC_IOMAP
2551 config X86_DEV_DMA_OPS
2553 depends on X86_64 || STA2X11
2555 config X86_DMA_REMAP
2563 source "net/Kconfig"
2565 source "drivers/Kconfig"
2567 source "drivers/firmware/Kconfig"
2571 source "arch/x86/Kconfig.debug"
2573 source "security/Kconfig"
2575 source "crypto/Kconfig"
2577 source "arch/x86/kvm/Kconfig"
2579 source "lib/Kconfig"
projects / linux-drm-fsl-dcu.git / blob