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_HAS_DEBUG_STRICT_USER_COPY_CHECKS
25 select ARCH_MIGHT_HAVE_PC_PARPORT
26 select HAVE_AOUT if X86_32
27 select HAVE_UNSTABLE_SCHED_CLOCK
28 select ARCH_SUPPORTS_NUMA_BALANCING
29 select ARCH_SUPPORTS_INT128 if X86_64
30 select ARCH_WANTS_PROT_NUMA_PROT_NONE
33 select HAVE_PCSPKR_PLATFORM
34 select HAVE_PERF_EVENTS
35 select HAVE_IOREMAP_PROT
38 select HAVE_MEMBLOCK_NODE_MAP
39 select ARCH_DISCARD_MEMBLOCK
40 select ARCH_WANT_OPTIONAL_GPIOLIB
41 select ARCH_WANT_FRAME_POINTERS
43 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
44 select HAVE_KRETPROBES
46 select HAVE_KPROBES_ON_FTRACE
47 select HAVE_FTRACE_MCOUNT_RECORD
48 select HAVE_FENTRY if X86_64
49 select HAVE_C_RECORDMCOUNT
50 select HAVE_DYNAMIC_FTRACE
51 select HAVE_DYNAMIC_FTRACE_WITH_REGS
52 select HAVE_FUNCTION_TRACER
53 select HAVE_FUNCTION_GRAPH_TRACER
54 select HAVE_FUNCTION_GRAPH_FP_TEST
55 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
56 select HAVE_SYSCALL_TRACEPOINTS
57 select SYSCTL_EXCEPTION_TRACE
60 select HAVE_ARCH_TRACEHOOK
61 select HAVE_GENERIC_DMA_COHERENT if X86_32
62 select HAVE_EFFICIENT_UNALIGNED_ACCESS
63 select USER_STACKTRACE_SUPPORT
64 select HAVE_REGS_AND_STACK_ACCESS_API
65 select HAVE_DMA_API_DEBUG
66 select HAVE_KERNEL_GZIP
67 select HAVE_KERNEL_BZIP2
68 select HAVE_KERNEL_LZMA
70 select HAVE_KERNEL_LZO
71 select HAVE_KERNEL_LZ4
72 select HAVE_HW_BREAKPOINT
73 select HAVE_MIXED_BREAKPOINTS_REGS
75 select HAVE_PERF_EVENTS_NMI
77 select HAVE_PERF_USER_STACK_DUMP
78 select HAVE_DEBUG_KMEMLEAK
80 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
81 select HAVE_CMPXCHG_LOCAL
82 select HAVE_CMPXCHG_DOUBLE
83 select HAVE_ARCH_KMEMCHECK
84 select HAVE_USER_RETURN_NOTIFIER
85 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
86 select HAVE_ARCH_JUMP_LABEL
87 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
89 select GENERIC_FIND_FIRST_BIT
90 select GENERIC_IRQ_PROBE
91 select GENERIC_PENDING_IRQ if SMP
92 select GENERIC_IRQ_SHOW
93 select GENERIC_CLOCKEVENTS_MIN_ADJUST
94 select IRQ_FORCED_THREADING
95 select HAVE_BPF_JIT if X86_64
96 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
98 select ARCH_HAVE_NMI_SAFE_CMPXCHG
100 select DCACHE_WORD_ACCESS
101 select GENERIC_SMP_IDLE_THREAD
102 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
103 select HAVE_ARCH_SECCOMP_FILTER
104 select BUILDTIME_EXTABLE_SORT
105 select GENERIC_CMOS_UPDATE
106 select HAVE_ARCH_SOFT_DIRTY
107 select CLOCKSOURCE_WATCHDOG
108 select GENERIC_CLOCKEVENTS
109 select ARCH_CLOCKSOURCE_DATA if X86_64
110 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
111 select GENERIC_TIME_VSYSCALL if X86_64
112 select KTIME_SCALAR if X86_32
113 select GENERIC_STRNCPY_FROM_USER
114 select GENERIC_STRNLEN_USER
115 select HAVE_CONTEXT_TRACKING if X86_64
116 select HAVE_IRQ_TIME_ACCOUNTING
118 select MODULES_USE_ELF_REL if X86_32
119 select MODULES_USE_ELF_RELA if X86_64
120 select CLONE_BACKWARDS if X86_32
121 select ARCH_USE_BUILTIN_BSWAP
122 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
123 select OLD_SIGACTION if X86_32
124 select COMPAT_OLD_SIGACTION if IA32_EMULATION
126 select HAVE_DEBUG_STACKOVERFLOW
127 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
128 select HAVE_CC_STACKPROTECTOR
130 config INSTRUCTION_DECODER
132 depends on KPROBES || PERF_EVENTS || UPROBES
136 default "elf32-i386" if X86_32
137 default "elf64-x86-64" if X86_64
139 config ARCH_DEFCONFIG
141 default "arch/x86/configs/i386_defconfig" if X86_32
142 default "arch/x86/configs/x86_64_defconfig" if X86_64
144 config LOCKDEP_SUPPORT
147 config STACKTRACE_SUPPORT
150 config HAVE_LATENCYTOP_SUPPORT
159 config NEED_DMA_MAP_STATE
161 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
163 config NEED_SG_DMA_LENGTH
166 config GENERIC_ISA_DMA
168 depends on ISA_DMA_API
173 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
175 config GENERIC_BUG_RELATIVE_POINTERS
178 config GENERIC_HWEIGHT
181 config ARCH_MAY_HAVE_PC_FDC
183 depends on ISA_DMA_API
185 config RWSEM_XCHGADD_ALGORITHM
188 config GENERIC_CALIBRATE_DELAY
191 config ARCH_HAS_CPU_RELAX
194 config ARCH_HAS_CACHE_LINE_SIZE
197 config ARCH_HAS_CPU_AUTOPROBE
200 config HAVE_SETUP_PER_CPU_AREA
203 config NEED_PER_CPU_EMBED_FIRST_CHUNK
206 config NEED_PER_CPU_PAGE_FIRST_CHUNK
209 config ARCH_HIBERNATION_POSSIBLE
212 config ARCH_SUSPEND_POSSIBLE
215 config ARCH_WANT_HUGE_PMD_SHARE
218 config ARCH_WANT_GENERAL_HUGETLB
229 config ARCH_SUPPORTS_OPTIMIZED_INLINING
232 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
235 config HAVE_INTEL_TXT
237 depends on INTEL_IOMMU && ACPI
241 depends on X86_32 && SMP
245 depends on X86_64 && SMP
251 config X86_32_LAZY_GS
253 depends on X86_32 && !CC_STACKPROTECTOR
255 config ARCH_HWEIGHT_CFLAGS
257 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
258 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
260 config ARCH_SUPPORTS_UPROBES
263 source "init/Kconfig"
264 source "kernel/Kconfig.freezer"
266 menu "Processor type and features"
269 bool "DMA memory allocation support" if EXPERT
272 DMA memory allocation support allows devices with less than 32-bit
273 addressing to allocate within the first 16MB of address space.
274 Disable if no such devices will be used.
279 bool "Symmetric multi-processing support"
281 This enables support for systems with more than one CPU. If you have
282 a system with only one CPU, like most personal computers, say N. If
283 you have a system with more than one CPU, say Y.
285 If you say N here, the kernel will run on single and multiprocessor
286 machines, but will use only one CPU of a multiprocessor machine. If
287 you say Y here, the kernel will run on many, but not all,
288 singleprocessor machines. On a singleprocessor machine, the kernel
289 will run faster if you say N here.
291 Note that if you say Y here and choose architecture "586" or
292 "Pentium" under "Processor family", the kernel will not work on 486
293 architectures. Similarly, multiprocessor kernels for the "PPro"
294 architecture may not work on all Pentium based boards.
296 People using multiprocessor machines who say Y here should also say
297 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
298 Management" code will be disabled if you say Y here.
300 See also <file:Documentation/x86/i386/IO-APIC.txt>,
301 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
302 <http://www.tldp.org/docs.html#howto>.
304 If you don't know what to do here, say N.
307 bool "Support x2apic"
308 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
310 This enables x2apic support on CPUs that have this feature.
312 This allows 32-bit apic IDs (so it can support very large systems),
313 and accesses the local apic via MSRs not via mmio.
315 If you don't know what to do here, say N.
318 bool "Enable MPS table" if ACPI || SFI
320 depends on X86_LOCAL_APIC
322 For old smp systems that do not have proper acpi support. Newer systems
323 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
326 bool "Support for big SMP systems with more than 8 CPUs"
327 depends on X86_32 && SMP
329 This option is needed for the systems that have more than 8 CPUs
333 depends on X86_GOLDFISH
336 config X86_EXTENDED_PLATFORM
337 bool "Support for extended (non-PC) x86 platforms"
340 If you disable this option then the kernel will only support
341 standard PC platforms. (which covers the vast majority of
344 If you enable this option then you'll be able to select support
345 for the following (non-PC) 32 bit x86 platforms:
346 Goldfish (Android emulator)
350 SGI 320/540 (Visual Workstation)
351 STA2X11-based (e.g. Northville)
352 Summit/EXA (IBM x440)
353 Unisys ES7000 IA32 series
354 Moorestown MID devices
356 If you have one of these systems, or if you want to build a
357 generic distribution kernel, say Y here - otherwise say N.
361 config X86_EXTENDED_PLATFORM
362 bool "Support for extended (non-PC) x86 platforms"
365 If you disable this option then the kernel will only support
366 standard PC platforms. (which covers the vast majority of
369 If you enable this option then you'll be able to select support
370 for the following (non-PC) 64 bit x86 platforms:
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.
378 # This is an alphabetically sorted list of 64 bit extended platforms
379 # Please maintain the alphabetic order if and when there are additions
381 bool "Numascale NumaChip"
383 depends on X86_EXTENDED_PLATFORM
386 depends on X86_X2APIC
387 depends on PCI_MMCONFIG
389 Adds support for Numascale NumaChip large-SMP systems. Needed to
390 enable more than ~168 cores.
391 If you don't have one of these, you should say N here.
395 select HYPERVISOR_GUEST
397 depends on X86_64 && PCI
398 depends on X86_EXTENDED_PLATFORM
401 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
402 supposed to run on these EM64T-based machines. Only choose this option
403 if you have one of these machines.
406 bool "SGI Ultraviolet"
408 depends on X86_EXTENDED_PLATFORM
410 depends on X86_X2APIC
412 This option is needed in order to support SGI Ultraviolet systems.
413 If you don't have one of these, you should say N here.
415 # Following is an alphabetically sorted list of 32 bit extended platforms
416 # Please maintain the alphabetic order if and when there are additions
419 bool "Goldfish (Virtual Platform)"
421 depends on X86_EXTENDED_PLATFORM
423 Enable support for the Goldfish virtual platform used primarily
424 for Android development. Unless you are building for the Android
425 Goldfish emulator say N here.
428 bool "CE4100 TV platform"
430 depends on PCI_GODIRECT
432 depends on X86_EXTENDED_PLATFORM
433 select X86_REBOOTFIXUPS
435 select OF_EARLY_FLATTREE
438 Select for the Intel CE media processor (CE4100) SOC.
439 This option compiles in support for the CE4100 SOC for settop
440 boxes and media devices.
443 bool "Intel MID platform support"
445 depends on X86_EXTENDED_PLATFORM
446 depends on X86_PLATFORM_DEVICES
449 depends on X86_IO_APIC
455 select MFD_INTEL_MSIC
457 Select to build a kernel capable of supporting Intel MID (Mobile
458 Internet Device) platform systems which do not have the PCI legacy
459 interfaces. If you are building for a PC class system say N here.
461 Intel MID platforms are based on an Intel processor and chipset which
462 consume less power than most of the x86 derivatives.
464 config X86_INTEL_LPSS
465 bool "Intel Low Power Subsystem Support"
470 Select to build support for Intel Low Power Subsystem such as
471 found on Intel Lynxpoint PCH. Selecting this option enables
472 things like clock tree (common clock framework) and pincontrol
473 which are needed by the LPSS peripheral drivers.
476 bool "RDC R-321x SoC"
478 depends on X86_EXTENDED_PLATFORM
480 select X86_REBOOTFIXUPS
482 This option is needed for RDC R-321x system-on-chip, also known
484 If you don't have one of these chips, you should say N here.
486 config X86_32_NON_STANDARD
487 bool "Support non-standard 32-bit SMP architectures"
488 depends on X86_32 && SMP
489 depends on X86_EXTENDED_PLATFORM
491 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
492 STA2X11, default subarchitectures. It is intended for a generic
493 binary kernel. If you select them all, kernel will probe it
494 one by one and will fallback to default.
496 # Alphabetically sorted list of Non standard 32 bit platforms
499 bool "NUMAQ (IBM/Sequent)"
500 depends on X86_32_NON_STANDARD
505 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
506 NUMA multiquad box. This changes the way that processors are
507 bootstrapped, and uses Clustered Logical APIC addressing mode instead
508 of Flat Logical. You will need a new lynxer.elf file to flash your
509 firmware with - send email to <Martin.Bligh@us.ibm.com>.
511 config X86_SUPPORTS_MEMORY_FAILURE
513 # MCE code calls memory_failure():
515 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
516 depends on !X86_NUMAQ
517 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
518 depends on X86_64 || !SPARSEMEM
519 select ARCH_SUPPORTS_MEMORY_FAILURE
522 bool "SGI 320/540 (Visual Workstation)"
523 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
524 depends on X86_32_NON_STANDARD
526 The SGI Visual Workstation series is an IA32-based workstation
527 based on SGI systems chips with some legacy PC hardware attached.
529 Say Y here to create a kernel to run on the SGI 320 or 540.
531 A kernel compiled for the Visual Workstation will run on general
532 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
535 bool "STA2X11 Companion Chip Support"
536 depends on X86_32_NON_STANDARD && PCI
537 select X86_DEV_DMA_OPS
541 select ARCH_REQUIRE_GPIOLIB
544 This adds support for boards based on the STA2X11 IO-Hub,
545 a.k.a. "ConneXt". The chip is used in place of the standard
546 PC chipset, so all "standard" peripherals are missing. If this
547 option is selected the kernel will still be able to boot on
548 standard PC machines.
551 bool "Summit/EXA (IBM x440)"
552 depends on X86_32_NON_STANDARD
554 This option is needed for IBM systems that use the Summit/EXA chipset.
555 In particular, it is needed for the x440.
558 bool "Unisys ES7000 IA32 series"
559 depends on X86_32_NON_STANDARD && X86_BIGSMP
561 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
562 supposed to run on an IA32-based Unisys ES7000 system.
565 tristate "Eurobraille/Iris poweroff module"
568 The Iris machines from EuroBraille do not have APM or ACPI support
569 to shut themselves down properly. A special I/O sequence is
570 needed to do so, which is what this module does at
573 This is only for Iris machines from EuroBraille.
577 config SCHED_OMIT_FRAME_POINTER
579 prompt "Single-depth WCHAN output"
582 Calculate simpler /proc/<PID>/wchan values. If this option
583 is disabled then wchan values will recurse back to the
584 caller function. This provides more accurate wchan values,
585 at the expense of slightly more scheduling overhead.
587 If in doubt, say "Y".
589 menuconfig HYPERVISOR_GUEST
590 bool "Linux guest support"
592 Say Y here to enable options for running Linux under various hyper-
593 visors. This option enables basic hypervisor detection and platform
596 If you say N, all options in this submenu will be skipped and
597 disabled, and Linux guest support won't be built in.
602 bool "Enable paravirtualization code"
604 This changes the kernel so it can modify itself when it is run
605 under a hypervisor, potentially improving performance significantly
606 over full virtualization. However, when run without a hypervisor
607 the kernel is theoretically slower and slightly larger.
609 config PARAVIRT_DEBUG
610 bool "paravirt-ops debugging"
611 depends on PARAVIRT && DEBUG_KERNEL
613 Enable to debug paravirt_ops internals. Specifically, BUG if
614 a paravirt_op is missing when it is called.
616 config PARAVIRT_SPINLOCKS
617 bool "Paravirtualization layer for spinlocks"
618 depends on PARAVIRT && SMP
619 select UNINLINE_SPIN_UNLOCK
621 Paravirtualized spinlocks allow a pvops backend to replace the
622 spinlock implementation with something virtualization-friendly
623 (for example, block the virtual CPU rather than spinning).
625 It has a minimal impact on native kernels and gives a nice performance
626 benefit on paravirtualized KVM / Xen kernels.
628 If you are unsure how to answer this question, answer Y.
630 source "arch/x86/xen/Kconfig"
633 bool "KVM Guest support (including kvmclock)"
635 select PARAVIRT_CLOCK
638 This option enables various optimizations for running under the KVM
639 hypervisor. It includes a paravirtualized clock, so that instead
640 of relying on a PIT (or probably other) emulation by the
641 underlying device model, the host provides the guest with
642 timing infrastructure such as time of day, and system time
645 bool "Enable debug information for KVM Guests in debugfs"
646 depends on KVM_GUEST && DEBUG_FS
649 This option enables collection of various statistics for KVM guest.
650 Statistics are displayed in debugfs filesystem. Enabling this option
651 may incur significant overhead.
653 source "arch/x86/lguest/Kconfig"
655 config PARAVIRT_TIME_ACCOUNTING
656 bool "Paravirtual steal time accounting"
660 Select this option to enable fine granularity task steal time
661 accounting. Time spent executing other tasks in parallel with
662 the current vCPU is discounted from the vCPU power. To account for
663 that, there can be a small performance impact.
665 If in doubt, say N here.
667 config PARAVIRT_CLOCK
670 endif #HYPERVISOR_GUEST
678 This option adds a kernel parameter 'memtest', which allows memtest
680 memtest=0, mean disabled; -- default
681 memtest=1, mean do 1 test pattern;
683 memtest=4, mean do 4 test patterns.
684 If you are unsure how to answer this question, answer N.
686 config X86_SUMMIT_NUMA
688 depends on X86_32 && NUMA && X86_32_NON_STANDARD
690 config X86_CYCLONE_TIMER
692 depends on X86_SUMMIT
694 source "arch/x86/Kconfig.cpu"
698 prompt "HPET Timer Support" if X86_32
700 Use the IA-PC HPET (High Precision Event Timer) to manage
701 time in preference to the PIT and RTC, if a HPET is
703 HPET is the next generation timer replacing legacy 8254s.
704 The HPET provides a stable time base on SMP
705 systems, unlike the TSC, but it is more expensive to access,
706 as it is off-chip. You can find the HPET spec at
707 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
709 You can safely choose Y here. However, HPET will only be
710 activated if the platform and the BIOS support this feature.
711 Otherwise the 8254 will be used for timing services.
713 Choose N to continue using the legacy 8254 timer.
715 config HPET_EMULATE_RTC
717 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
720 def_bool y if X86_INTEL_MID
721 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
723 depends on X86_INTEL_MID && SFI
725 APB timer is the replacement for 8254, HPET on X86 MID platforms.
726 The APBT provides a stable time base on SMP
727 systems, unlike the TSC, but it is more expensive to access,
728 as it is off-chip. APB timers are always running regardless of CPU
729 C states, they are used as per CPU clockevent device when possible.
731 # Mark as expert because too many people got it wrong.
732 # The code disables itself when not needed.
735 bool "Enable DMI scanning" if EXPERT
737 Enabled scanning of DMI to identify machine quirks. Say Y
738 here unless you have verified that your setup is not
739 affected by entries in the DMI blacklist. Required by PNP
743 bool "Old AMD GART IOMMU support"
745 depends on X86_64 && PCI && AMD_NB
747 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
748 GART based hardware IOMMUs.
750 The GART supports full DMA access for devices with 32-bit access
751 limitations, on systems with more than 3 GB. This is usually needed
752 for USB, sound, many IDE/SATA chipsets and some other devices.
754 Newer systems typically have a modern AMD IOMMU, supported via
755 the CONFIG_AMD_IOMMU=y config option.
757 In normal configurations this driver is only active when needed:
758 there's more than 3 GB of memory and the system contains a
759 32-bit limited device.
764 bool "IBM Calgary IOMMU support"
766 depends on X86_64 && PCI
768 Support for hardware IOMMUs in IBM's xSeries x366 and x460
769 systems. Needed to run systems with more than 3GB of memory
770 properly with 32-bit PCI devices that do not support DAC
771 (Double Address Cycle). Calgary also supports bus level
772 isolation, where all DMAs pass through the IOMMU. This
773 prevents them from going anywhere except their intended
774 destination. This catches hard-to-find kernel bugs and
775 mis-behaving drivers and devices that do not use the DMA-API
776 properly to set up their DMA buffers. The IOMMU can be
777 turned off at boot time with the iommu=off parameter.
778 Normally the kernel will make the right choice by itself.
781 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
783 prompt "Should Calgary be enabled by default?"
784 depends on CALGARY_IOMMU
786 Should Calgary be enabled by default? if you choose 'y', Calgary
787 will be used (if it exists). If you choose 'n', Calgary will not be
788 used even if it exists. If you choose 'n' and would like to use
789 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
792 # need this always selected by IOMMU for the VIA workaround
796 Support for software bounce buffers used on x86-64 systems
797 which don't have a hardware IOMMU. Using this PCI devices
798 which can only access 32-bits of memory can be used on systems
799 with more than 3 GB of memory.
804 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
807 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
808 depends on X86_64 && SMP && DEBUG_KERNEL
809 select CPUMASK_OFFSTACK
811 Enable maximum number of CPUS and NUMA Nodes for this architecture.
815 int "Maximum number of CPUs" if SMP && !MAXSMP
816 range 2 8 if SMP && X86_32 && !X86_BIGSMP
817 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
818 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
820 default "8192" if MAXSMP
821 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
824 This allows you to specify the maximum number of CPUs which this
825 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
826 supported value is 4096, otherwise the maximum value is 512. The
827 minimum value which makes sense is 2.
829 This is purely to save memory - each supported CPU adds
830 approximately eight kilobytes to the kernel image.
833 bool "SMT (Hyperthreading) scheduler support"
836 SMT scheduler support improves the CPU scheduler's decision making
837 when dealing with Intel Pentium 4 chips with HyperThreading at a
838 cost of slightly increased overhead in some places. If unsure say
843 prompt "Multi-core scheduler support"
846 Multi-core scheduler support improves the CPU scheduler's decision
847 making when dealing with multi-core CPU chips at a cost of slightly
848 increased overhead in some places. If unsure say N here.
850 source "kernel/Kconfig.preempt"
853 bool "Local APIC support on uniprocessors"
854 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
856 A local APIC (Advanced Programmable Interrupt Controller) is an
857 integrated interrupt controller in the CPU. If you have a single-CPU
858 system which has a processor with a local APIC, you can say Y here to
859 enable and use it. If you say Y here even though your machine doesn't
860 have a local APIC, then the kernel will still run with no slowdown at
861 all. The local APIC supports CPU-generated self-interrupts (timer,
862 performance counters), and the NMI watchdog which detects hard
866 bool "IO-APIC support on uniprocessors"
867 depends on X86_UP_APIC
869 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
870 SMP-capable replacement for PC-style interrupt controllers. Most
871 SMP systems and many recent uniprocessor systems have one.
873 If you have a single-CPU system with an IO-APIC, you can say Y here
874 to use it. If you say Y here even though your machine doesn't have
875 an IO-APIC, then the kernel will still run with no slowdown at all.
877 config X86_LOCAL_APIC
879 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
883 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
885 config X86_VISWS_APIC
887 depends on X86_32 && X86_VISWS
889 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
890 bool "Reroute for broken boot IRQs"
891 depends on X86_IO_APIC
893 This option enables a workaround that fixes a source of
894 spurious interrupts. This is recommended when threaded
895 interrupt handling is used on systems where the generation of
896 superfluous "boot interrupts" cannot be disabled.
898 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
899 entry in the chipset's IO-APIC is masked (as, e.g. the RT
900 kernel does during interrupt handling). On chipsets where this
901 boot IRQ generation cannot be disabled, this workaround keeps
902 the original IRQ line masked so that only the equivalent "boot
903 IRQ" is delivered to the CPUs. The workaround also tells the
904 kernel to set up the IRQ handler on the boot IRQ line. In this
905 way only one interrupt is delivered to the kernel. Otherwise
906 the spurious second interrupt may cause the kernel to bring
907 down (vital) interrupt lines.
909 Only affects "broken" chipsets. Interrupt sharing may be
910 increased on these systems.
913 bool "Machine Check / overheating reporting"
916 Machine Check support allows the processor to notify the
917 kernel if it detects a problem (e.g. overheating, data corruption).
918 The action the kernel takes depends on the severity of the problem,
919 ranging from warning messages to halting the machine.
923 prompt "Intel MCE features"
924 depends on X86_MCE && X86_LOCAL_APIC
926 Additional support for intel specific MCE features such as
931 prompt "AMD MCE features"
932 depends on X86_MCE && X86_LOCAL_APIC
934 Additional support for AMD specific MCE features such as
935 the DRAM Error Threshold.
937 config X86_ANCIENT_MCE
938 bool "Support for old Pentium 5 / WinChip machine checks"
939 depends on X86_32 && X86_MCE
941 Include support for machine check handling on old Pentium 5 or WinChip
942 systems. These typically need to be enabled explicitely on the command
945 config X86_MCE_THRESHOLD
946 depends on X86_MCE_AMD || X86_MCE_INTEL
949 config X86_MCE_INJECT
951 tristate "Machine check injector support"
953 Provide support for injecting machine checks for testing purposes.
954 If you don't know what a machine check is and you don't do kernel
955 QA it is safe to say n.
957 config X86_THERMAL_VECTOR
959 depends on X86_MCE_INTEL
962 bool "Enable VM86 support" if EXPERT
966 This option is required by programs like DOSEMU to run 16-bit legacy
967 code on X86 processors. It also may be needed by software like
968 XFree86 to initialize some video cards via BIOS. Disabling this
969 option saves about 6k.
972 tristate "Toshiba Laptop support"
975 This adds a driver to safely access the System Management Mode of
976 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
977 not work on models with a Phoenix BIOS. The System Management Mode
978 is used to set the BIOS and power saving options on Toshiba portables.
980 For information on utilities to make use of this driver see the
981 Toshiba Linux utilities web site at:
982 <http://www.buzzard.org.uk/toshiba/>.
984 Say Y if you intend to run this kernel on a Toshiba portable.
988 tristate "Dell laptop support"
991 This adds a driver to safely access the System Management Mode
992 of the CPU on the Dell Inspiron 8000. The System Management Mode
993 is used to read cpu temperature and cooling fan status and to
994 control the fans on the I8K portables.
996 This driver has been tested only on the Inspiron 8000 but it may
997 also work with other Dell laptops. You can force loading on other
998 models by passing the parameter `force=1' to the module. Use at
1001 For information on utilities to make use of this driver see the
1002 I8K Linux utilities web site at:
1003 <http://people.debian.org/~dz/i8k/>
1005 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1008 config X86_REBOOTFIXUPS
1009 bool "Enable X86 board specific fixups for reboot"
1012 This enables chipset and/or board specific fixups to be done
1013 in order to get reboot to work correctly. This is only needed on
1014 some combinations of hardware and BIOS. The symptom, for which
1015 this config is intended, is when reboot ends with a stalled/hung
1018 Currently, the only fixup is for the Geode machines using
1019 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1021 Say Y if you want to enable the fixup. Currently, it's safe to
1022 enable this option even if you don't need it.
1026 tristate "CPU microcode loading support"
1027 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1031 If you say Y here, you will be able to update the microcode on
1032 certain Intel and AMD processors. The Intel support is for the
1033 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1034 Xeon etc. The AMD support is for families 0x10 and later. You will
1035 obviously need the actual microcode binary data itself which is not
1036 shipped with the Linux kernel.
1038 This option selects the general module only, you need to select
1039 at least one vendor specific module as well.
1041 To compile this driver as a module, choose M here: the module
1042 will be called microcode.
1044 config MICROCODE_INTEL
1045 bool "Intel microcode loading support"
1046 depends on MICROCODE
1050 This options enables microcode patch loading support for Intel
1053 For the current Intel microcode data package go to
1054 <https://downloadcenter.intel.com> and search for
1055 'Linux Processor Microcode Data File'.
1057 config MICROCODE_AMD
1058 bool "AMD microcode loading support"
1059 depends on MICROCODE
1062 If you select this option, microcode patch loading support for AMD
1063 processors will be enabled.
1065 config MICROCODE_OLD_INTERFACE
1067 depends on MICROCODE
1069 config MICROCODE_INTEL_EARLY
1072 config MICROCODE_AMD_EARLY
1075 config MICROCODE_EARLY
1076 bool "Early load microcode"
1077 depends on MICROCODE=y && BLK_DEV_INITRD
1078 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1079 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1082 This option provides functionality to read additional microcode data
1083 at the beginning of initrd image. The data tells kernel to load
1084 microcode to CPU's as early as possible. No functional change if no
1085 microcode data is glued to the initrd, therefore it's safe to say Y.
1088 tristate "/dev/cpu/*/msr - Model-specific register support"
1090 This device gives privileged processes access to the x86
1091 Model-Specific Registers (MSRs). It is a character device with
1092 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1093 MSR accesses are directed to a specific CPU on multi-processor
1097 tristate "/dev/cpu/*/cpuid - CPU information support"
1099 This device gives processes access to the x86 CPUID instruction to
1100 be executed on a specific processor. It is a character device
1101 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1105 prompt "High Memory Support"
1106 default HIGHMEM64G if X86_NUMAQ
1112 depends on !X86_NUMAQ
1114 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1115 However, the address space of 32-bit x86 processors is only 4
1116 Gigabytes large. That means that, if you have a large amount of
1117 physical memory, not all of it can be "permanently mapped" by the
1118 kernel. The physical memory that's not permanently mapped is called
1121 If you are compiling a kernel which will never run on a machine with
1122 more than 1 Gigabyte total physical RAM, answer "off" here (default
1123 choice and suitable for most users). This will result in a "3GB/1GB"
1124 split: 3GB are mapped so that each process sees a 3GB virtual memory
1125 space and the remaining part of the 4GB virtual memory space is used
1126 by the kernel to permanently map as much physical memory as
1129 If the machine has between 1 and 4 Gigabytes physical RAM, then
1132 If more than 4 Gigabytes is used then answer "64GB" here. This
1133 selection turns Intel PAE (Physical Address Extension) mode on.
1134 PAE implements 3-level paging on IA32 processors. PAE is fully
1135 supported by Linux, PAE mode is implemented on all recent Intel
1136 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1137 then the kernel will not boot on CPUs that don't support PAE!
1139 The actual amount of total physical memory will either be
1140 auto detected or can be forced by using a kernel command line option
1141 such as "mem=256M". (Try "man bootparam" or see the documentation of
1142 your boot loader (lilo or loadlin) about how to pass options to the
1143 kernel at boot time.)
1145 If unsure, say "off".
1149 depends on !X86_NUMAQ
1151 Select this if you have a 32-bit processor and between 1 and 4
1152 gigabytes of physical RAM.
1159 Select this if you have a 32-bit processor and more than 4
1160 gigabytes of physical RAM.
1165 prompt "Memory split" if EXPERT
1169 Select the desired split between kernel and user memory.
1171 If the address range available to the kernel is less than the
1172 physical memory installed, the remaining memory will be available
1173 as "high memory". Accessing high memory is a little more costly
1174 than low memory, as it needs to be mapped into the kernel first.
1175 Note that increasing the kernel address space limits the range
1176 available to user programs, making the address space there
1177 tighter. Selecting anything other than the default 3G/1G split
1178 will also likely make your kernel incompatible with binary-only
1181 If you are not absolutely sure what you are doing, leave this
1185 bool "3G/1G user/kernel split"
1186 config VMSPLIT_3G_OPT
1188 bool "3G/1G user/kernel split (for full 1G low memory)"
1190 bool "2G/2G user/kernel split"
1191 config VMSPLIT_2G_OPT
1193 bool "2G/2G user/kernel split (for full 2G low memory)"
1195 bool "1G/3G user/kernel split"
1200 default 0xB0000000 if VMSPLIT_3G_OPT
1201 default 0x80000000 if VMSPLIT_2G
1202 default 0x78000000 if VMSPLIT_2G_OPT
1203 default 0x40000000 if VMSPLIT_1G
1209 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1212 bool "PAE (Physical Address Extension) Support"
1213 depends on X86_32 && !HIGHMEM4G
1215 PAE is required for NX support, and furthermore enables
1216 larger swapspace support for non-overcommit purposes. It
1217 has the cost of more pagetable lookup overhead, and also
1218 consumes more pagetable space per process.
1220 config ARCH_PHYS_ADDR_T_64BIT
1222 depends on X86_64 || X86_PAE
1224 config ARCH_DMA_ADDR_T_64BIT
1226 depends on X86_64 || HIGHMEM64G
1228 config DIRECT_GBPAGES
1229 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1233 Allow the kernel linear mapping to use 1GB pages on CPUs that
1234 support it. This can improve the kernel's performance a tiny bit by
1235 reducing TLB pressure. If in doubt, say "Y".
1237 # Common NUMA Features
1239 bool "Numa Memory Allocation and Scheduler Support"
1241 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1242 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1244 Enable NUMA (Non Uniform Memory Access) support.
1246 The kernel will try to allocate memory used by a CPU on the
1247 local memory controller of the CPU and add some more
1248 NUMA awareness to the kernel.
1250 For 64-bit this is recommended if the system is Intel Core i7
1251 (or later), AMD Opteron, or EM64T NUMA.
1253 For 32-bit this is only needed on (rare) 32-bit-only platforms
1254 that support NUMA topologies, such as NUMAQ / Summit, or if you
1255 boot a 32-bit kernel on a 64-bit NUMA platform.
1257 Otherwise, you should say N.
1259 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1260 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1264 prompt "Old style AMD Opteron NUMA detection"
1265 depends on X86_64 && NUMA && PCI
1267 Enable AMD NUMA node topology detection. You should say Y here if
1268 you have a multi processor AMD system. This uses an old method to
1269 read the NUMA configuration directly from the builtin Northbridge
1270 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1271 which also takes priority if both are compiled in.
1273 config X86_64_ACPI_NUMA
1275 prompt "ACPI NUMA detection"
1276 depends on X86_64 && NUMA && ACPI && PCI
1279 Enable ACPI SRAT based node topology detection.
1281 # Some NUMA nodes have memory ranges that span
1282 # other nodes. Even though a pfn is valid and
1283 # between a node's start and end pfns, it may not
1284 # reside on that node. See memmap_init_zone()
1286 config NODES_SPAN_OTHER_NODES
1288 depends on X86_64_ACPI_NUMA
1291 bool "NUMA emulation"
1294 Enable NUMA emulation. A flat machine will be split
1295 into virtual nodes when booted with "numa=fake=N", where N is the
1296 number of nodes. This is only useful for debugging.
1299 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1301 default "10" if MAXSMP
1302 default "6" if X86_64
1303 default "4" if X86_NUMAQ
1305 depends on NEED_MULTIPLE_NODES
1307 Specify the maximum number of NUMA Nodes available on the target
1308 system. Increases memory reserved to accommodate various tables.
1310 config ARCH_HAVE_MEMORY_PRESENT
1312 depends on X86_32 && DISCONTIGMEM
1314 config NEED_NODE_MEMMAP_SIZE
1316 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1318 config ARCH_FLATMEM_ENABLE
1320 depends on X86_32 && !NUMA
1322 config ARCH_DISCONTIGMEM_ENABLE
1324 depends on NUMA && X86_32
1326 config ARCH_DISCONTIGMEM_DEFAULT
1328 depends on NUMA && X86_32
1330 config ARCH_SPARSEMEM_ENABLE
1332 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1333 select SPARSEMEM_STATIC if X86_32
1334 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1336 config ARCH_SPARSEMEM_DEFAULT
1340 config ARCH_SELECT_MEMORY_MODEL
1342 depends on ARCH_SPARSEMEM_ENABLE
1344 config ARCH_MEMORY_PROBE
1345 bool "Enable sysfs memory/probe interface"
1346 depends on X86_64 && MEMORY_HOTPLUG
1348 This option enables a sysfs memory/probe interface for testing.
1349 See Documentation/memory-hotplug.txt for more information.
1350 If you are unsure how to answer this question, answer N.
1352 config ARCH_PROC_KCORE_TEXT
1354 depends on X86_64 && PROC_KCORE
1356 config ILLEGAL_POINTER_VALUE
1359 default 0xdead000000000000 if X86_64
1364 bool "Allocate 3rd-level pagetables from highmem"
1367 The VM uses one page table entry for each page of physical memory.
1368 For systems with a lot of RAM, this can be wasteful of precious
1369 low memory. Setting this option will put user-space page table
1370 entries in high memory.
1372 config X86_CHECK_BIOS_CORRUPTION
1373 bool "Check for low memory corruption"
1375 Periodically check for memory corruption in low memory, which
1376 is suspected to be caused by BIOS. Even when enabled in the
1377 configuration, it is disabled at runtime. Enable it by
1378 setting "memory_corruption_check=1" on the kernel command
1379 line. By default it scans the low 64k of memory every 60
1380 seconds; see the memory_corruption_check_size and
1381 memory_corruption_check_period parameters in
1382 Documentation/kernel-parameters.txt to adjust this.
1384 When enabled with the default parameters, this option has
1385 almost no overhead, as it reserves a relatively small amount
1386 of memory and scans it infrequently. It both detects corruption
1387 and prevents it from affecting the running system.
1389 It is, however, intended as a diagnostic tool; if repeatable
1390 BIOS-originated corruption always affects the same memory,
1391 you can use memmap= to prevent the kernel from using that
1394 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1395 bool "Set the default setting of memory_corruption_check"
1396 depends on X86_CHECK_BIOS_CORRUPTION
1399 Set whether the default state of memory_corruption_check is
1402 config X86_RESERVE_LOW
1403 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1407 Specify the amount of low memory to reserve for the BIOS.
1409 The first page contains BIOS data structures that the kernel
1410 must not use, so that page must always be reserved.
1412 By default we reserve the first 64K of physical RAM, as a
1413 number of BIOSes are known to corrupt that memory range
1414 during events such as suspend/resume or monitor cable
1415 insertion, so it must not be used by the kernel.
1417 You can set this to 4 if you are absolutely sure that you
1418 trust the BIOS to get all its memory reservations and usages
1419 right. If you know your BIOS have problems beyond the
1420 default 64K area, you can set this to 640 to avoid using the
1421 entire low memory range.
1423 If you have doubts about the BIOS (e.g. suspend/resume does
1424 not work or there's kernel crashes after certain hardware
1425 hotplug events) then you might want to enable
1426 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1427 typical corruption patterns.
1429 Leave this to the default value of 64 if you are unsure.
1431 config MATH_EMULATION
1433 prompt "Math emulation" if X86_32
1435 Linux can emulate a math coprocessor (used for floating point
1436 operations) if you don't have one. 486DX and Pentium processors have
1437 a math coprocessor built in, 486SX and 386 do not, unless you added
1438 a 487DX or 387, respectively. (The messages during boot time can
1439 give you some hints here ["man dmesg"].) Everyone needs either a
1440 coprocessor or this emulation.
1442 If you don't have a math coprocessor, you need to say Y here; if you
1443 say Y here even though you have a coprocessor, the coprocessor will
1444 be used nevertheless. (This behavior can be changed with the kernel
1445 command line option "no387", which comes handy if your coprocessor
1446 is broken. Try "man bootparam" or see the documentation of your boot
1447 loader (lilo or loadlin) about how to pass options to the kernel at
1448 boot time.) This means that it is a good idea to say Y here if you
1449 intend to use this kernel on different machines.
1451 More information about the internals of the Linux math coprocessor
1452 emulation can be found in <file:arch/x86/math-emu/README>.
1454 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1455 kernel, it won't hurt.
1459 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1461 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1462 the Memory Type Range Registers (MTRRs) may be used to control
1463 processor access to memory ranges. This is most useful if you have
1464 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1465 allows bus write transfers to be combined into a larger transfer
1466 before bursting over the PCI/AGP bus. This can increase performance
1467 of image write operations 2.5 times or more. Saying Y here creates a
1468 /proc/mtrr file which may be used to manipulate your processor's
1469 MTRRs. Typically the X server should use this.
1471 This code has a reasonably generic interface so that similar
1472 control registers on other processors can be easily supported
1475 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1476 Registers (ARRs) which provide a similar functionality to MTRRs. For
1477 these, the ARRs are used to emulate the MTRRs.
1478 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1479 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1480 write-combining. All of these processors are supported by this code
1481 and it makes sense to say Y here if you have one of them.
1483 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1484 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1485 can lead to all sorts of problems, so it's good to say Y here.
1487 You can safely say Y even if your machine doesn't have MTRRs, you'll
1488 just add about 9 KB to your kernel.
1490 See <file:Documentation/x86/mtrr.txt> for more information.
1492 config MTRR_SANITIZER
1494 prompt "MTRR cleanup support"
1497 Convert MTRR layout from continuous to discrete, so X drivers can
1498 add writeback entries.
1500 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1501 The largest mtrr entry size for a continuous block can be set with
1506 config MTRR_SANITIZER_ENABLE_DEFAULT
1507 int "MTRR cleanup enable value (0-1)"
1510 depends on MTRR_SANITIZER
1512 Enable mtrr cleanup default value
1514 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1515 int "MTRR cleanup spare reg num (0-7)"
1518 depends on MTRR_SANITIZER
1520 mtrr cleanup spare entries default, it can be changed via
1521 mtrr_spare_reg_nr=N on the kernel command line.
1525 prompt "x86 PAT support" if EXPERT
1528 Use PAT attributes to setup page level cache control.
1530 PATs are the modern equivalents of MTRRs and are much more
1531 flexible than MTRRs.
1533 Say N here if you see bootup problems (boot crash, boot hang,
1534 spontaneous reboots) or a non-working video driver.
1538 config ARCH_USES_PG_UNCACHED
1544 prompt "x86 architectural random number generator" if EXPERT
1546 Enable the x86 architectural RDRAND instruction
1547 (Intel Bull Mountain technology) to generate random numbers.
1548 If supported, this is a high bandwidth, cryptographically
1549 secure hardware random number generator.
1553 prompt "Supervisor Mode Access Prevention" if EXPERT
1555 Supervisor Mode Access Prevention (SMAP) is a security
1556 feature in newer Intel processors. There is a small
1557 performance cost if this enabled and turned on; there is
1558 also a small increase in the kernel size if this is enabled.
1563 bool "EFI runtime service support"
1567 This enables the kernel to use EFI runtime services that are
1568 available (such as the EFI variable services).
1570 This option is only useful on systems that have EFI firmware.
1571 In addition, you should use the latest ELILO loader available
1572 at <http://elilo.sourceforge.net> in order to take advantage
1573 of EFI runtime services. However, even with this option, the
1574 resultant kernel should continue to boot on existing non-EFI
1578 bool "EFI stub support"
1581 This kernel feature allows a bzImage to be loaded directly
1582 by EFI firmware without the use of a bootloader.
1584 See Documentation/efi-stub.txt for more information.
1588 prompt "Enable seccomp to safely compute untrusted bytecode"
1590 This kernel feature is useful for number crunching applications
1591 that may need to compute untrusted bytecode during their
1592 execution. By using pipes or other transports made available to
1593 the process as file descriptors supporting the read/write
1594 syscalls, it's possible to isolate those applications in
1595 their own address space using seccomp. Once seccomp is
1596 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1597 and the task is only allowed to execute a few safe syscalls
1598 defined by each seccomp mode.
1600 If unsure, say Y. Only embedded should say N here.
1602 source kernel/Kconfig.hz
1605 bool "kexec system call"
1607 kexec is a system call that implements the ability to shutdown your
1608 current kernel, and to start another kernel. It is like a reboot
1609 but it is independent of the system firmware. And like a reboot
1610 you can start any kernel with it, not just Linux.
1612 The name comes from the similarity to the exec system call.
1614 It is an ongoing process to be certain the hardware in a machine
1615 is properly shutdown, so do not be surprised if this code does not
1616 initially work for you. As of this writing the exact hardware
1617 interface is strongly in flux, so no good recommendation can be
1621 bool "kernel crash dumps"
1622 depends on X86_64 || (X86_32 && HIGHMEM)
1624 Generate crash dump after being started by kexec.
1625 This should be normally only set in special crash dump kernels
1626 which are loaded in the main kernel with kexec-tools into
1627 a specially reserved region and then later executed after
1628 a crash by kdump/kexec. The crash dump kernel must be compiled
1629 to a memory address not used by the main kernel or BIOS using
1630 PHYSICAL_START, or it must be built as a relocatable image
1631 (CONFIG_RELOCATABLE=y).
1632 For more details see Documentation/kdump/kdump.txt
1636 depends on KEXEC && HIBERNATION
1638 Jump between original kernel and kexeced kernel and invoke
1639 code in physical address mode via KEXEC
1641 config PHYSICAL_START
1642 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1645 This gives the physical address where the kernel is loaded.
1647 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1648 bzImage will decompress itself to above physical address and
1649 run from there. Otherwise, bzImage will run from the address where
1650 it has been loaded by the boot loader and will ignore above physical
1653 In normal kdump cases one does not have to set/change this option
1654 as now bzImage can be compiled as a completely relocatable image
1655 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1656 address. This option is mainly useful for the folks who don't want
1657 to use a bzImage for capturing the crash dump and want to use a
1658 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1659 to be specifically compiled to run from a specific memory area
1660 (normally a reserved region) and this option comes handy.
1662 So if you are using bzImage for capturing the crash dump,
1663 leave the value here unchanged to 0x1000000 and set
1664 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1665 for capturing the crash dump change this value to start of
1666 the reserved region. In other words, it can be set based on
1667 the "X" value as specified in the "crashkernel=YM@XM"
1668 command line boot parameter passed to the panic-ed
1669 kernel. Please take a look at Documentation/kdump/kdump.txt
1670 for more details about crash dumps.
1672 Usage of bzImage for capturing the crash dump is recommended as
1673 one does not have to build two kernels. Same kernel can be used
1674 as production kernel and capture kernel. Above option should have
1675 gone away after relocatable bzImage support is introduced. But it
1676 is present because there are users out there who continue to use
1677 vmlinux for dump capture. This option should go away down the
1680 Don't change this unless you know what you are doing.
1683 bool "Build a relocatable kernel"
1686 This builds a kernel image that retains relocation information
1687 so it can be loaded someplace besides the default 1MB.
1688 The relocations tend to make the kernel binary about 10% larger,
1689 but are discarded at runtime.
1691 One use is for the kexec on panic case where the recovery kernel
1692 must live at a different physical address than the primary
1695 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1696 it has been loaded at and the compile time physical address
1697 (CONFIG_PHYSICAL_START) is used as the minimum location.
1699 config RANDOMIZE_BASE
1700 bool "Randomize the address of the kernel image"
1701 depends on RELOCATABLE
1702 depends on !HIBERNATION
1705 Randomizes the physical and virtual address at which the
1706 kernel image is decompressed, as a security feature that
1707 deters exploit attempts relying on knowledge of the location
1708 of kernel internals.
1710 Entropy is generated using the RDRAND instruction if it is
1711 supported. If RDTSC is supported, it is used as well. If
1712 neither RDRAND nor RDTSC are supported, then randomness is
1713 read from the i8254 timer.
1715 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1716 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1717 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1718 minimum of 2MiB, only 10 bits of entropy is theoretically
1719 possible. At best, due to page table layouts, 64-bit can use
1720 9 bits of entropy and 32-bit uses 8 bits.
1724 config RANDOMIZE_BASE_MAX_OFFSET
1725 hex "Maximum kASLR offset allowed" if EXPERT
1726 depends on RANDOMIZE_BASE
1727 range 0x0 0x20000000 if X86_32
1728 default "0x20000000" if X86_32
1729 range 0x0 0x40000000 if X86_64
1730 default "0x40000000" if X86_64
1732 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1733 memory is used to determine the maximal offset in bytes that will
1734 be applied to the kernel when kernel Address Space Layout
1735 Randomization (kASLR) is active. This must be a multiple of
1738 On 32-bit this is limited to 512MiB by page table layouts. The
1741 On 64-bit this is limited by how the kernel fixmap page table is
1742 positioned, so this cannot be larger than 1GiB currently. Without
1743 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1744 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1745 modules area will shrink to compensate, up to the current maximum
1746 1GiB to 1GiB split. The default is 1GiB.
1748 If unsure, leave at the default value.
1750 # Relocation on x86 needs some additional build support
1751 config X86_NEED_RELOCS
1753 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1755 config PHYSICAL_ALIGN
1756 hex "Alignment value to which kernel should be aligned"
1758 range 0x2000 0x1000000 if X86_32
1759 range 0x200000 0x1000000 if X86_64
1761 This value puts the alignment restrictions on physical address
1762 where kernel is loaded and run from. Kernel is compiled for an
1763 address which meets above alignment restriction.
1765 If bootloader loads the kernel at a non-aligned address and
1766 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1767 address aligned to above value and run from there.
1769 If bootloader loads the kernel at a non-aligned address and
1770 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1771 load address and decompress itself to the address it has been
1772 compiled for and run from there. The address for which kernel is
1773 compiled already meets above alignment restrictions. Hence the
1774 end result is that kernel runs from a physical address meeting
1775 above alignment restrictions.
1777 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1778 this value must be a multiple of 0x200000.
1780 Don't change this unless you know what you are doing.
1783 bool "Support for hot-pluggable CPUs"
1786 Say Y here to allow turning CPUs off and on. CPUs can be
1787 controlled through /sys/devices/system/cpu.
1788 ( Note: power management support will enable this option
1789 automatically on SMP systems. )
1790 Say N if you want to disable CPU hotplug.
1792 config BOOTPARAM_HOTPLUG_CPU0
1793 bool "Set default setting of cpu0_hotpluggable"
1795 depends on HOTPLUG_CPU
1797 Set whether default state of cpu0_hotpluggable is on or off.
1799 Say Y here to enable CPU0 hotplug by default. If this switch
1800 is turned on, there is no need to give cpu0_hotplug kernel
1801 parameter and the CPU0 hotplug feature is enabled by default.
1803 Please note: there are two known CPU0 dependencies if you want
1804 to enable the CPU0 hotplug feature either by this switch or by
1805 cpu0_hotplug kernel parameter.
1807 First, resume from hibernate or suspend always starts from CPU0.
1808 So hibernate and suspend are prevented if CPU0 is offline.
1810 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1811 offline if any interrupt can not migrate out of CPU0. There may
1812 be other CPU0 dependencies.
1814 Please make sure the dependencies are under your control before
1815 you enable this feature.
1817 Say N if you don't want to enable CPU0 hotplug feature by default.
1818 You still can enable the CPU0 hotplug feature at boot by kernel
1819 parameter cpu0_hotplug.
1821 config DEBUG_HOTPLUG_CPU0
1823 prompt "Debug CPU0 hotplug"
1824 depends on HOTPLUG_CPU
1826 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1827 soon as possible and boots up userspace with CPU0 offlined. User
1828 can online CPU0 back after boot time.
1830 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1831 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1832 compilation or giving cpu0_hotplug kernel parameter at boot.
1838 prompt "Compat VDSO support"
1839 depends on X86_32 || IA32_EMULATION
1841 Map the 32-bit VDSO to the predictable old-style address too.
1843 Say N here if you are running a sufficiently recent glibc
1844 version (2.3.3 or later), to remove the high-mapped
1845 VDSO mapping and to exclusively use the randomized VDSO.
1850 bool "Built-in kernel command line"
1852 Allow for specifying boot arguments to the kernel at
1853 build time. On some systems (e.g. embedded ones), it is
1854 necessary or convenient to provide some or all of the
1855 kernel boot arguments with the kernel itself (that is,
1856 to not rely on the boot loader to provide them.)
1858 To compile command line arguments into the kernel,
1859 set this option to 'Y', then fill in the
1860 the boot arguments in CONFIG_CMDLINE.
1862 Systems with fully functional boot loaders (i.e. non-embedded)
1863 should leave this option set to 'N'.
1866 string "Built-in kernel command string"
1867 depends on CMDLINE_BOOL
1870 Enter arguments here that should be compiled into the kernel
1871 image and used at boot time. If the boot loader provides a
1872 command line at boot time, it is appended to this string to
1873 form the full kernel command line, when the system boots.
1875 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1876 change this behavior.
1878 In most cases, the command line (whether built-in or provided
1879 by the boot loader) should specify the device for the root
1882 config CMDLINE_OVERRIDE
1883 bool "Built-in command line overrides boot loader arguments"
1884 depends on CMDLINE_BOOL
1886 Set this option to 'Y' to have the kernel ignore the boot loader
1887 command line, and use ONLY the built-in command line.
1889 This is used to work around broken boot loaders. This should
1890 be set to 'N' under normal conditions.
1894 config ARCH_ENABLE_MEMORY_HOTPLUG
1896 depends on X86_64 || (X86_32 && HIGHMEM)
1898 config ARCH_ENABLE_MEMORY_HOTREMOVE
1900 depends on MEMORY_HOTPLUG
1902 config USE_PERCPU_NUMA_NODE_ID
1906 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1908 depends on X86_64 || X86_PAE
1910 menu "Power management and ACPI options"
1912 config ARCH_HIBERNATION_HEADER
1914 depends on X86_64 && HIBERNATION
1916 source "kernel/power/Kconfig"
1918 source "drivers/acpi/Kconfig"
1920 source "drivers/sfi/Kconfig"
1927 tristate "APM (Advanced Power Management) BIOS support"
1928 depends on X86_32 && PM_SLEEP
1930 APM is a BIOS specification for saving power using several different
1931 techniques. This is mostly useful for battery powered laptops with
1932 APM compliant BIOSes. If you say Y here, the system time will be
1933 reset after a RESUME operation, the /proc/apm device will provide
1934 battery status information, and user-space programs will receive
1935 notification of APM "events" (e.g. battery status change).
1937 If you select "Y" here, you can disable actual use of the APM
1938 BIOS by passing the "apm=off" option to the kernel at boot time.
1940 Note that the APM support is almost completely disabled for
1941 machines with more than one CPU.
1943 In order to use APM, you will need supporting software. For location
1944 and more information, read <file:Documentation/power/apm-acpi.txt>
1945 and the Battery Powered Linux mini-HOWTO, available from
1946 <http://www.tldp.org/docs.html#howto>.
1948 This driver does not spin down disk drives (see the hdparm(8)
1949 manpage ("man 8 hdparm") for that), and it doesn't turn off
1950 VESA-compliant "green" monitors.
1952 This driver does not support the TI 4000M TravelMate and the ACER
1953 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1954 desktop machines also don't have compliant BIOSes, and this driver
1955 may cause those machines to panic during the boot phase.
1957 Generally, if you don't have a battery in your machine, there isn't
1958 much point in using this driver and you should say N. If you get
1959 random kernel OOPSes or reboots that don't seem to be related to
1960 anything, try disabling/enabling this option (or disabling/enabling
1963 Some other things you should try when experiencing seemingly random,
1966 1) make sure that you have enough swap space and that it is
1968 2) pass the "no-hlt" option to the kernel
1969 3) switch on floating point emulation in the kernel and pass
1970 the "no387" option to the kernel
1971 4) pass the "floppy=nodma" option to the kernel
1972 5) pass the "mem=4M" option to the kernel (thereby disabling
1973 all but the first 4 MB of RAM)
1974 6) make sure that the CPU is not over clocked.
1975 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1976 8) disable the cache from your BIOS settings
1977 9) install a fan for the video card or exchange video RAM
1978 10) install a better fan for the CPU
1979 11) exchange RAM chips
1980 12) exchange the motherboard.
1982 To compile this driver as a module, choose M here: the
1983 module will be called apm.
1987 config APM_IGNORE_USER_SUSPEND
1988 bool "Ignore USER SUSPEND"
1990 This option will ignore USER SUSPEND requests. On machines with a
1991 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1992 series notebooks, it is necessary to say Y because of a BIOS bug.
1994 config APM_DO_ENABLE
1995 bool "Enable PM at boot time"
1997 Enable APM features at boot time. From page 36 of the APM BIOS
1998 specification: "When disabled, the APM BIOS does not automatically
1999 power manage devices, enter the Standby State, enter the Suspend
2000 State, or take power saving steps in response to CPU Idle calls."
2001 This driver will make CPU Idle calls when Linux is idle (unless this
2002 feature is turned off -- see "Do CPU IDLE calls", below). This
2003 should always save battery power, but more complicated APM features
2004 will be dependent on your BIOS implementation. You may need to turn
2005 this option off if your computer hangs at boot time when using APM
2006 support, or if it beeps continuously instead of suspending. Turn
2007 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2008 T400CDT. This is off by default since most machines do fine without
2013 bool "Make CPU Idle calls when idle"
2015 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2016 On some machines, this can activate improved power savings, such as
2017 a slowed CPU clock rate, when the machine is idle. These idle calls
2018 are made after the idle loop has run for some length of time (e.g.,
2019 333 mS). On some machines, this will cause a hang at boot time or
2020 whenever the CPU becomes idle. (On machines with more than one CPU,
2021 this option does nothing.)
2023 config APM_DISPLAY_BLANK
2024 bool "Enable console blanking using APM"
2026 Enable console blanking using the APM. Some laptops can use this to
2027 turn off the LCD backlight when the screen blanker of the Linux
2028 virtual console blanks the screen. Note that this is only used by
2029 the virtual console screen blanker, and won't turn off the backlight
2030 when using the X Window system. This also doesn't have anything to
2031 do with your VESA-compliant power-saving monitor. Further, this
2032 option doesn't work for all laptops -- it might not turn off your
2033 backlight at all, or it might print a lot of errors to the console,
2034 especially if you are using gpm.
2036 config APM_ALLOW_INTS
2037 bool "Allow interrupts during APM BIOS calls"
2039 Normally we disable external interrupts while we are making calls to
2040 the APM BIOS as a measure to lessen the effects of a badly behaving
2041 BIOS implementation. The BIOS should reenable interrupts if it
2042 needs to. Unfortunately, some BIOSes do not -- especially those in
2043 many of the newer IBM Thinkpads. If you experience hangs when you
2044 suspend, try setting this to Y. Otherwise, say N.
2048 source "drivers/cpufreq/Kconfig"
2050 source "drivers/cpuidle/Kconfig"
2052 source "drivers/idle/Kconfig"
2057 menu "Bus options (PCI etc.)"
2063 Find out whether you have a PCI motherboard. PCI is the name of a
2064 bus system, i.e. the way the CPU talks to the other stuff inside
2065 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2066 VESA. If you have PCI, say Y, otherwise N.
2069 prompt "PCI access mode"
2070 depends on X86_32 && PCI
2073 On PCI systems, the BIOS can be used to detect the PCI devices and
2074 determine their configuration. However, some old PCI motherboards
2075 have BIOS bugs and may crash if this is done. Also, some embedded
2076 PCI-based systems don't have any BIOS at all. Linux can also try to
2077 detect the PCI hardware directly without using the BIOS.
2079 With this option, you can specify how Linux should detect the
2080 PCI devices. If you choose "BIOS", the BIOS will be used,
2081 if you choose "Direct", the BIOS won't be used, and if you
2082 choose "MMConfig", then PCI Express MMCONFIG will be used.
2083 If you choose "Any", the kernel will try MMCONFIG, then the
2084 direct access method and falls back to the BIOS if that doesn't
2085 work. If unsure, go with the default, which is "Any".
2090 config PCI_GOMMCONFIG
2107 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2109 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2112 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2116 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2120 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2124 depends on PCI && XEN
2132 bool "Support mmconfig PCI config space access"
2133 depends on X86_64 && PCI && ACPI
2135 config PCI_CNB20LE_QUIRK
2136 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2139 Read the PCI windows out of the CNB20LE host bridge. This allows
2140 PCI hotplug to work on systems with the CNB20LE chipset which do
2143 There's no public spec for this chipset, and this functionality
2144 is known to be incomplete.
2146 You should say N unless you know you need this.
2148 source "drivers/pci/pcie/Kconfig"
2150 source "drivers/pci/Kconfig"
2152 # x86_64 have no ISA slots, but can have ISA-style DMA.
2154 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2157 Enables ISA-style DMA support for devices requiring such controllers.
2165 Find out whether you have ISA slots on your motherboard. ISA is the
2166 name of a bus system, i.e. the way the CPU talks to the other stuff
2167 inside your box. Other bus systems are PCI, EISA, MicroChannel
2168 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2169 newer boards don't support it. If you have ISA, say Y, otherwise N.
2175 The Extended Industry Standard Architecture (EISA) bus was
2176 developed as an open alternative to the IBM MicroChannel bus.
2178 The EISA bus provided some of the features of the IBM MicroChannel
2179 bus while maintaining backward compatibility with cards made for
2180 the older ISA bus. The EISA bus saw limited use between 1988 and
2181 1995 when it was made obsolete by the PCI bus.
2183 Say Y here if you are building a kernel for an EISA-based machine.
2187 source "drivers/eisa/Kconfig"
2190 tristate "NatSemi SCx200 support"
2192 This provides basic support for National Semiconductor's
2193 (now AMD's) Geode processors. The driver probes for the
2194 PCI-IDs of several on-chip devices, so its a good dependency
2195 for other scx200_* drivers.
2197 If compiled as a module, the driver is named scx200.
2199 config SCx200HR_TIMER
2200 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2204 This driver provides a clocksource built upon the on-chip
2205 27MHz high-resolution timer. Its also a workaround for
2206 NSC Geode SC-1100's buggy TSC, which loses time when the
2207 processor goes idle (as is done by the scheduler). The
2208 other workaround is idle=poll boot option.
2211 bool "One Laptop Per Child support"
2218 Add support for detecting the unique features of the OLPC
2222 bool "OLPC XO-1 Power Management"
2223 depends on OLPC && MFD_CS5535 && PM_SLEEP
2226 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2229 bool "OLPC XO-1 Real Time Clock"
2230 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2232 Add support for the XO-1 real time clock, which can be used as a
2233 programmable wakeup source.
2236 bool "OLPC XO-1 SCI extras"
2237 depends on OLPC && OLPC_XO1_PM
2243 Add support for SCI-based features of the OLPC XO-1 laptop:
2244 - EC-driven system wakeups
2248 - AC adapter status updates
2249 - Battery status updates
2251 config OLPC_XO15_SCI
2252 bool "OLPC XO-1.5 SCI extras"
2253 depends on OLPC && ACPI
2256 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2257 - EC-driven system wakeups
2258 - AC adapter status updates
2259 - Battery status updates
2262 bool "PCEngines ALIX System Support (LED setup)"
2265 This option enables system support for the PCEngines ALIX.
2266 At present this just sets up LEDs for GPIO control on
2267 ALIX2/3/6 boards. However, other system specific setup should
2270 Note: You must still enable the drivers for GPIO and LED support
2271 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2273 Note: You have to set alix.force=1 for boards with Award BIOS.
2276 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2279 This option enables system support for the Soekris Engineering net5501.
2282 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2286 This option enables system support for the Traverse Technologies GEOS.
2289 bool "Technologic Systems TS-5500 platform support"
2291 select CHECK_SIGNATURE
2295 This option enables system support for the Technologic Systems TS-5500.
2301 depends on CPU_SUP_AMD && PCI
2303 source "drivers/pcmcia/Kconfig"
2305 source "drivers/pci/hotplug/Kconfig"
2308 tristate "RapidIO support"
2312 If enabled this option will include drivers and the core
2313 infrastructure code to support RapidIO interconnect devices.
2315 source "drivers/rapidio/Kconfig"
2318 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2320 Firmwares often provide initial graphics framebuffers so the BIOS,
2321 bootloader or kernel can show basic video-output during boot for
2322 user-guidance and debugging. Historically, x86 used the VESA BIOS
2323 Extensions and EFI-framebuffers for this, which are mostly limited
2325 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2326 framebuffers so the new generic system-framebuffer drivers can be
2327 used on x86. If the framebuffer is not compatible with the generic
2328 modes, it is adverticed as fallback platform framebuffer so legacy
2329 drivers like efifb, vesafb and uvesafb can pick it up.
2330 If this option is not selected, all system framebuffers are always
2331 marked as fallback platform framebuffers as usual.
2333 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2334 not be able to pick up generic system framebuffers if this option
2335 is selected. You are highly encouraged to enable simplefb as
2336 replacement if you select this option. simplefb can correctly deal
2337 with generic system framebuffers. But you should still keep vesafb
2338 and others enabled as fallback if a system framebuffer is
2339 incompatible with simplefb.
2346 menu "Executable file formats / Emulations"
2348 source "fs/Kconfig.binfmt"
2350 config IA32_EMULATION
2351 bool "IA32 Emulation"
2354 select COMPAT_BINFMT_ELF
2357 Include code to run legacy 32-bit programs under a
2358 64-bit kernel. You should likely turn this on, unless you're
2359 100% sure that you don't have any 32-bit programs left.
2362 tristate "IA32 a.out support"
2363 depends on IA32_EMULATION
2365 Support old a.out binaries in the 32bit emulation.
2368 bool "x32 ABI for 64-bit mode"
2369 depends on X86_64 && IA32_EMULATION
2371 Include code to run binaries for the x32 native 32-bit ABI
2372 for 64-bit processors. An x32 process gets access to the
2373 full 64-bit register file and wide data path while leaving
2374 pointers at 32 bits for smaller memory footprint.
2376 You will need a recent binutils (2.22 or later) with
2377 elf32_x86_64 support enabled to compile a kernel with this
2382 depends on IA32_EMULATION || X86_X32
2383 select ARCH_WANT_OLD_COMPAT_IPC
2386 config COMPAT_FOR_U64_ALIGNMENT
2389 config SYSVIPC_COMPAT
2401 config HAVE_ATOMIC_IOMAP
2405 config X86_DEV_DMA_OPS
2407 depends on X86_64 || STA2X11
2409 config X86_DMA_REMAP
2417 To be selected by modules requiring access to the Intel OnChip System
2418 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms
2421 source "net/Kconfig"
2423 source "drivers/Kconfig"
2425 source "drivers/firmware/Kconfig"
2429 source "arch/x86/Kconfig.debug"
2431 source "security/Kconfig"
2433 source "crypto/Kconfig"
2435 source "arch/x86/kvm/Kconfig"
2437 source "lib/Kconfig"
projects / ~andy / linux / blob