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 ARCH_MIGHT_HAVE_PC_SERIO
27 select HAVE_AOUT if X86_32
28 select HAVE_UNSTABLE_SCHED_CLOCK
29 select ARCH_SUPPORTS_NUMA_BALANCING
30 select ARCH_SUPPORTS_INT128 if X86_64
31 select ARCH_WANTS_PROT_NUMA_PROT_NONE
34 select HAVE_PCSPKR_PLATFORM
35 select HAVE_PERF_EVENTS
36 select HAVE_IOREMAP_PROT
39 select HAVE_MEMBLOCK_NODE_MAP
40 select ARCH_DISCARD_MEMBLOCK
41 select ARCH_WANT_OPTIONAL_GPIOLIB
42 select ARCH_WANT_FRAME_POINTERS
44 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
45 select HAVE_KRETPROBES
47 select HAVE_KPROBES_ON_FTRACE
48 select HAVE_FTRACE_MCOUNT_RECORD
49 select HAVE_FENTRY if X86_64
50 select HAVE_C_RECORDMCOUNT
51 select HAVE_DYNAMIC_FTRACE
52 select HAVE_DYNAMIC_FTRACE_WITH_REGS
53 select HAVE_FUNCTION_TRACER
54 select HAVE_FUNCTION_GRAPH_TRACER
55 select HAVE_FUNCTION_GRAPH_FP_TEST
56 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
57 select HAVE_SYSCALL_TRACEPOINTS
58 select SYSCTL_EXCEPTION_TRACE
61 select HAVE_ARCH_TRACEHOOK
62 select HAVE_GENERIC_DMA_COHERENT if X86_32
63 select HAVE_EFFICIENT_UNALIGNED_ACCESS
64 select USER_STACKTRACE_SUPPORT
65 select HAVE_REGS_AND_STACK_ACCESS_API
66 select HAVE_DMA_API_DEBUG
67 select HAVE_KERNEL_GZIP
68 select HAVE_KERNEL_BZIP2
69 select HAVE_KERNEL_LZMA
71 select HAVE_KERNEL_LZO
72 select HAVE_KERNEL_LZ4
73 select HAVE_HW_BREAKPOINT
74 select HAVE_MIXED_BREAKPOINTS_REGS
76 select HAVE_PERF_EVENTS_NMI
78 select HAVE_PERF_USER_STACK_DUMP
79 select HAVE_DEBUG_KMEMLEAK
81 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
82 select HAVE_CMPXCHG_LOCAL
83 select HAVE_CMPXCHG_DOUBLE
84 select HAVE_ARCH_KMEMCHECK
85 select HAVE_USER_RETURN_NOTIFIER
86 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
87 select HAVE_ARCH_JUMP_LABEL
88 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
90 select GENERIC_FIND_FIRST_BIT
91 select GENERIC_IRQ_PROBE
92 select GENERIC_PENDING_IRQ if SMP
93 select GENERIC_IRQ_SHOW
94 select GENERIC_CLOCKEVENTS_MIN_ADJUST
95 select IRQ_FORCED_THREADING
96 select HAVE_BPF_JIT if X86_64
97 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
99 select ARCH_HAVE_NMI_SAFE_CMPXCHG
101 select DCACHE_WORD_ACCESS
102 select GENERIC_SMP_IDLE_THREAD
103 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
104 select HAVE_ARCH_SECCOMP_FILTER
105 select BUILDTIME_EXTABLE_SORT
106 select GENERIC_CMOS_UPDATE
107 select HAVE_ARCH_SOFT_DIRTY
108 select CLOCKSOURCE_WATCHDOG
109 select GENERIC_CLOCKEVENTS
110 select ARCH_CLOCKSOURCE_DATA if X86_64
111 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
112 select GENERIC_TIME_VSYSCALL if X86_64
113 select KTIME_SCALAR if X86_32
114 select GENERIC_STRNCPY_FROM_USER
115 select GENERIC_STRNLEN_USER
116 select HAVE_CONTEXT_TRACKING if X86_64
117 select HAVE_IRQ_TIME_ACCOUNTING
119 select MODULES_USE_ELF_REL if X86_32
120 select MODULES_USE_ELF_RELA if X86_64
121 select CLONE_BACKWARDS if X86_32
122 select ARCH_USE_BUILTIN_BSWAP
123 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
124 select OLD_SIGACTION if X86_32
125 select COMPAT_OLD_SIGACTION if IA32_EMULATION
127 select HAVE_DEBUG_STACKOVERFLOW
128 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
129 select HAVE_CC_STACKPROTECTOR
130 select GENERIC_CPU_AUTOPROBE
132 config INSTRUCTION_DECODER
134 depends on KPROBES || PERF_EVENTS || UPROBES
138 default "elf32-i386" if X86_32
139 default "elf64-x86-64" if X86_64
141 config ARCH_DEFCONFIG
143 default "arch/x86/configs/i386_defconfig" if X86_32
144 default "arch/x86/configs/x86_64_defconfig" if X86_64
146 config LOCKDEP_SUPPORT
149 config STACKTRACE_SUPPORT
152 config HAVE_LATENCYTOP_SUPPORT
161 config NEED_DMA_MAP_STATE
163 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
165 config NEED_SG_DMA_LENGTH
168 config GENERIC_ISA_DMA
170 depends on ISA_DMA_API
175 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
177 config GENERIC_BUG_RELATIVE_POINTERS
180 config GENERIC_HWEIGHT
183 config ARCH_MAY_HAVE_PC_FDC
185 depends on ISA_DMA_API
187 config RWSEM_XCHGADD_ALGORITHM
190 config GENERIC_CALIBRATE_DELAY
193 config ARCH_HAS_CPU_RELAX
196 config ARCH_HAS_CACHE_LINE_SIZE
199 config HAVE_SETUP_PER_CPU_AREA
202 config NEED_PER_CPU_EMBED_FIRST_CHUNK
205 config NEED_PER_CPU_PAGE_FIRST_CHUNK
208 config ARCH_HIBERNATION_POSSIBLE
211 config ARCH_SUSPEND_POSSIBLE
214 config ARCH_WANT_HUGE_PMD_SHARE
217 config ARCH_WANT_GENERAL_HUGETLB
228 config ARCH_SUPPORTS_OPTIMIZED_INLINING
231 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
234 config HAVE_INTEL_TXT
236 depends on INTEL_IOMMU && ACPI
240 depends on X86_32 && SMP
244 depends on X86_64 && SMP
250 config X86_32_LAZY_GS
252 depends on X86_32 && !CC_STACKPROTECTOR
254 config ARCH_HWEIGHT_CFLAGS
256 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
257 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
259 config ARCH_SUPPORTS_UPROBES
262 source "init/Kconfig"
263 source "kernel/Kconfig.freezer"
265 menu "Processor type and features"
268 bool "DMA memory allocation support" if EXPERT
271 DMA memory allocation support allows devices with less than 32-bit
272 addressing to allocate within the first 16MB of address space.
273 Disable if no such devices will be used.
278 bool "Symmetric multi-processing support"
280 This enables support for systems with more than one CPU. If you have
281 a system with only one CPU, say N. If you have a system with more
284 If you say N here, the kernel will run on uni- and multiprocessor
285 machines, but will use only one CPU of a multiprocessor machine. If
286 you say Y here, the kernel will run on many, but not all,
287 uniprocessor machines. On a uniprocessor machine, the kernel
288 will run faster if you say N here.
290 Note that if you say Y here and choose architecture "586" or
291 "Pentium" under "Processor family", the kernel will not work on 486
292 architectures. Similarly, multiprocessor kernels for the "PPro"
293 architecture may not work on all Pentium based boards.
295 People using multiprocessor machines who say Y here should also say
296 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
297 Management" code will be disabled if you say Y here.
299 See also <file:Documentation/x86/i386/IO-APIC.txt>,
300 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
301 <http://www.tldp.org/docs.html#howto>.
303 If you don't know what to do here, say N.
306 bool "Support x2apic"
307 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
309 This enables x2apic support on CPUs that have this feature.
311 This allows 32-bit apic IDs (so it can support very large systems),
312 and accesses the local apic via MSRs not via mmio.
314 If you don't know what to do here, say N.
317 bool "Enable MPS table" if ACPI || SFI
319 depends on X86_LOCAL_APIC
321 For old smp systems that do not have proper acpi support. Newer systems
322 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
325 bool "Support for big SMP systems with more than 8 CPUs"
326 depends on X86_32 && SMP
328 This option is needed for the systems that have more than 8 CPUs
332 depends on X86_GOLDFISH
335 config X86_EXTENDED_PLATFORM
336 bool "Support for extended (non-PC) x86 platforms"
339 If you disable this option then the kernel will only support
340 standard PC platforms. (which covers the vast majority of
343 If you enable this option then you'll be able to select support
344 for the following (non-PC) 32 bit x86 platforms:
345 Goldfish (Android emulator)
349 SGI 320/540 (Visual Workstation)
350 STA2X11-based (e.g. Northville)
351 Summit/EXA (IBM x440)
352 Unisys ES7000 IA32 series
353 Moorestown MID devices
355 If you have one of these systems, or if you want to build a
356 generic distribution kernel, say Y here - otherwise say N.
360 config X86_EXTENDED_PLATFORM
361 bool "Support for extended (non-PC) x86 platforms"
364 If you disable this option then the kernel will only support
365 standard PC platforms. (which covers the vast majority of
368 If you enable this option then you'll be able to select support
369 for the following (non-PC) 64 bit x86 platforms:
374 If you have one of these systems, or if you want to build a
375 generic distribution kernel, say Y here - otherwise say N.
377 # This is an alphabetically sorted list of 64 bit extended platforms
378 # Please maintain the alphabetic order if and when there are additions
380 bool "Numascale NumaChip"
382 depends on X86_EXTENDED_PLATFORM
385 depends on X86_X2APIC
386 depends on PCI_MMCONFIG
388 Adds support for Numascale NumaChip large-SMP systems. Needed to
389 enable more than ~168 cores.
390 If you don't have one of these, you should say N here.
394 select HYPERVISOR_GUEST
396 depends on X86_64 && PCI
397 depends on X86_EXTENDED_PLATFORM
400 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
401 supposed to run on these EM64T-based machines. Only choose this option
402 if you have one of these machines.
405 bool "SGI Ultraviolet"
407 depends on X86_EXTENDED_PLATFORM
409 depends on X86_X2APIC
411 This option is needed in order to support SGI Ultraviolet systems.
412 If you don't have one of these, you should say N here.
414 # Following is an alphabetically sorted list of 32 bit extended platforms
415 # Please maintain the alphabetic order if and when there are additions
418 bool "Goldfish (Virtual Platform)"
420 depends on X86_EXTENDED_PLATFORM
422 Enable support for the Goldfish virtual platform used primarily
423 for Android development. Unless you are building for the Android
424 Goldfish emulator say N here.
427 bool "CE4100 TV platform"
429 depends on PCI_GODIRECT
431 depends on X86_EXTENDED_PLATFORM
432 select X86_REBOOTFIXUPS
434 select OF_EARLY_FLATTREE
437 Select for the Intel CE media processor (CE4100) SOC.
438 This option compiles in support for the CE4100 SOC for settop
439 boxes and media devices.
442 bool "Intel MID platform support"
444 depends on X86_EXTENDED_PLATFORM
445 depends on X86_PLATFORM_DEVICES
448 depends on X86_IO_APIC
454 select MFD_INTEL_MSIC
456 Select to build a kernel capable of supporting Intel MID (Mobile
457 Internet Device) platform systems which do not have the PCI legacy
458 interfaces. If you are building for a PC class system say N here.
460 Intel MID platforms are based on an Intel processor and chipset which
461 consume less power than most of the x86 derivatives.
463 config X86_INTEL_LPSS
464 bool "Intel Low Power Subsystem Support"
469 Select to build support for Intel Low Power Subsystem such as
470 found on Intel Lynxpoint PCH. Selecting this option enables
471 things like clock tree (common clock framework) and pincontrol
472 which are needed by the LPSS peripheral drivers.
475 bool "RDC R-321x SoC"
477 depends on X86_EXTENDED_PLATFORM
479 select X86_REBOOTFIXUPS
481 This option is needed for RDC R-321x system-on-chip, also known
483 If you don't have one of these chips, you should say N here.
485 config X86_32_NON_STANDARD
486 bool "Support non-standard 32-bit SMP architectures"
487 depends on X86_32 && SMP
488 depends on X86_EXTENDED_PLATFORM
490 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
491 STA2X11, default subarchitectures. It is intended for a generic
492 binary kernel. If you select them all, kernel will probe it
493 one by one and will fallback to default.
495 # Alphabetically sorted list of Non standard 32 bit platforms
498 bool "NUMAQ (IBM/Sequent)"
499 depends on X86_32_NON_STANDARD
504 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
505 NUMA multiquad box. This changes the way that processors are
506 bootstrapped, and uses Clustered Logical APIC addressing mode instead
507 of Flat Logical. You will need a new lynxer.elf file to flash your
508 firmware with - send email to <Martin.Bligh@us.ibm.com>.
510 config X86_SUPPORTS_MEMORY_FAILURE
512 # MCE code calls memory_failure():
514 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
515 depends on !X86_NUMAQ
516 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
517 depends on X86_64 || !SPARSEMEM
518 select ARCH_SUPPORTS_MEMORY_FAILURE
521 bool "SGI 320/540 (Visual Workstation)"
522 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
523 depends on X86_32_NON_STANDARD
525 The SGI Visual Workstation series is an IA32-based workstation
526 based on SGI systems chips with some legacy PC hardware attached.
528 Say Y here to create a kernel to run on the SGI 320 or 540.
530 A kernel compiled for the Visual Workstation will run on general
531 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
534 bool "STA2X11 Companion Chip Support"
535 depends on X86_32_NON_STANDARD && PCI
536 select X86_DEV_DMA_OPS
540 select ARCH_REQUIRE_GPIOLIB
543 This adds support for boards based on the STA2X11 IO-Hub,
544 a.k.a. "ConneXt". The chip is used in place of the standard
545 PC chipset, so all "standard" peripherals are missing. If this
546 option is selected the kernel will still be able to boot on
547 standard PC machines.
550 bool "Summit/EXA (IBM x440)"
551 depends on X86_32_NON_STANDARD
553 This option is needed for IBM systems that use the Summit/EXA chipset.
554 In particular, it is needed for the x440.
557 bool "Unisys ES7000 IA32 series"
558 depends on X86_32_NON_STANDARD && X86_BIGSMP
560 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
561 supposed to run on an IA32-based Unisys ES7000 system.
564 tristate "Eurobraille/Iris poweroff module"
567 The Iris machines from EuroBraille do not have APM or ACPI support
568 to shut themselves down properly. A special I/O sequence is
569 needed to do so, which is what this module does at
572 This is only for Iris machines from EuroBraille.
576 config SCHED_OMIT_FRAME_POINTER
578 prompt "Single-depth WCHAN output"
581 Calculate simpler /proc/<PID>/wchan values. If this option
582 is disabled then wchan values will recurse back to the
583 caller function. This provides more accurate wchan values,
584 at the expense of slightly more scheduling overhead.
586 If in doubt, say "Y".
588 menuconfig HYPERVISOR_GUEST
589 bool "Linux guest support"
591 Say Y here to enable options for running Linux under various hyper-
592 visors. This option enables basic hypervisor detection and platform
595 If you say N, all options in this submenu will be skipped and
596 disabled, and Linux guest support won't be built in.
601 bool "Enable paravirtualization code"
603 This changes the kernel so it can modify itself when it is run
604 under a hypervisor, potentially improving performance significantly
605 over full virtualization. However, when run without a hypervisor
606 the kernel is theoretically slower and slightly larger.
608 config PARAVIRT_DEBUG
609 bool "paravirt-ops debugging"
610 depends on PARAVIRT && DEBUG_KERNEL
612 Enable to debug paravirt_ops internals. Specifically, BUG if
613 a paravirt_op is missing when it is called.
615 config PARAVIRT_SPINLOCKS
616 bool "Paravirtualization layer for spinlocks"
617 depends on PARAVIRT && SMP
618 select UNINLINE_SPIN_UNLOCK
620 Paravirtualized spinlocks allow a pvops backend to replace the
621 spinlock implementation with something virtualization-friendly
622 (for example, block the virtual CPU rather than spinning).
624 It has a minimal impact on native kernels and gives a nice performance
625 benefit on paravirtualized KVM / Xen kernels.
627 If you are unsure how to answer this question, answer Y.
629 source "arch/x86/xen/Kconfig"
632 bool "KVM Guest support (including kvmclock)"
634 select PARAVIRT_CLOCK
637 This option enables various optimizations for running under the KVM
638 hypervisor. It includes a paravirtualized clock, so that instead
639 of relying on a PIT (or probably other) emulation by the
640 underlying device model, the host provides the guest with
641 timing infrastructure such as time of day, and system time
644 bool "Enable debug information for KVM Guests in debugfs"
645 depends on KVM_GUEST && DEBUG_FS
648 This option enables collection of various statistics for KVM guest.
649 Statistics are displayed in debugfs filesystem. Enabling this option
650 may incur significant overhead.
652 source "arch/x86/lguest/Kconfig"
654 config PARAVIRT_TIME_ACCOUNTING
655 bool "Paravirtual steal time accounting"
659 Select this option to enable fine granularity task steal time
660 accounting. Time spent executing other tasks in parallel with
661 the current vCPU is discounted from the vCPU power. To account for
662 that, there can be a small performance impact.
664 If in doubt, say N here.
666 config PARAVIRT_CLOCK
669 endif #HYPERVISOR_GUEST
677 This option adds a kernel parameter 'memtest', which allows memtest
679 memtest=0, mean disabled; -- default
680 memtest=1, mean do 1 test pattern;
682 memtest=4, mean do 4 test patterns.
683 If you are unsure how to answer this question, answer N.
685 config X86_SUMMIT_NUMA
687 depends on X86_32 && NUMA && X86_32_NON_STANDARD
689 config X86_CYCLONE_TIMER
691 depends on X86_SUMMIT
693 source "arch/x86/Kconfig.cpu"
697 prompt "HPET Timer Support" if X86_32
699 Use the IA-PC HPET (High Precision Event Timer) to manage
700 time in preference to the PIT and RTC, if a HPET is
702 HPET is the next generation timer replacing legacy 8254s.
703 The HPET provides a stable time base on SMP
704 systems, unlike the TSC, but it is more expensive to access,
705 as it is off-chip. You can find the HPET spec at
706 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
708 You can safely choose Y here. However, HPET will only be
709 activated if the platform and the BIOS support this feature.
710 Otherwise the 8254 will be used for timing services.
712 Choose N to continue using the legacy 8254 timer.
714 config HPET_EMULATE_RTC
716 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
719 def_bool y if X86_INTEL_MID
720 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
722 depends on X86_INTEL_MID && SFI
724 APB timer is the replacement for 8254, HPET on X86 MID platforms.
725 The APBT provides a stable time base on SMP
726 systems, unlike the TSC, but it is more expensive to access,
727 as it is off-chip. APB timers are always running regardless of CPU
728 C states, they are used as per CPU clockevent device when possible.
730 # Mark as expert because too many people got it wrong.
731 # The code disables itself when not needed.
734 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
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 explicitly 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.
1587 bool "EFI mixed-mode support"
1588 depends on EFI_STUB && X86_64
1590 Enabling this feature allows a 64-bit kernel to be booted
1591 on a 32-bit firmware, provided that your CPU supports 64-bit
1594 Note that it is not possible to boot a mixed-mode enabled
1595 kernel via the EFI boot stub - a bootloader that supports
1596 the EFI handover protocol must be used.
1602 prompt "Enable seccomp to safely compute untrusted bytecode"
1604 This kernel feature is useful for number crunching applications
1605 that may need to compute untrusted bytecode during their
1606 execution. By using pipes or other transports made available to
1607 the process as file descriptors supporting the read/write
1608 syscalls, it's possible to isolate those applications in
1609 their own address space using seccomp. Once seccomp is
1610 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1611 and the task is only allowed to execute a few safe syscalls
1612 defined by each seccomp mode.
1614 If unsure, say Y. Only embedded should say N here.
1616 source kernel/Kconfig.hz
1619 bool "kexec system call"
1621 kexec is a system call that implements the ability to shutdown your
1622 current kernel, and to start another kernel. It is like a reboot
1623 but it is independent of the system firmware. And like a reboot
1624 you can start any kernel with it, not just Linux.
1626 The name comes from the similarity to the exec system call.
1628 It is an ongoing process to be certain the hardware in a machine
1629 is properly shutdown, so do not be surprised if this code does not
1630 initially work for you. As of this writing the exact hardware
1631 interface is strongly in flux, so no good recommendation can be
1635 bool "kernel crash dumps"
1636 depends on X86_64 || (X86_32 && HIGHMEM)
1638 Generate crash dump after being started by kexec.
1639 This should be normally only set in special crash dump kernels
1640 which are loaded in the main kernel with kexec-tools into
1641 a specially reserved region and then later executed after
1642 a crash by kdump/kexec. The crash dump kernel must be compiled
1643 to a memory address not used by the main kernel or BIOS using
1644 PHYSICAL_START, or it must be built as a relocatable image
1645 (CONFIG_RELOCATABLE=y).
1646 For more details see Documentation/kdump/kdump.txt
1650 depends on KEXEC && HIBERNATION
1652 Jump between original kernel and kexeced kernel and invoke
1653 code in physical address mode via KEXEC
1655 config PHYSICAL_START
1656 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1659 This gives the physical address where the kernel is loaded.
1661 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1662 bzImage will decompress itself to above physical address and
1663 run from there. Otherwise, bzImage will run from the address where
1664 it has been loaded by the boot loader and will ignore above physical
1667 In normal kdump cases one does not have to set/change this option
1668 as now bzImage can be compiled as a completely relocatable image
1669 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1670 address. This option is mainly useful for the folks who don't want
1671 to use a bzImage for capturing the crash dump and want to use a
1672 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1673 to be specifically compiled to run from a specific memory area
1674 (normally a reserved region) and this option comes handy.
1676 So if you are using bzImage for capturing the crash dump,
1677 leave the value here unchanged to 0x1000000 and set
1678 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1679 for capturing the crash dump change this value to start of
1680 the reserved region. In other words, it can be set based on
1681 the "X" value as specified in the "crashkernel=YM@XM"
1682 command line boot parameter passed to the panic-ed
1683 kernel. Please take a look at Documentation/kdump/kdump.txt
1684 for more details about crash dumps.
1686 Usage of bzImage for capturing the crash dump is recommended as
1687 one does not have to build two kernels. Same kernel can be used
1688 as production kernel and capture kernel. Above option should have
1689 gone away after relocatable bzImage support is introduced. But it
1690 is present because there are users out there who continue to use
1691 vmlinux for dump capture. This option should go away down the
1694 Don't change this unless you know what you are doing.
1697 bool "Build a relocatable kernel"
1700 This builds a kernel image that retains relocation information
1701 so it can be loaded someplace besides the default 1MB.
1702 The relocations tend to make the kernel binary about 10% larger,
1703 but are discarded at runtime.
1705 One use is for the kexec on panic case where the recovery kernel
1706 must live at a different physical address than the primary
1709 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1710 it has been loaded at and the compile time physical address
1711 (CONFIG_PHYSICAL_START) is used as the minimum location.
1713 config RANDOMIZE_BASE
1714 bool "Randomize the address of the kernel image"
1715 depends on RELOCATABLE
1716 depends on !HIBERNATION
1719 Randomizes the physical and virtual address at which the
1720 kernel image is decompressed, as a security feature that
1721 deters exploit attempts relying on knowledge of the location
1722 of kernel internals.
1724 Entropy is generated using the RDRAND instruction if it is
1725 supported. If RDTSC is supported, it is used as well. If
1726 neither RDRAND nor RDTSC are supported, then randomness is
1727 read from the i8254 timer.
1729 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1730 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1731 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1732 minimum of 2MiB, only 10 bits of entropy is theoretically
1733 possible. At best, due to page table layouts, 64-bit can use
1734 9 bits of entropy and 32-bit uses 8 bits.
1738 config RANDOMIZE_BASE_MAX_OFFSET
1739 hex "Maximum kASLR offset allowed" if EXPERT
1740 depends on RANDOMIZE_BASE
1741 range 0x0 0x20000000 if X86_32
1742 default "0x20000000" if X86_32
1743 range 0x0 0x40000000 if X86_64
1744 default "0x40000000" if X86_64
1746 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1747 memory is used to determine the maximal offset in bytes that will
1748 be applied to the kernel when kernel Address Space Layout
1749 Randomization (kASLR) is active. This must be a multiple of
1752 On 32-bit this is limited to 512MiB by page table layouts. The
1755 On 64-bit this is limited by how the kernel fixmap page table is
1756 positioned, so this cannot be larger than 1GiB currently. Without
1757 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1758 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1759 modules area will shrink to compensate, up to the current maximum
1760 1GiB to 1GiB split. The default is 1GiB.
1762 If unsure, leave at the default value.
1764 # Relocation on x86 needs some additional build support
1765 config X86_NEED_RELOCS
1767 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1769 config PHYSICAL_ALIGN
1770 hex "Alignment value to which kernel should be aligned"
1772 range 0x2000 0x1000000 if X86_32
1773 range 0x200000 0x1000000 if X86_64
1775 This value puts the alignment restrictions on physical address
1776 where kernel is loaded and run from. Kernel is compiled for an
1777 address which meets above alignment restriction.
1779 If bootloader loads the kernel at a non-aligned address and
1780 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1781 address aligned to above value and run from there.
1783 If bootloader loads the kernel at a non-aligned address and
1784 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1785 load address and decompress itself to the address it has been
1786 compiled for and run from there. The address for which kernel is
1787 compiled already meets above alignment restrictions. Hence the
1788 end result is that kernel runs from a physical address meeting
1789 above alignment restrictions.
1791 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1792 this value must be a multiple of 0x200000.
1794 Don't change this unless you know what you are doing.
1797 bool "Support for hot-pluggable CPUs"
1800 Say Y here to allow turning CPUs off and on. CPUs can be
1801 controlled through /sys/devices/system/cpu.
1802 ( Note: power management support will enable this option
1803 automatically on SMP systems. )
1804 Say N if you want to disable CPU hotplug.
1806 config BOOTPARAM_HOTPLUG_CPU0
1807 bool "Set default setting of cpu0_hotpluggable"
1809 depends on HOTPLUG_CPU
1811 Set whether default state of cpu0_hotpluggable is on or off.
1813 Say Y here to enable CPU0 hotplug by default. If this switch
1814 is turned on, there is no need to give cpu0_hotplug kernel
1815 parameter and the CPU0 hotplug feature is enabled by default.
1817 Please note: there are two known CPU0 dependencies if you want
1818 to enable the CPU0 hotplug feature either by this switch or by
1819 cpu0_hotplug kernel parameter.
1821 First, resume from hibernate or suspend always starts from CPU0.
1822 So hibernate and suspend are prevented if CPU0 is offline.
1824 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1825 offline if any interrupt can not migrate out of CPU0. There may
1826 be other CPU0 dependencies.
1828 Please make sure the dependencies are under your control before
1829 you enable this feature.
1831 Say N if you don't want to enable CPU0 hotplug feature by default.
1832 You still can enable the CPU0 hotplug feature at boot by kernel
1833 parameter cpu0_hotplug.
1835 config DEBUG_HOTPLUG_CPU0
1837 prompt "Debug CPU0 hotplug"
1838 depends on HOTPLUG_CPU
1840 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1841 soon as possible and boots up userspace with CPU0 offlined. User
1842 can online CPU0 back after boot time.
1844 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1845 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1846 compilation or giving cpu0_hotplug kernel parameter at boot.
1852 prompt "Compat VDSO support"
1853 depends on X86_32 || IA32_EMULATION
1855 Map the 32-bit VDSO to the predictable old-style address too.
1857 Say N here if you are running a sufficiently recent glibc
1858 version (2.3.3 or later), to remove the high-mapped
1859 VDSO mapping and to exclusively use the randomized VDSO.
1864 bool "Built-in kernel command line"
1866 Allow for specifying boot arguments to the kernel at
1867 build time. On some systems (e.g. embedded ones), it is
1868 necessary or convenient to provide some or all of the
1869 kernel boot arguments with the kernel itself (that is,
1870 to not rely on the boot loader to provide them.)
1872 To compile command line arguments into the kernel,
1873 set this option to 'Y', then fill in the
1874 the boot arguments in CONFIG_CMDLINE.
1876 Systems with fully functional boot loaders (i.e. non-embedded)
1877 should leave this option set to 'N'.
1880 string "Built-in kernel command string"
1881 depends on CMDLINE_BOOL
1884 Enter arguments here that should be compiled into the kernel
1885 image and used at boot time. If the boot loader provides a
1886 command line at boot time, it is appended to this string to
1887 form the full kernel command line, when the system boots.
1889 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1890 change this behavior.
1892 In most cases, the command line (whether built-in or provided
1893 by the boot loader) should specify the device for the root
1896 config CMDLINE_OVERRIDE
1897 bool "Built-in command line overrides boot loader arguments"
1898 depends on CMDLINE_BOOL
1900 Set this option to 'Y' to have the kernel ignore the boot loader
1901 command line, and use ONLY the built-in command line.
1903 This is used to work around broken boot loaders. This should
1904 be set to 'N' under normal conditions.
1908 config ARCH_ENABLE_MEMORY_HOTPLUG
1910 depends on X86_64 || (X86_32 && HIGHMEM)
1912 config ARCH_ENABLE_MEMORY_HOTREMOVE
1914 depends on MEMORY_HOTPLUG
1916 config USE_PERCPU_NUMA_NODE_ID
1920 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1922 depends on X86_64 || X86_PAE
1924 menu "Power management and ACPI options"
1926 config ARCH_HIBERNATION_HEADER
1928 depends on X86_64 && HIBERNATION
1930 source "kernel/power/Kconfig"
1932 source "drivers/acpi/Kconfig"
1934 source "drivers/sfi/Kconfig"
1941 tristate "APM (Advanced Power Management) BIOS support"
1942 depends on X86_32 && PM_SLEEP
1944 APM is a BIOS specification for saving power using several different
1945 techniques. This is mostly useful for battery powered laptops with
1946 APM compliant BIOSes. If you say Y here, the system time will be
1947 reset after a RESUME operation, the /proc/apm device will provide
1948 battery status information, and user-space programs will receive
1949 notification of APM "events" (e.g. battery status change).
1951 If you select "Y" here, you can disable actual use of the APM
1952 BIOS by passing the "apm=off" option to the kernel at boot time.
1954 Note that the APM support is almost completely disabled for
1955 machines with more than one CPU.
1957 In order to use APM, you will need supporting software. For location
1958 and more information, read <file:Documentation/power/apm-acpi.txt>
1959 and the Battery Powered Linux mini-HOWTO, available from
1960 <http://www.tldp.org/docs.html#howto>.
1962 This driver does not spin down disk drives (see the hdparm(8)
1963 manpage ("man 8 hdparm") for that), and it doesn't turn off
1964 VESA-compliant "green" monitors.
1966 This driver does not support the TI 4000M TravelMate and the ACER
1967 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1968 desktop machines also don't have compliant BIOSes, and this driver
1969 may cause those machines to panic during the boot phase.
1971 Generally, if you don't have a battery in your machine, there isn't
1972 much point in using this driver and you should say N. If you get
1973 random kernel OOPSes or reboots that don't seem to be related to
1974 anything, try disabling/enabling this option (or disabling/enabling
1977 Some other things you should try when experiencing seemingly random,
1980 1) make sure that you have enough swap space and that it is
1982 2) pass the "no-hlt" option to the kernel
1983 3) switch on floating point emulation in the kernel and pass
1984 the "no387" option to the kernel
1985 4) pass the "floppy=nodma" option to the kernel
1986 5) pass the "mem=4M" option to the kernel (thereby disabling
1987 all but the first 4 MB of RAM)
1988 6) make sure that the CPU is not over clocked.
1989 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1990 8) disable the cache from your BIOS settings
1991 9) install a fan for the video card or exchange video RAM
1992 10) install a better fan for the CPU
1993 11) exchange RAM chips
1994 12) exchange the motherboard.
1996 To compile this driver as a module, choose M here: the
1997 module will be called apm.
2001 config APM_IGNORE_USER_SUSPEND
2002 bool "Ignore USER SUSPEND"
2004 This option will ignore USER SUSPEND requests. On machines with a
2005 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2006 series notebooks, it is necessary to say Y because of a BIOS bug.
2008 config APM_DO_ENABLE
2009 bool "Enable PM at boot time"
2011 Enable APM features at boot time. From page 36 of the APM BIOS
2012 specification: "When disabled, the APM BIOS does not automatically
2013 power manage devices, enter the Standby State, enter the Suspend
2014 State, or take power saving steps in response to CPU Idle calls."
2015 This driver will make CPU Idle calls when Linux is idle (unless this
2016 feature is turned off -- see "Do CPU IDLE calls", below). This
2017 should always save battery power, but more complicated APM features
2018 will be dependent on your BIOS implementation. You may need to turn
2019 this option off if your computer hangs at boot time when using APM
2020 support, or if it beeps continuously instead of suspending. Turn
2021 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2022 T400CDT. This is off by default since most machines do fine without
2027 bool "Make CPU Idle calls when idle"
2029 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2030 On some machines, this can activate improved power savings, such as
2031 a slowed CPU clock rate, when the machine is idle. These idle calls
2032 are made after the idle loop has run for some length of time (e.g.,
2033 333 mS). On some machines, this will cause a hang at boot time or
2034 whenever the CPU becomes idle. (On machines with more than one CPU,
2035 this option does nothing.)
2037 config APM_DISPLAY_BLANK
2038 bool "Enable console blanking using APM"
2040 Enable console blanking using the APM. Some laptops can use this to
2041 turn off the LCD backlight when the screen blanker of the Linux
2042 virtual console blanks the screen. Note that this is only used by
2043 the virtual console screen blanker, and won't turn off the backlight
2044 when using the X Window system. This also doesn't have anything to
2045 do with your VESA-compliant power-saving monitor. Further, this
2046 option doesn't work for all laptops -- it might not turn off your
2047 backlight at all, or it might print a lot of errors to the console,
2048 especially if you are using gpm.
2050 config APM_ALLOW_INTS
2051 bool "Allow interrupts during APM BIOS calls"
2053 Normally we disable external interrupts while we are making calls to
2054 the APM BIOS as a measure to lessen the effects of a badly behaving
2055 BIOS implementation. The BIOS should reenable interrupts if it
2056 needs to. Unfortunately, some BIOSes do not -- especially those in
2057 many of the newer IBM Thinkpads. If you experience hangs when you
2058 suspend, try setting this to Y. Otherwise, say N.
2062 source "drivers/cpufreq/Kconfig"
2064 source "drivers/cpuidle/Kconfig"
2066 source "drivers/idle/Kconfig"
2071 menu "Bus options (PCI etc.)"
2077 Find out whether you have a PCI motherboard. PCI is the name of a
2078 bus system, i.e. the way the CPU talks to the other stuff inside
2079 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2080 VESA. If you have PCI, say Y, otherwise N.
2083 prompt "PCI access mode"
2084 depends on X86_32 && PCI
2087 On PCI systems, the BIOS can be used to detect the PCI devices and
2088 determine their configuration. However, some old PCI motherboards
2089 have BIOS bugs and may crash if this is done. Also, some embedded
2090 PCI-based systems don't have any BIOS at all. Linux can also try to
2091 detect the PCI hardware directly without using the BIOS.
2093 With this option, you can specify how Linux should detect the
2094 PCI devices. If you choose "BIOS", the BIOS will be used,
2095 if you choose "Direct", the BIOS won't be used, and if you
2096 choose "MMConfig", then PCI Express MMCONFIG will be used.
2097 If you choose "Any", the kernel will try MMCONFIG, then the
2098 direct access method and falls back to the BIOS if that doesn't
2099 work. If unsure, go with the default, which is "Any".
2104 config PCI_GOMMCONFIG
2121 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2123 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2126 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2130 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2134 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2138 depends on PCI && XEN
2146 bool "Support mmconfig PCI config space access"
2147 depends on X86_64 && PCI && ACPI
2149 config PCI_CNB20LE_QUIRK
2150 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2153 Read the PCI windows out of the CNB20LE host bridge. This allows
2154 PCI hotplug to work on systems with the CNB20LE chipset which do
2157 There's no public spec for this chipset, and this functionality
2158 is known to be incomplete.
2160 You should say N unless you know you need this.
2162 source "drivers/pci/pcie/Kconfig"
2164 source "drivers/pci/Kconfig"
2166 # x86_64 have no ISA slots, but can have ISA-style DMA.
2168 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2171 Enables ISA-style DMA support for devices requiring such controllers.
2179 Find out whether you have ISA slots on your motherboard. ISA is the
2180 name of a bus system, i.e. the way the CPU talks to the other stuff
2181 inside your box. Other bus systems are PCI, EISA, MicroChannel
2182 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2183 newer boards don't support it. If you have ISA, say Y, otherwise N.
2189 The Extended Industry Standard Architecture (EISA) bus was
2190 developed as an open alternative to the IBM MicroChannel bus.
2192 The EISA bus provided some of the features of the IBM MicroChannel
2193 bus while maintaining backward compatibility with cards made for
2194 the older ISA bus. The EISA bus saw limited use between 1988 and
2195 1995 when it was made obsolete by the PCI bus.
2197 Say Y here if you are building a kernel for an EISA-based machine.
2201 source "drivers/eisa/Kconfig"
2204 tristate "NatSemi SCx200 support"
2206 This provides basic support for National Semiconductor's
2207 (now AMD's) Geode processors. The driver probes for the
2208 PCI-IDs of several on-chip devices, so its a good dependency
2209 for other scx200_* drivers.
2211 If compiled as a module, the driver is named scx200.
2213 config SCx200HR_TIMER
2214 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2218 This driver provides a clocksource built upon the on-chip
2219 27MHz high-resolution timer. Its also a workaround for
2220 NSC Geode SC-1100's buggy TSC, which loses time when the
2221 processor goes idle (as is done by the scheduler). The
2222 other workaround is idle=poll boot option.
2225 bool "One Laptop Per Child support"
2232 Add support for detecting the unique features of the OLPC
2236 bool "OLPC XO-1 Power Management"
2237 depends on OLPC && MFD_CS5535 && PM_SLEEP
2240 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2243 bool "OLPC XO-1 Real Time Clock"
2244 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2246 Add support for the XO-1 real time clock, which can be used as a
2247 programmable wakeup source.
2250 bool "OLPC XO-1 SCI extras"
2251 depends on OLPC && OLPC_XO1_PM
2257 Add support for SCI-based features of the OLPC XO-1 laptop:
2258 - EC-driven system wakeups
2262 - AC adapter status updates
2263 - Battery status updates
2265 config OLPC_XO15_SCI
2266 bool "OLPC XO-1.5 SCI extras"
2267 depends on OLPC && ACPI
2270 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2271 - EC-driven system wakeups
2272 - AC adapter status updates
2273 - Battery status updates
2276 bool "PCEngines ALIX System Support (LED setup)"
2279 This option enables system support for the PCEngines ALIX.
2280 At present this just sets up LEDs for GPIO control on
2281 ALIX2/3/6 boards. However, other system specific setup should
2284 Note: You must still enable the drivers for GPIO and LED support
2285 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2287 Note: You have to set alix.force=1 for boards with Award BIOS.
2290 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2293 This option enables system support for the Soekris Engineering net5501.
2296 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2300 This option enables system support for the Traverse Technologies GEOS.
2303 bool "Technologic Systems TS-5500 platform support"
2305 select CHECK_SIGNATURE
2309 This option enables system support for the Technologic Systems TS-5500.
2315 depends on CPU_SUP_AMD && PCI
2317 source "drivers/pcmcia/Kconfig"
2319 source "drivers/pci/hotplug/Kconfig"
2322 tristate "RapidIO support"
2326 If enabled this option will include drivers and the core
2327 infrastructure code to support RapidIO interconnect devices.
2329 source "drivers/rapidio/Kconfig"
2332 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2334 Firmwares often provide initial graphics framebuffers so the BIOS,
2335 bootloader or kernel can show basic video-output during boot for
2336 user-guidance and debugging. Historically, x86 used the VESA BIOS
2337 Extensions and EFI-framebuffers for this, which are mostly limited
2339 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2340 framebuffers so the new generic system-framebuffer drivers can be
2341 used on x86. If the framebuffer is not compatible with the generic
2342 modes, it is adverticed as fallback platform framebuffer so legacy
2343 drivers like efifb, vesafb and uvesafb can pick it up.
2344 If this option is not selected, all system framebuffers are always
2345 marked as fallback platform framebuffers as usual.
2347 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2348 not be able to pick up generic system framebuffers if this option
2349 is selected. You are highly encouraged to enable simplefb as
2350 replacement if you select this option. simplefb can correctly deal
2351 with generic system framebuffers. But you should still keep vesafb
2352 and others enabled as fallback if a system framebuffer is
2353 incompatible with simplefb.
2360 menu "Executable file formats / Emulations"
2362 source "fs/Kconfig.binfmt"
2364 config IA32_EMULATION
2365 bool "IA32 Emulation"
2368 select COMPAT_BINFMT_ELF
2371 Include code to run legacy 32-bit programs under a
2372 64-bit kernel. You should likely turn this on, unless you're
2373 100% sure that you don't have any 32-bit programs left.
2376 tristate "IA32 a.out support"
2377 depends on IA32_EMULATION
2379 Support old a.out binaries in the 32bit emulation.
2382 bool "x32 ABI for 64-bit mode"
2383 depends on X86_64 && IA32_EMULATION
2385 Include code to run binaries for the x32 native 32-bit ABI
2386 for 64-bit processors. An x32 process gets access to the
2387 full 64-bit register file and wide data path while leaving
2388 pointers at 32 bits for smaller memory footprint.
2390 You will need a recent binutils (2.22 or later) with
2391 elf32_x86_64 support enabled to compile a kernel with this
2396 depends on IA32_EMULATION || X86_X32
2397 select ARCH_WANT_OLD_COMPAT_IPC
2400 config COMPAT_FOR_U64_ALIGNMENT
2403 config SYSVIPC_COMPAT
2415 config HAVE_ATOMIC_IOMAP
2419 config X86_DEV_DMA_OPS
2421 depends on X86_64 || STA2X11
2423 config X86_DMA_REMAP
2431 To be selected by modules requiring access to the Intel OnChip System
2432 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms
2435 source "net/Kconfig"
2437 source "drivers/Kconfig"
2439 source "drivers/firmware/Kconfig"
2443 source "arch/x86/Kconfig.debug"
2445 source "security/Kconfig"
2447 source "crypto/Kconfig"
2449 source "arch/x86/kvm/Kconfig"
2451 source "lib/Kconfig"
projects / linux-2.6-block.git / blob