| blob | e98e81a04971f1c953533982f6b127573e4058c1 |
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_COUNTERS 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 FAST_CMPXCHG_LOCAL
90 bool
91 default y
93 config MMU
94 def_bool y
96 config ZONE_DMA
97 def_bool y
99 config SBUS
100 bool
102 config GENERIC_ISA_DMA
103 def_bool y
105 config GENERIC_IOMAP
106 def_bool y
108 config GENERIC_BUG
109 def_bool y
110 depends on BUG
111 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
113 config GENERIC_BUG_RELATIVE_POINTERS
114 bool
116 config GENERIC_HWEIGHT
117 def_bool y
119 config GENERIC_GPIO
120 bool
122 config ARCH_MAY_HAVE_PC_FDC
123 def_bool y
125 config RWSEM_GENERIC_SPINLOCK
126 def_bool !X86_XADD
128 config RWSEM_XCHGADD_ALGORITHM
129 def_bool X86_XADD
131 config ARCH_HAS_CPU_IDLE_WAIT
132 def_bool y
134 config GENERIC_CALIBRATE_DELAY
135 def_bool y
137 config GENERIC_TIME_VSYSCALL
138 bool
139 default X86_64
141 config ARCH_HAS_CPU_RELAX
142 def_bool y
144 config ARCH_HAS_DEFAULT_IDLE
145 def_bool y
147 config ARCH_HAS_CACHE_LINE_SIZE
148 def_bool y
150 config HAVE_SETUP_PER_CPU_AREA
151 def_bool y
153 config NEED_PER_CPU_EMBED_FIRST_CHUNK
154 def_bool y
156 config NEED_PER_CPU_PAGE_FIRST_CHUNK
157 def_bool y
159 config HAVE_CPUMASK_OF_CPU_MAP
160 def_bool X86_64_SMP
162 config ARCH_HIBERNATION_POSSIBLE
163 def_bool y
165 config ARCH_SUSPEND_POSSIBLE
166 def_bool y
168 config ZONE_DMA32
169 bool
170 default X86_64
172 config ARCH_POPULATES_NODE_MAP
173 def_bool y
175 config AUDIT_ARCH
176 bool
177 default X86_64
179 config ARCH_SUPPORTS_OPTIMIZED_INLINING
180 def_bool y
182 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
183 def_bool y
185 config HAVE_INTEL_TXT
186 def_bool y
187 depends on EXPERIMENTAL && DMAR && ACPI
189 # Use the generic interrupt handling code in kernel/irq/:
190 config GENERIC_HARDIRQS
191 bool
192 default y
194 config GENERIC_HARDIRQS_NO__DO_IRQ
195 def_bool y
197 config GENERIC_IRQ_PROBE
198 bool
199 default y
201 config GENERIC_PENDING_IRQ
202 bool
203 depends on GENERIC_HARDIRQS && SMP
204 default y
206 config USE_GENERIC_SMP_HELPERS
207 def_bool y
208 depends on SMP
210 config X86_32_SMP
211 def_bool y
212 depends on X86_32 && SMP
214 config X86_64_SMP
215 def_bool y
216 depends on X86_64 && SMP
218 config X86_HT
219 bool
220 depends on SMP
221 default y
223 config X86_TRAMPOLINE
224 bool
225 depends on SMP || (64BIT && ACPI_SLEEP)
226 default y
228 config X86_32_LAZY_GS
229 def_bool y
230 depends on X86_32 && !CC_STACKPROTECTOR
232 config KTIME_SCALAR
233 def_bool X86_32
234 source "init/Kconfig"
235 source "kernel/Kconfig.freezer"
237 menu "Processor type and features"
239 source "kernel/time/Kconfig"
241 config SMP
242 bool "Symmetric multi-processing support"
243 ---help---
244 This enables support for systems with more than one CPU. If you have
245 a system with only one CPU, like most personal computers, say N. If
246 you have a system with more than one CPU, say Y.
248 If you say N here, the kernel will run on single and multiprocessor
249 machines, but will use only one CPU of a multiprocessor machine. If
250 you say Y here, the kernel will run on many, but not all,
251 singleprocessor machines. On a singleprocessor machine, the kernel
252 will run faster if you say N here.
254 Note that if you say Y here and choose architecture "586" or
255 "Pentium" under "Processor family", the kernel will not work on 486
256 architectures. Similarly, multiprocessor kernels for the "PPro"
257 architecture may not work on all Pentium based boards.
259 People using multiprocessor machines who say Y here should also say
260 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
261 Management" code will be disabled if you say Y here.
263 See also <file:Documentation/i386/IO-APIC.txt>,
264 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
265 <http://www.tldp.org/docs.html#howto>.
267 If you don't know what to do here, say N.
269 config X86_X2APIC
270 bool "Support x2apic"
271 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
272 ---help---
273 This enables x2apic support on CPUs that have this feature.
275 This allows 32-bit apic IDs (so it can support very large systems),
276 and accesses the local apic via MSRs not via mmio.
278 If you don't know what to do here, say N.
280 config SPARSE_IRQ
281 bool "Support sparse irq numbering"
282 depends on PCI_MSI || HT_IRQ
283 ---help---
284 This enables support for sparse irqs. This is useful for distro
285 kernels that want to define a high CONFIG_NR_CPUS value but still
286 want to have low kernel memory footprint on smaller machines.
288 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
289 out the irq_desc[] array in a more NUMA-friendly way. )
291 If you don't know what to do here, say N.
293 config NUMA_IRQ_DESC
294 def_bool y
295 depends on SPARSE_IRQ && NUMA
297 config X86_MPPARSE
298 bool "Enable MPS table" if ACPI
299 default y
300 depends on X86_LOCAL_APIC
301 ---help---
302 For old smp systems that do not have proper acpi support. Newer systems
303 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
305 config X86_BIGSMP
306 bool "Support for big SMP systems with more than 8 CPUs"
307 depends on X86_32 && SMP
308 ---help---
309 This option is needed for the systems that have more than 8 CPUs
311 if X86_32
312 config X86_EXTENDED_PLATFORM
313 bool "Support for extended (non-PC) x86 platforms"
314 default y
315 ---help---
316 If you disable this option then the kernel will only support
317 standard PC platforms. (which covers the vast majority of
318 systems out there.)
320 If you enable this option then you'll be able to select support
321 for the following (non-PC) 32 bit x86 platforms:
322 AMD Elan
323 NUMAQ (IBM/Sequent)
324 RDC R-321x SoC
325 SGI 320/540 (Visual Workstation)
326 Summit/EXA (IBM x440)
327 Unisys ES7000 IA32 series
329 If you have one of these systems, or if you want to build a
330 generic distribution kernel, say Y here - otherwise say N.
331 endif
333 if X86_64
334 config X86_EXTENDED_PLATFORM
335 bool "Support for extended (non-PC) x86 platforms"
336 default y
337 ---help---
338 If you disable this option then the kernel will only support
339 standard PC platforms. (which covers the vast majority of
340 systems out there.)
342 If you enable this option then you'll be able to select support
343 for the following (non-PC) 64 bit x86 platforms:
344 ScaleMP vSMP
345 SGI Ultraviolet
347 If you have one of these systems, or if you want to build a
348 generic distribution kernel, say Y here - otherwise say N.
349 endif
350 # This is an alphabetically sorted list of 64 bit extended platforms
351 # Please maintain the alphabetic order if and when there are additions
353 config X86_VSMP
354 bool "ScaleMP vSMP"
355 select PARAVIRT
356 depends on X86_64 && PCI
357 depends on X86_EXTENDED_PLATFORM
358 ---help---
359 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
360 supposed to run on these EM64T-based machines. Only choose this option
361 if you have one of these machines.
363 config X86_UV
364 bool "SGI Ultraviolet"
365 depends on X86_64
366 depends on X86_EXTENDED_PLATFORM
367 depends on NUMA
368 depends on X86_X2APIC
369 ---help---
370 This option is needed in order to support SGI Ultraviolet systems.
371 If you don't have one of these, you should say N here.
373 # Following is an alphabetically sorted list of 32 bit extended platforms
374 # Please maintain the alphabetic order if and when there are additions
376 config X86_ELAN
377 bool "AMD Elan"
378 depends on X86_32
379 depends on X86_EXTENDED_PLATFORM
380 ---help---
381 Select this for an AMD Elan processor.
383 Do not use this option for K6/Athlon/Opteron processors!
385 If unsure, choose "PC-compatible" instead.
387 config X86_RDC321X
388 bool "RDC R-321x SoC"
389 depends on X86_32
390 depends on X86_EXTENDED_PLATFORM
391 select M486
392 select X86_REBOOTFIXUPS
393 ---help---
394 This option is needed for RDC R-321x system-on-chip, also known
395 as R-8610-(G).
396 If you don't have one of these chips, you should say N here.
398 config X86_32_NON_STANDARD
399 bool "Support non-standard 32-bit SMP architectures"
400 depends on X86_32 && SMP
401 depends on X86_EXTENDED_PLATFORM
402 ---help---
403 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
404 subarchitectures. It is intended for a generic binary kernel.
405 if you select them all, kernel will probe it one by one. and will
406 fallback to default.
408 # Alphabetically sorted list of Non standard 32 bit platforms
410 config X86_NUMAQ
411 bool "NUMAQ (IBM/Sequent)"
412 depends on X86_32_NON_STANDARD
413 select NUMA
414 select X86_MPPARSE
415 ---help---
416 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
417 NUMA multiquad box. This changes the way that processors are
418 bootstrapped, and uses Clustered Logical APIC addressing mode instead
419 of Flat Logical. You will need a new lynxer.elf file to flash your
420 firmware with - send email to <Martin.Bligh@us.ibm.com>.
422 config X86_VISWS
423 bool "SGI 320/540 (Visual Workstation)"
424 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
425 depends on X86_32_NON_STANDARD
426 ---help---
427 The SGI Visual Workstation series is an IA32-based workstation
428 based on SGI systems chips with some legacy PC hardware attached.
430 Say Y here to create a kernel to run on the SGI 320 or 540.
432 A kernel compiled for the Visual Workstation will run on general
433 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
435 config X86_SUMMIT
436 bool "Summit/EXA (IBM x440)"
437 depends on X86_32_NON_STANDARD
438 ---help---
439 This option is needed for IBM systems that use the Summit/EXA chipset.
440 In particular, it is needed for the x440.
442 config X86_ES7000
443 bool "Unisys ES7000 IA32 series"
444 depends on X86_32_NON_STANDARD && X86_BIGSMP
445 ---help---
446 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
447 supposed to run on an IA32-based Unisys ES7000 system.
449 config SCHED_OMIT_FRAME_POINTER
450 def_bool y
451 prompt "Single-depth WCHAN output"
452 depends on X86
453 ---help---
454 Calculate simpler /proc/<PID>/wchan values. If this option
455 is disabled then wchan values will recurse back to the
456 caller function. This provides more accurate wchan values,
457 at the expense of slightly more scheduling overhead.
459 If in doubt, say "Y".
461 menuconfig PARAVIRT_GUEST
462 bool "Paravirtualized guest support"
463 ---help---
464 Say Y here to get to see options related to running Linux under
465 various hypervisors. This option alone does not add any kernel code.
467 If you say N, all options in this submenu will be skipped and disabled.
469 if PARAVIRT_GUEST
471 source "arch/x86/xen/Kconfig"
473 config VMI
474 bool "VMI Guest support"
475 select PARAVIRT
476 depends on X86_32
477 ---help---
478 VMI provides a paravirtualized interface to the VMware ESX server
479 (it could be used by other hypervisors in theory too, but is not
480 at the moment), by linking the kernel to a GPL-ed ROM module
481 provided by the hypervisor.
483 config KVM_CLOCK
484 bool "KVM paravirtualized clock"
485 select PARAVIRT
486 select PARAVIRT_CLOCK
487 ---help---
488 Turning on this option will allow you to run a paravirtualized clock
489 when running over the KVM hypervisor. Instead of relying on a PIT
490 (or probably other) emulation by the underlying device model, the host
491 provides the guest with timing infrastructure such as time of day, and
492 system time
494 config KVM_GUEST
495 bool "KVM Guest support"
496 select PARAVIRT
497 ---help---
498 This option enables various optimizations for running under the KVM
499 hypervisor.
501 source "arch/x86/lguest/Kconfig"
503 config PARAVIRT
504 bool "Enable paravirtualization code"
505 ---help---
506 This changes the kernel so it can modify itself when it is run
507 under a hypervisor, potentially improving performance significantly
508 over full virtualization. However, when run without a hypervisor
509 the kernel is theoretically slower and slightly larger.
511 config PARAVIRT_SPINLOCKS
512 bool "Paravirtualization layer for spinlocks"
513 depends on PARAVIRT && SMP && EXPERIMENTAL
514 ---help---
515 Paravirtualized spinlocks allow a pvops backend to replace the
516 spinlock implementation with something virtualization-friendly
517 (for example, block the virtual CPU rather than spinning).
519 Unfortunately the downside is an up to 5% performance hit on
520 native kernels, with various workloads.
522 If you are unsure how to answer this question, answer N.
524 config PARAVIRT_CLOCK
525 bool
526 default n
528 endif
530 config PARAVIRT_DEBUG
531 bool "paravirt-ops debugging"
532 depends on PARAVIRT && DEBUG_KERNEL
533 ---help---
534 Enable to debug paravirt_ops internals. Specifically, BUG if
535 a paravirt_op is missing when it is called.
537 config MEMTEST
538 bool "Memtest"
539 ---help---
540 This option adds a kernel parameter 'memtest', which allows memtest
541 to be set.
542 memtest=0, mean disabled; -- default
543 memtest=1, mean do 1 test pattern;
544 ...
545 memtest=4, mean do 4 test patterns.
546 If you are unsure how to answer this question, answer N.
548 config X86_SUMMIT_NUMA
549 def_bool y
550 depends on X86_32 && NUMA && X86_32_NON_STANDARD
552 config X86_CYCLONE_TIMER
553 def_bool y
554 depends on X86_32_NON_STANDARD
556 source "arch/x86/Kconfig.cpu"
558 config HPET_TIMER
559 def_bool X86_64
560 prompt "HPET Timer Support" if X86_32
561 ---help---
562 Use the IA-PC HPET (High Precision Event Timer) to manage
563 time in preference to the PIT and RTC, if a HPET is
564 present.
565 HPET is the next generation timer replacing legacy 8254s.
566 The HPET provides a stable time base on SMP
567 systems, unlike the TSC, but it is more expensive to access,
568 as it is off-chip. You can find the HPET spec at
569 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
571 You can safely choose Y here. However, HPET will only be
572 activated if the platform and the BIOS support this feature.
573 Otherwise the 8254 will be used for timing services.
575 Choose N to continue using the legacy 8254 timer.
577 config HPET_EMULATE_RTC
578 def_bool y
579 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
581 # Mark as embedded because too many people got it wrong.
582 # The code disables itself when not needed.
583 config DMI
584 default y
585 bool "Enable DMI scanning" if EMBEDDED
586 ---help---
587 Enabled scanning of DMI to identify machine quirks. Say Y
588 here unless you have verified that your setup is not
589 affected by entries in the DMI blacklist. Required by PNP
590 BIOS code.
592 config GART_IOMMU
593 bool "GART IOMMU support" if EMBEDDED
594 default y
595 select SWIOTLB
596 depends on X86_64 && PCI
597 ---help---
598 Support for full DMA access of devices with 32bit memory access only
599 on systems with more than 3GB. This is usually needed for USB,
600 sound, many IDE/SATA chipsets and some other devices.
601 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
602 based hardware IOMMU and a software bounce buffer based IOMMU used
603 on Intel systems and as fallback.
604 The code is only active when needed (enough memory and limited
605 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
606 too.
608 config CALGARY_IOMMU
609 bool "IBM Calgary IOMMU support"
610 select SWIOTLB
611 depends on X86_64 && PCI && EXPERIMENTAL
612 ---help---
613 Support for hardware IOMMUs in IBM's xSeries x366 and x460
614 systems. Needed to run systems with more than 3GB of memory
615 properly with 32-bit PCI devices that do not support DAC
616 (Double Address Cycle). Calgary also supports bus level
617 isolation, where all DMAs pass through the IOMMU. This
618 prevents them from going anywhere except their intended
619 destination. This catches hard-to-find kernel bugs and
620 mis-behaving drivers and devices that do not use the DMA-API
621 properly to set up their DMA buffers. The IOMMU can be
622 turned off at boot time with the iommu=off parameter.
623 Normally the kernel will make the right choice by itself.
624 If unsure, say Y.
626 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
627 def_bool y
628 prompt "Should Calgary be enabled by default?"
629 depends on CALGARY_IOMMU
630 ---help---
631 Should Calgary be enabled by default? if you choose 'y', Calgary
632 will be used (if it exists). If you choose 'n', Calgary will not be
633 used even if it exists. If you choose 'n' and would like to use
634 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
635 If unsure, say Y.
637 config AMD_IOMMU
638 bool "AMD IOMMU support"
639 select SWIOTLB
640 select PCI_MSI
641 depends on X86_64 && PCI && ACPI
642 ---help---
643 With this option you can enable support for AMD IOMMU hardware in
644 your system. An IOMMU is a hardware component which provides
645 remapping of DMA memory accesses from devices. With an AMD IOMMU you
646 can isolate the the DMA memory of different devices and protect the
647 system from misbehaving device drivers or hardware.
649 You can find out if your system has an AMD IOMMU if you look into
650 your BIOS for an option to enable it or if you have an IVRS ACPI
651 table.
653 config AMD_IOMMU_STATS
654 bool "Export AMD IOMMU statistics to debugfs"
655 depends on AMD_IOMMU
656 select DEBUG_FS
657 ---help---
658 This option enables code in the AMD IOMMU driver to collect various
659 statistics about whats happening in the driver and exports that
660 information to userspace via debugfs.
661 If unsure, say N.
663 # need this always selected by IOMMU for the VIA workaround
664 config SWIOTLB
665 def_bool y if X86_64
666 ---help---
667 Support for software bounce buffers used on x86-64 systems
668 which don't have a hardware IOMMU (e.g. the current generation
669 of Intel's x86-64 CPUs). Using this PCI devices which can only
670 access 32-bits of memory can be used on systems with more than
671 3 GB of memory. If unsure, say Y.
673 config IOMMU_HELPER
674 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
676 config IOMMU_API
677 def_bool (AMD_IOMMU || DMAR)
679 config MAXSMP
680 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
681 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
682 select CPUMASK_OFFSTACK
683 default n
684 ---help---
685 Configure maximum number of CPUS and NUMA Nodes for this architecture.
686 If unsure, say N.
688 config NR_CPUS
689 int "Maximum number of CPUs" if SMP && !MAXSMP
690 range 2 8 if SMP && X86_32 && !X86_BIGSMP
691 range 2 512 if SMP && !MAXSMP
692 default "1" if !SMP
693 default "4096" if MAXSMP
694 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
695 default "8" if SMP
696 ---help---
697 This allows you to specify the maximum number of CPUs which this
698 kernel will support. The maximum supported value is 512 and the
699 minimum value which makes sense is 2.
701 This is purely to save memory - each supported CPU adds
702 approximately eight kilobytes to the kernel image.
704 config SCHED_SMT
705 bool "SMT (Hyperthreading) scheduler support"
706 depends on X86_HT
707 ---help---
708 SMT scheduler support improves the CPU scheduler's decision making
709 when dealing with Intel Pentium 4 chips with HyperThreading at a
710 cost of slightly increased overhead in some places. If unsure say
711 N here.
713 config SCHED_MC
714 def_bool y
715 prompt "Multi-core scheduler support"
716 depends on X86_HT
717 ---help---
718 Multi-core scheduler support improves the CPU scheduler's decision
719 making when dealing with multi-core CPU chips at a cost of slightly
720 increased overhead in some places. If unsure say N here.
722 source "kernel/Kconfig.preempt"
724 config X86_UP_APIC
725 bool "Local APIC support on uniprocessors"
726 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
727 ---help---
728 A local APIC (Advanced Programmable Interrupt Controller) is an
729 integrated interrupt controller in the CPU. If you have a single-CPU
730 system which has a processor with a local APIC, you can say Y here to
731 enable and use it. If you say Y here even though your machine doesn't
732 have a local APIC, then the kernel will still run with no slowdown at
733 all. The local APIC supports CPU-generated self-interrupts (timer,
734 performance counters), and the NMI watchdog which detects hard
735 lockups.
737 config X86_UP_IOAPIC
738 bool "IO-APIC support on uniprocessors"
739 depends on X86_UP_APIC
740 ---help---
741 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
742 SMP-capable replacement for PC-style interrupt controllers. Most
743 SMP systems and many recent uniprocessor systems have one.
745 If you have a single-CPU system with an IO-APIC, you can say Y here
746 to use it. If you say Y here even though your machine doesn't have
747 an IO-APIC, then the kernel will still run with no slowdown at all.
749 config X86_LOCAL_APIC
750 def_bool y
751 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
753 config X86_IO_APIC
754 def_bool y
755 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
757 config X86_VISWS_APIC
758 def_bool y
759 depends on X86_32 && X86_VISWS
761 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
762 bool "Reroute for broken boot IRQs"
763 default n
764 depends on X86_IO_APIC
765 ---help---
766 This option enables a workaround that fixes a source of
767 spurious interrupts. This is recommended when threaded
768 interrupt handling is used on systems where the generation of
769 superfluous "boot interrupts" cannot be disabled.
771 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
772 entry in the chipset's IO-APIC is masked (as, e.g. the RT
773 kernel does during interrupt handling). On chipsets where this
774 boot IRQ generation cannot be disabled, this workaround keeps
775 the original IRQ line masked so that only the equivalent "boot
776 IRQ" is delivered to the CPUs. The workaround also tells the
777 kernel to set up the IRQ handler on the boot IRQ line. In this
778 way only one interrupt is delivered to the kernel. Otherwise
779 the spurious second interrupt may cause the kernel to bring
780 down (vital) interrupt lines.
782 Only affects "broken" chipsets. Interrupt sharing may be
783 increased on these systems.
785 config X86_MCE
786 bool "Machine Check Exception"
787 ---help---
788 Machine Check Exception support allows the processor to notify the
789 kernel if it detects a problem (e.g. overheating, component failure).
790 The action the kernel takes depends on the severity of the problem,
791 ranging from a warning message on the console, to halting the machine.
792 Your processor must be a Pentium or newer to support this - check the
793 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
794 have a design flaw which leads to false MCE events - hence MCE is
795 disabled on all P5 processors, unless explicitly enabled with "mce"
796 as a boot argument. Similarly, if MCE is built in and creates a
797 problem on some new non-standard machine, you can boot with "nomce"
798 to disable it. MCE support simply ignores non-MCE processors like
799 the 386 and 486, so nearly everyone can say Y here.
801 config X86_OLD_MCE
802 depends on X86_32 && X86_MCE
803 bool "Use legacy machine check code (will go away)"
804 default n
805 select X86_ANCIENT_MCE
806 ---help---
807 Use the old i386 machine check code. This is merely intended for
808 testing in a transition period. Try this if you run into any machine
809 check related software problems, but report the problem to
810 linux-kernel. When in doubt say no.
812 config X86_NEW_MCE
813 depends on X86_MCE
814 bool
815 default y if (!X86_OLD_MCE && X86_32) || X86_64
817 config X86_MCE_INTEL
818 def_bool y
819 prompt "Intel MCE features"
820 depends on X86_NEW_MCE && X86_LOCAL_APIC
821 ---help---
822 Additional support for intel specific MCE features such as
823 the thermal monitor.
825 config X86_MCE_AMD
826 def_bool y
827 prompt "AMD MCE features"
828 depends on X86_NEW_MCE && X86_LOCAL_APIC
829 ---help---
830 Additional support for AMD specific MCE features such as
831 the DRAM Error Threshold.
833 config X86_ANCIENT_MCE
834 def_bool n
835 depends on X86_32
836 prompt "Support for old Pentium 5 / WinChip machine checks"
837 ---help---
838 Include support for machine check handling on old Pentium 5 or WinChip
839 systems. These typically need to be enabled explicitely on the command
840 line.
842 config X86_MCE_THRESHOLD
843 depends on X86_MCE_AMD || X86_MCE_INTEL
844 bool
845 default y
847 config X86_MCE_INJECT
848 depends on X86_NEW_MCE
849 tristate "Machine check injector support"
850 ---help---
851 Provide support for injecting machine checks for testing purposes.
852 If you don't know what a machine check is and you don't do kernel
853 QA it is safe to say n.
855 config X86_MCE_NONFATAL
856 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
857 depends on X86_OLD_MCE
858 ---help---
859 Enabling this feature starts a timer that triggers every 5 seconds which
860 will look at the machine check registers to see if anything happened.
861 Non-fatal problems automatically get corrected (but still logged).
862 Disable this if you don't want to see these messages.
863 Seeing the messages this option prints out may be indicative of dying
864 or out-of-spec (ie, overclocked) hardware.
865 This option only does something on certain CPUs.
866 (AMD Athlon/Duron and Intel Pentium 4)
868 config X86_MCE_P4THERMAL
869 bool "check for P4 thermal throttling interrupt."
870 depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP)
871 ---help---
872 Enabling this feature will cause a message to be printed when the P4
873 enters thermal throttling.
875 config X86_THERMAL_VECTOR
876 def_bool y
877 depends on X86_MCE_P4THERMAL || X86_MCE_INTEL
879 config VM86
880 bool "Enable VM86 support" if EMBEDDED
881 default y
882 depends on X86_32
883 ---help---
884 This option is required by programs like DOSEMU to run 16-bit legacy
885 code on X86 processors. It also may be needed by software like
886 XFree86 to initialize some video cards via BIOS. Disabling this
887 option saves about 6k.
889 config TOSHIBA
890 tristate "Toshiba Laptop support"
891 depends on X86_32
892 ---help---
893 This adds a driver to safely access the System Management Mode of
894 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
895 not work on models with a Phoenix BIOS. The System Management Mode
896 is used to set the BIOS and power saving options on Toshiba portables.
898 For information on utilities to make use of this driver see the
899 Toshiba Linux utilities web site at:
900 <http://www.buzzard.org.uk/toshiba/>.
902 Say Y if you intend to run this kernel on a Toshiba portable.
903 Say N otherwise.
905 config I8K
906 tristate "Dell laptop support"
907 ---help---
908 This adds a driver to safely access the System Management Mode
909 of the CPU on the Dell Inspiron 8000. The System Management Mode
910 is used to read cpu temperature and cooling fan status and to
911 control the fans on the I8K portables.
913 This driver has been tested only on the Inspiron 8000 but it may
914 also work with other Dell laptops. You can force loading on other
915 models by passing the parameter `force=1' to the module. Use at
916 your own risk.
918 For information on utilities to make use of this driver see the
919 I8K Linux utilities web site at:
920 <http://people.debian.org/~dz/i8k/>
922 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
923 Say N otherwise.
925 config X86_REBOOTFIXUPS
926 bool "Enable X86 board specific fixups for reboot"
927 depends on X86_32
928 ---help---
929 This enables chipset and/or board specific fixups to be done
930 in order to get reboot to work correctly. This is only needed on
931 some combinations of hardware and BIOS. The symptom, for which
932 this config is intended, is when reboot ends with a stalled/hung
933 system.
935 Currently, the only fixup is for the Geode machines using
936 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
938 Say Y if you want to enable the fixup. Currently, it's safe to
939 enable this option even if you don't need it.
940 Say N otherwise.
942 config MICROCODE
943 tristate "/dev/cpu/microcode - microcode support"
944 select FW_LOADER
945 ---help---
946 If you say Y here, you will be able to update the microcode on
947 certain Intel and AMD processors. The Intel support is for the
948 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
949 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
950 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
951 You will obviously need the actual microcode binary data itself
952 which is not shipped with the Linux kernel.
954 This option selects the general module only, you need to select
955 at least one vendor specific module as well.
957 To compile this driver as a module, choose M here: the
958 module will be called microcode.
960 config MICROCODE_INTEL
961 bool "Intel microcode patch loading support"
962 depends on MICROCODE
963 default MICROCODE
964 select FW_LOADER
965 ---help---
966 This options enables microcode patch loading support for Intel
967 processors.
969 For latest news and information on obtaining all the required
970 Intel ingredients for this driver, check:
971 <http://www.urbanmyth.org/microcode/>.
973 config MICROCODE_AMD
974 bool "AMD microcode patch loading support"
975 depends on MICROCODE
976 select FW_LOADER
977 ---help---
978 If you select this option, microcode patch loading support for AMD
979 processors will be enabled.
981 config MICROCODE_OLD_INTERFACE
982 def_bool y
983 depends on MICROCODE
985 config X86_MSR
986 tristate "/dev/cpu/*/msr - Model-specific register support"
987 ---help---
988 This device gives privileged processes access to the x86
989 Model-Specific Registers (MSRs). It is a character device with
990 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
991 MSR accesses are directed to a specific CPU on multi-processor
992 systems.
994 config X86_CPUID
995 tristate "/dev/cpu/*/cpuid - CPU information support"
996 ---help---
997 This device gives processes access to the x86 CPUID instruction to
998 be executed on a specific processor. It is a character device
999 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1000 /dev/cpu/31/cpuid.
1002 config X86_CPU_DEBUG
1003 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
1004 ---help---
1005 If you select this option, this will provide various x86 CPUs
1006 information through debugfs.
1008 choice
1009 prompt "High Memory Support"
1010 default HIGHMEM4G if !X86_NUMAQ
1011 default HIGHMEM64G if X86_NUMAQ
1012 depends on X86_32
1014 config NOHIGHMEM
1015 bool "off"
1016 depends on !X86_NUMAQ
1017 ---help---
1018 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1019 However, the address space of 32-bit x86 processors is only 4
1020 Gigabytes large. That means that, if you have a large amount of
1021 physical memory, not all of it can be "permanently mapped" by the
1022 kernel. The physical memory that's not permanently mapped is called
1023 "high memory".
1025 If you are compiling a kernel which will never run on a machine with
1026 more than 1 Gigabyte total physical RAM, answer "off" here (default
1027 choice and suitable for most users). This will result in a "3GB/1GB"
1028 split: 3GB are mapped so that each process sees a 3GB virtual memory
1029 space and the remaining part of the 4GB virtual memory space is used
1030 by the kernel to permanently map as much physical memory as
1031 possible.
1033 If the machine has between 1 and 4 Gigabytes physical RAM, then
1034 answer "4GB" here.
1036 If more than 4 Gigabytes is used then answer "64GB" here. This
1037 selection turns Intel PAE (Physical Address Extension) mode on.
1038 PAE implements 3-level paging on IA32 processors. PAE is fully
1039 supported by Linux, PAE mode is implemented on all recent Intel
1040 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1041 then the kernel will not boot on CPUs that don't support PAE!
1043 The actual amount of total physical memory will either be
1044 auto detected or can be forced by using a kernel command line option
1045 such as "mem=256M". (Try "man bootparam" or see the documentation of
1046 your boot loader (lilo or loadlin) about how to pass options to the
1047 kernel at boot time.)
1049 If unsure, say "off".
1051 config HIGHMEM4G
1052 bool "4GB"
1053 depends on !X86_NUMAQ
1054 ---help---
1055 Select this if you have a 32-bit processor and between 1 and 4
1056 gigabytes of physical RAM.
1058 config HIGHMEM64G
1059 bool "64GB"
1060 depends on !M386 && !M486
1061 select X86_PAE
1062 ---help---
1063 Select this if you have a 32-bit processor and more than 4
1064 gigabytes of physical RAM.
1066 endchoice
1068 choice
1069 depends on EXPERIMENTAL
1070 prompt "Memory split" if EMBEDDED
1071 default VMSPLIT_3G
1072 depends on X86_32
1073 ---help---
1074 Select the desired split between kernel and user memory.
1076 If the address range available to the kernel is less than the
1077 physical memory installed, the remaining memory will be available
1078 as "high memory". Accessing high memory is a little more costly
1079 than low memory, as it needs to be mapped into the kernel first.
1080 Note that increasing the kernel address space limits the range
1081 available to user programs, making the address space there
1082 tighter. Selecting anything other than the default 3G/1G split
1083 will also likely make your kernel incompatible with binary-only
1084 kernel modules.
1086 If you are not absolutely sure what you are doing, leave this
1087 option alone!
1089 config VMSPLIT_3G
1090 bool "3G/1G user/kernel split"
1091 config VMSPLIT_3G_OPT
1092 depends on !X86_PAE
1093 bool "3G/1G user/kernel split (for full 1G low memory)"
1094 config VMSPLIT_2G
1095 bool "2G/2G user/kernel split"
1096 config VMSPLIT_2G_OPT
1097 depends on !X86_PAE
1098 bool "2G/2G user/kernel split (for full 2G low memory)"
1099 config VMSPLIT_1G
1100 bool "1G/3G user/kernel split"
1101 endchoice
1103 config PAGE_OFFSET
1104 hex
1105 default 0xB0000000 if VMSPLIT_3G_OPT
1106 default 0x80000000 if VMSPLIT_2G
1107 default 0x78000000 if VMSPLIT_2G_OPT
1108 default 0x40000000 if VMSPLIT_1G
1109 default 0xC0000000
1110 depends on X86_32
1112 config HIGHMEM
1113 def_bool y
1114 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1116 config X86_PAE
1117 bool "PAE (Physical Address Extension) Support"
1118 depends on X86_32 && !HIGHMEM4G
1119 ---help---
1120 PAE is required for NX support, and furthermore enables
1121 larger swapspace support for non-overcommit purposes. It
1122 has the cost of more pagetable lookup overhead, and also
1123 consumes more pagetable space per process.
1125 config ARCH_PHYS_ADDR_T_64BIT
1126 def_bool X86_64 || X86_PAE
1128 config DIRECT_GBPAGES
1129 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1130 default y
1131 depends on X86_64
1132 ---help---
1133 Allow the kernel linear mapping to use 1GB pages on CPUs that
1134 support it. This can improve the kernel's performance a tiny bit by
1135 reducing TLB pressure. If in doubt, say "Y".
1137 # Common NUMA Features
1138 config NUMA
1139 bool "Numa Memory Allocation and Scheduler Support"
1140 depends on SMP
1141 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1142 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1143 ---help---
1144 Enable NUMA (Non Uniform Memory Access) support.
1146 The kernel will try to allocate memory used by a CPU on the
1147 local memory controller of the CPU and add some more
1148 NUMA awareness to the kernel.
1150 For 64-bit this is recommended if the system is Intel Core i7
1151 (or later), AMD Opteron, or EM64T NUMA.
1153 For 32-bit this is only needed on (rare) 32-bit-only platforms
1154 that support NUMA topologies, such as NUMAQ / Summit, or if you
1155 boot a 32-bit kernel on a 64-bit NUMA platform.
1157 Otherwise, you should say N.
1159 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1160 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1162 config K8_NUMA
1163 def_bool y
1164 prompt "Old style AMD Opteron NUMA detection"
1165 depends on X86_64 && NUMA && PCI
1166 ---help---
1167 Enable K8 NUMA node topology detection. You should say Y here if
1168 you have a multi processor AMD K8 system. This uses an old
1169 method to read the NUMA configuration directly from the builtin
1170 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1171 instead, which also takes priority if both are compiled in.
1173 config X86_64_ACPI_NUMA
1174 def_bool y
1175 prompt "ACPI NUMA detection"
1176 depends on X86_64 && NUMA && ACPI && PCI
1177 select ACPI_NUMA
1178 ---help---
1179 Enable ACPI SRAT based node topology detection.
1181 # Some NUMA nodes have memory ranges that span
1182 # other nodes. Even though a pfn is valid and
1183 # between a node's start and end pfns, it may not
1184 # reside on that node. See memmap_init_zone()
1185 # for details.
1186 config NODES_SPAN_OTHER_NODES
1187 def_bool y
1188 depends on X86_64_ACPI_NUMA
1190 config NUMA_EMU
1191 bool "NUMA emulation"
1192 depends on X86_64 && NUMA
1193 ---help---
1194 Enable NUMA emulation. A flat machine will be split
1195 into virtual nodes when booted with "numa=fake=N", where N is the
1196 number of nodes. This is only useful for debugging.
1198 config NODES_SHIFT
1199 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1200 range 1 9
1201 default "9" if MAXSMP
1202 default "6" if X86_64
1203 default "4" if X86_NUMAQ
1204 default "3"
1205 depends on NEED_MULTIPLE_NODES
1206 ---help---
1207 Specify the maximum number of NUMA Nodes available on the target
1208 system. Increases memory reserved to accommodate various tables.
1210 config HAVE_ARCH_BOOTMEM
1211 def_bool y
1212 depends on X86_32 && NUMA
1214 config ARCH_HAVE_MEMORY_PRESENT
1215 def_bool y
1216 depends on X86_32 && DISCONTIGMEM
1218 config NEED_NODE_MEMMAP_SIZE
1219 def_bool y
1220 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1222 config HAVE_ARCH_ALLOC_REMAP
1223 def_bool y
1224 depends on X86_32 && NUMA
1226 config ARCH_FLATMEM_ENABLE
1227 def_bool y
1228 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1230 config ARCH_DISCONTIGMEM_ENABLE
1231 def_bool y
1232 depends on NUMA && X86_32
1234 config ARCH_DISCONTIGMEM_DEFAULT
1235 def_bool y
1236 depends on NUMA && X86_32
1238 config ARCH_SPARSEMEM_DEFAULT
1239 def_bool y
1240 depends on X86_64
1242 config ARCH_SPARSEMEM_ENABLE
1243 def_bool y
1244 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1245 select SPARSEMEM_STATIC if X86_32
1246 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1248 config ARCH_SELECT_MEMORY_MODEL
1249 def_bool y
1250 depends on ARCH_SPARSEMEM_ENABLE
1252 config ARCH_MEMORY_PROBE
1253 def_bool X86_64
1254 depends on MEMORY_HOTPLUG
1256 source "mm/Kconfig"
1258 config HIGHPTE
1259 bool "Allocate 3rd-level pagetables from highmem"
1260 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1261 ---help---
1262 The VM uses one page table entry for each page of physical memory.
1263 For systems with a lot of RAM, this can be wasteful of precious
1264 low memory. Setting this option will put user-space page table
1265 entries in high memory.
1267 config X86_CHECK_BIOS_CORRUPTION
1268 bool "Check for low memory corruption"
1269 ---help---
1270 Periodically check for memory corruption in low memory, which
1271 is suspected to be caused by BIOS. Even when enabled in the
1272 configuration, it is disabled at runtime. Enable it by
1273 setting "memory_corruption_check=1" on the kernel command
1274 line. By default it scans the low 64k of memory every 60
1275 seconds; see the memory_corruption_check_size and
1276 memory_corruption_check_period parameters in
1277 Documentation/kernel-parameters.txt to adjust this.
1279 When enabled with the default parameters, this option has
1280 almost no overhead, as it reserves a relatively small amount
1281 of memory and scans it infrequently. It both detects corruption
1282 and prevents it from affecting the running system.
1284 It is, however, intended as a diagnostic tool; if repeatable
1285 BIOS-originated corruption always affects the same memory,
1286 you can use memmap= to prevent the kernel from using that
1287 memory.
1289 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1290 bool "Set the default setting of memory_corruption_check"
1291 depends on X86_CHECK_BIOS_CORRUPTION
1292 default y
1293 ---help---
1294 Set whether the default state of memory_corruption_check is
1295 on or off.
1297 config X86_RESERVE_LOW_64K
1298 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1299 default y
1300 ---help---
1301 Reserve the first 64K of physical RAM on BIOSes that are known
1302 to potentially corrupt that memory range. A numbers of BIOSes are
1303 known to utilize this area during suspend/resume, so it must not
1304 be used by the kernel.
1306 Set this to N if you are absolutely sure that you trust the BIOS
1307 to get all its memory reservations and usages right.
1309 If you have doubts about the BIOS (e.g. suspend/resume does not
1310 work or there's kernel crashes after certain hardware hotplug
1311 events) and it's not AMI or Phoenix, then you might want to enable
1312 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1313 corruption patterns.
1315 Say Y if unsure.
1317 config MATH_EMULATION
1318 bool
1319 prompt "Math emulation" if X86_32
1320 ---help---
1321 Linux can emulate a math coprocessor (used for floating point
1322 operations) if you don't have one. 486DX and Pentium processors have
1323 a math coprocessor built in, 486SX and 386 do not, unless you added
1324 a 487DX or 387, respectively. (The messages during boot time can
1325 give you some hints here ["man dmesg"].) Everyone needs either a
1326 coprocessor or this emulation.
1328 If you don't have a math coprocessor, you need to say Y here; if you
1329 say Y here even though you have a coprocessor, the coprocessor will
1330 be used nevertheless. (This behavior can be changed with the kernel
1331 command line option "no387", which comes handy if your coprocessor
1332 is broken. Try "man bootparam" or see the documentation of your boot
1333 loader (lilo or loadlin) about how to pass options to the kernel at
1334 boot time.) This means that it is a good idea to say Y here if you
1335 intend to use this kernel on different machines.
1337 More information about the internals of the Linux math coprocessor
1338 emulation can be found in <file:arch/x86/math-emu/README>.
1340 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1341 kernel, it won't hurt.
1343 config MTRR
1344 bool "MTRR (Memory Type Range Register) support"
1345 ---help---
1346 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1347 the Memory Type Range Registers (MTRRs) may be used to control
1348 processor access to memory ranges. This is most useful if you have
1349 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1350 allows bus write transfers to be combined into a larger transfer
1351 before bursting over the PCI/AGP bus. This can increase performance
1352 of image write operations 2.5 times or more. Saying Y here creates a
1353 /proc/mtrr file which may be used to manipulate your processor's
1354 MTRRs. Typically the X server should use this.
1356 This code has a reasonably generic interface so that similar
1357 control registers on other processors can be easily supported
1358 as well:
1360 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1361 Registers (ARRs) which provide a similar functionality to MTRRs. For
1362 these, the ARRs are used to emulate the MTRRs.
1363 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1364 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1365 write-combining. All of these processors are supported by this code
1366 and it makes sense to say Y here if you have one of them.
1368 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1369 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1370 can lead to all sorts of problems, so it's good to say Y here.
1372 You can safely say Y even if your machine doesn't have MTRRs, you'll
1373 just add about 9 KB to your kernel.
1375 See <file:Documentation/x86/mtrr.txt> for more information.
1377 config MTRR_SANITIZER
1378 def_bool y
1379 prompt "MTRR cleanup support"
1380 depends on MTRR
1381 ---help---
1382 Convert MTRR layout from continuous to discrete, so X drivers can
1383 add writeback entries.
1385 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1386 The largest mtrr entry size for a continuous block can be set with
1387 mtrr_chunk_size.
1389 If unsure, say Y.
1391 config MTRR_SANITIZER_ENABLE_DEFAULT
1392 int "MTRR cleanup enable value (0-1)"
1393 range 0 1
1394 default "0"
1395 depends on MTRR_SANITIZER
1396 ---help---
1397 Enable mtrr cleanup default value
1399 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1400 int "MTRR cleanup spare reg num (0-7)"
1401 range 0 7
1402 default "1"
1403 depends on MTRR_SANITIZER
1404 ---help---
1405 mtrr cleanup spare entries default, it can be changed via
1406 mtrr_spare_reg_nr=N on the kernel command line.
1408 config X86_PAT
1409 bool
1410 prompt "x86 PAT support"
1411 depends on MTRR
1412 ---help---
1413 Use PAT attributes to setup page level cache control.
1415 PATs are the modern equivalents of MTRRs and are much more
1416 flexible than MTRRs.
1418 Say N here if you see bootup problems (boot crash, boot hang,
1419 spontaneous reboots) or a non-working video driver.
1421 If unsure, say Y.
1423 config ARCH_USES_PG_UNCACHED
1424 def_bool y
1425 depends on X86_PAT
1427 config EFI
1428 bool "EFI runtime service support"
1429 depends on ACPI
1430 ---help---
1431 This enables the kernel to use EFI runtime services that are
1432 available (such as the EFI variable services).
1434 This option is only useful on systems that have EFI firmware.
1435 In addition, you should use the latest ELILO loader available
1436 at <http://elilo.sourceforge.net> in order to take advantage
1437 of EFI runtime services. However, even with this option, the
1438 resultant kernel should continue to boot on existing non-EFI
1439 platforms.
1441 config SECCOMP
1442 def_bool y
1443 prompt "Enable seccomp to safely compute untrusted bytecode"
1444 ---help---
1445 This kernel feature is useful for number crunching applications
1446 that may need to compute untrusted bytecode during their
1447 execution. By using pipes or other transports made available to
1448 the process as file descriptors supporting the read/write
1449 syscalls, it's possible to isolate those applications in
1450 their own address space using seccomp. Once seccomp is
1451 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1452 and the task is only allowed to execute a few safe syscalls
1453 defined by each seccomp mode.
1455 If unsure, say Y. Only embedded should say N here.
1457 config CC_STACKPROTECTOR_ALL
1458 bool
1460 config CC_STACKPROTECTOR
1461 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1462 select CC_STACKPROTECTOR_ALL
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 config X86_APM_BOOT
1697 bool
1698 default y
1699 depends on APM || APM_MODULE
1701 menuconfig APM
1702 tristate "APM (Advanced Power Management) BIOS support"
1703 depends on X86_32 && PM_SLEEP
1704 ---help---
1705 APM is a BIOS specification for saving power using several different
1706 techniques. This is mostly useful for battery powered laptops with
1707 APM compliant BIOSes. If you say Y here, the system time will be
1708 reset after a RESUME operation, the /proc/apm device will provide
1709 battery status information, and user-space programs will receive
1710 notification of APM "events" (e.g. battery status change).
1712 If you select "Y" here, you can disable actual use of the APM
1713 BIOS by passing the "apm=off" option to the kernel at boot time.
1715 Note that the APM support is almost completely disabled for
1716 machines with more than one CPU.
1718 In order to use APM, you will need supporting software. For location
1719 and more information, read <file:Documentation/power/pm.txt> and the
1720 Battery Powered Linux mini-HOWTO, available from
1721 <http://www.tldp.org/docs.html#howto>.
1723 This driver does not spin down disk drives (see the hdparm(8)
1724 manpage ("man 8 hdparm") for that), and it doesn't turn off
1725 VESA-compliant "green" monitors.
1727 This driver does not support the TI 4000M TravelMate and the ACER
1728 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1729 desktop machines also don't have compliant BIOSes, and this driver
1730 may cause those machines to panic during the boot phase.
1732 Generally, if you don't have a battery in your machine, there isn't
1733 much point in using this driver and you should say N. If you get
1734 random kernel OOPSes or reboots that don't seem to be related to
1735 anything, try disabling/enabling this option (or disabling/enabling
1736 APM in your BIOS).
1738 Some other things you should try when experiencing seemingly random,
1739 "weird" problems:
1741 1) make sure that you have enough swap space and that it is
1742 enabled.
1743 2) pass the "no-hlt" option to the kernel
1744 3) switch on floating point emulation in the kernel and pass
1745 the "no387" option to the kernel
1746 4) pass the "floppy=nodma" option to the kernel
1747 5) pass the "mem=4M" option to the kernel (thereby disabling
1748 all but the first 4 MB of RAM)
1749 6) make sure that the CPU is not over clocked.
1750 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1751 8) disable the cache from your BIOS settings
1752 9) install a fan for the video card or exchange video RAM
1753 10) install a better fan for the CPU
1754 11) exchange RAM chips
1755 12) exchange the motherboard.
1757 To compile this driver as a module, choose M here: the
1758 module will be called apm.
1760 if APM
1762 config APM_IGNORE_USER_SUSPEND
1763 bool "Ignore USER SUSPEND"
1764 ---help---
1765 This option will ignore USER SUSPEND requests. On machines with a
1766 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1767 series notebooks, it is necessary to say Y because of a BIOS bug.
1769 config APM_DO_ENABLE
1770 bool "Enable PM at boot time"
1771 ---help---
1772 Enable APM features at boot time. From page 36 of the APM BIOS
1773 specification: "When disabled, the APM BIOS does not automatically
1774 power manage devices, enter the Standby State, enter the Suspend
1775 State, or take power saving steps in response to CPU Idle calls."
1776 This driver will make CPU Idle calls when Linux is idle (unless this
1777 feature is turned off -- see "Do CPU IDLE calls", below). This
1778 should always save battery power, but more complicated APM features
1779 will be dependent on your BIOS implementation. You may need to turn
1780 this option off if your computer hangs at boot time when using APM
1781 support, or if it beeps continuously instead of suspending. Turn
1782 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1783 T400CDT. This is off by default since most machines do fine without
1784 this feature.
1786 config APM_CPU_IDLE
1787 bool "Make CPU Idle calls when idle"
1788 ---help---
1789 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1790 On some machines, this can activate improved power savings, such as
1791 a slowed CPU clock rate, when the machine is idle. These idle calls
1792 are made after the idle loop has run for some length of time (e.g.,
1793 333 mS). On some machines, this will cause a hang at boot time or
1794 whenever the CPU becomes idle. (On machines with more than one CPU,
1795 this option does nothing.)
1797 config APM_DISPLAY_BLANK
1798 bool "Enable console blanking using APM"
1799 ---help---
1800 Enable console blanking using the APM. Some laptops can use this to
1801 turn off the LCD backlight when the screen blanker of the Linux
1802 virtual console blanks the screen. Note that this is only used by
1803 the virtual console screen blanker, and won't turn off the backlight
1804 when using the X Window system. This also doesn't have anything to
1805 do with your VESA-compliant power-saving monitor. Further, this
1806 option doesn't work for all laptops -- it might not turn off your
1807 backlight at all, or it might print a lot of errors to the console,
1808 especially if you are using gpm.
1810 config APM_ALLOW_INTS
1811 bool "Allow interrupts during APM BIOS calls"
1812 ---help---
1813 Normally we disable external interrupts while we are making calls to
1814 the APM BIOS as a measure to lessen the effects of a badly behaving
1815 BIOS implementation. The BIOS should reenable interrupts if it
1816 needs to. Unfortunately, some BIOSes do not -- especially those in
1817 many of the newer IBM Thinkpads. If you experience hangs when you
1818 suspend, try setting this to Y. Otherwise, say N.
1820 endif # APM
1822 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1824 source "drivers/cpuidle/Kconfig"
1826 source "drivers/idle/Kconfig"
1828 endmenu
1831 menu "Bus options (PCI etc.)"
1833 config PCI
1834 bool "PCI support"
1835 default y
1836 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1837 ---help---
1838 Find out whether you have a PCI motherboard. PCI is the name of a
1839 bus system, i.e. the way the CPU talks to the other stuff inside
1840 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1841 VESA. If you have PCI, say Y, otherwise N.
1843 choice
1844 prompt "PCI access mode"
1845 depends on X86_32 && PCI
1846 default PCI_GOANY
1847 ---help---
1848 On PCI systems, the BIOS can be used to detect the PCI devices and
1849 determine their configuration. However, some old PCI motherboards
1850 have BIOS bugs and may crash if this is done. Also, some embedded
1851 PCI-based systems don't have any BIOS at all. Linux can also try to
1852 detect the PCI hardware directly without using the BIOS.
1854 With this option, you can specify how Linux should detect the
1855 PCI devices. If you choose "BIOS", the BIOS will be used,
1856 if you choose "Direct", the BIOS won't be used, and if you
1857 choose "MMConfig", then PCI Express MMCONFIG will be used.
1858 If you choose "Any", the kernel will try MMCONFIG, then the
1859 direct access method and falls back to the BIOS if that doesn't
1860 work. If unsure, go with the default, which is "Any".
1862 config PCI_GOBIOS
1863 bool "BIOS"
1865 config PCI_GOMMCONFIG
1866 bool "MMConfig"
1868 config PCI_GODIRECT
1869 bool "Direct"
1871 config PCI_GOOLPC
1872 bool "OLPC"
1873 depends on OLPC
1875 config PCI_GOANY
1876 bool "Any"
1878 endchoice
1880 config PCI_BIOS
1881 def_bool y
1882 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1884 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1885 config PCI_DIRECT
1886 def_bool y
1887 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1889 config PCI_MMCONFIG
1890 def_bool y
1891 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1893 config PCI_OLPC
1894 def_bool y
1895 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1897 config PCI_DOMAINS
1898 def_bool y
1899 depends on PCI
1901 config PCI_MMCONFIG
1902 bool "Support mmconfig PCI config space access"
1903 depends on X86_64 && PCI && ACPI
1905 config DMAR
1906 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1907 depends on PCI_MSI && ACPI && EXPERIMENTAL
1908 help
1909 DMA remapping (DMAR) devices support enables independent address
1910 translations for Direct Memory Access (DMA) from devices.
1911 These DMA remapping devices are reported via ACPI tables
1912 and include PCI device scope covered by these DMA
1913 remapping devices.
1915 config DMAR_DEFAULT_ON
1916 def_bool y
1917 prompt "Enable DMA Remapping Devices by default"
1918 depends on DMAR
1919 help
1920 Selecting this option will enable a DMAR device at boot time if
1921 one is found. If this option is not selected, DMAR support can
1922 be enabled by passing intel_iommu=on to the kernel. It is
1923 recommended you say N here while the DMAR code remains
1924 experimental.
1926 config DMAR_BROKEN_GFX_WA
1927 def_bool n
1928 prompt "Workaround broken graphics drivers (going away soon)"
1929 depends on DMAR
1930 ---help---
1931 Current Graphics drivers tend to use physical address
1932 for DMA and avoid using DMA APIs. Setting this config
1933 option permits the IOMMU driver to set a unity map for
1934 all the OS-visible memory. Hence the driver can continue
1935 to use physical addresses for DMA, at least until this
1936 option is removed in the 2.6.32 kernel.
1938 config DMAR_FLOPPY_WA
1939 def_bool y
1940 depends on DMAR
1941 ---help---
1942 Floppy disk drivers are known to bypass DMA API calls
1943 thereby failing to work when IOMMU is enabled. This
1944 workaround will setup a 1:1 mapping for the first
1945 16MiB to make floppy (an ISA device) work.
1947 config INTR_REMAP
1948 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1949 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1950 ---help---
1951 Supports Interrupt remapping for IO-APIC and MSI devices.
1952 To use x2apic mode in the CPU's which support x2APIC enhancements or
1953 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1955 source "drivers/pci/pcie/Kconfig"
1957 source "drivers/pci/Kconfig"
1959 # x86_64 have no ISA slots, but do have ISA-style DMA.
1960 config ISA_DMA_API
1961 def_bool y
1963 if X86_32
1965 config ISA
1966 bool "ISA support"
1967 ---help---
1968 Find out whether you have ISA slots on your motherboard. ISA is the
1969 name of a bus system, i.e. the way the CPU talks to the other stuff
1970 inside your box. Other bus systems are PCI, EISA, MicroChannel
1971 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1972 newer boards don't support it. If you have ISA, say Y, otherwise N.
1974 config EISA
1975 bool "EISA support"
1976 depends on ISA
1977 ---help---
1978 The Extended Industry Standard Architecture (EISA) bus was
1979 developed as an open alternative to the IBM MicroChannel bus.
1981 The EISA bus provided some of the features of the IBM MicroChannel
1982 bus while maintaining backward compatibility with cards made for
1983 the older ISA bus. The EISA bus saw limited use between 1988 and
1984 1995 when it was made obsolete by the PCI bus.
1986 Say Y here if you are building a kernel for an EISA-based machine.
1988 Otherwise, say N.
1990 source "drivers/eisa/Kconfig"
1992 config MCA
1993 bool "MCA support"
1994 ---help---
1995 MicroChannel Architecture is found in some IBM PS/2 machines and
1996 laptops. It is a bus system similar to PCI or ISA. See
1997 <file:Documentation/mca.txt> (and especially the web page given
1998 there) before attempting to build an MCA bus kernel.
2000 source "drivers/mca/Kconfig"
2002 config SCx200
2003 tristate "NatSemi SCx200 support"
2004 ---help---
2005 This provides basic support for National Semiconductor's
2006 (now AMD's) Geode processors. The driver probes for the
2007 PCI-IDs of several on-chip devices, so its a good dependency
2008 for other scx200_* drivers.
2010 If compiled as a module, the driver is named scx200.
2012 config SCx200HR_TIMER
2013 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2014 depends on SCx200 && GENERIC_TIME
2015 default y
2016 ---help---
2017 This driver provides a clocksource built upon the on-chip
2018 27MHz high-resolution timer. Its also a workaround for
2019 NSC Geode SC-1100's buggy TSC, which loses time when the
2020 processor goes idle (as is done by the scheduler). The
2021 other workaround is idle=poll boot option.
2023 config GEODE_MFGPT_TIMER
2024 def_bool y
2025 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2026 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2027 ---help---
2028 This driver provides a clock event source based on the MFGPT
2029 timer(s) in the CS5535 and CS5536 companion chip for the geode.
2030 MFGPTs have a better resolution and max interval than the
2031 generic PIT, and are suitable for use as high-res timers.
2033 config OLPC
2034 bool "One Laptop Per Child support"
2035 default n
2036 ---help---
2037 Add support for detecting the unique features of the OLPC
2038 XO hardware.
2040 endif # X86_32
2042 config K8_NB
2043 def_bool y
2044 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2046 source "drivers/pcmcia/Kconfig"
2048 source "drivers/pci/hotplug/Kconfig"
2050 endmenu
2053 menu "Executable file formats / Emulations"
2055 source "fs/Kconfig.binfmt"
2057 config IA32_EMULATION
2058 bool "IA32 Emulation"
2059 depends on X86_64
2060 select COMPAT_BINFMT_ELF
2061 ---help---
2062 Include code to run 32-bit programs under a 64-bit kernel. You should
2063 likely turn this on, unless you're 100% sure that you don't have any
2064 32-bit programs left.
2066 config IA32_AOUT
2067 tristate "IA32 a.out support"
2068 depends on IA32_EMULATION
2069 ---help---
2070 Support old a.out binaries in the 32bit emulation.
2072 config COMPAT
2073 def_bool y
2074 depends on IA32_EMULATION
2076 config COMPAT_FOR_U64_ALIGNMENT
2077 def_bool COMPAT
2078 depends on X86_64
2080 config SYSVIPC_COMPAT
2081 def_bool y
2082 depends on COMPAT && SYSVIPC
2084 endmenu
2087 config HAVE_ATOMIC_IOMAP
2088 def_bool y
2089 depends on X86_32
2091 source "net/Kconfig"
2093 source "drivers/Kconfig"
2095 source "drivers/firmware/Kconfig"
2097 source "fs/Kconfig"
2099 source "arch/x86/Kconfig.debug"
2101 source "security/Kconfig"
2103 source "crypto/Kconfig"
2105 source "arch/x86/kvm/Kconfig"
2107 source "lib/Kconfig"