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[deliverable/linux.git] / arch / x86 / Kconfig
1 # Select 32 or 64 bit
2 config 64BIT
3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH != "i386"
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
8
9 config X86_32
10 def_bool y
11 depends on !64BIT
12 select CLKSRC_I8253
13 select HAVE_UID16
14
15 config X86_64
16 def_bool y
17 depends on 64BIT
18 select X86_DEV_DMA_OPS
19
20 ### Arch settings
21 config X86
22 def_bool y
23 select HAVE_AOUT if X86_32
24 select HAVE_UNSTABLE_SCHED_CLOCK
25 select ARCH_SUPPORTS_NUMA_BALANCING
26 select ARCH_WANTS_PROT_NUMA_PROT_NONE
27 select HAVE_IDE
28 select HAVE_OPROFILE
29 select HAVE_PCSPKR_PLATFORM
30 select HAVE_PERF_EVENTS
31 select HAVE_IOREMAP_PROT
32 select HAVE_KPROBES
33 select HAVE_MEMBLOCK
34 select HAVE_MEMBLOCK_NODE_MAP
35 select ARCH_DISCARD_MEMBLOCK
36 select ARCH_WANT_OPTIONAL_GPIOLIB
37 select ARCH_WANT_FRAME_POINTERS
38 select HAVE_DMA_ATTRS
39 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
40 select HAVE_KRETPROBES
41 select HAVE_OPTPROBES
42 select HAVE_KPROBES_ON_FTRACE
43 select HAVE_FTRACE_MCOUNT_RECORD
44 select HAVE_FENTRY if X86_64
45 select HAVE_C_RECORDMCOUNT
46 select HAVE_DYNAMIC_FTRACE
47 select HAVE_DYNAMIC_FTRACE_WITH_REGS
48 select HAVE_FUNCTION_TRACER
49 select HAVE_FUNCTION_GRAPH_TRACER
50 select HAVE_FUNCTION_GRAPH_FP_TEST
51 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
52 select HAVE_SYSCALL_TRACEPOINTS
53 select SYSCTL_EXCEPTION_TRACE
54 select HAVE_KVM
55 select HAVE_ARCH_KGDB
56 select HAVE_ARCH_TRACEHOOK
57 select HAVE_GENERIC_DMA_COHERENT if X86_32
58 select HAVE_EFFICIENT_UNALIGNED_ACCESS
59 select USER_STACKTRACE_SUPPORT
60 select HAVE_REGS_AND_STACK_ACCESS_API
61 select HAVE_DMA_API_DEBUG
62 select HAVE_KERNEL_GZIP
63 select HAVE_KERNEL_BZIP2
64 select HAVE_KERNEL_LZMA
65 select HAVE_KERNEL_XZ
66 select HAVE_KERNEL_LZO
67 select HAVE_HW_BREAKPOINT
68 select HAVE_MIXED_BREAKPOINTS_REGS
69 select PERF_EVENTS
70 select HAVE_PERF_EVENTS_NMI
71 select HAVE_PERF_REGS
72 select HAVE_PERF_USER_STACK_DUMP
73 select HAVE_DEBUG_KMEMLEAK
74 select ANON_INODES
75 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
76 select HAVE_CMPXCHG_LOCAL
77 select HAVE_CMPXCHG_DOUBLE
78 select HAVE_ARCH_KMEMCHECK
79 select HAVE_USER_RETURN_NOTIFIER
80 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
81 select HAVE_ARCH_JUMP_LABEL
82 select HAVE_TEXT_POKE_SMP
83 select HAVE_GENERIC_HARDIRQS
84 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
85 select SPARSE_IRQ
86 select GENERIC_FIND_FIRST_BIT
87 select GENERIC_IRQ_PROBE
88 select GENERIC_PENDING_IRQ if SMP
89 select GENERIC_IRQ_SHOW
90 select GENERIC_CLOCKEVENTS_MIN_ADJUST
91 select IRQ_FORCED_THREADING
92 select USE_GENERIC_SMP_HELPERS if SMP
93 select HAVE_BPF_JIT if X86_64
94 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
95 select CLKEVT_I8253
96 select ARCH_HAVE_NMI_SAFE_CMPXCHG
97 select GENERIC_IOMAP
98 select DCACHE_WORD_ACCESS
99 select GENERIC_SMP_IDLE_THREAD
100 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
101 select HAVE_ARCH_SECCOMP_FILTER
102 select BUILDTIME_EXTABLE_SORT
103 select GENERIC_CMOS_UPDATE
104 select CLOCKSOURCE_WATCHDOG
105 select GENERIC_CLOCKEVENTS
106 select ARCH_CLOCKSOURCE_DATA if X86_64
107 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
108 select GENERIC_TIME_VSYSCALL if X86_64
109 select KTIME_SCALAR if X86_32
110 select ALWAYS_USE_PERSISTENT_CLOCK
111 select GENERIC_STRNCPY_FROM_USER
112 select GENERIC_STRNLEN_USER
113 select HAVE_CONTEXT_TRACKING if X86_64
114 select HAVE_IRQ_TIME_ACCOUNTING
115 select HAVE_VIRT_TO_BUS
116 select MODULES_USE_ELF_REL if X86_32
117 select MODULES_USE_ELF_RELA if X86_64
118 select CLONE_BACKWARDS if X86_32
119 select ARCH_USE_BUILTIN_BSWAP
120 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
121 select OLD_SIGACTION if X86_32
122 select COMPAT_OLD_SIGACTION if IA32_EMULATION
123 select RTC_LIB
124
125 config INSTRUCTION_DECODER
126 def_bool y
127 depends on KPROBES || PERF_EVENTS || UPROBES
128
129 config OUTPUT_FORMAT
130 string
131 default "elf32-i386" if X86_32
132 default "elf64-x86-64" if X86_64
133
134 config ARCH_DEFCONFIG
135 string
136 default "arch/x86/configs/i386_defconfig" if X86_32
137 default "arch/x86/configs/x86_64_defconfig" if X86_64
138
139 config LOCKDEP_SUPPORT
140 def_bool y
141
142 config STACKTRACE_SUPPORT
143 def_bool y
144
145 config HAVE_LATENCYTOP_SUPPORT
146 def_bool y
147
148 config MMU
149 def_bool y
150
151 config SBUS
152 bool
153
154 config NEED_DMA_MAP_STATE
155 def_bool y
156 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
157
158 config NEED_SG_DMA_LENGTH
159 def_bool y
160
161 config GENERIC_ISA_DMA
162 def_bool y
163 depends on ISA_DMA_API
164
165 config GENERIC_BUG
166 def_bool y
167 depends on BUG
168 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
169
170 config GENERIC_BUG_RELATIVE_POINTERS
171 bool
172
173 config GENERIC_HWEIGHT
174 def_bool y
175
176 config GENERIC_GPIO
177 bool
178
179 config ARCH_MAY_HAVE_PC_FDC
180 def_bool y
181 depends on ISA_DMA_API
182
183 config RWSEM_XCHGADD_ALGORITHM
184 def_bool y
185
186 config GENERIC_CALIBRATE_DELAY
187 def_bool y
188
189 config ARCH_HAS_CPU_RELAX
190 def_bool y
191
192 config ARCH_HAS_DEFAULT_IDLE
193 def_bool y
194
195 config ARCH_HAS_CACHE_LINE_SIZE
196 def_bool y
197
198 config ARCH_HAS_CPU_AUTOPROBE
199 def_bool y
200
201 config HAVE_SETUP_PER_CPU_AREA
202 def_bool y
203
204 config NEED_PER_CPU_EMBED_FIRST_CHUNK
205 def_bool y
206
207 config NEED_PER_CPU_PAGE_FIRST_CHUNK
208 def_bool y
209
210 config ARCH_HIBERNATION_POSSIBLE
211 def_bool y
212
213 config ARCH_SUSPEND_POSSIBLE
214 def_bool y
215
216 config ZONE_DMA32
217 bool
218 default X86_64
219
220 config AUDIT_ARCH
221 bool
222 default X86_64
223
224 config ARCH_SUPPORTS_OPTIMIZED_INLINING
225 def_bool y
226
227 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
228 def_bool y
229
230 config HAVE_INTEL_TXT
231 def_bool y
232 depends on INTEL_IOMMU && ACPI
233
234 config X86_32_SMP
235 def_bool y
236 depends on X86_32 && SMP
237
238 config X86_64_SMP
239 def_bool y
240 depends on X86_64 && SMP
241
242 config X86_HT
243 def_bool y
244 depends on SMP
245
246 config X86_32_LAZY_GS
247 def_bool y
248 depends on X86_32 && !CC_STACKPROTECTOR
249
250 config ARCH_HWEIGHT_CFLAGS
251 string
252 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
253 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
254
255 config ARCH_CPU_PROBE_RELEASE
256 def_bool y
257 depends on HOTPLUG_CPU
258
259 config ARCH_SUPPORTS_UPROBES
260 def_bool y
261
262 source "init/Kconfig"
263 source "kernel/Kconfig.freezer"
264
265 menu "Processor type and features"
266
267 config ZONE_DMA
268 bool "DMA memory allocation support" if EXPERT
269 default y
270 help
271 DMA memory allocation support allows devices with less than 32-bit
272 addressing to allocate within the first 16MB of address space.
273 Disable if no such devices will be used.
274
275 If unsure, say Y.
276
277 config SMP
278 bool "Symmetric multi-processing support"
279 ---help---
280 This enables support for systems with more than one CPU. If you have
281 a system with only one CPU, like most personal computers, say N. If
282 you have a system with more than one CPU, say Y.
283
284 If you say N here, the kernel will run on single and multiprocessor
285 machines, but will use only one CPU of a multiprocessor machine. If
286 you say Y here, the kernel will run on many, but not all,
287 singleprocessor machines. On a singleprocessor machine, the kernel
288 will run faster if you say N here.
289
290 Note that if you say Y here and choose architecture "586" or
291 "Pentium" under "Processor family", the kernel will not work on 486
292 architectures. Similarly, multiprocessor kernels for the "PPro"
293 architecture may not work on all Pentium based boards.
294
295 People using multiprocessor machines who say Y here should also say
296 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
297 Management" code will be disabled if you say Y here.
298
299 See also <file:Documentation/x86/i386/IO-APIC.txt>,
300 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
301 <http://www.tldp.org/docs.html#howto>.
302
303 If you don't know what to do here, say N.
304
305 config X86_X2APIC
306 bool "Support x2apic"
307 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
308 ---help---
309 This enables x2apic support on CPUs that have this feature.
310
311 This allows 32-bit apic IDs (so it can support very large systems),
312 and accesses the local apic via MSRs not via mmio.
313
314 If you don't know what to do here, say N.
315
316 config X86_MPPARSE
317 bool "Enable MPS table" if ACPI || SFI
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
323
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
329
330 config GOLDFISH
331 def_bool y
332 depends on X86_GOLDFISH
333
334 if X86_32
335 config X86_EXTENDED_PLATFORM
336 bool "Support for extended (non-PC) x86 platforms"
337 default y
338 ---help---
339 If you disable this option then the kernel will only support
340 standard PC platforms. (which covers the vast majority of
341 systems out there.)
342
343 If you enable this option then you'll be able to select support
344 for the following (non-PC) 32 bit x86 platforms:
345 AMD Elan
346 NUMAQ (IBM/Sequent)
347 RDC R-321x SoC
348 SGI 320/540 (Visual Workstation)
349 STA2X11-based (e.g. Northville)
350 Summit/EXA (IBM x440)
351 Unisys ES7000 IA32 series
352 Moorestown MID devices
353
354 If you have one of these systems, or if you want to build a
355 generic distribution kernel, say Y here - otherwise say N.
356 endif
357
358 if X86_64
359 config X86_EXTENDED_PLATFORM
360 bool "Support for extended (non-PC) x86 platforms"
361 default y
362 ---help---
363 If you disable this option then the kernel will only support
364 standard PC platforms. (which covers the vast majority of
365 systems out there.)
366
367 If you enable this option then you'll be able to select support
368 for the following (non-PC) 64 bit x86 platforms:
369 Numascale NumaChip
370 ScaleMP vSMP
371 SGI Ultraviolet
372
373 If you have one of these systems, or if you want to build a
374 generic distribution kernel, say Y here - otherwise say N.
375 endif
376 # This is an alphabetically sorted list of 64 bit extended platforms
377 # Please maintain the alphabetic order if and when there are additions
378 config X86_NUMACHIP
379 bool "Numascale NumaChip"
380 depends on X86_64
381 depends on X86_EXTENDED_PLATFORM
382 depends on NUMA
383 depends on SMP
384 depends on X86_X2APIC
385 depends on PCI_MMCONFIG
386 ---help---
387 Adds support for Numascale NumaChip large-SMP systems. Needed to
388 enable more than ~168 cores.
389 If you don't have one of these, you should say N here.
390
391 config X86_VSMP
392 bool "ScaleMP vSMP"
393 select PARAVIRT_GUEST
394 select PARAVIRT
395 depends on X86_64 && PCI
396 depends on X86_EXTENDED_PLATFORM
397 depends on SMP
398 ---help---
399 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
400 supposed to run on these EM64T-based machines. Only choose this option
401 if you have one of these machines.
402
403 config X86_UV
404 bool "SGI Ultraviolet"
405 depends on X86_64
406 depends on X86_EXTENDED_PLATFORM
407 depends on NUMA
408 depends on X86_X2APIC
409 ---help---
410 This option is needed in order to support SGI Ultraviolet systems.
411 If you don't have one of these, you should say N here.
412
413 # Following is an alphabetically sorted list of 32 bit extended platforms
414 # Please maintain the alphabetic order if and when there are additions
415
416 config X86_GOLDFISH
417 bool "Goldfish (Virtual Platform)"
418 depends on X86_32
419 ---help---
420 Enable support for the Goldfish virtual platform used primarily
421 for Android development. Unless you are building for the Android
422 Goldfish emulator say N here.
423
424 config X86_INTEL_CE
425 bool "CE4100 TV platform"
426 depends on PCI
427 depends on PCI_GODIRECT
428 depends on X86_32
429 depends on X86_EXTENDED_PLATFORM
430 select X86_REBOOTFIXUPS
431 select OF
432 select OF_EARLY_FLATTREE
433 select IRQ_DOMAIN
434 ---help---
435 Select for the Intel CE media processor (CE4100) SOC.
436 This option compiles in support for the CE4100 SOC for settop
437 boxes and media devices.
438
439 config X86_WANT_INTEL_MID
440 bool "Intel MID platform support"
441 depends on X86_32
442 depends on X86_EXTENDED_PLATFORM
443 ---help---
444 Select to build a kernel capable of supporting Intel MID platform
445 systems which do not have the PCI legacy interfaces (Moorestown,
446 Medfield). If you are building for a PC class system say N here.
447
448 if X86_WANT_INTEL_MID
449
450 config X86_INTEL_MID
451 bool
452
453 config X86_MDFLD
454 bool "Medfield MID platform"
455 depends on PCI
456 depends on PCI_GOANY
457 depends on X86_IO_APIC
458 select X86_INTEL_MID
459 select SFI
460 select DW_APB_TIMER
461 select APB_TIMER
462 select I2C
463 select SPI
464 select INTEL_SCU_IPC
465 select X86_PLATFORM_DEVICES
466 select MFD_INTEL_MSIC
467 ---help---
468 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
469 Internet Device(MID) platform.
470 Unlike standard x86 PCs, Medfield does not have many legacy devices
471 nor standard legacy replacement devices/features. e.g. Medfield does
472 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
473
474 endif
475
476 config X86_INTEL_LPSS
477 bool "Intel Low Power Subsystem Support"
478 depends on ACPI
479 select COMMON_CLK
480 ---help---
481 Select to build support for Intel Low Power Subsystem such as
482 found on Intel Lynxpoint PCH. Selecting this option enables
483 things like clock tree (common clock framework) which are needed
484 by the LPSS peripheral drivers.
485
486 config X86_RDC321X
487 bool "RDC R-321x SoC"
488 depends on X86_32
489 depends on X86_EXTENDED_PLATFORM
490 select M486
491 select X86_REBOOTFIXUPS
492 ---help---
493 This option is needed for RDC R-321x system-on-chip, also known
494 as R-8610-(G).
495 If you don't have one of these chips, you should say N here.
496
497 config X86_32_NON_STANDARD
498 bool "Support non-standard 32-bit SMP architectures"
499 depends on X86_32 && SMP
500 depends on X86_EXTENDED_PLATFORM
501 ---help---
502 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
503 STA2X11, default subarchitectures. It is intended for a generic
504 binary kernel. If you select them all, kernel will probe it
505 one by one and will fallback to default.
506
507 # Alphabetically sorted list of Non standard 32 bit platforms
508
509 config X86_NUMAQ
510 bool "NUMAQ (IBM/Sequent)"
511 depends on X86_32_NON_STANDARD
512 depends on PCI
513 select NUMA
514 select X86_MPPARSE
515 ---help---
516 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
517 NUMA multiquad box. This changes the way that processors are
518 bootstrapped, and uses Clustered Logical APIC addressing mode instead
519 of Flat Logical. You will need a new lynxer.elf file to flash your
520 firmware with - send email to <Martin.Bligh@us.ibm.com>.
521
522 config X86_SUPPORTS_MEMORY_FAILURE
523 def_bool y
524 # MCE code calls memory_failure():
525 depends on X86_MCE
526 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
527 depends on !X86_NUMAQ
528 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
529 depends on X86_64 || !SPARSEMEM
530 select ARCH_SUPPORTS_MEMORY_FAILURE
531
532 config X86_VISWS
533 bool "SGI 320/540 (Visual Workstation)"
534 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
535 depends on X86_32_NON_STANDARD
536 ---help---
537 The SGI Visual Workstation series is an IA32-based workstation
538 based on SGI systems chips with some legacy PC hardware attached.
539
540 Say Y here to create a kernel to run on the SGI 320 or 540.
541
542 A kernel compiled for the Visual Workstation will run on general
543 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
544
545 config STA2X11
546 bool "STA2X11 Companion Chip Support"
547 depends on X86_32_NON_STANDARD && PCI
548 select X86_DEV_DMA_OPS
549 select X86_DMA_REMAP
550 select SWIOTLB
551 select MFD_STA2X11
552 select ARCH_REQUIRE_GPIOLIB
553 default n
554 ---help---
555 This adds support for boards based on the STA2X11 IO-Hub,
556 a.k.a. "ConneXt". The chip is used in place of the standard
557 PC chipset, so all "standard" peripherals are missing. If this
558 option is selected the kernel will still be able to boot on
559 standard PC machines.
560
561 config X86_SUMMIT
562 bool "Summit/EXA (IBM x440)"
563 depends on X86_32_NON_STANDARD
564 ---help---
565 This option is needed for IBM systems that use the Summit/EXA chipset.
566 In particular, it is needed for the x440.
567
568 config X86_ES7000
569 bool "Unisys ES7000 IA32 series"
570 depends on X86_32_NON_STANDARD && X86_BIGSMP
571 ---help---
572 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
573 supposed to run on an IA32-based Unisys ES7000 system.
574
575 config X86_32_IRIS
576 tristate "Eurobraille/Iris poweroff module"
577 depends on X86_32
578 ---help---
579 The Iris machines from EuroBraille do not have APM or ACPI support
580 to shut themselves down properly. A special I/O sequence is
581 needed to do so, which is what this module does at
582 kernel shutdown.
583
584 This is only for Iris machines from EuroBraille.
585
586 If unused, say N.
587
588 config SCHED_OMIT_FRAME_POINTER
589 def_bool y
590 prompt "Single-depth WCHAN output"
591 depends on X86
592 ---help---
593 Calculate simpler /proc/<PID>/wchan values. If this option
594 is disabled then wchan values will recurse back to the
595 caller function. This provides more accurate wchan values,
596 at the expense of slightly more scheduling overhead.
597
598 If in doubt, say "Y".
599
600 menuconfig PARAVIRT_GUEST
601 bool "Paravirtualized guest support"
602 ---help---
603 Say Y here to get to see options related to running Linux under
604 various hypervisors. This option alone does not add any kernel code.
605
606 If you say N, all options in this submenu will be skipped and disabled.
607
608 if PARAVIRT_GUEST
609
610 config PARAVIRT_TIME_ACCOUNTING
611 bool "Paravirtual steal time accounting"
612 select PARAVIRT
613 default n
614 ---help---
615 Select this option to enable fine granularity task steal time
616 accounting. Time spent executing other tasks in parallel with
617 the current vCPU is discounted from the vCPU power. To account for
618 that, there can be a small performance impact.
619
620 If in doubt, say N here.
621
622 source "arch/x86/xen/Kconfig"
623
624 config KVM_GUEST
625 bool "KVM Guest support (including kvmclock)"
626 select PARAVIRT
627 select PARAVIRT
628 select PARAVIRT_CLOCK
629 default y if PARAVIRT_GUEST
630 ---help---
631 This option enables various optimizations for running under the KVM
632 hypervisor. It includes a paravirtualized clock, so that instead
633 of relying on a PIT (or probably other) emulation by the
634 underlying device model, the host provides the guest with
635 timing infrastructure such as time of day, and system time
636
637 source "arch/x86/lguest/Kconfig"
638
639 config PARAVIRT
640 bool "Enable paravirtualization code"
641 ---help---
642 This changes the kernel so it can modify itself when it is run
643 under a hypervisor, potentially improving performance significantly
644 over full virtualization. However, when run without a hypervisor
645 the kernel is theoretically slower and slightly larger.
646
647 config PARAVIRT_SPINLOCKS
648 bool "Paravirtualization layer for spinlocks"
649 depends on PARAVIRT && SMP
650 ---help---
651 Paravirtualized spinlocks allow a pvops backend to replace the
652 spinlock implementation with something virtualization-friendly
653 (for example, block the virtual CPU rather than spinning).
654
655 Unfortunately the downside is an up to 5% performance hit on
656 native kernels, with various workloads.
657
658 If you are unsure how to answer this question, answer N.
659
660 config PARAVIRT_CLOCK
661 bool
662
663 endif
664
665 config PARAVIRT_DEBUG
666 bool "paravirt-ops debugging"
667 depends on PARAVIRT && DEBUG_KERNEL
668 ---help---
669 Enable to debug paravirt_ops internals. Specifically, BUG if
670 a paravirt_op is missing when it is called.
671
672 config NO_BOOTMEM
673 def_bool y
674
675 config MEMTEST
676 bool "Memtest"
677 ---help---
678 This option adds a kernel parameter 'memtest', which allows memtest
679 to be set.
680 memtest=0, mean disabled; -- default
681 memtest=1, mean do 1 test pattern;
682 ...
683 memtest=4, mean do 4 test patterns.
684 If you are unsure how to answer this question, answer N.
685
686 config X86_SUMMIT_NUMA
687 def_bool y
688 depends on X86_32 && NUMA && X86_32_NON_STANDARD
689
690 config X86_CYCLONE_TIMER
691 def_bool y
692 depends on X86_SUMMIT
693
694 source "arch/x86/Kconfig.cpu"
695
696 config HPET_TIMER
697 def_bool X86_64
698 prompt "HPET Timer Support" if X86_32
699 ---help---
700 Use the IA-PC HPET (High Precision Event Timer) to manage
701 time in preference to the PIT and RTC, if a HPET is
702 present.
703 HPET is the next generation timer replacing legacy 8254s.
704 The HPET provides a stable time base on SMP
705 systems, unlike the TSC, but it is more expensive to access,
706 as it is off-chip. You can find the HPET spec at
707 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
708
709 You can safely choose Y here. However, HPET will only be
710 activated if the platform and the BIOS support this feature.
711 Otherwise the 8254 will be used for timing services.
712
713 Choose N to continue using the legacy 8254 timer.
714
715 config HPET_EMULATE_RTC
716 def_bool y
717 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
718
719 config APB_TIMER
720 def_bool y if X86_INTEL_MID
721 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
722 select DW_APB_TIMER
723 depends on X86_INTEL_MID && SFI
724 help
725 APB timer is the replacement for 8254, HPET on X86 MID platforms.
726 The APBT provides a stable time base on SMP
727 systems, unlike the TSC, but it is more expensive to access,
728 as it is off-chip. APB timers are always running regardless of CPU
729 C states, they are used as per CPU clockevent device when possible.
730
731 # Mark as expert because too many people got it wrong.
732 # The code disables itself when not needed.
733 config DMI
734 default y
735 bool "Enable DMI scanning" if EXPERT
736 ---help---
737 Enabled scanning of DMI to identify machine quirks. Say Y
738 here unless you have verified that your setup is not
739 affected by entries in the DMI blacklist. Required by PNP
740 BIOS code.
741
742 config GART_IOMMU
743 bool "GART IOMMU support" if EXPERT
744 default y
745 select SWIOTLB
746 depends on X86_64 && PCI && AMD_NB
747 ---help---
748 Support for full DMA access of devices with 32bit memory access only
749 on systems with more than 3GB. This is usually needed for USB,
750 sound, many IDE/SATA chipsets and some other devices.
751 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
752 based hardware IOMMU and a software bounce buffer based IOMMU used
753 on Intel systems and as fallback.
754 The code is only active when needed (enough memory and limited
755 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
756 too.
757
758 config CALGARY_IOMMU
759 bool "IBM Calgary IOMMU support"
760 select SWIOTLB
761 depends on X86_64 && PCI
762 ---help---
763 Support for hardware IOMMUs in IBM's xSeries x366 and x460
764 systems. Needed to run systems with more than 3GB of memory
765 properly with 32-bit PCI devices that do not support DAC
766 (Double Address Cycle). Calgary also supports bus level
767 isolation, where all DMAs pass through the IOMMU. This
768 prevents them from going anywhere except their intended
769 destination. This catches hard-to-find kernel bugs and
770 mis-behaving drivers and devices that do not use the DMA-API
771 properly to set up their DMA buffers. The IOMMU can be
772 turned off at boot time with the iommu=off parameter.
773 Normally the kernel will make the right choice by itself.
774 If unsure, say Y.
775
776 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
777 def_bool y
778 prompt "Should Calgary be enabled by default?"
779 depends on CALGARY_IOMMU
780 ---help---
781 Should Calgary be enabled by default? if you choose 'y', Calgary
782 will be used (if it exists). If you choose 'n', Calgary will not be
783 used even if it exists. If you choose 'n' and would like to use
784 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
785 If unsure, say Y.
786
787 # need this always selected by IOMMU for the VIA workaround
788 config SWIOTLB
789 def_bool y if X86_64
790 ---help---
791 Support for software bounce buffers used on x86-64 systems
792 which don't have a hardware IOMMU. Using this PCI devices
793 which can only access 32-bits of memory can be used on systems
794 with more than 3 GB of memory.
795 If unsure, say Y.
796
797 config IOMMU_HELPER
798 def_bool y
799 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
800
801 config MAXSMP
802 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
803 depends on X86_64 && SMP && DEBUG_KERNEL
804 select CPUMASK_OFFSTACK
805 ---help---
806 Enable maximum number of CPUS and NUMA Nodes for this architecture.
807 If unsure, say N.
808
809 config NR_CPUS
810 int "Maximum number of CPUs" if SMP && !MAXSMP
811 range 2 8 if SMP && X86_32 && !X86_BIGSMP
812 range 2 512 if SMP && !MAXSMP
813 default "1" if !SMP
814 default "4096" if MAXSMP
815 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
816 default "8" if SMP
817 ---help---
818 This allows you to specify the maximum number of CPUs which this
819 kernel will support. The maximum supported value is 512 and the
820 minimum value which makes sense is 2.
821
822 This is purely to save memory - each supported CPU adds
823 approximately eight kilobytes to the kernel image.
824
825 config SCHED_SMT
826 bool "SMT (Hyperthreading) scheduler support"
827 depends on X86_HT
828 ---help---
829 SMT scheduler support improves the CPU scheduler's decision making
830 when dealing with Intel Pentium 4 chips with HyperThreading at a
831 cost of slightly increased overhead in some places. If unsure say
832 N here.
833
834 config SCHED_MC
835 def_bool y
836 prompt "Multi-core scheduler support"
837 depends on X86_HT
838 ---help---
839 Multi-core scheduler support improves the CPU scheduler's decision
840 making when dealing with multi-core CPU chips at a cost of slightly
841 increased overhead in some places. If unsure say N here.
842
843 source "kernel/Kconfig.preempt"
844
845 config X86_UP_APIC
846 bool "Local APIC support on uniprocessors"
847 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
848 ---help---
849 A local APIC (Advanced Programmable Interrupt Controller) is an
850 integrated interrupt controller in the CPU. If you have a single-CPU
851 system which has a processor with a local APIC, you can say Y here to
852 enable and use it. If you say Y here even though your machine doesn't
853 have a local APIC, then the kernel will still run with no slowdown at
854 all. The local APIC supports CPU-generated self-interrupts (timer,
855 performance counters), and the NMI watchdog which detects hard
856 lockups.
857
858 config X86_UP_IOAPIC
859 bool "IO-APIC support on uniprocessors"
860 depends on X86_UP_APIC
861 ---help---
862 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
863 SMP-capable replacement for PC-style interrupt controllers. Most
864 SMP systems and many recent uniprocessor systems have one.
865
866 If you have a single-CPU system with an IO-APIC, you can say Y here
867 to use it. If you say Y here even though your machine doesn't have
868 an IO-APIC, then the kernel will still run with no slowdown at all.
869
870 config X86_LOCAL_APIC
871 def_bool y
872 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
873
874 config X86_IO_APIC
875 def_bool y
876 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
877
878 config X86_VISWS_APIC
879 def_bool y
880 depends on X86_32 && X86_VISWS
881
882 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
883 bool "Reroute for broken boot IRQs"
884 depends on X86_IO_APIC
885 ---help---
886 This option enables a workaround that fixes a source of
887 spurious interrupts. This is recommended when threaded
888 interrupt handling is used on systems where the generation of
889 superfluous "boot interrupts" cannot be disabled.
890
891 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
892 entry in the chipset's IO-APIC is masked (as, e.g. the RT
893 kernel does during interrupt handling). On chipsets where this
894 boot IRQ generation cannot be disabled, this workaround keeps
895 the original IRQ line masked so that only the equivalent "boot
896 IRQ" is delivered to the CPUs. The workaround also tells the
897 kernel to set up the IRQ handler on the boot IRQ line. In this
898 way only one interrupt is delivered to the kernel. Otherwise
899 the spurious second interrupt may cause the kernel to bring
900 down (vital) interrupt lines.
901
902 Only affects "broken" chipsets. Interrupt sharing may be
903 increased on these systems.
904
905 config X86_MCE
906 bool "Machine Check / overheating reporting"
907 default y
908 ---help---
909 Machine Check support allows the processor to notify the
910 kernel if it detects a problem (e.g. overheating, data corruption).
911 The action the kernel takes depends on the severity of the problem,
912 ranging from warning messages to halting the machine.
913
914 config X86_MCE_INTEL
915 def_bool y
916 prompt "Intel MCE features"
917 depends on X86_MCE && X86_LOCAL_APIC
918 ---help---
919 Additional support for intel specific MCE features such as
920 the thermal monitor.
921
922 config X86_MCE_AMD
923 def_bool y
924 prompt "AMD MCE features"
925 depends on X86_MCE && X86_LOCAL_APIC
926 ---help---
927 Additional support for AMD specific MCE features such as
928 the DRAM Error Threshold.
929
930 config X86_ANCIENT_MCE
931 bool "Support for old Pentium 5 / WinChip machine checks"
932 depends on X86_32 && X86_MCE
933 ---help---
934 Include support for machine check handling on old Pentium 5 or WinChip
935 systems. These typically need to be enabled explicitely on the command
936 line.
937
938 config X86_MCE_THRESHOLD
939 depends on X86_MCE_AMD || X86_MCE_INTEL
940 def_bool y
941
942 config X86_MCE_INJECT
943 depends on X86_MCE
944 tristate "Machine check injector support"
945 ---help---
946 Provide support for injecting machine checks for testing purposes.
947 If you don't know what a machine check is and you don't do kernel
948 QA it is safe to say n.
949
950 config X86_THERMAL_VECTOR
951 def_bool y
952 depends on X86_MCE_INTEL
953
954 config VM86
955 bool "Enable VM86 support" if EXPERT
956 default y
957 depends on X86_32
958 ---help---
959 This option is required by programs like DOSEMU to run 16-bit legacy
960 code on X86 processors. It also may be needed by software like
961 XFree86 to initialize some video cards via BIOS. Disabling this
962 option saves about 6k.
963
964 config TOSHIBA
965 tristate "Toshiba Laptop support"
966 depends on X86_32
967 ---help---
968 This adds a driver to safely access the System Management Mode of
969 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
970 not work on models with a Phoenix BIOS. The System Management Mode
971 is used to set the BIOS and power saving options on Toshiba portables.
972
973 For information on utilities to make use of this driver see the
974 Toshiba Linux utilities web site at:
975 <http://www.buzzard.org.uk/toshiba/>.
976
977 Say Y if you intend to run this kernel on a Toshiba portable.
978 Say N otherwise.
979
980 config I8K
981 tristate "Dell laptop support"
982 select HWMON
983 ---help---
984 This adds a driver to safely access the System Management Mode
985 of the CPU on the Dell Inspiron 8000. The System Management Mode
986 is used to read cpu temperature and cooling fan status and to
987 control the fans on the I8K portables.
988
989 This driver has been tested only on the Inspiron 8000 but it may
990 also work with other Dell laptops. You can force loading on other
991 models by passing the parameter `force=1' to the module. Use at
992 your own risk.
993
994 For information on utilities to make use of this driver see the
995 I8K Linux utilities web site at:
996 <http://people.debian.org/~dz/i8k/>
997
998 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
999 Say N otherwise.
1000
1001 config X86_REBOOTFIXUPS
1002 bool "Enable X86 board specific fixups for reboot"
1003 depends on X86_32
1004 ---help---
1005 This enables chipset and/or board specific fixups to be done
1006 in order to get reboot to work correctly. This is only needed on
1007 some combinations of hardware and BIOS. The symptom, for which
1008 this config is intended, is when reboot ends with a stalled/hung
1009 system.
1010
1011 Currently, the only fixup is for the Geode machines using
1012 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1013
1014 Say Y if you want to enable the fixup. Currently, it's safe to
1015 enable this option even if you don't need it.
1016 Say N otherwise.
1017
1018 config MICROCODE
1019 tristate "CPU microcode loading support"
1020 select FW_LOADER
1021 ---help---
1022
1023 If you say Y here, you will be able to update the microcode on
1024 certain Intel and AMD processors. The Intel support is for the
1025 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1026 Xeon etc. The AMD support is for families 0x10 and later. You will
1027 obviously need the actual microcode binary data itself which is not
1028 shipped with the Linux kernel.
1029
1030 This option selects the general module only, you need to select
1031 at least one vendor specific module as well.
1032
1033 To compile this driver as a module, choose M here: the module
1034 will be called microcode.
1035
1036 config MICROCODE_INTEL
1037 bool "Intel microcode loading support"
1038 depends on MICROCODE
1039 default MICROCODE
1040 select FW_LOADER
1041 ---help---
1042 This options enables microcode patch loading support for Intel
1043 processors.
1044
1045 For latest news and information on obtaining all the required
1046 Intel ingredients for this driver, check:
1047 <http://www.urbanmyth.org/microcode/>.
1048
1049 config MICROCODE_AMD
1050 bool "AMD microcode loading support"
1051 depends on MICROCODE
1052 select FW_LOADER
1053 ---help---
1054 If you select this option, microcode patch loading support for AMD
1055 processors will be enabled.
1056
1057 config MICROCODE_OLD_INTERFACE
1058 def_bool y
1059 depends on MICROCODE
1060
1061 config MICROCODE_INTEL_LIB
1062 def_bool y
1063 depends on MICROCODE_INTEL
1064
1065 config MICROCODE_INTEL_EARLY
1066 bool "Early load microcode"
1067 depends on MICROCODE_INTEL && BLK_DEV_INITRD
1068 default y
1069 help
1070 This option provides functionality to read additional microcode data
1071 at the beginning of initrd image. The data tells kernel to load
1072 microcode to CPU's as early as possible. No functional change if no
1073 microcode data is glued to the initrd, therefore it's safe to say Y.
1074
1075 config MICROCODE_EARLY
1076 def_bool y
1077 depends on MICROCODE_INTEL_EARLY
1078
1079 config X86_MSR
1080 tristate "/dev/cpu/*/msr - Model-specific register support"
1081 ---help---
1082 This device gives privileged processes access to the x86
1083 Model-Specific Registers (MSRs). It is a character device with
1084 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1085 MSR accesses are directed to a specific CPU on multi-processor
1086 systems.
1087
1088 config X86_CPUID
1089 tristate "/dev/cpu/*/cpuid - CPU information support"
1090 ---help---
1091 This device gives processes access to the x86 CPUID instruction to
1092 be executed on a specific processor. It is a character device
1093 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1094 /dev/cpu/31/cpuid.
1095
1096 choice
1097 prompt "High Memory Support"
1098 default HIGHMEM64G if X86_NUMAQ
1099 default HIGHMEM4G
1100 depends on X86_32
1101
1102 config NOHIGHMEM
1103 bool "off"
1104 depends on !X86_NUMAQ
1105 ---help---
1106 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1107 However, the address space of 32-bit x86 processors is only 4
1108 Gigabytes large. That means that, if you have a large amount of
1109 physical memory, not all of it can be "permanently mapped" by the
1110 kernel. The physical memory that's not permanently mapped is called
1111 "high memory".
1112
1113 If you are compiling a kernel which will never run on a machine with
1114 more than 1 Gigabyte total physical RAM, answer "off" here (default
1115 choice and suitable for most users). This will result in a "3GB/1GB"
1116 split: 3GB are mapped so that each process sees a 3GB virtual memory
1117 space and the remaining part of the 4GB virtual memory space is used
1118 by the kernel to permanently map as much physical memory as
1119 possible.
1120
1121 If the machine has between 1 and 4 Gigabytes physical RAM, then
1122 answer "4GB" here.
1123
1124 If more than 4 Gigabytes is used then answer "64GB" here. This
1125 selection turns Intel PAE (Physical Address Extension) mode on.
1126 PAE implements 3-level paging on IA32 processors. PAE is fully
1127 supported by Linux, PAE mode is implemented on all recent Intel
1128 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1129 then the kernel will not boot on CPUs that don't support PAE!
1130
1131 The actual amount of total physical memory will either be
1132 auto detected or can be forced by using a kernel command line option
1133 such as "mem=256M". (Try "man bootparam" or see the documentation of
1134 your boot loader (lilo or loadlin) about how to pass options to the
1135 kernel at boot time.)
1136
1137 If unsure, say "off".
1138
1139 config HIGHMEM4G
1140 bool "4GB"
1141 depends on !X86_NUMAQ
1142 ---help---
1143 Select this if you have a 32-bit processor and between 1 and 4
1144 gigabytes of physical RAM.
1145
1146 config HIGHMEM64G
1147 bool "64GB"
1148 depends on !M486
1149 select X86_PAE
1150 ---help---
1151 Select this if you have a 32-bit processor and more than 4
1152 gigabytes of physical RAM.
1153
1154 endchoice
1155
1156 choice
1157 prompt "Memory split" if EXPERT
1158 default VMSPLIT_3G
1159 depends on X86_32
1160 ---help---
1161 Select the desired split between kernel and user memory.
1162
1163 If the address range available to the kernel is less than the
1164 physical memory installed, the remaining memory will be available
1165 as "high memory". Accessing high memory is a little more costly
1166 than low memory, as it needs to be mapped into the kernel first.
1167 Note that increasing the kernel address space limits the range
1168 available to user programs, making the address space there
1169 tighter. Selecting anything other than the default 3G/1G split
1170 will also likely make your kernel incompatible with binary-only
1171 kernel modules.
1172
1173 If you are not absolutely sure what you are doing, leave this
1174 option alone!
1175
1176 config VMSPLIT_3G
1177 bool "3G/1G user/kernel split"
1178 config VMSPLIT_3G_OPT
1179 depends on !X86_PAE
1180 bool "3G/1G user/kernel split (for full 1G low memory)"
1181 config VMSPLIT_2G
1182 bool "2G/2G user/kernel split"
1183 config VMSPLIT_2G_OPT
1184 depends on !X86_PAE
1185 bool "2G/2G user/kernel split (for full 2G low memory)"
1186 config VMSPLIT_1G
1187 bool "1G/3G user/kernel split"
1188 endchoice
1189
1190 config PAGE_OFFSET
1191 hex
1192 default 0xB0000000 if VMSPLIT_3G_OPT
1193 default 0x80000000 if VMSPLIT_2G
1194 default 0x78000000 if VMSPLIT_2G_OPT
1195 default 0x40000000 if VMSPLIT_1G
1196 default 0xC0000000
1197 depends on X86_32
1198
1199 config HIGHMEM
1200 def_bool y
1201 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1202
1203 config X86_PAE
1204 bool "PAE (Physical Address Extension) Support"
1205 depends on X86_32 && !HIGHMEM4G
1206 ---help---
1207 PAE is required for NX support, and furthermore enables
1208 larger swapspace support for non-overcommit purposes. It
1209 has the cost of more pagetable lookup overhead, and also
1210 consumes more pagetable space per process.
1211
1212 config ARCH_PHYS_ADDR_T_64BIT
1213 def_bool y
1214 depends on X86_64 || X86_PAE
1215
1216 config ARCH_DMA_ADDR_T_64BIT
1217 def_bool y
1218 depends on X86_64 || HIGHMEM64G
1219
1220 config DIRECT_GBPAGES
1221 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1222 default y
1223 depends on X86_64
1224 ---help---
1225 Allow the kernel linear mapping to use 1GB pages on CPUs that
1226 support it. This can improve the kernel's performance a tiny bit by
1227 reducing TLB pressure. If in doubt, say "Y".
1228
1229 # Common NUMA Features
1230 config NUMA
1231 bool "Numa Memory Allocation and Scheduler Support"
1232 depends on SMP
1233 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI))
1234 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1235 ---help---
1236 Enable NUMA (Non Uniform Memory Access) support.
1237
1238 The kernel will try to allocate memory used by a CPU on the
1239 local memory controller of the CPU and add some more
1240 NUMA awareness to the kernel.
1241
1242 For 64-bit this is recommended if the system is Intel Core i7
1243 (or later), AMD Opteron, or EM64T NUMA.
1244
1245 For 32-bit this is only needed on (rare) 32-bit-only platforms
1246 that support NUMA topologies, such as NUMAQ / Summit, or if you
1247 boot a 32-bit kernel on a 64-bit NUMA platform.
1248
1249 Otherwise, you should say N.
1250
1251 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1252 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1253
1254 config AMD_NUMA
1255 def_bool y
1256 prompt "Old style AMD Opteron NUMA detection"
1257 depends on X86_64 && NUMA && PCI
1258 ---help---
1259 Enable AMD NUMA node topology detection. You should say Y here if
1260 you have a multi processor AMD system. This uses an old method to
1261 read the NUMA configuration directly from the builtin Northbridge
1262 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1263 which also takes priority if both are compiled in.
1264
1265 config X86_64_ACPI_NUMA
1266 def_bool y
1267 prompt "ACPI NUMA detection"
1268 depends on X86_64 && NUMA && ACPI && PCI
1269 select ACPI_NUMA
1270 ---help---
1271 Enable ACPI SRAT based node topology detection.
1272
1273 # Some NUMA nodes have memory ranges that span
1274 # other nodes. Even though a pfn is valid and
1275 # between a node's start and end pfns, it may not
1276 # reside on that node. See memmap_init_zone()
1277 # for details.
1278 config NODES_SPAN_OTHER_NODES
1279 def_bool y
1280 depends on X86_64_ACPI_NUMA
1281
1282 config NUMA_EMU
1283 bool "NUMA emulation"
1284 depends on NUMA
1285 ---help---
1286 Enable NUMA emulation. A flat machine will be split
1287 into virtual nodes when booted with "numa=fake=N", where N is the
1288 number of nodes. This is only useful for debugging.
1289
1290 config NODES_SHIFT
1291 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1292 range 1 10
1293 default "10" if MAXSMP
1294 default "6" if X86_64
1295 default "4" if X86_NUMAQ
1296 default "3"
1297 depends on NEED_MULTIPLE_NODES
1298 ---help---
1299 Specify the maximum number of NUMA Nodes available on the target
1300 system. Increases memory reserved to accommodate various tables.
1301
1302 config ARCH_HAVE_MEMORY_PRESENT
1303 def_bool y
1304 depends on X86_32 && DISCONTIGMEM
1305
1306 config NEED_NODE_MEMMAP_SIZE
1307 def_bool y
1308 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1309
1310 config ARCH_FLATMEM_ENABLE
1311 def_bool y
1312 depends on X86_32 && !NUMA
1313
1314 config ARCH_DISCONTIGMEM_ENABLE
1315 def_bool y
1316 depends on NUMA && X86_32
1317
1318 config ARCH_DISCONTIGMEM_DEFAULT
1319 def_bool y
1320 depends on NUMA && X86_32
1321
1322 config ARCH_SPARSEMEM_ENABLE
1323 def_bool y
1324 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1325 select SPARSEMEM_STATIC if X86_32
1326 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1327
1328 config ARCH_SPARSEMEM_DEFAULT
1329 def_bool y
1330 depends on X86_64
1331
1332 config ARCH_SELECT_MEMORY_MODEL
1333 def_bool y
1334 depends on ARCH_SPARSEMEM_ENABLE
1335
1336 config ARCH_MEMORY_PROBE
1337 def_bool y
1338 depends on X86_64 && MEMORY_HOTPLUG
1339
1340 config ARCH_PROC_KCORE_TEXT
1341 def_bool y
1342 depends on X86_64 && PROC_KCORE
1343
1344 config ILLEGAL_POINTER_VALUE
1345 hex
1346 default 0 if X86_32
1347 default 0xdead000000000000 if X86_64
1348
1349 source "mm/Kconfig"
1350
1351 config HIGHPTE
1352 bool "Allocate 3rd-level pagetables from highmem"
1353 depends on HIGHMEM
1354 ---help---
1355 The VM uses one page table entry for each page of physical memory.
1356 For systems with a lot of RAM, this can be wasteful of precious
1357 low memory. Setting this option will put user-space page table
1358 entries in high memory.
1359
1360 config X86_CHECK_BIOS_CORRUPTION
1361 bool "Check for low memory corruption"
1362 ---help---
1363 Periodically check for memory corruption in low memory, which
1364 is suspected to be caused by BIOS. Even when enabled in the
1365 configuration, it is disabled at runtime. Enable it by
1366 setting "memory_corruption_check=1" on the kernel command
1367 line. By default it scans the low 64k of memory every 60
1368 seconds; see the memory_corruption_check_size and
1369 memory_corruption_check_period parameters in
1370 Documentation/kernel-parameters.txt to adjust this.
1371
1372 When enabled with the default parameters, this option has
1373 almost no overhead, as it reserves a relatively small amount
1374 of memory and scans it infrequently. It both detects corruption
1375 and prevents it from affecting the running system.
1376
1377 It is, however, intended as a diagnostic tool; if repeatable
1378 BIOS-originated corruption always affects the same memory,
1379 you can use memmap= to prevent the kernel from using that
1380 memory.
1381
1382 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1383 bool "Set the default setting of memory_corruption_check"
1384 depends on X86_CHECK_BIOS_CORRUPTION
1385 default y
1386 ---help---
1387 Set whether the default state of memory_corruption_check is
1388 on or off.
1389
1390 config X86_RESERVE_LOW
1391 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1392 default 64
1393 range 4 640
1394 ---help---
1395 Specify the amount of low memory to reserve for the BIOS.
1396
1397 The first page contains BIOS data structures that the kernel
1398 must not use, so that page must always be reserved.
1399
1400 By default we reserve the first 64K of physical RAM, as a
1401 number of BIOSes are known to corrupt that memory range
1402 during events such as suspend/resume or monitor cable
1403 insertion, so it must not be used by the kernel.
1404
1405 You can set this to 4 if you are absolutely sure that you
1406 trust the BIOS to get all its memory reservations and usages
1407 right. If you know your BIOS have problems beyond the
1408 default 64K area, you can set this to 640 to avoid using the
1409 entire low memory range.
1410
1411 If you have doubts about the BIOS (e.g. suspend/resume does
1412 not work or there's kernel crashes after certain hardware
1413 hotplug events) then you might want to enable
1414 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1415 typical corruption patterns.
1416
1417 Leave this to the default value of 64 if you are unsure.
1418
1419 config MATH_EMULATION
1420 bool
1421 prompt "Math emulation" if X86_32
1422 ---help---
1423 Linux can emulate a math coprocessor (used for floating point
1424 operations) if you don't have one. 486DX and Pentium processors have
1425 a math coprocessor built in, 486SX and 386 do not, unless you added
1426 a 487DX or 387, respectively. (The messages during boot time can
1427 give you some hints here ["man dmesg"].) Everyone needs either a
1428 coprocessor or this emulation.
1429
1430 If you don't have a math coprocessor, you need to say Y here; if you
1431 say Y here even though you have a coprocessor, the coprocessor will
1432 be used nevertheless. (This behavior can be changed with the kernel
1433 command line option "no387", which comes handy if your coprocessor
1434 is broken. Try "man bootparam" or see the documentation of your boot
1435 loader (lilo or loadlin) about how to pass options to the kernel at
1436 boot time.) This means that it is a good idea to say Y here if you
1437 intend to use this kernel on different machines.
1438
1439 More information about the internals of the Linux math coprocessor
1440 emulation can be found in <file:arch/x86/math-emu/README>.
1441
1442 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1443 kernel, it won't hurt.
1444
1445 config MTRR
1446 def_bool y
1447 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1448 ---help---
1449 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1450 the Memory Type Range Registers (MTRRs) may be used to control
1451 processor access to memory ranges. This is most useful if you have
1452 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1453 allows bus write transfers to be combined into a larger transfer
1454 before bursting over the PCI/AGP bus. This can increase performance
1455 of image write operations 2.5 times or more. Saying Y here creates a
1456 /proc/mtrr file which may be used to manipulate your processor's
1457 MTRRs. Typically the X server should use this.
1458
1459 This code has a reasonably generic interface so that similar
1460 control registers on other processors can be easily supported
1461 as well:
1462
1463 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1464 Registers (ARRs) which provide a similar functionality to MTRRs. For
1465 these, the ARRs are used to emulate the MTRRs.
1466 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1467 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1468 write-combining. All of these processors are supported by this code
1469 and it makes sense to say Y here if you have one of them.
1470
1471 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1472 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1473 can lead to all sorts of problems, so it's good to say Y here.
1474
1475 You can safely say Y even if your machine doesn't have MTRRs, you'll
1476 just add about 9 KB to your kernel.
1477
1478 See <file:Documentation/x86/mtrr.txt> for more information.
1479
1480 config MTRR_SANITIZER
1481 def_bool y
1482 prompt "MTRR cleanup support"
1483 depends on MTRR
1484 ---help---
1485 Convert MTRR layout from continuous to discrete, so X drivers can
1486 add writeback entries.
1487
1488 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1489 The largest mtrr entry size for a continuous block can be set with
1490 mtrr_chunk_size.
1491
1492 If unsure, say Y.
1493
1494 config MTRR_SANITIZER_ENABLE_DEFAULT
1495 int "MTRR cleanup enable value (0-1)"
1496 range 0 1
1497 default "0"
1498 depends on MTRR_SANITIZER
1499 ---help---
1500 Enable mtrr cleanup default value
1501
1502 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1503 int "MTRR cleanup spare reg num (0-7)"
1504 range 0 7
1505 default "1"
1506 depends on MTRR_SANITIZER
1507 ---help---
1508 mtrr cleanup spare entries default, it can be changed via
1509 mtrr_spare_reg_nr=N on the kernel command line.
1510
1511 config X86_PAT
1512 def_bool y
1513 prompt "x86 PAT support" if EXPERT
1514 depends on MTRR
1515 ---help---
1516 Use PAT attributes to setup page level cache control.
1517
1518 PATs are the modern equivalents of MTRRs and are much more
1519 flexible than MTRRs.
1520
1521 Say N here if you see bootup problems (boot crash, boot hang,
1522 spontaneous reboots) or a non-working video driver.
1523
1524 If unsure, say Y.
1525
1526 config ARCH_USES_PG_UNCACHED
1527 def_bool y
1528 depends on X86_PAT
1529
1530 config ARCH_RANDOM
1531 def_bool y
1532 prompt "x86 architectural random number generator" if EXPERT
1533 ---help---
1534 Enable the x86 architectural RDRAND instruction
1535 (Intel Bull Mountain technology) to generate random numbers.
1536 If supported, this is a high bandwidth, cryptographically
1537 secure hardware random number generator.
1538
1539 config X86_SMAP
1540 def_bool y
1541 prompt "Supervisor Mode Access Prevention" if EXPERT
1542 ---help---
1543 Supervisor Mode Access Prevention (SMAP) is a security
1544 feature in newer Intel processors. There is a small
1545 performance cost if this enabled and turned on; there is
1546 also a small increase in the kernel size if this is enabled.
1547
1548 If unsure, say Y.
1549
1550 config EFI
1551 bool "EFI runtime service support"
1552 depends on ACPI
1553 ---help---
1554 This enables the kernel to use EFI runtime services that are
1555 available (such as the EFI variable services).
1556
1557 This option is only useful on systems that have EFI firmware.
1558 In addition, you should use the latest ELILO loader available
1559 at <http://elilo.sourceforge.net> in order to take advantage
1560 of EFI runtime services. However, even with this option, the
1561 resultant kernel should continue to boot on existing non-EFI
1562 platforms.
1563
1564 config EFI_STUB
1565 bool "EFI stub support"
1566 depends on EFI
1567 ---help---
1568 This kernel feature allows a bzImage to be loaded directly
1569 by EFI firmware without the use of a bootloader.
1570
1571 See Documentation/x86/efi-stub.txt for more information.
1572
1573 config SECCOMP
1574 def_bool y
1575 prompt "Enable seccomp to safely compute untrusted bytecode"
1576 ---help---
1577 This kernel feature is useful for number crunching applications
1578 that may need to compute untrusted bytecode during their
1579 execution. By using pipes or other transports made available to
1580 the process as file descriptors supporting the read/write
1581 syscalls, it's possible to isolate those applications in
1582 their own address space using seccomp. Once seccomp is
1583 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1584 and the task is only allowed to execute a few safe syscalls
1585 defined by each seccomp mode.
1586
1587 If unsure, say Y. Only embedded should say N here.
1588
1589 config CC_STACKPROTECTOR
1590 bool "Enable -fstack-protector buffer overflow detection"
1591 ---help---
1592 This option turns on the -fstack-protector GCC feature. This
1593 feature puts, at the beginning of functions, a canary value on
1594 the stack just before the return address, and validates
1595 the value just before actually returning. Stack based buffer
1596 overflows (that need to overwrite this return address) now also
1597 overwrite the canary, which gets detected and the attack is then
1598 neutralized via a kernel panic.
1599
1600 This feature requires gcc version 4.2 or above, or a distribution
1601 gcc with the feature backported. Older versions are automatically
1602 detected and for those versions, this configuration option is
1603 ignored. (and a warning is printed during bootup)
1604
1605 source kernel/Kconfig.hz
1606
1607 config KEXEC
1608 bool "kexec system call"
1609 ---help---
1610 kexec is a system call that implements the ability to shutdown your
1611 current kernel, and to start another kernel. It is like a reboot
1612 but it is independent of the system firmware. And like a reboot
1613 you can start any kernel with it, not just Linux.
1614
1615 The name comes from the similarity to the exec system call.
1616
1617 It is an ongoing process to be certain the hardware in a machine
1618 is properly shutdown, so do not be surprised if this code does not
1619 initially work for you. It may help to enable device hotplugging
1620 support. As of this writing the exact hardware interface is
1621 strongly in flux, so no good recommendation can be made.
1622
1623 config CRASH_DUMP
1624 bool "kernel crash dumps"
1625 depends on X86_64 || (X86_32 && HIGHMEM)
1626 ---help---
1627 Generate crash dump after being started by kexec.
1628 This should be normally only set in special crash dump kernels
1629 which are loaded in the main kernel with kexec-tools into
1630 a specially reserved region and then later executed after
1631 a crash by kdump/kexec. The crash dump kernel must be compiled
1632 to a memory address not used by the main kernel or BIOS using
1633 PHYSICAL_START, or it must be built as a relocatable image
1634 (CONFIG_RELOCATABLE=y).
1635 For more details see Documentation/kdump/kdump.txt
1636
1637 config KEXEC_JUMP
1638 bool "kexec jump"
1639 depends on KEXEC && HIBERNATION
1640 ---help---
1641 Jump between original kernel and kexeced kernel and invoke
1642 code in physical address mode via KEXEC
1643
1644 config PHYSICAL_START
1645 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1646 default "0x1000000"
1647 ---help---
1648 This gives the physical address where the kernel is loaded.
1649
1650 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1651 bzImage will decompress itself to above physical address and
1652 run from there. Otherwise, bzImage will run from the address where
1653 it has been loaded by the boot loader and will ignore above physical
1654 address.
1655
1656 In normal kdump cases one does not have to set/change this option
1657 as now bzImage can be compiled as a completely relocatable image
1658 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1659 address. This option is mainly useful for the folks who don't want
1660 to use a bzImage for capturing the crash dump and want to use a
1661 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1662 to be specifically compiled to run from a specific memory area
1663 (normally a reserved region) and this option comes handy.
1664
1665 So if you are using bzImage for capturing the crash dump,
1666 leave the value here unchanged to 0x1000000 and set
1667 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1668 for capturing the crash dump change this value to start of
1669 the reserved region. In other words, it can be set based on
1670 the "X" value as specified in the "crashkernel=YM@XM"
1671 command line boot parameter passed to the panic-ed
1672 kernel. Please take a look at Documentation/kdump/kdump.txt
1673 for more details about crash dumps.
1674
1675 Usage of bzImage for capturing the crash dump is recommended as
1676 one does not have to build two kernels. Same kernel can be used
1677 as production kernel and capture kernel. Above option should have
1678 gone away after relocatable bzImage support is introduced. But it
1679 is present because there are users out there who continue to use
1680 vmlinux for dump capture. This option should go away down the
1681 line.
1682
1683 Don't change this unless you know what you are doing.
1684
1685 config RELOCATABLE
1686 bool "Build a relocatable kernel"
1687 default y
1688 ---help---
1689 This builds a kernel image that retains relocation information
1690 so it can be loaded someplace besides the default 1MB.
1691 The relocations tend to make the kernel binary about 10% larger,
1692 but are discarded at runtime.
1693
1694 One use is for the kexec on panic case where the recovery kernel
1695 must live at a different physical address than the primary
1696 kernel.
1697
1698 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1699 it has been loaded at and the compile time physical address
1700 (CONFIG_PHYSICAL_START) is ignored.
1701
1702 # Relocation on x86-32 needs some additional build support
1703 config X86_NEED_RELOCS
1704 def_bool y
1705 depends on X86_32 && RELOCATABLE
1706
1707 config PHYSICAL_ALIGN
1708 hex "Alignment value to which kernel should be aligned" if X86_32
1709 default "0x1000000"
1710 range 0x2000 0x1000000
1711 ---help---
1712 This value puts the alignment restrictions on physical address
1713 where kernel is loaded and run from. Kernel is compiled for an
1714 address which meets above alignment restriction.
1715
1716 If bootloader loads the kernel at a non-aligned address and
1717 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1718 address aligned to above value and run from there.
1719
1720 If bootloader loads the kernel at a non-aligned address and
1721 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1722 load address and decompress itself to the address it has been
1723 compiled for and run from there. The address for which kernel is
1724 compiled already meets above alignment restrictions. Hence the
1725 end result is that kernel runs from a physical address meeting
1726 above alignment restrictions.
1727
1728 Don't change this unless you know what you are doing.
1729
1730 config HOTPLUG_CPU
1731 bool "Support for hot-pluggable CPUs"
1732 depends on SMP && HOTPLUG
1733 ---help---
1734 Say Y here to allow turning CPUs off and on. CPUs can be
1735 controlled through /sys/devices/system/cpu.
1736 ( Note: power management support will enable this option
1737 automatically on SMP systems. )
1738 Say N if you want to disable CPU hotplug.
1739
1740 config BOOTPARAM_HOTPLUG_CPU0
1741 bool "Set default setting of cpu0_hotpluggable"
1742 default n
1743 depends on HOTPLUG_CPU
1744 ---help---
1745 Set whether default state of cpu0_hotpluggable is on or off.
1746
1747 Say Y here to enable CPU0 hotplug by default. If this switch
1748 is turned on, there is no need to give cpu0_hotplug kernel
1749 parameter and the CPU0 hotplug feature is enabled by default.
1750
1751 Please note: there are two known CPU0 dependencies if you want
1752 to enable the CPU0 hotplug feature either by this switch or by
1753 cpu0_hotplug kernel parameter.
1754
1755 First, resume from hibernate or suspend always starts from CPU0.
1756 So hibernate and suspend are prevented if CPU0 is offline.
1757
1758 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1759 offline if any interrupt can not migrate out of CPU0. There may
1760 be other CPU0 dependencies.
1761
1762 Please make sure the dependencies are under your control before
1763 you enable this feature.
1764
1765 Say N if you don't want to enable CPU0 hotplug feature by default.
1766 You still can enable the CPU0 hotplug feature at boot by kernel
1767 parameter cpu0_hotplug.
1768
1769 config DEBUG_HOTPLUG_CPU0
1770 def_bool n
1771 prompt "Debug CPU0 hotplug"
1772 depends on HOTPLUG_CPU
1773 ---help---
1774 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1775 soon as possible and boots up userspace with CPU0 offlined. User
1776 can online CPU0 back after boot time.
1777
1778 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1779 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1780 compilation or giving cpu0_hotplug kernel parameter at boot.
1781
1782 If unsure, say N.
1783
1784 config COMPAT_VDSO
1785 def_bool y
1786 prompt "Compat VDSO support"
1787 depends on X86_32 || IA32_EMULATION
1788 ---help---
1789 Map the 32-bit VDSO to the predictable old-style address too.
1790
1791 Say N here if you are running a sufficiently recent glibc
1792 version (2.3.3 or later), to remove the high-mapped
1793 VDSO mapping and to exclusively use the randomized VDSO.
1794
1795 If unsure, say Y.
1796
1797 config CMDLINE_BOOL
1798 bool "Built-in kernel command line"
1799 ---help---
1800 Allow for specifying boot arguments to the kernel at
1801 build time. On some systems (e.g. embedded ones), it is
1802 necessary or convenient to provide some or all of the
1803 kernel boot arguments with the kernel itself (that is,
1804 to not rely on the boot loader to provide them.)
1805
1806 To compile command line arguments into the kernel,
1807 set this option to 'Y', then fill in the
1808 the boot arguments in CONFIG_CMDLINE.
1809
1810 Systems with fully functional boot loaders (i.e. non-embedded)
1811 should leave this option set to 'N'.
1812
1813 config CMDLINE
1814 string "Built-in kernel command string"
1815 depends on CMDLINE_BOOL
1816 default ""
1817 ---help---
1818 Enter arguments here that should be compiled into the kernel
1819 image and used at boot time. If the boot loader provides a
1820 command line at boot time, it is appended to this string to
1821 form the full kernel command line, when the system boots.
1822
1823 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1824 change this behavior.
1825
1826 In most cases, the command line (whether built-in or provided
1827 by the boot loader) should specify the device for the root
1828 file system.
1829
1830 config CMDLINE_OVERRIDE
1831 bool "Built-in command line overrides boot loader arguments"
1832 depends on CMDLINE_BOOL
1833 ---help---
1834 Set this option to 'Y' to have the kernel ignore the boot loader
1835 command line, and use ONLY the built-in command line.
1836
1837 This is used to work around broken boot loaders. This should
1838 be set to 'N' under normal conditions.
1839
1840 endmenu
1841
1842 config ARCH_ENABLE_MEMORY_HOTPLUG
1843 def_bool y
1844 depends on X86_64 || (X86_32 && HIGHMEM)
1845
1846 config ARCH_ENABLE_MEMORY_HOTREMOVE
1847 def_bool y
1848 depends on MEMORY_HOTPLUG
1849
1850 config USE_PERCPU_NUMA_NODE_ID
1851 def_bool y
1852 depends on NUMA
1853
1854 menu "Power management and ACPI options"
1855
1856 config ARCH_HIBERNATION_HEADER
1857 def_bool y
1858 depends on X86_64 && HIBERNATION
1859
1860 source "kernel/power/Kconfig"
1861
1862 source "drivers/acpi/Kconfig"
1863
1864 source "drivers/sfi/Kconfig"
1865
1866 config X86_APM_BOOT
1867 def_bool y
1868 depends on APM
1869
1870 menuconfig APM
1871 tristate "APM (Advanced Power Management) BIOS support"
1872 depends on X86_32 && PM_SLEEP
1873 ---help---
1874 APM is a BIOS specification for saving power using several different
1875 techniques. This is mostly useful for battery powered laptops with
1876 APM compliant BIOSes. If you say Y here, the system time will be
1877 reset after a RESUME operation, the /proc/apm device will provide
1878 battery status information, and user-space programs will receive
1879 notification of APM "events" (e.g. battery status change).
1880
1881 If you select "Y" here, you can disable actual use of the APM
1882 BIOS by passing the "apm=off" option to the kernel at boot time.
1883
1884 Note that the APM support is almost completely disabled for
1885 machines with more than one CPU.
1886
1887 In order to use APM, you will need supporting software. For location
1888 and more information, read <file:Documentation/power/apm-acpi.txt>
1889 and the Battery Powered Linux mini-HOWTO, available from
1890 <http://www.tldp.org/docs.html#howto>.
1891
1892 This driver does not spin down disk drives (see the hdparm(8)
1893 manpage ("man 8 hdparm") for that), and it doesn't turn off
1894 VESA-compliant "green" monitors.
1895
1896 This driver does not support the TI 4000M TravelMate and the ACER
1897 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1898 desktop machines also don't have compliant BIOSes, and this driver
1899 may cause those machines to panic during the boot phase.
1900
1901 Generally, if you don't have a battery in your machine, there isn't
1902 much point in using this driver and you should say N. If you get
1903 random kernel OOPSes or reboots that don't seem to be related to
1904 anything, try disabling/enabling this option (or disabling/enabling
1905 APM in your BIOS).
1906
1907 Some other things you should try when experiencing seemingly random,
1908 "weird" problems:
1909
1910 1) make sure that you have enough swap space and that it is
1911 enabled.
1912 2) pass the "no-hlt" option to the kernel
1913 3) switch on floating point emulation in the kernel and pass
1914 the "no387" option to the kernel
1915 4) pass the "floppy=nodma" option to the kernel
1916 5) pass the "mem=4M" option to the kernel (thereby disabling
1917 all but the first 4 MB of RAM)
1918 6) make sure that the CPU is not over clocked.
1919 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1920 8) disable the cache from your BIOS settings
1921 9) install a fan for the video card or exchange video RAM
1922 10) install a better fan for the CPU
1923 11) exchange RAM chips
1924 12) exchange the motherboard.
1925
1926 To compile this driver as a module, choose M here: the
1927 module will be called apm.
1928
1929 if APM
1930
1931 config APM_IGNORE_USER_SUSPEND
1932 bool "Ignore USER SUSPEND"
1933 ---help---
1934 This option will ignore USER SUSPEND requests. On machines with a
1935 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1936 series notebooks, it is necessary to say Y because of a BIOS bug.
1937
1938 config APM_DO_ENABLE
1939 bool "Enable PM at boot time"
1940 ---help---
1941 Enable APM features at boot time. From page 36 of the APM BIOS
1942 specification: "When disabled, the APM BIOS does not automatically
1943 power manage devices, enter the Standby State, enter the Suspend
1944 State, or take power saving steps in response to CPU Idle calls."
1945 This driver will make CPU Idle calls when Linux is idle (unless this
1946 feature is turned off -- see "Do CPU IDLE calls", below). This
1947 should always save battery power, but more complicated APM features
1948 will be dependent on your BIOS implementation. You may need to turn
1949 this option off if your computer hangs at boot time when using APM
1950 support, or if it beeps continuously instead of suspending. Turn
1951 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1952 T400CDT. This is off by default since most machines do fine without
1953 this feature.
1954
1955 config APM_CPU_IDLE
1956 depends on CPU_IDLE
1957 bool "Make CPU Idle calls when idle"
1958 ---help---
1959 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1960 On some machines, this can activate improved power savings, such as
1961 a slowed CPU clock rate, when the machine is idle. These idle calls
1962 are made after the idle loop has run for some length of time (e.g.,
1963 333 mS). On some machines, this will cause a hang at boot time or
1964 whenever the CPU becomes idle. (On machines with more than one CPU,
1965 this option does nothing.)
1966
1967 config APM_DISPLAY_BLANK
1968 bool "Enable console blanking using APM"
1969 ---help---
1970 Enable console blanking using the APM. Some laptops can use this to
1971 turn off the LCD backlight when the screen blanker of the Linux
1972 virtual console blanks the screen. Note that this is only used by
1973 the virtual console screen blanker, and won't turn off the backlight
1974 when using the X Window system. This also doesn't have anything to
1975 do with your VESA-compliant power-saving monitor. Further, this
1976 option doesn't work for all laptops -- it might not turn off your
1977 backlight at all, or it might print a lot of errors to the console,
1978 especially if you are using gpm.
1979
1980 config APM_ALLOW_INTS
1981 bool "Allow interrupts during APM BIOS calls"
1982 ---help---
1983 Normally we disable external interrupts while we are making calls to
1984 the APM BIOS as a measure to lessen the effects of a badly behaving
1985 BIOS implementation. The BIOS should reenable interrupts if it
1986 needs to. Unfortunately, some BIOSes do not -- especially those in
1987 many of the newer IBM Thinkpads. If you experience hangs when you
1988 suspend, try setting this to Y. Otherwise, say N.
1989
1990 endif # APM
1991
1992 source "drivers/cpufreq/Kconfig"
1993
1994 source "drivers/cpuidle/Kconfig"
1995
1996 source "drivers/idle/Kconfig"
1997
1998 endmenu
1999
2000
2001 menu "Bus options (PCI etc.)"
2002
2003 config PCI
2004 bool "PCI support"
2005 default y
2006 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
2007 ---help---
2008 Find out whether you have a PCI motherboard. PCI is the name of a
2009 bus system, i.e. the way the CPU talks to the other stuff inside
2010 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2011 VESA. If you have PCI, say Y, otherwise N.
2012
2013 choice
2014 prompt "PCI access mode"
2015 depends on X86_32 && PCI
2016 default PCI_GOANY
2017 ---help---
2018 On PCI systems, the BIOS can be used to detect the PCI devices and
2019 determine their configuration. However, some old PCI motherboards
2020 have BIOS bugs and may crash if this is done. Also, some embedded
2021 PCI-based systems don't have any BIOS at all. Linux can also try to
2022 detect the PCI hardware directly without using the BIOS.
2023
2024 With this option, you can specify how Linux should detect the
2025 PCI devices. If you choose "BIOS", the BIOS will be used,
2026 if you choose "Direct", the BIOS won't be used, and if you
2027 choose "MMConfig", then PCI Express MMCONFIG will be used.
2028 If you choose "Any", the kernel will try MMCONFIG, then the
2029 direct access method and falls back to the BIOS if that doesn't
2030 work. If unsure, go with the default, which is "Any".
2031
2032 config PCI_GOBIOS
2033 bool "BIOS"
2034
2035 config PCI_GOMMCONFIG
2036 bool "MMConfig"
2037
2038 config PCI_GODIRECT
2039 bool "Direct"
2040
2041 config PCI_GOOLPC
2042 bool "OLPC XO-1"
2043 depends on OLPC
2044
2045 config PCI_GOANY
2046 bool "Any"
2047
2048 endchoice
2049
2050 config PCI_BIOS
2051 def_bool y
2052 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2053
2054 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2055 config PCI_DIRECT
2056 def_bool y
2057 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2058
2059 config PCI_MMCONFIG
2060 def_bool y
2061 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2062
2063 config PCI_OLPC
2064 def_bool y
2065 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2066
2067 config PCI_XEN
2068 def_bool y
2069 depends on PCI && XEN
2070 select SWIOTLB_XEN
2071
2072 config PCI_DOMAINS
2073 def_bool y
2074 depends on PCI
2075
2076 config PCI_MMCONFIG
2077 bool "Support mmconfig PCI config space access"
2078 depends on X86_64 && PCI && ACPI
2079
2080 config PCI_CNB20LE_QUIRK
2081 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2082 depends on PCI
2083 help
2084 Read the PCI windows out of the CNB20LE host bridge. This allows
2085 PCI hotplug to work on systems with the CNB20LE chipset which do
2086 not have ACPI.
2087
2088 There's no public spec for this chipset, and this functionality
2089 is known to be incomplete.
2090
2091 You should say N unless you know you need this.
2092
2093 source "drivers/pci/pcie/Kconfig"
2094
2095 source "drivers/pci/Kconfig"
2096
2097 # x86_64 have no ISA slots, but can have ISA-style DMA.
2098 config ISA_DMA_API
2099 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2100 default y
2101 help
2102 Enables ISA-style DMA support for devices requiring such controllers.
2103 If unsure, say Y.
2104
2105 if X86_32
2106
2107 config ISA
2108 bool "ISA support"
2109 ---help---
2110 Find out whether you have ISA slots on your motherboard. ISA is the
2111 name of a bus system, i.e. the way the CPU talks to the other stuff
2112 inside your box. Other bus systems are PCI, EISA, MicroChannel
2113 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2114 newer boards don't support it. If you have ISA, say Y, otherwise N.
2115
2116 config EISA
2117 bool "EISA support"
2118 depends on ISA
2119 ---help---
2120 The Extended Industry Standard Architecture (EISA) bus was
2121 developed as an open alternative to the IBM MicroChannel bus.
2122
2123 The EISA bus provided some of the features of the IBM MicroChannel
2124 bus while maintaining backward compatibility with cards made for
2125 the older ISA bus. The EISA bus saw limited use between 1988 and
2126 1995 when it was made obsolete by the PCI bus.
2127
2128 Say Y here if you are building a kernel for an EISA-based machine.
2129
2130 Otherwise, say N.
2131
2132 source "drivers/eisa/Kconfig"
2133
2134 config SCx200
2135 tristate "NatSemi SCx200 support"
2136 ---help---
2137 This provides basic support for National Semiconductor's
2138 (now AMD's) Geode processors. The driver probes for the
2139 PCI-IDs of several on-chip devices, so its a good dependency
2140 for other scx200_* drivers.
2141
2142 If compiled as a module, the driver is named scx200.
2143
2144 config SCx200HR_TIMER
2145 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2146 depends on SCx200
2147 default y
2148 ---help---
2149 This driver provides a clocksource built upon the on-chip
2150 27MHz high-resolution timer. Its also a workaround for
2151 NSC Geode SC-1100's buggy TSC, which loses time when the
2152 processor goes idle (as is done by the scheduler). The
2153 other workaround is idle=poll boot option.
2154
2155 config OLPC
2156 bool "One Laptop Per Child support"
2157 depends on !X86_PAE
2158 select GPIOLIB
2159 select OF
2160 select OF_PROMTREE
2161 select IRQ_DOMAIN
2162 ---help---
2163 Add support for detecting the unique features of the OLPC
2164 XO hardware.
2165
2166 config OLPC_XO1_PM
2167 bool "OLPC XO-1 Power Management"
2168 depends on OLPC && MFD_CS5535 && PM_SLEEP
2169 select MFD_CORE
2170 ---help---
2171 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2172
2173 config OLPC_XO1_RTC
2174 bool "OLPC XO-1 Real Time Clock"
2175 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2176 ---help---
2177 Add support for the XO-1 real time clock, which can be used as a
2178 programmable wakeup source.
2179
2180 config OLPC_XO1_SCI
2181 bool "OLPC XO-1 SCI extras"
2182 depends on OLPC && OLPC_XO1_PM
2183 depends on INPUT=y
2184 select POWER_SUPPLY
2185 select GPIO_CS5535
2186 select MFD_CORE
2187 ---help---
2188 Add support for SCI-based features of the OLPC XO-1 laptop:
2189 - EC-driven system wakeups
2190 - Power button
2191 - Ebook switch
2192 - Lid switch
2193 - AC adapter status updates
2194 - Battery status updates
2195
2196 config OLPC_XO15_SCI
2197 bool "OLPC XO-1.5 SCI extras"
2198 depends on OLPC && ACPI
2199 select POWER_SUPPLY
2200 ---help---
2201 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2202 - EC-driven system wakeups
2203 - AC adapter status updates
2204 - Battery status updates
2205
2206 config ALIX
2207 bool "PCEngines ALIX System Support (LED setup)"
2208 select GPIOLIB
2209 ---help---
2210 This option enables system support for the PCEngines ALIX.
2211 At present this just sets up LEDs for GPIO control on
2212 ALIX2/3/6 boards. However, other system specific setup should
2213 get added here.
2214
2215 Note: You must still enable the drivers for GPIO and LED support
2216 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2217
2218 Note: You have to set alix.force=1 for boards with Award BIOS.
2219
2220 config NET5501
2221 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2222 select GPIOLIB
2223 ---help---
2224 This option enables system support for the Soekris Engineering net5501.
2225
2226 config GEOS
2227 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2228 select GPIOLIB
2229 depends on DMI
2230 ---help---
2231 This option enables system support for the Traverse Technologies GEOS.
2232
2233 config TS5500
2234 bool "Technologic Systems TS-5500 platform support"
2235 depends on MELAN
2236 select CHECK_SIGNATURE
2237 select NEW_LEDS
2238 select LEDS_CLASS
2239 ---help---
2240 This option enables system support for the Technologic Systems TS-5500.
2241
2242 endif # X86_32
2243
2244 config AMD_NB
2245 def_bool y
2246 depends on CPU_SUP_AMD && PCI
2247
2248 source "drivers/pcmcia/Kconfig"
2249
2250 source "drivers/pci/hotplug/Kconfig"
2251
2252 config RAPIDIO
2253 bool "RapidIO support"
2254 depends on PCI
2255 default n
2256 help
2257 If you say Y here, the kernel will include drivers and
2258 infrastructure code to support RapidIO interconnect devices.
2259
2260 source "drivers/rapidio/Kconfig"
2261
2262 endmenu
2263
2264
2265 menu "Executable file formats / Emulations"
2266
2267 source "fs/Kconfig.binfmt"
2268
2269 config IA32_EMULATION
2270 bool "IA32 Emulation"
2271 depends on X86_64
2272 select COMPAT_BINFMT_ELF
2273 select HAVE_UID16
2274 ---help---
2275 Include code to run legacy 32-bit programs under a
2276 64-bit kernel. You should likely turn this on, unless you're
2277 100% sure that you don't have any 32-bit programs left.
2278
2279 config IA32_AOUT
2280 tristate "IA32 a.out support"
2281 depends on IA32_EMULATION
2282 ---help---
2283 Support old a.out binaries in the 32bit emulation.
2284
2285 config X86_X32
2286 bool "x32 ABI for 64-bit mode"
2287 depends on X86_64 && IA32_EMULATION
2288 ---help---
2289 Include code to run binaries for the x32 native 32-bit ABI
2290 for 64-bit processors. An x32 process gets access to the
2291 full 64-bit register file and wide data path while leaving
2292 pointers at 32 bits for smaller memory footprint.
2293
2294 You will need a recent binutils (2.22 or later) with
2295 elf32_x86_64 support enabled to compile a kernel with this
2296 option set.
2297
2298 config COMPAT
2299 def_bool y
2300 depends on IA32_EMULATION || X86_X32
2301 select ARCH_WANT_OLD_COMPAT_IPC
2302
2303 if COMPAT
2304 config COMPAT_FOR_U64_ALIGNMENT
2305 def_bool y
2306
2307 config SYSVIPC_COMPAT
2308 def_bool y
2309 depends on SYSVIPC
2310
2311 config KEYS_COMPAT
2312 def_bool y
2313 depends on KEYS
2314 endif
2315
2316 endmenu
2317
2318
2319 config HAVE_ATOMIC_IOMAP
2320 def_bool y
2321 depends on X86_32
2322
2323 config HAVE_TEXT_POKE_SMP
2324 bool
2325 select STOP_MACHINE if SMP
2326
2327 config X86_DEV_DMA_OPS
2328 bool
2329 depends on X86_64 || STA2X11
2330
2331 config X86_DMA_REMAP
2332 bool
2333 depends on STA2X11
2334
2335 source "net/Kconfig"
2336
2337 source "drivers/Kconfig"
2338
2339 source "drivers/firmware/Kconfig"
2340
2341 source "fs/Kconfig"
2342
2343 source "arch/x86/Kconfig.debug"
2344
2345 source "security/Kconfig"
2346
2347 source "crypto/Kconfig"
2348
2349 source "arch/x86/kvm/Kconfig"
2350
2351 source "lib/Kconfig"
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