Kconfig 67 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819920020120220320420520620720820921021121221321421521621721821922022122222322422522622722822923023123223323423523623723823924024124224324424524624724824925025125225325425525625725825926026126226326426526626726826927027127227327427527627727827928028128228328428528628728828929029129229329429529629729829930030130230330430530630730830931031131231331431531631731831932032132232332432532632732832933033133233333433533633733833934034134234334434534634734834935035135235335435535635735835936036136236336436536636736836937037137237337437537637737837938038138238338438538638738838939039139239339439539639739839940040140240340440540640740840941041141241341441541641741841942042142242342442542642742842943043143243343443543643743843944044144244344444544644744844945045145245345445545645745845946046146246346446546646746846947047147247347447547647747847948048148248348448548648748848949049149249349449549649749849950050150250350450550650750850951051151251351451551651751851952052152252352452552652752852953053153253353453553653753853954054154254354454554654754854955055155255355455555655755855956056156256356456556656756856957057157257357457557657757857958058158258358458558658758858959059159259359459559659759859960060160260360460560660760860961061161261361461561661761861962062162262362462562662762862963063163263363463563663763863964064164264364464564664764864965065165265365465565665765865966066166266366466566666766866967067167267367467567667767867968068168268368468568668768868969069169269369469569669769869970070170270370470570670770870971071171271371471571671771871972072172272372472572672772872973073173273373473573673773873974074174274374474574674774874975075175275375475575675775875976076176276376476576676776876977077177277377477577677777877978078178278378478578678778878979079179279379479579679779879980080180280380480580680780880981081181281381481581681781881982082182282382482582682782882983083183283383483583683783883984084184284384484584684784884985085185285385485585685785885986086186286386486586686786886987087187287387487587687787887988088188288388488588688788888989089189289389489589689789889990090190290390490590690790890991091191291391491591691791891992092192292392492592692792892993093193293393493593693793893994094194294394494594694794894995095195295395495595695795895996096196296396496596696796896997097197297397497597697797897998098198298398498598698798898999099199299399499599699799899910001001100210031004100510061007100810091010101110121013101410151016101710181019102010211022102310241025102610271028102910301031103210331034103510361037103810391040104110421043104410451046104710481049105010511052105310541055105610571058105910601061106210631064106510661067106810691070107110721073107410751076107710781079108010811082108310841085108610871088108910901091109210931094109510961097109810991100110111021103110411051106110711081109111011111112111311141115111611171118111911201121112211231124112511261127112811291130113111321133113411351136113711381139114011411142114311441145114611471148114911501151115211531154115511561157115811591160116111621163116411651166116711681169117011711172117311741175117611771178117911801181118211831184118511861187118811891190119111921193119411951196119711981199120012011202120312041205120612071208120912101211121212131214121512161217121812191220122112221223122412251226122712281229123012311232123312341235123612371238123912401241124212431244124512461247124812491250125112521253125412551256125712581259126012611262126312641265126612671268126912701271127212731274127512761277127812791280128112821283128412851286128712881289129012911292129312941295129612971298129913001301130213031304130513061307130813091310131113121313131413151316131713181319132013211322132313241325132613271328132913301331133213331334133513361337133813391340134113421343134413451346134713481349135013511352135313541355135613571358135913601361136213631364136513661367136813691370137113721373137413751376137713781379138013811382138313841385138613871388138913901391139213931394139513961397139813991400140114021403140414051406140714081409141014111412141314141415141614171418141914201421142214231424142514261427142814291430143114321433143414351436143714381439144014411442144314441445144614471448144914501451145214531454145514561457145814591460146114621463146414651466146714681469147014711472147314741475147614771478147914801481148214831484148514861487148814891490149114921493149414951496149714981499150015011502150315041505150615071508150915101511151215131514151515161517151815191520152115221523152415251526152715281529153015311532153315341535153615371538153915401541154215431544154515461547154815491550155115521553155415551556155715581559156015611562156315641565156615671568156915701571157215731574157515761577157815791580158115821583158415851586158715881589159015911592159315941595159615971598159916001601160216031604160516061607160816091610161116121613161416151616161716181619162016211622162316241625162616271628162916301631163216331634163516361637163816391640164116421643164416451646164716481649165016511652165316541655165616571658165916601661166216631664166516661667166816691670167116721673167416751676167716781679168016811682168316841685168616871688168916901691169216931694169516961697169816991700170117021703170417051706170717081709171017111712171317141715171617171718171917201721172217231724172517261727172817291730173117321733173417351736173717381739174017411742174317441745174617471748174917501751175217531754175517561757175817591760176117621763176417651766176717681769177017711772177317741775177617771778177917801781178217831784178517861787178817891790179117921793179417951796179717981799180018011802180318041805180618071808180918101811181218131814181518161817181818191820182118221823182418251826182718281829183018311832183318341835183618371838183918401841184218431844184518461847184818491850185118521853185418551856185718581859186018611862186318641865186618671868186918701871187218731874187518761877187818791880188118821883188418851886188718881889189018911892189318941895189618971898189919001901190219031904190519061907190819091910191119121913191419151916191719181919192019211922192319241925192619271928192919301931193219331934193519361937193819391940194119421943194419451946194719481949195019511952195319541955195619571958195919601961196219631964196519661967196819691970197119721973197419751976197719781979198019811982198319841985198619871988198919901991199219931994199519961997199819992000200120022003200420052006200720082009201020112012201320142015201620172018201920202021202220232024202520262027202820292030203120322033203420352036203720382039204020412042204320442045204620472048204920502051205220532054205520562057205820592060206120622063206420652066206720682069207020712072207320742075207620772078207920802081208220832084208520862087208820892090209120922093209420952096
  1. # x86 configuration
  2. mainmenu "Linux Kernel Configuration for x86"
  3. # Select 32 or 64 bit
  4. config 64BIT
  5. bool "64-bit kernel" if ARCH = "x86"
  6. default ARCH = "x86_64"
  7. ---help---
  8. Say yes to build a 64-bit kernel - formerly known as x86_64
  9. Say no to build a 32-bit kernel - formerly known as i386
  10. config X86_32
  11. def_bool !64BIT
  12. config X86_64
  13. def_bool 64BIT
  14. ### Arch settings
  15. config X86
  16. def_bool y
  17. select HAVE_AOUT if X86_32
  18. select HAVE_READQ
  19. select HAVE_WRITEQ
  20. select HAVE_UNSTABLE_SCHED_CLOCK
  21. select HAVE_IDE
  22. select HAVE_OPROFILE
  23. select HAVE_IOREMAP_PROT
  24. select HAVE_KPROBES
  25. select ARCH_WANT_OPTIONAL_GPIOLIB
  26. select ARCH_WANT_FRAME_POINTERS
  27. select HAVE_DMA_ATTRS
  28. select HAVE_KRETPROBES
  29. select HAVE_FTRACE_MCOUNT_RECORD
  30. select HAVE_DYNAMIC_FTRACE
  31. select HAVE_FUNCTION_TRACER
  32. select HAVE_FUNCTION_GRAPH_TRACER
  33. select HAVE_FUNCTION_GRAPH_FP_TEST
  34. select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  35. select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  36. select HAVE_FTRACE_SYSCALLS
  37. select HAVE_KVM
  38. select HAVE_ARCH_KGDB
  39. select HAVE_ARCH_TRACEHOOK
  40. select HAVE_GENERIC_DMA_COHERENT if X86_32
  41. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  42. select USER_STACKTRACE_SUPPORT
  43. select HAVE_DMA_API_DEBUG
  44. select HAVE_KERNEL_GZIP
  45. select HAVE_KERNEL_BZIP2
  46. select HAVE_KERNEL_LZMA
  47. select HAVE_ARCH_KMEMCHECK
  48. config OUTPUT_FORMAT
  49. string
  50. default "elf32-i386" if X86_32
  51. default "elf64-x86-64" if X86_64
  52. config ARCH_DEFCONFIG
  53. string
  54. default "arch/x86/configs/i386_defconfig" if X86_32
  55. default "arch/x86/configs/x86_64_defconfig" if X86_64
  56. config GENERIC_TIME
  57. def_bool y
  58. config GENERIC_CMOS_UPDATE
  59. def_bool y
  60. config CLOCKSOURCE_WATCHDOG
  61. def_bool y
  62. config GENERIC_CLOCKEVENTS
  63. def_bool y
  64. config GENERIC_CLOCKEVENTS_BROADCAST
  65. def_bool y
  66. depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  67. config LOCKDEP_SUPPORT
  68. def_bool y
  69. config STACKTRACE_SUPPORT
  70. def_bool y
  71. config HAVE_LATENCYTOP_SUPPORT
  72. def_bool y
  73. config FAST_CMPXCHG_LOCAL
  74. bool
  75. default y
  76. config MMU
  77. def_bool y
  78. config ZONE_DMA
  79. def_bool y
  80. config SBUS
  81. bool
  82. config GENERIC_ISA_DMA
  83. def_bool y
  84. config GENERIC_IOMAP
  85. def_bool y
  86. config GENERIC_BUG
  87. def_bool y
  88. depends on BUG
  89. select GENERIC_BUG_RELATIVE_POINTERS if X86_64
  90. config GENERIC_BUG_RELATIVE_POINTERS
  91. bool
  92. config GENERIC_HWEIGHT
  93. def_bool y
  94. config GENERIC_GPIO
  95. bool
  96. config ARCH_MAY_HAVE_PC_FDC
  97. def_bool y
  98. config RWSEM_GENERIC_SPINLOCK
  99. def_bool !X86_XADD
  100. config RWSEM_XCHGADD_ALGORITHM
  101. def_bool X86_XADD
  102. config ARCH_HAS_CPU_IDLE_WAIT
  103. def_bool y
  104. config GENERIC_CALIBRATE_DELAY
  105. def_bool y
  106. config GENERIC_TIME_VSYSCALL
  107. bool
  108. default X86_64
  109. config ARCH_HAS_CPU_RELAX
  110. def_bool y
  111. config ARCH_HAS_DEFAULT_IDLE
  112. def_bool y
  113. config ARCH_HAS_CACHE_LINE_SIZE
  114. def_bool y
  115. config HAVE_SETUP_PER_CPU_AREA
  116. def_bool y
  117. config HAVE_DYNAMIC_PER_CPU_AREA
  118. def_bool y
  119. config HAVE_CPUMASK_OF_CPU_MAP
  120. def_bool X86_64_SMP
  121. config ARCH_HIBERNATION_POSSIBLE
  122. def_bool y
  123. config ARCH_SUSPEND_POSSIBLE
  124. def_bool y
  125. config ZONE_DMA32
  126. bool
  127. default X86_64
  128. config ARCH_POPULATES_NODE_MAP
  129. def_bool y
  130. config AUDIT_ARCH
  131. bool
  132. default X86_64
  133. config ARCH_SUPPORTS_OPTIMIZED_INLINING
  134. def_bool y
  135. config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  136. def_bool y
  137. # Use the generic interrupt handling code in kernel/irq/:
  138. config GENERIC_HARDIRQS
  139. bool
  140. default y
  141. config GENERIC_HARDIRQS_NO__DO_IRQ
  142. def_bool y
  143. config GENERIC_IRQ_PROBE
  144. bool
  145. default y
  146. config GENERIC_PENDING_IRQ
  147. bool
  148. depends on GENERIC_HARDIRQS && SMP
  149. default y
  150. config USE_GENERIC_SMP_HELPERS
  151. def_bool y
  152. depends on SMP
  153. config X86_32_SMP
  154. def_bool y
  155. depends on X86_32 && SMP
  156. config X86_64_SMP
  157. def_bool y
  158. depends on X86_64 && SMP
  159. config X86_HT
  160. bool
  161. depends on SMP
  162. default y
  163. config X86_TRAMPOLINE
  164. bool
  165. depends on SMP || (64BIT && ACPI_SLEEP)
  166. default y
  167. config X86_32_LAZY_GS
  168. def_bool y
  169. depends on X86_32 && !CC_STACKPROTECTOR
  170. config KTIME_SCALAR
  171. def_bool X86_32
  172. source "init/Kconfig"
  173. source "kernel/Kconfig.freezer"
  174. menu "Processor type and features"
  175. source "kernel/time/Kconfig"
  176. config SMP
  177. bool "Symmetric multi-processing support"
  178. ---help---
  179. This enables support for systems with more than one CPU. If you have
  180. a system with only one CPU, like most personal computers, say N. If
  181. you have a system with more than one CPU, say Y.
  182. If you say N here, the kernel will run on single and multiprocessor
  183. machines, but will use only one CPU of a multiprocessor machine. If
  184. you say Y here, the kernel will run on many, but not all,
  185. singleprocessor machines. On a singleprocessor machine, the kernel
  186. will run faster if you say N here.
  187. Note that if you say Y here and choose architecture "586" or
  188. "Pentium" under "Processor family", the kernel will not work on 486
  189. architectures. Similarly, multiprocessor kernels for the "PPro"
  190. architecture may not work on all Pentium based boards.
  191. People using multiprocessor machines who say Y here should also say
  192. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  193. Management" code will be disabled if you say Y here.
  194. See also <file:Documentation/i386/IO-APIC.txt>,
  195. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  196. <http://www.tldp.org/docs.html#howto>.
  197. If you don't know what to do here, say N.
  198. config X86_X2APIC
  199. bool "Support x2apic"
  200. depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
  201. ---help---
  202. This enables x2apic support on CPUs that have this feature.
  203. This allows 32-bit apic IDs (so it can support very large systems),
  204. and accesses the local apic via MSRs not via mmio.
  205. If you don't know what to do here, say N.
  206. config SPARSE_IRQ
  207. bool "Support sparse irq numbering"
  208. depends on PCI_MSI || HT_IRQ
  209. ---help---
  210. This enables support for sparse irqs. This is useful for distro
  211. kernels that want to define a high CONFIG_NR_CPUS value but still
  212. want to have low kernel memory footprint on smaller machines.
  213. ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
  214. out the irq_desc[] array in a more NUMA-friendly way. )
  215. If you don't know what to do here, say N.
  216. config NUMA_IRQ_DESC
  217. def_bool y
  218. depends on SPARSE_IRQ && NUMA
  219. config X86_MPPARSE
  220. bool "Enable MPS table" if ACPI
  221. default y
  222. depends on X86_LOCAL_APIC
  223. ---help---
  224. For old smp systems that do not have proper acpi support. Newer systems
  225. (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
  226. config X86_BIGSMP
  227. bool "Support for big SMP systems with more than 8 CPUs"
  228. depends on X86_32 && SMP
  229. ---help---
  230. This option is needed for the systems that have more than 8 CPUs
  231. if X86_32
  232. config X86_EXTENDED_PLATFORM
  233. bool "Support for extended (non-PC) x86 platforms"
  234. default y
  235. ---help---
  236. If you disable this option then the kernel will only support
  237. standard PC platforms. (which covers the vast majority of
  238. systems out there.)
  239. If you enable this option then you'll be able to select support
  240. for the following (non-PC) 32 bit x86 platforms:
  241. AMD Elan
  242. NUMAQ (IBM/Sequent)
  243. RDC R-321x SoC
  244. SGI 320/540 (Visual Workstation)
  245. Summit/EXA (IBM x440)
  246. Unisys ES7000 IA32 series
  247. If you have one of these systems, or if you want to build a
  248. generic distribution kernel, say Y here - otherwise say N.
  249. endif
  250. if X86_64
  251. config X86_EXTENDED_PLATFORM
  252. bool "Support for extended (non-PC) x86 platforms"
  253. default y
  254. ---help---
  255. If you disable this option then the kernel will only support
  256. standard PC platforms. (which covers the vast majority of
  257. systems out there.)
  258. If you enable this option then you'll be able to select support
  259. for the following (non-PC) 64 bit x86 platforms:
  260. ScaleMP vSMP
  261. SGI Ultraviolet
  262. If you have one of these systems, or if you want to build a
  263. generic distribution kernel, say Y here - otherwise say N.
  264. endif
  265. # This is an alphabetically sorted list of 64 bit extended platforms
  266. # Please maintain the alphabetic order if and when there are additions
  267. config X86_VSMP
  268. bool "ScaleMP vSMP"
  269. select PARAVIRT
  270. depends on X86_64 && PCI
  271. depends on X86_EXTENDED_PLATFORM
  272. ---help---
  273. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  274. supposed to run on these EM64T-based machines. Only choose this option
  275. if you have one of these machines.
  276. config X86_UV
  277. bool "SGI Ultraviolet"
  278. depends on X86_64
  279. depends on X86_EXTENDED_PLATFORM
  280. depends on NUMA
  281. depends on X86_X2APIC
  282. ---help---
  283. This option is needed in order to support SGI Ultraviolet systems.
  284. If you don't have one of these, you should say N here.
  285. # Following is an alphabetically sorted list of 32 bit extended platforms
  286. # Please maintain the alphabetic order if and when there are additions
  287. config X86_ELAN
  288. bool "AMD Elan"
  289. depends on X86_32
  290. depends on X86_EXTENDED_PLATFORM
  291. ---help---
  292. Select this for an AMD Elan processor.
  293. Do not use this option for K6/Athlon/Opteron processors!
  294. If unsure, choose "PC-compatible" instead.
  295. config X86_RDC321X
  296. bool "RDC R-321x SoC"
  297. depends on X86_32
  298. depends on X86_EXTENDED_PLATFORM
  299. select M486
  300. select X86_REBOOTFIXUPS
  301. ---help---
  302. This option is needed for RDC R-321x system-on-chip, also known
  303. as R-8610-(G).
  304. If you don't have one of these chips, you should say N here.
  305. config X86_32_NON_STANDARD
  306. bool "Support non-standard 32-bit SMP architectures"
  307. depends on X86_32 && SMP
  308. depends on X86_EXTENDED_PLATFORM
  309. ---help---
  310. This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
  311. subarchitectures. It is intended for a generic binary kernel.
  312. if you select them all, kernel will probe it one by one. and will
  313. fallback to default.
  314. # Alphabetically sorted list of Non standard 32 bit platforms
  315. config X86_NUMAQ
  316. bool "NUMAQ (IBM/Sequent)"
  317. depends on X86_32_NON_STANDARD
  318. select NUMA
  319. select X86_MPPARSE
  320. ---help---
  321. This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
  322. NUMA multiquad box. This changes the way that processors are
  323. bootstrapped, and uses Clustered Logical APIC addressing mode instead
  324. of Flat Logical. You will need a new lynxer.elf file to flash your
  325. firmware with - send email to <Martin.Bligh@us.ibm.com>.
  326. config X86_VISWS
  327. bool "SGI 320/540 (Visual Workstation)"
  328. depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
  329. depends on X86_32_NON_STANDARD
  330. ---help---
  331. The SGI Visual Workstation series is an IA32-based workstation
  332. based on SGI systems chips with some legacy PC hardware attached.
  333. Say Y here to create a kernel to run on the SGI 320 or 540.
  334. A kernel compiled for the Visual Workstation will run on general
  335. PCs as well. See <file:Documentation/sgi-visws.txt> for details.
  336. config X86_SUMMIT
  337. bool "Summit/EXA (IBM x440)"
  338. depends on X86_32_NON_STANDARD
  339. ---help---
  340. This option is needed for IBM systems that use the Summit/EXA chipset.
  341. In particular, it is needed for the x440.
  342. config X86_ES7000
  343. bool "Unisys ES7000 IA32 series"
  344. depends on X86_32_NON_STANDARD && X86_BIGSMP
  345. ---help---
  346. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  347. supposed to run on an IA32-based Unisys ES7000 system.
  348. config SCHED_OMIT_FRAME_POINTER
  349. def_bool y
  350. prompt "Single-depth WCHAN output"
  351. depends on X86
  352. ---help---
  353. Calculate simpler /proc/<PID>/wchan values. If this option
  354. is disabled then wchan values will recurse back to the
  355. caller function. This provides more accurate wchan values,
  356. at the expense of slightly more scheduling overhead.
  357. If in doubt, say "Y".
  358. menuconfig PARAVIRT_GUEST
  359. bool "Paravirtualized guest support"
  360. ---help---
  361. Say Y here to get to see options related to running Linux under
  362. various hypervisors. This option alone does not add any kernel code.
  363. If you say N, all options in this submenu will be skipped and disabled.
  364. if PARAVIRT_GUEST
  365. source "arch/x86/xen/Kconfig"
  366. config VMI
  367. bool "VMI Guest support"
  368. select PARAVIRT
  369. depends on X86_32
  370. ---help---
  371. VMI provides a paravirtualized interface to the VMware ESX server
  372. (it could be used by other hypervisors in theory too, but is not
  373. at the moment), by linking the kernel to a GPL-ed ROM module
  374. provided by the hypervisor.
  375. config KVM_CLOCK
  376. bool "KVM paravirtualized clock"
  377. select PARAVIRT
  378. select PARAVIRT_CLOCK
  379. ---help---
  380. Turning on this option will allow you to run a paravirtualized clock
  381. when running over the KVM hypervisor. Instead of relying on a PIT
  382. (or probably other) emulation by the underlying device model, the host
  383. provides the guest with timing infrastructure such as time of day, and
  384. system time
  385. config KVM_GUEST
  386. bool "KVM Guest support"
  387. select PARAVIRT
  388. ---help---
  389. This option enables various optimizations for running under the KVM
  390. hypervisor.
  391. source "arch/x86/lguest/Kconfig"
  392. config PARAVIRT
  393. bool "Enable paravirtualization code"
  394. ---help---
  395. This changes the kernel so it can modify itself when it is run
  396. under a hypervisor, potentially improving performance significantly
  397. over full virtualization. However, when run without a hypervisor
  398. the kernel is theoretically slower and slightly larger.
  399. config PARAVIRT_SPINLOCKS
  400. bool "Paravirtualization layer for spinlocks"
  401. depends on PARAVIRT && SMP && EXPERIMENTAL
  402. ---help---
  403. Paravirtualized spinlocks allow a pvops backend to replace the
  404. spinlock implementation with something virtualization-friendly
  405. (for example, block the virtual CPU rather than spinning).
  406. Unfortunately the downside is an up to 5% performance hit on
  407. native kernels, with various workloads.
  408. If you are unsure how to answer this question, answer N.
  409. config PARAVIRT_CLOCK
  410. bool
  411. default n
  412. endif
  413. config PARAVIRT_DEBUG
  414. bool "paravirt-ops debugging"
  415. depends on PARAVIRT && DEBUG_KERNEL
  416. ---help---
  417. Enable to debug paravirt_ops internals. Specifically, BUG if
  418. a paravirt_op is missing when it is called.
  419. config MEMTEST
  420. bool "Memtest"
  421. ---help---
  422. This option adds a kernel parameter 'memtest', which allows memtest
  423. to be set.
  424. memtest=0, mean disabled; -- default
  425. memtest=1, mean do 1 test pattern;
  426. ...
  427. memtest=4, mean do 4 test patterns.
  428. If you are unsure how to answer this question, answer N.
  429. config X86_SUMMIT_NUMA
  430. def_bool y
  431. depends on X86_32 && NUMA && X86_32_NON_STANDARD
  432. config X86_CYCLONE_TIMER
  433. def_bool y
  434. depends on X86_32_NON_STANDARD
  435. source "arch/x86/Kconfig.cpu"
  436. config HPET_TIMER
  437. def_bool X86_64
  438. prompt "HPET Timer Support" if X86_32
  439. ---help---
  440. Use the IA-PC HPET (High Precision Event Timer) to manage
  441. time in preference to the PIT and RTC, if a HPET is
  442. present.
  443. HPET is the next generation timer replacing legacy 8254s.
  444. The HPET provides a stable time base on SMP
  445. systems, unlike the TSC, but it is more expensive to access,
  446. as it is off-chip. You can find the HPET spec at
  447. <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
  448. You can safely choose Y here. However, HPET will only be
  449. activated if the platform and the BIOS support this feature.
  450. Otherwise the 8254 will be used for timing services.
  451. Choose N to continue using the legacy 8254 timer.
  452. config HPET_EMULATE_RTC
  453. def_bool y
  454. depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
  455. # Mark as embedded because too many people got it wrong.
  456. # The code disables itself when not needed.
  457. config DMI
  458. default y
  459. bool "Enable DMI scanning" if EMBEDDED
  460. ---help---
  461. Enabled scanning of DMI to identify machine quirks. Say Y
  462. here unless you have verified that your setup is not
  463. affected by entries in the DMI blacklist. Required by PNP
  464. BIOS code.
  465. config GART_IOMMU
  466. bool "GART IOMMU support" if EMBEDDED
  467. default y
  468. select SWIOTLB
  469. select AGP
  470. depends on X86_64 && PCI
  471. ---help---
  472. Support for full DMA access of devices with 32bit memory access only
  473. on systems with more than 3GB. This is usually needed for USB,
  474. sound, many IDE/SATA chipsets and some other devices.
  475. Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
  476. based hardware IOMMU and a software bounce buffer based IOMMU used
  477. on Intel systems and as fallback.
  478. The code is only active when needed (enough memory and limited
  479. device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
  480. too.
  481. config CALGARY_IOMMU
  482. bool "IBM Calgary IOMMU support"
  483. select SWIOTLB
  484. depends on X86_64 && PCI && EXPERIMENTAL
  485. ---help---
  486. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  487. systems. Needed to run systems with more than 3GB of memory
  488. properly with 32-bit PCI devices that do not support DAC
  489. (Double Address Cycle). Calgary also supports bus level
  490. isolation, where all DMAs pass through the IOMMU. This
  491. prevents them from going anywhere except their intended
  492. destination. This catches hard-to-find kernel bugs and
  493. mis-behaving drivers and devices that do not use the DMA-API
  494. properly to set up their DMA buffers. The IOMMU can be
  495. turned off at boot time with the iommu=off parameter.
  496. Normally the kernel will make the right choice by itself.
  497. If unsure, say Y.
  498. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  499. def_bool y
  500. prompt "Should Calgary be enabled by default?"
  501. depends on CALGARY_IOMMU
  502. ---help---
  503. Should Calgary be enabled by default? if you choose 'y', Calgary
  504. will be used (if it exists). If you choose 'n', Calgary will not be
  505. used even if it exists. If you choose 'n' and would like to use
  506. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  507. If unsure, say Y.
  508. config AMD_IOMMU
  509. bool "AMD IOMMU support"
  510. select SWIOTLB
  511. select PCI_MSI
  512. depends on X86_64 && PCI && ACPI
  513. ---help---
  514. With this option you can enable support for AMD IOMMU hardware in
  515. your system. An IOMMU is a hardware component which provides
  516. remapping of DMA memory accesses from devices. With an AMD IOMMU you
  517. can isolate the the DMA memory of different devices and protect the
  518. system from misbehaving device drivers or hardware.
  519. You can find out if your system has an AMD IOMMU if you look into
  520. your BIOS for an option to enable it or if you have an IVRS ACPI
  521. table.
  522. config AMD_IOMMU_STATS
  523. bool "Export AMD IOMMU statistics to debugfs"
  524. depends on AMD_IOMMU
  525. select DEBUG_FS
  526. ---help---
  527. This option enables code in the AMD IOMMU driver to collect various
  528. statistics about whats happening in the driver and exports that
  529. information to userspace via debugfs.
  530. If unsure, say N.
  531. # need this always selected by IOMMU for the VIA workaround
  532. config SWIOTLB
  533. def_bool y if X86_64
  534. ---help---
  535. Support for software bounce buffers used on x86-64 systems
  536. which don't have a hardware IOMMU (e.g. the current generation
  537. of Intel's x86-64 CPUs). Using this PCI devices which can only
  538. access 32-bits of memory can be used on systems with more than
  539. 3 GB of memory. If unsure, say Y.
  540. config IOMMU_HELPER
  541. def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
  542. config IOMMU_API
  543. def_bool (AMD_IOMMU || DMAR)
  544. config MAXSMP
  545. bool "Configure Maximum number of SMP Processors and NUMA Nodes"
  546. depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
  547. select CPUMASK_OFFSTACK
  548. default n
  549. ---help---
  550. Configure maximum number of CPUS and NUMA Nodes for this architecture.
  551. If unsure, say N.
  552. config NR_CPUS
  553. int "Maximum number of CPUs" if SMP && !MAXSMP
  554. range 2 8 if SMP && X86_32 && !X86_BIGSMP
  555. range 2 512 if SMP && !MAXSMP
  556. default "1" if !SMP
  557. default "4096" if MAXSMP
  558. default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
  559. default "8" if SMP
  560. ---help---
  561. This allows you to specify the maximum number of CPUs which this
  562. kernel will support. The maximum supported value is 512 and the
  563. minimum value which makes sense is 2.
  564. This is purely to save memory - each supported CPU adds
  565. approximately eight kilobytes to the kernel image.
  566. config SCHED_SMT
  567. bool "SMT (Hyperthreading) scheduler support"
  568. depends on X86_HT
  569. ---help---
  570. SMT scheduler support improves the CPU scheduler's decision making
  571. when dealing with Intel Pentium 4 chips with HyperThreading at a
  572. cost of slightly increased overhead in some places. If unsure say
  573. N here.
  574. config SCHED_MC
  575. def_bool y
  576. prompt "Multi-core scheduler support"
  577. depends on X86_HT
  578. ---help---
  579. Multi-core scheduler support improves the CPU scheduler's decision
  580. making when dealing with multi-core CPU chips at a cost of slightly
  581. increased overhead in some places. If unsure say N here.
  582. source "kernel/Kconfig.preempt"
  583. config X86_UP_APIC
  584. bool "Local APIC support on uniprocessors"
  585. depends on X86_32 && !SMP && !X86_32_NON_STANDARD
  586. ---help---
  587. A local APIC (Advanced Programmable Interrupt Controller) is an
  588. integrated interrupt controller in the CPU. If you have a single-CPU
  589. system which has a processor with a local APIC, you can say Y here to
  590. enable and use it. If you say Y here even though your machine doesn't
  591. have a local APIC, then the kernel will still run with no slowdown at
  592. all. The local APIC supports CPU-generated self-interrupts (timer,
  593. performance counters), and the NMI watchdog which detects hard
  594. lockups.
  595. config X86_UP_IOAPIC
  596. bool "IO-APIC support on uniprocessors"
  597. depends on X86_UP_APIC
  598. ---help---
  599. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  600. SMP-capable replacement for PC-style interrupt controllers. Most
  601. SMP systems and many recent uniprocessor systems have one.
  602. If you have a single-CPU system with an IO-APIC, you can say Y here
  603. to use it. If you say Y here even though your machine doesn't have
  604. an IO-APIC, then the kernel will still run with no slowdown at all.
  605. config X86_LOCAL_APIC
  606. def_bool y
  607. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  608. select HAVE_PERF_COUNTERS if (!M386 && !M486)
  609. config X86_IO_APIC
  610. def_bool y
  611. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  612. config X86_VISWS_APIC
  613. def_bool y
  614. depends on X86_32 && X86_VISWS
  615. config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  616. bool "Reroute for broken boot IRQs"
  617. default n
  618. depends on X86_IO_APIC
  619. ---help---
  620. This option enables a workaround that fixes a source of
  621. spurious interrupts. This is recommended when threaded
  622. interrupt handling is used on systems where the generation of
  623. superfluous "boot interrupts" cannot be disabled.
  624. Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
  625. entry in the chipset's IO-APIC is masked (as, e.g. the RT
  626. kernel does during interrupt handling). On chipsets where this
  627. boot IRQ generation cannot be disabled, this workaround keeps
  628. the original IRQ line masked so that only the equivalent "boot
  629. IRQ" is delivered to the CPUs. The workaround also tells the
  630. kernel to set up the IRQ handler on the boot IRQ line. In this
  631. way only one interrupt is delivered to the kernel. Otherwise
  632. the spurious second interrupt may cause the kernel to bring
  633. down (vital) interrupt lines.
  634. Only affects "broken" chipsets. Interrupt sharing may be
  635. increased on these systems.
  636. config X86_MCE
  637. bool "Machine Check Exception"
  638. ---help---
  639. Machine Check Exception support allows the processor to notify the
  640. kernel if it detects a problem (e.g. overheating, component failure).
  641. The action the kernel takes depends on the severity of the problem,
  642. ranging from a warning message on the console, to halting the machine.
  643. Your processor must be a Pentium or newer to support this - check the
  644. flags in /proc/cpuinfo for mce. Note that some older Pentium systems
  645. have a design flaw which leads to false MCE events - hence MCE is
  646. disabled on all P5 processors, unless explicitly enabled with "mce"
  647. as a boot argument. Similarly, if MCE is built in and creates a
  648. problem on some new non-standard machine, you can boot with "nomce"
  649. to disable it. MCE support simply ignores non-MCE processors like
  650. the 386 and 486, so nearly everyone can say Y here.
  651. config X86_OLD_MCE
  652. depends on X86_32 && X86_MCE
  653. bool "Use legacy machine check code (will go away)"
  654. default n
  655. select X86_ANCIENT_MCE
  656. ---help---
  657. Use the old i386 machine check code. This is merely intended for
  658. testing in a transition period. Try this if you run into any machine
  659. check related software problems, but report the problem to
  660. linux-kernel. When in doubt say no.
  661. config X86_NEW_MCE
  662. depends on X86_MCE
  663. bool
  664. default y if (!X86_OLD_MCE && X86_32) || X86_64
  665. config X86_MCE_INTEL
  666. def_bool y
  667. prompt "Intel MCE features"
  668. depends on X86_NEW_MCE && X86_LOCAL_APIC
  669. ---help---
  670. Additional support for intel specific MCE features such as
  671. the thermal monitor.
  672. config X86_MCE_AMD
  673. def_bool y
  674. prompt "AMD MCE features"
  675. depends on X86_NEW_MCE && X86_LOCAL_APIC
  676. ---help---
  677. Additional support for AMD specific MCE features such as
  678. the DRAM Error Threshold.
  679. config X86_ANCIENT_MCE
  680. def_bool n
  681. depends on X86_32
  682. prompt "Support for old Pentium 5 / WinChip machine checks"
  683. ---help---
  684. Include support for machine check handling on old Pentium 5 or WinChip
  685. systems. These typically need to be enabled explicitely on the command
  686. line.
  687. config X86_MCE_THRESHOLD
  688. depends on X86_MCE_AMD || X86_MCE_INTEL
  689. bool
  690. default y
  691. config X86_MCE_INJECT
  692. depends on X86_NEW_MCE
  693. tristate "Machine check injector support"
  694. ---help---
  695. Provide support for injecting machine checks for testing purposes.
  696. If you don't know what a machine check is and you don't do kernel
  697. QA it is safe to say n.
  698. config X86_MCE_NONFATAL
  699. tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
  700. depends on X86_OLD_MCE
  701. ---help---
  702. Enabling this feature starts a timer that triggers every 5 seconds which
  703. will look at the machine check registers to see if anything happened.
  704. Non-fatal problems automatically get corrected (but still logged).
  705. Disable this if you don't want to see these messages.
  706. Seeing the messages this option prints out may be indicative of dying
  707. or out-of-spec (ie, overclocked) hardware.
  708. This option only does something on certain CPUs.
  709. (AMD Athlon/Duron and Intel Pentium 4)
  710. config X86_MCE_P4THERMAL
  711. bool "check for P4 thermal throttling interrupt."
  712. depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP)
  713. ---help---
  714. Enabling this feature will cause a message to be printed when the P4
  715. enters thermal throttling.
  716. config X86_THERMAL_VECTOR
  717. def_bool y
  718. depends on X86_MCE_P4THERMAL || X86_MCE_INTEL
  719. config VM86
  720. bool "Enable VM86 support" if EMBEDDED
  721. default y
  722. depends on X86_32
  723. ---help---
  724. This option is required by programs like DOSEMU to run 16-bit legacy
  725. code on X86 processors. It also may be needed by software like
  726. XFree86 to initialize some video cards via BIOS. Disabling this
  727. option saves about 6k.
  728. config TOSHIBA
  729. tristate "Toshiba Laptop support"
  730. depends on X86_32
  731. ---help---
  732. This adds a driver to safely access the System Management Mode of
  733. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  734. not work on models with a Phoenix BIOS. The System Management Mode
  735. is used to set the BIOS and power saving options on Toshiba portables.
  736. For information on utilities to make use of this driver see the
  737. Toshiba Linux utilities web site at:
  738. <http://www.buzzard.org.uk/toshiba/>.
  739. Say Y if you intend to run this kernel on a Toshiba portable.
  740. Say N otherwise.
  741. config I8K
  742. tristate "Dell laptop support"
  743. ---help---
  744. This adds a driver to safely access the System Management Mode
  745. of the CPU on the Dell Inspiron 8000. The System Management Mode
  746. is used to read cpu temperature and cooling fan status and to
  747. control the fans on the I8K portables.
  748. This driver has been tested only on the Inspiron 8000 but it may
  749. also work with other Dell laptops. You can force loading on other
  750. models by passing the parameter `force=1' to the module. Use at
  751. your own risk.
  752. For information on utilities to make use of this driver see the
  753. I8K Linux utilities web site at:
  754. <http://people.debian.org/~dz/i8k/>
  755. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  756. Say N otherwise.
  757. config X86_REBOOTFIXUPS
  758. bool "Enable X86 board specific fixups for reboot"
  759. depends on X86_32
  760. ---help---
  761. This enables chipset and/or board specific fixups to be done
  762. in order to get reboot to work correctly. This is only needed on
  763. some combinations of hardware and BIOS. The symptom, for which
  764. this config is intended, is when reboot ends with a stalled/hung
  765. system.
  766. Currently, the only fixup is for the Geode machines using
  767. CS5530A and CS5536 chipsets and the RDC R-321x SoC.
  768. Say Y if you want to enable the fixup. Currently, it's safe to
  769. enable this option even if you don't need it.
  770. Say N otherwise.
  771. config MICROCODE
  772. tristate "/dev/cpu/microcode - microcode support"
  773. select FW_LOADER
  774. ---help---
  775. If you say Y here, you will be able to update the microcode on
  776. certain Intel and AMD processors. The Intel support is for the
  777. IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
  778. Pentium 4, Xeon etc. The AMD support is for family 0x10 and
  779. 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
  780. You will obviously need the actual microcode binary data itself
  781. which is not shipped with the Linux kernel.
  782. This option selects the general module only, you need to select
  783. at least one vendor specific module as well.
  784. To compile this driver as a module, choose M here: the
  785. module will be called microcode.
  786. config MICROCODE_INTEL
  787. bool "Intel microcode patch loading support"
  788. depends on MICROCODE
  789. default MICROCODE
  790. select FW_LOADER
  791. ---help---
  792. This options enables microcode patch loading support for Intel
  793. processors.
  794. For latest news and information on obtaining all the required
  795. Intel ingredients for this driver, check:
  796. <http://www.urbanmyth.org/microcode/>.
  797. config MICROCODE_AMD
  798. bool "AMD microcode patch loading support"
  799. depends on MICROCODE
  800. select FW_LOADER
  801. ---help---
  802. If you select this option, microcode patch loading support for AMD
  803. processors will be enabled.
  804. config MICROCODE_OLD_INTERFACE
  805. def_bool y
  806. depends on MICROCODE
  807. config X86_MSR
  808. tristate "/dev/cpu/*/msr - Model-specific register support"
  809. ---help---
  810. This device gives privileged processes access to the x86
  811. Model-Specific Registers (MSRs). It is a character device with
  812. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  813. MSR accesses are directed to a specific CPU on multi-processor
  814. systems.
  815. config X86_CPUID
  816. tristate "/dev/cpu/*/cpuid - CPU information support"
  817. ---help---
  818. This device gives processes access to the x86 CPUID instruction to
  819. be executed on a specific processor. It is a character device
  820. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  821. /dev/cpu/31/cpuid.
  822. config X86_CPU_DEBUG
  823. tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
  824. ---help---
  825. If you select this option, this will provide various x86 CPUs
  826. information through debugfs.
  827. choice
  828. prompt "High Memory Support"
  829. default HIGHMEM4G if !X86_NUMAQ
  830. default HIGHMEM64G if X86_NUMAQ
  831. depends on X86_32
  832. config NOHIGHMEM
  833. bool "off"
  834. depends on !X86_NUMAQ
  835. ---help---
  836. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  837. However, the address space of 32-bit x86 processors is only 4
  838. Gigabytes large. That means that, if you have a large amount of
  839. physical memory, not all of it can be "permanently mapped" by the
  840. kernel. The physical memory that's not permanently mapped is called
  841. "high memory".
  842. If you are compiling a kernel which will never run on a machine with
  843. more than 1 Gigabyte total physical RAM, answer "off" here (default
  844. choice and suitable for most users). This will result in a "3GB/1GB"
  845. split: 3GB are mapped so that each process sees a 3GB virtual memory
  846. space and the remaining part of the 4GB virtual memory space is used
  847. by the kernel to permanently map as much physical memory as
  848. possible.
  849. If the machine has between 1 and 4 Gigabytes physical RAM, then
  850. answer "4GB" here.
  851. If more than 4 Gigabytes is used then answer "64GB" here. This
  852. selection turns Intel PAE (Physical Address Extension) mode on.
  853. PAE implements 3-level paging on IA32 processors. PAE is fully
  854. supported by Linux, PAE mode is implemented on all recent Intel
  855. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  856. then the kernel will not boot on CPUs that don't support PAE!
  857. The actual amount of total physical memory will either be
  858. auto detected or can be forced by using a kernel command line option
  859. such as "mem=256M". (Try "man bootparam" or see the documentation of
  860. your boot loader (lilo or loadlin) about how to pass options to the
  861. kernel at boot time.)
  862. If unsure, say "off".
  863. config HIGHMEM4G
  864. bool "4GB"
  865. depends on !X86_NUMAQ
  866. ---help---
  867. Select this if you have a 32-bit processor and between 1 and 4
  868. gigabytes of physical RAM.
  869. config HIGHMEM64G
  870. bool "64GB"
  871. depends on !M386 && !M486
  872. select X86_PAE
  873. ---help---
  874. Select this if you have a 32-bit processor and more than 4
  875. gigabytes of physical RAM.
  876. endchoice
  877. choice
  878. depends on EXPERIMENTAL
  879. prompt "Memory split" if EMBEDDED
  880. default VMSPLIT_3G
  881. depends on X86_32
  882. ---help---
  883. Select the desired split between kernel and user memory.
  884. If the address range available to the kernel is less than the
  885. physical memory installed, the remaining memory will be available
  886. as "high memory". Accessing high memory is a little more costly
  887. than low memory, as it needs to be mapped into the kernel first.
  888. Note that increasing the kernel address space limits the range
  889. available to user programs, making the address space there
  890. tighter. Selecting anything other than the default 3G/1G split
  891. will also likely make your kernel incompatible with binary-only
  892. kernel modules.
  893. If you are not absolutely sure what you are doing, leave this
  894. option alone!
  895. config VMSPLIT_3G
  896. bool "3G/1G user/kernel split"
  897. config VMSPLIT_3G_OPT
  898. depends on !X86_PAE
  899. bool "3G/1G user/kernel split (for full 1G low memory)"
  900. config VMSPLIT_2G
  901. bool "2G/2G user/kernel split"
  902. config VMSPLIT_2G_OPT
  903. depends on !X86_PAE
  904. bool "2G/2G user/kernel split (for full 2G low memory)"
  905. config VMSPLIT_1G
  906. bool "1G/3G user/kernel split"
  907. endchoice
  908. config PAGE_OFFSET
  909. hex
  910. default 0xB0000000 if VMSPLIT_3G_OPT
  911. default 0x80000000 if VMSPLIT_2G
  912. default 0x78000000 if VMSPLIT_2G_OPT
  913. default 0x40000000 if VMSPLIT_1G
  914. default 0xC0000000
  915. depends on X86_32
  916. config HIGHMEM
  917. def_bool y
  918. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  919. config X86_PAE
  920. bool "PAE (Physical Address Extension) Support"
  921. depends on X86_32 && !HIGHMEM4G
  922. ---help---
  923. PAE is required for NX support, and furthermore enables
  924. larger swapspace support for non-overcommit purposes. It
  925. has the cost of more pagetable lookup overhead, and also
  926. consumes more pagetable space per process.
  927. config ARCH_PHYS_ADDR_T_64BIT
  928. def_bool X86_64 || X86_PAE
  929. config DIRECT_GBPAGES
  930. bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
  931. default y
  932. depends on X86_64
  933. ---help---
  934. Allow the kernel linear mapping to use 1GB pages on CPUs that
  935. support it. This can improve the kernel's performance a tiny bit by
  936. reducing TLB pressure. If in doubt, say "Y".
  937. # Common NUMA Features
  938. config NUMA
  939. bool "Numa Memory Allocation and Scheduler Support"
  940. depends on SMP
  941. depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
  942. default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
  943. ---help---
  944. Enable NUMA (Non Uniform Memory Access) support.
  945. The kernel will try to allocate memory used by a CPU on the
  946. local memory controller of the CPU and add some more
  947. NUMA awareness to the kernel.
  948. For 64-bit this is recommended if the system is Intel Core i7
  949. (or later), AMD Opteron, or EM64T NUMA.
  950. For 32-bit this is only needed on (rare) 32-bit-only platforms
  951. that support NUMA topologies, such as NUMAQ / Summit, or if you
  952. boot a 32-bit kernel on a 64-bit NUMA platform.
  953. Otherwise, you should say N.
  954. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  955. depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  956. config K8_NUMA
  957. def_bool y
  958. prompt "Old style AMD Opteron NUMA detection"
  959. depends on X86_64 && NUMA && PCI
  960. ---help---
  961. Enable K8 NUMA node topology detection. You should say Y here if
  962. you have a multi processor AMD K8 system. This uses an old
  963. method to read the NUMA configuration directly from the builtin
  964. Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
  965. instead, which also takes priority if both are compiled in.
  966. config X86_64_ACPI_NUMA
  967. def_bool y
  968. prompt "ACPI NUMA detection"
  969. depends on X86_64 && NUMA && ACPI && PCI
  970. select ACPI_NUMA
  971. ---help---
  972. Enable ACPI SRAT based node topology detection.
  973. # Some NUMA nodes have memory ranges that span
  974. # other nodes. Even though a pfn is valid and
  975. # between a node's start and end pfns, it may not
  976. # reside on that node. See memmap_init_zone()
  977. # for details.
  978. config NODES_SPAN_OTHER_NODES
  979. def_bool y
  980. depends on X86_64_ACPI_NUMA
  981. config NUMA_EMU
  982. bool "NUMA emulation"
  983. depends on X86_64 && NUMA
  984. ---help---
  985. Enable NUMA emulation. A flat machine will be split
  986. into virtual nodes when booted with "numa=fake=N", where N is the
  987. number of nodes. This is only useful for debugging.
  988. config NODES_SHIFT
  989. int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
  990. range 1 9
  991. default "9" if MAXSMP
  992. default "6" if X86_64
  993. default "4" if X86_NUMAQ
  994. default "3"
  995. depends on NEED_MULTIPLE_NODES
  996. ---help---
  997. Specify the maximum number of NUMA Nodes available on the target
  998. system. Increases memory reserved to accommodate various tables.
  999. config HAVE_ARCH_BOOTMEM
  1000. def_bool y
  1001. depends on X86_32 && NUMA
  1002. config ARCH_HAVE_MEMORY_PRESENT
  1003. def_bool y
  1004. depends on X86_32 && DISCONTIGMEM
  1005. config NEED_NODE_MEMMAP_SIZE
  1006. def_bool y
  1007. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  1008. config HAVE_ARCH_ALLOC_REMAP
  1009. def_bool y
  1010. depends on X86_32 && NUMA
  1011. config ARCH_FLATMEM_ENABLE
  1012. def_bool y
  1013. depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
  1014. config ARCH_DISCONTIGMEM_ENABLE
  1015. def_bool y
  1016. depends on NUMA && X86_32
  1017. config ARCH_DISCONTIGMEM_DEFAULT
  1018. def_bool y
  1019. depends on NUMA && X86_32
  1020. config ARCH_SPARSEMEM_DEFAULT
  1021. def_bool y
  1022. depends on X86_64
  1023. config ARCH_SPARSEMEM_ENABLE
  1024. def_bool y
  1025. depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
  1026. select SPARSEMEM_STATIC if X86_32
  1027. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  1028. config ARCH_SELECT_MEMORY_MODEL
  1029. def_bool y
  1030. depends on ARCH_SPARSEMEM_ENABLE
  1031. config ARCH_MEMORY_PROBE
  1032. def_bool X86_64
  1033. depends on MEMORY_HOTPLUG
  1034. source "mm/Kconfig"
  1035. config HIGHPTE
  1036. bool "Allocate 3rd-level pagetables from highmem"
  1037. depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
  1038. ---help---
  1039. The VM uses one page table entry for each page of physical memory.
  1040. For systems with a lot of RAM, this can be wasteful of precious
  1041. low memory. Setting this option will put user-space page table
  1042. entries in high memory.
  1043. config X86_CHECK_BIOS_CORRUPTION
  1044. bool "Check for low memory corruption"
  1045. ---help---
  1046. Periodically check for memory corruption in low memory, which
  1047. is suspected to be caused by BIOS. Even when enabled in the
  1048. configuration, it is disabled at runtime. Enable it by
  1049. setting "memory_corruption_check=1" on the kernel command
  1050. line. By default it scans the low 64k of memory every 60
  1051. seconds; see the memory_corruption_check_size and
  1052. memory_corruption_check_period parameters in
  1053. Documentation/kernel-parameters.txt to adjust this.
  1054. When enabled with the default parameters, this option has
  1055. almost no overhead, as it reserves a relatively small amount
  1056. of memory and scans it infrequently. It both detects corruption
  1057. and prevents it from affecting the running system.
  1058. It is, however, intended as a diagnostic tool; if repeatable
  1059. BIOS-originated corruption always affects the same memory,
  1060. you can use memmap= to prevent the kernel from using that
  1061. memory.
  1062. config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
  1063. bool "Set the default setting of memory_corruption_check"
  1064. depends on X86_CHECK_BIOS_CORRUPTION
  1065. default y
  1066. ---help---
  1067. Set whether the default state of memory_corruption_check is
  1068. on or off.
  1069. config X86_RESERVE_LOW_64K
  1070. bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
  1071. default y
  1072. ---help---
  1073. Reserve the first 64K of physical RAM on BIOSes that are known
  1074. to potentially corrupt that memory range. A numbers of BIOSes are
  1075. known to utilize this area during suspend/resume, so it must not
  1076. be used by the kernel.
  1077. Set this to N if you are absolutely sure that you trust the BIOS
  1078. to get all its memory reservations and usages right.
  1079. If you have doubts about the BIOS (e.g. suspend/resume does not
  1080. work or there's kernel crashes after certain hardware hotplug
  1081. events) and it's not AMI or Phoenix, then you might want to enable
  1082. X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
  1083. corruption patterns.
  1084. Say Y if unsure.
  1085. config MATH_EMULATION
  1086. bool
  1087. prompt "Math emulation" if X86_32
  1088. ---help---
  1089. Linux can emulate a math coprocessor (used for floating point
  1090. operations) if you don't have one. 486DX and Pentium processors have
  1091. a math coprocessor built in, 486SX and 386 do not, unless you added
  1092. a 487DX or 387, respectively. (The messages during boot time can
  1093. give you some hints here ["man dmesg"].) Everyone needs either a
  1094. coprocessor or this emulation.
  1095. If you don't have a math coprocessor, you need to say Y here; if you
  1096. say Y here even though you have a coprocessor, the coprocessor will
  1097. be used nevertheless. (This behavior can be changed with the kernel
  1098. command line option "no387", which comes handy if your coprocessor
  1099. is broken. Try "man bootparam" or see the documentation of your boot
  1100. loader (lilo or loadlin) about how to pass options to the kernel at
  1101. boot time.) This means that it is a good idea to say Y here if you
  1102. intend to use this kernel on different machines.
  1103. More information about the internals of the Linux math coprocessor
  1104. emulation can be found in <file:arch/x86/math-emu/README>.
  1105. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  1106. kernel, it won't hurt.
  1107. config MTRR
  1108. bool "MTRR (Memory Type Range Register) support"
  1109. ---help---
  1110. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  1111. the Memory Type Range Registers (MTRRs) may be used to control
  1112. processor access to memory ranges. This is most useful if you have
  1113. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  1114. allows bus write transfers to be combined into a larger transfer
  1115. before bursting over the PCI/AGP bus. This can increase performance
  1116. of image write operations 2.5 times or more. Saying Y here creates a
  1117. /proc/mtrr file which may be used to manipulate your processor's
  1118. MTRRs. Typically the X server should use this.
  1119. This code has a reasonably generic interface so that similar
  1120. control registers on other processors can be easily supported
  1121. as well:
  1122. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  1123. Registers (ARRs) which provide a similar functionality to MTRRs. For
  1124. these, the ARRs are used to emulate the MTRRs.
  1125. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  1126. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  1127. write-combining. All of these processors are supported by this code
  1128. and it makes sense to say Y here if you have one of them.
  1129. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  1130. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  1131. can lead to all sorts of problems, so it's good to say Y here.
  1132. You can safely say Y even if your machine doesn't have MTRRs, you'll
  1133. just add about 9 KB to your kernel.
  1134. See <file:Documentation/x86/mtrr.txt> for more information.
  1135. config MTRR_SANITIZER
  1136. def_bool y
  1137. prompt "MTRR cleanup support"
  1138. depends on MTRR
  1139. ---help---
  1140. Convert MTRR layout from continuous to discrete, so X drivers can
  1141. add writeback entries.
  1142. Can be disabled with disable_mtrr_cleanup on the kernel command line.
  1143. The largest mtrr entry size for a continuous block can be set with
  1144. mtrr_chunk_size.
  1145. If unsure, say Y.
  1146. config MTRR_SANITIZER_ENABLE_DEFAULT
  1147. int "MTRR cleanup enable value (0-1)"
  1148. range 0 1
  1149. default "0"
  1150. depends on MTRR_SANITIZER
  1151. ---help---
  1152. Enable mtrr cleanup default value
  1153. config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
  1154. int "MTRR cleanup spare reg num (0-7)"
  1155. range 0 7
  1156. default "1"
  1157. depends on MTRR_SANITIZER
  1158. ---help---
  1159. mtrr cleanup spare entries default, it can be changed via
  1160. mtrr_spare_reg_nr=N on the kernel command line.
  1161. config X86_PAT
  1162. bool
  1163. prompt "x86 PAT support"
  1164. depends on MTRR
  1165. ---help---
  1166. Use PAT attributes to setup page level cache control.
  1167. PATs are the modern equivalents of MTRRs and are much more
  1168. flexible than MTRRs.
  1169. Say N here if you see bootup problems (boot crash, boot hang,
  1170. spontaneous reboots) or a non-working video driver.
  1171. If unsure, say Y.
  1172. config EFI
  1173. bool "EFI runtime service support"
  1174. depends on ACPI
  1175. ---help---
  1176. This enables the kernel to use EFI runtime services that are
  1177. available (such as the EFI variable services).
  1178. This option is only useful on systems that have EFI firmware.
  1179. In addition, you should use the latest ELILO loader available
  1180. at <http://elilo.sourceforge.net> in order to take advantage
  1181. of EFI runtime services. However, even with this option, the
  1182. resultant kernel should continue to boot on existing non-EFI
  1183. platforms.
  1184. config SECCOMP
  1185. def_bool y
  1186. prompt "Enable seccomp to safely compute untrusted bytecode"
  1187. ---help---
  1188. This kernel feature is useful for number crunching applications
  1189. that may need to compute untrusted bytecode during their
  1190. execution. By using pipes or other transports made available to
  1191. the process as file descriptors supporting the read/write
  1192. syscalls, it's possible to isolate those applications in
  1193. their own address space using seccomp. Once seccomp is
  1194. enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
  1195. and the task is only allowed to execute a few safe syscalls
  1196. defined by each seccomp mode.
  1197. If unsure, say Y. Only embedded should say N here.
  1198. config CC_STACKPROTECTOR_ALL
  1199. bool
  1200. config CC_STACKPROTECTOR
  1201. bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
  1202. select CC_STACKPROTECTOR_ALL
  1203. ---help---
  1204. This option turns on the -fstack-protector GCC feature. This
  1205. feature puts, at the beginning of functions, a canary value on
  1206. the stack just before the return address, and validates
  1207. the value just before actually returning. Stack based buffer
  1208. overflows (that need to overwrite this return address) now also
  1209. overwrite the canary, which gets detected and the attack is then
  1210. neutralized via a kernel panic.
  1211. This feature requires gcc version 4.2 or above, or a distribution
  1212. gcc with the feature backported. Older versions are automatically
  1213. detected and for those versions, this configuration option is
  1214. ignored. (and a warning is printed during bootup)
  1215. source kernel/Kconfig.hz
  1216. config KEXEC
  1217. bool "kexec system call"
  1218. ---help---
  1219. kexec is a system call that implements the ability to shutdown your
  1220. current kernel, and to start another kernel. It is like a reboot
  1221. but it is independent of the system firmware. And like a reboot
  1222. you can start any kernel with it, not just Linux.
  1223. The name comes from the similarity to the exec system call.
  1224. It is an ongoing process to be certain the hardware in a machine
  1225. is properly shutdown, so do not be surprised if this code does not
  1226. initially work for you. It may help to enable device hotplugging
  1227. support. As of this writing the exact hardware interface is
  1228. strongly in flux, so no good recommendation can be made.
  1229. config CRASH_DUMP
  1230. bool "kernel crash dumps"
  1231. depends on X86_64 || (X86_32 && HIGHMEM)
  1232. ---help---
  1233. Generate crash dump after being started by kexec.
  1234. This should be normally only set in special crash dump kernels
  1235. which are loaded in the main kernel with kexec-tools into
  1236. a specially reserved region and then later executed after
  1237. a crash by kdump/kexec. The crash dump kernel must be compiled
  1238. to a memory address not used by the main kernel or BIOS using
  1239. PHYSICAL_START, or it must be built as a relocatable image
  1240. (CONFIG_RELOCATABLE=y).
  1241. For more details see Documentation/kdump/kdump.txt
  1242. config KEXEC_JUMP
  1243. bool "kexec jump (EXPERIMENTAL)"
  1244. depends on EXPERIMENTAL
  1245. depends on KEXEC && HIBERNATION
  1246. ---help---
  1247. Jump between original kernel and kexeced kernel and invoke
  1248. code in physical address mode via KEXEC
  1249. config PHYSICAL_START
  1250. hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
  1251. default "0x1000000"
  1252. ---help---
  1253. This gives the physical address where the kernel is loaded.
  1254. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  1255. bzImage will decompress itself to above physical address and
  1256. run from there. Otherwise, bzImage will run from the address where
  1257. it has been loaded by the boot loader and will ignore above physical
  1258. address.
  1259. In normal kdump cases one does not have to set/change this option
  1260. as now bzImage can be compiled as a completely relocatable image
  1261. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  1262. address. This option is mainly useful for the folks who don't want
  1263. to use a bzImage for capturing the crash dump and want to use a
  1264. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  1265. to be specifically compiled to run from a specific memory area
  1266. (normally a reserved region) and this option comes handy.
  1267. So if you are using bzImage for capturing the crash dump,
  1268. leave the value here unchanged to 0x1000000 and set
  1269. CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
  1270. for capturing the crash dump change this value to start of
  1271. the reserved region. In other words, it can be set based on
  1272. the "X" value as specified in the "crashkernel=YM@XM"
  1273. command line boot parameter passed to the panic-ed
  1274. kernel. Please take a look at Documentation/kdump/kdump.txt
  1275. for more details about crash dumps.
  1276. Usage of bzImage for capturing the crash dump is recommended as
  1277. one does not have to build two kernels. Same kernel can be used
  1278. as production kernel and capture kernel. Above option should have
  1279. gone away after relocatable bzImage support is introduced. But it
  1280. is present because there are users out there who continue to use
  1281. vmlinux for dump capture. This option should go away down the
  1282. line.
  1283. Don't change this unless you know what you are doing.
  1284. config RELOCATABLE
  1285. bool "Build a relocatable kernel"
  1286. default y
  1287. ---help---
  1288. This builds a kernel image that retains relocation information
  1289. so it can be loaded someplace besides the default 1MB.
  1290. The relocations tend to make the kernel binary about 10% larger,
  1291. but are discarded at runtime.
  1292. One use is for the kexec on panic case where the recovery kernel
  1293. must live at a different physical address than the primary
  1294. kernel.
  1295. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  1296. it has been loaded at and the compile time physical address
  1297. (CONFIG_PHYSICAL_START) is ignored.
  1298. # Relocation on x86-32 needs some additional build support
  1299. config X86_NEED_RELOCS
  1300. def_bool y
  1301. depends on X86_32 && RELOCATABLE
  1302. config PHYSICAL_ALIGN
  1303. hex
  1304. prompt "Alignment value to which kernel should be aligned" if X86_32
  1305. default "0x1000000"
  1306. range 0x2000 0x1000000
  1307. ---help---
  1308. This value puts the alignment restrictions on physical address
  1309. where kernel is loaded and run from. Kernel is compiled for an
  1310. address which meets above alignment restriction.
  1311. If bootloader loads the kernel at a non-aligned address and
  1312. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  1313. address aligned to above value and run from there.
  1314. If bootloader loads the kernel at a non-aligned address and
  1315. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  1316. load address and decompress itself to the address it has been
  1317. compiled for and run from there. The address for which kernel is
  1318. compiled already meets above alignment restrictions. Hence the
  1319. end result is that kernel runs from a physical address meeting
  1320. above alignment restrictions.
  1321. Don't change this unless you know what you are doing.
  1322. config HOTPLUG_CPU
  1323. bool "Support for hot-pluggable CPUs"
  1324. depends on SMP && HOTPLUG
  1325. ---help---
  1326. Say Y here to allow turning CPUs off and on. CPUs can be
  1327. controlled through /sys/devices/system/cpu.
  1328. ( Note: power management support will enable this option
  1329. automatically on SMP systems. )
  1330. Say N if you want to disable CPU hotplug.
  1331. config COMPAT_VDSO
  1332. def_bool y
  1333. prompt "Compat VDSO support"
  1334. depends on X86_32 || IA32_EMULATION
  1335. ---help---
  1336. Map the 32-bit VDSO to the predictable old-style address too.
  1337. ---help---
  1338. Say N here if you are running a sufficiently recent glibc
  1339. version (2.3.3 or later), to remove the high-mapped
  1340. VDSO mapping and to exclusively use the randomized VDSO.
  1341. If unsure, say Y.
  1342. config CMDLINE_BOOL
  1343. bool "Built-in kernel command line"
  1344. default n
  1345. ---help---
  1346. Allow for specifying boot arguments to the kernel at
  1347. build time. On some systems (e.g. embedded ones), it is
  1348. necessary or convenient to provide some or all of the
  1349. kernel boot arguments with the kernel itself (that is,
  1350. to not rely on the boot loader to provide them.)
  1351. To compile command line arguments into the kernel,
  1352. set this option to 'Y', then fill in the
  1353. the boot arguments in CONFIG_CMDLINE.
  1354. Systems with fully functional boot loaders (i.e. non-embedded)
  1355. should leave this option set to 'N'.
  1356. config CMDLINE
  1357. string "Built-in kernel command string"
  1358. depends on CMDLINE_BOOL
  1359. default ""
  1360. ---help---
  1361. Enter arguments here that should be compiled into the kernel
  1362. image and used at boot time. If the boot loader provides a
  1363. command line at boot time, it is appended to this string to
  1364. form the full kernel command line, when the system boots.
  1365. However, you can use the CONFIG_CMDLINE_OVERRIDE option to
  1366. change this behavior.
  1367. In most cases, the command line (whether built-in or provided
  1368. by the boot loader) should specify the device for the root
  1369. file system.
  1370. config CMDLINE_OVERRIDE
  1371. bool "Built-in command line overrides boot loader arguments"
  1372. default n
  1373. depends on CMDLINE_BOOL
  1374. ---help---
  1375. Set this option to 'Y' to have the kernel ignore the boot loader
  1376. command line, and use ONLY the built-in command line.
  1377. This is used to work around broken boot loaders. This should
  1378. be set to 'N' under normal conditions.
  1379. endmenu
  1380. config ARCH_ENABLE_MEMORY_HOTPLUG
  1381. def_bool y
  1382. depends on X86_64 || (X86_32 && HIGHMEM)
  1383. config ARCH_ENABLE_MEMORY_HOTREMOVE
  1384. def_bool y
  1385. depends on MEMORY_HOTPLUG
  1386. config HAVE_ARCH_EARLY_PFN_TO_NID
  1387. def_bool X86_64
  1388. depends on NUMA
  1389. menu "Power management and ACPI options"
  1390. config ARCH_HIBERNATION_HEADER
  1391. def_bool y
  1392. depends on X86_64 && HIBERNATION
  1393. source "kernel/power/Kconfig"
  1394. source "drivers/acpi/Kconfig"
  1395. config X86_APM_BOOT
  1396. bool
  1397. default y
  1398. depends on APM || APM_MODULE
  1399. menuconfig APM
  1400. tristate "APM (Advanced Power Management) BIOS support"
  1401. depends on X86_32 && PM_SLEEP
  1402. ---help---
  1403. APM is a BIOS specification for saving power using several different
  1404. techniques. This is mostly useful for battery powered laptops with
  1405. APM compliant BIOSes. If you say Y here, the system time will be
  1406. reset after a RESUME operation, the /proc/apm device will provide
  1407. battery status information, and user-space programs will receive
  1408. notification of APM "events" (e.g. battery status change).
  1409. If you select "Y" here, you can disable actual use of the APM
  1410. BIOS by passing the "apm=off" option to the kernel at boot time.
  1411. Note that the APM support is almost completely disabled for
  1412. machines with more than one CPU.
  1413. In order to use APM, you will need supporting software. For location
  1414. and more information, read <file:Documentation/power/pm.txt> and the
  1415. Battery Powered Linux mini-HOWTO, available from
  1416. <http://www.tldp.org/docs.html#howto>.
  1417. This driver does not spin down disk drives (see the hdparm(8)
  1418. manpage ("man 8 hdparm") for that), and it doesn't turn off
  1419. VESA-compliant "green" monitors.
  1420. This driver does not support the TI 4000M TravelMate and the ACER
  1421. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  1422. desktop machines also don't have compliant BIOSes, and this driver
  1423. may cause those machines to panic during the boot phase.
  1424. Generally, if you don't have a battery in your machine, there isn't
  1425. much point in using this driver and you should say N. If you get
  1426. random kernel OOPSes or reboots that don't seem to be related to
  1427. anything, try disabling/enabling this option (or disabling/enabling
  1428. APM in your BIOS).
  1429. Some other things you should try when experiencing seemingly random,
  1430. "weird" problems:
  1431. 1) make sure that you have enough swap space and that it is
  1432. enabled.
  1433. 2) pass the "no-hlt" option to the kernel
  1434. 3) switch on floating point emulation in the kernel and pass
  1435. the "no387" option to the kernel
  1436. 4) pass the "floppy=nodma" option to the kernel
  1437. 5) pass the "mem=4M" option to the kernel (thereby disabling
  1438. all but the first 4 MB of RAM)
  1439. 6) make sure that the CPU is not over clocked.
  1440. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  1441. 8) disable the cache from your BIOS settings
  1442. 9) install a fan for the video card or exchange video RAM
  1443. 10) install a better fan for the CPU
  1444. 11) exchange RAM chips
  1445. 12) exchange the motherboard.
  1446. To compile this driver as a module, choose M here: the
  1447. module will be called apm.
  1448. if APM
  1449. config APM_IGNORE_USER_SUSPEND
  1450. bool "Ignore USER SUSPEND"
  1451. ---help---
  1452. This option will ignore USER SUSPEND requests. On machines with a
  1453. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  1454. series notebooks, it is necessary to say Y because of a BIOS bug.
  1455. config APM_DO_ENABLE
  1456. bool "Enable PM at boot time"
  1457. ---help---
  1458. Enable APM features at boot time. From page 36 of the APM BIOS
  1459. specification: "When disabled, the APM BIOS does not automatically
  1460. power manage devices, enter the Standby State, enter the Suspend
  1461. State, or take power saving steps in response to CPU Idle calls."
  1462. This driver will make CPU Idle calls when Linux is idle (unless this
  1463. feature is turned off -- see "Do CPU IDLE calls", below). This
  1464. should always save battery power, but more complicated APM features
  1465. will be dependent on your BIOS implementation. You may need to turn
  1466. this option off if your computer hangs at boot time when using APM
  1467. support, or if it beeps continuously instead of suspending. Turn
  1468. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  1469. T400CDT. This is off by default since most machines do fine without
  1470. this feature.
  1471. config APM_CPU_IDLE
  1472. bool "Make CPU Idle calls when idle"
  1473. ---help---
  1474. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  1475. On some machines, this can activate improved power savings, such as
  1476. a slowed CPU clock rate, when the machine is idle. These idle calls
  1477. are made after the idle loop has run for some length of time (e.g.,
  1478. 333 mS). On some machines, this will cause a hang at boot time or
  1479. whenever the CPU becomes idle. (On machines with more than one CPU,
  1480. this option does nothing.)
  1481. config APM_DISPLAY_BLANK
  1482. bool "Enable console blanking using APM"
  1483. ---help---
  1484. Enable console blanking using the APM. Some laptops can use this to
  1485. turn off the LCD backlight when the screen blanker of the Linux
  1486. virtual console blanks the screen. Note that this is only used by
  1487. the virtual console screen blanker, and won't turn off the backlight
  1488. when using the X Window system. This also doesn't have anything to
  1489. do with your VESA-compliant power-saving monitor. Further, this
  1490. option doesn't work for all laptops -- it might not turn off your
  1491. backlight at all, or it might print a lot of errors to the console,
  1492. especially if you are using gpm.
  1493. config APM_ALLOW_INTS
  1494. bool "Allow interrupts during APM BIOS calls"
  1495. ---help---
  1496. Normally we disable external interrupts while we are making calls to
  1497. the APM BIOS as a measure to lessen the effects of a badly behaving
  1498. BIOS implementation. The BIOS should reenable interrupts if it
  1499. needs to. Unfortunately, some BIOSes do not -- especially those in
  1500. many of the newer IBM Thinkpads. If you experience hangs when you
  1501. suspend, try setting this to Y. Otherwise, say N.
  1502. endif # APM
  1503. source "arch/x86/kernel/cpu/cpufreq/Kconfig"
  1504. source "drivers/cpuidle/Kconfig"
  1505. source "drivers/idle/Kconfig"
  1506. endmenu
  1507. menu "Bus options (PCI etc.)"
  1508. config PCI
  1509. bool "PCI support"
  1510. default y
  1511. select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
  1512. ---help---
  1513. Find out whether you have a PCI motherboard. PCI is the name of a
  1514. bus system, i.e. the way the CPU talks to the other stuff inside
  1515. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  1516. VESA. If you have PCI, say Y, otherwise N.
  1517. choice
  1518. prompt "PCI access mode"
  1519. depends on X86_32 && PCI
  1520. default PCI_GOANY
  1521. ---help---
  1522. On PCI systems, the BIOS can be used to detect the PCI devices and
  1523. determine their configuration. However, some old PCI motherboards
  1524. have BIOS bugs and may crash if this is done. Also, some embedded
  1525. PCI-based systems don't have any BIOS at all. Linux can also try to
  1526. detect the PCI hardware directly without using the BIOS.
  1527. With this option, you can specify how Linux should detect the
  1528. PCI devices. If you choose "BIOS", the BIOS will be used,
  1529. if you choose "Direct", the BIOS won't be used, and if you
  1530. choose "MMConfig", then PCI Express MMCONFIG will be used.
  1531. If you choose "Any", the kernel will try MMCONFIG, then the
  1532. direct access method and falls back to the BIOS if that doesn't
  1533. work. If unsure, go with the default, which is "Any".
  1534. config PCI_GOBIOS
  1535. bool "BIOS"
  1536. config PCI_GOMMCONFIG
  1537. bool "MMConfig"
  1538. config PCI_GODIRECT
  1539. bool "Direct"
  1540. config PCI_GOOLPC
  1541. bool "OLPC"
  1542. depends on OLPC
  1543. config PCI_GOANY
  1544. bool "Any"
  1545. endchoice
  1546. config PCI_BIOS
  1547. def_bool y
  1548. depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
  1549. # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
  1550. config PCI_DIRECT
  1551. def_bool y
  1552. depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
  1553. config PCI_MMCONFIG
  1554. def_bool y
  1555. depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
  1556. config PCI_OLPC
  1557. def_bool y
  1558. depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
  1559. config PCI_DOMAINS
  1560. def_bool y
  1561. depends on PCI
  1562. config PCI_MMCONFIG
  1563. bool "Support mmconfig PCI config space access"
  1564. depends on X86_64 && PCI && ACPI
  1565. config DMAR
  1566. bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
  1567. depends on PCI_MSI && ACPI && EXPERIMENTAL
  1568. help
  1569. DMA remapping (DMAR) devices support enables independent address
  1570. translations for Direct Memory Access (DMA) from devices.
  1571. These DMA remapping devices are reported via ACPI tables
  1572. and include PCI device scope covered by these DMA
  1573. remapping devices.
  1574. config DMAR_DEFAULT_ON
  1575. def_bool y
  1576. prompt "Enable DMA Remapping Devices by default"
  1577. depends on DMAR
  1578. help
  1579. Selecting this option will enable a DMAR device at boot time if
  1580. one is found. If this option is not selected, DMAR support can
  1581. be enabled by passing intel_iommu=on to the kernel. It is
  1582. recommended you say N here while the DMAR code remains
  1583. experimental.
  1584. config DMAR_GFX_WA
  1585. def_bool y
  1586. prompt "Support for Graphics workaround"
  1587. depends on DMAR
  1588. ---help---
  1589. Current Graphics drivers tend to use physical address
  1590. for DMA and avoid using DMA APIs. Setting this config
  1591. option permits the IOMMU driver to set a unity map for
  1592. all the OS-visible memory. Hence the driver can continue
  1593. to use physical addresses for DMA.
  1594. config DMAR_FLOPPY_WA
  1595. def_bool y
  1596. depends on DMAR
  1597. ---help---
  1598. Floppy disk drivers are know to bypass DMA API calls
  1599. thereby failing to work when IOMMU is enabled. This
  1600. workaround will setup a 1:1 mapping for the first
  1601. 16M to make floppy (an ISA device) work.
  1602. config INTR_REMAP
  1603. bool "Support for Interrupt Remapping (EXPERIMENTAL)"
  1604. depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
  1605. ---help---
  1606. Supports Interrupt remapping for IO-APIC and MSI devices.
  1607. To use x2apic mode in the CPU's which support x2APIC enhancements or
  1608. to support platforms with CPU's having > 8 bit APIC ID, say Y.
  1609. source "drivers/pci/pcie/Kconfig"
  1610. source "drivers/pci/Kconfig"
  1611. # x86_64 have no ISA slots, but do have ISA-style DMA.
  1612. config ISA_DMA_API
  1613. def_bool y
  1614. if X86_32
  1615. config ISA
  1616. bool "ISA support"
  1617. ---help---
  1618. Find out whether you have ISA slots on your motherboard. ISA is the
  1619. name of a bus system, i.e. the way the CPU talks to the other stuff
  1620. inside your box. Other bus systems are PCI, EISA, MicroChannel
  1621. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  1622. newer boards don't support it. If you have ISA, say Y, otherwise N.
  1623. config EISA
  1624. bool "EISA support"
  1625. depends on ISA
  1626. ---help---
  1627. The Extended Industry Standard Architecture (EISA) bus was
  1628. developed as an open alternative to the IBM MicroChannel bus.
  1629. The EISA bus provided some of the features of the IBM MicroChannel
  1630. bus while maintaining backward compatibility with cards made for
  1631. the older ISA bus. The EISA bus saw limited use between 1988 and
  1632. 1995 when it was made obsolete by the PCI bus.
  1633. Say Y here if you are building a kernel for an EISA-based machine.
  1634. Otherwise, say N.
  1635. source "drivers/eisa/Kconfig"
  1636. config MCA
  1637. bool "MCA support"
  1638. ---help---
  1639. MicroChannel Architecture is found in some IBM PS/2 machines and
  1640. laptops. It is a bus system similar to PCI or ISA. See
  1641. <file:Documentation/mca.txt> (and especially the web page given
  1642. there) before attempting to build an MCA bus kernel.
  1643. source "drivers/mca/Kconfig"
  1644. config SCx200
  1645. tristate "NatSemi SCx200 support"
  1646. ---help---
  1647. This provides basic support for National Semiconductor's
  1648. (now AMD's) Geode processors. The driver probes for the
  1649. PCI-IDs of several on-chip devices, so its a good dependency
  1650. for other scx200_* drivers.
  1651. If compiled as a module, the driver is named scx200.
  1652. config SCx200HR_TIMER
  1653. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  1654. depends on SCx200 && GENERIC_TIME
  1655. default y
  1656. ---help---
  1657. This driver provides a clocksource built upon the on-chip
  1658. 27MHz high-resolution timer. Its also a workaround for
  1659. NSC Geode SC-1100's buggy TSC, which loses time when the
  1660. processor goes idle (as is done by the scheduler). The
  1661. other workaround is idle=poll boot option.
  1662. config GEODE_MFGPT_TIMER
  1663. def_bool y
  1664. prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
  1665. depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
  1666. ---help---
  1667. This driver provides a clock event source based on the MFGPT
  1668. timer(s) in the CS5535 and CS5536 companion chip for the geode.
  1669. MFGPTs have a better resolution and max interval than the
  1670. generic PIT, and are suitable for use as high-res timers.
  1671. config OLPC
  1672. bool "One Laptop Per Child support"
  1673. default n
  1674. ---help---
  1675. Add support for detecting the unique features of the OLPC
  1676. XO hardware.
  1677. endif # X86_32
  1678. config K8_NB
  1679. def_bool y
  1680. depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
  1681. source "drivers/pcmcia/Kconfig"
  1682. source "drivers/pci/hotplug/Kconfig"
  1683. endmenu
  1684. menu "Executable file formats / Emulations"
  1685. source "fs/Kconfig.binfmt"
  1686. config IA32_EMULATION
  1687. bool "IA32 Emulation"
  1688. depends on X86_64
  1689. select COMPAT_BINFMT_ELF
  1690. ---help---
  1691. Include code to run 32-bit programs under a 64-bit kernel. You should
  1692. likely turn this on, unless you're 100% sure that you don't have any
  1693. 32-bit programs left.
  1694. config IA32_AOUT
  1695. tristate "IA32 a.out support"
  1696. depends on IA32_EMULATION
  1697. ---help---
  1698. Support old a.out binaries in the 32bit emulation.
  1699. config COMPAT
  1700. def_bool y
  1701. depends on IA32_EMULATION
  1702. config COMPAT_FOR_U64_ALIGNMENT
  1703. def_bool COMPAT
  1704. depends on X86_64
  1705. config SYSVIPC_COMPAT
  1706. def_bool y
  1707. depends on COMPAT && SYSVIPC
  1708. endmenu
  1709. config HAVE_ATOMIC_IOMAP
  1710. def_bool y
  1711. depends on X86_32
  1712. source "net/Kconfig"
  1713. source "drivers/Kconfig"
  1714. source "drivers/firmware/Kconfig"
  1715. source "fs/Kconfig"
  1716. source "arch/x86/Kconfig.debug"
  1717. source "security/Kconfig"
  1718. source "crypto/Kconfig"
  1719. source "arch/x86/kvm/Kconfig"
  1720. source "lib/Kconfig"