| blob | 4fdb669e84692a53dc07c2b21494ec18bd444e8d |
1 # x86 configuration
2 mainmenu "Linux Kernel Configuration for x86"
4 # Select 32 or 64 bit
5 config 64BIT
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
8 ---help---
9 Say yes to build a 64-bit kernel - formerly known as x86_64
10 Say no to build a 32-bit kernel - formerly known as i386
12 config X86_32
13 def_bool !64BIT
15 config X86_64
16 def_bool 64BIT
18 ### Arch settings
19 config X86
20 def_bool y
21 select HAVE_AOUT if X86_32
22 select HAVE_READQ
23 select HAVE_WRITEQ
24 select HAVE_UNSTABLE_SCHED_CLOCK
25 select HAVE_IDE
26 select HAVE_OPROFILE
27 select HAVE_PERF_EVENTS if (!M386 && !M486)
28 select HAVE_IOREMAP_PROT
29 select HAVE_KPROBES
30 select ARCH_WANT_OPTIONAL_GPIOLIB
31 select ARCH_WANT_FRAME_POINTERS
32 select HAVE_DMA_ATTRS
33 select HAVE_KRETPROBES
34 select HAVE_FTRACE_MCOUNT_RECORD
35 select HAVE_DYNAMIC_FTRACE
36 select HAVE_FUNCTION_TRACER
37 select HAVE_FUNCTION_GRAPH_TRACER
38 select HAVE_FUNCTION_GRAPH_FP_TEST
39 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
40 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
41 select HAVE_SYSCALL_TRACEPOINTS
42 select HAVE_KVM
43 select HAVE_ARCH_KGDB
44 select HAVE_ARCH_TRACEHOOK
45 select HAVE_GENERIC_DMA_COHERENT if X86_32
46 select HAVE_EFFICIENT_UNALIGNED_ACCESS
47 select USER_STACKTRACE_SUPPORT
48 select HAVE_DMA_API_DEBUG
49 select HAVE_KERNEL_GZIP
50 select HAVE_KERNEL_BZIP2
51 select HAVE_KERNEL_LZMA
52 select HAVE_ARCH_KMEMCHECK
54 config OUTPUT_FORMAT
55 string
56 default "elf32-i386" if X86_32
57 default "elf64-x86-64" if X86_64
59 config ARCH_DEFCONFIG
60 string
61 default "arch/x86/configs/i386_defconfig" if X86_32
62 default "arch/x86/configs/x86_64_defconfig" if X86_64
64 config GENERIC_TIME
65 def_bool y
67 config GENERIC_CMOS_UPDATE
68 def_bool y
70 config CLOCKSOURCE_WATCHDOG
71 def_bool y
73 config GENERIC_CLOCKEVENTS
74 def_bool y
76 config GENERIC_CLOCKEVENTS_BROADCAST
77 def_bool y
78 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
80 config LOCKDEP_SUPPORT
81 def_bool y
83 config STACKTRACE_SUPPORT
84 def_bool y
86 config HAVE_LATENCYTOP_SUPPORT
87 def_bool y
89 config MMU
90 def_bool y
92 config ZONE_DMA
93 def_bool y
95 config SBUS
96 bool
98 config GENERIC_ISA_DMA
99 def_bool y
101 config GENERIC_IOMAP
102 def_bool y
104 config GENERIC_BUG
105 def_bool y
106 depends on BUG
107 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
109 config GENERIC_BUG_RELATIVE_POINTERS
110 bool
112 config GENERIC_HWEIGHT
113 def_bool y
115 config GENERIC_GPIO
116 bool
118 config ARCH_MAY_HAVE_PC_FDC
119 def_bool y
121 config RWSEM_GENERIC_SPINLOCK
122 def_bool !X86_XADD
124 config RWSEM_XCHGADD_ALGORITHM
125 def_bool X86_XADD
127 config ARCH_HAS_CPU_IDLE_WAIT
128 def_bool y
130 config GENERIC_CALIBRATE_DELAY
131 def_bool y
133 config GENERIC_TIME_VSYSCALL
134 bool
135 default X86_64
137 config ARCH_HAS_CPU_RELAX
138 def_bool y
140 config ARCH_HAS_DEFAULT_IDLE
141 def_bool y
143 config ARCH_HAS_CACHE_LINE_SIZE
144 def_bool y
146 config HAVE_SETUP_PER_CPU_AREA
147 def_bool y
149 config NEED_PER_CPU_EMBED_FIRST_CHUNK
150 def_bool y
152 config NEED_PER_CPU_PAGE_FIRST_CHUNK
153 def_bool y
155 config HAVE_CPUMASK_OF_CPU_MAP
156 def_bool X86_64_SMP
158 config ARCH_HIBERNATION_POSSIBLE
159 def_bool y
161 config ARCH_SUSPEND_POSSIBLE
162 def_bool y
164 config ZONE_DMA32
165 bool
166 default X86_64
168 config ARCH_POPULATES_NODE_MAP
169 def_bool y
171 config AUDIT_ARCH
172 bool
173 default X86_64
175 config ARCH_SUPPORTS_OPTIMIZED_INLINING
176 def_bool y
178 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
179 def_bool y
181 config HAVE_INTEL_TXT
182 def_bool y
183 depends on EXPERIMENTAL && DMAR && ACPI
185 # Use the generic interrupt handling code in kernel/irq/:
186 config GENERIC_HARDIRQS
187 bool
188 default y
190 config GENERIC_HARDIRQS_NO__DO_IRQ
191 def_bool y
193 config GENERIC_IRQ_PROBE
194 bool
195 default y
197 config GENERIC_PENDING_IRQ
198 bool
199 depends on GENERIC_HARDIRQS && SMP
200 default y
202 config USE_GENERIC_SMP_HELPERS
203 def_bool y
204 depends on SMP
206 config X86_32_SMP
207 def_bool y
208 depends on X86_32 && SMP
210 config X86_64_SMP
211 def_bool y
212 depends on X86_64 && SMP
214 config X86_HT
215 bool
216 depends on SMP
217 default y
219 config X86_TRAMPOLINE
220 bool
221 depends on SMP || (64BIT && ACPI_SLEEP)
222 default y
224 config X86_32_LAZY_GS
225 def_bool y
226 depends on X86_32 && !CC_STACKPROTECTOR
228 config KTIME_SCALAR
229 def_bool X86_32
230 source "init/Kconfig"
231 source "kernel/Kconfig.freezer"
233 menu "Processor type and features"
235 source "kernel/time/Kconfig"
237 config SMP
238 bool "Symmetric multi-processing support"
239 ---help---
240 This enables support for systems with more than one CPU. If you have
241 a system with only one CPU, like most personal computers, say N. If
242 you have a system with more than one CPU, say Y.
244 If you say N here, the kernel will run on single and multiprocessor
245 machines, but will use only one CPU of a multiprocessor machine. If
246 you say Y here, the kernel will run on many, but not all,
247 singleprocessor machines. On a singleprocessor machine, the kernel
248 will run faster if you say N here.
250 Note that if you say Y here and choose architecture "586" or
251 "Pentium" under "Processor family", the kernel will not work on 486
252 architectures. Similarly, multiprocessor kernels for the "PPro"
253 architecture may not work on all Pentium based boards.
255 People using multiprocessor machines who say Y here should also say
256 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
257 Management" code will be disabled if you say Y here.
259 See also <file:Documentation/i386/IO-APIC.txt>,
260 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
261 <http://www.tldp.org/docs.html#howto>.
263 If you don't know what to do here, say N.
265 config X86_X2APIC
266 bool "Support x2apic"
267 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
268 ---help---
269 This enables x2apic support on CPUs that have this feature.
271 This allows 32-bit apic IDs (so it can support very large systems),
272 and accesses the local apic via MSRs not via mmio.
274 If you don't know what to do here, say N.
276 config SPARSE_IRQ
277 bool "Support sparse irq numbering"
278 depends on PCI_MSI || HT_IRQ
279 ---help---
280 This enables support for sparse irqs. This is useful for distro
281 kernels that want to define a high CONFIG_NR_CPUS value but still
282 want to have low kernel memory footprint on smaller machines.
284 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
285 out the irq_desc[] array in a more NUMA-friendly way. )
287 If you don't know what to do here, say N.
289 config NUMA_IRQ_DESC
290 def_bool y
291 depends on SPARSE_IRQ && NUMA
293 config X86_MPPARSE
294 bool "Enable MPS table" if ACPI
295 default y
296 depends on X86_LOCAL_APIC
297 ---help---
298 For old smp systems that do not have proper acpi support. Newer systems
299 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
301 config X86_BIGSMP
302 bool "Support for big SMP systems with more than 8 CPUs"
303 depends on X86_32 && SMP
304 ---help---
305 This option is needed for the systems that have more than 8 CPUs
307 if X86_32
308 config X86_EXTENDED_PLATFORM
309 bool "Support for extended (non-PC) x86 platforms"
310 default y
311 ---help---
312 If you disable this option then the kernel will only support
313 standard PC platforms. (which covers the vast majority of
314 systems out there.)
316 If you enable this option then you'll be able to select support
317 for the following (non-PC) 32 bit x86 platforms:
318 AMD Elan
319 NUMAQ (IBM/Sequent)
320 RDC R-321x SoC
321 SGI 320/540 (Visual Workstation)
322 Summit/EXA (IBM x440)
323 Unisys ES7000 IA32 series
324 Moorestown MID devices
326 If you have one of these systems, or if you want to build a
327 generic distribution kernel, say Y here - otherwise say N.
328 endif
330 if X86_64
331 config X86_EXTENDED_PLATFORM
332 bool "Support for extended (non-PC) x86 platforms"
333 default y
334 ---help---
335 If you disable this option then the kernel will only support
336 standard PC platforms. (which covers the vast majority of
337 systems out there.)
339 If you enable this option then you'll be able to select support
340 for the following (non-PC) 64 bit x86 platforms:
341 ScaleMP vSMP
342 SGI Ultraviolet
344 If you have one of these systems, or if you want to build a
345 generic distribution kernel, say Y here - otherwise say N.
346 endif
347 # This is an alphabetically sorted list of 64 bit extended platforms
348 # Please maintain the alphabetic order if and when there are additions
350 config X86_VSMP
351 bool "ScaleMP vSMP"
352 select PARAVIRT
353 depends on X86_64 && PCI
354 depends on X86_EXTENDED_PLATFORM
355 ---help---
356 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
357 supposed to run on these EM64T-based machines. Only choose this option
358 if you have one of these machines.
360 config X86_UV
361 bool "SGI Ultraviolet"
362 depends on X86_64
363 depends on X86_EXTENDED_PLATFORM
364 depends on NUMA
365 depends on X86_X2APIC
366 ---help---
367 This option is needed in order to support SGI Ultraviolet systems.
368 If you don't have one of these, you should say N here.
370 # Following is an alphabetically sorted list of 32 bit extended platforms
371 # Please maintain the alphabetic order if and when there are additions
373 config X86_ELAN
374 bool "AMD Elan"
375 depends on X86_32
376 depends on X86_EXTENDED_PLATFORM
377 ---help---
378 Select this for an AMD Elan processor.
380 Do not use this option for K6/Athlon/Opteron processors!
382 If unsure, choose "PC-compatible" instead.
384 config X86_MRST
385 bool "Moorestown MID platform"
386 depends on X86_32
387 depends on X86_EXTENDED_PLATFORM
388 ---help---
389 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
390 Internet Device(MID) platform. Moorestown consists of two chips:
391 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
392 Unlike standard x86 PCs, Moorestown does not have many legacy devices
393 nor standard legacy replacement devices/features. e.g. Moorestown does
394 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
396 config X86_RDC321X
397 bool "RDC R-321x SoC"
398 depends on X86_32
399 depends on X86_EXTENDED_PLATFORM
400 select M486
401 select X86_REBOOTFIXUPS
402 ---help---
403 This option is needed for RDC R-321x system-on-chip, also known
404 as R-8610-(G).
405 If you don't have one of these chips, you should say N here.
407 config X86_32_NON_STANDARD
408 bool "Support non-standard 32-bit SMP architectures"
409 depends on X86_32 && SMP
410 depends on X86_EXTENDED_PLATFORM
411 ---help---
412 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
413 subarchitectures. It is intended for a generic binary kernel.
414 if you select them all, kernel will probe it one by one. and will
415 fallback to default.
417 # Alphabetically sorted list of Non standard 32 bit platforms
419 config X86_NUMAQ
420 bool "NUMAQ (IBM/Sequent)"
421 depends on X86_32_NON_STANDARD
422 select NUMA
423 select X86_MPPARSE
424 ---help---
425 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
426 NUMA multiquad box. This changes the way that processors are
427 bootstrapped, and uses Clustered Logical APIC addressing mode instead
428 of Flat Logical. You will need a new lynxer.elf file to flash your
429 firmware with - send email to <Martin.Bligh@us.ibm.com>.
431 config X86_SUPPORTS_MEMORY_FAILURE
432 bool
433 # MCE code calls memory_failure():
434 depends on X86_MCE
435 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
436 depends on !X86_NUMAQ
437 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
438 depends on X86_64 || !SPARSEMEM
439 select ARCH_SUPPORTS_MEMORY_FAILURE
440 default y
442 config X86_VISWS
443 bool "SGI 320/540 (Visual Workstation)"
444 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
445 depends on X86_32_NON_STANDARD
446 ---help---
447 The SGI Visual Workstation series is an IA32-based workstation
448 based on SGI systems chips with some legacy PC hardware attached.
450 Say Y here to create a kernel to run on the SGI 320 or 540.
452 A kernel compiled for the Visual Workstation will run on general
453 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
455 config X86_SUMMIT
456 bool "Summit/EXA (IBM x440)"
457 depends on X86_32_NON_STANDARD
458 ---help---
459 This option is needed for IBM systems that use the Summit/EXA chipset.
460 In particular, it is needed for the x440.
462 config X86_ES7000
463 bool "Unisys ES7000 IA32 series"
464 depends on X86_32_NON_STANDARD && X86_BIGSMP
465 ---help---
466 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
467 supposed to run on an IA32-based Unisys ES7000 system.
469 config SCHED_OMIT_FRAME_POINTER
470 def_bool y
471 prompt "Single-depth WCHAN output"
472 depends on X86
473 ---help---
474 Calculate simpler /proc/<PID>/wchan values. If this option
475 is disabled then wchan values will recurse back to the
476 caller function. This provides more accurate wchan values,
477 at the expense of slightly more scheduling overhead.
479 If in doubt, say "Y".
481 menuconfig PARAVIRT_GUEST
482 bool "Paravirtualized guest support"
483 ---help---
484 Say Y here to get to see options related to running Linux under
485 various hypervisors. This option alone does not add any kernel code.
487 If you say N, all options in this submenu will be skipped and disabled.
489 if PARAVIRT_GUEST
491 source "arch/x86/xen/Kconfig"
493 config VMI
494 bool "VMI Guest support (DEPRECATED)"
495 select PARAVIRT
496 depends on X86_32
497 ---help---
498 VMI provides a paravirtualized interface to the VMware ESX server
499 (it could be used by other hypervisors in theory too, but is not
500 at the moment), by linking the kernel to a GPL-ed ROM module
501 provided by the hypervisor.
503 As of September 2009, VMware has started a phased retirement
504 of this feature from VMware's products. Please see
505 feature-removal-schedule.txt for details. If you are
506 planning to enable this option, please note that you cannot
507 live migrate a VMI enabled VM to a future VMware product,
508 which doesn't support VMI. So if you expect your kernel to
509 seamlessly migrate to newer VMware products, keep this
510 disabled.
512 config KVM_CLOCK
513 bool "KVM paravirtualized clock"
514 select PARAVIRT
515 select PARAVIRT_CLOCK
516 ---help---
517 Turning on this option will allow you to run a paravirtualized clock
518 when running over the KVM hypervisor. Instead of relying on a PIT
519 (or probably other) emulation by the underlying device model, the host
520 provides the guest with timing infrastructure such as time of day, and
521 system time
523 config KVM_GUEST
524 bool "KVM Guest support"
525 select PARAVIRT
526 ---help---
527 This option enables various optimizations for running under the KVM
528 hypervisor.
530 source "arch/x86/lguest/Kconfig"
532 config PARAVIRT
533 bool "Enable paravirtualization code"
534 ---help---
535 This changes the kernel so it can modify itself when it is run
536 under a hypervisor, potentially improving performance significantly
537 over full virtualization. However, when run without a hypervisor
538 the kernel is theoretically slower and slightly larger.
540 config PARAVIRT_SPINLOCKS
541 bool "Paravirtualization layer for spinlocks"
542 depends on PARAVIRT && SMP && EXPERIMENTAL
543 ---help---
544 Paravirtualized spinlocks allow a pvops backend to replace the
545 spinlock implementation with something virtualization-friendly
546 (for example, block the virtual CPU rather than spinning).
548 Unfortunately the downside is an up to 5% performance hit on
549 native kernels, with various workloads.
551 If you are unsure how to answer this question, answer N.
553 config PARAVIRT_CLOCK
554 bool
555 default n
557 endif
559 config PARAVIRT_DEBUG
560 bool "paravirt-ops debugging"
561 depends on PARAVIRT && DEBUG_KERNEL
562 ---help---
563 Enable to debug paravirt_ops internals. Specifically, BUG if
564 a paravirt_op is missing when it is called.
566 config MEMTEST
567 bool "Memtest"
568 ---help---
569 This option adds a kernel parameter 'memtest', which allows memtest
570 to be set.
571 memtest=0, mean disabled; -- default
572 memtest=1, mean do 1 test pattern;
573 ...
574 memtest=4, mean do 4 test patterns.
575 If you are unsure how to answer this question, answer N.
577 config X86_SUMMIT_NUMA
578 def_bool y
579 depends on X86_32 && NUMA && X86_32_NON_STANDARD
581 config X86_CYCLONE_TIMER
582 def_bool y
583 depends on X86_32_NON_STANDARD
585 source "arch/x86/Kconfig.cpu"
587 config HPET_TIMER
588 def_bool X86_64
589 prompt "HPET Timer Support" if X86_32
590 ---help---
591 Use the IA-PC HPET (High Precision Event Timer) to manage
592 time in preference to the PIT and RTC, if a HPET is
593 present.
594 HPET is the next generation timer replacing legacy 8254s.
595 The HPET provides a stable time base on SMP
596 systems, unlike the TSC, but it is more expensive to access,
597 as it is off-chip. You can find the HPET spec at
598 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
600 You can safely choose Y here. However, HPET will only be
601 activated if the platform and the BIOS support this feature.
602 Otherwise the 8254 will be used for timing services.
604 Choose N to continue using the legacy 8254 timer.
606 config HPET_EMULATE_RTC
607 def_bool y
608 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
610 # Mark as embedded because too many people got it wrong.
611 # The code disables itself when not needed.
612 config DMI
613 default y
614 bool "Enable DMI scanning" if EMBEDDED
615 ---help---
616 Enabled scanning of DMI to identify machine quirks. Say Y
617 here unless you have verified that your setup is not
618 affected by entries in the DMI blacklist. Required by PNP
619 BIOS code.
621 config GART_IOMMU
622 bool "GART IOMMU support" if EMBEDDED
623 default y
624 select SWIOTLB
625 depends on X86_64 && PCI
626 ---help---
627 Support for full DMA access of devices with 32bit memory access only
628 on systems with more than 3GB. This is usually needed for USB,
629 sound, many IDE/SATA chipsets and some other devices.
630 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
631 based hardware IOMMU and a software bounce buffer based IOMMU used
632 on Intel systems and as fallback.
633 The code is only active when needed (enough memory and limited
634 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
635 too.
637 config CALGARY_IOMMU
638 bool "IBM Calgary IOMMU support"
639 select SWIOTLB
640 depends on X86_64 && PCI && EXPERIMENTAL
641 ---help---
642 Support for hardware IOMMUs in IBM's xSeries x366 and x460
643 systems. Needed to run systems with more than 3GB of memory
644 properly with 32-bit PCI devices that do not support DAC
645 (Double Address Cycle). Calgary also supports bus level
646 isolation, where all DMAs pass through the IOMMU. This
647 prevents them from going anywhere except their intended
648 destination. This catches hard-to-find kernel bugs and
649 mis-behaving drivers and devices that do not use the DMA-API
650 properly to set up their DMA buffers. The IOMMU can be
651 turned off at boot time with the iommu=off parameter.
652 Normally the kernel will make the right choice by itself.
653 If unsure, say Y.
655 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
656 def_bool y
657 prompt "Should Calgary be enabled by default?"
658 depends on CALGARY_IOMMU
659 ---help---
660 Should Calgary be enabled by default? if you choose 'y', Calgary
661 will be used (if it exists). If you choose 'n', Calgary will not be
662 used even if it exists. If you choose 'n' and would like to use
663 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
664 If unsure, say Y.
666 config AMD_IOMMU
667 bool "AMD IOMMU support"
668 select SWIOTLB
669 select PCI_MSI
670 depends on X86_64 && PCI && ACPI
671 ---help---
672 With this option you can enable support for AMD IOMMU hardware in
673 your system. An IOMMU is a hardware component which provides
674 remapping of DMA memory accesses from devices. With an AMD IOMMU you
675 can isolate the the DMA memory of different devices and protect the
676 system from misbehaving device drivers or hardware.
678 You can find out if your system has an AMD IOMMU if you look into
679 your BIOS for an option to enable it or if you have an IVRS ACPI
680 table.
682 config AMD_IOMMU_STATS
683 bool "Export AMD IOMMU statistics to debugfs"
684 depends on AMD_IOMMU
685 select DEBUG_FS
686 ---help---
687 This option enables code in the AMD IOMMU driver to collect various
688 statistics about whats happening in the driver and exports that
689 information to userspace via debugfs.
690 If unsure, say N.
692 # need this always selected by IOMMU for the VIA workaround
693 config SWIOTLB
694 def_bool y if X86_64
695 ---help---
696 Support for software bounce buffers used on x86-64 systems
697 which don't have a hardware IOMMU (e.g. the current generation
698 of Intel's x86-64 CPUs). Using this PCI devices which can only
699 access 32-bits of memory can be used on systems with more than
700 3 GB of memory. If unsure, say Y.
702 config IOMMU_HELPER
703 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
705 config IOMMU_API
706 def_bool (AMD_IOMMU || DMAR)
708 config MAXSMP
709 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
710 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
711 select CPUMASK_OFFSTACK
712 default n
713 ---help---
714 Configure maximum number of CPUS and NUMA Nodes for this architecture.
715 If unsure, say N.
717 config NR_CPUS
718 int "Maximum number of CPUs" if SMP && !MAXSMP
719 range 2 8 if SMP && X86_32 && !X86_BIGSMP
720 range 2 512 if SMP && !MAXSMP
721 default "1" if !SMP
722 default "4096" if MAXSMP
723 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
724 default "8" if SMP
725 ---help---
726 This allows you to specify the maximum number of CPUs which this
727 kernel will support. The maximum supported value is 512 and the
728 minimum value which makes sense is 2.
730 This is purely to save memory - each supported CPU adds
731 approximately eight kilobytes to the kernel image.
733 config SCHED_SMT
734 bool "SMT (Hyperthreading) scheduler support"
735 depends on X86_HT
736 ---help---
737 SMT scheduler support improves the CPU scheduler's decision making
738 when dealing with Intel Pentium 4 chips with HyperThreading at a
739 cost of slightly increased overhead in some places. If unsure say
740 N here.
742 config SCHED_MC
743 def_bool y
744 prompt "Multi-core scheduler support"
745 depends on X86_HT
746 ---help---
747 Multi-core scheduler support improves the CPU scheduler's decision
748 making when dealing with multi-core CPU chips at a cost of slightly
749 increased overhead in some places. If unsure say N here.
751 source "kernel/Kconfig.preempt"
753 config X86_UP_APIC
754 bool "Local APIC support on uniprocessors"
755 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
756 ---help---
757 A local APIC (Advanced Programmable Interrupt Controller) is an
758 integrated interrupt controller in the CPU. If you have a single-CPU
759 system which has a processor with a local APIC, you can say Y here to
760 enable and use it. If you say Y here even though your machine doesn't
761 have a local APIC, then the kernel will still run with no slowdown at
762 all. The local APIC supports CPU-generated self-interrupts (timer,
763 performance counters), and the NMI watchdog which detects hard
764 lockups.
766 config X86_UP_IOAPIC
767 bool "IO-APIC support on uniprocessors"
768 depends on X86_UP_APIC
769 ---help---
770 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
771 SMP-capable replacement for PC-style interrupt controllers. Most
772 SMP systems and many recent uniprocessor systems have one.
774 If you have a single-CPU system with an IO-APIC, you can say Y here
775 to use it. If you say Y here even though your machine doesn't have
776 an IO-APIC, then the kernel will still run with no slowdown at all.
778 config X86_LOCAL_APIC
779 def_bool y
780 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
782 config X86_IO_APIC
783 def_bool y
784 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
786 config X86_VISWS_APIC
787 def_bool y
788 depends on X86_32 && X86_VISWS
790 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
791 bool "Reroute for broken boot IRQs"
792 default n
793 depends on X86_IO_APIC
794 ---help---
795 This option enables a workaround that fixes a source of
796 spurious interrupts. This is recommended when threaded
797 interrupt handling is used on systems where the generation of
798 superfluous "boot interrupts" cannot be disabled.
800 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
801 entry in the chipset's IO-APIC is masked (as, e.g. the RT
802 kernel does during interrupt handling). On chipsets where this
803 boot IRQ generation cannot be disabled, this workaround keeps
804 the original IRQ line masked so that only the equivalent "boot
805 IRQ" is delivered to the CPUs. The workaround also tells the
806 kernel to set up the IRQ handler on the boot IRQ line. In this
807 way only one interrupt is delivered to the kernel. Otherwise
808 the spurious second interrupt may cause the kernel to bring
809 down (vital) interrupt lines.
811 Only affects "broken" chipsets. Interrupt sharing may be
812 increased on these systems.
814 config X86_MCE
815 bool "Machine Check / overheating reporting"
816 ---help---
817 Machine Check support allows the processor to notify the
818 kernel if it detects a problem (e.g. overheating, data corruption).
819 The action the kernel takes depends on the severity of the problem,
820 ranging from warning messages to halting the machine.
822 config X86_MCE_INTEL
823 def_bool y
824 prompt "Intel MCE features"
825 depends on X86_MCE && X86_LOCAL_APIC
826 ---help---
827 Additional support for intel specific MCE features such as
828 the thermal monitor.
830 config X86_MCE_AMD
831 def_bool y
832 prompt "AMD MCE features"
833 depends on X86_MCE && X86_LOCAL_APIC
834 ---help---
835 Additional support for AMD specific MCE features such as
836 the DRAM Error Threshold.
838 config X86_ANCIENT_MCE
839 def_bool n
840 depends on X86_32 && X86_MCE
841 prompt "Support for old Pentium 5 / WinChip machine checks"
842 ---help---
843 Include support for machine check handling on old Pentium 5 or WinChip
844 systems. These typically need to be enabled explicitely on the command
845 line.
847 config X86_MCE_THRESHOLD
848 depends on X86_MCE_AMD || X86_MCE_INTEL
849 bool
850 default y
852 config X86_MCE_INJECT
853 depends on X86_MCE
854 tristate "Machine check injector support"
855 ---help---
856 Provide support for injecting machine checks for testing purposes.
857 If you don't know what a machine check is and you don't do kernel
858 QA it is safe to say n.
860 config X86_THERMAL_VECTOR
861 def_bool y
862 depends on X86_MCE_INTEL
864 config VM86
865 bool "Enable VM86 support" if EMBEDDED
866 default y
867 depends on X86_32
868 ---help---
869 This option is required by programs like DOSEMU to run 16-bit legacy
870 code on X86 processors. It also may be needed by software like
871 XFree86 to initialize some video cards via BIOS. Disabling this
872 option saves about 6k.
874 config TOSHIBA
875 tristate "Toshiba Laptop support"
876 depends on X86_32
877 ---help---
878 This adds a driver to safely access the System Management Mode of
879 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
880 not work on models with a Phoenix BIOS. The System Management Mode
881 is used to set the BIOS and power saving options on Toshiba portables.
883 For information on utilities to make use of this driver see the
884 Toshiba Linux utilities web site at:
885 <http://www.buzzard.org.uk/toshiba/>.
887 Say Y if you intend to run this kernel on a Toshiba portable.
888 Say N otherwise.
890 config I8K
891 tristate "Dell laptop support"
892 ---help---
893 This adds a driver to safely access the System Management Mode
894 of the CPU on the Dell Inspiron 8000. The System Management Mode
895 is used to read cpu temperature and cooling fan status and to
896 control the fans on the I8K portables.
898 This driver has been tested only on the Inspiron 8000 but it may
899 also work with other Dell laptops. You can force loading on other
900 models by passing the parameter `force=1' to the module. Use at
901 your own risk.
903 For information on utilities to make use of this driver see the
904 I8K Linux utilities web site at:
905 <http://people.debian.org/~dz/i8k/>
907 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
908 Say N otherwise.
910 config X86_REBOOTFIXUPS
911 bool "Enable X86 board specific fixups for reboot"
912 depends on X86_32
913 ---help---
914 This enables chipset and/or board specific fixups to be done
915 in order to get reboot to work correctly. This is only needed on
916 some combinations of hardware and BIOS. The symptom, for which
917 this config is intended, is when reboot ends with a stalled/hung
918 system.
920 Currently, the only fixup is for the Geode machines using
921 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
923 Say Y if you want to enable the fixup. Currently, it's safe to
924 enable this option even if you don't need it.
925 Say N otherwise.
927 config MICROCODE
928 tristate "/dev/cpu/microcode - microcode support"
929 select FW_LOADER
930 ---help---
931 If you say Y here, you will be able to update the microcode on
932 certain Intel and AMD processors. The Intel support is for the
933 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
934 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
935 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
936 You will obviously need the actual microcode binary data itself
937 which is not shipped with the Linux kernel.
939 This option selects the general module only, you need to select
940 at least one vendor specific module as well.
942 To compile this driver as a module, choose M here: the
943 module will be called microcode.
945 config MICROCODE_INTEL
946 bool "Intel microcode patch loading support"
947 depends on MICROCODE
948 default MICROCODE
949 select FW_LOADER
950 ---help---
951 This options enables microcode patch loading support for Intel
952 processors.
954 For latest news and information on obtaining all the required
955 Intel ingredients for this driver, check:
956 <http://www.urbanmyth.org/microcode/>.
958 config MICROCODE_AMD
959 bool "AMD microcode patch loading support"
960 depends on MICROCODE
961 select FW_LOADER
962 ---help---
963 If you select this option, microcode patch loading support for AMD
964 processors will be enabled.
966 config MICROCODE_OLD_INTERFACE
967 def_bool y
968 depends on MICROCODE
970 config X86_MSR
971 tristate "/dev/cpu/*/msr - Model-specific register support"
972 ---help---
973 This device gives privileged processes access to the x86
974 Model-Specific Registers (MSRs). It is a character device with
975 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
976 MSR accesses are directed to a specific CPU on multi-processor
977 systems.
979 config X86_CPUID
980 tristate "/dev/cpu/*/cpuid - CPU information support"
981 ---help---
982 This device gives processes access to the x86 CPUID instruction to
983 be executed on a specific processor. It is a character device
984 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
985 /dev/cpu/31/cpuid.
987 choice
988 prompt "High Memory Support"
989 default HIGHMEM4G if !X86_NUMAQ
990 default HIGHMEM64G if X86_NUMAQ
991 depends on X86_32
993 config NOHIGHMEM
994 bool "off"
995 depends on !X86_NUMAQ
996 ---help---
997 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
998 However, the address space of 32-bit x86 processors is only 4
999 Gigabytes large. That means that, if you have a large amount of
1000 physical memory, not all of it can be "permanently mapped" by the
1001 kernel. The physical memory that's not permanently mapped is called
1002 "high memory".
1004 If you are compiling a kernel which will never run on a machine with
1005 more than 1 Gigabyte total physical RAM, answer "off" here (default
1006 choice and suitable for most users). This will result in a "3GB/1GB"
1007 split: 3GB are mapped so that each process sees a 3GB virtual memory
1008 space and the remaining part of the 4GB virtual memory space is used
1009 by the kernel to permanently map as much physical memory as
1010 possible.
1012 If the machine has between 1 and 4 Gigabytes physical RAM, then
1013 answer "4GB" here.
1015 If more than 4 Gigabytes is used then answer "64GB" here. This
1016 selection turns Intel PAE (Physical Address Extension) mode on.
1017 PAE implements 3-level paging on IA32 processors. PAE is fully
1018 supported by Linux, PAE mode is implemented on all recent Intel
1019 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1020 then the kernel will not boot on CPUs that don't support PAE!
1022 The actual amount of total physical memory will either be
1023 auto detected or can be forced by using a kernel command line option
1024 such as "mem=256M". (Try "man bootparam" or see the documentation of
1025 your boot loader (lilo or loadlin) about how to pass options to the
1026 kernel at boot time.)
1028 If unsure, say "off".
1030 config HIGHMEM4G
1031 bool "4GB"
1032 depends on !X86_NUMAQ
1033 ---help---
1034 Select this if you have a 32-bit processor and between 1 and 4
1035 gigabytes of physical RAM.
1037 config HIGHMEM64G
1038 bool "64GB"
1039 depends on !M386 && !M486
1040 select X86_PAE
1041 ---help---
1042 Select this if you have a 32-bit processor and more than 4
1043 gigabytes of physical RAM.
1045 endchoice
1047 choice
1048 depends on EXPERIMENTAL
1049 prompt "Memory split" if EMBEDDED
1050 default VMSPLIT_3G
1051 depends on X86_32
1052 ---help---
1053 Select the desired split between kernel and user memory.
1055 If the address range available to the kernel is less than the
1056 physical memory installed, the remaining memory will be available
1057 as "high memory". Accessing high memory is a little more costly
1058 than low memory, as it needs to be mapped into the kernel first.
1059 Note that increasing the kernel address space limits the range
1060 available to user programs, making the address space there
1061 tighter. Selecting anything other than the default 3G/1G split
1062 will also likely make your kernel incompatible with binary-only
1063 kernel modules.
1065 If you are not absolutely sure what you are doing, leave this
1066 option alone!
1068 config VMSPLIT_3G
1069 bool "3G/1G user/kernel split"
1070 config VMSPLIT_3G_OPT
1071 depends on !X86_PAE
1072 bool "3G/1G user/kernel split (for full 1G low memory)"
1073 config VMSPLIT_2G
1074 bool "2G/2G user/kernel split"
1075 config VMSPLIT_2G_OPT
1076 depends on !X86_PAE
1077 bool "2G/2G user/kernel split (for full 2G low memory)"
1078 config VMSPLIT_1G
1079 bool "1G/3G user/kernel split"
1080 endchoice
1082 config PAGE_OFFSET
1083 hex
1084 default 0xB0000000 if VMSPLIT_3G_OPT
1085 default 0x80000000 if VMSPLIT_2G
1086 default 0x78000000 if VMSPLIT_2G_OPT
1087 default 0x40000000 if VMSPLIT_1G
1088 default 0xC0000000
1089 depends on X86_32
1091 config HIGHMEM
1092 def_bool y
1093 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1095 config X86_PAE
1096 bool "PAE (Physical Address Extension) Support"
1097 depends on X86_32 && !HIGHMEM4G
1098 ---help---
1099 PAE is required for NX support, and furthermore enables
1100 larger swapspace support for non-overcommit purposes. It
1101 has the cost of more pagetable lookup overhead, and also
1102 consumes more pagetable space per process.
1104 config ARCH_PHYS_ADDR_T_64BIT
1105 def_bool X86_64 || X86_PAE
1107 config DIRECT_GBPAGES
1108 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1109 default y
1110 depends on X86_64
1111 ---help---
1112 Allow the kernel linear mapping to use 1GB pages on CPUs that
1113 support it. This can improve the kernel's performance a tiny bit by
1114 reducing TLB pressure. If in doubt, say "Y".
1116 # Common NUMA Features
1117 config NUMA
1118 bool "Numa Memory Allocation and Scheduler Support"
1119 depends on SMP
1120 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1121 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1122 ---help---
1123 Enable NUMA (Non Uniform Memory Access) support.
1125 The kernel will try to allocate memory used by a CPU on the
1126 local memory controller of the CPU and add some more
1127 NUMA awareness to the kernel.
1129 For 64-bit this is recommended if the system is Intel Core i7
1130 (or later), AMD Opteron, or EM64T NUMA.
1132 For 32-bit this is only needed on (rare) 32-bit-only platforms
1133 that support NUMA topologies, such as NUMAQ / Summit, or if you
1134 boot a 32-bit kernel on a 64-bit NUMA platform.
1136 Otherwise, you should say N.
1138 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1139 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1141 config K8_NUMA
1142 def_bool y
1143 prompt "Old style AMD Opteron NUMA detection"
1144 depends on X86_64 && NUMA && PCI
1145 ---help---
1146 Enable K8 NUMA node topology detection. You should say Y here if
1147 you have a multi processor AMD K8 system. This uses an old
1148 method to read the NUMA configuration directly from the builtin
1149 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1150 instead, which also takes priority if both are compiled in.
1152 config X86_64_ACPI_NUMA
1153 def_bool y
1154 prompt "ACPI NUMA detection"
1155 depends on X86_64 && NUMA && ACPI && PCI
1156 select ACPI_NUMA
1157 ---help---
1158 Enable ACPI SRAT based node topology detection.
1160 # Some NUMA nodes have memory ranges that span
1161 # other nodes. Even though a pfn is valid and
1162 # between a node's start and end pfns, it may not
1163 # reside on that node. See memmap_init_zone()
1164 # for details.
1165 config NODES_SPAN_OTHER_NODES
1166 def_bool y
1167 depends on X86_64_ACPI_NUMA
1169 config NUMA_EMU
1170 bool "NUMA emulation"
1171 depends on X86_64 && NUMA
1172 ---help---
1173 Enable NUMA emulation. A flat machine will be split
1174 into virtual nodes when booted with "numa=fake=N", where N is the
1175 number of nodes. This is only useful for debugging.
1177 config NODES_SHIFT
1178 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1179 range 1 9
1180 default "9" if MAXSMP
1181 default "6" if X86_64
1182 default "4" if X86_NUMAQ
1183 default "3"
1184 depends on NEED_MULTIPLE_NODES
1185 ---help---
1186 Specify the maximum number of NUMA Nodes available on the target
1187 system. Increases memory reserved to accommodate various tables.
1189 config HAVE_ARCH_BOOTMEM
1190 def_bool y
1191 depends on X86_32 && NUMA
1193 config ARCH_HAVE_MEMORY_PRESENT
1194 def_bool y
1195 depends on X86_32 && DISCONTIGMEM
1197 config NEED_NODE_MEMMAP_SIZE
1198 def_bool y
1199 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1201 config HAVE_ARCH_ALLOC_REMAP
1202 def_bool y
1203 depends on X86_32 && NUMA
1205 config ARCH_FLATMEM_ENABLE
1206 def_bool y
1207 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1209 config ARCH_DISCONTIGMEM_ENABLE
1210 def_bool y
1211 depends on NUMA && X86_32
1213 config ARCH_DISCONTIGMEM_DEFAULT
1214 def_bool y
1215 depends on NUMA && X86_32
1217 config ARCH_PROC_KCORE_TEXT
1218 def_bool y
1219 depends on X86_64 && PROC_KCORE
1221 config ARCH_SPARSEMEM_DEFAULT
1222 def_bool y
1223 depends on X86_64
1225 config ARCH_SPARSEMEM_ENABLE
1226 def_bool y
1227 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1228 select SPARSEMEM_STATIC if X86_32
1229 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1231 config ARCH_SELECT_MEMORY_MODEL
1232 def_bool y
1233 depends on ARCH_SPARSEMEM_ENABLE
1235 config ARCH_MEMORY_PROBE
1236 def_bool X86_64
1237 depends on MEMORY_HOTPLUG
1239 source "mm/Kconfig"
1241 config HIGHPTE
1242 bool "Allocate 3rd-level pagetables from highmem"
1243 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1244 ---help---
1245 The VM uses one page table entry for each page of physical memory.
1246 For systems with a lot of RAM, this can be wasteful of precious
1247 low memory. Setting this option will put user-space page table
1248 entries in high memory.
1250 config X86_CHECK_BIOS_CORRUPTION
1251 bool "Check for low memory corruption"
1252 ---help---
1253 Periodically check for memory corruption in low memory, which
1254 is suspected to be caused by BIOS. Even when enabled in the
1255 configuration, it is disabled at runtime. Enable it by
1256 setting "memory_corruption_check=1" on the kernel command
1257 line. By default it scans the low 64k of memory every 60
1258 seconds; see the memory_corruption_check_size and
1259 memory_corruption_check_period parameters in
1260 Documentation/kernel-parameters.txt to adjust this.
1262 When enabled with the default parameters, this option has
1263 almost no overhead, as it reserves a relatively small amount
1264 of memory and scans it infrequently. It both detects corruption
1265 and prevents it from affecting the running system.
1267 It is, however, intended as a diagnostic tool; if repeatable
1268 BIOS-originated corruption always affects the same memory,
1269 you can use memmap= to prevent the kernel from using that
1270 memory.
1272 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1273 bool "Set the default setting of memory_corruption_check"
1274 depends on X86_CHECK_BIOS_CORRUPTION
1275 default y
1276 ---help---
1277 Set whether the default state of memory_corruption_check is
1278 on or off.
1280 config X86_RESERVE_LOW_64K
1281 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1282 default y
1283 ---help---
1284 Reserve the first 64K of physical RAM on BIOSes that are known
1285 to potentially corrupt that memory range. A numbers of BIOSes are
1286 known to utilize this area during suspend/resume, so it must not
1287 be used by the kernel.
1289 Set this to N if you are absolutely sure that you trust the BIOS
1290 to get all its memory reservations and usages right.
1292 If you have doubts about the BIOS (e.g. suspend/resume does not
1293 work or there's kernel crashes after certain hardware hotplug
1294 events) and it's not AMI or Phoenix, then you might want to enable
1295 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1296 corruption patterns.
1298 Say Y if unsure.
1300 config MATH_EMULATION
1301 bool
1302 prompt "Math emulation" if X86_32
1303 ---help---
1304 Linux can emulate a math coprocessor (used for floating point
1305 operations) if you don't have one. 486DX and Pentium processors have
1306 a math coprocessor built in, 486SX and 386 do not, unless you added
1307 a 487DX or 387, respectively. (The messages during boot time can
1308 give you some hints here ["man dmesg"].) Everyone needs either a
1309 coprocessor or this emulation.
1311 If you don't have a math coprocessor, you need to say Y here; if you
1312 say Y here even though you have a coprocessor, the coprocessor will
1313 be used nevertheless. (This behavior can be changed with the kernel
1314 command line option "no387", which comes handy if your coprocessor
1315 is broken. Try "man bootparam" or see the documentation of your boot
1316 loader (lilo or loadlin) about how to pass options to the kernel at
1317 boot time.) This means that it is a good idea to say Y here if you
1318 intend to use this kernel on different machines.
1320 More information about the internals of the Linux math coprocessor
1321 emulation can be found in <file:arch/x86/math-emu/README>.
1323 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1324 kernel, it won't hurt.
1326 config MTRR
1327 bool "MTRR (Memory Type Range Register) support"
1328 ---help---
1329 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1330 the Memory Type Range Registers (MTRRs) may be used to control
1331 processor access to memory ranges. This is most useful if you have
1332 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1333 allows bus write transfers to be combined into a larger transfer
1334 before bursting over the PCI/AGP bus. This can increase performance
1335 of image write operations 2.5 times or more. Saying Y here creates a
1336 /proc/mtrr file which may be used to manipulate your processor's
1337 MTRRs. Typically the X server should use this.
1339 This code has a reasonably generic interface so that similar
1340 control registers on other processors can be easily supported
1341 as well:
1343 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1344 Registers (ARRs) which provide a similar functionality to MTRRs. For
1345 these, the ARRs are used to emulate the MTRRs.
1346 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1347 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1348 write-combining. All of these processors are supported by this code
1349 and it makes sense to say Y here if you have one of them.
1351 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1352 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1353 can lead to all sorts of problems, so it's good to say Y here.
1355 You can safely say Y even if your machine doesn't have MTRRs, you'll
1356 just add about 9 KB to your kernel.
1358 See <file:Documentation/x86/mtrr.txt> for more information.
1360 config MTRR_SANITIZER
1361 def_bool y
1362 prompt "MTRR cleanup support"
1363 depends on MTRR
1364 ---help---
1365 Convert MTRR layout from continuous to discrete, so X drivers can
1366 add writeback entries.
1368 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1369 The largest mtrr entry size for a continuous block can be set with
1370 mtrr_chunk_size.
1372 If unsure, say Y.
1374 config MTRR_SANITIZER_ENABLE_DEFAULT
1375 int "MTRR cleanup enable value (0-1)"
1376 range 0 1
1377 default "0"
1378 depends on MTRR_SANITIZER
1379 ---help---
1380 Enable mtrr cleanup default value
1382 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1383 int "MTRR cleanup spare reg num (0-7)"
1384 range 0 7
1385 default "1"
1386 depends on MTRR_SANITIZER
1387 ---help---
1388 mtrr cleanup spare entries default, it can be changed via
1389 mtrr_spare_reg_nr=N on the kernel command line.
1391 config X86_PAT
1392 bool
1393 prompt "x86 PAT support"
1394 depends on MTRR
1395 ---help---
1396 Use PAT attributes to setup page level cache control.
1398 PATs are the modern equivalents of MTRRs and are much more
1399 flexible than MTRRs.
1401 Say N here if you see bootup problems (boot crash, boot hang,
1402 spontaneous reboots) or a non-working video driver.
1404 If unsure, say Y.
1406 config ARCH_USES_PG_UNCACHED
1407 def_bool y
1408 depends on X86_PAT
1410 config EFI
1411 bool "EFI runtime service support"
1412 depends on ACPI
1413 ---help---
1414 This enables the kernel to use EFI runtime services that are
1415 available (such as the EFI variable services).
1417 This option is only useful on systems that have EFI firmware.
1418 In addition, you should use the latest ELILO loader available
1419 at <http://elilo.sourceforge.net> in order to take advantage
1420 of EFI runtime services. However, even with this option, the
1421 resultant kernel should continue to boot on existing non-EFI
1422 platforms.
1424 config SECCOMP
1425 def_bool y
1426 prompt "Enable seccomp to safely compute untrusted bytecode"
1427 ---help---
1428 This kernel feature is useful for number crunching applications
1429 that may need to compute untrusted bytecode during their
1430 execution. By using pipes or other transports made available to
1431 the process as file descriptors supporting the read/write
1432 syscalls, it's possible to isolate those applications in
1433 their own address space using seccomp. Once seccomp is
1434 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1435 and the task is only allowed to execute a few safe syscalls
1436 defined by each seccomp mode.
1438 If unsure, say Y. Only embedded should say N here.
1440 config CC_STACKPROTECTOR
1441 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1442 ---help---
1443 This option turns on the -fstack-protector GCC feature. This
1444 feature puts, at the beginning of functions, a canary value on
1445 the stack just before the return address, and validates
1446 the value just before actually returning. Stack based buffer
1447 overflows (that need to overwrite this return address) now also
1448 overwrite the canary, which gets detected and the attack is then
1449 neutralized via a kernel panic.
1451 This feature requires gcc version 4.2 or above, or a distribution
1452 gcc with the feature backported. Older versions are automatically
1453 detected and for those versions, this configuration option is
1454 ignored. (and a warning is printed during bootup)
1456 source kernel/Kconfig.hz
1458 config KEXEC
1459 bool "kexec system call"
1460 ---help---
1461 kexec is a system call that implements the ability to shutdown your
1462 current kernel, and to start another kernel. It is like a reboot
1463 but it is independent of the system firmware. And like a reboot
1464 you can start any kernel with it, not just Linux.
1466 The name comes from the similarity to the exec system call.
1468 It is an ongoing process to be certain the hardware in a machine
1469 is properly shutdown, so do not be surprised if this code does not
1470 initially work for you. It may help to enable device hotplugging
1471 support. As of this writing the exact hardware interface is
1472 strongly in flux, so no good recommendation can be made.
1474 config CRASH_DUMP
1475 bool "kernel crash dumps"
1476 depends on X86_64 || (X86_32 && HIGHMEM)
1477 ---help---
1478 Generate crash dump after being started by kexec.
1479 This should be normally only set in special crash dump kernels
1480 which are loaded in the main kernel with kexec-tools into
1481 a specially reserved region and then later executed after
1482 a crash by kdump/kexec. The crash dump kernel must be compiled
1483 to a memory address not used by the main kernel or BIOS using
1484 PHYSICAL_START, or it must be built as a relocatable image
1485 (CONFIG_RELOCATABLE=y).
1486 For more details see Documentation/kdump/kdump.txt
1488 config KEXEC_JUMP
1489 bool "kexec jump (EXPERIMENTAL)"
1490 depends on EXPERIMENTAL
1491 depends on KEXEC && HIBERNATION
1492 ---help---
1493 Jump between original kernel and kexeced kernel and invoke
1494 code in physical address mode via KEXEC
1496 config PHYSICAL_START
1497 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1498 default "0x1000000"
1499 ---help---
1500 This gives the physical address where the kernel is loaded.
1502 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1503 bzImage will decompress itself to above physical address and
1504 run from there. Otherwise, bzImage will run from the address where
1505 it has been loaded by the boot loader and will ignore above physical
1506 address.
1508 In normal kdump cases one does not have to set/change this option
1509 as now bzImage can be compiled as a completely relocatable image
1510 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1511 address. This option is mainly useful for the folks who don't want
1512 to use a bzImage for capturing the crash dump and want to use a
1513 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1514 to be specifically compiled to run from a specific memory area
1515 (normally a reserved region) and this option comes handy.
1517 So if you are using bzImage for capturing the crash dump,
1518 leave the value here unchanged to 0x1000000 and set
1519 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1520 for capturing the crash dump change this value to start of
1521 the reserved region. In other words, it can be set based on
1522 the "X" value as specified in the "crashkernel=YM@XM"
1523 command line boot parameter passed to the panic-ed
1524 kernel. Please take a look at Documentation/kdump/kdump.txt
1525 for more details about crash dumps.
1527 Usage of bzImage for capturing the crash dump is recommended as
1528 one does not have to build two kernels. Same kernel can be used
1529 as production kernel and capture kernel. Above option should have
1530 gone away after relocatable bzImage support is introduced. But it
1531 is present because there are users out there who continue to use
1532 vmlinux for dump capture. This option should go away down the
1533 line.
1535 Don't change this unless you know what you are doing.
1537 config RELOCATABLE
1538 bool "Build a relocatable kernel"
1539 default y
1540 ---help---
1541 This builds a kernel image that retains relocation information
1542 so it can be loaded someplace besides the default 1MB.
1543 The relocations tend to make the kernel binary about 10% larger,
1544 but are discarded at runtime.
1546 One use is for the kexec on panic case where the recovery kernel
1547 must live at a different physical address than the primary
1548 kernel.
1550 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1551 it has been loaded at and the compile time physical address
1552 (CONFIG_PHYSICAL_START) is ignored.
1554 # Relocation on x86-32 needs some additional build support
1555 config X86_NEED_RELOCS
1556 def_bool y
1557 depends on X86_32 && RELOCATABLE
1559 config PHYSICAL_ALIGN
1560 hex
1561 prompt "Alignment value to which kernel should be aligned" if X86_32
1562 default "0x1000000"
1563 range 0x2000 0x1000000
1564 ---help---
1565 This value puts the alignment restrictions on physical address
1566 where kernel is loaded and run from. Kernel is compiled for an
1567 address which meets above alignment restriction.
1569 If bootloader loads the kernel at a non-aligned address and
1570 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1571 address aligned to above value and run from there.
1573 If bootloader loads the kernel at a non-aligned address and
1574 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1575 load address and decompress itself to the address it has been
1576 compiled for and run from there. The address for which kernel is
1577 compiled already meets above alignment restrictions. Hence the
1578 end result is that kernel runs from a physical address meeting
1579 above alignment restrictions.
1581 Don't change this unless you know what you are doing.
1583 config HOTPLUG_CPU
1584 bool "Support for hot-pluggable CPUs"
1585 depends on SMP && HOTPLUG
1586 ---help---
1587 Say Y here to allow turning CPUs off and on. CPUs can be
1588 controlled through /sys/devices/system/cpu.
1589 ( Note: power management support will enable this option
1590 automatically on SMP systems. )
1591 Say N if you want to disable CPU hotplug.
1593 config COMPAT_VDSO
1594 def_bool y
1595 prompt "Compat VDSO support"
1596 depends on X86_32 || IA32_EMULATION
1597 ---help---
1598 Map the 32-bit VDSO to the predictable old-style address too.
1599 ---help---
1600 Say N here if you are running a sufficiently recent glibc
1601 version (2.3.3 or later), to remove the high-mapped
1602 VDSO mapping and to exclusively use the randomized VDSO.
1604 If unsure, say Y.
1606 config CMDLINE_BOOL
1607 bool "Built-in kernel command line"
1608 default n
1609 ---help---
1610 Allow for specifying boot arguments to the kernel at
1611 build time. On some systems (e.g. embedded ones), it is
1612 necessary or convenient to provide some or all of the
1613 kernel boot arguments with the kernel itself (that is,
1614 to not rely on the boot loader to provide them.)
1616 To compile command line arguments into the kernel,
1617 set this option to 'Y', then fill in the
1618 the boot arguments in CONFIG_CMDLINE.
1620 Systems with fully functional boot loaders (i.e. non-embedded)
1621 should leave this option set to 'N'.
1623 config CMDLINE
1624 string "Built-in kernel command string"
1625 depends on CMDLINE_BOOL
1626 default ""
1627 ---help---
1628 Enter arguments here that should be compiled into the kernel
1629 image and used at boot time. If the boot loader provides a
1630 command line at boot time, it is appended to this string to
1631 form the full kernel command line, when the system boots.
1633 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1634 change this behavior.
1636 In most cases, the command line (whether built-in or provided
1637 by the boot loader) should specify the device for the root
1638 file system.
1640 config CMDLINE_OVERRIDE
1641 bool "Built-in command line overrides boot loader arguments"
1642 default n
1643 depends on CMDLINE_BOOL
1644 ---help---
1645 Set this option to 'Y' to have the kernel ignore the boot loader
1646 command line, and use ONLY the built-in command line.
1648 This is used to work around broken boot loaders. This should
1649 be set to 'N' under normal conditions.
1651 endmenu
1653 config ARCH_ENABLE_MEMORY_HOTPLUG
1654 def_bool y
1655 depends on X86_64 || (X86_32 && HIGHMEM)
1657 config ARCH_ENABLE_MEMORY_HOTREMOVE
1658 def_bool y
1659 depends on MEMORY_HOTPLUG
1661 config HAVE_ARCH_EARLY_PFN_TO_NID
1662 def_bool X86_64
1663 depends on NUMA
1665 menu "Power management and ACPI options"
1667 config ARCH_HIBERNATION_HEADER
1668 def_bool y
1669 depends on X86_64 && HIBERNATION
1671 source "kernel/power/Kconfig"
1673 source "drivers/acpi/Kconfig"
1675 source "drivers/sfi/Kconfig"
1677 config X86_APM_BOOT
1678 bool
1679 default y
1680 depends on APM || APM_MODULE
1682 menuconfig APM
1683 tristate "APM (Advanced Power Management) BIOS support"
1684 depends on X86_32 && PM_SLEEP
1685 ---help---
1686 APM is a BIOS specification for saving power using several different
1687 techniques. This is mostly useful for battery powered laptops with
1688 APM compliant BIOSes. If you say Y here, the system time will be
1689 reset after a RESUME operation, the /proc/apm device will provide
1690 battery status information, and user-space programs will receive
1691 notification of APM "events" (e.g. battery status change).
1693 If you select "Y" here, you can disable actual use of the APM
1694 BIOS by passing the "apm=off" option to the kernel at boot time.
1696 Note that the APM support is almost completely disabled for
1697 machines with more than one CPU.
1699 In order to use APM, you will need supporting software. For location
1700 and more information, read <file:Documentation/power/pm.txt> and the
1701 Battery Powered Linux mini-HOWTO, available from
1702 <http://www.tldp.org/docs.html#howto>.
1704 This driver does not spin down disk drives (see the hdparm(8)
1705 manpage ("man 8 hdparm") for that), and it doesn't turn off
1706 VESA-compliant "green" monitors.
1708 This driver does not support the TI 4000M TravelMate and the ACER
1709 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1710 desktop machines also don't have compliant BIOSes, and this driver
1711 may cause those machines to panic during the boot phase.
1713 Generally, if you don't have a battery in your machine, there isn't
1714 much point in using this driver and you should say N. If you get
1715 random kernel OOPSes or reboots that don't seem to be related to
1716 anything, try disabling/enabling this option (or disabling/enabling
1717 APM in your BIOS).
1719 Some other things you should try when experiencing seemingly random,
1720 "weird" problems:
1722 1) make sure that you have enough swap space and that it is
1723 enabled.
1724 2) pass the "no-hlt" option to the kernel
1725 3) switch on floating point emulation in the kernel and pass
1726 the "no387" option to the kernel
1727 4) pass the "floppy=nodma" option to the kernel
1728 5) pass the "mem=4M" option to the kernel (thereby disabling
1729 all but the first 4 MB of RAM)
1730 6) make sure that the CPU is not over clocked.
1731 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1732 8) disable the cache from your BIOS settings
1733 9) install a fan for the video card or exchange video RAM
1734 10) install a better fan for the CPU
1735 11) exchange RAM chips
1736 12) exchange the motherboard.
1738 To compile this driver as a module, choose M here: the
1739 module will be called apm.
1741 if APM
1743 config APM_IGNORE_USER_SUSPEND
1744 bool "Ignore USER SUSPEND"
1745 ---help---
1746 This option will ignore USER SUSPEND requests. On machines with a
1747 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1748 series notebooks, it is necessary to say Y because of a BIOS bug.
1750 config APM_DO_ENABLE
1751 bool "Enable PM at boot time"
1752 ---help---
1753 Enable APM features at boot time. From page 36 of the APM BIOS
1754 specification: "When disabled, the APM BIOS does not automatically
1755 power manage devices, enter the Standby State, enter the Suspend
1756 State, or take power saving steps in response to CPU Idle calls."
1757 This driver will make CPU Idle calls when Linux is idle (unless this
1758 feature is turned off -- see "Do CPU IDLE calls", below). This
1759 should always save battery power, but more complicated APM features
1760 will be dependent on your BIOS implementation. You may need to turn
1761 this option off if your computer hangs at boot time when using APM
1762 support, or if it beeps continuously instead of suspending. Turn
1763 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1764 T400CDT. This is off by default since most machines do fine without
1765 this feature.
1767 config APM_CPU_IDLE
1768 bool "Make CPU Idle calls when idle"
1769 ---help---
1770 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1771 On some machines, this can activate improved power savings, such as
1772 a slowed CPU clock rate, when the machine is idle. These idle calls
1773 are made after the idle loop has run for some length of time (e.g.,
1774 333 mS). On some machines, this will cause a hang at boot time or
1775 whenever the CPU becomes idle. (On machines with more than one CPU,
1776 this option does nothing.)
1778 config APM_DISPLAY_BLANK
1779 bool "Enable console blanking using APM"
1780 ---help---
1781 Enable console blanking using the APM. Some laptops can use this to
1782 turn off the LCD backlight when the screen blanker of the Linux
1783 virtual console blanks the screen. Note that this is only used by
1784 the virtual console screen blanker, and won't turn off the backlight
1785 when using the X Window system. This also doesn't have anything to
1786 do with your VESA-compliant power-saving monitor. Further, this
1787 option doesn't work for all laptops -- it might not turn off your
1788 backlight at all, or it might print a lot of errors to the console,
1789 especially if you are using gpm.
1791 config APM_ALLOW_INTS
1792 bool "Allow interrupts during APM BIOS calls"
1793 ---help---
1794 Normally we disable external interrupts while we are making calls to
1795 the APM BIOS as a measure to lessen the effects of a badly behaving
1796 BIOS implementation. The BIOS should reenable interrupts if it
1797 needs to. Unfortunately, some BIOSes do not -- especially those in
1798 many of the newer IBM Thinkpads. If you experience hangs when you
1799 suspend, try setting this to Y. Otherwise, say N.
1801 endif # APM
1803 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1805 source "drivers/cpuidle/Kconfig"
1807 source "drivers/idle/Kconfig"
1809 endmenu
1812 menu "Bus options (PCI etc.)"
1814 config PCI
1815 bool "PCI support"
1816 default y
1817 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1818 ---help---
1819 Find out whether you have a PCI motherboard. PCI is the name of a
1820 bus system, i.e. the way the CPU talks to the other stuff inside
1821 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1822 VESA. If you have PCI, say Y, otherwise N.
1824 choice
1825 prompt "PCI access mode"
1826 depends on X86_32 && PCI
1827 default PCI_GOANY
1828 ---help---
1829 On PCI systems, the BIOS can be used to detect the PCI devices and
1830 determine their configuration. However, some old PCI motherboards
1831 have BIOS bugs and may crash if this is done. Also, some embedded
1832 PCI-based systems don't have any BIOS at all. Linux can also try to
1833 detect the PCI hardware directly without using the BIOS.
1835 With this option, you can specify how Linux should detect the
1836 PCI devices. If you choose "BIOS", the BIOS will be used,
1837 if you choose "Direct", the BIOS won't be used, and if you
1838 choose "MMConfig", then PCI Express MMCONFIG will be used.
1839 If you choose "Any", the kernel will try MMCONFIG, then the
1840 direct access method and falls back to the BIOS if that doesn't
1841 work. If unsure, go with the default, which is "Any".
1843 config PCI_GOBIOS
1844 bool "BIOS"
1846 config PCI_GOMMCONFIG
1847 bool "MMConfig"
1849 config PCI_GODIRECT
1850 bool "Direct"
1852 config PCI_GOOLPC
1853 bool "OLPC"
1854 depends on OLPC
1856 config PCI_GOANY
1857 bool "Any"
1859 endchoice
1861 config PCI_BIOS
1862 def_bool y
1863 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1865 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1866 config PCI_DIRECT
1867 def_bool y
1868 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1870 config PCI_MMCONFIG
1871 def_bool y
1872 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1874 config PCI_OLPC
1875 def_bool y
1876 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1878 config PCI_DOMAINS
1879 def_bool y
1880 depends on PCI
1882 config PCI_MMCONFIG
1883 bool "Support mmconfig PCI config space access"
1884 depends on X86_64 && PCI && ACPI
1886 config DMAR
1887 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1888 depends on PCI_MSI && ACPI && EXPERIMENTAL
1889 help
1890 DMA remapping (DMAR) devices support enables independent address
1891 translations for Direct Memory Access (DMA) from devices.
1892 These DMA remapping devices are reported via ACPI tables
1893 and include PCI device scope covered by these DMA
1894 remapping devices.
1896 config DMAR_DEFAULT_ON
1897 def_bool y
1898 prompt "Enable DMA Remapping Devices by default"
1899 depends on DMAR
1900 help
1901 Selecting this option will enable a DMAR device at boot time if
1902 one is found. If this option is not selected, DMAR support can
1903 be enabled by passing intel_iommu=on to the kernel. It is
1904 recommended you say N here while the DMAR code remains
1905 experimental.
1907 config DMAR_BROKEN_GFX_WA
1908 def_bool n
1909 prompt "Workaround broken graphics drivers (going away soon)"
1910 depends on DMAR && BROKEN
1911 ---help---
1912 Current Graphics drivers tend to use physical address
1913 for DMA and avoid using DMA APIs. Setting this config
1914 option permits the IOMMU driver to set a unity map for
1915 all the OS-visible memory. Hence the driver can continue
1916 to use physical addresses for DMA, at least until this
1917 option is removed in the 2.6.32 kernel.
1919 config DMAR_FLOPPY_WA
1920 def_bool y
1921 depends on DMAR
1922 ---help---
1923 Floppy disk drivers are known to bypass DMA API calls
1924 thereby failing to work when IOMMU is enabled. This
1925 workaround will setup a 1:1 mapping for the first
1926 16MiB to make floppy (an ISA device) work.
1928 config INTR_REMAP
1929 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1930 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1931 ---help---
1932 Supports Interrupt remapping for IO-APIC and MSI devices.
1933 To use x2apic mode in the CPU's which support x2APIC enhancements or
1934 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1936 source "drivers/pci/pcie/Kconfig"
1938 source "drivers/pci/Kconfig"
1940 # x86_64 have no ISA slots, but do have ISA-style DMA.
1941 config ISA_DMA_API
1942 def_bool y
1944 if X86_32
1946 config ISA
1947 bool "ISA support"
1948 ---help---
1949 Find out whether you have ISA slots on your motherboard. ISA is the
1950 name of a bus system, i.e. the way the CPU talks to the other stuff
1951 inside your box. Other bus systems are PCI, EISA, MicroChannel
1952 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1953 newer boards don't support it. If you have ISA, say Y, otherwise N.
1955 config EISA
1956 bool "EISA support"
1957 depends on ISA
1958 ---help---
1959 The Extended Industry Standard Architecture (EISA) bus was
1960 developed as an open alternative to the IBM MicroChannel bus.
1962 The EISA bus provided some of the features of the IBM MicroChannel
1963 bus while maintaining backward compatibility with cards made for
1964 the older ISA bus. The EISA bus saw limited use between 1988 and
1965 1995 when it was made obsolete by the PCI bus.
1967 Say Y here if you are building a kernel for an EISA-based machine.
1969 Otherwise, say N.
1971 source "drivers/eisa/Kconfig"
1973 config MCA
1974 bool "MCA support"
1975 ---help---
1976 MicroChannel Architecture is found in some IBM PS/2 machines and
1977 laptops. It is a bus system similar to PCI or ISA. See
1978 <file:Documentation/mca.txt> (and especially the web page given
1979 there) before attempting to build an MCA bus kernel.
1981 source "drivers/mca/Kconfig"
1983 config SCx200
1984 tristate "NatSemi SCx200 support"
1985 ---help---
1986 This provides basic support for National Semiconductor's
1987 (now AMD's) Geode processors. The driver probes for the
1988 PCI-IDs of several on-chip devices, so its a good dependency
1989 for other scx200_* drivers.
1991 If compiled as a module, the driver is named scx200.
1993 config SCx200HR_TIMER
1994 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1995 depends on SCx200 && GENERIC_TIME
1996 default y
1997 ---help---
1998 This driver provides a clocksource built upon the on-chip
1999 27MHz high-resolution timer. Its also a workaround for
2000 NSC Geode SC-1100's buggy TSC, which loses time when the
2001 processor goes idle (as is done by the scheduler). The
2002 other workaround is idle=poll boot option.
2004 config GEODE_MFGPT_TIMER
2005 def_bool y
2006 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2007 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2008 ---help---
2009 This driver provides a clock event source based on the MFGPT
2010 timer(s) in the CS5535 and CS5536 companion chip for the geode.
2011 MFGPTs have a better resolution and max interval than the
2012 generic PIT, and are suitable for use as high-res timers.
2014 config OLPC
2015 bool "One Laptop Per Child support"
2016 default n
2017 ---help---
2018 Add support for detecting the unique features of the OLPC
2019 XO hardware.
2021 endif # X86_32
2023 config K8_NB
2024 def_bool y
2025 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2027 source "drivers/pcmcia/Kconfig"
2029 source "drivers/pci/hotplug/Kconfig"
2031 endmenu
2034 menu "Executable file formats / Emulations"
2036 source "fs/Kconfig.binfmt"
2038 config IA32_EMULATION
2039 bool "IA32 Emulation"
2040 depends on X86_64
2041 select COMPAT_BINFMT_ELF
2042 ---help---
2043 Include code to run 32-bit programs under a 64-bit kernel. You should
2044 likely turn this on, unless you're 100% sure that you don't have any
2045 32-bit programs left.
2047 config IA32_AOUT
2048 tristate "IA32 a.out support"
2049 depends on IA32_EMULATION
2050 ---help---
2051 Support old a.out binaries in the 32bit emulation.
2053 config COMPAT
2054 def_bool y
2055 depends on IA32_EMULATION
2057 config COMPAT_FOR_U64_ALIGNMENT
2058 def_bool COMPAT
2059 depends on X86_64
2061 config SYSVIPC_COMPAT
2062 def_bool y
2063 depends on COMPAT && SYSVIPC
2065 endmenu
2068 config HAVE_ATOMIC_IOMAP
2069 def_bool y
2070 depends on X86_32
2072 source "net/Kconfig"
2074 source "drivers/Kconfig"
2076 source "drivers/firmware/Kconfig"
2078 source "fs/Kconfig"
2080 source "arch/x86/Kconfig.debug"
2082 source "security/Kconfig"
2084 source "crypto/Kconfig"
2086 source "arch/x86/kvm/Kconfig"
2088 source "lib/Kconfig"