| blob | cea0cd9a316fb987bfa611a1dffa06cdba1f0332 |
1 # x86 configuration
2 mainmenu "Linux Kernel Configuration for x86"
4 # Select 32 or 64 bit
5 config 64BIT
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
8 ---help---
9 Say yes to build a 64-bit kernel - formerly known as x86_64
10 Say no to build a 32-bit kernel - formerly known as i386
12 config X86_32
13 def_bool !64BIT
15 config X86_64
16 def_bool 64BIT
18 ### Arch settings
19 config X86
20 def_bool y
21 select HAVE_AOUT if X86_32
22 select HAVE_READQ
23 select HAVE_WRITEQ
24 select HAVE_UNSTABLE_SCHED_CLOCK
25 select HAVE_IDE
26 select HAVE_OPROFILE
27 select HAVE_PERF_EVENTS if (!M386 && !M486)
28 select HAVE_IOREMAP_PROT
29 select HAVE_KPROBES
30 select ARCH_WANT_OPTIONAL_GPIOLIB
31 select ARCH_WANT_FRAME_POINTERS
32 select HAVE_DMA_ATTRS
33 select HAVE_KRETPROBES
34 select HAVE_OPTPROBES
35 select HAVE_FTRACE_MCOUNT_RECORD
36 select HAVE_DYNAMIC_FTRACE
37 select HAVE_FUNCTION_TRACER
38 select HAVE_FUNCTION_GRAPH_TRACER
39 select HAVE_FUNCTION_GRAPH_FP_TEST
40 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
41 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
42 select HAVE_SYSCALL_TRACEPOINTS
43 select HAVE_KVM
44 select HAVE_ARCH_KGDB
45 select HAVE_ARCH_TRACEHOOK
46 select HAVE_GENERIC_DMA_COHERENT if X86_32
47 select HAVE_EFFICIENT_UNALIGNED_ACCESS
48 select USER_STACKTRACE_SUPPORT
49 select HAVE_REGS_AND_STACK_ACCESS_API
50 select HAVE_DMA_API_DEBUG
51 select HAVE_KERNEL_GZIP
52 select HAVE_KERNEL_BZIP2
53 select HAVE_KERNEL_LZMA
54 select HAVE_KERNEL_LZO
55 select HAVE_HW_BREAKPOINT
56 select HAVE_MIXED_BREAKPOINTS_REGS
57 select PERF_EVENTS
58 select HAVE_PERF_EVENTS_NMI
59 select ANON_INODES
60 select HAVE_ARCH_KMEMCHECK
61 select HAVE_USER_RETURN_NOTIFIER
63 config INSTRUCTION_DECODER
64 def_bool (KPROBES || PERF_EVENTS)
66 config OUTPUT_FORMAT
67 string
68 default "elf32-i386" if X86_32
69 default "elf64-x86-64" if X86_64
71 config ARCH_DEFCONFIG
72 string
73 default "arch/x86/configs/i386_defconfig" if X86_32
74 default "arch/x86/configs/x86_64_defconfig" if X86_64
76 config GENERIC_CMOS_UPDATE
77 def_bool y
79 config CLOCKSOURCE_WATCHDOG
80 def_bool y
82 config GENERIC_CLOCKEVENTS
83 def_bool y
85 config GENERIC_CLOCKEVENTS_BROADCAST
86 def_bool y
87 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
89 config LOCKDEP_SUPPORT
90 def_bool y
92 config STACKTRACE_SUPPORT
93 def_bool y
95 config HAVE_LATENCYTOP_SUPPORT
96 def_bool y
98 config MMU
99 def_bool y
101 config ZONE_DMA
102 def_bool y
104 config SBUS
105 bool
107 config NEED_DMA_MAP_STATE
108 def_bool (X86_64 || DMAR || DMA_API_DEBUG)
110 config NEED_SG_DMA_LENGTH
111 def_bool y
113 config GENERIC_ISA_DMA
114 def_bool y
116 config GENERIC_IOMAP
117 def_bool y
119 config GENERIC_BUG
120 def_bool y
121 depends on BUG
122 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
124 config GENERIC_BUG_RELATIVE_POINTERS
125 bool
127 config GENERIC_HWEIGHT
128 def_bool y
130 config GENERIC_GPIO
131 bool
133 config ARCH_MAY_HAVE_PC_FDC
134 def_bool y
136 config RWSEM_GENERIC_SPINLOCK
137 def_bool !X86_XADD
139 config RWSEM_XCHGADD_ALGORITHM
140 def_bool X86_XADD
142 config ARCH_HAS_CPU_IDLE_WAIT
143 def_bool y
145 config GENERIC_CALIBRATE_DELAY
146 def_bool y
148 config GENERIC_TIME_VSYSCALL
149 bool
150 default X86_64
152 config ARCH_HAS_CPU_RELAX
153 def_bool y
155 config ARCH_HAS_DEFAULT_IDLE
156 def_bool y
158 config ARCH_HAS_CACHE_LINE_SIZE
159 def_bool y
161 config HAVE_SETUP_PER_CPU_AREA
162 def_bool y
164 config NEED_PER_CPU_EMBED_FIRST_CHUNK
165 def_bool y
167 config NEED_PER_CPU_PAGE_FIRST_CHUNK
168 def_bool y
170 config HAVE_CPUMASK_OF_CPU_MAP
171 def_bool X86_64_SMP
173 config ARCH_HIBERNATION_POSSIBLE
174 def_bool y
176 config ARCH_SUSPEND_POSSIBLE
177 def_bool y
179 config ZONE_DMA32
180 bool
181 default X86_64
183 config ARCH_POPULATES_NODE_MAP
184 def_bool y
186 config AUDIT_ARCH
187 bool
188 default X86_64
190 config ARCH_SUPPORTS_OPTIMIZED_INLINING
191 def_bool y
193 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
194 def_bool y
196 config HAVE_EARLY_RES
197 def_bool y
199 config HAVE_INTEL_TXT
200 def_bool y
201 depends on EXPERIMENTAL && DMAR && ACPI
203 # Use the generic interrupt handling code in kernel/irq/:
204 config GENERIC_HARDIRQS
205 def_bool y
207 config GENERIC_HARDIRQS_NO__DO_IRQ
208 def_bool y
210 config GENERIC_IRQ_PROBE
211 def_bool y
213 config GENERIC_PENDING_IRQ
214 def_bool y
215 depends on GENERIC_HARDIRQS && SMP
217 config USE_GENERIC_SMP_HELPERS
218 def_bool y
219 depends on SMP
221 config X86_32_SMP
222 def_bool y
223 depends on X86_32 && SMP
225 config X86_64_SMP
226 def_bool y
227 depends on X86_64 && SMP
229 config X86_HT
230 def_bool y
231 depends on SMP
233 config X86_TRAMPOLINE
234 def_bool y
235 depends on SMP || (64BIT && ACPI_SLEEP)
237 config X86_32_LAZY_GS
238 def_bool y
239 depends on X86_32 && !CC_STACKPROTECTOR
241 config ARCH_HWEIGHT_CFLAGS
242 string
243 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
244 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
246 config KTIME_SCALAR
247 def_bool X86_32
249 config ARCH_CPU_PROBE_RELEASE
250 def_bool y
251 depends on HOTPLUG_CPU
253 source "init/Kconfig"
254 source "kernel/Kconfig.freezer"
256 menu "Processor type and features"
258 source "kernel/time/Kconfig"
260 config SMP
261 bool "Symmetric multi-processing support"
262 ---help---
263 This enables support for systems with more than one CPU. If you have
264 a system with only one CPU, like most personal computers, say N. If
265 you have a system with more than one CPU, say Y.
267 If you say N here, the kernel will run on single and multiprocessor
268 machines, but will use only one CPU of a multiprocessor machine. If
269 you say Y here, the kernel will run on many, but not all,
270 singleprocessor machines. On a singleprocessor machine, the kernel
271 will run faster if you say N here.
273 Note that if you say Y here and choose architecture "586" or
274 "Pentium" under "Processor family", the kernel will not work on 486
275 architectures. Similarly, multiprocessor kernels for the "PPro"
276 architecture may not work on all Pentium based boards.
278 People using multiprocessor machines who say Y here should also say
279 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
280 Management" code will be disabled if you say Y here.
282 See also <file:Documentation/i386/IO-APIC.txt>,
283 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
284 <http://www.tldp.org/docs.html#howto>.
286 If you don't know what to do here, say N.
288 config X86_X2APIC
289 bool "Support x2apic"
290 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
291 ---help---
292 This enables x2apic support on CPUs that have this feature.
294 This allows 32-bit apic IDs (so it can support very large systems),
295 and accesses the local apic via MSRs not via mmio.
297 If you don't know what to do here, say N.
299 config SPARSE_IRQ
300 bool "Support sparse irq numbering"
301 depends on PCI_MSI || HT_IRQ
302 ---help---
303 This enables support for sparse irqs. This is useful for distro
304 kernels that want to define a high CONFIG_NR_CPUS value but still
305 want to have low kernel memory footprint on smaller machines.
307 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
308 out the irq_desc[] array in a more NUMA-friendly way. )
310 If you don't know what to do here, say N.
312 config NUMA_IRQ_DESC
313 def_bool y
314 depends on SPARSE_IRQ && NUMA
316 config X86_MPPARSE
317 bool "Enable MPS table" if ACPI
318 default y
319 depends on X86_LOCAL_APIC
320 ---help---
321 For old smp systems that do not have proper acpi support. Newer systems
322 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
324 config X86_BIGSMP
325 bool "Support for big SMP systems with more than 8 CPUs"
326 depends on X86_32 && SMP
327 ---help---
328 This option is needed for the systems that have more than 8 CPUs
330 if X86_32
331 config X86_EXTENDED_PLATFORM
332 bool "Support for extended (non-PC) x86 platforms"
333 default y
334 ---help---
335 If you disable this option then the kernel will only support
336 standard PC platforms. (which covers the vast majority of
337 systems out there.)
339 If you enable this option then you'll be able to select support
340 for the following (non-PC) 32 bit x86 platforms:
341 AMD Elan
342 NUMAQ (IBM/Sequent)
343 RDC R-321x SoC
344 SGI 320/540 (Visual Workstation)
345 Summit/EXA (IBM x440)
346 Unisys ES7000 IA32 series
347 Moorestown MID devices
349 If you have one of these systems, or if you want to build a
350 generic distribution kernel, say Y here - otherwise say N.
351 endif
353 if X86_64
354 config X86_EXTENDED_PLATFORM
355 bool "Support for extended (non-PC) x86 platforms"
356 default y
357 ---help---
358 If you disable this option then the kernel will only support
359 standard PC platforms. (which covers the vast majority of
360 systems out there.)
362 If you enable this option then you'll be able to select support
363 for the following (non-PC) 64 bit x86 platforms:
364 ScaleMP vSMP
365 SGI Ultraviolet
367 If you have one of these systems, or if you want to build a
368 generic distribution kernel, say Y here - otherwise say N.
369 endif
370 # This is an alphabetically sorted list of 64 bit extended platforms
371 # Please maintain the alphabetic order if and when there are additions
373 config X86_VSMP
374 bool "ScaleMP vSMP"
375 select PARAVIRT
376 depends on X86_64 && PCI
377 depends on X86_EXTENDED_PLATFORM
378 ---help---
379 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
380 supposed to run on these EM64T-based machines. Only choose this option
381 if you have one of these machines.
383 config X86_UV
384 bool "SGI Ultraviolet"
385 depends on X86_64
386 depends on X86_EXTENDED_PLATFORM
387 depends on NUMA
388 depends on X86_X2APIC
389 ---help---
390 This option is needed in order to support SGI Ultraviolet systems.
391 If you don't have one of these, you should say N here.
393 # Following is an alphabetically sorted list of 32 bit extended platforms
394 # Please maintain the alphabetic order if and when there are additions
396 config X86_ELAN
397 bool "AMD Elan"
398 depends on X86_32
399 depends on X86_EXTENDED_PLATFORM
400 ---help---
401 Select this for an AMD Elan processor.
403 Do not use this option for K6/Athlon/Opteron processors!
405 If unsure, choose "PC-compatible" instead.
407 config X86_MRST
408 bool "Moorestown MID platform"
409 depends on PCI
410 depends on PCI_GOANY
411 depends on X86_32
412 depends on X86_EXTENDED_PLATFORM
413 depends on X86_IO_APIC
414 select APB_TIMER
415 ---help---
416 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
417 Internet Device(MID) platform. Moorestown consists of two chips:
418 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
419 Unlike standard x86 PCs, Moorestown does not have many legacy devices
420 nor standard legacy replacement devices/features. e.g. Moorestown does
421 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
423 config X86_RDC321X
424 bool "RDC R-321x SoC"
425 depends on X86_32
426 depends on X86_EXTENDED_PLATFORM
427 select M486
428 select X86_REBOOTFIXUPS
429 ---help---
430 This option is needed for RDC R-321x system-on-chip, also known
431 as R-8610-(G).
432 If you don't have one of these chips, you should say N here.
434 config X86_32_NON_STANDARD
435 bool "Support non-standard 32-bit SMP architectures"
436 depends on X86_32 && SMP
437 depends on X86_EXTENDED_PLATFORM
438 ---help---
439 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
440 subarchitectures. It is intended for a generic binary kernel.
441 if you select them all, kernel will probe it one by one. and will
442 fallback to default.
444 # Alphabetically sorted list of Non standard 32 bit platforms
446 config X86_NUMAQ
447 bool "NUMAQ (IBM/Sequent)"
448 depends on X86_32_NON_STANDARD
449 depends on PCI
450 select NUMA
451 select X86_MPPARSE
452 ---help---
453 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
454 NUMA multiquad box. This changes the way that processors are
455 bootstrapped, and uses Clustered Logical APIC addressing mode instead
456 of Flat Logical. You will need a new lynxer.elf file to flash your
457 firmware with - send email to <Martin.Bligh@us.ibm.com>.
459 config X86_SUPPORTS_MEMORY_FAILURE
460 def_bool y
461 # MCE code calls memory_failure():
462 depends on X86_MCE
463 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
464 depends on !X86_NUMAQ
465 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
466 depends on X86_64 || !SPARSEMEM
467 select ARCH_SUPPORTS_MEMORY_FAILURE
469 config X86_VISWS
470 bool "SGI 320/540 (Visual Workstation)"
471 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
472 depends on X86_32_NON_STANDARD
473 ---help---
474 The SGI Visual Workstation series is an IA32-based workstation
475 based on SGI systems chips with some legacy PC hardware attached.
477 Say Y here to create a kernel to run on the SGI 320 or 540.
479 A kernel compiled for the Visual Workstation will run on general
480 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
482 config X86_SUMMIT
483 bool "Summit/EXA (IBM x440)"
484 depends on X86_32_NON_STANDARD
485 ---help---
486 This option is needed for IBM systems that use the Summit/EXA chipset.
487 In particular, it is needed for the x440.
489 config X86_ES7000
490 bool "Unisys ES7000 IA32 series"
491 depends on X86_32_NON_STANDARD && X86_BIGSMP
492 ---help---
493 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
494 supposed to run on an IA32-based Unisys ES7000 system.
496 config SCHED_OMIT_FRAME_POINTER
497 def_bool y
498 prompt "Single-depth WCHAN output"
499 depends on X86
500 ---help---
501 Calculate simpler /proc/<PID>/wchan values. If this option
502 is disabled then wchan values will recurse back to the
503 caller function. This provides more accurate wchan values,
504 at the expense of slightly more scheduling overhead.
506 If in doubt, say "Y".
508 menuconfig PARAVIRT_GUEST
509 bool "Paravirtualized guest support"
510 ---help---
511 Say Y here to get to see options related to running Linux under
512 various hypervisors. This option alone does not add any kernel code.
514 If you say N, all options in this submenu will be skipped and disabled.
516 if PARAVIRT_GUEST
518 source "arch/x86/xen/Kconfig"
520 config VMI
521 bool "VMI Guest support (DEPRECATED)"
522 select PARAVIRT
523 depends on X86_32
524 ---help---
525 VMI provides a paravirtualized interface to the VMware ESX server
526 (it could be used by other hypervisors in theory too, but is not
527 at the moment), by linking the kernel to a GPL-ed ROM module
528 provided by the hypervisor.
530 As of September 2009, VMware has started a phased retirement
531 of this feature from VMware's products. Please see
532 feature-removal-schedule.txt for details. If you are
533 planning to enable this option, please note that you cannot
534 live migrate a VMI enabled VM to a future VMware product,
535 which doesn't support VMI. So if you expect your kernel to
536 seamlessly migrate to newer VMware products, keep this
537 disabled.
539 config KVM_CLOCK
540 bool "KVM paravirtualized clock"
541 select PARAVIRT
542 select PARAVIRT_CLOCK
543 ---help---
544 Turning on this option will allow you to run a paravirtualized clock
545 when running over the KVM hypervisor. Instead of relying on a PIT
546 (or probably other) emulation by the underlying device model, the host
547 provides the guest with timing infrastructure such as time of day, and
548 system time
550 config KVM_GUEST
551 bool "KVM Guest support"
552 select PARAVIRT
553 ---help---
554 This option enables various optimizations for running under the KVM
555 hypervisor.
557 source "arch/x86/lguest/Kconfig"
559 config PARAVIRT
560 bool "Enable paravirtualization code"
561 ---help---
562 This changes the kernel so it can modify itself when it is run
563 under a hypervisor, potentially improving performance significantly
564 over full virtualization. However, when run without a hypervisor
565 the kernel is theoretically slower and slightly larger.
567 config PARAVIRT_SPINLOCKS
568 bool "Paravirtualization layer for spinlocks"
569 depends on PARAVIRT && SMP && EXPERIMENTAL
570 ---help---
571 Paravirtualized spinlocks allow a pvops backend to replace the
572 spinlock implementation with something virtualization-friendly
573 (for example, block the virtual CPU rather than spinning).
575 Unfortunately the downside is an up to 5% performance hit on
576 native kernels, with various workloads.
578 If you are unsure how to answer this question, answer N.
580 config PARAVIRT_CLOCK
581 bool
583 endif
585 config PARAVIRT_DEBUG
586 bool "paravirt-ops debugging"
587 depends on PARAVIRT && DEBUG_KERNEL
588 ---help---
589 Enable to debug paravirt_ops internals. Specifically, BUG if
590 a paravirt_op is missing when it is called.
592 config NO_BOOTMEM
593 default y
594 bool "Disable Bootmem code"
595 ---help---
596 Use early_res directly instead of bootmem before slab is ready.
597 - allocator (buddy) [generic]
598 - early allocator (bootmem) [generic]
599 - very early allocator (reserve_early*()) [x86]
600 - very very early allocator (early brk model) [x86]
601 So reduce one layer between early allocator to final allocator
604 config MEMTEST
605 bool "Memtest"
606 ---help---
607 This option adds a kernel parameter 'memtest', which allows memtest
608 to be set.
609 memtest=0, mean disabled; -- default
610 memtest=1, mean do 1 test pattern;
611 ...
612 memtest=4, mean do 4 test patterns.
613 If you are unsure how to answer this question, answer N.
615 config X86_SUMMIT_NUMA
616 def_bool y
617 depends on X86_32 && NUMA && X86_32_NON_STANDARD
619 config X86_CYCLONE_TIMER
620 def_bool y
621 depends on X86_32_NON_STANDARD
623 source "arch/x86/Kconfig.cpu"
625 config HPET_TIMER
626 def_bool X86_64
627 prompt "HPET Timer Support" if X86_32
628 ---help---
629 Use the IA-PC HPET (High Precision Event Timer) to manage
630 time in preference to the PIT and RTC, if a HPET is
631 present.
632 HPET is the next generation timer replacing legacy 8254s.
633 The HPET provides a stable time base on SMP
634 systems, unlike the TSC, but it is more expensive to access,
635 as it is off-chip. You can find the HPET spec at
636 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
638 You can safely choose Y here. However, HPET will only be
639 activated if the platform and the BIOS support this feature.
640 Otherwise the 8254 will be used for timing services.
642 Choose N to continue using the legacy 8254 timer.
644 config HPET_EMULATE_RTC
645 def_bool y
646 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
648 config APB_TIMER
649 def_bool y if MRST
650 prompt "Langwell APB Timer Support" if X86_MRST
651 help
652 APB timer is the replacement for 8254, HPET on X86 MID platforms.
653 The APBT provides a stable time base on SMP
654 systems, unlike the TSC, but it is more expensive to access,
655 as it is off-chip. APB timers are always running regardless of CPU
656 C states, they are used as per CPU clockevent device when possible.
658 # Mark as embedded because too many people got it wrong.
659 # The code disables itself when not needed.
660 config DMI
661 default y
662 bool "Enable DMI scanning" if EMBEDDED
663 ---help---
664 Enabled scanning of DMI to identify machine quirks. Say Y
665 here unless you have verified that your setup is not
666 affected by entries in the DMI blacklist. Required by PNP
667 BIOS code.
669 config GART_IOMMU
670 bool "GART IOMMU support" if EMBEDDED
671 default y
672 select SWIOTLB
673 depends on X86_64 && PCI && K8_NB
674 ---help---
675 Support for full DMA access of devices with 32bit memory access only
676 on systems with more than 3GB. This is usually needed for USB,
677 sound, many IDE/SATA chipsets and some other devices.
678 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
679 based hardware IOMMU and a software bounce buffer based IOMMU used
680 on Intel systems and as fallback.
681 The code is only active when needed (enough memory and limited
682 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
683 too.
685 config CALGARY_IOMMU
686 bool "IBM Calgary IOMMU support"
687 select SWIOTLB
688 depends on X86_64 && PCI && EXPERIMENTAL
689 ---help---
690 Support for hardware IOMMUs in IBM's xSeries x366 and x460
691 systems. Needed to run systems with more than 3GB of memory
692 properly with 32-bit PCI devices that do not support DAC
693 (Double Address Cycle). Calgary also supports bus level
694 isolation, where all DMAs pass through the IOMMU. This
695 prevents them from going anywhere except their intended
696 destination. This catches hard-to-find kernel bugs and
697 mis-behaving drivers and devices that do not use the DMA-API
698 properly to set up their DMA buffers. The IOMMU can be
699 turned off at boot time with the iommu=off parameter.
700 Normally the kernel will make the right choice by itself.
701 If unsure, say Y.
703 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
704 def_bool y
705 prompt "Should Calgary be enabled by default?"
706 depends on CALGARY_IOMMU
707 ---help---
708 Should Calgary be enabled by default? if you choose 'y', Calgary
709 will be used (if it exists). If you choose 'n', Calgary will not be
710 used even if it exists. If you choose 'n' and would like to use
711 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
712 If unsure, say Y.
714 config AMD_IOMMU
715 bool "AMD IOMMU support"
716 select SWIOTLB
717 select PCI_MSI
718 depends on X86_64 && PCI && ACPI
719 ---help---
720 With this option you can enable support for AMD IOMMU hardware in
721 your system. An IOMMU is a hardware component which provides
722 remapping of DMA memory accesses from devices. With an AMD IOMMU you
723 can isolate the the DMA memory of different devices and protect the
724 system from misbehaving device drivers or hardware.
726 You can find out if your system has an AMD IOMMU if you look into
727 your BIOS for an option to enable it or if you have an IVRS ACPI
728 table.
730 config AMD_IOMMU_STATS
731 bool "Export AMD IOMMU statistics to debugfs"
732 depends on AMD_IOMMU
733 select DEBUG_FS
734 ---help---
735 This option enables code in the AMD IOMMU driver to collect various
736 statistics about whats happening in the driver and exports that
737 information to userspace via debugfs.
738 If unsure, say N.
740 # need this always selected by IOMMU for the VIA workaround
741 config SWIOTLB
742 def_bool y if X86_64
743 ---help---
744 Support for software bounce buffers used on x86-64 systems
745 which don't have a hardware IOMMU (e.g. the current generation
746 of Intel's x86-64 CPUs). Using this PCI devices which can only
747 access 32-bits of memory can be used on systems with more than
748 3 GB of memory. If unsure, say Y.
750 config IOMMU_HELPER
751 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
753 config IOMMU_API
754 def_bool (AMD_IOMMU || DMAR)
756 config MAXSMP
757 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
758 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
759 select CPUMASK_OFFSTACK
760 ---help---
761 Enable maximum number of CPUS and NUMA Nodes for this architecture.
762 If unsure, say N.
764 config NR_CPUS
765 int "Maximum number of CPUs" if SMP && !MAXSMP
766 range 2 8 if SMP && X86_32 && !X86_BIGSMP
767 range 2 512 if SMP && !MAXSMP
768 default "1" if !SMP
769 default "4096" if MAXSMP
770 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
771 default "8" if SMP
772 ---help---
773 This allows you to specify the maximum number of CPUs which this
774 kernel will support. The maximum supported value is 512 and the
775 minimum value which makes sense is 2.
777 This is purely to save memory - each supported CPU adds
778 approximately eight kilobytes to the kernel image.
780 config SCHED_SMT
781 bool "SMT (Hyperthreading) scheduler support"
782 depends on X86_HT
783 ---help---
784 SMT scheduler support improves the CPU scheduler's decision making
785 when dealing with Intel Pentium 4 chips with HyperThreading at a
786 cost of slightly increased overhead in some places. If unsure say
787 N here.
789 config SCHED_MC
790 def_bool y
791 prompt "Multi-core scheduler support"
792 depends on X86_HT
793 ---help---
794 Multi-core scheduler support improves the CPU scheduler's decision
795 making when dealing with multi-core CPU chips at a cost of slightly
796 increased overhead in some places. If unsure say N here.
798 source "kernel/Kconfig.preempt"
800 config X86_UP_APIC
801 bool "Local APIC support on uniprocessors"
802 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
803 ---help---
804 A local APIC (Advanced Programmable Interrupt Controller) is an
805 integrated interrupt controller in the CPU. If you have a single-CPU
806 system which has a processor with a local APIC, you can say Y here to
807 enable and use it. If you say Y here even though your machine doesn't
808 have a local APIC, then the kernel will still run with no slowdown at
809 all. The local APIC supports CPU-generated self-interrupts (timer,
810 performance counters), and the NMI watchdog which detects hard
811 lockups.
813 config X86_UP_IOAPIC
814 bool "IO-APIC support on uniprocessors"
815 depends on X86_UP_APIC
816 ---help---
817 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
818 SMP-capable replacement for PC-style interrupt controllers. Most
819 SMP systems and many recent uniprocessor systems have one.
821 If you have a single-CPU system with an IO-APIC, you can say Y here
822 to use it. If you say Y here even though your machine doesn't have
823 an IO-APIC, then the kernel will still run with no slowdown at all.
825 config X86_LOCAL_APIC
826 def_bool y
827 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
829 config X86_IO_APIC
830 def_bool y
831 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
833 config X86_VISWS_APIC
834 def_bool y
835 depends on X86_32 && X86_VISWS
837 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
838 bool "Reroute for broken boot IRQs"
839 depends on X86_IO_APIC
840 ---help---
841 This option enables a workaround that fixes a source of
842 spurious interrupts. This is recommended when threaded
843 interrupt handling is used on systems where the generation of
844 superfluous "boot interrupts" cannot be disabled.
846 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
847 entry in the chipset's IO-APIC is masked (as, e.g. the RT
848 kernel does during interrupt handling). On chipsets where this
849 boot IRQ generation cannot be disabled, this workaround keeps
850 the original IRQ line masked so that only the equivalent "boot
851 IRQ" is delivered to the CPUs. The workaround also tells the
852 kernel to set up the IRQ handler on the boot IRQ line. In this
853 way only one interrupt is delivered to the kernel. Otherwise
854 the spurious second interrupt may cause the kernel to bring
855 down (vital) interrupt lines.
857 Only affects "broken" chipsets. Interrupt sharing may be
858 increased on these systems.
860 config X86_MCE
861 bool "Machine Check / overheating reporting"
862 ---help---
863 Machine Check support allows the processor to notify the
864 kernel if it detects a problem (e.g. overheating, data corruption).
865 The action the kernel takes depends on the severity of the problem,
866 ranging from warning messages to halting the machine.
868 config X86_MCE_INTEL
869 def_bool y
870 prompt "Intel MCE features"
871 depends on X86_MCE && X86_LOCAL_APIC
872 ---help---
873 Additional support for intel specific MCE features such as
874 the thermal monitor.
876 config X86_MCE_AMD
877 def_bool y
878 prompt "AMD MCE features"
879 depends on X86_MCE && X86_LOCAL_APIC
880 ---help---
881 Additional support for AMD specific MCE features such as
882 the DRAM Error Threshold.
884 config X86_ANCIENT_MCE
885 bool "Support for old Pentium 5 / WinChip machine checks"
886 depends on X86_32 && X86_MCE
887 ---help---
888 Include support for machine check handling on old Pentium 5 or WinChip
889 systems. These typically need to be enabled explicitely on the command
890 line.
892 config X86_MCE_THRESHOLD
893 depends on X86_MCE_AMD || X86_MCE_INTEL
894 def_bool y
896 config X86_MCE_INJECT
897 depends on X86_MCE
898 tristate "Machine check injector support"
899 ---help---
900 Provide support for injecting machine checks for testing purposes.
901 If you don't know what a machine check is and you don't do kernel
902 QA it is safe to say n.
904 config X86_THERMAL_VECTOR
905 def_bool y
906 depends on X86_MCE_INTEL
908 config VM86
909 bool "Enable VM86 support" if EMBEDDED
910 default y
911 depends on X86_32
912 ---help---
913 This option is required by programs like DOSEMU to run 16-bit legacy
914 code on X86 processors. It also may be needed by software like
915 XFree86 to initialize some video cards via BIOS. Disabling this
916 option saves about 6k.
918 config TOSHIBA
919 tristate "Toshiba Laptop support"
920 depends on X86_32
921 ---help---
922 This adds a driver to safely access the System Management Mode of
923 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
924 not work on models with a Phoenix BIOS. The System Management Mode
925 is used to set the BIOS and power saving options on Toshiba portables.
927 For information on utilities to make use of this driver see the
928 Toshiba Linux utilities web site at:
929 <http://www.buzzard.org.uk/toshiba/>.
931 Say Y if you intend to run this kernel on a Toshiba portable.
932 Say N otherwise.
934 config I8K
935 tristate "Dell laptop support"
936 ---help---
937 This adds a driver to safely access the System Management Mode
938 of the CPU on the Dell Inspiron 8000. The System Management Mode
939 is used to read cpu temperature and cooling fan status and to
940 control the fans on the I8K portables.
942 This driver has been tested only on the Inspiron 8000 but it may
943 also work with other Dell laptops. You can force loading on other
944 models by passing the parameter `force=1' to the module. Use at
945 your own risk.
947 For information on utilities to make use of this driver see the
948 I8K Linux utilities web site at:
949 <http://people.debian.org/~dz/i8k/>
951 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
952 Say N otherwise.
954 config X86_REBOOTFIXUPS
955 bool "Enable X86 board specific fixups for reboot"
956 depends on X86_32
957 ---help---
958 This enables chipset and/or board specific fixups to be done
959 in order to get reboot to work correctly. This is only needed on
960 some combinations of hardware and BIOS. The symptom, for which
961 this config is intended, is when reboot ends with a stalled/hung
962 system.
964 Currently, the only fixup is for the Geode machines using
965 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
967 Say Y if you want to enable the fixup. Currently, it's safe to
968 enable this option even if you don't need it.
969 Say N otherwise.
971 config MICROCODE
972 tristate "/dev/cpu/microcode - microcode support"
973 select FW_LOADER
974 ---help---
975 If you say Y here, you will be able to update the microcode on
976 certain Intel and AMD processors. The Intel support is for the
977 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
978 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
979 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
980 You will obviously need the actual microcode binary data itself
981 which is not shipped with the Linux kernel.
983 This option selects the general module only, you need to select
984 at least one vendor specific module as well.
986 To compile this driver as a module, choose M here: the
987 module will be called microcode.
989 config MICROCODE_INTEL
990 bool "Intel microcode patch loading support"
991 depends on MICROCODE
992 default MICROCODE
993 select FW_LOADER
994 ---help---
995 This options enables microcode patch loading support for Intel
996 processors.
998 For latest news and information on obtaining all the required
999 Intel ingredients for this driver, check:
1000 <http://www.urbanmyth.org/microcode/>.
1002 config MICROCODE_AMD
1003 bool "AMD microcode patch loading support"
1004 depends on MICROCODE
1005 select FW_LOADER
1006 ---help---
1007 If you select this option, microcode patch loading support for AMD
1008 processors will be enabled.
1010 config MICROCODE_OLD_INTERFACE
1011 def_bool y
1012 depends on MICROCODE
1014 config X86_MSR
1015 tristate "/dev/cpu/*/msr - Model-specific register support"
1016 ---help---
1017 This device gives privileged processes access to the x86
1018 Model-Specific Registers (MSRs). It is a character device with
1019 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1020 MSR accesses are directed to a specific CPU on multi-processor
1021 systems.
1023 config X86_CPUID
1024 tristate "/dev/cpu/*/cpuid - CPU information support"
1025 ---help---
1026 This device gives processes access to the x86 CPUID instruction to
1027 be executed on a specific processor. It is a character device
1028 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1029 /dev/cpu/31/cpuid.
1031 choice
1032 prompt "High Memory Support"
1033 default HIGHMEM64G if X86_NUMAQ
1034 default HIGHMEM4G
1035 depends on X86_32
1037 config NOHIGHMEM
1038 bool "off"
1039 depends on !X86_NUMAQ
1040 ---help---
1041 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1042 However, the address space of 32-bit x86 processors is only 4
1043 Gigabytes large. That means that, if you have a large amount of
1044 physical memory, not all of it can be "permanently mapped" by the
1045 kernel. The physical memory that's not permanently mapped is called
1046 "high memory".
1048 If you are compiling a kernel which will never run on a machine with
1049 more than 1 Gigabyte total physical RAM, answer "off" here (default
1050 choice and suitable for most users). This will result in a "3GB/1GB"
1051 split: 3GB are mapped so that each process sees a 3GB virtual memory
1052 space and the remaining part of the 4GB virtual memory space is used
1053 by the kernel to permanently map as much physical memory as
1054 possible.
1056 If the machine has between 1 and 4 Gigabytes physical RAM, then
1057 answer "4GB" here.
1059 If more than 4 Gigabytes is used then answer "64GB" here. This
1060 selection turns Intel PAE (Physical Address Extension) mode on.
1061 PAE implements 3-level paging on IA32 processors. PAE is fully
1062 supported by Linux, PAE mode is implemented on all recent Intel
1063 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1064 then the kernel will not boot on CPUs that don't support PAE!
1066 The actual amount of total physical memory will either be
1067 auto detected or can be forced by using a kernel command line option
1068 such as "mem=256M". (Try "man bootparam" or see the documentation of
1069 your boot loader (lilo or loadlin) about how to pass options to the
1070 kernel at boot time.)
1072 If unsure, say "off".
1074 config HIGHMEM4G
1075 bool "4GB"
1076 depends on !X86_NUMAQ
1077 ---help---
1078 Select this if you have a 32-bit processor and between 1 and 4
1079 gigabytes of physical RAM.
1081 config HIGHMEM64G
1082 bool "64GB"
1083 depends on !M386 && !M486
1084 select X86_PAE
1085 ---help---
1086 Select this if you have a 32-bit processor and more than 4
1087 gigabytes of physical RAM.
1089 endchoice
1091 choice
1092 depends on EXPERIMENTAL
1093 prompt "Memory split" if EMBEDDED
1094 default VMSPLIT_3G
1095 depends on X86_32
1096 ---help---
1097 Select the desired split between kernel and user memory.
1099 If the address range available to the kernel is less than the
1100 physical memory installed, the remaining memory will be available
1101 as "high memory". Accessing high memory is a little more costly
1102 than low memory, as it needs to be mapped into the kernel first.
1103 Note that increasing the kernel address space limits the range
1104 available to user programs, making the address space there
1105 tighter. Selecting anything other than the default 3G/1G split
1106 will also likely make your kernel incompatible with binary-only
1107 kernel modules.
1109 If you are not absolutely sure what you are doing, leave this
1110 option alone!
1112 config VMSPLIT_3G
1113 bool "3G/1G user/kernel split"
1114 config VMSPLIT_3G_OPT
1115 depends on !X86_PAE
1116 bool "3G/1G user/kernel split (for full 1G low memory)"
1117 config VMSPLIT_2G
1118 bool "2G/2G user/kernel split"
1119 config VMSPLIT_2G_OPT
1120 depends on !X86_PAE
1121 bool "2G/2G user/kernel split (for full 2G low memory)"
1122 config VMSPLIT_1G
1123 bool "1G/3G user/kernel split"
1124 endchoice
1126 config PAGE_OFFSET
1127 hex
1128 default 0xB0000000 if VMSPLIT_3G_OPT
1129 default 0x80000000 if VMSPLIT_2G
1130 default 0x78000000 if VMSPLIT_2G_OPT
1131 default 0x40000000 if VMSPLIT_1G
1132 default 0xC0000000
1133 depends on X86_32
1135 config HIGHMEM
1136 def_bool y
1137 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1139 config X86_PAE
1140 bool "PAE (Physical Address Extension) Support"
1141 depends on X86_32 && !HIGHMEM4G
1142 ---help---
1143 PAE is required for NX support, and furthermore enables
1144 larger swapspace support for non-overcommit purposes. It
1145 has the cost of more pagetable lookup overhead, and also
1146 consumes more pagetable space per process.
1148 config ARCH_PHYS_ADDR_T_64BIT
1149 def_bool X86_64 || X86_PAE
1151 config DIRECT_GBPAGES
1152 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1153 default y
1154 depends on X86_64
1155 ---help---
1156 Allow the kernel linear mapping to use 1GB pages on CPUs that
1157 support it. This can improve the kernel's performance a tiny bit by
1158 reducing TLB pressure. If in doubt, say "Y".
1160 # Common NUMA Features
1161 config NUMA
1162 bool "Numa Memory Allocation and Scheduler Support"
1163 depends on SMP
1164 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1165 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1166 ---help---
1167 Enable NUMA (Non Uniform Memory Access) support.
1169 The kernel will try to allocate memory used by a CPU on the
1170 local memory controller of the CPU and add some more
1171 NUMA awareness to the kernel.
1173 For 64-bit this is recommended if the system is Intel Core i7
1174 (or later), AMD Opteron, or EM64T NUMA.
1176 For 32-bit this is only needed on (rare) 32-bit-only platforms
1177 that support NUMA topologies, such as NUMAQ / Summit, or if you
1178 boot a 32-bit kernel on a 64-bit NUMA platform.
1180 Otherwise, you should say N.
1182 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1183 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1185 config K8_NUMA
1186 def_bool y
1187 prompt "Old style AMD Opteron NUMA detection"
1188 depends on X86_64 && NUMA && PCI
1189 ---help---
1190 Enable K8 NUMA node topology detection. You should say Y here if
1191 you have a multi processor AMD K8 system. This uses an old
1192 method to read the NUMA configuration directly from the builtin
1193 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1194 instead, which also takes priority if both are compiled in.
1196 config X86_64_ACPI_NUMA
1197 def_bool y
1198 prompt "ACPI NUMA detection"
1199 depends on X86_64 && NUMA && ACPI && PCI
1200 select ACPI_NUMA
1201 ---help---
1202 Enable ACPI SRAT based node topology detection.
1204 # Some NUMA nodes have memory ranges that span
1205 # other nodes. Even though a pfn is valid and
1206 # between a node's start and end pfns, it may not
1207 # reside on that node. See memmap_init_zone()
1208 # for details.
1209 config NODES_SPAN_OTHER_NODES
1210 def_bool y
1211 depends on X86_64_ACPI_NUMA
1213 config NUMA_EMU
1214 bool "NUMA emulation"
1215 depends on X86_64 && NUMA
1216 ---help---
1217 Enable NUMA emulation. A flat machine will be split
1218 into virtual nodes when booted with "numa=fake=N", where N is the
1219 number of nodes. This is only useful for debugging.
1221 config NODES_SHIFT
1222 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1223 range 1 10
1224 default "10" if MAXSMP
1225 default "6" if X86_64
1226 default "4" if X86_NUMAQ
1227 default "3"
1228 depends on NEED_MULTIPLE_NODES
1229 ---help---
1230 Specify the maximum number of NUMA Nodes available on the target
1231 system. Increases memory reserved to accommodate various tables.
1233 config HAVE_ARCH_BOOTMEM
1234 def_bool y
1235 depends on X86_32 && NUMA
1237 config ARCH_HAVE_MEMORY_PRESENT
1238 def_bool y
1239 depends on X86_32 && DISCONTIGMEM
1241 config NEED_NODE_MEMMAP_SIZE
1242 def_bool y
1243 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1245 config HAVE_ARCH_ALLOC_REMAP
1246 def_bool y
1247 depends on X86_32 && NUMA
1249 config ARCH_FLATMEM_ENABLE
1250 def_bool y
1251 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1253 config ARCH_DISCONTIGMEM_ENABLE
1254 def_bool y
1255 depends on NUMA && X86_32
1257 config ARCH_DISCONTIGMEM_DEFAULT
1258 def_bool y
1259 depends on NUMA && X86_32
1261 config ARCH_PROC_KCORE_TEXT
1262 def_bool y
1263 depends on X86_64 && PROC_KCORE
1265 config ARCH_SPARSEMEM_DEFAULT
1266 def_bool y
1267 depends on X86_64
1269 config ARCH_SPARSEMEM_ENABLE
1270 def_bool y
1271 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1272 select SPARSEMEM_STATIC if X86_32
1273 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1275 config ARCH_SELECT_MEMORY_MODEL
1276 def_bool y
1277 depends on ARCH_SPARSEMEM_ENABLE
1279 config ARCH_MEMORY_PROBE
1280 def_bool X86_64
1281 depends on MEMORY_HOTPLUG
1283 config ILLEGAL_POINTER_VALUE
1284 hex
1285 default 0 if X86_32
1286 default 0xdead000000000000 if X86_64
1288 source "mm/Kconfig"
1290 config HIGHPTE
1291 bool "Allocate 3rd-level pagetables from highmem"
1292 depends on HIGHMEM
1293 ---help---
1294 The VM uses one page table entry for each page of physical memory.
1295 For systems with a lot of RAM, this can be wasteful of precious
1296 low memory. Setting this option will put user-space page table
1297 entries in high memory.
1299 config X86_CHECK_BIOS_CORRUPTION
1300 bool "Check for low memory corruption"
1301 ---help---
1302 Periodically check for memory corruption in low memory, which
1303 is suspected to be caused by BIOS. Even when enabled in the
1304 configuration, it is disabled at runtime. Enable it by
1305 setting "memory_corruption_check=1" on the kernel command
1306 line. By default it scans the low 64k of memory every 60
1307 seconds; see the memory_corruption_check_size and
1308 memory_corruption_check_period parameters in
1309 Documentation/kernel-parameters.txt to adjust this.
1311 When enabled with the default parameters, this option has
1312 almost no overhead, as it reserves a relatively small amount
1313 of memory and scans it infrequently. It both detects corruption
1314 and prevents it from affecting the running system.
1316 It is, however, intended as a diagnostic tool; if repeatable
1317 BIOS-originated corruption always affects the same memory,
1318 you can use memmap= to prevent the kernel from using that
1319 memory.
1321 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1322 bool "Set the default setting of memory_corruption_check"
1323 depends on X86_CHECK_BIOS_CORRUPTION
1324 default y
1325 ---help---
1326 Set whether the default state of memory_corruption_check is
1327 on or off.
1329 config X86_RESERVE_LOW_64K
1330 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1331 default y
1332 ---help---
1333 Reserve the first 64K of physical RAM on BIOSes that are known
1334 to potentially corrupt that memory range. A numbers of BIOSes are
1335 known to utilize this area during suspend/resume, so it must not
1336 be used by the kernel.
1338 Set this to N if you are absolutely sure that you trust the BIOS
1339 to get all its memory reservations and usages right.
1341 If you have doubts about the BIOS (e.g. suspend/resume does not
1342 work or there's kernel crashes after certain hardware hotplug
1343 events) and it's not AMI or Phoenix, then you might want to enable
1344 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1345 corruption patterns.
1347 Say Y if unsure.
1349 config MATH_EMULATION
1350 bool
1351 prompt "Math emulation" if X86_32
1352 ---help---
1353 Linux can emulate a math coprocessor (used for floating point
1354 operations) if you don't have one. 486DX and Pentium processors have
1355 a math coprocessor built in, 486SX and 386 do not, unless you added
1356 a 487DX or 387, respectively. (The messages during boot time can
1357 give you some hints here ["man dmesg"].) Everyone needs either a
1358 coprocessor or this emulation.
1360 If you don't have a math coprocessor, you need to say Y here; if you
1361 say Y here even though you have a coprocessor, the coprocessor will
1362 be used nevertheless. (This behavior can be changed with the kernel
1363 command line option "no387", which comes handy if your coprocessor
1364 is broken. Try "man bootparam" or see the documentation of your boot
1365 loader (lilo or loadlin) about how to pass options to the kernel at
1366 boot time.) This means that it is a good idea to say Y here if you
1367 intend to use this kernel on different machines.
1369 More information about the internals of the Linux math coprocessor
1370 emulation can be found in <file:arch/x86/math-emu/README>.
1372 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1373 kernel, it won't hurt.
1375 config MTRR
1376 def_bool y
1377 prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1378 ---help---
1379 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1380 the Memory Type Range Registers (MTRRs) may be used to control
1381 processor access to memory ranges. This is most useful if you have
1382 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1383 allows bus write transfers to be combined into a larger transfer
1384 before bursting over the PCI/AGP bus. This can increase performance
1385 of image write operations 2.5 times or more. Saying Y here creates a
1386 /proc/mtrr file which may be used to manipulate your processor's
1387 MTRRs. Typically the X server should use this.
1389 This code has a reasonably generic interface so that similar
1390 control registers on other processors can be easily supported
1391 as well:
1393 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1394 Registers (ARRs) which provide a similar functionality to MTRRs. For
1395 these, the ARRs are used to emulate the MTRRs.
1396 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1397 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1398 write-combining. All of these processors are supported by this code
1399 and it makes sense to say Y here if you have one of them.
1401 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1402 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1403 can lead to all sorts of problems, so it's good to say Y here.
1405 You can safely say Y even if your machine doesn't have MTRRs, you'll
1406 just add about 9 KB to your kernel.
1408 See <file:Documentation/x86/mtrr.txt> for more information.
1410 config MTRR_SANITIZER
1411 def_bool y
1412 prompt "MTRR cleanup support"
1413 depends on MTRR
1414 ---help---
1415 Convert MTRR layout from continuous to discrete, so X drivers can
1416 add writeback entries.
1418 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1419 The largest mtrr entry size for a continuous block can be set with
1420 mtrr_chunk_size.
1422 If unsure, say Y.
1424 config MTRR_SANITIZER_ENABLE_DEFAULT
1425 int "MTRR cleanup enable value (0-1)"
1426 range 0 1
1427 default "0"
1428 depends on MTRR_SANITIZER
1429 ---help---
1430 Enable mtrr cleanup default value
1432 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1433 int "MTRR cleanup spare reg num (0-7)"
1434 range 0 7
1435 default "1"
1436 depends on MTRR_SANITIZER
1437 ---help---
1438 mtrr cleanup spare entries default, it can be changed via
1439 mtrr_spare_reg_nr=N on the kernel command line.
1441 config X86_PAT
1442 def_bool y
1443 prompt "x86 PAT support" if EMBEDDED
1444 depends on MTRR
1445 ---help---
1446 Use PAT attributes to setup page level cache control.
1448 PATs are the modern equivalents of MTRRs and are much more
1449 flexible than MTRRs.
1451 Say N here if you see bootup problems (boot crash, boot hang,
1452 spontaneous reboots) or a non-working video driver.
1454 If unsure, say Y.
1456 config ARCH_USES_PG_UNCACHED
1457 def_bool y
1458 depends on X86_PAT
1460 config EFI
1461 bool "EFI runtime service support"
1462 depends on ACPI
1463 ---help---
1464 This enables the kernel to use EFI runtime services that are
1465 available (such as the EFI variable services).
1467 This option is only useful on systems that have EFI firmware.
1468 In addition, you should use the latest ELILO loader available
1469 at <http://elilo.sourceforge.net> in order to take advantage
1470 of EFI runtime services. However, even with this option, the
1471 resultant kernel should continue to boot on existing non-EFI
1472 platforms.
1474 config SECCOMP
1475 def_bool y
1476 prompt "Enable seccomp to safely compute untrusted bytecode"
1477 ---help---
1478 This kernel feature is useful for number crunching applications
1479 that may need to compute untrusted bytecode during their
1480 execution. By using pipes or other transports made available to
1481 the process as file descriptors supporting the read/write
1482 syscalls, it's possible to isolate those applications in
1483 their own address space using seccomp. Once seccomp is
1484 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1485 and the task is only allowed to execute a few safe syscalls
1486 defined by each seccomp mode.
1488 If unsure, say Y. Only embedded should say N here.
1490 config CC_STACKPROTECTOR
1491 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1492 ---help---
1493 This option turns on the -fstack-protector GCC feature. This
1494 feature puts, at the beginning of functions, a canary value on
1495 the stack just before the return address, and validates
1496 the value just before actually returning. Stack based buffer
1497 overflows (that need to overwrite this return address) now also
1498 overwrite the canary, which gets detected and the attack is then
1499 neutralized via a kernel panic.
1501 This feature requires gcc version 4.2 or above, or a distribution
1502 gcc with the feature backported. Older versions are automatically
1503 detected and for those versions, this configuration option is
1504 ignored. (and a warning is printed during bootup)
1506 source kernel/Kconfig.hz
1508 config KEXEC
1509 bool "kexec system call"
1510 ---help---
1511 kexec is a system call that implements the ability to shutdown your
1512 current kernel, and to start another kernel. It is like a reboot
1513 but it is independent of the system firmware. And like a reboot
1514 you can start any kernel with it, not just Linux.
1516 The name comes from the similarity to the exec system call.
1518 It is an ongoing process to be certain the hardware in a machine
1519 is properly shutdown, so do not be surprised if this code does not
1520 initially work for you. It may help to enable device hotplugging
1521 support. As of this writing the exact hardware interface is
1522 strongly in flux, so no good recommendation can be made.
1524 config CRASH_DUMP
1525 bool "kernel crash dumps"
1526 depends on X86_64 || (X86_32 && HIGHMEM)
1527 ---help---
1528 Generate crash dump after being started by kexec.
1529 This should be normally only set in special crash dump kernels
1530 which are loaded in the main kernel with kexec-tools into
1531 a specially reserved region and then later executed after
1532 a crash by kdump/kexec. The crash dump kernel must be compiled
1533 to a memory address not used by the main kernel or BIOS using
1534 PHYSICAL_START, or it must be built as a relocatable image
1535 (CONFIG_RELOCATABLE=y).
1536 For more details see Documentation/kdump/kdump.txt
1538 config KEXEC_JUMP
1539 bool "kexec jump (EXPERIMENTAL)"
1540 depends on EXPERIMENTAL
1541 depends on KEXEC && HIBERNATION
1542 ---help---
1543 Jump between original kernel and kexeced kernel and invoke
1544 code in physical address mode via KEXEC
1546 config PHYSICAL_START
1547 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1548 default "0x1000000"
1549 ---help---
1550 This gives the physical address where the kernel is loaded.
1552 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1553 bzImage will decompress itself to above physical address and
1554 run from there. Otherwise, bzImage will run from the address where
1555 it has been loaded by the boot loader and will ignore above physical
1556 address.
1558 In normal kdump cases one does not have to set/change this option
1559 as now bzImage can be compiled as a completely relocatable image
1560 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1561 address. This option is mainly useful for the folks who don't want
1562 to use a bzImage for capturing the crash dump and want to use a
1563 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1564 to be specifically compiled to run from a specific memory area
1565 (normally a reserved region) and this option comes handy.
1567 So if you are using bzImage for capturing the crash dump,
1568 leave the value here unchanged to 0x1000000 and set
1569 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1570 for capturing the crash dump change this value to start of
1571 the reserved region. In other words, it can be set based on
1572 the "X" value as specified in the "crashkernel=YM@XM"
1573 command line boot parameter passed to the panic-ed
1574 kernel. Please take a look at Documentation/kdump/kdump.txt
1575 for more details about crash dumps.
1577 Usage of bzImage for capturing the crash dump is recommended as
1578 one does not have to build two kernels. Same kernel can be used
1579 as production kernel and capture kernel. Above option should have
1580 gone away after relocatable bzImage support is introduced. But it
1581 is present because there are users out there who continue to use
1582 vmlinux for dump capture. This option should go away down the
1583 line.
1585 Don't change this unless you know what you are doing.
1587 config RELOCATABLE
1588 bool "Build a relocatable kernel"
1589 default y
1590 ---help---
1591 This builds a kernel image that retains relocation information
1592 so it can be loaded someplace besides the default 1MB.
1593 The relocations tend to make the kernel binary about 10% larger,
1594 but are discarded at runtime.
1596 One use is for the kexec on panic case where the recovery kernel
1597 must live at a different physical address than the primary
1598 kernel.
1600 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1601 it has been loaded at and the compile time physical address
1602 (CONFIG_PHYSICAL_START) is ignored.
1604 # Relocation on x86-32 needs some additional build support
1605 config X86_NEED_RELOCS
1606 def_bool y
1607 depends on X86_32 && RELOCATABLE
1609 config PHYSICAL_ALIGN
1610 hex "Alignment value to which kernel should be aligned" if X86_32
1611 default "0x1000000"
1612 range 0x2000 0x1000000
1613 ---help---
1614 This value puts the alignment restrictions on physical address
1615 where kernel is loaded and run from. Kernel is compiled for an
1616 address which meets above alignment restriction.
1618 If bootloader loads the kernel at a non-aligned address and
1619 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1620 address aligned to above value and run from there.
1622 If bootloader loads the kernel at a non-aligned address and
1623 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1624 load address and decompress itself to the address it has been
1625 compiled for and run from there. The address for which kernel is
1626 compiled already meets above alignment restrictions. Hence the
1627 end result is that kernel runs from a physical address meeting
1628 above alignment restrictions.
1630 Don't change this unless you know what you are doing.
1632 config HOTPLUG_CPU
1633 bool "Support for hot-pluggable CPUs"
1634 depends on SMP && HOTPLUG
1635 ---help---
1636 Say Y here to allow turning CPUs off and on. CPUs can be
1637 controlled through /sys/devices/system/cpu.
1638 ( Note: power management support will enable this option
1639 automatically on SMP systems. )
1640 Say N if you want to disable CPU hotplug.
1642 config COMPAT_VDSO
1643 def_bool y
1644 prompt "Compat VDSO support"
1645 depends on X86_32 || IA32_EMULATION
1646 ---help---
1647 Map the 32-bit VDSO to the predictable old-style address too.
1649 Say N here if you are running a sufficiently recent glibc
1650 version (2.3.3 or later), to remove the high-mapped
1651 VDSO mapping and to exclusively use the randomized VDSO.
1653 If unsure, say Y.
1655 config CMDLINE_BOOL
1656 bool "Built-in kernel command line"
1657 ---help---
1658 Allow for specifying boot arguments to the kernel at
1659 build time. On some systems (e.g. embedded ones), it is
1660 necessary or convenient to provide some or all of the
1661 kernel boot arguments with the kernel itself (that is,
1662 to not rely on the boot loader to provide them.)
1664 To compile command line arguments into the kernel,
1665 set this option to 'Y', then fill in the
1666 the boot arguments in CONFIG_CMDLINE.
1668 Systems with fully functional boot loaders (i.e. non-embedded)
1669 should leave this option set to 'N'.
1671 config CMDLINE
1672 string "Built-in kernel command string"
1673 depends on CMDLINE_BOOL
1674 default ""
1675 ---help---
1676 Enter arguments here that should be compiled into the kernel
1677 image and used at boot time. If the boot loader provides a
1678 command line at boot time, it is appended to this string to
1679 form the full kernel command line, when the system boots.
1681 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1682 change this behavior.
1684 In most cases, the command line (whether built-in or provided
1685 by the boot loader) should specify the device for the root
1686 file system.
1688 config CMDLINE_OVERRIDE
1689 bool "Built-in command line overrides boot loader arguments"
1690 depends on CMDLINE_BOOL
1691 ---help---
1692 Set this option to 'Y' to have the kernel ignore the boot loader
1693 command line, and use ONLY the built-in command line.
1695 This is used to work around broken boot loaders. This should
1696 be set to 'N' under normal conditions.
1698 endmenu
1700 config ARCH_ENABLE_MEMORY_HOTPLUG
1701 def_bool y
1702 depends on X86_64 || (X86_32 && HIGHMEM)
1704 config ARCH_ENABLE_MEMORY_HOTREMOVE
1705 def_bool y
1706 depends on MEMORY_HOTPLUG
1708 config HAVE_ARCH_EARLY_PFN_TO_NID
1709 def_bool X86_64
1710 depends on NUMA
1712 config USE_PERCPU_NUMA_NODE_ID
1713 def_bool X86_64
1714 depends on NUMA
1716 menu "Power management and ACPI options"
1718 config ARCH_HIBERNATION_HEADER
1719 def_bool y
1720 depends on X86_64 && HIBERNATION
1722 source "kernel/power/Kconfig"
1724 source "drivers/acpi/Kconfig"
1726 source "drivers/sfi/Kconfig"
1728 config X86_APM_BOOT
1729 def_bool y
1730 depends on APM || APM_MODULE
1732 menuconfig APM
1733 tristate "APM (Advanced Power Management) BIOS support"
1734 depends on X86_32 && PM_SLEEP
1735 ---help---
1736 APM is a BIOS specification for saving power using several different
1737 techniques. This is mostly useful for battery powered laptops with
1738 APM compliant BIOSes. If you say Y here, the system time will be
1739 reset after a RESUME operation, the /proc/apm device will provide
1740 battery status information, and user-space programs will receive
1741 notification of APM "events" (e.g. battery status change).
1743 If you select "Y" here, you can disable actual use of the APM
1744 BIOS by passing the "apm=off" option to the kernel at boot time.
1746 Note that the APM support is almost completely disabled for
1747 machines with more than one CPU.
1749 In order to use APM, you will need supporting software. For location
1750 and more information, read <file:Documentation/power/pm.txt> and the
1751 Battery Powered Linux mini-HOWTO, available from
1752 <http://www.tldp.org/docs.html#howto>.
1754 This driver does not spin down disk drives (see the hdparm(8)
1755 manpage ("man 8 hdparm") for that), and it doesn't turn off
1756 VESA-compliant "green" monitors.
1758 This driver does not support the TI 4000M TravelMate and the ACER
1759 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1760 desktop machines also don't have compliant BIOSes, and this driver
1761 may cause those machines to panic during the boot phase.
1763 Generally, if you don't have a battery in your machine, there isn't
1764 much point in using this driver and you should say N. If you get
1765 random kernel OOPSes or reboots that don't seem to be related to
1766 anything, try disabling/enabling this option (or disabling/enabling
1767 APM in your BIOS).
1769 Some other things you should try when experiencing seemingly random,
1770 "weird" problems:
1772 1) make sure that you have enough swap space and that it is
1773 enabled.
1774 2) pass the "no-hlt" option to the kernel
1775 3) switch on floating point emulation in the kernel and pass
1776 the "no387" option to the kernel
1777 4) pass the "floppy=nodma" option to the kernel
1778 5) pass the "mem=4M" option to the kernel (thereby disabling
1779 all but the first 4 MB of RAM)
1780 6) make sure that the CPU is not over clocked.
1781 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1782 8) disable the cache from your BIOS settings
1783 9) install a fan for the video card or exchange video RAM
1784 10) install a better fan for the CPU
1785 11) exchange RAM chips
1786 12) exchange the motherboard.
1788 To compile this driver as a module, choose M here: the
1789 module will be called apm.
1791 if APM
1793 config APM_IGNORE_USER_SUSPEND
1794 bool "Ignore USER SUSPEND"
1795 ---help---
1796 This option will ignore USER SUSPEND requests. On machines with a
1797 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1798 series notebooks, it is necessary to say Y because of a BIOS bug.
1800 config APM_DO_ENABLE
1801 bool "Enable PM at boot time"
1802 ---help---
1803 Enable APM features at boot time. From page 36 of the APM BIOS
1804 specification: "When disabled, the APM BIOS does not automatically
1805 power manage devices, enter the Standby State, enter the Suspend
1806 State, or take power saving steps in response to CPU Idle calls."
1807 This driver will make CPU Idle calls when Linux is idle (unless this
1808 feature is turned off -- see "Do CPU IDLE calls", below). This
1809 should always save battery power, but more complicated APM features
1810 will be dependent on your BIOS implementation. You may need to turn
1811 this option off if your computer hangs at boot time when using APM
1812 support, or if it beeps continuously instead of suspending. Turn
1813 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1814 T400CDT. This is off by default since most machines do fine without
1815 this feature.
1817 config APM_CPU_IDLE
1818 bool "Make CPU Idle calls when idle"
1819 ---help---
1820 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1821 On some machines, this can activate improved power savings, such as
1822 a slowed CPU clock rate, when the machine is idle. These idle calls
1823 are made after the idle loop has run for some length of time (e.g.,
1824 333 mS). On some machines, this will cause a hang at boot time or
1825 whenever the CPU becomes idle. (On machines with more than one CPU,
1826 this option does nothing.)
1828 config APM_DISPLAY_BLANK
1829 bool "Enable console blanking using APM"
1830 ---help---
1831 Enable console blanking using the APM. Some laptops can use this to
1832 turn off the LCD backlight when the screen blanker of the Linux
1833 virtual console blanks the screen. Note that this is only used by
1834 the virtual console screen blanker, and won't turn off the backlight
1835 when using the X Window system. This also doesn't have anything to
1836 do with your VESA-compliant power-saving monitor. Further, this
1837 option doesn't work for all laptops -- it might not turn off your
1838 backlight at all, or it might print a lot of errors to the console,
1839 especially if you are using gpm.
1841 config APM_ALLOW_INTS
1842 bool "Allow interrupts during APM BIOS calls"
1843 ---help---
1844 Normally we disable external interrupts while we are making calls to
1845 the APM BIOS as a measure to lessen the effects of a badly behaving
1846 BIOS implementation. The BIOS should reenable interrupts if it
1847 needs to. Unfortunately, some BIOSes do not -- especially those in
1848 many of the newer IBM Thinkpads. If you experience hangs when you
1849 suspend, try setting this to Y. Otherwise, say N.
1851 endif # APM
1853 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1855 source "drivers/cpuidle/Kconfig"
1857 source "drivers/idle/Kconfig"
1859 endmenu
1862 menu "Bus options (PCI etc.)"
1864 config PCI
1865 bool "PCI support"
1866 default y
1867 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1868 ---help---
1869 Find out whether you have a PCI motherboard. PCI is the name of a
1870 bus system, i.e. the way the CPU talks to the other stuff inside
1871 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1872 VESA. If you have PCI, say Y, otherwise N.
1874 choice
1875 prompt "PCI access mode"
1876 depends on X86_32 && PCI
1877 default PCI_GOANY
1878 ---help---
1879 On PCI systems, the BIOS can be used to detect the PCI devices and
1880 determine their configuration. However, some old PCI motherboards
1881 have BIOS bugs and may crash if this is done. Also, some embedded
1882 PCI-based systems don't have any BIOS at all. Linux can also try to
1883 detect the PCI hardware directly without using the BIOS.
1885 With this option, you can specify how Linux should detect the
1886 PCI devices. If you choose "BIOS", the BIOS will be used,
1887 if you choose "Direct", the BIOS won't be used, and if you
1888 choose "MMConfig", then PCI Express MMCONFIG will be used.
1889 If you choose "Any", the kernel will try MMCONFIG, then the
1890 direct access method and falls back to the BIOS if that doesn't
1891 work. If unsure, go with the default, which is "Any".
1893 config PCI_GOBIOS
1894 bool "BIOS"
1896 config PCI_GOMMCONFIG
1897 bool "MMConfig"
1899 config PCI_GODIRECT
1900 bool "Direct"
1902 config PCI_GOOLPC
1903 bool "OLPC"
1904 depends on OLPC
1906 config PCI_GOANY
1907 bool "Any"
1909 endchoice
1911 config PCI_BIOS
1912 def_bool y
1913 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1915 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1916 config PCI_DIRECT
1917 def_bool y
1918 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1920 config PCI_MMCONFIG
1921 def_bool y
1922 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1924 config PCI_OLPC
1925 def_bool y
1926 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1928 config PCI_DOMAINS
1929 def_bool y
1930 depends on PCI
1932 config PCI_MMCONFIG
1933 bool "Support mmconfig PCI config space access"
1934 depends on X86_64 && PCI && ACPI
1936 config PCI_CNB20LE_QUIRK
1937 bool "Read CNB20LE Host Bridge Windows"
1938 depends on PCI
1939 help
1940 Read the PCI windows out of the CNB20LE host bridge. This allows
1941 PCI hotplug to work on systems with the CNB20LE chipset which do
1942 not have ACPI.
1944 config DMAR
1945 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1946 depends on PCI_MSI && ACPI && EXPERIMENTAL
1947 help
1948 DMA remapping (DMAR) devices support enables independent address
1949 translations for Direct Memory Access (DMA) from devices.
1950 These DMA remapping devices are reported via ACPI tables
1951 and include PCI device scope covered by these DMA
1952 remapping devices.
1954 config DMAR_DEFAULT_ON
1955 def_bool y
1956 prompt "Enable DMA Remapping Devices by default"
1957 depends on DMAR
1958 help
1959 Selecting this option will enable a DMAR device at boot time if
1960 one is found. If this option is not selected, DMAR support can
1961 be enabled by passing intel_iommu=on to the kernel. It is
1962 recommended you say N here while the DMAR code remains
1963 experimental.
1965 config DMAR_BROKEN_GFX_WA
1966 bool "Workaround broken graphics drivers (going away soon)"
1967 depends on DMAR && BROKEN
1968 ---help---
1969 Current Graphics drivers tend to use physical address
1970 for DMA and avoid using DMA APIs. Setting this config
1971 option permits the IOMMU driver to set a unity map for
1972 all the OS-visible memory. Hence the driver can continue
1973 to use physical addresses for DMA, at least until this
1974 option is removed in the 2.6.32 kernel.
1976 config DMAR_FLOPPY_WA
1977 def_bool y
1978 depends on DMAR
1979 ---help---
1980 Floppy disk drivers are known to bypass DMA API calls
1981 thereby failing to work when IOMMU is enabled. This
1982 workaround will setup a 1:1 mapping for the first
1983 16MiB to make floppy (an ISA device) work.
1985 config INTR_REMAP
1986 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1987 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1988 ---help---
1989 Supports Interrupt remapping for IO-APIC and MSI devices.
1990 To use x2apic mode in the CPU's which support x2APIC enhancements or
1991 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1993 source "drivers/pci/pcie/Kconfig"
1995 source "drivers/pci/Kconfig"
1997 # x86_64 have no ISA slots, but do have ISA-style DMA.
1998 config ISA_DMA_API
1999 def_bool y
2001 if X86_32
2003 config ISA
2004 bool "ISA support"
2005 ---help---
2006 Find out whether you have ISA slots on your motherboard. ISA is the
2007 name of a bus system, i.e. the way the CPU talks to the other stuff
2008 inside your box. Other bus systems are PCI, EISA, MicroChannel
2009 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2010 newer boards don't support it. If you have ISA, say Y, otherwise N.
2012 config EISA
2013 bool "EISA support"
2014 depends on ISA
2015 ---help---
2016 The Extended Industry Standard Architecture (EISA) bus was
2017 developed as an open alternative to the IBM MicroChannel bus.
2019 The EISA bus provided some of the features of the IBM MicroChannel
2020 bus while maintaining backward compatibility with cards made for
2021 the older ISA bus. The EISA bus saw limited use between 1988 and
2022 1995 when it was made obsolete by the PCI bus.
2024 Say Y here if you are building a kernel for an EISA-based machine.
2026 Otherwise, say N.
2028 source "drivers/eisa/Kconfig"
2030 config MCA
2031 bool "MCA support"
2032 ---help---
2033 MicroChannel Architecture is found in some IBM PS/2 machines and
2034 laptops. It is a bus system similar to PCI or ISA. See
2035 <file:Documentation/mca.txt> (and especially the web page given
2036 there) before attempting to build an MCA bus kernel.
2038 source "drivers/mca/Kconfig"
2040 config SCx200
2041 tristate "NatSemi SCx200 support"
2042 ---help---
2043 This provides basic support for National Semiconductor's
2044 (now AMD's) Geode processors. The driver probes for the
2045 PCI-IDs of several on-chip devices, so its a good dependency
2046 for other scx200_* drivers.
2048 If compiled as a module, the driver is named scx200.
2050 config SCx200HR_TIMER
2051 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2052 depends on SCx200
2053 default y
2054 ---help---
2055 This driver provides a clocksource built upon the on-chip
2056 27MHz high-resolution timer. Its also a workaround for
2057 NSC Geode SC-1100's buggy TSC, which loses time when the
2058 processor goes idle (as is done by the scheduler). The
2059 other workaround is idle=poll boot option.
2061 config OLPC
2062 bool "One Laptop Per Child support"
2063 select GPIOLIB
2064 ---help---
2065 Add support for detecting the unique features of the OLPC
2066 XO hardware.
2068 config OLPC_OPENFIRMWARE
2069 bool "Support for OLPC's Open Firmware"
2070 depends on !X86_64 && !X86_PAE
2071 default y if OLPC
2072 help
2073 This option adds support for the implementation of Open Firmware
2074 that is used on the OLPC XO-1 Children's Machine.
2075 If unsure, say N here.
2077 endif # X86_32
2079 config K8_NB
2080 def_bool y
2081 depends on CPU_SUP_AMD && PCI
2083 source "drivers/pcmcia/Kconfig"
2085 source "drivers/pci/hotplug/Kconfig"
2087 endmenu
2090 menu "Executable file formats / Emulations"
2092 source "fs/Kconfig.binfmt"
2094 config IA32_EMULATION
2095 bool "IA32 Emulation"
2096 depends on X86_64
2097 select COMPAT_BINFMT_ELF
2098 ---help---
2099 Include code to run 32-bit programs under a 64-bit kernel. You should
2100 likely turn this on, unless you're 100% sure that you don't have any
2101 32-bit programs left.
2103 config IA32_AOUT
2104 tristate "IA32 a.out support"
2105 depends on IA32_EMULATION
2106 ---help---
2107 Support old a.out binaries in the 32bit emulation.
2109 config COMPAT
2110 def_bool y
2111 depends on IA32_EMULATION
2113 config COMPAT_FOR_U64_ALIGNMENT
2114 def_bool COMPAT
2115 depends on X86_64
2117 config SYSVIPC_COMPAT
2118 def_bool y
2119 depends on COMPAT && SYSVIPC
2121 endmenu
2124 config HAVE_ATOMIC_IOMAP
2125 def_bool y
2126 depends on X86_32
2128 source "net/Kconfig"
2130 source "drivers/Kconfig"
2132 source "drivers/firmware/Kconfig"
2134 source "fs/Kconfig"
2136 source "arch/x86/Kconfig.debug"
2138 source "security/Kconfig"
2140 source "crypto/Kconfig"
2142 source "arch/x86/kvm/Kconfig"
2144 source "lib/Kconfig"