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 16-bit legacy
970 code on X86 processors. It also may be needed by software like
971 XFree86 to initialize some video cards via BIOS. Disabling this
972 option saves about 6k.
975 tristate "Toshiba Laptop support"
978 This adds a driver to safely access the System Management Mode of
979 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
980 not work on models with a Phoenix BIOS. The System Management Mode
981 is used to set the BIOS and power saving options on Toshiba portables.
983 For information on utilities to make use of this driver see the
984 Toshiba Linux utilities web site at:
985 <http://www.buzzard.org.uk/toshiba/>.
987 Say Y if you intend to run this kernel on a Toshiba portable.
991 tristate "Dell laptop support"
994 This adds a driver to safely access the System Management Mode
995 of the CPU on the Dell Inspiron 8000. The System Management Mode
996 is used to read cpu temperature and cooling fan status and to
997 control the fans on the I8K portables.
999 This driver has been tested only on the Inspiron 8000 but it may
1000 also work with other Dell laptops. You can force loading on other
1001 models by passing the parameter `force=1' to the module. Use at
1004 For information on utilities to make use of this driver see the
1005 I8K Linux utilities web site at:
1006 <http://people.debian.org/~dz/i8k/>
1008 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1011 config X86_REBOOTFIXUPS
1012 bool "Enable X86 board specific fixups for reboot"
1015 This enables chipset and/or board specific fixups to be done
1016 in order to get reboot to work correctly. This is only needed on
1017 some combinations of hardware and BIOS. The symptom, for which
1018 this config is intended, is when reboot ends with a stalled/hung
1021 Currently, the only fixup is for the Geode machines using
1022 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1024 Say Y if you want to enable the fixup. Currently, it's safe to
1025 enable this option even if you don't need it.
1029 tristate "CPU microcode loading support"
1030 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1034 If you say Y here, you will be able to update the microcode on
1035 certain Intel and AMD processors. The Intel support is for the
1036 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1037 Xeon etc. The AMD support is for families 0x10 and later. You will
1038 obviously need the actual microcode binary data itself which is not
1039 shipped with the Linux kernel.
1041 This option selects the general module only, you need to select
1042 at least one vendor specific module as well.
1044 To compile this driver as a module, choose M here: the module
1045 will be called microcode.
1047 config MICROCODE_INTEL
1048 bool "Intel microcode loading support"
1049 depends on MICROCODE
1053 This options enables microcode patch loading support for Intel
1056 For the current Intel microcode data package go to
1057 <https://downloadcenter.intel.com> and search for
1058 'Linux Processor Microcode Data File'.
1060 config MICROCODE_AMD
1061 bool "AMD microcode loading support"
1062 depends on MICROCODE
1065 If you select this option, microcode patch loading support for AMD
1066 processors will be enabled.
1068 config MICROCODE_OLD_INTERFACE
1070 depends on MICROCODE
1072 config MICROCODE_INTEL_EARLY
1075 config MICROCODE_AMD_EARLY
1078 config MICROCODE_EARLY
1079 bool "Early load microcode"
1080 depends on MICROCODE=y && BLK_DEV_INITRD
1081 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1082 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1085 This option provides functionality to read additional microcode data
1086 at the beginning of initrd image. The data tells kernel to load
1087 microcode to CPU's as early as possible. No functional change if no
1088 microcode data is glued to the initrd, therefore it's safe to say Y.
1091 tristate "/dev/cpu/*/msr - Model-specific register support"
1093 This device gives privileged processes access to the x86
1094 Model-Specific Registers (MSRs). It is a character device with
1095 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1096 MSR accesses are directed to a specific CPU on multi-processor
1100 tristate "/dev/cpu/*/cpuid - CPU information support"
1102 This device gives processes access to the x86 CPUID instruction to
1103 be executed on a specific processor. It is a character device
1104 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1108 prompt "High Memory Support"
1109 default HIGHMEM64G if X86_NUMAQ
1115 depends on !X86_NUMAQ
1117 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1118 However, the address space of 32-bit x86 processors is only 4
1119 Gigabytes large. That means that, if you have a large amount of
1120 physical memory, not all of it can be "permanently mapped" by the
1121 kernel. The physical memory that's not permanently mapped is called
1124 If you are compiling a kernel which will never run on a machine with
1125 more than 1 Gigabyte total physical RAM, answer "off" here (default
1126 choice and suitable for most users). This will result in a "3GB/1GB"
1127 split: 3GB are mapped so that each process sees a 3GB virtual memory
1128 space and the remaining part of the 4GB virtual memory space is used
1129 by the kernel to permanently map as much physical memory as
1132 If the machine has between 1 and 4 Gigabytes physical RAM, then
1135 If more than 4 Gigabytes is used then answer "64GB" here. This
1136 selection turns Intel PAE (Physical Address Extension) mode on.
1137 PAE implements 3-level paging on IA32 processors. PAE is fully
1138 supported by Linux, PAE mode is implemented on all recent Intel
1139 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1140 then the kernel will not boot on CPUs that don't support PAE!
1142 The actual amount of total physical memory will either be
1143 auto detected or can be forced by using a kernel command line option
1144 such as "mem=256M". (Try "man bootparam" or see the documentation of
1145 your boot loader (lilo or loadlin) about how to pass options to the
1146 kernel at boot time.)
1148 If unsure, say "off".
1152 depends on !X86_NUMAQ
1154 Select this if you have a 32-bit processor and between 1 and 4
1155 gigabytes of physical RAM.
1162 Select this if you have a 32-bit processor and more than 4
1163 gigabytes of physical RAM.
1168 prompt "Memory split" if EXPERT
1172 Select the desired split between kernel and user memory.
1174 If the address range available to the kernel is less than the
1175 physical memory installed, the remaining memory will be available
1176 as "high memory". Accessing high memory is a little more costly
1177 than low memory, as it needs to be mapped into the kernel first.
1178 Note that increasing the kernel address space limits the range
1179 available to user programs, making the address space there
1180 tighter. Selecting anything other than the default 3G/1G split
1181 will also likely make your kernel incompatible with binary-only
1184 If you are not absolutely sure what you are doing, leave this
1188 bool "3G/1G user/kernel split"
1189 config VMSPLIT_3G_OPT
1191 bool "3G/1G user/kernel split (for full 1G low memory)"
1193 bool "2G/2G user/kernel split"
1194 config VMSPLIT_2G_OPT
1196 bool "2G/2G user/kernel split (for full 2G low memory)"
1198 bool "1G/3G user/kernel split"
1203 default 0xB0000000 if VMSPLIT_3G_OPT
1204 default 0x80000000 if VMSPLIT_2G
1205 default 0x78000000 if VMSPLIT_2G_OPT
1206 default 0x40000000 if VMSPLIT_1G
1212 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1215 bool "PAE (Physical Address Extension) Support"
1216 depends on X86_32 && !HIGHMEM4G
1218 PAE is required for NX support, and furthermore enables
1219 larger swapspace support for non-overcommit purposes. It
1220 has the cost of more pagetable lookup overhead, and also
1221 consumes more pagetable space per process.
1223 config ARCH_PHYS_ADDR_T_64BIT
1225 depends on X86_64 || X86_PAE
1227 config ARCH_DMA_ADDR_T_64BIT
1229 depends on X86_64 || HIGHMEM64G
1231 config DIRECT_GBPAGES
1232 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1236 Allow the kernel linear mapping to use 1GB pages on CPUs that
1237 support it. This can improve the kernel's performance a tiny bit by
1238 reducing TLB pressure. If in doubt, say "Y".
1240 # Common NUMA Features
1242 bool "Numa Memory Allocation and Scheduler Support"
1244 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1245 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1247 Enable NUMA (Non Uniform Memory Access) support.
1249 The kernel will try to allocate memory used by a CPU on the
1250 local memory controller of the CPU and add some more
1251 NUMA awareness to the kernel.
1253 For 64-bit this is recommended if the system is Intel Core i7
1254 (or later), AMD Opteron, or EM64T NUMA.
1256 For 32-bit this is only needed on (rare) 32-bit-only platforms
1257 that support NUMA topologies, such as NUMAQ / Summit, or if you
1258 boot a 32-bit kernel on a 64-bit NUMA platform.
1260 Otherwise, you should say N.
1262 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1263 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1267 prompt "Old style AMD Opteron NUMA detection"
1268 depends on X86_64 && NUMA && PCI
1270 Enable AMD NUMA node topology detection. You should say Y here if
1271 you have a multi processor AMD system. This uses an old method to
1272 read the NUMA configuration directly from the builtin Northbridge
1273 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1274 which also takes priority if both are compiled in.
1276 config X86_64_ACPI_NUMA
1278 prompt "ACPI NUMA detection"
1279 depends on X86_64 && NUMA && ACPI && PCI
1282 Enable ACPI SRAT based node topology detection.
1284 # Some NUMA nodes have memory ranges that span
1285 # other nodes. Even though a pfn is valid and
1286 # between a node's start and end pfns, it may not
1287 # reside on that node. See memmap_init_zone()
1289 config NODES_SPAN_OTHER_NODES
1291 depends on X86_64_ACPI_NUMA
1294 bool "NUMA emulation"
1297 Enable NUMA emulation. A flat machine will be split
1298 into virtual nodes when booted with "numa=fake=N", where N is the
1299 number of nodes. This is only useful for debugging.
1302 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1304 default "10" if MAXSMP
1305 default "6" if X86_64
1306 default "4" if X86_NUMAQ
1308 depends on NEED_MULTIPLE_NODES
1310 Specify the maximum number of NUMA Nodes available on the target
1311 system. Increases memory reserved to accommodate various tables.
1313 config ARCH_HAVE_MEMORY_PRESENT
1315 depends on X86_32 && DISCONTIGMEM
1317 config NEED_NODE_MEMMAP_SIZE
1319 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1321 config ARCH_FLATMEM_ENABLE
1323 depends on X86_32 && !NUMA
1325 config ARCH_DISCONTIGMEM_ENABLE
1327 depends on NUMA && X86_32
1329 config ARCH_DISCONTIGMEM_DEFAULT
1331 depends on NUMA && X86_32
1333 config ARCH_SPARSEMEM_ENABLE
1335 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1336 select SPARSEMEM_STATIC if X86_32
1337 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1339 config ARCH_SPARSEMEM_DEFAULT
1343 config ARCH_SELECT_MEMORY_MODEL
1345 depends on ARCH_SPARSEMEM_ENABLE
1347 config ARCH_MEMORY_PROBE
1348 bool "Enable sysfs memory/probe interface"
1349 depends on X86_64 && MEMORY_HOTPLUG
1351 This option enables a sysfs memory/probe interface for testing.
1352 See Documentation/memory-hotplug.txt for more information.
1353 If you are unsure how to answer this question, answer N.
1355 config ARCH_PROC_KCORE_TEXT
1357 depends on X86_64 && PROC_KCORE
1359 config ILLEGAL_POINTER_VALUE
1362 default 0xdead000000000000 if X86_64
1367 bool "Allocate 3rd-level pagetables from highmem"
1370 The VM uses one page table entry for each page of physical memory.
1371 For systems with a lot of RAM, this can be wasteful of precious
1372 low memory. Setting this option will put user-space page table
1373 entries in high memory.
1375 config X86_CHECK_BIOS_CORRUPTION
1376 bool "Check for low memory corruption"
1378 Periodically check for memory corruption in low memory, which
1379 is suspected to be caused by BIOS. Even when enabled in the
1380 configuration, it is disabled at runtime. Enable it by
1381 setting "memory_corruption_check=1" on the kernel command
1382 line. By default it scans the low 64k of memory every 60
1383 seconds; see the memory_corruption_check_size and
1384 memory_corruption_check_period parameters in
1385 Documentation/kernel-parameters.txt to adjust this.
1387 When enabled with the default parameters, this option has
1388 almost no overhead, as it reserves a relatively small amount
1389 of memory and scans it infrequently. It both detects corruption
1390 and prevents it from affecting the running system.
1392 It is, however, intended as a diagnostic tool; if repeatable
1393 BIOS-originated corruption always affects the same memory,
1394 you can use memmap= to prevent the kernel from using that
1397 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1398 bool "Set the default setting of memory_corruption_check"
1399 depends on X86_CHECK_BIOS_CORRUPTION
1402 Set whether the default state of memory_corruption_check is
1405 config X86_RESERVE_LOW
1406 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1410 Specify the amount of low memory to reserve for the BIOS.
1412 The first page contains BIOS data structures that the kernel
1413 must not use, so that page must always be reserved.
1415 By default we reserve the first 64K of physical RAM, as a
1416 number of BIOSes are known to corrupt that memory range
1417 during events such as suspend/resume or monitor cable
1418 insertion, so it must not be used by the kernel.
1420 You can set this to 4 if you are absolutely sure that you
1421 trust the BIOS to get all its memory reservations and usages
1422 right. If you know your BIOS have problems beyond the
1423 default 64K area, you can set this to 640 to avoid using the
1424 entire low memory range.
1426 If you have doubts about the BIOS (e.g. suspend/resume does
1427 not work or there's kernel crashes after certain hardware
1428 hotplug events) then you might want to enable
1429 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1430 typical corruption patterns.
1432 Leave this to the default value of 64 if you are unsure.
1434 config MATH_EMULATION
1436 prompt "Math emulation" if X86_32
1438 Linux can emulate a math coprocessor (used for floating point
1439 operations) if you don't have one. 486DX and Pentium processors have
1440 a math coprocessor built in, 486SX and 386 do not, unless you added
1441 a 487DX or 387, respectively. (The messages during boot time can
1442 give you some hints here ["man dmesg"].) Everyone needs either a
1443 coprocessor or this emulation.
1445 If you don't have a math coprocessor, you need to say Y here; if you
1446 say Y here even though you have a coprocessor, the coprocessor will
1447 be used nevertheless. (This behavior can be changed with the kernel
1448 command line option "no387", which comes handy if your coprocessor
1449 is broken. Try "man bootparam" or see the documentation of your boot
1450 loader (lilo or loadlin) about how to pass options to the kernel at
1451 boot time.) This means that it is a good idea to say Y here if you
1452 intend to use this kernel on different machines.
1454 More information about the internals of the Linux math coprocessor
1455 emulation can be found in <file:arch/x86/math-emu/README>.
1457 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1458 kernel, it won't hurt.
1462 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1464 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1465 the Memory Type Range Registers (MTRRs) may be used to control
1466 processor access to memory ranges. This is most useful if you have
1467 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1468 allows bus write transfers to be combined into a larger transfer
1469 before bursting over the PCI/AGP bus. This can increase performance
1470 of image write operations 2.5 times or more. Saying Y here creates a
1471 /proc/mtrr file which may be used to manipulate your processor's
1472 MTRRs. Typically the X server should use this.
1474 This code has a reasonably generic interface so that similar
1475 control registers on other processors can be easily supported
1478 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1479 Registers (ARRs) which provide a similar functionality to MTRRs. For
1480 these, the ARRs are used to emulate the MTRRs.
1481 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1482 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1483 write-combining. All of these processors are supported by this code
1484 and it makes sense to say Y here if you have one of them.
1486 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1487 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1488 can lead to all sorts of problems, so it's good to say Y here.
1490 You can safely say Y even if your machine doesn't have MTRRs, you'll
1491 just add about 9 KB to your kernel.
1493 See <file:Documentation/x86/mtrr.txt> for more information.
1495 config MTRR_SANITIZER
1497 prompt "MTRR cleanup support"
1500 Convert MTRR layout from continuous to discrete, so X drivers can
1501 add writeback entries.
1503 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1504 The largest mtrr entry size for a continuous block can be set with
1509 config MTRR_SANITIZER_ENABLE_DEFAULT
1510 int "MTRR cleanup enable value (0-1)"
1513 depends on MTRR_SANITIZER
1515 Enable mtrr cleanup default value
1517 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1518 int "MTRR cleanup spare reg num (0-7)"
1521 depends on MTRR_SANITIZER
1523 mtrr cleanup spare entries default, it can be changed via
1524 mtrr_spare_reg_nr=N on the kernel command line.
1528 prompt "x86 PAT support" if EXPERT
1531 Use PAT attributes to setup page level cache control.
1533 PATs are the modern equivalents of MTRRs and are much more
1534 flexible than MTRRs.
1536 Say N here if you see bootup problems (boot crash, boot hang,
1537 spontaneous reboots) or a non-working video driver.
1541 config ARCH_USES_PG_UNCACHED
1547 prompt "x86 architectural random number generator" if EXPERT
1549 Enable the x86 architectural RDRAND instruction
1550 (Intel Bull Mountain technology) to generate random numbers.
1551 If supported, this is a high bandwidth, cryptographically
1552 secure hardware random number generator.
1556 prompt "Supervisor Mode Access Prevention" if EXPERT
1558 Supervisor Mode Access Prevention (SMAP) is a security
1559 feature in newer Intel processors. There is a small
1560 performance cost if this enabled and turned on; there is
1561 also a small increase in the kernel size if this is enabled.
1566 bool "EFI runtime service support"
1570 This enables the kernel to use EFI runtime services that are
1571 available (such as the EFI variable services).
1573 This option is only useful on systems that have EFI firmware.
1574 In addition, you should use the latest ELILO loader available
1575 at <http://elilo.sourceforge.net> in order to take advantage
1576 of EFI runtime services. However, even with this option, the
1577 resultant kernel should continue to boot on existing non-EFI
1581 bool "EFI stub support"
1584 This kernel feature allows a bzImage to be loaded directly
1585 by EFI firmware without the use of a bootloader.
1587 See Documentation/efi-stub.txt for more information.
1591 prompt "Enable seccomp to safely compute untrusted bytecode"
1593 This kernel feature is useful for number crunching applications
1594 that may need to compute untrusted bytecode during their
1595 execution. By using pipes or other transports made available to
1596 the process as file descriptors supporting the read/write
1597 syscalls, it's possible to isolate those applications in
1598 their own address space using seccomp. Once seccomp is
1599 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1600 and the task is only allowed to execute a few safe syscalls
1601 defined by each seccomp mode.
1603 If unsure, say Y. Only embedded should say N here.
1605 source kernel/Kconfig.hz
1608 bool "kexec system call"
1610 kexec is a system call that implements the ability to shutdown your
1611 current kernel, and to start another kernel. It is like a reboot
1612 but it is independent of the system firmware. And like a reboot
1613 you can start any kernel with it, not just Linux.
1615 The name comes from the similarity to the exec system call.
1617 It is an ongoing process to be certain the hardware in a machine
1618 is properly shutdown, so do not be surprised if this code does not
1619 initially work for you. As of this writing the exact hardware
1620 interface is strongly in flux, so no good recommendation can be
1624 bool "kernel crash dumps"
1625 depends on X86_64 || (X86_32 && HIGHMEM)
1627 Generate crash dump after being started by kexec.
1628 This should be normally only set in special crash dump kernels
1629 which are loaded in the main kernel with kexec-tools into
1630 a specially reserved region and then later executed after
1631 a crash by kdump/kexec. The crash dump kernel must be compiled
1632 to a memory address not used by the main kernel or BIOS using
1633 PHYSICAL_START, or it must be built as a relocatable image
1634 (CONFIG_RELOCATABLE=y).
1635 For more details see Documentation/kdump/kdump.txt
1639 depends on KEXEC && HIBERNATION
1641 Jump between original kernel and kexeced kernel and invoke
1642 code in physical address mode via KEXEC
1644 config PHYSICAL_START
1645 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1648 This gives the physical address where the kernel is loaded.
1650 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1651 bzImage will decompress itself to above physical address and
1652 run from there. Otherwise, bzImage will run from the address where
1653 it has been loaded by the boot loader and will ignore above physical
1656 In normal kdump cases one does not have to set/change this option
1657 as now bzImage can be compiled as a completely relocatable image
1658 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1659 address. This option is mainly useful for the folks who don't want
1660 to use a bzImage for capturing the crash dump and want to use a
1661 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1662 to be specifically compiled to run from a specific memory area
1663 (normally a reserved region) and this option comes handy.
1665 So if you are using bzImage for capturing the crash dump,
1666 leave the value here unchanged to 0x1000000 and set
1667 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1668 for capturing the crash dump change this value to start of
1669 the reserved region. In other words, it can be set based on
1670 the "X" value as specified in the "crashkernel=YM@XM"
1671 command line boot parameter passed to the panic-ed
1672 kernel. Please take a look at Documentation/kdump/kdump.txt
1673 for more details about crash dumps.
1675 Usage of bzImage for capturing the crash dump is recommended as
1676 one does not have to build two kernels. Same kernel can be used
1677 as production kernel and capture kernel. Above option should have
1678 gone away after relocatable bzImage support is introduced. But it
1679 is present because there are users out there who continue to use
1680 vmlinux for dump capture. This option should go away down the
1683 Don't change this unless you know what you are doing.
1686 bool "Build a relocatable kernel"
1689 This builds a kernel image that retains relocation information
1690 so it can be loaded someplace besides the default 1MB.
1691 The relocations tend to make the kernel binary about 10% larger,
1692 but are discarded at runtime.
1694 One use is for the kexec on panic case where the recovery kernel
1695 must live at a different physical address than the primary
1698 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1699 it has been loaded at and the compile time physical address
1700 (CONFIG_PHYSICAL_START) is used as the minimum location.
1702 config RANDOMIZE_BASE
1703 bool "Randomize the address of the kernel image"
1704 depends on RELOCATABLE
1705 depends on !HIBERNATION
1708 Randomizes the physical and virtual address at which the
1709 kernel image is decompressed, as a security feature that
1710 deters exploit attempts relying on knowledge of the location
1711 of kernel internals.
1713 Entropy is generated using the RDRAND instruction if it is
1714 supported. If RDTSC is supported, it is used as well. If
1715 neither RDRAND nor RDTSC are supported, then randomness is
1716 read from the i8254 timer.
1718 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1719 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1720 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1721 minimum of 2MiB, only 10 bits of entropy is theoretically
1722 possible. At best, due to page table layouts, 64-bit can use
1723 9 bits of entropy and 32-bit uses 8 bits.
1727 config RANDOMIZE_BASE_MAX_OFFSET
1728 hex "Maximum kASLR offset allowed" if EXPERT
1729 depends on RANDOMIZE_BASE
1730 range 0x0 0x20000000 if X86_32
1731 default "0x20000000" if X86_32
1732 range 0x0 0x40000000 if X86_64
1733 default "0x40000000" if X86_64
1735 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1736 memory is used to determine the maximal offset in bytes that will
1737 be applied to the kernel when kernel Address Space Layout
1738 Randomization (kASLR) is active. This must be a multiple of
1741 On 32-bit this is limited to 512MiB by page table layouts. The
1744 On 64-bit this is limited by how the kernel fixmap page table is
1745 positioned, so this cannot be larger than 1GiB currently. Without
1746 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1747 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1748 modules area will shrink to compensate, up to the current maximum
1749 1GiB to 1GiB split. The default is 1GiB.
1751 If unsure, leave at the default value.
1753 # Relocation on x86 needs some additional build support
1754 config X86_NEED_RELOCS
1756 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1758 config PHYSICAL_ALIGN
1759 hex "Alignment value to which kernel should be aligned"
1761 range 0x2000 0x1000000 if X86_32
1762 range 0x200000 0x1000000 if X86_64
1764 This value puts the alignment restrictions on physical address
1765 where kernel is loaded and run from. Kernel is compiled for an
1766 address which meets above alignment restriction.
1768 If bootloader loads the kernel at a non-aligned address and
1769 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1770 address aligned to above value and run from there.
1772 If bootloader loads the kernel at a non-aligned address and
1773 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1774 load address and decompress itself to the address it has been
1775 compiled for and run from there. The address for which kernel is
1776 compiled already meets above alignment restrictions. Hence the
1777 end result is that kernel runs from a physical address meeting
1778 above alignment restrictions.
1780 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1781 this value must be a multiple of 0x200000.
1783 Don't change this unless you know what you are doing.
1786 bool "Support for hot-pluggable CPUs"
1789 Say Y here to allow turning CPUs off and on. CPUs can be
1790 controlled through /sys/devices/system/cpu.
1791 ( Note: power management support will enable this option
1792 automatically on SMP systems. )
1793 Say N if you want to disable CPU hotplug.
1795 config BOOTPARAM_HOTPLUG_CPU0
1796 bool "Set default setting of cpu0_hotpluggable"
1798 depends on HOTPLUG_CPU
1800 Set whether default state of cpu0_hotpluggable is on or off.
1802 Say Y here to enable CPU0 hotplug by default. If this switch
1803 is turned on, there is no need to give cpu0_hotplug kernel
1804 parameter and the CPU0 hotplug feature is enabled by default.
1806 Please note: there are two known CPU0 dependencies if you want
1807 to enable the CPU0 hotplug feature either by this switch or by
1808 cpu0_hotplug kernel parameter.
1810 First, resume from hibernate or suspend always starts from CPU0.
1811 So hibernate and suspend are prevented if CPU0 is offline.
1813 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1814 offline if any interrupt can not migrate out of CPU0. There may
1815 be other CPU0 dependencies.
1817 Please make sure the dependencies are under your control before
1818 you enable this feature.
1820 Say N if you don't want to enable CPU0 hotplug feature by default.
1821 You still can enable the CPU0 hotplug feature at boot by kernel
1822 parameter cpu0_hotplug.
1824 config DEBUG_HOTPLUG_CPU0
1826 prompt "Debug CPU0 hotplug"
1827 depends on HOTPLUG_CPU
1829 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1830 soon as possible and boots up userspace with CPU0 offlined. User
1831 can online CPU0 back after boot time.
1833 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1834 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1835 compilation or giving cpu0_hotplug kernel parameter at boot.
1841 prompt "Compat VDSO support"
1842 depends on X86_32 || IA32_EMULATION
1844 Map the 32-bit VDSO to the predictable old-style address too.
1846 Say N here if you are running a sufficiently recent glibc
1847 version (2.3.3 or later), to remove the high-mapped
1848 VDSO mapping and to exclusively use the randomized VDSO.
1853 bool "Built-in kernel command line"
1855 Allow for specifying boot arguments to the kernel at
1856 build time. On some systems (e.g. embedded ones), it is
1857 necessary or convenient to provide some or all of the
1858 kernel boot arguments with the kernel itself (that is,
1859 to not rely on the boot loader to provide them.)
1861 To compile command line arguments into the kernel,
1862 set this option to 'Y', then fill in the
1863 the boot arguments in CONFIG_CMDLINE.
1865 Systems with fully functional boot loaders (i.e. non-embedded)
1866 should leave this option set to 'N'.
1869 string "Built-in kernel command string"
1870 depends on CMDLINE_BOOL
1873 Enter arguments here that should be compiled into the kernel
1874 image and used at boot time. If the boot loader provides a
1875 command line at boot time, it is appended to this string to
1876 form the full kernel command line, when the system boots.
1878 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1879 change this behavior.
1881 In most cases, the command line (whether built-in or provided
1882 by the boot loader) should specify the device for the root
1885 config CMDLINE_OVERRIDE
1886 bool "Built-in command line overrides boot loader arguments"
1887 depends on CMDLINE_BOOL
1889 Set this option to 'Y' to have the kernel ignore the boot loader
1890 command line, and use ONLY the built-in command line.
1892 This is used to work around broken boot loaders. This should
1893 be set to 'N' under normal conditions.
1897 config ARCH_ENABLE_MEMORY_HOTPLUG
1899 depends on X86_64 || (X86_32 && HIGHMEM)
1901 config ARCH_ENABLE_MEMORY_HOTREMOVE
1903 depends on MEMORY_HOTPLUG
1905 config USE_PERCPU_NUMA_NODE_ID
1909 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
1911 depends on X86_64 || X86_PAE
1913 config ARCH_ENABLE_HUGEPAGE_MIGRATION
1915 depends on X86_64 && HUGETLB_PAGE && MIGRATION
1917 menu "Power management and ACPI options"
1919 config ARCH_HIBERNATION_HEADER
1921 depends on X86_64 && HIBERNATION
1923 source "kernel/power/Kconfig"
1925 source "drivers/acpi/Kconfig"
1927 source "drivers/sfi/Kconfig"
1934 tristate "APM (Advanced Power Management) BIOS support"
1935 depends on X86_32 && PM_SLEEP
1937 APM is a BIOS specification for saving power using several different
1938 techniques. This is mostly useful for battery powered laptops with
1939 APM compliant BIOSes. If you say Y here, the system time will be
1940 reset after a RESUME operation, the /proc/apm device will provide
1941 battery status information, and user-space programs will receive
1942 notification of APM "events" (e.g. battery status change).
1944 If you select "Y" here, you can disable actual use of the APM
1945 BIOS by passing the "apm=off" option to the kernel at boot time.
1947 Note that the APM support is almost completely disabled for
1948 machines with more than one CPU.
1950 In order to use APM, you will need supporting software. For location
1951 and more information, read <file:Documentation/power/apm-acpi.txt>
1952 and the Battery Powered Linux mini-HOWTO, available from
1953 <http://www.tldp.org/docs.html#howto>.
1955 This driver does not spin down disk drives (see the hdparm(8)
1956 manpage ("man 8 hdparm") for that), and it doesn't turn off
1957 VESA-compliant "green" monitors.
1959 This driver does not support the TI 4000M TravelMate and the ACER
1960 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1961 desktop machines also don't have compliant BIOSes, and this driver
1962 may cause those machines to panic during the boot phase.
1964 Generally, if you don't have a battery in your machine, there isn't
1965 much point in using this driver and you should say N. If you get
1966 random kernel OOPSes or reboots that don't seem to be related to
1967 anything, try disabling/enabling this option (or disabling/enabling
1970 Some other things you should try when experiencing seemingly random,
1973 1) make sure that you have enough swap space and that it is
1975 2) pass the "no-hlt" option to the kernel
1976 3) switch on floating point emulation in the kernel and pass
1977 the "no387" option to the kernel
1978 4) pass the "floppy=nodma" option to the kernel
1979 5) pass the "mem=4M" option to the kernel (thereby disabling
1980 all but the first 4 MB of RAM)
1981 6) make sure that the CPU is not over clocked.
1982 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1983 8) disable the cache from your BIOS settings
1984 9) install a fan for the video card or exchange video RAM
1985 10) install a better fan for the CPU
1986 11) exchange RAM chips
1987 12) exchange the motherboard.
1989 To compile this driver as a module, choose M here: the
1990 module will be called apm.
1994 config APM_IGNORE_USER_SUSPEND
1995 bool "Ignore USER SUSPEND"
1997 This option will ignore USER SUSPEND requests. On machines with a
1998 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1999 series notebooks, it is necessary to say Y because of a BIOS bug.
2001 config APM_DO_ENABLE
2002 bool "Enable PM at boot time"
2004 Enable APM features at boot time. From page 36 of the APM BIOS
2005 specification: "When disabled, the APM BIOS does not automatically
2006 power manage devices, enter the Standby State, enter the Suspend
2007 State, or take power saving steps in response to CPU Idle calls."
2008 This driver will make CPU Idle calls when Linux is idle (unless this
2009 feature is turned off -- see "Do CPU IDLE calls", below). This
2010 should always save battery power, but more complicated APM features
2011 will be dependent on your BIOS implementation. You may need to turn
2012 this option off if your computer hangs at boot time when using APM
2013 support, or if it beeps continuously instead of suspending. Turn
2014 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2015 T400CDT. This is off by default since most machines do fine without
2020 bool "Make CPU Idle calls when idle"
2022 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2023 On some machines, this can activate improved power savings, such as
2024 a slowed CPU clock rate, when the machine is idle. These idle calls
2025 are made after the idle loop has run for some length of time (e.g.,
2026 333 mS). On some machines, this will cause a hang at boot time or
2027 whenever the CPU becomes idle. (On machines with more than one CPU,
2028 this option does nothing.)
2030 config APM_DISPLAY_BLANK
2031 bool "Enable console blanking using APM"
2033 Enable console blanking using the APM. Some laptops can use this to
2034 turn off the LCD backlight when the screen blanker of the Linux
2035 virtual console blanks the screen. Note that this is only used by
2036 the virtual console screen blanker, and won't turn off the backlight
2037 when using the X Window system. This also doesn't have anything to
2038 do with your VESA-compliant power-saving monitor. Further, this
2039 option doesn't work for all laptops -- it might not turn off your
2040 backlight at all, or it might print a lot of errors to the console,
2041 especially if you are using gpm.
2043 config APM_ALLOW_INTS
2044 bool "Allow interrupts during APM BIOS calls"
2046 Normally we disable external interrupts while we are making calls to
2047 the APM BIOS as a measure to lessen the effects of a badly behaving
2048 BIOS implementation. The BIOS should reenable interrupts if it
2049 needs to. Unfortunately, some BIOSes do not -- especially those in
2050 many of the newer IBM Thinkpads. If you experience hangs when you
2051 suspend, try setting this to Y. Otherwise, say N.
2055 source "drivers/cpufreq/Kconfig"
2057 source "drivers/cpuidle/Kconfig"
2059 source "drivers/idle/Kconfig"
2064 menu "Bus options (PCI etc.)"
2070 Find out whether you have a PCI motherboard. PCI is the name of a
2071 bus system, i.e. the way the CPU talks to the other stuff inside
2072 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2073 VESA. If you have PCI, say Y, otherwise N.
2076 prompt "PCI access mode"
2077 depends on X86_32 && PCI
2080 On PCI systems, the BIOS can be used to detect the PCI devices and
2081 determine their configuration. However, some old PCI motherboards
2082 have BIOS bugs and may crash if this is done. Also, some embedded
2083 PCI-based systems don't have any BIOS at all. Linux can also try to
2084 detect the PCI hardware directly without using the BIOS.
2086 With this option, you can specify how Linux should detect the
2087 PCI devices. If you choose "BIOS", the BIOS will be used,
2088 if you choose "Direct", the BIOS won't be used, and if you
2089 choose "MMConfig", then PCI Express MMCONFIG will be used.
2090 If you choose "Any", the kernel will try MMCONFIG, then the
2091 direct access method and falls back to the BIOS if that doesn't
2092 work. If unsure, go with the default, which is "Any".
2097 config PCI_GOMMCONFIG
2114 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2116 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2119 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2123 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2127 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2131 depends on PCI && XEN
2139 bool "Support mmconfig PCI config space access"
2140 depends on X86_64 && PCI && ACPI
2142 config PCI_CNB20LE_QUIRK
2143 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2146 Read the PCI windows out of the CNB20LE host bridge. This allows
2147 PCI hotplug to work on systems with the CNB20LE chipset which do
2150 There's no public spec for this chipset, and this functionality
2151 is known to be incomplete.
2153 You should say N unless you know you need this.
2155 source "drivers/pci/pcie/Kconfig"
2157 source "drivers/pci/Kconfig"
2159 # x86_64 have no ISA slots, but can have ISA-style DMA.
2161 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2164 Enables ISA-style DMA support for devices requiring such controllers.
2172 Find out whether you have ISA slots on your motherboard. ISA is the
2173 name of a bus system, i.e. the way the CPU talks to the other stuff
2174 inside your box. Other bus systems are PCI, EISA, MicroChannel
2175 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2176 newer boards don't support it. If you have ISA, say Y, otherwise N.
2182 The Extended Industry Standard Architecture (EISA) bus was
2183 developed as an open alternative to the IBM MicroChannel bus.
2185 The EISA bus provided some of the features of the IBM MicroChannel
2186 bus while maintaining backward compatibility with cards made for
2187 the older ISA bus. The EISA bus saw limited use between 1988 and
2188 1995 when it was made obsolete by the PCI bus.
2190 Say Y here if you are building a kernel for an EISA-based machine.
2194 source "drivers/eisa/Kconfig"
2197 tristate "NatSemi SCx200 support"
2199 This provides basic support for National Semiconductor's
2200 (now AMD's) Geode processors. The driver probes for the
2201 PCI-IDs of several on-chip devices, so its a good dependency
2202 for other scx200_* drivers.
2204 If compiled as a module, the driver is named scx200.
2206 config SCx200HR_TIMER
2207 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2211 This driver provides a clocksource built upon the on-chip
2212 27MHz high-resolution timer. Its also a workaround for
2213 NSC Geode SC-1100's buggy TSC, which loses time when the
2214 processor goes idle (as is done by the scheduler). The
2215 other workaround is idle=poll boot option.
2218 bool "One Laptop Per Child support"
2225 Add support for detecting the unique features of the OLPC
2229 bool "OLPC XO-1 Power Management"
2230 depends on OLPC && MFD_CS5535 && PM_SLEEP
2233 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2236 bool "OLPC XO-1 Real Time Clock"
2237 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2239 Add support for the XO-1 real time clock, which can be used as a
2240 programmable wakeup source.
2243 bool "OLPC XO-1 SCI extras"
2244 depends on OLPC && OLPC_XO1_PM
2250 Add support for SCI-based features of the OLPC XO-1 laptop:
2251 - EC-driven system wakeups
2255 - AC adapter status updates
2256 - Battery status updates
2258 config OLPC_XO15_SCI
2259 bool "OLPC XO-1.5 SCI extras"
2260 depends on OLPC && ACPI
2263 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2264 - EC-driven system wakeups
2265 - AC adapter status updates
2266 - Battery status updates
2269 bool "PCEngines ALIX System Support (LED setup)"
2272 This option enables system support for the PCEngines ALIX.
2273 At present this just sets up LEDs for GPIO control on
2274 ALIX2/3/6 boards. However, other system specific setup should
2277 Note: You must still enable the drivers for GPIO and LED support
2278 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2280 Note: You have to set alix.force=1 for boards with Award BIOS.
2283 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2286 This option enables system support for the Soekris Engineering net5501.
2289 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2293 This option enables system support for the Traverse Technologies GEOS.
2296 bool "Technologic Systems TS-5500 platform support"
2298 select CHECK_SIGNATURE
2302 This option enables system support for the Technologic Systems TS-5500.
2308 depends on CPU_SUP_AMD && PCI
2310 source "drivers/pcmcia/Kconfig"
2312 source "drivers/pci/hotplug/Kconfig"
2315 tristate "RapidIO support"
2319 If enabled this option will include drivers and the core
2320 infrastructure code to support RapidIO interconnect devices.
2322 source "drivers/rapidio/Kconfig"
2325 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2327 Firmwares often provide initial graphics framebuffers so the BIOS,
2328 bootloader or kernel can show basic video-output during boot for
2329 user-guidance and debugging. Historically, x86 used the VESA BIOS
2330 Extensions and EFI-framebuffers for this, which are mostly limited
2332 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2333 framebuffers so the new generic system-framebuffer drivers can be
2334 used on x86. If the framebuffer is not compatible with the generic
2335 modes, it is adverticed as fallback platform framebuffer so legacy
2336 drivers like efifb, vesafb and uvesafb can pick it up.
2337 If this option is not selected, all system framebuffers are always
2338 marked as fallback platform framebuffers as usual.
2340 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2341 not be able to pick up generic system framebuffers if this option
2342 is selected. You are highly encouraged to enable simplefb as
2343 replacement if you select this option. simplefb can correctly deal
2344 with generic system framebuffers. But you should still keep vesafb
2345 and others enabled as fallback if a system framebuffer is
2346 incompatible with simplefb.
2353 menu "Executable file formats / Emulations"
2355 source "fs/Kconfig.binfmt"
2357 config IA32_EMULATION
2358 bool "IA32 Emulation"
2361 select COMPAT_BINFMT_ELF
2364 Include code to run legacy 32-bit programs under a
2365 64-bit kernel. You should likely turn this on, unless you're
2366 100% sure that you don't have any 32-bit programs left.
2369 tristate "IA32 a.out support"
2370 depends on IA32_EMULATION
2372 Support old a.out binaries in the 32bit emulation.
2375 bool "x32 ABI for 64-bit mode"
2376 depends on X86_64 && IA32_EMULATION
2378 Include code to run binaries for the x32 native 32-bit ABI
2379 for 64-bit processors. An x32 process gets access to the
2380 full 64-bit register file and wide data path while leaving
2381 pointers at 32 bits for smaller memory footprint.
2383 You will need a recent binutils (2.22 or later) with
2384 elf32_x86_64 support enabled to compile a kernel with this
2389 depends on IA32_EMULATION || X86_X32
2390 select ARCH_WANT_OLD_COMPAT_IPC
2393 config COMPAT_FOR_U64_ALIGNMENT
2396 config SYSVIPC_COMPAT
2408 config HAVE_ATOMIC_IOMAP
2412 config X86_DEV_DMA_OPS
2414 depends on X86_64 || STA2X11
2416 config X86_DMA_REMAP
2424 To be selected by modules requiring access to the Intel OnChip System
2425 Fabric (IOSF) Sideband MailBox Interface (MBI). For MBI platforms
2428 source "net/Kconfig"
2430 source "drivers/Kconfig"
2432 source "drivers/firmware/Kconfig"
2436 source "arch/x86/Kconfig.debug"
2438 source "security/Kconfig"
2440 source "crypto/Kconfig"
2442 source "arch/x86/kvm/Kconfig"
2444 source "lib/Kconfig"
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / blob