| blob | 73ae02a44cc2e79f23a8fb9d34735c8f5345caee |
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
231 config ARCH_CPU_PROBE_RELEASE
232 def_bool y
233 depends on HOTPLUG_CPU
235 source "init/Kconfig"
236 source "kernel/Kconfig.freezer"
238 menu "Processor type and features"
240 source "kernel/time/Kconfig"
242 config SMP
243 bool "Symmetric multi-processing support"
244 ---help---
245 This enables support for systems with more than one CPU. If you have
246 a system with only one CPU, like most personal computers, say N. If
247 you have a system with more than one CPU, say Y.
249 If you say N here, the kernel will run on single and multiprocessor
250 machines, but will use only one CPU of a multiprocessor machine. If
251 you say Y here, the kernel will run on many, but not all,
252 singleprocessor machines. On a singleprocessor machine, the kernel
253 will run faster if you say N here.
255 Note that if you say Y here and choose architecture "586" or
256 "Pentium" under "Processor family", the kernel will not work on 486
257 architectures. Similarly, multiprocessor kernels for the "PPro"
258 architecture may not work on all Pentium based boards.
260 People using multiprocessor machines who say Y here should also say
261 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
262 Management" code will be disabled if you say Y here.
264 See also <file:Documentation/i386/IO-APIC.txt>,
265 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
266 <http://www.tldp.org/docs.html#howto>.
268 If you don't know what to do here, say N.
270 config X86_X2APIC
271 bool "Support x2apic"
272 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
273 ---help---
274 This enables x2apic support on CPUs that have this feature.
276 This allows 32-bit apic IDs (so it can support very large systems),
277 and accesses the local apic via MSRs not via mmio.
279 If you don't know what to do here, say N.
281 config SPARSE_IRQ
282 bool "Support sparse irq numbering"
283 depends on PCI_MSI || HT_IRQ
284 ---help---
285 This enables support for sparse irqs. This is useful for distro
286 kernels that want to define a high CONFIG_NR_CPUS value but still
287 want to have low kernel memory footprint on smaller machines.
289 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
290 out the irq_desc[] array in a more NUMA-friendly way. )
292 If you don't know what to do here, say N.
294 config NUMA_IRQ_DESC
295 def_bool y
296 depends on SPARSE_IRQ && NUMA
298 config X86_MPPARSE
299 bool "Enable MPS table" if ACPI
300 default y
301 depends on X86_LOCAL_APIC
302 ---help---
303 For old smp systems that do not have proper acpi support. Newer systems
304 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
306 config X86_BIGSMP
307 bool "Support for big SMP systems with more than 8 CPUs"
308 depends on X86_32 && SMP
309 ---help---
310 This option is needed for the systems that have more than 8 CPUs
312 if X86_32
313 config X86_EXTENDED_PLATFORM
314 bool "Support for extended (non-PC) x86 platforms"
315 default y
316 ---help---
317 If you disable this option then the kernel will only support
318 standard PC platforms. (which covers the vast majority of
319 systems out there.)
321 If you enable this option then you'll be able to select support
322 for the following (non-PC) 32 bit x86 platforms:
323 AMD Elan
324 NUMAQ (IBM/Sequent)
325 RDC R-321x SoC
326 SGI 320/540 (Visual Workstation)
327 Summit/EXA (IBM x440)
328 Unisys ES7000 IA32 series
329 Moorestown MID devices
331 If you have one of these systems, or if you want to build a
332 generic distribution kernel, say Y here - otherwise say N.
333 endif
335 if X86_64
336 config X86_EXTENDED_PLATFORM
337 bool "Support for extended (non-PC) x86 platforms"
338 default y
339 ---help---
340 If you disable this option then the kernel will only support
341 standard PC platforms. (which covers the vast majority of
342 systems out there.)
344 If you enable this option then you'll be able to select support
345 for the following (non-PC) 64 bit x86 platforms:
346 ScaleMP vSMP
347 SGI Ultraviolet
349 If you have one of these systems, or if you want to build a
350 generic distribution kernel, say Y here - otherwise say N.
351 endif
352 # This is an alphabetically sorted list of 64 bit extended platforms
353 # Please maintain the alphabetic order if and when there are additions
355 config X86_VSMP
356 bool "ScaleMP vSMP"
357 select PARAVIRT
358 depends on X86_64 && PCI
359 depends on X86_EXTENDED_PLATFORM
360 ---help---
361 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
362 supposed to run on these EM64T-based machines. Only choose this option
363 if you have one of these machines.
365 config X86_UV
366 bool "SGI Ultraviolet"
367 depends on X86_64
368 depends on X86_EXTENDED_PLATFORM
369 depends on NUMA
370 depends on X86_X2APIC
371 ---help---
372 This option is needed in order to support SGI Ultraviolet systems.
373 If you don't have one of these, you should say N here.
375 # Following is an alphabetically sorted list of 32 bit extended platforms
376 # Please maintain the alphabetic order if and when there are additions
378 config X86_ELAN
379 bool "AMD Elan"
380 depends on X86_32
381 depends on X86_EXTENDED_PLATFORM
382 ---help---
383 Select this for an AMD Elan processor.
385 Do not use this option for K6/Athlon/Opteron processors!
387 If unsure, choose "PC-compatible" instead.
389 config X86_MRST
390 bool "Moorestown MID platform"
391 depends on X86_32
392 depends on X86_EXTENDED_PLATFORM
393 ---help---
394 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
395 Internet Device(MID) platform. Moorestown consists of two chips:
396 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
397 Unlike standard x86 PCs, Moorestown does not have many legacy devices
398 nor standard legacy replacement devices/features. e.g. Moorestown does
399 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
401 config X86_RDC321X
402 bool "RDC R-321x SoC"
403 depends on X86_32
404 depends on X86_EXTENDED_PLATFORM
405 select M486
406 select X86_REBOOTFIXUPS
407 ---help---
408 This option is needed for RDC R-321x system-on-chip, also known
409 as R-8610-(G).
410 If you don't have one of these chips, you should say N here.
412 config X86_32_NON_STANDARD
413 bool "Support non-standard 32-bit SMP architectures"
414 depends on X86_32 && SMP
415 depends on X86_EXTENDED_PLATFORM
416 ---help---
417 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
418 subarchitectures. It is intended for a generic binary kernel.
419 if you select them all, kernel will probe it one by one. and will
420 fallback to default.
422 # Alphabetically sorted list of Non standard 32 bit platforms
424 config X86_NUMAQ
425 bool "NUMAQ (IBM/Sequent)"
426 depends on X86_32_NON_STANDARD
427 select NUMA
428 select X86_MPPARSE
429 ---help---
430 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
431 NUMA multiquad box. This changes the way that processors are
432 bootstrapped, and uses Clustered Logical APIC addressing mode instead
433 of Flat Logical. You will need a new lynxer.elf file to flash your
434 firmware with - send email to <Martin.Bligh@us.ibm.com>.
436 config X86_SUPPORTS_MEMORY_FAILURE
437 bool
438 # MCE code calls memory_failure():
439 depends on X86_MCE
440 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
441 depends on !X86_NUMAQ
442 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
443 depends on X86_64 || !SPARSEMEM
444 select ARCH_SUPPORTS_MEMORY_FAILURE
445 default y
447 config X86_VISWS
448 bool "SGI 320/540 (Visual Workstation)"
449 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
450 depends on X86_32_NON_STANDARD
451 ---help---
452 The SGI Visual Workstation series is an IA32-based workstation
453 based on SGI systems chips with some legacy PC hardware attached.
455 Say Y here to create a kernel to run on the SGI 320 or 540.
457 A kernel compiled for the Visual Workstation will run on general
458 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
460 config X86_SUMMIT
461 bool "Summit/EXA (IBM x440)"
462 depends on X86_32_NON_STANDARD
463 ---help---
464 This option is needed for IBM systems that use the Summit/EXA chipset.
465 In particular, it is needed for the x440.
467 config X86_ES7000
468 bool "Unisys ES7000 IA32 series"
469 depends on X86_32_NON_STANDARD && X86_BIGSMP
470 ---help---
471 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
472 supposed to run on an IA32-based Unisys ES7000 system.
474 config SCHED_OMIT_FRAME_POINTER
475 def_bool y
476 prompt "Single-depth WCHAN output"
477 depends on X86
478 ---help---
479 Calculate simpler /proc/<PID>/wchan values. If this option
480 is disabled then wchan values will recurse back to the
481 caller function. This provides more accurate wchan values,
482 at the expense of slightly more scheduling overhead.
484 If in doubt, say "Y".
486 menuconfig PARAVIRT_GUEST
487 bool "Paravirtualized guest support"
488 ---help---
489 Say Y here to get to see options related to running Linux under
490 various hypervisors. This option alone does not add any kernel code.
492 If you say N, all options in this submenu will be skipped and disabled.
494 if PARAVIRT_GUEST
496 source "arch/x86/xen/Kconfig"
498 config VMI
499 bool "VMI Guest support (DEPRECATED)"
500 select PARAVIRT
501 depends on X86_32
502 ---help---
503 VMI provides a paravirtualized interface to the VMware ESX server
504 (it could be used by other hypervisors in theory too, but is not
505 at the moment), by linking the kernel to a GPL-ed ROM module
506 provided by the hypervisor.
508 As of September 2009, VMware has started a phased retirement
509 of this feature from VMware's products. Please see
510 feature-removal-schedule.txt for details. If you are
511 planning to enable this option, please note that you cannot
512 live migrate a VMI enabled VM to a future VMware product,
513 which doesn't support VMI. So if you expect your kernel to
514 seamlessly migrate to newer VMware products, keep this
515 disabled.
517 config KVM_CLOCK
518 bool "KVM paravirtualized clock"
519 select PARAVIRT
520 select PARAVIRT_CLOCK
521 ---help---
522 Turning on this option will allow you to run a paravirtualized clock
523 when running over the KVM hypervisor. Instead of relying on a PIT
524 (or probably other) emulation by the underlying device model, the host
525 provides the guest with timing infrastructure such as time of day, and
526 system time
528 config KVM_GUEST
529 bool "KVM Guest support"
530 select PARAVIRT
531 ---help---
532 This option enables various optimizations for running under the KVM
533 hypervisor.
535 source "arch/x86/lguest/Kconfig"
537 config PARAVIRT
538 bool "Enable paravirtualization code"
539 ---help---
540 This changes the kernel so it can modify itself when it is run
541 under a hypervisor, potentially improving performance significantly
542 over full virtualization. However, when run without a hypervisor
543 the kernel is theoretically slower and slightly larger.
545 config PARAVIRT_SPINLOCKS
546 bool "Paravirtualization layer for spinlocks"
547 depends on PARAVIRT && SMP && EXPERIMENTAL
548 ---help---
549 Paravirtualized spinlocks allow a pvops backend to replace the
550 spinlock implementation with something virtualization-friendly
551 (for example, block the virtual CPU rather than spinning).
553 Unfortunately the downside is an up to 5% performance hit on
554 native kernels, with various workloads.
556 If you are unsure how to answer this question, answer N.
558 config PARAVIRT_CLOCK
559 bool
560 default n
562 endif
564 config PARAVIRT_DEBUG
565 bool "paravirt-ops debugging"
566 depends on PARAVIRT && DEBUG_KERNEL
567 ---help---
568 Enable to debug paravirt_ops internals. Specifically, BUG if
569 a paravirt_op is missing when it is called.
571 config MEMTEST
572 bool "Memtest"
573 ---help---
574 This option adds a kernel parameter 'memtest', which allows memtest
575 to be set.
576 memtest=0, mean disabled; -- default
577 memtest=1, mean do 1 test pattern;
578 ...
579 memtest=4, mean do 4 test patterns.
580 If you are unsure how to answer this question, answer N.
582 config X86_SUMMIT_NUMA
583 def_bool y
584 depends on X86_32 && NUMA && X86_32_NON_STANDARD
586 config X86_CYCLONE_TIMER
587 def_bool y
588 depends on X86_32_NON_STANDARD
590 source "arch/x86/Kconfig.cpu"
592 config HPET_TIMER
593 def_bool X86_64
594 prompt "HPET Timer Support" if X86_32
595 ---help---
596 Use the IA-PC HPET (High Precision Event Timer) to manage
597 time in preference to the PIT and RTC, if a HPET is
598 present.
599 HPET is the next generation timer replacing legacy 8254s.
600 The HPET provides a stable time base on SMP
601 systems, unlike the TSC, but it is more expensive to access,
602 as it is off-chip. You can find the HPET spec at
603 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
605 You can safely choose Y here. However, HPET will only be
606 activated if the platform and the BIOS support this feature.
607 Otherwise the 8254 will be used for timing services.
609 Choose N to continue using the legacy 8254 timer.
611 config HPET_EMULATE_RTC
612 def_bool y
613 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
615 # Mark as embedded because too many people got it wrong.
616 # The code disables itself when not needed.
617 config DMI
618 default y
619 bool "Enable DMI scanning" if EMBEDDED
620 ---help---
621 Enabled scanning of DMI to identify machine quirks. Say Y
622 here unless you have verified that your setup is not
623 affected by entries in the DMI blacklist. Required by PNP
624 BIOS code.
626 config GART_IOMMU
627 bool "GART IOMMU support" if EMBEDDED
628 default y
629 select SWIOTLB
630 depends on X86_64 && PCI && K8_NB
631 ---help---
632 Support for full DMA access of devices with 32bit memory access only
633 on systems with more than 3GB. This is usually needed for USB,
634 sound, many IDE/SATA chipsets and some other devices.
635 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
636 based hardware IOMMU and a software bounce buffer based IOMMU used
637 on Intel systems and as fallback.
638 The code is only active when needed (enough memory and limited
639 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
640 too.
642 config CALGARY_IOMMU
643 bool "IBM Calgary IOMMU support"
644 select SWIOTLB
645 depends on X86_64 && PCI && EXPERIMENTAL
646 ---help---
647 Support for hardware IOMMUs in IBM's xSeries x366 and x460
648 systems. Needed to run systems with more than 3GB of memory
649 properly with 32-bit PCI devices that do not support DAC
650 (Double Address Cycle). Calgary also supports bus level
651 isolation, where all DMAs pass through the IOMMU. This
652 prevents them from going anywhere except their intended
653 destination. This catches hard-to-find kernel bugs and
654 mis-behaving drivers and devices that do not use the DMA-API
655 properly to set up their DMA buffers. The IOMMU can be
656 turned off at boot time with the iommu=off parameter.
657 Normally the kernel will make the right choice by itself.
658 If unsure, say Y.
660 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
661 def_bool y
662 prompt "Should Calgary be enabled by default?"
663 depends on CALGARY_IOMMU
664 ---help---
665 Should Calgary be enabled by default? if you choose 'y', Calgary
666 will be used (if it exists). If you choose 'n', Calgary will not be
667 used even if it exists. If you choose 'n' and would like to use
668 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
669 If unsure, say Y.
671 config AMD_IOMMU
672 bool "AMD IOMMU support"
673 select SWIOTLB
674 select PCI_MSI
675 depends on X86_64 && PCI && ACPI
676 ---help---
677 With this option you can enable support for AMD IOMMU hardware in
678 your system. An IOMMU is a hardware component which provides
679 remapping of DMA memory accesses from devices. With an AMD IOMMU you
680 can isolate the the DMA memory of different devices and protect the
681 system from misbehaving device drivers or hardware.
683 You can find out if your system has an AMD IOMMU if you look into
684 your BIOS for an option to enable it or if you have an IVRS ACPI
685 table.
687 config AMD_IOMMU_STATS
688 bool "Export AMD IOMMU statistics to debugfs"
689 depends on AMD_IOMMU
690 select DEBUG_FS
691 ---help---
692 This option enables code in the AMD IOMMU driver to collect various
693 statistics about whats happening in the driver and exports that
694 information to userspace via debugfs.
695 If unsure, say N.
697 # need this always selected by IOMMU for the VIA workaround
698 config SWIOTLB
699 def_bool y if X86_64
700 ---help---
701 Support for software bounce buffers used on x86-64 systems
702 which don't have a hardware IOMMU (e.g. the current generation
703 of Intel's x86-64 CPUs). Using this PCI devices which can only
704 access 32-bits of memory can be used on systems with more than
705 3 GB of memory. If unsure, say Y.
707 config IOMMU_HELPER
708 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
710 config IOMMU_API
711 def_bool (AMD_IOMMU || DMAR)
713 config MAXSMP
714 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
715 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
716 select CPUMASK_OFFSTACK
717 default n
718 ---help---
719 Configure maximum number of CPUS and NUMA Nodes for this architecture.
720 If unsure, say N.
722 config NR_CPUS
723 int "Maximum number of CPUs" if SMP && !MAXSMP
724 range 2 8 if SMP && X86_32 && !X86_BIGSMP
725 range 2 512 if SMP && !MAXSMP
726 default "1" if !SMP
727 default "4096" if MAXSMP
728 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
729 default "8" if SMP
730 ---help---
731 This allows you to specify the maximum number of CPUs which this
732 kernel will support. The maximum supported value is 512 and the
733 minimum value which makes sense is 2.
735 This is purely to save memory - each supported CPU adds
736 approximately eight kilobytes to the kernel image.
738 config SCHED_SMT
739 bool "SMT (Hyperthreading) scheduler support"
740 depends on X86_HT
741 ---help---
742 SMT scheduler support improves the CPU scheduler's decision making
743 when dealing with Intel Pentium 4 chips with HyperThreading at a
744 cost of slightly increased overhead in some places. If unsure say
745 N here.
747 config SCHED_MC
748 def_bool y
749 prompt "Multi-core scheduler support"
750 depends on X86_HT
751 ---help---
752 Multi-core scheduler support improves the CPU scheduler's decision
753 making when dealing with multi-core CPU chips at a cost of slightly
754 increased overhead in some places. If unsure say N here.
756 config IRQ_TIME_ACCOUNTING
757 bool "Fine granularity task level IRQ time accounting"
758 default n
759 ---help---
760 Select this option to enable fine granularity task irq time
761 accounting. This is done by reading a timestamp on each
762 transitions between softirq and hardirq state, so there can be a
763 small performance impact.
765 If in doubt, say N here.
767 source "kernel/Kconfig.preempt"
769 config X86_UP_APIC
770 bool "Local APIC support on uniprocessors"
771 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
772 ---help---
773 A local APIC (Advanced Programmable Interrupt Controller) is an
774 integrated interrupt controller in the CPU. If you have a single-CPU
775 system which has a processor with a local APIC, you can say Y here to
776 enable and use it. If you say Y here even though your machine doesn't
777 have a local APIC, then the kernel will still run with no slowdown at
778 all. The local APIC supports CPU-generated self-interrupts (timer,
779 performance counters), and the NMI watchdog which detects hard
780 lockups.
782 config X86_UP_IOAPIC
783 bool "IO-APIC support on uniprocessors"
784 depends on X86_UP_APIC
785 ---help---
786 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
787 SMP-capable replacement for PC-style interrupt controllers. Most
788 SMP systems and many recent uniprocessor systems have one.
790 If you have a single-CPU system with an IO-APIC, you can say Y here
791 to use it. If you say Y here even though your machine doesn't have
792 an IO-APIC, then the kernel will still run with no slowdown at all.
794 config X86_LOCAL_APIC
795 def_bool y
796 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
798 config X86_IO_APIC
799 def_bool y
800 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
802 config X86_VISWS_APIC
803 def_bool y
804 depends on X86_32 && X86_VISWS
806 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
807 bool "Reroute for broken boot IRQs"
808 default n
809 depends on X86_IO_APIC
810 ---help---
811 This option enables a workaround that fixes a source of
812 spurious interrupts. This is recommended when threaded
813 interrupt handling is used on systems where the generation of
814 superfluous "boot interrupts" cannot be disabled.
816 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
817 entry in the chipset's IO-APIC is masked (as, e.g. the RT
818 kernel does during interrupt handling). On chipsets where this
819 boot IRQ generation cannot be disabled, this workaround keeps
820 the original IRQ line masked so that only the equivalent "boot
821 IRQ" is delivered to the CPUs. The workaround also tells the
822 kernel to set up the IRQ handler on the boot IRQ line. In this
823 way only one interrupt is delivered to the kernel. Otherwise
824 the spurious second interrupt may cause the kernel to bring
825 down (vital) interrupt lines.
827 Only affects "broken" chipsets. Interrupt sharing may be
828 increased on these systems.
830 config X86_MCE
831 bool "Machine Check / overheating reporting"
832 ---help---
833 Machine Check support allows the processor to notify the
834 kernel if it detects a problem (e.g. overheating, data corruption).
835 The action the kernel takes depends on the severity of the problem,
836 ranging from warning messages to halting the machine.
838 config X86_MCE_INTEL
839 def_bool y
840 prompt "Intel MCE features"
841 depends on X86_MCE && X86_LOCAL_APIC
842 ---help---
843 Additional support for intel specific MCE features such as
844 the thermal monitor.
846 config X86_MCE_AMD
847 def_bool y
848 prompt "AMD MCE features"
849 depends on X86_MCE && X86_LOCAL_APIC
850 ---help---
851 Additional support for AMD specific MCE features such as
852 the DRAM Error Threshold.
854 config X86_ANCIENT_MCE
855 def_bool n
856 depends on X86_32 && X86_MCE
857 prompt "Support for old Pentium 5 / WinChip machine checks"
858 ---help---
859 Include support for machine check handling on old Pentium 5 or WinChip
860 systems. These typically need to be enabled explicitely on the command
861 line.
863 config X86_MCE_THRESHOLD
864 depends on X86_MCE_AMD || X86_MCE_INTEL
865 bool
866 default y
868 config X86_MCE_INJECT
869 depends on X86_MCE
870 tristate "Machine check injector support"
871 ---help---
872 Provide support for injecting machine checks for testing purposes.
873 If you don't know what a machine check is and you don't do kernel
874 QA it is safe to say n.
876 config X86_THERMAL_VECTOR
877 def_bool y
878 depends on X86_MCE_INTEL
880 config VM86
881 bool "Enable VM86 support" if EMBEDDED
882 default y
883 depends on X86_32
884 ---help---
885 This option is required by programs like DOSEMU to run 16-bit legacy
886 code on X86 processors. It also may be needed by software like
887 XFree86 to initialize some video cards via BIOS. Disabling this
888 option saves about 6k.
890 config TOSHIBA
891 tristate "Toshiba Laptop support"
892 depends on X86_32
893 ---help---
894 This adds a driver to safely access the System Management Mode of
895 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
896 not work on models with a Phoenix BIOS. The System Management Mode
897 is used to set the BIOS and power saving options on Toshiba portables.
899 For information on utilities to make use of this driver see the
900 Toshiba Linux utilities web site at:
901 <http://www.buzzard.org.uk/toshiba/>.
903 Say Y if you intend to run this kernel on a Toshiba portable.
904 Say N otherwise.
906 config I8K
907 tristate "Dell laptop support"
908 ---help---
909 This adds a driver to safely access the System Management Mode
910 of the CPU on the Dell Inspiron 8000. The System Management Mode
911 is used to read cpu temperature and cooling fan status and to
912 control the fans on the I8K portables.
914 This driver has been tested only on the Inspiron 8000 but it may
915 also work with other Dell laptops. You can force loading on other
916 models by passing the parameter `force=1' to the module. Use at
917 your own risk.
919 For information on utilities to make use of this driver see the
920 I8K Linux utilities web site at:
921 <http://people.debian.org/~dz/i8k/>
923 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
924 Say N otherwise.
926 config X86_REBOOTFIXUPS
927 bool "Enable X86 board specific fixups for reboot"
928 depends on X86_32
929 ---help---
930 This enables chipset and/or board specific fixups to be done
931 in order to get reboot to work correctly. This is only needed on
932 some combinations of hardware and BIOS. The symptom, for which
933 this config is intended, is when reboot ends with a stalled/hung
934 system.
936 Currently, the only fixup is for the Geode machines using
937 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
939 Say Y if you want to enable the fixup. Currently, it's safe to
940 enable this option even if you don't need it.
941 Say N otherwise.
943 config MICROCODE
944 tristate "/dev/cpu/microcode - microcode support"
945 select FW_LOADER
946 ---help---
947 If you say Y here, you will be able to update the microcode on
948 certain Intel and AMD processors. The Intel support is for the
949 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
950 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
951 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
952 You will obviously need the actual microcode binary data itself
953 which is not shipped with the Linux kernel.
955 This option selects the general module only, you need to select
956 at least one vendor specific module as well.
958 To compile this driver as a module, choose M here: the
959 module will be called microcode.
961 config MICROCODE_INTEL
962 bool "Intel microcode patch loading support"
963 depends on MICROCODE
964 default MICROCODE
965 select FW_LOADER
966 ---help---
967 This options enables microcode patch loading support for Intel
968 processors.
970 For latest news and information on obtaining all the required
971 Intel ingredients for this driver, check:
972 <http://www.urbanmyth.org/microcode/>.
974 config MICROCODE_AMD
975 bool "AMD microcode patch loading support"
976 depends on MICROCODE
977 select FW_LOADER
978 ---help---
979 If you select this option, microcode patch loading support for AMD
980 processors will be enabled.
982 config MICROCODE_OLD_INTERFACE
983 def_bool y
984 depends on MICROCODE
986 config X86_MSR
987 tristate "/dev/cpu/*/msr - Model-specific register support"
988 ---help---
989 This device gives privileged processes access to the x86
990 Model-Specific Registers (MSRs). It is a character device with
991 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
992 MSR accesses are directed to a specific CPU on multi-processor
993 systems.
995 config X86_CPUID
996 tristate "/dev/cpu/*/cpuid - CPU information support"
997 ---help---
998 This device gives processes access to the x86 CPUID instruction to
999 be executed on a specific processor. It is a character device
1000 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1001 /dev/cpu/31/cpuid.
1003 choice
1004 prompt "High Memory Support"
1005 default HIGHMEM4G if !X86_NUMAQ
1006 default HIGHMEM64G if X86_NUMAQ
1007 depends on X86_32
1009 config NOHIGHMEM
1010 bool "off"
1011 depends on !X86_NUMAQ
1012 ---help---
1013 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1014 However, the address space of 32-bit x86 processors is only 4
1015 Gigabytes large. That means that, if you have a large amount of
1016 physical memory, not all of it can be "permanently mapped" by the
1017 kernel. The physical memory that's not permanently mapped is called
1018 "high memory".
1020 If you are compiling a kernel which will never run on a machine with
1021 more than 1 Gigabyte total physical RAM, answer "off" here (default
1022 choice and suitable for most users). This will result in a "3GB/1GB"
1023 split: 3GB are mapped so that each process sees a 3GB virtual memory
1024 space and the remaining part of the 4GB virtual memory space is used
1025 by the kernel to permanently map as much physical memory as
1026 possible.
1028 If the machine has between 1 and 4 Gigabytes physical RAM, then
1029 answer "4GB" here.
1031 If more than 4 Gigabytes is used then answer "64GB" here. This
1032 selection turns Intel PAE (Physical Address Extension) mode on.
1033 PAE implements 3-level paging on IA32 processors. PAE is fully
1034 supported by Linux, PAE mode is implemented on all recent Intel
1035 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1036 then the kernel will not boot on CPUs that don't support PAE!
1038 The actual amount of total physical memory will either be
1039 auto detected or can be forced by using a kernel command line option
1040 such as "mem=256M". (Try "man bootparam" or see the documentation of
1041 your boot loader (lilo or loadlin) about how to pass options to the
1042 kernel at boot time.)
1044 If unsure, say "off".
1046 config HIGHMEM4G
1047 bool "4GB"
1048 depends on !X86_NUMAQ
1049 ---help---
1050 Select this if you have a 32-bit processor and between 1 and 4
1051 gigabytes of physical RAM.
1053 config HIGHMEM64G
1054 bool "64GB"
1055 depends on !M386 && !M486
1056 select X86_PAE
1057 ---help---
1058 Select this if you have a 32-bit processor and more than 4
1059 gigabytes of physical RAM.
1061 endchoice
1063 choice
1064 depends on EXPERIMENTAL
1065 prompt "Memory split" if EMBEDDED
1066 default VMSPLIT_3G
1067 depends on X86_32
1068 ---help---
1069 Select the desired split between kernel and user memory.
1071 If the address range available to the kernel is less than the
1072 physical memory installed, the remaining memory will be available
1073 as "high memory". Accessing high memory is a little more costly
1074 than low memory, as it needs to be mapped into the kernel first.
1075 Note that increasing the kernel address space limits the range
1076 available to user programs, making the address space there
1077 tighter. Selecting anything other than the default 3G/1G split
1078 will also likely make your kernel incompatible with binary-only
1079 kernel modules.
1081 If you are not absolutely sure what you are doing, leave this
1082 option alone!
1084 config VMSPLIT_3G
1085 bool "3G/1G user/kernel split"
1086 config VMSPLIT_3G_OPT
1087 depends on !X86_PAE
1088 bool "3G/1G user/kernel split (for full 1G low memory)"
1089 config VMSPLIT_2G
1090 bool "2G/2G user/kernel split"
1091 config VMSPLIT_2G_OPT
1092 depends on !X86_PAE
1093 bool "2G/2G user/kernel split (for full 2G low memory)"
1094 config VMSPLIT_1G
1095 bool "1G/3G user/kernel split"
1096 endchoice
1098 config PAGE_OFFSET
1099 hex
1100 default 0xB0000000 if VMSPLIT_3G_OPT
1101 default 0x80000000 if VMSPLIT_2G
1102 default 0x78000000 if VMSPLIT_2G_OPT
1103 default 0x40000000 if VMSPLIT_1G
1104 default 0xC0000000
1105 depends on X86_32
1107 config HIGHMEM
1108 def_bool y
1109 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1111 config X86_PAE
1112 bool "PAE (Physical Address Extension) Support"
1113 depends on X86_32 && !HIGHMEM4G
1114 ---help---
1115 PAE is required for NX support, and furthermore enables
1116 larger swapspace support for non-overcommit purposes. It
1117 has the cost of more pagetable lookup overhead, and also
1118 consumes more pagetable space per process.
1120 config ARCH_PHYS_ADDR_T_64BIT
1121 def_bool X86_64 || X86_PAE
1123 config DIRECT_GBPAGES
1124 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1125 default y
1126 depends on X86_64
1127 ---help---
1128 Allow the kernel linear mapping to use 1GB pages on CPUs that
1129 support it. This can improve the kernel's performance a tiny bit by
1130 reducing TLB pressure. If in doubt, say "Y".
1132 # Common NUMA Features
1133 config NUMA
1134 bool "Numa Memory Allocation and Scheduler Support"
1135 depends on SMP
1136 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1137 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1138 ---help---
1139 Enable NUMA (Non Uniform Memory Access) support.
1141 The kernel will try to allocate memory used by a CPU on the
1142 local memory controller of the CPU and add some more
1143 NUMA awareness to the kernel.
1145 For 64-bit this is recommended if the system is Intel Core i7
1146 (or later), AMD Opteron, or EM64T NUMA.
1148 For 32-bit this is only needed on (rare) 32-bit-only platforms
1149 that support NUMA topologies, such as NUMAQ / Summit, or if you
1150 boot a 32-bit kernel on a 64-bit NUMA platform.
1152 Otherwise, you should say N.
1154 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1155 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1157 config K8_NUMA
1158 def_bool y
1159 prompt "Old style AMD Opteron NUMA detection"
1160 depends on X86_64 && NUMA && PCI
1161 ---help---
1162 Enable K8 NUMA node topology detection. You should say Y here if
1163 you have a multi processor AMD K8 system. This uses an old
1164 method to read the NUMA configuration directly from the builtin
1165 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1166 instead, which also takes priority if both are compiled in.
1168 config X86_64_ACPI_NUMA
1169 def_bool y
1170 prompt "ACPI NUMA detection"
1171 depends on X86_64 && NUMA && ACPI && PCI
1172 select ACPI_NUMA
1173 ---help---
1174 Enable ACPI SRAT based node topology detection.
1176 # Some NUMA nodes have memory ranges that span
1177 # other nodes. Even though a pfn is valid and
1178 # between a node's start and end pfns, it may not
1179 # reside on that node. See memmap_init_zone()
1180 # for details.
1181 config NODES_SPAN_OTHER_NODES
1182 def_bool y
1183 depends on X86_64_ACPI_NUMA
1185 config NUMA_EMU
1186 bool "NUMA emulation"
1187 depends on X86_64 && NUMA
1188 ---help---
1189 Enable NUMA emulation. A flat machine will be split
1190 into virtual nodes when booted with "numa=fake=N", where N is the
1191 number of nodes. This is only useful for debugging.
1193 config NODES_SHIFT
1194 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1195 range 1 9
1196 default "9" if MAXSMP
1197 default "6" if X86_64
1198 default "4" if X86_NUMAQ
1199 default "3"
1200 depends on NEED_MULTIPLE_NODES
1201 ---help---
1202 Specify the maximum number of NUMA Nodes available on the target
1203 system. Increases memory reserved to accommodate various tables.
1205 config HAVE_ARCH_BOOTMEM
1206 def_bool y
1207 depends on X86_32 && NUMA
1209 config ARCH_HAVE_MEMORY_PRESENT
1210 def_bool y
1211 depends on X86_32 && DISCONTIGMEM
1213 config NEED_NODE_MEMMAP_SIZE
1214 def_bool y
1215 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1217 config HAVE_ARCH_ALLOC_REMAP
1218 def_bool y
1219 depends on X86_32 && NUMA
1221 config ARCH_FLATMEM_ENABLE
1222 def_bool y
1223 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1225 config ARCH_DISCONTIGMEM_ENABLE
1226 def_bool y
1227 depends on NUMA && X86_32
1229 config ARCH_DISCONTIGMEM_DEFAULT
1230 def_bool y
1231 depends on NUMA && X86_32
1233 config ARCH_PROC_KCORE_TEXT
1234 def_bool y
1235 depends on X86_64 && PROC_KCORE
1237 config ARCH_SPARSEMEM_DEFAULT
1238 def_bool y
1239 depends on X86_64
1241 config ARCH_SPARSEMEM_ENABLE
1242 def_bool y
1243 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1244 select SPARSEMEM_STATIC if X86_32
1245 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1247 config ARCH_SELECT_MEMORY_MODEL
1248 def_bool y
1249 depends on ARCH_SPARSEMEM_ENABLE
1251 config ARCH_MEMORY_PROBE
1252 def_bool X86_64
1253 depends on MEMORY_HOTPLUG
1255 config ILLEGAL_POINTER_VALUE
1256 hex
1257 default 0 if X86_32
1258 default 0xdead000000000000 if X86_64
1260 source "mm/Kconfig"
1262 config HIGHPTE
1263 bool "Allocate 3rd-level pagetables from highmem"
1264 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1265 ---help---
1266 The VM uses one page table entry for each page of physical memory.
1267 For systems with a lot of RAM, this can be wasteful of precious
1268 low memory. Setting this option will put user-space page table
1269 entries in high memory.
1271 config X86_CHECK_BIOS_CORRUPTION
1272 bool "Check for low memory corruption"
1273 ---help---
1274 Periodically check for memory corruption in low memory, which
1275 is suspected to be caused by BIOS. Even when enabled in the
1276 configuration, it is disabled at runtime. Enable it by
1277 setting "memory_corruption_check=1" on the kernel command
1278 line. By default it scans the low 64k of memory every 60
1279 seconds; see the memory_corruption_check_size and
1280 memory_corruption_check_period parameters in
1281 Documentation/kernel-parameters.txt to adjust this.
1283 When enabled with the default parameters, this option has
1284 almost no overhead, as it reserves a relatively small amount
1285 of memory and scans it infrequently. It both detects corruption
1286 and prevents it from affecting the running system.
1288 It is, however, intended as a diagnostic tool; if repeatable
1289 BIOS-originated corruption always affects the same memory,
1290 you can use memmap= to prevent the kernel from using that
1291 memory.
1293 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1294 bool "Set the default setting of memory_corruption_check"
1295 depends on X86_CHECK_BIOS_CORRUPTION
1296 default y
1297 ---help---
1298 Set whether the default state of memory_corruption_check is
1299 on or off.
1301 config X86_RESERVE_LOW_64K
1302 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1303 default y
1304 ---help---
1305 Reserve the first 64K of physical RAM on BIOSes that are known
1306 to potentially corrupt that memory range. A numbers of BIOSes are
1307 known to utilize this area during suspend/resume, so it must not
1308 be used by the kernel.
1310 Set this to N if you are absolutely sure that you trust the BIOS
1311 to get all its memory reservations and usages right.
1313 If you have doubts about the BIOS (e.g. suspend/resume does not
1314 work or there's kernel crashes after certain hardware hotplug
1315 events) and it's not AMI or Phoenix, then you might want to enable
1316 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1317 corruption patterns.
1319 Say Y if unsure.
1321 config MATH_EMULATION
1322 bool
1323 prompt "Math emulation" if X86_32
1324 ---help---
1325 Linux can emulate a math coprocessor (used for floating point
1326 operations) if you don't have one. 486DX and Pentium processors have
1327 a math coprocessor built in, 486SX and 386 do not, unless you added
1328 a 487DX or 387, respectively. (The messages during boot time can
1329 give you some hints here ["man dmesg"].) Everyone needs either a
1330 coprocessor or this emulation.
1332 If you don't have a math coprocessor, you need to say Y here; if you
1333 say Y here even though you have a coprocessor, the coprocessor will
1334 be used nevertheless. (This behavior can be changed with the kernel
1335 command line option "no387", which comes handy if your coprocessor
1336 is broken. Try "man bootparam" or see the documentation of your boot
1337 loader (lilo or loadlin) about how to pass options to the kernel at
1338 boot time.) This means that it is a good idea to say Y here if you
1339 intend to use this kernel on different machines.
1341 More information about the internals of the Linux math coprocessor
1342 emulation can be found in <file:arch/x86/math-emu/README>.
1344 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1345 kernel, it won't hurt.
1347 config MTRR
1348 bool "MTRR (Memory Type Range Register) support"
1349 ---help---
1350 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1351 the Memory Type Range Registers (MTRRs) may be used to control
1352 processor access to memory ranges. This is most useful if you have
1353 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1354 allows bus write transfers to be combined into a larger transfer
1355 before bursting over the PCI/AGP bus. This can increase performance
1356 of image write operations 2.5 times or more. Saying Y here creates a
1357 /proc/mtrr file which may be used to manipulate your processor's
1358 MTRRs. Typically the X server should use this.
1360 This code has a reasonably generic interface so that similar
1361 control registers on other processors can be easily supported
1362 as well:
1364 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1365 Registers (ARRs) which provide a similar functionality to MTRRs. For
1366 these, the ARRs are used to emulate the MTRRs.
1367 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1368 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1369 write-combining. All of these processors are supported by this code
1370 and it makes sense to say Y here if you have one of them.
1372 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1373 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1374 can lead to all sorts of problems, so it's good to say Y here.
1376 You can safely say Y even if your machine doesn't have MTRRs, you'll
1377 just add about 9 KB to your kernel.
1379 See <file:Documentation/x86/mtrr.txt> for more information.
1381 config MTRR_SANITIZER
1382 def_bool y
1383 prompt "MTRR cleanup support"
1384 depends on MTRR
1385 ---help---
1386 Convert MTRR layout from continuous to discrete, so X drivers can
1387 add writeback entries.
1389 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1390 The largest mtrr entry size for a continuous block can be set with
1391 mtrr_chunk_size.
1393 If unsure, say Y.
1395 config MTRR_SANITIZER_ENABLE_DEFAULT
1396 int "MTRR cleanup enable value (0-1)"
1397 range 0 1
1398 default "0"
1399 depends on MTRR_SANITIZER
1400 ---help---
1401 Enable mtrr cleanup default value
1403 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1404 int "MTRR cleanup spare reg num (0-7)"
1405 range 0 7
1406 default "1"
1407 depends on MTRR_SANITIZER
1408 ---help---
1409 mtrr cleanup spare entries default, it can be changed via
1410 mtrr_spare_reg_nr=N on the kernel command line.
1412 config X86_PAT
1413 bool
1414 prompt "x86 PAT support"
1415 depends on MTRR
1416 ---help---
1417 Use PAT attributes to setup page level cache control.
1419 PATs are the modern equivalents of MTRRs and are much more
1420 flexible than MTRRs.
1422 Say N here if you see bootup problems (boot crash, boot hang,
1423 spontaneous reboots) or a non-working video driver.
1425 If unsure, say Y.
1427 config ARCH_USES_PG_UNCACHED
1428 def_bool y
1429 depends on X86_PAT
1431 config EFI
1432 bool "EFI runtime service support"
1433 depends on ACPI
1434 ---help---
1435 This enables the kernel to use EFI runtime services that are
1436 available (such as the EFI variable services).
1438 This option is only useful on systems that have EFI firmware.
1439 In addition, you should use the latest ELILO loader available
1440 at <http://elilo.sourceforge.net> in order to take advantage
1441 of EFI runtime services. However, even with this option, the
1442 resultant kernel should continue to boot on existing non-EFI
1443 platforms.
1445 config SECCOMP
1446 def_bool y
1447 prompt "Enable seccomp to safely compute untrusted bytecode"
1448 ---help---
1449 This kernel feature is useful for number crunching applications
1450 that may need to compute untrusted bytecode during their
1451 execution. By using pipes or other transports made available to
1452 the process as file descriptors supporting the read/write
1453 syscalls, it's possible to isolate those applications in
1454 their own address space using seccomp. Once seccomp is
1455 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1456 and the task is only allowed to execute a few safe syscalls
1457 defined by each seccomp mode.
1459 If unsure, say Y. Only embedded should say N here.
1461 config CC_STACKPROTECTOR
1462 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1463 ---help---
1464 This option turns on the -fstack-protector GCC feature. This
1465 feature puts, at the beginning of functions, a canary value on
1466 the stack just before the return address, and validates
1467 the value just before actually returning. Stack based buffer
1468 overflows (that need to overwrite this return address) now also
1469 overwrite the canary, which gets detected and the attack is then
1470 neutralized via a kernel panic.
1472 This feature requires gcc version 4.2 or above, or a distribution
1473 gcc with the feature backported. Older versions are automatically
1474 detected and for those versions, this configuration option is
1475 ignored. (and a warning is printed during bootup)
1477 source kernel/Kconfig.hz
1479 config KEXEC
1480 bool "kexec system call"
1481 ---help---
1482 kexec is a system call that implements the ability to shutdown your
1483 current kernel, and to start another kernel. It is like a reboot
1484 but it is independent of the system firmware. And like a reboot
1485 you can start any kernel with it, not just Linux.
1487 The name comes from the similarity to the exec system call.
1489 It is an ongoing process to be certain the hardware in a machine
1490 is properly shutdown, so do not be surprised if this code does not
1491 initially work for you. It may help to enable device hotplugging
1492 support. As of this writing the exact hardware interface is
1493 strongly in flux, so no good recommendation can be made.
1495 config CRASH_DUMP
1496 bool "kernel crash dumps"
1497 depends on X86_64 || (X86_32 && HIGHMEM)
1498 ---help---
1499 Generate crash dump after being started by kexec.
1500 This should be normally only set in special crash dump kernels
1501 which are loaded in the main kernel with kexec-tools into
1502 a specially reserved region and then later executed after
1503 a crash by kdump/kexec. The crash dump kernel must be compiled
1504 to a memory address not used by the main kernel or BIOS using
1505 PHYSICAL_START, or it must be built as a relocatable image
1506 (CONFIG_RELOCATABLE=y).
1507 For more details see Documentation/kdump/kdump.txt
1509 config KEXEC_JUMP
1510 bool "kexec jump (EXPERIMENTAL)"
1511 depends on EXPERIMENTAL
1512 depends on KEXEC && HIBERNATION
1513 ---help---
1514 Jump between original kernel and kexeced kernel and invoke
1515 code in physical address mode via KEXEC
1517 config PHYSICAL_START
1518 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1519 default "0x1000000"
1520 ---help---
1521 This gives the physical address where the kernel is loaded.
1523 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1524 bzImage will decompress itself to above physical address and
1525 run from there. Otherwise, bzImage will run from the address where
1526 it has been loaded by the boot loader and will ignore above physical
1527 address.
1529 In normal kdump cases one does not have to set/change this option
1530 as now bzImage can be compiled as a completely relocatable image
1531 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1532 address. This option is mainly useful for the folks who don't want
1533 to use a bzImage for capturing the crash dump and want to use a
1534 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1535 to be specifically compiled to run from a specific memory area
1536 (normally a reserved region) and this option comes handy.
1538 So if you are using bzImage for capturing the crash dump,
1539 leave the value here unchanged to 0x1000000 and set
1540 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1541 for capturing the crash dump change this value to start of
1542 the reserved region. In other words, it can be set based on
1543 the "X" value as specified in the "crashkernel=YM@XM"
1544 command line boot parameter passed to the panic-ed
1545 kernel. Please take a look at Documentation/kdump/kdump.txt
1546 for more details about crash dumps.
1548 Usage of bzImage for capturing the crash dump is recommended as
1549 one does not have to build two kernels. Same kernel can be used
1550 as production kernel and capture kernel. Above option should have
1551 gone away after relocatable bzImage support is introduced. But it
1552 is present because there are users out there who continue to use
1553 vmlinux for dump capture. This option should go away down the
1554 line.
1556 Don't change this unless you know what you are doing.
1558 config RELOCATABLE
1559 bool "Build a relocatable kernel"
1560 default y
1561 ---help---
1562 This builds a kernel image that retains relocation information
1563 so it can be loaded someplace besides the default 1MB.
1564 The relocations tend to make the kernel binary about 10% larger,
1565 but are discarded at runtime.
1567 One use is for the kexec on panic case where the recovery kernel
1568 must live at a different physical address than the primary
1569 kernel.
1571 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1572 it has been loaded at and the compile time physical address
1573 (CONFIG_PHYSICAL_START) is ignored.
1575 # Relocation on x86-32 needs some additional build support
1576 config X86_NEED_RELOCS
1577 def_bool y
1578 depends on X86_32 && RELOCATABLE
1580 config PHYSICAL_ALIGN
1581 hex
1582 prompt "Alignment value to which kernel should be aligned" if X86_32
1583 default "0x1000000"
1584 range 0x2000 0x1000000
1585 ---help---
1586 This value puts the alignment restrictions on physical address
1587 where kernel is loaded and run from. Kernel is compiled for an
1588 address which meets above alignment restriction.
1590 If bootloader loads the kernel at a non-aligned address and
1591 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1592 address aligned to above value and run from there.
1594 If bootloader loads the kernel at a non-aligned address and
1595 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1596 load address and decompress itself to the address it has been
1597 compiled for and run from there. The address for which kernel is
1598 compiled already meets above alignment restrictions. Hence the
1599 end result is that kernel runs from a physical address meeting
1600 above alignment restrictions.
1602 Don't change this unless you know what you are doing.
1604 config HOTPLUG_CPU
1605 bool "Support for hot-pluggable CPUs"
1606 depends on SMP && HOTPLUG
1607 ---help---
1608 Say Y here to allow turning CPUs off and on. CPUs can be
1609 controlled through /sys/devices/system/cpu.
1610 ( Note: power management support will enable this option
1611 automatically on SMP systems. )
1612 Say N if you want to disable CPU hotplug.
1614 config COMPAT_VDSO
1615 def_bool y
1616 prompt "Compat VDSO support"
1617 depends on X86_32 || IA32_EMULATION
1618 ---help---
1619 Map the 32-bit VDSO to the predictable old-style address too.
1620 ---help---
1621 Say N here if you are running a sufficiently recent glibc
1622 version (2.3.3 or later), to remove the high-mapped
1623 VDSO mapping and to exclusively use the randomized VDSO.
1625 If unsure, say Y.
1627 config CMDLINE_BOOL
1628 bool "Built-in kernel command line"
1629 default n
1630 ---help---
1631 Allow for specifying boot arguments to the kernel at
1632 build time. On some systems (e.g. embedded ones), it is
1633 necessary or convenient to provide some or all of the
1634 kernel boot arguments with the kernel itself (that is,
1635 to not rely on the boot loader to provide them.)
1637 To compile command line arguments into the kernel,
1638 set this option to 'Y', then fill in the
1639 the boot arguments in CONFIG_CMDLINE.
1641 Systems with fully functional boot loaders (i.e. non-embedded)
1642 should leave this option set to 'N'.
1644 config CMDLINE
1645 string "Built-in kernel command string"
1646 depends on CMDLINE_BOOL
1647 default ""
1648 ---help---
1649 Enter arguments here that should be compiled into the kernel
1650 image and used at boot time. If the boot loader provides a
1651 command line at boot time, it is appended to this string to
1652 form the full kernel command line, when the system boots.
1654 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1655 change this behavior.
1657 In most cases, the command line (whether built-in or provided
1658 by the boot loader) should specify the device for the root
1659 file system.
1661 config CMDLINE_OVERRIDE
1662 bool "Built-in command line overrides boot loader arguments"
1663 default n
1664 depends on CMDLINE_BOOL
1665 ---help---
1666 Set this option to 'Y' to have the kernel ignore the boot loader
1667 command line, and use ONLY the built-in command line.
1669 This is used to work around broken boot loaders. This should
1670 be set to 'N' under normal conditions.
1672 endmenu
1674 config ARCH_ENABLE_MEMORY_HOTPLUG
1675 def_bool y
1676 depends on X86_64 || (X86_32 && HIGHMEM)
1678 config ARCH_ENABLE_MEMORY_HOTREMOVE
1679 def_bool y
1680 depends on MEMORY_HOTPLUG
1682 config HAVE_ARCH_EARLY_PFN_TO_NID
1683 def_bool X86_64
1684 depends on NUMA
1686 menu "Power management and ACPI options"
1688 config ARCH_HIBERNATION_HEADER
1689 def_bool y
1690 depends on X86_64 && HIBERNATION
1692 source "kernel/power/Kconfig"
1694 source "drivers/acpi/Kconfig"
1696 source "drivers/sfi/Kconfig"
1698 config X86_APM_BOOT
1699 bool
1700 default y
1701 depends on APM || APM_MODULE
1703 menuconfig APM
1704 tristate "APM (Advanced Power Management) BIOS support"
1705 depends on X86_32 && PM_SLEEP
1706 ---help---
1707 APM is a BIOS specification for saving power using several different
1708 techniques. This is mostly useful for battery powered laptops with
1709 APM compliant BIOSes. If you say Y here, the system time will be
1710 reset after a RESUME operation, the /proc/apm device will provide
1711 battery status information, and user-space programs will receive
1712 notification of APM "events" (e.g. battery status change).
1714 If you select "Y" here, you can disable actual use of the APM
1715 BIOS by passing the "apm=off" option to the kernel at boot time.
1717 Note that the APM support is almost completely disabled for
1718 machines with more than one CPU.
1720 In order to use APM, you will need supporting software. For location
1721 and more information, read <file:Documentation/power/pm.txt> and the
1722 Battery Powered Linux mini-HOWTO, available from
1723 <http://www.tldp.org/docs.html#howto>.
1725 This driver does not spin down disk drives (see the hdparm(8)
1726 manpage ("man 8 hdparm") for that), and it doesn't turn off
1727 VESA-compliant "green" monitors.
1729 This driver does not support the TI 4000M TravelMate and the ACER
1730 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1731 desktop machines also don't have compliant BIOSes, and this driver
1732 may cause those machines to panic during the boot phase.
1734 Generally, if you don't have a battery in your machine, there isn't
1735 much point in using this driver and you should say N. If you get
1736 random kernel OOPSes or reboots that don't seem to be related to
1737 anything, try disabling/enabling this option (or disabling/enabling
1738 APM in your BIOS).
1740 Some other things you should try when experiencing seemingly random,
1741 "weird" problems:
1743 1) make sure that you have enough swap space and that it is
1744 enabled.
1745 2) pass the "no-hlt" option to the kernel
1746 3) switch on floating point emulation in the kernel and pass
1747 the "no387" option to the kernel
1748 4) pass the "floppy=nodma" option to the kernel
1749 5) pass the "mem=4M" option to the kernel (thereby disabling
1750 all but the first 4 MB of RAM)
1751 6) make sure that the CPU is not over clocked.
1752 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1753 8) disable the cache from your BIOS settings
1754 9) install a fan for the video card or exchange video RAM
1755 10) install a better fan for the CPU
1756 11) exchange RAM chips
1757 12) exchange the motherboard.
1759 To compile this driver as a module, choose M here: the
1760 module will be called apm.
1762 if APM
1764 config APM_IGNORE_USER_SUSPEND
1765 bool "Ignore USER SUSPEND"
1766 ---help---
1767 This option will ignore USER SUSPEND requests. On machines with a
1768 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1769 series notebooks, it is necessary to say Y because of a BIOS bug.
1771 config APM_DO_ENABLE
1772 bool "Enable PM at boot time"
1773 ---help---
1774 Enable APM features at boot time. From page 36 of the APM BIOS
1775 specification: "When disabled, the APM BIOS does not automatically
1776 power manage devices, enter the Standby State, enter the Suspend
1777 State, or take power saving steps in response to CPU Idle calls."
1778 This driver will make CPU Idle calls when Linux is idle (unless this
1779 feature is turned off -- see "Do CPU IDLE calls", below). This
1780 should always save battery power, but more complicated APM features
1781 will be dependent on your BIOS implementation. You may need to turn
1782 this option off if your computer hangs at boot time when using APM
1783 support, or if it beeps continuously instead of suspending. Turn
1784 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1785 T400CDT. This is off by default since most machines do fine without
1786 this feature.
1788 config APM_CPU_IDLE
1789 bool "Make CPU Idle calls when idle"
1790 ---help---
1791 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1792 On some machines, this can activate improved power savings, such as
1793 a slowed CPU clock rate, when the machine is idle. These idle calls
1794 are made after the idle loop has run for some length of time (e.g.,
1795 333 mS). On some machines, this will cause a hang at boot time or
1796 whenever the CPU becomes idle. (On machines with more than one CPU,
1797 this option does nothing.)
1799 config APM_DISPLAY_BLANK
1800 bool "Enable console blanking using APM"
1801 ---help---
1802 Enable console blanking using the APM. Some laptops can use this to
1803 turn off the LCD backlight when the screen blanker of the Linux
1804 virtual console blanks the screen. Note that this is only used by
1805 the virtual console screen blanker, and won't turn off the backlight
1806 when using the X Window system. This also doesn't have anything to
1807 do with your VESA-compliant power-saving monitor. Further, this
1808 option doesn't work for all laptops -- it might not turn off your
1809 backlight at all, or it might print a lot of errors to the console,
1810 especially if you are using gpm.
1812 config APM_ALLOW_INTS
1813 bool "Allow interrupts during APM BIOS calls"
1814 ---help---
1815 Normally we disable external interrupts while we are making calls to
1816 the APM BIOS as a measure to lessen the effects of a badly behaving
1817 BIOS implementation. The BIOS should reenable interrupts if it
1818 needs to. Unfortunately, some BIOSes do not -- especially those in
1819 many of the newer IBM Thinkpads. If you experience hangs when you
1820 suspend, try setting this to Y. Otherwise, say N.
1822 endif # APM
1824 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1826 source "drivers/cpuidle/Kconfig"
1828 source "drivers/idle/Kconfig"
1830 endmenu
1833 menu "Bus options (PCI etc.)"
1835 config PCI
1836 bool "PCI support"
1837 default y
1838 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1839 ---help---
1840 Find out whether you have a PCI motherboard. PCI is the name of a
1841 bus system, i.e. the way the CPU talks to the other stuff inside
1842 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1843 VESA. If you have PCI, say Y, otherwise N.
1845 choice
1846 prompt "PCI access mode"
1847 depends on X86_32 && PCI
1848 default PCI_GOANY
1849 ---help---
1850 On PCI systems, the BIOS can be used to detect the PCI devices and
1851 determine their configuration. However, some old PCI motherboards
1852 have BIOS bugs and may crash if this is done. Also, some embedded
1853 PCI-based systems don't have any BIOS at all. Linux can also try to
1854 detect the PCI hardware directly without using the BIOS.
1856 With this option, you can specify how Linux should detect the
1857 PCI devices. If you choose "BIOS", the BIOS will be used,
1858 if you choose "Direct", the BIOS won't be used, and if you
1859 choose "MMConfig", then PCI Express MMCONFIG will be used.
1860 If you choose "Any", the kernel will try MMCONFIG, then the
1861 direct access method and falls back to the BIOS if that doesn't
1862 work. If unsure, go with the default, which is "Any".
1864 config PCI_GOBIOS
1865 bool "BIOS"
1867 config PCI_GOMMCONFIG
1868 bool "MMConfig"
1870 config PCI_GODIRECT
1871 bool "Direct"
1873 config PCI_GOOLPC
1874 bool "OLPC"
1875 depends on OLPC
1877 config PCI_GOANY
1878 bool "Any"
1880 endchoice
1882 config PCI_BIOS
1883 def_bool y
1884 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1886 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1887 config PCI_DIRECT
1888 def_bool y
1889 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1891 config PCI_MMCONFIG
1892 def_bool y
1893 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1895 config PCI_OLPC
1896 def_bool y
1897 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1899 config PCI_DOMAINS
1900 def_bool y
1901 depends on PCI
1903 config PCI_MMCONFIG
1904 bool "Support mmconfig PCI config space access"
1905 depends on X86_64 && PCI && ACPI
1907 config DMAR
1908 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1909 depends on PCI_MSI && ACPI && EXPERIMENTAL
1910 help
1911 DMA remapping (DMAR) devices support enables independent address
1912 translations for Direct Memory Access (DMA) from devices.
1913 These DMA remapping devices are reported via ACPI tables
1914 and include PCI device scope covered by these DMA
1915 remapping devices.
1917 config DMAR_DEFAULT_ON
1918 def_bool y
1919 prompt "Enable DMA Remapping Devices by default"
1920 depends on DMAR
1921 help
1922 Selecting this option will enable a DMAR device at boot time if
1923 one is found. If this option is not selected, DMAR support can
1924 be enabled by passing intel_iommu=on to the kernel. It is
1925 recommended you say N here while the DMAR code remains
1926 experimental.
1928 config DMAR_BROKEN_GFX_WA
1929 def_bool n
1930 prompt "Workaround broken graphics drivers (going away soon)"
1931 depends on DMAR && BROKEN
1932 ---help---
1933 Current Graphics drivers tend to use physical address
1934 for DMA and avoid using DMA APIs. Setting this config
1935 option permits the IOMMU driver to set a unity map for
1936 all the OS-visible memory. Hence the driver can continue
1937 to use physical addresses for DMA, at least until this
1938 option is removed in the 2.6.32 kernel.
1940 config DMAR_FLOPPY_WA
1941 def_bool y
1942 depends on DMAR
1943 ---help---
1944 Floppy disk drivers are known to bypass DMA API calls
1945 thereby failing to work when IOMMU is enabled. This
1946 workaround will setup a 1:1 mapping for the first
1947 16MiB to make floppy (an ISA device) work.
1949 config INTR_REMAP
1950 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1951 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1952 ---help---
1953 Supports Interrupt remapping for IO-APIC and MSI devices.
1954 To use x2apic mode in the CPU's which support x2APIC enhancements or
1955 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1957 source "drivers/pci/pcie/Kconfig"
1959 source "drivers/pci/Kconfig"
1961 # x86_64 have no ISA slots, but do have ISA-style DMA.
1962 config ISA_DMA_API
1963 def_bool y
1965 if X86_32
1967 config ISA
1968 bool "ISA support"
1969 ---help---
1970 Find out whether you have ISA slots on your motherboard. ISA is the
1971 name of a bus system, i.e. the way the CPU talks to the other stuff
1972 inside your box. Other bus systems are PCI, EISA, MicroChannel
1973 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1974 newer boards don't support it. If you have ISA, say Y, otherwise N.
1976 config EISA
1977 bool "EISA support"
1978 depends on ISA
1979 ---help---
1980 The Extended Industry Standard Architecture (EISA) bus was
1981 developed as an open alternative to the IBM MicroChannel bus.
1983 The EISA bus provided some of the features of the IBM MicroChannel
1984 bus while maintaining backward compatibility with cards made for
1985 the older ISA bus. The EISA bus saw limited use between 1988 and
1986 1995 when it was made obsolete by the PCI bus.
1988 Say Y here if you are building a kernel for an EISA-based machine.
1990 Otherwise, say N.
1992 source "drivers/eisa/Kconfig"
1994 config MCA
1995 bool "MCA support"
1996 ---help---
1997 MicroChannel Architecture is found in some IBM PS/2 machines and
1998 laptops. It is a bus system similar to PCI or ISA. See
1999 <file:Documentation/mca.txt> (and especially the web page given
2000 there) before attempting to build an MCA bus kernel.
2002 source "drivers/mca/Kconfig"
2004 config SCx200
2005 tristate "NatSemi SCx200 support"
2006 ---help---
2007 This provides basic support for National Semiconductor's
2008 (now AMD's) Geode processors. The driver probes for the
2009 PCI-IDs of several on-chip devices, so its a good dependency
2010 for other scx200_* drivers.
2012 If compiled as a module, the driver is named scx200.
2014 config SCx200HR_TIMER
2015 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2016 depends on SCx200 && GENERIC_TIME
2017 default y
2018 ---help---
2019 This driver provides a clocksource built upon the on-chip
2020 27MHz high-resolution timer. Its also a workaround for
2021 NSC Geode SC-1100's buggy TSC, which loses time when the
2022 processor goes idle (as is done by the scheduler). The
2023 other workaround is idle=poll boot option.
2025 config GEODE_MFGPT_TIMER
2026 def_bool y
2027 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2028 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2029 ---help---
2030 This driver provides a clock event source based on the MFGPT
2031 timer(s) in the CS5535 and CS5536 companion chip for the geode.
2032 MFGPTs have a better resolution and max interval than the
2033 generic PIT, and are suitable for use as high-res timers.
2035 config OLPC
2036 bool "One Laptop Per Child support"
2037 default n
2038 ---help---
2039 Add support for detecting the unique features of the OLPC
2040 XO hardware.
2042 endif # X86_32
2044 config K8_NB
2045 def_bool y
2046 depends on CPU_SUP_AMD && PCI
2048 source "drivers/pcmcia/Kconfig"
2050 source "drivers/pci/hotplug/Kconfig"
2052 endmenu
2055 menu "Executable file formats / Emulations"
2057 source "fs/Kconfig.binfmt"
2059 config IA32_EMULATION
2060 bool "IA32 Emulation"
2061 depends on X86_64
2062 select COMPAT_BINFMT_ELF
2063 ---help---
2064 Include code to run 32-bit programs under a 64-bit kernel. You should
2065 likely turn this on, unless you're 100% sure that you don't have any
2066 32-bit programs left.
2068 config IA32_AOUT
2069 tristate "IA32 a.out support"
2070 depends on IA32_EMULATION
2071 ---help---
2072 Support old a.out binaries in the 32bit emulation.
2074 config COMPAT
2075 def_bool y
2076 depends on IA32_EMULATION
2078 config COMPAT_FOR_U64_ALIGNMENT
2079 def_bool COMPAT
2080 depends on X86_64
2082 config SYSVIPC_COMPAT
2083 def_bool y
2084 depends on COMPAT && SYSVIPC
2086 endmenu
2089 config HAVE_ATOMIC_IOMAP
2090 def_bool y
2091 depends on X86_32
2093 source "net/Kconfig"
2095 source "drivers/Kconfig"
2097 source "drivers/firmware/Kconfig"
2099 source "fs/Kconfig"
2101 source "arch/x86/Kconfig.debug"
2103 source "security/Kconfig"
2105 source "crypto/Kconfig"
2107 source "arch/x86/kvm/Kconfig"
2109 source "lib/Kconfig"