3 bool "64-bit kernel" if ARCH = "x86"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
24 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
25 select ARCH_MIGHT_HAVE_PC_PARPORT
26 select ARCH_MIGHT_HAVE_PC_SERIO
27 select HAVE_AOUT if X86_32
28 select HAVE_UNSTABLE_SCHED_CLOCK
29 select ARCH_SUPPORTS_NUMA_BALANCING
30 select ARCH_SUPPORTS_INT128 if X86_64
31 select ARCH_WANTS_PROT_NUMA_PROT_NONE
34 select HAVE_PCSPKR_PLATFORM
35 select HAVE_PERF_EVENTS
36 select HAVE_IOREMAP_PROT
39 select HAVE_MEMBLOCK_NODE_MAP
40 select ARCH_DISCARD_MEMBLOCK
41 select ARCH_WANT_OPTIONAL_GPIOLIB
42 select ARCH_WANT_FRAME_POINTERS
44 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
45 select HAVE_KRETPROBES
47 select HAVE_KPROBES_ON_FTRACE
48 select HAVE_FTRACE_MCOUNT_RECORD
49 select HAVE_FENTRY if X86_64
50 select HAVE_C_RECORDMCOUNT
51 select HAVE_DYNAMIC_FTRACE
52 select HAVE_DYNAMIC_FTRACE_WITH_REGS
53 select HAVE_FUNCTION_TRACER
54 select HAVE_FUNCTION_GRAPH_TRACER
55 select HAVE_FUNCTION_GRAPH_FP_TEST
56 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
57 select HAVE_SYSCALL_TRACEPOINTS
58 select SYSCTL_EXCEPTION_TRACE
61 select HAVE_ARCH_TRACEHOOK
62 select HAVE_GENERIC_DMA_COHERENT if X86_32
63 select HAVE_EFFICIENT_UNALIGNED_ACCESS
64 select USER_STACKTRACE_SUPPORT
65 select HAVE_REGS_AND_STACK_ACCESS_API
66 select HAVE_DMA_API_DEBUG
67 select HAVE_KERNEL_GZIP
68 select HAVE_KERNEL_BZIP2
69 select HAVE_KERNEL_LZMA
71 select HAVE_KERNEL_LZO
72 select HAVE_KERNEL_LZ4
73 select HAVE_HW_BREAKPOINT
74 select HAVE_MIXED_BREAKPOINTS_REGS
76 select HAVE_PERF_EVENTS_NMI
78 select HAVE_PERF_USER_STACK_DUMP
79 select HAVE_DEBUG_KMEMLEAK
81 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
82 select HAVE_CMPXCHG_LOCAL
83 select HAVE_CMPXCHG_DOUBLE
84 select HAVE_ARCH_KMEMCHECK
85 select HAVE_USER_RETURN_NOTIFIER
86 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
87 select HAVE_ARCH_JUMP_LABEL
88 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
90 select GENERIC_FIND_FIRST_BIT
91 select GENERIC_IRQ_PROBE
92 select GENERIC_PENDING_IRQ if SMP
93 select GENERIC_IRQ_SHOW
94 select GENERIC_CLOCKEVENTS_MIN_ADJUST
95 select IRQ_FORCED_THREADING
96 select HAVE_BPF_JIT if X86_64
97 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
99 select ARCH_HAVE_NMI_SAFE_CMPXCHG
101 select DCACHE_WORD_ACCESS
102 select GENERIC_SMP_IDLE_THREAD
103 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
104 select HAVE_ARCH_SECCOMP_FILTER
105 select BUILDTIME_EXTABLE_SORT
106 select GENERIC_CMOS_UPDATE
107 select HAVE_ARCH_SOFT_DIRTY
108 select CLOCKSOURCE_WATCHDOG
109 select GENERIC_CLOCKEVENTS
110 select ARCH_CLOCKSOURCE_DATA if X86_64
111 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
112 select GENERIC_TIME_VSYSCALL if X86_64
113 select KTIME_SCALAR if X86_32
114 select GENERIC_STRNCPY_FROM_USER
115 select GENERIC_STRNLEN_USER
116 select HAVE_CONTEXT_TRACKING if X86_64
117 select HAVE_IRQ_TIME_ACCOUNTING
119 select MODULES_USE_ELF_REL if X86_32
120 select MODULES_USE_ELF_RELA if X86_64
121 select CLONE_BACKWARDS if X86_32
122 select ARCH_USE_BUILTIN_BSWAP
123 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
124 select OLD_SIGACTION if X86_32
125 select COMPAT_OLD_SIGACTION if IA32_EMULATION
127 select HAVE_DEBUG_STACKOVERFLOW
128 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
129 select HAVE_CC_STACKPROTECTOR
130 select ARCH_SUPPORTS_ATOMIC_RMW
132 config INSTRUCTION_DECODER
134 depends on KPROBES || PERF_EVENTS || UPROBES
138 default "elf32-i386" if X86_32
139 default "elf64-x86-64" if X86_64
141 config ARCH_DEFCONFIG
143 default "arch/x86/configs/i386_defconfig" if X86_32
144 default "arch/x86/configs/x86_64_defconfig" if X86_64
146 config LOCKDEP_SUPPORT
149 config STACKTRACE_SUPPORT
152 config HAVE_LATENCYTOP_SUPPORT
161 config NEED_DMA_MAP_STATE
163 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
165 config NEED_SG_DMA_LENGTH
168 config GENERIC_ISA_DMA
170 depends on ISA_DMA_API
175 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
177 config GENERIC_BUG_RELATIVE_POINTERS
180 config GENERIC_HWEIGHT
183 config ARCH_MAY_HAVE_PC_FDC
185 depends on ISA_DMA_API
187 config RWSEM_XCHGADD_ALGORITHM
190 config GENERIC_CALIBRATE_DELAY
193 config ARCH_HAS_CPU_RELAX
196 config ARCH_HAS_CACHE_LINE_SIZE
199 config ARCH_HAS_CPU_AUTOPROBE
202 config HAVE_SETUP_PER_CPU_AREA
205 config NEED_PER_CPU_EMBED_FIRST_CHUNK
208 config NEED_PER_CPU_PAGE_FIRST_CHUNK
211 config ARCH_HIBERNATION_POSSIBLE
214 config ARCH_SUSPEND_POSSIBLE
217 config ARCH_WANT_HUGE_PMD_SHARE
220 config ARCH_WANT_GENERAL_HUGETLB
231 config ARCH_SUPPORTS_OPTIMIZED_INLINING
234 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
237 config HAVE_INTEL_TXT
239 depends on INTEL_IOMMU && ACPI
243 depends on X86_32 && SMP
247 depends on X86_64 && SMP
253 config X86_32_LAZY_GS
255 depends on X86_32 && !CC_STACKPROTECTOR
257 config ARCH_HWEIGHT_CFLAGS
259 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
260 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
262 config ARCH_SUPPORTS_UPROBES
265 source "init/Kconfig"
266 source "kernel/Kconfig.freezer"
268 menu "Processor type and features"
271 bool "DMA memory allocation support" if EXPERT
274 DMA memory allocation support allows devices with less than 32-bit
275 addressing to allocate within the first 16MB of address space.
276 Disable if no such devices will be used.
281 bool "Symmetric multi-processing support"
283 This enables support for systems with more than one CPU. If you have
284 a system with only one CPU, say N. If you have a system with more
287 If you say N here, the kernel will run on uni- and multiprocessor
288 machines, but will use only one CPU of a multiprocessor machine. If
289 you say Y here, the kernel will run on many, but not all,
290 uniprocessor machines. On a uniprocessor machine, the kernel
291 will run faster if you say N here.
293 Note that if you say Y here and choose architecture "586" or
294 "Pentium" under "Processor family", the kernel will not work on 486
295 architectures. Similarly, multiprocessor kernels for the "PPro"
296 architecture may not work on all Pentium based boards.
298 People using multiprocessor machines who say Y here should also say
299 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
300 Management" code will be disabled if you say Y here.
302 See also <file:Documentation/x86/i386/IO-APIC.txt>,
303 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
304 <http://www.tldp.org/docs.html#howto>.
306 If you don't know what to do here, say N.
309 bool "Support x2apic"
310 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
312 This enables x2apic support on CPUs that have this feature.
314 This allows 32-bit apic IDs (so it can support very large systems),
315 and accesses the local apic via MSRs not via mmio.
317 If you don't know what to do here, say N.
320 bool "Enable MPS table" if ACPI || SFI
322 depends on X86_LOCAL_APIC
324 For old smp systems that do not have proper acpi support. Newer systems
325 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
328 bool "Support for big SMP systems with more than 8 CPUs"
329 depends on X86_32 && SMP
331 This option is needed for the systems that have more than 8 CPUs
335 depends on X86_GOLDFISH
338 config X86_EXTENDED_PLATFORM
339 bool "Support for extended (non-PC) x86 platforms"
342 If you disable this option then the kernel will only support
343 standard PC platforms. (which covers the vast majority of
346 If you enable this option then you'll be able to select support
347 for the following (non-PC) 32 bit x86 platforms:
348 Goldfish (Android emulator)
352 SGI 320/540 (Visual Workstation)
353 STA2X11-based (e.g. Northville)
354 Summit/EXA (IBM x440)
355 Unisys ES7000 IA32 series
356 Moorestown MID devices
358 If you have one of these systems, or if you want to build a
359 generic distribution kernel, say Y here - otherwise say N.
363 config X86_EXTENDED_PLATFORM
364 bool "Support for extended (non-PC) x86 platforms"
367 If you disable this option then the kernel will only support
368 standard PC platforms. (which covers the vast majority of
371 If you enable this option then you'll be able to select support
372 for the following (non-PC) 64 bit x86 platforms:
377 If you have one of these systems, or if you want to build a
378 generic distribution kernel, say Y here - otherwise say N.
380 # This is an alphabetically sorted list of 64 bit extended platforms
381 # Please maintain the alphabetic order if and when there are additions
383 bool "Numascale NumaChip"
385 depends on X86_EXTENDED_PLATFORM
388 depends on X86_X2APIC
389 depends on PCI_MMCONFIG
391 Adds support for Numascale NumaChip large-SMP systems. Needed to
392 enable more than ~168 cores.
393 If you don't have one of these, you should say N here.
397 select HYPERVISOR_GUEST
399 depends on X86_64 && PCI
400 depends on X86_EXTENDED_PLATFORM
403 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
404 supposed to run on these EM64T-based machines. Only choose this option
405 if you have one of these machines.
408 bool "SGI Ultraviolet"
410 depends on X86_EXTENDED_PLATFORM
412 depends on X86_X2APIC
414 This option is needed in order to support SGI Ultraviolet systems.
415 If you don't have one of these, you should say N here.
417 # Following is an alphabetically sorted list of 32 bit extended platforms
418 # Please maintain the alphabetic order if and when there are additions
421 bool "Goldfish (Virtual Platform)"
423 depends on X86_EXTENDED_PLATFORM
425 Enable support for the Goldfish virtual platform used primarily
426 for Android development. Unless you are building for the Android
427 Goldfish emulator say N here.
430 bool "CE4100 TV platform"
432 depends on PCI_GODIRECT
434 depends on X86_EXTENDED_PLATFORM
435 select X86_REBOOTFIXUPS
437 select OF_EARLY_FLATTREE
440 Select for the Intel CE media processor (CE4100) SOC.
441 This option compiles in support for the CE4100 SOC for settop
442 boxes and media devices.
445 bool "Intel MID platform support"
447 depends on X86_EXTENDED_PLATFORM
448 depends on X86_PLATFORM_DEVICES
451 depends on X86_IO_APIC
457 select MFD_INTEL_MSIC
459 Select to build a kernel capable of supporting Intel MID (Mobile
460 Internet Device) platform systems which do not have the PCI legacy
461 interfaces. If you are building for a PC class system say N here.
463 Intel MID platforms are based on an Intel processor and chipset which
464 consume less power than most of the x86 derivatives.
466 config X86_INTEL_LPSS
467 bool "Intel Low Power Subsystem Support"
472 Select to build support for Intel Low Power Subsystem such as
473 found on Intel Lynxpoint PCH. Selecting this option enables
474 things like clock tree (common clock framework) and pincontrol
475 which are needed by the LPSS peripheral drivers.
478 bool "RDC R-321x SoC"
480 depends on X86_EXTENDED_PLATFORM
482 select X86_REBOOTFIXUPS
484 This option is needed for RDC R-321x system-on-chip, also known
486 If you don't have one of these chips, you should say N here.
488 config X86_32_NON_STANDARD
489 bool "Support non-standard 32-bit SMP architectures"
490 depends on X86_32 && SMP
491 depends on X86_EXTENDED_PLATFORM
493 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
494 STA2X11, default subarchitectures. It is intended for a generic
495 binary kernel. If you select them all, kernel will probe it
496 one by one and will fallback to default.
498 # Alphabetically sorted list of Non standard 32 bit platforms
501 bool "NUMAQ (IBM/Sequent)"
502 depends on X86_32_NON_STANDARD
507 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
508 NUMA multiquad box. This changes the way that processors are
509 bootstrapped, and uses Clustered Logical APIC addressing mode instead
510 of Flat Logical. You will need a new lynxer.elf file to flash your
511 firmware with - send email to <Martin.Bligh@us.ibm.com>.
513 config X86_SUPPORTS_MEMORY_FAILURE
515 # MCE code calls memory_failure():
517 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
518 depends on !X86_NUMAQ
519 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
520 depends on X86_64 || !SPARSEMEM
521 select ARCH_SUPPORTS_MEMORY_FAILURE
524 bool "SGI 320/540 (Visual Workstation)"
525 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
526 depends on X86_32_NON_STANDARD
528 The SGI Visual Workstation series is an IA32-based workstation
529 based on SGI systems chips with some legacy PC hardware attached.
531 Say Y here to create a kernel to run on the SGI 320 or 540.
533 A kernel compiled for the Visual Workstation will run on general
534 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
537 bool "STA2X11 Companion Chip Support"
538 depends on X86_32_NON_STANDARD && PCI
539 select X86_DEV_DMA_OPS
543 select ARCH_REQUIRE_GPIOLIB
546 This adds support for boards based on the STA2X11 IO-Hub,
547 a.k.a. "ConneXt". The chip is used in place of the standard
548 PC chipset, so all "standard" peripherals are missing. If this
549 option is selected the kernel will still be able to boot on
550 standard PC machines.
553 bool "Summit/EXA (IBM x440)"
554 depends on X86_32_NON_STANDARD
556 This option is needed for IBM systems that use the Summit/EXA chipset.
557 In particular, it is needed for the x440.
560 bool "Unisys ES7000 IA32 series"
561 depends on X86_32_NON_STANDARD && X86_BIGSMP
563 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
564 supposed to run on an IA32-based Unisys ES7000 system.
567 tristate "Eurobraille/Iris poweroff module"
570 The Iris machines from EuroBraille do not have APM or ACPI support
571 to shut themselves down properly. A special I/O sequence is
572 needed to do so, which is what this module does at
575 This is only for Iris machines from EuroBraille.
579 config SCHED_OMIT_FRAME_POINTER
581 prompt "Single-depth WCHAN output"
584 Calculate simpler /proc/<PID>/wchan values. If this option
585 is disabled then wchan values will recurse back to the
586 caller function. This provides more accurate wchan values,
587 at the expense of slightly more scheduling overhead.
589 If in doubt, say "Y".
591 menuconfig HYPERVISOR_GUEST
592 bool "Linux guest support"
594 Say Y here to enable options for running Linux under various hyper-
595 visors. This option enables basic hypervisor detection and platform
598 If you say N, all options in this submenu will be skipped and
599 disabled, and Linux guest support won't be built in.
604 bool "Enable paravirtualization code"
606 This changes the kernel so it can modify itself when it is run
607 under a hypervisor, potentially improving performance significantly
608 over full virtualization. However, when run without a hypervisor
609 the kernel is theoretically slower and slightly larger.
611 config PARAVIRT_DEBUG
612 bool "paravirt-ops debugging"
613 depends on PARAVIRT && DEBUG_KERNEL
615 Enable to debug paravirt_ops internals. Specifically, BUG if
616 a paravirt_op is missing when it is called.
618 config PARAVIRT_SPINLOCKS
619 bool "Paravirtualization layer for spinlocks"
620 depends on PARAVIRT && SMP
621 select UNINLINE_SPIN_UNLOCK
623 Paravirtualized spinlocks allow a pvops backend to replace the
624 spinlock implementation with something virtualization-friendly
625 (for example, block the virtual CPU rather than spinning).
627 It has a minimal impact on native kernels and gives a nice performance
628 benefit on paravirtualized KVM / Xen kernels.
630 If you are unsure how to answer this question, answer Y.
632 source "arch/x86/xen/Kconfig"
635 bool "KVM Guest support (including kvmclock)"
637 select PARAVIRT_CLOCK
640 This option enables various optimizations for running under the KVM
641 hypervisor. It includes a paravirtualized clock, so that instead
642 of relying on a PIT (or probably other) emulation by the
643 underlying device model, the host provides the guest with
644 timing infrastructure such as time of day, and system time
647 bool "Enable debug information for KVM Guests in debugfs"
648 depends on KVM_GUEST && DEBUG_FS
651 This option enables collection of various statistics for KVM guest.
652 Statistics are displayed in debugfs filesystem. Enabling this option
653 may incur significant overhead.
655 source "arch/x86/lguest/Kconfig"
657 config PARAVIRT_TIME_ACCOUNTING
658 bool "Paravirtual steal time accounting"
662 Select this option to enable fine granularity task steal time
663 accounting. Time spent executing other tasks in parallel with
664 the current vCPU is discounted from the vCPU power. To account for
665 that, there can be a small performance impact.
667 If in doubt, say N here.
669 config PARAVIRT_CLOCK
672 endif #HYPERVISOR_GUEST
680 This option adds a kernel parameter 'memtest', which allows memtest
682 memtest=0, mean disabled; -- default
683 memtest=1, mean do 1 test pattern;
685 memtest=4, mean do 4 test patterns.
686 If you are unsure how to answer this question, answer N.
688 config X86_SUMMIT_NUMA
690 depends on X86_32 && NUMA && X86_32_NON_STANDARD
692 config X86_CYCLONE_TIMER
694 depends on X86_SUMMIT
696 source "arch/x86/Kconfig.cpu"
700 prompt "HPET Timer Support" if X86_32
702 Use the IA-PC HPET (High Precision Event Timer) to manage
703 time in preference to the PIT and RTC, if a HPET is
705 HPET is the next generation timer replacing legacy 8254s.
706 The HPET provides a stable time base on SMP
707 systems, unlike the TSC, but it is more expensive to access,
708 as it is off-chip. You can find the HPET spec at
709 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
711 You can safely choose Y here. However, HPET will only be
712 activated if the platform and the BIOS support this feature.
713 Otherwise the 8254 will be used for timing services.
715 Choose N to continue using the legacy 8254 timer.
717 config HPET_EMULATE_RTC
719 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
722 def_bool y if X86_INTEL_MID
723 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
725 depends on X86_INTEL_MID && SFI
727 APB timer is the replacement for 8254, HPET on X86 MID platforms.
728 The APBT provides a stable time base on SMP
729 systems, unlike the TSC, but it is more expensive to access,
730 as it is off-chip. APB timers are always running regardless of CPU
731 C states, they are used as per CPU clockevent device when possible.
733 # Mark as expert because too many people got it wrong.
734 # The code disables itself when not needed.
737 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
738 bool "Enable DMI scanning" if EXPERT
740 Enabled scanning of DMI to identify machine quirks. Say Y
741 here unless you have verified that your setup is not
742 affected by entries in the DMI blacklist. Required by PNP
746 bool "Old AMD GART IOMMU support"
748 depends on X86_64 && PCI && AMD_NB
750 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
751 GART based hardware IOMMUs.
753 The GART supports full DMA access for devices with 32-bit access
754 limitations, on systems with more than 3 GB. This is usually needed
755 for USB, sound, many IDE/SATA chipsets and some other devices.
757 Newer systems typically have a modern AMD IOMMU, supported via
758 the CONFIG_AMD_IOMMU=y config option.
760 In normal configurations this driver is only active when needed:
761 there's more than 3 GB of memory and the system contains a
762 32-bit limited device.
767 bool "IBM Calgary IOMMU support"
769 depends on X86_64 && PCI
771 Support for hardware IOMMUs in IBM's xSeries x366 and x460
772 systems. Needed to run systems with more than 3GB of memory
773 properly with 32-bit PCI devices that do not support DAC
774 (Double Address Cycle). Calgary also supports bus level
775 isolation, where all DMAs pass through the IOMMU. This
776 prevents them from going anywhere except their intended
777 destination. This catches hard-to-find kernel bugs and
778 mis-behaving drivers and devices that do not use the DMA-API
779 properly to set up their DMA buffers. The IOMMU can be
780 turned off at boot time with the iommu=off parameter.
781 Normally the kernel will make the right choice by itself.
784 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
786 prompt "Should Calgary be enabled by default?"
787 depends on CALGARY_IOMMU
789 Should Calgary be enabled by default? if you choose 'y', Calgary
790 will be used (if it exists). If you choose 'n', Calgary will not be
791 used even if it exists. If you choose 'n' and would like to use
792 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
795 # need this always selected by IOMMU for the VIA workaround
799 Support for software bounce buffers used on x86-64 systems
800 which don't have a hardware IOMMU. Using this PCI devices
801 which can only access 32-bits of memory can be used on systems
802 with more than 3 GB of memory.
807 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
810 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
811 depends on X86_64 && SMP && DEBUG_KERNEL
812 select CPUMASK_OFFSTACK
814 Enable maximum number of CPUS and NUMA Nodes for this architecture.
818 int "Maximum number of CPUs" if SMP && !MAXSMP
819 range 2 8 if SMP && X86_32 && !X86_BIGSMP
820 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
821 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
823 default "8192" if MAXSMP
824 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
827 This allows you to specify the maximum number of CPUs which this
828 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
829 supported value is 4096, otherwise the maximum value is 512. The
830 minimum value which makes sense is 2.
832 This is purely to save memory - each supported CPU adds
833 approximately eight kilobytes to the kernel image.
836 bool "SMT (Hyperthreading) scheduler support"
839 SMT scheduler support improves the CPU scheduler's decision making
840 when dealing with Intel Pentium 4 chips with HyperThreading at a
841 cost of slightly increased overhead in some places. If unsure say
846 prompt "Multi-core scheduler support"
849 Multi-core scheduler support improves the CPU scheduler's decision
850 making when dealing with multi-core CPU chips at a cost of slightly
851 increased overhead in some places. If unsure say N here.
853 source "kernel/Kconfig.preempt"
856 bool "Local APIC support on uniprocessors"
857 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI
859 A local APIC (Advanced Programmable Interrupt Controller) is an
860 integrated interrupt controller in the CPU. If you have a single-CPU
861 system which has a processor with a local APIC, you can say Y here to
862 enable and use it. If you say Y here even though your machine doesn't
863 have a local APIC, then the kernel will still run with no slowdown at
864 all. The local APIC supports CPU-generated self-interrupts (timer,
865 performance counters), and the NMI watchdog which detects hard
869 bool "IO-APIC support on uniprocessors"
870 depends on X86_UP_APIC
872 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
873 SMP-capable replacement for PC-style interrupt controllers. Most
874 SMP systems and many recent uniprocessor systems have one.
876 If you have a single-CPU system with an IO-APIC, you can say Y here
877 to use it. If you say Y here even though your machine doesn't have
878 an IO-APIC, then the kernel will still run with no slowdown at all.
880 config X86_LOCAL_APIC
882 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
886 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI
888 config X86_VISWS_APIC
890 depends on X86_32 && X86_VISWS
892 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
893 bool "Reroute for broken boot IRQs"
894 depends on X86_IO_APIC
896 This option enables a workaround that fixes a source of
897 spurious interrupts. This is recommended when threaded
898 interrupt handling is used on systems where the generation of
899 superfluous "boot interrupts" cannot be disabled.
901 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
902 entry in the chipset's IO-APIC is masked (as, e.g. the RT
903 kernel does during interrupt handling). On chipsets where this
904 boot IRQ generation cannot be disabled, this workaround keeps
905 the original IRQ line masked so that only the equivalent "boot
906 IRQ" is delivered to the CPUs. The workaround also tells the
907 kernel to set up the IRQ handler on the boot IRQ line. In this
908 way only one interrupt is delivered to the kernel. Otherwise
909 the spurious second interrupt may cause the kernel to bring
910 down (vital) interrupt lines.
912 Only affects "broken" chipsets. Interrupt sharing may be
913 increased on these systems.
916 bool "Machine Check / overheating reporting"
919 Machine Check support allows the processor to notify the
920 kernel if it detects a problem (e.g. overheating, data corruption).
921 The action the kernel takes depends on the severity of the problem,
922 ranging from warning messages to halting the machine.
926 prompt "Intel MCE features"
927 depends on X86_MCE && X86_LOCAL_APIC
929 Additional support for intel specific MCE features such as
934 prompt "AMD MCE features"
935 depends on X86_MCE && X86_LOCAL_APIC
937 Additional support for AMD specific MCE features such as
938 the DRAM Error Threshold.
940 config X86_ANCIENT_MCE
941 bool "Support for old Pentium 5 / WinChip machine checks"
942 depends on X86_32 && X86_MCE
944 Include support for machine check handling on old Pentium 5 or WinChip
945 systems. These typically need to be enabled explicitly on the command
948 config X86_MCE_THRESHOLD
949 depends on X86_MCE_AMD || X86_MCE_INTEL
952 config X86_MCE_INJECT
954 tristate "Machine check injector support"
956 Provide support for injecting machine checks for testing purposes.
957 If you don't know what a machine check is and you don't do kernel
958 QA it is safe to say n.
960 config X86_THERMAL_VECTOR
962 depends on X86_MCE_INTEL
965 bool "Enable VM86 support" if EXPERT
969 This option is required by programs like DOSEMU to run
970 16-bit real mode legacy code on x86 processors. It also may
971 be needed by software like XFree86 to initialize some video
972 cards via BIOS. Disabling this option saves about 6K.
975 bool "Enable support for 16-bit segments" if EXPERT
978 This option is required by programs like Wine to run 16-bit
979 protected mode legacy code on x86 processors. Disabling
980 this option saves about 300 bytes on i386, or around 6K text
981 plus 16K runtime memory on x86-64,
985 depends on X86_16BIT && X86_32
989 depends on X86_16BIT && X86_64
992 tristate "Toshiba Laptop support"
995 This adds a driver to safely access the System Management Mode of
996 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
997 not work on models with a Phoenix BIOS. The System Management Mode
998 is used to set the BIOS and power saving options on Toshiba portables.
1000 For information on utilities to make use of this driver see the
1001 Toshiba Linux utilities web site at:
1002 <http://www.buzzard.org.uk/toshiba/>.
1004 Say Y if you intend to run this kernel on a Toshiba portable.
1008 tristate "Dell laptop support"
1011 This adds a driver to safely access the System Management Mode
1012 of the CPU on the Dell Inspiron 8000. The System Management Mode
1013 is used to read cpu temperature and cooling fan status and to
1014 control the fans on the I8K portables.
1016 This driver has been tested only on the Inspiron 8000 but it may
1017 also work with other Dell laptops. You can force loading on other
1018 models by passing the parameter `force=1' to the module. Use at
1021 For information on utilities to make use of this driver see the
1022 I8K Linux utilities web site at:
1023 <http://people.debian.org/~dz/i8k/>
1025 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1028 config X86_REBOOTFIXUPS
1029 bool "Enable X86 board specific fixups for reboot"
1032 This enables chipset and/or board specific fixups to be done
1033 in order to get reboot to work correctly. This is only needed on
1034 some combinations of hardware and BIOS. The symptom, for which
1035 this config is intended, is when reboot ends with a stalled/hung
1038 Currently, the only fixup is for the Geode machines using
1039 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1041 Say Y if you want to enable the fixup. Currently, it's safe to
1042 enable this option even if you don't need it.
1046 tristate "CPU microcode loading support"
1047 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1051 If you say Y here, you will be able to update the microcode on
1052 certain Intel and AMD processors. The Intel support is for the
1053 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1054 Xeon etc. The AMD support is for families 0x10 and later. You will
1055 obviously need the actual microcode binary data itself which is not
1056 shipped with the Linux kernel.
1058 This option selects the general module only, you need to select
1059 at least one vendor specific module as well.
1061 To compile this driver as a module, choose M here: the module
1062 will be called microcode.
1064 config MICROCODE_INTEL
1065 bool "Intel microcode loading support"
1066 depends on MICROCODE
1070 This options enables microcode patch loading support for Intel
1073 For the current Intel microcode data package go to
1074 <https://downloadcenter.intel.com> and search for
1075 'Linux Processor Microcode Data File'.
1077 config MICROCODE_AMD
1078 bool "AMD microcode loading support"
1079 depends on MICROCODE
1082 If you select this option, microcode patch loading support for AMD
1083 processors will be enabled.
1085 config MICROCODE_OLD_INTERFACE
1087 depends on MICROCODE
1089 config MICROCODE_INTEL_EARLY
1092 config MICROCODE_AMD_EARLY
1095 config MICROCODE_EARLY
1096 bool "Early load microcode"
1097 depends on MICROCODE=y && BLK_DEV_INITRD
1098 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1099 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1102 This option provides functionality to read additional microcode data
1103 at the beginning of initrd image. The data tells kernel to load
1104 microcode to CPU's as early as possible. No functional change if no
1105 microcode data is glued to the initrd, therefore it's safe to say Y.
1108 tristate "/dev/cpu/*/msr - Model-specific register support"
1110 This device gives privileged processes access to the x86
1111 Model-Specific Registers (MSRs). It is a character device with
1112 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1113 MSR accesses are directed to a specific CPU on multi-processor
1117 tristate "/dev/cpu/*/cpuid - CPU information support"
1119 This device gives processes access to the x86 CPUID instruction to
1120 be executed on a specific processor. It is a character device
1121 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1125 prompt "High Memory Support"
1126 default HIGHMEM64G if X86_NUMAQ
1132 depends on !X86_NUMAQ
1134 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1135 However, the address space of 32-bit x86 processors is only 4
1136 Gigabytes large. That means that, if you have a large amount of
1137 physical memory, not all of it can be "permanently mapped" by the
1138 kernel. The physical memory that's not permanently mapped is called
1141 If you are compiling a kernel which will never run on a machine with
1142 more than 1 Gigabyte total physical RAM, answer "off" here (default
1143 choice and suitable for most users). This will result in a "3GB/1GB"
1144 split: 3GB are mapped so that each process sees a 3GB virtual memory
1145 space and the remaining part of the 4GB virtual memory space is used
1146 by the kernel to permanently map as much physical memory as
1149 If the machine has between 1 and 4 Gigabytes physical RAM, then
1152 If more than 4 Gigabytes is used then answer "64GB" here. This
1153 selection turns Intel PAE (Physical Address Extension) mode on.
1154 PAE implements 3-level paging on IA32 processors. PAE is fully
1155 supported by Linux, PAE mode is implemented on all recent Intel
1156 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1157 then the kernel will not boot on CPUs that don't support PAE!
1159 The actual amount of total physical memory will either be
1160 auto detected or can be forced by using a kernel command line option
1161 such as "mem=256M". (Try "man bootparam" or see the documentation of
1162 your boot loader (lilo or loadlin) about how to pass options to the
1163 kernel at boot time.)
1165 If unsure, say "off".
1169 depends on !X86_NUMAQ
1171 Select this if you have a 32-bit processor and between 1 and 4
1172 gigabytes of physical RAM.
1179 Select this if you have a 32-bit processor and more than 4
1180 gigabytes of physical RAM.
1185 prompt "Memory split" if EXPERT
1189 Select the desired split between kernel and user memory.
1191 If the address range available to the kernel is less than the
1192 physical memory installed, the remaining memory will be available
1193 as "high memory". Accessing high memory is a little more costly
1194 than low memory, as it needs to be mapped into the kernel first.
1195 Note that increasing the kernel address space limits the range
1196 available to user programs, making the address space there
1197 tighter. Selecting anything other than the default 3G/1G split
1198 will also likely make your kernel incompatible with binary-only
1201 If you are not absolutely sure what you are doing, leave this
1205 bool "3G/1G user/kernel split"
1206 config VMSPLIT_3G_OPT
1208 bool "3G/1G user/kernel split (for full 1G low memory)"
1210 bool "2G/2G user/kernel split"
1211 config VMSPLIT_2G_OPT
1213 bool "2G/2G user/kernel split (for full 2G low memory)"
1215 bool "1G/3G user/kernel split"
1220 default 0xB0000000 if VMSPLIT_3G_OPT
1221 default 0x80000000 if VMSPLIT_2G
1222 default 0x78000000 if VMSPLIT_2G_OPT
1223 default 0x40000000 if VMSPLIT_1G
1229 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1232 bool "PAE (Physical Address Extension) Support"
1233 depends on X86_32 && !HIGHMEM4G
1235 PAE is required for NX support, and furthermore enables
1236 larger swapspace support for non-overcommit purposes. It
1237 has the cost of more pagetable lookup overhead, and also
1238 consumes more pagetable space per process.
1240 config ARCH_PHYS_ADDR_T_64BIT
1242 depends on X86_64 || X86_PAE
1244 config ARCH_DMA_ADDR_T_64BIT
1246 depends on X86_64 || HIGHMEM64G
1248 config DIRECT_GBPAGES
1249 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1253 Allow the kernel linear mapping to use 1GB pages on CPUs that
1254 support it. This can improve the kernel's performance a tiny bit by
1255 reducing TLB pressure. If in doubt, say "Y".
1257 # Common NUMA Features
1259 bool "Numa Memory Allocation and Scheduler Support"
1261 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1262 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1264 Enable NUMA (Non Uniform Memory Access) support.
1266 The kernel will try to allocate memory used by a CPU on the
1267 local memory controller of the CPU and add some more
1268 NUMA awareness to the kernel.
1270 For 64-bit this is recommended if the system is Intel Core i7
1271 (or later), AMD Opteron, or EM64T NUMA.
1273 For 32-bit this is only needed on (rare) 32-bit-only platforms
1274 that support NUMA topologies, such as NUMAQ / Summit, or if you
1275 boot a 32-bit kernel on a 64-bit NUMA platform.
1277 Otherwise, you should say N.
1279 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1280 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1284 prompt "Old style AMD Opteron NUMA detection"
1285 depends on X86_64 && NUMA && PCI
1287 Enable AMD NUMA node topology detection. You should say Y here if
1288 you have a multi processor AMD system. This uses an old method to
1289 read the NUMA configuration directly from the builtin Northbridge
1290 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1291 which also takes priority if both are compiled in.
1293 config X86_64_ACPI_NUMA
1295 prompt "ACPI NUMA detection"
1296 depends on X86_64 && NUMA && ACPI && PCI
1299 Enable ACPI SRAT based node topology detection.
1301 # Some NUMA nodes have memory ranges that span
1302 # other nodes. Even though a pfn is valid and
1303 # between a node's start and end pfns, it may not
1304 # reside on that node. See memmap_init_zone()
1306 config NODES_SPAN_OTHER_NODES
1308 depends on X86_64_ACPI_NUMA
1311 bool "NUMA emulation"
1314 Enable NUMA emulation. A flat machine will be split
1315 into virtual nodes when booted with "numa=fake=N", where N is the
1316 number of nodes. This is only useful for debugging.
1319 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1321 default "10" if MAXSMP
1322 default "6" if X86_64
1323 default "4" if X86_NUMAQ
1325 depends on NEED_MULTIPLE_NODES
1327 Specify the maximum number of NUMA Nodes available on the target
1328 system. Increases memory reserved to accommodate various tables.
1330 config ARCH_HAVE_MEMORY_PRESENT
1332 depends on X86_32 && DISCONTIGMEM
1334 config NEED_NODE_MEMMAP_SIZE
1336 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1338 config ARCH_FLATMEM_ENABLE
1340 depends on X86_32 && !NUMA
1342 config ARCH_DISCONTIGMEM_ENABLE
1344 depends on NUMA && X86_32
1346 config ARCH_DISCONTIGMEM_DEFAULT
1348 depends on NUMA && X86_32
1350 config ARCH_SPARSEMEM_ENABLE
1352 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1353 select SPARSEMEM_STATIC if X86_32
1354 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1356 config ARCH_SPARSEMEM_DEFAULT
1360 config ARCH_SELECT_MEMORY_MODEL
1362 depends on ARCH_SPARSEMEM_ENABLE
1364 config ARCH_MEMORY_PROBE
1365 bool "Enable sysfs memory/probe interface"
1366 depends on X86_64 && MEMORY_HOTPLUG
1368 This option enables a sysfs memory/probe interface for testing.
1369 See Documentation/memory-hotplug.txt for more information.
1370 If you are unsure how to answer this question, answer N.
1372 config ARCH_PROC_KCORE_TEXT
1374 depends on X86_64 && PROC_KCORE
1376 config ILLEGAL_POINTER_VALUE
1379 default 0xdead000000000000 if X86_64
1384 bool "Allocate 3rd-level pagetables from highmem"
1387 The VM uses one page table entry for each page of physical memory.
1388 For systems with a lot of RAM, this can be wasteful of precious
1389 low memory. Setting this option will put user-space page table
1390 entries in high memory.
1392 config X86_CHECK_BIOS_CORRUPTION
1393 bool "Check for low memory corruption"
1395 Periodically check for memory corruption in low memory, which
1396 is suspected to be caused by BIOS. Even when enabled in the
1397 configuration, it is disabled at runtime. Enable it by
1398 setting "memory_corruption_check=1" on the kernel command
1399 line. By default it scans the low 64k of memory every 60
1400 seconds; see the memory_corruption_check_size and
1401 memory_corruption_check_period parameters in
1402 Documentation/kernel-parameters.txt to adjust this.
1404 When enabled with the default parameters, this option has
1405 almost no overhead, as it reserves a relatively small amount
1406 of memory and scans it infrequently. It both detects corruption
1407 and prevents it from affecting the running system.
1409 It is, however, intended as a diagnostic tool; if repeatable
1410 BIOS-originated corruption always affects the same memory,
1411 you can use memmap= to prevent the kernel from using that
1414 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1415 bool "Set the default setting of memory_corruption_check"
1416 depends on X86_CHECK_BIOS_CORRUPTION
1419 Set whether the default state of memory_corruption_check is
1422 config X86_RESERVE_LOW
1423 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1427 Specify the amount of low memory to reserve for the BIOS.
1429 The first page contains BIOS data structures that the kernel
1430 must not use, so that page must always be reserved.
1432 By default we reserve the first 64K of physical RAM, as a
1433 number of BIOSes are known to corrupt that memory range
1434 during events such as suspend/resume or monitor cable
1435 insertion, so it must not be used by the kernel.
1437 You can set this to 4 if you are absolutely sure that you
1438 trust the BIOS to get all its memory reservations and usages
1439 right. If you know your BIOS have problems beyond the
1440 default 64K area, you can set this to 640 to avoid using the
1441 entire low memory range.
1443 If you have doubts about the BIOS (e.g. suspend/resume does
1444 not work or there's kernel crashes after certain hardware
1445 hotplug events) then you might want to enable
1446 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1447 typical corruption patterns.
1449 Leave this to the default value of 64 if you are unsure.
1451 config MATH_EMULATION
1453 prompt "Math emulation" if X86_32
1455 Linux can emulate a math coprocessor (used for floating point
1456 operations) if you don't have one. 486DX and Pentium processors have
1457 a math coprocessor built in, 486SX and 386 do not, unless you added
1458 a 487DX or 387, respectively. (The messages during boot time can
1459 give you some hints here ["man dmesg"].) Everyone needs either a
1460 coprocessor or this emulation.
1462 If you don't have a math coprocessor, you need to say Y here; if you
1463 say Y here even though you have a coprocessor, the coprocessor will
1464 be used nevertheless. (This behavior can be changed with the kernel
1465 command line option "no387", which comes handy if your coprocessor
1466 is broken. Try "man bootparam" or see the documentation of your boot
1467 loader (lilo or loadlin) about how to pass options to the kernel at
1468 boot time.) This means that it is a good idea to say Y here if you
1469 intend to use this kernel on different machines.
1471 More information about the internals of the Linux math coprocessor
1472 emulation can be found in <file:arch/x86/math-emu/README>.
1474 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1475 kernel, it won't hurt.
1479 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1481 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1482 the Memory Type Range Registers (MTRRs) may be used to control
1483 processor access to memory ranges. This is most useful if you have
1484 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1485 allows bus write transfers to be combined into a larger transfer
1486 before bursting over the PCI/AGP bus. This can increase performance
1487 of image write operations 2.5 times or more. Saying Y here creates a
1488 /proc/mtrr file which may be used to manipulate your processor's
1489 MTRRs. Typically the X server should use this.
1491 This code has a reasonably generic interface so that similar
1492 control registers on other processors can be easily supported
1495 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1496 Registers (ARRs) which provide a similar functionality to MTRRs. For
1497 these, the ARRs are used to emulate the MTRRs.
1498 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1499 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1500 write-combining. All of these processors are supported by this code
1501 and it makes sense to say Y here if you have one of them.
1503 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1504 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1505 can lead to all sorts of problems, so it's good to say Y here.
1507 You can safely say Y even if your machine doesn't have MTRRs, you'll
1508 just add about 9 KB to your kernel.
1510 See <file:Documentation/x86/mtrr.txt> for more information.
1512 config MTRR_SANITIZER
1514 prompt "MTRR cleanup support"
1517 Convert MTRR layout from continuous to discrete, so X drivers can
1518 add writeback entries.
1520 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1521 The largest mtrr entry size for a continuous block can be set with
1526 config MTRR_SANITIZER_ENABLE_DEFAULT
1527 int "MTRR cleanup enable value (0-1)"
1530 depends on MTRR_SANITIZER
1532 Enable mtrr cleanup default value
1534 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1535 int "MTRR cleanup spare reg num (0-7)"
1538 depends on MTRR_SANITIZER
1540 mtrr cleanup spare entries default, it can be changed via
1541 mtrr_spare_reg_nr=N on the kernel command line.
1545 prompt "x86 PAT support" if EXPERT
1548 Use PAT attributes to setup page level cache control.
1550 PATs are the modern equivalents of MTRRs and are much more
1551 flexible than MTRRs.
1553 Say N here if you see bootup problems (boot crash, boot hang,
1554 spontaneous reboots) or a non-working video driver.
1558 config ARCH_USES_PG_UNCACHED
1564 prompt "x86 architectural random number generator" if EXPERT
1566 Enable the x86 architectural RDRAND instruction
1567 (Intel Bull Mountain technology) to generate random numbers.
1568 If supported, this is a high bandwidth, cryptographically
1569 secure hardware random number generator.
1573 prompt "Supervisor Mode Access Prevention" if EXPERT
1575 Supervisor Mode Access Prevention (SMAP) is a security
1576 feature in newer Intel processors. There is a small
1577 performance cost if this enabled and turned on; there is
1578 also a small increase in the kernel size if this is enabled.
1583 bool "EFI runtime service support"
1587 This enables the kernel to use EFI runtime services that are
1588 available (such as the EFI variable services).
1590 This option is only useful on systems that have EFI firmware.
1591 In addition, you should use the latest ELILO loader available
1592 at <http://elilo.sourceforge.net> in order to take advantage
1593 of EFI runtime services. However, even with this option, the
1594 resultant kernel should continue to boot on existing non-EFI
1598 bool "EFI stub support"
1602 This kernel feature allows a bzImage to be loaded directly
1603 by EFI firmware without the use of a bootloader.
1605 See Documentation/efi-stub.txt for more information.
1609 prompt "Enable seccomp to safely compute untrusted bytecode"
1611 This kernel feature is useful for number crunching applications
1612 that may need to compute untrusted bytecode during their
1613 execution. By using pipes or other transports made available to
1614 the process as file descriptors supporting the read/write
1615 syscalls, it's possible to isolate those applications in
1616 their own address space using seccomp. Once seccomp is
1617 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1618 and the task is only allowed to execute a few safe syscalls
1619 defined by each seccomp mode.
1621 If unsure, say Y. Only embedded should say N here.
1623 source kernel/Kconfig.hz
1626 bool "kexec system call"
1628 kexec is a system call that implements the ability to shutdown your
1629 current kernel, and to start another kernel. It is like a reboot
1630 but it is independent of the system firmware. And like a reboot
1631 you can start any kernel with it, not just Linux.
1633 The name comes from the similarity to the exec system call.
1635 It is an ongoing process to be certain the hardware in a machine
1636 is properly shutdown, so do not be surprised if this code does not
1637 initially work for you. As of this writing the exact hardware
1638 interface is strongly in flux, so no good recommendation can be
1642 bool "kernel crash dumps"
1643 depends on X86_64 || (X86_32 && HIGHMEM)
1645 Generate crash dump after being started by kexec.
1646 This should be normally only set in special crash dump kernels
1647 which are loaded in the main kernel with kexec-tools into
1648 a specially reserved region and then later executed after
1649 a crash by kdump/kexec. The crash dump kernel must be compiled
1650 to a memory address not used by the main kernel or BIOS using
1651 PHYSICAL_START, or it must be built as a relocatable image
1652 (CONFIG_RELOCATABLE=y).
1653 For more details see Documentation/kdump/kdump.txt
1657 depends on KEXEC && HIBERNATION
1659 Jump between original kernel and kexeced kernel and invoke
1660 code in physical address mode via KEXEC
1662 config PHYSICAL_START
1663 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1666 This gives the physical address where the kernel is loaded.
1668 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1669 bzImage will decompress itself to above physical address and
1670 run from there. Otherwise, bzImage will run from the address where
1671 it has been loaded by the boot loader and will ignore above physical
1674 In normal kdump cases one does not have to set/change this option
1675 as now bzImage can be compiled as a completely relocatable image
1676 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1677 address. This option is mainly useful for the folks who don't want
1678 to use a bzImage for capturing the crash dump and want to use a
1679 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1680 to be specifically compiled to run from a specific memory area
1681 (normally a reserved region) and this option comes handy.
1683 So if you are using bzImage for capturing the crash dump,
1684 leave the value here unchanged to 0x1000000 and set
1685 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1686 for capturing the crash dump change this value to start of
1687 the reserved region. In other words, it can be set based on
1688 the "X" value as specified in the "crashkernel=YM@XM"
1689 command line boot parameter passed to the panic-ed
1690 kernel. Please take a look at Documentation/kdump/kdump.txt
1691 for more details about crash dumps.
1693 Usage of bzImage for capturing the crash dump is recommended as
1694 one does not have to build two kernels. Same kernel can be used
1695 as production kernel and capture kernel. Above option should have
1696 gone away after relocatable bzImage support is introduced. But it
1697 is present because there are users out there who continue to use
1698 vmlinux for dump capture. This option should go away down the
1701 Don't change this unless you know what you are doing.
1704 bool "Build a relocatable kernel"
1707 This builds a kernel image that retains relocation information
1708 so it can be loaded someplace besides the default 1MB.
1709 The relocations tend to make the kernel binary about 10% larger,
1710 but are discarded at runtime.
1712 One use is for the kexec on panic case where the recovery kernel
1713 must live at a different physical address than the primary
1716 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1717 it has been loaded at and the compile time physical address
1718 (CONFIG_PHYSICAL_START) is used as the minimum location.
1720 config RANDOMIZE_BASE
1721 bool "Randomize the address of the kernel image"
1722 depends on RELOCATABLE
1723 depends on !HIBERNATION
1726 Randomizes the physical and virtual address at which the
1727 kernel image is decompressed, as a security feature that
1728 deters exploit attempts relying on knowledge of the location
1729 of kernel internals.
1731 Entropy is generated using the RDRAND instruction if it is
1732 supported. If RDTSC is supported, it is used as well. If
1733 neither RDRAND nor RDTSC are supported, then randomness is
1734 read from the i8254 timer.
1736 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1737 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1738 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1739 minimum of 2MiB, only 10 bits of entropy is theoretically
1740 possible. At best, due to page table layouts, 64-bit can use
1741 9 bits of entropy and 32-bit uses 8 bits.
1745 config RANDOMIZE_BASE_MAX_OFFSET
1746 hex "Maximum kASLR offset allowed" if EXPERT
1747 depends on RANDOMIZE_BASE
1748 range 0x0 0x20000000 if X86_32
1749 default "0x20000000" if X86_32
1750 range 0x0 0x40000000 if X86_64
1751 default "0x40000000" if X86_64
1753 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1754 memory is used to determine the maximal offset in bytes that will
1755 be applied to the kernel when kernel Address Space Layout
1756 Randomization (kASLR) is active. This must be a multiple of
1759 On 32-bit this is limited to 512MiB by page table layouts. The
1762 On 64-bit this is limited by how the kernel fixmap page table is
1763 positioned, so this cannot be larger than 1GiB currently. Without
1764 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1765 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1766 modules area will shrink to compensate, up to the current maximum
1767 1GiB to 1GiB split. The default is 1GiB.
1769 If unsure, leave at the default value.
1771 # Relocation on x86 needs some additional build support
1772 config X86_NEED_RELOCS
1774 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1776 config PHYSICAL_ALIGN
1777 hex "Alignment value to which kernel should be aligned"
1779 range 0x2000 0x1000000 if X86_32
1780 range 0x200000 0x1000000 if X86_64
1782 This value puts the alignment restrictions on physical address
1783 where kernel is loaded and run from. Kernel is compiled for an
1784 address which meets above alignment restriction.
1786 If bootloader loads the kernel at a non-aligned address and
1787 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1788 address aligned to above value and run from there.
1790 If bootloader loads the kernel at a non-aligned address and
1791 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1792 load address and decompress itself to the address it has been
1793 compiled for and run from there. The address for which kernel is
1794 compiled already meets above alignment restrictions. Hence the
1795 end result is that kernel runs from a physical address meeting
1796 above alignment restrictions.
1798 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1799 this value must be a multiple of 0x200000.
1801 Don't change this unless you know what you are doing.
1804 bool "Support for hot-pluggable CPUs"
1807 Say Y here to allow turning CPUs off and on. CPUs can be
1808 controlled through /sys/devices/system/cpu.
1809 ( Note: power management support will enable this option
1810 automatically on SMP systems. )
1811 Say N if you want to disable CPU hotplug.
1813 config BOOTPARAM_HOTPLUG_CPU0
1814 bool "Set default setting of cpu0_hotpluggable"
1816 depends on HOTPLUG_CPU
1818 Set whether default state of cpu0_hotpluggable is on or off.
1820 Say Y here to enable CPU0 hotplug by default. If this switch
1821 is turned on, there is no need to give cpu0_hotplug kernel
1822 parameter and the CPU0 hotplug feature is enabled by default.
1824 Please note: there are two known CPU0 dependencies if you want
1825 to enable the CPU0 hotplug feature either by this switch or by
1826 cpu0_hotplug kernel parameter.
1828 First, resume from hibernate or suspend always starts from CPU0.
1829 So hibernate and suspend are prevented if CPU0 is offline.
1831 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1832 offline if any interrupt can not migrate out of CPU0. There may
1833 be other CPU0 dependencies.
1835 Please make sure the dependencies are under your control before
1836 you enable this feature.
1838 Say N if you don't want to enable CPU0 hotplug feature by default.
1839 You still can enable the CPU0 hotplug feature at boot by kernel
1840 parameter cpu0_hotplug.
1842 config DEBUG_HOTPLUG_CPU0
1844 prompt "Debug CPU0 hotplug"
1845 depends on HOTPLUG_CPU
1847 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1848 soon as possible and boots up userspace with CPU0 offlined. User
1849 can online CPU0 back after boot time.
1851 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1852 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1853 compilation or giving cpu0_hotplug kernel parameter at boot.
1859 prompt "Compat VDSO support"
1860 depends on X86_32 || IA32_EMULATION
1862 Map the 32-bit VDSO to the predictable old-style address too.
1864 Say N here if you are running a sufficiently recent glibc
1865 version (2.3.3 or later), to remove the high-mapped
1866 VDSO mapping and to exclusively use the randomized VDSO.
1871 bool "Built-in kernel command line"
1873 Allow for specifying boot arguments to the kernel at
1874 build time. On some systems (e.g. embedded ones), it is
1875 necessary or convenient to provide some or all of the
1876 kernel boot arguments with the kernel itself (that is,
1877 to not rely on the boot loader to provide them.)
1879 To compile command line arguments into the kernel,
1880 set this option to 'Y', then fill in the
1881 the boot arguments in CONFIG_CMDLINE.
1883 Systems with fully functional boot loaders (i.e. non-embedded)
1884 should leave this option set to 'N'.
1887 string "Built-in kernel command string"
1888 depends on CMDLINE_BOOL
1891 Enter arguments here that should be compiled into the kernel
1892 image and used at boot time. If the boot loader provides a
1893 command line at boot time, it is appended to this string to
1894 form the full kernel command line, when the system boots.
1896 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1897 change this behavior.
1899 In most cases, the command line (whether built-in or provided
1900 by the boot loader) should specify the device for the root
1903 config CMDLINE_OVERRIDE
1904 bool "Built-in command line overrides boot loader arguments"
1905 depends on CMDLINE_BOOL
1907 Set this option to 'Y' to have the kernel ignore the boot loader
1908 command line, and use ONLY the built-in command line.
1910 This is used to work around broken boot loaders. This should
1911 be set to 'N' under normal conditions.
1915 config ARCH_ENABLE_MEMORY_HOTPLUG
1917 depends on X86_64 || (X86_32 && HIGHMEM)
1919 config ARCH_ENABLE_MEMORY_HOTREMOVE
1921 depends on MEMORY_HOTPLUG
1923 config USE_PERCPU_NUMA_NODE_ID
1927 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1929 depends on X86_64 || X86_PAE
1931 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1933 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1935 menu "Power management and ACPI options"
1937 config ARCH_HIBERNATION_HEADER
1939 depends on X86_64 && HIBERNATION
1941 source "kernel/power/Kconfig"
1943 source "drivers/acpi/Kconfig"
1945 source "drivers/sfi/Kconfig"
1952 tristate "APM (Advanced Power Management) BIOS support"
1953 depends on X86_32 && PM_SLEEP
1955 APM is a BIOS specification for saving power using several different
1956 techniques. This is mostly useful for battery powered laptops with
1957 APM compliant BIOSes. If you say Y here, the system time will be
1958 reset after a RESUME operation, the /proc/apm device will provide
1959 battery status information, and user-space programs will receive
1960 notification of APM "events" (e.g. battery status change).
1962 If you select "Y" here, you can disable actual use of the APM
1963 BIOS by passing the "apm=off" option to the kernel at boot time.
1965 Note that the APM support is almost completely disabled for
1966 machines with more than one CPU.
1968 In order to use APM, you will need supporting software. For location
1969 and more information, read <file:Documentation/power/apm-acpi.txt>
1970 and the Battery Powered Linux mini-HOWTO, available from
1971 <http://www.tldp.org/docs.html#howto>.
1973 This driver does not spin down disk drives (see the hdparm(8)
1974 manpage ("man 8 hdparm") for that), and it doesn't turn off
1975 VESA-compliant "green" monitors.
1977 This driver does not support the TI 4000M TravelMate and the ACER
1978 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1979 desktop machines also don't have compliant BIOSes, and this driver
1980 may cause those machines to panic during the boot phase.
1982 Generally, if you don't have a battery in your machine, there isn't
1983 much point in using this driver and you should say N. If you get
1984 random kernel OOPSes or reboots that don't seem to be related to
1985 anything, try disabling/enabling this option (or disabling/enabling
1988 Some other things you should try when experiencing seemingly random,
1991 1) make sure that you have enough swap space and that it is
1993 2) pass the "no-hlt" option to the kernel
1994 3) switch on floating point emulation in the kernel and pass
1995 the "no387" option to the kernel
1996 4) pass the "floppy=nodma" option to the kernel
1997 5) pass the "mem=4M" option to the kernel (thereby disabling
1998 all but the first 4 MB of RAM)
1999 6) make sure that the CPU is not over clocked.
2000 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2001 8) disable the cache from your BIOS settings
2002 9) install a fan for the video card or exchange video RAM
2003 10) install a better fan for the CPU
2004 11) exchange RAM chips
2005 12) exchange the motherboard.
2007 To compile this driver as a module, choose M here: the
2008 module will be called apm.
2012 config APM_IGNORE_USER_SUSPEND
2013 bool "Ignore USER SUSPEND"
2015 This option will ignore USER SUSPEND requests. On machines with a
2016 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2017 series notebooks, it is necessary to say Y because of a BIOS bug.
2019 config APM_DO_ENABLE
2020 bool "Enable PM at boot time"
2022 Enable APM features at boot time. From page 36 of the APM BIOS
2023 specification: "When disabled, the APM BIOS does not automatically
2024 power manage devices, enter the Standby State, enter the Suspend
2025 State, or take power saving steps in response to CPU Idle calls."
2026 This driver will make CPU Idle calls when Linux is idle (unless this
2027 feature is turned off -- see "Do CPU IDLE calls", below). This
2028 should always save battery power, but more complicated APM features
2029 will be dependent on your BIOS implementation. You may need to turn
2030 this option off if your computer hangs at boot time when using APM
2031 support, or if it beeps continuously instead of suspending. Turn
2032 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2033 T400CDT. This is off by default since most machines do fine without
2038 bool "Make CPU Idle calls when idle"
2040 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2041 On some machines, this can activate improved power savings, such as
2042 a slowed CPU clock rate, when the machine is idle. These idle calls
2043 are made after the idle loop has run for some length of time (e.g.,
2044 333 mS). On some machines, this will cause a hang at boot time or
2045 whenever the CPU becomes idle. (On machines with more than one CPU,
2046 this option does nothing.)
2048 config APM_DISPLAY_BLANK
2049 bool "Enable console blanking using APM"
2051 Enable console blanking using the APM. Some laptops can use this to
2052 turn off the LCD backlight when the screen blanker of the Linux
2053 virtual console blanks the screen. Note that this is only used by
2054 the virtual console screen blanker, and won't turn off the backlight
2055 when using the X Window system. This also doesn't have anything to
2056 do with your VESA-compliant power-saving monitor. Further, this
2057 option doesn't work for all laptops -- it might not turn off your
2058 backlight at all, or it might print a lot of errors to the console,
2059 especially if you are using gpm.
2061 config APM_ALLOW_INTS
2062 bool "Allow interrupts during APM BIOS calls"
2064 Normally we disable external interrupts while we are making calls to
2065 the APM BIOS as a measure to lessen the effects of a badly behaving
2066 BIOS implementation. The BIOS should reenable interrupts if it
2067 needs to. Unfortunately, some BIOSes do not -- especially those in
2068 many of the newer IBM Thinkpads. If you experience hangs when you
2069 suspend, try setting this to Y. Otherwise, say N.
2073 source "drivers/cpufreq/Kconfig"
2075 source "drivers/cpuidle/Kconfig"
2077 source "drivers/idle/Kconfig"
2082 menu "Bus options (PCI etc.)"
2088 Find out whether you have a PCI motherboard. PCI is the name of a
2089 bus system, i.e. the way the CPU talks to the other stuff inside
2090 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2091 VESA. If you have PCI, say Y, otherwise N.
2094 prompt "PCI access mode"
2095 depends on X86_32 && PCI
2098 On PCI systems, the BIOS can be used to detect the PCI devices and
2099 determine their configuration. However, some old PCI motherboards
2100 have BIOS bugs and may crash if this is done. Also, some embedded
2101 PCI-based systems don't have any BIOS at all. Linux can also try to
2102 detect the PCI hardware directly without using the BIOS.
2104 With this option, you can specify how Linux should detect the
2105 PCI devices. If you choose "BIOS", the BIOS will be used,
2106 if you choose "Direct", the BIOS won't be used, and if you
2107 choose "MMConfig", then PCI Express MMCONFIG will be used.
2108 If you choose "Any", the kernel will try MMCONFIG, then the
2109 direct access method and falls back to the BIOS if that doesn't
2110 work. If unsure, go with the default, which is "Any".
2115 config PCI_GOMMCONFIG
2132 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2134 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2137 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2141 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2145 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2149 depends on PCI && XEN
2157 bool "Support mmconfig PCI config space access"
2158 depends on X86_64 && PCI && ACPI
2160 config PCI_CNB20LE_QUIRK
2161 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2164 Read the PCI windows out of the CNB20LE host bridge. This allows
2165 PCI hotplug to work on systems with the CNB20LE chipset which do
2168 There's no public spec for this chipset, and this functionality
2169 is known to be incomplete.
2171 You should say N unless you know you need this.
2173 source "drivers/pci/pcie/Kconfig"
2175 source "drivers/pci/Kconfig"
2177 # x86_64 have no ISA slots, but can have ISA-style DMA.
2179 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2182 Enables ISA-style DMA support for devices requiring such controllers.
2190 Find out whether you have ISA slots on your motherboard. ISA is the
2191 name of a bus system, i.e. the way the CPU talks to the other stuff
2192 inside your box. Other bus systems are PCI, EISA, MicroChannel
2193 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2194 newer boards don't support it. If you have ISA, say Y, otherwise N.
2200 The Extended Industry Standard Architecture (EISA) bus was
2201 developed as an open alternative to the IBM MicroChannel bus.
2203 The EISA bus provided some of the features of the IBM MicroChannel
2204 bus while maintaining backward compatibility with cards made for
2205 the older ISA bus. The EISA bus saw limited use between 1988 and
2206 1995 when it was made obsolete by the PCI bus.
2208 Say Y here if you are building a kernel for an EISA-based machine.
2212 source "drivers/eisa/Kconfig"
2215 tristate "NatSemi SCx200 support"
2217 This provides basic support for National Semiconductor's
2218 (now AMD's) Geode processors. The driver probes for the
2219 PCI-IDs of several on-chip devices, so its a good dependency
2220 for other scx200_* drivers.
2222 If compiled as a module, the driver is named scx200.
2224 config SCx200HR_TIMER
2225 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2229 This driver provides a clocksource built upon the on-chip
2230 27MHz high-resolution timer. Its also a workaround for
2231 NSC Geode SC-1100's buggy TSC, which loses time when the
2232 processor goes idle (as is done by the scheduler). The
2233 other workaround is idle=poll boot option.
2236 bool "One Laptop Per Child support"
2243 Add support for detecting the unique features of the OLPC
2247 bool "OLPC XO-1 Power Management"
2248 depends on OLPC && MFD_CS5535 && PM_SLEEP
2251 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2254 bool "OLPC XO-1 Real Time Clock"
2255 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2257 Add support for the XO-1 real time clock, which can be used as a
2258 programmable wakeup source.
2261 bool "OLPC XO-1 SCI extras"
2262 depends on OLPC && OLPC_XO1_PM
2268 Add support for SCI-based features of the OLPC XO-1 laptop:
2269 - EC-driven system wakeups
2273 - AC adapter status updates
2274 - Battery status updates
2276 config OLPC_XO15_SCI
2277 bool "OLPC XO-1.5 SCI extras"
2278 depends on OLPC && ACPI
2281 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2282 - EC-driven system wakeups
2283 - AC adapter status updates
2284 - Battery status updates
2287 bool "PCEngines ALIX System Support (LED setup)"
2290 This option enables system support for the PCEngines ALIX.
2291 At present this just sets up LEDs for GPIO control on
2292 ALIX2/3/6 boards. However, other system specific setup should
2295 Note: You must still enable the drivers for GPIO and LED support
2296 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2298 Note: You have to set alix.force=1 for boards with Award BIOS.
2301 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2304 This option enables system support for the Soekris Engineering net5501.
2307 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2311 This option enables system support for the Traverse Technologies GEOS.
2314 bool "Technologic Systems TS-5500 platform support"
2316 select CHECK_SIGNATURE
2320 This option enables system support for the Technologic Systems TS-5500.
2326 depends on CPU_SUP_AMD && PCI
2328 source "drivers/pcmcia/Kconfig"
2330 source "drivers/pci/hotplug/Kconfig"
2333 tristate "RapidIO support"
2337 If enabled this option will include drivers and the core
2338 infrastructure code to support RapidIO interconnect devices.
2340 source "drivers/rapidio/Kconfig"
2343 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2345 Firmwares often provide initial graphics framebuffers so the BIOS,
2346 bootloader or kernel can show basic video-output during boot for
2347 user-guidance and debugging. Historically, x86 used the VESA BIOS
2348 Extensions and EFI-framebuffers for this, which are mostly limited
2350 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2351 framebuffers so the new generic system-framebuffer drivers can be
2352 used on x86. If the framebuffer is not compatible with the generic
2353 modes, it is adverticed as fallback platform framebuffer so legacy
2354 drivers like efifb, vesafb and uvesafb can pick it up.
2355 If this option is not selected, all system framebuffers are always
2356 marked as fallback platform framebuffers as usual.
2358 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2359 not be able to pick up generic system framebuffers if this option
2360 is selected. You are highly encouraged to enable simplefb as
2361 replacement if you select this option. simplefb can correctly deal
2362 with generic system framebuffers. But you should still keep vesafb
2363 and others enabled as fallback if a system framebuffer is
2364 incompatible with simplefb.
2371 menu "Executable file formats / Emulations"
2373 source "fs/Kconfig.binfmt"
2375 config IA32_EMULATION
2376 bool "IA32 Emulation"
2379 select COMPAT_BINFMT_ELF
2382 Include code to run legacy 32-bit programs under a
2383 64-bit kernel. You should likely turn this on, unless you're
2384 100% sure that you don't have any 32-bit programs left.
2387 tristate "IA32 a.out support"
2388 depends on IA32_EMULATION
2390 Support old a.out binaries in the 32bit emulation.
2393 bool "x32 ABI for 64-bit mode"
2394 depends on X86_64 && IA32_EMULATION
2396 Include code to run binaries for the x32 native 32-bit ABI
2397 for 64-bit processors. An x32 process gets access to the
2398 full 64-bit register file and wide data path while leaving
2399 pointers at 32 bits for smaller memory footprint.
2401 You will need a recent binutils (2.22 or later) with
2402 elf32_x86_64 support enabled to compile a kernel with this
2407 depends on IA32_EMULATION || X86_X32
2408 select ARCH_WANT_OLD_COMPAT_IPC
2411 config COMPAT_FOR_U64_ALIGNMENT
2414 config SYSVIPC_COMPAT
2426 config HAVE_ATOMIC_IOMAP
2430 config X86_DEV_DMA_OPS
2432 depends on X86_64 || STA2X11
2434 config X86_DMA_REMAP
2442 To be selected by modules requiring access to the Intel OnChip System
2443 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms
2446 source "net/Kconfig"
2448 source "drivers/Kconfig"
2450 source "drivers/firmware/Kconfig"
2454 source "arch/x86/Kconfig.debug"
2456 source "security/Kconfig"
2458 source "crypto/Kconfig"
2460 source "arch/x86/kvm/Kconfig"
2462 source "lib/Kconfig"
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / blob