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
131 config INSTRUCTION_DECODER
133 depends on KPROBES || PERF_EVENTS || UPROBES
137 default "elf32-i386" if X86_32
138 default "elf64-x86-64" if X86_64
140 config ARCH_DEFCONFIG
142 default "arch/x86/configs/i386_defconfig" if X86_32
143 default "arch/x86/configs/x86_64_defconfig" if X86_64
145 config LOCKDEP_SUPPORT
148 config STACKTRACE_SUPPORT
151 config HAVE_LATENCYTOP_SUPPORT
160 config NEED_DMA_MAP_STATE
162 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
164 config NEED_SG_DMA_LENGTH
167 config GENERIC_ISA_DMA
169 depends on ISA_DMA_API
174 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
176 config GENERIC_BUG_RELATIVE_POINTERS
179 config GENERIC_HWEIGHT
182 config ARCH_MAY_HAVE_PC_FDC
184 depends on ISA_DMA_API
186 config RWSEM_XCHGADD_ALGORITHM
189 config GENERIC_CALIBRATE_DELAY
192 config ARCH_HAS_CPU_RELAX
195 config ARCH_HAS_CACHE_LINE_SIZE
198 config ARCH_HAS_CPU_AUTOPROBE
201 config HAVE_SETUP_PER_CPU_AREA
204 config NEED_PER_CPU_EMBED_FIRST_CHUNK
207 config NEED_PER_CPU_PAGE_FIRST_CHUNK
210 config ARCH_HIBERNATION_POSSIBLE
213 config ARCH_SUSPEND_POSSIBLE
216 config ARCH_WANT_HUGE_PMD_SHARE
219 config ARCH_WANT_GENERAL_HUGETLB
230 config ARCH_SUPPORTS_OPTIMIZED_INLINING
233 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
236 config HAVE_INTEL_TXT
238 depends on INTEL_IOMMU && ACPI
242 depends on X86_32 && SMP
246 depends on X86_64 && SMP
252 config X86_32_LAZY_GS
254 depends on X86_32 && !CC_STACKPROTECTOR
256 config ARCH_HWEIGHT_CFLAGS
258 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
259 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
261 config ARCH_SUPPORTS_UPROBES
264 source "init/Kconfig"
265 source "kernel/Kconfig.freezer"
267 menu "Processor type and features"
270 bool "DMA memory allocation support" if EXPERT
273 DMA memory allocation support allows devices with less than 32-bit
274 addressing to allocate within the first 16MB of address space.
275 Disable if no such devices will be used.
280 bool "Symmetric multi-processing support"
282 This enables support for systems with more than one CPU. If you have
283 a system with only one CPU, say N. If you have a system with more
286 If you say N here, the kernel will run on uni- and multiprocessor
287 machines, but will use only one CPU of a multiprocessor machine. If
288 you say Y here, the kernel will run on many, but not all,
289 uniprocessor machines. On a uniprocessor machine, the kernel
290 will run faster if you say N here.
292 Note that if you say Y here and choose architecture "586" or
293 "Pentium" under "Processor family", the kernel will not work on 486
294 architectures. Similarly, multiprocessor kernels for the "PPro"
295 architecture may not work on all Pentium based boards.
297 People using multiprocessor machines who say Y here should also say
298 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
299 Management" code will be disabled if you say Y here.
301 See also <file:Documentation/x86/i386/IO-APIC.txt>,
302 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
303 <http://www.tldp.org/docs.html#howto>.
305 If you don't know what to do here, say N.
308 bool "Support x2apic"
309 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
311 This enables x2apic support on CPUs that have this feature.
313 This allows 32-bit apic IDs (so it can support very large systems),
314 and accesses the local apic via MSRs not via mmio.
316 If you don't know what to do here, say N.
319 bool "Enable MPS table" if ACPI || SFI
321 depends on X86_LOCAL_APIC
323 For old smp systems that do not have proper acpi support. Newer systems
324 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
327 bool "Support for big SMP systems with more than 8 CPUs"
328 depends on X86_32 && SMP
330 This option is needed for the systems that have more than 8 CPUs
334 depends on X86_GOLDFISH
337 config X86_EXTENDED_PLATFORM
338 bool "Support for extended (non-PC) x86 platforms"
341 If you disable this option then the kernel will only support
342 standard PC platforms. (which covers the vast majority of
345 If you enable this option then you'll be able to select support
346 for the following (non-PC) 32 bit x86 platforms:
347 Goldfish (Android emulator)
351 SGI 320/540 (Visual Workstation)
352 STA2X11-based (e.g. Northville)
353 Summit/EXA (IBM x440)
354 Unisys ES7000 IA32 series
355 Moorestown MID devices
357 If you have one of these systems, or if you want to build a
358 generic distribution kernel, say Y here - otherwise say N.
362 config X86_EXTENDED_PLATFORM
363 bool "Support for extended (non-PC) x86 platforms"
366 If you disable this option then the kernel will only support
367 standard PC platforms. (which covers the vast majority of
370 If you enable this option then you'll be able to select support
371 for the following (non-PC) 64 bit x86 platforms:
376 If you have one of these systems, or if you want to build a
377 generic distribution kernel, say Y here - otherwise say N.
379 # This is an alphabetically sorted list of 64 bit extended platforms
380 # Please maintain the alphabetic order if and when there are additions
382 bool "Numascale NumaChip"
384 depends on X86_EXTENDED_PLATFORM
387 depends on X86_X2APIC
388 depends on PCI_MMCONFIG
390 Adds support for Numascale NumaChip large-SMP systems. Needed to
391 enable more than ~168 cores.
392 If you don't have one of these, you should say N here.
396 select HYPERVISOR_GUEST
398 depends on X86_64 && PCI
399 depends on X86_EXTENDED_PLATFORM
402 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
403 supposed to run on these EM64T-based machines. Only choose this option
404 if you have one of these machines.
407 bool "SGI Ultraviolet"
409 depends on X86_EXTENDED_PLATFORM
411 depends on X86_X2APIC
413 This option is needed in order to support SGI Ultraviolet systems.
414 If you don't have one of these, you should say N here.
416 # Following is an alphabetically sorted list of 32 bit extended platforms
417 # Please maintain the alphabetic order if and when there are additions
420 bool "Goldfish (Virtual Platform)"
422 depends on X86_EXTENDED_PLATFORM
424 Enable support for the Goldfish virtual platform used primarily
425 for Android development. Unless you are building for the Android
426 Goldfish emulator say N here.
429 bool "CE4100 TV platform"
431 depends on PCI_GODIRECT
433 depends on X86_EXTENDED_PLATFORM
434 select X86_REBOOTFIXUPS
436 select OF_EARLY_FLATTREE
439 Select for the Intel CE media processor (CE4100) SOC.
440 This option compiles in support for the CE4100 SOC for settop
441 boxes and media devices.
444 bool "Intel MID platform support"
446 depends on X86_EXTENDED_PLATFORM
447 depends on X86_PLATFORM_DEVICES
450 depends on X86_IO_APIC
456 select MFD_INTEL_MSIC
458 Select to build a kernel capable of supporting Intel MID (Mobile
459 Internet Device) platform systems which do not have the PCI legacy
460 interfaces. If you are building for a PC class system say N here.
462 Intel MID platforms are based on an Intel processor and chipset which
463 consume less power than most of the x86 derivatives.
465 config X86_INTEL_LPSS
466 bool "Intel Low Power Subsystem Support"
471 Select to build support for Intel Low Power Subsystem such as
472 found on Intel Lynxpoint PCH. Selecting this option enables
473 things like clock tree (common clock framework) and pincontrol
474 which are needed by the LPSS peripheral drivers.
477 bool "RDC R-321x SoC"
479 depends on X86_EXTENDED_PLATFORM
481 select X86_REBOOTFIXUPS
483 This option is needed for RDC R-321x system-on-chip, also known
485 If you don't have one of these chips, you should say N here.
487 config X86_32_NON_STANDARD
488 bool "Support non-standard 32-bit SMP architectures"
489 depends on X86_32 && SMP
490 depends on X86_EXTENDED_PLATFORM
492 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
493 STA2X11, default subarchitectures. It is intended for a generic
494 binary kernel. If you select them all, kernel will probe it
495 one by one and will fallback to default.
497 # Alphabetically sorted list of Non standard 32 bit platforms
500 bool "NUMAQ (IBM/Sequent)"
501 depends on X86_32_NON_STANDARD
506 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
507 NUMA multiquad box. This changes the way that processors are
508 bootstrapped, and uses Clustered Logical APIC addressing mode instead
509 of Flat Logical. You will need a new lynxer.elf file to flash your
512 config X86_SUPPORTS_MEMORY_FAILURE
514 # MCE code calls memory_failure():
516 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
517 depends on !X86_NUMAQ
518 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
519 depends on X86_64 || !SPARSEMEM
520 select ARCH_SUPPORTS_MEMORY_FAILURE
523 bool "SGI 320/540 (Visual Workstation)"
524 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
525 depends on X86_32_NON_STANDARD
527 The SGI Visual Workstation series is an IA32-based workstation
528 based on SGI systems chips with some legacy PC hardware attached.
530 Say Y here to create a kernel to run on the SGI 320 or 540.
532 A kernel compiled for the Visual Workstation will run on general
533 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
536 bool "STA2X11 Companion Chip Support"
537 depends on X86_32_NON_STANDARD && PCI
538 select X86_DEV_DMA_OPS
542 select ARCH_REQUIRE_GPIOLIB
545 This adds support for boards based on the STA2X11 IO-Hub,
546 a.k.a. "ConneXt". The chip is used in place of the standard
547 PC chipset, so all "standard" peripherals are missing. If this
548 option is selected the kernel will still be able to boot on
549 standard PC machines.
552 bool "Summit/EXA (IBM x440)"
553 depends on X86_32_NON_STANDARD
555 This option is needed for IBM systems that use the Summit/EXA chipset.
556 In particular, it is needed for the x440.
559 bool "Unisys ES7000 IA32 series"
560 depends on X86_32_NON_STANDARD && X86_BIGSMP
562 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
563 supposed to run on an IA32-based Unisys ES7000 system.
566 tristate "Eurobraille/Iris poweroff module"
569 The Iris machines from EuroBraille do not have APM or ACPI support
570 to shut themselves down properly. A special I/O sequence is
571 needed to do so, which is what this module does at
574 This is only for Iris machines from EuroBraille.
578 config SCHED_OMIT_FRAME_POINTER
580 prompt "Single-depth WCHAN output"
583 Calculate simpler /proc/<PID>/wchan values. If this option
584 is disabled then wchan values will recurse back to the
585 caller function. This provides more accurate wchan values,
586 at the expense of slightly more scheduling overhead.
588 If in doubt, say "Y".
590 menuconfig HYPERVISOR_GUEST
591 bool "Linux guest support"
593 Say Y here to enable options for running Linux under various hyper-
594 visors. This option enables basic hypervisor detection and platform
597 If you say N, all options in this submenu will be skipped and
598 disabled, and Linux guest support won't be built in.
603 bool "Enable paravirtualization code"
605 This changes the kernel so it can modify itself when it is run
606 under a hypervisor, potentially improving performance significantly
607 over full virtualization. However, when run without a hypervisor
608 the kernel is theoretically slower and slightly larger.
610 config PARAVIRT_DEBUG
611 bool "paravirt-ops debugging"
612 depends on PARAVIRT && DEBUG_KERNEL
614 Enable to debug paravirt_ops internals. Specifically, BUG if
615 a paravirt_op is missing when it is called.
617 config PARAVIRT_SPINLOCKS
618 bool "Paravirtualization layer for spinlocks"
619 depends on PARAVIRT && SMP
620 select UNINLINE_SPIN_UNLOCK
622 Paravirtualized spinlocks allow a pvops backend to replace the
623 spinlock implementation with something virtualization-friendly
624 (for example, block the virtual CPU rather than spinning).
626 It has a minimal impact on native kernels and gives a nice performance
627 benefit on paravirtualized KVM / Xen kernels.
629 If you are unsure how to answer this question, answer Y.
631 source "arch/x86/xen/Kconfig"
634 bool "KVM Guest support (including kvmclock)"
636 select PARAVIRT_CLOCK
639 This option enables various optimizations for running under the KVM
640 hypervisor. It includes a paravirtualized clock, so that instead
641 of relying on a PIT (or probably other) emulation by the
642 underlying device model, the host provides the guest with
643 timing infrastructure such as time of day, and system time
646 bool "Enable debug information for KVM Guests in debugfs"
647 depends on KVM_GUEST && DEBUG_FS
650 This option enables collection of various statistics for KVM guest.
651 Statistics are displayed in debugfs filesystem. Enabling this option
652 may incur significant overhead.
654 source "arch/x86/lguest/Kconfig"
656 config PARAVIRT_TIME_ACCOUNTING
657 bool "Paravirtual steal time accounting"
661 Select this option to enable fine granularity task steal time
662 accounting. Time spent executing other tasks in parallel with
663 the current vCPU is discounted from the vCPU power. To account for
664 that, there can be a small performance impact.
666 If in doubt, say N here.
668 config PARAVIRT_CLOCK
671 endif #HYPERVISOR_GUEST
679 This option adds a kernel parameter 'memtest', which allows memtest
681 memtest=0, mean disabled; -- default
682 memtest=1, mean do 1 test pattern;
684 memtest=4, mean do 4 test patterns.
685 If you are unsure how to answer this question, answer N.
687 config X86_SUMMIT_NUMA
689 depends on X86_32 && NUMA && X86_32_NON_STANDARD
691 config X86_CYCLONE_TIMER
693 depends on X86_SUMMIT
695 source "arch/x86/Kconfig.cpu"
699 prompt "HPET Timer Support" if X86_32
701 Use the IA-PC HPET (High Precision Event Timer) to manage
702 time in preference to the PIT and RTC, if a HPET is
704 HPET is the next generation timer replacing legacy 8254s.
705 The HPET provides a stable time base on SMP
706 systems, unlike the TSC, but it is more expensive to access,
707 as it is off-chip. You can find the HPET spec at
708 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
710 You can safely choose Y here. However, HPET will only be
711 activated if the platform and the BIOS support this feature.
712 Otherwise the 8254 will be used for timing services.
714 Choose N to continue using the legacy 8254 timer.
716 config HPET_EMULATE_RTC
718 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
721 def_bool y if X86_INTEL_MID
722 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
724 depends on X86_INTEL_MID && SFI
726 APB timer is the replacement for 8254, HPET on X86 MID platforms.
727 The APBT provides a stable time base on SMP
728 systems, unlike the TSC, but it is more expensive to access,
729 as it is off-chip. APB timers are always running regardless of CPU
730 C states, they are used as per CPU clockevent device when possible.
732 # Mark as expert because too many people got it wrong.
733 # The code disables itself when not needed.
736 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
737 bool "Enable DMI scanning" if EXPERT
739 Enabled scanning of DMI to identify machine quirks. Say Y
740 here unless you have verified that your setup is not
741 affected by entries in the DMI blacklist. Required by PNP
745 bool "Old AMD GART IOMMU support"
747 depends on X86_64 && PCI && AMD_NB
749 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
750 GART based hardware IOMMUs.
752 The GART supports full DMA access for devices with 32-bit access
753 limitations, on systems with more than 3 GB. This is usually needed
754 for USB, sound, many IDE/SATA chipsets and some other devices.
756 Newer systems typically have a modern AMD IOMMU, supported via
757 the CONFIG_AMD_IOMMU=y config option.
759 In normal configurations this driver is only active when needed:
760 there's more than 3 GB of memory and the system contains a
761 32-bit limited device.
766 bool "IBM Calgary IOMMU support"
768 depends on X86_64 && PCI
770 Support for hardware IOMMUs in IBM's xSeries x366 and x460
771 systems. Needed to run systems with more than 3GB of memory
772 properly with 32-bit PCI devices that do not support DAC
773 (Double Address Cycle). Calgary also supports bus level
774 isolation, where all DMAs pass through the IOMMU. This
775 prevents them from going anywhere except their intended
776 destination. This catches hard-to-find kernel bugs and
777 mis-behaving drivers and devices that do not use the DMA-API
778 properly to set up their DMA buffers. The IOMMU can be
779 turned off at boot time with the iommu=off parameter.
780 Normally the kernel will make the right choice by itself.
783 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
785 prompt "Should Calgary be enabled by default?"
786 depends on CALGARY_IOMMU
788 Should Calgary be enabled by default? if you choose 'y', Calgary
789 will be used (if it exists). If you choose 'n', Calgary will not be
790 used even if it exists. If you choose 'n' and would like to use
791 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
794 # need this always selected by IOMMU for the VIA workaround
798 Support for software bounce buffers used on x86-64 systems
799 which don't have a hardware IOMMU. Using this PCI devices
800 which can only access 32-bits of memory can be used on systems
801 with more than 3 GB of memory.
806 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
809 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
810 depends on X86_64 && SMP && DEBUG_KERNEL
811 select CPUMASK_OFFSTACK
813 Enable maximum number of CPUS and NUMA Nodes for this architecture.
817 int "Maximum number of CPUs" if SMP && !MAXSMP
818 range 2 8 if SMP && X86_32 && !X86_BIGSMP
819 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
820 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
822 default "8192" if MAXSMP
823 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
826 This allows you to specify the maximum number of CPUs which this
827 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
828 supported value is 4096, otherwise the maximum value is 512. The
829 minimum value which makes sense is 2.
831 This is purely to save memory - each supported CPU adds
832 approximately eight kilobytes to the kernel image.
835 bool "SMT (Hyperthreading) scheduler support"
838 SMT scheduler support improves the CPU scheduler's decision making
839 when dealing with Intel Pentium 4 chips with HyperThreading at a
840 cost of slightly increased overhead in some places. If unsure say
845 prompt "Multi-core scheduler support"
848 Multi-core scheduler support improves the CPU scheduler's decision
849 making when dealing with multi-core CPU chips at a cost of slightly
850 increased overhead in some places. If unsure say N here.
852 source "kernel/Kconfig.preempt"
855 bool "Local APIC support on uniprocessors"
856 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
858 A local APIC (Advanced Programmable Interrupt Controller) is an
859 integrated interrupt controller in the CPU. If you have a single-CPU
860 system which has a processor with a local APIC, you can say Y here to
861 enable and use it. If you say Y here even though your machine doesn't
862 have a local APIC, then the kernel will still run with no slowdown at
863 all. The local APIC supports CPU-generated self-interrupts (timer,
864 performance counters), and the NMI watchdog which detects hard
868 bool "IO-APIC support on uniprocessors"
869 depends on X86_UP_APIC
871 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
872 SMP-capable replacement for PC-style interrupt controllers. Most
873 SMP systems and many recent uniprocessor systems have one.
875 If you have a single-CPU system with an IO-APIC, you can say Y here
876 to use it. If you say Y here even though your machine doesn't have
877 an IO-APIC, then the kernel will still run with no slowdown at all.
879 config X86_LOCAL_APIC
881 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
885 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
887 config X86_VISWS_APIC
889 depends on X86_32 && X86_VISWS
891 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
892 bool "Reroute for broken boot IRQs"
893 depends on X86_IO_APIC
895 This option enables a workaround that fixes a source of
896 spurious interrupts. This is recommended when threaded
897 interrupt handling is used on systems where the generation of
898 superfluous "boot interrupts" cannot be disabled.
900 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
901 entry in the chipset's IO-APIC is masked (as, e.g. the RT
902 kernel does during interrupt handling). On chipsets where this
903 boot IRQ generation cannot be disabled, this workaround keeps
904 the original IRQ line masked so that only the equivalent "boot
905 IRQ" is delivered to the CPUs. The workaround also tells the
906 kernel to set up the IRQ handler on the boot IRQ line. In this
907 way only one interrupt is delivered to the kernel. Otherwise
908 the spurious second interrupt may cause the kernel to bring
909 down (vital) interrupt lines.
911 Only affects "broken" chipsets. Interrupt sharing may be
912 increased on these systems.
915 bool "Machine Check / overheating reporting"
918 Machine Check support allows the processor to notify the
919 kernel if it detects a problem (e.g. overheating, data corruption).
920 The action the kernel takes depends on the severity of the problem,
921 ranging from warning messages to halting the machine.
925 prompt "Intel MCE features"
926 depends on X86_MCE && X86_LOCAL_APIC
928 Additional support for intel specific MCE features such as
933 prompt "AMD MCE features"
934 depends on X86_MCE && X86_LOCAL_APIC
936 Additional support for AMD specific MCE features such as
937 the DRAM Error Threshold.
939 config X86_ANCIENT_MCE
940 bool "Support for old Pentium 5 / WinChip machine checks"
941 depends on X86_32 && X86_MCE
943 Include support for machine check handling on old Pentium 5 or WinChip
944 systems. These typically need to be enabled explicitly on the command
947 config X86_MCE_THRESHOLD
948 depends on X86_MCE_AMD || X86_MCE_INTEL
951 config X86_MCE_INJECT
953 tristate "Machine check injector support"
955 Provide support for injecting machine checks for testing purposes.
956 If you don't know what a machine check is and you don't do kernel
957 QA it is safe to say n.
959 config X86_THERMAL_VECTOR
961 depends on X86_MCE_INTEL
964 bool "Enable VM86 support" if EXPERT
968 This option is required by programs like DOSEMU to run 16-bit legacy
969 code on X86 processors. It also may be needed by software like
970 XFree86 to initialize some video cards via BIOS. Disabling this
971 option saves about 6k.
974 tristate "Toshiba Laptop support"
977 This adds a driver to safely access the System Management Mode of
978 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
979 not work on models with a Phoenix BIOS. The System Management Mode
980 is used to set the BIOS and power saving options on Toshiba portables.
982 For information on utilities to make use of this driver see the
983 Toshiba Linux utilities web site at:
984 <http://www.buzzard.org.uk/toshiba/>.
986 Say Y if you intend to run this kernel on a Toshiba portable.
990 tristate "Dell laptop support"
993 This adds a driver to safely access the System Management Mode
994 of the CPU on the Dell Inspiron 8000. The System Management Mode
995 is used to read cpu temperature and cooling fan status and to
996 control the fans on the I8K portables.
998 This driver has been tested only on the Inspiron 8000 but it may
999 also work with other Dell laptops. You can force loading on other
1000 models by passing the parameter `force=1' to the module. Use at
1003 For information on utilities to make use of this driver see the
1004 I8K Linux utilities web site at:
1005 <http://people.debian.org/~dz/i8k/>
1007 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1010 config X86_REBOOTFIXUPS
1011 bool "Enable X86 board specific fixups for reboot"
1014 This enables chipset and/or board specific fixups to be done
1015 in order to get reboot to work correctly. This is only needed on
1016 some combinations of hardware and BIOS. The symptom, for which
1017 this config is intended, is when reboot ends with a stalled/hung
1020 Currently, the only fixup is for the Geode machines using
1021 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1023 Say Y if you want to enable the fixup. Currently, it's safe to
1024 enable this option even if you don't need it.
1028 tristate "CPU microcode loading support"
1029 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1033 If you say Y here, you will be able to update the microcode on
1034 certain Intel and AMD processors. The Intel support is for the
1035 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1036 Xeon etc. The AMD support is for families 0x10 and later. You will
1037 obviously need the actual microcode binary data itself which is not
1038 shipped with the Linux kernel.
1040 This option selects the general module only, you need to select
1041 at least one vendor specific module as well.
1043 To compile this driver as a module, choose M here: the module
1044 will be called microcode.
1046 config MICROCODE_INTEL
1047 bool "Intel microcode loading support"
1048 depends on MICROCODE
1052 This options enables microcode patch loading support for Intel
1055 For the current Intel microcode data package go to
1056 <https://downloadcenter.intel.com> and search for
1057 'Linux Processor Microcode Data File'.
1059 config MICROCODE_AMD
1060 bool "AMD microcode loading support"
1061 depends on MICROCODE
1064 If you select this option, microcode patch loading support for AMD
1065 processors will be enabled.
1067 config MICROCODE_OLD_INTERFACE
1069 depends on MICROCODE
1071 config MICROCODE_INTEL_EARLY
1074 config MICROCODE_AMD_EARLY
1077 config MICROCODE_EARLY
1078 bool "Early load microcode"
1079 depends on MICROCODE=y && BLK_DEV_INITRD
1080 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1081 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1084 This option provides functionality to read additional microcode data
1085 at the beginning of initrd image. The data tells kernel to load
1086 microcode to CPU's as early as possible. No functional change if no
1087 microcode data is glued to the initrd, therefore it's safe to say Y.
1090 tristate "/dev/cpu/*/msr - Model-specific register support"
1092 This device gives privileged processes access to the x86
1093 Model-Specific Registers (MSRs). It is a character device with
1094 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1095 MSR accesses are directed to a specific CPU on multi-processor
1099 tristate "/dev/cpu/*/cpuid - CPU information support"
1101 This device gives processes access to the x86 CPUID instruction to
1102 be executed on a specific processor. It is a character device
1103 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1107 prompt "High Memory Support"
1108 default HIGHMEM64G if X86_NUMAQ
1114 depends on !X86_NUMAQ
1116 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1117 However, the address space of 32-bit x86 processors is only 4
1118 Gigabytes large. That means that, if you have a large amount of
1119 physical memory, not all of it can be "permanently mapped" by the
1120 kernel. The physical memory that's not permanently mapped is called
1123 If you are compiling a kernel which will never run on a machine with
1124 more than 1 Gigabyte total physical RAM, answer "off" here (default
1125 choice and suitable for most users). This will result in a "3GB/1GB"
1126 split: 3GB are mapped so that each process sees a 3GB virtual memory
1127 space and the remaining part of the 4GB virtual memory space is used
1128 by the kernel to permanently map as much physical memory as
1131 If the machine has between 1 and 4 Gigabytes physical RAM, then
1134 If more than 4 Gigabytes is used then answer "64GB" here. This
1135 selection turns Intel PAE (Physical Address Extension) mode on.
1136 PAE implements 3-level paging on IA32 processors. PAE is fully
1137 supported by Linux, PAE mode is implemented on all recent Intel
1138 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1139 then the kernel will not boot on CPUs that don't support PAE!
1141 The actual amount of total physical memory will either be
1142 auto detected or can be forced by using a kernel command line option
1143 such as "mem=256M". (Try "man bootparam" or see the documentation of
1144 your boot loader (lilo or loadlin) about how to pass options to the
1145 kernel at boot time.)
1147 If unsure, say "off".
1151 depends on !X86_NUMAQ
1153 Select this if you have a 32-bit processor and between 1 and 4
1154 gigabytes of physical RAM.
1161 Select this if you have a 32-bit processor and more than 4
1162 gigabytes of physical RAM.
1167 prompt "Memory split" if EXPERT
1171 Select the desired split between kernel and user memory.
1173 If the address range available to the kernel is less than the
1174 physical memory installed, the remaining memory will be available
1175 as "high memory". Accessing high memory is a little more costly
1176 than low memory, as it needs to be mapped into the kernel first.
1177 Note that increasing the kernel address space limits the range
1178 available to user programs, making the address space there
1179 tighter. Selecting anything other than the default 3G/1G split
1180 will also likely make your kernel incompatible with binary-only
1183 If you are not absolutely sure what you are doing, leave this
1187 bool "3G/1G user/kernel split"
1188 config VMSPLIT_3G_OPT
1190 bool "3G/1G user/kernel split (for full 1G low memory)"
1192 bool "2G/2G user/kernel split"
1193 config VMSPLIT_2G_OPT
1195 bool "2G/2G user/kernel split (for full 2G low memory)"
1197 bool "1G/3G user/kernel split"
1202 default 0xB0000000 if VMSPLIT_3G_OPT
1203 default 0x80000000 if VMSPLIT_2G
1204 default 0x78000000 if VMSPLIT_2G_OPT
1205 default 0x40000000 if VMSPLIT_1G
1211 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1214 bool "PAE (Physical Address Extension) Support"
1215 depends on X86_32 && !HIGHMEM4G
1217 PAE is required for NX support, and furthermore enables
1218 larger swapspace support for non-overcommit purposes. It
1219 has the cost of more pagetable lookup overhead, and also
1220 consumes more pagetable space per process.
1222 config ARCH_PHYS_ADDR_T_64BIT
1224 depends on X86_64 || X86_PAE
1226 config ARCH_DMA_ADDR_T_64BIT
1228 depends on X86_64 || HIGHMEM64G
1230 config DIRECT_GBPAGES
1231 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1235 Allow the kernel linear mapping to use 1GB pages on CPUs that
1236 support it. This can improve the kernel's performance a tiny bit by
1237 reducing TLB pressure. If in doubt, say "Y".
1239 # Common NUMA Features
1241 bool "Numa Memory Allocation and Scheduler Support"
1243 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1244 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1246 Enable NUMA (Non Uniform Memory Access) support.
1248 The kernel will try to allocate memory used by a CPU on the
1249 local memory controller of the CPU and add some more
1250 NUMA awareness to the kernel.
1252 For 64-bit this is recommended if the system is Intel Core i7
1253 (or later), AMD Opteron, or EM64T NUMA.
1255 For 32-bit this is only needed on (rare) 32-bit-only platforms
1256 that support NUMA topologies, such as NUMAQ / Summit, or if you
1257 boot a 32-bit kernel on a 64-bit NUMA platform.
1259 Otherwise, you should say N.
1261 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1262 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1266 prompt "Old style AMD Opteron NUMA detection"
1267 depends on X86_64 && NUMA && PCI
1269 Enable AMD NUMA node topology detection. You should say Y here if
1270 you have a multi processor AMD system. This uses an old method to
1271 read the NUMA configuration directly from the builtin Northbridge
1272 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1273 which also takes priority if both are compiled in.
1275 config X86_64_ACPI_NUMA
1277 prompt "ACPI NUMA detection"
1278 depends on X86_64 && NUMA && ACPI && PCI
1281 Enable ACPI SRAT based node topology detection.
1283 # Some NUMA nodes have memory ranges that span
1284 # other nodes. Even though a pfn is valid and
1285 # between a node's start and end pfns, it may not
1286 # reside on that node. See memmap_init_zone()
1288 config NODES_SPAN_OTHER_NODES
1290 depends on X86_64_ACPI_NUMA
1293 bool "NUMA emulation"
1296 Enable NUMA emulation. A flat machine will be split
1297 into virtual nodes when booted with "numa=fake=N", where N is the
1298 number of nodes. This is only useful for debugging.
1301 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1303 default "10" if MAXSMP
1304 default "6" if X86_64
1305 default "4" if X86_NUMAQ
1307 depends on NEED_MULTIPLE_NODES
1309 Specify the maximum number of NUMA Nodes available on the target
1310 system. Increases memory reserved to accommodate various tables.
1312 config ARCH_HAVE_MEMORY_PRESENT
1314 depends on X86_32 && DISCONTIGMEM
1316 config NEED_NODE_MEMMAP_SIZE
1318 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1320 config ARCH_FLATMEM_ENABLE
1322 depends on X86_32 && !NUMA
1324 config ARCH_DISCONTIGMEM_ENABLE
1326 depends on NUMA && X86_32
1328 config ARCH_DISCONTIGMEM_DEFAULT
1330 depends on NUMA && X86_32
1332 config ARCH_SPARSEMEM_ENABLE
1334 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1335 select SPARSEMEM_STATIC if X86_32
1336 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1338 config ARCH_SPARSEMEM_DEFAULT
1342 config ARCH_SELECT_MEMORY_MODEL
1344 depends on ARCH_SPARSEMEM_ENABLE
1346 config ARCH_MEMORY_PROBE
1347 bool "Enable sysfs memory/probe interface"
1348 depends on X86_64 && MEMORY_HOTPLUG
1350 This option enables a sysfs memory/probe interface for testing.
1351 See Documentation/memory-hotplug.txt for more information.
1352 If you are unsure how to answer this question, answer N.
1354 config ARCH_PROC_KCORE_TEXT
1356 depends on X86_64 && PROC_KCORE
1358 config ILLEGAL_POINTER_VALUE
1361 default 0xdead000000000000 if X86_64
1366 bool "Allocate 3rd-level pagetables from highmem"
1369 The VM uses one page table entry for each page of physical memory.
1370 For systems with a lot of RAM, this can be wasteful of precious
1371 low memory. Setting this option will put user-space page table
1372 entries in high memory.
1374 config X86_CHECK_BIOS_CORRUPTION
1375 bool "Check for low memory corruption"
1377 Periodically check for memory corruption in low memory, which
1378 is suspected to be caused by BIOS. Even when enabled in the
1379 configuration, it is disabled at runtime. Enable it by
1380 setting "memory_corruption_check=1" on the kernel command
1381 line. By default it scans the low 64k of memory every 60
1382 seconds; see the memory_corruption_check_size and
1383 memory_corruption_check_period parameters in
1384 Documentation/kernel-parameters.txt to adjust this.
1386 When enabled with the default parameters, this option has
1387 almost no overhead, as it reserves a relatively small amount
1388 of memory and scans it infrequently. It both detects corruption
1389 and prevents it from affecting the running system.
1391 It is, however, intended as a diagnostic tool; if repeatable
1392 BIOS-originated corruption always affects the same memory,
1393 you can use memmap= to prevent the kernel from using that
1396 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1397 bool "Set the default setting of memory_corruption_check"
1398 depends on X86_CHECK_BIOS_CORRUPTION
1401 Set whether the default state of memory_corruption_check is
1404 config X86_RESERVE_LOW
1405 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1409 Specify the amount of low memory to reserve for the BIOS.
1411 The first page contains BIOS data structures that the kernel
1412 must not use, so that page must always be reserved.
1414 By default we reserve the first 64K of physical RAM, as a
1415 number of BIOSes are known to corrupt that memory range
1416 during events such as suspend/resume or monitor cable
1417 insertion, so it must not be used by the kernel.
1419 You can set this to 4 if you are absolutely sure that you
1420 trust the BIOS to get all its memory reservations and usages
1421 right. If you know your BIOS have problems beyond the
1422 default 64K area, you can set this to 640 to avoid using the
1423 entire low memory range.
1425 If you have doubts about the BIOS (e.g. suspend/resume does
1426 not work or there's kernel crashes after certain hardware
1427 hotplug events) then you might want to enable
1428 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1429 typical corruption patterns.
1431 Leave this to the default value of 64 if you are unsure.
1433 config MATH_EMULATION
1435 prompt "Math emulation" if X86_32
1437 Linux can emulate a math coprocessor (used for floating point
1438 operations) if you don't have one. 486DX and Pentium processors have
1439 a math coprocessor built in, 486SX and 386 do not, unless you added
1440 a 487DX or 387, respectively. (The messages during boot time can
1441 give you some hints here ["man dmesg"].) Everyone needs either a
1442 coprocessor or this emulation.
1444 If you don't have a math coprocessor, you need to say Y here; if you
1445 say Y here even though you have a coprocessor, the coprocessor will
1446 be used nevertheless. (This behavior can be changed with the kernel
1447 command line option "no387", which comes handy if your coprocessor
1448 is broken. Try "man bootparam" or see the documentation of your boot
1449 loader (lilo or loadlin) about how to pass options to the kernel at
1450 boot time.) This means that it is a good idea to say Y here if you
1451 intend to use this kernel on different machines.
1453 More information about the internals of the Linux math coprocessor
1454 emulation can be found in <file:arch/x86/math-emu/README>.
1456 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1457 kernel, it won't hurt.
1461 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1463 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1464 the Memory Type Range Registers (MTRRs) may be used to control
1465 processor access to memory ranges. This is most useful if you have
1466 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1467 allows bus write transfers to be combined into a larger transfer
1468 before bursting over the PCI/AGP bus. This can increase performance
1469 of image write operations 2.5 times or more. Saying Y here creates a
1470 /proc/mtrr file which may be used to manipulate your processor's
1471 MTRRs. Typically the X server should use this.
1473 This code has a reasonably generic interface so that similar
1474 control registers on other processors can be easily supported
1477 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1478 Registers (ARRs) which provide a similar functionality to MTRRs. For
1479 these, the ARRs are used to emulate the MTRRs.
1480 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1481 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1482 write-combining. All of these processors are supported by this code
1483 and it makes sense to say Y here if you have one of them.
1485 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1486 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1487 can lead to all sorts of problems, so it's good to say Y here.
1489 You can safely say Y even if your machine doesn't have MTRRs, you'll
1490 just add about 9 KB to your kernel.
1492 See <file:Documentation/x86/mtrr.txt> for more information.
1494 config MTRR_SANITIZER
1496 prompt "MTRR cleanup support"
1499 Convert MTRR layout from continuous to discrete, so X drivers can
1500 add writeback entries.
1502 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1503 The largest mtrr entry size for a continuous block can be set with
1508 config MTRR_SANITIZER_ENABLE_DEFAULT
1509 int "MTRR cleanup enable value (0-1)"
1512 depends on MTRR_SANITIZER
1514 Enable mtrr cleanup default value
1516 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1517 int "MTRR cleanup spare reg num (0-7)"
1520 depends on MTRR_SANITIZER
1522 mtrr cleanup spare entries default, it can be changed via
1523 mtrr_spare_reg_nr=N on the kernel command line.
1527 prompt "x86 PAT support" if EXPERT
1530 Use PAT attributes to setup page level cache control.
1532 PATs are the modern equivalents of MTRRs and are much more
1533 flexible than MTRRs.
1535 Say N here if you see bootup problems (boot crash, boot hang,
1536 spontaneous reboots) or a non-working video driver.
1540 config ARCH_USES_PG_UNCACHED
1546 prompt "x86 architectural random number generator" if EXPERT
1548 Enable the x86 architectural RDRAND instruction
1549 (Intel Bull Mountain technology) to generate random numbers.
1550 If supported, this is a high bandwidth, cryptographically
1551 secure hardware random number generator.
1555 prompt "Supervisor Mode Access Prevention" if EXPERT
1557 Supervisor Mode Access Prevention (SMAP) is a security
1558 feature in newer Intel processors. There is a small
1559 performance cost if this enabled and turned on; there is
1560 also a small increase in the kernel size if this is enabled.
1565 bool "EFI runtime service support"
1569 This enables the kernel to use EFI runtime services that are
1570 available (such as the EFI variable services).
1572 This option is only useful on systems that have EFI firmware.
1573 In addition, you should use the latest ELILO loader available
1574 at <http://elilo.sourceforge.net> in order to take advantage
1575 of EFI runtime services. However, even with this option, the
1576 resultant kernel should continue to boot on existing non-EFI
1580 bool "EFI stub support"
1583 This kernel feature allows a bzImage to be loaded directly
1584 by EFI firmware without the use of a bootloader.
1586 See Documentation/efi-stub.txt for more information.
1590 prompt "Enable seccomp to safely compute untrusted bytecode"
1592 This kernel feature is useful for number crunching applications
1593 that may need to compute untrusted bytecode during their
1594 execution. By using pipes or other transports made available to
1595 the process as file descriptors supporting the read/write
1596 syscalls, it's possible to isolate those applications in
1597 their own address space using seccomp. Once seccomp is
1598 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1599 and the task is only allowed to execute a few safe syscalls
1600 defined by each seccomp mode.
1602 If unsure, say Y. Only embedded should say N here.
1604 source kernel/Kconfig.hz
1607 bool "kexec system call"
1609 kexec is a system call that implements the ability to shutdown your
1610 current kernel, and to start another kernel. It is like a reboot
1611 but it is independent of the system firmware. And like a reboot
1612 you can start any kernel with it, not just Linux.
1614 The name comes from the similarity to the exec system call.
1616 It is an ongoing process to be certain the hardware in a machine
1617 is properly shutdown, so do not be surprised if this code does not
1618 initially work for you. As of this writing the exact hardware
1619 interface is strongly in flux, so no good recommendation can be
1623 bool "kernel crash dumps"
1624 depends on X86_64 || (X86_32 && HIGHMEM)
1626 Generate crash dump after being started by kexec.
1627 This should be normally only set in special crash dump kernels
1628 which are loaded in the main kernel with kexec-tools into
1629 a specially reserved region and then later executed after
1630 a crash by kdump/kexec. The crash dump kernel must be compiled
1631 to a memory address not used by the main kernel or BIOS using
1632 PHYSICAL_START, or it must be built as a relocatable image
1633 (CONFIG_RELOCATABLE=y).
1634 For more details see Documentation/kdump/kdump.txt
1638 depends on KEXEC && HIBERNATION
1640 Jump between original kernel and kexeced kernel and invoke
1641 code in physical address mode via KEXEC
1643 config PHYSICAL_START
1644 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1647 This gives the physical address where the kernel is loaded.
1649 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1650 bzImage will decompress itself to above physical address and
1651 run from there. Otherwise, bzImage will run from the address where
1652 it has been loaded by the boot loader and will ignore above physical
1655 In normal kdump cases one does not have to set/change this option
1656 as now bzImage can be compiled as a completely relocatable image
1657 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1658 address. This option is mainly useful for the folks who don't want
1659 to use a bzImage for capturing the crash dump and want to use a
1660 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1661 to be specifically compiled to run from a specific memory area
1662 (normally a reserved region) and this option comes handy.
1664 So if you are using bzImage for capturing the crash dump,
1665 leave the value here unchanged to 0x1000000 and set
1666 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1667 for capturing the crash dump change this value to start of
1668 the reserved region. In other words, it can be set based on
1669 the "X" value as specified in the "crashkernel=YM@XM"
1670 command line boot parameter passed to the panic-ed
1671 kernel. Please take a look at Documentation/kdump/kdump.txt
1672 for more details about crash dumps.
1674 Usage of bzImage for capturing the crash dump is recommended as
1675 one does not have to build two kernels. Same kernel can be used
1676 as production kernel and capture kernel. Above option should have
1677 gone away after relocatable bzImage support is introduced. But it
1678 is present because there are users out there who continue to use
1679 vmlinux for dump capture. This option should go away down the
1682 Don't change this unless you know what you are doing.
1685 bool "Build a relocatable kernel"
1688 This builds a kernel image that retains relocation information
1689 so it can be loaded someplace besides the default 1MB.
1690 The relocations tend to make the kernel binary about 10% larger,
1691 but are discarded at runtime.
1693 One use is for the kexec on panic case where the recovery kernel
1694 must live at a different physical address than the primary
1697 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1698 it has been loaded at and the compile time physical address
1699 (CONFIG_PHYSICAL_START) is used as the minimum location.
1701 config RANDOMIZE_BASE
1702 bool "Randomize the address of the kernel image"
1703 depends on RELOCATABLE
1704 depends on !HIBERNATION
1707 Randomizes the physical and virtual address at which the
1708 kernel image is decompressed, as a security feature that
1709 deters exploit attempts relying on knowledge of the location
1710 of kernel internals.
1712 Entropy is generated using the RDRAND instruction if it is
1713 supported. If RDTSC is supported, it is used as well. If
1714 neither RDRAND nor RDTSC are supported, then randomness is
1715 read from the i8254 timer.
1717 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1718 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1719 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1720 minimum of 2MiB, only 10 bits of entropy is theoretically
1721 possible. At best, due to page table layouts, 64-bit can use
1722 9 bits of entropy and 32-bit uses 8 bits.
1726 config RANDOMIZE_BASE_MAX_OFFSET
1727 hex "Maximum kASLR offset allowed" if EXPERT
1728 depends on RANDOMIZE_BASE
1729 range 0x0 0x20000000 if X86_32
1730 default "0x20000000" if X86_32
1731 range 0x0 0x40000000 if X86_64
1732 default "0x40000000" if X86_64
1734 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1735 memory is used to determine the maximal offset in bytes that will
1736 be applied to the kernel when kernel Address Space Layout
1737 Randomization (kASLR) is active. This must be a multiple of
1740 On 32-bit this is limited to 512MiB by page table layouts. The
1743 On 64-bit this is limited by how the kernel fixmap page table is
1744 positioned, so this cannot be larger than 1GiB currently. Without
1745 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1746 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1747 modules area will shrink to compensate, up to the current maximum
1748 1GiB to 1GiB split. The default is 1GiB.
1750 If unsure, leave at the default value.
1752 # Relocation on x86 needs some additional build support
1753 config X86_NEED_RELOCS
1755 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1757 config PHYSICAL_ALIGN
1758 hex "Alignment value to which kernel should be aligned"
1760 range 0x2000 0x1000000 if X86_32
1761 range 0x200000 0x1000000 if X86_64
1763 This value puts the alignment restrictions on physical address
1764 where kernel is loaded and run from. Kernel is compiled for an
1765 address which meets above alignment restriction.
1767 If bootloader loads the kernel at a non-aligned address and
1768 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1769 address aligned to above value and run from there.
1771 If bootloader loads the kernel at a non-aligned address and
1772 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1773 load address and decompress itself to the address it has been
1774 compiled for and run from there. The address for which kernel is
1775 compiled already meets above alignment restrictions. Hence the
1776 end result is that kernel runs from a physical address meeting
1777 above alignment restrictions.
1779 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1780 this value must be a multiple of 0x200000.
1782 Don't change this unless you know what you are doing.
1785 bool "Support for hot-pluggable CPUs"
1788 Say Y here to allow turning CPUs off and on. CPUs can be
1789 controlled through /sys/devices/system/cpu.
1790 ( Note: power management support will enable this option
1791 automatically on SMP systems. )
1792 Say N if you want to disable CPU hotplug.
1794 config BOOTPARAM_HOTPLUG_CPU0
1795 bool "Set default setting of cpu0_hotpluggable"
1797 depends on HOTPLUG_CPU
1799 Set whether default state of cpu0_hotpluggable is on or off.
1801 Say Y here to enable CPU0 hotplug by default. If this switch
1802 is turned on, there is no need to give cpu0_hotplug kernel
1803 parameter and the CPU0 hotplug feature is enabled by default.
1805 Please note: there are two known CPU0 dependencies if you want
1806 to enable the CPU0 hotplug feature either by this switch or by
1807 cpu0_hotplug kernel parameter.
1809 First, resume from hibernate or suspend always starts from CPU0.
1810 So hibernate and suspend are prevented if CPU0 is offline.
1812 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1813 offline if any interrupt can not migrate out of CPU0. There may
1814 be other CPU0 dependencies.
1816 Please make sure the dependencies are under your control before
1817 you enable this feature.
1819 Say N if you don't want to enable CPU0 hotplug feature by default.
1820 You still can enable the CPU0 hotplug feature at boot by kernel
1821 parameter cpu0_hotplug.
1823 config DEBUG_HOTPLUG_CPU0
1825 prompt "Debug CPU0 hotplug"
1826 depends on HOTPLUG_CPU
1828 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1829 soon as possible and boots up userspace with CPU0 offlined. User
1830 can online CPU0 back after boot time.
1832 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1833 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1834 compilation or giving cpu0_hotplug kernel parameter at boot.
1840 prompt "Compat VDSO support"
1841 depends on X86_32 || IA32_EMULATION
1843 Map the 32-bit VDSO to the predictable old-style address too.
1845 Say N here if you are running a sufficiently recent glibc
1846 version (2.3.3 or later), to remove the high-mapped
1847 VDSO mapping and to exclusively use the randomized VDSO.
1852 bool "Built-in kernel command line"
1854 Allow for specifying boot arguments to the kernel at
1855 build time. On some systems (e.g. embedded ones), it is
1856 necessary or convenient to provide some or all of the
1857 kernel boot arguments with the kernel itself (that is,
1858 to not rely on the boot loader to provide them.)
1860 To compile command line arguments into the kernel,
1861 set this option to 'Y', then fill in the
1862 the boot arguments in CONFIG_CMDLINE.
1864 Systems with fully functional boot loaders (i.e. non-embedded)
1865 should leave this option set to 'N'.
1868 string "Built-in kernel command string"
1869 depends on CMDLINE_BOOL
1872 Enter arguments here that should be compiled into the kernel
1873 image and used at boot time. If the boot loader provides a
1874 command line at boot time, it is appended to this string to
1875 form the full kernel command line, when the system boots.
1877 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1878 change this behavior.
1880 In most cases, the command line (whether built-in or provided
1881 by the boot loader) should specify the device for the root
1884 config CMDLINE_OVERRIDE
1885 bool "Built-in command line overrides boot loader arguments"
1886 depends on CMDLINE_BOOL
1888 Set this option to 'Y' to have the kernel ignore the boot loader
1889 command line, and use ONLY the built-in command line.
1891 This is used to work around broken boot loaders. This should
1892 be set to 'N' under normal conditions.
1896 config ARCH_ENABLE_MEMORY_HOTPLUG
1898 depends on X86_64 || (X86_32 && HIGHMEM)
1900 config ARCH_ENABLE_MEMORY_HOTREMOVE
1902 depends on MEMORY_HOTPLUG
1904 config USE_PERCPU_NUMA_NODE_ID
1908 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1910 depends on X86_64 || X86_PAE
1912 menu "Power management and ACPI options"
1914 config ARCH_HIBERNATION_HEADER
1916 depends on X86_64 && HIBERNATION
1918 source "kernel/power/Kconfig"
1920 source "drivers/acpi/Kconfig"
1922 source "drivers/sfi/Kconfig"
1929 tristate "APM (Advanced Power Management) BIOS support"
1930 depends on X86_32 && PM_SLEEP
1932 APM is a BIOS specification for saving power using several different
1933 techniques. This is mostly useful for battery powered laptops with
1934 APM compliant BIOSes. If you say Y here, the system time will be
1935 reset after a RESUME operation, the /proc/apm device will provide
1936 battery status information, and user-space programs will receive
1937 notification of APM "events" (e.g. battery status change).
1939 If you select "Y" here, you can disable actual use of the APM
1940 BIOS by passing the "apm=off" option to the kernel at boot time.
1942 Note that the APM support is almost completely disabled for
1943 machines with more than one CPU.
1945 In order to use APM, you will need supporting software. For location
1946 and more information, read <file:Documentation/power/apm-acpi.txt>
1947 and the Battery Powered Linux mini-HOWTO, available from
1948 <http://www.tldp.org/docs.html#howto>.
1950 This driver does not spin down disk drives (see the hdparm(8)
1951 manpage ("man 8 hdparm") for that), and it doesn't turn off
1952 VESA-compliant "green" monitors.
1954 This driver does not support the TI 4000M TravelMate and the ACER
1955 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1956 desktop machines also don't have compliant BIOSes, and this driver
1957 may cause those machines to panic during the boot phase.
1959 Generally, if you don't have a battery in your machine, there isn't
1960 much point in using this driver and you should say N. If you get
1961 random kernel OOPSes or reboots that don't seem to be related to
1962 anything, try disabling/enabling this option (or disabling/enabling
1965 Some other things you should try when experiencing seemingly random,
1968 1) make sure that you have enough swap space and that it is
1970 2) pass the "no-hlt" option to the kernel
1971 3) switch on floating point emulation in the kernel and pass
1972 the "no387" option to the kernel
1973 4) pass the "floppy=nodma" option to the kernel
1974 5) pass the "mem=4M" option to the kernel (thereby disabling
1975 all but the first 4 MB of RAM)
1976 6) make sure that the CPU is not over clocked.
1977 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1978 8) disable the cache from your BIOS settings
1979 9) install a fan for the video card or exchange video RAM
1980 10) install a better fan for the CPU
1981 11) exchange RAM chips
1982 12) exchange the motherboard.
1984 To compile this driver as a module, choose M here: the
1985 module will be called apm.
1989 config APM_IGNORE_USER_SUSPEND
1990 bool "Ignore USER SUSPEND"
1992 This option will ignore USER SUSPEND requests. On machines with a
1993 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1994 series notebooks, it is necessary to say Y because of a BIOS bug.
1996 config APM_DO_ENABLE
1997 bool "Enable PM at boot time"
1999 Enable APM features at boot time. From page 36 of the APM BIOS
2000 specification: "When disabled, the APM BIOS does not automatically
2001 power manage devices, enter the Standby State, enter the Suspend
2002 State, or take power saving steps in response to CPU Idle calls."
2003 This driver will make CPU Idle calls when Linux is idle (unless this
2004 feature is turned off -- see "Do CPU IDLE calls", below). This
2005 should always save battery power, but more complicated APM features
2006 will be dependent on your BIOS implementation. You may need to turn
2007 this option off if your computer hangs at boot time when using APM
2008 support, or if it beeps continuously instead of suspending. Turn
2009 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2010 T400CDT. This is off by default since most machines do fine without
2015 bool "Make CPU Idle calls when idle"
2017 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2018 On some machines, this can activate improved power savings, such as
2019 a slowed CPU clock rate, when the machine is idle. These idle calls
2020 are made after the idle loop has run for some length of time (e.g.,
2021 333 mS). On some machines, this will cause a hang at boot time or
2022 whenever the CPU becomes idle. (On machines with more than one CPU,
2023 this option does nothing.)
2025 config APM_DISPLAY_BLANK
2026 bool "Enable console blanking using APM"
2028 Enable console blanking using the APM. Some laptops can use this to
2029 turn off the LCD backlight when the screen blanker of the Linux
2030 virtual console blanks the screen. Note that this is only used by
2031 the virtual console screen blanker, and won't turn off the backlight
2032 when using the X Window system. This also doesn't have anything to
2033 do with your VESA-compliant power-saving monitor. Further, this
2034 option doesn't work for all laptops -- it might not turn off your
2035 backlight at all, or it might print a lot of errors to the console,
2036 especially if you are using gpm.
2038 config APM_ALLOW_INTS
2039 bool "Allow interrupts during APM BIOS calls"
2041 Normally we disable external interrupts while we are making calls to
2042 the APM BIOS as a measure to lessen the effects of a badly behaving
2043 BIOS implementation. The BIOS should reenable interrupts if it
2044 needs to. Unfortunately, some BIOSes do not -- especially those in
2045 many of the newer IBM Thinkpads. If you experience hangs when you
2046 suspend, try setting this to Y. Otherwise, say N.
2050 source "drivers/cpufreq/Kconfig"
2052 source "drivers/cpuidle/Kconfig"
2054 source "drivers/idle/Kconfig"
2059 menu "Bus options (PCI etc.)"
2065 Find out whether you have a PCI motherboard. PCI is the name of a
2066 bus system, i.e. the way the CPU talks to the other stuff inside
2067 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2068 VESA. If you have PCI, say Y, otherwise N.
2071 prompt "PCI access mode"
2072 depends on X86_32 && PCI
2075 On PCI systems, the BIOS can be used to detect the PCI devices and
2076 determine their configuration. However, some old PCI motherboards
2077 have BIOS bugs and may crash if this is done. Also, some embedded
2078 PCI-based systems don't have any BIOS at all. Linux can also try to
2079 detect the PCI hardware directly without using the BIOS.
2081 With this option, you can specify how Linux should detect the
2082 PCI devices. If you choose "BIOS", the BIOS will be used,
2083 if you choose "Direct", the BIOS won't be used, and if you
2084 choose "MMConfig", then PCI Express MMCONFIG will be used.
2085 If you choose "Any", the kernel will try MMCONFIG, then the
2086 direct access method and falls back to the BIOS if that doesn't
2087 work. If unsure, go with the default, which is "Any".
2092 config PCI_GOMMCONFIG
2109 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2111 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2114 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2118 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2122 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2126 depends on PCI && XEN
2134 bool "Support mmconfig PCI config space access"
2135 depends on X86_64 && PCI && ACPI
2137 config PCI_CNB20LE_QUIRK
2138 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2141 Read the PCI windows out of the CNB20LE host bridge. This allows
2142 PCI hotplug to work on systems with the CNB20LE chipset which do
2145 There's no public spec for this chipset, and this functionality
2146 is known to be incomplete.
2148 You should say N unless you know you need this.
2150 source "drivers/pci/pcie/Kconfig"
2152 source "drivers/pci/Kconfig"
2154 # x86_64 have no ISA slots, but can have ISA-style DMA.
2156 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2159 Enables ISA-style DMA support for devices requiring such controllers.
2167 Find out whether you have ISA slots on your motherboard. ISA is the
2168 name of a bus system, i.e. the way the CPU talks to the other stuff
2169 inside your box. Other bus systems are PCI, EISA, MicroChannel
2170 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2171 newer boards don't support it. If you have ISA, say Y, otherwise N.
2177 The Extended Industry Standard Architecture (EISA) bus was
2178 developed as an open alternative to the IBM MicroChannel bus.
2180 The EISA bus provided some of the features of the IBM MicroChannel
2181 bus while maintaining backward compatibility with cards made for
2182 the older ISA bus. The EISA bus saw limited use between 1988 and
2183 1995 when it was made obsolete by the PCI bus.
2185 Say Y here if you are building a kernel for an EISA-based machine.
2189 source "drivers/eisa/Kconfig"
2192 tristate "NatSemi SCx200 support"
2194 This provides basic support for National Semiconductor's
2195 (now AMD's) Geode processors. The driver probes for the
2196 PCI-IDs of several on-chip devices, so its a good dependency
2197 for other scx200_* drivers.
2199 If compiled as a module, the driver is named scx200.
2201 config SCx200HR_TIMER
2202 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2206 This driver provides a clocksource built upon the on-chip
2207 27MHz high-resolution timer. Its also a workaround for
2208 NSC Geode SC-1100's buggy TSC, which loses time when the
2209 processor goes idle (as is done by the scheduler). The
2210 other workaround is idle=poll boot option.
2213 bool "One Laptop Per Child support"
2220 Add support for detecting the unique features of the OLPC
2224 bool "OLPC XO-1 Power Management"
2225 depends on OLPC && MFD_CS5535 && PM_SLEEP
2228 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2231 bool "OLPC XO-1 Real Time Clock"
2232 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2234 Add support for the XO-1 real time clock, which can be used as a
2235 programmable wakeup source.
2238 bool "OLPC XO-1 SCI extras"
2239 depends on OLPC && OLPC_XO1_PM
2245 Add support for SCI-based features of the OLPC XO-1 laptop:
2246 - EC-driven system wakeups
2250 - AC adapter status updates
2251 - Battery status updates
2253 config OLPC_XO15_SCI
2254 bool "OLPC XO-1.5 SCI extras"
2255 depends on OLPC && ACPI
2258 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2259 - EC-driven system wakeups
2260 - AC adapter status updates
2261 - Battery status updates
2264 bool "PCEngines ALIX System Support (LED setup)"
2267 This option enables system support for the PCEngines ALIX.
2268 At present this just sets up LEDs for GPIO control on
2269 ALIX2/3/6 boards. However, other system specific setup should
2272 Note: You must still enable the drivers for GPIO and LED support
2273 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2275 Note: You have to set alix.force=1 for boards with Award BIOS.
2278 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2281 This option enables system support for the Soekris Engineering net5501.
2284 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2288 This option enables system support for the Traverse Technologies GEOS.
2291 bool "Technologic Systems TS-5500 platform support"
2293 select CHECK_SIGNATURE
2297 This option enables system support for the Technologic Systems TS-5500.
2303 depends on CPU_SUP_AMD && PCI
2305 source "drivers/pcmcia/Kconfig"
2307 source "drivers/pci/hotplug/Kconfig"
2310 tristate "RapidIO support"
2314 If enabled this option will include drivers and the core
2315 infrastructure code to support RapidIO interconnect devices.
2317 source "drivers/rapidio/Kconfig"
2320 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2322 Firmwares often provide initial graphics framebuffers so the BIOS,
2323 bootloader or kernel can show basic video-output during boot for
2324 user-guidance and debugging. Historically, x86 used the VESA BIOS
2325 Extensions and EFI-framebuffers for this, which are mostly limited
2327 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2328 framebuffers so the new generic system-framebuffer drivers can be
2329 used on x86. If the framebuffer is not compatible with the generic
2330 modes, it is adverticed as fallback platform framebuffer so legacy
2331 drivers like efifb, vesafb and uvesafb can pick it up.
2332 If this option is not selected, all system framebuffers are always
2333 marked as fallback platform framebuffers as usual.
2335 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2336 not be able to pick up generic system framebuffers if this option
2337 is selected. You are highly encouraged to enable simplefb as
2338 replacement if you select this option. simplefb can correctly deal
2339 with generic system framebuffers. But you should still keep vesafb
2340 and others enabled as fallback if a system framebuffer is
2341 incompatible with simplefb.
2348 menu "Executable file formats / Emulations"
2350 source "fs/Kconfig.binfmt"
2352 config IA32_EMULATION
2353 bool "IA32 Emulation"
2356 select COMPAT_BINFMT_ELF
2359 Include code to run legacy 32-bit programs under a
2360 64-bit kernel. You should likely turn this on, unless you're
2361 100% sure that you don't have any 32-bit programs left.
2364 tristate "IA32 a.out support"
2365 depends on IA32_EMULATION
2367 Support old a.out binaries in the 32bit emulation.
2370 bool "x32 ABI for 64-bit mode"
2371 depends on X86_64 && IA32_EMULATION
2373 Include code to run binaries for the x32 native 32-bit ABI
2374 for 64-bit processors. An x32 process gets access to the
2375 full 64-bit register file and wide data path while leaving
2376 pointers at 32 bits for smaller memory footprint.
2378 You will need a recent binutils (2.22 or later) with
2379 elf32_x86_64 support enabled to compile a kernel with this
2384 depends on IA32_EMULATION || X86_X32
2385 select ARCH_WANT_OLD_COMPAT_IPC
2388 config COMPAT_FOR_U64_ALIGNMENT
2391 config SYSVIPC_COMPAT
2403 config HAVE_ATOMIC_IOMAP
2407 config X86_DEV_DMA_OPS
2409 depends on X86_64 || STA2X11
2411 config X86_DMA_REMAP
2419 To be selected by modules requiring access to the Intel OnChip System
2420 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms
2423 source "net/Kconfig"
2425 source "drivers/Kconfig"
2427 source "drivers/firmware/Kconfig"
2431 source "arch/x86/Kconfig.debug"
2433 source "security/Kconfig"
2435 source "crypto/Kconfig"
2437 source "arch/x86/kvm/Kconfig"
2439 source "lib/Kconfig"
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