3 bool "64-bit kernel" if ARCH = "x86"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
24 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
25 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
26 select ARCH_HAS_FAST_MULTIPLIER
27 select ARCH_MIGHT_HAVE_PC_PARPORT
28 select ARCH_MIGHT_HAVE_PC_SERIO
29 select HAVE_AOUT if X86_32
30 select HAVE_UNSTABLE_SCHED_CLOCK
31 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
32 select ARCH_SUPPORTS_INT128 if X86_64
33 select ARCH_WANTS_PROT_NUMA_PROT_NONE
36 select HAVE_PCSPKR_PLATFORM
37 select HAVE_PERF_EVENTS
38 select HAVE_IOREMAP_PROT
41 select HAVE_MEMBLOCK_NODE_MAP
42 select ARCH_DISCARD_MEMBLOCK
43 select ARCH_WANT_OPTIONAL_GPIOLIB
44 select ARCH_WANT_FRAME_POINTERS
46 select HAVE_DMA_CONTIGUOUS
47 select HAVE_KRETPROBES
48 select GENERIC_EARLY_IOREMAP
50 select HAVE_KPROBES_ON_FTRACE
51 select HAVE_FTRACE_MCOUNT_RECORD
52 select HAVE_FENTRY if X86_64
53 select HAVE_C_RECORDMCOUNT
54 select HAVE_DYNAMIC_FTRACE
55 select HAVE_DYNAMIC_FTRACE_WITH_REGS
56 select HAVE_FUNCTION_TRACER
57 select HAVE_FUNCTION_GRAPH_TRACER
58 select HAVE_FUNCTION_GRAPH_FP_TEST
59 select HAVE_SYSCALL_TRACEPOINTS
60 select SYSCTL_EXCEPTION_TRACE
63 select HAVE_ARCH_TRACEHOOK
64 select HAVE_GENERIC_DMA_COHERENT if X86_32
65 select HAVE_EFFICIENT_UNALIGNED_ACCESS
66 select USER_STACKTRACE_SUPPORT
67 select HAVE_REGS_AND_STACK_ACCESS_API
68 select HAVE_DMA_API_DEBUG
69 select HAVE_KERNEL_GZIP
70 select HAVE_KERNEL_BZIP2
71 select HAVE_KERNEL_LZMA
73 select HAVE_KERNEL_LZO
74 select HAVE_KERNEL_LZ4
75 select HAVE_HW_BREAKPOINT
76 select HAVE_MIXED_BREAKPOINTS_REGS
78 select HAVE_PERF_EVENTS_NMI
80 select HAVE_PERF_USER_STACK_DUMP
81 select HAVE_DEBUG_KMEMLEAK
83 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
84 select HAVE_CMPXCHG_LOCAL
85 select HAVE_CMPXCHG_DOUBLE
86 select HAVE_ARCH_KMEMCHECK
87 select HAVE_USER_RETURN_NOTIFIER
88 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
89 select HAVE_ARCH_JUMP_LABEL
90 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
92 select GENERIC_FIND_FIRST_BIT
93 select GENERIC_IRQ_PROBE
94 select GENERIC_PENDING_IRQ if SMP
95 select GENERIC_IRQ_SHOW
96 select GENERIC_CLOCKEVENTS_MIN_ADJUST
97 select IRQ_FORCED_THREADING
98 select HAVE_BPF_JIT if X86_64
99 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
100 select ARCH_HAS_SG_CHAIN
102 select ARCH_HAVE_NMI_SAFE_CMPXCHG
104 select DCACHE_WORD_ACCESS
105 select GENERIC_SMP_IDLE_THREAD
106 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
107 select HAVE_ARCH_SECCOMP_FILTER
108 select BUILDTIME_EXTABLE_SORT
109 select GENERIC_CMOS_UPDATE
110 select HAVE_ARCH_SOFT_DIRTY if X86_64
111 select CLOCKSOURCE_WATCHDOG
112 select GENERIC_CLOCKEVENTS
113 select ARCH_CLOCKSOURCE_DATA
114 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
115 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
116 select GENERIC_TIME_VSYSCALL
117 select GENERIC_STRNCPY_FROM_USER
118 select GENERIC_STRNLEN_USER
119 select HAVE_CONTEXT_TRACKING if X86_64
120 select HAVE_IRQ_TIME_ACCOUNTING
122 select MODULES_USE_ELF_REL if X86_32
123 select MODULES_USE_ELF_RELA if X86_64
124 select CLONE_BACKWARDS if X86_32
125 select ARCH_USE_BUILTIN_BSWAP
126 select ARCH_USE_QUEUE_RWLOCK
127 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
128 select OLD_SIGACTION if X86_32
129 select COMPAT_OLD_SIGACTION if IA32_EMULATION
131 select HAVE_DEBUG_STACKOVERFLOW
132 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
133 select HAVE_CC_STACKPROTECTOR
134 select GENERIC_CPU_AUTOPROBE
135 select HAVE_ARCH_AUDITSYSCALL
136 select ARCH_SUPPORTS_ATOMIC_RMW
137 select HAVE_ACPI_APEI if ACPI
138 select HAVE_ACPI_APEI_NMI if ACPI
139 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
140 select X86_FEATURE_NAMES if PROC_FS
142 config INSTRUCTION_DECODER
144 depends on KPROBES || PERF_EVENTS || UPROBES
148 default "elf32-i386" if X86_32
149 default "elf64-x86-64" if X86_64
151 config ARCH_DEFCONFIG
153 default "arch/x86/configs/i386_defconfig" if X86_32
154 default "arch/x86/configs/x86_64_defconfig" if X86_64
156 config LOCKDEP_SUPPORT
159 config STACKTRACE_SUPPORT
162 config HAVE_LATENCYTOP_SUPPORT
171 config NEED_DMA_MAP_STATE
173 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
175 config NEED_SG_DMA_LENGTH
178 config GENERIC_ISA_DMA
180 depends on ISA_DMA_API
185 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
187 config GENERIC_BUG_RELATIVE_POINTERS
190 config GENERIC_HWEIGHT
193 config ARCH_MAY_HAVE_PC_FDC
195 depends on ISA_DMA_API
197 config RWSEM_XCHGADD_ALGORITHM
200 config GENERIC_CALIBRATE_DELAY
203 config ARCH_HAS_CPU_RELAX
206 config ARCH_HAS_CACHE_LINE_SIZE
209 config HAVE_SETUP_PER_CPU_AREA
212 config NEED_PER_CPU_EMBED_FIRST_CHUNK
215 config NEED_PER_CPU_PAGE_FIRST_CHUNK
218 config ARCH_HIBERNATION_POSSIBLE
221 config ARCH_SUSPEND_POSSIBLE
224 config ARCH_WANT_HUGE_PMD_SHARE
227 config ARCH_WANT_GENERAL_HUGETLB
238 config ARCH_SUPPORTS_OPTIMIZED_INLINING
241 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
244 config HAVE_INTEL_TXT
246 depends on INTEL_IOMMU && ACPI
250 depends on X86_32 && SMP
254 depends on X86_64 && SMP
260 config X86_32_LAZY_GS
262 depends on X86_32 && !CC_STACKPROTECTOR
264 config ARCH_HWEIGHT_CFLAGS
266 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
267 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
269 config ARCH_SUPPORTS_UPROBES
272 config FIX_EARLYCON_MEM
275 source "init/Kconfig"
276 source "kernel/Kconfig.freezer"
278 menu "Processor type and features"
281 bool "DMA memory allocation support" if EXPERT
284 DMA memory allocation support allows devices with less than 32-bit
285 addressing to allocate within the first 16MB of address space.
286 Disable if no such devices will be used.
291 bool "Symmetric multi-processing support"
293 This enables support for systems with more than one CPU. If you have
294 a system with only one CPU, say N. If you have a system with more
297 If you say N here, the kernel will run on uni- and multiprocessor
298 machines, but will use only one CPU of a multiprocessor machine. If
299 you say Y here, the kernel will run on many, but not all,
300 uniprocessor machines. On a uniprocessor machine, the kernel
301 will run faster if you say N here.
303 Note that if you say Y here and choose architecture "586" or
304 "Pentium" under "Processor family", the kernel will not work on 486
305 architectures. Similarly, multiprocessor kernels for the "PPro"
306 architecture may not work on all Pentium based boards.
308 People using multiprocessor machines who say Y here should also say
309 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
310 Management" code will be disabled if you say Y here.
312 See also <file:Documentation/x86/i386/IO-APIC.txt>,
313 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
314 <http://www.tldp.org/docs.html#howto>.
316 If you don't know what to do here, say N.
318 config X86_FEATURE_NAMES
319 bool "Processor feature human-readable names" if EMBEDDED
322 This option compiles in a table of x86 feature bits and corresponding
323 names. This is required to support /proc/cpuinfo and a few kernel
324 messages. You can disable this to save space, at the expense of
325 making those few kernel messages show numeric feature bits instead.
330 bool "Support x2apic"
331 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
333 This enables x2apic support on CPUs that have this feature.
335 This allows 32-bit apic IDs (so it can support very large systems),
336 and accesses the local apic via MSRs not via mmio.
338 If you don't know what to do here, say N.
341 bool "Enable MPS table" if ACPI || SFI
343 depends on X86_LOCAL_APIC
345 For old smp systems that do not have proper acpi support. Newer systems
346 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
349 bool "Support for big SMP systems with more than 8 CPUs"
350 depends on X86_32 && SMP
352 This option is needed for the systems that have more than 8 CPUs
356 depends on X86_GOLDFISH
359 config X86_EXTENDED_PLATFORM
360 bool "Support for extended (non-PC) x86 platforms"
363 If you disable this option then the kernel will only support
364 standard PC platforms. (which covers the vast majority of
367 If you enable this option then you'll be able to select support
368 for the following (non-PC) 32 bit x86 platforms:
369 Goldfish (Android emulator)
372 SGI 320/540 (Visual Workstation)
373 STA2X11-based (e.g. Northville)
374 Moorestown MID devices
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.
381 config X86_EXTENDED_PLATFORM
382 bool "Support for extended (non-PC) x86 platforms"
385 If you disable this option then the kernel will only support
386 standard PC platforms. (which covers the vast majority of
389 If you enable this option then you'll be able to select support
390 for the following (non-PC) 64 bit x86 platforms:
395 If you have one of these systems, or if you want to build a
396 generic distribution kernel, say Y here - otherwise say N.
398 # This is an alphabetically sorted list of 64 bit extended platforms
399 # Please maintain the alphabetic order if and when there are additions
401 bool "Numascale NumaChip"
403 depends on X86_EXTENDED_PLATFORM
406 depends on X86_X2APIC
407 depends on PCI_MMCONFIG
409 Adds support for Numascale NumaChip large-SMP systems. Needed to
410 enable more than ~168 cores.
411 If you don't have one of these, you should say N here.
415 select HYPERVISOR_GUEST
417 depends on X86_64 && PCI
418 depends on X86_EXTENDED_PLATFORM
421 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
422 supposed to run on these EM64T-based machines. Only choose this option
423 if you have one of these machines.
426 bool "SGI Ultraviolet"
428 depends on X86_EXTENDED_PLATFORM
430 depends on X86_X2APIC
432 This option is needed in order to support SGI Ultraviolet systems.
433 If you don't have one of these, you should say N here.
435 # Following is an alphabetically sorted list of 32 bit extended platforms
436 # Please maintain the alphabetic order if and when there are additions
439 bool "Goldfish (Virtual Platform)"
440 depends on X86_EXTENDED_PLATFORM
442 Enable support for the Goldfish virtual platform used primarily
443 for Android development. Unless you are building for the Android
444 Goldfish emulator say N here.
447 bool "CE4100 TV platform"
449 depends on PCI_GODIRECT
450 depends on X86_IO_APIC
452 depends on X86_EXTENDED_PLATFORM
453 select X86_REBOOTFIXUPS
455 select OF_EARLY_FLATTREE
458 Select for the Intel CE media processor (CE4100) SOC.
459 This option compiles in support for the CE4100 SOC for settop
460 boxes and media devices.
463 bool "Intel MID platform support"
465 depends on X86_EXTENDED_PLATFORM
466 depends on X86_PLATFORM_DEVICES
469 depends on X86_IO_APIC
475 select MFD_INTEL_MSIC
477 Select to build a kernel capable of supporting Intel MID (Mobile
478 Internet Device) platform systems which do not have the PCI legacy
479 interfaces. If you are building for a PC class system say N here.
481 Intel MID platforms are based on an Intel processor and chipset which
482 consume less power than most of the x86 derivatives.
484 config X86_INTEL_LPSS
485 bool "Intel Low Power Subsystem Support"
490 Select to build support for Intel Low Power Subsystem such as
491 found on Intel Lynxpoint PCH. Selecting this option enables
492 things like clock tree (common clock framework) and pincontrol
493 which are needed by the LPSS peripheral drivers.
496 bool "RDC R-321x SoC"
498 depends on X86_EXTENDED_PLATFORM
500 select X86_REBOOTFIXUPS
502 This option is needed for RDC R-321x system-on-chip, also known
504 If you don't have one of these chips, you should say N here.
506 config X86_32_NON_STANDARD
507 bool "Support non-standard 32-bit SMP architectures"
508 depends on X86_32 && SMP
509 depends on X86_EXTENDED_PLATFORM
511 This option compiles in the bigsmp and STA2X11 default
512 subarchitectures. It is intended for a generic binary
513 kernel. If you select them all, kernel will probe it one by
514 one and will fallback to default.
516 # Alphabetically sorted list of Non standard 32 bit platforms
518 config X86_SUPPORTS_MEMORY_FAILURE
520 # MCE code calls memory_failure():
522 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
523 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
524 depends on X86_64 || !SPARSEMEM
525 select ARCH_SUPPORTS_MEMORY_FAILURE
528 bool "STA2X11 Companion Chip Support"
529 depends on X86_32_NON_STANDARD && PCI
530 select X86_DEV_DMA_OPS
534 select ARCH_REQUIRE_GPIOLIB
537 This adds support for boards based on the STA2X11 IO-Hub,
538 a.k.a. "ConneXt". The chip is used in place of the standard
539 PC chipset, so all "standard" peripherals are missing. If this
540 option is selected the kernel will still be able to boot on
541 standard PC machines.
544 tristate "Eurobraille/Iris poweroff module"
547 The Iris machines from EuroBraille do not have APM or ACPI support
548 to shut themselves down properly. A special I/O sequence is
549 needed to do so, which is what this module does at
552 This is only for Iris machines from EuroBraille.
556 config SCHED_OMIT_FRAME_POINTER
558 prompt "Single-depth WCHAN output"
561 Calculate simpler /proc/<PID>/wchan values. If this option
562 is disabled then wchan values will recurse back to the
563 caller function. This provides more accurate wchan values,
564 at the expense of slightly more scheduling overhead.
566 If in doubt, say "Y".
568 menuconfig HYPERVISOR_GUEST
569 bool "Linux guest support"
571 Say Y here to enable options for running Linux under various hyper-
572 visors. This option enables basic hypervisor detection and platform
575 If you say N, all options in this submenu will be skipped and
576 disabled, and Linux guest support won't be built in.
581 bool "Enable paravirtualization code"
583 This changes the kernel so it can modify itself when it is run
584 under a hypervisor, potentially improving performance significantly
585 over full virtualization. However, when run without a hypervisor
586 the kernel is theoretically slower and slightly larger.
588 config PARAVIRT_DEBUG
589 bool "paravirt-ops debugging"
590 depends on PARAVIRT && DEBUG_KERNEL
592 Enable to debug paravirt_ops internals. Specifically, BUG if
593 a paravirt_op is missing when it is called.
595 config PARAVIRT_SPINLOCKS
596 bool "Paravirtualization layer for spinlocks"
597 depends on PARAVIRT && SMP
598 select UNINLINE_SPIN_UNLOCK
600 Paravirtualized spinlocks allow a pvops backend to replace the
601 spinlock implementation with something virtualization-friendly
602 (for example, block the virtual CPU rather than spinning).
604 It has a minimal impact on native kernels and gives a nice performance
605 benefit on paravirtualized KVM / Xen kernels.
607 If you are unsure how to answer this question, answer Y.
609 source "arch/x86/xen/Kconfig"
612 bool "KVM Guest support (including kvmclock)"
614 select PARAVIRT_CLOCK
617 This option enables various optimizations for running under the KVM
618 hypervisor. It includes a paravirtualized clock, so that instead
619 of relying on a PIT (or probably other) emulation by the
620 underlying device model, the host provides the guest with
621 timing infrastructure such as time of day, and system time
624 bool "Enable debug information for KVM Guests in debugfs"
625 depends on KVM_GUEST && DEBUG_FS
628 This option enables collection of various statistics for KVM guest.
629 Statistics are displayed in debugfs filesystem. Enabling this option
630 may incur significant overhead.
632 source "arch/x86/lguest/Kconfig"
634 config PARAVIRT_TIME_ACCOUNTING
635 bool "Paravirtual steal time accounting"
639 Select this option to enable fine granularity task steal time
640 accounting. Time spent executing other tasks in parallel with
641 the current vCPU is discounted from the vCPU power. To account for
642 that, there can be a small performance impact.
644 If in doubt, say N here.
646 config PARAVIRT_CLOCK
649 endif #HYPERVISOR_GUEST
657 This option adds a kernel parameter 'memtest', which allows memtest
659 memtest=0, mean disabled; -- default
660 memtest=1, mean do 1 test pattern;
662 memtest=4, mean do 4 test patterns.
663 If you are unsure how to answer this question, answer N.
665 source "arch/x86/Kconfig.cpu"
669 prompt "HPET Timer Support" if X86_32
671 Use the IA-PC HPET (High Precision Event Timer) to manage
672 time in preference to the PIT and RTC, if a HPET is
674 HPET is the next generation timer replacing legacy 8254s.
675 The HPET provides a stable time base on SMP
676 systems, unlike the TSC, but it is more expensive to access,
677 as it is off-chip. You can find the HPET spec at
678 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
680 You can safely choose Y here. However, HPET will only be
681 activated if the platform and the BIOS support this feature.
682 Otherwise the 8254 will be used for timing services.
684 Choose N to continue using the legacy 8254 timer.
686 config HPET_EMULATE_RTC
688 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
691 def_bool y if X86_INTEL_MID
692 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
694 depends on X86_INTEL_MID && SFI
696 APB timer is the replacement for 8254, HPET on X86 MID platforms.
697 The APBT provides a stable time base on SMP
698 systems, unlike the TSC, but it is more expensive to access,
699 as it is off-chip. APB timers are always running regardless of CPU
700 C states, they are used as per CPU clockevent device when possible.
702 # Mark as expert because too many people got it wrong.
703 # The code disables itself when not needed.
706 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
707 bool "Enable DMI scanning" if EXPERT
709 Enabled scanning of DMI to identify machine quirks. Say Y
710 here unless you have verified that your setup is not
711 affected by entries in the DMI blacklist. Required by PNP
715 bool "Old AMD GART IOMMU support"
717 depends on X86_64 && PCI && AMD_NB
719 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
720 GART based hardware IOMMUs.
722 The GART supports full DMA access for devices with 32-bit access
723 limitations, on systems with more than 3 GB. This is usually needed
724 for USB, sound, many IDE/SATA chipsets and some other devices.
726 Newer systems typically have a modern AMD IOMMU, supported via
727 the CONFIG_AMD_IOMMU=y config option.
729 In normal configurations this driver is only active when needed:
730 there's more than 3 GB of memory and the system contains a
731 32-bit limited device.
736 bool "IBM Calgary IOMMU support"
738 depends on X86_64 && PCI
740 Support for hardware IOMMUs in IBM's xSeries x366 and x460
741 systems. Needed to run systems with more than 3GB of memory
742 properly with 32-bit PCI devices that do not support DAC
743 (Double Address Cycle). Calgary also supports bus level
744 isolation, where all DMAs pass through the IOMMU. This
745 prevents them from going anywhere except their intended
746 destination. This catches hard-to-find kernel bugs and
747 mis-behaving drivers and devices that do not use the DMA-API
748 properly to set up their DMA buffers. The IOMMU can be
749 turned off at boot time with the iommu=off parameter.
750 Normally the kernel will make the right choice by itself.
753 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
755 prompt "Should Calgary be enabled by default?"
756 depends on CALGARY_IOMMU
758 Should Calgary be enabled by default? if you choose 'y', Calgary
759 will be used (if it exists). If you choose 'n', Calgary will not be
760 used even if it exists. If you choose 'n' and would like to use
761 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
764 # need this always selected by IOMMU for the VIA workaround
768 Support for software bounce buffers used on x86-64 systems
769 which don't have a hardware IOMMU. Using this PCI devices
770 which can only access 32-bits of memory can be used on systems
771 with more than 3 GB of memory.
776 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
779 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
780 depends on X86_64 && SMP && DEBUG_KERNEL
781 select CPUMASK_OFFSTACK
783 Enable maximum number of CPUS and NUMA Nodes for this architecture.
787 int "Maximum number of CPUs" if SMP && !MAXSMP
788 range 2 8 if SMP && X86_32 && !X86_BIGSMP
789 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
790 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
792 default "8192" if MAXSMP
793 default "32" if SMP && X86_BIGSMP
796 This allows you to specify the maximum number of CPUs which this
797 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
798 supported value is 4096, otherwise the maximum value is 512. The
799 minimum value which makes sense is 2.
801 This is purely to save memory - each supported CPU adds
802 approximately eight kilobytes to the kernel image.
805 bool "SMT (Hyperthreading) scheduler support"
808 SMT scheduler support improves the CPU scheduler's decision making
809 when dealing with Intel Pentium 4 chips with HyperThreading at a
810 cost of slightly increased overhead in some places. If unsure say
815 prompt "Multi-core scheduler support"
818 Multi-core scheduler support improves the CPU scheduler's decision
819 making when dealing with multi-core CPU chips at a cost of slightly
820 increased overhead in some places. If unsure say N here.
822 source "kernel/Kconfig.preempt"
825 bool "Local APIC support on uniprocessors"
826 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
828 A local APIC (Advanced Programmable Interrupt Controller) is an
829 integrated interrupt controller in the CPU. If you have a single-CPU
830 system which has a processor with a local APIC, you can say Y here to
831 enable and use it. If you say Y here even though your machine doesn't
832 have a local APIC, then the kernel will still run with no slowdown at
833 all. The local APIC supports CPU-generated self-interrupts (timer,
834 performance counters), and the NMI watchdog which detects hard
838 bool "IO-APIC support on uniprocessors"
839 depends on X86_UP_APIC
841 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
842 SMP-capable replacement for PC-style interrupt controllers. Most
843 SMP systems and many recent uniprocessor systems have one.
845 If you have a single-CPU system with an IO-APIC, you can say Y here
846 to use it. If you say Y here even though your machine doesn't have
847 an IO-APIC, then the kernel will still run with no slowdown at all.
849 config X86_LOCAL_APIC
851 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
855 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
856 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
859 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
860 bool "Reroute for broken boot IRQs"
861 depends on X86_IO_APIC
863 This option enables a workaround that fixes a source of
864 spurious interrupts. This is recommended when threaded
865 interrupt handling is used on systems where the generation of
866 superfluous "boot interrupts" cannot be disabled.
868 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
869 entry in the chipset's IO-APIC is masked (as, e.g. the RT
870 kernel does during interrupt handling). On chipsets where this
871 boot IRQ generation cannot be disabled, this workaround keeps
872 the original IRQ line masked so that only the equivalent "boot
873 IRQ" is delivered to the CPUs. The workaround also tells the
874 kernel to set up the IRQ handler on the boot IRQ line. In this
875 way only one interrupt is delivered to the kernel. Otherwise
876 the spurious second interrupt may cause the kernel to bring
877 down (vital) interrupt lines.
879 Only affects "broken" chipsets. Interrupt sharing may be
880 increased on these systems.
883 bool "Machine Check / overheating reporting"
886 Machine Check support allows the processor to notify the
887 kernel if it detects a problem (e.g. overheating, data corruption).
888 The action the kernel takes depends on the severity of the problem,
889 ranging from warning messages to halting the machine.
893 prompt "Intel MCE features"
894 depends on X86_MCE && X86_LOCAL_APIC
896 Additional support for intel specific MCE features such as
901 prompt "AMD MCE features"
902 depends on X86_MCE && X86_LOCAL_APIC
904 Additional support for AMD specific MCE features such as
905 the DRAM Error Threshold.
907 config X86_ANCIENT_MCE
908 bool "Support for old Pentium 5 / WinChip machine checks"
909 depends on X86_32 && X86_MCE
911 Include support for machine check handling on old Pentium 5 or WinChip
912 systems. These typically need to be enabled explicitly on the command
915 config X86_MCE_THRESHOLD
916 depends on X86_MCE_AMD || X86_MCE_INTEL
919 config X86_MCE_INJECT
921 tristate "Machine check injector support"
923 Provide support for injecting machine checks for testing purposes.
924 If you don't know what a machine check is and you don't do kernel
925 QA it is safe to say n.
927 config X86_THERMAL_VECTOR
929 depends on X86_MCE_INTEL
932 bool "Enable VM86 support" if EXPERT
936 This option is required by programs like DOSEMU to run
937 16-bit real mode legacy code on x86 processors. It also may
938 be needed by software like XFree86 to initialize some video
939 cards via BIOS. Disabling this option saves about 6K.
942 bool "Enable support for 16-bit segments" if EXPERT
945 This option is required by programs like Wine to run 16-bit
946 protected mode legacy code on x86 processors. Disabling
947 this option saves about 300 bytes on i386, or around 6K text
948 plus 16K runtime memory on x86-64,
952 depends on X86_16BIT && X86_32
956 depends on X86_16BIT && X86_64
959 tristate "Toshiba Laptop support"
962 This adds a driver to safely access the System Management Mode of
963 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
964 not work on models with a Phoenix BIOS. The System Management Mode
965 is used to set the BIOS and power saving options on Toshiba portables.
967 For information on utilities to make use of this driver see the
968 Toshiba Linux utilities web site at:
969 <http://www.buzzard.org.uk/toshiba/>.
971 Say Y if you intend to run this kernel on a Toshiba portable.
975 tristate "Dell laptop support"
978 This adds a driver to safely access the System Management Mode
979 of the CPU on the Dell Inspiron 8000. The System Management Mode
980 is used to read cpu temperature and cooling fan status and to
981 control the fans on the I8K portables.
983 This driver has been tested only on the Inspiron 8000 but it may
984 also work with other Dell laptops. You can force loading on other
985 models by passing the parameter `force=1' to the module. Use at
988 For information on utilities to make use of this driver see the
989 I8K Linux utilities web site at:
990 <http://people.debian.org/~dz/i8k/>
992 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
995 config X86_REBOOTFIXUPS
996 bool "Enable X86 board specific fixups for reboot"
999 This enables chipset and/or board specific fixups to be done
1000 in order to get reboot to work correctly. This is only needed on
1001 some combinations of hardware and BIOS. The symptom, for which
1002 this config is intended, is when reboot ends with a stalled/hung
1005 Currently, the only fixup is for the Geode machines using
1006 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1008 Say Y if you want to enable the fixup. Currently, it's safe to
1009 enable this option even if you don't need it.
1013 tristate "CPU microcode loading support"
1014 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1018 If you say Y here, you will be able to update the microcode on
1019 certain Intel and AMD processors. The Intel support is for the
1020 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1021 Xeon etc. The AMD support is for families 0x10 and later. You will
1022 obviously need the actual microcode binary data itself which is not
1023 shipped with the Linux kernel.
1025 This option selects the general module only, you need to select
1026 at least one vendor specific module as well.
1028 To compile this driver as a module, choose M here: the module
1029 will be called microcode.
1031 config MICROCODE_INTEL
1032 bool "Intel microcode loading support"
1033 depends on MICROCODE
1037 This options enables microcode patch loading support for Intel
1040 For the current Intel microcode data package go to
1041 <https://downloadcenter.intel.com> and search for
1042 'Linux Processor Microcode Data File'.
1044 config MICROCODE_AMD
1045 bool "AMD microcode loading support"
1046 depends on MICROCODE
1049 If you select this option, microcode patch loading support for AMD
1050 processors will be enabled.
1052 config MICROCODE_OLD_INTERFACE
1054 depends on MICROCODE
1056 config MICROCODE_INTEL_EARLY
1059 config MICROCODE_AMD_EARLY
1062 config MICROCODE_EARLY
1063 bool "Early load microcode"
1064 depends on MICROCODE=y && BLK_DEV_INITRD
1065 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1066 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1069 This option provides functionality to read additional microcode data
1070 at the beginning of initrd image. The data tells kernel to load
1071 microcode to CPU's as early as possible. No functional change if no
1072 microcode data is glued to the initrd, therefore it's safe to say Y.
1075 tristate "/dev/cpu/*/msr - Model-specific register support"
1077 This device gives privileged processes access to the x86
1078 Model-Specific Registers (MSRs). It is a character device with
1079 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1080 MSR accesses are directed to a specific CPU on multi-processor
1084 tristate "/dev/cpu/*/cpuid - CPU information support"
1086 This device gives processes access to the x86 CPUID instruction to
1087 be executed on a specific processor. It is a character device
1088 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1092 prompt "High Memory Support"
1099 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1100 However, the address space of 32-bit x86 processors is only 4
1101 Gigabytes large. That means that, if you have a large amount of
1102 physical memory, not all of it can be "permanently mapped" by the
1103 kernel. The physical memory that's not permanently mapped is called
1106 If you are compiling a kernel which will never run on a machine with
1107 more than 1 Gigabyte total physical RAM, answer "off" here (default
1108 choice and suitable for most users). This will result in a "3GB/1GB"
1109 split: 3GB are mapped so that each process sees a 3GB virtual memory
1110 space and the remaining part of the 4GB virtual memory space is used
1111 by the kernel to permanently map as much physical memory as
1114 If the machine has between 1 and 4 Gigabytes physical RAM, then
1117 If more than 4 Gigabytes is used then answer "64GB" here. This
1118 selection turns Intel PAE (Physical Address Extension) mode on.
1119 PAE implements 3-level paging on IA32 processors. PAE is fully
1120 supported by Linux, PAE mode is implemented on all recent Intel
1121 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1122 then the kernel will not boot on CPUs that don't support PAE!
1124 The actual amount of total physical memory will either be
1125 auto detected or can be forced by using a kernel command line option
1126 such as "mem=256M". (Try "man bootparam" or see the documentation of
1127 your boot loader (lilo or loadlin) about how to pass options to the
1128 kernel at boot time.)
1130 If unsure, say "off".
1135 Select this if you have a 32-bit processor and between 1 and 4
1136 gigabytes of physical RAM.
1143 Select this if you have a 32-bit processor and more than 4
1144 gigabytes of physical RAM.
1149 prompt "Memory split" if EXPERT
1153 Select the desired split between kernel and user memory.
1155 If the address range available to the kernel is less than the
1156 physical memory installed, the remaining memory will be available
1157 as "high memory". Accessing high memory is a little more costly
1158 than low memory, as it needs to be mapped into the kernel first.
1159 Note that increasing the kernel address space limits the range
1160 available to user programs, making the address space there
1161 tighter. Selecting anything other than the default 3G/1G split
1162 will also likely make your kernel incompatible with binary-only
1165 If you are not absolutely sure what you are doing, leave this
1169 bool "3G/1G user/kernel split"
1170 config VMSPLIT_3G_OPT
1172 bool "3G/1G user/kernel split (for full 1G low memory)"
1174 bool "2G/2G user/kernel split"
1175 config VMSPLIT_2G_OPT
1177 bool "2G/2G user/kernel split (for full 2G low memory)"
1179 bool "1G/3G user/kernel split"
1184 default 0xB0000000 if VMSPLIT_3G_OPT
1185 default 0x80000000 if VMSPLIT_2G
1186 default 0x78000000 if VMSPLIT_2G_OPT
1187 default 0x40000000 if VMSPLIT_1G
1193 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1196 bool "PAE (Physical Address Extension) Support"
1197 depends on X86_32 && !HIGHMEM4G
1199 PAE is required for NX support, and furthermore enables
1200 larger swapspace support for non-overcommit purposes. It
1201 has the cost of more pagetable lookup overhead, and also
1202 consumes more pagetable space per process.
1204 config ARCH_PHYS_ADDR_T_64BIT
1206 depends on X86_64 || X86_PAE
1208 config ARCH_DMA_ADDR_T_64BIT
1210 depends on X86_64 || HIGHMEM64G
1212 config DIRECT_GBPAGES
1213 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1217 Allow the kernel linear mapping to use 1GB pages on CPUs that
1218 support it. This can improve the kernel's performance a tiny bit by
1219 reducing TLB pressure. If in doubt, say "Y".
1221 # Common NUMA Features
1223 bool "Numa Memory Allocation and Scheduler Support"
1225 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1226 default y if X86_BIGSMP
1228 Enable NUMA (Non Uniform Memory Access) support.
1230 The kernel will try to allocate memory used by a CPU on the
1231 local memory controller of the CPU and add some more
1232 NUMA awareness to the kernel.
1234 For 64-bit this is recommended if the system is Intel Core i7
1235 (or later), AMD Opteron, or EM64T NUMA.
1237 For 32-bit this is only needed if you boot a 32-bit
1238 kernel on a 64-bit NUMA platform.
1240 Otherwise, you should say N.
1244 prompt "Old style AMD Opteron NUMA detection"
1245 depends on X86_64 && NUMA && PCI
1247 Enable AMD NUMA node topology detection. You should say Y here if
1248 you have a multi processor AMD system. This uses an old method to
1249 read the NUMA configuration directly from the builtin Northbridge
1250 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1251 which also takes priority if both are compiled in.
1253 config X86_64_ACPI_NUMA
1255 prompt "ACPI NUMA detection"
1256 depends on X86_64 && NUMA && ACPI && PCI
1259 Enable ACPI SRAT based node topology detection.
1261 # Some NUMA nodes have memory ranges that span
1262 # other nodes. Even though a pfn is valid and
1263 # between a node's start and end pfns, it may not
1264 # reside on that node. See memmap_init_zone()
1266 config NODES_SPAN_OTHER_NODES
1268 depends on X86_64_ACPI_NUMA
1271 bool "NUMA emulation"
1274 Enable NUMA emulation. A flat machine will be split
1275 into virtual nodes when booted with "numa=fake=N", where N is the
1276 number of nodes. This is only useful for debugging.
1279 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1281 default "10" if MAXSMP
1282 default "6" if X86_64
1284 depends on NEED_MULTIPLE_NODES
1286 Specify the maximum number of NUMA Nodes available on the target
1287 system. Increases memory reserved to accommodate various tables.
1289 config ARCH_HAVE_MEMORY_PRESENT
1291 depends on X86_32 && DISCONTIGMEM
1293 config NEED_NODE_MEMMAP_SIZE
1295 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1297 config ARCH_FLATMEM_ENABLE
1299 depends on X86_32 && !NUMA
1301 config ARCH_DISCONTIGMEM_ENABLE
1303 depends on NUMA && X86_32
1305 config ARCH_DISCONTIGMEM_DEFAULT
1307 depends on NUMA && X86_32
1309 config ARCH_SPARSEMEM_ENABLE
1311 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1312 select SPARSEMEM_STATIC if X86_32
1313 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1315 config ARCH_SPARSEMEM_DEFAULT
1319 config ARCH_SELECT_MEMORY_MODEL
1321 depends on ARCH_SPARSEMEM_ENABLE
1323 config ARCH_MEMORY_PROBE
1324 bool "Enable sysfs memory/probe interface"
1325 depends on X86_64 && MEMORY_HOTPLUG
1327 This option enables a sysfs memory/probe interface for testing.
1328 See Documentation/memory-hotplug.txt for more information.
1329 If you are unsure how to answer this question, answer N.
1331 config ARCH_PROC_KCORE_TEXT
1333 depends on X86_64 && PROC_KCORE
1335 config ILLEGAL_POINTER_VALUE
1338 default 0xdead000000000000 if X86_64
1343 bool "Allocate 3rd-level pagetables from highmem"
1346 The VM uses one page table entry for each page of physical memory.
1347 For systems with a lot of RAM, this can be wasteful of precious
1348 low memory. Setting this option will put user-space page table
1349 entries in high memory.
1351 config X86_CHECK_BIOS_CORRUPTION
1352 bool "Check for low memory corruption"
1354 Periodically check for memory corruption in low memory, which
1355 is suspected to be caused by BIOS. Even when enabled in the
1356 configuration, it is disabled at runtime. Enable it by
1357 setting "memory_corruption_check=1" on the kernel command
1358 line. By default it scans the low 64k of memory every 60
1359 seconds; see the memory_corruption_check_size and
1360 memory_corruption_check_period parameters in
1361 Documentation/kernel-parameters.txt to adjust this.
1363 When enabled with the default parameters, this option has
1364 almost no overhead, as it reserves a relatively small amount
1365 of memory and scans it infrequently. It both detects corruption
1366 and prevents it from affecting the running system.
1368 It is, however, intended as a diagnostic tool; if repeatable
1369 BIOS-originated corruption always affects the same memory,
1370 you can use memmap= to prevent the kernel from using that
1373 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1374 bool "Set the default setting of memory_corruption_check"
1375 depends on X86_CHECK_BIOS_CORRUPTION
1378 Set whether the default state of memory_corruption_check is
1381 config X86_RESERVE_LOW
1382 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1386 Specify the amount of low memory to reserve for the BIOS.
1388 The first page contains BIOS data structures that the kernel
1389 must not use, so that page must always be reserved.
1391 By default we reserve the first 64K of physical RAM, as a
1392 number of BIOSes are known to corrupt that memory range
1393 during events such as suspend/resume or monitor cable
1394 insertion, so it must not be used by the kernel.
1396 You can set this to 4 if you are absolutely sure that you
1397 trust the BIOS to get all its memory reservations and usages
1398 right. If you know your BIOS have problems beyond the
1399 default 64K area, you can set this to 640 to avoid using the
1400 entire low memory range.
1402 If you have doubts about the BIOS (e.g. suspend/resume does
1403 not work or there's kernel crashes after certain hardware
1404 hotplug events) then you might want to enable
1405 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1406 typical corruption patterns.
1408 Leave this to the default value of 64 if you are unsure.
1410 config MATH_EMULATION
1412 prompt "Math emulation" if X86_32
1414 Linux can emulate a math coprocessor (used for floating point
1415 operations) if you don't have one. 486DX and Pentium processors have
1416 a math coprocessor built in, 486SX and 386 do not, unless you added
1417 a 487DX or 387, respectively. (The messages during boot time can
1418 give you some hints here ["man dmesg"].) Everyone needs either a
1419 coprocessor or this emulation.
1421 If you don't have a math coprocessor, you need to say Y here; if you
1422 say Y here even though you have a coprocessor, the coprocessor will
1423 be used nevertheless. (This behavior can be changed with the kernel
1424 command line option "no387", which comes handy if your coprocessor
1425 is broken. Try "man bootparam" or see the documentation of your boot
1426 loader (lilo or loadlin) about how to pass options to the kernel at
1427 boot time.) This means that it is a good idea to say Y here if you
1428 intend to use this kernel on different machines.
1430 More information about the internals of the Linux math coprocessor
1431 emulation can be found in <file:arch/x86/math-emu/README>.
1433 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1434 kernel, it won't hurt.
1438 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1440 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1441 the Memory Type Range Registers (MTRRs) may be used to control
1442 processor access to memory ranges. This is most useful if you have
1443 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1444 allows bus write transfers to be combined into a larger transfer
1445 before bursting over the PCI/AGP bus. This can increase performance
1446 of image write operations 2.5 times or more. Saying Y here creates a
1447 /proc/mtrr file which may be used to manipulate your processor's
1448 MTRRs. Typically the X server should use this.
1450 This code has a reasonably generic interface so that similar
1451 control registers on other processors can be easily supported
1454 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1455 Registers (ARRs) which provide a similar functionality to MTRRs. For
1456 these, the ARRs are used to emulate the MTRRs.
1457 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1458 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1459 write-combining. All of these processors are supported by this code
1460 and it makes sense to say Y here if you have one of them.
1462 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1463 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1464 can lead to all sorts of problems, so it's good to say Y here.
1466 You can safely say Y even if your machine doesn't have MTRRs, you'll
1467 just add about 9 KB to your kernel.
1469 See <file:Documentation/x86/mtrr.txt> for more information.
1471 config MTRR_SANITIZER
1473 prompt "MTRR cleanup support"
1476 Convert MTRR layout from continuous to discrete, so X drivers can
1477 add writeback entries.
1479 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1480 The largest mtrr entry size for a continuous block can be set with
1485 config MTRR_SANITIZER_ENABLE_DEFAULT
1486 int "MTRR cleanup enable value (0-1)"
1489 depends on MTRR_SANITIZER
1491 Enable mtrr cleanup default value
1493 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1494 int "MTRR cleanup spare reg num (0-7)"
1497 depends on MTRR_SANITIZER
1499 mtrr cleanup spare entries default, it can be changed via
1500 mtrr_spare_reg_nr=N on the kernel command line.
1504 prompt "x86 PAT support" if EXPERT
1507 Use PAT attributes to setup page level cache control.
1509 PATs are the modern equivalents of MTRRs and are much more
1510 flexible than MTRRs.
1512 Say N here if you see bootup problems (boot crash, boot hang,
1513 spontaneous reboots) or a non-working video driver.
1517 config ARCH_USES_PG_UNCACHED
1523 prompt "x86 architectural random number generator" if EXPERT
1525 Enable the x86 architectural RDRAND instruction
1526 (Intel Bull Mountain technology) to generate random numbers.
1527 If supported, this is a high bandwidth, cryptographically
1528 secure hardware random number generator.
1532 prompt "Supervisor Mode Access Prevention" if EXPERT
1534 Supervisor Mode Access Prevention (SMAP) is a security
1535 feature in newer Intel processors. There is a small
1536 performance cost if this enabled and turned on; there is
1537 also a small increase in the kernel size if this is enabled.
1542 bool "EFI runtime service support"
1545 select EFI_RUNTIME_WRAPPERS
1547 This enables the kernel to use EFI runtime services that are
1548 available (such as the EFI variable services).
1550 This option is only useful on systems that have EFI firmware.
1551 In addition, you should use the latest ELILO loader available
1552 at <http://elilo.sourceforge.net> in order to take advantage
1553 of EFI runtime services. However, even with this option, the
1554 resultant kernel should continue to boot on existing non-EFI
1558 bool "EFI stub support"
1559 depends on EFI && !X86_USE_3DNOW
1562 This kernel feature allows a bzImage to be loaded directly
1563 by EFI firmware without the use of a bootloader.
1565 See Documentation/efi-stub.txt for more information.
1568 bool "EFI mixed-mode support"
1569 depends on EFI_STUB && X86_64
1571 Enabling this feature allows a 64-bit kernel to be booted
1572 on a 32-bit firmware, provided that your CPU supports 64-bit
1575 Note that it is not possible to boot a mixed-mode enabled
1576 kernel via the EFI boot stub - a bootloader that supports
1577 the EFI handover protocol must be used.
1583 prompt "Enable seccomp to safely compute untrusted bytecode"
1585 This kernel feature is useful for number crunching applications
1586 that may need to compute untrusted bytecode during their
1587 execution. By using pipes or other transports made available to
1588 the process as file descriptors supporting the read/write
1589 syscalls, it's possible to isolate those applications in
1590 their own address space using seccomp. Once seccomp is
1591 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1592 and the task is only allowed to execute a few safe syscalls
1593 defined by each seccomp mode.
1595 If unsure, say Y. Only embedded should say N here.
1597 source kernel/Kconfig.hz
1600 bool "kexec system call"
1602 kexec is a system call that implements the ability to shutdown your
1603 current kernel, and to start another kernel. It is like a reboot
1604 but it is independent of the system firmware. And like a reboot
1605 you can start any kernel with it, not just Linux.
1607 The name comes from the similarity to the exec system call.
1609 It is an ongoing process to be certain the hardware in a machine
1610 is properly shutdown, so do not be surprised if this code does not
1611 initially work for you. As of this writing the exact hardware
1612 interface is strongly in flux, so no good recommendation can be
1616 bool "kexec file based system call"
1621 depends on CRYPTO_SHA256=y
1623 This is new version of kexec system call. This system call is
1624 file based and takes file descriptors as system call argument
1625 for kernel and initramfs as opposed to list of segments as
1626 accepted by previous system call.
1628 config KEXEC_VERIFY_SIG
1629 bool "Verify kernel signature during kexec_file_load() syscall"
1630 depends on KEXEC_FILE
1632 This option makes kernel signature verification mandatory for
1633 kexec_file_load() syscall. If kernel is signature can not be
1634 verified, kexec_file_load() will fail.
1636 This option enforces signature verification at generic level.
1637 One needs to enable signature verification for type of kernel
1638 image being loaded to make sure it works. For example, enable
1639 bzImage signature verification option to be able to load and
1640 verify signatures of bzImage. Otherwise kernel loading will fail.
1642 config KEXEC_BZIMAGE_VERIFY_SIG
1643 bool "Enable bzImage signature verification support"
1644 depends on KEXEC_VERIFY_SIG
1645 depends on SIGNED_PE_FILE_VERIFICATION
1646 select SYSTEM_TRUSTED_KEYRING
1648 Enable bzImage signature verification support.
1651 bool "kernel crash dumps"
1652 depends on X86_64 || (X86_32 && HIGHMEM)
1654 Generate crash dump after being started by kexec.
1655 This should be normally only set in special crash dump kernels
1656 which are loaded in the main kernel with kexec-tools into
1657 a specially reserved region and then later executed after
1658 a crash by kdump/kexec. The crash dump kernel must be compiled
1659 to a memory address not used by the main kernel or BIOS using
1660 PHYSICAL_START, or it must be built as a relocatable image
1661 (CONFIG_RELOCATABLE=y).
1662 For more details see Documentation/kdump/kdump.txt
1666 depends on KEXEC && HIBERNATION
1668 Jump between original kernel and kexeced kernel and invoke
1669 code in physical address mode via KEXEC
1671 config PHYSICAL_START
1672 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1675 This gives the physical address where the kernel is loaded.
1677 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1678 bzImage will decompress itself to above physical address and
1679 run from there. Otherwise, bzImage will run from the address where
1680 it has been loaded by the boot loader and will ignore above physical
1683 In normal kdump cases one does not have to set/change this option
1684 as now bzImage can be compiled as a completely relocatable image
1685 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1686 address. This option is mainly useful for the folks who don't want
1687 to use a bzImage for capturing the crash dump and want to use a
1688 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1689 to be specifically compiled to run from a specific memory area
1690 (normally a reserved region) and this option comes handy.
1692 So if you are using bzImage for capturing the crash dump,
1693 leave the value here unchanged to 0x1000000 and set
1694 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1695 for capturing the crash dump change this value to start of
1696 the reserved region. In other words, it can be set based on
1697 the "X" value as specified in the "crashkernel=YM@XM"
1698 command line boot parameter passed to the panic-ed
1699 kernel. Please take a look at Documentation/kdump/kdump.txt
1700 for more details about crash dumps.
1702 Usage of bzImage for capturing the crash dump is recommended as
1703 one does not have to build two kernels. Same kernel can be used
1704 as production kernel and capture kernel. Above option should have
1705 gone away after relocatable bzImage support is introduced. But it
1706 is present because there are users out there who continue to use
1707 vmlinux for dump capture. This option should go away down the
1710 Don't change this unless you know what you are doing.
1713 bool "Build a relocatable kernel"
1716 This builds a kernel image that retains relocation information
1717 so it can be loaded someplace besides the default 1MB.
1718 The relocations tend to make the kernel binary about 10% larger,
1719 but are discarded at runtime.
1721 One use is for the kexec on panic case where the recovery kernel
1722 must live at a different physical address than the primary
1725 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1726 it has been loaded at and the compile time physical address
1727 (CONFIG_PHYSICAL_START) is used as the minimum location.
1729 config RANDOMIZE_BASE
1730 bool "Randomize the address of the kernel image"
1731 depends on RELOCATABLE
1734 Randomizes the physical and virtual address at which the
1735 kernel image is decompressed, as a security feature that
1736 deters exploit attempts relying on knowledge of the location
1737 of kernel internals.
1739 Entropy is generated using the RDRAND instruction if it is
1740 supported. If RDTSC is supported, it is used as well. If
1741 neither RDRAND nor RDTSC are supported, then randomness is
1742 read from the i8254 timer.
1744 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1745 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1746 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1747 minimum of 2MiB, only 10 bits of entropy is theoretically
1748 possible. At best, due to page table layouts, 64-bit can use
1749 9 bits of entropy and 32-bit uses 8 bits.
1753 config RANDOMIZE_BASE_MAX_OFFSET
1754 hex "Maximum kASLR offset allowed" if EXPERT
1755 depends on RANDOMIZE_BASE
1756 range 0x0 0x20000000 if X86_32
1757 default "0x20000000" if X86_32
1758 range 0x0 0x40000000 if X86_64
1759 default "0x40000000" if X86_64
1761 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1762 memory is used to determine the maximal offset in bytes that will
1763 be applied to the kernel when kernel Address Space Layout
1764 Randomization (kASLR) is active. This must be a multiple of
1767 On 32-bit this is limited to 512MiB by page table layouts. The
1770 On 64-bit this is limited by how the kernel fixmap page table is
1771 positioned, so this cannot be larger than 1GiB currently. Without
1772 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1773 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1774 modules area will shrink to compensate, up to the current maximum
1775 1GiB to 1GiB split. The default is 1GiB.
1777 If unsure, leave at the default value.
1779 # Relocation on x86 needs some additional build support
1780 config X86_NEED_RELOCS
1782 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1784 config PHYSICAL_ALIGN
1785 hex "Alignment value to which kernel should be aligned"
1787 range 0x2000 0x1000000 if X86_32
1788 range 0x200000 0x1000000 if X86_64
1790 This value puts the alignment restrictions on physical address
1791 where kernel is loaded and run from. Kernel is compiled for an
1792 address which meets above alignment restriction.
1794 If bootloader loads the kernel at a non-aligned address and
1795 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1796 address aligned to above value and run from there.
1798 If bootloader loads the kernel at a non-aligned address and
1799 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1800 load address and decompress itself to the address it has been
1801 compiled for and run from there. The address for which kernel is
1802 compiled already meets above alignment restrictions. Hence the
1803 end result is that kernel runs from a physical address meeting
1804 above alignment restrictions.
1806 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1807 this value must be a multiple of 0x200000.
1809 Don't change this unless you know what you are doing.
1812 bool "Support for hot-pluggable CPUs"
1815 Say Y here to allow turning CPUs off and on. CPUs can be
1816 controlled through /sys/devices/system/cpu.
1817 ( Note: power management support will enable this option
1818 automatically on SMP systems. )
1819 Say N if you want to disable CPU hotplug.
1821 config BOOTPARAM_HOTPLUG_CPU0
1822 bool "Set default setting of cpu0_hotpluggable"
1824 depends on HOTPLUG_CPU
1826 Set whether default state of cpu0_hotpluggable is on or off.
1828 Say Y here to enable CPU0 hotplug by default. If this switch
1829 is turned on, there is no need to give cpu0_hotplug kernel
1830 parameter and the CPU0 hotplug feature is enabled by default.
1832 Please note: there are two known CPU0 dependencies if you want
1833 to enable the CPU0 hotplug feature either by this switch or by
1834 cpu0_hotplug kernel parameter.
1836 First, resume from hibernate or suspend always starts from CPU0.
1837 So hibernate and suspend are prevented if CPU0 is offline.
1839 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1840 offline if any interrupt can not migrate out of CPU0. There may
1841 be other CPU0 dependencies.
1843 Please make sure the dependencies are under your control before
1844 you enable this feature.
1846 Say N if you don't want to enable CPU0 hotplug feature by default.
1847 You still can enable the CPU0 hotplug feature at boot by kernel
1848 parameter cpu0_hotplug.
1850 config DEBUG_HOTPLUG_CPU0
1852 prompt "Debug CPU0 hotplug"
1853 depends on HOTPLUG_CPU
1855 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1856 soon as possible and boots up userspace with CPU0 offlined. User
1857 can online CPU0 back after boot time.
1859 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1860 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1861 compilation or giving cpu0_hotplug kernel parameter at boot.
1867 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1868 depends on X86_32 || IA32_EMULATION
1870 Certain buggy versions of glibc will crash if they are
1871 presented with a 32-bit vDSO that is not mapped at the address
1872 indicated in its segment table.
1874 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1875 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1876 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1877 the only released version with the bug, but OpenSUSE 9
1878 contains a buggy "glibc 2.3.2".
1880 The symptom of the bug is that everything crashes on startup, saying:
1881 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1883 Saying Y here changes the default value of the vdso32 boot
1884 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1885 This works around the glibc bug but hurts performance.
1887 If unsure, say N: if you are compiling your own kernel, you
1888 are unlikely to be using a buggy version of glibc.
1891 bool "Built-in kernel command line"
1893 Allow for specifying boot arguments to the kernel at
1894 build time. On some systems (e.g. embedded ones), it is
1895 necessary or convenient to provide some or all of the
1896 kernel boot arguments with the kernel itself (that is,
1897 to not rely on the boot loader to provide them.)
1899 To compile command line arguments into the kernel,
1900 set this option to 'Y', then fill in the
1901 the boot arguments in CONFIG_CMDLINE.
1903 Systems with fully functional boot loaders (i.e. non-embedded)
1904 should leave this option set to 'N'.
1907 string "Built-in kernel command string"
1908 depends on CMDLINE_BOOL
1911 Enter arguments here that should be compiled into the kernel
1912 image and used at boot time. If the boot loader provides a
1913 command line at boot time, it is appended to this string to
1914 form the full kernel command line, when the system boots.
1916 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1917 change this behavior.
1919 In most cases, the command line (whether built-in or provided
1920 by the boot loader) should specify the device for the root
1923 config CMDLINE_OVERRIDE
1924 bool "Built-in command line overrides boot loader arguments"
1925 depends on CMDLINE_BOOL
1927 Set this option to 'Y' to have the kernel ignore the boot loader
1928 command line, and use ONLY the built-in command line.
1930 This is used to work around broken boot loaders. This should
1931 be set to 'N' under normal conditions.
1935 config ARCH_ENABLE_MEMORY_HOTPLUG
1937 depends on X86_64 || (X86_32 && HIGHMEM)
1939 config ARCH_ENABLE_MEMORY_HOTREMOVE
1941 depends on MEMORY_HOTPLUG
1943 config USE_PERCPU_NUMA_NODE_ID
1947 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1949 depends on X86_64 || X86_PAE
1951 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1953 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1955 menu "Power management and ACPI options"
1957 config ARCH_HIBERNATION_HEADER
1959 depends on X86_64 && HIBERNATION
1961 source "kernel/power/Kconfig"
1963 source "drivers/acpi/Kconfig"
1965 source "drivers/sfi/Kconfig"
1972 tristate "APM (Advanced Power Management) BIOS support"
1973 depends on X86_32 && PM_SLEEP
1975 APM is a BIOS specification for saving power using several different
1976 techniques. This is mostly useful for battery powered laptops with
1977 APM compliant BIOSes. If you say Y here, the system time will be
1978 reset after a RESUME operation, the /proc/apm device will provide
1979 battery status information, and user-space programs will receive
1980 notification of APM "events" (e.g. battery status change).
1982 If you select "Y" here, you can disable actual use of the APM
1983 BIOS by passing the "apm=off" option to the kernel at boot time.
1985 Note that the APM support is almost completely disabled for
1986 machines with more than one CPU.
1988 In order to use APM, you will need supporting software. For location
1989 and more information, read <file:Documentation/power/apm-acpi.txt>
1990 and the Battery Powered Linux mini-HOWTO, available from
1991 <http://www.tldp.org/docs.html#howto>.
1993 This driver does not spin down disk drives (see the hdparm(8)
1994 manpage ("man 8 hdparm") for that), and it doesn't turn off
1995 VESA-compliant "green" monitors.
1997 This driver does not support the TI 4000M TravelMate and the ACER
1998 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1999 desktop machines also don't have compliant BIOSes, and this driver
2000 may cause those machines to panic during the boot phase.
2002 Generally, if you don't have a battery in your machine, there isn't
2003 much point in using this driver and you should say N. If you get
2004 random kernel OOPSes or reboots that don't seem to be related to
2005 anything, try disabling/enabling this option (or disabling/enabling
2008 Some other things you should try when experiencing seemingly random,
2011 1) make sure that you have enough swap space and that it is
2013 2) pass the "no-hlt" option to the kernel
2014 3) switch on floating point emulation in the kernel and pass
2015 the "no387" option to the kernel
2016 4) pass the "floppy=nodma" option to the kernel
2017 5) pass the "mem=4M" option to the kernel (thereby disabling
2018 all but the first 4 MB of RAM)
2019 6) make sure that the CPU is not over clocked.
2020 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2021 8) disable the cache from your BIOS settings
2022 9) install a fan for the video card or exchange video RAM
2023 10) install a better fan for the CPU
2024 11) exchange RAM chips
2025 12) exchange the motherboard.
2027 To compile this driver as a module, choose M here: the
2028 module will be called apm.
2032 config APM_IGNORE_USER_SUSPEND
2033 bool "Ignore USER SUSPEND"
2035 This option will ignore USER SUSPEND requests. On machines with a
2036 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2037 series notebooks, it is necessary to say Y because of a BIOS bug.
2039 config APM_DO_ENABLE
2040 bool "Enable PM at boot time"
2042 Enable APM features at boot time. From page 36 of the APM BIOS
2043 specification: "When disabled, the APM BIOS does not automatically
2044 power manage devices, enter the Standby State, enter the Suspend
2045 State, or take power saving steps in response to CPU Idle calls."
2046 This driver will make CPU Idle calls when Linux is idle (unless this
2047 feature is turned off -- see "Do CPU IDLE calls", below). This
2048 should always save battery power, but more complicated APM features
2049 will be dependent on your BIOS implementation. You may need to turn
2050 this option off if your computer hangs at boot time when using APM
2051 support, or if it beeps continuously instead of suspending. Turn
2052 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2053 T400CDT. This is off by default since most machines do fine without
2058 bool "Make CPU Idle calls when idle"
2060 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2061 On some machines, this can activate improved power savings, such as
2062 a slowed CPU clock rate, when the machine is idle. These idle calls
2063 are made after the idle loop has run for some length of time (e.g.,
2064 333 mS). On some machines, this will cause a hang at boot time or
2065 whenever the CPU becomes idle. (On machines with more than one CPU,
2066 this option does nothing.)
2068 config APM_DISPLAY_BLANK
2069 bool "Enable console blanking using APM"
2071 Enable console blanking using the APM. Some laptops can use this to
2072 turn off the LCD backlight when the screen blanker of the Linux
2073 virtual console blanks the screen. Note that this is only used by
2074 the virtual console screen blanker, and won't turn off the backlight
2075 when using the X Window system. This also doesn't have anything to
2076 do with your VESA-compliant power-saving monitor. Further, this
2077 option doesn't work for all laptops -- it might not turn off your
2078 backlight at all, or it might print a lot of errors to the console,
2079 especially if you are using gpm.
2081 config APM_ALLOW_INTS
2082 bool "Allow interrupts during APM BIOS calls"
2084 Normally we disable external interrupts while we are making calls to
2085 the APM BIOS as a measure to lessen the effects of a badly behaving
2086 BIOS implementation. The BIOS should reenable interrupts if it
2087 needs to. Unfortunately, some BIOSes do not -- especially those in
2088 many of the newer IBM Thinkpads. If you experience hangs when you
2089 suspend, try setting this to Y. Otherwise, say N.
2093 source "drivers/cpufreq/Kconfig"
2095 source "drivers/cpuidle/Kconfig"
2097 source "drivers/idle/Kconfig"
2102 menu "Bus options (PCI etc.)"
2108 Find out whether you have a PCI motherboard. PCI is the name of a
2109 bus system, i.e. the way the CPU talks to the other stuff inside
2110 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2111 VESA. If you have PCI, say Y, otherwise N.
2114 prompt "PCI access mode"
2115 depends on X86_32 && PCI
2118 On PCI systems, the BIOS can be used to detect the PCI devices and
2119 determine their configuration. However, some old PCI motherboards
2120 have BIOS bugs and may crash if this is done. Also, some embedded
2121 PCI-based systems don't have any BIOS at all. Linux can also try to
2122 detect the PCI hardware directly without using the BIOS.
2124 With this option, you can specify how Linux should detect the
2125 PCI devices. If you choose "BIOS", the BIOS will be used,
2126 if you choose "Direct", the BIOS won't be used, and if you
2127 choose "MMConfig", then PCI Express MMCONFIG will be used.
2128 If you choose "Any", the kernel will try MMCONFIG, then the
2129 direct access method and falls back to the BIOS if that doesn't
2130 work. If unsure, go with the default, which is "Any".
2135 config PCI_GOMMCONFIG
2152 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2154 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2157 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2161 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2165 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2169 depends on PCI && XEN
2177 bool "Support mmconfig PCI config space access"
2178 depends on X86_64 && PCI && ACPI
2180 config PCI_CNB20LE_QUIRK
2181 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2184 Read the PCI windows out of the CNB20LE host bridge. This allows
2185 PCI hotplug to work on systems with the CNB20LE chipset which do
2188 There's no public spec for this chipset, and this functionality
2189 is known to be incomplete.
2191 You should say N unless you know you need this.
2193 source "drivers/pci/pcie/Kconfig"
2195 source "drivers/pci/Kconfig"
2197 # x86_64 have no ISA slots, but can have ISA-style DMA.
2199 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2202 Enables ISA-style DMA support for devices requiring such controllers.
2210 Find out whether you have ISA slots on your motherboard. ISA is the
2211 name of a bus system, i.e. the way the CPU talks to the other stuff
2212 inside your box. Other bus systems are PCI, EISA, MicroChannel
2213 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2214 newer boards don't support it. If you have ISA, say Y, otherwise N.
2220 The Extended Industry Standard Architecture (EISA) bus was
2221 developed as an open alternative to the IBM MicroChannel bus.
2223 The EISA bus provided some of the features of the IBM MicroChannel
2224 bus while maintaining backward compatibility with cards made for
2225 the older ISA bus. The EISA bus saw limited use between 1988 and
2226 1995 when it was made obsolete by the PCI bus.
2228 Say Y here if you are building a kernel for an EISA-based machine.
2232 source "drivers/eisa/Kconfig"
2235 tristate "NatSemi SCx200 support"
2237 This provides basic support for National Semiconductor's
2238 (now AMD's) Geode processors. The driver probes for the
2239 PCI-IDs of several on-chip devices, so its a good dependency
2240 for other scx200_* drivers.
2242 If compiled as a module, the driver is named scx200.
2244 config SCx200HR_TIMER
2245 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2249 This driver provides a clocksource built upon the on-chip
2250 27MHz high-resolution timer. Its also a workaround for
2251 NSC Geode SC-1100's buggy TSC, which loses time when the
2252 processor goes idle (as is done by the scheduler). The
2253 other workaround is idle=poll boot option.
2256 bool "One Laptop Per Child support"
2263 Add support for detecting the unique features of the OLPC
2267 bool "OLPC XO-1 Power Management"
2268 depends on OLPC && MFD_CS5535 && PM_SLEEP
2271 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2274 bool "OLPC XO-1 Real Time Clock"
2275 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2277 Add support for the XO-1 real time clock, which can be used as a
2278 programmable wakeup source.
2281 bool "OLPC XO-1 SCI extras"
2282 depends on OLPC && OLPC_XO1_PM
2288 Add support for SCI-based features of the OLPC XO-1 laptop:
2289 - EC-driven system wakeups
2293 - AC adapter status updates
2294 - Battery status updates
2296 config OLPC_XO15_SCI
2297 bool "OLPC XO-1.5 SCI extras"
2298 depends on OLPC && ACPI
2301 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2302 - EC-driven system wakeups
2303 - AC adapter status updates
2304 - Battery status updates
2307 bool "PCEngines ALIX System Support (LED setup)"
2310 This option enables system support for the PCEngines ALIX.
2311 At present this just sets up LEDs for GPIO control on
2312 ALIX2/3/6 boards. However, other system specific setup should
2315 Note: You must still enable the drivers for GPIO and LED support
2316 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2318 Note: You have to set alix.force=1 for boards with Award BIOS.
2321 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2324 This option enables system support for the Soekris Engineering net5501.
2327 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2331 This option enables system support for the Traverse Technologies GEOS.
2334 bool "Technologic Systems TS-5500 platform support"
2336 select CHECK_SIGNATURE
2340 This option enables system support for the Technologic Systems TS-5500.
2346 depends on CPU_SUP_AMD && PCI
2348 source "drivers/pcmcia/Kconfig"
2350 source "drivers/pci/hotplug/Kconfig"
2353 tristate "RapidIO support"
2357 If enabled this option will include drivers and the core
2358 infrastructure code to support RapidIO interconnect devices.
2360 source "drivers/rapidio/Kconfig"
2363 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2365 Firmwares often provide initial graphics framebuffers so the BIOS,
2366 bootloader or kernel can show basic video-output during boot for
2367 user-guidance and debugging. Historically, x86 used the VESA BIOS
2368 Extensions and EFI-framebuffers for this, which are mostly limited
2370 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2371 framebuffers so the new generic system-framebuffer drivers can be
2372 used on x86. If the framebuffer is not compatible with the generic
2373 modes, it is adverticed as fallback platform framebuffer so legacy
2374 drivers like efifb, vesafb and uvesafb can pick it up.
2375 If this option is not selected, all system framebuffers are always
2376 marked as fallback platform framebuffers as usual.
2378 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2379 not be able to pick up generic system framebuffers if this option
2380 is selected. You are highly encouraged to enable simplefb as
2381 replacement if you select this option. simplefb can correctly deal
2382 with generic system framebuffers. But you should still keep vesafb
2383 and others enabled as fallback if a system framebuffer is
2384 incompatible with simplefb.
2391 menu "Executable file formats / Emulations"
2393 source "fs/Kconfig.binfmt"
2395 config IA32_EMULATION
2396 bool "IA32 Emulation"
2399 select COMPAT_BINFMT_ELF
2402 Include code to run legacy 32-bit programs under a
2403 64-bit kernel. You should likely turn this on, unless you're
2404 100% sure that you don't have any 32-bit programs left.
2407 tristate "IA32 a.out support"
2408 depends on IA32_EMULATION
2410 Support old a.out binaries in the 32bit emulation.
2413 bool "x32 ABI for 64-bit mode"
2414 depends on X86_64 && IA32_EMULATION
2416 Include code to run binaries for the x32 native 32-bit ABI
2417 for 64-bit processors. An x32 process gets access to the
2418 full 64-bit register file and wide data path while leaving
2419 pointers at 32 bits for smaller memory footprint.
2421 You will need a recent binutils (2.22 or later) with
2422 elf32_x86_64 support enabled to compile a kernel with this
2427 depends on IA32_EMULATION || X86_X32
2428 select ARCH_WANT_OLD_COMPAT_IPC
2431 config COMPAT_FOR_U64_ALIGNMENT
2434 config SYSVIPC_COMPAT
2446 config HAVE_ATOMIC_IOMAP
2450 config X86_DEV_DMA_OPS
2452 depends on X86_64 || STA2X11
2454 config X86_DMA_REMAP
2467 source "net/Kconfig"
2469 source "drivers/Kconfig"
2471 source "drivers/firmware/Kconfig"
2475 source "arch/x86/Kconfig.debug"
2477 source "security/Kconfig"
2479 source "crypto/Kconfig"
2481 source "arch/x86/kvm/Kconfig"
2483 source "lib/Kconfig"