| blob | 55298e891571edc6d07486f235a46ffddd622729 |
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_HW_BREAKPOINT
53 select PERF_EVENTS
54 select ANON_INODES
55 select HAVE_ARCH_KMEMCHECK
56 select HAVE_USER_RETURN_NOTIFIER
58 config OUTPUT_FORMAT
59 string
60 default "elf32-i386" if X86_32
61 default "elf64-x86-64" if X86_64
63 config ARCH_DEFCONFIG
64 string
65 default "arch/x86/configs/i386_defconfig" if X86_32
66 default "arch/x86/configs/x86_64_defconfig" if X86_64
68 config GENERIC_TIME
69 def_bool y
71 config GENERIC_CMOS_UPDATE
72 def_bool y
74 config CLOCKSOURCE_WATCHDOG
75 def_bool y
77 config GENERIC_CLOCKEVENTS
78 def_bool y
80 config GENERIC_CLOCKEVENTS_BROADCAST
81 def_bool y
82 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
84 config LOCKDEP_SUPPORT
85 def_bool y
87 config STACKTRACE_SUPPORT
88 def_bool y
90 config HAVE_LATENCYTOP_SUPPORT
91 def_bool y
93 config MMU
94 def_bool y
96 config ZONE_DMA
97 def_bool y
99 config SBUS
100 bool
102 config GENERIC_ISA_DMA
103 def_bool y
105 config GENERIC_IOMAP
106 def_bool y
108 config GENERIC_BUG
109 def_bool y
110 depends on BUG
111 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
113 config GENERIC_BUG_RELATIVE_POINTERS
114 bool
116 config GENERIC_HWEIGHT
117 def_bool y
119 config GENERIC_GPIO
120 bool
122 config ARCH_MAY_HAVE_PC_FDC
123 def_bool y
125 config RWSEM_GENERIC_SPINLOCK
126 def_bool !X86_XADD
128 config RWSEM_XCHGADD_ALGORITHM
129 def_bool X86_XADD
131 config ARCH_HAS_CPU_IDLE_WAIT
132 def_bool y
134 config GENERIC_CALIBRATE_DELAY
135 def_bool y
137 config GENERIC_TIME_VSYSCALL
138 bool
139 default X86_64
141 config ARCH_HAS_CPU_RELAX
142 def_bool y
144 config ARCH_HAS_DEFAULT_IDLE
145 def_bool y
147 config ARCH_HAS_CACHE_LINE_SIZE
148 def_bool y
150 config HAVE_SETUP_PER_CPU_AREA
151 def_bool y
153 config NEED_PER_CPU_EMBED_FIRST_CHUNK
154 def_bool y
156 config NEED_PER_CPU_PAGE_FIRST_CHUNK
157 def_bool y
159 config HAVE_CPUMASK_OF_CPU_MAP
160 def_bool X86_64_SMP
162 config ARCH_HIBERNATION_POSSIBLE
163 def_bool y
165 config ARCH_SUSPEND_POSSIBLE
166 def_bool y
168 config ZONE_DMA32
169 bool
170 default X86_64
172 config ARCH_POPULATES_NODE_MAP
173 def_bool y
175 config AUDIT_ARCH
176 bool
177 default X86_64
179 config ARCH_SUPPORTS_OPTIMIZED_INLINING
180 def_bool y
182 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
183 def_bool y
185 config HAVE_INTEL_TXT
186 def_bool y
187 depends on EXPERIMENTAL && DMAR && ACPI
189 # Use the generic interrupt handling code in kernel/irq/:
190 config GENERIC_HARDIRQS
191 bool
192 default y
194 config GENERIC_HARDIRQS_NO__DO_IRQ
195 def_bool y
197 config GENERIC_IRQ_PROBE
198 bool
199 default y
201 config GENERIC_PENDING_IRQ
202 bool
203 depends on GENERIC_HARDIRQS && SMP
204 default y
206 config USE_GENERIC_SMP_HELPERS
207 def_bool y
208 depends on SMP
210 config X86_32_SMP
211 def_bool y
212 depends on X86_32 && SMP
214 config X86_64_SMP
215 def_bool y
216 depends on X86_64 && SMP
218 config X86_HT
219 bool
220 depends on SMP
221 default y
223 config X86_TRAMPOLINE
224 bool
225 depends on SMP || (64BIT && ACPI_SLEEP)
226 default y
228 config X86_32_LAZY_GS
229 def_bool y
230 depends on X86_32 && !CC_STACKPROTECTOR
232 config KTIME_SCALAR
233 def_bool X86_32
234 source "init/Kconfig"
235 source "kernel/Kconfig.freezer"
237 menu "Processor type and features"
239 source "kernel/time/Kconfig"
241 config SMP
242 bool "Symmetric multi-processing support"
243 ---help---
244 This enables support for systems with more than one CPU. If you have
245 a system with only one CPU, like most personal computers, say N. If
246 you have a system with more than one CPU, say Y.
248 If you say N here, the kernel will run on single and multiprocessor
249 machines, but will use only one CPU of a multiprocessor machine. If
250 you say Y here, the kernel will run on many, but not all,
251 singleprocessor machines. On a singleprocessor machine, the kernel
252 will run faster if you say N here.
254 Note that if you say Y here and choose architecture "586" or
255 "Pentium" under "Processor family", the kernel will not work on 486
256 architectures. Similarly, multiprocessor kernels for the "PPro"
257 architecture may not work on all Pentium based boards.
259 People using multiprocessor machines who say Y here should also say
260 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
261 Management" code will be disabled if you say Y here.
263 See also <file:Documentation/i386/IO-APIC.txt>,
264 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
265 <http://www.tldp.org/docs.html#howto>.
267 If you don't know what to do here, say N.
269 config X86_X2APIC
270 bool "Support x2apic"
271 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
272 ---help---
273 This enables x2apic support on CPUs that have this feature.
275 This allows 32-bit apic IDs (so it can support very large systems),
276 and accesses the local apic via MSRs not via mmio.
278 If you don't know what to do here, say N.
280 config SPARSE_IRQ
281 bool "Support sparse irq numbering"
282 depends on PCI_MSI || HT_IRQ
283 ---help---
284 This enables support for sparse irqs. This is useful for distro
285 kernels that want to define a high CONFIG_NR_CPUS value but still
286 want to have low kernel memory footprint on smaller machines.
288 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
289 out the irq_desc[] array in a more NUMA-friendly way. )
291 If you don't know what to do here, say N.
293 config NUMA_IRQ_DESC
294 def_bool y
295 depends on SPARSE_IRQ && NUMA
297 config X86_MPPARSE
298 bool "Enable MPS table" if ACPI
299 default y
300 depends on X86_LOCAL_APIC
301 ---help---
302 For old smp systems that do not have proper acpi support. Newer systems
303 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
305 config X86_BIGSMP
306 bool "Support for big SMP systems with more than 8 CPUs"
307 depends on X86_32 && SMP
308 ---help---
309 This option is needed for the systems that have more than 8 CPUs
311 if X86_32
312 config X86_EXTENDED_PLATFORM
313 bool "Support for extended (non-PC) x86 platforms"
314 default y
315 ---help---
316 If you disable this option then the kernel will only support
317 standard PC platforms. (which covers the vast majority of
318 systems out there.)
320 If you enable this option then you'll be able to select support
321 for the following (non-PC) 32 bit x86 platforms:
322 AMD Elan
323 NUMAQ (IBM/Sequent)
324 RDC R-321x SoC
325 SGI 320/540 (Visual Workstation)
326 Summit/EXA (IBM x440)
327 Unisys ES7000 IA32 series
328 Moorestown MID devices
330 If you have one of these systems, or if you want to build a
331 generic distribution kernel, say Y here - otherwise say N.
332 endif
334 if X86_64
335 config X86_EXTENDED_PLATFORM
336 bool "Support for extended (non-PC) x86 platforms"
337 default y
338 ---help---
339 If you disable this option then the kernel will only support
340 standard PC platforms. (which covers the vast majority of
341 systems out there.)
343 If you enable this option then you'll be able to select support
344 for the following (non-PC) 64 bit x86 platforms:
345 ScaleMP vSMP
346 SGI Ultraviolet
348 If you have one of these systems, or if you want to build a
349 generic distribution kernel, say Y here - otherwise say N.
350 endif
351 # This is an alphabetically sorted list of 64 bit extended platforms
352 # Please maintain the alphabetic order if and when there are additions
354 config X86_VSMP
355 bool "ScaleMP vSMP"
356 select PARAVIRT
357 depends on X86_64 && PCI
358 depends on X86_EXTENDED_PLATFORM
359 ---help---
360 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
361 supposed to run on these EM64T-based machines. Only choose this option
362 if you have one of these machines.
364 config X86_UV
365 bool "SGI Ultraviolet"
366 depends on X86_64
367 depends on X86_EXTENDED_PLATFORM
368 depends on NUMA
369 depends on X86_X2APIC
370 ---help---
371 This option is needed in order to support SGI Ultraviolet systems.
372 If you don't have one of these, you should say N here.
374 # Following is an alphabetically sorted list of 32 bit extended platforms
375 # Please maintain the alphabetic order if and when there are additions
377 config X86_ELAN
378 bool "AMD Elan"
379 depends on X86_32
380 depends on X86_EXTENDED_PLATFORM
381 ---help---
382 Select this for an AMD Elan processor.
384 Do not use this option for K6/Athlon/Opteron processors!
386 If unsure, choose "PC-compatible" instead.
388 config X86_MRST
389 bool "Moorestown MID platform"
390 depends on X86_32
391 depends on X86_EXTENDED_PLATFORM
392 ---help---
393 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
394 Internet Device(MID) platform. Moorestown consists of two chips:
395 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
396 Unlike standard x86 PCs, Moorestown does not have many legacy devices
397 nor standard legacy replacement devices/features. e.g. Moorestown does
398 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
400 config X86_RDC321X
401 bool "RDC R-321x SoC"
402 depends on X86_32
403 depends on X86_EXTENDED_PLATFORM
404 select M486
405 select X86_REBOOTFIXUPS
406 ---help---
407 This option is needed for RDC R-321x system-on-chip, also known
408 as R-8610-(G).
409 If you don't have one of these chips, you should say N here.
411 config X86_32_NON_STANDARD
412 bool "Support non-standard 32-bit SMP architectures"
413 depends on X86_32 && SMP
414 depends on X86_EXTENDED_PLATFORM
415 ---help---
416 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
417 subarchitectures. It is intended for a generic binary kernel.
418 if you select them all, kernel will probe it one by one. and will
419 fallback to default.
421 # Alphabetically sorted list of Non standard 32 bit platforms
423 config X86_NUMAQ
424 bool "NUMAQ (IBM/Sequent)"
425 depends on X86_32_NON_STANDARD
426 select NUMA
427 select X86_MPPARSE
428 ---help---
429 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
430 NUMA multiquad box. This changes the way that processors are
431 bootstrapped, and uses Clustered Logical APIC addressing mode instead
432 of Flat Logical. You will need a new lynxer.elf file to flash your
433 firmware with - send email to <Martin.Bligh@us.ibm.com>.
435 config X86_SUPPORTS_MEMORY_FAILURE
436 bool
437 # MCE code calls memory_failure():
438 depends on X86_MCE
439 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
440 depends on !X86_NUMAQ
441 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
442 depends on X86_64 || !SPARSEMEM
443 select ARCH_SUPPORTS_MEMORY_FAILURE
444 default y
446 config X86_VISWS
447 bool "SGI 320/540 (Visual Workstation)"
448 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
449 depends on X86_32_NON_STANDARD
450 ---help---
451 The SGI Visual Workstation series is an IA32-based workstation
452 based on SGI systems chips with some legacy PC hardware attached.
454 Say Y here to create a kernel to run on the SGI 320 or 540.
456 A kernel compiled for the Visual Workstation will run on general
457 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
459 config X86_SUMMIT
460 bool "Summit/EXA (IBM x440)"
461 depends on X86_32_NON_STANDARD
462 ---help---
463 This option is needed for IBM systems that use the Summit/EXA chipset.
464 In particular, it is needed for the x440.
466 config X86_ES7000
467 bool "Unisys ES7000 IA32 series"
468 depends on X86_32_NON_STANDARD && X86_BIGSMP
469 ---help---
470 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
471 supposed to run on an IA32-based Unisys ES7000 system.
473 config SCHED_OMIT_FRAME_POINTER
474 def_bool y
475 prompt "Single-depth WCHAN output"
476 depends on X86
477 ---help---
478 Calculate simpler /proc/<PID>/wchan values. If this option
479 is disabled then wchan values will recurse back to the
480 caller function. This provides more accurate wchan values,
481 at the expense of slightly more scheduling overhead.
483 If in doubt, say "Y".
485 menuconfig PARAVIRT_GUEST
486 bool "Paravirtualized guest support"
487 ---help---
488 Say Y here to get to see options related to running Linux under
489 various hypervisors. This option alone does not add any kernel code.
491 If you say N, all options in this submenu will be skipped and disabled.
493 if PARAVIRT_GUEST
495 source "arch/x86/xen/Kconfig"
497 config VMI
498 bool "VMI Guest support (DEPRECATED)"
499 select PARAVIRT
500 depends on X86_32
501 ---help---
502 VMI provides a paravirtualized interface to the VMware ESX server
503 (it could be used by other hypervisors in theory too, but is not
504 at the moment), by linking the kernel to a GPL-ed ROM module
505 provided by the hypervisor.
507 As of September 2009, VMware has started a phased retirement
508 of this feature from VMware's products. Please see
509 feature-removal-schedule.txt for details. If you are
510 planning to enable this option, please note that you cannot
511 live migrate a VMI enabled VM to a future VMware product,
512 which doesn't support VMI. So if you expect your kernel to
513 seamlessly migrate to newer VMware products, keep this
514 disabled.
516 config KVM_CLOCK
517 bool "KVM paravirtualized clock"
518 select PARAVIRT
519 select PARAVIRT_CLOCK
520 ---help---
521 Turning on this option will allow you to run a paravirtualized clock
522 when running over the KVM hypervisor. Instead of relying on a PIT
523 (or probably other) emulation by the underlying device model, the host
524 provides the guest with timing infrastructure such as time of day, and
525 system time
527 config KVM_GUEST
528 bool "KVM Guest support"
529 select PARAVIRT
530 ---help---
531 This option enables various optimizations for running under the KVM
532 hypervisor.
534 source "arch/x86/lguest/Kconfig"
536 config PARAVIRT
537 bool "Enable paravirtualization code"
538 ---help---
539 This changes the kernel so it can modify itself when it is run
540 under a hypervisor, potentially improving performance significantly
541 over full virtualization. However, when run without a hypervisor
542 the kernel is theoretically slower and slightly larger.
544 config PARAVIRT_SPINLOCKS
545 bool "Paravirtualization layer for spinlocks"
546 depends on PARAVIRT && SMP && EXPERIMENTAL
547 ---help---
548 Paravirtualized spinlocks allow a pvops backend to replace the
549 spinlock implementation with something virtualization-friendly
550 (for example, block the virtual CPU rather than spinning).
552 Unfortunately the downside is an up to 5% performance hit on
553 native kernels, with various workloads.
555 If you are unsure how to answer this question, answer N.
557 config PARAVIRT_CLOCK
558 bool
559 default n
561 endif
563 config PARAVIRT_DEBUG
564 bool "paravirt-ops debugging"
565 depends on PARAVIRT && DEBUG_KERNEL
566 ---help---
567 Enable to debug paravirt_ops internals. Specifically, BUG if
568 a paravirt_op is missing when it is called.
570 config MEMTEST
571 bool "Memtest"
572 ---help---
573 This option adds a kernel parameter 'memtest', which allows memtest
574 to be set.
575 memtest=0, mean disabled; -- default
576 memtest=1, mean do 1 test pattern;
577 ...
578 memtest=4, mean do 4 test patterns.
579 If you are unsure how to answer this question, answer N.
581 config X86_SUMMIT_NUMA
582 def_bool y
583 depends on X86_32 && NUMA && X86_32_NON_STANDARD
585 config X86_CYCLONE_TIMER
586 def_bool y
587 depends on X86_32_NON_STANDARD
589 source "arch/x86/Kconfig.cpu"
591 config HPET_TIMER
592 def_bool X86_64
593 prompt "HPET Timer Support" if X86_32
594 ---help---
595 Use the IA-PC HPET (High Precision Event Timer) to manage
596 time in preference to the PIT and RTC, if a HPET is
597 present.
598 HPET is the next generation timer replacing legacy 8254s.
599 The HPET provides a stable time base on SMP
600 systems, unlike the TSC, but it is more expensive to access,
601 as it is off-chip. You can find the HPET spec at
602 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
604 You can safely choose Y here. However, HPET will only be
605 activated if the platform and the BIOS support this feature.
606 Otherwise the 8254 will be used for timing services.
608 Choose N to continue using the legacy 8254 timer.
610 config HPET_EMULATE_RTC
611 def_bool y
612 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
614 # Mark as embedded because too many people got it wrong.
615 # The code disables itself when not needed.
616 config DMI
617 default y
618 bool "Enable DMI scanning" if EMBEDDED
619 ---help---
620 Enabled scanning of DMI to identify machine quirks. Say Y
621 here unless you have verified that your setup is not
622 affected by entries in the DMI blacklist. Required by PNP
623 BIOS code.
625 config GART_IOMMU
626 bool "GART IOMMU support" if EMBEDDED
627 default y
628 select SWIOTLB
629 depends on X86_64 && PCI
630 ---help---
631 Support for full DMA access of devices with 32bit memory access only
632 on systems with more than 3GB. This is usually needed for USB,
633 sound, many IDE/SATA chipsets and some other devices.
634 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
635 based hardware IOMMU and a software bounce buffer based IOMMU used
636 on Intel systems and as fallback.
637 The code is only active when needed (enough memory and limited
638 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
639 too.
641 config CALGARY_IOMMU
642 bool "IBM Calgary IOMMU support"
643 select SWIOTLB
644 depends on X86_64 && PCI && EXPERIMENTAL
645 ---help---
646 Support for hardware IOMMUs in IBM's xSeries x366 and x460
647 systems. Needed to run systems with more than 3GB of memory
648 properly with 32-bit PCI devices that do not support DAC
649 (Double Address Cycle). Calgary also supports bus level
650 isolation, where all DMAs pass through the IOMMU. This
651 prevents them from going anywhere except their intended
652 destination. This catches hard-to-find kernel bugs and
653 mis-behaving drivers and devices that do not use the DMA-API
654 properly to set up their DMA buffers. The IOMMU can be
655 turned off at boot time with the iommu=off parameter.
656 Normally the kernel will make the right choice by itself.
657 If unsure, say Y.
659 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
660 def_bool y
661 prompt "Should Calgary be enabled by default?"
662 depends on CALGARY_IOMMU
663 ---help---
664 Should Calgary be enabled by default? if you choose 'y', Calgary
665 will be used (if it exists). If you choose 'n', Calgary will not be
666 used even if it exists. If you choose 'n' and would like to use
667 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
668 If unsure, say Y.
670 config AMD_IOMMU
671 bool "AMD IOMMU support"
672 select SWIOTLB
673 select PCI_MSI
674 depends on X86_64 && PCI && ACPI
675 ---help---
676 With this option you can enable support for AMD IOMMU hardware in
677 your system. An IOMMU is a hardware component which provides
678 remapping of DMA memory accesses from devices. With an AMD IOMMU you
679 can isolate the the DMA memory of different devices and protect the
680 system from misbehaving device drivers or hardware.
682 You can find out if your system has an AMD IOMMU if you look into
683 your BIOS for an option to enable it or if you have an IVRS ACPI
684 table.
686 config AMD_IOMMU_STATS
687 bool "Export AMD IOMMU statistics to debugfs"
688 depends on AMD_IOMMU
689 select DEBUG_FS
690 ---help---
691 This option enables code in the AMD IOMMU driver to collect various
692 statistics about whats happening in the driver and exports that
693 information to userspace via debugfs.
694 If unsure, say N.
696 # need this always selected by IOMMU for the VIA workaround
697 config SWIOTLB
698 def_bool y if X86_64
699 ---help---
700 Support for software bounce buffers used on x86-64 systems
701 which don't have a hardware IOMMU (e.g. the current generation
702 of Intel's x86-64 CPUs). Using this PCI devices which can only
703 access 32-bits of memory can be used on systems with more than
704 3 GB of memory. If unsure, say Y.
706 config IOMMU_HELPER
707 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
709 config IOMMU_API
710 def_bool (AMD_IOMMU || DMAR)
712 config MAXSMP
713 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
714 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
715 select CPUMASK_OFFSTACK
716 default n
717 ---help---
718 Configure maximum number of CPUS and NUMA Nodes for this architecture.
719 If unsure, say N.
721 config NR_CPUS
722 int "Maximum number of CPUs" if SMP && !MAXSMP
723 range 2 8 if SMP && X86_32 && !X86_BIGSMP
724 range 2 512 if SMP && !MAXSMP
725 default "1" if !SMP
726 default "4096" if MAXSMP
727 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
728 default "8" if SMP
729 ---help---
730 This allows you to specify the maximum number of CPUs which this
731 kernel will support. The maximum supported value is 512 and the
732 minimum value which makes sense is 2.
734 This is purely to save memory - each supported CPU adds
735 approximately eight kilobytes to the kernel image.
737 config SCHED_SMT
738 bool "SMT (Hyperthreading) scheduler support"
739 depends on X86_HT
740 ---help---
741 SMT scheduler support improves the CPU scheduler's decision making
742 when dealing with Intel Pentium 4 chips with HyperThreading at a
743 cost of slightly increased overhead in some places. If unsure say
744 N here.
746 config SCHED_MC
747 def_bool y
748 prompt "Multi-core scheduler support"
749 depends on X86_HT
750 ---help---
751 Multi-core scheduler support improves the CPU scheduler's decision
752 making when dealing with multi-core CPU chips at a cost of slightly
753 increased overhead in some places. If unsure say N here.
755 source "kernel/Kconfig.preempt"
757 config X86_UP_APIC
758 bool "Local APIC support on uniprocessors"
759 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
760 ---help---
761 A local APIC (Advanced Programmable Interrupt Controller) is an
762 integrated interrupt controller in the CPU. If you have a single-CPU
763 system which has a processor with a local APIC, you can say Y here to
764 enable and use it. If you say Y here even though your machine doesn't
765 have a local APIC, then the kernel will still run with no slowdown at
766 all. The local APIC supports CPU-generated self-interrupts (timer,
767 performance counters), and the NMI watchdog which detects hard
768 lockups.
770 config X86_UP_IOAPIC
771 bool "IO-APIC support on uniprocessors"
772 depends on X86_UP_APIC
773 ---help---
774 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
775 SMP-capable replacement for PC-style interrupt controllers. Most
776 SMP systems and many recent uniprocessor systems have one.
778 If you have a single-CPU system with an IO-APIC, you can say Y here
779 to use it. If you say Y here even though your machine doesn't have
780 an IO-APIC, then the kernel will still run with no slowdown at all.
782 config X86_LOCAL_APIC
783 def_bool y
784 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
786 config X86_IO_APIC
787 def_bool y
788 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
790 config X86_VISWS_APIC
791 def_bool y
792 depends on X86_32 && X86_VISWS
794 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
795 bool "Reroute for broken boot IRQs"
796 default n
797 depends on X86_IO_APIC
798 ---help---
799 This option enables a workaround that fixes a source of
800 spurious interrupts. This is recommended when threaded
801 interrupt handling is used on systems where the generation of
802 superfluous "boot interrupts" cannot be disabled.
804 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
805 entry in the chipset's IO-APIC is masked (as, e.g. the RT
806 kernel does during interrupt handling). On chipsets where this
807 boot IRQ generation cannot be disabled, this workaround keeps
808 the original IRQ line masked so that only the equivalent "boot
809 IRQ" is delivered to the CPUs. The workaround also tells the
810 kernel to set up the IRQ handler on the boot IRQ line. In this
811 way only one interrupt is delivered to the kernel. Otherwise
812 the spurious second interrupt may cause the kernel to bring
813 down (vital) interrupt lines.
815 Only affects "broken" chipsets. Interrupt sharing may be
816 increased on these systems.
818 config X86_MCE
819 bool "Machine Check / overheating reporting"
820 ---help---
821 Machine Check support allows the processor to notify the
822 kernel if it detects a problem (e.g. overheating, data corruption).
823 The action the kernel takes depends on the severity of the problem,
824 ranging from warning messages to halting the machine.
826 config X86_MCE_INTEL
827 def_bool y
828 prompt "Intel MCE features"
829 depends on X86_MCE && X86_LOCAL_APIC
830 ---help---
831 Additional support for intel specific MCE features such as
832 the thermal monitor.
834 config X86_MCE_AMD
835 def_bool y
836 prompt "AMD MCE features"
837 depends on X86_MCE && X86_LOCAL_APIC
838 ---help---
839 Additional support for AMD specific MCE features such as
840 the DRAM Error Threshold.
842 config X86_ANCIENT_MCE
843 def_bool n
844 depends on X86_32 && X86_MCE
845 prompt "Support for old Pentium 5 / WinChip machine checks"
846 ---help---
847 Include support for machine check handling on old Pentium 5 or WinChip
848 systems. These typically need to be enabled explicitely on the command
849 line.
851 config X86_MCE_THRESHOLD
852 depends on X86_MCE_AMD || X86_MCE_INTEL
853 bool
854 default y
856 config X86_MCE_INJECT
857 depends on X86_MCE
858 tristate "Machine check injector support"
859 ---help---
860 Provide support for injecting machine checks for testing purposes.
861 If you don't know what a machine check is and you don't do kernel
862 QA it is safe to say n.
864 config X86_THERMAL_VECTOR
865 def_bool y
866 depends on X86_MCE_INTEL
868 config VM86
869 bool "Enable VM86 support" if EMBEDDED
870 default y
871 depends on X86_32
872 ---help---
873 This option is required by programs like DOSEMU to run 16-bit legacy
874 code on X86 processors. It also may be needed by software like
875 XFree86 to initialize some video cards via BIOS. Disabling this
876 option saves about 6k.
878 config TOSHIBA
879 tristate "Toshiba Laptop support"
880 depends on X86_32
881 ---help---
882 This adds a driver to safely access the System Management Mode of
883 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
884 not work on models with a Phoenix BIOS. The System Management Mode
885 is used to set the BIOS and power saving options on Toshiba portables.
887 For information on utilities to make use of this driver see the
888 Toshiba Linux utilities web site at:
889 <http://www.buzzard.org.uk/toshiba/>.
891 Say Y if you intend to run this kernel on a Toshiba portable.
892 Say N otherwise.
894 config I8K
895 tristate "Dell laptop support"
896 ---help---
897 This adds a driver to safely access the System Management Mode
898 of the CPU on the Dell Inspiron 8000. The System Management Mode
899 is used to read cpu temperature and cooling fan status and to
900 control the fans on the I8K portables.
902 This driver has been tested only on the Inspiron 8000 but it may
903 also work with other Dell laptops. You can force loading on other
904 models by passing the parameter `force=1' to the module. Use at
905 your own risk.
907 For information on utilities to make use of this driver see the
908 I8K Linux utilities web site at:
909 <http://people.debian.org/~dz/i8k/>
911 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
912 Say N otherwise.
914 config X86_REBOOTFIXUPS
915 bool "Enable X86 board specific fixups for reboot"
916 depends on X86_32
917 ---help---
918 This enables chipset and/or board specific fixups to be done
919 in order to get reboot to work correctly. This is only needed on
920 some combinations of hardware and BIOS. The symptom, for which
921 this config is intended, is when reboot ends with a stalled/hung
922 system.
924 Currently, the only fixup is for the Geode machines using
925 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
927 Say Y if you want to enable the fixup. Currently, it's safe to
928 enable this option even if you don't need it.
929 Say N otherwise.
931 config MICROCODE
932 tristate "/dev/cpu/microcode - microcode support"
933 select FW_LOADER
934 ---help---
935 If you say Y here, you will be able to update the microcode on
936 certain Intel and AMD processors. The Intel support is for the
937 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
938 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
939 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
940 You will obviously need the actual microcode binary data itself
941 which is not shipped with the Linux kernel.
943 This option selects the general module only, you need to select
944 at least one vendor specific module as well.
946 To compile this driver as a module, choose M here: the
947 module will be called microcode.
949 config MICROCODE_INTEL
950 bool "Intel microcode patch loading support"
951 depends on MICROCODE
952 default MICROCODE
953 select FW_LOADER
954 ---help---
955 This options enables microcode patch loading support for Intel
956 processors.
958 For latest news and information on obtaining all the required
959 Intel ingredients for this driver, check:
960 <http://www.urbanmyth.org/microcode/>.
962 config MICROCODE_AMD
963 bool "AMD microcode patch loading support"
964 depends on MICROCODE
965 select FW_LOADER
966 ---help---
967 If you select this option, microcode patch loading support for AMD
968 processors will be enabled.
970 config MICROCODE_OLD_INTERFACE
971 def_bool y
972 depends on MICROCODE
974 config X86_MSR
975 tristate "/dev/cpu/*/msr - Model-specific register support"
976 ---help---
977 This device gives privileged processes access to the x86
978 Model-Specific Registers (MSRs). It is a character device with
979 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
980 MSR accesses are directed to a specific CPU on multi-processor
981 systems.
983 config X86_CPUID
984 tristate "/dev/cpu/*/cpuid - CPU information support"
985 ---help---
986 This device gives processes access to the x86 CPUID instruction to
987 be executed on a specific processor. It is a character device
988 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
989 /dev/cpu/31/cpuid.
991 config X86_CPU_DEBUG
992 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
993 ---help---
994 If you select this option, this will provide various x86 CPUs
995 information through debugfs.
997 choice
998 prompt "High Memory Support"
999 default HIGHMEM4G if !X86_NUMAQ
1000 default HIGHMEM64G if X86_NUMAQ
1001 depends on X86_32
1003 config NOHIGHMEM
1004 bool "off"
1005 depends on !X86_NUMAQ
1006 ---help---
1007 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1008 However, the address space of 32-bit x86 processors is only 4
1009 Gigabytes large. That means that, if you have a large amount of
1010 physical memory, not all of it can be "permanently mapped" by the
1011 kernel. The physical memory that's not permanently mapped is called
1012 "high memory".
1014 If you are compiling a kernel which will never run on a machine with
1015 more than 1 Gigabyte total physical RAM, answer "off" here (default
1016 choice and suitable for most users). This will result in a "3GB/1GB"
1017 split: 3GB are mapped so that each process sees a 3GB virtual memory
1018 space and the remaining part of the 4GB virtual memory space is used
1019 by the kernel to permanently map as much physical memory as
1020 possible.
1022 If the machine has between 1 and 4 Gigabytes physical RAM, then
1023 answer "4GB" here.
1025 If more than 4 Gigabytes is used then answer "64GB" here. This
1026 selection turns Intel PAE (Physical Address Extension) mode on.
1027 PAE implements 3-level paging on IA32 processors. PAE is fully
1028 supported by Linux, PAE mode is implemented on all recent Intel
1029 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1030 then the kernel will not boot on CPUs that don't support PAE!
1032 The actual amount of total physical memory will either be
1033 auto detected or can be forced by using a kernel command line option
1034 such as "mem=256M". (Try "man bootparam" or see the documentation of
1035 your boot loader (lilo or loadlin) about how to pass options to the
1036 kernel at boot time.)
1038 If unsure, say "off".
1040 config HIGHMEM4G
1041 bool "4GB"
1042 depends on !X86_NUMAQ
1043 ---help---
1044 Select this if you have a 32-bit processor and between 1 and 4
1045 gigabytes of physical RAM.
1047 config HIGHMEM64G
1048 bool "64GB"
1049 depends on !M386 && !M486
1050 select X86_PAE
1051 ---help---
1052 Select this if you have a 32-bit processor and more than 4
1053 gigabytes of physical RAM.
1055 endchoice
1057 choice
1058 depends on EXPERIMENTAL
1059 prompt "Memory split" if EMBEDDED
1060 default VMSPLIT_3G
1061 depends on X86_32
1062 ---help---
1063 Select the desired split between kernel and user memory.
1065 If the address range available to the kernel is less than the
1066 physical memory installed, the remaining memory will be available
1067 as "high memory". Accessing high memory is a little more costly
1068 than low memory, as it needs to be mapped into the kernel first.
1069 Note that increasing the kernel address space limits the range
1070 available to user programs, making the address space there
1071 tighter. Selecting anything other than the default 3G/1G split
1072 will also likely make your kernel incompatible with binary-only
1073 kernel modules.
1075 If you are not absolutely sure what you are doing, leave this
1076 option alone!
1078 config VMSPLIT_3G
1079 bool "3G/1G user/kernel split"
1080 config VMSPLIT_3G_OPT
1081 depends on !X86_PAE
1082 bool "3G/1G user/kernel split (for full 1G low memory)"
1083 config VMSPLIT_2G
1084 bool "2G/2G user/kernel split"
1085 config VMSPLIT_2G_OPT
1086 depends on !X86_PAE
1087 bool "2G/2G user/kernel split (for full 2G low memory)"
1088 config VMSPLIT_1G
1089 bool "1G/3G user/kernel split"
1090 endchoice
1092 config PAGE_OFFSET
1093 hex
1094 default 0xB0000000 if VMSPLIT_3G_OPT
1095 default 0x80000000 if VMSPLIT_2G
1096 default 0x78000000 if VMSPLIT_2G_OPT
1097 default 0x40000000 if VMSPLIT_1G
1098 default 0xC0000000
1099 depends on X86_32
1101 config HIGHMEM
1102 def_bool y
1103 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1105 config X86_PAE
1106 bool "PAE (Physical Address Extension) Support"
1107 depends on X86_32 && !HIGHMEM4G
1108 ---help---
1109 PAE is required for NX support, and furthermore enables
1110 larger swapspace support for non-overcommit purposes. It
1111 has the cost of more pagetable lookup overhead, and also
1112 consumes more pagetable space per process.
1114 config ARCH_PHYS_ADDR_T_64BIT
1115 def_bool X86_64 || X86_PAE
1117 config DIRECT_GBPAGES
1118 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1119 default y
1120 depends on X86_64
1121 ---help---
1122 Allow the kernel linear mapping to use 1GB pages on CPUs that
1123 support it. This can improve the kernel's performance a tiny bit by
1124 reducing TLB pressure. If in doubt, say "Y".
1126 # Common NUMA Features
1127 config NUMA
1128 bool "Numa Memory Allocation and Scheduler Support"
1129 depends on SMP
1130 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1131 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1132 ---help---
1133 Enable NUMA (Non Uniform Memory Access) support.
1135 The kernel will try to allocate memory used by a CPU on the
1136 local memory controller of the CPU and add some more
1137 NUMA awareness to the kernel.
1139 For 64-bit this is recommended if the system is Intel Core i7
1140 (or later), AMD Opteron, or EM64T NUMA.
1142 For 32-bit this is only needed on (rare) 32-bit-only platforms
1143 that support NUMA topologies, such as NUMAQ / Summit, or if you
1144 boot a 32-bit kernel on a 64-bit NUMA platform.
1146 Otherwise, you should say N.
1148 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1149 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1151 config K8_NUMA
1152 def_bool y
1153 prompt "Old style AMD Opteron NUMA detection"
1154 depends on X86_64 && NUMA && PCI
1155 ---help---
1156 Enable K8 NUMA node topology detection. You should say Y here if
1157 you have a multi processor AMD K8 system. This uses an old
1158 method to read the NUMA configuration directly from the builtin
1159 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1160 instead, which also takes priority if both are compiled in.
1162 config X86_64_ACPI_NUMA
1163 def_bool y
1164 prompt "ACPI NUMA detection"
1165 depends on X86_64 && NUMA && ACPI && PCI
1166 select ACPI_NUMA
1167 ---help---
1168 Enable ACPI SRAT based node topology detection.
1170 # Some NUMA nodes have memory ranges that span
1171 # other nodes. Even though a pfn is valid and
1172 # between a node's start and end pfns, it may not
1173 # reside on that node. See memmap_init_zone()
1174 # for details.
1175 config NODES_SPAN_OTHER_NODES
1176 def_bool y
1177 depends on X86_64_ACPI_NUMA
1179 config NUMA_EMU
1180 bool "NUMA emulation"
1181 depends on X86_64 && NUMA
1182 ---help---
1183 Enable NUMA emulation. A flat machine will be split
1184 into virtual nodes when booted with "numa=fake=N", where N is the
1185 number of nodes. This is only useful for debugging.
1187 config NODES_SHIFT
1188 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1189 range 1 9
1190 default "9" if MAXSMP
1191 default "6" if X86_64
1192 default "4" if X86_NUMAQ
1193 default "3"
1194 depends on NEED_MULTIPLE_NODES
1195 ---help---
1196 Specify the maximum number of NUMA Nodes available on the target
1197 system. Increases memory reserved to accommodate various tables.
1199 config HAVE_ARCH_BOOTMEM
1200 def_bool y
1201 depends on X86_32 && NUMA
1203 config ARCH_HAVE_MEMORY_PRESENT
1204 def_bool y
1205 depends on X86_32 && DISCONTIGMEM
1207 config NEED_NODE_MEMMAP_SIZE
1208 def_bool y
1209 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1211 config HAVE_ARCH_ALLOC_REMAP
1212 def_bool y
1213 depends on X86_32 && NUMA
1215 config ARCH_FLATMEM_ENABLE
1216 def_bool y
1217 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1219 config ARCH_DISCONTIGMEM_ENABLE
1220 def_bool y
1221 depends on NUMA && X86_32
1223 config ARCH_DISCONTIGMEM_DEFAULT
1224 def_bool y
1225 depends on NUMA && X86_32
1227 config ARCH_PROC_KCORE_TEXT
1228 def_bool y
1229 depends on X86_64 && PROC_KCORE
1231 config ARCH_SPARSEMEM_DEFAULT
1232 def_bool y
1233 depends on X86_64
1235 config ARCH_SPARSEMEM_ENABLE
1236 def_bool y
1237 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1238 select SPARSEMEM_STATIC if X86_32
1239 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1241 config ARCH_SELECT_MEMORY_MODEL
1242 def_bool y
1243 depends on ARCH_SPARSEMEM_ENABLE
1245 config ARCH_MEMORY_PROBE
1246 def_bool X86_64
1247 depends on MEMORY_HOTPLUG
1249 source "mm/Kconfig"
1251 config HIGHPTE
1252 bool "Allocate 3rd-level pagetables from highmem"
1253 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1254 ---help---
1255 The VM uses one page table entry for each page of physical memory.
1256 For systems with a lot of RAM, this can be wasteful of precious
1257 low memory. Setting this option will put user-space page table
1258 entries in high memory.
1260 config X86_CHECK_BIOS_CORRUPTION
1261 bool "Check for low memory corruption"
1262 ---help---
1263 Periodically check for memory corruption in low memory, which
1264 is suspected to be caused by BIOS. Even when enabled in the
1265 configuration, it is disabled at runtime. Enable it by
1266 setting "memory_corruption_check=1" on the kernel command
1267 line. By default it scans the low 64k of memory every 60
1268 seconds; see the memory_corruption_check_size and
1269 memory_corruption_check_period parameters in
1270 Documentation/kernel-parameters.txt to adjust this.
1272 When enabled with the default parameters, this option has
1273 almost no overhead, as it reserves a relatively small amount
1274 of memory and scans it infrequently. It both detects corruption
1275 and prevents it from affecting the running system.
1277 It is, however, intended as a diagnostic tool; if repeatable
1278 BIOS-originated corruption always affects the same memory,
1279 you can use memmap= to prevent the kernel from using that
1280 memory.
1282 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1283 bool "Set the default setting of memory_corruption_check"
1284 depends on X86_CHECK_BIOS_CORRUPTION
1285 default y
1286 ---help---
1287 Set whether the default state of memory_corruption_check is
1288 on or off.
1290 config X86_RESERVE_LOW_64K
1291 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1292 default y
1293 ---help---
1294 Reserve the first 64K of physical RAM on BIOSes that are known
1295 to potentially corrupt that memory range. A numbers of BIOSes are
1296 known to utilize this area during suspend/resume, so it must not
1297 be used by the kernel.
1299 Set this to N if you are absolutely sure that you trust the BIOS
1300 to get all its memory reservations and usages right.
1302 If you have doubts about the BIOS (e.g. suspend/resume does not
1303 work or there's kernel crashes after certain hardware hotplug
1304 events) and it's not AMI or Phoenix, then you might want to enable
1305 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1306 corruption patterns.
1308 Say Y if unsure.
1310 config MATH_EMULATION
1311 bool
1312 prompt "Math emulation" if X86_32
1313 ---help---
1314 Linux can emulate a math coprocessor (used for floating point
1315 operations) if you don't have one. 486DX and Pentium processors have
1316 a math coprocessor built in, 486SX and 386 do not, unless you added
1317 a 487DX or 387, respectively. (The messages during boot time can
1318 give you some hints here ["man dmesg"].) Everyone needs either a
1319 coprocessor or this emulation.
1321 If you don't have a math coprocessor, you need to say Y here; if you
1322 say Y here even though you have a coprocessor, the coprocessor will
1323 be used nevertheless. (This behavior can be changed with the kernel
1324 command line option "no387", which comes handy if your coprocessor
1325 is broken. Try "man bootparam" or see the documentation of your boot
1326 loader (lilo or loadlin) about how to pass options to the kernel at
1327 boot time.) This means that it is a good idea to say Y here if you
1328 intend to use this kernel on different machines.
1330 More information about the internals of the Linux math coprocessor
1331 emulation can be found in <file:arch/x86/math-emu/README>.
1333 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1334 kernel, it won't hurt.
1336 config MTRR
1337 bool
1338 default y
1339 prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1340 ---help---
1341 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1342 the Memory Type Range Registers (MTRRs) may be used to control
1343 processor access to memory ranges. This is most useful if you have
1344 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1345 allows bus write transfers to be combined into a larger transfer
1346 before bursting over the PCI/AGP bus. This can increase performance
1347 of image write operations 2.5 times or more. Saying Y here creates a
1348 /proc/mtrr file which may be used to manipulate your processor's
1349 MTRRs. Typically the X server should use this.
1351 This code has a reasonably generic interface so that similar
1352 control registers on other processors can be easily supported
1353 as well:
1355 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1356 Registers (ARRs) which provide a similar functionality to MTRRs. For
1357 these, the ARRs are used to emulate the MTRRs.
1358 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1359 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1360 write-combining. All of these processors are supported by this code
1361 and it makes sense to say Y here if you have one of them.
1363 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1364 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1365 can lead to all sorts of problems, so it's good to say Y here.
1367 You can safely say Y even if your machine doesn't have MTRRs, you'll
1368 just add about 9 KB to your kernel.
1370 See <file:Documentation/x86/mtrr.txt> for more information.
1372 config MTRR_SANITIZER
1373 def_bool y
1374 prompt "MTRR cleanup support"
1375 depends on MTRR
1376 ---help---
1377 Convert MTRR layout from continuous to discrete, so X drivers can
1378 add writeback entries.
1380 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1381 The largest mtrr entry size for a continuous block can be set with
1382 mtrr_chunk_size.
1384 If unsure, say Y.
1386 config MTRR_SANITIZER_ENABLE_DEFAULT
1387 int "MTRR cleanup enable value (0-1)"
1388 range 0 1
1389 default "0"
1390 depends on MTRR_SANITIZER
1391 ---help---
1392 Enable mtrr cleanup default value
1394 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1395 int "MTRR cleanup spare reg num (0-7)"
1396 range 0 7
1397 default "1"
1398 depends on MTRR_SANITIZER
1399 ---help---
1400 mtrr cleanup spare entries default, it can be changed via
1401 mtrr_spare_reg_nr=N on the kernel command line.
1403 config X86_PAT
1404 bool
1405 default y
1406 prompt "x86 PAT support" if EMBEDDED
1407 depends on MTRR
1408 ---help---
1409 Use PAT attributes to setup page level cache control.
1411 PATs are the modern equivalents of MTRRs and are much more
1412 flexible than MTRRs.
1414 Say N here if you see bootup problems (boot crash, boot hang,
1415 spontaneous reboots) or a non-working video driver.
1417 If unsure, say Y.
1419 config ARCH_USES_PG_UNCACHED
1420 def_bool y
1421 depends on X86_PAT
1423 config EFI
1424 bool "EFI runtime service support"
1425 depends on ACPI
1426 ---help---
1427 This enables the kernel to use EFI runtime services that are
1428 available (such as the EFI variable services).
1430 This option is only useful on systems that have EFI firmware.
1431 In addition, you should use the latest ELILO loader available
1432 at <http://elilo.sourceforge.net> in order to take advantage
1433 of EFI runtime services. However, even with this option, the
1434 resultant kernel should continue to boot on existing non-EFI
1435 platforms.
1437 config SECCOMP
1438 def_bool y
1439 prompt "Enable seccomp to safely compute untrusted bytecode"
1440 ---help---
1441 This kernel feature is useful for number crunching applications
1442 that may need to compute untrusted bytecode during their
1443 execution. By using pipes or other transports made available to
1444 the process as file descriptors supporting the read/write
1445 syscalls, it's possible to isolate those applications in
1446 their own address space using seccomp. Once seccomp is
1447 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1448 and the task is only allowed to execute a few safe syscalls
1449 defined by each seccomp mode.
1451 If unsure, say Y. Only embedded should say N here.
1453 config CC_STACKPROTECTOR
1454 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1455 ---help---
1456 This option turns on the -fstack-protector GCC feature. This
1457 feature puts, at the beginning of functions, a canary value on
1458 the stack just before the return address, and validates
1459 the value just before actually returning. Stack based buffer
1460 overflows (that need to overwrite this return address) now also
1461 overwrite the canary, which gets detected and the attack is then
1462 neutralized via a kernel panic.
1464 This feature requires gcc version 4.2 or above, or a distribution
1465 gcc with the feature backported. Older versions are automatically
1466 detected and for those versions, this configuration option is
1467 ignored. (and a warning is printed during bootup)
1469 source kernel/Kconfig.hz
1471 config KEXEC
1472 bool "kexec system call"
1473 ---help---
1474 kexec is a system call that implements the ability to shutdown your
1475 current kernel, and to start another kernel. It is like a reboot
1476 but it is independent of the system firmware. And like a reboot
1477 you can start any kernel with it, not just Linux.
1479 The name comes from the similarity to the exec system call.
1481 It is an ongoing process to be certain the hardware in a machine
1482 is properly shutdown, so do not be surprised if this code does not
1483 initially work for you. It may help to enable device hotplugging
1484 support. As of this writing the exact hardware interface is
1485 strongly in flux, so no good recommendation can be made.
1487 config CRASH_DUMP
1488 bool "kernel crash dumps"
1489 depends on X86_64 || (X86_32 && HIGHMEM)
1490 ---help---
1491 Generate crash dump after being started by kexec.
1492 This should be normally only set in special crash dump kernels
1493 which are loaded in the main kernel with kexec-tools into
1494 a specially reserved region and then later executed after
1495 a crash by kdump/kexec. The crash dump kernel must be compiled
1496 to a memory address not used by the main kernel or BIOS using
1497 PHYSICAL_START, or it must be built as a relocatable image
1498 (CONFIG_RELOCATABLE=y).
1499 For more details see Documentation/kdump/kdump.txt
1501 config KEXEC_JUMP
1502 bool "kexec jump (EXPERIMENTAL)"
1503 depends on EXPERIMENTAL
1504 depends on KEXEC && HIBERNATION
1505 ---help---
1506 Jump between original kernel and kexeced kernel and invoke
1507 code in physical address mode via KEXEC
1509 config PHYSICAL_START
1510 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1511 default "0x1000000"
1512 ---help---
1513 This gives the physical address where the kernel is loaded.
1515 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1516 bzImage will decompress itself to above physical address and
1517 run from there. Otherwise, bzImage will run from the address where
1518 it has been loaded by the boot loader and will ignore above physical
1519 address.
1521 In normal kdump cases one does not have to set/change this option
1522 as now bzImage can be compiled as a completely relocatable image
1523 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1524 address. This option is mainly useful for the folks who don't want
1525 to use a bzImage for capturing the crash dump and want to use a
1526 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1527 to be specifically compiled to run from a specific memory area
1528 (normally a reserved region) and this option comes handy.
1530 So if you are using bzImage for capturing the crash dump,
1531 leave the value here unchanged to 0x1000000 and set
1532 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1533 for capturing the crash dump change this value to start of
1534 the reserved region. In other words, it can be set based on
1535 the "X" value as specified in the "crashkernel=YM@XM"
1536 command line boot parameter passed to the panic-ed
1537 kernel. Please take a look at Documentation/kdump/kdump.txt
1538 for more details about crash dumps.
1540 Usage of bzImage for capturing the crash dump is recommended as
1541 one does not have to build two kernels. Same kernel can be used
1542 as production kernel and capture kernel. Above option should have
1543 gone away after relocatable bzImage support is introduced. But it
1544 is present because there are users out there who continue to use
1545 vmlinux for dump capture. This option should go away down the
1546 line.
1548 Don't change this unless you know what you are doing.
1550 config RELOCATABLE
1551 bool "Build a relocatable kernel"
1552 default y
1553 ---help---
1554 This builds a kernel image that retains relocation information
1555 so it can be loaded someplace besides the default 1MB.
1556 The relocations tend to make the kernel binary about 10% larger,
1557 but are discarded at runtime.
1559 One use is for the kexec on panic case where the recovery kernel
1560 must live at a different physical address than the primary
1561 kernel.
1563 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1564 it has been loaded at and the compile time physical address
1565 (CONFIG_PHYSICAL_START) is ignored.
1567 # Relocation on x86-32 needs some additional build support
1568 config X86_NEED_RELOCS
1569 def_bool y
1570 depends on X86_32 && RELOCATABLE
1572 config PHYSICAL_ALIGN
1573 hex
1574 prompt "Alignment value to which kernel should be aligned" if X86_32
1575 default "0x1000000"
1576 range 0x2000 0x1000000
1577 ---help---
1578 This value puts the alignment restrictions on physical address
1579 where kernel is loaded and run from. Kernel is compiled for an
1580 address which meets above alignment restriction.
1582 If bootloader loads the kernel at a non-aligned address and
1583 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1584 address aligned to above value and run from there.
1586 If bootloader loads the kernel at a non-aligned address and
1587 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1588 load address and decompress itself to the address it has been
1589 compiled for and run from there. The address for which kernel is
1590 compiled already meets above alignment restrictions. Hence the
1591 end result is that kernel runs from a physical address meeting
1592 above alignment restrictions.
1594 Don't change this unless you know what you are doing.
1596 config HOTPLUG_CPU
1597 bool "Support for hot-pluggable CPUs"
1598 depends on SMP && HOTPLUG
1599 ---help---
1600 Say Y here to allow turning CPUs off and on. CPUs can be
1601 controlled through /sys/devices/system/cpu.
1602 ( Note: power management support will enable this option
1603 automatically on SMP systems. )
1604 Say N if you want to disable CPU hotplug.
1606 config COMPAT_VDSO
1607 def_bool y
1608 prompt "Compat VDSO support"
1609 depends on X86_32 || IA32_EMULATION
1610 ---help---
1611 Map the 32-bit VDSO to the predictable old-style address too.
1613 Say N here if you are running a sufficiently recent glibc
1614 version (2.3.3 or later), to remove the high-mapped
1615 VDSO mapping and to exclusively use the randomized VDSO.
1617 If unsure, say Y.
1619 config CMDLINE_BOOL
1620 bool "Built-in kernel command line"
1621 default n
1622 ---help---
1623 Allow for specifying boot arguments to the kernel at
1624 build time. On some systems (e.g. embedded ones), it is
1625 necessary or convenient to provide some or all of the
1626 kernel boot arguments with the kernel itself (that is,
1627 to not rely on the boot loader to provide them.)
1629 To compile command line arguments into the kernel,
1630 set this option to 'Y', then fill in the
1631 the boot arguments in CONFIG_CMDLINE.
1633 Systems with fully functional boot loaders (i.e. non-embedded)
1634 should leave this option set to 'N'.
1636 config CMDLINE
1637 string "Built-in kernel command string"
1638 depends on CMDLINE_BOOL
1639 default ""
1640 ---help---
1641 Enter arguments here that should be compiled into the kernel
1642 image and used at boot time. If the boot loader provides a
1643 command line at boot time, it is appended to this string to
1644 form the full kernel command line, when the system boots.
1646 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1647 change this behavior.
1649 In most cases, the command line (whether built-in or provided
1650 by the boot loader) should specify the device for the root
1651 file system.
1653 config CMDLINE_OVERRIDE
1654 bool "Built-in command line overrides boot loader arguments"
1655 default n
1656 depends on CMDLINE_BOOL
1657 ---help---
1658 Set this option to 'Y' to have the kernel ignore the boot loader
1659 command line, and use ONLY the built-in command line.
1661 This is used to work around broken boot loaders. This should
1662 be set to 'N' under normal conditions.
1664 endmenu
1666 config ARCH_ENABLE_MEMORY_HOTPLUG
1667 def_bool y
1668 depends on X86_64 || (X86_32 && HIGHMEM)
1670 config ARCH_ENABLE_MEMORY_HOTREMOVE
1671 def_bool y
1672 depends on MEMORY_HOTPLUG
1674 config HAVE_ARCH_EARLY_PFN_TO_NID
1675 def_bool X86_64
1676 depends on NUMA
1678 menu "Power management and ACPI options"
1680 config ARCH_HIBERNATION_HEADER
1681 def_bool y
1682 depends on X86_64 && HIBERNATION
1684 source "kernel/power/Kconfig"
1686 source "drivers/acpi/Kconfig"
1688 source "drivers/sfi/Kconfig"
1690 config X86_APM_BOOT
1691 bool
1692 default y
1693 depends on APM || APM_MODULE
1695 menuconfig APM
1696 tristate "APM (Advanced Power Management) BIOS support"
1697 depends on X86_32 && PM_SLEEP
1698 ---help---
1699 APM is a BIOS specification for saving power using several different
1700 techniques. This is mostly useful for battery powered laptops with
1701 APM compliant BIOSes. If you say Y here, the system time will be
1702 reset after a RESUME operation, the /proc/apm device will provide
1703 battery status information, and user-space programs will receive
1704 notification of APM "events" (e.g. battery status change).
1706 If you select "Y" here, you can disable actual use of the APM
1707 BIOS by passing the "apm=off" option to the kernel at boot time.
1709 Note that the APM support is almost completely disabled for
1710 machines with more than one CPU.
1712 In order to use APM, you will need supporting software. For location
1713 and more information, read <file:Documentation/power/pm.txt> and the
1714 Battery Powered Linux mini-HOWTO, available from
1715 <http://www.tldp.org/docs.html#howto>.
1717 This driver does not spin down disk drives (see the hdparm(8)
1718 manpage ("man 8 hdparm") for that), and it doesn't turn off
1719 VESA-compliant "green" monitors.
1721 This driver does not support the TI 4000M TravelMate and the ACER
1722 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1723 desktop machines also don't have compliant BIOSes, and this driver
1724 may cause those machines to panic during the boot phase.
1726 Generally, if you don't have a battery in your machine, there isn't
1727 much point in using this driver and you should say N. If you get
1728 random kernel OOPSes or reboots that don't seem to be related to
1729 anything, try disabling/enabling this option (or disabling/enabling
1730 APM in your BIOS).
1732 Some other things you should try when experiencing seemingly random,
1733 "weird" problems:
1735 1) make sure that you have enough swap space and that it is
1736 enabled.
1737 2) pass the "no-hlt" option to the kernel
1738 3) switch on floating point emulation in the kernel and pass
1739 the "no387" option to the kernel
1740 4) pass the "floppy=nodma" option to the kernel
1741 5) pass the "mem=4M" option to the kernel (thereby disabling
1742 all but the first 4 MB of RAM)
1743 6) make sure that the CPU is not over clocked.
1744 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1745 8) disable the cache from your BIOS settings
1746 9) install a fan for the video card or exchange video RAM
1747 10) install a better fan for the CPU
1748 11) exchange RAM chips
1749 12) exchange the motherboard.
1751 To compile this driver as a module, choose M here: the
1752 module will be called apm.
1754 if APM
1756 config APM_IGNORE_USER_SUSPEND
1757 bool "Ignore USER SUSPEND"
1758 ---help---
1759 This option will ignore USER SUSPEND requests. On machines with a
1760 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1761 series notebooks, it is necessary to say Y because of a BIOS bug.
1763 config APM_DO_ENABLE
1764 bool "Enable PM at boot time"
1765 ---help---
1766 Enable APM features at boot time. From page 36 of the APM BIOS
1767 specification: "When disabled, the APM BIOS does not automatically
1768 power manage devices, enter the Standby State, enter the Suspend
1769 State, or take power saving steps in response to CPU Idle calls."
1770 This driver will make CPU Idle calls when Linux is idle (unless this
1771 feature is turned off -- see "Do CPU IDLE calls", below). This
1772 should always save battery power, but more complicated APM features
1773 will be dependent on your BIOS implementation. You may need to turn
1774 this option off if your computer hangs at boot time when using APM
1775 support, or if it beeps continuously instead of suspending. Turn
1776 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1777 T400CDT. This is off by default since most machines do fine without
1778 this feature.
1780 config APM_CPU_IDLE
1781 bool "Make CPU Idle calls when idle"
1782 ---help---
1783 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1784 On some machines, this can activate improved power savings, such as
1785 a slowed CPU clock rate, when the machine is idle. These idle calls
1786 are made after the idle loop has run for some length of time (e.g.,
1787 333 mS). On some machines, this will cause a hang at boot time or
1788 whenever the CPU becomes idle. (On machines with more than one CPU,
1789 this option does nothing.)
1791 config APM_DISPLAY_BLANK
1792 bool "Enable console blanking using APM"
1793 ---help---
1794 Enable console blanking using the APM. Some laptops can use this to
1795 turn off the LCD backlight when the screen blanker of the Linux
1796 virtual console blanks the screen. Note that this is only used by
1797 the virtual console screen blanker, and won't turn off the backlight
1798 when using the X Window system. This also doesn't have anything to
1799 do with your VESA-compliant power-saving monitor. Further, this
1800 option doesn't work for all laptops -- it might not turn off your
1801 backlight at all, or it might print a lot of errors to the console,
1802 especially if you are using gpm.
1804 config APM_ALLOW_INTS
1805 bool "Allow interrupts during APM BIOS calls"
1806 ---help---
1807 Normally we disable external interrupts while we are making calls to
1808 the APM BIOS as a measure to lessen the effects of a badly behaving
1809 BIOS implementation. The BIOS should reenable interrupts if it
1810 needs to. Unfortunately, some BIOSes do not -- especially those in
1811 many of the newer IBM Thinkpads. If you experience hangs when you
1812 suspend, try setting this to Y. Otherwise, say N.
1814 endif # APM
1816 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1818 source "drivers/cpuidle/Kconfig"
1820 source "drivers/idle/Kconfig"
1822 endmenu
1825 menu "Bus options (PCI etc.)"
1827 config PCI
1828 bool "PCI support"
1829 default y
1830 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1831 ---help---
1832 Find out whether you have a PCI motherboard. PCI is the name of a
1833 bus system, i.e. the way the CPU talks to the other stuff inside
1834 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1835 VESA. If you have PCI, say Y, otherwise N.
1837 choice
1838 prompt "PCI access mode"
1839 depends on X86_32 && PCI
1840 default PCI_GOANY
1841 ---help---
1842 On PCI systems, the BIOS can be used to detect the PCI devices and
1843 determine their configuration. However, some old PCI motherboards
1844 have BIOS bugs and may crash if this is done. Also, some embedded
1845 PCI-based systems don't have any BIOS at all. Linux can also try to
1846 detect the PCI hardware directly without using the BIOS.
1848 With this option, you can specify how Linux should detect the
1849 PCI devices. If you choose "BIOS", the BIOS will be used,
1850 if you choose "Direct", the BIOS won't be used, and if you
1851 choose "MMConfig", then PCI Express MMCONFIG will be used.
1852 If you choose "Any", the kernel will try MMCONFIG, then the
1853 direct access method and falls back to the BIOS if that doesn't
1854 work. If unsure, go with the default, which is "Any".
1856 config PCI_GOBIOS
1857 bool "BIOS"
1859 config PCI_GOMMCONFIG
1860 bool "MMConfig"
1862 config PCI_GODIRECT
1863 bool "Direct"
1865 config PCI_GOOLPC
1866 bool "OLPC"
1867 depends on OLPC
1869 config PCI_GOANY
1870 bool "Any"
1872 endchoice
1874 config PCI_BIOS
1875 def_bool y
1876 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1878 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1879 config PCI_DIRECT
1880 def_bool y
1881 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1883 config PCI_MMCONFIG
1884 def_bool y
1885 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1887 config PCI_OLPC
1888 def_bool y
1889 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1891 config PCI_DOMAINS
1892 def_bool y
1893 depends on PCI
1895 config PCI_MMCONFIG
1896 bool "Support mmconfig PCI config space access"
1897 depends on X86_64 && PCI && ACPI
1899 config DMAR
1900 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1901 depends on PCI_MSI && ACPI && EXPERIMENTAL
1902 help
1903 DMA remapping (DMAR) devices support enables independent address
1904 translations for Direct Memory Access (DMA) from devices.
1905 These DMA remapping devices are reported via ACPI tables
1906 and include PCI device scope covered by these DMA
1907 remapping devices.
1909 config DMAR_DEFAULT_ON
1910 def_bool y
1911 prompt "Enable DMA Remapping Devices by default"
1912 depends on DMAR
1913 help
1914 Selecting this option will enable a DMAR device at boot time if
1915 one is found. If this option is not selected, DMAR support can
1916 be enabled by passing intel_iommu=on to the kernel. It is
1917 recommended you say N here while the DMAR code remains
1918 experimental.
1920 config DMAR_BROKEN_GFX_WA
1921 def_bool n
1922 prompt "Workaround broken graphics drivers (going away soon)"
1923 depends on DMAR && BROKEN
1924 ---help---
1925 Current Graphics drivers tend to use physical address
1926 for DMA and avoid using DMA APIs. Setting this config
1927 option permits the IOMMU driver to set a unity map for
1928 all the OS-visible memory. Hence the driver can continue
1929 to use physical addresses for DMA, at least until this
1930 option is removed in the 2.6.32 kernel.
1932 config DMAR_FLOPPY_WA
1933 def_bool y
1934 depends on DMAR
1935 ---help---
1936 Floppy disk drivers are known to bypass DMA API calls
1937 thereby failing to work when IOMMU is enabled. This
1938 workaround will setup a 1:1 mapping for the first
1939 16MiB to make floppy (an ISA device) work.
1941 config INTR_REMAP
1942 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1943 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1944 ---help---
1945 Supports Interrupt remapping for IO-APIC and MSI devices.
1946 To use x2apic mode in the CPU's which support x2APIC enhancements or
1947 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1949 source "drivers/pci/pcie/Kconfig"
1951 source "drivers/pci/Kconfig"
1953 # x86_64 have no ISA slots, but do have ISA-style DMA.
1954 config ISA_DMA_API
1955 def_bool y
1957 if X86_32
1959 config ISA
1960 bool "ISA support"
1961 ---help---
1962 Find out whether you have ISA slots on your motherboard. ISA is the
1963 name of a bus system, i.e. the way the CPU talks to the other stuff
1964 inside your box. Other bus systems are PCI, EISA, MicroChannel
1965 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1966 newer boards don't support it. If you have ISA, say Y, otherwise N.
1968 config EISA
1969 bool "EISA support"
1970 depends on ISA
1971 ---help---
1972 The Extended Industry Standard Architecture (EISA) bus was
1973 developed as an open alternative to the IBM MicroChannel bus.
1975 The EISA bus provided some of the features of the IBM MicroChannel
1976 bus while maintaining backward compatibility with cards made for
1977 the older ISA bus. The EISA bus saw limited use between 1988 and
1978 1995 when it was made obsolete by the PCI bus.
1980 Say Y here if you are building a kernel for an EISA-based machine.
1982 Otherwise, say N.
1984 source "drivers/eisa/Kconfig"
1986 config MCA
1987 bool "MCA support"
1988 ---help---
1989 MicroChannel Architecture is found in some IBM PS/2 machines and
1990 laptops. It is a bus system similar to PCI or ISA. See
1991 <file:Documentation/mca.txt> (and especially the web page given
1992 there) before attempting to build an MCA bus kernel.
1994 source "drivers/mca/Kconfig"
1996 config SCx200
1997 tristate "NatSemi SCx200 support"
1998 ---help---
1999 This provides basic support for National Semiconductor's
2000 (now AMD's) Geode processors. The driver probes for the
2001 PCI-IDs of several on-chip devices, so its a good dependency
2002 for other scx200_* drivers.
2004 If compiled as a module, the driver is named scx200.
2006 config SCx200HR_TIMER
2007 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2008 depends on SCx200 && GENERIC_TIME
2009 default y
2010 ---help---
2011 This driver provides a clocksource built upon the on-chip
2012 27MHz high-resolution timer. Its also a workaround for
2013 NSC Geode SC-1100's buggy TSC, which loses time when the
2014 processor goes idle (as is done by the scheduler). The
2015 other workaround is idle=poll boot option.
2017 config OLPC
2018 bool "One Laptop Per Child support"
2019 select GPIOLIB
2020 default n
2021 ---help---
2022 Add support for detecting the unique features of the OLPC
2023 XO hardware.
2025 endif # X86_32
2027 config K8_NB
2028 def_bool y
2029 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2031 source "drivers/pcmcia/Kconfig"
2033 source "drivers/pci/hotplug/Kconfig"
2035 endmenu
2038 menu "Executable file formats / Emulations"
2040 source "fs/Kconfig.binfmt"
2042 config IA32_EMULATION
2043 bool "IA32 Emulation"
2044 depends on X86_64
2045 select COMPAT_BINFMT_ELF
2046 ---help---
2047 Include code to run 32-bit programs under a 64-bit kernel. You should
2048 likely turn this on, unless you're 100% sure that you don't have any
2049 32-bit programs left.
2051 config IA32_AOUT
2052 tristate "IA32 a.out support"
2053 depends on IA32_EMULATION
2054 ---help---
2055 Support old a.out binaries in the 32bit emulation.
2057 config COMPAT
2058 def_bool y
2059 depends on IA32_EMULATION
2061 config COMPAT_FOR_U64_ALIGNMENT
2062 def_bool COMPAT
2063 depends on X86_64
2065 config SYSVIPC_COMPAT
2066 def_bool y
2067 depends on COMPAT && SYSVIPC
2069 endmenu
2072 config HAVE_ATOMIC_IOMAP
2073 def_bool y
2074 depends on X86_32
2076 source "net/Kconfig"
2078 source "drivers/Kconfig"
2080 source "drivers/firmware/Kconfig"
2082 source "fs/Kconfig"
2084 source "arch/x86/Kconfig.debug"
2086 source "security/Kconfig"
2088 source "crypto/Kconfig"
2090 source "arch/x86/kvm/Kconfig"
2092 source "lib/Kconfig"