Kconfig 69 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819920020120220320420520620720820921021121221321421521621721821922022122222322422522622722822923023123223323423523623723823924024124224324424524624724824925025125225325425525625725825926026126226326426526626726826927027127227327427527627727827928028128228328428528628728828929029129229329429529629729829930030130230330430530630730830931031131231331431531631731831932032132232332432532632732832933033133233333433533633733833934034134234334434534634734834935035135235335435535635735835936036136236336436536636736836937037137237337437537637737837938038138238338438538638738838939039139239339439539639739839940040140240340440540640740840941041141241341441541641741841942042142242342442542642742842943043143243343443543643743843944044144244344444544644744844945045145245345445545645745845946046146246346446546646746846947047147247347447547647747847948048148248348448548648748848949049149249349449549649749849950050150250350450550650750850951051151251351451551651751851952052152252352452552652752852953053153253353453553653753853954054154254354454554654754854955055155255355455555655755855956056156256356456556656756856957057157257357457557657757857958058158258358458558658758858959059159259359459559659759859960060160260360460560660760860961061161261361461561661761861962062162262362462562662762862963063163263363463563663763863964064164264364464564664764864965065165265365465565665765865966066166266366466566666766866967067167267367467567667767867968068168268368468568668768868969069169269369469569669769869970070170270370470570670770870971071171271371471571671771871972072172272372472572672772872973073173273373473573673773873974074174274374474574674774874975075175275375475575675775875976076176276376476576676776876977077177277377477577677777877978078178278378478578678778878979079179279379479579679779879980080180280380480580680780880981081181281381481581681781881982082182282382482582682782882983083183283383483583683783883984084184284384484584684784884985085185285385485585685785885986086186286386486586686786886987087187287387487587687787887988088188288388488588688788888989089189289389489589689789889990090190290390490590690790890991091191291391491591691791891992092192292392492592692792892993093193293393493593693793893994094194294394494594694794894995095195295395495595695795895996096196296396496596696796896997097197297397497597697797897998098198298398498598698798898999099199299399499599699799899910001001100210031004100510061007100810091010101110121013101410151016101710181019102010211022102310241025102610271028102910301031103210331034103510361037103810391040104110421043104410451046104710481049105010511052105310541055105610571058105910601061106210631064106510661067106810691070107110721073107410751076107710781079108010811082108310841085108610871088108910901091109210931094109510961097109810991100110111021103110411051106110711081109111011111112111311141115111611171118111911201121112211231124112511261127112811291130113111321133113411351136113711381139114011411142114311441145114611471148114911501151115211531154115511561157115811591160116111621163116411651166116711681169117011711172117311741175117611771178117911801181118211831184118511861187118811891190119111921193119411951196119711981199120012011202120312041205120612071208120912101211121212131214121512161217121812191220122112221223122412251226122712281229123012311232123312341235123612371238123912401241124212431244124512461247124812491250125112521253125412551256125712581259126012611262126312641265126612671268126912701271127212731274127512761277127812791280128112821283128412851286128712881289129012911292129312941295129612971298129913001301130213031304130513061307130813091310131113121313131413151316131713181319132013211322132313241325132613271328132913301331133213331334133513361337133813391340134113421343134413451346134713481349135013511352135313541355135613571358135913601361136213631364136513661367136813691370137113721373137413751376137713781379138013811382138313841385138613871388138913901391139213931394139513961397139813991400140114021403140414051406140714081409141014111412141314141415141614171418141914201421142214231424142514261427142814291430143114321433143414351436143714381439144014411442144314441445144614471448144914501451145214531454145514561457145814591460146114621463146414651466146714681469147014711472147314741475147614771478147914801481148214831484148514861487148814891490149114921493149414951496149714981499150015011502150315041505150615071508150915101511151215131514151515161517151815191520152115221523152415251526152715281529153015311532153315341535153615371538153915401541154215431544154515461547154815491550155115521553155415551556155715581559156015611562156315641565156615671568156915701571157215731574157515761577157815791580158115821583158415851586158715881589159015911592159315941595159615971598159916001601160216031604160516061607160816091610161116121613161416151616161716181619162016211622162316241625162616271628162916301631163216331634163516361637163816391640164116421643164416451646164716481649165016511652165316541655165616571658165916601661166216631664166516661667166816691670167116721673167416751676167716781679168016811682168316841685168616871688168916901691169216931694169516961697169816991700170117021703170417051706170717081709171017111712171317141715171617171718171917201721172217231724172517261727172817291730173117321733173417351736173717381739174017411742174317441745174617471748174917501751175217531754175517561757175817591760176117621763176417651766176717681769177017711772177317741775177617771778177917801781178217831784178517861787178817891790179117921793179417951796179717981799180018011802180318041805180618071808180918101811181218131814181518161817181818191820182118221823182418251826182718281829183018311832183318341835183618371838183918401841184218431844184518461847184818491850185118521853185418551856185718581859186018611862186318641865186618671868186918701871187218731874187518761877187818791880188118821883188418851886188718881889189018911892189318941895189618971898189919001901190219031904190519061907190819091910191119121913191419151916191719181919192019211922192319241925192619271928192919301931193219331934193519361937193819391940194119421943194419451946194719481949195019511952195319541955195619571958195919601961196219631964196519661967196819691970197119721973197419751976197719781979198019811982198319841985198619871988198919901991199219931994199519961997199819992000200120022003200420052006200720082009201020112012201320142015201620172018201920202021202220232024202520262027202820292030203120322033203420352036203720382039204020412042204320442045204620472048204920502051205220532054205520562057205820592060206120622063206420652066206720682069207020712072207320742075207620772078207920802081208220832084208520862087208820892090209120922093209420952096209720982099210021012102210321042105210621072108210921102111211221132114211521162117211821192120212121222123212421252126212721282129213021312132213321342135213621372138213921402141214221432144214521462147214821492150215121522153215421552156215721582159216021612162216321642165216621672168216921702171217221732174217521762177
  1. # Select 32 or 64 bit
  2. config 64BIT
  3. bool "64-bit kernel" if ARCH = "x86"
  4. default ARCH = "x86_64"
  5. ---help---
  6. Say yes to build a 64-bit kernel - formerly known as x86_64
  7. Say no to build a 32-bit kernel - formerly known as i386
  8. config X86_32
  9. def_bool !64BIT
  10. config X86_64
  11. def_bool 64BIT
  12. ### Arch settings
  13. config X86
  14. def_bool y
  15. select HAVE_AOUT if X86_32
  16. select HAVE_READQ
  17. select HAVE_WRITEQ
  18. select HAVE_UNSTABLE_SCHED_CLOCK
  19. select HAVE_IDE
  20. select HAVE_OPROFILE
  21. select HAVE_PERF_EVENTS
  22. select HAVE_IRQ_WORK
  23. select HAVE_IOREMAP_PROT
  24. select HAVE_KPROBES
  25. select HAVE_MEMBLOCK
  26. select ARCH_WANT_OPTIONAL_GPIOLIB
  27. select ARCH_WANT_FRAME_POINTERS
  28. select HAVE_DMA_ATTRS
  29. select HAVE_KRETPROBES
  30. select HAVE_OPTPROBES
  31. select HAVE_FTRACE_MCOUNT_RECORD
  32. select HAVE_C_RECORDMCOUNT
  33. select HAVE_DYNAMIC_FTRACE
  34. select HAVE_FUNCTION_TRACER
  35. select HAVE_FUNCTION_GRAPH_TRACER
  36. select HAVE_FUNCTION_GRAPH_FP_TEST
  37. select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  38. select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  39. select HAVE_SYSCALL_TRACEPOINTS
  40. select HAVE_KVM
  41. select HAVE_ARCH_KGDB
  42. select HAVE_ARCH_TRACEHOOK
  43. select HAVE_GENERIC_DMA_COHERENT if X86_32
  44. select HAVE_EFFICIENT_UNALIGNED_ACCESS
  45. select USER_STACKTRACE_SUPPORT
  46. select HAVE_REGS_AND_STACK_ACCESS_API
  47. select HAVE_DMA_API_DEBUG
  48. select HAVE_KERNEL_GZIP
  49. select HAVE_KERNEL_BZIP2
  50. select HAVE_KERNEL_LZMA
  51. select HAVE_KERNEL_XZ
  52. select HAVE_KERNEL_LZO
  53. select HAVE_HW_BREAKPOINT
  54. select HAVE_MIXED_BREAKPOINTS_REGS
  55. select PERF_EVENTS
  56. select HAVE_PERF_EVENTS_NMI
  57. select ANON_INODES
  58. select HAVE_ARCH_KMEMCHECK
  59. select HAVE_USER_RETURN_NOTIFIER
  60. select HAVE_ARCH_JUMP_LABEL
  61. select HAVE_TEXT_POKE_SMP
  62. select HAVE_GENERIC_HARDIRQS
  63. select HAVE_SPARSE_IRQ
  64. select GENERIC_FIND_FIRST_BIT
  65. select GENERIC_FIND_NEXT_BIT
  66. select GENERIC_IRQ_PROBE
  67. select GENERIC_PENDING_IRQ if SMP
  68. select GENERIC_IRQ_SHOW
  69. select IRQ_FORCED_THREADING
  70. select USE_GENERIC_SMP_HELPERS if SMP
  71. select ARCH_NO_SYSDEV_OPS
  72. select HAVE_BPF_JIT if X86_64
  73. config INSTRUCTION_DECODER
  74. def_bool (KPROBES || PERF_EVENTS)
  75. config OUTPUT_FORMAT
  76. string
  77. default "elf32-i386" if X86_32
  78. default "elf64-x86-64" if X86_64
  79. config ARCH_DEFCONFIG
  80. string
  81. default "arch/x86/configs/i386_defconfig" if X86_32
  82. default "arch/x86/configs/x86_64_defconfig" if X86_64
  83. config GENERIC_CMOS_UPDATE
  84. def_bool y
  85. config CLOCKSOURCE_WATCHDOG
  86. def_bool y
  87. config GENERIC_CLOCKEVENTS
  88. def_bool y
  89. config GENERIC_CLOCKEVENTS_BROADCAST
  90. def_bool y
  91. depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  92. config LOCKDEP_SUPPORT
  93. def_bool y
  94. config STACKTRACE_SUPPORT
  95. def_bool y
  96. config HAVE_LATENCYTOP_SUPPORT
  97. def_bool y
  98. config MMU
  99. def_bool y
  100. config ZONE_DMA
  101. def_bool y
  102. config SBUS
  103. bool
  104. config NEED_DMA_MAP_STATE
  105. def_bool (X86_64 || DMAR || DMA_API_DEBUG)
  106. config NEED_SG_DMA_LENGTH
  107. def_bool y
  108. config GENERIC_ISA_DMA
  109. def_bool ISA_DMA_API
  110. config GENERIC_IOMAP
  111. def_bool y
  112. config GENERIC_BUG
  113. def_bool y
  114. depends on BUG
  115. select GENERIC_BUG_RELATIVE_POINTERS if X86_64
  116. config GENERIC_BUG_RELATIVE_POINTERS
  117. bool
  118. config GENERIC_HWEIGHT
  119. def_bool y
  120. config GENERIC_GPIO
  121. bool
  122. config ARCH_MAY_HAVE_PC_FDC
  123. def_bool ISA_DMA_API
  124. config RWSEM_GENERIC_SPINLOCK
  125. def_bool !X86_XADD
  126. config RWSEM_XCHGADD_ALGORITHM
  127. def_bool X86_XADD
  128. config ARCH_HAS_CPU_IDLE_WAIT
  129. def_bool y
  130. config GENERIC_CALIBRATE_DELAY
  131. def_bool y
  132. config GENERIC_TIME_VSYSCALL
  133. bool
  134. default X86_64
  135. config ARCH_HAS_CPU_RELAX
  136. def_bool y
  137. config ARCH_HAS_DEFAULT_IDLE
  138. def_bool y
  139. config ARCH_HAS_CACHE_LINE_SIZE
  140. def_bool y
  141. config HAVE_SETUP_PER_CPU_AREA
  142. def_bool y
  143. config NEED_PER_CPU_EMBED_FIRST_CHUNK
  144. def_bool y
  145. config NEED_PER_CPU_PAGE_FIRST_CHUNK
  146. def_bool y
  147. config HAVE_CPUMASK_OF_CPU_MAP
  148. def_bool X86_64_SMP
  149. config ARCH_HIBERNATION_POSSIBLE
  150. def_bool y
  151. config ARCH_SUSPEND_POSSIBLE
  152. def_bool y
  153. config ZONE_DMA32
  154. bool
  155. default X86_64
  156. config ARCH_POPULATES_NODE_MAP
  157. def_bool y
  158. config AUDIT_ARCH
  159. bool
  160. default X86_64
  161. config ARCH_SUPPORTS_OPTIMIZED_INLINING
  162. def_bool y
  163. config ARCH_SUPPORTS_DEBUG_PAGEALLOC
  164. def_bool y
  165. config HAVE_INTEL_TXT
  166. def_bool y
  167. depends on EXPERIMENTAL && DMAR && ACPI
  168. config X86_32_SMP
  169. def_bool y
  170. depends on X86_32 && SMP
  171. config X86_64_SMP
  172. def_bool y
  173. depends on X86_64 && SMP
  174. config X86_HT
  175. def_bool y
  176. depends on SMP
  177. config X86_32_LAZY_GS
  178. def_bool y
  179. depends on X86_32 && !CC_STACKPROTECTOR
  180. config ARCH_HWEIGHT_CFLAGS
  181. string
  182. default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
  183. 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
  184. config KTIME_SCALAR
  185. def_bool X86_32
  186. config ARCH_CPU_PROBE_RELEASE
  187. def_bool y
  188. depends on HOTPLUG_CPU
  189. source "init/Kconfig"
  190. source "kernel/Kconfig.freezer"
  191. menu "Processor type and features"
  192. source "kernel/time/Kconfig"
  193. config SMP
  194. bool "Symmetric multi-processing support"
  195. ---help---
  196. This enables support for systems with more than one CPU. If you have
  197. a system with only one CPU, like most personal computers, say N. If
  198. you have a system with more than one CPU, say Y.
  199. If you say N here, the kernel will run on single and multiprocessor
  200. machines, but will use only one CPU of a multiprocessor machine. If
  201. you say Y here, the kernel will run on many, but not all,
  202. singleprocessor machines. On a singleprocessor machine, the kernel
  203. will run faster if you say N here.
  204. Note that if you say Y here and choose architecture "586" or
  205. "Pentium" under "Processor family", the kernel will not work on 486
  206. architectures. Similarly, multiprocessor kernels for the "PPro"
  207. architecture may not work on all Pentium based boards.
  208. People using multiprocessor machines who say Y here should also say
  209. Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
  210. Management" code will be disabled if you say Y here.
  211. See also <file:Documentation/i386/IO-APIC.txt>,
  212. <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
  213. <http://www.tldp.org/docs.html#howto>.
  214. If you don't know what to do here, say N.
  215. config X86_X2APIC
  216. bool "Support x2apic"
  217. depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
  218. ---help---
  219. This enables x2apic support on CPUs that have this feature.
  220. This allows 32-bit apic IDs (so it can support very large systems),
  221. and accesses the local apic via MSRs not via mmio.
  222. If you don't know what to do here, say N.
  223. config X86_MPPARSE
  224. bool "Enable MPS table" if ACPI
  225. default y
  226. depends on X86_LOCAL_APIC
  227. ---help---
  228. For old smp systems that do not have proper acpi support. Newer systems
  229. (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
  230. config X86_BIGSMP
  231. bool "Support for big SMP systems with more than 8 CPUs"
  232. depends on X86_32 && SMP
  233. ---help---
  234. This option is needed for the systems that have more than 8 CPUs
  235. if X86_32
  236. config X86_EXTENDED_PLATFORM
  237. bool "Support for extended (non-PC) x86 platforms"
  238. default y
  239. ---help---
  240. If you disable this option then the kernel will only support
  241. standard PC platforms. (which covers the vast majority of
  242. systems out there.)
  243. If you enable this option then you'll be able to select support
  244. for the following (non-PC) 32 bit x86 platforms:
  245. AMD Elan
  246. NUMAQ (IBM/Sequent)
  247. RDC R-321x SoC
  248. SGI 320/540 (Visual Workstation)
  249. Summit/EXA (IBM x440)
  250. Unisys ES7000 IA32 series
  251. Moorestown MID devices
  252. If you have one of these systems, or if you want to build a
  253. generic distribution kernel, say Y here - otherwise say N.
  254. endif
  255. if X86_64
  256. config X86_EXTENDED_PLATFORM
  257. bool "Support for extended (non-PC) x86 platforms"
  258. default y
  259. ---help---
  260. If you disable this option then the kernel will only support
  261. standard PC platforms. (which covers the vast majority of
  262. systems out there.)
  263. If you enable this option then you'll be able to select support
  264. for the following (non-PC) 64 bit x86 platforms:
  265. ScaleMP vSMP
  266. SGI Ultraviolet
  267. If you have one of these systems, or if you want to build a
  268. generic distribution kernel, say Y here - otherwise say N.
  269. endif
  270. # This is an alphabetically sorted list of 64 bit extended platforms
  271. # Please maintain the alphabetic order if and when there are additions
  272. config X86_VSMP
  273. bool "ScaleMP vSMP"
  274. select PARAVIRT_GUEST
  275. select PARAVIRT
  276. depends on X86_64 && PCI
  277. depends on X86_EXTENDED_PLATFORM
  278. ---help---
  279. Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
  280. supposed to run on these EM64T-based machines. Only choose this option
  281. if you have one of these machines.
  282. config X86_UV
  283. bool "SGI Ultraviolet"
  284. depends on X86_64
  285. depends on X86_EXTENDED_PLATFORM
  286. depends on NUMA
  287. depends on X86_X2APIC
  288. ---help---
  289. This option is needed in order to support SGI Ultraviolet systems.
  290. If you don't have one of these, you should say N here.
  291. # Following is an alphabetically sorted list of 32 bit extended platforms
  292. # Please maintain the alphabetic order if and when there are additions
  293. config X86_ELAN
  294. bool "AMD Elan"
  295. depends on X86_32
  296. depends on X86_EXTENDED_PLATFORM
  297. ---help---
  298. Select this for an AMD Elan processor.
  299. Do not use this option for K6/Athlon/Opteron processors!
  300. If unsure, choose "PC-compatible" instead.
  301. config X86_INTEL_CE
  302. bool "CE4100 TV platform"
  303. depends on PCI
  304. depends on PCI_GODIRECT
  305. depends on X86_32
  306. depends on X86_EXTENDED_PLATFORM
  307. select X86_REBOOTFIXUPS
  308. select OF
  309. select OF_EARLY_FLATTREE
  310. ---help---
  311. Select for the Intel CE media processor (CE4100) SOC.
  312. This option compiles in support for the CE4100 SOC for settop
  313. boxes and media devices.
  314. config X86_MRST
  315. bool "Moorestown MID platform"
  316. depends on PCI
  317. depends on PCI_GOANY
  318. depends on X86_32
  319. depends on X86_EXTENDED_PLATFORM
  320. depends on X86_IO_APIC
  321. select APB_TIMER
  322. select I2C
  323. select SPI
  324. select INTEL_SCU_IPC
  325. select X86_PLATFORM_DEVICES
  326. ---help---
  327. Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
  328. Internet Device(MID) platform. Moorestown consists of two chips:
  329. Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
  330. Unlike standard x86 PCs, Moorestown does not have many legacy devices
  331. nor standard legacy replacement devices/features. e.g. Moorestown does
  332. not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
  333. config X86_RDC321X
  334. bool "RDC R-321x SoC"
  335. depends on X86_32
  336. depends on X86_EXTENDED_PLATFORM
  337. select M486
  338. select X86_REBOOTFIXUPS
  339. ---help---
  340. This option is needed for RDC R-321x system-on-chip, also known
  341. as R-8610-(G).
  342. If you don't have one of these chips, you should say N here.
  343. config X86_32_NON_STANDARD
  344. bool "Support non-standard 32-bit SMP architectures"
  345. depends on X86_32 && SMP
  346. depends on X86_EXTENDED_PLATFORM
  347. ---help---
  348. This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
  349. subarchitectures. It is intended for a generic binary kernel.
  350. if you select them all, kernel will probe it one by one. and will
  351. fallback to default.
  352. # Alphabetically sorted list of Non standard 32 bit platforms
  353. config X86_NUMAQ
  354. bool "NUMAQ (IBM/Sequent)"
  355. depends on X86_32_NON_STANDARD
  356. depends on PCI
  357. select NUMA
  358. select X86_MPPARSE
  359. ---help---
  360. This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
  361. NUMA multiquad box. This changes the way that processors are
  362. bootstrapped, and uses Clustered Logical APIC addressing mode instead
  363. of Flat Logical. You will need a new lynxer.elf file to flash your
  364. firmware with - send email to <Martin.Bligh@us.ibm.com>.
  365. config X86_SUPPORTS_MEMORY_FAILURE
  366. def_bool y
  367. # MCE code calls memory_failure():
  368. depends on X86_MCE
  369. # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
  370. depends on !X86_NUMAQ
  371. # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
  372. depends on X86_64 || !SPARSEMEM
  373. select ARCH_SUPPORTS_MEMORY_FAILURE
  374. config X86_VISWS
  375. bool "SGI 320/540 (Visual Workstation)"
  376. depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
  377. depends on X86_32_NON_STANDARD
  378. ---help---
  379. The SGI Visual Workstation series is an IA32-based workstation
  380. based on SGI systems chips with some legacy PC hardware attached.
  381. Say Y here to create a kernel to run on the SGI 320 or 540.
  382. A kernel compiled for the Visual Workstation will run on general
  383. PCs as well. See <file:Documentation/sgi-visws.txt> for details.
  384. config X86_SUMMIT
  385. bool "Summit/EXA (IBM x440)"
  386. depends on X86_32_NON_STANDARD
  387. ---help---
  388. This option is needed for IBM systems that use the Summit/EXA chipset.
  389. In particular, it is needed for the x440.
  390. config X86_ES7000
  391. bool "Unisys ES7000 IA32 series"
  392. depends on X86_32_NON_STANDARD && X86_BIGSMP
  393. ---help---
  394. Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
  395. supposed to run on an IA32-based Unisys ES7000 system.
  396. config X86_32_IRIS
  397. tristate "Eurobraille/Iris poweroff module"
  398. depends on X86_32
  399. ---help---
  400. The Iris machines from EuroBraille do not have APM or ACPI support
  401. to shut themselves down properly. A special I/O sequence is
  402. needed to do so, which is what this module does at
  403. kernel shutdown.
  404. This is only for Iris machines from EuroBraille.
  405. If unused, say N.
  406. config SCHED_OMIT_FRAME_POINTER
  407. def_bool y
  408. prompt "Single-depth WCHAN output"
  409. depends on X86
  410. ---help---
  411. Calculate simpler /proc/<PID>/wchan values. If this option
  412. is disabled then wchan values will recurse back to the
  413. caller function. This provides more accurate wchan values,
  414. at the expense of slightly more scheduling overhead.
  415. If in doubt, say "Y".
  416. menuconfig PARAVIRT_GUEST
  417. bool "Paravirtualized guest support"
  418. ---help---
  419. Say Y here to get to see options related to running Linux under
  420. various hypervisors. This option alone does not add any kernel code.
  421. If you say N, all options in this submenu will be skipped and disabled.
  422. if PARAVIRT_GUEST
  423. source "arch/x86/xen/Kconfig"
  424. config KVM_CLOCK
  425. bool "KVM paravirtualized clock"
  426. select PARAVIRT
  427. select PARAVIRT_CLOCK
  428. ---help---
  429. Turning on this option will allow you to run a paravirtualized clock
  430. when running over the KVM hypervisor. Instead of relying on a PIT
  431. (or probably other) emulation by the underlying device model, the host
  432. provides the guest with timing infrastructure such as time of day, and
  433. system time
  434. config KVM_GUEST
  435. bool "KVM Guest support"
  436. select PARAVIRT
  437. ---help---
  438. This option enables various optimizations for running under the KVM
  439. hypervisor.
  440. source "arch/x86/lguest/Kconfig"
  441. config PARAVIRT
  442. bool "Enable paravirtualization code"
  443. ---help---
  444. This changes the kernel so it can modify itself when it is run
  445. under a hypervisor, potentially improving performance significantly
  446. over full virtualization. However, when run without a hypervisor
  447. the kernel is theoretically slower and slightly larger.
  448. config PARAVIRT_SPINLOCKS
  449. bool "Paravirtualization layer for spinlocks"
  450. depends on PARAVIRT && SMP && EXPERIMENTAL
  451. ---help---
  452. Paravirtualized spinlocks allow a pvops backend to replace the
  453. spinlock implementation with something virtualization-friendly
  454. (for example, block the virtual CPU rather than spinning).
  455. Unfortunately the downside is an up to 5% performance hit on
  456. native kernels, with various workloads.
  457. If you are unsure how to answer this question, answer N.
  458. config PARAVIRT_CLOCK
  459. bool
  460. endif
  461. config PARAVIRT_DEBUG
  462. bool "paravirt-ops debugging"
  463. depends on PARAVIRT && DEBUG_KERNEL
  464. ---help---
  465. Enable to debug paravirt_ops internals. Specifically, BUG if
  466. a paravirt_op is missing when it is called.
  467. config NO_BOOTMEM
  468. def_bool y
  469. config MEMTEST
  470. bool "Memtest"
  471. ---help---
  472. This option adds a kernel parameter 'memtest', which allows memtest
  473. to be set.
  474. memtest=0, mean disabled; -- default
  475. memtest=1, mean do 1 test pattern;
  476. ...
  477. memtest=4, mean do 4 test patterns.
  478. If you are unsure how to answer this question, answer N.
  479. config X86_SUMMIT_NUMA
  480. def_bool y
  481. depends on X86_32 && NUMA && X86_32_NON_STANDARD
  482. config X86_CYCLONE_TIMER
  483. def_bool y
  484. depends on X86_32_NON_STANDARD
  485. source "arch/x86/Kconfig.cpu"
  486. config HPET_TIMER
  487. def_bool X86_64
  488. prompt "HPET Timer Support" if X86_32
  489. ---help---
  490. Use the IA-PC HPET (High Precision Event Timer) to manage
  491. time in preference to the PIT and RTC, if a HPET is
  492. present.
  493. HPET is the next generation timer replacing legacy 8254s.
  494. The HPET provides a stable time base on SMP
  495. systems, unlike the TSC, but it is more expensive to access,
  496. as it is off-chip. You can find the HPET spec at
  497. <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
  498. You can safely choose Y here. However, HPET will only be
  499. activated if the platform and the BIOS support this feature.
  500. Otherwise the 8254 will be used for timing services.
  501. Choose N to continue using the legacy 8254 timer.
  502. config HPET_EMULATE_RTC
  503. def_bool y
  504. depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
  505. config APB_TIMER
  506. def_bool y if MRST
  507. prompt "Langwell APB Timer Support" if X86_MRST
  508. help
  509. APB timer is the replacement for 8254, HPET on X86 MID platforms.
  510. The APBT provides a stable time base on SMP
  511. systems, unlike the TSC, but it is more expensive to access,
  512. as it is off-chip. APB timers are always running regardless of CPU
  513. C states, they are used as per CPU clockevent device when possible.
  514. # Mark as expert because too many people got it wrong.
  515. # The code disables itself when not needed.
  516. config DMI
  517. default y
  518. bool "Enable DMI scanning" if EXPERT
  519. ---help---
  520. Enabled scanning of DMI to identify machine quirks. Say Y
  521. here unless you have verified that your setup is not
  522. affected by entries in the DMI blacklist. Required by PNP
  523. BIOS code.
  524. config GART_IOMMU
  525. bool "GART IOMMU support" if EXPERT
  526. default y
  527. select SWIOTLB
  528. depends on X86_64 && PCI && AMD_NB
  529. ---help---
  530. Support for full DMA access of devices with 32bit memory access only
  531. on systems with more than 3GB. This is usually needed for USB,
  532. sound, many IDE/SATA chipsets and some other devices.
  533. Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
  534. based hardware IOMMU and a software bounce buffer based IOMMU used
  535. on Intel systems and as fallback.
  536. The code is only active when needed (enough memory and limited
  537. device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
  538. too.
  539. config CALGARY_IOMMU
  540. bool "IBM Calgary IOMMU support"
  541. select SWIOTLB
  542. depends on X86_64 && PCI && EXPERIMENTAL
  543. ---help---
  544. Support for hardware IOMMUs in IBM's xSeries x366 and x460
  545. systems. Needed to run systems with more than 3GB of memory
  546. properly with 32-bit PCI devices that do not support DAC
  547. (Double Address Cycle). Calgary also supports bus level
  548. isolation, where all DMAs pass through the IOMMU. This
  549. prevents them from going anywhere except their intended
  550. destination. This catches hard-to-find kernel bugs and
  551. mis-behaving drivers and devices that do not use the DMA-API
  552. properly to set up their DMA buffers. The IOMMU can be
  553. turned off at boot time with the iommu=off parameter.
  554. Normally the kernel will make the right choice by itself.
  555. If unsure, say Y.
  556. config CALGARY_IOMMU_ENABLED_BY_DEFAULT
  557. def_bool y
  558. prompt "Should Calgary be enabled by default?"
  559. depends on CALGARY_IOMMU
  560. ---help---
  561. Should Calgary be enabled by default? if you choose 'y', Calgary
  562. will be used (if it exists). If you choose 'n', Calgary will not be
  563. used even if it exists. If you choose 'n' and would like to use
  564. Calgary anyway, pass 'iommu=calgary' on the kernel command line.
  565. If unsure, say Y.
  566. config AMD_IOMMU
  567. bool "AMD IOMMU support"
  568. select SWIOTLB
  569. select PCI_MSI
  570. depends on X86_64 && PCI && ACPI
  571. ---help---
  572. With this option you can enable support for AMD IOMMU hardware in
  573. your system. An IOMMU is a hardware component which provides
  574. remapping of DMA memory accesses from devices. With an AMD IOMMU you
  575. can isolate the the DMA memory of different devices and protect the
  576. system from misbehaving device drivers or hardware.
  577. You can find out if your system has an AMD IOMMU if you look into
  578. your BIOS for an option to enable it or if you have an IVRS ACPI
  579. table.
  580. config AMD_IOMMU_STATS
  581. bool "Export AMD IOMMU statistics to debugfs"
  582. depends on AMD_IOMMU
  583. select DEBUG_FS
  584. ---help---
  585. This option enables code in the AMD IOMMU driver to collect various
  586. statistics about whats happening in the driver and exports that
  587. information to userspace via debugfs.
  588. If unsure, say N.
  589. # need this always selected by IOMMU for the VIA workaround
  590. config SWIOTLB
  591. def_bool y if X86_64
  592. ---help---
  593. Support for software bounce buffers used on x86-64 systems
  594. which don't have a hardware IOMMU (e.g. the current generation
  595. of Intel's x86-64 CPUs). Using this PCI devices which can only
  596. access 32-bits of memory can be used on systems with more than
  597. 3 GB of memory. If unsure, say Y.
  598. config IOMMU_HELPER
  599. def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
  600. config IOMMU_API
  601. def_bool (AMD_IOMMU || DMAR)
  602. config MAXSMP
  603. bool "Enable Maximum number of SMP Processors and NUMA Nodes"
  604. depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
  605. select CPUMASK_OFFSTACK
  606. ---help---
  607. Enable maximum number of CPUS and NUMA Nodes for this architecture.
  608. If unsure, say N.
  609. config NR_CPUS
  610. int "Maximum number of CPUs" if SMP && !MAXSMP
  611. range 2 8 if SMP && X86_32 && !X86_BIGSMP
  612. range 2 512 if SMP && !MAXSMP
  613. default "1" if !SMP
  614. default "4096" if MAXSMP
  615. default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
  616. default "8" if SMP
  617. ---help---
  618. This allows you to specify the maximum number of CPUs which this
  619. kernel will support. The maximum supported value is 512 and the
  620. minimum value which makes sense is 2.
  621. This is purely to save memory - each supported CPU adds
  622. approximately eight kilobytes to the kernel image.
  623. config SCHED_SMT
  624. bool "SMT (Hyperthreading) scheduler support"
  625. depends on X86_HT
  626. ---help---
  627. SMT scheduler support improves the CPU scheduler's decision making
  628. when dealing with Intel Pentium 4 chips with HyperThreading at a
  629. cost of slightly increased overhead in some places. If unsure say
  630. N here.
  631. config SCHED_MC
  632. def_bool y
  633. prompt "Multi-core scheduler support"
  634. depends on X86_HT
  635. ---help---
  636. Multi-core scheduler support improves the CPU scheduler's decision
  637. making when dealing with multi-core CPU chips at a cost of slightly
  638. increased overhead in some places. If unsure say N here.
  639. config IRQ_TIME_ACCOUNTING
  640. bool "Fine granularity task level IRQ time accounting"
  641. default n
  642. ---help---
  643. Select this option to enable fine granularity task irq time
  644. accounting. This is done by reading a timestamp on each
  645. transitions between softirq and hardirq state, so there can be a
  646. small performance impact.
  647. If in doubt, say N here.
  648. source "kernel/Kconfig.preempt"
  649. config X86_UP_APIC
  650. bool "Local APIC support on uniprocessors"
  651. depends on X86_32 && !SMP && !X86_32_NON_STANDARD
  652. ---help---
  653. A local APIC (Advanced Programmable Interrupt Controller) is an
  654. integrated interrupt controller in the CPU. If you have a single-CPU
  655. system which has a processor with a local APIC, you can say Y here to
  656. enable and use it. If you say Y here even though your machine doesn't
  657. have a local APIC, then the kernel will still run with no slowdown at
  658. all. The local APIC supports CPU-generated self-interrupts (timer,
  659. performance counters), and the NMI watchdog which detects hard
  660. lockups.
  661. config X86_UP_IOAPIC
  662. bool "IO-APIC support on uniprocessors"
  663. depends on X86_UP_APIC
  664. ---help---
  665. An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
  666. SMP-capable replacement for PC-style interrupt controllers. Most
  667. SMP systems and many recent uniprocessor systems have one.
  668. If you have a single-CPU system with an IO-APIC, you can say Y here
  669. to use it. If you say Y here even though your machine doesn't have
  670. an IO-APIC, then the kernel will still run with no slowdown at all.
  671. config X86_LOCAL_APIC
  672. def_bool y
  673. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
  674. config X86_IO_APIC
  675. def_bool y
  676. depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
  677. config X86_VISWS_APIC
  678. def_bool y
  679. depends on X86_32 && X86_VISWS
  680. config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
  681. bool "Reroute for broken boot IRQs"
  682. depends on X86_IO_APIC
  683. ---help---
  684. This option enables a workaround that fixes a source of
  685. spurious interrupts. This is recommended when threaded
  686. interrupt handling is used on systems where the generation of
  687. superfluous "boot interrupts" cannot be disabled.
  688. Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
  689. entry in the chipset's IO-APIC is masked (as, e.g. the RT
  690. kernel does during interrupt handling). On chipsets where this
  691. boot IRQ generation cannot be disabled, this workaround keeps
  692. the original IRQ line masked so that only the equivalent "boot
  693. IRQ" is delivered to the CPUs. The workaround also tells the
  694. kernel to set up the IRQ handler on the boot IRQ line. In this
  695. way only one interrupt is delivered to the kernel. Otherwise
  696. the spurious second interrupt may cause the kernel to bring
  697. down (vital) interrupt lines.
  698. Only affects "broken" chipsets. Interrupt sharing may be
  699. increased on these systems.
  700. config X86_MCE
  701. bool "Machine Check / overheating reporting"
  702. ---help---
  703. Machine Check support allows the processor to notify the
  704. kernel if it detects a problem (e.g. overheating, data corruption).
  705. The action the kernel takes depends on the severity of the problem,
  706. ranging from warning messages to halting the machine.
  707. config X86_MCE_INTEL
  708. def_bool y
  709. prompt "Intel MCE features"
  710. depends on X86_MCE && X86_LOCAL_APIC
  711. ---help---
  712. Additional support for intel specific MCE features such as
  713. the thermal monitor.
  714. config X86_MCE_AMD
  715. def_bool y
  716. prompt "AMD MCE features"
  717. depends on X86_MCE && X86_LOCAL_APIC
  718. ---help---
  719. Additional support for AMD specific MCE features such as
  720. the DRAM Error Threshold.
  721. config X86_ANCIENT_MCE
  722. bool "Support for old Pentium 5 / WinChip machine checks"
  723. depends on X86_32 && X86_MCE
  724. ---help---
  725. Include support for machine check handling on old Pentium 5 or WinChip
  726. systems. These typically need to be enabled explicitely on the command
  727. line.
  728. config X86_MCE_THRESHOLD
  729. depends on X86_MCE_AMD || X86_MCE_INTEL
  730. def_bool y
  731. config X86_MCE_INJECT
  732. depends on X86_MCE
  733. tristate "Machine check injector support"
  734. ---help---
  735. Provide support for injecting machine checks for testing purposes.
  736. If you don't know what a machine check is and you don't do kernel
  737. QA it is safe to say n.
  738. config X86_THERMAL_VECTOR
  739. def_bool y
  740. depends on X86_MCE_INTEL
  741. config VM86
  742. bool "Enable VM86 support" if EXPERT
  743. default y
  744. depends on X86_32
  745. ---help---
  746. This option is required by programs like DOSEMU to run 16-bit legacy
  747. code on X86 processors. It also may be needed by software like
  748. XFree86 to initialize some video cards via BIOS. Disabling this
  749. option saves about 6k.
  750. config TOSHIBA
  751. tristate "Toshiba Laptop support"
  752. depends on X86_32
  753. ---help---
  754. This adds a driver to safely access the System Management Mode of
  755. the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
  756. not work on models with a Phoenix BIOS. The System Management Mode
  757. is used to set the BIOS and power saving options on Toshiba portables.
  758. For information on utilities to make use of this driver see the
  759. Toshiba Linux utilities web site at:
  760. <http://www.buzzard.org.uk/toshiba/>.
  761. Say Y if you intend to run this kernel on a Toshiba portable.
  762. Say N otherwise.
  763. config I8K
  764. tristate "Dell laptop support"
  765. ---help---
  766. This adds a driver to safely access the System Management Mode
  767. of the CPU on the Dell Inspiron 8000. The System Management Mode
  768. is used to read cpu temperature and cooling fan status and to
  769. control the fans on the I8K portables.
  770. This driver has been tested only on the Inspiron 8000 but it may
  771. also work with other Dell laptops. You can force loading on other
  772. models by passing the parameter `force=1' to the module. Use at
  773. your own risk.
  774. For information on utilities to make use of this driver see the
  775. I8K Linux utilities web site at:
  776. <http://people.debian.org/~dz/i8k/>
  777. Say Y if you intend to run this kernel on a Dell Inspiron 8000.
  778. Say N otherwise.
  779. config X86_REBOOTFIXUPS
  780. bool "Enable X86 board specific fixups for reboot"
  781. depends on X86_32
  782. ---help---
  783. This enables chipset and/or board specific fixups to be done
  784. in order to get reboot to work correctly. This is only needed on
  785. some combinations of hardware and BIOS. The symptom, for which
  786. this config is intended, is when reboot ends with a stalled/hung
  787. system.
  788. Currently, the only fixup is for the Geode machines using
  789. CS5530A and CS5536 chipsets and the RDC R-321x SoC.
  790. Say Y if you want to enable the fixup. Currently, it's safe to
  791. enable this option even if you don't need it.
  792. Say N otherwise.
  793. config MICROCODE
  794. tristate "/dev/cpu/microcode - microcode support"
  795. select FW_LOADER
  796. ---help---
  797. If you say Y here, you will be able to update the microcode on
  798. certain Intel and AMD processors. The Intel support is for the
  799. IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
  800. Pentium 4, Xeon etc. The AMD support is for family 0x10 and
  801. 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
  802. You will obviously need the actual microcode binary data itself
  803. which is not shipped with the Linux kernel.
  804. This option selects the general module only, you need to select
  805. at least one vendor specific module as well.
  806. To compile this driver as a module, choose M here: the
  807. module will be called microcode.
  808. config MICROCODE_INTEL
  809. bool "Intel microcode patch loading support"
  810. depends on MICROCODE
  811. default MICROCODE
  812. select FW_LOADER
  813. ---help---
  814. This options enables microcode patch loading support for Intel
  815. processors.
  816. For latest news and information on obtaining all the required
  817. Intel ingredients for this driver, check:
  818. <http://www.urbanmyth.org/microcode/>.
  819. config MICROCODE_AMD
  820. bool "AMD microcode patch loading support"
  821. depends on MICROCODE
  822. select FW_LOADER
  823. ---help---
  824. If you select this option, microcode patch loading support for AMD
  825. processors will be enabled.
  826. config MICROCODE_OLD_INTERFACE
  827. def_bool y
  828. depends on MICROCODE
  829. config X86_MSR
  830. tristate "/dev/cpu/*/msr - Model-specific register support"
  831. ---help---
  832. This device gives privileged processes access to the x86
  833. Model-Specific Registers (MSRs). It is a character device with
  834. major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
  835. MSR accesses are directed to a specific CPU on multi-processor
  836. systems.
  837. config X86_CPUID
  838. tristate "/dev/cpu/*/cpuid - CPU information support"
  839. ---help---
  840. This device gives processes access to the x86 CPUID instruction to
  841. be executed on a specific processor. It is a character device
  842. with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
  843. /dev/cpu/31/cpuid.
  844. choice
  845. prompt "High Memory Support"
  846. default HIGHMEM64G if X86_NUMAQ
  847. default HIGHMEM4G
  848. depends on X86_32
  849. config NOHIGHMEM
  850. bool "off"
  851. depends on !X86_NUMAQ
  852. ---help---
  853. Linux can use up to 64 Gigabytes of physical memory on x86 systems.
  854. However, the address space of 32-bit x86 processors is only 4
  855. Gigabytes large. That means that, if you have a large amount of
  856. physical memory, not all of it can be "permanently mapped" by the
  857. kernel. The physical memory that's not permanently mapped is called
  858. "high memory".
  859. If you are compiling a kernel which will never run on a machine with
  860. more than 1 Gigabyte total physical RAM, answer "off" here (default
  861. choice and suitable for most users). This will result in a "3GB/1GB"
  862. split: 3GB are mapped so that each process sees a 3GB virtual memory
  863. space and the remaining part of the 4GB virtual memory space is used
  864. by the kernel to permanently map as much physical memory as
  865. possible.
  866. If the machine has between 1 and 4 Gigabytes physical RAM, then
  867. answer "4GB" here.
  868. If more than 4 Gigabytes is used then answer "64GB" here. This
  869. selection turns Intel PAE (Physical Address Extension) mode on.
  870. PAE implements 3-level paging on IA32 processors. PAE is fully
  871. supported by Linux, PAE mode is implemented on all recent Intel
  872. processors (Pentium Pro and better). NOTE: If you say "64GB" here,
  873. then the kernel will not boot on CPUs that don't support PAE!
  874. The actual amount of total physical memory will either be
  875. auto detected or can be forced by using a kernel command line option
  876. such as "mem=256M". (Try "man bootparam" or see the documentation of
  877. your boot loader (lilo or loadlin) about how to pass options to the
  878. kernel at boot time.)
  879. If unsure, say "off".
  880. config HIGHMEM4G
  881. bool "4GB"
  882. depends on !X86_NUMAQ
  883. ---help---
  884. Select this if you have a 32-bit processor and between 1 and 4
  885. gigabytes of physical RAM.
  886. config HIGHMEM64G
  887. bool "64GB"
  888. depends on !M386 && !M486
  889. select X86_PAE
  890. ---help---
  891. Select this if you have a 32-bit processor and more than 4
  892. gigabytes of physical RAM.
  893. endchoice
  894. choice
  895. depends on EXPERIMENTAL
  896. prompt "Memory split" if EXPERT
  897. default VMSPLIT_3G
  898. depends on X86_32
  899. ---help---
  900. Select the desired split between kernel and user memory.
  901. If the address range available to the kernel is less than the
  902. physical memory installed, the remaining memory will be available
  903. as "high memory". Accessing high memory is a little more costly
  904. than low memory, as it needs to be mapped into the kernel first.
  905. Note that increasing the kernel address space limits the range
  906. available to user programs, making the address space there
  907. tighter. Selecting anything other than the default 3G/1G split
  908. will also likely make your kernel incompatible with binary-only
  909. kernel modules.
  910. If you are not absolutely sure what you are doing, leave this
  911. option alone!
  912. config VMSPLIT_3G
  913. bool "3G/1G user/kernel split"
  914. config VMSPLIT_3G_OPT
  915. depends on !X86_PAE
  916. bool "3G/1G user/kernel split (for full 1G low memory)"
  917. config VMSPLIT_2G
  918. bool "2G/2G user/kernel split"
  919. config VMSPLIT_2G_OPT
  920. depends on !X86_PAE
  921. bool "2G/2G user/kernel split (for full 2G low memory)"
  922. config VMSPLIT_1G
  923. bool "1G/3G user/kernel split"
  924. endchoice
  925. config PAGE_OFFSET
  926. hex
  927. default 0xB0000000 if VMSPLIT_3G_OPT
  928. default 0x80000000 if VMSPLIT_2G
  929. default 0x78000000 if VMSPLIT_2G_OPT
  930. default 0x40000000 if VMSPLIT_1G
  931. default 0xC0000000
  932. depends on X86_32
  933. config HIGHMEM
  934. def_bool y
  935. depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
  936. config X86_PAE
  937. bool "PAE (Physical Address Extension) Support"
  938. depends on X86_32 && !HIGHMEM4G
  939. ---help---
  940. PAE is required for NX support, and furthermore enables
  941. larger swapspace support for non-overcommit purposes. It
  942. has the cost of more pagetable lookup overhead, and also
  943. consumes more pagetable space per process.
  944. config ARCH_PHYS_ADDR_T_64BIT
  945. def_bool X86_64 || X86_PAE
  946. config ARCH_DMA_ADDR_T_64BIT
  947. def_bool X86_64 || HIGHMEM64G
  948. config DIRECT_GBPAGES
  949. bool "Enable 1GB pages for kernel pagetables" if EXPERT
  950. default y
  951. depends on X86_64
  952. ---help---
  953. Allow the kernel linear mapping to use 1GB pages on CPUs that
  954. support it. This can improve the kernel's performance a tiny bit by
  955. reducing TLB pressure. If in doubt, say "Y".
  956. # Common NUMA Features
  957. config NUMA
  958. bool "Numa Memory Allocation and Scheduler Support"
  959. depends on SMP
  960. depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
  961. default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
  962. ---help---
  963. Enable NUMA (Non Uniform Memory Access) support.
  964. The kernel will try to allocate memory used by a CPU on the
  965. local memory controller of the CPU and add some more
  966. NUMA awareness to the kernel.
  967. For 64-bit this is recommended if the system is Intel Core i7
  968. (or later), AMD Opteron, or EM64T NUMA.
  969. For 32-bit this is only needed on (rare) 32-bit-only platforms
  970. that support NUMA topologies, such as NUMAQ / Summit, or if you
  971. boot a 32-bit kernel on a 64-bit NUMA platform.
  972. Otherwise, you should say N.
  973. comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
  974. depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
  975. config AMD_NUMA
  976. def_bool y
  977. prompt "Old style AMD Opteron NUMA detection"
  978. depends on X86_64 && NUMA && PCI
  979. ---help---
  980. Enable AMD NUMA node topology detection. You should say Y here if
  981. you have a multi processor AMD system. This uses an old method to
  982. read the NUMA configuration directly from the builtin Northbridge
  983. of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
  984. which also takes priority if both are compiled in.
  985. config X86_64_ACPI_NUMA
  986. def_bool y
  987. prompt "ACPI NUMA detection"
  988. depends on X86_64 && NUMA && ACPI && PCI
  989. select ACPI_NUMA
  990. ---help---
  991. Enable ACPI SRAT based node topology detection.
  992. # Some NUMA nodes have memory ranges that span
  993. # other nodes. Even though a pfn is valid and
  994. # between a node's start and end pfns, it may not
  995. # reside on that node. See memmap_init_zone()
  996. # for details.
  997. config NODES_SPAN_OTHER_NODES
  998. def_bool y
  999. depends on X86_64_ACPI_NUMA
  1000. config NUMA_EMU
  1001. bool "NUMA emulation"
  1002. depends on X86_64 && NUMA
  1003. ---help---
  1004. Enable NUMA emulation. A flat machine will be split
  1005. into virtual nodes when booted with "numa=fake=N", where N is the
  1006. number of nodes. This is only useful for debugging.
  1007. config NODES_SHIFT
  1008. int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
  1009. range 1 10
  1010. default "10" if MAXSMP
  1011. default "6" if X86_64
  1012. default "4" if X86_NUMAQ
  1013. default "3"
  1014. depends on NEED_MULTIPLE_NODES
  1015. ---help---
  1016. Specify the maximum number of NUMA Nodes available on the target
  1017. system. Increases memory reserved to accommodate various tables.
  1018. config HAVE_ARCH_BOOTMEM
  1019. def_bool y
  1020. depends on X86_32 && NUMA
  1021. config ARCH_HAVE_MEMORY_PRESENT
  1022. def_bool y
  1023. depends on X86_32 && DISCONTIGMEM
  1024. config NEED_NODE_MEMMAP_SIZE
  1025. def_bool y
  1026. depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
  1027. config HAVE_ARCH_ALLOC_REMAP
  1028. def_bool y
  1029. depends on X86_32 && NUMA
  1030. config ARCH_FLATMEM_ENABLE
  1031. def_bool y
  1032. depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
  1033. config ARCH_DISCONTIGMEM_ENABLE
  1034. def_bool y
  1035. depends on NUMA && X86_32
  1036. config ARCH_DISCONTIGMEM_DEFAULT
  1037. def_bool y
  1038. depends on NUMA && X86_32
  1039. config ARCH_PROC_KCORE_TEXT
  1040. def_bool y
  1041. depends on X86_64 && PROC_KCORE
  1042. config ARCH_SPARSEMEM_DEFAULT
  1043. def_bool y
  1044. depends on X86_64
  1045. config ARCH_SPARSEMEM_ENABLE
  1046. def_bool y
  1047. depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
  1048. select SPARSEMEM_STATIC if X86_32
  1049. select SPARSEMEM_VMEMMAP_ENABLE if X86_64
  1050. config ARCH_SELECT_MEMORY_MODEL
  1051. def_bool y
  1052. depends on ARCH_SPARSEMEM_ENABLE
  1053. config ARCH_MEMORY_PROBE
  1054. def_bool X86_64
  1055. depends on MEMORY_HOTPLUG
  1056. config ILLEGAL_POINTER_VALUE
  1057. hex
  1058. default 0 if X86_32
  1059. default 0xdead000000000000 if X86_64
  1060. source "mm/Kconfig"
  1061. config HIGHPTE
  1062. bool "Allocate 3rd-level pagetables from highmem"
  1063. depends on HIGHMEM
  1064. ---help---
  1065. The VM uses one page table entry for each page of physical memory.
  1066. For systems with a lot of RAM, this can be wasteful of precious
  1067. low memory. Setting this option will put user-space page table
  1068. entries in high memory.
  1069. config X86_CHECK_BIOS_CORRUPTION
  1070. bool "Check for low memory corruption"
  1071. ---help---
  1072. Periodically check for memory corruption in low memory, which
  1073. is suspected to be caused by BIOS. Even when enabled in the
  1074. configuration, it is disabled at runtime. Enable it by
  1075. setting "memory_corruption_check=1" on the kernel command
  1076. line. By default it scans the low 64k of memory every 60
  1077. seconds; see the memory_corruption_check_size and
  1078. memory_corruption_check_period parameters in
  1079. Documentation/kernel-parameters.txt to adjust this.
  1080. When enabled with the default parameters, this option has
  1081. almost no overhead, as it reserves a relatively small amount
  1082. of memory and scans it infrequently. It both detects corruption
  1083. and prevents it from affecting the running system.
  1084. It is, however, intended as a diagnostic tool; if repeatable
  1085. BIOS-originated corruption always affects the same memory,
  1086. you can use memmap= to prevent the kernel from using that
  1087. memory.
  1088. config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
  1089. bool "Set the default setting of memory_corruption_check"
  1090. depends on X86_CHECK_BIOS_CORRUPTION
  1091. default y
  1092. ---help---
  1093. Set whether the default state of memory_corruption_check is
  1094. on or off.
  1095. config X86_RESERVE_LOW
  1096. int "Amount of low memory, in kilobytes, to reserve for the BIOS"
  1097. default 64
  1098. range 4 640
  1099. ---help---
  1100. Specify the amount of low memory to reserve for the BIOS.
  1101. The first page contains BIOS data structures that the kernel
  1102. must not use, so that page must always be reserved.
  1103. By default we reserve the first 64K of physical RAM, as a
  1104. number of BIOSes are known to corrupt that memory range
  1105. during events such as suspend/resume or monitor cable
  1106. insertion, so it must not be used by the kernel.
  1107. You can set this to 4 if you are absolutely sure that you
  1108. trust the BIOS to get all its memory reservations and usages
  1109. right. If you know your BIOS have problems beyond the
  1110. default 64K area, you can set this to 640 to avoid using the
  1111. entire low memory range.
  1112. If you have doubts about the BIOS (e.g. suspend/resume does
  1113. not work or there's kernel crashes after certain hardware
  1114. hotplug events) then you might want to enable
  1115. X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
  1116. typical corruption patterns.
  1117. Leave this to the default value of 64 if you are unsure.
  1118. config MATH_EMULATION
  1119. bool
  1120. prompt "Math emulation" if X86_32
  1121. ---help---
  1122. Linux can emulate a math coprocessor (used for floating point
  1123. operations) if you don't have one. 486DX and Pentium processors have
  1124. a math coprocessor built in, 486SX and 386 do not, unless you added
  1125. a 487DX or 387, respectively. (The messages during boot time can
  1126. give you some hints here ["man dmesg"].) Everyone needs either a
  1127. coprocessor or this emulation.
  1128. If you don't have a math coprocessor, you need to say Y here; if you
  1129. say Y here even though you have a coprocessor, the coprocessor will
  1130. be used nevertheless. (This behavior can be changed with the kernel
  1131. command line option "no387", which comes handy if your coprocessor
  1132. is broken. Try "man bootparam" or see the documentation of your boot
  1133. loader (lilo or loadlin) about how to pass options to the kernel at
  1134. boot time.) This means that it is a good idea to say Y here if you
  1135. intend to use this kernel on different machines.
  1136. More information about the internals of the Linux math coprocessor
  1137. emulation can be found in <file:arch/x86/math-emu/README>.
  1138. If you are not sure, say Y; apart from resulting in a 66 KB bigger
  1139. kernel, it won't hurt.
  1140. config MTRR
  1141. def_bool y
  1142. prompt "MTRR (Memory Type Range Register) support" if EXPERT
  1143. ---help---
  1144. On Intel P6 family processors (Pentium Pro, Pentium II and later)
  1145. the Memory Type Range Registers (MTRRs) may be used to control
  1146. processor access to memory ranges. This is most useful if you have
  1147. a video (VGA) card on a PCI or AGP bus. Enabling write-combining
  1148. allows bus write transfers to be combined into a larger transfer
  1149. before bursting over the PCI/AGP bus. This can increase performance
  1150. of image write operations 2.5 times or more. Saying Y here creates a
  1151. /proc/mtrr file which may be used to manipulate your processor's
  1152. MTRRs. Typically the X server should use this.
  1153. This code has a reasonably generic interface so that similar
  1154. control registers on other processors can be easily supported
  1155. as well:
  1156. The Cyrix 6x86, 6x86MX and M II processors have Address Range
  1157. Registers (ARRs) which provide a similar functionality to MTRRs. For
  1158. these, the ARRs are used to emulate the MTRRs.
  1159. The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
  1160. MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
  1161. write-combining. All of these processors are supported by this code
  1162. and it makes sense to say Y here if you have one of them.
  1163. Saying Y here also fixes a problem with buggy SMP BIOSes which only
  1164. set the MTRRs for the boot CPU and not for the secondary CPUs. This
  1165. can lead to all sorts of problems, so it's good to say Y here.
  1166. You can safely say Y even if your machine doesn't have MTRRs, you'll
  1167. just add about 9 KB to your kernel.
  1168. See <file:Documentation/x86/mtrr.txt> for more information.
  1169. config MTRR_SANITIZER
  1170. def_bool y
  1171. prompt "MTRR cleanup support"
  1172. depends on MTRR
  1173. ---help---
  1174. Convert MTRR layout from continuous to discrete, so X drivers can
  1175. add writeback entries.
  1176. Can be disabled with disable_mtrr_cleanup on the kernel command line.
  1177. The largest mtrr entry size for a continuous block can be set with
  1178. mtrr_chunk_size.
  1179. If unsure, say Y.
  1180. config MTRR_SANITIZER_ENABLE_DEFAULT
  1181. int "MTRR cleanup enable value (0-1)"
  1182. range 0 1
  1183. default "0"
  1184. depends on MTRR_SANITIZER
  1185. ---help---
  1186. Enable mtrr cleanup default value
  1187. config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
  1188. int "MTRR cleanup spare reg num (0-7)"
  1189. range 0 7
  1190. default "1"
  1191. depends on MTRR_SANITIZER
  1192. ---help---
  1193. mtrr cleanup spare entries default, it can be changed via
  1194. mtrr_spare_reg_nr=N on the kernel command line.
  1195. config X86_PAT
  1196. def_bool y
  1197. prompt "x86 PAT support" if EXPERT
  1198. depends on MTRR
  1199. ---help---
  1200. Use PAT attributes to setup page level cache control.
  1201. PATs are the modern equivalents of MTRRs and are much more
  1202. flexible than MTRRs.
  1203. Say N here if you see bootup problems (boot crash, boot hang,
  1204. spontaneous reboots) or a non-working video driver.
  1205. If unsure, say Y.
  1206. config ARCH_USES_PG_UNCACHED
  1207. def_bool y
  1208. depends on X86_PAT
  1209. config EFI
  1210. bool "EFI runtime service support"
  1211. depends on ACPI
  1212. ---help---
  1213. This enables the kernel to use EFI runtime services that are
  1214. available (such as the EFI variable services).
  1215. This option is only useful on systems that have EFI firmware.
  1216. In addition, you should use the latest ELILO loader available
  1217. at <http://elilo.sourceforge.net> in order to take advantage
  1218. of EFI runtime services. However, even with this option, the
  1219. resultant kernel should continue to boot on existing non-EFI
  1220. platforms.
  1221. config SECCOMP
  1222. def_bool y
  1223. prompt "Enable seccomp to safely compute untrusted bytecode"
  1224. ---help---
  1225. This kernel feature is useful for number crunching applications
  1226. that may need to compute untrusted bytecode during their
  1227. execution. By using pipes or other transports made available to
  1228. the process as file descriptors supporting the read/write
  1229. syscalls, it's possible to isolate those applications in
  1230. their own address space using seccomp. Once seccomp is
  1231. enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
  1232. and the task is only allowed to execute a few safe syscalls
  1233. defined by each seccomp mode.
  1234. If unsure, say Y. Only embedded should say N here.
  1235. config CC_STACKPROTECTOR
  1236. bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
  1237. ---help---
  1238. This option turns on the -fstack-protector GCC feature. This
  1239. feature puts, at the beginning of functions, a canary value on
  1240. the stack just before the return address, and validates
  1241. the value just before actually returning. Stack based buffer
  1242. overflows (that need to overwrite this return address) now also
  1243. overwrite the canary, which gets detected and the attack is then
  1244. neutralized via a kernel panic.
  1245. This feature requires gcc version 4.2 or above, or a distribution
  1246. gcc with the feature backported. Older versions are automatically
  1247. detected and for those versions, this configuration option is
  1248. ignored. (and a warning is printed during bootup)
  1249. source kernel/Kconfig.hz
  1250. config KEXEC
  1251. bool "kexec system call"
  1252. ---help---
  1253. kexec is a system call that implements the ability to shutdown your
  1254. current kernel, and to start another kernel. It is like a reboot
  1255. but it is independent of the system firmware. And like a reboot
  1256. you can start any kernel with it, not just Linux.
  1257. The name comes from the similarity to the exec system call.
  1258. It is an ongoing process to be certain the hardware in a machine
  1259. is properly shutdown, so do not be surprised if this code does not
  1260. initially work for you. It may help to enable device hotplugging
  1261. support. As of this writing the exact hardware interface is
  1262. strongly in flux, so no good recommendation can be made.
  1263. config CRASH_DUMP
  1264. bool "kernel crash dumps"
  1265. depends on X86_64 || (X86_32 && HIGHMEM)
  1266. ---help---
  1267. Generate crash dump after being started by kexec.
  1268. This should be normally only set in special crash dump kernels
  1269. which are loaded in the main kernel with kexec-tools into
  1270. a specially reserved region and then later executed after
  1271. a crash by kdump/kexec. The crash dump kernel must be compiled
  1272. to a memory address not used by the main kernel or BIOS using
  1273. PHYSICAL_START, or it must be built as a relocatable image
  1274. (CONFIG_RELOCATABLE=y).
  1275. For more details see Documentation/kdump/kdump.txt
  1276. config KEXEC_JUMP
  1277. bool "kexec jump (EXPERIMENTAL)"
  1278. depends on EXPERIMENTAL
  1279. depends on KEXEC && HIBERNATION
  1280. ---help---
  1281. Jump between original kernel and kexeced kernel and invoke
  1282. code in physical address mode via KEXEC
  1283. config PHYSICAL_START
  1284. hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
  1285. default "0x1000000"
  1286. ---help---
  1287. This gives the physical address where the kernel is loaded.
  1288. If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
  1289. bzImage will decompress itself to above physical address and
  1290. run from there. Otherwise, bzImage will run from the address where
  1291. it has been loaded by the boot loader and will ignore above physical
  1292. address.
  1293. In normal kdump cases one does not have to set/change this option
  1294. as now bzImage can be compiled as a completely relocatable image
  1295. (CONFIG_RELOCATABLE=y) and be used to load and run from a different
  1296. address. This option is mainly useful for the folks who don't want
  1297. to use a bzImage for capturing the crash dump and want to use a
  1298. vmlinux instead. vmlinux is not relocatable hence a kernel needs
  1299. to be specifically compiled to run from a specific memory area
  1300. (normally a reserved region) and this option comes handy.
  1301. So if you are using bzImage for capturing the crash dump,
  1302. leave the value here unchanged to 0x1000000 and set
  1303. CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
  1304. for capturing the crash dump change this value to start of
  1305. the reserved region. In other words, it can be set based on
  1306. the "X" value as specified in the "crashkernel=YM@XM"
  1307. command line boot parameter passed to the panic-ed
  1308. kernel. Please take a look at Documentation/kdump/kdump.txt
  1309. for more details about crash dumps.
  1310. Usage of bzImage for capturing the crash dump is recommended as
  1311. one does not have to build two kernels. Same kernel can be used
  1312. as production kernel and capture kernel. Above option should have
  1313. gone away after relocatable bzImage support is introduced. But it
  1314. is present because there are users out there who continue to use
  1315. vmlinux for dump capture. This option should go away down the
  1316. line.
  1317. Don't change this unless you know what you are doing.
  1318. config RELOCATABLE
  1319. bool "Build a relocatable kernel"
  1320. default y
  1321. ---help---
  1322. This builds a kernel image that retains relocation information
  1323. so it can be loaded someplace besides the default 1MB.
  1324. The relocations tend to make the kernel binary about 10% larger,
  1325. but are discarded at runtime.
  1326. One use is for the kexec on panic case where the recovery kernel
  1327. must live at a different physical address than the primary
  1328. kernel.
  1329. Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
  1330. it has been loaded at and the compile time physical address
  1331. (CONFIG_PHYSICAL_START) is ignored.
  1332. # Relocation on x86-32 needs some additional build support
  1333. config X86_NEED_RELOCS
  1334. def_bool y
  1335. depends on X86_32 && RELOCATABLE
  1336. config PHYSICAL_ALIGN
  1337. hex "Alignment value to which kernel should be aligned" if X86_32
  1338. default "0x1000000"
  1339. range 0x2000 0x1000000
  1340. ---help---
  1341. This value puts the alignment restrictions on physical address
  1342. where kernel is loaded and run from. Kernel is compiled for an
  1343. address which meets above alignment restriction.
  1344. If bootloader loads the kernel at a non-aligned address and
  1345. CONFIG_RELOCATABLE is set, kernel will move itself to nearest
  1346. address aligned to above value and run from there.
  1347. If bootloader loads the kernel at a non-aligned address and
  1348. CONFIG_RELOCATABLE is not set, kernel will ignore the run time
  1349. load address and decompress itself to the address it has been
  1350. compiled for and run from there. The address for which kernel is
  1351. compiled already meets above alignment restrictions. Hence the
  1352. end result is that kernel runs from a physical address meeting
  1353. above alignment restrictions.
  1354. Don't change this unless you know what you are doing.
  1355. config HOTPLUG_CPU
  1356. bool "Support for hot-pluggable CPUs"
  1357. depends on SMP && HOTPLUG
  1358. ---help---
  1359. Say Y here to allow turning CPUs off and on. CPUs can be
  1360. controlled through /sys/devices/system/cpu.
  1361. ( Note: power management support will enable this option
  1362. automatically on SMP systems. )
  1363. Say N if you want to disable CPU hotplug.
  1364. config COMPAT_VDSO
  1365. def_bool y
  1366. prompt "Compat VDSO support"
  1367. depends on X86_32 || IA32_EMULATION
  1368. ---help---
  1369. Map the 32-bit VDSO to the predictable old-style address too.
  1370. Say N here if you are running a sufficiently recent glibc
  1371. version (2.3.3 or later), to remove the high-mapped
  1372. VDSO mapping and to exclusively use the randomized VDSO.
  1373. If unsure, say Y.
  1374. config CMDLINE_BOOL
  1375. bool "Built-in kernel command line"
  1376. ---help---
  1377. Allow for specifying boot arguments to the kernel at
  1378. build time. On some systems (e.g. embedded ones), it is
  1379. necessary or convenient to provide some or all of the
  1380. kernel boot arguments with the kernel itself (that is,
  1381. to not rely on the boot loader to provide them.)
  1382. To compile command line arguments into the kernel,
  1383. set this option to 'Y', then fill in the
  1384. the boot arguments in CONFIG_CMDLINE.
  1385. Systems with fully functional boot loaders (i.e. non-embedded)
  1386. should leave this option set to 'N'.
  1387. config CMDLINE
  1388. string "Built-in kernel command string"
  1389. depends on CMDLINE_BOOL
  1390. default ""
  1391. ---help---
  1392. Enter arguments here that should be compiled into the kernel
  1393. image and used at boot time. If the boot loader provides a
  1394. command line at boot time, it is appended to this string to
  1395. form the full kernel command line, when the system boots.
  1396. However, you can use the CONFIG_CMDLINE_OVERRIDE option to
  1397. change this behavior.
  1398. In most cases, the command line (whether built-in or provided
  1399. by the boot loader) should specify the device for the root
  1400. file system.
  1401. config CMDLINE_OVERRIDE
  1402. bool "Built-in command line overrides boot loader arguments"
  1403. depends on CMDLINE_BOOL
  1404. ---help---
  1405. Set this option to 'Y' to have the kernel ignore the boot loader
  1406. command line, and use ONLY the built-in command line.
  1407. This is used to work around broken boot loaders. This should
  1408. be set to 'N' under normal conditions.
  1409. endmenu
  1410. config ARCH_ENABLE_MEMORY_HOTPLUG
  1411. def_bool y
  1412. depends on X86_64 || (X86_32 && HIGHMEM)
  1413. config ARCH_ENABLE_MEMORY_HOTREMOVE
  1414. def_bool y
  1415. depends on MEMORY_HOTPLUG
  1416. config HAVE_ARCH_EARLY_PFN_TO_NID
  1417. def_bool X86_64
  1418. depends on NUMA
  1419. config USE_PERCPU_NUMA_NODE_ID
  1420. def_bool y
  1421. depends on NUMA
  1422. menu "Power management and ACPI options"
  1423. config ARCH_HIBERNATION_HEADER
  1424. def_bool y
  1425. depends on X86_64 && HIBERNATION
  1426. source "kernel/power/Kconfig"
  1427. source "drivers/acpi/Kconfig"
  1428. source "drivers/sfi/Kconfig"
  1429. config X86_APM_BOOT
  1430. def_bool y
  1431. depends on APM || APM_MODULE
  1432. menuconfig APM
  1433. tristate "APM (Advanced Power Management) BIOS support"
  1434. depends on X86_32 && PM_SLEEP
  1435. ---help---
  1436. APM is a BIOS specification for saving power using several different
  1437. techniques. This is mostly useful for battery powered laptops with
  1438. APM compliant BIOSes. If you say Y here, the system time will be
  1439. reset after a RESUME operation, the /proc/apm device will provide
  1440. battery status information, and user-space programs will receive
  1441. notification of APM "events" (e.g. battery status change).
  1442. If you select "Y" here, you can disable actual use of the APM
  1443. BIOS by passing the "apm=off" option to the kernel at boot time.
  1444. Note that the APM support is almost completely disabled for
  1445. machines with more than one CPU.
  1446. In order to use APM, you will need supporting software. For location
  1447. and more information, read <file:Documentation/power/pm.txt> and the
  1448. Battery Powered Linux mini-HOWTO, available from
  1449. <http://www.tldp.org/docs.html#howto>.
  1450. This driver does not spin down disk drives (see the hdparm(8)
  1451. manpage ("man 8 hdparm") for that), and it doesn't turn off
  1452. VESA-compliant "green" monitors.
  1453. This driver does not support the TI 4000M TravelMate and the ACER
  1454. 486/DX4/75 because they don't have compliant BIOSes. Many "green"
  1455. desktop machines also don't have compliant BIOSes, and this driver
  1456. may cause those machines to panic during the boot phase.
  1457. Generally, if you don't have a battery in your machine, there isn't
  1458. much point in using this driver and you should say N. If you get
  1459. random kernel OOPSes or reboots that don't seem to be related to
  1460. anything, try disabling/enabling this option (or disabling/enabling
  1461. APM in your BIOS).
  1462. Some other things you should try when experiencing seemingly random,
  1463. "weird" problems:
  1464. 1) make sure that you have enough swap space and that it is
  1465. enabled.
  1466. 2) pass the "no-hlt" option to the kernel
  1467. 3) switch on floating point emulation in the kernel and pass
  1468. the "no387" option to the kernel
  1469. 4) pass the "floppy=nodma" option to the kernel
  1470. 5) pass the "mem=4M" option to the kernel (thereby disabling
  1471. all but the first 4 MB of RAM)
  1472. 6) make sure that the CPU is not over clocked.
  1473. 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
  1474. 8) disable the cache from your BIOS settings
  1475. 9) install a fan for the video card or exchange video RAM
  1476. 10) install a better fan for the CPU
  1477. 11) exchange RAM chips
  1478. 12) exchange the motherboard.
  1479. To compile this driver as a module, choose M here: the
  1480. module will be called apm.
  1481. if APM
  1482. config APM_IGNORE_USER_SUSPEND
  1483. bool "Ignore USER SUSPEND"
  1484. ---help---
  1485. This option will ignore USER SUSPEND requests. On machines with a
  1486. compliant APM BIOS, you want to say N. However, on the NEC Versa M
  1487. series notebooks, it is necessary to say Y because of a BIOS bug.
  1488. config APM_DO_ENABLE
  1489. bool "Enable PM at boot time"
  1490. ---help---
  1491. Enable APM features at boot time. From page 36 of the APM BIOS
  1492. specification: "When disabled, the APM BIOS does not automatically
  1493. power manage devices, enter the Standby State, enter the Suspend
  1494. State, or take power saving steps in response to CPU Idle calls."
  1495. This driver will make CPU Idle calls when Linux is idle (unless this
  1496. feature is turned off -- see "Do CPU IDLE calls", below). This
  1497. should always save battery power, but more complicated APM features
  1498. will be dependent on your BIOS implementation. You may need to turn
  1499. this option off if your computer hangs at boot time when using APM
  1500. support, or if it beeps continuously instead of suspending. Turn
  1501. this off if you have a NEC UltraLite Versa 33/C or a Toshiba
  1502. T400CDT. This is off by default since most machines do fine without
  1503. this feature.
  1504. config APM_CPU_IDLE
  1505. bool "Make CPU Idle calls when idle"
  1506. ---help---
  1507. Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
  1508. On some machines, this can activate improved power savings, such as
  1509. a slowed CPU clock rate, when the machine is idle. These idle calls
  1510. are made after the idle loop has run for some length of time (e.g.,
  1511. 333 mS). On some machines, this will cause a hang at boot time or
  1512. whenever the CPU becomes idle. (On machines with more than one CPU,
  1513. this option does nothing.)
  1514. config APM_DISPLAY_BLANK
  1515. bool "Enable console blanking using APM"
  1516. ---help---
  1517. Enable console blanking using the APM. Some laptops can use this to
  1518. turn off the LCD backlight when the screen blanker of the Linux
  1519. virtual console blanks the screen. Note that this is only used by
  1520. the virtual console screen blanker, and won't turn off the backlight
  1521. when using the X Window system. This also doesn't have anything to
  1522. do with your VESA-compliant power-saving monitor. Further, this
  1523. option doesn't work for all laptops -- it might not turn off your
  1524. backlight at all, or it might print a lot of errors to the console,
  1525. especially if you are using gpm.
  1526. config APM_ALLOW_INTS
  1527. bool "Allow interrupts during APM BIOS calls"
  1528. ---help---
  1529. Normally we disable external interrupts while we are making calls to
  1530. the APM BIOS as a measure to lessen the effects of a badly behaving
  1531. BIOS implementation. The BIOS should reenable interrupts if it
  1532. needs to. Unfortunately, some BIOSes do not -- especially those in
  1533. many of the newer IBM Thinkpads. If you experience hangs when you
  1534. suspend, try setting this to Y. Otherwise, say N.
  1535. endif # APM
  1536. source "arch/x86/kernel/cpu/cpufreq/Kconfig"
  1537. source "drivers/cpuidle/Kconfig"
  1538. source "drivers/idle/Kconfig"
  1539. endmenu
  1540. menu "Bus options (PCI etc.)"
  1541. config PCI
  1542. bool "PCI support"
  1543. default y
  1544. select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
  1545. ---help---
  1546. Find out whether you have a PCI motherboard. PCI is the name of a
  1547. bus system, i.e. the way the CPU talks to the other stuff inside
  1548. your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
  1549. VESA. If you have PCI, say Y, otherwise N.
  1550. choice
  1551. prompt "PCI access mode"
  1552. depends on X86_32 && PCI
  1553. default PCI_GOANY
  1554. ---help---
  1555. On PCI systems, the BIOS can be used to detect the PCI devices and
  1556. determine their configuration. However, some old PCI motherboards
  1557. have BIOS bugs and may crash if this is done. Also, some embedded
  1558. PCI-based systems don't have any BIOS at all. Linux can also try to
  1559. detect the PCI hardware directly without using the BIOS.
  1560. With this option, you can specify how Linux should detect the
  1561. PCI devices. If you choose "BIOS", the BIOS will be used,
  1562. if you choose "Direct", the BIOS won't be used, and if you
  1563. choose "MMConfig", then PCI Express MMCONFIG will be used.
  1564. If you choose "Any", the kernel will try MMCONFIG, then the
  1565. direct access method and falls back to the BIOS if that doesn't
  1566. work. If unsure, go with the default, which is "Any".
  1567. config PCI_GOBIOS
  1568. bool "BIOS"
  1569. config PCI_GOMMCONFIG
  1570. bool "MMConfig"
  1571. config PCI_GODIRECT
  1572. bool "Direct"
  1573. config PCI_GOOLPC
  1574. bool "OLPC XO-1"
  1575. depends on OLPC
  1576. config PCI_GOANY
  1577. bool "Any"
  1578. endchoice
  1579. config PCI_BIOS
  1580. def_bool y
  1581. depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
  1582. # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
  1583. config PCI_DIRECT
  1584. def_bool y
  1585. depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
  1586. config PCI_MMCONFIG
  1587. def_bool y
  1588. depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
  1589. config PCI_OLPC
  1590. def_bool y
  1591. depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
  1592. config PCI_XEN
  1593. def_bool y
  1594. depends on PCI && XEN
  1595. select SWIOTLB_XEN
  1596. config PCI_DOMAINS
  1597. def_bool y
  1598. depends on PCI
  1599. config PCI_MMCONFIG
  1600. bool "Support mmconfig PCI config space access"
  1601. depends on X86_64 && PCI && ACPI
  1602. config PCI_CNB20LE_QUIRK
  1603. bool "Read CNB20LE Host Bridge Windows" if EXPERT
  1604. default n
  1605. depends on PCI && EXPERIMENTAL
  1606. help
  1607. Read the PCI windows out of the CNB20LE host bridge. This allows
  1608. PCI hotplug to work on systems with the CNB20LE chipset which do
  1609. not have ACPI.
  1610. There's no public spec for this chipset, and this functionality
  1611. is known to be incomplete.
  1612. You should say N unless you know you need this.
  1613. config DMAR
  1614. bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
  1615. depends on PCI_MSI && ACPI && EXPERIMENTAL
  1616. help
  1617. DMA remapping (DMAR) devices support enables independent address
  1618. translations for Direct Memory Access (DMA) from devices.
  1619. These DMA remapping devices are reported via ACPI tables
  1620. and include PCI device scope covered by these DMA
  1621. remapping devices.
  1622. config DMAR_DEFAULT_ON
  1623. def_bool y
  1624. prompt "Enable DMA Remapping Devices by default"
  1625. depends on DMAR
  1626. help
  1627. Selecting this option will enable a DMAR device at boot time if
  1628. one is found. If this option is not selected, DMAR support can
  1629. be enabled by passing intel_iommu=on to the kernel. It is
  1630. recommended you say N here while the DMAR code remains
  1631. experimental.
  1632. config DMAR_BROKEN_GFX_WA
  1633. bool "Workaround broken graphics drivers (going away soon)"
  1634. depends on DMAR && BROKEN
  1635. ---help---
  1636. Current Graphics drivers tend to use physical address
  1637. for DMA and avoid using DMA APIs. Setting this config
  1638. option permits the IOMMU driver to set a unity map for
  1639. all the OS-visible memory. Hence the driver can continue
  1640. to use physical addresses for DMA, at least until this
  1641. option is removed in the 2.6.32 kernel.
  1642. config DMAR_FLOPPY_WA
  1643. def_bool y
  1644. depends on DMAR
  1645. ---help---
  1646. Floppy disk drivers are known to bypass DMA API calls
  1647. thereby failing to work when IOMMU is enabled. This
  1648. workaround will setup a 1:1 mapping for the first
  1649. 16MiB to make floppy (an ISA device) work.
  1650. config INTR_REMAP
  1651. bool "Support for Interrupt Remapping (EXPERIMENTAL)"
  1652. depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
  1653. ---help---
  1654. Supports Interrupt remapping for IO-APIC and MSI devices.
  1655. To use x2apic mode in the CPU's which support x2APIC enhancements or
  1656. to support platforms with CPU's having > 8 bit APIC ID, say Y.
  1657. source "drivers/pci/pcie/Kconfig"
  1658. source "drivers/pci/Kconfig"
  1659. # x86_64 have no ISA slots, but can have ISA-style DMA.
  1660. config ISA_DMA_API
  1661. bool "ISA-style DMA support" if (X86_64 && EXPERT)
  1662. default y
  1663. help
  1664. Enables ISA-style DMA support for devices requiring such controllers.
  1665. If unsure, say Y.
  1666. if X86_32
  1667. config ISA
  1668. bool "ISA support"
  1669. ---help---
  1670. Find out whether you have ISA slots on your motherboard. ISA is the
  1671. name of a bus system, i.e. the way the CPU talks to the other stuff
  1672. inside your box. Other bus systems are PCI, EISA, MicroChannel
  1673. (MCA) or VESA. ISA is an older system, now being displaced by PCI;
  1674. newer boards don't support it. If you have ISA, say Y, otherwise N.
  1675. config EISA
  1676. bool "EISA support"
  1677. depends on ISA
  1678. ---help---
  1679. The Extended Industry Standard Architecture (EISA) bus was
  1680. developed as an open alternative to the IBM MicroChannel bus.
  1681. The EISA bus provided some of the features of the IBM MicroChannel
  1682. bus while maintaining backward compatibility with cards made for
  1683. the older ISA bus. The EISA bus saw limited use between 1988 and
  1684. 1995 when it was made obsolete by the PCI bus.
  1685. Say Y here if you are building a kernel for an EISA-based machine.
  1686. Otherwise, say N.
  1687. source "drivers/eisa/Kconfig"
  1688. config MCA
  1689. bool "MCA support"
  1690. ---help---
  1691. MicroChannel Architecture is found in some IBM PS/2 machines and
  1692. laptops. It is a bus system similar to PCI or ISA. See
  1693. <file:Documentation/mca.txt> (and especially the web page given
  1694. there) before attempting to build an MCA bus kernel.
  1695. source "drivers/mca/Kconfig"
  1696. config SCx200
  1697. tristate "NatSemi SCx200 support"
  1698. ---help---
  1699. This provides basic support for National Semiconductor's
  1700. (now AMD's) Geode processors. The driver probes for the
  1701. PCI-IDs of several on-chip devices, so its a good dependency
  1702. for other scx200_* drivers.
  1703. If compiled as a module, the driver is named scx200.
  1704. config SCx200HR_TIMER
  1705. tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
  1706. depends on SCx200
  1707. default y
  1708. ---help---
  1709. This driver provides a clocksource built upon the on-chip
  1710. 27MHz high-resolution timer. Its also a workaround for
  1711. NSC Geode SC-1100's buggy TSC, which loses time when the
  1712. processor goes idle (as is done by the scheduler). The
  1713. other workaround is idle=poll boot option.
  1714. config OLPC
  1715. bool "One Laptop Per Child support"
  1716. depends on !X86_PAE
  1717. select GPIOLIB
  1718. select OF
  1719. select OF_PROMTREE if PROC_DEVICETREE
  1720. ---help---
  1721. Add support for detecting the unique features of the OLPC
  1722. XO hardware.
  1723. config OLPC_XO1
  1724. tristate "OLPC XO-1 support"
  1725. depends on OLPC && MFD_CS5535
  1726. ---help---
  1727. Add support for non-essential features of the OLPC XO-1 laptop.
  1728. endif # X86_32
  1729. config AMD_NB
  1730. def_bool y
  1731. depends on CPU_SUP_AMD && PCI
  1732. source "drivers/pcmcia/Kconfig"
  1733. source "drivers/pci/hotplug/Kconfig"
  1734. config RAPIDIO
  1735. bool "RapidIO support"
  1736. depends on PCI
  1737. default n
  1738. help
  1739. If you say Y here, the kernel will include drivers and
  1740. infrastructure code to support RapidIO interconnect devices.
  1741. source "drivers/rapidio/Kconfig"
  1742. endmenu
  1743. menu "Executable file formats / Emulations"
  1744. source "fs/Kconfig.binfmt"
  1745. config IA32_EMULATION
  1746. bool "IA32 Emulation"
  1747. depends on X86_64
  1748. select COMPAT_BINFMT_ELF
  1749. ---help---
  1750. Include code to run 32-bit programs under a 64-bit kernel. You should
  1751. likely turn this on, unless you're 100% sure that you don't have any
  1752. 32-bit programs left.
  1753. config IA32_AOUT
  1754. tristate "IA32 a.out support"
  1755. depends on IA32_EMULATION
  1756. ---help---
  1757. Support old a.out binaries in the 32bit emulation.
  1758. config COMPAT
  1759. def_bool y
  1760. depends on IA32_EMULATION
  1761. config COMPAT_FOR_U64_ALIGNMENT
  1762. def_bool COMPAT
  1763. depends on X86_64
  1764. config SYSVIPC_COMPAT
  1765. def_bool y
  1766. depends on COMPAT && SYSVIPC
  1767. config KEYS_COMPAT
  1768. bool
  1769. depends on COMPAT && KEYS
  1770. default y
  1771. endmenu
  1772. config HAVE_ATOMIC_IOMAP
  1773. def_bool y
  1774. depends on X86_32
  1775. config HAVE_TEXT_POKE_SMP
  1776. bool
  1777. select STOP_MACHINE if SMP
  1778. source "net/Kconfig"
  1779. source "drivers/Kconfig"
  1780. source "drivers/firmware/Kconfig"
  1781. source "fs/Kconfig"
  1782. source "arch/x86/Kconfig.debug"
  1783. source "security/Kconfig"
  1784. source "crypto/Kconfig"
  1785. source "arch/x86/kvm/Kconfig"
  1786. source "lib/Kconfig"