3 bool "64-bit kernel" if ARCH = "x86"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
24 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
25 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
26 select ARCH_HAS_FAST_MULTIPLIER
27 select ARCH_MIGHT_HAVE_PC_PARPORT
28 select ARCH_MIGHT_HAVE_PC_SERIO
29 select HAVE_AOUT if X86_32
30 select HAVE_UNSTABLE_SCHED_CLOCK
31 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
32 select ARCH_SUPPORTS_INT128 if X86_64
35 select HAVE_PCSPKR_PLATFORM
36 select HAVE_PERF_EVENTS
37 select HAVE_IOREMAP_PROT
40 select HAVE_MEMBLOCK_NODE_MAP
41 select ARCH_DISCARD_MEMBLOCK
42 select ARCH_WANT_OPTIONAL_GPIOLIB
43 select ARCH_WANT_FRAME_POINTERS
45 select HAVE_DMA_CONTIGUOUS
46 select HAVE_KRETPROBES
47 select GENERIC_EARLY_IOREMAP
49 select HAVE_KPROBES_ON_FTRACE
50 select HAVE_FTRACE_MCOUNT_RECORD
51 select HAVE_FENTRY if X86_64
52 select HAVE_C_RECORDMCOUNT
53 select HAVE_DYNAMIC_FTRACE
54 select HAVE_DYNAMIC_FTRACE_WITH_REGS
55 select HAVE_FUNCTION_TRACER
56 select HAVE_FUNCTION_GRAPH_TRACER
57 select HAVE_FUNCTION_GRAPH_FP_TEST
58 select HAVE_SYSCALL_TRACEPOINTS
59 select SYSCTL_EXCEPTION_TRACE
62 select HAVE_ARCH_TRACEHOOK
63 select HAVE_GENERIC_DMA_COHERENT if X86_32
64 select HAVE_EFFICIENT_UNALIGNED_ACCESS
65 select USER_STACKTRACE_SUPPORT
66 select HAVE_REGS_AND_STACK_ACCESS_API
67 select HAVE_DMA_API_DEBUG
68 select HAVE_KERNEL_GZIP
69 select HAVE_KERNEL_BZIP2
70 select HAVE_KERNEL_LZMA
72 select HAVE_KERNEL_LZO
73 select HAVE_KERNEL_LZ4
74 select HAVE_HW_BREAKPOINT
75 select HAVE_MIXED_BREAKPOINTS_REGS
77 select HAVE_PERF_EVENTS_NMI
79 select HAVE_PERF_USER_STACK_DUMP
80 select HAVE_DEBUG_KMEMLEAK
82 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
83 select HAVE_CMPXCHG_LOCAL
84 select HAVE_CMPXCHG_DOUBLE
85 select HAVE_ARCH_KMEMCHECK
86 select HAVE_USER_RETURN_NOTIFIER
87 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
88 select HAVE_ARCH_JUMP_LABEL
89 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
91 select GENERIC_FIND_FIRST_BIT
92 select GENERIC_IRQ_PROBE
93 select GENERIC_PENDING_IRQ if SMP
94 select GENERIC_IRQ_SHOW
95 select GENERIC_CLOCKEVENTS_MIN_ADJUST
96 select IRQ_FORCED_THREADING
97 select HAVE_BPF_JIT if X86_64
98 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
99 select ARCH_HAS_SG_CHAIN
101 select ARCH_HAVE_NMI_SAFE_CMPXCHG
103 select DCACHE_WORD_ACCESS
104 select GENERIC_SMP_IDLE_THREAD
105 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
106 select HAVE_ARCH_SECCOMP_FILTER
107 select BUILDTIME_EXTABLE_SORT
108 select GENERIC_CMOS_UPDATE
109 select HAVE_ARCH_SOFT_DIRTY if X86_64
110 select CLOCKSOURCE_WATCHDOG
111 select GENERIC_CLOCKEVENTS
112 select ARCH_CLOCKSOURCE_DATA
113 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
114 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
115 select GENERIC_TIME_VSYSCALL
116 select GENERIC_STRNCPY_FROM_USER
117 select GENERIC_STRNLEN_USER
118 select HAVE_CONTEXT_TRACKING if X86_64
119 select HAVE_IRQ_TIME_ACCOUNTING
121 select MODULES_USE_ELF_REL if X86_32
122 select MODULES_USE_ELF_RELA if X86_64
123 select CLONE_BACKWARDS if X86_32
124 select ARCH_USE_BUILTIN_BSWAP
125 select ARCH_USE_QUEUE_RWLOCK
126 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
127 select OLD_SIGACTION if X86_32
128 select COMPAT_OLD_SIGACTION if IA32_EMULATION
130 select HAVE_DEBUG_STACKOVERFLOW
131 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
132 select HAVE_CC_STACKPROTECTOR
133 select GENERIC_CPU_AUTOPROBE
134 select HAVE_ARCH_AUDITSYSCALL
135 select ARCH_SUPPORTS_ATOMIC_RMW
136 select HAVE_ACPI_APEI if ACPI
137 select HAVE_ACPI_APEI_NMI if ACPI
138 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
139 select X86_FEATURE_NAMES if PROC_FS
141 config INSTRUCTION_DECODER
143 depends on KPROBES || PERF_EVENTS || UPROBES
147 default "elf32-i386" if X86_32
148 default "elf64-x86-64" if X86_64
150 config ARCH_DEFCONFIG
152 default "arch/x86/configs/i386_defconfig" if X86_32
153 default "arch/x86/configs/x86_64_defconfig" if X86_64
155 config LOCKDEP_SUPPORT
158 config STACKTRACE_SUPPORT
161 config HAVE_LATENCYTOP_SUPPORT
170 config NEED_DMA_MAP_STATE
172 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
174 config NEED_SG_DMA_LENGTH
177 config GENERIC_ISA_DMA
179 depends on ISA_DMA_API
184 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
186 config GENERIC_BUG_RELATIVE_POINTERS
189 config GENERIC_HWEIGHT
192 config ARCH_MAY_HAVE_PC_FDC
194 depends on ISA_DMA_API
196 config RWSEM_XCHGADD_ALGORITHM
199 config GENERIC_CALIBRATE_DELAY
202 config ARCH_HAS_CPU_RELAX
205 config ARCH_HAS_CACHE_LINE_SIZE
208 config HAVE_SETUP_PER_CPU_AREA
211 config NEED_PER_CPU_EMBED_FIRST_CHUNK
214 config NEED_PER_CPU_PAGE_FIRST_CHUNK
217 config ARCH_HIBERNATION_POSSIBLE
220 config ARCH_SUSPEND_POSSIBLE
223 config ARCH_WANT_HUGE_PMD_SHARE
226 config ARCH_WANT_GENERAL_HUGETLB
237 config ARCH_SUPPORTS_OPTIMIZED_INLINING
240 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
243 config HAVE_INTEL_TXT
245 depends on INTEL_IOMMU && ACPI
249 depends on X86_32 && SMP
253 depends on X86_64 && SMP
259 config X86_32_LAZY_GS
261 depends on X86_32 && !CC_STACKPROTECTOR
263 config ARCH_HWEIGHT_CFLAGS
265 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
266 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
268 config ARCH_SUPPORTS_UPROBES
271 config FIX_EARLYCON_MEM
274 source "init/Kconfig"
275 source "kernel/Kconfig.freezer"
277 menu "Processor type and features"
280 bool "DMA memory allocation support" if EXPERT
283 DMA memory allocation support allows devices with less than 32-bit
284 addressing to allocate within the first 16MB of address space.
285 Disable if no such devices will be used.
290 bool "Symmetric multi-processing support"
292 This enables support for systems with more than one CPU. If you have
293 a system with only one CPU, say N. If you have a system with more
296 If you say N here, the kernel will run on uni- and multiprocessor
297 machines, but will use only one CPU of a multiprocessor machine. If
298 you say Y here, the kernel will run on many, but not all,
299 uniprocessor machines. On a uniprocessor machine, the kernel
300 will run faster if you say N here.
302 Note that if you say Y here and choose architecture "586" or
303 "Pentium" under "Processor family", the kernel will not work on 486
304 architectures. Similarly, multiprocessor kernels for the "PPro"
305 architecture may not work on all Pentium based boards.
307 People using multiprocessor machines who say Y here should also say
308 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
309 Management" code will be disabled if you say Y here.
311 See also <file:Documentation/x86/i386/IO-APIC.txt>,
312 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
313 <http://www.tldp.org/docs.html#howto>.
315 If you don't know what to do here, say N.
317 config X86_FEATURE_NAMES
318 bool "Processor feature human-readable names" if EMBEDDED
321 This option compiles in a table of x86 feature bits and corresponding
322 names. This is required to support /proc/cpuinfo and a few kernel
323 messages. You can disable this to save space, at the expense of
324 making those few kernel messages show numeric feature bits instead.
329 bool "Support x2apic"
330 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
332 This enables x2apic support on CPUs that have this feature.
334 This allows 32-bit apic IDs (so it can support very large systems),
335 and accesses the local apic via MSRs not via mmio.
337 If you don't know what to do here, say N.
340 bool "Enable MPS table" if ACPI || SFI
342 depends on X86_LOCAL_APIC
344 For old smp systems that do not have proper acpi support. Newer systems
345 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
348 bool "Support for big SMP systems with more than 8 CPUs"
349 depends on X86_32 && SMP
351 This option is needed for the systems that have more than 8 CPUs
355 depends on X86_GOLDFISH
358 config X86_EXTENDED_PLATFORM
359 bool "Support for extended (non-PC) x86 platforms"
362 If you disable this option then the kernel will only support
363 standard PC platforms. (which covers the vast majority of
366 If you enable this option then you'll be able to select support
367 for the following (non-PC) 32 bit x86 platforms:
368 Goldfish (Android emulator)
371 SGI 320/540 (Visual Workstation)
372 STA2X11-based (e.g. Northville)
373 Moorestown MID devices
375 If you have one of these systems, or if you want to build a
376 generic distribution kernel, say Y here - otherwise say N.
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) 64 bit x86 platforms:
394 If you have one of these systems, or if you want to build a
395 generic distribution kernel, say Y here - otherwise say N.
397 # This is an alphabetically sorted list of 64 bit extended platforms
398 # Please maintain the alphabetic order if and when there are additions
400 bool "Numascale NumaChip"
402 depends on X86_EXTENDED_PLATFORM
405 depends on X86_X2APIC
406 depends on PCI_MMCONFIG
408 Adds support for Numascale NumaChip large-SMP systems. Needed to
409 enable more than ~168 cores.
410 If you don't have one of these, you should say N here.
414 select HYPERVISOR_GUEST
416 depends on X86_64 && PCI
417 depends on X86_EXTENDED_PLATFORM
420 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
421 supposed to run on these EM64T-based machines. Only choose this option
422 if you have one of these machines.
425 bool "SGI Ultraviolet"
427 depends on X86_EXTENDED_PLATFORM
429 depends on X86_X2APIC
431 This option is needed in order to support SGI Ultraviolet systems.
432 If you don't have one of these, you should say N here.
434 # Following is an alphabetically sorted list of 32 bit extended platforms
435 # Please maintain the alphabetic order if and when there are additions
438 bool "Goldfish (Virtual Platform)"
439 depends on X86_EXTENDED_PLATFORM
441 Enable support for the Goldfish virtual platform used primarily
442 for Android development. Unless you are building for the Android
443 Goldfish emulator say N here.
446 bool "CE4100 TV platform"
448 depends on PCI_GODIRECT
449 depends on X86_IO_APIC
451 depends on X86_EXTENDED_PLATFORM
452 select X86_REBOOTFIXUPS
454 select OF_EARLY_FLATTREE
457 Select for the Intel CE media processor (CE4100) SOC.
458 This option compiles in support for the CE4100 SOC for settop
459 boxes and media devices.
462 bool "Intel MID platform support"
464 depends on X86_EXTENDED_PLATFORM
465 depends on X86_PLATFORM_DEVICES
468 depends on X86_IO_APIC
474 select MFD_INTEL_MSIC
476 Select to build a kernel capable of supporting Intel MID (Mobile
477 Internet Device) platform systems which do not have the PCI legacy
478 interfaces. If you are building for a PC class system say N here.
480 Intel MID platforms are based on an Intel processor and chipset which
481 consume less power than most of the x86 derivatives.
483 config X86_INTEL_LPSS
484 bool "Intel Low Power Subsystem Support"
489 Select to build support for Intel Low Power Subsystem such as
490 found on Intel Lynxpoint PCH. Selecting this option enables
491 things like clock tree (common clock framework) and pincontrol
492 which are needed by the LPSS peripheral drivers.
495 bool "RDC R-321x SoC"
497 depends on X86_EXTENDED_PLATFORM
499 select X86_REBOOTFIXUPS
501 This option is needed for RDC R-321x system-on-chip, also known
503 If you don't have one of these chips, you should say N here.
505 config X86_32_NON_STANDARD
506 bool "Support non-standard 32-bit SMP architectures"
507 depends on X86_32 && SMP
508 depends on X86_EXTENDED_PLATFORM
510 This option compiles in the bigsmp and STA2X11 default
511 subarchitectures. It is intended for a generic binary
512 kernel. If you select them all, kernel will probe it one by
513 one and will fallback to default.
515 # Alphabetically sorted list of Non standard 32 bit platforms
517 config X86_SUPPORTS_MEMORY_FAILURE
519 # MCE code calls memory_failure():
521 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
522 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
523 depends on X86_64 || !SPARSEMEM
524 select ARCH_SUPPORTS_MEMORY_FAILURE
527 bool "STA2X11 Companion Chip Support"
528 depends on X86_32_NON_STANDARD && PCI
529 select X86_DEV_DMA_OPS
533 select ARCH_REQUIRE_GPIOLIB
536 This adds support for boards based on the STA2X11 IO-Hub,
537 a.k.a. "ConneXt". The chip is used in place of the standard
538 PC chipset, so all "standard" peripherals are missing. If this
539 option is selected the kernel will still be able to boot on
540 standard PC machines.
543 tristate "Eurobraille/Iris poweroff module"
546 The Iris machines from EuroBraille do not have APM or ACPI support
547 to shut themselves down properly. A special I/O sequence is
548 needed to do so, which is what this module does at
551 This is only for Iris machines from EuroBraille.
555 config SCHED_OMIT_FRAME_POINTER
557 prompt "Single-depth WCHAN output"
560 Calculate simpler /proc/<PID>/wchan values. If this option
561 is disabled then wchan values will recurse back to the
562 caller function. This provides more accurate wchan values,
563 at the expense of slightly more scheduling overhead.
565 If in doubt, say "Y".
567 menuconfig HYPERVISOR_GUEST
568 bool "Linux guest support"
570 Say Y here to enable options for running Linux under various hyper-
571 visors. This option enables basic hypervisor detection and platform
574 If you say N, all options in this submenu will be skipped and
575 disabled, and Linux guest support won't be built in.
580 bool "Enable paravirtualization code"
582 This changes the kernel so it can modify itself when it is run
583 under a hypervisor, potentially improving performance significantly
584 over full virtualization. However, when run without a hypervisor
585 the kernel is theoretically slower and slightly larger.
587 config PARAVIRT_DEBUG
588 bool "paravirt-ops debugging"
589 depends on PARAVIRT && DEBUG_KERNEL
591 Enable to debug paravirt_ops internals. Specifically, BUG if
592 a paravirt_op is missing when it is called.
594 config PARAVIRT_SPINLOCKS
595 bool "Paravirtualization layer for spinlocks"
596 depends on PARAVIRT && SMP
597 select UNINLINE_SPIN_UNLOCK
599 Paravirtualized spinlocks allow a pvops backend to replace the
600 spinlock implementation with something virtualization-friendly
601 (for example, block the virtual CPU rather than spinning).
603 It has a minimal impact on native kernels and gives a nice performance
604 benefit on paravirtualized KVM / Xen kernels.
606 If you are unsure how to answer this question, answer Y.
608 source "arch/x86/xen/Kconfig"
611 bool "KVM Guest support (including kvmclock)"
613 select PARAVIRT_CLOCK
616 This option enables various optimizations for running under the KVM
617 hypervisor. It includes a paravirtualized clock, so that instead
618 of relying on a PIT (or probably other) emulation by the
619 underlying device model, the host provides the guest with
620 timing infrastructure such as time of day, and system time
623 bool "Enable debug information for KVM Guests in debugfs"
624 depends on KVM_GUEST && DEBUG_FS
627 This option enables collection of various statistics for KVM guest.
628 Statistics are displayed in debugfs filesystem. Enabling this option
629 may incur significant overhead.
631 source "arch/x86/lguest/Kconfig"
633 config PARAVIRT_TIME_ACCOUNTING
634 bool "Paravirtual steal time accounting"
638 Select this option to enable fine granularity task steal time
639 accounting. Time spent executing other tasks in parallel with
640 the current vCPU is discounted from the vCPU power. To account for
641 that, there can be a small performance impact.
643 If in doubt, say N here.
645 config PARAVIRT_CLOCK
648 endif #HYPERVISOR_GUEST
656 This option adds a kernel parameter 'memtest', which allows memtest
658 memtest=0, mean disabled; -- default
659 memtest=1, mean do 1 test pattern;
661 memtest=4, mean do 4 test patterns.
662 If you are unsure how to answer this question, answer N.
664 source "arch/x86/Kconfig.cpu"
668 prompt "HPET Timer Support" if X86_32
670 Use the IA-PC HPET (High Precision Event Timer) to manage
671 time in preference to the PIT and RTC, if a HPET is
673 HPET is the next generation timer replacing legacy 8254s.
674 The HPET provides a stable time base on SMP
675 systems, unlike the TSC, but it is more expensive to access,
676 as it is off-chip. You can find the HPET spec at
677 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
679 You can safely choose Y here. However, HPET will only be
680 activated if the platform and the BIOS support this feature.
681 Otherwise the 8254 will be used for timing services.
683 Choose N to continue using the legacy 8254 timer.
685 config HPET_EMULATE_RTC
687 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
690 def_bool y if X86_INTEL_MID
691 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
693 depends on X86_INTEL_MID && SFI
695 APB timer is the replacement for 8254, HPET on X86 MID platforms.
696 The APBT provides a stable time base on SMP
697 systems, unlike the TSC, but it is more expensive to access,
698 as it is off-chip. APB timers are always running regardless of CPU
699 C states, they are used as per CPU clockevent device when possible.
701 # Mark as expert because too many people got it wrong.
702 # The code disables itself when not needed.
705 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
706 bool "Enable DMI scanning" if EXPERT
708 Enabled scanning of DMI to identify machine quirks. Say Y
709 here unless you have verified that your setup is not
710 affected by entries in the DMI blacklist. Required by PNP
714 bool "Old AMD GART IOMMU support"
716 depends on X86_64 && PCI && AMD_NB
718 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
719 GART based hardware IOMMUs.
721 The GART supports full DMA access for devices with 32-bit access
722 limitations, on systems with more than 3 GB. This is usually needed
723 for USB, sound, many IDE/SATA chipsets and some other devices.
725 Newer systems typically have a modern AMD IOMMU, supported via
726 the CONFIG_AMD_IOMMU=y config option.
728 In normal configurations this driver is only active when needed:
729 there's more than 3 GB of memory and the system contains a
730 32-bit limited device.
735 bool "IBM Calgary IOMMU support"
737 depends on X86_64 && PCI
739 Support for hardware IOMMUs in IBM's xSeries x366 and x460
740 systems. Needed to run systems with more than 3GB of memory
741 properly with 32-bit PCI devices that do not support DAC
742 (Double Address Cycle). Calgary also supports bus level
743 isolation, where all DMAs pass through the IOMMU. This
744 prevents them from going anywhere except their intended
745 destination. This catches hard-to-find kernel bugs and
746 mis-behaving drivers and devices that do not use the DMA-API
747 properly to set up their DMA buffers. The IOMMU can be
748 turned off at boot time with the iommu=off parameter.
749 Normally the kernel will make the right choice by itself.
752 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
754 prompt "Should Calgary be enabled by default?"
755 depends on CALGARY_IOMMU
757 Should Calgary be enabled by default? if you choose 'y', Calgary
758 will be used (if it exists). If you choose 'n', Calgary will not be
759 used even if it exists. If you choose 'n' and would like to use
760 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
763 # need this always selected by IOMMU for the VIA workaround
767 Support for software bounce buffers used on x86-64 systems
768 which don't have a hardware IOMMU. Using this PCI devices
769 which can only access 32-bits of memory can be used on systems
770 with more than 3 GB of memory.
775 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
778 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
779 depends on X86_64 && SMP && DEBUG_KERNEL
780 select CPUMASK_OFFSTACK
782 Enable maximum number of CPUS and NUMA Nodes for this architecture.
786 int "Maximum number of CPUs" if SMP && !MAXSMP
787 range 2 8 if SMP && X86_32 && !X86_BIGSMP
788 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
789 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
791 default "8192" if MAXSMP
792 default "32" if SMP && X86_BIGSMP
795 This allows you to specify the maximum number of CPUs which this
796 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
797 supported value is 4096, otherwise the maximum value is 512. The
798 minimum value which makes sense is 2.
800 This is purely to save memory - each supported CPU adds
801 approximately eight kilobytes to the kernel image.
804 bool "SMT (Hyperthreading) scheduler support"
807 SMT scheduler support improves the CPU scheduler's decision making
808 when dealing with Intel Pentium 4 chips with HyperThreading at a
809 cost of slightly increased overhead in some places. If unsure say
814 prompt "Multi-core scheduler support"
817 Multi-core scheduler support improves the CPU scheduler's decision
818 making when dealing with multi-core CPU chips at a cost of slightly
819 increased overhead in some places. If unsure say N here.
821 source "kernel/Kconfig.preempt"
824 bool "Local APIC support on uniprocessors"
825 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
827 A local APIC (Advanced Programmable Interrupt Controller) is an
828 integrated interrupt controller in the CPU. If you have a single-CPU
829 system which has a processor with a local APIC, you can say Y here to
830 enable and use it. If you say Y here even though your machine doesn't
831 have a local APIC, then the kernel will still run with no slowdown at
832 all. The local APIC supports CPU-generated self-interrupts (timer,
833 performance counters), and the NMI watchdog which detects hard
837 bool "IO-APIC support on uniprocessors"
838 depends on X86_UP_APIC
840 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
841 SMP-capable replacement for PC-style interrupt controllers. Most
842 SMP systems and many recent uniprocessor systems have one.
844 If you have a single-CPU system with an IO-APIC, you can say Y here
845 to use it. If you say Y here even though your machine doesn't have
846 an IO-APIC, then the kernel will still run with no slowdown at all.
848 config X86_LOCAL_APIC
850 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
854 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
855 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
858 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
859 bool "Reroute for broken boot IRQs"
860 depends on X86_IO_APIC
862 This option enables a workaround that fixes a source of
863 spurious interrupts. This is recommended when threaded
864 interrupt handling is used on systems where the generation of
865 superfluous "boot interrupts" cannot be disabled.
867 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
868 entry in the chipset's IO-APIC is masked (as, e.g. the RT
869 kernel does during interrupt handling). On chipsets where this
870 boot IRQ generation cannot be disabled, this workaround keeps
871 the original IRQ line masked so that only the equivalent "boot
872 IRQ" is delivered to the CPUs. The workaround also tells the
873 kernel to set up the IRQ handler on the boot IRQ line. In this
874 way only one interrupt is delivered to the kernel. Otherwise
875 the spurious second interrupt may cause the kernel to bring
876 down (vital) interrupt lines.
878 Only affects "broken" chipsets. Interrupt sharing may be
879 increased on these systems.
882 bool "Machine Check / overheating reporting"
885 Machine Check support allows the processor to notify the
886 kernel if it detects a problem (e.g. overheating, data corruption).
887 The action the kernel takes depends on the severity of the problem,
888 ranging from warning messages to halting the machine.
892 prompt "Intel MCE features"
893 depends on X86_MCE && X86_LOCAL_APIC
895 Additional support for intel specific MCE features such as
900 prompt "AMD MCE features"
901 depends on X86_MCE && X86_LOCAL_APIC
903 Additional support for AMD specific MCE features such as
904 the DRAM Error Threshold.
906 config X86_ANCIENT_MCE
907 bool "Support for old Pentium 5 / WinChip machine checks"
908 depends on X86_32 && X86_MCE
910 Include support for machine check handling on old Pentium 5 or WinChip
911 systems. These typically need to be enabled explicitly on the command
914 config X86_MCE_THRESHOLD
915 depends on X86_MCE_AMD || X86_MCE_INTEL
918 config X86_MCE_INJECT
920 tristate "Machine check injector support"
922 Provide support for injecting machine checks for testing purposes.
923 If you don't know what a machine check is and you don't do kernel
924 QA it is safe to say n.
926 config X86_THERMAL_VECTOR
928 depends on X86_MCE_INTEL
931 bool "Enable VM86 support" if EXPERT
935 This option is required by programs like DOSEMU to run
936 16-bit real mode legacy code on x86 processors. It also may
937 be needed by software like XFree86 to initialize some video
938 cards via BIOS. Disabling this option saves about 6K.
941 bool "Enable support for 16-bit segments" if EXPERT
944 This option is required by programs like Wine to run 16-bit
945 protected mode legacy code on x86 processors. Disabling
946 this option saves about 300 bytes on i386, or around 6K text
947 plus 16K runtime memory on x86-64,
951 depends on X86_16BIT && X86_32
955 depends on X86_16BIT && X86_64
958 tristate "Toshiba Laptop support"
961 This adds a driver to safely access the System Management Mode of
962 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
963 not work on models with a Phoenix BIOS. The System Management Mode
964 is used to set the BIOS and power saving options on Toshiba portables.
966 For information on utilities to make use of this driver see the
967 Toshiba Linux utilities web site at:
968 <http://www.buzzard.org.uk/toshiba/>.
970 Say Y if you intend to run this kernel on a Toshiba portable.
974 tristate "Dell laptop support"
977 This adds a driver to safely access the System Management Mode
978 of the CPU on the Dell Inspiron 8000. The System Management Mode
979 is used to read cpu temperature and cooling fan status and to
980 control the fans on the I8K portables.
982 This driver has been tested only on the Inspiron 8000 but it may
983 also work with other Dell laptops. You can force loading on other
984 models by passing the parameter `force=1' to the module. Use at
987 For information on utilities to make use of this driver see the
988 I8K Linux utilities web site at:
989 <http://people.debian.org/~dz/i8k/>
991 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
994 config X86_REBOOTFIXUPS
995 bool "Enable X86 board specific fixups for reboot"
998 This enables chipset and/or board specific fixups to be done
999 in order to get reboot to work correctly. This is only needed on
1000 some combinations of hardware and BIOS. The symptom, for which
1001 this config is intended, is when reboot ends with a stalled/hung
1004 Currently, the only fixup is for the Geode machines using
1005 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1007 Say Y if you want to enable the fixup. Currently, it's safe to
1008 enable this option even if you don't need it.
1012 tristate "CPU microcode loading support"
1013 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1017 If you say Y here, you will be able to update the microcode on
1018 certain Intel and AMD processors. The Intel support is for the
1019 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1020 Xeon etc. The AMD support is for families 0x10 and later. You will
1021 obviously need the actual microcode binary data itself which is not
1022 shipped with the Linux kernel.
1024 This option selects the general module only, you need to select
1025 at least one vendor specific module as well.
1027 To compile this driver as a module, choose M here: the module
1028 will be called microcode.
1030 config MICROCODE_INTEL
1031 bool "Intel microcode loading support"
1032 depends on MICROCODE
1036 This options enables microcode patch loading support for Intel
1039 For the current Intel microcode data package go to
1040 <https://downloadcenter.intel.com> and search for
1041 'Linux Processor Microcode Data File'.
1043 config MICROCODE_AMD
1044 bool "AMD microcode loading support"
1045 depends on MICROCODE
1048 If you select this option, microcode patch loading support for AMD
1049 processors will be enabled.
1051 config MICROCODE_OLD_INTERFACE
1053 depends on MICROCODE
1055 config MICROCODE_INTEL_EARLY
1058 config MICROCODE_AMD_EARLY
1061 config MICROCODE_EARLY
1062 bool "Early load microcode"
1063 depends on MICROCODE=y && BLK_DEV_INITRD
1064 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1065 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1068 This option provides functionality to read additional microcode data
1069 at the beginning of initrd image. The data tells kernel to load
1070 microcode to CPU's as early as possible. No functional change if no
1071 microcode data is glued to the initrd, therefore it's safe to say Y.
1074 tristate "/dev/cpu/*/msr - Model-specific register support"
1076 This device gives privileged processes access to the x86
1077 Model-Specific Registers (MSRs). It is a character device with
1078 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1079 MSR accesses are directed to a specific CPU on multi-processor
1083 tristate "/dev/cpu/*/cpuid - CPU information support"
1085 This device gives processes access to the x86 CPUID instruction to
1086 be executed on a specific processor. It is a character device
1087 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1091 prompt "High Memory Support"
1098 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1099 However, the address space of 32-bit x86 processors is only 4
1100 Gigabytes large. That means that, if you have a large amount of
1101 physical memory, not all of it can be "permanently mapped" by the
1102 kernel. The physical memory that's not permanently mapped is called
1105 If you are compiling a kernel which will never run on a machine with
1106 more than 1 Gigabyte total physical RAM, answer "off" here (default
1107 choice and suitable for most users). This will result in a "3GB/1GB"
1108 split: 3GB are mapped so that each process sees a 3GB virtual memory
1109 space and the remaining part of the 4GB virtual memory space is used
1110 by the kernel to permanently map as much physical memory as
1113 If the machine has between 1 and 4 Gigabytes physical RAM, then
1116 If more than 4 Gigabytes is used then answer "64GB" here. This
1117 selection turns Intel PAE (Physical Address Extension) mode on.
1118 PAE implements 3-level paging on IA32 processors. PAE is fully
1119 supported by Linux, PAE mode is implemented on all recent Intel
1120 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1121 then the kernel will not boot on CPUs that don't support PAE!
1123 The actual amount of total physical memory will either be
1124 auto detected or can be forced by using a kernel command line option
1125 such as "mem=256M". (Try "man bootparam" or see the documentation of
1126 your boot loader (lilo or loadlin) about how to pass options to the
1127 kernel at boot time.)
1129 If unsure, say "off".
1134 Select this if you have a 32-bit processor and between 1 and 4
1135 gigabytes of physical RAM.
1142 Select this if you have a 32-bit processor and more than 4
1143 gigabytes of physical RAM.
1148 prompt "Memory split" if EXPERT
1152 Select the desired split between kernel and user memory.
1154 If the address range available to the kernel is less than the
1155 physical memory installed, the remaining memory will be available
1156 as "high memory". Accessing high memory is a little more costly
1157 than low memory, as it needs to be mapped into the kernel first.
1158 Note that increasing the kernel address space limits the range
1159 available to user programs, making the address space there
1160 tighter. Selecting anything other than the default 3G/1G split
1161 will also likely make your kernel incompatible with binary-only
1164 If you are not absolutely sure what you are doing, leave this
1168 bool "3G/1G user/kernel split"
1169 config VMSPLIT_3G_OPT
1171 bool "3G/1G user/kernel split (for full 1G low memory)"
1173 bool "2G/2G user/kernel split"
1174 config VMSPLIT_2G_OPT
1176 bool "2G/2G user/kernel split (for full 2G low memory)"
1178 bool "1G/3G user/kernel split"
1183 default 0xB0000000 if VMSPLIT_3G_OPT
1184 default 0x80000000 if VMSPLIT_2G
1185 default 0x78000000 if VMSPLIT_2G_OPT
1186 default 0x40000000 if VMSPLIT_1G
1192 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1195 bool "PAE (Physical Address Extension) Support"
1196 depends on X86_32 && !HIGHMEM4G
1198 PAE is required for NX support, and furthermore enables
1199 larger swapspace support for non-overcommit purposes. It
1200 has the cost of more pagetable lookup overhead, and also
1201 consumes more pagetable space per process.
1203 config ARCH_PHYS_ADDR_T_64BIT
1205 depends on X86_64 || X86_PAE
1207 config ARCH_DMA_ADDR_T_64BIT
1209 depends on X86_64 || HIGHMEM64G
1211 config DIRECT_GBPAGES
1212 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1216 Allow the kernel linear mapping to use 1GB pages on CPUs that
1217 support it. This can improve the kernel's performance a tiny bit by
1218 reducing TLB pressure. If in doubt, say "Y".
1220 # Common NUMA Features
1222 bool "Numa Memory Allocation and Scheduler Support"
1224 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1225 default y if X86_BIGSMP
1227 Enable NUMA (Non Uniform Memory Access) support.
1229 The kernel will try to allocate memory used by a CPU on the
1230 local memory controller of the CPU and add some more
1231 NUMA awareness to the kernel.
1233 For 64-bit this is recommended if the system is Intel Core i7
1234 (or later), AMD Opteron, or EM64T NUMA.
1236 For 32-bit this is only needed if you boot a 32-bit
1237 kernel on a 64-bit NUMA platform.
1239 Otherwise, you should say N.
1243 prompt "Old style AMD Opteron NUMA detection"
1244 depends on X86_64 && NUMA && PCI
1246 Enable AMD NUMA node topology detection. You should say Y here if
1247 you have a multi processor AMD system. This uses an old method to
1248 read the NUMA configuration directly from the builtin Northbridge
1249 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1250 which also takes priority if both are compiled in.
1252 config X86_64_ACPI_NUMA
1254 prompt "ACPI NUMA detection"
1255 depends on X86_64 && NUMA && ACPI && PCI
1258 Enable ACPI SRAT based node topology detection.
1260 # Some NUMA nodes have memory ranges that span
1261 # other nodes. Even though a pfn is valid and
1262 # between a node's start and end pfns, it may not
1263 # reside on that node. See memmap_init_zone()
1265 config NODES_SPAN_OTHER_NODES
1267 depends on X86_64_ACPI_NUMA
1270 bool "NUMA emulation"
1273 Enable NUMA emulation. A flat machine will be split
1274 into virtual nodes when booted with "numa=fake=N", where N is the
1275 number of nodes. This is only useful for debugging.
1278 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1280 default "10" if MAXSMP
1281 default "6" if X86_64
1283 depends on NEED_MULTIPLE_NODES
1285 Specify the maximum number of NUMA Nodes available on the target
1286 system. Increases memory reserved to accommodate various tables.
1288 config ARCH_HAVE_MEMORY_PRESENT
1290 depends on X86_32 && DISCONTIGMEM
1292 config NEED_NODE_MEMMAP_SIZE
1294 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1296 config ARCH_FLATMEM_ENABLE
1298 depends on X86_32 && !NUMA
1300 config ARCH_DISCONTIGMEM_ENABLE
1302 depends on NUMA && X86_32
1304 config ARCH_DISCONTIGMEM_DEFAULT
1306 depends on NUMA && X86_32
1308 config ARCH_SPARSEMEM_ENABLE
1310 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1311 select SPARSEMEM_STATIC if X86_32
1312 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1314 config ARCH_SPARSEMEM_DEFAULT
1318 config ARCH_SELECT_MEMORY_MODEL
1320 depends on ARCH_SPARSEMEM_ENABLE
1322 config ARCH_MEMORY_PROBE
1323 bool "Enable sysfs memory/probe interface"
1324 depends on X86_64 && MEMORY_HOTPLUG
1326 This option enables a sysfs memory/probe interface for testing.
1327 See Documentation/memory-hotplug.txt for more information.
1328 If you are unsure how to answer this question, answer N.
1330 config ARCH_PROC_KCORE_TEXT
1332 depends on X86_64 && PROC_KCORE
1334 config ILLEGAL_POINTER_VALUE
1337 default 0xdead000000000000 if X86_64
1342 bool "Allocate 3rd-level pagetables from highmem"
1345 The VM uses one page table entry for each page of physical memory.
1346 For systems with a lot of RAM, this can be wasteful of precious
1347 low memory. Setting this option will put user-space page table
1348 entries in high memory.
1350 config X86_CHECK_BIOS_CORRUPTION
1351 bool "Check for low memory corruption"
1353 Periodically check for memory corruption in low memory, which
1354 is suspected to be caused by BIOS. Even when enabled in the
1355 configuration, it is disabled at runtime. Enable it by
1356 setting "memory_corruption_check=1" on the kernel command
1357 line. By default it scans the low 64k of memory every 60
1358 seconds; see the memory_corruption_check_size and
1359 memory_corruption_check_period parameters in
1360 Documentation/kernel-parameters.txt to adjust this.
1362 When enabled with the default parameters, this option has
1363 almost no overhead, as it reserves a relatively small amount
1364 of memory and scans it infrequently. It both detects corruption
1365 and prevents it from affecting the running system.
1367 It is, however, intended as a diagnostic tool; if repeatable
1368 BIOS-originated corruption always affects the same memory,
1369 you can use memmap= to prevent the kernel from using that
1372 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1373 bool "Set the default setting of memory_corruption_check"
1374 depends on X86_CHECK_BIOS_CORRUPTION
1377 Set whether the default state of memory_corruption_check is
1380 config X86_RESERVE_LOW
1381 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1385 Specify the amount of low memory to reserve for the BIOS.
1387 The first page contains BIOS data structures that the kernel
1388 must not use, so that page must always be reserved.
1390 By default we reserve the first 64K of physical RAM, as a
1391 number of BIOSes are known to corrupt that memory range
1392 during events such as suspend/resume or monitor cable
1393 insertion, so it must not be used by the kernel.
1395 You can set this to 4 if you are absolutely sure that you
1396 trust the BIOS to get all its memory reservations and usages
1397 right. If you know your BIOS have problems beyond the
1398 default 64K area, you can set this to 640 to avoid using the
1399 entire low memory range.
1401 If you have doubts about the BIOS (e.g. suspend/resume does
1402 not work or there's kernel crashes after certain hardware
1403 hotplug events) then you might want to enable
1404 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1405 typical corruption patterns.
1407 Leave this to the default value of 64 if you are unsure.
1409 config MATH_EMULATION
1411 prompt "Math emulation" if X86_32
1413 Linux can emulate a math coprocessor (used for floating point
1414 operations) if you don't have one. 486DX and Pentium processors have
1415 a math coprocessor built in, 486SX and 386 do not, unless you added
1416 a 487DX or 387, respectively. (The messages during boot time can
1417 give you some hints here ["man dmesg"].) Everyone needs either a
1418 coprocessor or this emulation.
1420 If you don't have a math coprocessor, you need to say Y here; if you
1421 say Y here even though you have a coprocessor, the coprocessor will
1422 be used nevertheless. (This behavior can be changed with the kernel
1423 command line option "no387", which comes handy if your coprocessor
1424 is broken. Try "man bootparam" or see the documentation of your boot
1425 loader (lilo or loadlin) about how to pass options to the kernel at
1426 boot time.) This means that it is a good idea to say Y here if you
1427 intend to use this kernel on different machines.
1429 More information about the internals of the Linux math coprocessor
1430 emulation can be found in <file:arch/x86/math-emu/README>.
1432 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1433 kernel, it won't hurt.
1437 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1439 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1440 the Memory Type Range Registers (MTRRs) may be used to control
1441 processor access to memory ranges. This is most useful if you have
1442 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1443 allows bus write transfers to be combined into a larger transfer
1444 before bursting over the PCI/AGP bus. This can increase performance
1445 of image write operations 2.5 times or more. Saying Y here creates a
1446 /proc/mtrr file which may be used to manipulate your processor's
1447 MTRRs. Typically the X server should use this.
1449 This code has a reasonably generic interface so that similar
1450 control registers on other processors can be easily supported
1453 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1454 Registers (ARRs) which provide a similar functionality to MTRRs. For
1455 these, the ARRs are used to emulate the MTRRs.
1456 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1457 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1458 write-combining. All of these processors are supported by this code
1459 and it makes sense to say Y here if you have one of them.
1461 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1462 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1463 can lead to all sorts of problems, so it's good to say Y here.
1465 You can safely say Y even if your machine doesn't have MTRRs, you'll
1466 just add about 9 KB to your kernel.
1468 See <file:Documentation/x86/mtrr.txt> for more information.
1470 config MTRR_SANITIZER
1472 prompt "MTRR cleanup support"
1475 Convert MTRR layout from continuous to discrete, so X drivers can
1476 add writeback entries.
1478 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1479 The largest mtrr entry size for a continuous block can be set with
1484 config MTRR_SANITIZER_ENABLE_DEFAULT
1485 int "MTRR cleanup enable value (0-1)"
1488 depends on MTRR_SANITIZER
1490 Enable mtrr cleanup default value
1492 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1493 int "MTRR cleanup spare reg num (0-7)"
1496 depends on MTRR_SANITIZER
1498 mtrr cleanup spare entries default, it can be changed via
1499 mtrr_spare_reg_nr=N on the kernel command line.
1503 prompt "x86 PAT support" if EXPERT
1506 Use PAT attributes to setup page level cache control.
1508 PATs are the modern equivalents of MTRRs and are much more
1509 flexible than MTRRs.
1511 Say N here if you see bootup problems (boot crash, boot hang,
1512 spontaneous reboots) or a non-working video driver.
1516 config ARCH_USES_PG_UNCACHED
1522 prompt "x86 architectural random number generator" if EXPERT
1524 Enable the x86 architectural RDRAND instruction
1525 (Intel Bull Mountain technology) to generate random numbers.
1526 If supported, this is a high bandwidth, cryptographically
1527 secure hardware random number generator.
1531 prompt "Supervisor Mode Access Prevention" if EXPERT
1533 Supervisor Mode Access Prevention (SMAP) is a security
1534 feature in newer Intel processors. There is a small
1535 performance cost if this enabled and turned on; there is
1536 also a small increase in the kernel size if this is enabled.
1541 bool "EFI runtime service support"
1544 select EFI_RUNTIME_WRAPPERS
1546 This enables the kernel to use EFI runtime services that are
1547 available (such as the EFI variable services).
1549 This option is only useful on systems that have EFI firmware.
1550 In addition, you should use the latest ELILO loader available
1551 at <http://elilo.sourceforge.net> in order to take advantage
1552 of EFI runtime services. However, even with this option, the
1553 resultant kernel should continue to boot on existing non-EFI
1557 bool "EFI stub support"
1558 depends on EFI && !X86_USE_3DNOW
1561 This kernel feature allows a bzImage to be loaded directly
1562 by EFI firmware without the use of a bootloader.
1564 See Documentation/efi-stub.txt for more information.
1567 bool "EFI mixed-mode support"
1568 depends on EFI_STUB && X86_64
1570 Enabling this feature allows a 64-bit kernel to be booted
1571 on a 32-bit firmware, provided that your CPU supports 64-bit
1574 Note that it is not possible to boot a mixed-mode enabled
1575 kernel via the EFI boot stub - a bootloader that supports
1576 the EFI handover protocol must be used.
1582 prompt "Enable seccomp to safely compute untrusted bytecode"
1584 This kernel feature is useful for number crunching applications
1585 that may need to compute untrusted bytecode during their
1586 execution. By using pipes or other transports made available to
1587 the process as file descriptors supporting the read/write
1588 syscalls, it's possible to isolate those applications in
1589 their own address space using seccomp. Once seccomp is
1590 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1591 and the task is only allowed to execute a few safe syscalls
1592 defined by each seccomp mode.
1594 If unsure, say Y. Only embedded should say N here.
1596 source kernel/Kconfig.hz
1599 bool "kexec system call"
1601 kexec is a system call that implements the ability to shutdown your
1602 current kernel, and to start another kernel. It is like a reboot
1603 but it is independent of the system firmware. And like a reboot
1604 you can start any kernel with it, not just Linux.
1606 The name comes from the similarity to the exec system call.
1608 It is an ongoing process to be certain the hardware in a machine
1609 is properly shutdown, so do not be surprised if this code does not
1610 initially work for you. As of this writing the exact hardware
1611 interface is strongly in flux, so no good recommendation can be
1615 bool "kexec file based system call"
1620 depends on CRYPTO_SHA256=y
1622 This is new version of kexec system call. This system call is
1623 file based and takes file descriptors as system call argument
1624 for kernel and initramfs as opposed to list of segments as
1625 accepted by previous system call.
1627 config KEXEC_VERIFY_SIG
1628 bool "Verify kernel signature during kexec_file_load() syscall"
1629 depends on KEXEC_FILE
1631 This option makes kernel signature verification mandatory for
1632 kexec_file_load() syscall. If kernel is signature can not be
1633 verified, kexec_file_load() will fail.
1635 This option enforces signature verification at generic level.
1636 One needs to enable signature verification for type of kernel
1637 image being loaded to make sure it works. For example, enable
1638 bzImage signature verification option to be able to load and
1639 verify signatures of bzImage. Otherwise kernel loading will fail.
1641 config KEXEC_BZIMAGE_VERIFY_SIG
1642 bool "Enable bzImage signature verification support"
1643 depends on KEXEC_VERIFY_SIG
1644 depends on SIGNED_PE_FILE_VERIFICATION
1645 select SYSTEM_TRUSTED_KEYRING
1647 Enable bzImage signature verification support.
1650 bool "kernel crash dumps"
1651 depends on X86_64 || (X86_32 && HIGHMEM)
1653 Generate crash dump after being started by kexec.
1654 This should be normally only set in special crash dump kernels
1655 which are loaded in the main kernel with kexec-tools into
1656 a specially reserved region and then later executed after
1657 a crash by kdump/kexec. The crash dump kernel must be compiled
1658 to a memory address not used by the main kernel or BIOS using
1659 PHYSICAL_START, or it must be built as a relocatable image
1660 (CONFIG_RELOCATABLE=y).
1661 For more details see Documentation/kdump/kdump.txt
1665 depends on KEXEC && HIBERNATION
1667 Jump between original kernel and kexeced kernel and invoke
1668 code in physical address mode via KEXEC
1670 config PHYSICAL_START
1671 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1674 This gives the physical address where the kernel is loaded.
1676 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1677 bzImage will decompress itself to above physical address and
1678 run from there. Otherwise, bzImage will run from the address where
1679 it has been loaded by the boot loader and will ignore above physical
1682 In normal kdump cases one does not have to set/change this option
1683 as now bzImage can be compiled as a completely relocatable image
1684 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1685 address. This option is mainly useful for the folks who don't want
1686 to use a bzImage for capturing the crash dump and want to use a
1687 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1688 to be specifically compiled to run from a specific memory area
1689 (normally a reserved region) and this option comes handy.
1691 So if you are using bzImage for capturing the crash dump,
1692 leave the value here unchanged to 0x1000000 and set
1693 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1694 for capturing the crash dump change this value to start of
1695 the reserved region. In other words, it can be set based on
1696 the "X" value as specified in the "crashkernel=YM@XM"
1697 command line boot parameter passed to the panic-ed
1698 kernel. Please take a look at Documentation/kdump/kdump.txt
1699 for more details about crash dumps.
1701 Usage of bzImage for capturing the crash dump is recommended as
1702 one does not have to build two kernels. Same kernel can be used
1703 as production kernel and capture kernel. Above option should have
1704 gone away after relocatable bzImage support is introduced. But it
1705 is present because there are users out there who continue to use
1706 vmlinux for dump capture. This option should go away down the
1709 Don't change this unless you know what you are doing.
1712 bool "Build a relocatable kernel"
1715 This builds a kernel image that retains relocation information
1716 so it can be loaded someplace besides the default 1MB.
1717 The relocations tend to make the kernel binary about 10% larger,
1718 but are discarded at runtime.
1720 One use is for the kexec on panic case where the recovery kernel
1721 must live at a different physical address than the primary
1724 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1725 it has been loaded at and the compile time physical address
1726 (CONFIG_PHYSICAL_START) is used as the minimum location.
1728 config RANDOMIZE_BASE
1729 bool "Randomize the address of the kernel image"
1730 depends on RELOCATABLE
1733 Randomizes the physical and virtual address at which the
1734 kernel image is decompressed, as a security feature that
1735 deters exploit attempts relying on knowledge of the location
1736 of kernel internals.
1738 Entropy is generated using the RDRAND instruction if it is
1739 supported. If RDTSC is supported, it is used as well. If
1740 neither RDRAND nor RDTSC are supported, then randomness is
1741 read from the i8254 timer.
1743 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1744 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1745 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1746 minimum of 2MiB, only 10 bits of entropy is theoretically
1747 possible. At best, due to page table layouts, 64-bit can use
1748 9 bits of entropy and 32-bit uses 8 bits.
1752 config RANDOMIZE_BASE_MAX_OFFSET
1753 hex "Maximum kASLR offset allowed" if EXPERT
1754 depends on RANDOMIZE_BASE
1755 range 0x0 0x20000000 if X86_32
1756 default "0x20000000" if X86_32
1757 range 0x0 0x40000000 if X86_64
1758 default "0x40000000" if X86_64
1760 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1761 memory is used to determine the maximal offset in bytes that will
1762 be applied to the kernel when kernel Address Space Layout
1763 Randomization (kASLR) is active. This must be a multiple of
1766 On 32-bit this is limited to 512MiB by page table layouts. The
1769 On 64-bit this is limited by how the kernel fixmap page table is
1770 positioned, so this cannot be larger than 1GiB currently. Without
1771 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1772 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1773 modules area will shrink to compensate, up to the current maximum
1774 1GiB to 1GiB split. The default is 1GiB.
1776 If unsure, leave at the default value.
1778 # Relocation on x86 needs some additional build support
1779 config X86_NEED_RELOCS
1781 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1783 config PHYSICAL_ALIGN
1784 hex "Alignment value to which kernel should be aligned"
1786 range 0x2000 0x1000000 if X86_32
1787 range 0x200000 0x1000000 if X86_64
1789 This value puts the alignment restrictions on physical address
1790 where kernel is loaded and run from. Kernel is compiled for an
1791 address which meets above alignment restriction.
1793 If bootloader loads the kernel at a non-aligned address and
1794 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1795 address aligned to above value and run from there.
1797 If bootloader loads the kernel at a non-aligned address and
1798 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1799 load address and decompress itself to the address it has been
1800 compiled for and run from there. The address for which kernel is
1801 compiled already meets above alignment restrictions. Hence the
1802 end result is that kernel runs from a physical address meeting
1803 above alignment restrictions.
1805 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1806 this value must be a multiple of 0x200000.
1808 Don't change this unless you know what you are doing.
1811 bool "Support for hot-pluggable CPUs"
1814 Say Y here to allow turning CPUs off and on. CPUs can be
1815 controlled through /sys/devices/system/cpu.
1816 ( Note: power management support will enable this option
1817 automatically on SMP systems. )
1818 Say N if you want to disable CPU hotplug.
1820 config BOOTPARAM_HOTPLUG_CPU0
1821 bool "Set default setting of cpu0_hotpluggable"
1823 depends on HOTPLUG_CPU
1825 Set whether default state of cpu0_hotpluggable is on or off.
1827 Say Y here to enable CPU0 hotplug by default. If this switch
1828 is turned on, there is no need to give cpu0_hotplug kernel
1829 parameter and the CPU0 hotplug feature is enabled by default.
1831 Please note: there are two known CPU0 dependencies if you want
1832 to enable the CPU0 hotplug feature either by this switch or by
1833 cpu0_hotplug kernel parameter.
1835 First, resume from hibernate or suspend always starts from CPU0.
1836 So hibernate and suspend are prevented if CPU0 is offline.
1838 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1839 offline if any interrupt can not migrate out of CPU0. There may
1840 be other CPU0 dependencies.
1842 Please make sure the dependencies are under your control before
1843 you enable this feature.
1845 Say N if you don't want to enable CPU0 hotplug feature by default.
1846 You still can enable the CPU0 hotplug feature at boot by kernel
1847 parameter cpu0_hotplug.
1849 config DEBUG_HOTPLUG_CPU0
1851 prompt "Debug CPU0 hotplug"
1852 depends on HOTPLUG_CPU
1854 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1855 soon as possible and boots up userspace with CPU0 offlined. User
1856 can online CPU0 back after boot time.
1858 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1859 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1860 compilation or giving cpu0_hotplug kernel parameter at boot.
1866 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1867 depends on X86_32 || IA32_EMULATION
1869 Certain buggy versions of glibc will crash if they are
1870 presented with a 32-bit vDSO that is not mapped at the address
1871 indicated in its segment table.
1873 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1874 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1875 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1876 the only released version with the bug, but OpenSUSE 9
1877 contains a buggy "glibc 2.3.2".
1879 The symptom of the bug is that everything crashes on startup, saying:
1880 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1882 Saying Y here changes the default value of the vdso32 boot
1883 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1884 This works around the glibc bug but hurts performance.
1886 If unsure, say N: if you are compiling your own kernel, you
1887 are unlikely to be using a buggy version of glibc.
1890 bool "Built-in kernel command line"
1892 Allow for specifying boot arguments to the kernel at
1893 build time. On some systems (e.g. embedded ones), it is
1894 necessary or convenient to provide some or all of the
1895 kernel boot arguments with the kernel itself (that is,
1896 to not rely on the boot loader to provide them.)
1898 To compile command line arguments into the kernel,
1899 set this option to 'Y', then fill in the
1900 the boot arguments in CONFIG_CMDLINE.
1902 Systems with fully functional boot loaders (i.e. non-embedded)
1903 should leave this option set to 'N'.
1906 string "Built-in kernel command string"
1907 depends on CMDLINE_BOOL
1910 Enter arguments here that should be compiled into the kernel
1911 image and used at boot time. If the boot loader provides a
1912 command line at boot time, it is appended to this string to
1913 form the full kernel command line, when the system boots.
1915 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1916 change this behavior.
1918 In most cases, the command line (whether built-in or provided
1919 by the boot loader) should specify the device for the root
1922 config CMDLINE_OVERRIDE
1923 bool "Built-in command line overrides boot loader arguments"
1924 depends on CMDLINE_BOOL
1926 Set this option to 'Y' to have the kernel ignore the boot loader
1927 command line, and use ONLY the built-in command line.
1929 This is used to work around broken boot loaders. This should
1930 be set to 'N' under normal conditions.
1934 config ARCH_ENABLE_MEMORY_HOTPLUG
1936 depends on X86_64 || (X86_32 && HIGHMEM)
1938 config ARCH_ENABLE_MEMORY_HOTREMOVE
1940 depends on MEMORY_HOTPLUG
1942 config USE_PERCPU_NUMA_NODE_ID
1946 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1948 depends on X86_64 || X86_PAE
1950 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1952 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1954 menu "Power management and ACPI options"
1956 config ARCH_HIBERNATION_HEADER
1958 depends on X86_64 && HIBERNATION
1960 source "kernel/power/Kconfig"
1962 source "drivers/acpi/Kconfig"
1964 source "drivers/sfi/Kconfig"
1971 tristate "APM (Advanced Power Management) BIOS support"
1972 depends on X86_32 && PM_SLEEP
1974 APM is a BIOS specification for saving power using several different
1975 techniques. This is mostly useful for battery powered laptops with
1976 APM compliant BIOSes. If you say Y here, the system time will be
1977 reset after a RESUME operation, the /proc/apm device will provide
1978 battery status information, and user-space programs will receive
1979 notification of APM "events" (e.g. battery status change).
1981 If you select "Y" here, you can disable actual use of the APM
1982 BIOS by passing the "apm=off" option to the kernel at boot time.
1984 Note that the APM support is almost completely disabled for
1985 machines with more than one CPU.
1987 In order to use APM, you will need supporting software. For location
1988 and more information, read <file:Documentation/power/apm-acpi.txt>
1989 and the Battery Powered Linux mini-HOWTO, available from
1990 <http://www.tldp.org/docs.html#howto>.
1992 This driver does not spin down disk drives (see the hdparm(8)
1993 manpage ("man 8 hdparm") for that), and it doesn't turn off
1994 VESA-compliant "green" monitors.
1996 This driver does not support the TI 4000M TravelMate and the ACER
1997 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1998 desktop machines also don't have compliant BIOSes, and this driver
1999 may cause those machines to panic during the boot phase.
2001 Generally, if you don't have a battery in your machine, there isn't
2002 much point in using this driver and you should say N. If you get
2003 random kernel OOPSes or reboots that don't seem to be related to
2004 anything, try disabling/enabling this option (or disabling/enabling
2007 Some other things you should try when experiencing seemingly random,
2010 1) make sure that you have enough swap space and that it is
2012 2) pass the "no-hlt" option to the kernel
2013 3) switch on floating point emulation in the kernel and pass
2014 the "no387" option to the kernel
2015 4) pass the "floppy=nodma" option to the kernel
2016 5) pass the "mem=4M" option to the kernel (thereby disabling
2017 all but the first 4 MB of RAM)
2018 6) make sure that the CPU is not over clocked.
2019 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2020 8) disable the cache from your BIOS settings
2021 9) install a fan for the video card or exchange video RAM
2022 10) install a better fan for the CPU
2023 11) exchange RAM chips
2024 12) exchange the motherboard.
2026 To compile this driver as a module, choose M here: the
2027 module will be called apm.
2031 config APM_IGNORE_USER_SUSPEND
2032 bool "Ignore USER SUSPEND"
2034 This option will ignore USER SUSPEND requests. On machines with a
2035 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2036 series notebooks, it is necessary to say Y because of a BIOS bug.
2038 config APM_DO_ENABLE
2039 bool "Enable PM at boot time"
2041 Enable APM features at boot time. From page 36 of the APM BIOS
2042 specification: "When disabled, the APM BIOS does not automatically
2043 power manage devices, enter the Standby State, enter the Suspend
2044 State, or take power saving steps in response to CPU Idle calls."
2045 This driver will make CPU Idle calls when Linux is idle (unless this
2046 feature is turned off -- see "Do CPU IDLE calls", below). This
2047 should always save battery power, but more complicated APM features
2048 will be dependent on your BIOS implementation. You may need to turn
2049 this option off if your computer hangs at boot time when using APM
2050 support, or if it beeps continuously instead of suspending. Turn
2051 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2052 T400CDT. This is off by default since most machines do fine without
2057 bool "Make CPU Idle calls when idle"
2059 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2060 On some machines, this can activate improved power savings, such as
2061 a slowed CPU clock rate, when the machine is idle. These idle calls
2062 are made after the idle loop has run for some length of time (e.g.,
2063 333 mS). On some machines, this will cause a hang at boot time or
2064 whenever the CPU becomes idle. (On machines with more than one CPU,
2065 this option does nothing.)
2067 config APM_DISPLAY_BLANK
2068 bool "Enable console blanking using APM"
2070 Enable console blanking using the APM. Some laptops can use this to
2071 turn off the LCD backlight when the screen blanker of the Linux
2072 virtual console blanks the screen. Note that this is only used by
2073 the virtual console screen blanker, and won't turn off the backlight
2074 when using the X Window system. This also doesn't have anything to
2075 do with your VESA-compliant power-saving monitor. Further, this
2076 option doesn't work for all laptops -- it might not turn off your
2077 backlight at all, or it might print a lot of errors to the console,
2078 especially if you are using gpm.
2080 config APM_ALLOW_INTS
2081 bool "Allow interrupts during APM BIOS calls"
2083 Normally we disable external interrupts while we are making calls to
2084 the APM BIOS as a measure to lessen the effects of a badly behaving
2085 BIOS implementation. The BIOS should reenable interrupts if it
2086 needs to. Unfortunately, some BIOSes do not -- especially those in
2087 many of the newer IBM Thinkpads. If you experience hangs when you
2088 suspend, try setting this to Y. Otherwise, say N.
2092 source "drivers/cpufreq/Kconfig"
2094 source "drivers/cpuidle/Kconfig"
2096 source "drivers/idle/Kconfig"
2101 menu "Bus options (PCI etc.)"
2107 Find out whether you have a PCI motherboard. PCI is the name of a
2108 bus system, i.e. the way the CPU talks to the other stuff inside
2109 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2110 VESA. If you have PCI, say Y, otherwise N.
2113 prompt "PCI access mode"
2114 depends on X86_32 && PCI
2117 On PCI systems, the BIOS can be used to detect the PCI devices and
2118 determine their configuration. However, some old PCI motherboards
2119 have BIOS bugs and may crash if this is done. Also, some embedded
2120 PCI-based systems don't have any BIOS at all. Linux can also try to
2121 detect the PCI hardware directly without using the BIOS.
2123 With this option, you can specify how Linux should detect the
2124 PCI devices. If you choose "BIOS", the BIOS will be used,
2125 if you choose "Direct", the BIOS won't be used, and if you
2126 choose "MMConfig", then PCI Express MMCONFIG will be used.
2127 If you choose "Any", the kernel will try MMCONFIG, then the
2128 direct access method and falls back to the BIOS if that doesn't
2129 work. If unsure, go with the default, which is "Any".
2134 config PCI_GOMMCONFIG
2151 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2153 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2156 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2160 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2164 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2168 depends on PCI && XEN
2176 bool "Support mmconfig PCI config space access"
2177 depends on X86_64 && PCI && ACPI
2179 config PCI_CNB20LE_QUIRK
2180 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2183 Read the PCI windows out of the CNB20LE host bridge. This allows
2184 PCI hotplug to work on systems with the CNB20LE chipset which do
2187 There's no public spec for this chipset, and this functionality
2188 is known to be incomplete.
2190 You should say N unless you know you need this.
2192 source "drivers/pci/pcie/Kconfig"
2194 source "drivers/pci/Kconfig"
2196 # x86_64 have no ISA slots, but can have ISA-style DMA.
2198 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2201 Enables ISA-style DMA support for devices requiring such controllers.
2209 Find out whether you have ISA slots on your motherboard. ISA is the
2210 name of a bus system, i.e. the way the CPU talks to the other stuff
2211 inside your box. Other bus systems are PCI, EISA, MicroChannel
2212 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2213 newer boards don't support it. If you have ISA, say Y, otherwise N.
2219 The Extended Industry Standard Architecture (EISA) bus was
2220 developed as an open alternative to the IBM MicroChannel bus.
2222 The EISA bus provided some of the features of the IBM MicroChannel
2223 bus while maintaining backward compatibility with cards made for
2224 the older ISA bus. The EISA bus saw limited use between 1988 and
2225 1995 when it was made obsolete by the PCI bus.
2227 Say Y here if you are building a kernel for an EISA-based machine.
2231 source "drivers/eisa/Kconfig"
2234 tristate "NatSemi SCx200 support"
2236 This provides basic support for National Semiconductor's
2237 (now AMD's) Geode processors. The driver probes for the
2238 PCI-IDs of several on-chip devices, so its a good dependency
2239 for other scx200_* drivers.
2241 If compiled as a module, the driver is named scx200.
2243 config SCx200HR_TIMER
2244 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2248 This driver provides a clocksource built upon the on-chip
2249 27MHz high-resolution timer. Its also a workaround for
2250 NSC Geode SC-1100's buggy TSC, which loses time when the
2251 processor goes idle (as is done by the scheduler). The
2252 other workaround is idle=poll boot option.
2255 bool "One Laptop Per Child support"
2262 Add support for detecting the unique features of the OLPC
2266 bool "OLPC XO-1 Power Management"
2267 depends on OLPC && MFD_CS5535 && PM_SLEEP
2270 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2273 bool "OLPC XO-1 Real Time Clock"
2274 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2276 Add support for the XO-1 real time clock, which can be used as a
2277 programmable wakeup source.
2280 bool "OLPC XO-1 SCI extras"
2281 depends on OLPC && OLPC_XO1_PM
2287 Add support for SCI-based features of the OLPC XO-1 laptop:
2288 - EC-driven system wakeups
2292 - AC adapter status updates
2293 - Battery status updates
2295 config OLPC_XO15_SCI
2296 bool "OLPC XO-1.5 SCI extras"
2297 depends on OLPC && ACPI
2300 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2301 - EC-driven system wakeups
2302 - AC adapter status updates
2303 - Battery status updates
2306 bool "PCEngines ALIX System Support (LED setup)"
2309 This option enables system support for the PCEngines ALIX.
2310 At present this just sets up LEDs for GPIO control on
2311 ALIX2/3/6 boards. However, other system specific setup should
2314 Note: You must still enable the drivers for GPIO and LED support
2315 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2317 Note: You have to set alix.force=1 for boards with Award BIOS.
2320 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2323 This option enables system support for the Soekris Engineering net5501.
2326 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2330 This option enables system support for the Traverse Technologies GEOS.
2333 bool "Technologic Systems TS-5500 platform support"
2335 select CHECK_SIGNATURE
2339 This option enables system support for the Technologic Systems TS-5500.
2345 depends on CPU_SUP_AMD && PCI
2347 source "drivers/pcmcia/Kconfig"
2349 source "drivers/pci/hotplug/Kconfig"
2352 tristate "RapidIO support"
2356 If enabled this option will include drivers and the core
2357 infrastructure code to support RapidIO interconnect devices.
2359 source "drivers/rapidio/Kconfig"
2362 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2364 Firmwares often provide initial graphics framebuffers so the BIOS,
2365 bootloader or kernel can show basic video-output during boot for
2366 user-guidance and debugging. Historically, x86 used the VESA BIOS
2367 Extensions and EFI-framebuffers for this, which are mostly limited
2369 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2370 framebuffers so the new generic system-framebuffer drivers can be
2371 used on x86. If the framebuffer is not compatible with the generic
2372 modes, it is adverticed as fallback platform framebuffer so legacy
2373 drivers like efifb, vesafb and uvesafb can pick it up.
2374 If this option is not selected, all system framebuffers are always
2375 marked as fallback platform framebuffers as usual.
2377 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2378 not be able to pick up generic system framebuffers if this option
2379 is selected. You are highly encouraged to enable simplefb as
2380 replacement if you select this option. simplefb can correctly deal
2381 with generic system framebuffers. But you should still keep vesafb
2382 and others enabled as fallback if a system framebuffer is
2383 incompatible with simplefb.
2390 menu "Executable file formats / Emulations"
2392 source "fs/Kconfig.binfmt"
2394 config IA32_EMULATION
2395 bool "IA32 Emulation"
2398 select COMPAT_BINFMT_ELF
2401 Include code to run legacy 32-bit programs under a
2402 64-bit kernel. You should likely turn this on, unless you're
2403 100% sure that you don't have any 32-bit programs left.
2406 tristate "IA32 a.out support"
2407 depends on IA32_EMULATION
2409 Support old a.out binaries in the 32bit emulation.
2412 bool "x32 ABI for 64-bit mode"
2413 depends on X86_64 && IA32_EMULATION
2415 Include code to run binaries for the x32 native 32-bit ABI
2416 for 64-bit processors. An x32 process gets access to the
2417 full 64-bit register file and wide data path while leaving
2418 pointers at 32 bits for smaller memory footprint.
2420 You will need a recent binutils (2.22 or later) with
2421 elf32_x86_64 support enabled to compile a kernel with this
2426 depends on IA32_EMULATION || X86_X32
2427 select ARCH_WANT_OLD_COMPAT_IPC
2430 config COMPAT_FOR_U64_ALIGNMENT
2433 config SYSVIPC_COMPAT
2445 config HAVE_ATOMIC_IOMAP
2449 config X86_DEV_DMA_OPS
2451 depends on X86_64 || STA2X11
2453 config X86_DMA_REMAP
2466 source "net/Kconfig"
2468 source "drivers/Kconfig"
2470 source "drivers/firmware/Kconfig"
2474 source "arch/x86/Kconfig.debug"
2476 source "security/Kconfig"
2478 source "crypto/Kconfig"
2480 source "arch/x86/kvm/Kconfig"
2482 source "lib/Kconfig"