| blob | e25b6358fbe39b3f11e7583021987c4fb91b0c4f |
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_IOREMAP_PROT
28 select HAVE_KPROBES
29 select ARCH_WANT_OPTIONAL_GPIOLIB
30 select ARCH_WANT_FRAME_POINTERS
31 select HAVE_KRETPROBES
32 select HAVE_FTRACE_MCOUNT_RECORD
33 select HAVE_DYNAMIC_FTRACE
34 select HAVE_FUNCTION_TRACER
35 select HAVE_FUNCTION_GRAPH_TRACER
36 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
37 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
38 select HAVE_FTRACE_SYSCALLS
39 select HAVE_KVM
40 select HAVE_ARCH_KGDB
41 select HAVE_ARCH_TRACEHOOK
42 select HAVE_GENERIC_DMA_COHERENT if X86_32
43 select HAVE_EFFICIENT_UNALIGNED_ACCESS
44 select USER_STACKTRACE_SUPPORT
45 select HAVE_DMA_API_DEBUG
46 select HAVE_KERNEL_GZIP
47 select HAVE_KERNEL_BZIP2
48 select HAVE_KERNEL_LZMA
50 config ARCH_DEFCONFIG
51 string
52 default "arch/x86/configs/i386_defconfig" if X86_32
53 default "arch/x86/configs/x86_64_defconfig" if X86_64
55 config GENERIC_TIME
56 def_bool y
58 config GENERIC_CMOS_UPDATE
59 def_bool y
61 config CLOCKSOURCE_WATCHDOG
62 def_bool y
64 config GENERIC_CLOCKEVENTS
65 def_bool y
67 config GENERIC_CLOCKEVENTS_BROADCAST
68 def_bool y
69 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
71 config LOCKDEP_SUPPORT
72 def_bool y
74 config STACKTRACE_SUPPORT
75 def_bool y
77 config HAVE_LATENCYTOP_SUPPORT
78 def_bool y
80 config FAST_CMPXCHG_LOCAL
81 bool
82 default y
84 config MMU
85 def_bool y
87 config ZONE_DMA
88 def_bool y
90 config SBUS
91 bool
93 config GENERIC_ISA_DMA
94 def_bool y
96 config GENERIC_IOMAP
97 def_bool y
99 config GENERIC_BUG
100 def_bool y
101 depends on BUG
102 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
104 config GENERIC_BUG_RELATIVE_POINTERS
105 bool
107 config GENERIC_HWEIGHT
108 def_bool y
110 config GENERIC_GPIO
111 bool
113 config ARCH_MAY_HAVE_PC_FDC
114 def_bool y
116 config RWSEM_GENERIC_SPINLOCK
117 def_bool !X86_XADD
119 config RWSEM_XCHGADD_ALGORITHM
120 def_bool X86_XADD
122 config ARCH_HAS_CPU_IDLE_WAIT
123 def_bool y
125 config GENERIC_CALIBRATE_DELAY
126 def_bool y
128 config GENERIC_TIME_VSYSCALL
129 bool
130 default X86_64
132 config ARCH_HAS_CPU_RELAX
133 def_bool y
135 config ARCH_HAS_DEFAULT_IDLE
136 def_bool y
138 config ARCH_HAS_CACHE_LINE_SIZE
139 def_bool y
141 config HAVE_SETUP_PER_CPU_AREA
142 def_bool y
144 config HAVE_DYNAMIC_PER_CPU_AREA
145 def_bool y
147 config HAVE_CPUMASK_OF_CPU_MAP
148 def_bool X86_64_SMP
150 config ARCH_HIBERNATION_POSSIBLE
151 def_bool y
153 config ARCH_SUSPEND_POSSIBLE
154 def_bool y
156 config ZONE_DMA32
157 bool
158 default X86_64
160 config ARCH_POPULATES_NODE_MAP
161 def_bool y
163 config AUDIT_ARCH
164 bool
165 default X86_64
167 config ARCH_SUPPORTS_OPTIMIZED_INLINING
168 def_bool y
170 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
171 def_bool y
173 # Use the generic interrupt handling code in kernel/irq/:
174 config GENERIC_HARDIRQS
175 bool
176 default y
178 config GENERIC_HARDIRQS_NO__DO_IRQ
179 def_bool y
181 config GENERIC_IRQ_PROBE
182 bool
183 default y
185 config GENERIC_PENDING_IRQ
186 bool
187 depends on GENERIC_HARDIRQS && SMP
188 default y
190 config USE_GENERIC_SMP_HELPERS
191 def_bool y
192 depends on SMP
194 config X86_32_SMP
195 def_bool y
196 depends on X86_32 && SMP
198 config X86_64_SMP
199 def_bool y
200 depends on X86_64 && SMP
202 config X86_HT
203 bool
204 depends on SMP
205 default y
207 config X86_TRAMPOLINE
208 bool
209 depends on SMP || (64BIT && ACPI_SLEEP)
210 default y
212 config X86_32_LAZY_GS
213 def_bool y
214 depends on X86_32 && !CC_STACKPROTECTOR
216 config KTIME_SCALAR
217 def_bool X86_32
218 source "init/Kconfig"
219 source "kernel/Kconfig.freezer"
221 menu "Processor type and features"
223 source "kernel/time/Kconfig"
225 config SMP
226 bool "Symmetric multi-processing support"
227 ---help---
228 This enables support for systems with more than one CPU. If you have
229 a system with only one CPU, like most personal computers, say N. If
230 you have a system with more than one CPU, say Y.
232 If you say N here, the kernel will run on single and multiprocessor
233 machines, but will use only one CPU of a multiprocessor machine. If
234 you say Y here, the kernel will run on many, but not all,
235 singleprocessor machines. On a singleprocessor machine, the kernel
236 will run faster if you say N here.
238 Note that if you say Y here and choose architecture "586" or
239 "Pentium" under "Processor family", the kernel will not work on 486
240 architectures. Similarly, multiprocessor kernels for the "PPro"
241 architecture may not work on all Pentium based boards.
243 People using multiprocessor machines who say Y here should also say
244 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
245 Management" code will be disabled if you say Y here.
247 See also <file:Documentation/i386/IO-APIC.txt>,
248 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
249 <http://www.tldp.org/docs.html#howto>.
251 If you don't know what to do here, say N.
253 config X86_X2APIC
254 bool "Support x2apic"
255 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
256 ---help---
257 This enables x2apic support on CPUs that have this feature.
259 This allows 32-bit apic IDs (so it can support very large systems),
260 and accesses the local apic via MSRs not via mmio.
262 If you don't know what to do here, say N.
264 config SPARSE_IRQ
265 bool "Support sparse irq numbering"
266 depends on PCI_MSI || HT_IRQ
267 ---help---
268 This enables support for sparse irqs. This is useful for distro
269 kernels that want to define a high CONFIG_NR_CPUS value but still
270 want to have low kernel memory footprint on smaller machines.
272 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
273 out the irq_desc[] array in a more NUMA-friendly way. )
275 If you don't know what to do here, say N.
277 config NUMA_MIGRATE_IRQ_DESC
278 bool "Move irq desc when changing irq smp_affinity"
279 depends on SPARSE_IRQ && NUMA
280 depends on BROKEN
281 default n
282 ---help---
283 This enables moving irq_desc to cpu/node that irq will use handled.
285 If you don't know what to do here, say N.
287 config X86_MPPARSE
288 bool "Enable MPS table" if ACPI
289 default y
290 depends on X86_LOCAL_APIC
291 ---help---
292 For old smp systems that do not have proper acpi support. Newer systems
293 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
295 config X86_BIGSMP
296 bool "Support for big SMP systems with more than 8 CPUs"
297 depends on X86_32 && SMP
298 ---help---
299 This option is needed for the systems that have more than 8 CPUs
301 if X86_32
302 config X86_EXTENDED_PLATFORM
303 bool "Support for extended (non-PC) x86 platforms"
304 default y
305 ---help---
306 If you disable this option then the kernel will only support
307 standard PC platforms. (which covers the vast majority of
308 systems out there.)
310 If you enable this option then you'll be able to select support
311 for the following (non-PC) 32 bit x86 platforms:
312 AMD Elan
313 NUMAQ (IBM/Sequent)
314 RDC R-321x SoC
315 SGI 320/540 (Visual Workstation)
316 Summit/EXA (IBM x440)
317 Unisys ES7000 IA32 series
319 If you have one of these systems, or if you want to build a
320 generic distribution kernel, say Y here - otherwise say N.
321 endif
323 if X86_64
324 config X86_EXTENDED_PLATFORM
325 bool "Support for extended (non-PC) x86 platforms"
326 default y
327 ---help---
328 If you disable this option then the kernel will only support
329 standard PC platforms. (which covers the vast majority of
330 systems out there.)
332 If you enable this option then you'll be able to select support
333 for the following (non-PC) 64 bit x86 platforms:
334 ScaleMP vSMP
335 SGI Ultraviolet
337 If you have one of these systems, or if you want to build a
338 generic distribution kernel, say Y here - otherwise say N.
339 endif
340 # This is an alphabetically sorted list of 64 bit extended platforms
341 # Please maintain the alphabetic order if and when there are additions
343 config X86_VSMP
344 bool "ScaleMP vSMP"
345 select PARAVIRT
346 depends on X86_64 && PCI
347 depends on X86_EXTENDED_PLATFORM
348 ---help---
349 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
350 supposed to run on these EM64T-based machines. Only choose this option
351 if you have one of these machines.
353 config X86_UV
354 bool "SGI Ultraviolet"
355 depends on X86_64
356 depends on X86_EXTENDED_PLATFORM
357 depends on NUMA
358 select X86_X2APIC
359 ---help---
360 This option is needed in order to support SGI Ultraviolet systems.
361 If you don't have one of these, you should say N here.
363 # Following is an alphabetically sorted list of 32 bit extended platforms
364 # Please maintain the alphabetic order if and when there are additions
366 config X86_ELAN
367 bool "AMD Elan"
368 depends on X86_32
369 depends on X86_EXTENDED_PLATFORM
370 ---help---
371 Select this for an AMD Elan processor.
373 Do not use this option for K6/Athlon/Opteron processors!
375 If unsure, choose "PC-compatible" instead.
377 config X86_RDC321X
378 bool "RDC R-321x SoC"
379 depends on X86_32
380 depends on X86_EXTENDED_PLATFORM
381 select M486
382 select X86_REBOOTFIXUPS
383 ---help---
384 This option is needed for RDC R-321x system-on-chip, also known
385 as R-8610-(G).
386 If you don't have one of these chips, you should say N here.
388 config X86_32_NON_STANDARD
389 bool "Support non-standard 32-bit SMP architectures"
390 depends on X86_32 && SMP
391 depends on X86_EXTENDED_PLATFORM
392 ---help---
393 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
394 subarchitectures. It is intended for a generic binary kernel.
395 if you select them all, kernel will probe it one by one. and will
396 fallback to default.
398 # Alphabetically sorted list of Non standard 32 bit platforms
400 config X86_NUMAQ
401 bool "NUMAQ (IBM/Sequent)"
402 depends on X86_32_NON_STANDARD
403 select NUMA
404 select X86_MPPARSE
405 ---help---
406 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
407 NUMA multiquad box. This changes the way that processors are
408 bootstrapped, and uses Clustered Logical APIC addressing mode instead
409 of Flat Logical. You will need a new lynxer.elf file to flash your
410 firmware with - send email to <Martin.Bligh@us.ibm.com>.
412 config X86_VISWS
413 bool "SGI 320/540 (Visual Workstation)"
414 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
415 depends on X86_32_NON_STANDARD
416 ---help---
417 The SGI Visual Workstation series is an IA32-based workstation
418 based on SGI systems chips with some legacy PC hardware attached.
420 Say Y here to create a kernel to run on the SGI 320 or 540.
422 A kernel compiled for the Visual Workstation will run on general
423 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
425 config X86_SUMMIT
426 bool "Summit/EXA (IBM x440)"
427 depends on X86_32_NON_STANDARD
428 ---help---
429 This option is needed for IBM systems that use the Summit/EXA chipset.
430 In particular, it is needed for the x440.
432 config X86_ES7000
433 bool "Unisys ES7000 IA32 series"
434 depends on X86_32_NON_STANDARD && X86_BIGSMP
435 ---help---
436 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
437 supposed to run on an IA32-based Unisys ES7000 system.
439 config SCHED_OMIT_FRAME_POINTER
440 def_bool y
441 prompt "Single-depth WCHAN output"
442 depends on X86
443 ---help---
444 Calculate simpler /proc/<PID>/wchan values. If this option
445 is disabled then wchan values will recurse back to the
446 caller function. This provides more accurate wchan values,
447 at the expense of slightly more scheduling overhead.
449 If in doubt, say "Y".
451 menuconfig PARAVIRT_GUEST
452 bool "Paravirtualized guest support"
453 ---help---
454 Say Y here to get to see options related to running Linux under
455 various hypervisors. This option alone does not add any kernel code.
457 If you say N, all options in this submenu will be skipped and disabled.
459 if PARAVIRT_GUEST
461 source "arch/x86/xen/Kconfig"
463 config VMI
464 bool "VMI Guest support"
465 select PARAVIRT
466 depends on X86_32
467 ---help---
468 VMI provides a paravirtualized interface to the VMware ESX server
469 (it could be used by other hypervisors in theory too, but is not
470 at the moment), by linking the kernel to a GPL-ed ROM module
471 provided by the hypervisor.
473 config KVM_CLOCK
474 bool "KVM paravirtualized clock"
475 select PARAVIRT
476 select PARAVIRT_CLOCK
477 ---help---
478 Turning on this option will allow you to run a paravirtualized clock
479 when running over the KVM hypervisor. Instead of relying on a PIT
480 (or probably other) emulation by the underlying device model, the host
481 provides the guest with timing infrastructure such as time of day, and
482 system time
484 config KVM_GUEST
485 bool "KVM Guest support"
486 select PARAVIRT
487 ---help---
488 This option enables various optimizations for running under the KVM
489 hypervisor.
491 source "arch/x86/lguest/Kconfig"
493 config PARAVIRT
494 bool "Enable paravirtualization code"
495 ---help---
496 This changes the kernel so it can modify itself when it is run
497 under a hypervisor, potentially improving performance significantly
498 over full virtualization. However, when run without a hypervisor
499 the kernel is theoretically slower and slightly larger.
501 config PARAVIRT_SPINLOCKS
502 bool "Paravirtualization layer for spinlocks"
503 depends on PARAVIRT && SMP && EXPERIMENTAL
504 ---help---
505 Paravirtualized spinlocks allow a pvops backend to replace the
506 spinlock implementation with something virtualization-friendly
507 (for example, block the virtual CPU rather than spinning).
509 Unfortunately the downside is an up to 5% performance hit on
510 native kernels, with various workloads.
512 If you are unsure how to answer this question, answer N.
514 config PARAVIRT_CLOCK
515 bool
516 default n
518 endif
520 config PARAVIRT_DEBUG
521 bool "paravirt-ops debugging"
522 depends on PARAVIRT && DEBUG_KERNEL
523 ---help---
524 Enable to debug paravirt_ops internals. Specifically, BUG if
525 a paravirt_op is missing when it is called.
527 config MEMTEST
528 bool "Memtest"
529 ---help---
530 This option adds a kernel parameter 'memtest', which allows memtest
531 to be set.
532 memtest=0, mean disabled; -- default
533 memtest=1, mean do 1 test pattern;
534 ...
535 memtest=4, mean do 4 test patterns.
536 If you are unsure how to answer this question, answer N.
538 config X86_SUMMIT_NUMA
539 def_bool y
540 depends on X86_32 && NUMA && X86_32_NON_STANDARD
542 config X86_CYCLONE_TIMER
543 def_bool y
544 depends on X86_32_NON_STANDARD
546 source "arch/x86/Kconfig.cpu"
548 config HPET_TIMER
549 def_bool X86_64
550 prompt "HPET Timer Support" if X86_32
551 ---help---
552 Use the IA-PC HPET (High Precision Event Timer) to manage
553 time in preference to the PIT and RTC, if a HPET is
554 present.
555 HPET is the next generation timer replacing legacy 8254s.
556 The HPET provides a stable time base on SMP
557 systems, unlike the TSC, but it is more expensive to access,
558 as it is off-chip. You can find the HPET spec at
559 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
561 You can safely choose Y here. However, HPET will only be
562 activated if the platform and the BIOS support this feature.
563 Otherwise the 8254 will be used for timing services.
565 Choose N to continue using the legacy 8254 timer.
567 config HPET_EMULATE_RTC
568 def_bool y
569 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
571 # Mark as embedded because too many people got it wrong.
572 # The code disables itself when not needed.
573 config DMI
574 default y
575 bool "Enable DMI scanning" if EMBEDDED
576 ---help---
577 Enabled scanning of DMI to identify machine quirks. Say Y
578 here unless you have verified that your setup is not
579 affected by entries in the DMI blacklist. Required by PNP
580 BIOS code.
582 config GART_IOMMU
583 bool "GART IOMMU support" if EMBEDDED
584 default y
585 select SWIOTLB
586 select AGP
587 depends on X86_64 && PCI
588 ---help---
589 Support for full DMA access of devices with 32bit memory access only
590 on systems with more than 3GB. This is usually needed for USB,
591 sound, many IDE/SATA chipsets and some other devices.
592 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
593 based hardware IOMMU and a software bounce buffer based IOMMU used
594 on Intel systems and as fallback.
595 The code is only active when needed (enough memory and limited
596 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
597 too.
599 config CALGARY_IOMMU
600 bool "IBM Calgary IOMMU support"
601 select SWIOTLB
602 depends on X86_64 && PCI && EXPERIMENTAL
603 ---help---
604 Support for hardware IOMMUs in IBM's xSeries x366 and x460
605 systems. Needed to run systems with more than 3GB of memory
606 properly with 32-bit PCI devices that do not support DAC
607 (Double Address Cycle). Calgary also supports bus level
608 isolation, where all DMAs pass through the IOMMU. This
609 prevents them from going anywhere except their intended
610 destination. This catches hard-to-find kernel bugs and
611 mis-behaving drivers and devices that do not use the DMA-API
612 properly to set up their DMA buffers. The IOMMU can be
613 turned off at boot time with the iommu=off parameter.
614 Normally the kernel will make the right choice by itself.
615 If unsure, say Y.
617 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
618 def_bool y
619 prompt "Should Calgary be enabled by default?"
620 depends on CALGARY_IOMMU
621 ---help---
622 Should Calgary be enabled by default? if you choose 'y', Calgary
623 will be used (if it exists). If you choose 'n', Calgary will not be
624 used even if it exists. If you choose 'n' and would like to use
625 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
626 If unsure, say Y.
628 config AMD_IOMMU
629 bool "AMD IOMMU support"
630 select SWIOTLB
631 select PCI_MSI
632 depends on X86_64 && PCI && ACPI
633 ---help---
634 With this option you can enable support for AMD IOMMU hardware in
635 your system. An IOMMU is a hardware component which provides
636 remapping of DMA memory accesses from devices. With an AMD IOMMU you
637 can isolate the the DMA memory of different devices and protect the
638 system from misbehaving device drivers or hardware.
640 You can find out if your system has an AMD IOMMU if you look into
641 your BIOS for an option to enable it or if you have an IVRS ACPI
642 table.
644 config AMD_IOMMU_STATS
645 bool "Export AMD IOMMU statistics to debugfs"
646 depends on AMD_IOMMU
647 select DEBUG_FS
648 ---help---
649 This option enables code in the AMD IOMMU driver to collect various
650 statistics about whats happening in the driver and exports that
651 information to userspace via debugfs.
652 If unsure, say N.
654 # need this always selected by IOMMU for the VIA workaround
655 config SWIOTLB
656 def_bool y if X86_64
657 ---help---
658 Support for software bounce buffers used on x86-64 systems
659 which don't have a hardware IOMMU (e.g. the current generation
660 of Intel's x86-64 CPUs). Using this PCI devices which can only
661 access 32-bits of memory can be used on systems with more than
662 3 GB of memory. If unsure, say Y.
664 config IOMMU_HELPER
665 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
667 config IOMMU_API
668 def_bool (AMD_IOMMU || DMAR)
670 config MAXSMP
671 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
672 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
673 select CPUMASK_OFFSTACK
674 default n
675 ---help---
676 Configure maximum number of CPUS and NUMA Nodes for this architecture.
677 If unsure, say N.
679 config NR_CPUS
680 int "Maximum number of CPUs" if SMP && !MAXSMP
681 range 2 8 if SMP && X86_32 && !X86_BIGSMP
682 range 2 512 if SMP && !MAXSMP
683 default "1" if !SMP
684 default "4096" if MAXSMP
685 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
686 default "8" if SMP
687 ---help---
688 This allows you to specify the maximum number of CPUs which this
689 kernel will support. The maximum supported value is 512 and the
690 minimum value which makes sense is 2.
692 This is purely to save memory - each supported CPU adds
693 approximately eight kilobytes to the kernel image.
695 config SCHED_SMT
696 bool "SMT (Hyperthreading) scheduler support"
697 depends on X86_HT
698 ---help---
699 SMT scheduler support improves the CPU scheduler's decision making
700 when dealing with Intel Pentium 4 chips with HyperThreading at a
701 cost of slightly increased overhead in some places. If unsure say
702 N here.
704 config SCHED_MC
705 def_bool y
706 prompt "Multi-core scheduler support"
707 depends on X86_HT
708 ---help---
709 Multi-core scheduler support improves the CPU scheduler's decision
710 making when dealing with multi-core CPU chips at a cost of slightly
711 increased overhead in some places. If unsure say N here.
713 source "kernel/Kconfig.preempt"
715 config X86_UP_APIC
716 bool "Local APIC support on uniprocessors"
717 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
718 ---help---
719 A local APIC (Advanced Programmable Interrupt Controller) is an
720 integrated interrupt controller in the CPU. If you have a single-CPU
721 system which has a processor with a local APIC, you can say Y here to
722 enable and use it. If you say Y here even though your machine doesn't
723 have a local APIC, then the kernel will still run with no slowdown at
724 all. The local APIC supports CPU-generated self-interrupts (timer,
725 performance counters), and the NMI watchdog which detects hard
726 lockups.
728 config X86_UP_IOAPIC
729 bool "IO-APIC support on uniprocessors"
730 depends on X86_UP_APIC
731 ---help---
732 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
733 SMP-capable replacement for PC-style interrupt controllers. Most
734 SMP systems and many recent uniprocessor systems have one.
736 If you have a single-CPU system with an IO-APIC, you can say Y here
737 to use it. If you say Y here even though your machine doesn't have
738 an IO-APIC, then the kernel will still run with no slowdown at all.
740 config X86_LOCAL_APIC
741 def_bool y
742 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
744 config X86_IO_APIC
745 def_bool y
746 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
748 config X86_VISWS_APIC
749 def_bool y
750 depends on X86_32 && X86_VISWS
752 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
753 bool "Reroute for broken boot IRQs"
754 default n
755 depends on X86_IO_APIC
756 ---help---
757 This option enables a workaround that fixes a source of
758 spurious interrupts. This is recommended when threaded
759 interrupt handling is used on systems where the generation of
760 superfluous "boot interrupts" cannot be disabled.
762 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
763 entry in the chipset's IO-APIC is masked (as, e.g. the RT
764 kernel does during interrupt handling). On chipsets where this
765 boot IRQ generation cannot be disabled, this workaround keeps
766 the original IRQ line masked so that only the equivalent "boot
767 IRQ" is delivered to the CPUs. The workaround also tells the
768 kernel to set up the IRQ handler on the boot IRQ line. In this
769 way only one interrupt is delivered to the kernel. Otherwise
770 the spurious second interrupt may cause the kernel to bring
771 down (vital) interrupt lines.
773 Only affects "broken" chipsets. Interrupt sharing may be
774 increased on these systems.
776 config X86_MCE
777 bool "Machine Check Exception"
778 ---help---
779 Machine Check Exception support allows the processor to notify the
780 kernel if it detects a problem (e.g. overheating, component failure).
781 The action the kernel takes depends on the severity of the problem,
782 ranging from a warning message on the console, to halting the machine.
783 Your processor must be a Pentium or newer to support this - check the
784 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
785 have a design flaw which leads to false MCE events - hence MCE is
786 disabled on all P5 processors, unless explicitly enabled with "mce"
787 as a boot argument. Similarly, if MCE is built in and creates a
788 problem on some new non-standard machine, you can boot with "nomce"
789 to disable it. MCE support simply ignores non-MCE processors like
790 the 386 and 486, so nearly everyone can say Y here.
792 config X86_OLD_MCE
793 depends on X86_32 && X86_MCE
794 bool "Use legacy machine check code (will go away)"
795 default n
796 select X86_ANCIENT_MCE
797 ---help---
798 Use the old i386 machine check code. This is merely intended for
799 testing in a transition period. Try this if you run into any machine
800 check related software problems, but report the problem to
801 linux-kernel. When in doubt say no.
803 config X86_NEW_MCE
804 depends on X86_MCE
805 bool
806 default y if (!X86_OLD_MCE && X86_32) || X86_64
808 config X86_MCE_INTEL
809 def_bool y
810 prompt "Intel MCE features"
811 depends on X86_NEW_MCE && X86_LOCAL_APIC
812 ---help---
813 Additional support for intel specific MCE features such as
814 the thermal monitor.
816 config X86_MCE_AMD
817 def_bool y
818 prompt "AMD MCE features"
819 depends on X86_NEW_MCE && X86_LOCAL_APIC
820 ---help---
821 Additional support for AMD specific MCE features such as
822 the DRAM Error Threshold.
824 config X86_ANCIENT_MCE
825 def_bool n
826 depends on X86_32
827 prompt "Support for old Pentium 5 / WinChip machine checks"
828 ---help---
829 Include support for machine check handling on old Pentium 5 or WinChip
830 systems. These typically need to be enabled explicitely on the command
831 line.
833 config X86_MCE_THRESHOLD
834 depends on X86_MCE_AMD || X86_MCE_INTEL
835 bool
836 default y
838 config X86_MCE_INJECT
839 depends on X86_NEW_MCE
840 tristate "Machine check injector support"
841 ---help---
842 Provide support for injecting machine checks for testing purposes.
843 If you don't know what a machine check is and you don't do kernel
844 QA it is safe to say n.
846 config X86_MCE_NONFATAL
847 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
848 depends on X86_OLD_MCE
849 ---help---
850 Enabling this feature starts a timer that triggers every 5 seconds which
851 will look at the machine check registers to see if anything happened.
852 Non-fatal problems automatically get corrected (but still logged).
853 Disable this if you don't want to see these messages.
854 Seeing the messages this option prints out may be indicative of dying
855 or out-of-spec (ie, overclocked) hardware.
856 This option only does something on certain CPUs.
857 (AMD Athlon/Duron and Intel Pentium 4)
859 config X86_MCE_P4THERMAL
860 bool "check for P4 thermal throttling interrupt."
861 depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP)
862 ---help---
863 Enabling this feature will cause a message to be printed when the P4
864 enters thermal throttling.
866 config X86_THERMAL_VECTOR
867 def_bool y
868 depends on X86_MCE_P4THERMAL || X86_MCE_INTEL
870 config VM86
871 bool "Enable VM86 support" if EMBEDDED
872 default y
873 depends on X86_32
874 ---help---
875 This option is required by programs like DOSEMU to run 16-bit legacy
876 code on X86 processors. It also may be needed by software like
877 XFree86 to initialize some video cards via BIOS. Disabling this
878 option saves about 6k.
880 config TOSHIBA
881 tristate "Toshiba Laptop support"
882 depends on X86_32
883 ---help---
884 This adds a driver to safely access the System Management Mode of
885 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
886 not work on models with a Phoenix BIOS. The System Management Mode
887 is used to set the BIOS and power saving options on Toshiba portables.
889 For information on utilities to make use of this driver see the
890 Toshiba Linux utilities web site at:
891 <http://www.buzzard.org.uk/toshiba/>.
893 Say Y if you intend to run this kernel on a Toshiba portable.
894 Say N otherwise.
896 config I8K
897 tristate "Dell laptop support"
898 ---help---
899 This adds a driver to safely access the System Management Mode
900 of the CPU on the Dell Inspiron 8000. The System Management Mode
901 is used to read cpu temperature and cooling fan status and to
902 control the fans on the I8K portables.
904 This driver has been tested only on the Inspiron 8000 but it may
905 also work with other Dell laptops. You can force loading on other
906 models by passing the parameter `force=1' to the module. Use at
907 your own risk.
909 For information on utilities to make use of this driver see the
910 I8K Linux utilities web site at:
911 <http://people.debian.org/~dz/i8k/>
913 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
914 Say N otherwise.
916 config X86_REBOOTFIXUPS
917 bool "Enable X86 board specific fixups for reboot"
918 depends on X86_32
919 ---help---
920 This enables chipset and/or board specific fixups to be done
921 in order to get reboot to work correctly. This is only needed on
922 some combinations of hardware and BIOS. The symptom, for which
923 this config is intended, is when reboot ends with a stalled/hung
924 system.
926 Currently, the only fixup is for the Geode machines using
927 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
929 Say Y if you want to enable the fixup. Currently, it's safe to
930 enable this option even if you don't need it.
931 Say N otherwise.
933 config MICROCODE
934 tristate "/dev/cpu/microcode - microcode support"
935 select FW_LOADER
936 ---help---
937 If you say Y here, you will be able to update the microcode on
938 certain Intel and AMD processors. The Intel support is for the
939 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
940 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
941 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
942 You will obviously need the actual microcode binary data itself
943 which is not shipped with the Linux kernel.
945 This option selects the general module only, you need to select
946 at least one vendor specific module as well.
948 To compile this driver as a module, choose M here: the
949 module will be called microcode.
951 config MICROCODE_INTEL
952 bool "Intel microcode patch loading support"
953 depends on MICROCODE
954 default MICROCODE
955 select FW_LOADER
956 ---help---
957 This options enables microcode patch loading support for Intel
958 processors.
960 For latest news and information on obtaining all the required
961 Intel ingredients for this driver, check:
962 <http://www.urbanmyth.org/microcode/>.
964 config MICROCODE_AMD
965 bool "AMD microcode patch loading support"
966 depends on MICROCODE
967 select FW_LOADER
968 ---help---
969 If you select this option, microcode patch loading support for AMD
970 processors will be enabled.
972 config MICROCODE_OLD_INTERFACE
973 def_bool y
974 depends on MICROCODE
976 config X86_MSR
977 tristate "/dev/cpu/*/msr - Model-specific register support"
978 ---help---
979 This device gives privileged processes access to the x86
980 Model-Specific Registers (MSRs). It is a character device with
981 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
982 MSR accesses are directed to a specific CPU on multi-processor
983 systems.
985 config X86_CPUID
986 tristate "/dev/cpu/*/cpuid - CPU information support"
987 ---help---
988 This device gives processes access to the x86 CPUID instruction to
989 be executed on a specific processor. It is a character device
990 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
991 /dev/cpu/31/cpuid.
993 config X86_CPU_DEBUG
994 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
995 ---help---
996 If you select this option, this will provide various x86 CPUs
997 information through debugfs.
999 choice
1000 prompt "High Memory Support"
1001 default HIGHMEM4G if !X86_NUMAQ
1002 default HIGHMEM64G if X86_NUMAQ
1003 depends on X86_32
1005 config NOHIGHMEM
1006 bool "off"
1007 depends on !X86_NUMAQ
1008 ---help---
1009 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1010 However, the address space of 32-bit x86 processors is only 4
1011 Gigabytes large. That means that, if you have a large amount of
1012 physical memory, not all of it can be "permanently mapped" by the
1013 kernel. The physical memory that's not permanently mapped is called
1014 "high memory".
1016 If you are compiling a kernel which will never run on a machine with
1017 more than 1 Gigabyte total physical RAM, answer "off" here (default
1018 choice and suitable for most users). This will result in a "3GB/1GB"
1019 split: 3GB are mapped so that each process sees a 3GB virtual memory
1020 space and the remaining part of the 4GB virtual memory space is used
1021 by the kernel to permanently map as much physical memory as
1022 possible.
1024 If the machine has between 1 and 4 Gigabytes physical RAM, then
1025 answer "4GB" here.
1027 If more than 4 Gigabytes is used then answer "64GB" here. This
1028 selection turns Intel PAE (Physical Address Extension) mode on.
1029 PAE implements 3-level paging on IA32 processors. PAE is fully
1030 supported by Linux, PAE mode is implemented on all recent Intel
1031 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1032 then the kernel will not boot on CPUs that don't support PAE!
1034 The actual amount of total physical memory will either be
1035 auto detected or can be forced by using a kernel command line option
1036 such as "mem=256M". (Try "man bootparam" or see the documentation of
1037 your boot loader (lilo or loadlin) about how to pass options to the
1038 kernel at boot time.)
1040 If unsure, say "off".
1042 config HIGHMEM4G
1043 bool "4GB"
1044 depends on !X86_NUMAQ
1045 ---help---
1046 Select this if you have a 32-bit processor and between 1 and 4
1047 gigabytes of physical RAM.
1049 config HIGHMEM64G
1050 bool "64GB"
1051 depends on !M386 && !M486
1052 select X86_PAE
1053 ---help---
1054 Select this if you have a 32-bit processor and more than 4
1055 gigabytes of physical RAM.
1057 endchoice
1059 choice
1060 depends on EXPERIMENTAL
1061 prompt "Memory split" if EMBEDDED
1062 default VMSPLIT_3G
1063 depends on X86_32
1064 ---help---
1065 Select the desired split between kernel and user memory.
1067 If the address range available to the kernel is less than the
1068 physical memory installed, the remaining memory will be available
1069 as "high memory". Accessing high memory is a little more costly
1070 than low memory, as it needs to be mapped into the kernel first.
1071 Note that increasing the kernel address space limits the range
1072 available to user programs, making the address space there
1073 tighter. Selecting anything other than the default 3G/1G split
1074 will also likely make your kernel incompatible with binary-only
1075 kernel modules.
1077 If you are not absolutely sure what you are doing, leave this
1078 option alone!
1080 config VMSPLIT_3G
1081 bool "3G/1G user/kernel split"
1082 config VMSPLIT_3G_OPT
1083 depends on !X86_PAE
1084 bool "3G/1G user/kernel split (for full 1G low memory)"
1085 config VMSPLIT_2G
1086 bool "2G/2G user/kernel split"
1087 config VMSPLIT_2G_OPT
1088 depends on !X86_PAE
1089 bool "2G/2G user/kernel split (for full 2G low memory)"
1090 config VMSPLIT_1G
1091 bool "1G/3G user/kernel split"
1092 endchoice
1094 config PAGE_OFFSET
1095 hex
1096 default 0xB0000000 if VMSPLIT_3G_OPT
1097 default 0x80000000 if VMSPLIT_2G
1098 default 0x78000000 if VMSPLIT_2G_OPT
1099 default 0x40000000 if VMSPLIT_1G
1100 default 0xC0000000
1101 depends on X86_32
1103 config HIGHMEM
1104 def_bool y
1105 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1107 config X86_PAE
1108 bool "PAE (Physical Address Extension) Support"
1109 depends on X86_32 && !HIGHMEM4G
1110 ---help---
1111 PAE is required for NX support, and furthermore enables
1112 larger swapspace support for non-overcommit purposes. It
1113 has the cost of more pagetable lookup overhead, and also
1114 consumes more pagetable space per process.
1116 config ARCH_PHYS_ADDR_T_64BIT
1117 def_bool X86_64 || X86_PAE
1119 config DIRECT_GBPAGES
1120 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1121 default y
1122 depends on X86_64
1123 ---help---
1124 Allow the kernel linear mapping to use 1GB pages on CPUs that
1125 support it. This can improve the kernel's performance a tiny bit by
1126 reducing TLB pressure. If in doubt, say "Y".
1128 # Common NUMA Features
1129 config NUMA
1130 bool "Numa Memory Allocation and Scheduler Support"
1131 depends on SMP
1132 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1133 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1134 ---help---
1135 Enable NUMA (Non Uniform Memory Access) support.
1137 The kernel will try to allocate memory used by a CPU on the
1138 local memory controller of the CPU and add some more
1139 NUMA awareness to the kernel.
1141 For 64-bit this is recommended if the system is Intel Core i7
1142 (or later), AMD Opteron, or EM64T NUMA.
1144 For 32-bit this is only needed on (rare) 32-bit-only platforms
1145 that support NUMA topologies, such as NUMAQ / Summit, or if you
1146 boot a 32-bit kernel on a 64-bit NUMA platform.
1148 Otherwise, you should say N.
1150 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1151 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1153 config K8_NUMA
1154 def_bool y
1155 prompt "Old style AMD Opteron NUMA detection"
1156 depends on X86_64 && NUMA && PCI
1157 ---help---
1158 Enable K8 NUMA node topology detection. You should say Y here if
1159 you have a multi processor AMD K8 system. This uses an old
1160 method to read the NUMA configuration directly from the builtin
1161 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1162 instead, which also takes priority if both are compiled in.
1164 config X86_64_ACPI_NUMA
1165 def_bool y
1166 prompt "ACPI NUMA detection"
1167 depends on X86_64 && NUMA && ACPI && PCI
1168 select ACPI_NUMA
1169 ---help---
1170 Enable ACPI SRAT based node topology detection.
1172 # Some NUMA nodes have memory ranges that span
1173 # other nodes. Even though a pfn is valid and
1174 # between a node's start and end pfns, it may not
1175 # reside on that node. See memmap_init_zone()
1176 # for details.
1177 config NODES_SPAN_OTHER_NODES
1178 def_bool y
1179 depends on X86_64_ACPI_NUMA
1181 config NUMA_EMU
1182 bool "NUMA emulation"
1183 depends on X86_64 && NUMA
1184 ---help---
1185 Enable NUMA emulation. A flat machine will be split
1186 into virtual nodes when booted with "numa=fake=N", where N is the
1187 number of nodes. This is only useful for debugging.
1189 config NODES_SHIFT
1190 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1191 range 1 9
1192 default "9" if MAXSMP
1193 default "6" if X86_64
1194 default "4" if X86_NUMAQ
1195 default "3"
1196 depends on NEED_MULTIPLE_NODES
1197 ---help---
1198 Specify the maximum number of NUMA Nodes available on the target
1199 system. Increases memory reserved to accommodate various tables.
1201 config HAVE_ARCH_BOOTMEM
1202 def_bool y
1203 depends on X86_32 && NUMA
1205 config ARCH_HAVE_MEMORY_PRESENT
1206 def_bool y
1207 depends on X86_32 && DISCONTIGMEM
1209 config NEED_NODE_MEMMAP_SIZE
1210 def_bool y
1211 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1213 config HAVE_ARCH_ALLOC_REMAP
1214 def_bool y
1215 depends on X86_32 && NUMA
1217 config ARCH_FLATMEM_ENABLE
1218 def_bool y
1219 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1221 config ARCH_DISCONTIGMEM_ENABLE
1222 def_bool y
1223 depends on NUMA && X86_32
1225 config ARCH_DISCONTIGMEM_DEFAULT
1226 def_bool y
1227 depends on NUMA && X86_32
1229 config ARCH_SPARSEMEM_DEFAULT
1230 def_bool y
1231 depends on X86_64
1233 config ARCH_SPARSEMEM_ENABLE
1234 def_bool y
1235 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1236 select SPARSEMEM_STATIC if X86_32
1237 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1239 config ARCH_SELECT_MEMORY_MODEL
1240 def_bool y
1241 depends on ARCH_SPARSEMEM_ENABLE
1243 config ARCH_MEMORY_PROBE
1244 def_bool X86_64
1245 depends on MEMORY_HOTPLUG
1247 source "mm/Kconfig"
1249 config HIGHPTE
1250 bool "Allocate 3rd-level pagetables from highmem"
1251 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1252 ---help---
1253 The VM uses one page table entry for each page of physical memory.
1254 For systems with a lot of RAM, this can be wasteful of precious
1255 low memory. Setting this option will put user-space page table
1256 entries in high memory.
1258 config X86_CHECK_BIOS_CORRUPTION
1259 bool "Check for low memory corruption"
1260 ---help---
1261 Periodically check for memory corruption in low memory, which
1262 is suspected to be caused by BIOS. Even when enabled in the
1263 configuration, it is disabled at runtime. Enable it by
1264 setting "memory_corruption_check=1" on the kernel command
1265 line. By default it scans the low 64k of memory every 60
1266 seconds; see the memory_corruption_check_size and
1267 memory_corruption_check_period parameters in
1268 Documentation/kernel-parameters.txt to adjust this.
1270 When enabled with the default parameters, this option has
1271 almost no overhead, as it reserves a relatively small amount
1272 of memory and scans it infrequently. It both detects corruption
1273 and prevents it from affecting the running system.
1275 It is, however, intended as a diagnostic tool; if repeatable
1276 BIOS-originated corruption always affects the same memory,
1277 you can use memmap= to prevent the kernel from using that
1278 memory.
1280 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1281 bool "Set the default setting of memory_corruption_check"
1282 depends on X86_CHECK_BIOS_CORRUPTION
1283 default y
1284 ---help---
1285 Set whether the default state of memory_corruption_check is
1286 on or off.
1288 config X86_RESERVE_LOW_64K
1289 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1290 default y
1291 ---help---
1292 Reserve the first 64K of physical RAM on BIOSes that are known
1293 to potentially corrupt that memory range. A numbers of BIOSes are
1294 known to utilize this area during suspend/resume, so it must not
1295 be used by the kernel.
1297 Set this to N if you are absolutely sure that you trust the BIOS
1298 to get all its memory reservations and usages right.
1300 If you have doubts about the BIOS (e.g. suspend/resume does not
1301 work or there's kernel crashes after certain hardware hotplug
1302 events) and it's not AMI or Phoenix, then you might want to enable
1303 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1304 corruption patterns.
1306 Say Y if unsure.
1308 config MATH_EMULATION
1309 bool
1310 prompt "Math emulation" if X86_32
1311 ---help---
1312 Linux can emulate a math coprocessor (used for floating point
1313 operations) if you don't have one. 486DX and Pentium processors have
1314 a math coprocessor built in, 486SX and 386 do not, unless you added
1315 a 487DX or 387, respectively. (The messages during boot time can
1316 give you some hints here ["man dmesg"].) Everyone needs either a
1317 coprocessor or this emulation.
1319 If you don't have a math coprocessor, you need to say Y here; if you
1320 say Y here even though you have a coprocessor, the coprocessor will
1321 be used nevertheless. (This behavior can be changed with the kernel
1322 command line option "no387", which comes handy if your coprocessor
1323 is broken. Try "man bootparam" or see the documentation of your boot
1324 loader (lilo or loadlin) about how to pass options to the kernel at
1325 boot time.) This means that it is a good idea to say Y here if you
1326 intend to use this kernel on different machines.
1328 More information about the internals of the Linux math coprocessor
1329 emulation can be found in <file:arch/x86/math-emu/README>.
1331 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1332 kernel, it won't hurt.
1334 config MTRR
1335 bool "MTRR (Memory Type Range Register) support"
1336 ---help---
1337 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1338 the Memory Type Range Registers (MTRRs) may be used to control
1339 processor access to memory ranges. This is most useful if you have
1340 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1341 allows bus write transfers to be combined into a larger transfer
1342 before bursting over the PCI/AGP bus. This can increase performance
1343 of image write operations 2.5 times or more. Saying Y here creates a
1344 /proc/mtrr file which may be used to manipulate your processor's
1345 MTRRs. Typically the X server should use this.
1347 This code has a reasonably generic interface so that similar
1348 control registers on other processors can be easily supported
1349 as well:
1351 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1352 Registers (ARRs) which provide a similar functionality to MTRRs. For
1353 these, the ARRs are used to emulate the MTRRs.
1354 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1355 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1356 write-combining. All of these processors are supported by this code
1357 and it makes sense to say Y here if you have one of them.
1359 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1360 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1361 can lead to all sorts of problems, so it's good to say Y here.
1363 You can safely say Y even if your machine doesn't have MTRRs, you'll
1364 just add about 9 KB to your kernel.
1366 See <file:Documentation/x86/mtrr.txt> for more information.
1368 config MTRR_SANITIZER
1369 def_bool y
1370 prompt "MTRR cleanup support"
1371 depends on MTRR
1372 ---help---
1373 Convert MTRR layout from continuous to discrete, so X drivers can
1374 add writeback entries.
1376 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1377 The largest mtrr entry size for a continuous block can be set with
1378 mtrr_chunk_size.
1380 If unsure, say Y.
1382 config MTRR_SANITIZER_ENABLE_DEFAULT
1383 int "MTRR cleanup enable value (0-1)"
1384 range 0 1
1385 default "0"
1386 depends on MTRR_SANITIZER
1387 ---help---
1388 Enable mtrr cleanup default value
1390 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1391 int "MTRR cleanup spare reg num (0-7)"
1392 range 0 7
1393 default "1"
1394 depends on MTRR_SANITIZER
1395 ---help---
1396 mtrr cleanup spare entries default, it can be changed via
1397 mtrr_spare_reg_nr=N on the kernel command line.
1399 config X86_PAT
1400 bool
1401 prompt "x86 PAT support"
1402 depends on MTRR
1403 ---help---
1404 Use PAT attributes to setup page level cache control.
1406 PATs are the modern equivalents of MTRRs and are much more
1407 flexible than MTRRs.
1409 Say N here if you see bootup problems (boot crash, boot hang,
1410 spontaneous reboots) or a non-working video driver.
1412 If unsure, say Y.
1414 config EFI
1415 bool "EFI runtime service support"
1416 depends on ACPI
1417 ---help---
1418 This enables the kernel to use EFI runtime services that are
1419 available (such as the EFI variable services).
1421 This option is only useful on systems that have EFI firmware.
1422 In addition, you should use the latest ELILO loader available
1423 at <http://elilo.sourceforge.net> in order to take advantage
1424 of EFI runtime services. However, even with this option, the
1425 resultant kernel should continue to boot on existing non-EFI
1426 platforms.
1428 config SECCOMP
1429 def_bool y
1430 prompt "Enable seccomp to safely compute untrusted bytecode"
1431 ---help---
1432 This kernel feature is useful for number crunching applications
1433 that may need to compute untrusted bytecode during their
1434 execution. By using pipes or other transports made available to
1435 the process as file descriptors supporting the read/write
1436 syscalls, it's possible to isolate those applications in
1437 their own address space using seccomp. Once seccomp is
1438 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1439 and the task is only allowed to execute a few safe syscalls
1440 defined by each seccomp mode.
1442 If unsure, say Y. Only embedded should say N here.
1444 config CC_STACKPROTECTOR_ALL
1445 bool
1447 config CC_STACKPROTECTOR
1448 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1449 select CC_STACKPROTECTOR_ALL
1450 ---help---
1451 This option turns on the -fstack-protector GCC feature. This
1452 feature puts, at the beginning of functions, a canary value on
1453 the stack just before the return address, and validates
1454 the value just before actually returning. Stack based buffer
1455 overflows (that need to overwrite this return address) now also
1456 overwrite the canary, which gets detected and the attack is then
1457 neutralized via a kernel panic.
1459 This feature requires gcc version 4.2 or above, or a distribution
1460 gcc with the feature backported. Older versions are automatically
1461 detected and for those versions, this configuration option is
1462 ignored. (and a warning is printed during bootup)
1464 source kernel/Kconfig.hz
1466 config KEXEC
1467 bool "kexec system call"
1468 ---help---
1469 kexec is a system call that implements the ability to shutdown your
1470 current kernel, and to start another kernel. It is like a reboot
1471 but it is independent of the system firmware. And like a reboot
1472 you can start any kernel with it, not just Linux.
1474 The name comes from the similarity to the exec system call.
1476 It is an ongoing process to be certain the hardware in a machine
1477 is properly shutdown, so do not be surprised if this code does not
1478 initially work for you. It may help to enable device hotplugging
1479 support. As of this writing the exact hardware interface is
1480 strongly in flux, so no good recommendation can be made.
1482 config CRASH_DUMP
1483 bool "kernel crash dumps"
1484 depends on X86_64 || (X86_32 && HIGHMEM)
1485 ---help---
1486 Generate crash dump after being started by kexec.
1487 This should be normally only set in special crash dump kernels
1488 which are loaded in the main kernel with kexec-tools into
1489 a specially reserved region and then later executed after
1490 a crash by kdump/kexec. The crash dump kernel must be compiled
1491 to a memory address not used by the main kernel or BIOS using
1492 PHYSICAL_START, or it must be built as a relocatable image
1493 (CONFIG_RELOCATABLE=y).
1494 For more details see Documentation/kdump/kdump.txt
1496 config KEXEC_JUMP
1497 bool "kexec jump (EXPERIMENTAL)"
1498 depends on EXPERIMENTAL
1499 depends on KEXEC && HIBERNATION
1500 ---help---
1501 Jump between original kernel and kexeced kernel and invoke
1502 code in physical address mode via KEXEC
1504 config PHYSICAL_START
1505 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1506 default "0x1000000" if X86_NUMAQ
1507 default "0x200000" if X86_64
1508 default "0x100000"
1509 ---help---
1510 This gives the physical address where the kernel is loaded.
1512 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1513 bzImage will decompress itself to above physical address and
1514 run from there. Otherwise, bzImage will run from the address where
1515 it has been loaded by the boot loader and will ignore above physical
1516 address.
1518 In normal kdump cases one does not have to set/change this option
1519 as now bzImage can be compiled as a completely relocatable image
1520 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1521 address. This option is mainly useful for the folks who don't want
1522 to use a bzImage for capturing the crash dump and want to use a
1523 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1524 to be specifically compiled to run from a specific memory area
1525 (normally a reserved region) and this option comes handy.
1527 So if you are using bzImage for capturing the crash dump, leave
1528 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1529 Otherwise if you plan to use vmlinux for capturing the crash dump
1530 change this value to start of the reserved region (Typically 16MB
1531 0x1000000). In other words, it can be set based on the "X" value as
1532 specified in the "crashkernel=YM@XM" command line boot parameter
1533 passed to the panic-ed kernel. Typically this parameter is set as
1534 crashkernel=64M@16M. Please take a look at
1535 Documentation/kdump/kdump.txt for more details about crash dumps.
1537 Usage of bzImage for capturing the crash dump is recommended as
1538 one does not have to build two kernels. Same kernel can be used
1539 as production kernel and capture kernel. Above option should have
1540 gone away after relocatable bzImage support is introduced. But it
1541 is present because there are users out there who continue to use
1542 vmlinux for dump capture. This option should go away down the
1543 line.
1545 Don't change this unless you know what you are doing.
1547 config RELOCATABLE
1548 bool "Build a relocatable kernel (EXPERIMENTAL)"
1549 depends on EXPERIMENTAL
1550 ---help---
1551 This builds a kernel image that retains relocation information
1552 so it can be loaded someplace besides the default 1MB.
1553 The relocations tend to make the kernel binary about 10% larger,
1554 but are discarded at runtime.
1556 One use is for the kexec on panic case where the recovery kernel
1557 must live at a different physical address than the primary
1558 kernel.
1560 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1561 it has been loaded at and the compile time physical address
1562 (CONFIG_PHYSICAL_START) is ignored.
1564 config PHYSICAL_ALIGN
1565 hex
1566 prompt "Alignment value to which kernel should be aligned" if X86_32
1567 default "0x100000" if X86_32
1568 default "0x200000" if X86_64
1569 range 0x2000 0x400000
1570 ---help---
1571 This value puts the alignment restrictions on physical address
1572 where kernel is loaded and run from. Kernel is compiled for an
1573 address which meets above alignment restriction.
1575 If bootloader loads the kernel at a non-aligned address and
1576 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1577 address aligned to above value and run from there.
1579 If bootloader loads the kernel at a non-aligned address and
1580 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1581 load address and decompress itself to the address it has been
1582 compiled for and run from there. The address for which kernel is
1583 compiled already meets above alignment restrictions. Hence the
1584 end result is that kernel runs from a physical address meeting
1585 above alignment restrictions.
1587 Don't change this unless you know what you are doing.
1589 config HOTPLUG_CPU
1590 bool "Support for hot-pluggable CPUs"
1591 depends on SMP && HOTPLUG
1592 ---help---
1593 Say Y here to allow turning CPUs off and on. CPUs can be
1594 controlled through /sys/devices/system/cpu.
1595 ( Note: power management support will enable this option
1596 automatically on SMP systems. )
1597 Say N if you want to disable CPU hotplug.
1599 config COMPAT_VDSO
1600 def_bool y
1601 prompt "Compat VDSO support"
1602 depends on X86_32 || IA32_EMULATION
1603 ---help---
1604 Map the 32-bit VDSO to the predictable old-style address too.
1605 ---help---
1606 Say N here if you are running a sufficiently recent glibc
1607 version (2.3.3 or later), to remove the high-mapped
1608 VDSO mapping and to exclusively use the randomized VDSO.
1610 If unsure, say Y.
1612 config CMDLINE_BOOL
1613 bool "Built-in kernel command line"
1614 default n
1615 ---help---
1616 Allow for specifying boot arguments to the kernel at
1617 build time. On some systems (e.g. embedded ones), it is
1618 necessary or convenient to provide some or all of the
1619 kernel boot arguments with the kernel itself (that is,
1620 to not rely on the boot loader to provide them.)
1622 To compile command line arguments into the kernel,
1623 set this option to 'Y', then fill in the
1624 the boot arguments in CONFIG_CMDLINE.
1626 Systems with fully functional boot loaders (i.e. non-embedded)
1627 should leave this option set to 'N'.
1629 config CMDLINE
1630 string "Built-in kernel command string"
1631 depends on CMDLINE_BOOL
1632 default ""
1633 ---help---
1634 Enter arguments here that should be compiled into the kernel
1635 image and used at boot time. If the boot loader provides a
1636 command line at boot time, it is appended to this string to
1637 form the full kernel command line, when the system boots.
1639 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1640 change this behavior.
1642 In most cases, the command line (whether built-in or provided
1643 by the boot loader) should specify the device for the root
1644 file system.
1646 config CMDLINE_OVERRIDE
1647 bool "Built-in command line overrides boot loader arguments"
1648 default n
1649 depends on CMDLINE_BOOL
1650 ---help---
1651 Set this option to 'Y' to have the kernel ignore the boot loader
1652 command line, and use ONLY the built-in command line.
1654 This is used to work around broken boot loaders. This should
1655 be set to 'N' under normal conditions.
1657 endmenu
1659 config ARCH_ENABLE_MEMORY_HOTPLUG
1660 def_bool y
1661 depends on X86_64 || (X86_32 && HIGHMEM)
1663 config ARCH_ENABLE_MEMORY_HOTREMOVE
1664 def_bool y
1665 depends on MEMORY_HOTPLUG
1667 config HAVE_ARCH_EARLY_PFN_TO_NID
1668 def_bool X86_64
1669 depends on NUMA
1671 menu "Power management and ACPI options"
1673 config ARCH_HIBERNATION_HEADER
1674 def_bool y
1675 depends on X86_64 && HIBERNATION
1677 source "kernel/power/Kconfig"
1679 source "drivers/acpi/Kconfig"
1681 config X86_APM_BOOT
1682 bool
1683 default y
1684 depends on APM || APM_MODULE
1686 menuconfig APM
1687 tristate "APM (Advanced Power Management) BIOS support"
1688 depends on X86_32 && PM_SLEEP
1689 ---help---
1690 APM is a BIOS specification for saving power using several different
1691 techniques. This is mostly useful for battery powered laptops with
1692 APM compliant BIOSes. If you say Y here, the system time will be
1693 reset after a RESUME operation, the /proc/apm device will provide
1694 battery status information, and user-space programs will receive
1695 notification of APM "events" (e.g. battery status change).
1697 If you select "Y" here, you can disable actual use of the APM
1698 BIOS by passing the "apm=off" option to the kernel at boot time.
1700 Note that the APM support is almost completely disabled for
1701 machines with more than one CPU.
1703 In order to use APM, you will need supporting software. For location
1704 and more information, read <file:Documentation/power/pm.txt> and the
1705 Battery Powered Linux mini-HOWTO, available from
1706 <http://www.tldp.org/docs.html#howto>.
1708 This driver does not spin down disk drives (see the hdparm(8)
1709 manpage ("man 8 hdparm") for that), and it doesn't turn off
1710 VESA-compliant "green" monitors.
1712 This driver does not support the TI 4000M TravelMate and the ACER
1713 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1714 desktop machines also don't have compliant BIOSes, and this driver
1715 may cause those machines to panic during the boot phase.
1717 Generally, if you don't have a battery in your machine, there isn't
1718 much point in using this driver and you should say N. If you get
1719 random kernel OOPSes or reboots that don't seem to be related to
1720 anything, try disabling/enabling this option (or disabling/enabling
1721 APM in your BIOS).
1723 Some other things you should try when experiencing seemingly random,
1724 "weird" problems:
1726 1) make sure that you have enough swap space and that it is
1727 enabled.
1728 2) pass the "no-hlt" option to the kernel
1729 3) switch on floating point emulation in the kernel and pass
1730 the "no387" option to the kernel
1731 4) pass the "floppy=nodma" option to the kernel
1732 5) pass the "mem=4M" option to the kernel (thereby disabling
1733 all but the first 4 MB of RAM)
1734 6) make sure that the CPU is not over clocked.
1735 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1736 8) disable the cache from your BIOS settings
1737 9) install a fan for the video card or exchange video RAM
1738 10) install a better fan for the CPU
1739 11) exchange RAM chips
1740 12) exchange the motherboard.
1742 To compile this driver as a module, choose M here: the
1743 module will be called apm.
1745 if APM
1747 config APM_IGNORE_USER_SUSPEND
1748 bool "Ignore USER SUSPEND"
1749 ---help---
1750 This option will ignore USER SUSPEND requests. On machines with a
1751 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1752 series notebooks, it is necessary to say Y because of a BIOS bug.
1754 config APM_DO_ENABLE
1755 bool "Enable PM at boot time"
1756 ---help---
1757 Enable APM features at boot time. From page 36 of the APM BIOS
1758 specification: "When disabled, the APM BIOS does not automatically
1759 power manage devices, enter the Standby State, enter the Suspend
1760 State, or take power saving steps in response to CPU Idle calls."
1761 This driver will make CPU Idle calls when Linux is idle (unless this
1762 feature is turned off -- see "Do CPU IDLE calls", below). This
1763 should always save battery power, but more complicated APM features
1764 will be dependent on your BIOS implementation. You may need to turn
1765 this option off if your computer hangs at boot time when using APM
1766 support, or if it beeps continuously instead of suspending. Turn
1767 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1768 T400CDT. This is off by default since most machines do fine without
1769 this feature.
1771 config APM_CPU_IDLE
1772 bool "Make CPU Idle calls when idle"
1773 ---help---
1774 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1775 On some machines, this can activate improved power savings, such as
1776 a slowed CPU clock rate, when the machine is idle. These idle calls
1777 are made after the idle loop has run for some length of time (e.g.,
1778 333 mS). On some machines, this will cause a hang at boot time or
1779 whenever the CPU becomes idle. (On machines with more than one CPU,
1780 this option does nothing.)
1782 config APM_DISPLAY_BLANK
1783 bool "Enable console blanking using APM"
1784 ---help---
1785 Enable console blanking using the APM. Some laptops can use this to
1786 turn off the LCD backlight when the screen blanker of the Linux
1787 virtual console blanks the screen. Note that this is only used by
1788 the virtual console screen blanker, and won't turn off the backlight
1789 when using the X Window system. This also doesn't have anything to
1790 do with your VESA-compliant power-saving monitor. Further, this
1791 option doesn't work for all laptops -- it might not turn off your
1792 backlight at all, or it might print a lot of errors to the console,
1793 especially if you are using gpm.
1795 config APM_ALLOW_INTS
1796 bool "Allow interrupts during APM BIOS calls"
1797 ---help---
1798 Normally we disable external interrupts while we are making calls to
1799 the APM BIOS as a measure to lessen the effects of a badly behaving
1800 BIOS implementation. The BIOS should reenable interrupts if it
1801 needs to. Unfortunately, some BIOSes do not -- especially those in
1802 many of the newer IBM Thinkpads. If you experience hangs when you
1803 suspend, try setting this to Y. Otherwise, say N.
1805 endif # APM
1807 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1809 source "drivers/cpuidle/Kconfig"
1811 source "drivers/idle/Kconfig"
1813 endmenu
1816 menu "Bus options (PCI etc.)"
1818 config PCI
1819 bool "PCI support"
1820 default y
1821 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1822 ---help---
1823 Find out whether you have a PCI motherboard. PCI is the name of a
1824 bus system, i.e. the way the CPU talks to the other stuff inside
1825 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1826 VESA. If you have PCI, say Y, otherwise N.
1828 choice
1829 prompt "PCI access mode"
1830 depends on X86_32 && PCI
1831 default PCI_GOANY
1832 ---help---
1833 On PCI systems, the BIOS can be used to detect the PCI devices and
1834 determine their configuration. However, some old PCI motherboards
1835 have BIOS bugs and may crash if this is done. Also, some embedded
1836 PCI-based systems don't have any BIOS at all. Linux can also try to
1837 detect the PCI hardware directly without using the BIOS.
1839 With this option, you can specify how Linux should detect the
1840 PCI devices. If you choose "BIOS", the BIOS will be used,
1841 if you choose "Direct", the BIOS won't be used, and if you
1842 choose "MMConfig", then PCI Express MMCONFIG will be used.
1843 If you choose "Any", the kernel will try MMCONFIG, then the
1844 direct access method and falls back to the BIOS if that doesn't
1845 work. If unsure, go with the default, which is "Any".
1847 config PCI_GOBIOS
1848 bool "BIOS"
1850 config PCI_GOMMCONFIG
1851 bool "MMConfig"
1853 config PCI_GODIRECT
1854 bool "Direct"
1856 config PCI_GOOLPC
1857 bool "OLPC"
1858 depends on OLPC
1860 config PCI_GOANY
1861 bool "Any"
1863 endchoice
1865 config PCI_BIOS
1866 def_bool y
1867 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1869 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1870 config PCI_DIRECT
1871 def_bool y
1872 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1874 config PCI_MMCONFIG
1875 def_bool y
1876 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1878 config PCI_OLPC
1879 def_bool y
1880 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1882 config PCI_DOMAINS
1883 def_bool y
1884 depends on PCI
1886 config PCI_MMCONFIG
1887 bool "Support mmconfig PCI config space access"
1888 depends on X86_64 && PCI && ACPI
1890 config DMAR
1891 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1892 depends on PCI_MSI && ACPI && EXPERIMENTAL
1893 help
1894 DMA remapping (DMAR) devices support enables independent address
1895 translations for Direct Memory Access (DMA) from devices.
1896 These DMA remapping devices are reported via ACPI tables
1897 and include PCI device scope covered by these DMA
1898 remapping devices.
1900 config DMAR_DEFAULT_ON
1901 def_bool y
1902 prompt "Enable DMA Remapping Devices by default"
1903 depends on DMAR
1904 help
1905 Selecting this option will enable a DMAR device at boot time if
1906 one is found. If this option is not selected, DMAR support can
1907 be enabled by passing intel_iommu=on to the kernel. It is
1908 recommended you say N here while the DMAR code remains
1909 experimental.
1911 config DMAR_GFX_WA
1912 def_bool y
1913 prompt "Support for Graphics workaround"
1914 depends on DMAR
1915 ---help---
1916 Current Graphics drivers tend to use physical address
1917 for DMA and avoid using DMA APIs. Setting this config
1918 option permits the IOMMU driver to set a unity map for
1919 all the OS-visible memory. Hence the driver can continue
1920 to use physical addresses for DMA.
1922 config DMAR_FLOPPY_WA
1923 def_bool y
1924 depends on DMAR
1925 ---help---
1926 Floppy disk drivers are know to bypass DMA API calls
1927 thereby failing to work when IOMMU is enabled. This
1928 workaround will setup a 1:1 mapping for the first
1929 16M to make floppy (an ISA device) work.
1931 config INTR_REMAP
1932 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1933 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1934 ---help---
1935 Supports Interrupt remapping for IO-APIC and MSI devices.
1936 To use x2apic mode in the CPU's which support x2APIC enhancements or
1937 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1939 source "drivers/pci/pcie/Kconfig"
1941 source "drivers/pci/Kconfig"
1943 # x86_64 have no ISA slots, but do have ISA-style DMA.
1944 config ISA_DMA_API
1945 def_bool y
1947 if X86_32
1949 config ISA
1950 bool "ISA support"
1951 ---help---
1952 Find out whether you have ISA slots on your motherboard. ISA is the
1953 name of a bus system, i.e. the way the CPU talks to the other stuff
1954 inside your box. Other bus systems are PCI, EISA, MicroChannel
1955 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1956 newer boards don't support it. If you have ISA, say Y, otherwise N.
1958 config EISA
1959 bool "EISA support"
1960 depends on ISA
1961 ---help---
1962 The Extended Industry Standard Architecture (EISA) bus was
1963 developed as an open alternative to the IBM MicroChannel bus.
1965 The EISA bus provided some of the features of the IBM MicroChannel
1966 bus while maintaining backward compatibility with cards made for
1967 the older ISA bus. The EISA bus saw limited use between 1988 and
1968 1995 when it was made obsolete by the PCI bus.
1970 Say Y here if you are building a kernel for an EISA-based machine.
1972 Otherwise, say N.
1974 source "drivers/eisa/Kconfig"
1976 config MCA
1977 bool "MCA support"
1978 ---help---
1979 MicroChannel Architecture is found in some IBM PS/2 machines and
1980 laptops. It is a bus system similar to PCI or ISA. See
1981 <file:Documentation/mca.txt> (and especially the web page given
1982 there) before attempting to build an MCA bus kernel.
1984 source "drivers/mca/Kconfig"
1986 config SCx200
1987 tristate "NatSemi SCx200 support"
1988 ---help---
1989 This provides basic support for National Semiconductor's
1990 (now AMD's) Geode processors. The driver probes for the
1991 PCI-IDs of several on-chip devices, so its a good dependency
1992 for other scx200_* drivers.
1994 If compiled as a module, the driver is named scx200.
1996 config SCx200HR_TIMER
1997 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1998 depends on SCx200 && GENERIC_TIME
1999 default y
2000 ---help---
2001 This driver provides a clocksource built upon the on-chip
2002 27MHz high-resolution timer. Its also a workaround for
2003 NSC Geode SC-1100's buggy TSC, which loses time when the
2004 processor goes idle (as is done by the scheduler). The
2005 other workaround is idle=poll boot option.
2007 config GEODE_MFGPT_TIMER
2008 def_bool y
2009 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2010 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2011 ---help---
2012 This driver provides a clock event source based on the MFGPT
2013 timer(s) in the CS5535 and CS5536 companion chip for the geode.
2014 MFGPTs have a better resolution and max interval than the
2015 generic PIT, and are suitable for use as high-res timers.
2017 config OLPC
2018 bool "One Laptop Per Child support"
2019 default n
2020 ---help---
2021 Add support for detecting the unique features of the OLPC
2022 XO hardware.
2024 endif # X86_32
2026 config K8_NB
2027 def_bool y
2028 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2030 source "drivers/pcmcia/Kconfig"
2032 source "drivers/pci/hotplug/Kconfig"
2034 endmenu
2037 menu "Executable file formats / Emulations"
2039 source "fs/Kconfig.binfmt"
2041 config IA32_EMULATION
2042 bool "IA32 Emulation"
2043 depends on X86_64
2044 select COMPAT_BINFMT_ELF
2045 ---help---
2046 Include code to run 32-bit programs under a 64-bit kernel. You should
2047 likely turn this on, unless you're 100% sure that you don't have any
2048 32-bit programs left.
2050 config IA32_AOUT
2051 tristate "IA32 a.out support"
2052 depends on IA32_EMULATION
2053 ---help---
2054 Support old a.out binaries in the 32bit emulation.
2056 config COMPAT
2057 def_bool y
2058 depends on IA32_EMULATION
2060 config COMPAT_FOR_U64_ALIGNMENT
2061 def_bool COMPAT
2062 depends on X86_64
2064 config SYSVIPC_COMPAT
2065 def_bool y
2066 depends on COMPAT && SYSVIPC
2068 endmenu
2071 config HAVE_ATOMIC_IOMAP
2072 def_bool y
2073 depends on X86_32
2075 source "net/Kconfig"
2077 source "drivers/Kconfig"
2079 source "drivers/firmware/Kconfig"
2081 source "fs/Kconfig"
2083 source "arch/x86/Kconfig.debug"
2085 source "security/Kconfig"
2087 source "crypto/Kconfig"
2089 source "arch/x86/kvm/Kconfig"
2091 source "lib/Kconfig"