| blob | 140e254fe546e195c125915392d0f1ece1d38d8f |
1 # Select 32 or 64 bit
2 config 64BIT
3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
5 ---help---
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
9 config X86_32
10 def_bool !64BIT
12 config X86_64
13 def_bool 64BIT
15 ### Arch settings
16 config X86
17 def_bool y
18 select HAVE_AOUT if X86_32
19 select HAVE_READQ
20 select HAVE_WRITEQ
21 select HAVE_UNSTABLE_SCHED_CLOCK
22 select HAVE_IDE
23 select HAVE_OPROFILE
24 select HAVE_PERF_EVENTS
25 select HAVE_IRQ_WORK
26 select HAVE_IOREMAP_PROT
27 select HAVE_KPROBES
28 select HAVE_MEMBLOCK
29 select ARCH_WANT_OPTIONAL_GPIOLIB
30 select ARCH_WANT_FRAME_POINTERS
31 select HAVE_DMA_ATTRS
32 select HAVE_KRETPROBES
33 select HAVE_OPTPROBES
34 select HAVE_FTRACE_MCOUNT_RECORD
35 select HAVE_C_RECORDMCOUNT
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_XZ
55 select HAVE_KERNEL_LZO
56 select HAVE_HW_BREAKPOINT
57 select HAVE_MIXED_BREAKPOINTS_REGS
58 select PERF_EVENTS
59 select HAVE_PERF_EVENTS_NMI
60 select ANON_INODES
61 select HAVE_ARCH_KMEMCHECK
62 select HAVE_USER_RETURN_NOTIFIER
63 select HAVE_ARCH_JUMP_LABEL
64 select HAVE_TEXT_POKE_SMP
65 select HAVE_GENERIC_HARDIRQS
66 select HAVE_SPARSE_IRQ
67 select GENERIC_FIND_FIRST_BIT
68 select GENERIC_FIND_NEXT_BIT
69 select GENERIC_IRQ_PROBE
70 select GENERIC_PENDING_IRQ if SMP
71 select GENERIC_IRQ_SHOW
72 select IRQ_FORCED_THREADING
73 select USE_GENERIC_SMP_HELPERS if SMP
75 config INSTRUCTION_DECODER
76 def_bool (KPROBES || PERF_EVENTS)
78 config OUTPUT_FORMAT
79 string
80 default "elf32-i386" if X86_32
81 default "elf64-x86-64" if X86_64
83 config ARCH_DEFCONFIG
84 string
85 default "arch/x86/configs/i386_defconfig" if X86_32
86 default "arch/x86/configs/x86_64_defconfig" if X86_64
88 config GENERIC_CMOS_UPDATE
89 def_bool y
91 config CLOCKSOURCE_WATCHDOG
92 def_bool y
94 config GENERIC_CLOCKEVENTS
95 def_bool y
97 config GENERIC_CLOCKEVENTS_BROADCAST
98 def_bool y
99 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
101 config LOCKDEP_SUPPORT
102 def_bool y
104 config STACKTRACE_SUPPORT
105 def_bool y
107 config HAVE_LATENCYTOP_SUPPORT
108 def_bool y
110 config MMU
111 def_bool y
113 config ZONE_DMA
114 def_bool y
116 config SBUS
117 bool
119 config NEED_DMA_MAP_STATE
120 def_bool (X86_64 || DMAR || DMA_API_DEBUG)
122 config NEED_SG_DMA_LENGTH
123 def_bool y
125 config GENERIC_ISA_DMA
126 def_bool ISA_DMA_API
128 config GENERIC_IOMAP
129 def_bool y
131 config GENERIC_BUG
132 def_bool y
133 depends on BUG
134 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
136 config GENERIC_BUG_RELATIVE_POINTERS
137 bool
139 config GENERIC_HWEIGHT
140 def_bool y
142 config GENERIC_GPIO
143 bool
145 config ARCH_MAY_HAVE_PC_FDC
146 def_bool ISA_DMA_API
148 config RWSEM_GENERIC_SPINLOCK
149 def_bool !X86_XADD
151 config RWSEM_XCHGADD_ALGORITHM
152 def_bool X86_XADD
154 config ARCH_HAS_CPU_IDLE_WAIT
155 def_bool y
157 config GENERIC_CALIBRATE_DELAY
158 def_bool y
160 config GENERIC_TIME_VSYSCALL
161 bool
162 default X86_64
164 config ARCH_HAS_CPU_RELAX
165 def_bool y
167 config ARCH_HAS_DEFAULT_IDLE
168 def_bool y
170 config ARCH_HAS_CACHE_LINE_SIZE
171 def_bool y
173 config HAVE_SETUP_PER_CPU_AREA
174 def_bool y
176 config NEED_PER_CPU_EMBED_FIRST_CHUNK
177 def_bool y
179 config NEED_PER_CPU_PAGE_FIRST_CHUNK
180 def_bool y
182 config HAVE_CPUMASK_OF_CPU_MAP
183 def_bool X86_64_SMP
185 config ARCH_HIBERNATION_POSSIBLE
186 def_bool y
188 config ARCH_SUSPEND_POSSIBLE
189 def_bool y
191 config ZONE_DMA32
192 bool
193 default X86_64
195 config ARCH_POPULATES_NODE_MAP
196 def_bool y
198 config AUDIT_ARCH
199 bool
200 default X86_64
202 config ARCH_SUPPORTS_OPTIMIZED_INLINING
203 def_bool y
205 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
206 def_bool y
208 config HAVE_INTEL_TXT
209 def_bool y
210 depends on EXPERIMENTAL && DMAR && ACPI
212 config X86_32_SMP
213 def_bool y
214 depends on X86_32 && SMP
216 config X86_64_SMP
217 def_bool y
218 depends on X86_64 && SMP
220 config X86_HT
221 def_bool y
222 depends on SMP
224 config X86_32_LAZY_GS
225 def_bool y
226 depends on X86_32 && !CC_STACKPROTECTOR
228 config ARCH_HWEIGHT_CFLAGS
229 string
230 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
231 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
233 config KTIME_SCALAR
234 def_bool X86_32
236 config ARCH_CPU_PROBE_RELEASE
237 def_bool y
238 depends on HOTPLUG_CPU
240 source "init/Kconfig"
241 source "kernel/Kconfig.freezer"
243 menu "Processor type and features"
245 source "kernel/time/Kconfig"
247 config SMP
248 bool "Symmetric multi-processing support"
249 ---help---
250 This enables support for systems with more than one CPU. If you have
251 a system with only one CPU, like most personal computers, say N. If
252 you have a system with more than one CPU, say Y.
254 If you say N here, the kernel will run on single and multiprocessor
255 machines, but will use only one CPU of a multiprocessor machine. If
256 you say Y here, the kernel will run on many, but not all,
257 singleprocessor machines. On a singleprocessor machine, the kernel
258 will run faster if you say N here.
260 Note that if you say Y here and choose architecture "586" or
261 "Pentium" under "Processor family", the kernel will not work on 486
262 architectures. Similarly, multiprocessor kernels for the "PPro"
263 architecture may not work on all Pentium based boards.
265 People using multiprocessor machines who say Y here should also say
266 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
267 Management" code will be disabled if you say Y here.
269 See also <file:Documentation/i386/IO-APIC.txt>,
270 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
271 <http://www.tldp.org/docs.html#howto>.
273 If you don't know what to do here, say N.
275 config X86_X2APIC
276 bool "Support x2apic"
277 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
278 ---help---
279 This enables x2apic support on CPUs that have this feature.
281 This allows 32-bit apic IDs (so it can support very large systems),
282 and accesses the local apic via MSRs not via mmio.
284 If you don't know what to do here, say N.
286 config X86_MPPARSE
287 bool "Enable MPS table" if ACPI
288 default y
289 depends on X86_LOCAL_APIC
290 ---help---
291 For old smp systems that do not have proper acpi support. Newer systems
292 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
294 config X86_BIGSMP
295 bool "Support for big SMP systems with more than 8 CPUs"
296 depends on X86_32 && SMP
297 ---help---
298 This option is needed for the systems that have more than 8 CPUs
300 if X86_32
301 config X86_EXTENDED_PLATFORM
302 bool "Support for extended (non-PC) x86 platforms"
303 default y
304 ---help---
305 If you disable this option then the kernel will only support
306 standard PC platforms. (which covers the vast majority of
307 systems out there.)
309 If you enable this option then you'll be able to select support
310 for the following (non-PC) 32 bit x86 platforms:
311 AMD Elan
312 NUMAQ (IBM/Sequent)
313 RDC R-321x SoC
314 SGI 320/540 (Visual Workstation)
315 Summit/EXA (IBM x440)
316 Unisys ES7000 IA32 series
317 Moorestown MID devices
319 If you have one of these systems, or if you want to build a
320 generic distribution kernel, say Y here - otherwise say N.
321 endif
323 if X86_64
324 config X86_EXTENDED_PLATFORM
325 bool "Support for extended (non-PC) x86 platforms"
326 default y
327 ---help---
328 If you disable this option then the kernel will only support
329 standard PC platforms. (which covers the vast majority of
330 systems out there.)
332 If you enable this option then you'll be able to select support
333 for the following (non-PC) 64 bit x86 platforms:
334 ScaleMP vSMP
335 SGI Ultraviolet
337 If you have one of these systems, or if you want to build a
338 generic distribution kernel, say Y here - otherwise say N.
339 endif
340 # This is an alphabetically sorted list of 64 bit extended platforms
341 # Please maintain the alphabetic order if and when there are additions
343 config X86_VSMP
344 bool "ScaleMP vSMP"
345 select PARAVIRT_GUEST
346 select PARAVIRT
347 depends on X86_64 && PCI
348 depends on X86_EXTENDED_PLATFORM
349 ---help---
350 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
351 supposed to run on these EM64T-based machines. Only choose this option
352 if you have one of these machines.
354 config X86_UV
355 bool "SGI Ultraviolet"
356 depends on X86_64
357 depends on X86_EXTENDED_PLATFORM
358 depends on NUMA
359 depends on X86_X2APIC
360 ---help---
361 This option is needed in order to support SGI Ultraviolet systems.
362 If you don't have one of these, you should say N here.
364 # Following is an alphabetically sorted list of 32 bit extended platforms
365 # Please maintain the alphabetic order if and when there are additions
367 config X86_ELAN
368 bool "AMD Elan"
369 depends on X86_32
370 depends on X86_EXTENDED_PLATFORM
371 ---help---
372 Select this for an AMD Elan processor.
374 Do not use this option for K6/Athlon/Opteron processors!
376 If unsure, choose "PC-compatible" instead.
378 config X86_INTEL_CE
379 bool "CE4100 TV platform"
380 depends on PCI
381 depends on PCI_GODIRECT
382 depends on X86_32
383 depends on X86_EXTENDED_PLATFORM
384 select X86_REBOOTFIXUPS
385 select OF
386 select OF_EARLY_FLATTREE
387 ---help---
388 Select for the Intel CE media processor (CE4100) SOC.
389 This option compiles in support for the CE4100 SOC for settop
390 boxes and media devices.
392 config X86_MRST
393 bool "Moorestown MID platform"
394 depends on PCI
395 depends on PCI_GOANY
396 depends on X86_32
397 depends on X86_EXTENDED_PLATFORM
398 depends on X86_IO_APIC
399 select APB_TIMER
400 select I2C
401 select SPI
402 select INTEL_SCU_IPC
403 select X86_PLATFORM_DEVICES
404 ---help---
405 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
406 Internet Device(MID) platform. Moorestown consists of two chips:
407 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
408 Unlike standard x86 PCs, Moorestown does not have many legacy devices
409 nor standard legacy replacement devices/features. e.g. Moorestown does
410 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
412 config X86_RDC321X
413 bool "RDC R-321x SoC"
414 depends on X86_32
415 depends on X86_EXTENDED_PLATFORM
416 select M486
417 select X86_REBOOTFIXUPS
418 ---help---
419 This option is needed for RDC R-321x system-on-chip, also known
420 as R-8610-(G).
421 If you don't have one of these chips, you should say N here.
423 config X86_32_NON_STANDARD
424 bool "Support non-standard 32-bit SMP architectures"
425 depends on X86_32 && SMP
426 depends on X86_EXTENDED_PLATFORM
427 ---help---
428 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
429 subarchitectures. It is intended for a generic binary kernel.
430 if you select them all, kernel will probe it one by one. and will
431 fallback to default.
433 # Alphabetically sorted list of Non standard 32 bit platforms
435 config X86_NUMAQ
436 bool "NUMAQ (IBM/Sequent)"
437 depends on X86_32_NON_STANDARD
438 depends on PCI
439 select NUMA
440 select X86_MPPARSE
441 ---help---
442 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
443 NUMA multiquad box. This changes the way that processors are
444 bootstrapped, and uses Clustered Logical APIC addressing mode instead
445 of Flat Logical. You will need a new lynxer.elf file to flash your
446 firmware with - send email to <Martin.Bligh@us.ibm.com>.
448 config X86_SUPPORTS_MEMORY_FAILURE
449 def_bool y
450 # MCE code calls memory_failure():
451 depends on X86_MCE
452 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
453 depends on !X86_NUMAQ
454 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
455 depends on X86_64 || !SPARSEMEM
456 select ARCH_SUPPORTS_MEMORY_FAILURE
458 config X86_VISWS
459 bool "SGI 320/540 (Visual Workstation)"
460 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
461 depends on X86_32_NON_STANDARD
462 ---help---
463 The SGI Visual Workstation series is an IA32-based workstation
464 based on SGI systems chips with some legacy PC hardware attached.
466 Say Y here to create a kernel to run on the SGI 320 or 540.
468 A kernel compiled for the Visual Workstation will run on general
469 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
471 config X86_SUMMIT
472 bool "Summit/EXA (IBM x440)"
473 depends on X86_32_NON_STANDARD
474 ---help---
475 This option is needed for IBM systems that use the Summit/EXA chipset.
476 In particular, it is needed for the x440.
478 config X86_ES7000
479 bool "Unisys ES7000 IA32 series"
480 depends on X86_32_NON_STANDARD && X86_BIGSMP
481 ---help---
482 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
483 supposed to run on an IA32-based Unisys ES7000 system.
485 config X86_32_IRIS
486 tristate "Eurobraille/Iris poweroff module"
487 depends on X86_32
488 ---help---
489 The Iris machines from EuroBraille do not have APM or ACPI support
490 to shut themselves down properly. A special I/O sequence is
491 needed to do so, which is what this module does at
492 kernel shutdown.
494 This is only for Iris machines from EuroBraille.
496 If unused, say N.
498 config SCHED_OMIT_FRAME_POINTER
499 def_bool y
500 prompt "Single-depth WCHAN output"
501 depends on X86
502 ---help---
503 Calculate simpler /proc/<PID>/wchan values. If this option
504 is disabled then wchan values will recurse back to the
505 caller function. This provides more accurate wchan values,
506 at the expense of slightly more scheduling overhead.
508 If in doubt, say "Y".
510 menuconfig PARAVIRT_GUEST
511 bool "Paravirtualized guest support"
512 ---help---
513 Say Y here to get to see options related to running Linux under
514 various hypervisors. This option alone does not add any kernel code.
516 If you say N, all options in this submenu will be skipped and disabled.
518 if PARAVIRT_GUEST
520 source "arch/x86/xen/Kconfig"
522 config KVM_CLOCK
523 bool "KVM paravirtualized clock"
524 select PARAVIRT
525 select PARAVIRT_CLOCK
526 ---help---
527 Turning on this option will allow you to run a paravirtualized clock
528 when running over the KVM hypervisor. Instead of relying on a PIT
529 (or probably other) emulation by the underlying device model, the host
530 provides the guest with timing infrastructure such as time of day, and
531 system time
533 config KVM_GUEST
534 bool "KVM Guest support"
535 select PARAVIRT
536 ---help---
537 This option enables various optimizations for running under the KVM
538 hypervisor.
540 source "arch/x86/lguest/Kconfig"
542 config PARAVIRT
543 bool "Enable paravirtualization code"
544 ---help---
545 This changes the kernel so it can modify itself when it is run
546 under a hypervisor, potentially improving performance significantly
547 over full virtualization. However, when run without a hypervisor
548 the kernel is theoretically slower and slightly larger.
550 config PARAVIRT_SPINLOCKS
551 bool "Paravirtualization layer for spinlocks"
552 depends on PARAVIRT && SMP && EXPERIMENTAL
553 ---help---
554 Paravirtualized spinlocks allow a pvops backend to replace the
555 spinlock implementation with something virtualization-friendly
556 (for example, block the virtual CPU rather than spinning).
558 Unfortunately the downside is an up to 5% performance hit on
559 native kernels, with various workloads.
561 If you are unsure how to answer this question, answer N.
563 config PARAVIRT_CLOCK
564 bool
566 endif
568 config PARAVIRT_DEBUG
569 bool "paravirt-ops debugging"
570 depends on PARAVIRT && DEBUG_KERNEL
571 ---help---
572 Enable to debug paravirt_ops internals. Specifically, BUG if
573 a paravirt_op is missing when it is called.
575 config NO_BOOTMEM
576 def_bool y
578 config MEMTEST
579 bool "Memtest"
580 ---help---
581 This option adds a kernel parameter 'memtest', which allows memtest
582 to be set.
583 memtest=0, mean disabled; -- default
584 memtest=1, mean do 1 test pattern;
585 ...
586 memtest=4, mean do 4 test patterns.
587 If you are unsure how to answer this question, answer N.
589 config X86_SUMMIT_NUMA
590 def_bool y
591 depends on X86_32 && NUMA && X86_32_NON_STANDARD
593 config X86_CYCLONE_TIMER
594 def_bool y
595 depends on X86_32_NON_STANDARD
597 source "arch/x86/Kconfig.cpu"
599 config HPET_TIMER
600 def_bool X86_64
601 prompt "HPET Timer Support" if X86_32
602 ---help---
603 Use the IA-PC HPET (High Precision Event Timer) to manage
604 time in preference to the PIT and RTC, if a HPET is
605 present.
606 HPET is the next generation timer replacing legacy 8254s.
607 The HPET provides a stable time base on SMP
608 systems, unlike the TSC, but it is more expensive to access,
609 as it is off-chip. You can find the HPET spec at
610 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
612 You can safely choose Y here. However, HPET will only be
613 activated if the platform and the BIOS support this feature.
614 Otherwise the 8254 will be used for timing services.
616 Choose N to continue using the legacy 8254 timer.
618 config HPET_EMULATE_RTC
619 def_bool y
620 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
622 config APB_TIMER
623 def_bool y if MRST
624 prompt "Langwell APB Timer Support" if X86_MRST
625 help
626 APB timer is the replacement for 8254, HPET on X86 MID platforms.
627 The APBT provides a stable time base on SMP
628 systems, unlike the TSC, but it is more expensive to access,
629 as it is off-chip. APB timers are always running regardless of CPU
630 C states, they are used as per CPU clockevent device when possible.
632 # Mark as expert because too many people got it wrong.
633 # The code disables itself when not needed.
634 config DMI
635 default y
636 bool "Enable DMI scanning" if EXPERT
637 ---help---
638 Enabled scanning of DMI to identify machine quirks. Say Y
639 here unless you have verified that your setup is not
640 affected by entries in the DMI blacklist. Required by PNP
641 BIOS code.
643 config GART_IOMMU
644 bool "GART IOMMU support" if EXPERT
645 default y
646 select SWIOTLB
647 depends on X86_64 && PCI && AMD_NB
648 ---help---
649 Support for full DMA access of devices with 32bit memory access only
650 on systems with more than 3GB. This is usually needed for USB,
651 sound, many IDE/SATA chipsets and some other devices.
652 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
653 based hardware IOMMU and a software bounce buffer based IOMMU used
654 on Intel systems and as fallback.
655 The code is only active when needed (enough memory and limited
656 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
657 too.
659 config CALGARY_IOMMU
660 bool "IBM Calgary IOMMU support"
661 select SWIOTLB
662 depends on X86_64 && PCI && EXPERIMENTAL
663 ---help---
664 Support for hardware IOMMUs in IBM's xSeries x366 and x460
665 systems. Needed to run systems with more than 3GB of memory
666 properly with 32-bit PCI devices that do not support DAC
667 (Double Address Cycle). Calgary also supports bus level
668 isolation, where all DMAs pass through the IOMMU. This
669 prevents them from going anywhere except their intended
670 destination. This catches hard-to-find kernel bugs and
671 mis-behaving drivers and devices that do not use the DMA-API
672 properly to set up their DMA buffers. The IOMMU can be
673 turned off at boot time with the iommu=off parameter.
674 Normally the kernel will make the right choice by itself.
675 If unsure, say Y.
677 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
678 def_bool y
679 prompt "Should Calgary be enabled by default?"
680 depends on CALGARY_IOMMU
681 ---help---
682 Should Calgary be enabled by default? if you choose 'y', Calgary
683 will be used (if it exists). If you choose 'n', Calgary will not be
684 used even if it exists. If you choose 'n' and would like to use
685 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
686 If unsure, say Y.
688 config AMD_IOMMU
689 bool "AMD IOMMU support"
690 select SWIOTLB
691 select PCI_MSI
692 depends on X86_64 && PCI && ACPI
693 ---help---
694 With this option you can enable support for AMD IOMMU hardware in
695 your system. An IOMMU is a hardware component which provides
696 remapping of DMA memory accesses from devices. With an AMD IOMMU you
697 can isolate the the DMA memory of different devices and protect the
698 system from misbehaving device drivers or hardware.
700 You can find out if your system has an AMD IOMMU if you look into
701 your BIOS for an option to enable it or if you have an IVRS ACPI
702 table.
704 config AMD_IOMMU_STATS
705 bool "Export AMD IOMMU statistics to debugfs"
706 depends on AMD_IOMMU
707 select DEBUG_FS
708 ---help---
709 This option enables code in the AMD IOMMU driver to collect various
710 statistics about whats happening in the driver and exports that
711 information to userspace via debugfs.
712 If unsure, say N.
714 # need this always selected by IOMMU for the VIA workaround
715 config SWIOTLB
716 def_bool y if X86_64
717 ---help---
718 Support for software bounce buffers used on x86-64 systems
719 which don't have a hardware IOMMU (e.g. the current generation
720 of Intel's x86-64 CPUs). Using this PCI devices which can only
721 access 32-bits of memory can be used on systems with more than
722 3 GB of memory. If unsure, say Y.
724 config IOMMU_HELPER
725 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
727 config IOMMU_API
728 def_bool (AMD_IOMMU || DMAR)
730 config MAXSMP
731 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
732 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
733 select CPUMASK_OFFSTACK
734 ---help---
735 Enable maximum number of CPUS and NUMA Nodes for this architecture.
736 If unsure, say N.
738 config NR_CPUS
739 int "Maximum number of CPUs" if SMP && !MAXSMP
740 range 2 8 if SMP && X86_32 && !X86_BIGSMP
741 range 2 512 if SMP && !MAXSMP
742 default "1" if !SMP
743 default "4096" if MAXSMP
744 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
745 default "8" if SMP
746 ---help---
747 This allows you to specify the maximum number of CPUs which this
748 kernel will support. The maximum supported value is 512 and the
749 minimum value which makes sense is 2.
751 This is purely to save memory - each supported CPU adds
752 approximately eight kilobytes to the kernel image.
754 config SCHED_SMT
755 bool "SMT (Hyperthreading) scheduler support"
756 depends on X86_HT
757 ---help---
758 SMT scheduler support improves the CPU scheduler's decision making
759 when dealing with Intel Pentium 4 chips with HyperThreading at a
760 cost of slightly increased overhead in some places. If unsure say
761 N here.
763 config SCHED_MC
764 def_bool y
765 prompt "Multi-core scheduler support"
766 depends on X86_HT
767 ---help---
768 Multi-core scheduler support improves the CPU scheduler's decision
769 making when dealing with multi-core CPU chips at a cost of slightly
770 increased overhead in some places. If unsure say N here.
772 config IRQ_TIME_ACCOUNTING
773 bool "Fine granularity task level IRQ time accounting"
774 default n
775 ---help---
776 Select this option to enable fine granularity task irq time
777 accounting. This is done by reading a timestamp on each
778 transitions between softirq and hardirq state, so there can be a
779 small performance impact.
781 If in doubt, say N here.
783 source "kernel/Kconfig.preempt"
785 config X86_UP_APIC
786 bool "Local APIC support on uniprocessors"
787 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
788 ---help---
789 A local APIC (Advanced Programmable Interrupt Controller) is an
790 integrated interrupt controller in the CPU. If you have a single-CPU
791 system which has a processor with a local APIC, you can say Y here to
792 enable and use it. If you say Y here even though your machine doesn't
793 have a local APIC, then the kernel will still run with no slowdown at
794 all. The local APIC supports CPU-generated self-interrupts (timer,
795 performance counters), and the NMI watchdog which detects hard
796 lockups.
798 config X86_UP_IOAPIC
799 bool "IO-APIC support on uniprocessors"
800 depends on X86_UP_APIC
801 ---help---
802 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
803 SMP-capable replacement for PC-style interrupt controllers. Most
804 SMP systems and many recent uniprocessor systems have one.
806 If you have a single-CPU system with an IO-APIC, you can say Y here
807 to use it. If you say Y here even though your machine doesn't have
808 an IO-APIC, then the kernel will still run with no slowdown at all.
810 config X86_LOCAL_APIC
811 def_bool y
812 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
814 config X86_IO_APIC
815 def_bool y
816 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
818 config X86_VISWS_APIC
819 def_bool y
820 depends on X86_32 && X86_VISWS
822 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
823 bool "Reroute for broken boot IRQs"
824 depends on X86_IO_APIC
825 ---help---
826 This option enables a workaround that fixes a source of
827 spurious interrupts. This is recommended when threaded
828 interrupt handling is used on systems where the generation of
829 superfluous "boot interrupts" cannot be disabled.
831 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
832 entry in the chipset's IO-APIC is masked (as, e.g. the RT
833 kernel does during interrupt handling). On chipsets where this
834 boot IRQ generation cannot be disabled, this workaround keeps
835 the original IRQ line masked so that only the equivalent "boot
836 IRQ" is delivered to the CPUs. The workaround also tells the
837 kernel to set up the IRQ handler on the boot IRQ line. In this
838 way only one interrupt is delivered to the kernel. Otherwise
839 the spurious second interrupt may cause the kernel to bring
840 down (vital) interrupt lines.
842 Only affects "broken" chipsets. Interrupt sharing may be
843 increased on these systems.
845 config X86_MCE
846 bool "Machine Check / overheating reporting"
847 ---help---
848 Machine Check support allows the processor to notify the
849 kernel if it detects a problem (e.g. overheating, data corruption).
850 The action the kernel takes depends on the severity of the problem,
851 ranging from warning messages to halting the machine.
853 config X86_MCE_INTEL
854 def_bool y
855 prompt "Intel MCE features"
856 depends on X86_MCE && X86_LOCAL_APIC
857 ---help---
858 Additional support for intel specific MCE features such as
859 the thermal monitor.
861 config X86_MCE_AMD
862 def_bool y
863 prompt "AMD MCE features"
864 depends on X86_MCE && X86_LOCAL_APIC
865 ---help---
866 Additional support for AMD specific MCE features such as
867 the DRAM Error Threshold.
869 config X86_ANCIENT_MCE
870 bool "Support for old Pentium 5 / WinChip machine checks"
871 depends on X86_32 && X86_MCE
872 ---help---
873 Include support for machine check handling on old Pentium 5 or WinChip
874 systems. These typically need to be enabled explicitely on the command
875 line.
877 config X86_MCE_THRESHOLD
878 depends on X86_MCE_AMD || X86_MCE_INTEL
879 def_bool y
881 config X86_MCE_INJECT
882 depends on X86_MCE
883 tristate "Machine check injector support"
884 ---help---
885 Provide support for injecting machine checks for testing purposes.
886 If you don't know what a machine check is and you don't do kernel
887 QA it is safe to say n.
889 config X86_THERMAL_VECTOR
890 def_bool y
891 depends on X86_MCE_INTEL
893 config VM86
894 bool "Enable VM86 support" if EXPERT
895 default y
896 depends on X86_32
897 ---help---
898 This option is required by programs like DOSEMU to run 16-bit legacy
899 code on X86 processors. It also may be needed by software like
900 XFree86 to initialize some video cards via BIOS. Disabling this
901 option saves about 6k.
903 config TOSHIBA
904 tristate "Toshiba Laptop support"
905 depends on X86_32
906 ---help---
907 This adds a driver to safely access the System Management Mode of
908 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
909 not work on models with a Phoenix BIOS. The System Management Mode
910 is used to set the BIOS and power saving options on Toshiba portables.
912 For information on utilities to make use of this driver see the
913 Toshiba Linux utilities web site at:
914 <http://www.buzzard.org.uk/toshiba/>.
916 Say Y if you intend to run this kernel on a Toshiba portable.
917 Say N otherwise.
919 config I8K
920 tristate "Dell laptop support"
921 ---help---
922 This adds a driver to safely access the System Management Mode
923 of the CPU on the Dell Inspiron 8000. The System Management Mode
924 is used to read cpu temperature and cooling fan status and to
925 control the fans on the I8K portables.
927 This driver has been tested only on the Inspiron 8000 but it may
928 also work with other Dell laptops. You can force loading on other
929 models by passing the parameter `force=1' to the module. Use at
930 your own risk.
932 For information on utilities to make use of this driver see the
933 I8K Linux utilities web site at:
934 <http://people.debian.org/~dz/i8k/>
936 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
937 Say N otherwise.
939 config X86_REBOOTFIXUPS
940 bool "Enable X86 board specific fixups for reboot"
941 depends on X86_32
942 ---help---
943 This enables chipset and/or board specific fixups to be done
944 in order to get reboot to work correctly. This is only needed on
945 some combinations of hardware and BIOS. The symptom, for which
946 this config is intended, is when reboot ends with a stalled/hung
947 system.
949 Currently, the only fixup is for the Geode machines using
950 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
952 Say Y if you want to enable the fixup. Currently, it's safe to
953 enable this option even if you don't need it.
954 Say N otherwise.
956 config MICROCODE
957 tristate "/dev/cpu/microcode - microcode support"
958 select FW_LOADER
959 ---help---
960 If you say Y here, you will be able to update the microcode on
961 certain Intel and AMD processors. The Intel support is for the
962 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
963 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
964 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
965 You will obviously need the actual microcode binary data itself
966 which is not shipped with the Linux kernel.
968 This option selects the general module only, you need to select
969 at least one vendor specific module as well.
971 To compile this driver as a module, choose M here: the
972 module will be called microcode.
974 config MICROCODE_INTEL
975 bool "Intel microcode patch loading support"
976 depends on MICROCODE
977 default MICROCODE
978 select FW_LOADER
979 ---help---
980 This options enables microcode patch loading support for Intel
981 processors.
983 For latest news and information on obtaining all the required
984 Intel ingredients for this driver, check:
985 <http://www.urbanmyth.org/microcode/>.
987 config MICROCODE_AMD
988 bool "AMD microcode patch loading support"
989 depends on MICROCODE
990 select FW_LOADER
991 ---help---
992 If you select this option, microcode patch loading support for AMD
993 processors will be enabled.
995 config MICROCODE_OLD_INTERFACE
996 def_bool y
997 depends on MICROCODE
999 config X86_MSR
1000 tristate "/dev/cpu/*/msr - Model-specific register support"
1001 ---help---
1002 This device gives privileged processes access to the x86
1003 Model-Specific Registers (MSRs). It is a character device with
1004 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1005 MSR accesses are directed to a specific CPU on multi-processor
1006 systems.
1008 config X86_CPUID
1009 tristate "/dev/cpu/*/cpuid - CPU information support"
1010 ---help---
1011 This device gives processes access to the x86 CPUID instruction to
1012 be executed on a specific processor. It is a character device
1013 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1014 /dev/cpu/31/cpuid.
1016 choice
1017 prompt "High Memory Support"
1018 default HIGHMEM64G if X86_NUMAQ
1019 default HIGHMEM4G
1020 depends on X86_32
1022 config NOHIGHMEM
1023 bool "off"
1024 depends on !X86_NUMAQ
1025 ---help---
1026 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1027 However, the address space of 32-bit x86 processors is only 4
1028 Gigabytes large. That means that, if you have a large amount of
1029 physical memory, not all of it can be "permanently mapped" by the
1030 kernel. The physical memory that's not permanently mapped is called
1031 "high memory".
1033 If you are compiling a kernel which will never run on a machine with
1034 more than 1 Gigabyte total physical RAM, answer "off" here (default
1035 choice and suitable for most users). This will result in a "3GB/1GB"
1036 split: 3GB are mapped so that each process sees a 3GB virtual memory
1037 space and the remaining part of the 4GB virtual memory space is used
1038 by the kernel to permanently map as much physical memory as
1039 possible.
1041 If the machine has between 1 and 4 Gigabytes physical RAM, then
1042 answer "4GB" here.
1044 If more than 4 Gigabytes is used then answer "64GB" here. This
1045 selection turns Intel PAE (Physical Address Extension) mode on.
1046 PAE implements 3-level paging on IA32 processors. PAE is fully
1047 supported by Linux, PAE mode is implemented on all recent Intel
1048 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1049 then the kernel will not boot on CPUs that don't support PAE!
1051 The actual amount of total physical memory will either be
1052 auto detected or can be forced by using a kernel command line option
1053 such as "mem=256M". (Try "man bootparam" or see the documentation of
1054 your boot loader (lilo or loadlin) about how to pass options to the
1055 kernel at boot time.)
1057 If unsure, say "off".
1059 config HIGHMEM4G
1060 bool "4GB"
1061 depends on !X86_NUMAQ
1062 ---help---
1063 Select this if you have a 32-bit processor and between 1 and 4
1064 gigabytes of physical RAM.
1066 config HIGHMEM64G
1067 bool "64GB"
1068 depends on !M386 && !M486
1069 select X86_PAE
1070 ---help---
1071 Select this if you have a 32-bit processor and more than 4
1072 gigabytes of physical RAM.
1074 endchoice
1076 choice
1077 depends on EXPERIMENTAL
1078 prompt "Memory split" if EXPERT
1079 default VMSPLIT_3G
1080 depends on X86_32
1081 ---help---
1082 Select the desired split between kernel and user memory.
1084 If the address range available to the kernel is less than the
1085 physical memory installed, the remaining memory will be available
1086 as "high memory". Accessing high memory is a little more costly
1087 than low memory, as it needs to be mapped into the kernel first.
1088 Note that increasing the kernel address space limits the range
1089 available to user programs, making the address space there
1090 tighter. Selecting anything other than the default 3G/1G split
1091 will also likely make your kernel incompatible with binary-only
1092 kernel modules.
1094 If you are not absolutely sure what you are doing, leave this
1095 option alone!
1097 config VMSPLIT_3G
1098 bool "3G/1G user/kernel split"
1099 config VMSPLIT_3G_OPT
1100 depends on !X86_PAE
1101 bool "3G/1G user/kernel split (for full 1G low memory)"
1102 config VMSPLIT_2G
1103 bool "2G/2G user/kernel split"
1104 config VMSPLIT_2G_OPT
1105 depends on !X86_PAE
1106 bool "2G/2G user/kernel split (for full 2G low memory)"
1107 config VMSPLIT_1G
1108 bool "1G/3G user/kernel split"
1109 endchoice
1111 config PAGE_OFFSET
1112 hex
1113 default 0xB0000000 if VMSPLIT_3G_OPT
1114 default 0x80000000 if VMSPLIT_2G
1115 default 0x78000000 if VMSPLIT_2G_OPT
1116 default 0x40000000 if VMSPLIT_1G
1117 default 0xC0000000
1118 depends on X86_32
1120 config HIGHMEM
1121 def_bool y
1122 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1124 config X86_PAE
1125 bool "PAE (Physical Address Extension) Support"
1126 depends on X86_32 && !HIGHMEM4G
1127 ---help---
1128 PAE is required for NX support, and furthermore enables
1129 larger swapspace support for non-overcommit purposes. It
1130 has the cost of more pagetable lookup overhead, and also
1131 consumes more pagetable space per process.
1133 config ARCH_PHYS_ADDR_T_64BIT
1134 def_bool X86_64 || X86_PAE
1136 config ARCH_DMA_ADDR_T_64BIT
1137 def_bool X86_64 || HIGHMEM64G
1139 config DIRECT_GBPAGES
1140 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1141 default y
1142 depends on X86_64
1143 ---help---
1144 Allow the kernel linear mapping to use 1GB pages on CPUs that
1145 support it. This can improve the kernel's performance a tiny bit by
1146 reducing TLB pressure. If in doubt, say "Y".
1148 # Common NUMA Features
1149 config NUMA
1150 bool "Numa Memory Allocation and Scheduler Support"
1151 depends on SMP
1152 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1153 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1154 ---help---
1155 Enable NUMA (Non Uniform Memory Access) support.
1157 The kernel will try to allocate memory used by a CPU on the
1158 local memory controller of the CPU and add some more
1159 NUMA awareness to the kernel.
1161 For 64-bit this is recommended if the system is Intel Core i7
1162 (or later), AMD Opteron, or EM64T NUMA.
1164 For 32-bit this is only needed on (rare) 32-bit-only platforms
1165 that support NUMA topologies, such as NUMAQ / Summit, or if you
1166 boot a 32-bit kernel on a 64-bit NUMA platform.
1168 Otherwise, you should say N.
1170 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1171 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1173 config AMD_NUMA
1174 def_bool y
1175 prompt "Old style AMD Opteron NUMA detection"
1176 depends on X86_64 && NUMA && PCI
1177 ---help---
1178 Enable AMD NUMA node topology detection. You should say Y here if
1179 you have a multi processor AMD system. This uses an old method to
1180 read the NUMA configuration directly from the builtin Northbridge
1181 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1182 which also takes priority if both are compiled in.
1184 config X86_64_ACPI_NUMA
1185 def_bool y
1186 prompt "ACPI NUMA detection"
1187 depends on X86_64 && NUMA && ACPI && PCI
1188 select ACPI_NUMA
1189 ---help---
1190 Enable ACPI SRAT based node topology detection.
1192 # Some NUMA nodes have memory ranges that span
1193 # other nodes. Even though a pfn is valid and
1194 # between a node's start and end pfns, it may not
1195 # reside on that node. See memmap_init_zone()
1196 # for details.
1197 config NODES_SPAN_OTHER_NODES
1198 def_bool y
1199 depends on X86_64_ACPI_NUMA
1201 config NUMA_EMU
1202 bool "NUMA emulation"
1203 depends on X86_64 && NUMA
1204 ---help---
1205 Enable NUMA emulation. A flat machine will be split
1206 into virtual nodes when booted with "numa=fake=N", where N is the
1207 number of nodes. This is only useful for debugging.
1209 config NODES_SHIFT
1210 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1211 range 1 10
1212 default "10" if MAXSMP
1213 default "6" if X86_64
1214 default "4" if X86_NUMAQ
1215 default "3"
1216 depends on NEED_MULTIPLE_NODES
1217 ---help---
1218 Specify the maximum number of NUMA Nodes available on the target
1219 system. Increases memory reserved to accommodate various tables.
1221 config HAVE_ARCH_BOOTMEM
1222 def_bool y
1223 depends on X86_32 && NUMA
1225 config ARCH_HAVE_MEMORY_PRESENT
1226 def_bool y
1227 depends on X86_32 && DISCONTIGMEM
1229 config NEED_NODE_MEMMAP_SIZE
1230 def_bool y
1231 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1233 config HAVE_ARCH_ALLOC_REMAP
1234 def_bool y
1235 depends on X86_32 && NUMA
1237 config ARCH_FLATMEM_ENABLE
1238 def_bool y
1239 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1241 config ARCH_DISCONTIGMEM_ENABLE
1242 def_bool y
1243 depends on NUMA && X86_32
1245 config ARCH_DISCONTIGMEM_DEFAULT
1246 def_bool y
1247 depends on NUMA && X86_32
1249 config ARCH_PROC_KCORE_TEXT
1250 def_bool y
1251 depends on X86_64 && PROC_KCORE
1253 config ARCH_SPARSEMEM_DEFAULT
1254 def_bool y
1255 depends on X86_64
1257 config ARCH_SPARSEMEM_ENABLE
1258 def_bool y
1259 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1260 select SPARSEMEM_STATIC if X86_32
1261 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1263 config ARCH_SELECT_MEMORY_MODEL
1264 def_bool y
1265 depends on ARCH_SPARSEMEM_ENABLE
1267 config ARCH_MEMORY_PROBE
1268 def_bool X86_64
1269 depends on MEMORY_HOTPLUG
1271 config ILLEGAL_POINTER_VALUE
1272 hex
1273 default 0 if X86_32
1274 default 0xdead000000000000 if X86_64
1276 source "mm/Kconfig"
1278 config HIGHPTE
1279 bool "Allocate 3rd-level pagetables from highmem"
1280 depends on HIGHMEM
1281 ---help---
1282 The VM uses one page table entry for each page of physical memory.
1283 For systems with a lot of RAM, this can be wasteful of precious
1284 low memory. Setting this option will put user-space page table
1285 entries in high memory.
1287 config X86_CHECK_BIOS_CORRUPTION
1288 bool "Check for low memory corruption"
1289 ---help---
1290 Periodically check for memory corruption in low memory, which
1291 is suspected to be caused by BIOS. Even when enabled in the
1292 configuration, it is disabled at runtime. Enable it by
1293 setting "memory_corruption_check=1" on the kernel command
1294 line. By default it scans the low 64k of memory every 60
1295 seconds; see the memory_corruption_check_size and
1296 memory_corruption_check_period parameters in
1297 Documentation/kernel-parameters.txt to adjust this.
1299 When enabled with the default parameters, this option has
1300 almost no overhead, as it reserves a relatively small amount
1301 of memory and scans it infrequently. It both detects corruption
1302 and prevents it from affecting the running system.
1304 It is, however, intended as a diagnostic tool; if repeatable
1305 BIOS-originated corruption always affects the same memory,
1306 you can use memmap= to prevent the kernel from using that
1307 memory.
1309 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1310 bool "Set the default setting of memory_corruption_check"
1311 depends on X86_CHECK_BIOS_CORRUPTION
1312 default y
1313 ---help---
1314 Set whether the default state of memory_corruption_check is
1315 on or off.
1317 config X86_RESERVE_LOW
1318 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1319 default 64
1320 range 4 640
1321 ---help---
1322 Specify the amount of low memory to reserve for the BIOS.
1324 The first page contains BIOS data structures that the kernel
1325 must not use, so that page must always be reserved.
1327 By default we reserve the first 64K of physical RAM, as a
1328 number of BIOSes are known to corrupt that memory range
1329 during events such as suspend/resume or monitor cable
1330 insertion, so it must not be used by the kernel.
1332 You can set this to 4 if you are absolutely sure that you
1333 trust the BIOS to get all its memory reservations and usages
1334 right. If you know your BIOS have problems beyond the
1335 default 64K area, you can set this to 640 to avoid using the
1336 entire low memory range.
1338 If you have doubts about the BIOS (e.g. suspend/resume does
1339 not work or there's kernel crashes after certain hardware
1340 hotplug events) then you might want to enable
1341 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1342 typical corruption patterns.
1344 Leave this to the default value of 64 if you are unsure.
1346 config MATH_EMULATION
1347 bool
1348 prompt "Math emulation" if X86_32
1349 ---help---
1350 Linux can emulate a math coprocessor (used for floating point
1351 operations) if you don't have one. 486DX and Pentium processors have
1352 a math coprocessor built in, 486SX and 386 do not, unless you added
1353 a 487DX or 387, respectively. (The messages during boot time can
1354 give you some hints here ["man dmesg"].) Everyone needs either a
1355 coprocessor or this emulation.
1357 If you don't have a math coprocessor, you need to say Y here; if you
1358 say Y here even though you have a coprocessor, the coprocessor will
1359 be used nevertheless. (This behavior can be changed with the kernel
1360 command line option "no387", which comes handy if your coprocessor
1361 is broken. Try "man bootparam" or see the documentation of your boot
1362 loader (lilo or loadlin) about how to pass options to the kernel at
1363 boot time.) This means that it is a good idea to say Y here if you
1364 intend to use this kernel on different machines.
1366 More information about the internals of the Linux math coprocessor
1367 emulation can be found in <file:arch/x86/math-emu/README>.
1369 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1370 kernel, it won't hurt.
1372 config MTRR
1373 def_bool y
1374 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1375 ---help---
1376 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1377 the Memory Type Range Registers (MTRRs) may be used to control
1378 processor access to memory ranges. This is most useful if you have
1379 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1380 allows bus write transfers to be combined into a larger transfer
1381 before bursting over the PCI/AGP bus. This can increase performance
1382 of image write operations 2.5 times or more. Saying Y here creates a
1383 /proc/mtrr file which may be used to manipulate your processor's
1384 MTRRs. Typically the X server should use this.
1386 This code has a reasonably generic interface so that similar
1387 control registers on other processors can be easily supported
1388 as well:
1390 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1391 Registers (ARRs) which provide a similar functionality to MTRRs. For
1392 these, the ARRs are used to emulate the MTRRs.
1393 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1394 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1395 write-combining. All of these processors are supported by this code
1396 and it makes sense to say Y here if you have one of them.
1398 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1399 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1400 can lead to all sorts of problems, so it's good to say Y here.
1402 You can safely say Y even if your machine doesn't have MTRRs, you'll
1403 just add about 9 KB to your kernel.
1405 See <file:Documentation/x86/mtrr.txt> for more information.
1407 config MTRR_SANITIZER
1408 def_bool y
1409 prompt "MTRR cleanup support"
1410 depends on MTRR
1411 ---help---
1412 Convert MTRR layout from continuous to discrete, so X drivers can
1413 add writeback entries.
1415 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1416 The largest mtrr entry size for a continuous block can be set with
1417 mtrr_chunk_size.
1419 If unsure, say Y.
1421 config MTRR_SANITIZER_ENABLE_DEFAULT
1422 int "MTRR cleanup enable value (0-1)"
1423 range 0 1
1424 default "0"
1425 depends on MTRR_SANITIZER
1426 ---help---
1427 Enable mtrr cleanup default value
1429 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1430 int "MTRR cleanup spare reg num (0-7)"
1431 range 0 7
1432 default "1"
1433 depends on MTRR_SANITIZER
1434 ---help---
1435 mtrr cleanup spare entries default, it can be changed via
1436 mtrr_spare_reg_nr=N on the kernel command line.
1438 config X86_PAT
1439 def_bool y
1440 prompt "x86 PAT support" if EXPERT
1441 depends on MTRR
1442 ---help---
1443 Use PAT attributes to setup page level cache control.
1445 PATs are the modern equivalents of MTRRs and are much more
1446 flexible than MTRRs.
1448 Say N here if you see bootup problems (boot crash, boot hang,
1449 spontaneous reboots) or a non-working video driver.
1451 If unsure, say Y.
1453 config ARCH_USES_PG_UNCACHED
1454 def_bool y
1455 depends on X86_PAT
1457 config EFI
1458 bool "EFI runtime service support"
1459 depends on ACPI
1460 ---help---
1461 This enables the kernel to use EFI runtime services that are
1462 available (such as the EFI variable services).
1464 This option is only useful on systems that have EFI firmware.
1465 In addition, you should use the latest ELILO loader available
1466 at <http://elilo.sourceforge.net> in order to take advantage
1467 of EFI runtime services. However, even with this option, the
1468 resultant kernel should continue to boot on existing non-EFI
1469 platforms.
1471 config SECCOMP
1472 def_bool y
1473 prompt "Enable seccomp to safely compute untrusted bytecode"
1474 ---help---
1475 This kernel feature is useful for number crunching applications
1476 that may need to compute untrusted bytecode during their
1477 execution. By using pipes or other transports made available to
1478 the process as file descriptors supporting the read/write
1479 syscalls, it's possible to isolate those applications in
1480 their own address space using seccomp. Once seccomp is
1481 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1482 and the task is only allowed to execute a few safe syscalls
1483 defined by each seccomp mode.
1485 If unsure, say Y. Only embedded should say N here.
1487 config CC_STACKPROTECTOR
1488 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1489 ---help---
1490 This option turns on the -fstack-protector GCC feature. This
1491 feature puts, at the beginning of functions, a canary value on
1492 the stack just before the return address, and validates
1493 the value just before actually returning. Stack based buffer
1494 overflows (that need to overwrite this return address) now also
1495 overwrite the canary, which gets detected and the attack is then
1496 neutralized via a kernel panic.
1498 This feature requires gcc version 4.2 or above, or a distribution
1499 gcc with the feature backported. Older versions are automatically
1500 detected and for those versions, this configuration option is
1501 ignored. (and a warning is printed during bootup)
1503 source kernel/Kconfig.hz
1505 config KEXEC
1506 bool "kexec system call"
1507 ---help---
1508 kexec is a system call that implements the ability to shutdown your
1509 current kernel, and to start another kernel. It is like a reboot
1510 but it is independent of the system firmware. And like a reboot
1511 you can start any kernel with it, not just Linux.
1513 The name comes from the similarity to the exec system call.
1515 It is an ongoing process to be certain the hardware in a machine
1516 is properly shutdown, so do not be surprised if this code does not
1517 initially work for you. It may help to enable device hotplugging
1518 support. As of this writing the exact hardware interface is
1519 strongly in flux, so no good recommendation can be made.
1521 config CRASH_DUMP
1522 bool "kernel crash dumps"
1523 depends on X86_64 || (X86_32 && HIGHMEM)
1524 ---help---
1525 Generate crash dump after being started by kexec.
1526 This should be normally only set in special crash dump kernels
1527 which are loaded in the main kernel with kexec-tools into
1528 a specially reserved region and then later executed after
1529 a crash by kdump/kexec. The crash dump kernel must be compiled
1530 to a memory address not used by the main kernel or BIOS using
1531 PHYSICAL_START, or it must be built as a relocatable image
1532 (CONFIG_RELOCATABLE=y).
1533 For more details see Documentation/kdump/kdump.txt
1535 config KEXEC_JUMP
1536 bool "kexec jump (EXPERIMENTAL)"
1537 depends on EXPERIMENTAL
1538 depends on KEXEC && HIBERNATION
1539 ---help---
1540 Jump between original kernel and kexeced kernel and invoke
1541 code in physical address mode via KEXEC
1543 config PHYSICAL_START
1544 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1545 default "0x1000000"
1546 ---help---
1547 This gives the physical address where the kernel is loaded.
1549 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1550 bzImage will decompress itself to above physical address and
1551 run from there. Otherwise, bzImage will run from the address where
1552 it has been loaded by the boot loader and will ignore above physical
1553 address.
1555 In normal kdump cases one does not have to set/change this option
1556 as now bzImage can be compiled as a completely relocatable image
1557 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1558 address. This option is mainly useful for the folks who don't want
1559 to use a bzImage for capturing the crash dump and want to use a
1560 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1561 to be specifically compiled to run from a specific memory area
1562 (normally a reserved region) and this option comes handy.
1564 So if you are using bzImage for capturing the crash dump,
1565 leave the value here unchanged to 0x1000000 and set
1566 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1567 for capturing the crash dump change this value to start of
1568 the reserved region. In other words, it can be set based on
1569 the "X" value as specified in the "crashkernel=YM@XM"
1570 command line boot parameter passed to the panic-ed
1571 kernel. Please take a look at Documentation/kdump/kdump.txt
1572 for more details about crash dumps.
1574 Usage of bzImage for capturing the crash dump is recommended as
1575 one does not have to build two kernels. Same kernel can be used
1576 as production kernel and capture kernel. Above option should have
1577 gone away after relocatable bzImage support is introduced. But it
1578 is present because there are users out there who continue to use
1579 vmlinux for dump capture. This option should go away down the
1580 line.
1582 Don't change this unless you know what you are doing.
1584 config RELOCATABLE
1585 bool "Build a relocatable kernel"
1586 default y
1587 ---help---
1588 This builds a kernel image that retains relocation information
1589 so it can be loaded someplace besides the default 1MB.
1590 The relocations tend to make the kernel binary about 10% larger,
1591 but are discarded at runtime.
1593 One use is for the kexec on panic case where the recovery kernel
1594 must live at a different physical address than the primary
1595 kernel.
1597 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1598 it has been loaded at and the compile time physical address
1599 (CONFIG_PHYSICAL_START) is ignored.
1601 # Relocation on x86-32 needs some additional build support
1602 config X86_NEED_RELOCS
1603 def_bool y
1604 depends on X86_32 && RELOCATABLE
1606 config PHYSICAL_ALIGN
1607 hex "Alignment value to which kernel should be aligned" if X86_32
1608 default "0x1000000"
1609 range 0x2000 0x1000000
1610 ---help---
1611 This value puts the alignment restrictions on physical address
1612 where kernel is loaded and run from. Kernel is compiled for an
1613 address which meets above alignment restriction.
1615 If bootloader loads the kernel at a non-aligned address and
1616 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1617 address aligned to above value and run from there.
1619 If bootloader loads the kernel at a non-aligned address and
1620 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1621 load address and decompress itself to the address it has been
1622 compiled for and run from there. The address for which kernel is
1623 compiled already meets above alignment restrictions. Hence the
1624 end result is that kernel runs from a physical address meeting
1625 above alignment restrictions.
1627 Don't change this unless you know what you are doing.
1629 config HOTPLUG_CPU
1630 bool "Support for hot-pluggable CPUs"
1631 depends on SMP && HOTPLUG
1632 ---help---
1633 Say Y here to allow turning CPUs off and on. CPUs can be
1634 controlled through /sys/devices/system/cpu.
1635 ( Note: power management support will enable this option
1636 automatically on SMP systems. )
1637 Say N if you want to disable CPU hotplug.
1639 config COMPAT_VDSO
1640 def_bool y
1641 prompt "Compat VDSO support"
1642 depends on X86_32 || IA32_EMULATION
1643 ---help---
1644 Map the 32-bit VDSO to the predictable old-style address too.
1646 Say N here if you are running a sufficiently recent glibc
1647 version (2.3.3 or later), to remove the high-mapped
1648 VDSO mapping and to exclusively use the randomized VDSO.
1650 If unsure, say Y.
1652 config CMDLINE_BOOL
1653 bool "Built-in kernel command line"
1654 ---help---
1655 Allow for specifying boot arguments to the kernel at
1656 build time. On some systems (e.g. embedded ones), it is
1657 necessary or convenient to provide some or all of the
1658 kernel boot arguments with the kernel itself (that is,
1659 to not rely on the boot loader to provide them.)
1661 To compile command line arguments into the kernel,
1662 set this option to 'Y', then fill in the
1663 the boot arguments in CONFIG_CMDLINE.
1665 Systems with fully functional boot loaders (i.e. non-embedded)
1666 should leave this option set to 'N'.
1668 config CMDLINE
1669 string "Built-in kernel command string"
1670 depends on CMDLINE_BOOL
1671 default ""
1672 ---help---
1673 Enter arguments here that should be compiled into the kernel
1674 image and used at boot time. If the boot loader provides a
1675 command line at boot time, it is appended to this string to
1676 form the full kernel command line, when the system boots.
1678 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1679 change this behavior.
1681 In most cases, the command line (whether built-in or provided
1682 by the boot loader) should specify the device for the root
1683 file system.
1685 config CMDLINE_OVERRIDE
1686 bool "Built-in command line overrides boot loader arguments"
1687 depends on CMDLINE_BOOL
1688 ---help---
1689 Set this option to 'Y' to have the kernel ignore the boot loader
1690 command line, and use ONLY the built-in command line.
1692 This is used to work around broken boot loaders. This should
1693 be set to 'N' under normal conditions.
1695 endmenu
1697 config ARCH_ENABLE_MEMORY_HOTPLUG
1698 def_bool y
1699 depends on X86_64 || (X86_32 && HIGHMEM)
1701 config ARCH_ENABLE_MEMORY_HOTREMOVE
1702 def_bool y
1703 depends on MEMORY_HOTPLUG
1705 config HAVE_ARCH_EARLY_PFN_TO_NID
1706 def_bool X86_64
1707 depends on NUMA
1709 config USE_PERCPU_NUMA_NODE_ID
1710 def_bool y
1711 depends on NUMA
1713 menu "Power management and ACPI options"
1715 config ARCH_HIBERNATION_HEADER
1716 def_bool y
1717 depends on X86_64 && HIBERNATION
1719 source "kernel/power/Kconfig"
1721 source "drivers/acpi/Kconfig"
1723 source "drivers/sfi/Kconfig"
1725 config X86_APM_BOOT
1726 def_bool y
1727 depends on APM || APM_MODULE
1729 menuconfig APM
1730 tristate "APM (Advanced Power Management) BIOS support"
1731 depends on X86_32 && PM_SLEEP
1732 ---help---
1733 APM is a BIOS specification for saving power using several different
1734 techniques. This is mostly useful for battery powered laptops with
1735 APM compliant BIOSes. If you say Y here, the system time will be
1736 reset after a RESUME operation, the /proc/apm device will provide
1737 battery status information, and user-space programs will receive
1738 notification of APM "events" (e.g. battery status change).
1740 If you select "Y" here, you can disable actual use of the APM
1741 BIOS by passing the "apm=off" option to the kernel at boot time.
1743 Note that the APM support is almost completely disabled for
1744 machines with more than one CPU.
1746 In order to use APM, you will need supporting software. For location
1747 and more information, read <file:Documentation/power/pm.txt> and the
1748 Battery Powered Linux mini-HOWTO, available from
1749 <http://www.tldp.org/docs.html#howto>.
1751 This driver does not spin down disk drives (see the hdparm(8)
1752 manpage ("man 8 hdparm") for that), and it doesn't turn off
1753 VESA-compliant "green" monitors.
1755 This driver does not support the TI 4000M TravelMate and the ACER
1756 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1757 desktop machines also don't have compliant BIOSes, and this driver
1758 may cause those machines to panic during the boot phase.
1760 Generally, if you don't have a battery in your machine, there isn't
1761 much point in using this driver and you should say N. If you get
1762 random kernel OOPSes or reboots that don't seem to be related to
1763 anything, try disabling/enabling this option (or disabling/enabling
1764 APM in your BIOS).
1766 Some other things you should try when experiencing seemingly random,
1767 "weird" problems:
1769 1) make sure that you have enough swap space and that it is
1770 enabled.
1771 2) pass the "no-hlt" option to the kernel
1772 3) switch on floating point emulation in the kernel and pass
1773 the "no387" option to the kernel
1774 4) pass the "floppy=nodma" option to the kernel
1775 5) pass the "mem=4M" option to the kernel (thereby disabling
1776 all but the first 4 MB of RAM)
1777 6) make sure that the CPU is not over clocked.
1778 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1779 8) disable the cache from your BIOS settings
1780 9) install a fan for the video card or exchange video RAM
1781 10) install a better fan for the CPU
1782 11) exchange RAM chips
1783 12) exchange the motherboard.
1785 To compile this driver as a module, choose M here: the
1786 module will be called apm.
1788 if APM
1790 config APM_IGNORE_USER_SUSPEND
1791 bool "Ignore USER SUSPEND"
1792 ---help---
1793 This option will ignore USER SUSPEND requests. On machines with a
1794 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1795 series notebooks, it is necessary to say Y because of a BIOS bug.
1797 config APM_DO_ENABLE
1798 bool "Enable PM at boot time"
1799 ---help---
1800 Enable APM features at boot time. From page 36 of the APM BIOS
1801 specification: "When disabled, the APM BIOS does not automatically
1802 power manage devices, enter the Standby State, enter the Suspend
1803 State, or take power saving steps in response to CPU Idle calls."
1804 This driver will make CPU Idle calls when Linux is idle (unless this
1805 feature is turned off -- see "Do CPU IDLE calls", below). This
1806 should always save battery power, but more complicated APM features
1807 will be dependent on your BIOS implementation. You may need to turn
1808 this option off if your computer hangs at boot time when using APM
1809 support, or if it beeps continuously instead of suspending. Turn
1810 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1811 T400CDT. This is off by default since most machines do fine without
1812 this feature.
1814 config APM_CPU_IDLE
1815 bool "Make CPU Idle calls when idle"
1816 ---help---
1817 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1818 On some machines, this can activate improved power savings, such as
1819 a slowed CPU clock rate, when the machine is idle. These idle calls
1820 are made after the idle loop has run for some length of time (e.g.,
1821 333 mS). On some machines, this will cause a hang at boot time or
1822 whenever the CPU becomes idle. (On machines with more than one CPU,
1823 this option does nothing.)
1825 config APM_DISPLAY_BLANK
1826 bool "Enable console blanking using APM"
1827 ---help---
1828 Enable console blanking using the APM. Some laptops can use this to
1829 turn off the LCD backlight when the screen blanker of the Linux
1830 virtual console blanks the screen. Note that this is only used by
1831 the virtual console screen blanker, and won't turn off the backlight
1832 when using the X Window system. This also doesn't have anything to
1833 do with your VESA-compliant power-saving monitor. Further, this
1834 option doesn't work for all laptops -- it might not turn off your
1835 backlight at all, or it might print a lot of errors to the console,
1836 especially if you are using gpm.
1838 config APM_ALLOW_INTS
1839 bool "Allow interrupts during APM BIOS calls"
1840 ---help---
1841 Normally we disable external interrupts while we are making calls to
1842 the APM BIOS as a measure to lessen the effects of a badly behaving
1843 BIOS implementation. The BIOS should reenable interrupts if it
1844 needs to. Unfortunately, some BIOSes do not -- especially those in
1845 many of the newer IBM Thinkpads. If you experience hangs when you
1846 suspend, try setting this to Y. Otherwise, say N.
1848 endif # APM
1850 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1852 source "drivers/cpuidle/Kconfig"
1854 source "drivers/idle/Kconfig"
1856 endmenu
1859 menu "Bus options (PCI etc.)"
1861 config PCI
1862 bool "PCI support"
1863 default y
1864 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1865 ---help---
1866 Find out whether you have a PCI motherboard. PCI is the name of a
1867 bus system, i.e. the way the CPU talks to the other stuff inside
1868 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1869 VESA. If you have PCI, say Y, otherwise N.
1871 choice
1872 prompt "PCI access mode"
1873 depends on X86_32 && PCI
1874 default PCI_GOANY
1875 ---help---
1876 On PCI systems, the BIOS can be used to detect the PCI devices and
1877 determine their configuration. However, some old PCI motherboards
1878 have BIOS bugs and may crash if this is done. Also, some embedded
1879 PCI-based systems don't have any BIOS at all. Linux can also try to
1880 detect the PCI hardware directly without using the BIOS.
1882 With this option, you can specify how Linux should detect the
1883 PCI devices. If you choose "BIOS", the BIOS will be used,
1884 if you choose "Direct", the BIOS won't be used, and if you
1885 choose "MMConfig", then PCI Express MMCONFIG will be used.
1886 If you choose "Any", the kernel will try MMCONFIG, then the
1887 direct access method and falls back to the BIOS if that doesn't
1888 work. If unsure, go with the default, which is "Any".
1890 config PCI_GOBIOS
1891 bool "BIOS"
1893 config PCI_GOMMCONFIG
1894 bool "MMConfig"
1896 config PCI_GODIRECT
1897 bool "Direct"
1899 config PCI_GOOLPC
1900 bool "OLPC XO-1"
1901 depends on OLPC
1903 config PCI_GOANY
1904 bool "Any"
1906 endchoice
1908 config PCI_BIOS
1909 def_bool y
1910 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1912 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1913 config PCI_DIRECT
1914 def_bool y
1915 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1917 config PCI_MMCONFIG
1918 def_bool y
1919 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1921 config PCI_OLPC
1922 def_bool y
1923 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1925 config PCI_XEN
1926 def_bool y
1927 depends on PCI && XEN
1928 select SWIOTLB_XEN
1930 config PCI_DOMAINS
1931 def_bool y
1932 depends on PCI
1934 config PCI_MMCONFIG
1935 bool "Support mmconfig PCI config space access"
1936 depends on X86_64 && PCI && ACPI
1938 config PCI_CNB20LE_QUIRK
1939 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1940 default n
1941 depends on PCI && EXPERIMENTAL
1942 help
1943 Read the PCI windows out of the CNB20LE host bridge. This allows
1944 PCI hotplug to work on systems with the CNB20LE chipset which do
1945 not have ACPI.
1947 There's no public spec for this chipset, and this functionality
1948 is known to be incomplete.
1950 You should say N unless you know you need this.
1952 config DMAR
1953 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1954 depends on PCI_MSI && ACPI && EXPERIMENTAL
1955 help
1956 DMA remapping (DMAR) devices support enables independent address
1957 translations for Direct Memory Access (DMA) from devices.
1958 These DMA remapping devices are reported via ACPI tables
1959 and include PCI device scope covered by these DMA
1960 remapping devices.
1962 config DMAR_DEFAULT_ON
1963 def_bool y
1964 prompt "Enable DMA Remapping Devices by default"
1965 depends on DMAR
1966 help
1967 Selecting this option will enable a DMAR device at boot time if
1968 one is found. If this option is not selected, DMAR support can
1969 be enabled by passing intel_iommu=on to the kernel. It is
1970 recommended you say N here while the DMAR code remains
1971 experimental.
1973 config DMAR_BROKEN_GFX_WA
1974 bool "Workaround broken graphics drivers (going away soon)"
1975 depends on DMAR && BROKEN
1976 ---help---
1977 Current Graphics drivers tend to use physical address
1978 for DMA and avoid using DMA APIs. Setting this config
1979 option permits the IOMMU driver to set a unity map for
1980 all the OS-visible memory. Hence the driver can continue
1981 to use physical addresses for DMA, at least until this
1982 option is removed in the 2.6.32 kernel.
1984 config DMAR_FLOPPY_WA
1985 def_bool y
1986 depends on DMAR
1987 ---help---
1988 Floppy disk drivers are known to bypass DMA API calls
1989 thereby failing to work when IOMMU is enabled. This
1990 workaround will setup a 1:1 mapping for the first
1991 16MiB to make floppy (an ISA device) work.
1993 config INTR_REMAP
1994 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1995 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1996 ---help---
1997 Supports Interrupt remapping for IO-APIC and MSI devices.
1998 To use x2apic mode in the CPU's which support x2APIC enhancements or
1999 to support platforms with CPU's having > 8 bit APIC ID, say Y.
2001 source "drivers/pci/pcie/Kconfig"
2003 source "drivers/pci/Kconfig"
2005 # x86_64 have no ISA slots, but can have ISA-style DMA.
2006 config ISA_DMA_API
2007 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2008 default y
2009 help
2010 Enables ISA-style DMA support for devices requiring such controllers.
2011 If unsure, say Y.
2013 if X86_32
2015 config ISA
2016 bool "ISA support"
2017 ---help---
2018 Find out whether you have ISA slots on your motherboard. ISA is the
2019 name of a bus system, i.e. the way the CPU talks to the other stuff
2020 inside your box. Other bus systems are PCI, EISA, MicroChannel
2021 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2022 newer boards don't support it. If you have ISA, say Y, otherwise N.
2024 config EISA
2025 bool "EISA support"
2026 depends on ISA
2027 ---help---
2028 The Extended Industry Standard Architecture (EISA) bus was
2029 developed as an open alternative to the IBM MicroChannel bus.
2031 The EISA bus provided some of the features of the IBM MicroChannel
2032 bus while maintaining backward compatibility with cards made for
2033 the older ISA bus. The EISA bus saw limited use between 1988 and
2034 1995 when it was made obsolete by the PCI bus.
2036 Say Y here if you are building a kernel for an EISA-based machine.
2038 Otherwise, say N.
2040 source "drivers/eisa/Kconfig"
2042 config MCA
2043 bool "MCA support"
2044 ---help---
2045 MicroChannel Architecture is found in some IBM PS/2 machines and
2046 laptops. It is a bus system similar to PCI or ISA. See
2047 <file:Documentation/mca.txt> (and especially the web page given
2048 there) before attempting to build an MCA bus kernel.
2050 source "drivers/mca/Kconfig"
2052 config SCx200
2053 tristate "NatSemi SCx200 support"
2054 ---help---
2055 This provides basic support for National Semiconductor's
2056 (now AMD's) Geode processors. The driver probes for the
2057 PCI-IDs of several on-chip devices, so its a good dependency
2058 for other scx200_* drivers.
2060 If compiled as a module, the driver is named scx200.
2062 config SCx200HR_TIMER
2063 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2064 depends on SCx200
2065 default y
2066 ---help---
2067 This driver provides a clocksource built upon the on-chip
2068 27MHz high-resolution timer. Its also a workaround for
2069 NSC Geode SC-1100's buggy TSC, which loses time when the
2070 processor goes idle (as is done by the scheduler). The
2071 other workaround is idle=poll boot option.
2073 config OLPC
2074 bool "One Laptop Per Child support"
2075 depends on !X86_PAE
2076 select GPIOLIB
2077 select OF
2078 select OF_PROMTREE if PROC_DEVICETREE
2079 ---help---
2080 Add support for detecting the unique features of the OLPC
2081 XO hardware.
2083 config OLPC_XO1
2084 tristate "OLPC XO-1 support"
2085 depends on OLPC && MFD_CS5535
2086 ---help---
2087 Add support for non-essential features of the OLPC XO-1 laptop.
2089 endif # X86_32
2091 config AMD_NB
2092 def_bool y
2093 depends on CPU_SUP_AMD && PCI
2095 source "drivers/pcmcia/Kconfig"
2097 source "drivers/pci/hotplug/Kconfig"
2099 config RAPIDIO
2100 bool "RapidIO support"
2101 depends on PCI
2102 default n
2103 help
2104 If you say Y here, the kernel will include drivers and
2105 infrastructure code to support RapidIO interconnect devices.
2107 source "drivers/rapidio/Kconfig"
2109 endmenu
2112 menu "Executable file formats / Emulations"
2114 source "fs/Kconfig.binfmt"
2116 config IA32_EMULATION
2117 bool "IA32 Emulation"
2118 depends on X86_64
2119 select COMPAT_BINFMT_ELF
2120 ---help---
2121 Include code to run 32-bit programs under a 64-bit kernel. You should
2122 likely turn this on, unless you're 100% sure that you don't have any
2123 32-bit programs left.
2125 config IA32_AOUT
2126 tristate "IA32 a.out support"
2127 depends on IA32_EMULATION
2128 ---help---
2129 Support old a.out binaries in the 32bit emulation.
2131 config COMPAT
2132 def_bool y
2133 depends on IA32_EMULATION
2135 config COMPAT_FOR_U64_ALIGNMENT
2136 def_bool COMPAT
2137 depends on X86_64
2139 config SYSVIPC_COMPAT
2140 def_bool y
2141 depends on COMPAT && SYSVIPC
2143 config KEYS_COMPAT
2144 bool
2145 depends on COMPAT && KEYS
2146 default y
2148 endmenu
2151 config HAVE_ATOMIC_IOMAP
2152 def_bool y
2153 depends on X86_32
2155 config HAVE_TEXT_POKE_SMP
2156 bool
2157 select STOP_MACHINE if SMP
2159 source "net/Kconfig"
2161 source "drivers/Kconfig"
2163 source "drivers/firmware/Kconfig"
2165 source "fs/Kconfig"
2167 source "arch/x86/Kconfig.debug"
2169 source "security/Kconfig"
2171 source "crypto/Kconfig"
2173 source "arch/x86/kvm/Kconfig"
2175 source "lib/Kconfig"